1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * OMAP2 McSPI controller driver
4 *
5 * Copyright (C) 2005, 2006 Nokia Corporation
6 * Author: Samuel Ortiz <samuel.ortiz@nokia.com> and
7 * Juha Yrjola <juha.yrjola@nokia.com>
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/interrupt.h>
12 #include <linux/module.h>
13 #include <linux/device.h>
14 #include <linux/delay.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/dmaengine.h>
17 #include <linux/pinctrl/consumer.h>
18 #include <linux/platform_device.h>
19 #include <linux/err.h>
20 #include <linux/clk.h>
21 #include <linux/io.h>
22 #include <linux/slab.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/of.h>
25 #include <linux/of_device.h>
26 #include <linux/gcd.h>
27
28 #include <linux/spi/spi.h>
29
30 #include "internals.h"
31
32 #include <linux/platform_data/spi-omap2-mcspi.h>
33
34 #define OMAP2_MCSPI_MAX_FREQ 48000000
35 #define OMAP2_MCSPI_MAX_DIVIDER 4096
36 #define OMAP2_MCSPI_MAX_FIFODEPTH 64
37 #define OMAP2_MCSPI_MAX_FIFOWCNT 0xFFFF
38 #define SPI_AUTOSUSPEND_TIMEOUT 2000
39
40 #define OMAP2_MCSPI_REVISION 0x00
41 #define OMAP2_MCSPI_SYSSTATUS 0x14
42 #define OMAP2_MCSPI_IRQSTATUS 0x18
43 #define OMAP2_MCSPI_IRQENABLE 0x1c
44 #define OMAP2_MCSPI_WAKEUPENABLE 0x20
45 #define OMAP2_MCSPI_SYST 0x24
46 #define OMAP2_MCSPI_MODULCTRL 0x28
47 #define OMAP2_MCSPI_XFERLEVEL 0x7c
48
49 /* per-channel banks, 0x14 bytes each, first is: */
50 #define OMAP2_MCSPI_CHCONF0 0x2c
51 #define OMAP2_MCSPI_CHSTAT0 0x30
52 #define OMAP2_MCSPI_CHCTRL0 0x34
53 #define OMAP2_MCSPI_TX0 0x38
54 #define OMAP2_MCSPI_RX0 0x3c
55
56 /* per-register bitmasks: */
57 #define OMAP2_MCSPI_IRQSTATUS_EOW BIT(17)
58
59 #define OMAP2_MCSPI_MODULCTRL_SINGLE BIT(0)
60 #define OMAP2_MCSPI_MODULCTRL_MS BIT(2)
61 #define OMAP2_MCSPI_MODULCTRL_STEST BIT(3)
62
63 #define OMAP2_MCSPI_CHCONF_PHA BIT(0)
64 #define OMAP2_MCSPI_CHCONF_POL BIT(1)
65 #define OMAP2_MCSPI_CHCONF_CLKD_MASK (0x0f << 2)
66 #define OMAP2_MCSPI_CHCONF_EPOL BIT(6)
67 #define OMAP2_MCSPI_CHCONF_WL_MASK (0x1f << 7)
68 #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY BIT(12)
69 #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY BIT(13)
70 #define OMAP2_MCSPI_CHCONF_TRM_MASK (0x03 << 12)
71 #define OMAP2_MCSPI_CHCONF_DMAW BIT(14)
72 #define OMAP2_MCSPI_CHCONF_DMAR BIT(15)
73 #define OMAP2_MCSPI_CHCONF_DPE0 BIT(16)
74 #define OMAP2_MCSPI_CHCONF_DPE1 BIT(17)
75 #define OMAP2_MCSPI_CHCONF_IS BIT(18)
76 #define OMAP2_MCSPI_CHCONF_TURBO BIT(19)
77 #define OMAP2_MCSPI_CHCONF_FORCE BIT(20)
78 #define OMAP2_MCSPI_CHCONF_FFET BIT(27)
79 #define OMAP2_MCSPI_CHCONF_FFER BIT(28)
80 #define OMAP2_MCSPI_CHCONF_CLKG BIT(29)
81
82 #define OMAP2_MCSPI_CHSTAT_RXS BIT(0)
83 #define OMAP2_MCSPI_CHSTAT_TXS BIT(1)
84 #define OMAP2_MCSPI_CHSTAT_EOT BIT(2)
85 #define OMAP2_MCSPI_CHSTAT_TXFFE BIT(3)
86
87 #define OMAP2_MCSPI_CHCTRL_EN BIT(0)
88 #define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK (0xff << 8)
89
90 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN BIT(0)
91
92 /* We have 2 DMA channels per CS, one for RX and one for TX */
93 struct omap2_mcspi_dma {
94 struct dma_chan *dma_tx;
95 struct dma_chan *dma_rx;
96
97 struct completion dma_tx_completion;
98 struct completion dma_rx_completion;
99
100 char dma_rx_ch_name[14];
101 char dma_tx_ch_name[14];
102 };
103
104 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
105 * cache operations; better heuristics consider wordsize and bitrate.
106 */
107 #define DMA_MIN_BYTES 160
108
109
110 /*
111 * Used for context save and restore, structure members to be updated whenever
112 * corresponding registers are modified.
113 */
114 struct omap2_mcspi_regs {
115 u32 modulctrl;
116 u32 wakeupenable;
117 struct list_head cs;
118 };
119
120 struct omap2_mcspi {
121 struct completion txdone;
122 struct spi_controller *ctlr;
123 /* Virtual base address of the controller */
124 void __iomem *base;
125 unsigned long phys;
126 /* SPI1 has 4 channels, while SPI2 has 2 */
127 struct omap2_mcspi_dma *dma_channels;
128 struct device *dev;
129 struct omap2_mcspi_regs ctx;
130 struct clk *ref_clk;
131 int fifo_depth;
132 bool target_aborted;
133 unsigned int pin_dir:1;
134 size_t max_xfer_len;
135 u32 ref_clk_hz;
136 bool use_multi_mode;
137 bool last_msg_kept_cs;
138 };
139
140 struct omap2_mcspi_cs {
141 void __iomem *base;
142 unsigned long phys;
143 int word_len;
144 u16 mode;
145 struct list_head node;
146 /* Context save and restore shadow register */
147 u32 chconf0, chctrl0;
148 };
149
mcspi_write_reg(struct spi_controller * ctlr,int idx,u32 val)150 static inline void mcspi_write_reg(struct spi_controller *ctlr,
151 int idx, u32 val)
152 {
153 struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
154
155 writel_relaxed(val, mcspi->base + idx);
156 }
157
mcspi_read_reg(struct spi_controller * ctlr,int idx)158 static inline u32 mcspi_read_reg(struct spi_controller *ctlr, int idx)
159 {
160 struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
161
162 return readl_relaxed(mcspi->base + idx);
163 }
164
mcspi_write_cs_reg(const struct spi_device * spi,int idx,u32 val)165 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
166 int idx, u32 val)
167 {
168 struct omap2_mcspi_cs *cs = spi->controller_state;
169
170 writel_relaxed(val, cs->base + idx);
171 }
172
mcspi_read_cs_reg(const struct spi_device * spi,int idx)173 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
174 {
175 struct omap2_mcspi_cs *cs = spi->controller_state;
176
177 return readl_relaxed(cs->base + idx);
178 }
179
mcspi_cached_chconf0(const struct spi_device * spi)180 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
181 {
182 struct omap2_mcspi_cs *cs = spi->controller_state;
183
184 return cs->chconf0;
185 }
186
mcspi_write_chconf0(const struct spi_device * spi,u32 val)187 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
188 {
189 struct omap2_mcspi_cs *cs = spi->controller_state;
190
191 cs->chconf0 = val;
192 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
193 mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
194 }
195
mcspi_bytes_per_word(int word_len)196 static inline int mcspi_bytes_per_word(int word_len)
197 {
198 if (word_len <= 8)
199 return 1;
200 else if (word_len <= 16)
201 return 2;
202 else /* word_len <= 32 */
203 return 4;
204 }
205
omap2_mcspi_set_dma_req(const struct spi_device * spi,int is_read,int enable)206 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
207 int is_read, int enable)
208 {
209 u32 l, rw;
210
211 l = mcspi_cached_chconf0(spi);
212
213 if (is_read) /* 1 is read, 0 write */
214 rw = OMAP2_MCSPI_CHCONF_DMAR;
215 else
216 rw = OMAP2_MCSPI_CHCONF_DMAW;
217
218 if (enable)
219 l |= rw;
220 else
221 l &= ~rw;
222
223 mcspi_write_chconf0(spi, l);
224 }
225
omap2_mcspi_set_enable(const struct spi_device * spi,int enable)226 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
227 {
228 struct omap2_mcspi_cs *cs = spi->controller_state;
229 u32 l;
230
231 l = cs->chctrl0;
232 if (enable)
233 l |= OMAP2_MCSPI_CHCTRL_EN;
234 else
235 l &= ~OMAP2_MCSPI_CHCTRL_EN;
236 cs->chctrl0 = l;
237 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
238 /* Flash post-writes */
239 mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
240 }
241
omap2_mcspi_set_cs(struct spi_device * spi,bool enable)242 static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable)
243 {
244 struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
245 u32 l;
246
247 /* The controller handles the inverted chip selects
248 * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert
249 * the inversion from the core spi_set_cs function.
250 */
251 if (spi->mode & SPI_CS_HIGH)
252 enable = !enable;
253
254 if (spi->controller_state) {
255 int err = pm_runtime_resume_and_get(mcspi->dev);
256 if (err < 0) {
257 dev_err(mcspi->dev, "failed to get sync: %d\n", err);
258 return;
259 }
260
261 l = mcspi_cached_chconf0(spi);
262
263 /* Only enable chip select manually if single mode is used */
264 if (mcspi->use_multi_mode) {
265 l &= ~OMAP2_MCSPI_CHCONF_FORCE;
266 } else {
267 if (enable)
268 l &= ~OMAP2_MCSPI_CHCONF_FORCE;
269 else
270 l |= OMAP2_MCSPI_CHCONF_FORCE;
271 }
272
273 mcspi_write_chconf0(spi, l);
274
275 pm_runtime_put_autosuspend(mcspi->dev);
276 }
277 }
278
omap2_mcspi_set_mode(struct spi_controller * ctlr)279 static void omap2_mcspi_set_mode(struct spi_controller *ctlr)
280 {
281 struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
282 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
283 u32 l;
284
285 /*
286 * Choose host or target mode
287 */
288 l = mcspi_read_reg(ctlr, OMAP2_MCSPI_MODULCTRL);
289 l &= ~(OMAP2_MCSPI_MODULCTRL_STEST);
290 if (spi_controller_is_target(ctlr)) {
291 l |= (OMAP2_MCSPI_MODULCTRL_MS);
292 } else {
293 l &= ~(OMAP2_MCSPI_MODULCTRL_MS);
294
295 /* Enable single mode if needed */
296 if (mcspi->use_multi_mode)
297 l &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
298 else
299 l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
300 }
301 mcspi_write_reg(ctlr, OMAP2_MCSPI_MODULCTRL, l);
302
303 ctx->modulctrl = l;
304 }
305
omap2_mcspi_set_fifo(const struct spi_device * spi,struct spi_transfer * t,int enable)306 static void omap2_mcspi_set_fifo(const struct spi_device *spi,
307 struct spi_transfer *t, int enable)
308 {
309 struct spi_controller *ctlr = spi->controller;
310 struct omap2_mcspi_cs *cs = spi->controller_state;
311 struct omap2_mcspi *mcspi;
312 unsigned int wcnt;
313 int max_fifo_depth, bytes_per_word;
314 u32 chconf, xferlevel;
315
316 mcspi = spi_controller_get_devdata(ctlr);
317
318 chconf = mcspi_cached_chconf0(spi);
319 if (enable) {
320 bytes_per_word = mcspi_bytes_per_word(cs->word_len);
321 if (t->len % bytes_per_word != 0)
322 goto disable_fifo;
323
324 if (t->rx_buf != NULL && t->tx_buf != NULL)
325 max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
326 else
327 max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
328
329 wcnt = t->len / bytes_per_word;
330 if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
331 goto disable_fifo;
332
333 xferlevel = wcnt << 16;
334 if (t->rx_buf != NULL) {
335 chconf |= OMAP2_MCSPI_CHCONF_FFER;
336 xferlevel |= (bytes_per_word - 1) << 8;
337 }
338
339 if (t->tx_buf != NULL) {
340 chconf |= OMAP2_MCSPI_CHCONF_FFET;
341 xferlevel |= bytes_per_word - 1;
342 }
343
344 mcspi_write_reg(ctlr, OMAP2_MCSPI_XFERLEVEL, xferlevel);
345 mcspi_write_chconf0(spi, chconf);
346 mcspi->fifo_depth = max_fifo_depth;
347
348 return;
349 }
350
351 disable_fifo:
352 if (t->rx_buf != NULL)
353 chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
354
355 if (t->tx_buf != NULL)
356 chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
357
358 mcspi_write_chconf0(spi, chconf);
359 mcspi->fifo_depth = 0;
360 }
361
mcspi_wait_for_reg_bit(void __iomem * reg,unsigned long bit)362 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
363 {
364 unsigned long timeout;
365
366 timeout = jiffies + msecs_to_jiffies(1000);
367 while (!(readl_relaxed(reg) & bit)) {
368 if (time_after(jiffies, timeout)) {
369 if (!(readl_relaxed(reg) & bit))
370 return -ETIMEDOUT;
371 else
372 return 0;
373 }
374 cpu_relax();
375 }
376 return 0;
377 }
378
mcspi_wait_for_completion(struct omap2_mcspi * mcspi,struct completion * x)379 static int mcspi_wait_for_completion(struct omap2_mcspi *mcspi,
380 struct completion *x)
381 {
382 if (spi_controller_is_target(mcspi->ctlr)) {
383 if (wait_for_completion_interruptible(x) ||
384 mcspi->target_aborted)
385 return -EINTR;
386 } else {
387 wait_for_completion(x);
388 }
389
390 return 0;
391 }
392
omap2_mcspi_rx_callback(void * data)393 static void omap2_mcspi_rx_callback(void *data)
394 {
395 struct spi_device *spi = data;
396 struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
397 struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
398
399 /* We must disable the DMA RX request */
400 omap2_mcspi_set_dma_req(spi, 1, 0);
401
402 complete(&mcspi_dma->dma_rx_completion);
403 }
404
omap2_mcspi_tx_callback(void * data)405 static void omap2_mcspi_tx_callback(void *data)
406 {
407 struct spi_device *spi = data;
408 struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
409 struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
410
411 /* We must disable the DMA TX request */
412 omap2_mcspi_set_dma_req(spi, 0, 0);
413
414 complete(&mcspi_dma->dma_tx_completion);
415 }
416
omap2_mcspi_tx_dma(struct spi_device * spi,struct spi_transfer * xfer,struct dma_slave_config cfg)417 static void omap2_mcspi_tx_dma(struct spi_device *spi,
418 struct spi_transfer *xfer,
419 struct dma_slave_config cfg)
420 {
421 struct omap2_mcspi *mcspi;
422 struct omap2_mcspi_dma *mcspi_dma;
423 struct dma_async_tx_descriptor *tx;
424
425 mcspi = spi_controller_get_devdata(spi->controller);
426 mcspi_dma = &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
427
428 dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
429
430 tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl,
431 xfer->tx_sg.nents,
432 DMA_MEM_TO_DEV,
433 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
434 if (tx) {
435 tx->callback = omap2_mcspi_tx_callback;
436 tx->callback_param = spi;
437 dmaengine_submit(tx);
438 } else {
439 /* FIXME: fall back to PIO? */
440 }
441 dma_async_issue_pending(mcspi_dma->dma_tx);
442 omap2_mcspi_set_dma_req(spi, 0, 1);
443 }
444
445 static unsigned
omap2_mcspi_rx_dma(struct spi_device * spi,struct spi_transfer * xfer,struct dma_slave_config cfg,unsigned es)446 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
447 struct dma_slave_config cfg,
448 unsigned es)
449 {
450 struct omap2_mcspi *mcspi;
451 struct omap2_mcspi_dma *mcspi_dma;
452 unsigned int count, transfer_reduction = 0;
453 struct scatterlist *sg_out[2];
454 int nb_sizes = 0, out_mapped_nents[2], ret, x;
455 size_t sizes[2];
456 u32 l;
457 int elements = 0;
458 int word_len, element_count;
459 struct omap2_mcspi_cs *cs = spi->controller_state;
460 void __iomem *chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
461 struct dma_async_tx_descriptor *tx;
462
463 mcspi = spi_controller_get_devdata(spi->controller);
464 mcspi_dma = &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
465 count = xfer->len;
466
467 /*
468 * In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM
469 * it mentions reducing DMA transfer length by one element in host
470 * normal mode.
471 */
472 if (mcspi->fifo_depth == 0)
473 transfer_reduction = es;
474
475 word_len = cs->word_len;
476 l = mcspi_cached_chconf0(spi);
477
478 if (word_len <= 8)
479 element_count = count;
480 else if (word_len <= 16)
481 element_count = count >> 1;
482 else /* word_len <= 32 */
483 element_count = count >> 2;
484
485
486 dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
487
488 /*
489 * Reduce DMA transfer length by one more if McSPI is
490 * configured in turbo mode.
491 */
492 if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
493 transfer_reduction += es;
494
495 if (transfer_reduction) {
496 /* Split sgl into two. The second sgl won't be used. */
497 sizes[0] = count - transfer_reduction;
498 sizes[1] = transfer_reduction;
499 nb_sizes = 2;
500 } else {
501 /*
502 * Don't bother splitting the sgl. This essentially
503 * clones the original sgl.
504 */
505 sizes[0] = count;
506 nb_sizes = 1;
507 }
508
509 ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents, 0, nb_sizes,
510 sizes, sg_out, out_mapped_nents, GFP_KERNEL);
511
512 if (ret < 0) {
513 dev_err(&spi->dev, "sg_split failed\n");
514 return 0;
515 }
516
517 tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, sg_out[0],
518 out_mapped_nents[0], DMA_DEV_TO_MEM,
519 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
520 if (tx) {
521 tx->callback = omap2_mcspi_rx_callback;
522 tx->callback_param = spi;
523 dmaengine_submit(tx);
524 } else {
525 /* FIXME: fall back to PIO? */
526 }
527
528 dma_async_issue_pending(mcspi_dma->dma_rx);
529 omap2_mcspi_set_dma_req(spi, 1, 1);
530
531 ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_rx_completion);
532 if (ret || mcspi->target_aborted) {
533 dmaengine_terminate_sync(mcspi_dma->dma_rx);
534 omap2_mcspi_set_dma_req(spi, 1, 0);
535 return 0;
536 }
537
538 for (x = 0; x < nb_sizes; x++)
539 kfree(sg_out[x]);
540
541 if (mcspi->fifo_depth > 0)
542 return count;
543
544 /*
545 * Due to the DMA transfer length reduction the missing bytes must
546 * be read manually to receive all of the expected data.
547 */
548 omap2_mcspi_set_enable(spi, 0);
549
550 elements = element_count - 1;
551
552 if (l & OMAP2_MCSPI_CHCONF_TURBO) {
553 elements--;
554
555 if (!mcspi_wait_for_reg_bit(chstat_reg,
556 OMAP2_MCSPI_CHSTAT_RXS)) {
557 u32 w;
558
559 w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
560 if (word_len <= 8)
561 ((u8 *)xfer->rx_buf)[elements++] = w;
562 else if (word_len <= 16)
563 ((u16 *)xfer->rx_buf)[elements++] = w;
564 else /* word_len <= 32 */
565 ((u32 *)xfer->rx_buf)[elements++] = w;
566 } else {
567 int bytes_per_word = mcspi_bytes_per_word(word_len);
568 dev_err(&spi->dev, "DMA RX penultimate word empty\n");
569 count -= (bytes_per_word << 1);
570 omap2_mcspi_set_enable(spi, 1);
571 return count;
572 }
573 }
574 if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) {
575 u32 w;
576
577 w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
578 if (word_len <= 8)
579 ((u8 *)xfer->rx_buf)[elements] = w;
580 else if (word_len <= 16)
581 ((u16 *)xfer->rx_buf)[elements] = w;
582 else /* word_len <= 32 */
583 ((u32 *)xfer->rx_buf)[elements] = w;
584 } else {
585 dev_err(&spi->dev, "DMA RX last word empty\n");
586 count -= mcspi_bytes_per_word(word_len);
587 }
588 omap2_mcspi_set_enable(spi, 1);
589 return count;
590 }
591
592 static unsigned
omap2_mcspi_txrx_dma(struct spi_device * spi,struct spi_transfer * xfer)593 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
594 {
595 struct omap2_mcspi *mcspi;
596 struct omap2_mcspi_cs *cs = spi->controller_state;
597 struct omap2_mcspi_dma *mcspi_dma;
598 unsigned int count;
599 u8 *rx;
600 const u8 *tx;
601 struct dma_slave_config cfg;
602 enum dma_slave_buswidth width;
603 unsigned es;
604 void __iomem *chstat_reg;
605 void __iomem *irqstat_reg;
606 int wait_res;
607
608 mcspi = spi_controller_get_devdata(spi->controller);
609 mcspi_dma = &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
610
611 if (cs->word_len <= 8) {
612 width = DMA_SLAVE_BUSWIDTH_1_BYTE;
613 es = 1;
614 } else if (cs->word_len <= 16) {
615 width = DMA_SLAVE_BUSWIDTH_2_BYTES;
616 es = 2;
617 } else {
618 width = DMA_SLAVE_BUSWIDTH_4_BYTES;
619 es = 4;
620 }
621
622 count = xfer->len;
623
624 memset(&cfg, 0, sizeof(cfg));
625 cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
626 cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
627 cfg.src_addr_width = width;
628 cfg.dst_addr_width = width;
629 cfg.src_maxburst = 1;
630 cfg.dst_maxburst = 1;
631
632 rx = xfer->rx_buf;
633 tx = xfer->tx_buf;
634
635 mcspi->target_aborted = false;
636 reinit_completion(&mcspi_dma->dma_tx_completion);
637 reinit_completion(&mcspi_dma->dma_rx_completion);
638 reinit_completion(&mcspi->txdone);
639 if (tx) {
640 /* Enable EOW IRQ to know end of tx in target mode */
641 if (spi_controller_is_target(spi->controller))
642 mcspi_write_reg(spi->controller,
643 OMAP2_MCSPI_IRQENABLE,
644 OMAP2_MCSPI_IRQSTATUS_EOW);
645 omap2_mcspi_tx_dma(spi, xfer, cfg);
646 }
647
648 if (rx != NULL)
649 count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
650
651 if (tx != NULL) {
652 int ret;
653
654 ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_tx_completion);
655 if (ret || mcspi->target_aborted) {
656 dmaengine_terminate_sync(mcspi_dma->dma_tx);
657 omap2_mcspi_set_dma_req(spi, 0, 0);
658 return 0;
659 }
660
661 if (spi_controller_is_target(mcspi->ctlr)) {
662 ret = mcspi_wait_for_completion(mcspi, &mcspi->txdone);
663 if (ret || mcspi->target_aborted)
664 return 0;
665 }
666
667 if (mcspi->fifo_depth > 0) {
668 irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
669
670 if (mcspi_wait_for_reg_bit(irqstat_reg,
671 OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
672 dev_err(&spi->dev, "EOW timed out\n");
673
674 mcspi_write_reg(mcspi->ctlr, OMAP2_MCSPI_IRQSTATUS,
675 OMAP2_MCSPI_IRQSTATUS_EOW);
676 }
677
678 /* for TX_ONLY mode, be sure all words have shifted out */
679 if (rx == NULL) {
680 chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
681 if (mcspi->fifo_depth > 0) {
682 wait_res = mcspi_wait_for_reg_bit(chstat_reg,
683 OMAP2_MCSPI_CHSTAT_TXFFE);
684 if (wait_res < 0)
685 dev_err(&spi->dev, "TXFFE timed out\n");
686 } else {
687 wait_res = mcspi_wait_for_reg_bit(chstat_reg,
688 OMAP2_MCSPI_CHSTAT_TXS);
689 if (wait_res < 0)
690 dev_err(&spi->dev, "TXS timed out\n");
691 }
692 if (wait_res >= 0 &&
693 (mcspi_wait_for_reg_bit(chstat_reg,
694 OMAP2_MCSPI_CHSTAT_EOT) < 0))
695 dev_err(&spi->dev, "EOT timed out\n");
696 }
697 }
698 return count;
699 }
700
701 static unsigned
omap2_mcspi_txrx_pio(struct spi_device * spi,struct spi_transfer * xfer)702 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
703 {
704 struct omap2_mcspi_cs *cs = spi->controller_state;
705 unsigned int count, c;
706 u32 l;
707 void __iomem *base = cs->base;
708 void __iomem *tx_reg;
709 void __iomem *rx_reg;
710 void __iomem *chstat_reg;
711 int word_len;
712
713 count = xfer->len;
714 c = count;
715 word_len = cs->word_len;
716
717 l = mcspi_cached_chconf0(spi);
718
719 /* We store the pre-calculated register addresses on stack to speed
720 * up the transfer loop. */
721 tx_reg = base + OMAP2_MCSPI_TX0;
722 rx_reg = base + OMAP2_MCSPI_RX0;
723 chstat_reg = base + OMAP2_MCSPI_CHSTAT0;
724
725 if (c < (word_len>>3))
726 return 0;
727
728 if (word_len <= 8) {
729 u8 *rx;
730 const u8 *tx;
731
732 rx = xfer->rx_buf;
733 tx = xfer->tx_buf;
734
735 do {
736 c -= 1;
737 if (tx != NULL) {
738 if (mcspi_wait_for_reg_bit(chstat_reg,
739 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
740 dev_err(&spi->dev, "TXS timed out\n");
741 goto out;
742 }
743 dev_vdbg(&spi->dev, "write-%d %02x\n",
744 word_len, *tx);
745 writel_relaxed(*tx++, tx_reg);
746 }
747 if (rx != NULL) {
748 if (mcspi_wait_for_reg_bit(chstat_reg,
749 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
750 dev_err(&spi->dev, "RXS timed out\n");
751 goto out;
752 }
753
754 if (c == 1 && tx == NULL &&
755 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
756 omap2_mcspi_set_enable(spi, 0);
757 *rx++ = readl_relaxed(rx_reg);
758 dev_vdbg(&spi->dev, "read-%d %02x\n",
759 word_len, *(rx - 1));
760 if (mcspi_wait_for_reg_bit(chstat_reg,
761 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
762 dev_err(&spi->dev,
763 "RXS timed out\n");
764 goto out;
765 }
766 c = 0;
767 } else if (c == 0 && tx == NULL) {
768 omap2_mcspi_set_enable(spi, 0);
769 }
770
771 *rx++ = readl_relaxed(rx_reg);
772 dev_vdbg(&spi->dev, "read-%d %02x\n",
773 word_len, *(rx - 1));
774 }
775 /* Add word delay between each word */
776 spi_delay_exec(&xfer->word_delay, xfer);
777 } while (c);
778 } else if (word_len <= 16) {
779 u16 *rx;
780 const u16 *tx;
781
782 rx = xfer->rx_buf;
783 tx = xfer->tx_buf;
784 do {
785 c -= 2;
786 if (tx != NULL) {
787 if (mcspi_wait_for_reg_bit(chstat_reg,
788 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
789 dev_err(&spi->dev, "TXS timed out\n");
790 goto out;
791 }
792 dev_vdbg(&spi->dev, "write-%d %04x\n",
793 word_len, *tx);
794 writel_relaxed(*tx++, tx_reg);
795 }
796 if (rx != NULL) {
797 if (mcspi_wait_for_reg_bit(chstat_reg,
798 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
799 dev_err(&spi->dev, "RXS timed out\n");
800 goto out;
801 }
802
803 if (c == 2 && tx == NULL &&
804 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
805 omap2_mcspi_set_enable(spi, 0);
806 *rx++ = readl_relaxed(rx_reg);
807 dev_vdbg(&spi->dev, "read-%d %04x\n",
808 word_len, *(rx - 1));
809 if (mcspi_wait_for_reg_bit(chstat_reg,
810 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
811 dev_err(&spi->dev,
812 "RXS timed out\n");
813 goto out;
814 }
815 c = 0;
816 } else if (c == 0 && tx == NULL) {
817 omap2_mcspi_set_enable(spi, 0);
818 }
819
820 *rx++ = readl_relaxed(rx_reg);
821 dev_vdbg(&spi->dev, "read-%d %04x\n",
822 word_len, *(rx - 1));
823 }
824 /* Add word delay between each word */
825 spi_delay_exec(&xfer->word_delay, xfer);
826 } while (c >= 2);
827 } else if (word_len <= 32) {
828 u32 *rx;
829 const u32 *tx;
830
831 rx = xfer->rx_buf;
832 tx = xfer->tx_buf;
833 do {
834 c -= 4;
835 if (tx != NULL) {
836 if (mcspi_wait_for_reg_bit(chstat_reg,
837 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
838 dev_err(&spi->dev, "TXS timed out\n");
839 goto out;
840 }
841 dev_vdbg(&spi->dev, "write-%d %08x\n",
842 word_len, *tx);
843 writel_relaxed(*tx++, tx_reg);
844 }
845 if (rx != NULL) {
846 if (mcspi_wait_for_reg_bit(chstat_reg,
847 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
848 dev_err(&spi->dev, "RXS timed out\n");
849 goto out;
850 }
851
852 if (c == 4 && tx == NULL &&
853 (l & OMAP2_MCSPI_CHCONF_TURBO)) {
854 omap2_mcspi_set_enable(spi, 0);
855 *rx++ = readl_relaxed(rx_reg);
856 dev_vdbg(&spi->dev, "read-%d %08x\n",
857 word_len, *(rx - 1));
858 if (mcspi_wait_for_reg_bit(chstat_reg,
859 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
860 dev_err(&spi->dev,
861 "RXS timed out\n");
862 goto out;
863 }
864 c = 0;
865 } else if (c == 0 && tx == NULL) {
866 omap2_mcspi_set_enable(spi, 0);
867 }
868
869 *rx++ = readl_relaxed(rx_reg);
870 dev_vdbg(&spi->dev, "read-%d %08x\n",
871 word_len, *(rx - 1));
872 }
873 /* Add word delay between each word */
874 spi_delay_exec(&xfer->word_delay, xfer);
875 } while (c >= 4);
876 }
877
878 /* for TX_ONLY mode, be sure all words have shifted out */
879 if (xfer->rx_buf == NULL) {
880 if (mcspi_wait_for_reg_bit(chstat_reg,
881 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
882 dev_err(&spi->dev, "TXS timed out\n");
883 } else if (mcspi_wait_for_reg_bit(chstat_reg,
884 OMAP2_MCSPI_CHSTAT_EOT) < 0)
885 dev_err(&spi->dev, "EOT timed out\n");
886
887 /* disable chan to purge rx datas received in TX_ONLY transfer,
888 * otherwise these rx datas will affect the direct following
889 * RX_ONLY transfer.
890 */
891 omap2_mcspi_set_enable(spi, 0);
892 }
893 out:
894 omap2_mcspi_set_enable(spi, 1);
895 return count - c;
896 }
897
omap2_mcspi_calc_divisor(u32 speed_hz,u32 ref_clk_hz)898 static u32 omap2_mcspi_calc_divisor(u32 speed_hz, u32 ref_clk_hz)
899 {
900 u32 div;
901
902 for (div = 0; div < 15; div++)
903 if (speed_hz >= (ref_clk_hz >> div))
904 return div;
905
906 return 15;
907 }
908
909 /* called only when no transfer is active to this device */
omap2_mcspi_setup_transfer(struct spi_device * spi,struct spi_transfer * t)910 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
911 struct spi_transfer *t)
912 {
913 struct omap2_mcspi_cs *cs = spi->controller_state;
914 struct omap2_mcspi *mcspi;
915 u32 ref_clk_hz, l = 0, clkd = 0, div, extclk = 0, clkg = 0;
916 u8 word_len = spi->bits_per_word;
917 u32 speed_hz = spi->max_speed_hz;
918
919 mcspi = spi_controller_get_devdata(spi->controller);
920
921 if (t != NULL && t->bits_per_word)
922 word_len = t->bits_per_word;
923
924 cs->word_len = word_len;
925
926 if (t && t->speed_hz)
927 speed_hz = t->speed_hz;
928
929 ref_clk_hz = mcspi->ref_clk_hz;
930 speed_hz = min_t(u32, speed_hz, ref_clk_hz);
931 if (speed_hz < (ref_clk_hz / OMAP2_MCSPI_MAX_DIVIDER)) {
932 clkd = omap2_mcspi_calc_divisor(speed_hz, ref_clk_hz);
933 speed_hz = ref_clk_hz >> clkd;
934 clkg = 0;
935 } else {
936 div = (ref_clk_hz + speed_hz - 1) / speed_hz;
937 speed_hz = ref_clk_hz / div;
938 clkd = (div - 1) & 0xf;
939 extclk = (div - 1) >> 4;
940 clkg = OMAP2_MCSPI_CHCONF_CLKG;
941 }
942
943 l = mcspi_cached_chconf0(spi);
944
945 /* standard 4-wire host mode: SCK, MOSI/out, MISO/in, nCS
946 * REVISIT: this controller could support SPI_3WIRE mode.
947 */
948 if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
949 l &= ~OMAP2_MCSPI_CHCONF_IS;
950 l &= ~OMAP2_MCSPI_CHCONF_DPE1;
951 l |= OMAP2_MCSPI_CHCONF_DPE0;
952 } else {
953 l |= OMAP2_MCSPI_CHCONF_IS;
954 l |= OMAP2_MCSPI_CHCONF_DPE1;
955 l &= ~OMAP2_MCSPI_CHCONF_DPE0;
956 }
957
958 /* wordlength */
959 l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
960 l |= (word_len - 1) << 7;
961
962 /* set chipselect polarity; manage with FORCE */
963 if (!(spi->mode & SPI_CS_HIGH))
964 l |= OMAP2_MCSPI_CHCONF_EPOL; /* active-low; normal */
965 else
966 l &= ~OMAP2_MCSPI_CHCONF_EPOL;
967
968 /* set clock divisor */
969 l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
970 l |= clkd << 2;
971
972 /* set clock granularity */
973 l &= ~OMAP2_MCSPI_CHCONF_CLKG;
974 l |= clkg;
975 if (clkg) {
976 cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
977 cs->chctrl0 |= extclk << 8;
978 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
979 }
980
981 /* set SPI mode 0..3 */
982 if (spi->mode & SPI_CPOL)
983 l |= OMAP2_MCSPI_CHCONF_POL;
984 else
985 l &= ~OMAP2_MCSPI_CHCONF_POL;
986 if (spi->mode & SPI_CPHA)
987 l |= OMAP2_MCSPI_CHCONF_PHA;
988 else
989 l &= ~OMAP2_MCSPI_CHCONF_PHA;
990
991 mcspi_write_chconf0(spi, l | OMAP2_MCSPI_CHCONF_FORCE);
992 mcspi_write_chconf0(spi, l);
993
994 cs->mode = spi->mode;
995
996 dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
997 speed_hz,
998 (spi->mode & SPI_CPHA) ? "trailing" : "leading",
999 (spi->mode & SPI_CPOL) ? "inverted" : "normal");
1000
1001 return 0;
1002 }
1003
1004 /*
1005 * Note that we currently allow DMA only if we get a channel
1006 * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
1007 */
omap2_mcspi_request_dma(struct omap2_mcspi * mcspi,struct omap2_mcspi_dma * mcspi_dma)1008 static int omap2_mcspi_request_dma(struct omap2_mcspi *mcspi,
1009 struct omap2_mcspi_dma *mcspi_dma)
1010 {
1011 int ret = 0;
1012
1013 mcspi_dma->dma_rx = dma_request_chan(mcspi->dev,
1014 mcspi_dma->dma_rx_ch_name);
1015 if (IS_ERR(mcspi_dma->dma_rx)) {
1016 ret = PTR_ERR(mcspi_dma->dma_rx);
1017 mcspi_dma->dma_rx = NULL;
1018 goto no_dma;
1019 }
1020
1021 mcspi_dma->dma_tx = dma_request_chan(mcspi->dev,
1022 mcspi_dma->dma_tx_ch_name);
1023 if (IS_ERR(mcspi_dma->dma_tx)) {
1024 ret = PTR_ERR(mcspi_dma->dma_tx);
1025 mcspi_dma->dma_tx = NULL;
1026 dma_release_channel(mcspi_dma->dma_rx);
1027 mcspi_dma->dma_rx = NULL;
1028 }
1029
1030 init_completion(&mcspi_dma->dma_rx_completion);
1031 init_completion(&mcspi_dma->dma_tx_completion);
1032
1033 no_dma:
1034 return ret;
1035 }
1036
omap2_mcspi_release_dma(struct spi_controller * ctlr)1037 static void omap2_mcspi_release_dma(struct spi_controller *ctlr)
1038 {
1039 struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1040 struct omap2_mcspi_dma *mcspi_dma;
1041 int i;
1042
1043 for (i = 0; i < ctlr->num_chipselect; i++) {
1044 mcspi_dma = &mcspi->dma_channels[i];
1045
1046 if (mcspi_dma->dma_rx) {
1047 dma_release_channel(mcspi_dma->dma_rx);
1048 mcspi_dma->dma_rx = NULL;
1049 }
1050 if (mcspi_dma->dma_tx) {
1051 dma_release_channel(mcspi_dma->dma_tx);
1052 mcspi_dma->dma_tx = NULL;
1053 }
1054 }
1055 }
1056
omap2_mcspi_cleanup(struct spi_device * spi)1057 static void omap2_mcspi_cleanup(struct spi_device *spi)
1058 {
1059 struct omap2_mcspi_cs *cs;
1060
1061 if (spi->controller_state) {
1062 /* Unlink controller state from context save list */
1063 cs = spi->controller_state;
1064 list_del(&cs->node);
1065
1066 kfree(cs);
1067 }
1068 }
1069
omap2_mcspi_setup(struct spi_device * spi)1070 static int omap2_mcspi_setup(struct spi_device *spi)
1071 {
1072 bool initial_setup = false;
1073 int ret;
1074 struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
1075 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1076 struct omap2_mcspi_cs *cs = spi->controller_state;
1077
1078 if (!cs) {
1079 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
1080 if (!cs)
1081 return -ENOMEM;
1082 cs->base = mcspi->base + spi_get_chipselect(spi, 0) * 0x14;
1083 cs->phys = mcspi->phys + spi_get_chipselect(spi, 0) * 0x14;
1084 cs->mode = 0;
1085 cs->chconf0 = 0;
1086 cs->chctrl0 = 0;
1087 spi->controller_state = cs;
1088 /* Link this to context save list */
1089 list_add_tail(&cs->node, &ctx->cs);
1090 initial_setup = true;
1091 }
1092
1093 ret = pm_runtime_resume_and_get(mcspi->dev);
1094 if (ret < 0) {
1095 if (initial_setup)
1096 omap2_mcspi_cleanup(spi);
1097
1098 return ret;
1099 }
1100
1101 ret = omap2_mcspi_setup_transfer(spi, NULL);
1102 if (ret && initial_setup)
1103 omap2_mcspi_cleanup(spi);
1104
1105 pm_runtime_put_autosuspend(mcspi->dev);
1106
1107 return ret;
1108 }
1109
omap2_mcspi_irq_handler(int irq,void * data)1110 static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data)
1111 {
1112 struct omap2_mcspi *mcspi = data;
1113 u32 irqstat;
1114
1115 irqstat = mcspi_read_reg(mcspi->ctlr, OMAP2_MCSPI_IRQSTATUS);
1116 if (!irqstat)
1117 return IRQ_NONE;
1118
1119 /* Disable IRQ and wakeup target xfer task */
1120 mcspi_write_reg(mcspi->ctlr, OMAP2_MCSPI_IRQENABLE, 0);
1121 if (irqstat & OMAP2_MCSPI_IRQSTATUS_EOW)
1122 complete(&mcspi->txdone);
1123
1124 return IRQ_HANDLED;
1125 }
1126
omap2_mcspi_target_abort(struct spi_controller * ctlr)1127 static int omap2_mcspi_target_abort(struct spi_controller *ctlr)
1128 {
1129 struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1130 struct omap2_mcspi_dma *mcspi_dma = mcspi->dma_channels;
1131
1132 mcspi->target_aborted = true;
1133 complete(&mcspi_dma->dma_rx_completion);
1134 complete(&mcspi_dma->dma_tx_completion);
1135 complete(&mcspi->txdone);
1136
1137 return 0;
1138 }
1139
omap2_mcspi_transfer_one(struct spi_controller * ctlr,struct spi_device * spi,struct spi_transfer * t)1140 static int omap2_mcspi_transfer_one(struct spi_controller *ctlr,
1141 struct spi_device *spi,
1142 struct spi_transfer *t)
1143 {
1144
1145 /* We only enable one channel at a time -- the one whose message is
1146 * -- although this controller would gladly
1147 * arbitrate among multiple channels. This corresponds to "single
1148 * channel" host mode. As a side effect, we need to manage the
1149 * chipselect with the FORCE bit ... CS != channel enable.
1150 */
1151
1152 struct omap2_mcspi *mcspi;
1153 struct omap2_mcspi_dma *mcspi_dma;
1154 struct omap2_mcspi_cs *cs;
1155 struct omap2_mcspi_device_config *cd;
1156 int par_override = 0;
1157 int status = 0;
1158 u32 chconf;
1159
1160 mcspi = spi_controller_get_devdata(ctlr);
1161 mcspi_dma = mcspi->dma_channels + spi_get_chipselect(spi, 0);
1162 cs = spi->controller_state;
1163 cd = spi->controller_data;
1164
1165 /*
1166 * The target driver could have changed spi->mode in which case
1167 * it will be different from cs->mode (the current hardware setup).
1168 * If so, set par_override (even though its not a parity issue) so
1169 * omap2_mcspi_setup_transfer will be called to configure the hardware
1170 * with the correct mode on the first iteration of the loop below.
1171 */
1172 if (spi->mode != cs->mode)
1173 par_override = 1;
1174
1175 omap2_mcspi_set_enable(spi, 0);
1176
1177 if (spi_get_csgpiod(spi, 0))
1178 omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH);
1179
1180 if (par_override ||
1181 (t->speed_hz != spi->max_speed_hz) ||
1182 (t->bits_per_word != spi->bits_per_word)) {
1183 par_override = 1;
1184 status = omap2_mcspi_setup_transfer(spi, t);
1185 if (status < 0)
1186 goto out;
1187 if (t->speed_hz == spi->max_speed_hz &&
1188 t->bits_per_word == spi->bits_per_word)
1189 par_override = 0;
1190 }
1191
1192 chconf = mcspi_cached_chconf0(spi);
1193 chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1194 chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1195
1196 if (t->tx_buf == NULL)
1197 chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1198 else if (t->rx_buf == NULL)
1199 chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1200
1201 if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1202 /* Turbo mode is for more than one word */
1203 if (t->len > ((cs->word_len + 7) >> 3))
1204 chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1205 }
1206
1207 mcspi_write_chconf0(spi, chconf);
1208
1209 if (t->len) {
1210 unsigned count;
1211
1212 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1213 spi_xfer_is_dma_mapped(ctlr, spi, t))
1214 omap2_mcspi_set_fifo(spi, t, 1);
1215
1216 omap2_mcspi_set_enable(spi, 1);
1217
1218 /* RX_ONLY mode needs dummy data in TX reg */
1219 if (t->tx_buf == NULL)
1220 writel_relaxed(0, cs->base
1221 + OMAP2_MCSPI_TX0);
1222
1223 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1224 spi_xfer_is_dma_mapped(ctlr, spi, t))
1225 count = omap2_mcspi_txrx_dma(spi, t);
1226 else
1227 count = omap2_mcspi_txrx_pio(spi, t);
1228
1229 if (count != t->len) {
1230 status = -EIO;
1231 goto out;
1232 }
1233 }
1234
1235 omap2_mcspi_set_enable(spi, 0);
1236
1237 if (mcspi->fifo_depth > 0)
1238 omap2_mcspi_set_fifo(spi, t, 0);
1239
1240 out:
1241 /* Restore defaults if they were overriden */
1242 if (par_override) {
1243 par_override = 0;
1244 status = omap2_mcspi_setup_transfer(spi, NULL);
1245 }
1246
1247 omap2_mcspi_set_enable(spi, 0);
1248
1249 if (spi_get_csgpiod(spi, 0))
1250 omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH));
1251
1252 if (mcspi->fifo_depth > 0 && t)
1253 omap2_mcspi_set_fifo(spi, t, 0);
1254
1255 return status;
1256 }
1257
omap2_mcspi_prepare_message(struct spi_controller * ctlr,struct spi_message * msg)1258 static int omap2_mcspi_prepare_message(struct spi_controller *ctlr,
1259 struct spi_message *msg)
1260 {
1261 struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1262 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1263 struct omap2_mcspi_cs *cs;
1264 struct spi_transfer *tr;
1265 u8 bits_per_word;
1266
1267 /*
1268 * The conditions are strict, it is mandatory to check each transfer of the list to see if
1269 * multi-mode is applicable.
1270 */
1271 mcspi->use_multi_mode = true;
1272
1273 if (mcspi->last_msg_kept_cs)
1274 mcspi->use_multi_mode = false;
1275
1276 list_for_each_entry(tr, &msg->transfers, transfer_list) {
1277 if (!tr->bits_per_word)
1278 bits_per_word = msg->spi->bits_per_word;
1279 else
1280 bits_per_word = tr->bits_per_word;
1281
1282 /*
1283 * Check if this transfer contains only one word;
1284 */
1285 if (bits_per_word < 8 && tr->len == 1) {
1286 /* multi-mode is applicable, only one word (1..7 bits) */
1287 } else if (bits_per_word >= 8 && tr->len == bits_per_word / 8) {
1288 /* multi-mode is applicable, only one word (8..32 bits) */
1289 } else {
1290 /* multi-mode is not applicable: more than one word in the transfer */
1291 mcspi->use_multi_mode = false;
1292 }
1293
1294 if (list_is_last(&tr->transfer_list, &msg->transfers)) {
1295 /* Check if transfer asks to keep the CS status after the whole message */
1296 if (tr->cs_change) {
1297 mcspi->use_multi_mode = false;
1298 mcspi->last_msg_kept_cs = true;
1299 } else {
1300 mcspi->last_msg_kept_cs = false;
1301 }
1302 } else {
1303 /* Check if transfer asks to change the CS status after the transfer */
1304 if (!tr->cs_change)
1305 mcspi->use_multi_mode = false;
1306 }
1307 }
1308
1309 omap2_mcspi_set_mode(ctlr);
1310
1311 /* In single mode only a single channel can have the FORCE bit enabled
1312 * in its chconf0 register.
1313 * Scan all channels and disable them except the current one.
1314 * A FORCE can remain from a last transfer having cs_change enabled
1315 *
1316 * In multi mode all FORCE bits must be disabled.
1317 */
1318 list_for_each_entry(cs, &ctx->cs, node) {
1319 if (msg->spi->controller_state == cs && !mcspi->use_multi_mode) {
1320 continue;
1321 }
1322
1323 if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
1324 cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1325 writel_relaxed(cs->chconf0,
1326 cs->base + OMAP2_MCSPI_CHCONF0);
1327 readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
1328 }
1329 }
1330
1331 return 0;
1332 }
1333
omap2_mcspi_can_dma(struct spi_controller * ctlr,struct spi_device * spi,struct spi_transfer * xfer)1334 static bool omap2_mcspi_can_dma(struct spi_controller *ctlr,
1335 struct spi_device *spi,
1336 struct spi_transfer *xfer)
1337 {
1338 struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
1339 struct omap2_mcspi_dma *mcspi_dma =
1340 &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
1341
1342 if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx)
1343 return false;
1344
1345 if (spi_controller_is_target(ctlr))
1346 return true;
1347
1348 ctlr->dma_rx = mcspi_dma->dma_rx;
1349 ctlr->dma_tx = mcspi_dma->dma_tx;
1350
1351 return (xfer->len >= DMA_MIN_BYTES);
1352 }
1353
omap2_mcspi_max_xfer_size(struct spi_device * spi)1354 static size_t omap2_mcspi_max_xfer_size(struct spi_device *spi)
1355 {
1356 struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
1357 struct omap2_mcspi_dma *mcspi_dma =
1358 &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
1359
1360 if (mcspi->max_xfer_len && mcspi_dma->dma_rx)
1361 return mcspi->max_xfer_len;
1362
1363 return SIZE_MAX;
1364 }
1365
omap2_mcspi_controller_setup(struct omap2_mcspi * mcspi)1366 static int omap2_mcspi_controller_setup(struct omap2_mcspi *mcspi)
1367 {
1368 struct spi_controller *ctlr = mcspi->ctlr;
1369 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1370 int ret = 0;
1371
1372 ret = pm_runtime_resume_and_get(mcspi->dev);
1373 if (ret < 0)
1374 return ret;
1375
1376 mcspi_write_reg(ctlr, OMAP2_MCSPI_WAKEUPENABLE,
1377 OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1378 ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1379
1380 omap2_mcspi_set_mode(ctlr);
1381 pm_runtime_put_autosuspend(mcspi->dev);
1382 return 0;
1383 }
1384
omap_mcspi_runtime_suspend(struct device * dev)1385 static int omap_mcspi_runtime_suspend(struct device *dev)
1386 {
1387 int error;
1388
1389 error = pinctrl_pm_select_idle_state(dev);
1390 if (error)
1391 dev_warn(dev, "%s: failed to set pins: %i\n", __func__, error);
1392
1393 return 0;
1394 }
1395
1396 /*
1397 * When SPI wake up from off-mode, CS is in activate state. If it was in
1398 * inactive state when driver was suspend, then force it to inactive state at
1399 * wake up.
1400 */
omap_mcspi_runtime_resume(struct device * dev)1401 static int omap_mcspi_runtime_resume(struct device *dev)
1402 {
1403 struct spi_controller *ctlr = dev_get_drvdata(dev);
1404 struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1405 struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1406 struct omap2_mcspi_cs *cs;
1407 int error;
1408
1409 error = pinctrl_pm_select_default_state(dev);
1410 if (error)
1411 dev_warn(dev, "%s: failed to set pins: %i\n", __func__, error);
1412
1413 /* McSPI: context restore */
1414 mcspi_write_reg(ctlr, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
1415 mcspi_write_reg(ctlr, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
1416
1417 list_for_each_entry(cs, &ctx->cs, node) {
1418 /*
1419 * We need to toggle CS state for OMAP take this
1420 * change in account.
1421 */
1422 if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1423 cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1424 writel_relaxed(cs->chconf0,
1425 cs->base + OMAP2_MCSPI_CHCONF0);
1426 cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1427 writel_relaxed(cs->chconf0,
1428 cs->base + OMAP2_MCSPI_CHCONF0);
1429 } else {
1430 writel_relaxed(cs->chconf0,
1431 cs->base + OMAP2_MCSPI_CHCONF0);
1432 }
1433 }
1434
1435 return 0;
1436 }
1437
1438 static struct omap2_mcspi_platform_config omap2_pdata = {
1439 .regs_offset = 0,
1440 };
1441
1442 static struct omap2_mcspi_platform_config omap4_pdata = {
1443 .regs_offset = OMAP4_MCSPI_REG_OFFSET,
1444 };
1445
1446 static struct omap2_mcspi_platform_config am654_pdata = {
1447 .regs_offset = OMAP4_MCSPI_REG_OFFSET,
1448 .max_xfer_len = SZ_4K - 1,
1449 };
1450
1451 static const struct of_device_id omap_mcspi_of_match[] = {
1452 {
1453 .compatible = "ti,omap2-mcspi",
1454 .data = &omap2_pdata,
1455 },
1456 {
1457 .compatible = "ti,omap4-mcspi",
1458 .data = &omap4_pdata,
1459 },
1460 {
1461 .compatible = "ti,am654-mcspi",
1462 .data = &am654_pdata,
1463 },
1464 { },
1465 };
1466 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1467
omap2_mcspi_probe(struct platform_device * pdev)1468 static int omap2_mcspi_probe(struct platform_device *pdev)
1469 {
1470 struct spi_controller *ctlr;
1471 const struct omap2_mcspi_platform_config *pdata;
1472 struct omap2_mcspi *mcspi;
1473 struct resource *r;
1474 int status = 0, i;
1475 u32 regs_offset = 0;
1476 struct device_node *node = pdev->dev.of_node;
1477 const struct of_device_id *match;
1478
1479 if (of_property_read_bool(node, "spi-slave"))
1480 ctlr = spi_alloc_target(&pdev->dev, sizeof(*mcspi));
1481 else
1482 ctlr = spi_alloc_host(&pdev->dev, sizeof(*mcspi));
1483 if (!ctlr)
1484 return -ENOMEM;
1485
1486 /* the spi->mode bits understood by this driver: */
1487 ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1488 ctlr->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1489 ctlr->setup = omap2_mcspi_setup;
1490 ctlr->auto_runtime_pm = true;
1491 ctlr->prepare_message = omap2_mcspi_prepare_message;
1492 ctlr->can_dma = omap2_mcspi_can_dma;
1493 ctlr->transfer_one = omap2_mcspi_transfer_one;
1494 ctlr->set_cs = omap2_mcspi_set_cs;
1495 ctlr->cleanup = omap2_mcspi_cleanup;
1496 ctlr->target_abort = omap2_mcspi_target_abort;
1497 ctlr->dev.of_node = node;
1498 ctlr->use_gpio_descriptors = true;
1499
1500 platform_set_drvdata(pdev, ctlr);
1501
1502 mcspi = spi_controller_get_devdata(ctlr);
1503 mcspi->ctlr = ctlr;
1504
1505 match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1506 if (match) {
1507 u32 num_cs = 1; /* default number of chipselect */
1508 pdata = match->data;
1509
1510 of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1511 ctlr->num_chipselect = num_cs;
1512 if (of_property_read_bool(node, "ti,pindir-d0-out-d1-in"))
1513 mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1514 } else {
1515 pdata = dev_get_platdata(&pdev->dev);
1516 ctlr->num_chipselect = pdata->num_cs;
1517 mcspi->pin_dir = pdata->pin_dir;
1518 }
1519 regs_offset = pdata->regs_offset;
1520 if (pdata->max_xfer_len) {
1521 mcspi->max_xfer_len = pdata->max_xfer_len;
1522 ctlr->max_transfer_size = omap2_mcspi_max_xfer_size;
1523 }
1524
1525 mcspi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &r);
1526 if (IS_ERR(mcspi->base)) {
1527 status = PTR_ERR(mcspi->base);
1528 goto free_ctlr;
1529 }
1530 mcspi->phys = r->start + regs_offset;
1531 mcspi->base += regs_offset;
1532
1533 mcspi->dev = &pdev->dev;
1534
1535 INIT_LIST_HEAD(&mcspi->ctx.cs);
1536
1537 mcspi->dma_channels = devm_kcalloc(&pdev->dev, ctlr->num_chipselect,
1538 sizeof(struct omap2_mcspi_dma),
1539 GFP_KERNEL);
1540 if (mcspi->dma_channels == NULL) {
1541 status = -ENOMEM;
1542 goto free_ctlr;
1543 }
1544
1545 for (i = 0; i < ctlr->num_chipselect; i++) {
1546 sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
1547 sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
1548
1549 status = omap2_mcspi_request_dma(mcspi,
1550 &mcspi->dma_channels[i]);
1551 if (status == -EPROBE_DEFER)
1552 goto free_ctlr;
1553 }
1554
1555 status = platform_get_irq(pdev, 0);
1556 if (status < 0)
1557 goto free_ctlr;
1558 init_completion(&mcspi->txdone);
1559 status = devm_request_irq(&pdev->dev, status,
1560 omap2_mcspi_irq_handler, 0, pdev->name,
1561 mcspi);
1562 if (status) {
1563 dev_err(&pdev->dev, "Cannot request IRQ");
1564 goto free_ctlr;
1565 }
1566
1567 mcspi->ref_clk = devm_clk_get_optional_enabled(&pdev->dev, NULL);
1568 if (IS_ERR(mcspi->ref_clk)) {
1569 status = PTR_ERR(mcspi->ref_clk);
1570 dev_err_probe(&pdev->dev, status, "Failed to get ref_clk");
1571 goto free_ctlr;
1572 }
1573 if (mcspi->ref_clk)
1574 mcspi->ref_clk_hz = clk_get_rate(mcspi->ref_clk);
1575 else
1576 mcspi->ref_clk_hz = OMAP2_MCSPI_MAX_FREQ;
1577 ctlr->max_speed_hz = mcspi->ref_clk_hz;
1578 ctlr->min_speed_hz = mcspi->ref_clk_hz >> 15;
1579
1580 pm_runtime_use_autosuspend(&pdev->dev);
1581 pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1582 pm_runtime_enable(&pdev->dev);
1583
1584 status = omap2_mcspi_controller_setup(mcspi);
1585 if (status < 0)
1586 goto disable_pm;
1587
1588 status = devm_spi_register_controller(&pdev->dev, ctlr);
1589 if (status < 0)
1590 goto disable_pm;
1591
1592 return status;
1593
1594 disable_pm:
1595 pm_runtime_dont_use_autosuspend(&pdev->dev);
1596 pm_runtime_put_sync(&pdev->dev);
1597 pm_runtime_disable(&pdev->dev);
1598 free_ctlr:
1599 omap2_mcspi_release_dma(ctlr);
1600 spi_controller_put(ctlr);
1601 return status;
1602 }
1603
omap2_mcspi_remove(struct platform_device * pdev)1604 static void omap2_mcspi_remove(struct platform_device *pdev)
1605 {
1606 struct spi_controller *ctlr = platform_get_drvdata(pdev);
1607 struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1608
1609 omap2_mcspi_release_dma(ctlr);
1610
1611 pm_runtime_dont_use_autosuspend(mcspi->dev);
1612 pm_runtime_put_sync(mcspi->dev);
1613 pm_runtime_disable(&pdev->dev);
1614 }
1615
1616 /* work with hotplug and coldplug */
1617 MODULE_ALIAS("platform:omap2_mcspi");
1618
omap2_mcspi_suspend(struct device * dev)1619 static int __maybe_unused omap2_mcspi_suspend(struct device *dev)
1620 {
1621 struct spi_controller *ctlr = dev_get_drvdata(dev);
1622 struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1623 int error;
1624
1625 error = pinctrl_pm_select_sleep_state(dev);
1626 if (error)
1627 dev_warn(mcspi->dev, "%s: failed to set pins: %i\n",
1628 __func__, error);
1629
1630 error = spi_controller_suspend(ctlr);
1631 if (error)
1632 dev_warn(mcspi->dev, "%s: controller suspend failed: %i\n",
1633 __func__, error);
1634
1635 return pm_runtime_force_suspend(dev);
1636 }
1637
omap2_mcspi_resume(struct device * dev)1638 static int __maybe_unused omap2_mcspi_resume(struct device *dev)
1639 {
1640 struct spi_controller *ctlr = dev_get_drvdata(dev);
1641 struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1642 int error;
1643
1644 error = spi_controller_resume(ctlr);
1645 if (error)
1646 dev_warn(mcspi->dev, "%s: controller resume failed: %i\n",
1647 __func__, error);
1648
1649 return pm_runtime_force_resume(dev);
1650 }
1651
1652 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1653 SET_SYSTEM_SLEEP_PM_OPS(omap2_mcspi_suspend,
1654 omap2_mcspi_resume)
1655 .runtime_suspend = omap_mcspi_runtime_suspend,
1656 .runtime_resume = omap_mcspi_runtime_resume,
1657 };
1658
1659 static struct platform_driver omap2_mcspi_driver = {
1660 .driver = {
1661 .name = "omap2_mcspi",
1662 .pm = &omap2_mcspi_pm_ops,
1663 .of_match_table = omap_mcspi_of_match,
1664 },
1665 .probe = omap2_mcspi_probe,
1666 .remove = omap2_mcspi_remove,
1667 };
1668
1669 module_platform_driver(omap2_mcspi_driver);
1670 MODULE_DESCRIPTION("OMAP2 McSPI controller driver");
1671 MODULE_LICENSE("GPL");
1672