Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

Linux/drivers/spi/spi-fsl-espi.c

  1 /*
  2  * Freescale eSPI controller driver.
  3  *
  4  * Copyright 2010 Freescale Semiconductor, Inc.
  5  *
  6  * This program is free software; you can redistribute  it and/or modify it
  7  * under  the terms of  the GNU General  Public License as published by the
  8  * Free Software Foundation;  either version 2 of the  License, or (at your
  9  * option) any later version.
 10  */
 11 #include <linux/module.h>
 12 #include <linux/delay.h>
 13 #include <linux/irq.h>
 14 #include <linux/spi/spi.h>
 15 #include <linux/platform_device.h>
 16 #include <linux/fsl_devices.h>
 17 #include <linux/mm.h>
 18 #include <linux/of.h>
 19 #include <linux/of_address.h>
 20 #include <linux/of_irq.h>
 21 #include <linux/of_platform.h>
 22 #include <linux/interrupt.h>
 23 #include <linux/err.h>
 24 #include <sysdev/fsl_soc.h>
 25 
 26 #include "spi-fsl-lib.h"
 27 
 28 /* eSPI Controller registers */
 29 struct fsl_espi_reg {
 30         __be32 mode;            /* 0x000 - eSPI mode register */
 31         __be32 event;           /* 0x004 - eSPI event register */
 32         __be32 mask;            /* 0x008 - eSPI mask register */
 33         __be32 command;         /* 0x00c - eSPI command register */
 34         __be32 transmit;        /* 0x010 - eSPI transmit FIFO access register*/
 35         __be32 receive;         /* 0x014 - eSPI receive FIFO access register*/
 36         u8 res[8];              /* 0x018 - 0x01c reserved */
 37         __be32 csmode[4];       /* 0x020 - 0x02c eSPI cs mode register */
 38 };
 39 
 40 struct fsl_espi_transfer {
 41         const void *tx_buf;
 42         void *rx_buf;
 43         unsigned len;
 44         unsigned n_tx;
 45         unsigned n_rx;
 46         unsigned actual_length;
 47         int status;
 48 };
 49 
 50 /* eSPI Controller mode register definitions */
 51 #define SPMODE_ENABLE           (1 << 31)
 52 #define SPMODE_LOOP             (1 << 30)
 53 #define SPMODE_TXTHR(x)         ((x) << 8)
 54 #define SPMODE_RXTHR(x)         ((x) << 0)
 55 
 56 /* eSPI Controller CS mode register definitions */
 57 #define CSMODE_CI_INACTIVEHIGH  (1 << 31)
 58 #define CSMODE_CP_BEGIN_EDGECLK (1 << 30)
 59 #define CSMODE_REV              (1 << 29)
 60 #define CSMODE_DIV16            (1 << 28)
 61 #define CSMODE_PM(x)            ((x) << 24)
 62 #define CSMODE_POL_1            (1 << 20)
 63 #define CSMODE_LEN(x)           ((x) << 16)
 64 #define CSMODE_BEF(x)           ((x) << 12)
 65 #define CSMODE_AFT(x)           ((x) << 8)
 66 #define CSMODE_CG(x)            ((x) << 3)
 67 
 68 /* Default mode/csmode for eSPI controller */
 69 #define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(3))
 70 #define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \
 71                 | CSMODE_AFT(0) | CSMODE_CG(1))
 72 
 73 /* SPIE register values */
 74 #define SPIE_NE         0x00000200      /* Not empty */
 75 #define SPIE_NF         0x00000100      /* Not full */
 76 
 77 /* SPIM register values */
 78 #define SPIM_NE         0x00000200      /* Not empty */
 79 #define SPIM_NF         0x00000100      /* Not full */
 80 #define SPIE_RXCNT(reg)     ((reg >> 24) & 0x3F)
 81 #define SPIE_TXCNT(reg)     ((reg >> 16) & 0x3F)
 82 
 83 /* SPCOM register values */
 84 #define SPCOM_CS(x)             ((x) << 30)
 85 #define SPCOM_TRANLEN(x)        ((x) << 0)
 86 #define SPCOM_TRANLEN_MAX       0xFFFF  /* Max transaction length */
 87 
 88 static void fsl_espi_change_mode(struct spi_device *spi)
 89 {
 90         struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
 91         struct spi_mpc8xxx_cs *cs = spi->controller_state;
 92         struct fsl_espi_reg *reg_base = mspi->reg_base;
 93         __be32 __iomem *mode = &reg_base->csmode[spi->chip_select];
 94         __be32 __iomem *espi_mode = &reg_base->mode;
 95         u32 tmp;
 96         unsigned long flags;
 97 
 98         /* Turn off IRQs locally to minimize time that SPI is disabled. */
 99         local_irq_save(flags);
100 
101         /* Turn off SPI unit prior changing mode */
102         tmp = mpc8xxx_spi_read_reg(espi_mode);
103         mpc8xxx_spi_write_reg(espi_mode, tmp & ~SPMODE_ENABLE);
104         mpc8xxx_spi_write_reg(mode, cs->hw_mode);
105         mpc8xxx_spi_write_reg(espi_mode, tmp);
106 
107         local_irq_restore(flags);
108 }
109 
110 static u32 fsl_espi_tx_buf_lsb(struct mpc8xxx_spi *mpc8xxx_spi)
111 {
112         u32 data;
113         u16 data_h;
114         u16 data_l;
115         const u32 *tx = mpc8xxx_spi->tx;
116 
117         if (!tx)
118                 return 0;
119 
120         data = *tx++ << mpc8xxx_spi->tx_shift;
121         data_l = data & 0xffff;
122         data_h = (data >> 16) & 0xffff;
123         swab16s(&data_l);
124         swab16s(&data_h);
125         data = data_h | data_l;
126 
127         mpc8xxx_spi->tx = tx;
128         return data;
129 }
130 
131 static int fsl_espi_setup_transfer(struct spi_device *spi,
132                                         struct spi_transfer *t)
133 {
134         struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
135         int bits_per_word = 0;
136         u8 pm;
137         u32 hz = 0;
138         struct spi_mpc8xxx_cs *cs = spi->controller_state;
139 
140         if (t) {
141                 bits_per_word = t->bits_per_word;
142                 hz = t->speed_hz;
143         }
144 
145         /* spi_transfer level calls that work per-word */
146         if (!bits_per_word)
147                 bits_per_word = spi->bits_per_word;
148 
149         if (!hz)
150                 hz = spi->max_speed_hz;
151 
152         cs->rx_shift = 0;
153         cs->tx_shift = 0;
154         cs->get_rx = mpc8xxx_spi_rx_buf_u32;
155         cs->get_tx = mpc8xxx_spi_tx_buf_u32;
156         if (bits_per_word <= 8) {
157                 cs->rx_shift = 8 - bits_per_word;
158         } else {
159                 cs->rx_shift = 16 - bits_per_word;
160                 if (spi->mode & SPI_LSB_FIRST)
161                         cs->get_tx = fsl_espi_tx_buf_lsb;
162         }
163 
164         mpc8xxx_spi->rx_shift = cs->rx_shift;
165         mpc8xxx_spi->tx_shift = cs->tx_shift;
166         mpc8xxx_spi->get_rx = cs->get_rx;
167         mpc8xxx_spi->get_tx = cs->get_tx;
168 
169         bits_per_word = bits_per_word - 1;
170 
171         /* mask out bits we are going to set */
172         cs->hw_mode &= ~(CSMODE_LEN(0xF) | CSMODE_DIV16 | CSMODE_PM(0xF));
173 
174         cs->hw_mode |= CSMODE_LEN(bits_per_word);
175 
176         if ((mpc8xxx_spi->spibrg / hz) > 64) {
177                 cs->hw_mode |= CSMODE_DIV16;
178                 pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 16 * 4);
179 
180                 WARN_ONCE(pm > 33, "%s: Requested speed is too low: %d Hz. "
181                           "Will use %d Hz instead.\n", dev_name(&spi->dev),
182                                 hz, mpc8xxx_spi->spibrg / (4 * 16 * (32 + 1)));
183                 if (pm > 33)
184                         pm = 33;
185         } else {
186                 pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 4);
187         }
188         if (pm)
189                 pm--;
190         if (pm < 2)
191                 pm = 2;
192 
193         cs->hw_mode |= CSMODE_PM(pm);
194 
195         fsl_espi_change_mode(spi);
196         return 0;
197 }
198 
199 static int fsl_espi_cpu_bufs(struct mpc8xxx_spi *mspi, struct spi_transfer *t,
200                 unsigned int len)
201 {
202         u32 word;
203         struct fsl_espi_reg *reg_base = mspi->reg_base;
204 
205         mspi->count = len;
206 
207         /* enable rx ints */
208         mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
209 
210         /* transmit word */
211         word = mspi->get_tx(mspi);
212         mpc8xxx_spi_write_reg(&reg_base->transmit, word);
213 
214         return 0;
215 }
216 
217 static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
218 {
219         struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
220         struct fsl_espi_reg *reg_base = mpc8xxx_spi->reg_base;
221         unsigned int len = t->len;
222         int ret;
223 
224         mpc8xxx_spi->len = t->len;
225         len = roundup(len, 4) / 4;
226 
227         mpc8xxx_spi->tx = t->tx_buf;
228         mpc8xxx_spi->rx = t->rx_buf;
229 
230         reinit_completion(&mpc8xxx_spi->done);
231 
232         /* Set SPCOM[CS] and SPCOM[TRANLEN] field */
233         if ((t->len - 1) > SPCOM_TRANLEN_MAX) {
234                 dev_err(mpc8xxx_spi->dev, "Transaction length (%d)"
235                                 " beyond the SPCOM[TRANLEN] field\n", t->len);
236                 return -EINVAL;
237         }
238         mpc8xxx_spi_write_reg(&reg_base->command,
239                 (SPCOM_CS(spi->chip_select) | SPCOM_TRANLEN(t->len - 1)));
240 
241         ret = fsl_espi_cpu_bufs(mpc8xxx_spi, t, len);
242         if (ret)
243                 return ret;
244 
245         wait_for_completion(&mpc8xxx_spi->done);
246 
247         /* disable rx ints */
248         mpc8xxx_spi_write_reg(&reg_base->mask, 0);
249 
250         return mpc8xxx_spi->count;
251 }
252 
253 static inline void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd)
254 {
255         if (cmd) {
256                 cmd[1] = (u8)(addr >> 16);
257                 cmd[2] = (u8)(addr >> 8);
258                 cmd[3] = (u8)(addr >> 0);
259         }
260 }
261 
262 static inline unsigned int fsl_espi_cmd2addr(u8 *cmd)
263 {
264         if (cmd)
265                 return cmd[1] << 16 | cmd[2] << 8 | cmd[3] << 0;
266 
267         return 0;
268 }
269 
270 static void fsl_espi_do_trans(struct spi_message *m,
271                                 struct fsl_espi_transfer *tr)
272 {
273         struct spi_device *spi = m->spi;
274         struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
275         struct fsl_espi_transfer *espi_trans = tr;
276         struct spi_message message;
277         struct spi_transfer *t, *first, trans;
278         int status = 0;
279 
280         spi_message_init(&message);
281         memset(&trans, 0, sizeof(trans));
282 
283         first = list_first_entry(&m->transfers, struct spi_transfer,
284                         transfer_list);
285         list_for_each_entry(t, &m->transfers, transfer_list) {
286                 if ((first->bits_per_word != t->bits_per_word) ||
287                         (first->speed_hz != t->speed_hz)) {
288                         espi_trans->status = -EINVAL;
289                         dev_err(mspi->dev,
290                                 "bits_per_word/speed_hz should be same for the same SPI transfer\n");
291                         return;
292                 }
293 
294                 trans.speed_hz = t->speed_hz;
295                 trans.bits_per_word = t->bits_per_word;
296                 trans.delay_usecs = max(first->delay_usecs, t->delay_usecs);
297         }
298 
299         trans.len = espi_trans->len;
300         trans.tx_buf = espi_trans->tx_buf;
301         trans.rx_buf = espi_trans->rx_buf;
302         spi_message_add_tail(&trans, &message);
303 
304         list_for_each_entry(t, &message.transfers, transfer_list) {
305                 if (t->bits_per_word || t->speed_hz) {
306                         status = -EINVAL;
307 
308                         status = fsl_espi_setup_transfer(spi, t);
309                         if (status < 0)
310                                 break;
311                 }
312 
313                 if (t->len)
314                         status = fsl_espi_bufs(spi, t);
315 
316                 if (status) {
317                         status = -EMSGSIZE;
318                         break;
319                 }
320 
321                 if (t->delay_usecs)
322                         udelay(t->delay_usecs);
323         }
324 
325         espi_trans->status = status;
326         fsl_espi_setup_transfer(spi, NULL);
327 }
328 
329 static void fsl_espi_cmd_trans(struct spi_message *m,
330                                 struct fsl_espi_transfer *trans, u8 *rx_buff)
331 {
332         struct spi_transfer *t;
333         u8 *local_buf;
334         int i = 0;
335         struct fsl_espi_transfer *espi_trans = trans;
336 
337         local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
338         if (!local_buf) {
339                 espi_trans->status = -ENOMEM;
340                 return;
341         }
342 
343         list_for_each_entry(t, &m->transfers, transfer_list) {
344                 if (t->tx_buf) {
345                         memcpy(local_buf + i, t->tx_buf, t->len);
346                         i += t->len;
347                 }
348         }
349 
350         espi_trans->tx_buf = local_buf;
351         espi_trans->rx_buf = local_buf;
352         fsl_espi_do_trans(m, espi_trans);
353 
354         espi_trans->actual_length = espi_trans->len;
355         kfree(local_buf);
356 }
357 
358 static void fsl_espi_rw_trans(struct spi_message *m,
359                                 struct fsl_espi_transfer *trans, u8 *rx_buff)
360 {
361         struct fsl_espi_transfer *espi_trans = trans;
362         unsigned int n_tx = espi_trans->n_tx;
363         unsigned int n_rx = espi_trans->n_rx;
364         struct spi_transfer *t;
365         u8 *local_buf;
366         u8 *rx_buf = rx_buff;
367         unsigned int trans_len;
368         unsigned int addr;
369         int i, pos, loop;
370 
371         local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
372         if (!local_buf) {
373                 espi_trans->status = -ENOMEM;
374                 return;
375         }
376 
377         for (pos = 0, loop = 0; pos < n_rx; pos += trans_len, loop++) {
378                 trans_len = n_rx - pos;
379                 if (trans_len > SPCOM_TRANLEN_MAX - n_tx)
380                         trans_len = SPCOM_TRANLEN_MAX - n_tx;
381 
382                 i = 0;
383                 list_for_each_entry(t, &m->transfers, transfer_list) {
384                         if (t->tx_buf) {
385                                 memcpy(local_buf + i, t->tx_buf, t->len);
386                                 i += t->len;
387                         }
388                 }
389 
390                 if (pos > 0) {
391                         addr = fsl_espi_cmd2addr(local_buf);
392                         addr += pos;
393                         fsl_espi_addr2cmd(addr, local_buf);
394                 }
395 
396                 espi_trans->n_tx = n_tx;
397                 espi_trans->n_rx = trans_len;
398                 espi_trans->len = trans_len + n_tx;
399                 espi_trans->tx_buf = local_buf;
400                 espi_trans->rx_buf = local_buf;
401                 fsl_espi_do_trans(m, espi_trans);
402 
403                 memcpy(rx_buf + pos, espi_trans->rx_buf + n_tx, trans_len);
404 
405                 if (loop > 0)
406                         espi_trans->actual_length += espi_trans->len - n_tx;
407                 else
408                         espi_trans->actual_length += espi_trans->len;
409         }
410 
411         kfree(local_buf);
412 }
413 
414 static void fsl_espi_do_one_msg(struct spi_message *m)
415 {
416         struct spi_transfer *t;
417         u8 *rx_buf = NULL;
418         unsigned int n_tx = 0;
419         unsigned int n_rx = 0;
420         struct fsl_espi_transfer espi_trans;
421 
422         list_for_each_entry(t, &m->transfers, transfer_list) {
423                 if (t->tx_buf)
424                         n_tx += t->len;
425                 if (t->rx_buf) {
426                         n_rx += t->len;
427                         rx_buf = t->rx_buf;
428                 }
429         }
430 
431         espi_trans.n_tx = n_tx;
432         espi_trans.n_rx = n_rx;
433         espi_trans.len = n_tx + n_rx;
434         espi_trans.actual_length = 0;
435         espi_trans.status = 0;
436 
437         if (!rx_buf)
438                 fsl_espi_cmd_trans(m, &espi_trans, NULL);
439         else
440                 fsl_espi_rw_trans(m, &espi_trans, rx_buf);
441 
442         m->actual_length = espi_trans.actual_length;
443         m->status = espi_trans.status;
444         if (m->complete)
445                 m->complete(m->context);
446 }
447 
448 static int fsl_espi_setup(struct spi_device *spi)
449 {
450         struct mpc8xxx_spi *mpc8xxx_spi;
451         struct fsl_espi_reg *reg_base;
452         int retval;
453         u32 hw_mode;
454         u32 loop_mode;
455         struct spi_mpc8xxx_cs *cs = spi->controller_state;
456 
457         if (!spi->max_speed_hz)
458                 return -EINVAL;
459 
460         if (!cs) {
461                 cs = devm_kzalloc(&spi->dev, sizeof(*cs), GFP_KERNEL);
462                 if (!cs)
463                         return -ENOMEM;
464                 spi->controller_state = cs;
465         }
466 
467         mpc8xxx_spi = spi_master_get_devdata(spi->master);
468         reg_base = mpc8xxx_spi->reg_base;
469 
470         hw_mode = cs->hw_mode; /* Save original settings */
471         cs->hw_mode = mpc8xxx_spi_read_reg(
472                         &reg_base->csmode[spi->chip_select]);
473         /* mask out bits we are going to set */
474         cs->hw_mode &= ~(CSMODE_CP_BEGIN_EDGECLK | CSMODE_CI_INACTIVEHIGH
475                          | CSMODE_REV);
476 
477         if (spi->mode & SPI_CPHA)
478                 cs->hw_mode |= CSMODE_CP_BEGIN_EDGECLK;
479         if (spi->mode & SPI_CPOL)
480                 cs->hw_mode |= CSMODE_CI_INACTIVEHIGH;
481         if (!(spi->mode & SPI_LSB_FIRST))
482                 cs->hw_mode |= CSMODE_REV;
483 
484         /* Handle the loop mode */
485         loop_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
486         loop_mode &= ~SPMODE_LOOP;
487         if (spi->mode & SPI_LOOP)
488                 loop_mode |= SPMODE_LOOP;
489         mpc8xxx_spi_write_reg(&reg_base->mode, loop_mode);
490 
491         retval = fsl_espi_setup_transfer(spi, NULL);
492         if (retval < 0) {
493                 cs->hw_mode = hw_mode; /* Restore settings */
494                 return retval;
495         }
496         return 0;
497 }
498 
499 void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
500 {
501         struct fsl_espi_reg *reg_base = mspi->reg_base;
502 
503         /* We need handle RX first */
504         if (events & SPIE_NE) {
505                 u32 rx_data, tmp;
506                 u8 rx_data_8;
507 
508                 /* Spin until RX is done */
509                 while (SPIE_RXCNT(events) < min(4, mspi->len)) {
510                         cpu_relax();
511                         events = mpc8xxx_spi_read_reg(&reg_base->event);
512                 }
513 
514                 if (mspi->len >= 4) {
515                         rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
516                 } else {
517                         tmp = mspi->len;
518                         rx_data = 0;
519                         while (tmp--) {
520                                 rx_data_8 = in_8((u8 *)&reg_base->receive);
521                                 rx_data |= (rx_data_8 << (tmp * 8));
522                         }
523 
524                         rx_data <<= (4 - mspi->len) * 8;
525                 }
526 
527                 mspi->len -= 4;
528 
529                 if (mspi->rx)
530                         mspi->get_rx(rx_data, mspi);
531         }
532 
533         if (!(events & SPIE_NF)) {
534                 int ret;
535 
536                 /* spin until TX is done */
537                 ret = spin_event_timeout(((events = mpc8xxx_spi_read_reg(
538                                 &reg_base->event)) & SPIE_NF) == 0, 1000, 0);
539                 if (!ret) {
540                         dev_err(mspi->dev, "tired waiting for SPIE_NF\n");
541                         return;
542                 }
543         }
544 
545         /* Clear the events */
546         mpc8xxx_spi_write_reg(&reg_base->event, events);
547 
548         mspi->count -= 1;
549         if (mspi->count) {
550                 u32 word = mspi->get_tx(mspi);
551 
552                 mpc8xxx_spi_write_reg(&reg_base->transmit, word);
553         } else {
554                 complete(&mspi->done);
555         }
556 }
557 
558 static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)
559 {
560         struct mpc8xxx_spi *mspi = context_data;
561         struct fsl_espi_reg *reg_base = mspi->reg_base;
562         irqreturn_t ret = IRQ_NONE;
563         u32 events;
564 
565         /* Get interrupt events(tx/rx) */
566         events = mpc8xxx_spi_read_reg(&reg_base->event);
567         if (events)
568                 ret = IRQ_HANDLED;
569 
570         dev_vdbg(mspi->dev, "%s: events %x\n", __func__, events);
571 
572         fsl_espi_cpu_irq(mspi, events);
573 
574         return ret;
575 }
576 
577 static void fsl_espi_remove(struct mpc8xxx_spi *mspi)
578 {
579         iounmap(mspi->reg_base);
580 }
581 
582 static struct spi_master * fsl_espi_probe(struct device *dev,
583                 struct resource *mem, unsigned int irq)
584 {
585         struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
586         struct spi_master *master;
587         struct mpc8xxx_spi *mpc8xxx_spi;
588         struct fsl_espi_reg *reg_base;
589         struct device_node *nc;
590         const __be32 *prop;
591         u32 regval, csmode;
592         int i, len, ret = 0;
593 
594         master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
595         if (!master) {
596                 ret = -ENOMEM;
597                 goto err;
598         }
599 
600         dev_set_drvdata(dev, master);
601 
602         ret = mpc8xxx_spi_probe(dev, mem, irq);
603         if (ret)
604                 goto err_probe;
605 
606         master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
607         master->setup = fsl_espi_setup;
608 
609         mpc8xxx_spi = spi_master_get_devdata(master);
610         mpc8xxx_spi->spi_do_one_msg = fsl_espi_do_one_msg;
611         mpc8xxx_spi->spi_remove = fsl_espi_remove;
612 
613         mpc8xxx_spi->reg_base = ioremap(mem->start, resource_size(mem));
614         if (!mpc8xxx_spi->reg_base) {
615                 ret = -ENOMEM;
616                 goto err_probe;
617         }
618 
619         reg_base = mpc8xxx_spi->reg_base;
620 
621         /* Register for SPI Interrupt */
622         ret = request_irq(mpc8xxx_spi->irq, fsl_espi_irq,
623                           0, "fsl_espi", mpc8xxx_spi);
624         if (ret)
625                 goto free_irq;
626 
627         if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
628                 mpc8xxx_spi->rx_shift = 16;
629                 mpc8xxx_spi->tx_shift = 24;
630         }
631 
632         /* SPI controller initializations */
633         mpc8xxx_spi_write_reg(&reg_base->mode, 0);
634         mpc8xxx_spi_write_reg(&reg_base->mask, 0);
635         mpc8xxx_spi_write_reg(&reg_base->command, 0);
636         mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
637 
638         /* Init eSPI CS mode register */
639         for_each_available_child_of_node(master->dev.of_node, nc) {
640                 /* get chip select */
641                 prop = of_get_property(nc, "reg", &len);
642                 if (!prop || len < sizeof(*prop))
643                         continue;
644                 i = be32_to_cpup(prop);
645                 if (i < 0 || i >= pdata->max_chipselect)
646                         continue;
647 
648                 csmode = CSMODE_INIT_VAL;
649                 /* check if CSBEF is set in device tree */
650                 prop = of_get_property(nc, "fsl,csbef", &len);
651                 if (prop && len >= sizeof(*prop)) {
652                         csmode &= ~(CSMODE_BEF(0xf));
653                         csmode |= CSMODE_BEF(be32_to_cpup(prop));
654                 }
655                 /* check if CSAFT is set in device tree */
656                 prop = of_get_property(nc, "fsl,csaft", &len);
657                 if (prop && len >= sizeof(*prop)) {
658                         csmode &= ~(CSMODE_AFT(0xf));
659                         csmode |= CSMODE_AFT(be32_to_cpup(prop));
660                 }
661                 mpc8xxx_spi_write_reg(&reg_base->csmode[i], csmode);
662 
663                 dev_info(dev, "cs=%d, init_csmode=0x%x\n", i, csmode);
664         }
665 
666         /* Enable SPI interface */
667         regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
668 
669         mpc8xxx_spi_write_reg(&reg_base->mode, regval);
670 
671         ret = spi_register_master(master);
672         if (ret < 0)
673                 goto unreg_master;
674 
675         dev_info(dev, "at 0x%p (irq = %d)\n", reg_base, mpc8xxx_spi->irq);
676 
677         return master;
678 
679 unreg_master:
680         free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
681 free_irq:
682         iounmap(mpc8xxx_spi->reg_base);
683 err_probe:
684         spi_master_put(master);
685 err:
686         return ERR_PTR(ret);
687 }
688 
689 static int of_fsl_espi_get_chipselects(struct device *dev)
690 {
691         struct device_node *np = dev->of_node;
692         struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
693         const u32 *prop;
694         int len;
695 
696         prop = of_get_property(np, "fsl,espi-num-chipselects", &len);
697         if (!prop || len < sizeof(*prop)) {
698                 dev_err(dev, "No 'fsl,espi-num-chipselects' property\n");
699                 return -EINVAL;
700         }
701 
702         pdata->max_chipselect = *prop;
703         pdata->cs_control = NULL;
704 
705         return 0;
706 }
707 
708 static int of_fsl_espi_probe(struct platform_device *ofdev)
709 {
710         struct device *dev = &ofdev->dev;
711         struct device_node *np = ofdev->dev.of_node;
712         struct spi_master *master;
713         struct resource mem;
714         unsigned int irq;
715         int ret = -ENOMEM;
716 
717         ret = of_mpc8xxx_spi_probe(ofdev);
718         if (ret)
719                 return ret;
720 
721         ret = of_fsl_espi_get_chipselects(dev);
722         if (ret)
723                 goto err;
724 
725         ret = of_address_to_resource(np, 0, &mem);
726         if (ret)
727                 goto err;
728 
729         irq = irq_of_parse_and_map(np, 0);
730         if (!irq) {
731                 ret = -EINVAL;
732                 goto err;
733         }
734 
735         master = fsl_espi_probe(dev, &mem, irq);
736         if (IS_ERR(master)) {
737                 ret = PTR_ERR(master);
738                 goto err;
739         }
740 
741         return 0;
742 
743 err:
744         return ret;
745 }
746 
747 static int of_fsl_espi_remove(struct platform_device *dev)
748 {
749         return mpc8xxx_spi_remove(&dev->dev);
750 }
751 
752 #ifdef CONFIG_PM_SLEEP
753 static int of_fsl_espi_suspend(struct device *dev)
754 {
755         struct spi_master *master = dev_get_drvdata(dev);
756         struct mpc8xxx_spi *mpc8xxx_spi;
757         struct fsl_espi_reg *reg_base;
758         u32 regval;
759         int ret;
760 
761         mpc8xxx_spi = spi_master_get_devdata(master);
762         reg_base = mpc8xxx_spi->reg_base;
763 
764         ret = spi_master_suspend(master);
765         if (ret) {
766                 dev_warn(dev, "cannot suspend master\n");
767                 return ret;
768         }
769 
770         regval = mpc8xxx_spi_read_reg(&reg_base->mode);
771         regval &= ~SPMODE_ENABLE;
772         mpc8xxx_spi_write_reg(&reg_base->mode, regval);
773 
774         return 0;
775 }
776 
777 static int of_fsl_espi_resume(struct device *dev)
778 {
779         struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
780         struct spi_master *master = dev_get_drvdata(dev);
781         struct mpc8xxx_spi *mpc8xxx_spi;
782         struct fsl_espi_reg *reg_base;
783         u32 regval;
784         int i;
785 
786         mpc8xxx_spi = spi_master_get_devdata(master);
787         reg_base = mpc8xxx_spi->reg_base;
788 
789         /* SPI controller initializations */
790         mpc8xxx_spi_write_reg(&reg_base->mode, 0);
791         mpc8xxx_spi_write_reg(&reg_base->mask, 0);
792         mpc8xxx_spi_write_reg(&reg_base->command, 0);
793         mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
794 
795         /* Init eSPI CS mode register */
796         for (i = 0; i < pdata->max_chipselect; i++)
797                 mpc8xxx_spi_write_reg(&reg_base->csmode[i], CSMODE_INIT_VAL);
798 
799         /* Enable SPI interface */
800         regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
801 
802         mpc8xxx_spi_write_reg(&reg_base->mode, regval);
803 
804         return spi_master_resume(master);
805 }
806 #endif /* CONFIG_PM_SLEEP */
807 
808 static const struct dev_pm_ops espi_pm = {
809         SET_SYSTEM_SLEEP_PM_OPS(of_fsl_espi_suspend, of_fsl_espi_resume)
810 };
811 
812 static const struct of_device_id of_fsl_espi_match[] = {
813         { .compatible = "fsl,mpc8536-espi" },
814         {}
815 };
816 MODULE_DEVICE_TABLE(of, of_fsl_espi_match);
817 
818 static struct platform_driver fsl_espi_driver = {
819         .driver = {
820                 .name = "fsl_espi",
821                 .owner = THIS_MODULE,
822                 .of_match_table = of_fsl_espi_match,
823                 .pm = &espi_pm,
824         },
825         .probe          = of_fsl_espi_probe,
826         .remove         = of_fsl_espi_remove,
827 };
828 module_platform_driver(fsl_espi_driver);
829 
830 MODULE_AUTHOR("Mingkai Hu");
831 MODULE_DESCRIPTION("Enhanced Freescale SPI Driver");
832 MODULE_LICENSE("GPL");
833 

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