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[mirror_ubuntu-artful-kernel.git] / drivers / spi / spi-omap2-mcspi.c
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/pinctrl/consumer.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 struct completion dma_tx_completion;
106 struct completion dma_rx_completion;
107
108 char dma_rx_ch_name[14];
109 char dma_tx_ch_name[14];
110 };
111
112 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
113 * cache operations; better heuristics consider wordsize and bitrate.
114 */
115 #define DMA_MIN_BYTES 160
116
117
118 /*
119 * Used for context save and restore, structure members to be updated whenever
120 * corresponding registers are modified.
121 */
122 struct omap2_mcspi_regs {
123 u32 modulctrl;
124 u32 wakeupenable;
125 struct list_head cs;
126 };
127
128 struct omap2_mcspi {
129 struct spi_master *master;
130 /* Virtual base address of the controller */
131 void __iomem *base;
132 unsigned long phys;
133 /* SPI1 has 4 channels, while SPI2 has 2 */
134 struct omap2_mcspi_dma *dma_channels;
135 struct device *dev;
136 struct omap2_mcspi_regs ctx;
137 int fifo_depth;
138 unsigned int pin_dir:1;
139 };
140
141 struct omap2_mcspi_cs {
142 void __iomem *base;
143 unsigned long phys;
144 int word_len;
145 u16 mode;
146 struct list_head node;
147 /* Context save and restore shadow register */
148 u32 chconf0, chctrl0;
149 };
150
151 static inline void mcspi_write_reg(struct spi_master *master,
152 int idx, u32 val)
153 {
154 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
155
156 writel_relaxed(val, mcspi->base + idx);
157 }
158
159 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
160 {
161 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
162
163 return readl_relaxed(mcspi->base + idx);
164 }
165
166 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
167 int idx, u32 val)
168 {
169 struct omap2_mcspi_cs *cs = spi->controller_state;
170
171 writel_relaxed(val, cs->base + idx);
172 }
173
174 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
175 {
176 struct omap2_mcspi_cs *cs = spi->controller_state;
177
178 return readl_relaxed(cs->base + idx);
179 }
180
181 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
182 {
183 struct omap2_mcspi_cs *cs = spi->controller_state;
184
185 return cs->chconf0;
186 }
187
188 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
189 {
190 struct omap2_mcspi_cs *cs = spi->controller_state;
191
192 cs->chconf0 = val;
193 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
194 mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
195 }
196
197 static inline int mcspi_bytes_per_word(int word_len)
198 {
199 if (word_len <= 8)
200 return 1;
201 else if (word_len <= 16)
202 return 2;
203 else /* word_len <= 32 */
204 return 4;
205 }
206
207 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
208 int is_read, int enable)
209 {
210 u32 l, rw;
211
212 l = mcspi_cached_chconf0(spi);
213
214 if (is_read) /* 1 is read, 0 write */
215 rw = OMAP2_MCSPI_CHCONF_DMAR;
216 else
217 rw = OMAP2_MCSPI_CHCONF_DMAW;
218
219 if (enable)
220 l |= rw;
221 else
222 l &= ~rw;
223
224 mcspi_write_chconf0(spi, l);
225 }
226
227 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
228 {
229 struct omap2_mcspi_cs *cs = spi->controller_state;
230 u32 l;
231
232 l = cs->chctrl0;
233 if (enable)
234 l |= OMAP2_MCSPI_CHCTRL_EN;
235 else
236 l &= ~OMAP2_MCSPI_CHCTRL_EN;
237 cs->chctrl0 = l;
238 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
239 /* Flash post-writes */
240 mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
241 }
242
243 static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable)
244 {
245 struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
246 u32 l;
247
248 /* The controller handles the inverted chip selects
249 * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert
250 * the inversion from the core spi_set_cs function.
251 */
252 if (spi->mode & SPI_CS_HIGH)
253 enable = !enable;
254
255 if (spi->controller_state) {
256 int err = pm_runtime_get_sync(mcspi->dev);
257 if (err < 0) {
258 dev_err(mcspi->dev, "failed to get sync: %d\n", err);
259 return;
260 }
261
262 l = mcspi_cached_chconf0(spi);
263
264 if (enable)
265 l &= ~OMAP2_MCSPI_CHCONF_FORCE;
266 else
267 l |= OMAP2_MCSPI_CHCONF_FORCE;
268
269 mcspi_write_chconf0(spi, l);
270
271 pm_runtime_mark_last_busy(mcspi->dev);
272 pm_runtime_put_autosuspend(mcspi->dev);
273 }
274 }
275
276 static void omap2_mcspi_set_master_mode(struct spi_master *master)
277 {
278 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
279 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
280 u32 l;
281
282 /*
283 * Setup when switching from (reset default) slave mode
284 * to single-channel master mode
285 */
286 l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
287 l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS);
288 l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
289 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
290
291 ctx->modulctrl = l;
292 }
293
294 static void omap2_mcspi_set_fifo(const struct spi_device *spi,
295 struct spi_transfer *t, int enable)
296 {
297 struct spi_master *master = spi->master;
298 struct omap2_mcspi_cs *cs = spi->controller_state;
299 struct omap2_mcspi *mcspi;
300 unsigned int wcnt;
301 int max_fifo_depth, fifo_depth, bytes_per_word;
302 u32 chconf, xferlevel;
303
304 mcspi = spi_master_get_devdata(master);
305
306 chconf = mcspi_cached_chconf0(spi);
307 if (enable) {
308 bytes_per_word = mcspi_bytes_per_word(cs->word_len);
309 if (t->len % bytes_per_word != 0)
310 goto disable_fifo;
311
312 if (t->rx_buf != NULL && t->tx_buf != NULL)
313 max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
314 else
315 max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
316
317 fifo_depth = gcd(t->len, max_fifo_depth);
318 if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0)
319 goto disable_fifo;
320
321 wcnt = t->len / bytes_per_word;
322 if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
323 goto disable_fifo;
324
325 xferlevel = wcnt << 16;
326 if (t->rx_buf != NULL) {
327 chconf |= OMAP2_MCSPI_CHCONF_FFER;
328 xferlevel |= (fifo_depth - 1) << 8;
329 }
330 if (t->tx_buf != NULL) {
331 chconf |= OMAP2_MCSPI_CHCONF_FFET;
332 xferlevel |= fifo_depth - 1;
333 }
334
335 mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
336 mcspi_write_chconf0(spi, chconf);
337 mcspi->fifo_depth = fifo_depth;
338
339 return;
340 }
341
342 disable_fifo:
343 if (t->rx_buf != NULL)
344 chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
345
346 if (t->tx_buf != NULL)
347 chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
348
349 mcspi_write_chconf0(spi, chconf);
350 mcspi->fifo_depth = 0;
351 }
352
353 static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
354 {
355 struct spi_master *spi_cntrl = mcspi->master;
356 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
357 struct omap2_mcspi_cs *cs;
358
359 /* McSPI: context restore */
360 mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
361 mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
362
363 list_for_each_entry(cs, &ctx->cs, node)
364 writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
365 }
366
367 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
368 {
369 unsigned long timeout;
370
371 timeout = jiffies + msecs_to_jiffies(1000);
372 while (!(readl_relaxed(reg) & bit)) {
373 if (time_after(jiffies, timeout)) {
374 if (!(readl_relaxed(reg) & bit))
375 return -ETIMEDOUT;
376 else
377 return 0;
378 }
379 cpu_relax();
380 }
381 return 0;
382 }
383
384 static void omap2_mcspi_rx_callback(void *data)
385 {
386 struct spi_device *spi = data;
387 struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
388 struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
389
390 /* We must disable the DMA RX request */
391 omap2_mcspi_set_dma_req(spi, 1, 0);
392
393 complete(&mcspi_dma->dma_rx_completion);
394 }
395
396 static void omap2_mcspi_tx_callback(void *data)
397 {
398 struct spi_device *spi = data;
399 struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
400 struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
401
402 /* We must disable the DMA TX request */
403 omap2_mcspi_set_dma_req(spi, 0, 0);
404
405 complete(&mcspi_dma->dma_tx_completion);
406 }
407
408 static void omap2_mcspi_tx_dma(struct spi_device *spi,
409 struct spi_transfer *xfer,
410 struct dma_slave_config cfg)
411 {
412 struct omap2_mcspi *mcspi;
413 struct omap2_mcspi_dma *mcspi_dma;
414 unsigned int count;
415
416 mcspi = spi_master_get_devdata(spi->master);
417 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
418 count = xfer->len;
419
420 if (mcspi_dma->dma_tx) {
421 struct dma_async_tx_descriptor *tx;
422
423 dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
424
425 tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl,
426 xfer->tx_sg.nents,
427 DMA_MEM_TO_DEV,
428 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
429 if (tx) {
430 tx->callback = omap2_mcspi_tx_callback;
431 tx->callback_param = spi;
432 dmaengine_submit(tx);
433 } else {
434 /* FIXME: fall back to PIO? */
435 }
436 }
437 dma_async_issue_pending(mcspi_dma->dma_tx);
438 omap2_mcspi_set_dma_req(spi, 0, 1);
439
440 }
441
442 static unsigned
443 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
444 struct dma_slave_config cfg,
445 unsigned es)
446 {
447 struct omap2_mcspi *mcspi;
448 struct omap2_mcspi_dma *mcspi_dma;
449 unsigned int count, transfer_reduction = 0;
450 struct scatterlist *sg_out[2];
451 int nb_sizes = 0, out_mapped_nents[2], ret, x;
452 size_t sizes[2];
453 u32 l;
454 int elements = 0;
455 int word_len, element_count;
456 struct omap2_mcspi_cs *cs = spi->controller_state;
457 void __iomem *chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
458
459 mcspi = spi_master_get_devdata(spi->master);
460 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
461 count = xfer->len;
462
463 /*
464 * In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM
465 * it mentions reducing DMA transfer length by one element in master
466 * normal mode.
467 */
468 if (mcspi->fifo_depth == 0)
469 transfer_reduction = es;
470
471 word_len = cs->word_len;
472 l = mcspi_cached_chconf0(spi);
473
474 if (word_len <= 8)
475 element_count = count;
476 else if (word_len <= 16)
477 element_count = count >> 1;
478 else /* word_len <= 32 */
479 element_count = count >> 2;
480
481 if (mcspi_dma->dma_rx) {
482 struct dma_async_tx_descriptor *tx;
483
484 dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
485
486 /*
487 * Reduce DMA transfer length by one more if McSPI is
488 * configured in turbo mode.
489 */
490 if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
491 transfer_reduction += es;
492
493 if (transfer_reduction) {
494 /* Split sgl into two. The second sgl won't be used. */
495 sizes[0] = count - transfer_reduction;
496 sizes[1] = transfer_reduction;
497 nb_sizes = 2;
498 } else {
499 /*
500 * Don't bother splitting the sgl. This essentially
501 * clones the original sgl.
502 */
503 sizes[0] = count;
504 nb_sizes = 1;
505 }
506
507 ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents,
508 0, nb_sizes,
509 sizes,
510 sg_out, out_mapped_nents,
511 GFP_KERNEL);
512
513 if (ret < 0) {
514 dev_err(&spi->dev, "sg_split failed\n");
515 return 0;
516 }
517
518 tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx,
519 sg_out[0],
520 out_mapped_nents[0],
521 DMA_DEV_TO_MEM,
522 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
523 if (tx) {
524 tx->callback = omap2_mcspi_rx_callback;
525 tx->callback_param = spi;
526 dmaengine_submit(tx);
527 } else {
528 /* FIXME: fall back to PIO? */
529 }
530 }
531
532 dma_async_issue_pending(mcspi_dma->dma_rx);
533 omap2_mcspi_set_dma_req(spi, 1, 1);
534
535 wait_for_completion(&mcspi_dma->dma_rx_completion);
536
537 for (x = 0; x < nb_sizes; x++)
538 kfree(sg_out[x]);
539
540 if (mcspi->fifo_depth > 0)
541 return count;
542
543 /*
544 * Due to the DMA transfer length reduction the missing bytes must
545 * be read manually to receive all of the expected data.
546 */
547 omap2_mcspi_set_enable(spi, 0);
548
549 elements = element_count - 1;
550
551 if (l & OMAP2_MCSPI_CHCONF_TURBO) {
552 elements--;
553
554 if (!mcspi_wait_for_reg_bit(chstat_reg,
555 OMAP2_MCSPI_CHSTAT_RXS)) {
556 u32 w;
557
558 w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
559 if (word_len <= 8)
560 ((u8 *)xfer->rx_buf)[elements++] = w;
561 else if (word_len <= 16)
562 ((u16 *)xfer->rx_buf)[elements++] = w;
563 else /* word_len <= 32 */
564 ((u32 *)xfer->rx_buf)[elements++] = w;
565 } else {
566 int bytes_per_word = mcspi_bytes_per_word(word_len);
567 dev_err(&spi->dev, "DMA RX penultimate word empty\n");
568 count -= (bytes_per_word << 1);
569 omap2_mcspi_set_enable(spi, 1);
570 return count;
571 }
572 }
573 if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) {
574 u32 w;
575
576 w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
577 if (word_len <= 8)
578 ((u8 *)xfer->rx_buf)[elements] = w;
579 else if (word_len <= 16)
580 ((u16 *)xfer->rx_buf)[elements] = w;
581 else /* word_len <= 32 */
582 ((u32 *)xfer->rx_buf)[elements] = w;
583 } else {
584 dev_err(&spi->dev, "DMA RX last word empty\n");
585 count -= mcspi_bytes_per_word(word_len);
586 }
587 omap2_mcspi_set_enable(spi, 1);
588 return count;
589 }
590
591 static unsigned
592 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
593 {
594 struct omap2_mcspi *mcspi;
595 struct omap2_mcspi_cs *cs = spi->controller_state;
596 struct omap2_mcspi_dma *mcspi_dma;
597 unsigned int count;
598 u32 l;
599 u8 *rx;
600 const u8 *tx;
601 struct dma_slave_config cfg;
602 enum dma_slave_buswidth width;
603 unsigned es;
604 u32 burst;
605 void __iomem *chstat_reg;
606 void __iomem *irqstat_reg;
607 int wait_res;
608
609 mcspi = spi_master_get_devdata(spi->master);
610 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
611 l = mcspi_cached_chconf0(spi);
612
613
614 if (cs->word_len <= 8) {
615 width = DMA_SLAVE_BUSWIDTH_1_BYTE;
616 es = 1;
617 } else if (cs->word_len <= 16) {
618 width = DMA_SLAVE_BUSWIDTH_2_BYTES;
619 es = 2;
620 } else {
621 width = DMA_SLAVE_BUSWIDTH_4_BYTES;
622 es = 4;
623 }
624
625 count = xfer->len;
626 burst = 1;
627
628 if (mcspi->fifo_depth > 0) {
629 if (count > mcspi->fifo_depth)
630 burst = mcspi->fifo_depth / es;
631 else
632 burst = count / es;
633 }
634
635 memset(&cfg, 0, sizeof(cfg));
636 cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
637 cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
638 cfg.src_addr_width = width;
639 cfg.dst_addr_width = width;
640 cfg.src_maxburst = burst;
641 cfg.dst_maxburst = burst;
642
643 rx = xfer->rx_buf;
644 tx = xfer->tx_buf;
645
646 if (tx != NULL)
647 omap2_mcspi_tx_dma(spi, xfer, cfg);
648
649 if (rx != NULL)
650 count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
651
652 if (tx != NULL) {
653 wait_for_completion(&mcspi_dma->dma_tx_completion);
654
655 if (mcspi->fifo_depth > 0) {
656 irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
657
658 if (mcspi_wait_for_reg_bit(irqstat_reg,
659 OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
660 dev_err(&spi->dev, "EOW timed out\n");
661
662 mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
663 OMAP2_MCSPI_IRQSTATUS_EOW);
664 }
665
666 /* for TX_ONLY mode, be sure all words have shifted out */
667 if (rx == NULL) {
668 chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
669 if (mcspi->fifo_depth > 0) {
670 wait_res = mcspi_wait_for_reg_bit(chstat_reg,
671 OMAP2_MCSPI_CHSTAT_TXFFE);
672 if (wait_res < 0)
673 dev_err(&spi->dev, "TXFFE timed out\n");
674 } else {
675 wait_res = mcspi_wait_for_reg_bit(chstat_reg,
676 OMAP2_MCSPI_CHSTAT_TXS);
677 if (wait_res < 0)
678 dev_err(&spi->dev, "TXS timed out\n");
679 }
680 if (wait_res >= 0 &&
681 (mcspi_wait_for_reg_bit(chstat_reg,
682 OMAP2_MCSPI_CHSTAT_EOT) < 0))
683 dev_err(&spi->dev, "EOT timed out\n");
684 }
685 }
686 return count;
687 }
688
689 static unsigned
690 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
691 {
692 struct omap2_mcspi *mcspi;
693 struct omap2_mcspi_cs *cs = spi->controller_state;
694 unsigned int count, c;
695 u32 l;
696 void __iomem *base = cs->base;
697 void __iomem *tx_reg;
698 void __iomem *rx_reg;
699 void __iomem *chstat_reg;
700 int word_len;
701
702 mcspi = spi_master_get_devdata(spi->master);
703 count = xfer->len;
704 c = count;
705 word_len = cs->word_len;
706
707 l = mcspi_cached_chconf0(spi);
708
709 /* We store the pre-calculated register addresses on stack to speed
710 * up the transfer loop. */
711 tx_reg = base + OMAP2_MCSPI_TX0;
712 rx_reg = base + OMAP2_MCSPI_RX0;
713 chstat_reg = base + OMAP2_MCSPI_CHSTAT0;
714
715 if (c < (word_len>>3))
716 return 0;
717
718 if (word_len <= 8) {
719 u8 *rx;
720 const u8 *tx;
721
722 rx = xfer->rx_buf;
723 tx = xfer->tx_buf;
724
725 do {
726 c -= 1;
727 if (tx != NULL) {
728 if (mcspi_wait_for_reg_bit(chstat_reg,
729 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
730 dev_err(&spi->dev, "TXS timed out\n");
731 goto out;
732 }
733 dev_vdbg(&spi->dev, "write-%d %02x\n",
734 word_len, *tx);
735 writel_relaxed(*tx++, tx_reg);
736 }
737 if (rx != NULL) {
738 if (mcspi_wait_for_reg_bit(chstat_reg,
739 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
740 dev_err(&spi->dev, "RXS timed out\n");
741 goto out;
742 }
743
744 if (c == 1 && tx == NULL &&
745 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
746 omap2_mcspi_set_enable(spi, 0);
747 *rx++ = readl_relaxed(rx_reg);
748 dev_vdbg(&spi->dev, "read-%d %02x\n",
749 word_len, *(rx - 1));
750 if (mcspi_wait_for_reg_bit(chstat_reg,
751 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
752 dev_err(&spi->dev,
753 "RXS timed out\n");
754 goto out;
755 }
756 c = 0;
757 } else if (c == 0 && tx == NULL) {
758 omap2_mcspi_set_enable(spi, 0);
759 }
760
761 *rx++ = readl_relaxed(rx_reg);
762 dev_vdbg(&spi->dev, "read-%d %02x\n",
763 word_len, *(rx - 1));
764 }
765 } while (c);
766 } else if (word_len <= 16) {
767 u16 *rx;
768 const u16 *tx;
769
770 rx = xfer->rx_buf;
771 tx = xfer->tx_buf;
772 do {
773 c -= 2;
774 if (tx != NULL) {
775 if (mcspi_wait_for_reg_bit(chstat_reg,
776 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
777 dev_err(&spi->dev, "TXS timed out\n");
778 goto out;
779 }
780 dev_vdbg(&spi->dev, "write-%d %04x\n",
781 word_len, *tx);
782 writel_relaxed(*tx++, tx_reg);
783 }
784 if (rx != NULL) {
785 if (mcspi_wait_for_reg_bit(chstat_reg,
786 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
787 dev_err(&spi->dev, "RXS timed out\n");
788 goto out;
789 }
790
791 if (c == 2 && tx == NULL &&
792 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
793 omap2_mcspi_set_enable(spi, 0);
794 *rx++ = readl_relaxed(rx_reg);
795 dev_vdbg(&spi->dev, "read-%d %04x\n",
796 word_len, *(rx - 1));
797 if (mcspi_wait_for_reg_bit(chstat_reg,
798 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
799 dev_err(&spi->dev,
800 "RXS timed out\n");
801 goto out;
802 }
803 c = 0;
804 } else if (c == 0 && tx == NULL) {
805 omap2_mcspi_set_enable(spi, 0);
806 }
807
808 *rx++ = readl_relaxed(rx_reg);
809 dev_vdbg(&spi->dev, "read-%d %04x\n",
810 word_len, *(rx - 1));
811 }
812 } while (c >= 2);
813 } else if (word_len <= 32) {
814 u32 *rx;
815 const u32 *tx;
816
817 rx = xfer->rx_buf;
818 tx = xfer->tx_buf;
819 do {
820 c -= 4;
821 if (tx != NULL) {
822 if (mcspi_wait_for_reg_bit(chstat_reg,
823 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
824 dev_err(&spi->dev, "TXS timed out\n");
825 goto out;
826 }
827 dev_vdbg(&spi->dev, "write-%d %08x\n",
828 word_len, *tx);
829 writel_relaxed(*tx++, tx_reg);
830 }
831 if (rx != NULL) {
832 if (mcspi_wait_for_reg_bit(chstat_reg,
833 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
834 dev_err(&spi->dev, "RXS timed out\n");
835 goto out;
836 }
837
838 if (c == 4 && tx == NULL &&
839 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
840 omap2_mcspi_set_enable(spi, 0);
841 *rx++ = readl_relaxed(rx_reg);
842 dev_vdbg(&spi->dev, "read-%d %08x\n",
843 word_len, *(rx - 1));
844 if (mcspi_wait_for_reg_bit(chstat_reg,
845 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
846 dev_err(&spi->dev,
847 "RXS timed out\n");
848 goto out;
849 }
850 c = 0;
851 } else if (c == 0 && tx == NULL) {
852 omap2_mcspi_set_enable(spi, 0);
853 }
854
855 *rx++ = readl_relaxed(rx_reg);
856 dev_vdbg(&spi->dev, "read-%d %08x\n",
857 word_len, *(rx - 1));
858 }
859 } while (c >= 4);
860 }
861
862 /* for TX_ONLY mode, be sure all words have shifted out */
863 if (xfer->rx_buf == NULL) {
864 if (mcspi_wait_for_reg_bit(chstat_reg,
865 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
866 dev_err(&spi->dev, "TXS timed out\n");
867 } else if (mcspi_wait_for_reg_bit(chstat_reg,
868 OMAP2_MCSPI_CHSTAT_EOT) < 0)
869 dev_err(&spi->dev, "EOT timed out\n");
870
871 /* disable chan to purge rx datas received in TX_ONLY transfer,
872 * otherwise these rx datas will affect the direct following
873 * RX_ONLY transfer.
874 */
875 omap2_mcspi_set_enable(spi, 0);
876 }
877 out:
878 omap2_mcspi_set_enable(spi, 1);
879 return count - c;
880 }
881
882 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
883 {
884 u32 div;
885
886 for (div = 0; div < 15; div++)
887 if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
888 return div;
889
890 return 15;
891 }
892
893 /* called only when no transfer is active to this device */
894 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
895 struct spi_transfer *t)
896 {
897 struct omap2_mcspi_cs *cs = spi->controller_state;
898 struct omap2_mcspi *mcspi;
899 struct spi_master *spi_cntrl;
900 u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
901 u8 word_len = spi->bits_per_word;
902 u32 speed_hz = spi->max_speed_hz;
903
904 mcspi = spi_master_get_devdata(spi->master);
905 spi_cntrl = mcspi->master;
906
907 if (t != NULL && t->bits_per_word)
908 word_len = t->bits_per_word;
909
910 cs->word_len = word_len;
911
912 if (t && t->speed_hz)
913 speed_hz = t->speed_hz;
914
915 speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
916 if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
917 clkd = omap2_mcspi_calc_divisor(speed_hz);
918 speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
919 clkg = 0;
920 } else {
921 div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
922 speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
923 clkd = (div - 1) & 0xf;
924 extclk = (div - 1) >> 4;
925 clkg = OMAP2_MCSPI_CHCONF_CLKG;
926 }
927
928 l = mcspi_cached_chconf0(spi);
929
930 /* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS
931 * REVISIT: this controller could support SPI_3WIRE mode.
932 */
933 if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
934 l &= ~OMAP2_MCSPI_CHCONF_IS;
935 l &= ~OMAP2_MCSPI_CHCONF_DPE1;
936 l |= OMAP2_MCSPI_CHCONF_DPE0;
937 } else {
938 l |= OMAP2_MCSPI_CHCONF_IS;
939 l |= OMAP2_MCSPI_CHCONF_DPE1;
940 l &= ~OMAP2_MCSPI_CHCONF_DPE0;
941 }
942
943 /* wordlength */
944 l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
945 l |= (word_len - 1) << 7;
946
947 /* set chipselect polarity; manage with FORCE */
948 if (!(spi->mode & SPI_CS_HIGH))
949 l |= OMAP2_MCSPI_CHCONF_EPOL; /* active-low; normal */
950 else
951 l &= ~OMAP2_MCSPI_CHCONF_EPOL;
952
953 /* set clock divisor */
954 l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
955 l |= clkd << 2;
956
957 /* set clock granularity */
958 l &= ~OMAP2_MCSPI_CHCONF_CLKG;
959 l |= clkg;
960 if (clkg) {
961 cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
962 cs->chctrl0 |= extclk << 8;
963 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
964 }
965
966 /* set SPI mode 0..3 */
967 if (spi->mode & SPI_CPOL)
968 l |= OMAP2_MCSPI_CHCONF_POL;
969 else
970 l &= ~OMAP2_MCSPI_CHCONF_POL;
971 if (spi->mode & SPI_CPHA)
972 l |= OMAP2_MCSPI_CHCONF_PHA;
973 else
974 l &= ~OMAP2_MCSPI_CHCONF_PHA;
975
976 mcspi_write_chconf0(spi, l);
977
978 cs->mode = spi->mode;
979
980 dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
981 speed_hz,
982 (spi->mode & SPI_CPHA) ? "trailing" : "leading",
983 (spi->mode & SPI_CPOL) ? "inverted" : "normal");
984
985 return 0;
986 }
987
988 /*
989 * Note that we currently allow DMA only if we get a channel
990 * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
991 */
992 static int omap2_mcspi_request_dma(struct spi_device *spi)
993 {
994 struct spi_master *master = spi->master;
995 struct omap2_mcspi *mcspi;
996 struct omap2_mcspi_dma *mcspi_dma;
997 int ret = 0;
998
999 mcspi = spi_master_get_devdata(master);
1000 mcspi_dma = mcspi->dma_channels + spi->chip_select;
1001
1002 init_completion(&mcspi_dma->dma_rx_completion);
1003 init_completion(&mcspi_dma->dma_tx_completion);
1004
1005 mcspi_dma->dma_rx = dma_request_chan(&master->dev,
1006 mcspi_dma->dma_rx_ch_name);
1007 if (IS_ERR(mcspi_dma->dma_rx)) {
1008 ret = PTR_ERR(mcspi_dma->dma_rx);
1009 mcspi_dma->dma_rx = NULL;
1010 goto no_dma;
1011 }
1012
1013 mcspi_dma->dma_tx = dma_request_chan(&master->dev,
1014 mcspi_dma->dma_tx_ch_name);
1015 if (IS_ERR(mcspi_dma->dma_tx)) {
1016 ret = PTR_ERR(mcspi_dma->dma_tx);
1017 mcspi_dma->dma_tx = NULL;
1018 dma_release_channel(mcspi_dma->dma_rx);
1019 mcspi_dma->dma_rx = NULL;
1020 }
1021
1022 no_dma:
1023 return ret;
1024 }
1025
1026 static int omap2_mcspi_setup(struct spi_device *spi)
1027 {
1028 int ret;
1029 struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
1030 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1031 struct omap2_mcspi_dma *mcspi_dma;
1032 struct omap2_mcspi_cs *cs = spi->controller_state;
1033
1034 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1035
1036 if (!cs) {
1037 cs = kzalloc(sizeof *cs, GFP_KERNEL);
1038 if (!cs)
1039 return -ENOMEM;
1040 cs->base = mcspi->base + spi->chip_select * 0x14;
1041 cs->phys = mcspi->phys + spi->chip_select * 0x14;
1042 cs->mode = 0;
1043 cs->chconf0 = 0;
1044 cs->chctrl0 = 0;
1045 spi->controller_state = cs;
1046 /* Link this to context save list */
1047 list_add_tail(&cs->node, &ctx->cs);
1048
1049 if (gpio_is_valid(spi->cs_gpio)) {
1050 ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
1051 if (ret) {
1052 dev_err(&spi->dev, "failed to request gpio\n");
1053 return ret;
1054 }
1055 gpio_direction_output(spi->cs_gpio,
1056 !(spi->mode & SPI_CS_HIGH));
1057 }
1058 }
1059
1060 if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
1061 ret = omap2_mcspi_request_dma(spi);
1062 if (ret)
1063 dev_warn(&spi->dev, "not using DMA for McSPI (%d)\n",
1064 ret);
1065 }
1066
1067 ret = pm_runtime_get_sync(mcspi->dev);
1068 if (ret < 0)
1069 return ret;
1070
1071 ret = omap2_mcspi_setup_transfer(spi, NULL);
1072 pm_runtime_mark_last_busy(mcspi->dev);
1073 pm_runtime_put_autosuspend(mcspi->dev);
1074
1075 return ret;
1076 }
1077
1078 static void omap2_mcspi_cleanup(struct spi_device *spi)
1079 {
1080 struct omap2_mcspi *mcspi;
1081 struct omap2_mcspi_dma *mcspi_dma;
1082 struct omap2_mcspi_cs *cs;
1083
1084 mcspi = spi_master_get_devdata(spi->master);
1085
1086 if (spi->controller_state) {
1087 /* Unlink controller state from context save list */
1088 cs = spi->controller_state;
1089 list_del(&cs->node);
1090
1091 kfree(cs);
1092 }
1093
1094 if (spi->chip_select < spi->master->num_chipselect) {
1095 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1096
1097 if (mcspi_dma->dma_rx) {
1098 dma_release_channel(mcspi_dma->dma_rx);
1099 mcspi_dma->dma_rx = NULL;
1100 }
1101 if (mcspi_dma->dma_tx) {
1102 dma_release_channel(mcspi_dma->dma_tx);
1103 mcspi_dma->dma_tx = NULL;
1104 }
1105 }
1106
1107 if (gpio_is_valid(spi->cs_gpio))
1108 gpio_free(spi->cs_gpio);
1109 }
1110
1111 static int omap2_mcspi_transfer_one(struct spi_master *master,
1112 struct spi_device *spi,
1113 struct spi_transfer *t)
1114 {
1115
1116 /* We only enable one channel at a time -- the one whose message is
1117 * -- although this controller would gladly
1118 * arbitrate among multiple channels. This corresponds to "single
1119 * channel" master mode. As a side effect, we need to manage the
1120 * chipselect with the FORCE bit ... CS != channel enable.
1121 */
1122
1123 struct omap2_mcspi *mcspi;
1124 struct omap2_mcspi_dma *mcspi_dma;
1125 struct omap2_mcspi_cs *cs;
1126 struct omap2_mcspi_device_config *cd;
1127 int par_override = 0;
1128 int status = 0;
1129 u32 chconf;
1130
1131 mcspi = spi_master_get_devdata(master);
1132 mcspi_dma = mcspi->dma_channels + spi->chip_select;
1133 cs = spi->controller_state;
1134 cd = spi->controller_data;
1135
1136 /*
1137 * The slave driver could have changed spi->mode in which case
1138 * it will be different from cs->mode (the current hardware setup).
1139 * If so, set par_override (even though its not a parity issue) so
1140 * omap2_mcspi_setup_transfer will be called to configure the hardware
1141 * with the correct mode on the first iteration of the loop below.
1142 */
1143 if (spi->mode != cs->mode)
1144 par_override = 1;
1145
1146 omap2_mcspi_set_enable(spi, 0);
1147
1148 if (gpio_is_valid(spi->cs_gpio))
1149 omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH);
1150
1151 if (par_override ||
1152 (t->speed_hz != spi->max_speed_hz) ||
1153 (t->bits_per_word != spi->bits_per_word)) {
1154 par_override = 1;
1155 status = omap2_mcspi_setup_transfer(spi, t);
1156 if (status < 0)
1157 goto out;
1158 if (t->speed_hz == spi->max_speed_hz &&
1159 t->bits_per_word == spi->bits_per_word)
1160 par_override = 0;
1161 }
1162 if (cd && cd->cs_per_word) {
1163 chconf = mcspi->ctx.modulctrl;
1164 chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1165 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1166 mcspi->ctx.modulctrl =
1167 mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1168 }
1169
1170 chconf = mcspi_cached_chconf0(spi);
1171 chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1172 chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1173
1174 if (t->tx_buf == NULL)
1175 chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1176 else if (t->rx_buf == NULL)
1177 chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1178
1179 if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1180 /* Turbo mode is for more than one word */
1181 if (t->len > ((cs->word_len + 7) >> 3))
1182 chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1183 }
1184
1185 mcspi_write_chconf0(spi, chconf);
1186
1187 if (t->len) {
1188 unsigned count;
1189
1190 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1191 master->cur_msg_mapped &&
1192 master->can_dma(master, spi, t))
1193 omap2_mcspi_set_fifo(spi, t, 1);
1194
1195 omap2_mcspi_set_enable(spi, 1);
1196
1197 /* RX_ONLY mode needs dummy data in TX reg */
1198 if (t->tx_buf == NULL)
1199 writel_relaxed(0, cs->base
1200 + OMAP2_MCSPI_TX0);
1201
1202 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1203 master->cur_msg_mapped &&
1204 master->can_dma(master, spi, t))
1205 count = omap2_mcspi_txrx_dma(spi, t);
1206 else
1207 count = omap2_mcspi_txrx_pio(spi, t);
1208
1209 if (count != t->len) {
1210 status = -EIO;
1211 goto out;
1212 }
1213 }
1214
1215 omap2_mcspi_set_enable(spi, 0);
1216
1217 if (mcspi->fifo_depth > 0)
1218 omap2_mcspi_set_fifo(spi, t, 0);
1219
1220 out:
1221 /* Restore defaults if they were overriden */
1222 if (par_override) {
1223 par_override = 0;
1224 status = omap2_mcspi_setup_transfer(spi, NULL);
1225 }
1226
1227 if (cd && cd->cs_per_word) {
1228 chconf = mcspi->ctx.modulctrl;
1229 chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1230 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1231 mcspi->ctx.modulctrl =
1232 mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1233 }
1234
1235 omap2_mcspi_set_enable(spi, 0);
1236
1237 if (gpio_is_valid(spi->cs_gpio))
1238 omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH));
1239
1240 if (mcspi->fifo_depth > 0 && t)
1241 omap2_mcspi_set_fifo(spi, t, 0);
1242
1243 return status;
1244 }
1245
1246 static int omap2_mcspi_prepare_message(struct spi_master *master,
1247 struct spi_message *msg)
1248 {
1249 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1250 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1251 struct omap2_mcspi_cs *cs;
1252
1253 /* Only a single channel can have the FORCE bit enabled
1254 * in its chconf0 register.
1255 * Scan all channels and disable them except the current one.
1256 * A FORCE can remain from a last transfer having cs_change enabled
1257 */
1258 list_for_each_entry(cs, &ctx->cs, node) {
1259 if (msg->spi->controller_state == cs)
1260 continue;
1261
1262 if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
1263 cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1264 writel_relaxed(cs->chconf0,
1265 cs->base + OMAP2_MCSPI_CHCONF0);
1266 readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
1267 }
1268 }
1269
1270 return 0;
1271 }
1272
1273 static bool omap2_mcspi_can_dma(struct spi_master *master,
1274 struct spi_device *spi,
1275 struct spi_transfer *xfer)
1276 {
1277 return (xfer->len >= DMA_MIN_BYTES);
1278 }
1279
1280 static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
1281 {
1282 struct spi_master *master = mcspi->master;
1283 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1284 int ret = 0;
1285
1286 ret = pm_runtime_get_sync(mcspi->dev);
1287 if (ret < 0)
1288 return ret;
1289
1290 mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1291 OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1292 ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1293
1294 omap2_mcspi_set_master_mode(master);
1295 pm_runtime_mark_last_busy(mcspi->dev);
1296 pm_runtime_put_autosuspend(mcspi->dev);
1297 return 0;
1298 }
1299
1300 static int omap_mcspi_runtime_resume(struct device *dev)
1301 {
1302 struct omap2_mcspi *mcspi;
1303 struct spi_master *master;
1304
1305 master = dev_get_drvdata(dev);
1306 mcspi = spi_master_get_devdata(master);
1307 omap2_mcspi_restore_ctx(mcspi);
1308
1309 return 0;
1310 }
1311
1312 static struct omap2_mcspi_platform_config omap2_pdata = {
1313 .regs_offset = 0,
1314 };
1315
1316 static struct omap2_mcspi_platform_config omap4_pdata = {
1317 .regs_offset = OMAP4_MCSPI_REG_OFFSET,
1318 };
1319
1320 static const struct of_device_id omap_mcspi_of_match[] = {
1321 {
1322 .compatible = "ti,omap2-mcspi",
1323 .data = &omap2_pdata,
1324 },
1325 {
1326 .compatible = "ti,omap4-mcspi",
1327 .data = &omap4_pdata,
1328 },
1329 { },
1330 };
1331 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1332
1333 static int omap2_mcspi_probe(struct platform_device *pdev)
1334 {
1335 struct spi_master *master;
1336 const struct omap2_mcspi_platform_config *pdata;
1337 struct omap2_mcspi *mcspi;
1338 struct resource *r;
1339 int status = 0, i;
1340 u32 regs_offset = 0;
1341 static int bus_num = 1;
1342 struct device_node *node = pdev->dev.of_node;
1343 const struct of_device_id *match;
1344
1345 master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1346 if (master == NULL) {
1347 dev_dbg(&pdev->dev, "master allocation failed\n");
1348 return -ENOMEM;
1349 }
1350
1351 /* the spi->mode bits understood by this driver: */
1352 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1353 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1354 master->setup = omap2_mcspi_setup;
1355 master->auto_runtime_pm = true;
1356 master->prepare_message = omap2_mcspi_prepare_message;
1357 master->can_dma = omap2_mcspi_can_dma;
1358 master->transfer_one = omap2_mcspi_transfer_one;
1359 master->set_cs = omap2_mcspi_set_cs;
1360 master->cleanup = omap2_mcspi_cleanup;
1361 master->dev.of_node = node;
1362 master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1363 master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1364
1365 platform_set_drvdata(pdev, master);
1366
1367 mcspi = spi_master_get_devdata(master);
1368 mcspi->master = master;
1369
1370 match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1371 if (match) {
1372 u32 num_cs = 1; /* default number of chipselect */
1373 pdata = match->data;
1374
1375 of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1376 master->num_chipselect = num_cs;
1377 master->bus_num = bus_num++;
1378 if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1379 mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1380 } else {
1381 pdata = dev_get_platdata(&pdev->dev);
1382 master->num_chipselect = pdata->num_cs;
1383 if (pdev->id != -1)
1384 master->bus_num = pdev->id;
1385 mcspi->pin_dir = pdata->pin_dir;
1386 }
1387 regs_offset = pdata->regs_offset;
1388
1389 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1390 mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1391 if (IS_ERR(mcspi->base)) {
1392 status = PTR_ERR(mcspi->base);
1393 goto free_master;
1394 }
1395 mcspi->phys = r->start + regs_offset;
1396 mcspi->base += regs_offset;
1397
1398 mcspi->dev = &pdev->dev;
1399
1400 INIT_LIST_HEAD(&mcspi->ctx.cs);
1401
1402 mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1403 sizeof(struct omap2_mcspi_dma),
1404 GFP_KERNEL);
1405 if (mcspi->dma_channels == NULL) {
1406 status = -ENOMEM;
1407 goto free_master;
1408 }
1409
1410 for (i = 0; i < master->num_chipselect; i++) {
1411 sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
1412 sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
1413 }
1414
1415 pm_runtime_use_autosuspend(&pdev->dev);
1416 pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1417 pm_runtime_enable(&pdev->dev);
1418
1419 status = omap2_mcspi_master_setup(mcspi);
1420 if (status < 0)
1421 goto disable_pm;
1422
1423 status = devm_spi_register_master(&pdev->dev, master);
1424 if (status < 0)
1425 goto disable_pm;
1426
1427 return status;
1428
1429 disable_pm:
1430 pm_runtime_dont_use_autosuspend(&pdev->dev);
1431 pm_runtime_put_sync(&pdev->dev);
1432 pm_runtime_disable(&pdev->dev);
1433 free_master:
1434 spi_master_put(master);
1435 return status;
1436 }
1437
1438 static int omap2_mcspi_remove(struct platform_device *pdev)
1439 {
1440 struct spi_master *master = platform_get_drvdata(pdev);
1441 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1442
1443 pm_runtime_dont_use_autosuspend(mcspi->dev);
1444 pm_runtime_put_sync(mcspi->dev);
1445 pm_runtime_disable(&pdev->dev);
1446
1447 return 0;
1448 }
1449
1450 /* work with hotplug and coldplug */
1451 MODULE_ALIAS("platform:omap2_mcspi");
1452
1453 #ifdef CONFIG_SUSPEND
1454 /*
1455 * When SPI wake up from off-mode, CS is in activate state. If it was in
1456 * unactive state when driver was suspend, then force it to unactive state at
1457 * wake up.
1458 */
1459 static int omap2_mcspi_resume(struct device *dev)
1460 {
1461 struct spi_master *master = dev_get_drvdata(dev);
1462 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1463 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1464 struct omap2_mcspi_cs *cs;
1465
1466 pm_runtime_get_sync(mcspi->dev);
1467 list_for_each_entry(cs, &ctx->cs, node) {
1468 if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1469 /*
1470 * We need to toggle CS state for OMAP take this
1471 * change in account.
1472 */
1473 cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1474 writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1475 cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1476 writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1477 }
1478 }
1479 pm_runtime_mark_last_busy(mcspi->dev);
1480 pm_runtime_put_autosuspend(mcspi->dev);
1481
1482 return pinctrl_pm_select_default_state(dev);
1483 }
1484
1485 static int omap2_mcspi_suspend(struct device *dev)
1486 {
1487 return pinctrl_pm_select_sleep_state(dev);
1488 }
1489
1490 #else
1491 #define omap2_mcspi_suspend NULL
1492 #define omap2_mcspi_resume NULL
1493 #endif
1494
1495 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1496 .resume = omap2_mcspi_resume,
1497 .suspend = omap2_mcspi_suspend,
1498 .runtime_resume = omap_mcspi_runtime_resume,
1499 };
1500
1501 static struct platform_driver omap2_mcspi_driver = {
1502 .driver = {
1503 .name = "omap2_mcspi",
1504 .pm = &omap2_mcspi_pm_ops,
1505 .of_match_table = omap_mcspi_of_match,
1506 },
1507 .probe = omap2_mcspi_probe,
1508 .remove = omap2_mcspi_remove,
1509 };
1510
1511 module_platform_driver(omap2_mcspi_driver);
1512 MODULE_LICENSE("GPL");
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