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Linux/drivers/spi/spi-pxa2xx.c

  1 /*
  2  * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
  3  * Copyright (C) 2013, Intel Corporation
  4  *
  5  * This program is free software; you can redistribute it and/or modify
  6  * it under the terms of the GNU General Public License as published by
  7  * the Free Software Foundation; either version 2 of the License, or
  8  * (at your option) any later version.
  9  *
 10  * This program is distributed in the hope that it will be useful,
 11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13  * GNU General Public License for more details.
 14  */
 15 
 16 #include <linux/bitops.h>
 17 #include <linux/init.h>
 18 #include <linux/module.h>
 19 #include <linux/device.h>
 20 #include <linux/ioport.h>
 21 #include <linux/errno.h>
 22 #include <linux/err.h>
 23 #include <linux/interrupt.h>
 24 #include <linux/kernel.h>
 25 #include <linux/pci.h>
 26 #include <linux/platform_device.h>
 27 #include <linux/spi/pxa2xx_spi.h>
 28 #include <linux/spi/spi.h>
 29 #include <linux/delay.h>
 30 #include <linux/gpio.h>
 31 #include <linux/slab.h>
 32 #include <linux/clk.h>
 33 #include <linux/pm_runtime.h>
 34 #include <linux/acpi.h>
 35 
 36 #include "spi-pxa2xx.h"
 37 
 38 MODULE_AUTHOR("Stephen Street");
 39 MODULE_DESCRIPTION("PXA2xx SSP SPI Controller");
 40 MODULE_LICENSE("GPL");
 41 MODULE_ALIAS("platform:pxa2xx-spi");
 42 
 43 #define TIMOUT_DFLT             1000
 44 
 45 /*
 46  * for testing SSCR1 changes that require SSP restart, basically
 47  * everything except the service and interrupt enables, the pxa270 developer
 48  * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this
 49  * list, but the PXA255 dev man says all bits without really meaning the
 50  * service and interrupt enables
 51  */
 52 #define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \
 53                                 | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
 54                                 | SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \
 55                                 | SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \
 56                                 | SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
 57                                 | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
 58 
 59 #define QUARK_X1000_SSCR1_CHANGE_MASK (QUARK_X1000_SSCR1_STRF   \
 60                                 | QUARK_X1000_SSCR1_EFWR        \
 61                                 | QUARK_X1000_SSCR1_RFT         \
 62                                 | QUARK_X1000_SSCR1_TFT         \
 63                                 | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
 64 
 65 #define LPSS_GENERAL_REG_RXTO_HOLDOFF_DISABLE   BIT(24)
 66 #define LPSS_CS_CONTROL_SW_MODE                 BIT(0)
 67 #define LPSS_CS_CONTROL_CS_HIGH                 BIT(1)
 68 #define LPSS_CAPS_CS_EN_SHIFT                   9
 69 #define LPSS_CAPS_CS_EN_MASK                    (0xf << LPSS_CAPS_CS_EN_SHIFT)
 70 
 71 struct lpss_config {
 72         /* LPSS offset from drv_data->ioaddr */
 73         unsigned offset;
 74         /* Register offsets from drv_data->lpss_base or -1 */
 75         int reg_general;
 76         int reg_ssp;
 77         int reg_cs_ctrl;
 78         int reg_capabilities;
 79         /* FIFO thresholds */
 80         u32 rx_threshold;
 81         u32 tx_threshold_lo;
 82         u32 tx_threshold_hi;
 83         /* Chip select control */
 84         unsigned cs_sel_shift;
 85         unsigned cs_sel_mask;
 86         unsigned cs_num;
 87 };
 88 
 89 /* Keep these sorted with enum pxa_ssp_type */
 90 static const struct lpss_config lpss_platforms[] = {
 91         {       /* LPSS_LPT_SSP */
 92                 .offset = 0x800,
 93                 .reg_general = 0x08,
 94                 .reg_ssp = 0x0c,
 95                 .reg_cs_ctrl = 0x18,
 96                 .reg_capabilities = -1,
 97                 .rx_threshold = 64,
 98                 .tx_threshold_lo = 160,
 99                 .tx_threshold_hi = 224,
100         },
101         {       /* LPSS_BYT_SSP */
102                 .offset = 0x400,
103                 .reg_general = 0x08,
104                 .reg_ssp = 0x0c,
105                 .reg_cs_ctrl = 0x18,
106                 .reg_capabilities = -1,
107                 .rx_threshold = 64,
108                 .tx_threshold_lo = 160,
109                 .tx_threshold_hi = 224,
110         },
111         {       /* LPSS_BSW_SSP */
112                 .offset = 0x400,
113                 .reg_general = 0x08,
114                 .reg_ssp = 0x0c,
115                 .reg_cs_ctrl = 0x18,
116                 .reg_capabilities = -1,
117                 .rx_threshold = 64,
118                 .tx_threshold_lo = 160,
119                 .tx_threshold_hi = 224,
120                 .cs_sel_shift = 2,
121                 .cs_sel_mask = 1 << 2,
122                 .cs_num = 2,
123         },
124         {       /* LPSS_SPT_SSP */
125                 .offset = 0x200,
126                 .reg_general = -1,
127                 .reg_ssp = 0x20,
128                 .reg_cs_ctrl = 0x24,
129                 .reg_capabilities = -1,
130                 .rx_threshold = 1,
131                 .tx_threshold_lo = 32,
132                 .tx_threshold_hi = 56,
133         },
134         {       /* LPSS_BXT_SSP */
135                 .offset = 0x200,
136                 .reg_general = -1,
137                 .reg_ssp = 0x20,
138                 .reg_cs_ctrl = 0x24,
139                 .reg_capabilities = 0xfc,
140                 .rx_threshold = 1,
141                 .tx_threshold_lo = 16,
142                 .tx_threshold_hi = 48,
143                 .cs_sel_shift = 8,
144                 .cs_sel_mask = 3 << 8,
145         },
146 };
147 
148 static inline const struct lpss_config
149 *lpss_get_config(const struct driver_data *drv_data)
150 {
151         return &lpss_platforms[drv_data->ssp_type - LPSS_LPT_SSP];
152 }
153 
154 static bool is_lpss_ssp(const struct driver_data *drv_data)
155 {
156         switch (drv_data->ssp_type) {
157         case LPSS_LPT_SSP:
158         case LPSS_BYT_SSP:
159         case LPSS_BSW_SSP:
160         case LPSS_SPT_SSP:
161         case LPSS_BXT_SSP:
162                 return true;
163         default:
164                 return false;
165         }
166 }
167 
168 static bool is_quark_x1000_ssp(const struct driver_data *drv_data)
169 {
170         return drv_data->ssp_type == QUARK_X1000_SSP;
171 }
172 
173 static u32 pxa2xx_spi_get_ssrc1_change_mask(const struct driver_data *drv_data)
174 {
175         switch (drv_data->ssp_type) {
176         case QUARK_X1000_SSP:
177                 return QUARK_X1000_SSCR1_CHANGE_MASK;
178         default:
179                 return SSCR1_CHANGE_MASK;
180         }
181 }
182 
183 static u32
184 pxa2xx_spi_get_rx_default_thre(const struct driver_data *drv_data)
185 {
186         switch (drv_data->ssp_type) {
187         case QUARK_X1000_SSP:
188                 return RX_THRESH_QUARK_X1000_DFLT;
189         default:
190                 return RX_THRESH_DFLT;
191         }
192 }
193 
194 static bool pxa2xx_spi_txfifo_full(const struct driver_data *drv_data)
195 {
196         u32 mask;
197 
198         switch (drv_data->ssp_type) {
199         case QUARK_X1000_SSP:
200                 mask = QUARK_X1000_SSSR_TFL_MASK;
201                 break;
202         default:
203                 mask = SSSR_TFL_MASK;
204                 break;
205         }
206 
207         return (pxa2xx_spi_read(drv_data, SSSR) & mask) == mask;
208 }
209 
210 static void pxa2xx_spi_clear_rx_thre(const struct driver_data *drv_data,
211                                      u32 *sccr1_reg)
212 {
213         u32 mask;
214 
215         switch (drv_data->ssp_type) {
216         case QUARK_X1000_SSP:
217                 mask = QUARK_X1000_SSCR1_RFT;
218                 break;
219         default:
220                 mask = SSCR1_RFT;
221                 break;
222         }
223         *sccr1_reg &= ~mask;
224 }
225 
226 static void pxa2xx_spi_set_rx_thre(const struct driver_data *drv_data,
227                                    u32 *sccr1_reg, u32 threshold)
228 {
229         switch (drv_data->ssp_type) {
230         case QUARK_X1000_SSP:
231                 *sccr1_reg |= QUARK_X1000_SSCR1_RxTresh(threshold);
232                 break;
233         default:
234                 *sccr1_reg |= SSCR1_RxTresh(threshold);
235                 break;
236         }
237 }
238 
239 static u32 pxa2xx_configure_sscr0(const struct driver_data *drv_data,
240                                   u32 clk_div, u8 bits)
241 {
242         switch (drv_data->ssp_type) {
243         case QUARK_X1000_SSP:
244                 return clk_div
245                         | QUARK_X1000_SSCR0_Motorola
246                         | QUARK_X1000_SSCR0_DataSize(bits > 32 ? 8 : bits)
247                         | SSCR0_SSE;
248         default:
249                 return clk_div
250                         | SSCR0_Motorola
251                         | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
252                         | SSCR0_SSE
253                         | (bits > 16 ? SSCR0_EDSS : 0);
254         }
255 }
256 
257 /*
258  * Read and write LPSS SSP private registers. Caller must first check that
259  * is_lpss_ssp() returns true before these can be called.
260  */
261 static u32 __lpss_ssp_read_priv(struct driver_data *drv_data, unsigned offset)
262 {
263         WARN_ON(!drv_data->lpss_base);
264         return readl(drv_data->lpss_base + offset);
265 }
266 
267 static void __lpss_ssp_write_priv(struct driver_data *drv_data,
268                                   unsigned offset, u32 value)
269 {
270         WARN_ON(!drv_data->lpss_base);
271         writel(value, drv_data->lpss_base + offset);
272 }
273 
274 /*
275  * lpss_ssp_setup - perform LPSS SSP specific setup
276  * @drv_data: pointer to the driver private data
277  *
278  * Perform LPSS SSP specific setup. This function must be called first if
279  * one is going to use LPSS SSP private registers.
280  */
281 static void lpss_ssp_setup(struct driver_data *drv_data)
282 {
283         const struct lpss_config *config;
284         u32 value;
285 
286         config = lpss_get_config(drv_data);
287         drv_data->lpss_base = drv_data->ioaddr + config->offset;
288 
289         /* Enable software chip select control */
290         value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
291         value &= ~(LPSS_CS_CONTROL_SW_MODE | LPSS_CS_CONTROL_CS_HIGH);
292         value |= LPSS_CS_CONTROL_SW_MODE | LPSS_CS_CONTROL_CS_HIGH;
293         __lpss_ssp_write_priv(drv_data, config->reg_cs_ctrl, value);
294 
295         /* Enable multiblock DMA transfers */
296         if (drv_data->master_info->enable_dma) {
297                 __lpss_ssp_write_priv(drv_data, config->reg_ssp, 1);
298 
299                 if (config->reg_general >= 0) {
300                         value = __lpss_ssp_read_priv(drv_data,
301                                                      config->reg_general);
302                         value |= LPSS_GENERAL_REG_RXTO_HOLDOFF_DISABLE;
303                         __lpss_ssp_write_priv(drv_data,
304                                               config->reg_general, value);
305                 }
306         }
307 }
308 
309 static void lpss_ssp_select_cs(struct driver_data *drv_data,
310                                const struct lpss_config *config)
311 {
312         u32 value, cs;
313 
314         if (!config->cs_sel_mask)
315                 return;
316 
317         value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
318 
319         cs = drv_data->cur_msg->spi->chip_select;
320         cs <<= config->cs_sel_shift;
321         if (cs != (value & config->cs_sel_mask)) {
322                 /*
323                  * When switching another chip select output active the
324                  * output must be selected first and wait 2 ssp_clk cycles
325                  * before changing state to active. Otherwise a short
326                  * glitch will occur on the previous chip select since
327                  * output select is latched but state control is not.
328                  */
329                 value &= ~config->cs_sel_mask;
330                 value |= cs;
331                 __lpss_ssp_write_priv(drv_data,
332                                       config->reg_cs_ctrl, value);
333                 ndelay(1000000000 /
334                        (drv_data->master->max_speed_hz / 2));
335         }
336 }
337 
338 static void lpss_ssp_cs_control(struct driver_data *drv_data, bool enable)
339 {
340         const struct lpss_config *config;
341         u32 value;
342 
343         config = lpss_get_config(drv_data);
344 
345         if (enable)
346                 lpss_ssp_select_cs(drv_data, config);
347 
348         value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
349         if (enable)
350                 value &= ~LPSS_CS_CONTROL_CS_HIGH;
351         else
352                 value |= LPSS_CS_CONTROL_CS_HIGH;
353         __lpss_ssp_write_priv(drv_data, config->reg_cs_ctrl, value);
354 }
355 
356 static void cs_assert(struct driver_data *drv_data)
357 {
358         struct chip_data *chip = drv_data->cur_chip;
359 
360         if (drv_data->ssp_type == CE4100_SSP) {
361                 pxa2xx_spi_write(drv_data, SSSR, drv_data->cur_chip->frm);
362                 return;
363         }
364 
365         if (chip->cs_control) {
366                 chip->cs_control(PXA2XX_CS_ASSERT);
367                 return;
368         }
369 
370         if (gpio_is_valid(chip->gpio_cs)) {
371                 gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
372                 return;
373         }
374 
375         if (is_lpss_ssp(drv_data))
376                 lpss_ssp_cs_control(drv_data, true);
377 }
378 
379 static void cs_deassert(struct driver_data *drv_data)
380 {
381         struct chip_data *chip = drv_data->cur_chip;
382 
383         if (drv_data->ssp_type == CE4100_SSP)
384                 return;
385 
386         if (chip->cs_control) {
387                 chip->cs_control(PXA2XX_CS_DEASSERT);
388                 return;
389         }
390 
391         if (gpio_is_valid(chip->gpio_cs)) {
392                 gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted);
393                 return;
394         }
395 
396         if (is_lpss_ssp(drv_data))
397                 lpss_ssp_cs_control(drv_data, false);
398 }
399 
400 int pxa2xx_spi_flush(struct driver_data *drv_data)
401 {
402         unsigned long limit = loops_per_jiffy << 1;
403 
404         do {
405                 while (pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
406                         pxa2xx_spi_read(drv_data, SSDR);
407         } while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_BSY) && --limit);
408         write_SSSR_CS(drv_data, SSSR_ROR);
409 
410         return limit;
411 }
412 
413 static int null_writer(struct driver_data *drv_data)
414 {
415         u8 n_bytes = drv_data->n_bytes;
416 
417         if (pxa2xx_spi_txfifo_full(drv_data)
418                 || (drv_data->tx == drv_data->tx_end))
419                 return 0;
420 
421         pxa2xx_spi_write(drv_data, SSDR, 0);
422         drv_data->tx += n_bytes;
423 
424         return 1;
425 }
426 
427 static int null_reader(struct driver_data *drv_data)
428 {
429         u8 n_bytes = drv_data->n_bytes;
430 
431         while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
432                && (drv_data->rx < drv_data->rx_end)) {
433                 pxa2xx_spi_read(drv_data, SSDR);
434                 drv_data->rx += n_bytes;
435         }
436 
437         return drv_data->rx == drv_data->rx_end;
438 }
439 
440 static int u8_writer(struct driver_data *drv_data)
441 {
442         if (pxa2xx_spi_txfifo_full(drv_data)
443                 || (drv_data->tx == drv_data->tx_end))
444                 return 0;
445 
446         pxa2xx_spi_write(drv_data, SSDR, *(u8 *)(drv_data->tx));
447         ++drv_data->tx;
448 
449         return 1;
450 }
451 
452 static int u8_reader(struct driver_data *drv_data)
453 {
454         while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
455                && (drv_data->rx < drv_data->rx_end)) {
456                 *(u8 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
457                 ++drv_data->rx;
458         }
459 
460         return drv_data->rx == drv_data->rx_end;
461 }
462 
463 static int u16_writer(struct driver_data *drv_data)
464 {
465         if (pxa2xx_spi_txfifo_full(drv_data)
466                 || (drv_data->tx == drv_data->tx_end))
467                 return 0;
468 
469         pxa2xx_spi_write(drv_data, SSDR, *(u16 *)(drv_data->tx));
470         drv_data->tx += 2;
471 
472         return 1;
473 }
474 
475 static int u16_reader(struct driver_data *drv_data)
476 {
477         while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
478                && (drv_data->rx < drv_data->rx_end)) {
479                 *(u16 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
480                 drv_data->rx += 2;
481         }
482 
483         return drv_data->rx == drv_data->rx_end;
484 }
485 
486 static int u32_writer(struct driver_data *drv_data)
487 {
488         if (pxa2xx_spi_txfifo_full(drv_data)
489                 || (drv_data->tx == drv_data->tx_end))
490                 return 0;
491 
492         pxa2xx_spi_write(drv_data, SSDR, *(u32 *)(drv_data->tx));
493         drv_data->tx += 4;
494 
495         return 1;
496 }
497 
498 static int u32_reader(struct driver_data *drv_data)
499 {
500         while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
501                && (drv_data->rx < drv_data->rx_end)) {
502                 *(u32 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
503                 drv_data->rx += 4;
504         }
505 
506         return drv_data->rx == drv_data->rx_end;
507 }
508 
509 void *pxa2xx_spi_next_transfer(struct driver_data *drv_data)
510 {
511         struct spi_message *msg = drv_data->cur_msg;
512         struct spi_transfer *trans = drv_data->cur_transfer;
513 
514         /* Move to next transfer */
515         if (trans->transfer_list.next != &msg->transfers) {
516                 drv_data->cur_transfer =
517                         list_entry(trans->transfer_list.next,
518                                         struct spi_transfer,
519                                         transfer_list);
520                 return RUNNING_STATE;
521         } else
522                 return DONE_STATE;
523 }
524 
525 /* caller already set message->status; dma and pio irqs are blocked */
526 static void giveback(struct driver_data *drv_data)
527 {
528         struct spi_transfer* last_transfer;
529         struct spi_message *msg;
530         unsigned long timeout;
531 
532         msg = drv_data->cur_msg;
533         drv_data->cur_msg = NULL;
534         drv_data->cur_transfer = NULL;
535 
536         last_transfer = list_last_entry(&msg->transfers, struct spi_transfer,
537                                         transfer_list);
538 
539         /* Delay if requested before any change in chip select */
540         if (last_transfer->delay_usecs)
541                 udelay(last_transfer->delay_usecs);
542 
543         /* Wait until SSP becomes idle before deasserting the CS */
544         timeout = jiffies + msecs_to_jiffies(10);
545         while (pxa2xx_spi_read(drv_data, SSSR) & SSSR_BSY &&
546                !time_after(jiffies, timeout))
547                 cpu_relax();
548 
549         /* Drop chip select UNLESS cs_change is true or we are returning
550          * a message with an error, or next message is for another chip
551          */
552         if (!last_transfer->cs_change)
553                 cs_deassert(drv_data);
554         else {
555                 struct spi_message *next_msg;
556 
557                 /* Holding of cs was hinted, but we need to make sure
558                  * the next message is for the same chip.  Don't waste
559                  * time with the following tests unless this was hinted.
560                  *
561                  * We cannot postpone this until pump_messages, because
562                  * after calling msg->complete (below) the driver that
563                  * sent the current message could be unloaded, which
564                  * could invalidate the cs_control() callback...
565                  */
566 
567                 /* get a pointer to the next message, if any */
568                 next_msg = spi_get_next_queued_message(drv_data->master);
569 
570                 /* see if the next and current messages point
571                  * to the same chip
572                  */
573                 if (next_msg && next_msg->spi != msg->spi)
574                         next_msg = NULL;
575                 if (!next_msg || msg->state == ERROR_STATE)
576                         cs_deassert(drv_data);
577         }
578 
579         drv_data->cur_chip = NULL;
580         spi_finalize_current_message(drv_data->master);
581 }
582 
583 static void reset_sccr1(struct driver_data *drv_data)
584 {
585         struct chip_data *chip = drv_data->cur_chip;
586         u32 sccr1_reg;
587 
588         sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1) & ~drv_data->int_cr1;
589         sccr1_reg &= ~SSCR1_RFT;
590         sccr1_reg |= chip->threshold;
591         pxa2xx_spi_write(drv_data, SSCR1, sccr1_reg);
592 }
593 
594 static void int_error_stop(struct driver_data *drv_data, const char* msg)
595 {
596         /* Stop and reset SSP */
597         write_SSSR_CS(drv_data, drv_data->clear_sr);
598         reset_sccr1(drv_data);
599         if (!pxa25x_ssp_comp(drv_data))
600                 pxa2xx_spi_write(drv_data, SSTO, 0);
601         pxa2xx_spi_flush(drv_data);
602         pxa2xx_spi_write(drv_data, SSCR0,
603                          pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE);
604 
605         dev_err(&drv_data->pdev->dev, "%s\n", msg);
606 
607         drv_data->cur_msg->state = ERROR_STATE;
608         tasklet_schedule(&drv_data->pump_transfers);
609 }
610 
611 static void int_transfer_complete(struct driver_data *drv_data)
612 {
613         /* Clear and disable interrupts */
614         write_SSSR_CS(drv_data, drv_data->clear_sr);
615         reset_sccr1(drv_data);
616         if (!pxa25x_ssp_comp(drv_data))
617                 pxa2xx_spi_write(drv_data, SSTO, 0);
618 
619         /* Update total byte transferred return count actual bytes read */
620         drv_data->cur_msg->actual_length += drv_data->len -
621                                 (drv_data->rx_end - drv_data->rx);
622 
623         /* Transfer delays and chip select release are
624          * handled in pump_transfers or giveback
625          */
626 
627         /* Move to next transfer */
628         drv_data->cur_msg->state = pxa2xx_spi_next_transfer(drv_data);
629 
630         /* Schedule transfer tasklet */
631         tasklet_schedule(&drv_data->pump_transfers);
632 }
633 
634 static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
635 {
636         u32 irq_mask = (pxa2xx_spi_read(drv_data, SSCR1) & SSCR1_TIE) ?
637                        drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
638 
639         u32 irq_status = pxa2xx_spi_read(drv_data, SSSR) & irq_mask;
640 
641         if (irq_status & SSSR_ROR) {
642                 int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
643                 return IRQ_HANDLED;
644         }
645 
646         if (irq_status & SSSR_TINT) {
647                 pxa2xx_spi_write(drv_data, SSSR, SSSR_TINT);
648                 if (drv_data->read(drv_data)) {
649                         int_transfer_complete(drv_data);
650                         return IRQ_HANDLED;
651                 }
652         }
653 
654         /* Drain rx fifo, Fill tx fifo and prevent overruns */
655         do {
656                 if (drv_data->read(drv_data)) {
657                         int_transfer_complete(drv_data);
658                         return IRQ_HANDLED;
659                 }
660         } while (drv_data->write(drv_data));
661 
662         if (drv_data->read(drv_data)) {
663                 int_transfer_complete(drv_data);
664                 return IRQ_HANDLED;
665         }
666 
667         if (drv_data->tx == drv_data->tx_end) {
668                 u32 bytes_left;
669                 u32 sccr1_reg;
670 
671                 sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1);
672                 sccr1_reg &= ~SSCR1_TIE;
673 
674                 /*
675                  * PXA25x_SSP has no timeout, set up rx threshould for the
676                  * remaining RX bytes.
677                  */
678                 if (pxa25x_ssp_comp(drv_data)) {
679                         u32 rx_thre;
680 
681                         pxa2xx_spi_clear_rx_thre(drv_data, &sccr1_reg);
682 
683                         bytes_left = drv_data->rx_end - drv_data->rx;
684                         switch (drv_data->n_bytes) {
685                         case 4:
686                                 bytes_left >>= 1;
687                         case 2:
688                                 bytes_left >>= 1;
689                         }
690 
691                         rx_thre = pxa2xx_spi_get_rx_default_thre(drv_data);
692                         if (rx_thre > bytes_left)
693                                 rx_thre = bytes_left;
694 
695                         pxa2xx_spi_set_rx_thre(drv_data, &sccr1_reg, rx_thre);
696                 }
697                 pxa2xx_spi_write(drv_data, SSCR1, sccr1_reg);
698         }
699 
700         /* We did something */
701         return IRQ_HANDLED;
702 }
703 
704 static irqreturn_t ssp_int(int irq, void *dev_id)
705 {
706         struct driver_data *drv_data = dev_id;
707         u32 sccr1_reg;
708         u32 mask = drv_data->mask_sr;
709         u32 status;
710 
711         /*
712          * The IRQ might be shared with other peripherals so we must first
713          * check that are we RPM suspended or not. If we are we assume that
714          * the IRQ was not for us (we shouldn't be RPM suspended when the
715          * interrupt is enabled).
716          */
717         if (pm_runtime_suspended(&drv_data->pdev->dev))
718                 return IRQ_NONE;
719 
720         /*
721          * If the device is not yet in RPM suspended state and we get an
722          * interrupt that is meant for another device, check if status bits
723          * are all set to one. That means that the device is already
724          * powered off.
725          */
726         status = pxa2xx_spi_read(drv_data, SSSR);
727         if (status == ~0)
728                 return IRQ_NONE;
729 
730         sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1);
731 
732         /* Ignore possible writes if we don't need to write */
733         if (!(sccr1_reg & SSCR1_TIE))
734                 mask &= ~SSSR_TFS;
735 
736         /* Ignore RX timeout interrupt if it is disabled */
737         if (!(sccr1_reg & SSCR1_TINTE))
738                 mask &= ~SSSR_TINT;
739 
740         if (!(status & mask))
741                 return IRQ_NONE;
742 
743         if (!drv_data->cur_msg) {
744 
745                 pxa2xx_spi_write(drv_data, SSCR0,
746                                  pxa2xx_spi_read(drv_data, SSCR0)
747                                  & ~SSCR0_SSE);
748                 pxa2xx_spi_write(drv_data, SSCR1,
749                                  pxa2xx_spi_read(drv_data, SSCR1)
750                                  & ~drv_data->int_cr1);
751                 if (!pxa25x_ssp_comp(drv_data))
752                         pxa2xx_spi_write(drv_data, SSTO, 0);
753                 write_SSSR_CS(drv_data, drv_data->clear_sr);
754 
755                 dev_err(&drv_data->pdev->dev,
756                         "bad message state in interrupt handler\n");
757 
758                 /* Never fail */
759                 return IRQ_HANDLED;
760         }
761 
762         return drv_data->transfer_handler(drv_data);
763 }
764 
765 /*
766  * The Quark SPI has an additional 24 bit register (DDS_CLK_RATE) to multiply
767  * input frequency by fractions of 2^24. It also has a divider by 5.
768  *
769  * There are formulas to get baud rate value for given input frequency and
770  * divider parameters, such as DDS_CLK_RATE and SCR:
771  *
772  * Fsys = 200MHz
773  *
774  * Fssp = Fsys * DDS_CLK_RATE / 2^24                    (1)
775  * Baud rate = Fsclk = Fssp / (2 * (SCR + 1))           (2)
776  *
777  * DDS_CLK_RATE either 2^n or 2^n / 5.
778  * SCR is in range 0 .. 255
779  *
780  * Divisor = 5^i * 2^j * 2 * k
781  *       i = [0, 1]      i = 1 iff j = 0 or j > 3
782  *       j = [0, 23]     j = 0 iff i = 1
783  *       k = [1, 256]
784  * Special case: j = 0, i = 1: Divisor = 2 / 5
785  *
786  * Accordingly to the specification the recommended values for DDS_CLK_RATE
787  * are:
788  *      Case 1:         2^n, n = [0, 23]
789  *      Case 2:         2^24 * 2 / 5 (0x666666)
790  *      Case 3:         less than or equal to 2^24 / 5 / 16 (0x33333)
791  *
792  * In all cases the lowest possible value is better.
793  *
794  * The function calculates parameters for all cases and chooses the one closest
795  * to the asked baud rate.
796  */
797 static unsigned int quark_x1000_get_clk_div(int rate, u32 *dds)
798 {
799         unsigned long xtal = 200000000;
800         unsigned long fref = xtal / 2;          /* mandatory division by 2,
801                                                    see (2) */
802                                                 /* case 3 */
803         unsigned long fref1 = fref / 2;         /* case 1 */
804         unsigned long fref2 = fref * 2 / 5;     /* case 2 */
805         unsigned long scale;
806         unsigned long q, q1, q2;
807         long r, r1, r2;
808         u32 mul;
809 
810         /* Case 1 */
811 
812         /* Set initial value for DDS_CLK_RATE */
813         mul = (1 << 24) >> 1;
814 
815         /* Calculate initial quot */
816         q1 = DIV_ROUND_UP(fref1, rate);
817 
818         /* Scale q1 if it's too big */
819         if (q1 > 256) {
820                 /* Scale q1 to range [1, 512] */
821                 scale = fls_long(q1 - 1);
822                 if (scale > 9) {
823                         q1 >>= scale - 9;
824                         mul >>= scale - 9;
825                 }
826 
827                 /* Round the result if we have a remainder */
828                 q1 += q1 & 1;
829         }
830 
831         /* Decrease DDS_CLK_RATE as much as we can without loss in precision */
832         scale = __ffs(q1);
833         q1 >>= scale;
834         mul >>= scale;
835 
836         /* Get the remainder */
837         r1 = abs(fref1 / (1 << (24 - fls_long(mul))) / q1 - rate);
838 
839         /* Case 2 */
840 
841         q2 = DIV_ROUND_UP(fref2, rate);
842         r2 = abs(fref2 / q2 - rate);
843 
844         /*
845          * Choose the best between two: less remainder we have the better. We
846          * can't go case 2 if q2 is greater than 256 since SCR register can
847          * hold only values 0 .. 255.
848          */
849         if (r2 >= r1 || q2 > 256) {
850                 /* case 1 is better */
851                 r = r1;
852                 q = q1;
853         } else {
854                 /* case 2 is better */
855                 r = r2;
856                 q = q2;
857                 mul = (1 << 24) * 2 / 5;
858         }
859 
860         /* Check case 3 only if the divisor is big enough */
861         if (fref / rate >= 80) {
862                 u64 fssp;
863                 u32 m;
864 
865                 /* Calculate initial quot */
866                 q1 = DIV_ROUND_UP(fref, rate);
867                 m = (1 << 24) / q1;
868 
869                 /* Get the remainder */
870                 fssp = (u64)fref * m;
871                 do_div(fssp, 1 << 24);
872                 r1 = abs(fssp - rate);
873 
874                 /* Choose this one if it suits better */
875                 if (r1 < r) {
876                         /* case 3 is better */
877                         q = 1;
878                         mul = m;
879                 }
880         }
881 
882         *dds = mul;
883         return q - 1;
884 }
885 
886 static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate)
887 {
888         unsigned long ssp_clk = drv_data->master->max_speed_hz;
889         const struct ssp_device *ssp = drv_data->ssp;
890 
891         rate = min_t(int, ssp_clk, rate);
892 
893         if (ssp->type == PXA25x_SSP || ssp->type == CE4100_SSP)
894                 return (ssp_clk / (2 * rate) - 1) & 0xff;
895         else
896                 return (ssp_clk / rate - 1) & 0xfff;
897 }
898 
899 static unsigned int pxa2xx_ssp_get_clk_div(struct driver_data *drv_data,
900                                            int rate)
901 {
902         struct chip_data *chip = drv_data->cur_chip;
903         unsigned int clk_div;
904 
905         switch (drv_data->ssp_type) {
906         case QUARK_X1000_SSP:
907                 clk_div = quark_x1000_get_clk_div(rate, &chip->dds_rate);
908                 break;
909         default:
910                 clk_div = ssp_get_clk_div(drv_data, rate);
911                 break;
912         }
913         return clk_div << 8;
914 }
915 
916 static void pump_transfers(unsigned long data)
917 {
918         struct driver_data *drv_data = (struct driver_data *)data;
919         struct spi_message *message = NULL;
920         struct spi_transfer *transfer = NULL;
921         struct spi_transfer *previous = NULL;
922         struct chip_data *chip = NULL;
923         u32 clk_div = 0;
924         u8 bits = 0;
925         u32 speed = 0;
926         u32 cr0;
927         u32 cr1;
928         u32 dma_thresh = drv_data->cur_chip->dma_threshold;
929         u32 dma_burst = drv_data->cur_chip->dma_burst_size;
930         u32 change_mask = pxa2xx_spi_get_ssrc1_change_mask(drv_data);
931 
932         /* Get current state information */
933         message = drv_data->cur_msg;
934         transfer = drv_data->cur_transfer;
935         chip = drv_data->cur_chip;
936 
937         /* Handle for abort */
938         if (message->state == ERROR_STATE) {
939                 message->status = -EIO;
940                 giveback(drv_data);
941                 return;
942         }
943 
944         /* Handle end of message */
945         if (message->state == DONE_STATE) {
946                 message->status = 0;
947                 giveback(drv_data);
948                 return;
949         }
950 
951         /* Delay if requested at end of transfer before CS change */
952         if (message->state == RUNNING_STATE) {
953                 previous = list_entry(transfer->transfer_list.prev,
954                                         struct spi_transfer,
955                                         transfer_list);
956                 if (previous->delay_usecs)
957                         udelay(previous->delay_usecs);
958 
959                 /* Drop chip select only if cs_change is requested */
960                 if (previous->cs_change)
961                         cs_deassert(drv_data);
962         }
963 
964         /* Check if we can DMA this transfer */
965         if (!pxa2xx_spi_dma_is_possible(transfer->len) && chip->enable_dma) {
966 
967                 /* reject already-mapped transfers; PIO won't always work */
968                 if (message->is_dma_mapped
969                                 || transfer->rx_dma || transfer->tx_dma) {
970                         dev_err(&drv_data->pdev->dev,
971                                 "pump_transfers: mapped transfer length of "
972                                 "%u is greater than %d\n",
973                                 transfer->len, MAX_DMA_LEN);
974                         message->status = -EINVAL;
975                         giveback(drv_data);
976                         return;
977                 }
978 
979                 /* warn ... we force this to PIO mode */
980                 dev_warn_ratelimited(&message->spi->dev,
981                                      "pump_transfers: DMA disabled for transfer length %ld "
982                                      "greater than %d\n",
983                                      (long)drv_data->len, MAX_DMA_LEN);
984         }
985 
986         /* Setup the transfer state based on the type of transfer */
987         if (pxa2xx_spi_flush(drv_data) == 0) {
988                 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
989                 message->status = -EIO;
990                 giveback(drv_data);
991                 return;
992         }
993         drv_data->n_bytes = chip->n_bytes;
994         drv_data->tx = (void *)transfer->tx_buf;
995         drv_data->tx_end = drv_data->tx + transfer->len;
996         drv_data->rx = transfer->rx_buf;
997         drv_data->rx_end = drv_data->rx + transfer->len;
998         drv_data->len = transfer->len;
999         drv_data->write = drv_data->tx ? chip->write : null_writer;
1000         drv_data->read = drv_data->rx ? chip->read : null_reader;
1001 
1002         /* Change speed and bit per word on a per transfer */
1003         bits = transfer->bits_per_word;
1004         speed = transfer->speed_hz;
1005 
1006         clk_div = pxa2xx_ssp_get_clk_div(drv_data, speed);
1007 
1008         if (bits <= 8) {
1009                 drv_data->n_bytes = 1;
1010                 drv_data->read = drv_data->read != null_reader ?
1011                                         u8_reader : null_reader;
1012                 drv_data->write = drv_data->write != null_writer ?
1013                                         u8_writer : null_writer;
1014         } else if (bits <= 16) {
1015                 drv_data->n_bytes = 2;
1016                 drv_data->read = drv_data->read != null_reader ?
1017                                         u16_reader : null_reader;
1018                 drv_data->write = drv_data->write != null_writer ?
1019                                         u16_writer : null_writer;
1020         } else if (bits <= 32) {
1021                 drv_data->n_bytes = 4;
1022                 drv_data->read = drv_data->read != null_reader ?
1023                                         u32_reader : null_reader;
1024                 drv_data->write = drv_data->write != null_writer ?
1025                                         u32_writer : null_writer;
1026         }
1027         /*
1028          * if bits/word is changed in dma mode, then must check the
1029          * thresholds and burst also
1030          */
1031         if (chip->enable_dma) {
1032                 if (pxa2xx_spi_set_dma_burst_and_threshold(chip,
1033                                                 message->spi,
1034                                                 bits, &dma_burst,
1035                                                 &dma_thresh))
1036                         dev_warn_ratelimited(&message->spi->dev,
1037                                              "pump_transfers: DMA burst size reduced to match bits_per_word\n");
1038         }
1039 
1040         message->state = RUNNING_STATE;
1041 
1042         drv_data->dma_mapped = 0;
1043         if (pxa2xx_spi_dma_is_possible(drv_data->len))
1044                 drv_data->dma_mapped = pxa2xx_spi_map_dma_buffers(drv_data);
1045         if (drv_data->dma_mapped) {
1046 
1047                 /* Ensure we have the correct interrupt handler */
1048                 drv_data->transfer_handler = pxa2xx_spi_dma_transfer;
1049 
1050                 pxa2xx_spi_dma_prepare(drv_data, dma_burst);
1051 
1052                 /* Clear status and start DMA engine */
1053                 cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
1054                 pxa2xx_spi_write(drv_data, SSSR, drv_data->clear_sr);
1055 
1056                 pxa2xx_spi_dma_start(drv_data);
1057         } else {
1058                 /* Ensure we have the correct interrupt handler */
1059                 drv_data->transfer_handler = interrupt_transfer;
1060 
1061                 /* Clear status  */
1062                 cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1;
1063                 write_SSSR_CS(drv_data, drv_data->clear_sr);
1064         }
1065 
1066         /* NOTE:  PXA25x_SSP _could_ use external clocking ... */
1067         cr0 = pxa2xx_configure_sscr0(drv_data, clk_div, bits);
1068         if (!pxa25x_ssp_comp(drv_data))
1069                 dev_dbg(&message->spi->dev, "%u Hz actual, %s\n",
1070                         drv_data->master->max_speed_hz
1071                                 / (1 + ((cr0 & SSCR0_SCR(0xfff)) >> 8)),
1072                         drv_data->dma_mapped ? "DMA" : "PIO");
1073         else
1074                 dev_dbg(&message->spi->dev, "%u Hz actual, %s\n",
1075                         drv_data->master->max_speed_hz / 2
1076                                 / (1 + ((cr0 & SSCR0_SCR(0x0ff)) >> 8)),
1077                         drv_data->dma_mapped ? "DMA" : "PIO");
1078 
1079         if (is_lpss_ssp(drv_data)) {
1080                 if ((pxa2xx_spi_read(drv_data, SSIRF) & 0xff)
1081                     != chip->lpss_rx_threshold)
1082                         pxa2xx_spi_write(drv_data, SSIRF,
1083                                          chip->lpss_rx_threshold);
1084                 if ((pxa2xx_spi_read(drv_data, SSITF) & 0xffff)
1085                     != chip->lpss_tx_threshold)
1086                         pxa2xx_spi_write(drv_data, SSITF,
1087                                          chip->lpss_tx_threshold);
1088         }
1089 
1090         if (is_quark_x1000_ssp(drv_data) &&
1091             (pxa2xx_spi_read(drv_data, DDS_RATE) != chip->dds_rate))
1092                 pxa2xx_spi_write(drv_data, DDS_RATE, chip->dds_rate);
1093 
1094         /* see if we need to reload the config registers */
1095         if ((pxa2xx_spi_read(drv_data, SSCR0) != cr0)
1096             || (pxa2xx_spi_read(drv_data, SSCR1) & change_mask)
1097             != (cr1 & change_mask)) {
1098                 /* stop the SSP, and update the other bits */
1099                 pxa2xx_spi_write(drv_data, SSCR0, cr0 & ~SSCR0_SSE);
1100                 if (!pxa25x_ssp_comp(drv_data))
1101                         pxa2xx_spi_write(drv_data, SSTO, chip->timeout);
1102                 /* first set CR1 without interrupt and service enables */
1103                 pxa2xx_spi_write(drv_data, SSCR1, cr1 & change_mask);
1104                 /* restart the SSP */
1105                 pxa2xx_spi_write(drv_data, SSCR0, cr0);
1106 
1107         } else {
1108                 if (!pxa25x_ssp_comp(drv_data))
1109                         pxa2xx_spi_write(drv_data, SSTO, chip->timeout);
1110         }
1111 
1112         cs_assert(drv_data);
1113 
1114         /* after chip select, release the data by enabling service
1115          * requests and interrupts, without changing any mode bits */
1116         pxa2xx_spi_write(drv_data, SSCR1, cr1);
1117 }
1118 
1119 static int pxa2xx_spi_transfer_one_message(struct spi_master *master,
1120                                            struct spi_message *msg)
1121 {
1122         struct driver_data *drv_data = spi_master_get_devdata(master);
1123 
1124         drv_data->cur_msg = msg;
1125         /* Initial message state*/
1126         drv_data->cur_msg->state = START_STATE;
1127         drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
1128                                                 struct spi_transfer,
1129                                                 transfer_list);
1130 
1131         /* prepare to setup the SSP, in pump_transfers, using the per
1132          * chip configuration */
1133         drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
1134 
1135         /* Mark as busy and launch transfers */
1136         tasklet_schedule(&drv_data->pump_transfers);
1137         return 0;
1138 }
1139 
1140 static int pxa2xx_spi_unprepare_transfer(struct spi_master *master)
1141 {
1142         struct driver_data *drv_data = spi_master_get_devdata(master);
1143 
1144         /* Disable the SSP now */
1145         pxa2xx_spi_write(drv_data, SSCR0,
1146                          pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE);
1147 
1148         return 0;
1149 }
1150 
1151 static int setup_cs(struct spi_device *spi, struct chip_data *chip,
1152                     struct pxa2xx_spi_chip *chip_info)
1153 {
1154         int err = 0;
1155 
1156         if (chip == NULL || chip_info == NULL)
1157                 return 0;
1158 
1159         /* NOTE: setup() can be called multiple times, possibly with
1160          * different chip_info, release previously requested GPIO
1161          */
1162         if (gpio_is_valid(chip->gpio_cs))
1163                 gpio_free(chip->gpio_cs);
1164 
1165         /* If (*cs_control) is provided, ignore GPIO chip select */
1166         if (chip_info->cs_control) {
1167                 chip->cs_control = chip_info->cs_control;
1168                 return 0;
1169         }
1170 
1171         if (gpio_is_valid(chip_info->gpio_cs)) {
1172                 err = gpio_request(chip_info->gpio_cs, "SPI_CS");
1173                 if (err) {
1174                         dev_err(&spi->dev, "failed to request chip select GPIO%d\n",
1175                                 chip_info->gpio_cs);
1176                         return err;
1177                 }
1178 
1179                 chip->gpio_cs = chip_info->gpio_cs;
1180                 chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
1181 
1182                 err = gpio_direction_output(chip->gpio_cs,
1183                                         !chip->gpio_cs_inverted);
1184         }
1185 
1186         return err;
1187 }
1188 
1189 static int setup(struct spi_device *spi)
1190 {
1191         struct pxa2xx_spi_chip *chip_info = NULL;
1192         struct chip_data *chip;
1193         const struct lpss_config *config;
1194         struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1195         uint tx_thres, tx_hi_thres, rx_thres;
1196 
1197         switch (drv_data->ssp_type) {
1198         case QUARK_X1000_SSP:
1199                 tx_thres = TX_THRESH_QUARK_X1000_DFLT;
1200                 tx_hi_thres = 0;
1201                 rx_thres = RX_THRESH_QUARK_X1000_DFLT;
1202                 break;
1203         case LPSS_LPT_SSP:
1204         case LPSS_BYT_SSP:
1205         case LPSS_BSW_SSP:
1206         case LPSS_SPT_SSP:
1207         case LPSS_BXT_SSP:
1208                 config = lpss_get_config(drv_data);
1209                 tx_thres = config->tx_threshold_lo;
1210                 tx_hi_thres = config->tx_threshold_hi;
1211                 rx_thres = config->rx_threshold;
1212                 break;
1213         default:
1214                 tx_thres = TX_THRESH_DFLT;
1215                 tx_hi_thres = 0;
1216                 rx_thres = RX_THRESH_DFLT;
1217                 break;
1218         }
1219 
1220         /* Only alloc on first setup */
1221         chip = spi_get_ctldata(spi);
1222         if (!chip) {
1223                 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1224                 if (!chip)
1225                         return -ENOMEM;
1226 
1227                 if (drv_data->ssp_type == CE4100_SSP) {
1228                         if (spi->chip_select > 4) {
1229                                 dev_err(&spi->dev,
1230                                         "failed setup: cs number must not be > 4.\n");
1231                                 kfree(chip);
1232                                 return -EINVAL;
1233                         }
1234 
1235                         chip->frm = spi->chip_select;
1236                 } else
1237                         chip->gpio_cs = -1;
1238                 chip->enable_dma = 0;
1239                 chip->timeout = TIMOUT_DFLT;
1240         }
1241 
1242         /* protocol drivers may change the chip settings, so...
1243          * if chip_info exists, use it */
1244         chip_info = spi->controller_data;
1245 
1246         /* chip_info isn't always needed */
1247         chip->cr1 = 0;
1248         if (chip_info) {
1249                 if (chip_info->timeout)
1250                         chip->timeout = chip_info->timeout;
1251                 if (chip_info->tx_threshold)
1252                         tx_thres = chip_info->tx_threshold;
1253                 if (chip_info->tx_hi_threshold)
1254                         tx_hi_thres = chip_info->tx_hi_threshold;
1255                 if (chip_info->rx_threshold)
1256                         rx_thres = chip_info->rx_threshold;
1257                 chip->enable_dma = drv_data->master_info->enable_dma;
1258                 chip->dma_threshold = 0;
1259                 if (chip_info->enable_loopback)
1260                         chip->cr1 = SSCR1_LBM;
1261         } else if (ACPI_HANDLE(&spi->dev)) {
1262                 /*
1263                  * Slave devices enumerated from ACPI namespace don't
1264                  * usually have chip_info but we still might want to use
1265                  * DMA with them.
1266                  */
1267                 chip->enable_dma = drv_data->master_info->enable_dma;
1268         }
1269 
1270         chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres);
1271         chip->lpss_tx_threshold = SSITF_TxLoThresh(tx_thres)
1272                                 | SSITF_TxHiThresh(tx_hi_thres);
1273 
1274         /* set dma burst and threshold outside of chip_info path so that if
1275          * chip_info goes away after setting chip->enable_dma, the
1276          * burst and threshold can still respond to changes in bits_per_word */
1277         if (chip->enable_dma) {
1278                 /* set up legal burst and threshold for dma */
1279                 if (pxa2xx_spi_set_dma_burst_and_threshold(chip, spi,
1280                                                 spi->bits_per_word,
1281                                                 &chip->dma_burst_size,
1282                                                 &chip->dma_threshold)) {
1283                         dev_warn(&spi->dev,
1284                                  "in setup: DMA burst size reduced to match bits_per_word\n");
1285                 }
1286         }
1287 
1288         switch (drv_data->ssp_type) {
1289         case QUARK_X1000_SSP:
1290                 chip->threshold = (QUARK_X1000_SSCR1_RxTresh(rx_thres)
1291                                    & QUARK_X1000_SSCR1_RFT)
1292                                    | (QUARK_X1000_SSCR1_TxTresh(tx_thres)
1293                                    & QUARK_X1000_SSCR1_TFT);
1294                 break;
1295         default:
1296                 chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
1297                         (SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
1298                 break;
1299         }
1300 
1301         chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
1302         chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
1303                         | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
1304 
1305         if (spi->mode & SPI_LOOP)
1306                 chip->cr1 |= SSCR1_LBM;
1307 
1308         if (spi->bits_per_word <= 8) {
1309                 chip->n_bytes = 1;
1310                 chip->read = u8_reader;
1311                 chip->write = u8_writer;
1312         } else if (spi->bits_per_word <= 16) {
1313                 chip->n_bytes = 2;
1314                 chip->read = u16_reader;
1315                 chip->write = u16_writer;
1316         } else if (spi->bits_per_word <= 32) {
1317                 chip->n_bytes = 4;
1318                 chip->read = u32_reader;
1319                 chip->write = u32_writer;
1320         }
1321 
1322         spi_set_ctldata(spi, chip);
1323 
1324         if (drv_data->ssp_type == CE4100_SSP)
1325                 return 0;
1326 
1327         return setup_cs(spi, chip, chip_info);
1328 }
1329 
1330 static void cleanup(struct spi_device *spi)
1331 {
1332         struct chip_data *chip = spi_get_ctldata(spi);
1333         struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1334 
1335         if (!chip)
1336                 return;
1337 
1338         if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs))
1339                 gpio_free(chip->gpio_cs);
1340 
1341         kfree(chip);
1342 }
1343 
1344 #ifdef CONFIG_PCI
1345 #ifdef CONFIG_ACPI
1346 
1347 static const struct acpi_device_id pxa2xx_spi_acpi_match[] = {
1348         { "INT33C0", LPSS_LPT_SSP },
1349         { "INT33C1", LPSS_LPT_SSP },
1350         { "INT3430", LPSS_LPT_SSP },
1351         { "INT3431", LPSS_LPT_SSP },
1352         { "80860F0E", LPSS_BYT_SSP },
1353         { "8086228E", LPSS_BSW_SSP },
1354         { },
1355 };
1356 MODULE_DEVICE_TABLE(acpi, pxa2xx_spi_acpi_match);
1357 
1358 static int pxa2xx_spi_get_port_id(struct acpi_device *adev)
1359 {
1360         unsigned int devid;
1361         int port_id = -1;
1362 
1363         if (adev && adev->pnp.unique_id &&
1364             !kstrtouint(adev->pnp.unique_id, 0, &devid))
1365                 port_id = devid;
1366         return port_id;
1367 }
1368 #else /* !CONFIG_ACPI */
1369 static int pxa2xx_spi_get_port_id(struct acpi_device *adev)
1370 {
1371         return -1;
1372 }
1373 #endif
1374 
1375 /*
1376  * PCI IDs of compound devices that integrate both host controller and private
1377  * integrated DMA engine. Please note these are not used in module
1378  * autoloading and probing in this module but matching the LPSS SSP type.
1379  */
1380 static const struct pci_device_id pxa2xx_spi_pci_compound_match[] = {
1381         /* SPT-LP */
1382         { PCI_VDEVICE(INTEL, 0x9d29), LPSS_SPT_SSP },
1383         { PCI_VDEVICE(INTEL, 0x9d2a), LPSS_SPT_SSP },
1384         /* SPT-H */
1385         { PCI_VDEVICE(INTEL, 0xa129), LPSS_SPT_SSP },
1386         { PCI_VDEVICE(INTEL, 0xa12a), LPSS_SPT_SSP },
1387         /* BXT A-Step */
1388         { PCI_VDEVICE(INTEL, 0x0ac2), LPSS_BXT_SSP },
1389         { PCI_VDEVICE(INTEL, 0x0ac4), LPSS_BXT_SSP },
1390         { PCI_VDEVICE(INTEL, 0x0ac6), LPSS_BXT_SSP },
1391         /* BXT B-Step */
1392         { PCI_VDEVICE(INTEL, 0x1ac2), LPSS_BXT_SSP },
1393         { PCI_VDEVICE(INTEL, 0x1ac4), LPSS_BXT_SSP },
1394         { PCI_VDEVICE(INTEL, 0x1ac6), LPSS_BXT_SSP },
1395         /* APL */
1396         { PCI_VDEVICE(INTEL, 0x5ac2), LPSS_BXT_SSP },
1397         { PCI_VDEVICE(INTEL, 0x5ac4), LPSS_BXT_SSP },
1398         { PCI_VDEVICE(INTEL, 0x5ac6), LPSS_BXT_SSP },
1399         { },
1400 };
1401 
1402 static bool pxa2xx_spi_idma_filter(struct dma_chan *chan, void *param)
1403 {
1404         struct device *dev = param;
1405 
1406         if (dev != chan->device->dev->parent)
1407                 return false;
1408 
1409         return true;
1410 }
1411 
1412 static struct pxa2xx_spi_master *
1413 pxa2xx_spi_init_pdata(struct platform_device *pdev)
1414 {
1415         struct pxa2xx_spi_master *pdata;
1416         struct acpi_device *adev;
1417         struct ssp_device *ssp;
1418         struct resource *res;
1419         const struct acpi_device_id *adev_id = NULL;
1420         const struct pci_device_id *pcidev_id = NULL;
1421         int type;
1422 
1423         adev = ACPI_COMPANION(&pdev->dev);
1424 
1425         if (dev_is_pci(pdev->dev.parent))
1426                 pcidev_id = pci_match_id(pxa2xx_spi_pci_compound_match,
1427                                          to_pci_dev(pdev->dev.parent));
1428         else if (adev)
1429                 adev_id = acpi_match_device(pdev->dev.driver->acpi_match_table,
1430                                             &pdev->dev);
1431         else
1432                 return NULL;
1433 
1434         if (adev_id)
1435                 type = (int)adev_id->driver_data;
1436         else if (pcidev_id)
1437                 type = (int)pcidev_id->driver_data;
1438         else
1439                 return NULL;
1440 
1441         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1442         if (!pdata)
1443                 return NULL;
1444 
1445         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1446         if (!res)
1447                 return NULL;
1448 
1449         ssp = &pdata->ssp;
1450 
1451         ssp->phys_base = res->start;
1452         ssp->mmio_base = devm_ioremap_resource(&pdev->dev, res);
1453         if (IS_ERR(ssp->mmio_base))
1454                 return NULL;
1455 
1456         if (pcidev_id) {
1457                 pdata->tx_param = pdev->dev.parent;
1458                 pdata->rx_param = pdev->dev.parent;
1459                 pdata->dma_filter = pxa2xx_spi_idma_filter;
1460         }
1461 
1462         ssp->clk = devm_clk_get(&pdev->dev, NULL);
1463         ssp->irq = platform_get_irq(pdev, 0);
1464         ssp->type = type;
1465         ssp->pdev = pdev;
1466         ssp->port_id = pxa2xx_spi_get_port_id(adev);
1467 
1468         pdata->num_chipselect = 1;
1469         pdata->enable_dma = true;
1470 
1471         return pdata;
1472 }
1473 
1474 #else /* !CONFIG_PCI */
1475 static inline struct pxa2xx_spi_master *
1476 pxa2xx_spi_init_pdata(struct platform_device *pdev)
1477 {
1478         return NULL;
1479 }
1480 #endif
1481 
1482 static int pxa2xx_spi_fw_translate_cs(struct spi_master *master, unsigned cs)
1483 {
1484         struct driver_data *drv_data = spi_master_get_devdata(master);
1485 
1486         if (has_acpi_companion(&drv_data->pdev->dev)) {
1487                 switch (drv_data->ssp_type) {
1488                 /*
1489                  * For Atoms the ACPI DeviceSelection used by the Windows
1490                  * driver starts from 1 instead of 0 so translate it here
1491                  * to match what Linux expects.
1492                  */
1493                 case LPSS_BYT_SSP:
1494                 case LPSS_BSW_SSP:
1495                         return cs - 1;
1496 
1497                 default:
1498                         break;
1499                 }
1500         }
1501 
1502         return cs;
1503 }
1504 
1505 static int pxa2xx_spi_probe(struct platform_device *pdev)
1506 {
1507         struct device *dev = &pdev->dev;
1508         struct pxa2xx_spi_master *platform_info;
1509         struct spi_master *master;
1510         struct driver_data *drv_data;
1511         struct ssp_device *ssp;
1512         const struct lpss_config *config;
1513         int status;
1514         u32 tmp;
1515 
1516         platform_info = dev_get_platdata(dev);
1517         if (!platform_info) {
1518                 platform_info = pxa2xx_spi_init_pdata(pdev);
1519                 if (!platform_info) {
1520                         dev_err(&pdev->dev, "missing platform data\n");
1521                         return -ENODEV;
1522                 }
1523         }
1524 
1525         ssp = pxa_ssp_request(pdev->id, pdev->name);
1526         if (!ssp)
1527                 ssp = &platform_info->ssp;
1528 
1529         if (!ssp->mmio_base) {
1530                 dev_err(&pdev->dev, "failed to get ssp\n");
1531                 return -ENODEV;
1532         }
1533 
1534         master = spi_alloc_master(dev, sizeof(struct driver_data));
1535         if (!master) {
1536                 dev_err(&pdev->dev, "cannot alloc spi_master\n");
1537                 pxa_ssp_free(ssp);
1538                 return -ENOMEM;
1539         }
1540         drv_data = spi_master_get_devdata(master);
1541         drv_data->master = master;
1542         drv_data->master_info = platform_info;
1543         drv_data->pdev = pdev;
1544         drv_data->ssp = ssp;
1545 
1546         master->dev.parent = &pdev->dev;
1547         master->dev.of_node = pdev->dev.of_node;
1548         /* the spi->mode bits understood by this driver: */
1549         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
1550 
1551         master->bus_num = ssp->port_id;
1552         master->dma_alignment = DMA_ALIGNMENT;
1553         master->cleanup = cleanup;
1554         master->setup = setup;
1555         master->transfer_one_message = pxa2xx_spi_transfer_one_message;
1556         master->unprepare_transfer_hardware = pxa2xx_spi_unprepare_transfer;
1557         master->fw_translate_cs = pxa2xx_spi_fw_translate_cs;
1558         master->auto_runtime_pm = true;
1559 
1560         drv_data->ssp_type = ssp->type;
1561 
1562         drv_data->ioaddr = ssp->mmio_base;
1563         drv_data->ssdr_physical = ssp->phys_base + SSDR;
1564         if (pxa25x_ssp_comp(drv_data)) {
1565                 switch (drv_data->ssp_type) {
1566                 case QUARK_X1000_SSP:
1567                         master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1568                         break;
1569                 default:
1570                         master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
1571                         break;
1572                 }
1573 
1574                 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
1575                 drv_data->dma_cr1 = 0;
1576                 drv_data->clear_sr = SSSR_ROR;
1577                 drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR;
1578         } else {
1579                 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1580                 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
1581                 drv_data->dma_cr1 = DEFAULT_DMA_CR1;
1582                 drv_data->clear_sr = SSSR_ROR | SSSR_TINT;
1583                 drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
1584         }
1585 
1586         status = request_irq(ssp->irq, ssp_int, IRQF_SHARED, dev_name(dev),
1587                         drv_data);
1588         if (status < 0) {
1589                 dev_err(&pdev->dev, "cannot get IRQ %d\n", ssp->irq);
1590                 goto out_error_master_alloc;
1591         }
1592 
1593         /* Setup DMA if requested */
1594         if (platform_info->enable_dma) {
1595                 status = pxa2xx_spi_dma_setup(drv_data);
1596                 if (status) {
1597                         dev_dbg(dev, "no DMA channels available, using PIO\n");
1598                         platform_info->enable_dma = false;
1599                 }
1600         }
1601 
1602         /* Enable SOC clock */
1603         clk_prepare_enable(ssp->clk);
1604 
1605         master->max_speed_hz = clk_get_rate(ssp->clk);
1606 
1607         /* Load default SSP configuration */
1608         pxa2xx_spi_write(drv_data, SSCR0, 0);
1609         switch (drv_data->ssp_type) {
1610         case QUARK_X1000_SSP:
1611                 tmp = QUARK_X1000_SSCR1_RxTresh(RX_THRESH_QUARK_X1000_DFLT)
1612                       | QUARK_X1000_SSCR1_TxTresh(TX_THRESH_QUARK_X1000_DFLT);
1613                 pxa2xx_spi_write(drv_data, SSCR1, tmp);
1614 
1615                 /* using the Motorola SPI protocol and use 8 bit frame */
1616                 pxa2xx_spi_write(drv_data, SSCR0,
1617                                  QUARK_X1000_SSCR0_Motorola
1618                                  | QUARK_X1000_SSCR0_DataSize(8));
1619                 break;
1620         default:
1621                 tmp = SSCR1_RxTresh(RX_THRESH_DFLT) |
1622                       SSCR1_TxTresh(TX_THRESH_DFLT);
1623                 pxa2xx_spi_write(drv_data, SSCR1, tmp);
1624                 tmp = SSCR0_SCR(2) | SSCR0_Motorola | SSCR0_DataSize(8);
1625                 pxa2xx_spi_write(drv_data, SSCR0, tmp);
1626                 break;
1627         }
1628 
1629         if (!pxa25x_ssp_comp(drv_data))
1630                 pxa2xx_spi_write(drv_data, SSTO, 0);
1631 
1632         if (!is_quark_x1000_ssp(drv_data))
1633                 pxa2xx_spi_write(drv_data, SSPSP, 0);
1634 
1635         if (is_lpss_ssp(drv_data)) {
1636                 lpss_ssp_setup(drv_data);
1637                 config = lpss_get_config(drv_data);
1638                 if (config->reg_capabilities >= 0) {
1639                         tmp = __lpss_ssp_read_priv(drv_data,
1640                                                    config->reg_capabilities);
1641                         tmp &= LPSS_CAPS_CS_EN_MASK;
1642                         tmp >>= LPSS_CAPS_CS_EN_SHIFT;
1643                         platform_info->num_chipselect = ffz(tmp);
1644                 } else if (config->cs_num) {
1645                         platform_info->num_chipselect = config->cs_num;
1646                 }
1647         }
1648         master->num_chipselect = platform_info->num_chipselect;
1649 
1650         tasklet_init(&drv_data->pump_transfers, pump_transfers,
1651                      (unsigned long)drv_data);
1652 
1653         pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
1654         pm_runtime_use_autosuspend(&pdev->dev);
1655         pm_runtime_set_active(&pdev->dev);
1656         pm_runtime_enable(&pdev->dev);
1657 
1658         /* Register with the SPI framework */
1659         platform_set_drvdata(pdev, drv_data);
1660         status = devm_spi_register_master(&pdev->dev, master);
1661         if (status != 0) {
1662                 dev_err(&pdev->dev, "problem registering spi master\n");
1663                 goto out_error_clock_enabled;
1664         }
1665 
1666         return status;
1667 
1668 out_error_clock_enabled:
1669         clk_disable_unprepare(ssp->clk);
1670         pxa2xx_spi_dma_release(drv_data);
1671         free_irq(ssp->irq, drv_data);
1672 
1673 out_error_master_alloc:
1674         spi_master_put(master);
1675         pxa_ssp_free(ssp);
1676         return status;
1677 }
1678 
1679 static int pxa2xx_spi_remove(struct platform_device *pdev)
1680 {
1681         struct driver_data *drv_data = platform_get_drvdata(pdev);
1682         struct ssp_device *ssp;
1683 
1684         if (!drv_data)
1685                 return 0;
1686         ssp = drv_data->ssp;
1687 
1688         pm_runtime_get_sync(&pdev->dev);
1689 
1690         /* Disable the SSP at the peripheral and SOC level */
1691         pxa2xx_spi_write(drv_data, SSCR0, 0);
1692         clk_disable_unprepare(ssp->clk);
1693 
1694         /* Release DMA */
1695         if (drv_data->master_info->enable_dma)
1696                 pxa2xx_spi_dma_release(drv_data);
1697 
1698         pm_runtime_put_noidle(&pdev->dev);
1699         pm_runtime_disable(&pdev->dev);
1700 
1701         /* Release IRQ */
1702         free_irq(ssp->irq, drv_data);
1703 
1704         /* Release SSP */
1705         pxa_ssp_free(ssp);
1706 
1707         return 0;
1708 }
1709 
1710 static void pxa2xx_spi_shutdown(struct platform_device *pdev)
1711 {
1712         int status = 0;
1713 
1714         if ((status = pxa2xx_spi_remove(pdev)) != 0)
1715                 dev_err(&pdev->dev, "shutdown failed with %d\n", status);
1716 }
1717 
1718 #ifdef CONFIG_PM_SLEEP
1719 static int pxa2xx_spi_suspend(struct device *dev)
1720 {
1721         struct driver_data *drv_data = dev_get_drvdata(dev);
1722         struct ssp_device *ssp = drv_data->ssp;
1723         int status = 0;
1724 
1725         status = spi_master_suspend(drv_data->master);
1726         if (status != 0)
1727                 return status;
1728         pxa2xx_spi_write(drv_data, SSCR0, 0);
1729 
1730         if (!pm_runtime_suspended(dev))
1731                 clk_disable_unprepare(ssp->clk);
1732 
1733         return 0;
1734 }
1735 
1736 static int pxa2xx_spi_resume(struct device *dev)
1737 {
1738         struct driver_data *drv_data = dev_get_drvdata(dev);
1739         struct ssp_device *ssp = drv_data->ssp;
1740         int status = 0;
1741 
1742         /* Enable the SSP clock */
1743         if (!pm_runtime_suspended(dev))
1744                 clk_prepare_enable(ssp->clk);
1745 
1746         /* Restore LPSS private register bits */
1747         if (is_lpss_ssp(drv_data))
1748                 lpss_ssp_setup(drv_data);
1749 
1750         /* Start the queue running */
1751         status = spi_master_resume(drv_data->master);
1752         if (status != 0) {
1753                 dev_err(dev, "problem starting queue (%d)\n", status);
1754                 return status;
1755         }
1756 
1757         return 0;
1758 }
1759 #endif
1760 
1761 #ifdef CONFIG_PM
1762 static int pxa2xx_spi_runtime_suspend(struct device *dev)
1763 {
1764         struct driver_data *drv_data = dev_get_drvdata(dev);
1765 
1766         clk_disable_unprepare(drv_data->ssp->clk);
1767         return 0;
1768 }
1769 
1770 static int pxa2xx_spi_runtime_resume(struct device *dev)
1771 {
1772         struct driver_data *drv_data = dev_get_drvdata(dev);
1773 
1774         clk_prepare_enable(drv_data->ssp->clk);
1775         return 0;
1776 }
1777 #endif
1778 
1779 static const struct dev_pm_ops pxa2xx_spi_pm_ops = {
1780         SET_SYSTEM_SLEEP_PM_OPS(pxa2xx_spi_suspend, pxa2xx_spi_resume)
1781         SET_RUNTIME_PM_OPS(pxa2xx_spi_runtime_suspend,
1782                            pxa2xx_spi_runtime_resume, NULL)
1783 };
1784 
1785 static struct platform_driver driver = {
1786         .driver = {
1787                 .name   = "pxa2xx-spi",
1788                 .pm     = &pxa2xx_spi_pm_ops,
1789                 .acpi_match_table = ACPI_PTR(pxa2xx_spi_acpi_match),
1790         },
1791         .probe = pxa2xx_spi_probe,
1792         .remove = pxa2xx_spi_remove,
1793         .shutdown = pxa2xx_spi_shutdown,
1794 };
1795 
1796 static int __init pxa2xx_spi_init(void)
1797 {
1798         return platform_driver_register(&driver);
1799 }
1800 subsys_initcall(pxa2xx_spi_init);
1801 
1802 static void __exit pxa2xx_spi_exit(void)
1803 {
1804         platform_driver_unregister(&driver);
1805 }
1806 module_exit(pxa2xx_spi_exit);
1807 

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