1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Freescale eSPI controller driver.
4 *
5 * Copyright 2010 Freescale Semiconductor, Inc.
6 */
7 #include <linux/delay.h>
8 #include <linux/err.h>
9 #include <linux/fsl_devices.h>
10 #include <linux/interrupt.h>
11 #include <linux/module.h>
12 #include <linux/mm.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/of_irq.h>
16 #include <linux/of_platform.h>
17 #include <linux/platform_device.h>
18 #include <linux/spi/spi.h>
19 #include <linux/pm_runtime.h>
20 #include <sysdev/fsl_soc.h>
21
22 /* eSPI Controller registers */
23 #define ESPI_SPMODE 0x00 /* eSPI mode register */
24 #define ESPI_SPIE 0x04 /* eSPI event register */
25 #define ESPI_SPIM 0x08 /* eSPI mask register */
26 #define ESPI_SPCOM 0x0c /* eSPI command register */
27 #define ESPI_SPITF 0x10 /* eSPI transmit FIFO access register*/
28 #define ESPI_SPIRF 0x14 /* eSPI receive FIFO access register*/
29 #define ESPI_SPMODE0 0x20 /* eSPI cs0 mode register */
30
31 #define ESPI_SPMODEx(x) (ESPI_SPMODE0 + (x) * 4)
32
33 /* eSPI Controller mode register definitions */
34 #define SPMODE_ENABLE BIT(31)
35 #define SPMODE_LOOP BIT(30)
36 #define SPMODE_TXTHR(x) ((x) << 8)
37 #define SPMODE_RXTHR(x) ((x) << 0)
38
39 /* eSPI Controller CS mode register definitions */
40 #define CSMODE_CI_INACTIVEHIGH BIT(31)
41 #define CSMODE_CP_BEGIN_EDGECLK BIT(30)
42 #define CSMODE_REV BIT(29)
43 #define CSMODE_DIV16 BIT(28)
44 #define CSMODE_PM(x) ((x) << 24)
45 #define CSMODE_POL_1 BIT(20)
46 #define CSMODE_LEN(x) ((x) << 16)
47 #define CSMODE_BEF(x) ((x) << 12)
48 #define CSMODE_AFT(x) ((x) << 8)
49 #define CSMODE_CG(x) ((x) << 3)
50
51 #define FSL_ESPI_FIFO_SIZE 32
52 #define FSL_ESPI_RXTHR 15
53
54 /* Default mode/csmode for eSPI controller */
55 #define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(FSL_ESPI_RXTHR))
56 #define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \
57 | CSMODE_AFT(0) | CSMODE_CG(1))
58
59 /* SPIE register values */
60 #define SPIE_RXCNT(reg) ((reg >> 24) & 0x3F)
61 #define SPIE_TXCNT(reg) ((reg >> 16) & 0x3F)
62 #define SPIE_TXE BIT(15) /* TX FIFO empty */
63 #define SPIE_DON BIT(14) /* TX done */
64 #define SPIE_RXT BIT(13) /* RX FIFO threshold */
65 #define SPIE_RXF BIT(12) /* RX FIFO full */
66 #define SPIE_TXT BIT(11) /* TX FIFO threshold*/
67 #define SPIE_RNE BIT(9) /* RX FIFO not empty */
68 #define SPIE_TNF BIT(8) /* TX FIFO not full */
69
70 /* SPIM register values */
71 #define SPIM_TXE BIT(15) /* TX FIFO empty */
72 #define SPIM_DON BIT(14) /* TX done */
73 #define SPIM_RXT BIT(13) /* RX FIFO threshold */
74 #define SPIM_RXF BIT(12) /* RX FIFO full */
75 #define SPIM_TXT BIT(11) /* TX FIFO threshold*/
76 #define SPIM_RNE BIT(9) /* RX FIFO not empty */
77 #define SPIM_TNF BIT(8) /* TX FIFO not full */
78
79 /* SPCOM register values */
80 #define SPCOM_CS(x) ((x) << 30)
81 #define SPCOM_DO BIT(28) /* Dual output */
82 #define SPCOM_TO BIT(27) /* TX only */
83 #define SPCOM_RXSKIP(x) ((x) << 16)
84 #define SPCOM_TRANLEN(x) ((x) << 0)
85
86 #define SPCOM_TRANLEN_MAX 0x10000 /* Max transaction length */
87
88 #define AUTOSUSPEND_TIMEOUT 2000
89
90 struct fsl_espi {
91 struct device *dev;
92 void __iomem *reg_base;
93
94 struct list_head *m_transfers;
95 struct spi_transfer *tx_t;
96 unsigned int tx_pos;
97 bool tx_done;
98 struct spi_transfer *rx_t;
99 unsigned int rx_pos;
100 bool rx_done;
101
102 bool swab;
103 unsigned int rxskip;
104
105 spinlock_t lock;
106
107 u32 spibrg; /* SPIBRG input clock */
108
109 struct completion done;
110 };
111
112 struct fsl_espi_cs {
113 u32 hw_mode;
114 };
115
fsl_espi_read_reg(struct fsl_espi * espi,int offset)116 static inline u32 fsl_espi_read_reg(struct fsl_espi *espi, int offset)
117 {
118 return ioread32be(espi->reg_base + offset);
119 }
120
fsl_espi_read_reg16(struct fsl_espi * espi,int offset)121 static inline u16 fsl_espi_read_reg16(struct fsl_espi *espi, int offset)
122 {
123 return ioread16be(espi->reg_base + offset);
124 }
125
fsl_espi_read_reg8(struct fsl_espi * espi,int offset)126 static inline u8 fsl_espi_read_reg8(struct fsl_espi *espi, int offset)
127 {
128 return ioread8(espi->reg_base + offset);
129 }
130
fsl_espi_write_reg(struct fsl_espi * espi,int offset,u32 val)131 static inline void fsl_espi_write_reg(struct fsl_espi *espi, int offset,
132 u32 val)
133 {
134 iowrite32be(val, espi->reg_base + offset);
135 }
136
fsl_espi_write_reg16(struct fsl_espi * espi,int offset,u16 val)137 static inline void fsl_espi_write_reg16(struct fsl_espi *espi, int offset,
138 u16 val)
139 {
140 iowrite16be(val, espi->reg_base + offset);
141 }
142
fsl_espi_write_reg8(struct fsl_espi * espi,int offset,u8 val)143 static inline void fsl_espi_write_reg8(struct fsl_espi *espi, int offset,
144 u8 val)
145 {
146 iowrite8(val, espi->reg_base + offset);
147 }
148
fsl_espi_check_message(struct spi_message * m)149 static int fsl_espi_check_message(struct spi_message *m)
150 {
151 struct fsl_espi *espi = spi_master_get_devdata(m->spi->master);
152 struct spi_transfer *t, *first;
153
154 if (m->frame_length > SPCOM_TRANLEN_MAX) {
155 dev_err(espi->dev, "message too long, size is %u bytes\n",
156 m->frame_length);
157 return -EMSGSIZE;
158 }
159
160 first = list_first_entry(&m->transfers, struct spi_transfer,
161 transfer_list);
162
163 list_for_each_entry(t, &m->transfers, transfer_list) {
164 if (first->bits_per_word != t->bits_per_word ||
165 first->speed_hz != t->speed_hz) {
166 dev_err(espi->dev, "bits_per_word/speed_hz should be the same for all transfers\n");
167 return -EINVAL;
168 }
169 }
170
171 /* ESPI supports MSB-first transfers for word size 8 / 16 only */
172 if (!(m->spi->mode & SPI_LSB_FIRST) && first->bits_per_word != 8 &&
173 first->bits_per_word != 16) {
174 dev_err(espi->dev,
175 "MSB-first transfer not supported for wordsize %u\n",
176 first->bits_per_word);
177 return -EINVAL;
178 }
179
180 return 0;
181 }
182
fsl_espi_check_rxskip_mode(struct spi_message * m)183 static unsigned int fsl_espi_check_rxskip_mode(struct spi_message *m)
184 {
185 struct spi_transfer *t;
186 unsigned int i = 0, rxskip = 0;
187
188 /*
189 * prerequisites for ESPI rxskip mode:
190 * - message has two transfers
191 * - first transfer is a write and second is a read
192 *
193 * In addition the current low-level transfer mechanism requires
194 * that the rxskip bytes fit into the TX FIFO. Else the transfer
195 * would hang because after the first FSL_ESPI_FIFO_SIZE bytes
196 * the TX FIFO isn't re-filled.
197 */
198 list_for_each_entry(t, &m->transfers, transfer_list) {
199 if (i == 0) {
200 if (!t->tx_buf || t->rx_buf ||
201 t->len > FSL_ESPI_FIFO_SIZE)
202 return 0;
203 rxskip = t->len;
204 } else if (i == 1) {
205 if (t->tx_buf || !t->rx_buf)
206 return 0;
207 }
208 i++;
209 }
210
211 return i == 2 ? rxskip : 0;
212 }
213
fsl_espi_fill_tx_fifo(struct fsl_espi * espi,u32 events)214 static void fsl_espi_fill_tx_fifo(struct fsl_espi *espi, u32 events)
215 {
216 u32 tx_fifo_avail;
217 unsigned int tx_left;
218 const void *tx_buf;
219
220 /* if events is zero transfer has not started and tx fifo is empty */
221 tx_fifo_avail = events ? SPIE_TXCNT(events) : FSL_ESPI_FIFO_SIZE;
222 start:
223 tx_left = espi->tx_t->len - espi->tx_pos;
224 tx_buf = espi->tx_t->tx_buf;
225 while (tx_fifo_avail >= min(4U, tx_left) && tx_left) {
226 if (tx_left >= 4) {
227 if (!tx_buf)
228 fsl_espi_write_reg(espi, ESPI_SPITF, 0);
229 else if (espi->swab)
230 fsl_espi_write_reg(espi, ESPI_SPITF,
231 swahb32p(tx_buf + espi->tx_pos));
232 else
233 fsl_espi_write_reg(espi, ESPI_SPITF,
234 *(u32 *)(tx_buf + espi->tx_pos));
235 espi->tx_pos += 4;
236 tx_left -= 4;
237 tx_fifo_avail -= 4;
238 } else if (tx_left >= 2 && tx_buf && espi->swab) {
239 fsl_espi_write_reg16(espi, ESPI_SPITF,
240 swab16p(tx_buf + espi->tx_pos));
241 espi->tx_pos += 2;
242 tx_left -= 2;
243 tx_fifo_avail -= 2;
244 } else {
245 if (!tx_buf)
246 fsl_espi_write_reg8(espi, ESPI_SPITF, 0);
247 else
248 fsl_espi_write_reg8(espi, ESPI_SPITF,
249 *(u8 *)(tx_buf + espi->tx_pos));
250 espi->tx_pos += 1;
251 tx_left -= 1;
252 tx_fifo_avail -= 1;
253 }
254 }
255
256 if (!tx_left) {
257 /* Last transfer finished, in rxskip mode only one is needed */
258 if (list_is_last(&espi->tx_t->transfer_list,
259 espi->m_transfers) || espi->rxskip) {
260 espi->tx_done = true;
261 return;
262 }
263 espi->tx_t = list_next_entry(espi->tx_t, transfer_list);
264 espi->tx_pos = 0;
265 /* continue with next transfer if tx fifo is not full */
266 if (tx_fifo_avail)
267 goto start;
268 }
269 }
270
fsl_espi_read_rx_fifo(struct fsl_espi * espi,u32 events)271 static void fsl_espi_read_rx_fifo(struct fsl_espi *espi, u32 events)
272 {
273 u32 rx_fifo_avail = SPIE_RXCNT(events);
274 unsigned int rx_left;
275 void *rx_buf;
276
277 start:
278 rx_left = espi->rx_t->len - espi->rx_pos;
279 rx_buf = espi->rx_t->rx_buf;
280 while (rx_fifo_avail >= min(4U, rx_left) && rx_left) {
281 if (rx_left >= 4) {
282 u32 val = fsl_espi_read_reg(espi, ESPI_SPIRF);
283
284 if (rx_buf && espi->swab)
285 *(u32 *)(rx_buf + espi->rx_pos) = swahb32(val);
286 else if (rx_buf)
287 *(u32 *)(rx_buf + espi->rx_pos) = val;
288 espi->rx_pos += 4;
289 rx_left -= 4;
290 rx_fifo_avail -= 4;
291 } else if (rx_left >= 2 && rx_buf && espi->swab) {
292 u16 val = fsl_espi_read_reg16(espi, ESPI_SPIRF);
293
294 *(u16 *)(rx_buf + espi->rx_pos) = swab16(val);
295 espi->rx_pos += 2;
296 rx_left -= 2;
297 rx_fifo_avail -= 2;
298 } else {
299 u8 val = fsl_espi_read_reg8(espi, ESPI_SPIRF);
300
301 if (rx_buf)
302 *(u8 *)(rx_buf + espi->rx_pos) = val;
303 espi->rx_pos += 1;
304 rx_left -= 1;
305 rx_fifo_avail -= 1;
306 }
307 }
308
309 if (!rx_left) {
310 if (list_is_last(&espi->rx_t->transfer_list,
311 espi->m_transfers)) {
312 espi->rx_done = true;
313 return;
314 }
315 espi->rx_t = list_next_entry(espi->rx_t, transfer_list);
316 espi->rx_pos = 0;
317 /* continue with next transfer if rx fifo is not empty */
318 if (rx_fifo_avail)
319 goto start;
320 }
321 }
322
fsl_espi_setup_transfer(struct spi_device * spi,struct spi_transfer * t)323 static void fsl_espi_setup_transfer(struct spi_device *spi,
324 struct spi_transfer *t)
325 {
326 struct fsl_espi *espi = spi_master_get_devdata(spi->master);
327 int bits_per_word = t ? t->bits_per_word : spi->bits_per_word;
328 u32 pm, hz = t ? t->speed_hz : spi->max_speed_hz;
329 struct fsl_espi_cs *cs = spi_get_ctldata(spi);
330 u32 hw_mode_old = cs->hw_mode;
331
332 /* mask out bits we are going to set */
333 cs->hw_mode &= ~(CSMODE_LEN(0xF) | CSMODE_DIV16 | CSMODE_PM(0xF));
334
335 cs->hw_mode |= CSMODE_LEN(bits_per_word - 1);
336
337 pm = DIV_ROUND_UP(espi->spibrg, hz * 4) - 1;
338
339 if (pm > 15) {
340 cs->hw_mode |= CSMODE_DIV16;
341 pm = DIV_ROUND_UP(espi->spibrg, hz * 16 * 4) - 1;
342 }
343
344 cs->hw_mode |= CSMODE_PM(pm);
345
346 /* don't write the mode register if the mode doesn't change */
347 if (cs->hw_mode != hw_mode_old)
348 fsl_espi_write_reg(espi, ESPI_SPMODEx(spi->chip_select),
349 cs->hw_mode);
350 }
351
fsl_espi_bufs(struct spi_device * spi,struct spi_transfer * t)352 static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
353 {
354 struct fsl_espi *espi = spi_master_get_devdata(spi->master);
355 unsigned int rx_len = t->len;
356 u32 mask, spcom;
357 int ret;
358
359 reinit_completion(&espi->done);
360
361 /* Set SPCOM[CS] and SPCOM[TRANLEN] field */
362 spcom = SPCOM_CS(spi->chip_select);
363 spcom |= SPCOM_TRANLEN(t->len - 1);
364
365 /* configure RXSKIP mode */
366 if (espi->rxskip) {
367 spcom |= SPCOM_RXSKIP(espi->rxskip);
368 rx_len = t->len - espi->rxskip;
369 if (t->rx_nbits == SPI_NBITS_DUAL)
370 spcom |= SPCOM_DO;
371 }
372
373 fsl_espi_write_reg(espi, ESPI_SPCOM, spcom);
374
375 /* enable interrupts */
376 mask = SPIM_DON;
377 if (rx_len > FSL_ESPI_FIFO_SIZE)
378 mask |= SPIM_RXT;
379 fsl_espi_write_reg(espi, ESPI_SPIM, mask);
380
381 /* Prevent filling the fifo from getting interrupted */
382 spin_lock_irq(&espi->lock);
383 fsl_espi_fill_tx_fifo(espi, 0);
384 spin_unlock_irq(&espi->lock);
385
386 /* Won't hang up forever, SPI bus sometimes got lost interrupts... */
387 ret = wait_for_completion_timeout(&espi->done, 2 * HZ);
388 if (ret == 0)
389 dev_err(espi->dev, "Transfer timed out!\n");
390
391 /* disable rx ints */
392 fsl_espi_write_reg(espi, ESPI_SPIM, 0);
393
394 return ret == 0 ? -ETIMEDOUT : 0;
395 }
396
fsl_espi_trans(struct spi_message * m,struct spi_transfer * trans)397 static int fsl_espi_trans(struct spi_message *m, struct spi_transfer *trans)
398 {
399 struct fsl_espi *espi = spi_master_get_devdata(m->spi->master);
400 struct spi_device *spi = m->spi;
401 int ret;
402
403 /* In case of LSB-first and bits_per_word > 8 byte-swap all words */
404 espi->swab = spi->mode & SPI_LSB_FIRST && trans->bits_per_word > 8;
405
406 espi->m_transfers = &m->transfers;
407 espi->tx_t = list_first_entry(&m->transfers, struct spi_transfer,
408 transfer_list);
409 espi->tx_pos = 0;
410 espi->tx_done = false;
411 espi->rx_t = list_first_entry(&m->transfers, struct spi_transfer,
412 transfer_list);
413 espi->rx_pos = 0;
414 espi->rx_done = false;
415
416 espi->rxskip = fsl_espi_check_rxskip_mode(m);
417 if (trans->rx_nbits == SPI_NBITS_DUAL && !espi->rxskip) {
418 dev_err(espi->dev, "Dual output mode requires RXSKIP mode!\n");
419 return -EINVAL;
420 }
421
422 /* In RXSKIP mode skip first transfer for reads */
423 if (espi->rxskip)
424 espi->rx_t = list_next_entry(espi->rx_t, transfer_list);
425
426 fsl_espi_setup_transfer(spi, trans);
427
428 ret = fsl_espi_bufs(spi, trans);
429
430 spi_transfer_delay_exec(trans);
431
432 return ret;
433 }
434
fsl_espi_do_one_msg(struct spi_master * master,struct spi_message * m)435 static int fsl_espi_do_one_msg(struct spi_master *master,
436 struct spi_message *m)
437 {
438 unsigned int delay_usecs = 0, rx_nbits = 0;
439 unsigned int delay_nsecs = 0, delay_nsecs1 = 0;
440 struct spi_transfer *t, trans = {};
441 int ret;
442
443 ret = fsl_espi_check_message(m);
444 if (ret)
445 goto out;
446
447 list_for_each_entry(t, &m->transfers, transfer_list) {
448 if (t->delay_usecs) {
449 if (t->delay_usecs > delay_usecs) {
450 delay_usecs = t->delay_usecs;
451 delay_nsecs = delay_usecs * 1000;
452 }
453 } else {
454 delay_nsecs1 = spi_delay_to_ns(&t->delay, t);
455 if (delay_nsecs1 > delay_nsecs)
456 delay_nsecs = delay_nsecs1;
457 }
458 if (t->rx_nbits > rx_nbits)
459 rx_nbits = t->rx_nbits;
460 }
461
462 t = list_first_entry(&m->transfers, struct spi_transfer,
463 transfer_list);
464
465 trans.len = m->frame_length;
466 trans.speed_hz = t->speed_hz;
467 trans.bits_per_word = t->bits_per_word;
468 trans.delay.value = delay_nsecs;
469 trans.delay.unit = SPI_DELAY_UNIT_NSECS;
470 trans.rx_nbits = rx_nbits;
471
472 if (trans.len)
473 ret = fsl_espi_trans(m, &trans);
474
475 m->actual_length = ret ? 0 : trans.len;
476 out:
477 if (m->status == -EINPROGRESS)
478 m->status = ret;
479
480 spi_finalize_current_message(master);
481
482 return ret;
483 }
484
fsl_espi_setup(struct spi_device * spi)485 static int fsl_espi_setup(struct spi_device *spi)
486 {
487 struct fsl_espi *espi;
488 u32 loop_mode;
489 struct fsl_espi_cs *cs = spi_get_ctldata(spi);
490
491 if (!cs) {
492 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
493 if (!cs)
494 return -ENOMEM;
495 spi_set_ctldata(spi, cs);
496 }
497
498 espi = spi_master_get_devdata(spi->master);
499
500 pm_runtime_get_sync(espi->dev);
501
502 cs->hw_mode = fsl_espi_read_reg(espi, ESPI_SPMODEx(spi->chip_select));
503 /* mask out bits we are going to set */
504 cs->hw_mode &= ~(CSMODE_CP_BEGIN_EDGECLK | CSMODE_CI_INACTIVEHIGH
505 | CSMODE_REV);
506
507 if (spi->mode & SPI_CPHA)
508 cs->hw_mode |= CSMODE_CP_BEGIN_EDGECLK;
509 if (spi->mode & SPI_CPOL)
510 cs->hw_mode |= CSMODE_CI_INACTIVEHIGH;
511 if (!(spi->mode & SPI_LSB_FIRST))
512 cs->hw_mode |= CSMODE_REV;
513
514 /* Handle the loop mode */
515 loop_mode = fsl_espi_read_reg(espi, ESPI_SPMODE);
516 loop_mode &= ~SPMODE_LOOP;
517 if (spi->mode & SPI_LOOP)
518 loop_mode |= SPMODE_LOOP;
519 fsl_espi_write_reg(espi, ESPI_SPMODE, loop_mode);
520
521 fsl_espi_setup_transfer(spi, NULL);
522
523 pm_runtime_mark_last_busy(espi->dev);
524 pm_runtime_put_autosuspend(espi->dev);
525
526 return 0;
527 }
528
fsl_espi_cleanup(struct spi_device * spi)529 static void fsl_espi_cleanup(struct spi_device *spi)
530 {
531 struct fsl_espi_cs *cs = spi_get_ctldata(spi);
532
533 kfree(cs);
534 spi_set_ctldata(spi, NULL);
535 }
536
fsl_espi_cpu_irq(struct fsl_espi * espi,u32 events)537 static void fsl_espi_cpu_irq(struct fsl_espi *espi, u32 events)
538 {
539 if (!espi->rx_done)
540 fsl_espi_read_rx_fifo(espi, events);
541
542 if (!espi->tx_done)
543 fsl_espi_fill_tx_fifo(espi, events);
544
545 if (!espi->tx_done || !espi->rx_done)
546 return;
547
548 /* we're done, but check for errors before returning */
549 events = fsl_espi_read_reg(espi, ESPI_SPIE);
550
551 if (!(events & SPIE_DON))
552 dev_err(espi->dev,
553 "Transfer done but SPIE_DON isn't set!\n");
554
555 if (SPIE_RXCNT(events) || SPIE_TXCNT(events) != FSL_ESPI_FIFO_SIZE) {
556 dev_err(espi->dev, "Transfer done but rx/tx fifo's aren't empty!\n");
557 dev_err(espi->dev, "SPIE_RXCNT = %d, SPIE_TXCNT = %d\n",
558 SPIE_RXCNT(events), SPIE_TXCNT(events));
559 }
560
561 complete(&espi->done);
562 }
563
fsl_espi_irq(s32 irq,void * context_data)564 static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)
565 {
566 struct fsl_espi *espi = context_data;
567 u32 events, mask;
568
569 spin_lock(&espi->lock);
570
571 /* Get interrupt events(tx/rx) */
572 events = fsl_espi_read_reg(espi, ESPI_SPIE);
573 mask = fsl_espi_read_reg(espi, ESPI_SPIM);
574 if (!(events & mask)) {
575 spin_unlock(&espi->lock);
576 return IRQ_NONE;
577 }
578
579 dev_vdbg(espi->dev, "%s: events %x\n", __func__, events);
580
581 fsl_espi_cpu_irq(espi, events);
582
583 /* Clear the events */
584 fsl_espi_write_reg(espi, ESPI_SPIE, events);
585
586 spin_unlock(&espi->lock);
587
588 return IRQ_HANDLED;
589 }
590
591 #ifdef CONFIG_PM
fsl_espi_runtime_suspend(struct device * dev)592 static int fsl_espi_runtime_suspend(struct device *dev)
593 {
594 struct spi_master *master = dev_get_drvdata(dev);
595 struct fsl_espi *espi = spi_master_get_devdata(master);
596 u32 regval;
597
598 regval = fsl_espi_read_reg(espi, ESPI_SPMODE);
599 regval &= ~SPMODE_ENABLE;
600 fsl_espi_write_reg(espi, ESPI_SPMODE, regval);
601
602 return 0;
603 }
604
fsl_espi_runtime_resume(struct device * dev)605 static int fsl_espi_runtime_resume(struct device *dev)
606 {
607 struct spi_master *master = dev_get_drvdata(dev);
608 struct fsl_espi *espi = spi_master_get_devdata(master);
609 u32 regval;
610
611 regval = fsl_espi_read_reg(espi, ESPI_SPMODE);
612 regval |= SPMODE_ENABLE;
613 fsl_espi_write_reg(espi, ESPI_SPMODE, regval);
614
615 return 0;
616 }
617 #endif
618
fsl_espi_max_message_size(struct spi_device * spi)619 static size_t fsl_espi_max_message_size(struct spi_device *spi)
620 {
621 return SPCOM_TRANLEN_MAX;
622 }
623
fsl_espi_init_regs(struct device * dev,bool initial)624 static void fsl_espi_init_regs(struct device *dev, bool initial)
625 {
626 struct spi_master *master = dev_get_drvdata(dev);
627 struct fsl_espi *espi = spi_master_get_devdata(master);
628 struct device_node *nc;
629 u32 csmode, cs, prop;
630 int ret;
631
632 /* SPI controller initializations */
633 fsl_espi_write_reg(espi, ESPI_SPMODE, 0);
634 fsl_espi_write_reg(espi, ESPI_SPIM, 0);
635 fsl_espi_write_reg(espi, ESPI_SPCOM, 0);
636 fsl_espi_write_reg(espi, ESPI_SPIE, 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 ret = of_property_read_u32(nc, "reg", &cs);
642 if (ret || cs >= master->num_chipselect)
643 continue;
644
645 csmode = CSMODE_INIT_VAL;
646
647 /* check if CSBEF is set in device tree */
648 ret = of_property_read_u32(nc, "fsl,csbef", &prop);
649 if (!ret) {
650 csmode &= ~(CSMODE_BEF(0xf));
651 csmode |= CSMODE_BEF(prop);
652 }
653
654 /* check if CSAFT is set in device tree */
655 ret = of_property_read_u32(nc, "fsl,csaft", &prop);
656 if (!ret) {
657 csmode &= ~(CSMODE_AFT(0xf));
658 csmode |= CSMODE_AFT(prop);
659 }
660
661 fsl_espi_write_reg(espi, ESPI_SPMODEx(cs), csmode);
662
663 if (initial)
664 dev_info(dev, "cs=%u, init_csmode=0x%x\n", cs, csmode);
665 }
666
667 /* Enable SPI interface */
668 fsl_espi_write_reg(espi, ESPI_SPMODE, SPMODE_INIT_VAL | SPMODE_ENABLE);
669 }
670
fsl_espi_probe(struct device * dev,struct resource * mem,unsigned int irq,unsigned int num_cs)671 static int fsl_espi_probe(struct device *dev, struct resource *mem,
672 unsigned int irq, unsigned int num_cs)
673 {
674 struct spi_master *master;
675 struct fsl_espi *espi;
676 int ret;
677
678 master = spi_alloc_master(dev, sizeof(struct fsl_espi));
679 if (!master)
680 return -ENOMEM;
681
682 dev_set_drvdata(dev, master);
683
684 master->mode_bits = SPI_RX_DUAL | SPI_CPOL | SPI_CPHA | SPI_CS_HIGH |
685 SPI_LSB_FIRST | SPI_LOOP;
686 master->dev.of_node = dev->of_node;
687 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
688 master->setup = fsl_espi_setup;
689 master->cleanup = fsl_espi_cleanup;
690 master->transfer_one_message = fsl_espi_do_one_msg;
691 master->auto_runtime_pm = true;
692 master->max_message_size = fsl_espi_max_message_size;
693 master->num_chipselect = num_cs;
694
695 espi = spi_master_get_devdata(master);
696 spin_lock_init(&espi->lock);
697
698 espi->dev = dev;
699 espi->spibrg = fsl_get_sys_freq();
700 if (espi->spibrg == -1) {
701 dev_err(dev, "Can't get sys frequency!\n");
702 ret = -EINVAL;
703 goto err_probe;
704 }
705 /* determined by clock divider fields DIV16/PM in register SPMODEx */
706 master->min_speed_hz = DIV_ROUND_UP(espi->spibrg, 4 * 16 * 16);
707 master->max_speed_hz = DIV_ROUND_UP(espi->spibrg, 4);
708
709 init_completion(&espi->done);
710
711 espi->reg_base = devm_ioremap_resource(dev, mem);
712 if (IS_ERR(espi->reg_base)) {
713 ret = PTR_ERR(espi->reg_base);
714 goto err_probe;
715 }
716
717 /* Register for SPI Interrupt */
718 ret = devm_request_irq(dev, irq, fsl_espi_irq, 0, "fsl_espi", espi);
719 if (ret)
720 goto err_probe;
721
722 fsl_espi_init_regs(dev, true);
723
724 pm_runtime_set_autosuspend_delay(dev, AUTOSUSPEND_TIMEOUT);
725 pm_runtime_use_autosuspend(dev);
726 pm_runtime_set_active(dev);
727 pm_runtime_enable(dev);
728 pm_runtime_get_sync(dev);
729
730 ret = devm_spi_register_master(dev, master);
731 if (ret < 0)
732 goto err_pm;
733
734 dev_info(dev, "irq = %u\n", irq);
735
736 pm_runtime_mark_last_busy(dev);
737 pm_runtime_put_autosuspend(dev);
738
739 return 0;
740
741 err_pm:
742 pm_runtime_put_noidle(dev);
743 pm_runtime_disable(dev);
744 pm_runtime_set_suspended(dev);
745 err_probe:
746 spi_master_put(master);
747 return ret;
748 }
749
of_fsl_espi_get_chipselects(struct device * dev)750 static int of_fsl_espi_get_chipselects(struct device *dev)
751 {
752 struct device_node *np = dev->of_node;
753 u32 num_cs;
754 int ret;
755
756 ret = of_property_read_u32(np, "fsl,espi-num-chipselects", &num_cs);
757 if (ret) {
758 dev_err(dev, "No 'fsl,espi-num-chipselects' property\n");
759 return 0;
760 }
761
762 return num_cs;
763 }
764
of_fsl_espi_probe(struct platform_device * ofdev)765 static int of_fsl_espi_probe(struct platform_device *ofdev)
766 {
767 struct device *dev = &ofdev->dev;
768 struct device_node *np = ofdev->dev.of_node;
769 struct resource mem;
770 unsigned int irq, num_cs;
771 int ret;
772
773 if (of_property_read_bool(np, "mode")) {
774 dev_err(dev, "mode property is not supported on ESPI!\n");
775 return -EINVAL;
776 }
777
778 num_cs = of_fsl_espi_get_chipselects(dev);
779 if (!num_cs)
780 return -EINVAL;
781
782 ret = of_address_to_resource(np, 0, &mem);
783 if (ret)
784 return ret;
785
786 irq = irq_of_parse_and_map(np, 0);
787 if (!irq)
788 return -EINVAL;
789
790 return fsl_espi_probe(dev, &mem, irq, num_cs);
791 }
792
of_fsl_espi_remove(struct platform_device * dev)793 static int of_fsl_espi_remove(struct platform_device *dev)
794 {
795 pm_runtime_disable(&dev->dev);
796
797 return 0;
798 }
799
800 #ifdef CONFIG_PM_SLEEP
of_fsl_espi_suspend(struct device * dev)801 static int of_fsl_espi_suspend(struct device *dev)
802 {
803 struct spi_master *master = dev_get_drvdata(dev);
804 int ret;
805
806 ret = spi_master_suspend(master);
807 if (ret)
808 return ret;
809
810 return pm_runtime_force_suspend(dev);
811 }
812
of_fsl_espi_resume(struct device * dev)813 static int of_fsl_espi_resume(struct device *dev)
814 {
815 struct spi_master *master = dev_get_drvdata(dev);
816 int ret;
817
818 fsl_espi_init_regs(dev, false);
819
820 ret = pm_runtime_force_resume(dev);
821 if (ret < 0)
822 return ret;
823
824 return spi_master_resume(master);
825 }
826 #endif /* CONFIG_PM_SLEEP */
827
828 static const struct dev_pm_ops espi_pm = {
829 SET_RUNTIME_PM_OPS(fsl_espi_runtime_suspend,
830 fsl_espi_runtime_resume, NULL)
831 SET_SYSTEM_SLEEP_PM_OPS(of_fsl_espi_suspend, of_fsl_espi_resume)
832 };
833
834 static const struct of_device_id of_fsl_espi_match[] = {
835 { .compatible = "fsl,mpc8536-espi" },
836 {}
837 };
838 MODULE_DEVICE_TABLE(of, of_fsl_espi_match);
839
840 static struct platform_driver fsl_espi_driver = {
841 .driver = {
842 .name = "fsl_espi",
843 .of_match_table = of_fsl_espi_match,
844 .pm = &espi_pm,
845 },
846 .probe = of_fsl_espi_probe,
847 .remove = of_fsl_espi_remove,
848 };
849 module_platform_driver(fsl_espi_driver);
850
851 MODULE_AUTHOR("Mingkai Hu");
852 MODULE_DESCRIPTION("Enhanced Freescale SPI Driver");
853 MODULE_LICENSE("GPL");
854