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[deliverable/linux.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 mcspi = spi_master_get_devdata(spi->master);
458 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
459 count = xfer->len;
460
461 /*
462 * In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM
463 * it mentions reducing DMA transfer length by one element in master
464 * normal mode.
465 */
466 if (mcspi->fifo_depth == 0)
467 transfer_reduction = es;
468
469 word_len = cs->word_len;
470 l = mcspi_cached_chconf0(spi);
471
472 if (word_len <= 8)
473 element_count = count;
474 else if (word_len <= 16)
475 element_count = count >> 1;
476 else /* word_len <= 32 */
477 element_count = count >> 2;
478
479 if (mcspi_dma->dma_rx) {
480 struct dma_async_tx_descriptor *tx;
481
482 dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
483
484 /*
485 * Reduce DMA transfer length by one more if McSPI is
486 * configured in turbo mode.
487 */
488 if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
489 transfer_reduction += es;
490
491 if (transfer_reduction) {
492 /* Split sgl into two. The second sgl won't be used. */
493 sizes[0] = count - transfer_reduction;
494 sizes[1] = transfer_reduction;
495 nb_sizes = 2;
496 } else {
497 /*
498 * Don't bother splitting the sgl. This essentially
499 * clones the original sgl.
500 */
501 sizes[0] = count;
502 nb_sizes = 1;
503 }
504
505 ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents,
506 0, nb_sizes,
507 sizes,
508 sg_out, out_mapped_nents,
509 GFP_KERNEL);
510
511 if (ret < 0) {
512 dev_err(&spi->dev, "sg_split failed\n");
513 return 0;
514 }
515
516 tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx,
517 sg_out[0],
518 out_mapped_nents[0],
519 DMA_DEV_TO_MEM,
520 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
521 if (tx) {
522 tx->callback = omap2_mcspi_rx_callback;
523 tx->callback_param = spi;
524 dmaengine_submit(tx);
525 } else {
526 /* FIXME: fall back to PIO? */
527 }
528 }
529
530 dma_async_issue_pending(mcspi_dma->dma_rx);
531 omap2_mcspi_set_dma_req(spi, 1, 1);
532
533 wait_for_completion(&mcspi_dma->dma_rx_completion);
534
535 for (x = 0; x < nb_sizes; x++)
536 kfree(sg_out[x]);
537
538 if (mcspi->fifo_depth > 0)
539 return count;
540
541 /*
542 * Due to the DMA transfer length reduction the missing bytes must
543 * be read manually to receive all of the expected data.
544 */
545 omap2_mcspi_set_enable(spi, 0);
546
547 elements = element_count - 1;
548
549 if (l & OMAP2_MCSPI_CHCONF_TURBO) {
550 elements--;
551
552 if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
553 & OMAP2_MCSPI_CHSTAT_RXS)) {
554 u32 w;
555
556 w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
557 if (word_len <= 8)
558 ((u8 *)xfer->rx_buf)[elements++] = w;
559 else if (word_len <= 16)
560 ((u16 *)xfer->rx_buf)[elements++] = w;
561 else /* word_len <= 32 */
562 ((u32 *)xfer->rx_buf)[elements++] = w;
563 } else {
564 int bytes_per_word = mcspi_bytes_per_word(word_len);
565 dev_err(&spi->dev, "DMA RX penultimate word empty\n");
566 count -= (bytes_per_word << 1);
567 omap2_mcspi_set_enable(spi, 1);
568 return count;
569 }
570 }
571 if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
572 & OMAP2_MCSPI_CHSTAT_RXS)) {
573 u32 w;
574
575 w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
576 if (word_len <= 8)
577 ((u8 *)xfer->rx_buf)[elements] = w;
578 else if (word_len <= 16)
579 ((u16 *)xfer->rx_buf)[elements] = w;
580 else /* word_len <= 32 */
581 ((u32 *)xfer->rx_buf)[elements] = w;
582 } else {
583 dev_err(&spi->dev, "DMA RX last word empty\n");
584 count -= mcspi_bytes_per_word(word_len);
585 }
586 omap2_mcspi_set_enable(spi, 1);
587 return count;
588 }
589
590 static unsigned
591 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
592 {
593 struct omap2_mcspi *mcspi;
594 struct omap2_mcspi_cs *cs = spi->controller_state;
595 struct omap2_mcspi_dma *mcspi_dma;
596 unsigned int count;
597 u32 l;
598 u8 *rx;
599 const u8 *tx;
600 struct dma_slave_config cfg;
601 enum dma_slave_buswidth width;
602 unsigned es;
603 u32 burst;
604 void __iomem *chstat_reg;
605 void __iomem *irqstat_reg;
606 int wait_res;
607
608 mcspi = spi_master_get_devdata(spi->master);
609 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
610 l = mcspi_cached_chconf0(spi);
611
612
613 if (cs->word_len <= 8) {
614 width = DMA_SLAVE_BUSWIDTH_1_BYTE;
615 es = 1;
616 } else if (cs->word_len <= 16) {
617 width = DMA_SLAVE_BUSWIDTH_2_BYTES;
618 es = 2;
619 } else {
620 width = DMA_SLAVE_BUSWIDTH_4_BYTES;
621 es = 4;
622 }
623
624 count = xfer->len;
625 burst = 1;
626
627 if (mcspi->fifo_depth > 0) {
628 if (count > mcspi->fifo_depth)
629 burst = mcspi->fifo_depth / es;
630 else
631 burst = count / es;
632 }
633
634 memset(&cfg, 0, sizeof(cfg));
635 cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
636 cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
637 cfg.src_addr_width = width;
638 cfg.dst_addr_width = width;
639 cfg.src_maxburst = burst;
640 cfg.dst_maxburst = burst;
641
642 rx = xfer->rx_buf;
643 tx = xfer->tx_buf;
644
645 if (tx != NULL)
646 omap2_mcspi_tx_dma(spi, xfer, cfg);
647
648 if (rx != NULL)
649 count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
650
651 if (tx != NULL) {
652 wait_for_completion(&mcspi_dma->dma_tx_completion);
653
654 if (mcspi->fifo_depth > 0) {
655 irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
656
657 if (mcspi_wait_for_reg_bit(irqstat_reg,
658 OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
659 dev_err(&spi->dev, "EOW timed out\n");
660
661 mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
662 OMAP2_MCSPI_IRQSTATUS_EOW);
663 }
664
665 /* for TX_ONLY mode, be sure all words have shifted out */
666 if (rx == NULL) {
667 chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
668 if (mcspi->fifo_depth > 0) {
669 wait_res = mcspi_wait_for_reg_bit(chstat_reg,
670 OMAP2_MCSPI_CHSTAT_TXFFE);
671 if (wait_res < 0)
672 dev_err(&spi->dev, "TXFFE timed out\n");
673 } else {
674 wait_res = mcspi_wait_for_reg_bit(chstat_reg,
675 OMAP2_MCSPI_CHSTAT_TXS);
676 if (wait_res < 0)
677 dev_err(&spi->dev, "TXS timed out\n");
678 }
679 if (wait_res >= 0 &&
680 (mcspi_wait_for_reg_bit(chstat_reg,
681 OMAP2_MCSPI_CHSTAT_EOT) < 0))
682 dev_err(&spi->dev, "EOT timed out\n");
683 }
684 }
685 return count;
686 }
687
688 static unsigned
689 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
690 {
691 struct omap2_mcspi *mcspi;
692 struct omap2_mcspi_cs *cs = spi->controller_state;
693 unsigned int count, c;
694 u32 l;
695 void __iomem *base = cs->base;
696 void __iomem *tx_reg;
697 void __iomem *rx_reg;
698 void __iomem *chstat_reg;
699 int word_len;
700
701 mcspi = spi_master_get_devdata(spi->master);
702 count = xfer->len;
703 c = count;
704 word_len = cs->word_len;
705
706 l = mcspi_cached_chconf0(spi);
707
708 /* We store the pre-calculated register addresses on stack to speed
709 * up the transfer loop. */
710 tx_reg = base + OMAP2_MCSPI_TX0;
711 rx_reg = base + OMAP2_MCSPI_RX0;
712 chstat_reg = base + OMAP2_MCSPI_CHSTAT0;
713
714 if (c < (word_len>>3))
715 return 0;
716
717 if (word_len <= 8) {
718 u8 *rx;
719 const u8 *tx;
720
721 rx = xfer->rx_buf;
722 tx = xfer->tx_buf;
723
724 do {
725 c -= 1;
726 if (tx != NULL) {
727 if (mcspi_wait_for_reg_bit(chstat_reg,
728 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
729 dev_err(&spi->dev, "TXS timed out\n");
730 goto out;
731 }
732 dev_vdbg(&spi->dev, "write-%d %02x\n",
733 word_len, *tx);
734 writel_relaxed(*tx++, tx_reg);
735 }
736 if (rx != NULL) {
737 if (mcspi_wait_for_reg_bit(chstat_reg,
738 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
739 dev_err(&spi->dev, "RXS timed out\n");
740 goto out;
741 }
742
743 if (c == 1 && tx == NULL &&
744 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
745 omap2_mcspi_set_enable(spi, 0);
746 *rx++ = readl_relaxed(rx_reg);
747 dev_vdbg(&spi->dev, "read-%d %02x\n",
748 word_len, *(rx - 1));
749 if (mcspi_wait_for_reg_bit(chstat_reg,
750 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
751 dev_err(&spi->dev,
752 "RXS timed out\n");
753 goto out;
754 }
755 c = 0;
756 } else if (c == 0 && tx == NULL) {
757 omap2_mcspi_set_enable(spi, 0);
758 }
759
760 *rx++ = readl_relaxed(rx_reg);
761 dev_vdbg(&spi->dev, "read-%d %02x\n",
762 word_len, *(rx - 1));
763 }
764 } while (c);
765 } else if (word_len <= 16) {
766 u16 *rx;
767 const u16 *tx;
768
769 rx = xfer->rx_buf;
770 tx = xfer->tx_buf;
771 do {
772 c -= 2;
773 if (tx != NULL) {
774 if (mcspi_wait_for_reg_bit(chstat_reg,
775 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
776 dev_err(&spi->dev, "TXS timed out\n");
777 goto out;
778 }
779 dev_vdbg(&spi->dev, "write-%d %04x\n",
780 word_len, *tx);
781 writel_relaxed(*tx++, tx_reg);
782 }
783 if (rx != NULL) {
784 if (mcspi_wait_for_reg_bit(chstat_reg,
785 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
786 dev_err(&spi->dev, "RXS timed out\n");
787 goto out;
788 }
789
790 if (c == 2 && tx == NULL &&
791 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
792 omap2_mcspi_set_enable(spi, 0);
793 *rx++ = readl_relaxed(rx_reg);
794 dev_vdbg(&spi->dev, "read-%d %04x\n",
795 word_len, *(rx - 1));
796 if (mcspi_wait_for_reg_bit(chstat_reg,
797 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
798 dev_err(&spi->dev,
799 "RXS timed out\n");
800 goto out;
801 }
802 c = 0;
803 } else if (c == 0 && tx == NULL) {
804 omap2_mcspi_set_enable(spi, 0);
805 }
806
807 *rx++ = readl_relaxed(rx_reg);
808 dev_vdbg(&spi->dev, "read-%d %04x\n",
809 word_len, *(rx - 1));
810 }
811 } while (c >= 2);
812 } else if (word_len <= 32) {
813 u32 *rx;
814 const u32 *tx;
815
816 rx = xfer->rx_buf;
817 tx = xfer->tx_buf;
818 do {
819 c -= 4;
820 if (tx != NULL) {
821 if (mcspi_wait_for_reg_bit(chstat_reg,
822 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
823 dev_err(&spi->dev, "TXS timed out\n");
824 goto out;
825 }
826 dev_vdbg(&spi->dev, "write-%d %08x\n",
827 word_len, *tx);
828 writel_relaxed(*tx++, tx_reg);
829 }
830 if (rx != NULL) {
831 if (mcspi_wait_for_reg_bit(chstat_reg,
832 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
833 dev_err(&spi->dev, "RXS timed out\n");
834 goto out;
835 }
836
837 if (c == 4 && tx == NULL &&
838 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
839 omap2_mcspi_set_enable(spi, 0);
840 *rx++ = readl_relaxed(rx_reg);
841 dev_vdbg(&spi->dev, "read-%d %08x\n",
842 word_len, *(rx - 1));
843 if (mcspi_wait_for_reg_bit(chstat_reg,
844 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
845 dev_err(&spi->dev,
846 "RXS timed out\n");
847 goto out;
848 }
849 c = 0;
850 } else if (c == 0 && tx == NULL) {
851 omap2_mcspi_set_enable(spi, 0);
852 }
853
854 *rx++ = readl_relaxed(rx_reg);
855 dev_vdbg(&spi->dev, "read-%d %08x\n",
856 word_len, *(rx - 1));
857 }
858 } while (c >= 4);
859 }
860
861 /* for TX_ONLY mode, be sure all words have shifted out */
862 if (xfer->rx_buf == NULL) {
863 if (mcspi_wait_for_reg_bit(chstat_reg,
864 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
865 dev_err(&spi->dev, "TXS timed out\n");
866 } else if (mcspi_wait_for_reg_bit(chstat_reg,
867 OMAP2_MCSPI_CHSTAT_EOT) < 0)
868 dev_err(&spi->dev, "EOT timed out\n");
869
870 /* disable chan to purge rx datas received in TX_ONLY transfer,
871 * otherwise these rx datas will affect the direct following
872 * RX_ONLY transfer.
873 */
874 omap2_mcspi_set_enable(spi, 0);
875 }
876 out:
877 omap2_mcspi_set_enable(spi, 1);
878 return count - c;
879 }
880
881 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
882 {
883 u32 div;
884
885 for (div = 0; div < 15; div++)
886 if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
887 return div;
888
889 return 15;
890 }
891
892 /* called only when no transfer is active to this device */
893 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
894 struct spi_transfer *t)
895 {
896 struct omap2_mcspi_cs *cs = spi->controller_state;
897 struct omap2_mcspi *mcspi;
898 struct spi_master *spi_cntrl;
899 u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
900 u8 word_len = spi->bits_per_word;
901 u32 speed_hz = spi->max_speed_hz;
902
903 mcspi = spi_master_get_devdata(spi->master);
904 spi_cntrl = mcspi->master;
905
906 if (t != NULL && t->bits_per_word)
907 word_len = t->bits_per_word;
908
909 cs->word_len = word_len;
910
911 if (t && t->speed_hz)
912 speed_hz = t->speed_hz;
913
914 speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
915 if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
916 clkd = omap2_mcspi_calc_divisor(speed_hz);
917 speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
918 clkg = 0;
919 } else {
920 div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
921 speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
922 clkd = (div - 1) & 0xf;
923 extclk = (div - 1) >> 4;
924 clkg = OMAP2_MCSPI_CHCONF_CLKG;
925 }
926
927 l = mcspi_cached_chconf0(spi);
928
929 /* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS
930 * REVISIT: this controller could support SPI_3WIRE mode.
931 */
932 if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
933 l &= ~OMAP2_MCSPI_CHCONF_IS;
934 l &= ~OMAP2_MCSPI_CHCONF_DPE1;
935 l |= OMAP2_MCSPI_CHCONF_DPE0;
936 } else {
937 l |= OMAP2_MCSPI_CHCONF_IS;
938 l |= OMAP2_MCSPI_CHCONF_DPE1;
939 l &= ~OMAP2_MCSPI_CHCONF_DPE0;
940 }
941
942 /* wordlength */
943 l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
944 l |= (word_len - 1) << 7;
945
946 /* set chipselect polarity; manage with FORCE */
947 if (!(spi->mode & SPI_CS_HIGH))
948 l |= OMAP2_MCSPI_CHCONF_EPOL; /* active-low; normal */
949 else
950 l &= ~OMAP2_MCSPI_CHCONF_EPOL;
951
952 /* set clock divisor */
953 l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
954 l |= clkd << 2;
955
956 /* set clock granularity */
957 l &= ~OMAP2_MCSPI_CHCONF_CLKG;
958 l |= clkg;
959 if (clkg) {
960 cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
961 cs->chctrl0 |= extclk << 8;
962 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
963 }
964
965 /* set SPI mode 0..3 */
966 if (spi->mode & SPI_CPOL)
967 l |= OMAP2_MCSPI_CHCONF_POL;
968 else
969 l &= ~OMAP2_MCSPI_CHCONF_POL;
970 if (spi->mode & SPI_CPHA)
971 l |= OMAP2_MCSPI_CHCONF_PHA;
972 else
973 l &= ~OMAP2_MCSPI_CHCONF_PHA;
974
975 mcspi_write_chconf0(spi, l);
976
977 cs->mode = spi->mode;
978
979 dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
980 speed_hz,
981 (spi->mode & SPI_CPHA) ? "trailing" : "leading",
982 (spi->mode & SPI_CPOL) ? "inverted" : "normal");
983
984 return 0;
985 }
986
987 /*
988 * Note that we currently allow DMA only if we get a channel
989 * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
990 */
991 static int omap2_mcspi_request_dma(struct spi_device *spi)
992 {
993 struct spi_master *master = spi->master;
994 struct omap2_mcspi *mcspi;
995 struct omap2_mcspi_dma *mcspi_dma;
996 int ret = 0;
997
998 mcspi = spi_master_get_devdata(master);
999 mcspi_dma = mcspi->dma_channels + spi->chip_select;
1000
1001 init_completion(&mcspi_dma->dma_rx_completion);
1002 init_completion(&mcspi_dma->dma_tx_completion);
1003
1004 mcspi_dma->dma_rx = dma_request_chan(&master->dev,
1005 mcspi_dma->dma_rx_ch_name);
1006 if (IS_ERR(mcspi_dma->dma_rx)) {
1007 ret = PTR_ERR(mcspi_dma->dma_rx);
1008 mcspi_dma->dma_rx = NULL;
1009 goto no_dma;
1010 }
1011
1012 mcspi_dma->dma_tx = dma_request_chan(&master->dev,
1013 mcspi_dma->dma_tx_ch_name);
1014 if (IS_ERR(mcspi_dma->dma_tx)) {
1015 ret = PTR_ERR(mcspi_dma->dma_tx);
1016 mcspi_dma->dma_tx = NULL;
1017 dma_release_channel(mcspi_dma->dma_rx);
1018 mcspi_dma->dma_rx = NULL;
1019 }
1020
1021 no_dma:
1022 return ret;
1023 }
1024
1025 static int omap2_mcspi_setup(struct spi_device *spi)
1026 {
1027 int ret;
1028 struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
1029 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1030 struct omap2_mcspi_dma *mcspi_dma;
1031 struct omap2_mcspi_cs *cs = spi->controller_state;
1032
1033 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1034
1035 if (!cs) {
1036 cs = kzalloc(sizeof *cs, GFP_KERNEL);
1037 if (!cs)
1038 return -ENOMEM;
1039 cs->base = mcspi->base + spi->chip_select * 0x14;
1040 cs->phys = mcspi->phys + spi->chip_select * 0x14;
1041 cs->mode = 0;
1042 cs->chconf0 = 0;
1043 cs->chctrl0 = 0;
1044 spi->controller_state = cs;
1045 /* Link this to context save list */
1046 list_add_tail(&cs->node, &ctx->cs);
1047
1048 if (gpio_is_valid(spi->cs_gpio)) {
1049 ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
1050 if (ret) {
1051 dev_err(&spi->dev, "failed to request gpio\n");
1052 return ret;
1053 }
1054 gpio_direction_output(spi->cs_gpio,
1055 !(spi->mode & SPI_CS_HIGH));
1056 }
1057 }
1058
1059 if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
1060 ret = omap2_mcspi_request_dma(spi);
1061 if (ret)
1062 dev_warn(&spi->dev, "not using DMA for McSPI (%d)\n",
1063 ret);
1064 }
1065
1066 ret = pm_runtime_get_sync(mcspi->dev);
1067 if (ret < 0)
1068 return ret;
1069
1070 ret = omap2_mcspi_setup_transfer(spi, NULL);
1071 pm_runtime_mark_last_busy(mcspi->dev);
1072 pm_runtime_put_autosuspend(mcspi->dev);
1073
1074 return ret;
1075 }
1076
1077 static void omap2_mcspi_cleanup(struct spi_device *spi)
1078 {
1079 struct omap2_mcspi *mcspi;
1080 struct omap2_mcspi_dma *mcspi_dma;
1081 struct omap2_mcspi_cs *cs;
1082
1083 mcspi = spi_master_get_devdata(spi->master);
1084
1085 if (spi->controller_state) {
1086 /* Unlink controller state from context save list */
1087 cs = spi->controller_state;
1088 list_del(&cs->node);
1089
1090 kfree(cs);
1091 }
1092
1093 if (spi->chip_select < spi->master->num_chipselect) {
1094 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1095
1096 if (mcspi_dma->dma_rx) {
1097 dma_release_channel(mcspi_dma->dma_rx);
1098 mcspi_dma->dma_rx = NULL;
1099 }
1100 if (mcspi_dma->dma_tx) {
1101 dma_release_channel(mcspi_dma->dma_tx);
1102 mcspi_dma->dma_tx = NULL;
1103 }
1104 }
1105
1106 if (gpio_is_valid(spi->cs_gpio))
1107 gpio_free(spi->cs_gpio);
1108 }
1109
1110 static int omap2_mcspi_transfer_one(struct spi_master *master,
1111 struct spi_device *spi,
1112 struct spi_transfer *t)
1113 {
1114
1115 /* We only enable one channel at a time -- the one whose message is
1116 * -- although this controller would gladly
1117 * arbitrate among multiple channels. This corresponds to "single
1118 * channel" master mode. As a side effect, we need to manage the
1119 * chipselect with the FORCE bit ... CS != channel enable.
1120 */
1121
1122 struct omap2_mcspi *mcspi;
1123 struct omap2_mcspi_dma *mcspi_dma;
1124 struct omap2_mcspi_cs *cs;
1125 struct omap2_mcspi_device_config *cd;
1126 int par_override = 0;
1127 int status = 0;
1128 u32 chconf;
1129
1130 mcspi = spi_master_get_devdata(master);
1131 mcspi_dma = mcspi->dma_channels + spi->chip_select;
1132 cs = spi->controller_state;
1133 cd = spi->controller_data;
1134
1135 /*
1136 * The slave driver could have changed spi->mode in which case
1137 * it will be different from cs->mode (the current hardware setup).
1138 * If so, set par_override (even though its not a parity issue) so
1139 * omap2_mcspi_setup_transfer will be called to configure the hardware
1140 * with the correct mode on the first iteration of the loop below.
1141 */
1142 if (spi->mode != cs->mode)
1143 par_override = 1;
1144
1145 omap2_mcspi_set_enable(spi, 0);
1146
1147 if (gpio_is_valid(spi->cs_gpio))
1148 omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH);
1149
1150 if (par_override ||
1151 (t->speed_hz != spi->max_speed_hz) ||
1152 (t->bits_per_word != spi->bits_per_word)) {
1153 par_override = 1;
1154 status = omap2_mcspi_setup_transfer(spi, t);
1155 if (status < 0)
1156 goto out;
1157 if (t->speed_hz == spi->max_speed_hz &&
1158 t->bits_per_word == spi->bits_per_word)
1159 par_override = 0;
1160 }
1161 if (cd && cd->cs_per_word) {
1162 chconf = mcspi->ctx.modulctrl;
1163 chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1164 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1165 mcspi->ctx.modulctrl =
1166 mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1167 }
1168
1169 chconf = mcspi_cached_chconf0(spi);
1170 chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1171 chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1172
1173 if (t->tx_buf == NULL)
1174 chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1175 else if (t->rx_buf == NULL)
1176 chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1177
1178 if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1179 /* Turbo mode is for more than one word */
1180 if (t->len > ((cs->word_len + 7) >> 3))
1181 chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1182 }
1183
1184 mcspi_write_chconf0(spi, chconf);
1185
1186 if (t->len) {
1187 unsigned count;
1188
1189 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1190 master->cur_msg_mapped &&
1191 master->can_dma(master, spi, t))
1192 omap2_mcspi_set_fifo(spi, t, 1);
1193
1194 omap2_mcspi_set_enable(spi, 1);
1195
1196 /* RX_ONLY mode needs dummy data in TX reg */
1197 if (t->tx_buf == NULL)
1198 writel_relaxed(0, cs->base
1199 + OMAP2_MCSPI_TX0);
1200
1201 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1202 master->cur_msg_mapped &&
1203 master->can_dma(master, spi, t))
1204 count = omap2_mcspi_txrx_dma(spi, t);
1205 else
1206 count = omap2_mcspi_txrx_pio(spi, t);
1207
1208 if (count != t->len) {
1209 status = -EIO;
1210 goto out;
1211 }
1212 }
1213
1214 omap2_mcspi_set_enable(spi, 0);
1215
1216 if (mcspi->fifo_depth > 0)
1217 omap2_mcspi_set_fifo(spi, t, 0);
1218
1219 out:
1220 /* Restore defaults if they were overriden */
1221 if (par_override) {
1222 par_override = 0;
1223 status = omap2_mcspi_setup_transfer(spi, NULL);
1224 }
1225
1226 if (cd && cd->cs_per_word) {
1227 chconf = mcspi->ctx.modulctrl;
1228 chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1229 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1230 mcspi->ctx.modulctrl =
1231 mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1232 }
1233
1234 omap2_mcspi_set_enable(spi, 0);
1235
1236 if (gpio_is_valid(spi->cs_gpio))
1237 omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH));
1238
1239 if (mcspi->fifo_depth > 0 && t)
1240 omap2_mcspi_set_fifo(spi, t, 0);
1241
1242 return status;
1243 }
1244
1245 static int omap2_mcspi_prepare_message(struct spi_master *master,
1246 struct spi_message *msg)
1247 {
1248 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1249 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1250 struct omap2_mcspi_cs *cs;
1251
1252 /* Only a single channel can have the FORCE bit enabled
1253 * in its chconf0 register.
1254 * Scan all channels and disable them except the current one.
1255 * A FORCE can remain from a last transfer having cs_change enabled
1256 */
1257 list_for_each_entry(cs, &ctx->cs, node) {
1258 if (msg->spi->controller_state == cs)
1259 continue;
1260
1261 if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
1262 cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1263 writel_relaxed(cs->chconf0,
1264 cs->base + OMAP2_MCSPI_CHCONF0);
1265 readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
1266 }
1267 }
1268
1269 return 0;
1270 }
1271
1272 static bool omap2_mcspi_can_dma(struct spi_master *master,
1273 struct spi_device *spi,
1274 struct spi_transfer *xfer)
1275 {
1276 return (xfer->len >= DMA_MIN_BYTES);
1277 }
1278
1279 static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
1280 {
1281 struct spi_master *master = mcspi->master;
1282 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1283 int ret = 0;
1284
1285 ret = pm_runtime_get_sync(mcspi->dev);
1286 if (ret < 0)
1287 return ret;
1288
1289 mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1290 OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1291 ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1292
1293 omap2_mcspi_set_master_mode(master);
1294 pm_runtime_mark_last_busy(mcspi->dev);
1295 pm_runtime_put_autosuspend(mcspi->dev);
1296 return 0;
1297 }
1298
1299 static int omap_mcspi_runtime_resume(struct device *dev)
1300 {
1301 struct omap2_mcspi *mcspi;
1302 struct spi_master *master;
1303
1304 master = dev_get_drvdata(dev);
1305 mcspi = spi_master_get_devdata(master);
1306 omap2_mcspi_restore_ctx(mcspi);
1307
1308 return 0;
1309 }
1310
1311 static struct omap2_mcspi_platform_config omap2_pdata = {
1312 .regs_offset = 0,
1313 };
1314
1315 static struct omap2_mcspi_platform_config omap4_pdata = {
1316 .regs_offset = OMAP4_MCSPI_REG_OFFSET,
1317 };
1318
1319 static const struct of_device_id omap_mcspi_of_match[] = {
1320 {
1321 .compatible = "ti,omap2-mcspi",
1322 .data = &omap2_pdata,
1323 },
1324 {
1325 .compatible = "ti,omap4-mcspi",
1326 .data = &omap4_pdata,
1327 },
1328 { },
1329 };
1330 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1331
1332 static int omap2_mcspi_probe(struct platform_device *pdev)
1333 {
1334 struct spi_master *master;
1335 const struct omap2_mcspi_platform_config *pdata;
1336 struct omap2_mcspi *mcspi;
1337 struct resource *r;
1338 int status = 0, i;
1339 u32 regs_offset = 0;
1340 static int bus_num = 1;
1341 struct device_node *node = pdev->dev.of_node;
1342 const struct of_device_id *match;
1343
1344 master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1345 if (master == NULL) {
1346 dev_dbg(&pdev->dev, "master allocation failed\n");
1347 return -ENOMEM;
1348 }
1349
1350 /* the spi->mode bits understood by this driver: */
1351 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1352 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1353 master->setup = omap2_mcspi_setup;
1354 master->auto_runtime_pm = true;
1355 master->prepare_message = omap2_mcspi_prepare_message;
1356 master->can_dma = omap2_mcspi_can_dma;
1357 master->transfer_one = omap2_mcspi_transfer_one;
1358 master->set_cs = omap2_mcspi_set_cs;
1359 master->cleanup = omap2_mcspi_cleanup;
1360 master->dev.of_node = node;
1361 master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1362 master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1363
1364 platform_set_drvdata(pdev, master);
1365
1366 mcspi = spi_master_get_devdata(master);
1367 mcspi->master = master;
1368
1369 match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1370 if (match) {
1371 u32 num_cs = 1; /* default number of chipselect */
1372 pdata = match->data;
1373
1374 of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1375 master->num_chipselect = num_cs;
1376 master->bus_num = bus_num++;
1377 if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1378 mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1379 } else {
1380 pdata = dev_get_platdata(&pdev->dev);
1381 master->num_chipselect = pdata->num_cs;
1382 if (pdev->id != -1)
1383 master->bus_num = pdev->id;
1384 mcspi->pin_dir = pdata->pin_dir;
1385 }
1386 regs_offset = pdata->regs_offset;
1387
1388 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1389 if (r == NULL) {
1390 status = -ENODEV;
1391 goto free_master;
1392 }
1393
1394 r->start += regs_offset;
1395 r->end += regs_offset;
1396 mcspi->phys = r->start;
1397
1398 mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1399 if (IS_ERR(mcspi->base)) {
1400 status = PTR_ERR(mcspi->base);
1401 goto free_master;
1402 }
1403
1404 mcspi->dev = &pdev->dev;
1405
1406 INIT_LIST_HEAD(&mcspi->ctx.cs);
1407
1408 mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1409 sizeof(struct omap2_mcspi_dma),
1410 GFP_KERNEL);
1411 if (mcspi->dma_channels == NULL) {
1412 status = -ENOMEM;
1413 goto free_master;
1414 }
1415
1416 for (i = 0; i < master->num_chipselect; i++) {
1417 sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
1418 sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
1419 }
1420
1421 if (status < 0)
1422 goto free_master;
1423
1424 pm_runtime_use_autosuspend(&pdev->dev);
1425 pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1426 pm_runtime_enable(&pdev->dev);
1427
1428 status = omap2_mcspi_master_setup(mcspi);
1429 if (status < 0)
1430 goto disable_pm;
1431
1432 status = devm_spi_register_master(&pdev->dev, master);
1433 if (status < 0)
1434 goto disable_pm;
1435
1436 return status;
1437
1438 disable_pm:
1439 pm_runtime_dont_use_autosuspend(&pdev->dev);
1440 pm_runtime_put_sync(&pdev->dev);
1441 pm_runtime_disable(&pdev->dev);
1442 free_master:
1443 spi_master_put(master);
1444 return status;
1445 }
1446
1447 static int omap2_mcspi_remove(struct platform_device *pdev)
1448 {
1449 struct spi_master *master = platform_get_drvdata(pdev);
1450 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1451
1452 pm_runtime_dont_use_autosuspend(mcspi->dev);
1453 pm_runtime_put_sync(mcspi->dev);
1454 pm_runtime_disable(&pdev->dev);
1455
1456 return 0;
1457 }
1458
1459 /* work with hotplug and coldplug */
1460 MODULE_ALIAS("platform:omap2_mcspi");
1461
1462 #ifdef CONFIG_SUSPEND
1463 /*
1464 * When SPI wake up from off-mode, CS is in activate state. If it was in
1465 * unactive state when driver was suspend, then force it to unactive state at
1466 * wake up.
1467 */
1468 static int omap2_mcspi_resume(struct device *dev)
1469 {
1470 struct spi_master *master = dev_get_drvdata(dev);
1471 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1472 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1473 struct omap2_mcspi_cs *cs;
1474
1475 pm_runtime_get_sync(mcspi->dev);
1476 list_for_each_entry(cs, &ctx->cs, node) {
1477 if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1478 /*
1479 * We need to toggle CS state for OMAP take this
1480 * change in account.
1481 */
1482 cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1483 writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1484 cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1485 writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1486 }
1487 }
1488 pm_runtime_mark_last_busy(mcspi->dev);
1489 pm_runtime_put_autosuspend(mcspi->dev);
1490
1491 return pinctrl_pm_select_default_state(dev);
1492 }
1493
1494 static int omap2_mcspi_suspend(struct device *dev)
1495 {
1496 return pinctrl_pm_select_sleep_state(dev);
1497 }
1498
1499 #else
1500 #define omap2_mcspi_suspend NULL
1501 #define omap2_mcspi_resume NULL
1502 #endif
1503
1504 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1505 .resume = omap2_mcspi_resume,
1506 .suspend = omap2_mcspi_suspend,
1507 .runtime_resume = omap_mcspi_runtime_resume,
1508 };
1509
1510 static struct platform_driver omap2_mcspi_driver = {
1511 .driver = {
1512 .name = "omap2_mcspi",
1513 .pm = &omap2_mcspi_pm_ops,
1514 .of_match_table = omap_mcspi_of_match,
1515 },
1516 .probe = omap2_mcspi_probe,
1517 .remove = omap2_mcspi_remove,
1518 };
1519
1520 module_platform_driver(omap2_mcspi_driver);
1521 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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