1 /*
2 * OMAP2 McSPI controller driver
3 *
4 * Copyright (C) 2005, 2006 Nokia Corporation
5 * Author: Samuel Ortiz <samuel.ortiz@nokia.com> and
6 * Juha Yrj�l� <juha.yrjola@nokia.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/interrupt.h>
21 #include <linux/module.h>
22 #include <linux/device.h>
23 #include <linux/delay.h>
24 #include <linux/dma-mapping.h>
25 #include <linux/dmaengine.h>
26 #include <linux/omap-dma.h>
27 #include <linux/platform_device.h>
28 #include <linux/err.h>
29 #include <linux/clk.h>
30 #include <linux/io.h>
31 #include <linux/slab.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/of.h>
34 #include <linux/of_device.h>
35 #include <linux/gcd.h>
36
37 #include <linux/spi/spi.h>
38 #include <linux/gpio.h>
39
40 #include <linux/platform_data/spi-omap2-mcspi.h>
41
42 #define OMAP2_MCSPI_MAX_FREQ 48000000
43 #define OMAP2_MCSPI_MAX_DIVIDER 4096
44 #define OMAP2_MCSPI_MAX_FIFODEPTH 64
45 #define OMAP2_MCSPI_MAX_FIFOWCNT 0xFFFF
46 #define SPI_AUTOSUSPEND_TIMEOUT 2000
47
48 #define OMAP2_MCSPI_REVISION 0x00
49 #define OMAP2_MCSPI_SYSSTATUS 0x14
50 #define OMAP2_MCSPI_IRQSTATUS 0x18
51 #define OMAP2_MCSPI_IRQENABLE 0x1c
52 #define OMAP2_MCSPI_WAKEUPENABLE 0x20
53 #define OMAP2_MCSPI_SYST 0x24
54 #define OMAP2_MCSPI_MODULCTRL 0x28
55 #define OMAP2_MCSPI_XFERLEVEL 0x7c
56
57 /* per-channel banks, 0x14 bytes each, first is: */
58 #define OMAP2_MCSPI_CHCONF0 0x2c
59 #define OMAP2_MCSPI_CHSTAT0 0x30
60 #define OMAP2_MCSPI_CHCTRL0 0x34
61 #define OMAP2_MCSPI_TX0 0x38
62 #define OMAP2_MCSPI_RX0 0x3c
63
64 /* per-register bitmasks: */
65 #define OMAP2_MCSPI_IRQSTATUS_EOW BIT(17)
66
67 #define OMAP2_MCSPI_MODULCTRL_SINGLE BIT(0)
68 #define OMAP2_MCSPI_MODULCTRL_MS BIT(2)
69 #define OMAP2_MCSPI_MODULCTRL_STEST BIT(3)
70
71 #define OMAP2_MCSPI_CHCONF_PHA BIT(0)
72 #define OMAP2_MCSPI_CHCONF_POL BIT(1)
73 #define OMAP2_MCSPI_CHCONF_CLKD_MASK (0x0f << 2)
74 #define OMAP2_MCSPI_CHCONF_EPOL BIT(6)
75 #define OMAP2_MCSPI_CHCONF_WL_MASK (0x1f << 7)
76 #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY BIT(12)
77 #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY BIT(13)
78 #define OMAP2_MCSPI_CHCONF_TRM_MASK (0x03 << 12)
79 #define OMAP2_MCSPI_CHCONF_DMAW BIT(14)
80 #define OMAP2_MCSPI_CHCONF_DMAR BIT(15)
81 #define OMAP2_MCSPI_CHCONF_DPE0 BIT(16)
82 #define OMAP2_MCSPI_CHCONF_DPE1 BIT(17)
83 #define OMAP2_MCSPI_CHCONF_IS BIT(18)
84 #define OMAP2_MCSPI_CHCONF_TURBO BIT(19)
85 #define OMAP2_MCSPI_CHCONF_FORCE BIT(20)
86 #define OMAP2_MCSPI_CHCONF_FFET BIT(27)
87 #define OMAP2_MCSPI_CHCONF_FFER BIT(28)
88 #define OMAP2_MCSPI_CHCONF_CLKG BIT(29)
89
90 #define OMAP2_MCSPI_CHSTAT_RXS BIT(0)
91 #define OMAP2_MCSPI_CHSTAT_TXS BIT(1)
92 #define OMAP2_MCSPI_CHSTAT_EOT BIT(2)
93 #define OMAP2_MCSPI_CHSTAT_TXFFE BIT(3)
94
95 #define OMAP2_MCSPI_CHCTRL_EN BIT(0)
96 #define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK (0xff << 8)
97
98 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN BIT(0)
99
100 /* We have 2 DMA channels per CS, one for RX and one for TX */
101 struct omap2_mcspi_dma {
102 struct dma_chan *dma_tx;
103 struct dma_chan *dma_rx;
104
105 int dma_tx_sync_dev;
106 int dma_rx_sync_dev;
107
108 struct completion dma_tx_completion;
109 struct completion dma_rx_completion;
110
111 char dma_rx_ch_name[14];
112 char dma_tx_ch_name[14];
113 };
114
115 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
116 * cache operations; better heuristics consider wordsize and bitrate.
117 */
118 #define DMA_MIN_BYTES 160
119
120
121 /*
122 * Used for context save and restore, structure members to be updated whenever
123 * corresponding registers are modified.
124 */
125 struct omap2_mcspi_regs {
126 u32 modulctrl;
127 u32 wakeupenable;
128 struct list_head cs;
129 };
130
131 struct omap2_mcspi {
132 struct spi_master *master;
133 /* Virtual base address of the controller */
134 void __iomem *base;
135 unsigned long phys;
136 /* SPI1 has 4 channels, while SPI2 has 2 */
137 struct omap2_mcspi_dma *dma_channels;
138 struct device *dev;
139 struct omap2_mcspi_regs ctx;
140 int fifo_depth;
141 unsigned int pin_dir:1;
142 };
143
144 struct omap2_mcspi_cs {
145 void __iomem *base;
146 unsigned long phys;
147 int word_len;
148 u16 mode;
149 struct list_head node;
150 /* Context save and restore shadow register */
151 u32 chconf0, chctrl0;
152 };
153
mcspi_write_reg(struct spi_master * master,int idx,u32 val)154 static inline void mcspi_write_reg(struct spi_master *master,
155 int idx, u32 val)
156 {
157 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
158
159 writel_relaxed(val, mcspi->base + idx);
160 }
161
mcspi_read_reg(struct spi_master * master,int idx)162 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
163 {
164 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
165
166 return readl_relaxed(mcspi->base + idx);
167 }
168
mcspi_write_cs_reg(const struct spi_device * spi,int idx,u32 val)169 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
170 int idx, u32 val)
171 {
172 struct omap2_mcspi_cs *cs = spi->controller_state;
173
174 writel_relaxed(val, cs->base + idx);
175 }
176
mcspi_read_cs_reg(const struct spi_device * spi,int idx)177 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
178 {
179 struct omap2_mcspi_cs *cs = spi->controller_state;
180
181 return readl_relaxed(cs->base + idx);
182 }
183
mcspi_cached_chconf0(const struct spi_device * spi)184 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
185 {
186 struct omap2_mcspi_cs *cs = spi->controller_state;
187
188 return cs->chconf0;
189 }
190
mcspi_write_chconf0(const struct spi_device * spi,u32 val)191 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
192 {
193 struct omap2_mcspi_cs *cs = spi->controller_state;
194
195 cs->chconf0 = val;
196 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
197 mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
198 }
199
mcspi_bytes_per_word(int word_len)200 static inline int mcspi_bytes_per_word(int word_len)
201 {
202 if (word_len <= 8)
203 return 1;
204 else if (word_len <= 16)
205 return 2;
206 else /* word_len <= 32 */
207 return 4;
208 }
209
omap2_mcspi_set_dma_req(const struct spi_device * spi,int is_read,int enable)210 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
211 int is_read, int enable)
212 {
213 u32 l, rw;
214
215 l = mcspi_cached_chconf0(spi);
216
217 if (is_read) /* 1 is read, 0 write */
218 rw = OMAP2_MCSPI_CHCONF_DMAR;
219 else
220 rw = OMAP2_MCSPI_CHCONF_DMAW;
221
222 if (enable)
223 l |= rw;
224 else
225 l &= ~rw;
226
227 mcspi_write_chconf0(spi, l);
228 }
229
omap2_mcspi_set_enable(const struct spi_device * spi,int enable)230 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
231 {
232 struct omap2_mcspi_cs *cs = spi->controller_state;
233 u32 l;
234
235 l = cs->chctrl0;
236 if (enable)
237 l |= OMAP2_MCSPI_CHCTRL_EN;
238 else
239 l &= ~OMAP2_MCSPI_CHCTRL_EN;
240 cs->chctrl0 = l;
241 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
242 /* Flash post-writes */
243 mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
244 }
245
omap2_mcspi_set_cs(struct spi_device * spi,bool enable)246 static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable)
247 {
248 struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
249 u32 l;
250
251 /* The controller handles the inverted chip selects
252 * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert
253 * the inversion from the core spi_set_cs function.
254 */
255 if (spi->mode & SPI_CS_HIGH)
256 enable = !enable;
257
258 if (spi->controller_state) {
259 int err = pm_runtime_get_sync(mcspi->dev);
260 if (err < 0) {
261 dev_err(mcspi->dev, "failed to get sync: %d\n", err);
262 return;
263 }
264
265 l = mcspi_cached_chconf0(spi);
266
267 if (enable)
268 l &= ~OMAP2_MCSPI_CHCONF_FORCE;
269 else
270 l |= OMAP2_MCSPI_CHCONF_FORCE;
271
272 mcspi_write_chconf0(spi, l);
273
274 pm_runtime_mark_last_busy(mcspi->dev);
275 pm_runtime_put_autosuspend(mcspi->dev);
276 }
277 }
278
omap2_mcspi_set_master_mode(struct spi_master * master)279 static void omap2_mcspi_set_master_mode(struct spi_master *master)
280 {
281 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
282 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
283 u32 l;
284
285 /*
286 * Setup when switching from (reset default) slave mode
287 * to single-channel master mode
288 */
289 l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
290 l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS);
291 l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
292 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
293
294 ctx->modulctrl = l;
295 }
296
omap2_mcspi_set_fifo(const struct spi_device * spi,struct spi_transfer * t,int enable)297 static void omap2_mcspi_set_fifo(const struct spi_device *spi,
298 struct spi_transfer *t, int enable)
299 {
300 struct spi_master *master = spi->master;
301 struct omap2_mcspi_cs *cs = spi->controller_state;
302 struct omap2_mcspi *mcspi;
303 unsigned int wcnt;
304 int max_fifo_depth, fifo_depth, bytes_per_word;
305 u32 chconf, xferlevel;
306
307 mcspi = spi_master_get_devdata(master);
308
309 chconf = mcspi_cached_chconf0(spi);
310 if (enable) {
311 bytes_per_word = mcspi_bytes_per_word(cs->word_len);
312 if (t->len % bytes_per_word != 0)
313 goto disable_fifo;
314
315 if (t->rx_buf != NULL && t->tx_buf != NULL)
316 max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
317 else
318 max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
319
320 fifo_depth = gcd(t->len, max_fifo_depth);
321 if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0)
322 goto disable_fifo;
323
324 wcnt = t->len / bytes_per_word;
325 if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
326 goto disable_fifo;
327
328 xferlevel = wcnt << 16;
329 if (t->rx_buf != NULL) {
330 chconf |= OMAP2_MCSPI_CHCONF_FFER;
331 xferlevel |= (fifo_depth - 1) << 8;
332 }
333 if (t->tx_buf != NULL) {
334 chconf |= OMAP2_MCSPI_CHCONF_FFET;
335 xferlevel |= fifo_depth - 1;
336 }
337
338 mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
339 mcspi_write_chconf0(spi, chconf);
340 mcspi->fifo_depth = fifo_depth;
341
342 return;
343 }
344
345 disable_fifo:
346 if (t->rx_buf != NULL)
347 chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
348
349 if (t->tx_buf != NULL)
350 chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
351
352 mcspi_write_chconf0(spi, chconf);
353 mcspi->fifo_depth = 0;
354 }
355
omap2_mcspi_restore_ctx(struct omap2_mcspi * mcspi)356 static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
357 {
358 struct spi_master *spi_cntrl = mcspi->master;
359 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
360 struct omap2_mcspi_cs *cs;
361
362 /* McSPI: context restore */
363 mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
364 mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
365
366 list_for_each_entry(cs, &ctx->cs, node)
367 writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
368 }
369
mcspi_wait_for_reg_bit(void __iomem * reg,unsigned long bit)370 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
371 {
372 unsigned long timeout;
373
374 timeout = jiffies + msecs_to_jiffies(1000);
375 while (!(readl_relaxed(reg) & bit)) {
376 if (time_after(jiffies, timeout)) {
377 if (!(readl_relaxed(reg) & bit))
378 return -ETIMEDOUT;
379 else
380 return 0;
381 }
382 cpu_relax();
383 }
384 return 0;
385 }
386
omap2_mcspi_rx_callback(void * data)387 static void omap2_mcspi_rx_callback(void *data)
388 {
389 struct spi_device *spi = data;
390 struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
391 struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
392
393 /* We must disable the DMA RX request */
394 omap2_mcspi_set_dma_req(spi, 1, 0);
395
396 complete(&mcspi_dma->dma_rx_completion);
397 }
398
omap2_mcspi_tx_callback(void * data)399 static void omap2_mcspi_tx_callback(void *data)
400 {
401 struct spi_device *spi = data;
402 struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
403 struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
404
405 /* We must disable the DMA TX request */
406 omap2_mcspi_set_dma_req(spi, 0, 0);
407
408 complete(&mcspi_dma->dma_tx_completion);
409 }
410
omap2_mcspi_tx_dma(struct spi_device * spi,struct spi_transfer * xfer,struct dma_slave_config cfg)411 static void omap2_mcspi_tx_dma(struct spi_device *spi,
412 struct spi_transfer *xfer,
413 struct dma_slave_config cfg)
414 {
415 struct omap2_mcspi *mcspi;
416 struct omap2_mcspi_dma *mcspi_dma;
417 unsigned int count;
418
419 mcspi = spi_master_get_devdata(spi->master);
420 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
421 count = xfer->len;
422
423 if (mcspi_dma->dma_tx) {
424 struct dma_async_tx_descriptor *tx;
425 struct scatterlist sg;
426
427 dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
428
429 sg_init_table(&sg, 1);
430 sg_dma_address(&sg) = xfer->tx_dma;
431 sg_dma_len(&sg) = xfer->len;
432
433 tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
434 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
435 if (tx) {
436 tx->callback = omap2_mcspi_tx_callback;
437 tx->callback_param = spi;
438 dmaengine_submit(tx);
439 } else {
440 /* FIXME: fall back to PIO? */
441 }
442 }
443 dma_async_issue_pending(mcspi_dma->dma_tx);
444 omap2_mcspi_set_dma_req(spi, 0, 1);
445
446 }
447
448 static unsigned
omap2_mcspi_rx_dma(struct spi_device * spi,struct spi_transfer * xfer,struct dma_slave_config cfg,unsigned es)449 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
450 struct dma_slave_config cfg,
451 unsigned es)
452 {
453 struct omap2_mcspi *mcspi;
454 struct omap2_mcspi_dma *mcspi_dma;
455 unsigned int count, dma_count;
456 u32 l;
457 int elements = 0;
458 int word_len, element_count;
459 struct omap2_mcspi_cs *cs = spi->controller_state;
460 mcspi = spi_master_get_devdata(spi->master);
461 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
462 count = xfer->len;
463 dma_count = xfer->len;
464
465 if (mcspi->fifo_depth == 0)
466 dma_count -= es;
467
468 word_len = cs->word_len;
469 l = mcspi_cached_chconf0(spi);
470
471 if (word_len <= 8)
472 element_count = count;
473 else if (word_len <= 16)
474 element_count = count >> 1;
475 else /* word_len <= 32 */
476 element_count = count >> 2;
477
478 if (mcspi_dma->dma_rx) {
479 struct dma_async_tx_descriptor *tx;
480 struct scatterlist sg;
481
482 dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
483
484 if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
485 dma_count -= es;
486
487 sg_init_table(&sg, 1);
488 sg_dma_address(&sg) = xfer->rx_dma;
489 sg_dma_len(&sg) = dma_count;
490
491 tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
492 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
493 DMA_CTRL_ACK);
494 if (tx) {
495 tx->callback = omap2_mcspi_rx_callback;
496 tx->callback_param = spi;
497 dmaengine_submit(tx);
498 } else {
499 /* FIXME: fall back to PIO? */
500 }
501 }
502
503 dma_async_issue_pending(mcspi_dma->dma_rx);
504 omap2_mcspi_set_dma_req(spi, 1, 1);
505
506 wait_for_completion(&mcspi_dma->dma_rx_completion);
507 dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
508 DMA_FROM_DEVICE);
509
510 if (mcspi->fifo_depth > 0)
511 return count;
512
513 omap2_mcspi_set_enable(spi, 0);
514
515 elements = element_count - 1;
516
517 if (l & OMAP2_MCSPI_CHCONF_TURBO) {
518 elements--;
519
520 if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
521 & OMAP2_MCSPI_CHSTAT_RXS)) {
522 u32 w;
523
524 w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
525 if (word_len <= 8)
526 ((u8 *)xfer->rx_buf)[elements++] = w;
527 else if (word_len <= 16)
528 ((u16 *)xfer->rx_buf)[elements++] = w;
529 else /* word_len <= 32 */
530 ((u32 *)xfer->rx_buf)[elements++] = w;
531 } else {
532 int bytes_per_word = mcspi_bytes_per_word(word_len);
533 dev_err(&spi->dev, "DMA RX penultimate word empty\n");
534 count -= (bytes_per_word << 1);
535 omap2_mcspi_set_enable(spi, 1);
536 return count;
537 }
538 }
539 if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
540 & OMAP2_MCSPI_CHSTAT_RXS)) {
541 u32 w;
542
543 w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
544 if (word_len <= 8)
545 ((u8 *)xfer->rx_buf)[elements] = w;
546 else if (word_len <= 16)
547 ((u16 *)xfer->rx_buf)[elements] = w;
548 else /* word_len <= 32 */
549 ((u32 *)xfer->rx_buf)[elements] = w;
550 } else {
551 dev_err(&spi->dev, "DMA RX last word empty\n");
552 count -= mcspi_bytes_per_word(word_len);
553 }
554 omap2_mcspi_set_enable(spi, 1);
555 return count;
556 }
557
558 static unsigned
omap2_mcspi_txrx_dma(struct spi_device * spi,struct spi_transfer * xfer)559 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
560 {
561 struct omap2_mcspi *mcspi;
562 struct omap2_mcspi_cs *cs = spi->controller_state;
563 struct omap2_mcspi_dma *mcspi_dma;
564 unsigned int count;
565 u32 l;
566 u8 *rx;
567 const u8 *tx;
568 struct dma_slave_config cfg;
569 enum dma_slave_buswidth width;
570 unsigned es;
571 u32 burst;
572 void __iomem *chstat_reg;
573 void __iomem *irqstat_reg;
574 int wait_res;
575
576 mcspi = spi_master_get_devdata(spi->master);
577 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
578 l = mcspi_cached_chconf0(spi);
579
580
581 if (cs->word_len <= 8) {
582 width = DMA_SLAVE_BUSWIDTH_1_BYTE;
583 es = 1;
584 } else if (cs->word_len <= 16) {
585 width = DMA_SLAVE_BUSWIDTH_2_BYTES;
586 es = 2;
587 } else {
588 width = DMA_SLAVE_BUSWIDTH_4_BYTES;
589 es = 4;
590 }
591
592 count = xfer->len;
593 burst = 1;
594
595 if (mcspi->fifo_depth > 0) {
596 if (count > mcspi->fifo_depth)
597 burst = mcspi->fifo_depth / es;
598 else
599 burst = count / es;
600 }
601
602 memset(&cfg, 0, sizeof(cfg));
603 cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
604 cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
605 cfg.src_addr_width = width;
606 cfg.dst_addr_width = width;
607 cfg.src_maxburst = burst;
608 cfg.dst_maxburst = burst;
609
610 rx = xfer->rx_buf;
611 tx = xfer->tx_buf;
612
613 if (tx != NULL)
614 omap2_mcspi_tx_dma(spi, xfer, cfg);
615
616 if (rx != NULL)
617 count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
618
619 if (tx != NULL) {
620 wait_for_completion(&mcspi_dma->dma_tx_completion);
621 dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
622 DMA_TO_DEVICE);
623
624 if (mcspi->fifo_depth > 0) {
625 irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
626
627 if (mcspi_wait_for_reg_bit(irqstat_reg,
628 OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
629 dev_err(&spi->dev, "EOW timed out\n");
630
631 mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
632 OMAP2_MCSPI_IRQSTATUS_EOW);
633 }
634
635 /* for TX_ONLY mode, be sure all words have shifted out */
636 if (rx == NULL) {
637 chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
638 if (mcspi->fifo_depth > 0) {
639 wait_res = mcspi_wait_for_reg_bit(chstat_reg,
640 OMAP2_MCSPI_CHSTAT_TXFFE);
641 if (wait_res < 0)
642 dev_err(&spi->dev, "TXFFE timed out\n");
643 } else {
644 wait_res = mcspi_wait_for_reg_bit(chstat_reg,
645 OMAP2_MCSPI_CHSTAT_TXS);
646 if (wait_res < 0)
647 dev_err(&spi->dev, "TXS timed out\n");
648 }
649 if (wait_res >= 0 &&
650 (mcspi_wait_for_reg_bit(chstat_reg,
651 OMAP2_MCSPI_CHSTAT_EOT) < 0))
652 dev_err(&spi->dev, "EOT timed out\n");
653 }
654 }
655 return count;
656 }
657
658 static unsigned
omap2_mcspi_txrx_pio(struct spi_device * spi,struct spi_transfer * xfer)659 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
660 {
661 struct omap2_mcspi *mcspi;
662 struct omap2_mcspi_cs *cs = spi->controller_state;
663 unsigned int count, c;
664 u32 l;
665 void __iomem *base = cs->base;
666 void __iomem *tx_reg;
667 void __iomem *rx_reg;
668 void __iomem *chstat_reg;
669 int word_len;
670
671 mcspi = spi_master_get_devdata(spi->master);
672 count = xfer->len;
673 c = count;
674 word_len = cs->word_len;
675
676 l = mcspi_cached_chconf0(spi);
677
678 /* We store the pre-calculated register addresses on stack to speed
679 * up the transfer loop. */
680 tx_reg = base + OMAP2_MCSPI_TX0;
681 rx_reg = base + OMAP2_MCSPI_RX0;
682 chstat_reg = base + OMAP2_MCSPI_CHSTAT0;
683
684 if (c < (word_len>>3))
685 return 0;
686
687 if (word_len <= 8) {
688 u8 *rx;
689 const u8 *tx;
690
691 rx = xfer->rx_buf;
692 tx = xfer->tx_buf;
693
694 do {
695 c -= 1;
696 if (tx != NULL) {
697 if (mcspi_wait_for_reg_bit(chstat_reg,
698 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
699 dev_err(&spi->dev, "TXS timed out\n");
700 goto out;
701 }
702 dev_vdbg(&spi->dev, "write-%d %02x\n",
703 word_len, *tx);
704 writel_relaxed(*tx++, tx_reg);
705 }
706 if (rx != NULL) {
707 if (mcspi_wait_for_reg_bit(chstat_reg,
708 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
709 dev_err(&spi->dev, "RXS timed out\n");
710 goto out;
711 }
712
713 if (c == 1 && tx == NULL &&
714 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
715 omap2_mcspi_set_enable(spi, 0);
716 *rx++ = readl_relaxed(rx_reg);
717 dev_vdbg(&spi->dev, "read-%d %02x\n",
718 word_len, *(rx - 1));
719 if (mcspi_wait_for_reg_bit(chstat_reg,
720 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
721 dev_err(&spi->dev,
722 "RXS timed out\n");
723 goto out;
724 }
725 c = 0;
726 } else if (c == 0 && tx == NULL) {
727 omap2_mcspi_set_enable(spi, 0);
728 }
729
730 *rx++ = readl_relaxed(rx_reg);
731 dev_vdbg(&spi->dev, "read-%d %02x\n",
732 word_len, *(rx - 1));
733 }
734 } while (c);
735 } else if (word_len <= 16) {
736 u16 *rx;
737 const u16 *tx;
738
739 rx = xfer->rx_buf;
740 tx = xfer->tx_buf;
741 do {
742 c -= 2;
743 if (tx != NULL) {
744 if (mcspi_wait_for_reg_bit(chstat_reg,
745 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
746 dev_err(&spi->dev, "TXS timed out\n");
747 goto out;
748 }
749 dev_vdbg(&spi->dev, "write-%d %04x\n",
750 word_len, *tx);
751 writel_relaxed(*tx++, tx_reg);
752 }
753 if (rx != NULL) {
754 if (mcspi_wait_for_reg_bit(chstat_reg,
755 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
756 dev_err(&spi->dev, "RXS timed out\n");
757 goto out;
758 }
759
760 if (c == 2 && tx == NULL &&
761 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
762 omap2_mcspi_set_enable(spi, 0);
763 *rx++ = readl_relaxed(rx_reg);
764 dev_vdbg(&spi->dev, "read-%d %04x\n",
765 word_len, *(rx - 1));
766 if (mcspi_wait_for_reg_bit(chstat_reg,
767 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
768 dev_err(&spi->dev,
769 "RXS timed out\n");
770 goto out;
771 }
772 c = 0;
773 } else if (c == 0 && tx == NULL) {
774 omap2_mcspi_set_enable(spi, 0);
775 }
776
777 *rx++ = readl_relaxed(rx_reg);
778 dev_vdbg(&spi->dev, "read-%d %04x\n",
779 word_len, *(rx - 1));
780 }
781 } while (c >= 2);
782 } else if (word_len <= 32) {
783 u32 *rx;
784 const u32 *tx;
785
786 rx = xfer->rx_buf;
787 tx = xfer->tx_buf;
788 do {
789 c -= 4;
790 if (tx != NULL) {
791 if (mcspi_wait_for_reg_bit(chstat_reg,
792 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
793 dev_err(&spi->dev, "TXS timed out\n");
794 goto out;
795 }
796 dev_vdbg(&spi->dev, "write-%d %08x\n",
797 word_len, *tx);
798 writel_relaxed(*tx++, tx_reg);
799 }
800 if (rx != NULL) {
801 if (mcspi_wait_for_reg_bit(chstat_reg,
802 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
803 dev_err(&spi->dev, "RXS timed out\n");
804 goto out;
805 }
806
807 if (c == 4 && tx == NULL &&
808 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
809 omap2_mcspi_set_enable(spi, 0);
810 *rx++ = readl_relaxed(rx_reg);
811 dev_vdbg(&spi->dev, "read-%d %08x\n",
812 word_len, *(rx - 1));
813 if (mcspi_wait_for_reg_bit(chstat_reg,
814 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
815 dev_err(&spi->dev,
816 "RXS timed out\n");
817 goto out;
818 }
819 c = 0;
820 } else if (c == 0 && tx == NULL) {
821 omap2_mcspi_set_enable(spi, 0);
822 }
823
824 *rx++ = readl_relaxed(rx_reg);
825 dev_vdbg(&spi->dev, "read-%d %08x\n",
826 word_len, *(rx - 1));
827 }
828 } while (c >= 4);
829 }
830
831 /* for TX_ONLY mode, be sure all words have shifted out */
832 if (xfer->rx_buf == NULL) {
833 if (mcspi_wait_for_reg_bit(chstat_reg,
834 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
835 dev_err(&spi->dev, "TXS timed out\n");
836 } else if (mcspi_wait_for_reg_bit(chstat_reg,
837 OMAP2_MCSPI_CHSTAT_EOT) < 0)
838 dev_err(&spi->dev, "EOT timed out\n");
839
840 /* disable chan to purge rx datas received in TX_ONLY transfer,
841 * otherwise these rx datas will affect the direct following
842 * RX_ONLY transfer.
843 */
844 omap2_mcspi_set_enable(spi, 0);
845 }
846 out:
847 omap2_mcspi_set_enable(spi, 1);
848 return count - c;
849 }
850
omap2_mcspi_calc_divisor(u32 speed_hz)851 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
852 {
853 u32 div;
854
855 for (div = 0; div < 15; div++)
856 if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
857 return div;
858
859 return 15;
860 }
861
862 /* called only when no transfer is active to this device */
omap2_mcspi_setup_transfer(struct spi_device * spi,struct spi_transfer * t)863 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
864 struct spi_transfer *t)
865 {
866 struct omap2_mcspi_cs *cs = spi->controller_state;
867 struct omap2_mcspi *mcspi;
868 struct spi_master *spi_cntrl;
869 u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
870 u8 word_len = spi->bits_per_word;
871 u32 speed_hz = spi->max_speed_hz;
872
873 mcspi = spi_master_get_devdata(spi->master);
874 spi_cntrl = mcspi->master;
875
876 if (t != NULL && t->bits_per_word)
877 word_len = t->bits_per_word;
878
879 cs->word_len = word_len;
880
881 if (t && t->speed_hz)
882 speed_hz = t->speed_hz;
883
884 speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
885 if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
886 clkd = omap2_mcspi_calc_divisor(speed_hz);
887 speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
888 clkg = 0;
889 } else {
890 div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
891 speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
892 clkd = (div - 1) & 0xf;
893 extclk = (div - 1) >> 4;
894 clkg = OMAP2_MCSPI_CHCONF_CLKG;
895 }
896
897 l = mcspi_cached_chconf0(spi);
898
899 /* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS
900 * REVISIT: this controller could support SPI_3WIRE mode.
901 */
902 if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
903 l &= ~OMAP2_MCSPI_CHCONF_IS;
904 l &= ~OMAP2_MCSPI_CHCONF_DPE1;
905 l |= OMAP2_MCSPI_CHCONF_DPE0;
906 } else {
907 l |= OMAP2_MCSPI_CHCONF_IS;
908 l |= OMAP2_MCSPI_CHCONF_DPE1;
909 l &= ~OMAP2_MCSPI_CHCONF_DPE0;
910 }
911
912 /* wordlength */
913 l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
914 l |= (word_len - 1) << 7;
915
916 /* set chipselect polarity; manage with FORCE */
917 if (!(spi->mode & SPI_CS_HIGH))
918 l |= OMAP2_MCSPI_CHCONF_EPOL; /* active-low; normal */
919 else
920 l &= ~OMAP2_MCSPI_CHCONF_EPOL;
921
922 /* set clock divisor */
923 l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
924 l |= clkd << 2;
925
926 /* set clock granularity */
927 l &= ~OMAP2_MCSPI_CHCONF_CLKG;
928 l |= clkg;
929 if (clkg) {
930 cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
931 cs->chctrl0 |= extclk << 8;
932 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
933 }
934
935 /* set SPI mode 0..3 */
936 if (spi->mode & SPI_CPOL)
937 l |= OMAP2_MCSPI_CHCONF_POL;
938 else
939 l &= ~OMAP2_MCSPI_CHCONF_POL;
940 if (spi->mode & SPI_CPHA)
941 l |= OMAP2_MCSPI_CHCONF_PHA;
942 else
943 l &= ~OMAP2_MCSPI_CHCONF_PHA;
944
945 mcspi_write_chconf0(spi, l);
946
947 cs->mode = spi->mode;
948
949 dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
950 speed_hz,
951 (spi->mode & SPI_CPHA) ? "trailing" : "leading",
952 (spi->mode & SPI_CPOL) ? "inverted" : "normal");
953
954 return 0;
955 }
956
957 /*
958 * Note that we currently allow DMA only if we get a channel
959 * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
960 */
omap2_mcspi_request_dma(struct spi_device * spi)961 static int omap2_mcspi_request_dma(struct spi_device *spi)
962 {
963 struct spi_master *master = spi->master;
964 struct omap2_mcspi *mcspi;
965 struct omap2_mcspi_dma *mcspi_dma;
966 dma_cap_mask_t mask;
967 unsigned sig;
968
969 mcspi = spi_master_get_devdata(master);
970 mcspi_dma = mcspi->dma_channels + spi->chip_select;
971
972 init_completion(&mcspi_dma->dma_rx_completion);
973 init_completion(&mcspi_dma->dma_tx_completion);
974
975 dma_cap_zero(mask);
976 dma_cap_set(DMA_SLAVE, mask);
977 sig = mcspi_dma->dma_rx_sync_dev;
978
979 mcspi_dma->dma_rx =
980 dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
981 &sig, &master->dev,
982 mcspi_dma->dma_rx_ch_name);
983 if (!mcspi_dma->dma_rx)
984 goto no_dma;
985
986 sig = mcspi_dma->dma_tx_sync_dev;
987 mcspi_dma->dma_tx =
988 dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
989 &sig, &master->dev,
990 mcspi_dma->dma_tx_ch_name);
991
992 if (!mcspi_dma->dma_tx) {
993 dma_release_channel(mcspi_dma->dma_rx);
994 mcspi_dma->dma_rx = NULL;
995 goto no_dma;
996 }
997
998 return 0;
999
1000 no_dma:
1001 dev_warn(&spi->dev, "not using DMA for McSPI\n");
1002 return -EAGAIN;
1003 }
1004
omap2_mcspi_setup(struct spi_device * spi)1005 static int omap2_mcspi_setup(struct spi_device *spi)
1006 {
1007 int ret;
1008 struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
1009 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1010 struct omap2_mcspi_dma *mcspi_dma;
1011 struct omap2_mcspi_cs *cs = spi->controller_state;
1012
1013 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1014
1015 if (!cs) {
1016 cs = kzalloc(sizeof *cs, GFP_KERNEL);
1017 if (!cs)
1018 return -ENOMEM;
1019 cs->base = mcspi->base + spi->chip_select * 0x14;
1020 cs->phys = mcspi->phys + spi->chip_select * 0x14;
1021 cs->mode = 0;
1022 cs->chconf0 = 0;
1023 cs->chctrl0 = 0;
1024 spi->controller_state = cs;
1025 /* Link this to context save list */
1026 list_add_tail(&cs->node, &ctx->cs);
1027
1028 if (gpio_is_valid(spi->cs_gpio)) {
1029 ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
1030 if (ret) {
1031 dev_err(&spi->dev, "failed to request gpio\n");
1032 return ret;
1033 }
1034 gpio_direction_output(spi->cs_gpio,
1035 !(spi->mode & SPI_CS_HIGH));
1036 }
1037 }
1038
1039 if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
1040 ret = omap2_mcspi_request_dma(spi);
1041 if (ret < 0 && ret != -EAGAIN)
1042 return ret;
1043 }
1044
1045 ret = pm_runtime_get_sync(mcspi->dev);
1046 if (ret < 0)
1047 return ret;
1048
1049 ret = omap2_mcspi_setup_transfer(spi, NULL);
1050 pm_runtime_mark_last_busy(mcspi->dev);
1051 pm_runtime_put_autosuspend(mcspi->dev);
1052
1053 return ret;
1054 }
1055
omap2_mcspi_cleanup(struct spi_device * spi)1056 static void omap2_mcspi_cleanup(struct spi_device *spi)
1057 {
1058 struct omap2_mcspi *mcspi;
1059 struct omap2_mcspi_dma *mcspi_dma;
1060 struct omap2_mcspi_cs *cs;
1061
1062 mcspi = spi_master_get_devdata(spi->master);
1063
1064 if (spi->controller_state) {
1065 /* Unlink controller state from context save list */
1066 cs = spi->controller_state;
1067 list_del(&cs->node);
1068
1069 kfree(cs);
1070 }
1071
1072 if (spi->chip_select < spi->master->num_chipselect) {
1073 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1074
1075 if (mcspi_dma->dma_rx) {
1076 dma_release_channel(mcspi_dma->dma_rx);
1077 mcspi_dma->dma_rx = NULL;
1078 }
1079 if (mcspi_dma->dma_tx) {
1080 dma_release_channel(mcspi_dma->dma_tx);
1081 mcspi_dma->dma_tx = NULL;
1082 }
1083 }
1084
1085 if (gpio_is_valid(spi->cs_gpio))
1086 gpio_free(spi->cs_gpio);
1087 }
1088
omap2_mcspi_work_one(struct omap2_mcspi * mcspi,struct spi_device * spi,struct spi_transfer * t)1089 static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
1090 struct spi_device *spi, struct spi_transfer *t)
1091 {
1092
1093 /* We only enable one channel at a time -- the one whose message is
1094 * -- although this controller would gladly
1095 * arbitrate among multiple channels. This corresponds to "single
1096 * channel" master mode. As a side effect, we need to manage the
1097 * chipselect with the FORCE bit ... CS != channel enable.
1098 */
1099
1100 struct spi_master *master;
1101 struct omap2_mcspi_dma *mcspi_dma;
1102 struct omap2_mcspi_cs *cs;
1103 struct omap2_mcspi_device_config *cd;
1104 int par_override = 0;
1105 int status = 0;
1106 u32 chconf;
1107
1108 master = spi->master;
1109 mcspi_dma = mcspi->dma_channels + spi->chip_select;
1110 cs = spi->controller_state;
1111 cd = spi->controller_data;
1112
1113 /*
1114 * The slave driver could have changed spi->mode in which case
1115 * it will be different from cs->mode (the current hardware setup).
1116 * If so, set par_override (even though its not a parity issue) so
1117 * omap2_mcspi_setup_transfer will be called to configure the hardware
1118 * with the correct mode on the first iteration of the loop below.
1119 */
1120 if (spi->mode != cs->mode)
1121 par_override = 1;
1122
1123 omap2_mcspi_set_enable(spi, 0);
1124
1125 if (gpio_is_valid(spi->cs_gpio))
1126 omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH);
1127
1128 if (par_override ||
1129 (t->speed_hz != spi->max_speed_hz) ||
1130 (t->bits_per_word != spi->bits_per_word)) {
1131 par_override = 1;
1132 status = omap2_mcspi_setup_transfer(spi, t);
1133 if (status < 0)
1134 goto out;
1135 if (t->speed_hz == spi->max_speed_hz &&
1136 t->bits_per_word == spi->bits_per_word)
1137 par_override = 0;
1138 }
1139 if (cd && cd->cs_per_word) {
1140 chconf = mcspi->ctx.modulctrl;
1141 chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1142 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1143 mcspi->ctx.modulctrl =
1144 mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1145 }
1146
1147 chconf = mcspi_cached_chconf0(spi);
1148 chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1149 chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1150
1151 if (t->tx_buf == NULL)
1152 chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1153 else if (t->rx_buf == NULL)
1154 chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1155
1156 if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1157 /* Turbo mode is for more than one word */
1158 if (t->len > ((cs->word_len + 7) >> 3))
1159 chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1160 }
1161
1162 mcspi_write_chconf0(spi, chconf);
1163
1164 if (t->len) {
1165 unsigned count;
1166
1167 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1168 (t->len >= DMA_MIN_BYTES))
1169 omap2_mcspi_set_fifo(spi, t, 1);
1170
1171 omap2_mcspi_set_enable(spi, 1);
1172
1173 /* RX_ONLY mode needs dummy data in TX reg */
1174 if (t->tx_buf == NULL)
1175 writel_relaxed(0, cs->base
1176 + OMAP2_MCSPI_TX0);
1177
1178 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1179 (t->len >= DMA_MIN_BYTES))
1180 count = omap2_mcspi_txrx_dma(spi, t);
1181 else
1182 count = omap2_mcspi_txrx_pio(spi, t);
1183
1184 if (count != t->len) {
1185 status = -EIO;
1186 goto out;
1187 }
1188 }
1189
1190 omap2_mcspi_set_enable(spi, 0);
1191
1192 if (mcspi->fifo_depth > 0)
1193 omap2_mcspi_set_fifo(spi, t, 0);
1194
1195 out:
1196 /* Restore defaults if they were overriden */
1197 if (par_override) {
1198 par_override = 0;
1199 status = omap2_mcspi_setup_transfer(spi, NULL);
1200 }
1201
1202 if (cd && cd->cs_per_word) {
1203 chconf = mcspi->ctx.modulctrl;
1204 chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1205 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1206 mcspi->ctx.modulctrl =
1207 mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1208 }
1209
1210 omap2_mcspi_set_enable(spi, 0);
1211
1212 if (gpio_is_valid(spi->cs_gpio))
1213 omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH));
1214
1215 if (mcspi->fifo_depth > 0 && t)
1216 omap2_mcspi_set_fifo(spi, t, 0);
1217
1218 return status;
1219 }
1220
omap2_mcspi_prepare_message(struct spi_master * master,struct spi_message * msg)1221 static int omap2_mcspi_prepare_message(struct spi_master *master,
1222 struct spi_message *msg)
1223 {
1224 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1225 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1226 struct omap2_mcspi_cs *cs;
1227
1228 /* Only a single channel can have the FORCE bit enabled
1229 * in its chconf0 register.
1230 * Scan all channels and disable them except the current one.
1231 * A FORCE can remain from a last transfer having cs_change enabled
1232 */
1233 list_for_each_entry(cs, &ctx->cs, node) {
1234 if (msg->spi->controller_state == cs)
1235 continue;
1236
1237 if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
1238 cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1239 writel_relaxed(cs->chconf0,
1240 cs->base + OMAP2_MCSPI_CHCONF0);
1241 readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
1242 }
1243 }
1244
1245 return 0;
1246 }
1247
omap2_mcspi_transfer_one(struct spi_master * master,struct spi_device * spi,struct spi_transfer * t)1248 static int omap2_mcspi_transfer_one(struct spi_master *master,
1249 struct spi_device *spi, struct spi_transfer *t)
1250 {
1251 struct omap2_mcspi *mcspi;
1252 struct omap2_mcspi_dma *mcspi_dma;
1253 const void *tx_buf = t->tx_buf;
1254 void *rx_buf = t->rx_buf;
1255 unsigned len = t->len;
1256
1257 mcspi = spi_master_get_devdata(master);
1258 mcspi_dma = mcspi->dma_channels + spi->chip_select;
1259
1260 if ((len && !(rx_buf || tx_buf))) {
1261 dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
1262 t->speed_hz,
1263 len,
1264 tx_buf ? "tx" : "",
1265 rx_buf ? "rx" : "",
1266 t->bits_per_word);
1267 return -EINVAL;
1268 }
1269
1270 if (len < DMA_MIN_BYTES)
1271 goto skip_dma_map;
1272
1273 if (mcspi_dma->dma_tx && tx_buf != NULL) {
1274 t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
1275 len, DMA_TO_DEVICE);
1276 if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
1277 dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1278 'T', len);
1279 return -EINVAL;
1280 }
1281 }
1282 if (mcspi_dma->dma_rx && rx_buf != NULL) {
1283 t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
1284 DMA_FROM_DEVICE);
1285 if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
1286 dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1287 'R', len);
1288 if (tx_buf != NULL)
1289 dma_unmap_single(mcspi->dev, t->tx_dma,
1290 len, DMA_TO_DEVICE);
1291 return -EINVAL;
1292 }
1293 }
1294
1295 skip_dma_map:
1296 return omap2_mcspi_work_one(mcspi, spi, t);
1297 }
1298
omap2_mcspi_master_setup(struct omap2_mcspi * mcspi)1299 static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
1300 {
1301 struct spi_master *master = mcspi->master;
1302 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1303 int ret = 0;
1304
1305 ret = pm_runtime_get_sync(mcspi->dev);
1306 if (ret < 0)
1307 return ret;
1308
1309 mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1310 OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1311 ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1312
1313 omap2_mcspi_set_master_mode(master);
1314 pm_runtime_mark_last_busy(mcspi->dev);
1315 pm_runtime_put_autosuspend(mcspi->dev);
1316 return 0;
1317 }
1318
omap_mcspi_runtime_resume(struct device * dev)1319 static int omap_mcspi_runtime_resume(struct device *dev)
1320 {
1321 struct omap2_mcspi *mcspi;
1322 struct spi_master *master;
1323
1324 master = dev_get_drvdata(dev);
1325 mcspi = spi_master_get_devdata(master);
1326 omap2_mcspi_restore_ctx(mcspi);
1327
1328 return 0;
1329 }
1330
1331 static struct omap2_mcspi_platform_config omap2_pdata = {
1332 .regs_offset = 0,
1333 };
1334
1335 static struct omap2_mcspi_platform_config omap4_pdata = {
1336 .regs_offset = OMAP4_MCSPI_REG_OFFSET,
1337 };
1338
1339 static const struct of_device_id omap_mcspi_of_match[] = {
1340 {
1341 .compatible = "ti,omap2-mcspi",
1342 .data = &omap2_pdata,
1343 },
1344 {
1345 .compatible = "ti,omap4-mcspi",
1346 .data = &omap4_pdata,
1347 },
1348 { },
1349 };
1350 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1351
omap2_mcspi_probe(struct platform_device * pdev)1352 static int omap2_mcspi_probe(struct platform_device *pdev)
1353 {
1354 struct spi_master *master;
1355 const struct omap2_mcspi_platform_config *pdata;
1356 struct omap2_mcspi *mcspi;
1357 struct resource *r;
1358 int status = 0, i;
1359 u32 regs_offset = 0;
1360 static int bus_num = 1;
1361 struct device_node *node = pdev->dev.of_node;
1362 const struct of_device_id *match;
1363
1364 master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1365 if (master == NULL) {
1366 dev_dbg(&pdev->dev, "master allocation failed\n");
1367 return -ENOMEM;
1368 }
1369
1370 /* the spi->mode bits understood by this driver: */
1371 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1372 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1373 master->setup = omap2_mcspi_setup;
1374 master->auto_runtime_pm = true;
1375 master->prepare_message = omap2_mcspi_prepare_message;
1376 master->transfer_one = omap2_mcspi_transfer_one;
1377 master->set_cs = omap2_mcspi_set_cs;
1378 master->cleanup = omap2_mcspi_cleanup;
1379 master->dev.of_node = node;
1380 master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1381 master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1382
1383 platform_set_drvdata(pdev, master);
1384
1385 mcspi = spi_master_get_devdata(master);
1386 mcspi->master = master;
1387
1388 match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1389 if (match) {
1390 u32 num_cs = 1; /* default number of chipselect */
1391 pdata = match->data;
1392
1393 of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1394 master->num_chipselect = num_cs;
1395 master->bus_num = bus_num++;
1396 if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1397 mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1398 } else {
1399 pdata = dev_get_platdata(&pdev->dev);
1400 master->num_chipselect = pdata->num_cs;
1401 if (pdev->id != -1)
1402 master->bus_num = pdev->id;
1403 mcspi->pin_dir = pdata->pin_dir;
1404 }
1405 regs_offset = pdata->regs_offset;
1406
1407 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1408 if (r == NULL) {
1409 status = -ENODEV;
1410 goto free_master;
1411 }
1412
1413 r->start += regs_offset;
1414 r->end += regs_offset;
1415 mcspi->phys = r->start;
1416
1417 mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1418 if (IS_ERR(mcspi->base)) {
1419 status = PTR_ERR(mcspi->base);
1420 goto free_master;
1421 }
1422
1423 mcspi->dev = &pdev->dev;
1424
1425 INIT_LIST_HEAD(&mcspi->ctx.cs);
1426
1427 mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1428 sizeof(struct omap2_mcspi_dma),
1429 GFP_KERNEL);
1430 if (mcspi->dma_channels == NULL) {
1431 status = -ENOMEM;
1432 goto free_master;
1433 }
1434
1435 for (i = 0; i < master->num_chipselect; i++) {
1436 char *dma_rx_ch_name = mcspi->dma_channels[i].dma_rx_ch_name;
1437 char *dma_tx_ch_name = mcspi->dma_channels[i].dma_tx_ch_name;
1438 struct resource *dma_res;
1439
1440 sprintf(dma_rx_ch_name, "rx%d", i);
1441 if (!pdev->dev.of_node) {
1442 dma_res =
1443 platform_get_resource_byname(pdev,
1444 IORESOURCE_DMA,
1445 dma_rx_ch_name);
1446 if (!dma_res) {
1447 dev_dbg(&pdev->dev,
1448 "cannot get DMA RX channel\n");
1449 status = -ENODEV;
1450 break;
1451 }
1452
1453 mcspi->dma_channels[i].dma_rx_sync_dev =
1454 dma_res->start;
1455 }
1456 sprintf(dma_tx_ch_name, "tx%d", i);
1457 if (!pdev->dev.of_node) {
1458 dma_res =
1459 platform_get_resource_byname(pdev,
1460 IORESOURCE_DMA,
1461 dma_tx_ch_name);
1462 if (!dma_res) {
1463 dev_dbg(&pdev->dev,
1464 "cannot get DMA TX channel\n");
1465 status = -ENODEV;
1466 break;
1467 }
1468
1469 mcspi->dma_channels[i].dma_tx_sync_dev =
1470 dma_res->start;
1471 }
1472 }
1473
1474 if (status < 0)
1475 goto free_master;
1476
1477 pm_runtime_use_autosuspend(&pdev->dev);
1478 pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1479 pm_runtime_enable(&pdev->dev);
1480
1481 status = omap2_mcspi_master_setup(mcspi);
1482 if (status < 0)
1483 goto disable_pm;
1484
1485 status = devm_spi_register_master(&pdev->dev, master);
1486 if (status < 0)
1487 goto disable_pm;
1488
1489 return status;
1490
1491 disable_pm:
1492 pm_runtime_disable(&pdev->dev);
1493 free_master:
1494 spi_master_put(master);
1495 return status;
1496 }
1497
omap2_mcspi_remove(struct platform_device * pdev)1498 static int omap2_mcspi_remove(struct platform_device *pdev)
1499 {
1500 struct spi_master *master = platform_get_drvdata(pdev);
1501 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1502
1503 pm_runtime_put_sync(mcspi->dev);
1504 pm_runtime_disable(&pdev->dev);
1505
1506 return 0;
1507 }
1508
1509 /* work with hotplug and coldplug */
1510 MODULE_ALIAS("platform:omap2_mcspi");
1511
1512 #ifdef CONFIG_SUSPEND
1513 /*
1514 * When SPI wake up from off-mode, CS is in activate state. If it was in
1515 * unactive state when driver was suspend, then force it to unactive state at
1516 * wake up.
1517 */
omap2_mcspi_resume(struct device * dev)1518 static int omap2_mcspi_resume(struct device *dev)
1519 {
1520 struct spi_master *master = dev_get_drvdata(dev);
1521 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1522 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1523 struct omap2_mcspi_cs *cs;
1524
1525 pm_runtime_get_sync(mcspi->dev);
1526 list_for_each_entry(cs, &ctx->cs, node) {
1527 if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1528 /*
1529 * We need to toggle CS state for OMAP take this
1530 * change in account.
1531 */
1532 cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1533 writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1534 cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1535 writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1536 }
1537 }
1538 pm_runtime_mark_last_busy(mcspi->dev);
1539 pm_runtime_put_autosuspend(mcspi->dev);
1540 return 0;
1541 }
1542 #else
1543 #define omap2_mcspi_resume NULL
1544 #endif
1545
1546 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1547 .resume = omap2_mcspi_resume,
1548 .runtime_resume = omap_mcspi_runtime_resume,
1549 };
1550
1551 static struct platform_driver omap2_mcspi_driver = {
1552 .driver = {
1553 .name = "omap2_mcspi",
1554 .pm = &omap2_mcspi_pm_ops,
1555 .of_match_table = omap_mcspi_of_match,
1556 },
1557 .probe = omap2_mcspi_probe,
1558 .remove = omap2_mcspi_remove,
1559 };
1560
1561 module_platform_driver(omap2_mcspi_driver);
1562 MODULE_LICENSE("GPL");
1563