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