Version:  2.0.40 2.2.26 2.4.37 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6

Linux/drivers/mtd/nand/atmel_nand.c

  1 /*
  2  *  Copyright © 2003 Rick Bronson
  3  *
  4  *  Derived from drivers/mtd/nand/autcpu12.c
  5  *       Copyright © 2001 Thomas Gleixner (gleixner@autronix.de)
  6  *
  7  *  Derived from drivers/mtd/spia.c
  8  *       Copyright © 2000 Steven J. Hill (sjhill@cotw.com)
  9  *
 10  *
 11  *  Add Hardware ECC support for AT91SAM9260 / AT91SAM9263
 12  *     Richard Genoud (richard.genoud@gmail.com), Adeneo Copyright © 2007
 13  *
 14  *     Derived from Das U-Boot source code
 15  *              (u-boot-1.1.5/board/atmel/at91sam9263ek/nand.c)
 16  *     © Copyright 2006 ATMEL Rousset, Lacressonniere Nicolas
 17  *
 18  *  Add Programmable Multibit ECC support for various AT91 SoC
 19  *     © Copyright 2012 ATMEL, Hong Xu
 20  *
 21  *  Add Nand Flash Controller support for SAMA5 SoC
 22  *     © Copyright 2013 ATMEL, Josh Wu (josh.wu@atmel.com)
 23  *
 24  * This program is free software; you can redistribute it and/or modify
 25  * it under the terms of the GNU General Public License version 2 as
 26  * published by the Free Software Foundation.
 27  *
 28  */
 29 
 30 #include <linux/clk.h>
 31 #include <linux/dma-mapping.h>
 32 #include <linux/slab.h>
 33 #include <linux/module.h>
 34 #include <linux/moduleparam.h>
 35 #include <linux/platform_device.h>
 36 #include <linux/of.h>
 37 #include <linux/of_device.h>
 38 #include <linux/of_gpio.h>
 39 #include <linux/of_mtd.h>
 40 #include <linux/mtd/mtd.h>
 41 #include <linux/mtd/nand.h>
 42 #include <linux/mtd/partitions.h>
 43 
 44 #include <linux/delay.h>
 45 #include <linux/dmaengine.h>
 46 #include <linux/gpio.h>
 47 #include <linux/interrupt.h>
 48 #include <linux/io.h>
 49 #include <linux/platform_data/atmel.h>
 50 
 51 static int use_dma = 1;
 52 module_param(use_dma, int, 0);
 53 
 54 static int on_flash_bbt = 0;
 55 module_param(on_flash_bbt, int, 0);
 56 
 57 /* Register access macros */
 58 #define ecc_readl(add, reg)                             \
 59         __raw_readl(add + ATMEL_ECC_##reg)
 60 #define ecc_writel(add, reg, value)                     \
 61         __raw_writel((value), add + ATMEL_ECC_##reg)
 62 
 63 #include "atmel_nand_ecc.h"     /* Hardware ECC registers */
 64 #include "atmel_nand_nfc.h"     /* Nand Flash Controller definition */
 65 
 66 struct atmel_nand_caps {
 67         bool pmecc_correct_erase_page;
 68         uint8_t pmecc_max_correction;
 69 };
 70 
 71 struct atmel_nand_nfc_caps {
 72         uint32_t rb_mask;
 73 };
 74 
 75 /* oob layout for large page size
 76  * bad block info is on bytes 0 and 1
 77  * the bytes have to be consecutives to avoid
 78  * several NAND_CMD_RNDOUT during read
 79  */
 80 static struct nand_ecclayout atmel_oobinfo_large = {
 81         .eccbytes = 4,
 82         .eccpos = {60, 61, 62, 63},
 83         .oobfree = {
 84                 {2, 58}
 85         },
 86 };
 87 
 88 /* oob layout for small page size
 89  * bad block info is on bytes 4 and 5
 90  * the bytes have to be consecutives to avoid
 91  * several NAND_CMD_RNDOUT during read
 92  */
 93 static struct nand_ecclayout atmel_oobinfo_small = {
 94         .eccbytes = 4,
 95         .eccpos = {0, 1, 2, 3},
 96         .oobfree = {
 97                 {6, 10}
 98         },
 99 };
100 
101 struct atmel_nfc {
102         void __iomem            *base_cmd_regs;
103         void __iomem            *hsmc_regs;
104         void                    *sram_bank0;
105         dma_addr_t              sram_bank0_phys;
106         bool                    use_nfc_sram;
107         bool                    write_by_sram;
108 
109         struct clk              *clk;
110 
111         bool                    is_initialized;
112         struct completion       comp_ready;
113         struct completion       comp_cmd_done;
114         struct completion       comp_xfer_done;
115 
116         /* Point to the sram bank which include readed data via NFC */
117         void                    *data_in_sram;
118         bool                    will_write_sram;
119         const struct atmel_nand_nfc_caps *caps;
120 };
121 static struct atmel_nfc nand_nfc;
122 
123 struct atmel_nand_host {
124         struct nand_chip        nand_chip;
125         void __iomem            *io_base;
126         dma_addr_t              io_phys;
127         struct atmel_nand_data  board;
128         struct device           *dev;
129         void __iomem            *ecc;
130 
131         struct completion       comp;
132         struct dma_chan         *dma_chan;
133 
134         struct atmel_nfc        *nfc;
135 
136         const struct atmel_nand_caps    *caps;
137         bool                    has_pmecc;
138         u8                      pmecc_corr_cap;
139         u16                     pmecc_sector_size;
140         bool                    has_no_lookup_table;
141         u32                     pmecc_lookup_table_offset;
142         u32                     pmecc_lookup_table_offset_512;
143         u32                     pmecc_lookup_table_offset_1024;
144 
145         int                     pmecc_degree;   /* Degree of remainders */
146         int                     pmecc_cw_len;   /* Length of codeword */
147 
148         void __iomem            *pmerrloc_base;
149         void __iomem            *pmerrloc_el_base;
150         void __iomem            *pmecc_rom_base;
151 
152         /* lookup table for alpha_to and index_of */
153         void __iomem            *pmecc_alpha_to;
154         void __iomem            *pmecc_index_of;
155 
156         /* data for pmecc computation */
157         int16_t                 *pmecc_partial_syn;
158         int16_t                 *pmecc_si;
159         int16_t                 *pmecc_smu;     /* Sigma table */
160         int16_t                 *pmecc_lmu;     /* polynomal order */
161         int                     *pmecc_mu;
162         int                     *pmecc_dmu;
163         int                     *pmecc_delta;
164 };
165 
166 static struct nand_ecclayout atmel_pmecc_oobinfo;
167 
168 /*
169  * Enable NAND.
170  */
171 static void atmel_nand_enable(struct atmel_nand_host *host)
172 {
173         if (gpio_is_valid(host->board.enable_pin))
174                 gpio_set_value(host->board.enable_pin, 0);
175 }
176 
177 /*
178  * Disable NAND.
179  */
180 static void atmel_nand_disable(struct atmel_nand_host *host)
181 {
182         if (gpio_is_valid(host->board.enable_pin))
183                 gpio_set_value(host->board.enable_pin, 1);
184 }
185 
186 /*
187  * Hardware specific access to control-lines
188  */
189 static void atmel_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
190 {
191         struct nand_chip *nand_chip = mtd_to_nand(mtd);
192         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
193 
194         if (ctrl & NAND_CTRL_CHANGE) {
195                 if (ctrl & NAND_NCE)
196                         atmel_nand_enable(host);
197                 else
198                         atmel_nand_disable(host);
199         }
200         if (cmd == NAND_CMD_NONE)
201                 return;
202 
203         if (ctrl & NAND_CLE)
204                 writeb(cmd, host->io_base + (1 << host->board.cle));
205         else
206                 writeb(cmd, host->io_base + (1 << host->board.ale));
207 }
208 
209 /*
210  * Read the Device Ready pin.
211  */
212 static int atmel_nand_device_ready(struct mtd_info *mtd)
213 {
214         struct nand_chip *nand_chip = mtd_to_nand(mtd);
215         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
216 
217         return gpio_get_value(host->board.rdy_pin) ^
218                 !!host->board.rdy_pin_active_low;
219 }
220 
221 /* Set up for hardware ready pin and enable pin. */
222 static int atmel_nand_set_enable_ready_pins(struct mtd_info *mtd)
223 {
224         struct nand_chip *chip = mtd_to_nand(mtd);
225         struct atmel_nand_host *host = nand_get_controller_data(chip);
226         int res = 0;
227 
228         if (gpio_is_valid(host->board.rdy_pin)) {
229                 res = devm_gpio_request(host->dev,
230                                 host->board.rdy_pin, "nand_rdy");
231                 if (res < 0) {
232                         dev_err(host->dev,
233                                 "can't request rdy gpio %d\n",
234                                 host->board.rdy_pin);
235                         return res;
236                 }
237 
238                 res = gpio_direction_input(host->board.rdy_pin);
239                 if (res < 0) {
240                         dev_err(host->dev,
241                                 "can't request input direction rdy gpio %d\n",
242                                 host->board.rdy_pin);
243                         return res;
244                 }
245 
246                 chip->dev_ready = atmel_nand_device_ready;
247         }
248 
249         if (gpio_is_valid(host->board.enable_pin)) {
250                 res = devm_gpio_request(host->dev,
251                                 host->board.enable_pin, "nand_enable");
252                 if (res < 0) {
253                         dev_err(host->dev,
254                                 "can't request enable gpio %d\n",
255                                 host->board.enable_pin);
256                         return res;
257                 }
258 
259                 res = gpio_direction_output(host->board.enable_pin, 1);
260                 if (res < 0) {
261                         dev_err(host->dev,
262                                 "can't request output direction enable gpio %d\n",
263                                 host->board.enable_pin);
264                         return res;
265                 }
266         }
267 
268         return res;
269 }
270 
271 /*
272  * Minimal-overhead PIO for data access.
273  */
274 static void atmel_read_buf8(struct mtd_info *mtd, u8 *buf, int len)
275 {
276         struct nand_chip        *nand_chip = mtd_to_nand(mtd);
277         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
278 
279         if (host->nfc && host->nfc->use_nfc_sram && host->nfc->data_in_sram) {
280                 memcpy(buf, host->nfc->data_in_sram, len);
281                 host->nfc->data_in_sram += len;
282         } else {
283                 __raw_readsb(nand_chip->IO_ADDR_R, buf, len);
284         }
285 }
286 
287 static void atmel_read_buf16(struct mtd_info *mtd, u8 *buf, int len)
288 {
289         struct nand_chip        *nand_chip = mtd_to_nand(mtd);
290         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
291 
292         if (host->nfc && host->nfc->use_nfc_sram && host->nfc->data_in_sram) {
293                 memcpy(buf, host->nfc->data_in_sram, len);
294                 host->nfc->data_in_sram += len;
295         } else {
296                 __raw_readsw(nand_chip->IO_ADDR_R, buf, len / 2);
297         }
298 }
299 
300 static void atmel_write_buf8(struct mtd_info *mtd, const u8 *buf, int len)
301 {
302         struct nand_chip        *nand_chip = mtd_to_nand(mtd);
303 
304         __raw_writesb(nand_chip->IO_ADDR_W, buf, len);
305 }
306 
307 static void atmel_write_buf16(struct mtd_info *mtd, const u8 *buf, int len)
308 {
309         struct nand_chip        *nand_chip = mtd_to_nand(mtd);
310 
311         __raw_writesw(nand_chip->IO_ADDR_W, buf, len / 2);
312 }
313 
314 static void dma_complete_func(void *completion)
315 {
316         complete(completion);
317 }
318 
319 static int nfc_set_sram_bank(struct atmel_nand_host *host, unsigned int bank)
320 {
321         /* NFC only has two banks. Must be 0 or 1 */
322         if (bank > 1)
323                 return -EINVAL;
324 
325         if (bank) {
326                 struct mtd_info *mtd = nand_to_mtd(&host->nand_chip);
327 
328                 /* Only for a 2k-page or lower flash, NFC can handle 2 banks */
329                 if (mtd->writesize > 2048)
330                         return -EINVAL;
331                 nfc_writel(host->nfc->hsmc_regs, BANK, ATMEL_HSMC_NFC_BANK1);
332         } else {
333                 nfc_writel(host->nfc->hsmc_regs, BANK, ATMEL_HSMC_NFC_BANK0);
334         }
335 
336         return 0;
337 }
338 
339 static uint nfc_get_sram_off(struct atmel_nand_host *host)
340 {
341         if (nfc_readl(host->nfc->hsmc_regs, BANK) & ATMEL_HSMC_NFC_BANK1)
342                 return NFC_SRAM_BANK1_OFFSET;
343         else
344                 return 0;
345 }
346 
347 static dma_addr_t nfc_sram_phys(struct atmel_nand_host *host)
348 {
349         if (nfc_readl(host->nfc->hsmc_regs, BANK) & ATMEL_HSMC_NFC_BANK1)
350                 return host->nfc->sram_bank0_phys + NFC_SRAM_BANK1_OFFSET;
351         else
352                 return host->nfc->sram_bank0_phys;
353 }
354 
355 static int atmel_nand_dma_op(struct mtd_info *mtd, void *buf, int len,
356                                int is_read)
357 {
358         struct dma_device *dma_dev;
359         enum dma_ctrl_flags flags;
360         dma_addr_t dma_src_addr, dma_dst_addr, phys_addr;
361         struct dma_async_tx_descriptor *tx = NULL;
362         dma_cookie_t cookie;
363         struct nand_chip *chip = mtd_to_nand(mtd);
364         struct atmel_nand_host *host = nand_get_controller_data(chip);
365         void *p = buf;
366         int err = -EIO;
367         enum dma_data_direction dir = is_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
368         struct atmel_nfc *nfc = host->nfc;
369 
370         if (buf >= high_memory)
371                 goto err_buf;
372 
373         dma_dev = host->dma_chan->device;
374 
375         flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
376 
377         phys_addr = dma_map_single(dma_dev->dev, p, len, dir);
378         if (dma_mapping_error(dma_dev->dev, phys_addr)) {
379                 dev_err(host->dev, "Failed to dma_map_single\n");
380                 goto err_buf;
381         }
382 
383         if (is_read) {
384                 if (nfc && nfc->data_in_sram)
385                         dma_src_addr = nfc_sram_phys(host) + (nfc->data_in_sram
386                                 - (nfc->sram_bank0 + nfc_get_sram_off(host)));
387                 else
388                         dma_src_addr = host->io_phys;
389 
390                 dma_dst_addr = phys_addr;
391         } else {
392                 dma_src_addr = phys_addr;
393 
394                 if (nfc && nfc->write_by_sram)
395                         dma_dst_addr = nfc_sram_phys(host);
396                 else
397                         dma_dst_addr = host->io_phys;
398         }
399 
400         tx = dma_dev->device_prep_dma_memcpy(host->dma_chan, dma_dst_addr,
401                                              dma_src_addr, len, flags);
402         if (!tx) {
403                 dev_err(host->dev, "Failed to prepare DMA memcpy\n");
404                 goto err_dma;
405         }
406 
407         init_completion(&host->comp);
408         tx->callback = dma_complete_func;
409         tx->callback_param = &host->comp;
410 
411         cookie = tx->tx_submit(tx);
412         if (dma_submit_error(cookie)) {
413                 dev_err(host->dev, "Failed to do DMA tx_submit\n");
414                 goto err_dma;
415         }
416 
417         dma_async_issue_pending(host->dma_chan);
418         wait_for_completion(&host->comp);
419 
420         if (is_read && nfc && nfc->data_in_sram)
421                 /* After read data from SRAM, need to increase the position */
422                 nfc->data_in_sram += len;
423 
424         err = 0;
425 
426 err_dma:
427         dma_unmap_single(dma_dev->dev, phys_addr, len, dir);
428 err_buf:
429         if (err != 0)
430                 dev_dbg(host->dev, "Fall back to CPU I/O\n");
431         return err;
432 }
433 
434 static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len)
435 {
436         struct nand_chip *chip = mtd_to_nand(mtd);
437         struct atmel_nand_host *host = nand_get_controller_data(chip);
438 
439         if (use_dma && len > mtd->oobsize)
440                 /* only use DMA for bigger than oob size: better performances */
441                 if (atmel_nand_dma_op(mtd, buf, len, 1) == 0)
442                         return;
443 
444         if (host->board.bus_width_16)
445                 atmel_read_buf16(mtd, buf, len);
446         else
447                 atmel_read_buf8(mtd, buf, len);
448 }
449 
450 static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
451 {
452         struct nand_chip *chip = mtd_to_nand(mtd);
453         struct atmel_nand_host *host = nand_get_controller_data(chip);
454 
455         if (use_dma && len > mtd->oobsize)
456                 /* only use DMA for bigger than oob size: better performances */
457                 if (atmel_nand_dma_op(mtd, (void *)buf, len, 0) == 0)
458                         return;
459 
460         if (host->board.bus_width_16)
461                 atmel_write_buf16(mtd, buf, len);
462         else
463                 atmel_write_buf8(mtd, buf, len);
464 }
465 
466 /*
467  * Return number of ecc bytes per sector according to sector size and
468  * correction capability
469  *
470  * Following table shows what at91 PMECC supported:
471  * Correction Capability        Sector_512_bytes        Sector_1024_bytes
472  * =====================        ================        =================
473  *                2-bits                 4-bytes                  4-bytes
474  *                4-bits                 7-bytes                  7-bytes
475  *                8-bits                13-bytes                 14-bytes
476  *               12-bits                20-bytes                 21-bytes
477  *               24-bits                39-bytes                 42-bytes
478  *               32-bits                52-bytes                 56-bytes
479  */
480 static int pmecc_get_ecc_bytes(int cap, int sector_size)
481 {
482         int m = 12 + sector_size / 512;
483         return (m * cap + 7) / 8;
484 }
485 
486 static void pmecc_config_ecc_layout(struct nand_ecclayout *layout,
487                                     int oobsize, int ecc_len)
488 {
489         int i;
490 
491         layout->eccbytes = ecc_len;
492 
493         /* ECC will occupy the last ecc_len bytes continuously */
494         for (i = 0; i < ecc_len; i++)
495                 layout->eccpos[i] = oobsize - ecc_len + i;
496 
497         layout->oobfree[0].offset = PMECC_OOB_RESERVED_BYTES;
498         layout->oobfree[0].length =
499                 oobsize - ecc_len - layout->oobfree[0].offset;
500 }
501 
502 static void __iomem *pmecc_get_alpha_to(struct atmel_nand_host *host)
503 {
504         int table_size;
505 
506         table_size = host->pmecc_sector_size == 512 ?
507                 PMECC_LOOKUP_TABLE_SIZE_512 : PMECC_LOOKUP_TABLE_SIZE_1024;
508 
509         return host->pmecc_rom_base + host->pmecc_lookup_table_offset +
510                         table_size * sizeof(int16_t);
511 }
512 
513 static int pmecc_data_alloc(struct atmel_nand_host *host)
514 {
515         const int cap = host->pmecc_corr_cap;
516         int size;
517 
518         size = (2 * cap + 1) * sizeof(int16_t);
519         host->pmecc_partial_syn = devm_kzalloc(host->dev, size, GFP_KERNEL);
520         host->pmecc_si = devm_kzalloc(host->dev, size, GFP_KERNEL);
521         host->pmecc_lmu = devm_kzalloc(host->dev,
522                         (cap + 1) * sizeof(int16_t), GFP_KERNEL);
523         host->pmecc_smu = devm_kzalloc(host->dev,
524                         (cap + 2) * size, GFP_KERNEL);
525 
526         size = (cap + 1) * sizeof(int);
527         host->pmecc_mu = devm_kzalloc(host->dev, size, GFP_KERNEL);
528         host->pmecc_dmu = devm_kzalloc(host->dev, size, GFP_KERNEL);
529         host->pmecc_delta = devm_kzalloc(host->dev, size, GFP_KERNEL);
530 
531         if (!host->pmecc_partial_syn ||
532                 !host->pmecc_si ||
533                 !host->pmecc_lmu ||
534                 !host->pmecc_smu ||
535                 !host->pmecc_mu ||
536                 !host->pmecc_dmu ||
537                 !host->pmecc_delta)
538                 return -ENOMEM;
539 
540         return 0;
541 }
542 
543 static void pmecc_gen_syndrome(struct mtd_info *mtd, int sector)
544 {
545         struct nand_chip *nand_chip = mtd_to_nand(mtd);
546         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
547         int i;
548         uint32_t value;
549 
550         /* Fill odd syndromes */
551         for (i = 0; i < host->pmecc_corr_cap; i++) {
552                 value = pmecc_readl_rem_relaxed(host->ecc, sector, i / 2);
553                 if (i & 1)
554                         value >>= 16;
555                 value &= 0xffff;
556                 host->pmecc_partial_syn[(2 * i) + 1] = (int16_t)value;
557         }
558 }
559 
560 static void pmecc_substitute(struct mtd_info *mtd)
561 {
562         struct nand_chip *nand_chip = mtd_to_nand(mtd);
563         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
564         int16_t __iomem *alpha_to = host->pmecc_alpha_to;
565         int16_t __iomem *index_of = host->pmecc_index_of;
566         int16_t *partial_syn = host->pmecc_partial_syn;
567         const int cap = host->pmecc_corr_cap;
568         int16_t *si;
569         int i, j;
570 
571         /* si[] is a table that holds the current syndrome value,
572          * an element of that table belongs to the field
573          */
574         si = host->pmecc_si;
575 
576         memset(&si[1], 0, sizeof(int16_t) * (2 * cap - 1));
577 
578         /* Computation 2t syndromes based on S(x) */
579         /* Odd syndromes */
580         for (i = 1; i < 2 * cap; i += 2) {
581                 for (j = 0; j < host->pmecc_degree; j++) {
582                         if (partial_syn[i] & ((unsigned short)0x1 << j))
583                                 si[i] = readw_relaxed(alpha_to + i * j) ^ si[i];
584                 }
585         }
586         /* Even syndrome = (Odd syndrome) ** 2 */
587         for (i = 2, j = 1; j <= cap; i = ++j << 1) {
588                 if (si[j] == 0) {
589                         si[i] = 0;
590                 } else {
591                         int16_t tmp;
592 
593                         tmp = readw_relaxed(index_of + si[j]);
594                         tmp = (tmp * 2) % host->pmecc_cw_len;
595                         si[i] = readw_relaxed(alpha_to + tmp);
596                 }
597         }
598 
599         return;
600 }
601 
602 static void pmecc_get_sigma(struct mtd_info *mtd)
603 {
604         struct nand_chip *nand_chip = mtd_to_nand(mtd);
605         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
606 
607         int16_t *lmu = host->pmecc_lmu;
608         int16_t *si = host->pmecc_si;
609         int *mu = host->pmecc_mu;
610         int *dmu = host->pmecc_dmu;     /* Discrepancy */
611         int *delta = host->pmecc_delta; /* Delta order */
612         int cw_len = host->pmecc_cw_len;
613         const int16_t cap = host->pmecc_corr_cap;
614         const int num = 2 * cap + 1;
615         int16_t __iomem *index_of = host->pmecc_index_of;
616         int16_t __iomem *alpha_to = host->pmecc_alpha_to;
617         int i, j, k;
618         uint32_t dmu_0_count, tmp;
619         int16_t *smu = host->pmecc_smu;
620 
621         /* index of largest delta */
622         int ro;
623         int largest;
624         int diff;
625 
626         dmu_0_count = 0;
627 
628         /* First Row */
629 
630         /* Mu */
631         mu[0] = -1;
632 
633         memset(smu, 0, sizeof(int16_t) * num);
634         smu[0] = 1;
635 
636         /* discrepancy set to 1 */
637         dmu[0] = 1;
638         /* polynom order set to 0 */
639         lmu[0] = 0;
640         delta[0] = (mu[0] * 2 - lmu[0]) >> 1;
641 
642         /* Second Row */
643 
644         /* Mu */
645         mu[1] = 0;
646         /* Sigma(x) set to 1 */
647         memset(&smu[num], 0, sizeof(int16_t) * num);
648         smu[num] = 1;
649 
650         /* discrepancy set to S1 */
651         dmu[1] = si[1];
652 
653         /* polynom order set to 0 */
654         lmu[1] = 0;
655 
656         delta[1] = (mu[1] * 2 - lmu[1]) >> 1;
657 
658         /* Init the Sigma(x) last row */
659         memset(&smu[(cap + 1) * num], 0, sizeof(int16_t) * num);
660 
661         for (i = 1; i <= cap; i++) {
662                 mu[i + 1] = i << 1;
663                 /* Begin Computing Sigma (Mu+1) and L(mu) */
664                 /* check if discrepancy is set to 0 */
665                 if (dmu[i] == 0) {
666                         dmu_0_count++;
667 
668                         tmp = ((cap - (lmu[i] >> 1) - 1) / 2);
669                         if ((cap - (lmu[i] >> 1) - 1) & 0x1)
670                                 tmp += 2;
671                         else
672                                 tmp += 1;
673 
674                         if (dmu_0_count == tmp) {
675                                 for (j = 0; j <= (lmu[i] >> 1) + 1; j++)
676                                         smu[(cap + 1) * num + j] =
677                                                         smu[i * num + j];
678 
679                                 lmu[cap + 1] = lmu[i];
680                                 return;
681                         }
682 
683                         /* copy polynom */
684                         for (j = 0; j <= lmu[i] >> 1; j++)
685                                 smu[(i + 1) * num + j] = smu[i * num + j];
686 
687                         /* copy previous polynom order to the next */
688                         lmu[i + 1] = lmu[i];
689                 } else {
690                         ro = 0;
691                         largest = -1;
692                         /* find largest delta with dmu != 0 */
693                         for (j = 0; j < i; j++) {
694                                 if ((dmu[j]) && (delta[j] > largest)) {
695                                         largest = delta[j];
696                                         ro = j;
697                                 }
698                         }
699 
700                         /* compute difference */
701                         diff = (mu[i] - mu[ro]);
702 
703                         /* Compute degree of the new smu polynomial */
704                         if ((lmu[i] >> 1) > ((lmu[ro] >> 1) + diff))
705                                 lmu[i + 1] = lmu[i];
706                         else
707                                 lmu[i + 1] = ((lmu[ro] >> 1) + diff) * 2;
708 
709                         /* Init smu[i+1] with 0 */
710                         for (k = 0; k < num; k++)
711                                 smu[(i + 1) * num + k] = 0;
712 
713                         /* Compute smu[i+1] */
714                         for (k = 0; k <= lmu[ro] >> 1; k++) {
715                                 int16_t a, b, c;
716 
717                                 if (!(smu[ro * num + k] && dmu[i]))
718                                         continue;
719                                 a = readw_relaxed(index_of + dmu[i]);
720                                 b = readw_relaxed(index_of + dmu[ro]);
721                                 c = readw_relaxed(index_of + smu[ro * num + k]);
722                                 tmp = a + (cw_len - b) + c;
723                                 a = readw_relaxed(alpha_to + tmp % cw_len);
724                                 smu[(i + 1) * num + (k + diff)] = a;
725                         }
726 
727                         for (k = 0; k <= lmu[i] >> 1; k++)
728                                 smu[(i + 1) * num + k] ^= smu[i * num + k];
729                 }
730 
731                 /* End Computing Sigma (Mu+1) and L(mu) */
732                 /* In either case compute delta */
733                 delta[i + 1] = (mu[i + 1] * 2 - lmu[i + 1]) >> 1;
734 
735                 /* Do not compute discrepancy for the last iteration */
736                 if (i >= cap)
737                         continue;
738 
739                 for (k = 0; k <= (lmu[i + 1] >> 1); k++) {
740                         tmp = 2 * (i - 1);
741                         if (k == 0) {
742                                 dmu[i + 1] = si[tmp + 3];
743                         } else if (smu[(i + 1) * num + k] && si[tmp + 3 - k]) {
744                                 int16_t a, b, c;
745                                 a = readw_relaxed(index_of +
746                                                 smu[(i + 1) * num + k]);
747                                 b = si[2 * (i - 1) + 3 - k];
748                                 c = readw_relaxed(index_of + b);
749                                 tmp = a + c;
750                                 tmp %= cw_len;
751                                 dmu[i + 1] = readw_relaxed(alpha_to + tmp) ^
752                                         dmu[i + 1];
753                         }
754                 }
755         }
756 
757         return;
758 }
759 
760 static int pmecc_err_location(struct mtd_info *mtd)
761 {
762         struct nand_chip *nand_chip = mtd_to_nand(mtd);
763         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
764         unsigned long end_time;
765         const int cap = host->pmecc_corr_cap;
766         const int num = 2 * cap + 1;
767         int sector_size = host->pmecc_sector_size;
768         int err_nbr = 0;        /* number of error */
769         int roots_nbr;          /* number of roots */
770         int i;
771         uint32_t val;
772         int16_t *smu = host->pmecc_smu;
773 
774         pmerrloc_writel(host->pmerrloc_base, ELDIS, PMERRLOC_DISABLE);
775 
776         for (i = 0; i <= host->pmecc_lmu[cap + 1] >> 1; i++) {
777                 pmerrloc_writel_sigma_relaxed(host->pmerrloc_base, i,
778                                       smu[(cap + 1) * num + i]);
779                 err_nbr++;
780         }
781 
782         val = (err_nbr - 1) << 16;
783         if (sector_size == 1024)
784                 val |= 1;
785 
786         pmerrloc_writel(host->pmerrloc_base, ELCFG, val);
787         pmerrloc_writel(host->pmerrloc_base, ELEN,
788                         sector_size * 8 + host->pmecc_degree * cap);
789 
790         end_time = jiffies + msecs_to_jiffies(PMECC_MAX_TIMEOUT_MS);
791         while (!(pmerrloc_readl_relaxed(host->pmerrloc_base, ELISR)
792                  & PMERRLOC_CALC_DONE)) {
793                 if (unlikely(time_after(jiffies, end_time))) {
794                         dev_err(host->dev, "PMECC: Timeout to calculate error location.\n");
795                         return -1;
796                 }
797                 cpu_relax();
798         }
799 
800         roots_nbr = (pmerrloc_readl_relaxed(host->pmerrloc_base, ELISR)
801                 & PMERRLOC_ERR_NUM_MASK) >> 8;
802         /* Number of roots == degree of smu hence <= cap */
803         if (roots_nbr == host->pmecc_lmu[cap + 1] >> 1)
804                 return err_nbr - 1;
805 
806         /* Number of roots does not match the degree of smu
807          * unable to correct error */
808         return -1;
809 }
810 
811 static void pmecc_correct_data(struct mtd_info *mtd, uint8_t *buf, uint8_t *ecc,
812                 int sector_num, int extra_bytes, int err_nbr)
813 {
814         struct nand_chip *nand_chip = mtd_to_nand(mtd);
815         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
816         int i = 0;
817         int byte_pos, bit_pos, sector_size, pos;
818         uint32_t tmp;
819         uint8_t err_byte;
820 
821         sector_size = host->pmecc_sector_size;
822 
823         while (err_nbr) {
824                 tmp = pmerrloc_readl_el_relaxed(host->pmerrloc_el_base, i) - 1;
825                 byte_pos = tmp / 8;
826                 bit_pos  = tmp % 8;
827 
828                 if (byte_pos >= (sector_size + extra_bytes))
829                         BUG();  /* should never happen */
830 
831                 if (byte_pos < sector_size) {
832                         err_byte = *(buf + byte_pos);
833                         *(buf + byte_pos) ^= (1 << bit_pos);
834 
835                         pos = sector_num * host->pmecc_sector_size + byte_pos;
836                         dev_dbg(host->dev, "Bit flip in data area, byte_pos: %d, bit_pos: %d, 0x%02x -> 0x%02x\n",
837                                 pos, bit_pos, err_byte, *(buf + byte_pos));
838                 } else {
839                         /* Bit flip in OOB area */
840                         tmp = sector_num * nand_chip->ecc.bytes
841                                         + (byte_pos - sector_size);
842                         err_byte = ecc[tmp];
843                         ecc[tmp] ^= (1 << bit_pos);
844 
845                         pos = tmp + nand_chip->ecc.layout->eccpos[0];
846                         dev_dbg(host->dev, "Bit flip in OOB, oob_byte_pos: %d, bit_pos: %d, 0x%02x -> 0x%02x\n",
847                                 pos, bit_pos, err_byte, ecc[tmp]);
848                 }
849 
850                 i++;
851                 err_nbr--;
852         }
853 
854         return;
855 }
856 
857 static int pmecc_correction(struct mtd_info *mtd, u32 pmecc_stat, uint8_t *buf,
858         u8 *ecc)
859 {
860         struct nand_chip *nand_chip = mtd_to_nand(mtd);
861         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
862         int i, err_nbr;
863         uint8_t *buf_pos;
864         int max_bitflips = 0;
865 
866         /* If can correct bitfilps from erased page, do the normal check */
867         if (host->caps->pmecc_correct_erase_page)
868                 goto normal_check;
869 
870         for (i = 0; i < nand_chip->ecc.total; i++)
871                 if (ecc[i] != 0xff)
872                         goto normal_check;
873         /* Erased page, return OK */
874         return 0;
875 
876 normal_check:
877         for (i = 0; i < nand_chip->ecc.steps; i++) {
878                 err_nbr = 0;
879                 if (pmecc_stat & 0x1) {
880                         buf_pos = buf + i * host->pmecc_sector_size;
881 
882                         pmecc_gen_syndrome(mtd, i);
883                         pmecc_substitute(mtd);
884                         pmecc_get_sigma(mtd);
885 
886                         err_nbr = pmecc_err_location(mtd);
887                         if (err_nbr == -1) {
888                                 dev_err(host->dev, "PMECC: Too many errors\n");
889                                 mtd->ecc_stats.failed++;
890                                 return -EIO;
891                         } else {
892                                 pmecc_correct_data(mtd, buf_pos, ecc, i,
893                                         nand_chip->ecc.bytes, err_nbr);
894                                 mtd->ecc_stats.corrected += err_nbr;
895                                 max_bitflips = max_t(int, max_bitflips, err_nbr);
896                         }
897                 }
898                 pmecc_stat >>= 1;
899         }
900 
901         return max_bitflips;
902 }
903 
904 static void pmecc_enable(struct atmel_nand_host *host, int ecc_op)
905 {
906         u32 val;
907 
908         if (ecc_op != NAND_ECC_READ && ecc_op != NAND_ECC_WRITE) {
909                 dev_err(host->dev, "atmel_nand: wrong pmecc operation type!");
910                 return;
911         }
912 
913         pmecc_writel(host->ecc, CTRL, PMECC_CTRL_RST);
914         pmecc_writel(host->ecc, CTRL, PMECC_CTRL_DISABLE);
915         val = pmecc_readl_relaxed(host->ecc, CFG);
916 
917         if (ecc_op == NAND_ECC_READ)
918                 pmecc_writel(host->ecc, CFG, (val & ~PMECC_CFG_WRITE_OP)
919                         | PMECC_CFG_AUTO_ENABLE);
920         else
921                 pmecc_writel(host->ecc, CFG, (val | PMECC_CFG_WRITE_OP)
922                         & ~PMECC_CFG_AUTO_ENABLE);
923 
924         pmecc_writel(host->ecc, CTRL, PMECC_CTRL_ENABLE);
925         pmecc_writel(host->ecc, CTRL, PMECC_CTRL_DATA);
926 }
927 
928 static int atmel_nand_pmecc_read_page(struct mtd_info *mtd,
929         struct nand_chip *chip, uint8_t *buf, int oob_required, int page)
930 {
931         struct atmel_nand_host *host = nand_get_controller_data(chip);
932         int eccsize = chip->ecc.size * chip->ecc.steps;
933         uint8_t *oob = chip->oob_poi;
934         uint32_t *eccpos = chip->ecc.layout->eccpos;
935         uint32_t stat;
936         unsigned long end_time;
937         int bitflips = 0;
938 
939         if (!host->nfc || !host->nfc->use_nfc_sram)
940                 pmecc_enable(host, NAND_ECC_READ);
941 
942         chip->read_buf(mtd, buf, eccsize);
943         chip->read_buf(mtd, oob, mtd->oobsize);
944 
945         end_time = jiffies + msecs_to_jiffies(PMECC_MAX_TIMEOUT_MS);
946         while ((pmecc_readl_relaxed(host->ecc, SR) & PMECC_SR_BUSY)) {
947                 if (unlikely(time_after(jiffies, end_time))) {
948                         dev_err(host->dev, "PMECC: Timeout to get error status.\n");
949                         return -EIO;
950                 }
951                 cpu_relax();
952         }
953 
954         stat = pmecc_readl_relaxed(host->ecc, ISR);
955         if (stat != 0) {
956                 bitflips = pmecc_correction(mtd, stat, buf, &oob[eccpos[0]]);
957                 if (bitflips < 0)
958                         /* uncorrectable errors */
959                         return 0;
960         }
961 
962         return bitflips;
963 }
964 
965 static int atmel_nand_pmecc_write_page(struct mtd_info *mtd,
966                 struct nand_chip *chip, const uint8_t *buf, int oob_required,
967                 int page)
968 {
969         struct atmel_nand_host *host = nand_get_controller_data(chip);
970         uint32_t *eccpos = chip->ecc.layout->eccpos;
971         int i, j;
972         unsigned long end_time;
973 
974         if (!host->nfc || !host->nfc->write_by_sram) {
975                 pmecc_enable(host, NAND_ECC_WRITE);
976                 chip->write_buf(mtd, (u8 *)buf, mtd->writesize);
977         }
978 
979         end_time = jiffies + msecs_to_jiffies(PMECC_MAX_TIMEOUT_MS);
980         while ((pmecc_readl_relaxed(host->ecc, SR) & PMECC_SR_BUSY)) {
981                 if (unlikely(time_after(jiffies, end_time))) {
982                         dev_err(host->dev, "PMECC: Timeout to get ECC value.\n");
983                         return -EIO;
984                 }
985                 cpu_relax();
986         }
987 
988         for (i = 0; i < chip->ecc.steps; i++) {
989                 for (j = 0; j < chip->ecc.bytes; j++) {
990                         int pos;
991 
992                         pos = i * chip->ecc.bytes + j;
993                         chip->oob_poi[eccpos[pos]] =
994                                 pmecc_readb_ecc_relaxed(host->ecc, i, j);
995                 }
996         }
997         chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
998 
999         return 0;
1000 }
1001 
1002 static void atmel_pmecc_core_init(struct mtd_info *mtd)
1003 {
1004         struct nand_chip *nand_chip = mtd_to_nand(mtd);
1005         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
1006         uint32_t val = 0;
1007         struct nand_ecclayout *ecc_layout;
1008 
1009         pmecc_writel(host->ecc, CTRL, PMECC_CTRL_RST);
1010         pmecc_writel(host->ecc, CTRL, PMECC_CTRL_DISABLE);
1011 
1012         switch (host->pmecc_corr_cap) {
1013         case 2:
1014                 val = PMECC_CFG_BCH_ERR2;
1015                 break;
1016         case 4:
1017                 val = PMECC_CFG_BCH_ERR4;
1018                 break;
1019         case 8:
1020                 val = PMECC_CFG_BCH_ERR8;
1021                 break;
1022         case 12:
1023                 val = PMECC_CFG_BCH_ERR12;
1024                 break;
1025         case 24:
1026                 val = PMECC_CFG_BCH_ERR24;
1027                 break;
1028         case 32:
1029                 val = PMECC_CFG_BCH_ERR32;
1030                 break;
1031         }
1032 
1033         if (host->pmecc_sector_size == 512)
1034                 val |= PMECC_CFG_SECTOR512;
1035         else if (host->pmecc_sector_size == 1024)
1036                 val |= PMECC_CFG_SECTOR1024;
1037 
1038         switch (nand_chip->ecc.steps) {
1039         case 1:
1040                 val |= PMECC_CFG_PAGE_1SECTOR;
1041                 break;
1042         case 2:
1043                 val |= PMECC_CFG_PAGE_2SECTORS;
1044                 break;
1045         case 4:
1046                 val |= PMECC_CFG_PAGE_4SECTORS;
1047                 break;
1048         case 8:
1049                 val |= PMECC_CFG_PAGE_8SECTORS;
1050                 break;
1051         }
1052 
1053         val |= (PMECC_CFG_READ_OP | PMECC_CFG_SPARE_DISABLE
1054                 | PMECC_CFG_AUTO_DISABLE);
1055         pmecc_writel(host->ecc, CFG, val);
1056 
1057         ecc_layout = nand_chip->ecc.layout;
1058         pmecc_writel(host->ecc, SAREA, mtd->oobsize - 1);
1059         pmecc_writel(host->ecc, SADDR, ecc_layout->eccpos[0]);
1060         pmecc_writel(host->ecc, EADDR,
1061                         ecc_layout->eccpos[ecc_layout->eccbytes - 1]);
1062         /* See datasheet about PMECC Clock Control Register */
1063         pmecc_writel(host->ecc, CLK, 2);
1064         pmecc_writel(host->ecc, IDR, 0xff);
1065         pmecc_writel(host->ecc, CTRL, PMECC_CTRL_ENABLE);
1066 }
1067 
1068 /*
1069  * Get minimum ecc requirements from NAND.
1070  * If pmecc-cap, pmecc-sector-size in DTS are not specified, this function
1071  * will set them according to minimum ecc requirement. Otherwise, use the
1072  * value in DTS file.
1073  * return 0 if success. otherwise return error code.
1074  */
1075 static int pmecc_choose_ecc(struct atmel_nand_host *host,
1076                 int *cap, int *sector_size)
1077 {
1078         /* Get minimum ECC requirements */
1079         if (host->nand_chip.ecc_strength_ds) {
1080                 *cap = host->nand_chip.ecc_strength_ds;
1081                 *sector_size = host->nand_chip.ecc_step_ds;
1082                 dev_info(host->dev, "minimum ECC: %d bits in %d bytes\n",
1083                                 *cap, *sector_size);
1084         } else {
1085                 *cap = 2;
1086                 *sector_size = 512;
1087                 dev_info(host->dev, "can't detect min. ECC, assume 2 bits in 512 bytes\n");
1088         }
1089 
1090         /* If device tree doesn't specify, use NAND's minimum ECC parameters */
1091         if (host->pmecc_corr_cap == 0) {
1092                 if (*cap > host->caps->pmecc_max_correction)
1093                         return -EINVAL;
1094 
1095                 /* use the most fitable ecc bits (the near bigger one ) */
1096                 if (*cap <= 2)
1097                         host->pmecc_corr_cap = 2;
1098                 else if (*cap <= 4)
1099                         host->pmecc_corr_cap = 4;
1100                 else if (*cap <= 8)
1101                         host->pmecc_corr_cap = 8;
1102                 else if (*cap <= 12)
1103                         host->pmecc_corr_cap = 12;
1104                 else if (*cap <= 24)
1105                         host->pmecc_corr_cap = 24;
1106                 else if (*cap <= 32)
1107                         host->pmecc_corr_cap = 32;
1108                 else
1109                         return -EINVAL;
1110         }
1111         if (host->pmecc_sector_size == 0) {
1112                 /* use the most fitable sector size (the near smaller one ) */
1113                 if (*sector_size >= 1024)
1114                         host->pmecc_sector_size = 1024;
1115                 else if (*sector_size >= 512)
1116                         host->pmecc_sector_size = 512;
1117                 else
1118                         return -EINVAL;
1119         }
1120         return 0;
1121 }
1122 
1123 static inline int deg(unsigned int poly)
1124 {
1125         /* polynomial degree is the most-significant bit index */
1126         return fls(poly) - 1;
1127 }
1128 
1129 static int build_gf_tables(int mm, unsigned int poly,
1130                 int16_t *index_of, int16_t *alpha_to)
1131 {
1132         unsigned int i, x = 1;
1133         const unsigned int k = 1 << deg(poly);
1134         unsigned int nn = (1 << mm) - 1;
1135 
1136         /* primitive polynomial must be of degree m */
1137         if (k != (1u << mm))
1138                 return -EINVAL;
1139 
1140         for (i = 0; i < nn; i++) {
1141                 alpha_to[i] = x;
1142                 index_of[x] = i;
1143                 if (i && (x == 1))
1144                         /* polynomial is not primitive (a^i=1 with 0<i<2^m-1) */
1145                         return -EINVAL;
1146                 x <<= 1;
1147                 if (x & k)
1148                         x ^= poly;
1149         }
1150         alpha_to[nn] = 1;
1151         index_of[0] = 0;
1152 
1153         return 0;
1154 }
1155 
1156 static uint16_t *create_lookup_table(struct device *dev, int sector_size)
1157 {
1158         int degree = (sector_size == 512) ?
1159                         PMECC_GF_DIMENSION_13 :
1160                         PMECC_GF_DIMENSION_14;
1161         unsigned int poly = (sector_size == 512) ?
1162                         PMECC_GF_13_PRIMITIVE_POLY :
1163                         PMECC_GF_14_PRIMITIVE_POLY;
1164         int table_size = (sector_size == 512) ?
1165                         PMECC_LOOKUP_TABLE_SIZE_512 :
1166                         PMECC_LOOKUP_TABLE_SIZE_1024;
1167 
1168         int16_t *addr = devm_kzalloc(dev, 2 * table_size * sizeof(uint16_t),
1169                         GFP_KERNEL);
1170         if (addr && build_gf_tables(degree, poly, addr, addr + table_size))
1171                 return NULL;
1172 
1173         return addr;
1174 }
1175 
1176 static int atmel_pmecc_nand_init_params(struct platform_device *pdev,
1177                                          struct atmel_nand_host *host)
1178 {
1179         struct nand_chip *nand_chip = &host->nand_chip;
1180         struct mtd_info *mtd = nand_to_mtd(nand_chip);
1181         struct resource *regs, *regs_pmerr, *regs_rom;
1182         uint16_t *galois_table;
1183         int cap, sector_size, err_no;
1184 
1185         err_no = pmecc_choose_ecc(host, &cap, &sector_size);
1186         if (err_no) {
1187                 dev_err(host->dev, "The NAND flash's ECC requirement are not support!");
1188                 return err_no;
1189         }
1190 
1191         if (cap > host->pmecc_corr_cap ||
1192                         sector_size != host->pmecc_sector_size)
1193                 dev_info(host->dev, "WARNING: Be Caution! Using different PMECC parameters from Nand ONFI ECC reqirement.\n");
1194 
1195         cap = host->pmecc_corr_cap;
1196         sector_size = host->pmecc_sector_size;
1197         host->pmecc_lookup_table_offset = (sector_size == 512) ?
1198                         host->pmecc_lookup_table_offset_512 :
1199                         host->pmecc_lookup_table_offset_1024;
1200 
1201         dev_info(host->dev, "Initialize PMECC params, cap: %d, sector: %d\n",
1202                  cap, sector_size);
1203 
1204         regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1205         if (!regs) {
1206                 dev_warn(host->dev,
1207                         "Can't get I/O resource regs for PMECC controller, rolling back on software ECC\n");
1208                 nand_chip->ecc.mode = NAND_ECC_SOFT;
1209                 return 0;
1210         }
1211 
1212         host->ecc = devm_ioremap_resource(&pdev->dev, regs);
1213         if (IS_ERR(host->ecc)) {
1214                 err_no = PTR_ERR(host->ecc);
1215                 goto err;
1216         }
1217 
1218         regs_pmerr = platform_get_resource(pdev, IORESOURCE_MEM, 2);
1219         host->pmerrloc_base = devm_ioremap_resource(&pdev->dev, regs_pmerr);
1220         if (IS_ERR(host->pmerrloc_base)) {
1221                 err_no = PTR_ERR(host->pmerrloc_base);
1222                 goto err;
1223         }
1224         host->pmerrloc_el_base = host->pmerrloc_base + ATMEL_PMERRLOC_SIGMAx +
1225                 (host->caps->pmecc_max_correction + 1) * 4;
1226 
1227         if (!host->has_no_lookup_table) {
1228                 regs_rom = platform_get_resource(pdev, IORESOURCE_MEM, 3);
1229                 host->pmecc_rom_base = devm_ioremap_resource(&pdev->dev,
1230                                                                 regs_rom);
1231                 if (IS_ERR(host->pmecc_rom_base)) {
1232                         dev_err(host->dev, "Can not get I/O resource for ROM, will build a lookup table in runtime!\n");
1233                         host->has_no_lookup_table = true;
1234                 }
1235         }
1236 
1237         if (host->has_no_lookup_table) {
1238                 /* Build the look-up table in runtime */
1239                 galois_table = create_lookup_table(host->dev, sector_size);
1240                 if (!galois_table) {
1241                         dev_err(host->dev, "Failed to build a lookup table in runtime!\n");
1242                         err_no = -EINVAL;
1243                         goto err;
1244                 }
1245 
1246                 host->pmecc_rom_base = (void __iomem *)galois_table;
1247                 host->pmecc_lookup_table_offset = 0;
1248         }
1249 
1250         nand_chip->ecc.size = sector_size;
1251 
1252         /* set ECC page size and oob layout */
1253         switch (mtd->writesize) {
1254         case 512:
1255         case 1024:
1256         case 2048:
1257         case 4096:
1258         case 8192:
1259                 if (sector_size > mtd->writesize) {
1260                         dev_err(host->dev, "pmecc sector size is bigger than the page size!\n");
1261                         err_no = -EINVAL;
1262                         goto err;
1263                 }
1264 
1265                 host->pmecc_degree = (sector_size == 512) ?
1266                         PMECC_GF_DIMENSION_13 : PMECC_GF_DIMENSION_14;
1267                 host->pmecc_cw_len = (1 << host->pmecc_degree) - 1;
1268                 host->pmecc_alpha_to = pmecc_get_alpha_to(host);
1269                 host->pmecc_index_of = host->pmecc_rom_base +
1270                         host->pmecc_lookup_table_offset;
1271 
1272                 nand_chip->ecc.strength = cap;
1273                 nand_chip->ecc.bytes = pmecc_get_ecc_bytes(cap, sector_size);
1274                 nand_chip->ecc.steps = mtd->writesize / sector_size;
1275                 nand_chip->ecc.total = nand_chip->ecc.bytes *
1276                         nand_chip->ecc.steps;
1277                 if (nand_chip->ecc.total >
1278                                 mtd->oobsize - PMECC_OOB_RESERVED_BYTES) {
1279                         dev_err(host->dev, "No room for ECC bytes\n");
1280                         err_no = -EINVAL;
1281                         goto err;
1282                 }
1283                 pmecc_config_ecc_layout(&atmel_pmecc_oobinfo,
1284                                         mtd->oobsize,
1285                                         nand_chip->ecc.total);
1286 
1287                 nand_chip->ecc.layout = &atmel_pmecc_oobinfo;
1288                 break;
1289         default:
1290                 dev_warn(host->dev,
1291                         "Unsupported page size for PMECC, use Software ECC\n");
1292                 /* page size not handled by HW ECC */
1293                 /* switching back to soft ECC */
1294                 nand_chip->ecc.mode = NAND_ECC_SOFT;
1295                 return 0;
1296         }
1297 
1298         /* Allocate data for PMECC computation */
1299         err_no = pmecc_data_alloc(host);
1300         if (err_no) {
1301                 dev_err(host->dev,
1302                                 "Cannot allocate memory for PMECC computation!\n");
1303                 goto err;
1304         }
1305 
1306         nand_chip->options |= NAND_NO_SUBPAGE_WRITE;
1307         nand_chip->ecc.read_page = atmel_nand_pmecc_read_page;
1308         nand_chip->ecc.write_page = atmel_nand_pmecc_write_page;
1309 
1310         atmel_pmecc_core_init(mtd);
1311 
1312         return 0;
1313 
1314 err:
1315         return err_no;
1316 }
1317 
1318 /*
1319  * Calculate HW ECC
1320  *
1321  * function called after a write
1322  *
1323  * mtd:        MTD block structure
1324  * dat:        raw data (unused)
1325  * ecc_code:   buffer for ECC
1326  */
1327 static int atmel_nand_calculate(struct mtd_info *mtd,
1328                 const u_char *dat, unsigned char *ecc_code)
1329 {
1330         struct nand_chip *nand_chip = mtd_to_nand(mtd);
1331         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
1332         unsigned int ecc_value;
1333 
1334         /* get the first 2 ECC bytes */
1335         ecc_value = ecc_readl(host->ecc, PR);
1336 
1337         ecc_code[0] = ecc_value & 0xFF;
1338         ecc_code[1] = (ecc_value >> 8) & 0xFF;
1339 
1340         /* get the last 2 ECC bytes */
1341         ecc_value = ecc_readl(host->ecc, NPR) & ATMEL_ECC_NPARITY;
1342 
1343         ecc_code[2] = ecc_value & 0xFF;
1344         ecc_code[3] = (ecc_value >> 8) & 0xFF;
1345 
1346         return 0;
1347 }
1348 
1349 /*
1350  * HW ECC read page function
1351  *
1352  * mtd:        mtd info structure
1353  * chip:       nand chip info structure
1354  * buf:        buffer to store read data
1355  * oob_required:    caller expects OOB data read to chip->oob_poi
1356  */
1357 static int atmel_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
1358                                 uint8_t *buf, int oob_required, int page)
1359 {
1360         int eccsize = chip->ecc.size;
1361         int eccbytes = chip->ecc.bytes;
1362         uint32_t *eccpos = chip->ecc.layout->eccpos;
1363         uint8_t *p = buf;
1364         uint8_t *oob = chip->oob_poi;
1365         uint8_t *ecc_pos;
1366         int stat;
1367         unsigned int max_bitflips = 0;
1368 
1369         /*
1370          * Errata: ALE is incorrectly wired up to the ECC controller
1371          * on the AP7000, so it will include the address cycles in the
1372          * ECC calculation.
1373          *
1374          * Workaround: Reset the parity registers before reading the
1375          * actual data.
1376          */
1377         struct atmel_nand_host *host = nand_get_controller_data(chip);
1378         if (host->board.need_reset_workaround)
1379                 ecc_writel(host->ecc, CR, ATMEL_ECC_RST);
1380 
1381         /* read the page */
1382         chip->read_buf(mtd, p, eccsize);
1383 
1384         /* move to ECC position if needed */
1385         if (eccpos[0] != 0) {
1386                 /* This only works on large pages
1387                  * because the ECC controller waits for
1388                  * NAND_CMD_RNDOUTSTART after the
1389                  * NAND_CMD_RNDOUT.
1390                  * anyway, for small pages, the eccpos[0] == 0
1391                  */
1392                 chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
1393                                 mtd->writesize + eccpos[0], -1);
1394         }
1395 
1396         /* the ECC controller needs to read the ECC just after the data */
1397         ecc_pos = oob + eccpos[0];
1398         chip->read_buf(mtd, ecc_pos, eccbytes);
1399 
1400         /* check if there's an error */
1401         stat = chip->ecc.correct(mtd, p, oob, NULL);
1402 
1403         if (stat < 0) {
1404                 mtd->ecc_stats.failed++;
1405         } else {
1406                 mtd->ecc_stats.corrected += stat;
1407                 max_bitflips = max_t(unsigned int, max_bitflips, stat);
1408         }
1409 
1410         /* get back to oob start (end of page) */
1411         chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
1412 
1413         /* read the oob */
1414         chip->read_buf(mtd, oob, mtd->oobsize);
1415 
1416         return max_bitflips;
1417 }
1418 
1419 /*
1420  * HW ECC Correction
1421  *
1422  * function called after a read
1423  *
1424  * mtd:        MTD block structure
1425  * dat:        raw data read from the chip
1426  * read_ecc:   ECC from the chip (unused)
1427  * isnull:     unused
1428  *
1429  * Detect and correct a 1 bit error for a page
1430  */
1431 static int atmel_nand_correct(struct mtd_info *mtd, u_char *dat,
1432                 u_char *read_ecc, u_char *isnull)
1433 {
1434         struct nand_chip *nand_chip = mtd_to_nand(mtd);
1435         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
1436         unsigned int ecc_status;
1437         unsigned int ecc_word, ecc_bit;
1438 
1439         /* get the status from the Status Register */
1440         ecc_status = ecc_readl(host->ecc, SR);
1441 
1442         /* if there's no error */
1443         if (likely(!(ecc_status & ATMEL_ECC_RECERR)))
1444                 return 0;
1445 
1446         /* get error bit offset (4 bits) */
1447         ecc_bit = ecc_readl(host->ecc, PR) & ATMEL_ECC_BITADDR;
1448         /* get word address (12 bits) */
1449         ecc_word = ecc_readl(host->ecc, PR) & ATMEL_ECC_WORDADDR;
1450         ecc_word >>= 4;
1451 
1452         /* if there are multiple errors */
1453         if (ecc_status & ATMEL_ECC_MULERR) {
1454                 /* check if it is a freshly erased block
1455                  * (filled with 0xff) */
1456                 if ((ecc_bit == ATMEL_ECC_BITADDR)
1457                                 && (ecc_word == (ATMEL_ECC_WORDADDR >> 4))) {
1458                         /* the block has just been erased, return OK */
1459                         return 0;
1460                 }
1461                 /* it doesn't seems to be a freshly
1462                  * erased block.
1463                  * We can't correct so many errors */
1464                 dev_dbg(host->dev, "atmel_nand : multiple errors detected."
1465                                 " Unable to correct.\n");
1466                 return -EBADMSG;
1467         }
1468 
1469         /* if there's a single bit error : we can correct it */
1470         if (ecc_status & ATMEL_ECC_ECCERR) {
1471                 /* there's nothing much to do here.
1472                  * the bit error is on the ECC itself.
1473                  */
1474                 dev_dbg(host->dev, "atmel_nand : one bit error on ECC code."
1475                                 " Nothing to correct\n");
1476                 return 0;
1477         }
1478 
1479         dev_dbg(host->dev, "atmel_nand : one bit error on data."
1480                         " (word offset in the page :"
1481                         " 0x%x bit offset : 0x%x)\n",
1482                         ecc_word, ecc_bit);
1483         /* correct the error */
1484         if (nand_chip->options & NAND_BUSWIDTH_16) {
1485                 /* 16 bits words */
1486                 ((unsigned short *) dat)[ecc_word] ^= (1 << ecc_bit);
1487         } else {
1488                 /* 8 bits words */
1489                 dat[ecc_word] ^= (1 << ecc_bit);
1490         }
1491         dev_dbg(host->dev, "atmel_nand : error corrected\n");
1492         return 1;
1493 }
1494 
1495 /*
1496  * Enable HW ECC : unused on most chips
1497  */
1498 static void atmel_nand_hwctl(struct mtd_info *mtd, int mode)
1499 {
1500         struct nand_chip *nand_chip = mtd_to_nand(mtd);
1501         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
1502 
1503         if (host->board.need_reset_workaround)
1504                 ecc_writel(host->ecc, CR, ATMEL_ECC_RST);
1505 }
1506 
1507 static int atmel_of_init_port(struct atmel_nand_host *host,
1508                               struct device_node *np)
1509 {
1510         u32 val;
1511         u32 offset[2];
1512         int ecc_mode;
1513         struct atmel_nand_data *board = &host->board;
1514         enum of_gpio_flags flags = 0;
1515 
1516         host->caps = (struct atmel_nand_caps *)
1517                 of_device_get_match_data(host->dev);
1518 
1519         if (of_property_read_u32(np, "atmel,nand-addr-offset", &val) == 0) {
1520                 if (val >= 32) {
1521                         dev_err(host->dev, "invalid addr-offset %u\n", val);
1522                         return -EINVAL;
1523                 }
1524                 board->ale = val;
1525         }
1526 
1527         if (of_property_read_u32(np, "atmel,nand-cmd-offset", &val) == 0) {
1528                 if (val >= 32) {
1529                         dev_err(host->dev, "invalid cmd-offset %u\n", val);
1530                         return -EINVAL;
1531                 }
1532                 board->cle = val;
1533         }
1534 
1535         ecc_mode = of_get_nand_ecc_mode(np);
1536 
1537         board->ecc_mode = ecc_mode < 0 ? NAND_ECC_SOFT : ecc_mode;
1538 
1539         board->on_flash_bbt = of_get_nand_on_flash_bbt(np);
1540 
1541         board->has_dma = of_property_read_bool(np, "atmel,nand-has-dma");
1542 
1543         if (of_get_nand_bus_width(np) == 16)
1544                 board->bus_width_16 = 1;
1545 
1546         board->rdy_pin = of_get_gpio_flags(np, 0, &flags);
1547         board->rdy_pin_active_low = (flags == OF_GPIO_ACTIVE_LOW);
1548 
1549         board->enable_pin = of_get_gpio(np, 1);
1550         board->det_pin = of_get_gpio(np, 2);
1551 
1552         host->has_pmecc = of_property_read_bool(np, "atmel,has-pmecc");
1553 
1554         /* load the nfc driver if there is */
1555         of_platform_populate(np, NULL, NULL, host->dev);
1556 
1557         if (!(board->ecc_mode == NAND_ECC_HW) || !host->has_pmecc)
1558                 return 0;       /* Not using PMECC */
1559 
1560         /* use PMECC, get correction capability, sector size and lookup
1561          * table offset.
1562          * If correction bits and sector size are not specified, then find
1563          * them from NAND ONFI parameters.
1564          */
1565         if (of_property_read_u32(np, "atmel,pmecc-cap", &val) == 0) {
1566                 if (val > host->caps->pmecc_max_correction) {
1567                         dev_err(host->dev,
1568                                 "Required ECC strength too high: %u max %u\n",
1569                                 val, host->caps->pmecc_max_correction);
1570                         return -EINVAL;
1571                 }
1572                 if ((val != 2)  && (val != 4)  && (val != 8) &&
1573                     (val != 12) && (val != 24) && (val != 32)) {
1574                         dev_err(host->dev,
1575                                 "Required ECC strength not supported: %u\n",
1576                                 val);
1577                         return -EINVAL;
1578                 }
1579                 host->pmecc_corr_cap = (u8)val;
1580         }
1581 
1582         if (of_property_read_u32(np, "atmel,pmecc-sector-size", &val) == 0) {
1583                 if ((val != 512) && (val != 1024)) {
1584                         dev_err(host->dev,
1585                                 "Required ECC sector size not supported: %u\n",
1586                                 val);
1587                         return -EINVAL;
1588                 }
1589                 host->pmecc_sector_size = (u16)val;
1590         }
1591 
1592         if (of_property_read_u32_array(np, "atmel,pmecc-lookup-table-offset",
1593                         offset, 2) != 0) {
1594                 dev_err(host->dev, "Cannot get PMECC lookup table offset, will build a lookup table in runtime.\n");
1595                 host->has_no_lookup_table = true;
1596                 /* Will build a lookup table and initialize the offset later */
1597                 return 0;
1598         }
1599         if (!offset[0] && !offset[1]) {
1600                 dev_err(host->dev, "Invalid PMECC lookup table offset\n");
1601                 return -EINVAL;
1602         }
1603         host->pmecc_lookup_table_offset_512 = offset[0];
1604         host->pmecc_lookup_table_offset_1024 = offset[1];
1605 
1606         return 0;
1607 }
1608 
1609 static int atmel_hw_nand_init_params(struct platform_device *pdev,
1610                                          struct atmel_nand_host *host)
1611 {
1612         struct nand_chip *nand_chip = &host->nand_chip;
1613         struct mtd_info *mtd = nand_to_mtd(nand_chip);
1614         struct resource         *regs;
1615 
1616         regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1617         if (!regs) {
1618                 dev_err(host->dev,
1619                         "Can't get I/O resource regs, use software ECC\n");
1620                 nand_chip->ecc.mode = NAND_ECC_SOFT;
1621                 return 0;
1622         }
1623 
1624         host->ecc = devm_ioremap_resource(&pdev->dev, regs);
1625         if (IS_ERR(host->ecc))
1626                 return PTR_ERR(host->ecc);
1627 
1628         /* ECC is calculated for the whole page (1 step) */
1629         nand_chip->ecc.size = mtd->writesize;
1630 
1631         /* set ECC page size and oob layout */
1632         switch (mtd->writesize) {
1633         case 512:
1634                 nand_chip->ecc.layout = &atmel_oobinfo_small;
1635                 ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_528);
1636                 break;
1637         case 1024:
1638                 nand_chip->ecc.layout = &atmel_oobinfo_large;
1639                 ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_1056);
1640                 break;
1641         case 2048:
1642                 nand_chip->ecc.layout = &atmel_oobinfo_large;
1643                 ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_2112);
1644                 break;
1645         case 4096:
1646                 nand_chip->ecc.layout = &atmel_oobinfo_large;
1647                 ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_4224);
1648                 break;
1649         default:
1650                 /* page size not handled by HW ECC */
1651                 /* switching back to soft ECC */
1652                 nand_chip->ecc.mode = NAND_ECC_SOFT;
1653                 return 0;
1654         }
1655 
1656         /* set up for HW ECC */
1657         nand_chip->ecc.calculate = atmel_nand_calculate;
1658         nand_chip->ecc.correct = atmel_nand_correct;
1659         nand_chip->ecc.hwctl = atmel_nand_hwctl;
1660         nand_chip->ecc.read_page = atmel_nand_read_page;
1661         nand_chip->ecc.bytes = 4;
1662         nand_chip->ecc.strength = 1;
1663 
1664         return 0;
1665 }
1666 
1667 static inline u32 nfc_read_status(struct atmel_nand_host *host)
1668 {
1669         u32 err_flags = NFC_SR_DTOE | NFC_SR_UNDEF | NFC_SR_AWB | NFC_SR_ASE;
1670         u32 nfc_status = nfc_readl(host->nfc->hsmc_regs, SR);
1671 
1672         if (unlikely(nfc_status & err_flags)) {
1673                 if (nfc_status & NFC_SR_DTOE)
1674                         dev_err(host->dev, "NFC: Waiting Nand R/B Timeout Error\n");
1675                 else if (nfc_status & NFC_SR_UNDEF)
1676                         dev_err(host->dev, "NFC: Access Undefined Area Error\n");
1677                 else if (nfc_status & NFC_SR_AWB)
1678                         dev_err(host->dev, "NFC: Access memory While NFC is busy\n");
1679                 else if (nfc_status & NFC_SR_ASE)
1680                         dev_err(host->dev, "NFC: Access memory Size Error\n");
1681         }
1682 
1683         return nfc_status;
1684 }
1685 
1686 /* SMC interrupt service routine */
1687 static irqreturn_t hsmc_interrupt(int irq, void *dev_id)
1688 {
1689         struct atmel_nand_host *host = dev_id;
1690         u32 status, mask, pending;
1691         irqreturn_t ret = IRQ_NONE;
1692 
1693         status = nfc_read_status(host);
1694         mask = nfc_readl(host->nfc->hsmc_regs, IMR);
1695         pending = status & mask;
1696 
1697         if (pending & NFC_SR_XFR_DONE) {
1698                 complete(&host->nfc->comp_xfer_done);
1699                 nfc_writel(host->nfc->hsmc_regs, IDR, NFC_SR_XFR_DONE);
1700                 ret = IRQ_HANDLED;
1701         }
1702         if (pending & host->nfc->caps->rb_mask) {
1703                 complete(&host->nfc->comp_ready);
1704                 nfc_writel(host->nfc->hsmc_regs, IDR, host->nfc->caps->rb_mask);
1705                 ret = IRQ_HANDLED;
1706         }
1707         if (pending & NFC_SR_CMD_DONE) {
1708                 complete(&host->nfc->comp_cmd_done);
1709                 nfc_writel(host->nfc->hsmc_regs, IDR, NFC_SR_CMD_DONE);
1710                 ret = IRQ_HANDLED;
1711         }
1712 
1713         return ret;
1714 }
1715 
1716 /* NFC(Nand Flash Controller) related functions */
1717 static void nfc_prepare_interrupt(struct atmel_nand_host *host, u32 flag)
1718 {
1719         if (flag & NFC_SR_XFR_DONE)
1720                 init_completion(&host->nfc->comp_xfer_done);
1721 
1722         if (flag & host->nfc->caps->rb_mask)
1723                 init_completion(&host->nfc->comp_ready);
1724 
1725         if (flag & NFC_SR_CMD_DONE)
1726                 init_completion(&host->nfc->comp_cmd_done);
1727 
1728         /* Enable interrupt that need to wait for */
1729         nfc_writel(host->nfc->hsmc_regs, IER, flag);
1730 }
1731 
1732 static int nfc_wait_interrupt(struct atmel_nand_host *host, u32 flag)
1733 {
1734         int i, index = 0;
1735         struct completion *comp[3];     /* Support 3 interrupt completion */
1736 
1737         if (flag & NFC_SR_XFR_DONE)
1738                 comp[index++] = &host->nfc->comp_xfer_done;
1739 
1740         if (flag & host->nfc->caps->rb_mask)
1741                 comp[index++] = &host->nfc->comp_ready;
1742 
1743         if (flag & NFC_SR_CMD_DONE)
1744                 comp[index++] = &host->nfc->comp_cmd_done;
1745 
1746         if (index == 0) {
1747                 dev_err(host->dev, "Unknown interrupt flag: 0x%08x\n", flag);
1748                 return -EINVAL;
1749         }
1750 
1751         for (i = 0; i < index; i++) {
1752                 if (wait_for_completion_timeout(comp[i],
1753                                 msecs_to_jiffies(NFC_TIME_OUT_MS)))
1754                         continue;       /* wait for next completion */
1755                 else
1756                         goto err_timeout;
1757         }
1758 
1759         return 0;
1760 
1761 err_timeout:
1762         dev_err(host->dev, "Time out to wait for interrupt: 0x%08x\n", flag);
1763         /* Disable the interrupt as it is not handled by interrupt handler */
1764         nfc_writel(host->nfc->hsmc_regs, IDR, flag);
1765         return -ETIMEDOUT;
1766 }
1767 
1768 static int nfc_send_command(struct atmel_nand_host *host,
1769         unsigned int cmd, unsigned int addr, unsigned char cycle0)
1770 {
1771         unsigned long timeout;
1772         u32 flag = NFC_SR_CMD_DONE;
1773         flag |= cmd & NFCADDR_CMD_DATAEN ? NFC_SR_XFR_DONE : 0;
1774 
1775         dev_dbg(host->dev,
1776                 "nfc_cmd: 0x%08x, addr1234: 0x%08x, cycle0: 0x%02x\n",
1777                 cmd, addr, cycle0);
1778 
1779         timeout = jiffies + msecs_to_jiffies(NFC_TIME_OUT_MS);
1780         while (nfc_readl(host->nfc->hsmc_regs, SR) & NFC_SR_BUSY) {
1781                 if (time_after(jiffies, timeout)) {
1782                         dev_err(host->dev,
1783                                 "Time out to wait for NFC ready!\n");
1784                         return -ETIMEDOUT;
1785                 }
1786         }
1787 
1788         nfc_prepare_interrupt(host, flag);
1789         nfc_writel(host->nfc->hsmc_regs, CYCLE0, cycle0);
1790         nfc_cmd_addr1234_writel(cmd, addr, host->nfc->base_cmd_regs);
1791         return nfc_wait_interrupt(host, flag);
1792 }
1793 
1794 static int nfc_device_ready(struct mtd_info *mtd)
1795 {
1796         u32 status, mask;
1797         struct nand_chip *nand_chip = mtd_to_nand(mtd);
1798         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
1799 
1800         status = nfc_read_status(host);
1801         mask = nfc_readl(host->nfc->hsmc_regs, IMR);
1802 
1803         /* The mask should be 0. If not we may lost interrupts */
1804         if (unlikely(mask & status))
1805                 dev_err(host->dev, "Lost the interrupt flags: 0x%08x\n",
1806                                 mask & status);
1807 
1808         return status & host->nfc->caps->rb_mask;
1809 }
1810 
1811 static void nfc_select_chip(struct mtd_info *mtd, int chip)
1812 {
1813         struct nand_chip *nand_chip = mtd_to_nand(mtd);
1814         struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
1815 
1816         if (chip == -1)
1817                 nfc_writel(host->nfc->hsmc_regs, CTRL, NFC_CTRL_DISABLE);
1818         else
1819                 nfc_writel(host->nfc->hsmc_regs, CTRL, NFC_CTRL_ENABLE);
1820 }
1821 
1822 static int nfc_make_addr(struct mtd_info *mtd, int command, int column,
1823                 int page_addr, unsigned int *addr1234, unsigned int *cycle0)
1824 {
1825         struct nand_chip *chip = mtd_to_nand(mtd);
1826 
1827         int acycle = 0;
1828         unsigned char addr_bytes[8];
1829         int index = 0, bit_shift;
1830 
1831         BUG_ON(addr1234 == NULL || cycle0 == NULL);
1832 
1833         *cycle0 = 0;
1834         *addr1234 = 0;
1835 
1836         if (column != -1) {
1837                 if (chip->options & NAND_BUSWIDTH_16 &&
1838                                 !nand_opcode_8bits(command))
1839                         column >>= 1;
1840                 addr_bytes[acycle++] = column & 0xff;
1841                 if (mtd->writesize > 512)
1842                         addr_bytes[acycle++] = (column >> 8) & 0xff;
1843         }
1844 
1845         if (page_addr != -1) {
1846                 addr_bytes[acycle++] = page_addr & 0xff;
1847                 addr_bytes[acycle++] = (page_addr >> 8) & 0xff;
1848                 if (chip->chipsize > (128 << 20))
1849                         addr_bytes[acycle++] = (page_addr >> 16) & 0xff;
1850         }
1851 
1852         if (acycle > 4)
1853                 *cycle0 = addr_bytes[index++];
1854 
1855         for (bit_shift = 0; index < acycle; bit_shift += 8)
1856                 *addr1234 += addr_bytes[index++] << bit_shift;
1857 
1858         /* return acycle in cmd register */
1859         return acycle << NFCADDR_CMD_ACYCLE_BIT_POS;
1860 }
1861 
1862 static void nfc_nand_command(struct mtd_info *mtd, unsigned int command,
1863                                 int column, int page_addr)
1864 {
1865         struct nand_chip *chip = mtd_to_nand(mtd);
1866         struct atmel_nand_host *host = nand_get_controller_data(chip);
1867         unsigned long timeout;
1868         unsigned int nfc_addr_cmd = 0;
1869 
1870         unsigned int cmd1 = command << NFCADDR_CMD_CMD1_BIT_POS;
1871 
1872         /* Set default settings: no cmd2, no addr cycle. read from nand */
1873         unsigned int cmd2 = 0;
1874         unsigned int vcmd2 = 0;
1875         int acycle = NFCADDR_CMD_ACYCLE_NONE;
1876         int csid = NFCADDR_CMD_CSID_3;
1877         int dataen = NFCADDR_CMD_DATADIS;
1878         int nfcwr = NFCADDR_CMD_NFCRD;
1879         unsigned int addr1234 = 0;
1880         unsigned int cycle0 = 0;
1881         bool do_addr = true;
1882         host->nfc->data_in_sram = NULL;
1883 
1884         dev_dbg(host->dev, "%s: cmd = 0x%02x, col = 0x%08x, page = 0x%08x\n",
1885              __func__, command, column, page_addr);
1886 
1887         switch (command) {
1888         case NAND_CMD_RESET:
1889                 nfc_addr_cmd = cmd1 | acycle | csid | dataen | nfcwr;
1890                 nfc_send_command(host, nfc_addr_cmd, addr1234, cycle0);
1891                 udelay(chip->chip_delay);
1892 
1893                 nfc_nand_command(mtd, NAND_CMD_STATUS, -1, -1);
1894                 timeout = jiffies + msecs_to_jiffies(NFC_TIME_OUT_MS);
1895                 while (!(chip->read_byte(mtd) & NAND_STATUS_READY)) {
1896                         if (time_after(jiffies, timeout)) {
1897                                 dev_err(host->dev,
1898                                         "Time out to wait status ready!\n");
1899                                 break;
1900                         }
1901                 }
1902                 return;
1903         case NAND_CMD_STATUS:
1904                 do_addr = false;
1905                 break;
1906         case NAND_CMD_PARAM:
1907         case NAND_CMD_READID:
1908                 do_addr = false;
1909                 acycle = NFCADDR_CMD_ACYCLE_1;
1910                 if (column != -1)
1911                         addr1234 = column;
1912                 break;
1913         case NAND_CMD_RNDOUT:
1914                 cmd2 = NAND_CMD_RNDOUTSTART << NFCADDR_CMD_CMD2_BIT_POS;
1915                 vcmd2 = NFCADDR_CMD_VCMD2;
1916                 break;
1917         case NAND_CMD_READ0:
1918         case NAND_CMD_READOOB:
1919                 if (command == NAND_CMD_READOOB) {
1920                         column += mtd->writesize;
1921                         command = NAND_CMD_READ0; /* only READ0 is valid */
1922                         cmd1 = command << NFCADDR_CMD_CMD1_BIT_POS;
1923                 }
1924                 if (host->nfc->use_nfc_sram) {
1925                         /* Enable Data transfer to sram */
1926                         dataen = NFCADDR_CMD_DATAEN;
1927 
1928                         /* Need enable PMECC now, since NFC will transfer
1929                          * data in bus after sending nfc read command.
1930                          */
1931                         if (chip->ecc.mode == NAND_ECC_HW && host->has_pmecc)
1932                                 pmecc_enable(host, NAND_ECC_READ);
1933                 }
1934 
1935                 cmd2 = NAND_CMD_READSTART << NFCADDR_CMD_CMD2_BIT_POS;
1936                 vcmd2 = NFCADDR_CMD_VCMD2;
1937                 break;
1938         /* For prgramming command, the cmd need set to write enable */
1939         case NAND_CMD_PAGEPROG:
1940         case NAND_CMD_SEQIN:
1941         case NAND_CMD_RNDIN:
1942                 nfcwr = NFCADDR_CMD_NFCWR;
1943                 if (host->nfc->will_write_sram && command == NAND_CMD_SEQIN)
1944                         dataen = NFCADDR_CMD_DATAEN;
1945                 break;
1946         default:
1947                 break;
1948         }
1949 
1950         if (do_addr)
1951                 acycle = nfc_make_addr(mtd, command, column, page_addr,
1952                                 &addr1234, &cycle0);
1953 
1954         nfc_addr_cmd = cmd1 | cmd2 | vcmd2 | acycle | csid | dataen | nfcwr;
1955         nfc_send_command(host, nfc_addr_cmd, addr1234, cycle0);
1956 
1957         /*
1958          * Program and erase have their own busy handlers status, sequential
1959          * in, and deplete1 need no delay.
1960          */
1961         switch (command) {
1962         case NAND_CMD_CACHEDPROG:
1963         case NAND_CMD_PAGEPROG:
1964         case NAND_CMD_ERASE1:
1965         case NAND_CMD_ERASE2:
1966         case NAND_CMD_RNDIN:
1967         case NAND_CMD_STATUS:
1968         case NAND_CMD_RNDOUT:
1969         case NAND_CMD_SEQIN:
1970         case NAND_CMD_READID:
1971                 return;
1972 
1973         case NAND_CMD_READ0:
1974                 if (dataen == NFCADDR_CMD_DATAEN) {
1975                         host->nfc->data_in_sram = host->nfc->sram_bank0 +
1976                                 nfc_get_sram_off(host);
1977                         return;
1978                 }
1979                 /* fall through */
1980         default:
1981                 nfc_prepare_interrupt(host, host->nfc->caps->rb_mask);
1982                 nfc_wait_interrupt(host, host->nfc->caps->rb_mask);
1983         }
1984 }
1985 
1986 static int nfc_sram_write_page(struct mtd_info *mtd, struct nand_chip *chip,
1987                         uint32_t offset, int data_len, const uint8_t *buf,
1988                         int oob_required, int page, int cached, int raw)
1989 {
1990         int cfg, len;
1991         int status = 0;
1992         struct atmel_nand_host *host = nand_get_controller_data(chip);
1993         void *sram = host->nfc->sram_bank0 + nfc_get_sram_off(host);
1994 
1995         /* Subpage write is not supported */
1996         if (offset || (data_len < mtd->writesize))
1997                 return -EINVAL;
1998 
1999         len = mtd->writesize;
2000         /* Copy page data to sram that will write to nand via NFC */
2001         if (use_dma) {
2002                 if (atmel_nand_dma_op(mtd, (void *)buf, len, 0) != 0)
2003                         /* Fall back to use cpu copy */
2004                         memcpy(sram, buf, len);
2005         } else {
2006                 memcpy(sram, buf, len);
2007         }
2008 
2009         cfg = nfc_readl(host->nfc->hsmc_regs, CFG);
2010         if (unlikely(raw) && oob_required) {
2011                 memcpy(sram + len, chip->oob_poi, mtd->oobsize);
2012                 len += mtd->oobsize;
2013                 nfc_writel(host->nfc->hsmc_regs, CFG, cfg | NFC_CFG_WSPARE);
2014         } else {
2015                 nfc_writel(host->nfc->hsmc_regs, CFG, cfg & ~NFC_CFG_WSPARE);
2016         }
2017 
2018         if (chip->ecc.mode == NAND_ECC_HW && host->has_pmecc)
2019                 /*
2020                  * When use NFC sram, need set up PMECC before send
2021                  * NAND_CMD_SEQIN command. Since when the nand command
2022                  * is sent, nfc will do transfer from sram and nand.
2023                  */
2024                 pmecc_enable(host, NAND_ECC_WRITE);
2025 
2026         host->nfc->will_write_sram = true;
2027         chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
2028         host->nfc->will_write_sram = false;
2029 
2030         if (likely(!raw))
2031                 /* Need to write ecc into oob */
2032                 status = chip->ecc.write_page(mtd, chip, buf, oob_required,
2033                                               page);
2034 
2035         if (status < 0)
2036                 return status;
2037 
2038         chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
2039         status = chip->waitfunc(mtd, chip);
2040 
2041         if ((status & NAND_STATUS_FAIL) && (chip->errstat))
2042                 status = chip->errstat(mtd, chip, FL_WRITING, status, page);
2043 
2044         if (status & NAND_STATUS_FAIL)
2045                 return -EIO;
2046 
2047         return 0;
2048 }
2049 
2050 static int nfc_sram_init(struct mtd_info *mtd)
2051 {
2052         struct nand_chip *chip = mtd_to_nand(mtd);
2053         struct atmel_nand_host *host = nand_get_controller_data(chip);
2054         int res = 0;
2055 
2056         /* Initialize the NFC CFG register */
2057         unsigned int cfg_nfc = 0;
2058 
2059         /* set page size and oob layout */
2060         switch (mtd->writesize) {
2061         case 512:
2062                 cfg_nfc = NFC_CFG_PAGESIZE_512;
2063                 break;
2064         case 1024:
2065                 cfg_nfc = NFC_CFG_PAGESIZE_1024;
2066                 break;
2067         case 2048:
2068                 cfg_nfc = NFC_CFG_PAGESIZE_2048;
2069                 break;
2070         case 4096:
2071                 cfg_nfc = NFC_CFG_PAGESIZE_4096;
2072                 break;
2073         case 8192:
2074                 cfg_nfc = NFC_CFG_PAGESIZE_8192;
2075                 break;
2076         default:
2077                 dev_err(host->dev, "Unsupported page size for NFC.\n");
2078                 res = -ENXIO;
2079                 return res;
2080         }
2081 
2082         /* oob bytes size = (NFCSPARESIZE + 1) * 4
2083          * Max support spare size is 512 bytes. */
2084         cfg_nfc |= (((mtd->oobsize / 4) - 1) << NFC_CFG_NFC_SPARESIZE_BIT_POS
2085                 & NFC_CFG_NFC_SPARESIZE);
2086         /* default set a max timeout */
2087         cfg_nfc |= NFC_CFG_RSPARE |
2088                         NFC_CFG_NFC_DTOCYC | NFC_CFG_NFC_DTOMUL;
2089 
2090         nfc_writel(host->nfc->hsmc_regs, CFG, cfg_nfc);
2091 
2092         host->nfc->will_write_sram = false;
2093         nfc_set_sram_bank(host, 0);
2094 
2095         /* Use Write page with NFC SRAM only for PMECC or ECC NONE. */
2096         if (host->nfc->write_by_sram) {
2097                 if ((chip->ecc.mode == NAND_ECC_HW && host->has_pmecc) ||
2098                                 chip->ecc.mode == NAND_ECC_NONE)
2099                         chip->write_page = nfc_sram_write_page;
2100                 else
2101                         host->nfc->write_by_sram = false;
2102         }
2103 
2104         dev_info(host->dev, "Using NFC Sram read %s\n",
2105                         host->nfc->write_by_sram ? "and write" : "");
2106         return 0;
2107 }
2108 
2109 static struct platform_driver atmel_nand_nfc_driver;
2110 /*
2111  * Probe for the NAND device.
2112  */
2113 static int atmel_nand_probe(struct platform_device *pdev)
2114 {
2115         struct atmel_nand_host *host;
2116         struct mtd_info *mtd;
2117         struct nand_chip *nand_chip;
2118         struct resource *mem;
2119         int res, irq;
2120 
2121         /* Allocate memory for the device structure (and zero it) */
2122         host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
2123         if (!host)
2124                 return -ENOMEM;
2125 
2126         res = platform_driver_register(&atmel_nand_nfc_driver);
2127         if (res)
2128                 dev_err(&pdev->dev, "atmel_nand: can't register NFC driver\n");
2129 
2130         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2131         host->io_base = devm_ioremap_resource(&pdev->dev, mem);
2132         if (IS_ERR(host->io_base)) {
2133                 res = PTR_ERR(host->io_base);
2134                 goto err_nand_ioremap;
2135         }
2136         host->io_phys = (dma_addr_t)mem->start;
2137 
2138         nand_chip = &host->nand_chip;
2139         mtd = nand_to_mtd(nand_chip);
2140         host->dev = &pdev->dev;
2141         if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
2142                 nand_set_flash_node(nand_chip, pdev->dev.of_node);
2143                 /* Only when CONFIG_OF is enabled of_node can be parsed */
2144                 res = atmel_of_init_port(host, pdev->dev.of_node);
2145                 if (res)
2146                         goto err_nand_ioremap;
2147         } else {
2148                 memcpy(&host->board, dev_get_platdata(&pdev->dev),
2149                        sizeof(struct atmel_nand_data));
2150         }
2151 
2152          /* link the private data structures */
2153         nand_set_controller_data(nand_chip, host);
2154         mtd->dev.parent = &pdev->dev;
2155 
2156         /* Set address of NAND IO lines */
2157         nand_chip->IO_ADDR_R = host->io_base;
2158         nand_chip->IO_ADDR_W = host->io_base;
2159 
2160         if (nand_nfc.is_initialized) {
2161                 /* NFC driver is probed and initialized */
2162                 host->nfc = &nand_nfc;
2163 
2164                 nand_chip->select_chip = nfc_select_chip;
2165                 nand_chip->dev_ready = nfc_device_ready;
2166                 nand_chip->cmdfunc = nfc_nand_command;
2167 
2168                 /* Initialize the interrupt for NFC */
2169                 irq = platform_get_irq(pdev, 0);
2170                 if (irq < 0) {
2171                         dev_err(host->dev, "Cannot get HSMC irq!\n");
2172                         res = irq;
2173                         goto err_nand_ioremap;
2174                 }
2175 
2176                 res = devm_request_irq(&pdev->dev, irq, hsmc_interrupt,
2177                                 0, "hsmc", host);
2178                 if (res) {
2179                         dev_err(&pdev->dev, "Unable to request HSMC irq %d\n",
2180                                 irq);
2181                         goto err_nand_ioremap;
2182                 }
2183         } else {
2184                 res = atmel_nand_set_enable_ready_pins(mtd);
2185                 if (res)
2186                         goto err_nand_ioremap;
2187 
2188                 nand_chip->cmd_ctrl = atmel_nand_cmd_ctrl;
2189         }
2190 
2191         nand_chip->ecc.mode = host->board.ecc_mode;
2192         nand_chip->chip_delay = 40;             /* 40us command delay time */
2193 
2194         if (host->board.bus_width_16)   /* 16-bit bus width */
2195                 nand_chip->options |= NAND_BUSWIDTH_16;
2196 
2197         nand_chip->read_buf = atmel_read_buf;
2198         nand_chip->write_buf = atmel_write_buf;
2199 
2200         platform_set_drvdata(pdev, host);
2201         atmel_nand_enable(host);
2202 
2203         if (gpio_is_valid(host->board.det_pin)) {
2204                 res = devm_gpio_request(&pdev->dev,
2205                                 host->board.det_pin, "nand_det");
2206                 if (res < 0) {
2207                         dev_err(&pdev->dev,
2208                                 "can't request det gpio %d\n",
2209                                 host->board.det_pin);
2210                         goto err_no_card;
2211                 }
2212 
2213                 res = gpio_direction_input(host->board.det_pin);
2214                 if (res < 0) {
2215                         dev_err(&pdev->dev,
2216                                 "can't request input direction det gpio %d\n",
2217                                 host->board.det_pin);
2218                         goto err_no_card;
2219                 }
2220 
2221                 if (gpio_get_value(host->board.det_pin)) {
2222                         dev_info(&pdev->dev, "No SmartMedia card inserted.\n");
2223                         res = -ENXIO;
2224                         goto err_no_card;
2225                 }
2226         }
2227 
2228         if (host->board.on_flash_bbt || on_flash_bbt) {
2229                 dev_info(&pdev->dev, "Use On Flash BBT\n");
2230                 nand_chip->bbt_options |= NAND_BBT_USE_FLASH;
2231         }
2232 
2233         if (!host->board.has_dma)
2234                 use_dma = 0;
2235 
2236         if (use_dma) {
2237                 dma_cap_mask_t mask;
2238 
2239                 dma_cap_zero(mask);
2240                 dma_cap_set(DMA_MEMCPY, mask);
2241                 host->dma_chan = dma_request_channel(mask, NULL, NULL);
2242                 if (!host->dma_chan) {
2243                         dev_err(host->dev, "Failed to request DMA channel\n");
2244                         use_dma = 0;
2245                 }
2246         }
2247         if (use_dma)
2248                 dev_info(host->dev, "Using %s for DMA transfers.\n",
2249                                         dma_chan_name(host->dma_chan));
2250         else
2251                 dev_info(host->dev, "No DMA support for NAND access.\n");
2252 
2253         /* first scan to find the device and get the page size */
2254         if (nand_scan_ident(mtd, 1, NULL)) {
2255                 res = -ENXIO;
2256                 goto err_scan_ident;
2257         }
2258 
2259         if (nand_chip->ecc.mode == NAND_ECC_HW) {
2260                 if (host->has_pmecc)
2261                         res = atmel_pmecc_nand_init_params(pdev, host);
2262                 else
2263                         res = atmel_hw_nand_init_params(pdev, host);
2264 
2265                 if (res != 0)
2266                         goto err_hw_ecc;
2267         }
2268 
2269         /* initialize the nfc configuration register */
2270         if (host->nfc && host->nfc->use_nfc_sram) {
2271                 res = nfc_sram_init(mtd);
2272                 if (res) {
2273                         host->nfc->use_nfc_sram = false;
2274                         dev_err(host->dev, "Disable use nfc sram for data transfer.\n");
2275                 }
2276         }
2277 
2278         /* second phase scan */
2279         if (nand_scan_tail(mtd)) {
2280                 res = -ENXIO;
2281                 goto err_scan_tail;
2282         }
2283 
2284         mtd->name = "atmel_nand";
2285         res = mtd_device_register(mtd, host->board.parts,
2286                                   host->board.num_parts);
2287         if (!res)
2288                 return res;
2289 
2290 err_scan_tail:
2291         if (host->has_pmecc && host->nand_chip.ecc.mode == NAND_ECC_HW)
2292                 pmecc_writel(host->ecc, CTRL, PMECC_CTRL_DISABLE);
2293 err_hw_ecc:
2294 err_scan_ident:
2295 err_no_card:
2296         atmel_nand_disable(host);
2297         if (host->dma_chan)
2298                 dma_release_channel(host->dma_chan);
2299 err_nand_ioremap:
2300         return res;
2301 }
2302 
2303 /*
2304  * Remove a NAND device.
2305  */
2306 static int atmel_nand_remove(struct platform_device *pdev)
2307 {
2308         struct atmel_nand_host *host = platform_get_drvdata(pdev);
2309         struct mtd_info *mtd = nand_to_mtd(&host->nand_chip);
2310 
2311         nand_release(mtd);
2312 
2313         atmel_nand_disable(host);
2314 
2315         if (host->has_pmecc && host->nand_chip.ecc.mode == NAND_ECC_HW) {
2316                 pmecc_writel(host->ecc, CTRL, PMECC_CTRL_DISABLE);
2317                 pmerrloc_writel(host->pmerrloc_base, ELDIS,
2318                                 PMERRLOC_DISABLE);
2319         }
2320 
2321         if (host->dma_chan)
2322                 dma_release_channel(host->dma_chan);
2323 
2324         platform_driver_unregister(&atmel_nand_nfc_driver);
2325 
2326         return 0;
2327 }
2328 
2329 /*
2330  * AT91RM9200 does not have PMECC or PMECC Errloc peripherals for
2331  * BCH ECC. Combined with the "atmel,has-pmecc", it is used to describe
2332  * devices from the SAM9 family that have those.
2333  */
2334 static const struct atmel_nand_caps at91rm9200_caps = {
2335         .pmecc_correct_erase_page = false,
2336         .pmecc_max_correction = 24,
2337 };
2338 
2339 static const struct atmel_nand_caps sama5d4_caps = {
2340         .pmecc_correct_erase_page = true,
2341         .pmecc_max_correction = 24,
2342 };
2343 
2344 /*
2345  * The PMECC Errloc controller starting in SAMA5D2 is not compatible,
2346  * as the increased correction strength requires more registers.
2347  */
2348 static const struct atmel_nand_caps sama5d2_caps = {
2349         .pmecc_correct_erase_page = true,
2350         .pmecc_max_correction = 32,
2351 };
2352 
2353 static const struct of_device_id atmel_nand_dt_ids[] = {
2354         { .compatible = "atmel,at91rm9200-nand", .data = &at91rm9200_caps },
2355         { .compatible = "atmel,sama5d4-nand", .data = &sama5d4_caps },
2356         { .compatible = "atmel,sama5d2-nand", .data = &sama5d2_caps },
2357         { /* sentinel */ }
2358 };
2359 
2360 MODULE_DEVICE_TABLE(of, atmel_nand_dt_ids);
2361 
2362 static int atmel_nand_nfc_probe(struct platform_device *pdev)
2363 {
2364         struct atmel_nfc *nfc = &nand_nfc;
2365         struct resource *nfc_cmd_regs, *nfc_hsmc_regs, *nfc_sram;
2366         int ret;
2367 
2368         nfc_cmd_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2369         nfc->base_cmd_regs = devm_ioremap_resource(&pdev->dev, nfc_cmd_regs);
2370         if (IS_ERR(nfc->base_cmd_regs))
2371                 return PTR_ERR(nfc->base_cmd_regs);
2372 
2373         nfc_hsmc_regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
2374         nfc->hsmc_regs = devm_ioremap_resource(&pdev->dev, nfc_hsmc_regs);
2375         if (IS_ERR(nfc->hsmc_regs))
2376                 return PTR_ERR(nfc->hsmc_regs);
2377 
2378         nfc_sram = platform_get_resource(pdev, IORESOURCE_MEM, 2);
2379         if (nfc_sram) {
2380                 nfc->sram_bank0 = (void * __force)
2381                                 devm_ioremap_resource(&pdev->dev, nfc_sram);
2382                 if (IS_ERR(nfc->sram_bank0)) {
2383                         dev_warn(&pdev->dev, "Fail to ioremap the NFC sram with error: %ld. So disable NFC sram.\n",
2384                                         PTR_ERR(nfc->sram_bank0));
2385                 } else {
2386                         nfc->use_nfc_sram = true;
2387                         nfc->sram_bank0_phys = (dma_addr_t)nfc_sram->start;
2388 
2389                         if (pdev->dev.of_node)
2390                                 nfc->write_by_sram = of_property_read_bool(
2391                                                 pdev->dev.of_node,
2392                                                 "atmel,write-by-sram");
2393                 }
2394         }
2395 
2396         nfc->caps = (const struct atmel_nand_nfc_caps *)
2397                 of_device_get_match_data(&pdev->dev);
2398         if (!nfc->caps)
2399                 return -ENODEV;
2400 
2401         nfc_writel(nfc->hsmc_regs, IDR, 0xffffffff);
2402         nfc_readl(nfc->hsmc_regs, SR);  /* clear the NFC_SR */
2403 
2404         nfc->clk = devm_clk_get(&pdev->dev, NULL);
2405         if (!IS_ERR(nfc->clk)) {
2406                 ret = clk_prepare_enable(nfc->clk);
2407                 if (ret)
2408                         return ret;
2409         } else {
2410                 dev_warn(&pdev->dev, "NFC clock missing, update your Device Tree");
2411         }
2412 
2413         nfc->is_initialized = true;
2414         dev_info(&pdev->dev, "NFC is probed.\n");
2415 
2416         return 0;
2417 }
2418 
2419 static int atmel_nand_nfc_remove(struct platform_device *pdev)
2420 {
2421         struct atmel_nfc *nfc = &nand_nfc;
2422 
2423         if (!IS_ERR(nfc->clk))
2424                 clk_disable_unprepare(nfc->clk);
2425 
2426         return 0;
2427 }
2428 
2429 static const struct atmel_nand_nfc_caps sama5d3_nfc_caps = {
2430         .rb_mask = NFC_SR_RB_EDGE0,
2431 };
2432 
2433 static const struct atmel_nand_nfc_caps sama5d4_nfc_caps = {
2434         .rb_mask = NFC_SR_RB_EDGE3,
2435 };
2436 
2437 static const struct of_device_id atmel_nand_nfc_match[] = {
2438         { .compatible = "atmel,sama5d3-nfc", .data = &sama5d3_nfc_caps },
2439         { .compatible = "atmel,sama5d4-nfc", .data = &sama5d4_nfc_caps },
2440         { /* sentinel */ }
2441 };
2442 MODULE_DEVICE_TABLE(of, atmel_nand_nfc_match);
2443 
2444 static struct platform_driver atmel_nand_nfc_driver = {
2445         .driver = {
2446                 .name = "atmel_nand_nfc",
2447                 .of_match_table = of_match_ptr(atmel_nand_nfc_match),
2448         },
2449         .probe = atmel_nand_nfc_probe,
2450         .remove = atmel_nand_nfc_remove,
2451 };
2452 
2453 static struct platform_driver atmel_nand_driver = {
2454         .probe          = atmel_nand_probe,
2455         .remove         = atmel_nand_remove,
2456         .driver         = {
2457                 .name   = "atmel_nand",
2458                 .of_match_table = of_match_ptr(atmel_nand_dt_ids),
2459         },
2460 };
2461 
2462 module_platform_driver(atmel_nand_driver);
2463 
2464 MODULE_LICENSE("GPL");
2465 MODULE_AUTHOR("Rick Bronson");
2466 MODULE_DESCRIPTION("NAND/SmartMedia driver for AT91 / AVR32");
2467 MODULE_ALIAS("platform:atmel_nand");
2468 

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