xref: /openbmc/linux/drivers/spi/spi-omap2-mcspi.c (revision b593bce5)
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 Yrj�l� <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 #include <linux/iopoll.h>
28 
29 #include <linux/spi/spi.h>
30 #include <linux/gpio.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_master	*master;
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 	int			fifo_depth;
131 	bool			slave_aborted;
132 	unsigned int		pin_dir:1;
133 };
134 
135 struct omap2_mcspi_cs {
136 	void __iomem		*base;
137 	unsigned long		phys;
138 	int			word_len;
139 	u16			mode;
140 	struct list_head	node;
141 	/* Context save and restore shadow register */
142 	u32			chconf0, chctrl0;
143 };
144 
145 static inline void mcspi_write_reg(struct spi_master *master,
146 		int idx, u32 val)
147 {
148 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
149 
150 	writel_relaxed(val, mcspi->base + idx);
151 }
152 
153 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
154 {
155 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
156 
157 	return readl_relaxed(mcspi->base + idx);
158 }
159 
160 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
161 		int idx, u32 val)
162 {
163 	struct omap2_mcspi_cs	*cs = spi->controller_state;
164 
165 	writel_relaxed(val, cs->base +  idx);
166 }
167 
168 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
169 {
170 	struct omap2_mcspi_cs	*cs = spi->controller_state;
171 
172 	return readl_relaxed(cs->base + idx);
173 }
174 
175 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
176 {
177 	struct omap2_mcspi_cs *cs = spi->controller_state;
178 
179 	return cs->chconf0;
180 }
181 
182 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
183 {
184 	struct omap2_mcspi_cs *cs = spi->controller_state;
185 
186 	cs->chconf0 = val;
187 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
188 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
189 }
190 
191 static inline int mcspi_bytes_per_word(int word_len)
192 {
193 	if (word_len <= 8)
194 		return 1;
195 	else if (word_len <= 16)
196 		return 2;
197 	else /* word_len <= 32 */
198 		return 4;
199 }
200 
201 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
202 		int is_read, int enable)
203 {
204 	u32 l, rw;
205 
206 	l = mcspi_cached_chconf0(spi);
207 
208 	if (is_read) /* 1 is read, 0 write */
209 		rw = OMAP2_MCSPI_CHCONF_DMAR;
210 	else
211 		rw = OMAP2_MCSPI_CHCONF_DMAW;
212 
213 	if (enable)
214 		l |= rw;
215 	else
216 		l &= ~rw;
217 
218 	mcspi_write_chconf0(spi, l);
219 }
220 
221 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
222 {
223 	struct omap2_mcspi_cs *cs = spi->controller_state;
224 	u32 l;
225 
226 	l = cs->chctrl0;
227 	if (enable)
228 		l |= OMAP2_MCSPI_CHCTRL_EN;
229 	else
230 		l &= ~OMAP2_MCSPI_CHCTRL_EN;
231 	cs->chctrl0 = l;
232 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
233 	/* Flash post-writes */
234 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
235 }
236 
237 static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable)
238 {
239 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
240 	u32 l;
241 
242 	/* The controller handles the inverted chip selects
243 	 * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert
244 	 * the inversion from the core spi_set_cs function.
245 	 */
246 	if (spi->mode & SPI_CS_HIGH)
247 		enable = !enable;
248 
249 	if (spi->controller_state) {
250 		int err = pm_runtime_get_sync(mcspi->dev);
251 		if (err < 0) {
252 			pm_runtime_put_noidle(mcspi->dev);
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 
271 static void omap2_mcspi_set_mode(struct spi_master *master)
272 {
273 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
274 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
275 	u32 l;
276 
277 	/*
278 	 * Choose master or slave mode
279 	 */
280 	l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
281 	l &= ~(OMAP2_MCSPI_MODULCTRL_STEST);
282 	if (spi_controller_is_slave(master)) {
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(master, OMAP2_MCSPI_MODULCTRL, l);
289 
290 	ctx->modulctrl = l;
291 }
292 
293 static void omap2_mcspi_set_fifo(const struct spi_device *spi,
294 				struct spi_transfer *t, int enable)
295 {
296 	struct spi_master *master = spi->master;
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_master_get_devdata(master);
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(master, 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 
349 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
350 {
351 	u32 val;
352 
353 	return readl_poll_timeout(reg, val, val & bit, 1, MSEC_PER_SEC);
354 }
355 
356 static int mcspi_wait_for_completion(struct  omap2_mcspi *mcspi,
357 				     struct completion *x)
358 {
359 	if (spi_controller_is_slave(mcspi->master)) {
360 		if (wait_for_completion_interruptible(x) ||
361 		    mcspi->slave_aborted)
362 			return -EINTR;
363 	} else {
364 		wait_for_completion(x);
365 	}
366 
367 	return 0;
368 }
369 
370 static void omap2_mcspi_rx_callback(void *data)
371 {
372 	struct spi_device *spi = data;
373 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
374 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
375 
376 	/* We must disable the DMA RX request */
377 	omap2_mcspi_set_dma_req(spi, 1, 0);
378 
379 	complete(&mcspi_dma->dma_rx_completion);
380 }
381 
382 static void omap2_mcspi_tx_callback(void *data)
383 {
384 	struct spi_device *spi = data;
385 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
386 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
387 
388 	/* We must disable the DMA TX request */
389 	omap2_mcspi_set_dma_req(spi, 0, 0);
390 
391 	complete(&mcspi_dma->dma_tx_completion);
392 }
393 
394 static void omap2_mcspi_tx_dma(struct spi_device *spi,
395 				struct spi_transfer *xfer,
396 				struct dma_slave_config cfg)
397 {
398 	struct omap2_mcspi	*mcspi;
399 	struct omap2_mcspi_dma  *mcspi_dma;
400 
401 	mcspi = spi_master_get_devdata(spi->master);
402 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
403 
404 	if (mcspi_dma->dma_tx) {
405 		struct dma_async_tx_descriptor *tx;
406 
407 		dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
408 
409 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl,
410 					     xfer->tx_sg.nents,
411 					     DMA_MEM_TO_DEV,
412 					     DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
413 		if (tx) {
414 			tx->callback = omap2_mcspi_tx_callback;
415 			tx->callback_param = spi;
416 			dmaengine_submit(tx);
417 		} else {
418 			/* FIXME: fall back to PIO? */
419 		}
420 	}
421 	dma_async_issue_pending(mcspi_dma->dma_tx);
422 	omap2_mcspi_set_dma_req(spi, 0, 1);
423 
424 }
425 
426 static unsigned
427 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
428 				struct dma_slave_config cfg,
429 				unsigned es)
430 {
431 	struct omap2_mcspi	*mcspi;
432 	struct omap2_mcspi_dma  *mcspi_dma;
433 	unsigned int		count, transfer_reduction = 0;
434 	struct scatterlist	*sg_out[2];
435 	int			nb_sizes = 0, out_mapped_nents[2], ret, x;
436 	size_t			sizes[2];
437 	u32			l;
438 	int			elements = 0;
439 	int			word_len, element_count;
440 	struct omap2_mcspi_cs	*cs = spi->controller_state;
441 	void __iomem		*chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
442 
443 	mcspi = spi_master_get_devdata(spi->master);
444 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
445 	count = xfer->len;
446 
447 	/*
448 	 *  In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM
449 	 *  it mentions reducing DMA transfer length by one element in master
450 	 *  normal mode.
451 	 */
452 	if (mcspi->fifo_depth == 0)
453 		transfer_reduction = es;
454 
455 	word_len = cs->word_len;
456 	l = mcspi_cached_chconf0(spi);
457 
458 	if (word_len <= 8)
459 		element_count = count;
460 	else if (word_len <= 16)
461 		element_count = count >> 1;
462 	else /* word_len <= 32 */
463 		element_count = count >> 2;
464 
465 	if (mcspi_dma->dma_rx) {
466 		struct dma_async_tx_descriptor *tx;
467 
468 		dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
469 
470 		/*
471 		 *  Reduce DMA transfer length by one more if McSPI is
472 		 *  configured in turbo mode.
473 		 */
474 		if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
475 			transfer_reduction += es;
476 
477 		if (transfer_reduction) {
478 			/* Split sgl into two. The second sgl won't be used. */
479 			sizes[0] = count - transfer_reduction;
480 			sizes[1] = transfer_reduction;
481 			nb_sizes = 2;
482 		} else {
483 			/*
484 			 * Don't bother splitting the sgl. This essentially
485 			 * clones the original sgl.
486 			 */
487 			sizes[0] = count;
488 			nb_sizes = 1;
489 		}
490 
491 		ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents,
492 			       0, nb_sizes,
493 			       sizes,
494 			       sg_out, out_mapped_nents,
495 			       GFP_KERNEL);
496 
497 		if (ret < 0) {
498 			dev_err(&spi->dev, "sg_split failed\n");
499 			return 0;
500 		}
501 
502 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx,
503 					     sg_out[0],
504 					     out_mapped_nents[0],
505 					     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 
516 	dma_async_issue_pending(mcspi_dma->dma_rx);
517 	omap2_mcspi_set_dma_req(spi, 1, 1);
518 
519 	ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_rx_completion);
520 	if (ret || mcspi->slave_aborted) {
521 		dmaengine_terminate_sync(mcspi_dma->dma_rx);
522 		omap2_mcspi_set_dma_req(spi, 1, 0);
523 		return 0;
524 	}
525 
526 	for (x = 0; x < nb_sizes; x++)
527 		kfree(sg_out[x]);
528 
529 	if (mcspi->fifo_depth > 0)
530 		return count;
531 
532 	/*
533 	 *  Due to the DMA transfer length reduction the missing bytes must
534 	 *  be read manually to receive all of the expected data.
535 	 */
536 	omap2_mcspi_set_enable(spi, 0);
537 
538 	elements = element_count - 1;
539 
540 	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
541 		elements--;
542 
543 		if (!mcspi_wait_for_reg_bit(chstat_reg,
544 					    OMAP2_MCSPI_CHSTAT_RXS)) {
545 			u32 w;
546 
547 			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
548 			if (word_len <= 8)
549 				((u8 *)xfer->rx_buf)[elements++] = w;
550 			else if (word_len <= 16)
551 				((u16 *)xfer->rx_buf)[elements++] = w;
552 			else /* word_len <= 32 */
553 				((u32 *)xfer->rx_buf)[elements++] = w;
554 		} else {
555 			int bytes_per_word = mcspi_bytes_per_word(word_len);
556 			dev_err(&spi->dev, "DMA RX penultimate word empty\n");
557 			count -= (bytes_per_word << 1);
558 			omap2_mcspi_set_enable(spi, 1);
559 			return count;
560 		}
561 	}
562 	if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) {
563 		u32 w;
564 
565 		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
566 		if (word_len <= 8)
567 			((u8 *)xfer->rx_buf)[elements] = w;
568 		else if (word_len <= 16)
569 			((u16 *)xfer->rx_buf)[elements] = w;
570 		else /* word_len <= 32 */
571 			((u32 *)xfer->rx_buf)[elements] = w;
572 	} else {
573 		dev_err(&spi->dev, "DMA RX last word empty\n");
574 		count -= mcspi_bytes_per_word(word_len);
575 	}
576 	omap2_mcspi_set_enable(spi, 1);
577 	return count;
578 }
579 
580 static unsigned
581 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
582 {
583 	struct omap2_mcspi	*mcspi;
584 	struct omap2_mcspi_cs	*cs = spi->controller_state;
585 	struct omap2_mcspi_dma  *mcspi_dma;
586 	unsigned int		count;
587 	u8			*rx;
588 	const u8		*tx;
589 	struct dma_slave_config	cfg;
590 	enum dma_slave_buswidth width;
591 	unsigned es;
592 	void __iomem		*chstat_reg;
593 	void __iomem            *irqstat_reg;
594 	int			wait_res;
595 
596 	mcspi = spi_master_get_devdata(spi->master);
597 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
598 
599 	if (cs->word_len <= 8) {
600 		width = DMA_SLAVE_BUSWIDTH_1_BYTE;
601 		es = 1;
602 	} else if (cs->word_len <= 16) {
603 		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
604 		es = 2;
605 	} else {
606 		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
607 		es = 4;
608 	}
609 
610 	count = xfer->len;
611 
612 	memset(&cfg, 0, sizeof(cfg));
613 	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
614 	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
615 	cfg.src_addr_width = width;
616 	cfg.dst_addr_width = width;
617 	cfg.src_maxburst = 1;
618 	cfg.dst_maxburst = 1;
619 
620 	rx = xfer->rx_buf;
621 	tx = xfer->tx_buf;
622 
623 	mcspi->slave_aborted = false;
624 	reinit_completion(&mcspi_dma->dma_tx_completion);
625 	reinit_completion(&mcspi_dma->dma_rx_completion);
626 	reinit_completion(&mcspi->txdone);
627 	if (tx) {
628 		/* Enable EOW IRQ to know end of tx in slave mode */
629 		if (spi_controller_is_slave(spi->master))
630 			mcspi_write_reg(spi->master,
631 					OMAP2_MCSPI_IRQENABLE,
632 					OMAP2_MCSPI_IRQSTATUS_EOW);
633 		omap2_mcspi_tx_dma(spi, xfer, cfg);
634 	}
635 
636 	if (rx != NULL)
637 		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
638 
639 	if (tx != NULL) {
640 		int ret;
641 
642 		ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_tx_completion);
643 		if (ret || mcspi->slave_aborted) {
644 			dmaengine_terminate_sync(mcspi_dma->dma_tx);
645 			omap2_mcspi_set_dma_req(spi, 0, 0);
646 			return 0;
647 		}
648 
649 		if (spi_controller_is_slave(mcspi->master)) {
650 			ret = mcspi_wait_for_completion(mcspi, &mcspi->txdone);
651 			if (ret || mcspi->slave_aborted)
652 				return 0;
653 		}
654 
655 		if (mcspi->fifo_depth > 0) {
656 			irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
657 
658 			if (mcspi_wait_for_reg_bit(irqstat_reg,
659 						OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
660 				dev_err(&spi->dev, "EOW timed out\n");
661 
662 			mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
663 					OMAP2_MCSPI_IRQSTATUS_EOW);
664 		}
665 
666 		/* for TX_ONLY mode, be sure all words have shifted out */
667 		if (rx == NULL) {
668 			chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
669 			if (mcspi->fifo_depth > 0) {
670 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
671 						OMAP2_MCSPI_CHSTAT_TXFFE);
672 				if (wait_res < 0)
673 					dev_err(&spi->dev, "TXFFE timed out\n");
674 			} else {
675 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
676 						OMAP2_MCSPI_CHSTAT_TXS);
677 				if (wait_res < 0)
678 					dev_err(&spi->dev, "TXS timed out\n");
679 			}
680 			if (wait_res >= 0 &&
681 				(mcspi_wait_for_reg_bit(chstat_reg,
682 					OMAP2_MCSPI_CHSTAT_EOT) < 0))
683 				dev_err(&spi->dev, "EOT timed out\n");
684 		}
685 	}
686 	return count;
687 }
688 
689 static unsigned
690 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
691 {
692 	struct omap2_mcspi_cs	*cs = spi->controller_state;
693 	unsigned int		count, c;
694 	u32			l;
695 	void __iomem		*base = cs->base;
696 	void __iomem		*tx_reg;
697 	void __iomem		*rx_reg;
698 	void __iomem		*chstat_reg;
699 	int			word_len;
700 
701 	count = xfer->len;
702 	c = count;
703 	word_len = cs->word_len;
704 
705 	l = mcspi_cached_chconf0(spi);
706 
707 	/* We store the pre-calculated register addresses on stack to speed
708 	 * up the transfer loop. */
709 	tx_reg		= base + OMAP2_MCSPI_TX0;
710 	rx_reg		= base + OMAP2_MCSPI_RX0;
711 	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
712 
713 	if (c < (word_len>>3))
714 		return 0;
715 
716 	if (word_len <= 8) {
717 		u8		*rx;
718 		const u8	*tx;
719 
720 		rx = xfer->rx_buf;
721 		tx = xfer->tx_buf;
722 
723 		do {
724 			c -= 1;
725 			if (tx != NULL) {
726 				if (mcspi_wait_for_reg_bit(chstat_reg,
727 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
728 					dev_err(&spi->dev, "TXS timed out\n");
729 					goto out;
730 				}
731 				dev_vdbg(&spi->dev, "write-%d %02x\n",
732 						word_len, *tx);
733 				writel_relaxed(*tx++, tx_reg);
734 			}
735 			if (rx != NULL) {
736 				if (mcspi_wait_for_reg_bit(chstat_reg,
737 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
738 					dev_err(&spi->dev, "RXS timed out\n");
739 					goto out;
740 				}
741 
742 				if (c == 1 && tx == NULL &&
743 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
744 					omap2_mcspi_set_enable(spi, 0);
745 					*rx++ = readl_relaxed(rx_reg);
746 					dev_vdbg(&spi->dev, "read-%d %02x\n",
747 						    word_len, *(rx - 1));
748 					if (mcspi_wait_for_reg_bit(chstat_reg,
749 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
750 						dev_err(&spi->dev,
751 							"RXS timed out\n");
752 						goto out;
753 					}
754 					c = 0;
755 				} else if (c == 0 && tx == NULL) {
756 					omap2_mcspi_set_enable(spi, 0);
757 				}
758 
759 				*rx++ = readl_relaxed(rx_reg);
760 				dev_vdbg(&spi->dev, "read-%d %02x\n",
761 						word_len, *(rx - 1));
762 			}
763 		} while (c);
764 	} else if (word_len <= 16) {
765 		u16		*rx;
766 		const u16	*tx;
767 
768 		rx = xfer->rx_buf;
769 		tx = xfer->tx_buf;
770 		do {
771 			c -= 2;
772 			if (tx != NULL) {
773 				if (mcspi_wait_for_reg_bit(chstat_reg,
774 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
775 					dev_err(&spi->dev, "TXS timed out\n");
776 					goto out;
777 				}
778 				dev_vdbg(&spi->dev, "write-%d %04x\n",
779 						word_len, *tx);
780 				writel_relaxed(*tx++, tx_reg);
781 			}
782 			if (rx != NULL) {
783 				if (mcspi_wait_for_reg_bit(chstat_reg,
784 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
785 					dev_err(&spi->dev, "RXS timed out\n");
786 					goto out;
787 				}
788 
789 				if (c == 2 && tx == NULL &&
790 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
791 					omap2_mcspi_set_enable(spi, 0);
792 					*rx++ = readl_relaxed(rx_reg);
793 					dev_vdbg(&spi->dev, "read-%d %04x\n",
794 						    word_len, *(rx - 1));
795 					if (mcspi_wait_for_reg_bit(chstat_reg,
796 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
797 						dev_err(&spi->dev,
798 							"RXS timed out\n");
799 						goto out;
800 					}
801 					c = 0;
802 				} else if (c == 0 && tx == NULL) {
803 					omap2_mcspi_set_enable(spi, 0);
804 				}
805 
806 				*rx++ = readl_relaxed(rx_reg);
807 				dev_vdbg(&spi->dev, "read-%d %04x\n",
808 						word_len, *(rx - 1));
809 			}
810 		} while (c >= 2);
811 	} else if (word_len <= 32) {
812 		u32		*rx;
813 		const u32	*tx;
814 
815 		rx = xfer->rx_buf;
816 		tx = xfer->tx_buf;
817 		do {
818 			c -= 4;
819 			if (tx != NULL) {
820 				if (mcspi_wait_for_reg_bit(chstat_reg,
821 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
822 					dev_err(&spi->dev, "TXS timed out\n");
823 					goto out;
824 				}
825 				dev_vdbg(&spi->dev, "write-%d %08x\n",
826 						word_len, *tx);
827 				writel_relaxed(*tx++, tx_reg);
828 			}
829 			if (rx != NULL) {
830 				if (mcspi_wait_for_reg_bit(chstat_reg,
831 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
832 					dev_err(&spi->dev, "RXS timed out\n");
833 					goto out;
834 				}
835 
836 				if (c == 4 && tx == NULL &&
837 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
838 					omap2_mcspi_set_enable(spi, 0);
839 					*rx++ = readl_relaxed(rx_reg);
840 					dev_vdbg(&spi->dev, "read-%d %08x\n",
841 						    word_len, *(rx - 1));
842 					if (mcspi_wait_for_reg_bit(chstat_reg,
843 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
844 						dev_err(&spi->dev,
845 							"RXS timed out\n");
846 						goto out;
847 					}
848 					c = 0;
849 				} else if (c == 0 && tx == NULL) {
850 					omap2_mcspi_set_enable(spi, 0);
851 				}
852 
853 				*rx++ = readl_relaxed(rx_reg);
854 				dev_vdbg(&spi->dev, "read-%d %08x\n",
855 						word_len, *(rx - 1));
856 			}
857 		} while (c >= 4);
858 	}
859 
860 	/* for TX_ONLY mode, be sure all words have shifted out */
861 	if (xfer->rx_buf == NULL) {
862 		if (mcspi_wait_for_reg_bit(chstat_reg,
863 				OMAP2_MCSPI_CHSTAT_TXS) < 0) {
864 			dev_err(&spi->dev, "TXS timed out\n");
865 		} else if (mcspi_wait_for_reg_bit(chstat_reg,
866 				OMAP2_MCSPI_CHSTAT_EOT) < 0)
867 			dev_err(&spi->dev, "EOT timed out\n");
868 
869 		/* disable chan to purge rx datas received in TX_ONLY transfer,
870 		 * otherwise these rx datas will affect the direct following
871 		 * RX_ONLY transfer.
872 		 */
873 		omap2_mcspi_set_enable(spi, 0);
874 	}
875 out:
876 	omap2_mcspi_set_enable(spi, 1);
877 	return count - c;
878 }
879 
880 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
881 {
882 	u32 div;
883 
884 	for (div = 0; div < 15; div++)
885 		if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
886 			return div;
887 
888 	return 15;
889 }
890 
891 /* called only when no transfer is active to this device */
892 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
893 		struct spi_transfer *t)
894 {
895 	struct omap2_mcspi_cs *cs = spi->controller_state;
896 	struct omap2_mcspi *mcspi;
897 	u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
898 	u8 word_len = spi->bits_per_word;
899 	u32 speed_hz = spi->max_speed_hz;
900 
901 	mcspi = spi_master_get_devdata(spi->master);
902 
903 	if (t != NULL && t->bits_per_word)
904 		word_len = t->bits_per_word;
905 
906 	cs->word_len = word_len;
907 
908 	if (t && t->speed_hz)
909 		speed_hz = t->speed_hz;
910 
911 	speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
912 	if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
913 		clkd = omap2_mcspi_calc_divisor(speed_hz);
914 		speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
915 		clkg = 0;
916 	} else {
917 		div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
918 		speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
919 		clkd = (div - 1) & 0xf;
920 		extclk = (div - 1) >> 4;
921 		clkg = OMAP2_MCSPI_CHCONF_CLKG;
922 	}
923 
924 	l = mcspi_cached_chconf0(spi);
925 
926 	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
927 	 * REVISIT: this controller could support SPI_3WIRE mode.
928 	 */
929 	if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
930 		l &= ~OMAP2_MCSPI_CHCONF_IS;
931 		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
932 		l |= OMAP2_MCSPI_CHCONF_DPE0;
933 	} else {
934 		l |= OMAP2_MCSPI_CHCONF_IS;
935 		l |= OMAP2_MCSPI_CHCONF_DPE1;
936 		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
937 	}
938 
939 	/* wordlength */
940 	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
941 	l |= (word_len - 1) << 7;
942 
943 	/* set chipselect polarity; manage with FORCE */
944 	if (!(spi->mode & SPI_CS_HIGH))
945 		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
946 	else
947 		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
948 
949 	/* set clock divisor */
950 	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
951 	l |= clkd << 2;
952 
953 	/* set clock granularity */
954 	l &= ~OMAP2_MCSPI_CHCONF_CLKG;
955 	l |= clkg;
956 	if (clkg) {
957 		cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
958 		cs->chctrl0 |= extclk << 8;
959 		mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
960 	}
961 
962 	/* set SPI mode 0..3 */
963 	if (spi->mode & SPI_CPOL)
964 		l |= OMAP2_MCSPI_CHCONF_POL;
965 	else
966 		l &= ~OMAP2_MCSPI_CHCONF_POL;
967 	if (spi->mode & SPI_CPHA)
968 		l |= OMAP2_MCSPI_CHCONF_PHA;
969 	else
970 		l &= ~OMAP2_MCSPI_CHCONF_PHA;
971 
972 	mcspi_write_chconf0(spi, l);
973 
974 	cs->mode = spi->mode;
975 
976 	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
977 			speed_hz,
978 			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
979 			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
980 
981 	return 0;
982 }
983 
984 /*
985  * Note that we currently allow DMA only if we get a channel
986  * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
987  */
988 static int omap2_mcspi_request_dma(struct spi_device *spi)
989 {
990 	struct spi_master	*master = spi->master;
991 	struct omap2_mcspi	*mcspi;
992 	struct omap2_mcspi_dma	*mcspi_dma;
993 	int ret = 0;
994 
995 	mcspi = spi_master_get_devdata(master);
996 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
997 
998 	init_completion(&mcspi_dma->dma_rx_completion);
999 	init_completion(&mcspi_dma->dma_tx_completion);
1000 
1001 	mcspi_dma->dma_rx = dma_request_chan(&master->dev,
1002 					     mcspi_dma->dma_rx_ch_name);
1003 	if (IS_ERR(mcspi_dma->dma_rx)) {
1004 		ret = PTR_ERR(mcspi_dma->dma_rx);
1005 		mcspi_dma->dma_rx = NULL;
1006 		goto no_dma;
1007 	}
1008 
1009 	mcspi_dma->dma_tx = dma_request_chan(&master->dev,
1010 					     mcspi_dma->dma_tx_ch_name);
1011 	if (IS_ERR(mcspi_dma->dma_tx)) {
1012 		ret = PTR_ERR(mcspi_dma->dma_tx);
1013 		mcspi_dma->dma_tx = NULL;
1014 		dma_release_channel(mcspi_dma->dma_rx);
1015 		mcspi_dma->dma_rx = NULL;
1016 	}
1017 
1018 no_dma:
1019 	return ret;
1020 }
1021 
1022 static int omap2_mcspi_setup(struct spi_device *spi)
1023 {
1024 	int			ret;
1025 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(spi->master);
1026 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1027 	struct omap2_mcspi_dma	*mcspi_dma;
1028 	struct omap2_mcspi_cs	*cs = spi->controller_state;
1029 
1030 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1031 
1032 	if (!cs) {
1033 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
1034 		if (!cs)
1035 			return -ENOMEM;
1036 		cs->base = mcspi->base + spi->chip_select * 0x14;
1037 		cs->phys = mcspi->phys + spi->chip_select * 0x14;
1038 		cs->mode = 0;
1039 		cs->chconf0 = 0;
1040 		cs->chctrl0 = 0;
1041 		spi->controller_state = cs;
1042 		/* Link this to context save list */
1043 		list_add_tail(&cs->node, &ctx->cs);
1044 
1045 		if (gpio_is_valid(spi->cs_gpio)) {
1046 			ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
1047 			if (ret) {
1048 				dev_err(&spi->dev, "failed to request gpio\n");
1049 				return ret;
1050 			}
1051 			gpio_direction_output(spi->cs_gpio,
1052 					 !(spi->mode & SPI_CS_HIGH));
1053 		}
1054 	}
1055 
1056 	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
1057 		ret = omap2_mcspi_request_dma(spi);
1058 		if (ret)
1059 			dev_warn(&spi->dev, "not using DMA for McSPI (%d)\n",
1060 				 ret);
1061 	}
1062 
1063 	ret = pm_runtime_get_sync(mcspi->dev);
1064 	if (ret < 0) {
1065 		pm_runtime_put_noidle(mcspi->dev);
1066 
1067 		return ret;
1068 	}
1069 
1070 	ret = omap2_mcspi_setup_transfer(spi, NULL);
1071 	pm_runtime_mark_last_busy(mcspi->dev);
1072 	pm_runtime_put_autosuspend(mcspi->dev);
1073 
1074 	return ret;
1075 }
1076 
1077 static void omap2_mcspi_cleanup(struct spi_device *spi)
1078 {
1079 	struct omap2_mcspi	*mcspi;
1080 	struct omap2_mcspi_dma	*mcspi_dma;
1081 	struct omap2_mcspi_cs	*cs;
1082 
1083 	mcspi = spi_master_get_devdata(spi->master);
1084 
1085 	if (spi->controller_state) {
1086 		/* Unlink controller state from context save list */
1087 		cs = spi->controller_state;
1088 		list_del(&cs->node);
1089 
1090 		kfree(cs);
1091 	}
1092 
1093 	if (spi->chip_select < spi->master->num_chipselect) {
1094 		mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1095 
1096 		if (mcspi_dma->dma_rx) {
1097 			dma_release_channel(mcspi_dma->dma_rx);
1098 			mcspi_dma->dma_rx = NULL;
1099 		}
1100 		if (mcspi_dma->dma_tx) {
1101 			dma_release_channel(mcspi_dma->dma_tx);
1102 			mcspi_dma->dma_tx = NULL;
1103 		}
1104 	}
1105 
1106 	if (gpio_is_valid(spi->cs_gpio))
1107 		gpio_free(spi->cs_gpio);
1108 }
1109 
1110 static 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->master, OMAP2_MCSPI_IRQSTATUS);
1116 	if (!irqstat)
1117 		return IRQ_NONE;
1118 
1119 	/* Disable IRQ and wakeup slave xfer task */
1120 	mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQENABLE, 0);
1121 	if (irqstat & OMAP2_MCSPI_IRQSTATUS_EOW)
1122 		complete(&mcspi->txdone);
1123 
1124 	return IRQ_HANDLED;
1125 }
1126 
1127 static int omap2_mcspi_slave_abort(struct spi_master *master)
1128 {
1129 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1130 	struct omap2_mcspi_dma *mcspi_dma = mcspi->dma_channels;
1131 
1132 	mcspi->slave_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 
1140 static int omap2_mcspi_transfer_one(struct spi_master *master,
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" master 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_master_get_devdata(master);
1161 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1162 	cs = spi->controller_state;
1163 	cd = spi->controller_data;
1164 
1165 	/*
1166 	 * The slave 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 (gpio_is_valid(spi->cs_gpio))
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 	if (cd && cd->cs_per_word) {
1192 		chconf = mcspi->ctx.modulctrl;
1193 		chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1194 		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1195 		mcspi->ctx.modulctrl =
1196 			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1197 	}
1198 
1199 	chconf = mcspi_cached_chconf0(spi);
1200 	chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1201 	chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1202 
1203 	if (t->tx_buf == NULL)
1204 		chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1205 	else if (t->rx_buf == NULL)
1206 		chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1207 
1208 	if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1209 		/* Turbo mode is for more than one word */
1210 		if (t->len > ((cs->word_len + 7) >> 3))
1211 			chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1212 	}
1213 
1214 	mcspi_write_chconf0(spi, chconf);
1215 
1216 	if (t->len) {
1217 		unsigned	count;
1218 
1219 		if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1220 		    master->cur_msg_mapped &&
1221 		    master->can_dma(master, spi, t))
1222 			omap2_mcspi_set_fifo(spi, t, 1);
1223 
1224 		omap2_mcspi_set_enable(spi, 1);
1225 
1226 		/* RX_ONLY mode needs dummy data in TX reg */
1227 		if (t->tx_buf == NULL)
1228 			writel_relaxed(0, cs->base
1229 					+ OMAP2_MCSPI_TX0);
1230 
1231 		if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1232 		    master->cur_msg_mapped &&
1233 		    master->can_dma(master, spi, t))
1234 			count = omap2_mcspi_txrx_dma(spi, t);
1235 		else
1236 			count = omap2_mcspi_txrx_pio(spi, t);
1237 
1238 		if (count != t->len) {
1239 			status = -EIO;
1240 			goto out;
1241 		}
1242 	}
1243 
1244 	omap2_mcspi_set_enable(spi, 0);
1245 
1246 	if (mcspi->fifo_depth > 0)
1247 		omap2_mcspi_set_fifo(spi, t, 0);
1248 
1249 out:
1250 	/* Restore defaults if they were overriden */
1251 	if (par_override) {
1252 		par_override = 0;
1253 		status = omap2_mcspi_setup_transfer(spi, NULL);
1254 	}
1255 
1256 	if (cd && cd->cs_per_word) {
1257 		chconf = mcspi->ctx.modulctrl;
1258 		chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1259 		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1260 		mcspi->ctx.modulctrl =
1261 			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1262 	}
1263 
1264 	omap2_mcspi_set_enable(spi, 0);
1265 
1266 	if (gpio_is_valid(spi->cs_gpio))
1267 		omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH));
1268 
1269 	if (mcspi->fifo_depth > 0 && t)
1270 		omap2_mcspi_set_fifo(spi, t, 0);
1271 
1272 	return status;
1273 }
1274 
1275 static int omap2_mcspi_prepare_message(struct spi_master *master,
1276 				       struct spi_message *msg)
1277 {
1278 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1279 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1280 	struct omap2_mcspi_cs	*cs;
1281 
1282 	/* Only a single channel can have the FORCE bit enabled
1283 	 * in its chconf0 register.
1284 	 * Scan all channels and disable them except the current one.
1285 	 * A FORCE can remain from a last transfer having cs_change enabled
1286 	 */
1287 	list_for_each_entry(cs, &ctx->cs, node) {
1288 		if (msg->spi->controller_state == cs)
1289 			continue;
1290 
1291 		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
1292 			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1293 			writel_relaxed(cs->chconf0,
1294 					cs->base + OMAP2_MCSPI_CHCONF0);
1295 			readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
1296 		}
1297 	}
1298 
1299 	return 0;
1300 }
1301 
1302 static bool omap2_mcspi_can_dma(struct spi_master *master,
1303 				struct spi_device *spi,
1304 				struct spi_transfer *xfer)
1305 {
1306 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
1307 	struct omap2_mcspi_dma *mcspi_dma =
1308 		&mcspi->dma_channels[spi->chip_select];
1309 
1310 	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx)
1311 		return false;
1312 
1313 	if (spi_controller_is_slave(master))
1314 		return true;
1315 
1316 	return (xfer->len >= DMA_MIN_BYTES);
1317 }
1318 
1319 static int omap2_mcspi_controller_setup(struct omap2_mcspi *mcspi)
1320 {
1321 	struct spi_master	*master = mcspi->master;
1322 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1323 	int			ret = 0;
1324 
1325 	ret = pm_runtime_get_sync(mcspi->dev);
1326 	if (ret < 0) {
1327 		pm_runtime_put_noidle(mcspi->dev);
1328 
1329 		return ret;
1330 	}
1331 
1332 	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1333 			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1334 	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1335 
1336 	omap2_mcspi_set_mode(master);
1337 	pm_runtime_mark_last_busy(mcspi->dev);
1338 	pm_runtime_put_autosuspend(mcspi->dev);
1339 	return 0;
1340 }
1341 
1342 /*
1343  * When SPI wake up from off-mode, CS is in activate state. If it was in
1344  * inactive state when driver was suspend, then force it to inactive state at
1345  * wake up.
1346  */
1347 static int omap_mcspi_runtime_resume(struct device *dev)
1348 {
1349 	struct spi_master *master = dev_get_drvdata(dev);
1350 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1351 	struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1352 	struct omap2_mcspi_cs *cs;
1353 
1354 	/* McSPI: context restore */
1355 	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
1356 	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
1357 
1358 	list_for_each_entry(cs, &ctx->cs, node) {
1359 		/*
1360 		 * We need to toggle CS state for OMAP take this
1361 		 * change in account.
1362 		 */
1363 		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1364 			cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1365 			writel_relaxed(cs->chconf0,
1366 				       cs->base + OMAP2_MCSPI_CHCONF0);
1367 			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1368 			writel_relaxed(cs->chconf0,
1369 				       cs->base + OMAP2_MCSPI_CHCONF0);
1370 		} else {
1371 			writel_relaxed(cs->chconf0,
1372 				       cs->base + OMAP2_MCSPI_CHCONF0);
1373 		}
1374 	}
1375 
1376 	return 0;
1377 }
1378 
1379 static struct omap2_mcspi_platform_config omap2_pdata = {
1380 	.regs_offset = 0,
1381 };
1382 
1383 static struct omap2_mcspi_platform_config omap4_pdata = {
1384 	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1385 };
1386 
1387 static const struct of_device_id omap_mcspi_of_match[] = {
1388 	{
1389 		.compatible = "ti,omap2-mcspi",
1390 		.data = &omap2_pdata,
1391 	},
1392 	{
1393 		.compatible = "ti,omap4-mcspi",
1394 		.data = &omap4_pdata,
1395 	},
1396 	{ },
1397 };
1398 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1399 
1400 static int omap2_mcspi_probe(struct platform_device *pdev)
1401 {
1402 	struct spi_master	*master;
1403 	const struct omap2_mcspi_platform_config *pdata;
1404 	struct omap2_mcspi	*mcspi;
1405 	struct resource		*r;
1406 	int			status = 0, i;
1407 	u32			regs_offset = 0;
1408 	struct device_node	*node = pdev->dev.of_node;
1409 	const struct of_device_id *match;
1410 
1411 	if (of_property_read_bool(node, "spi-slave"))
1412 		master = spi_alloc_slave(&pdev->dev, sizeof(*mcspi));
1413 	else
1414 		master = spi_alloc_master(&pdev->dev, sizeof(*mcspi));
1415 	if (!master)
1416 		return -ENOMEM;
1417 
1418 	/* the spi->mode bits understood by this driver: */
1419 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1420 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1421 	master->setup = omap2_mcspi_setup;
1422 	master->auto_runtime_pm = true;
1423 	master->prepare_message = omap2_mcspi_prepare_message;
1424 	master->can_dma = omap2_mcspi_can_dma;
1425 	master->transfer_one = omap2_mcspi_transfer_one;
1426 	master->set_cs = omap2_mcspi_set_cs;
1427 	master->cleanup = omap2_mcspi_cleanup;
1428 	master->slave_abort = omap2_mcspi_slave_abort;
1429 	master->dev.of_node = node;
1430 	master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1431 	master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1432 
1433 	platform_set_drvdata(pdev, master);
1434 
1435 	mcspi = spi_master_get_devdata(master);
1436 	mcspi->master = master;
1437 
1438 	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1439 	if (match) {
1440 		u32 num_cs = 1; /* default number of chipselect */
1441 		pdata = match->data;
1442 
1443 		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1444 		master->num_chipselect = num_cs;
1445 		if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1446 			mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1447 	} else {
1448 		pdata = dev_get_platdata(&pdev->dev);
1449 		master->num_chipselect = pdata->num_cs;
1450 		mcspi->pin_dir = pdata->pin_dir;
1451 	}
1452 	regs_offset = pdata->regs_offset;
1453 
1454 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1455 	mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1456 	if (IS_ERR(mcspi->base)) {
1457 		status = PTR_ERR(mcspi->base);
1458 		goto free_master;
1459 	}
1460 	mcspi->phys = r->start + regs_offset;
1461 	mcspi->base += regs_offset;
1462 
1463 	mcspi->dev = &pdev->dev;
1464 
1465 	INIT_LIST_HEAD(&mcspi->ctx.cs);
1466 
1467 	mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1468 					   sizeof(struct omap2_mcspi_dma),
1469 					   GFP_KERNEL);
1470 	if (mcspi->dma_channels == NULL) {
1471 		status = -ENOMEM;
1472 		goto free_master;
1473 	}
1474 
1475 	for (i = 0; i < master->num_chipselect; i++) {
1476 		sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
1477 		sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
1478 	}
1479 
1480 	status = platform_get_irq(pdev, 0);
1481 	if (status == -EPROBE_DEFER)
1482 		goto free_master;
1483 	if (status < 0) {
1484 		dev_err(&pdev->dev, "no irq resource found\n");
1485 		goto free_master;
1486 	}
1487 	init_completion(&mcspi->txdone);
1488 	status = devm_request_irq(&pdev->dev, status,
1489 				  omap2_mcspi_irq_handler, 0, pdev->name,
1490 				  mcspi);
1491 	if (status) {
1492 		dev_err(&pdev->dev, "Cannot request IRQ");
1493 		goto free_master;
1494 	}
1495 
1496 	pm_runtime_use_autosuspend(&pdev->dev);
1497 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1498 	pm_runtime_enable(&pdev->dev);
1499 
1500 	status = omap2_mcspi_controller_setup(mcspi);
1501 	if (status < 0)
1502 		goto disable_pm;
1503 
1504 	status = devm_spi_register_controller(&pdev->dev, master);
1505 	if (status < 0)
1506 		goto disable_pm;
1507 
1508 	return status;
1509 
1510 disable_pm:
1511 	pm_runtime_dont_use_autosuspend(&pdev->dev);
1512 	pm_runtime_put_sync(&pdev->dev);
1513 	pm_runtime_disable(&pdev->dev);
1514 free_master:
1515 	spi_master_put(master);
1516 	return status;
1517 }
1518 
1519 static int omap2_mcspi_remove(struct platform_device *pdev)
1520 {
1521 	struct spi_master *master = platform_get_drvdata(pdev);
1522 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1523 
1524 	pm_runtime_dont_use_autosuspend(mcspi->dev);
1525 	pm_runtime_put_sync(mcspi->dev);
1526 	pm_runtime_disable(&pdev->dev);
1527 
1528 	return 0;
1529 }
1530 
1531 /* work with hotplug and coldplug */
1532 MODULE_ALIAS("platform:omap2_mcspi");
1533 
1534 static int __maybe_unused omap2_mcspi_suspend(struct device *dev)
1535 {
1536 	struct spi_master *master = dev_get_drvdata(dev);
1537 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1538 	int error;
1539 
1540 	error = pinctrl_pm_select_sleep_state(dev);
1541 	if (error)
1542 		dev_warn(mcspi->dev, "%s: failed to set pins: %i\n",
1543 			 __func__, error);
1544 
1545 	error = spi_master_suspend(master);
1546 	if (error)
1547 		dev_warn(mcspi->dev, "%s: master suspend failed: %i\n",
1548 			 __func__, error);
1549 
1550 	return pm_runtime_force_suspend(dev);
1551 }
1552 
1553 static int __maybe_unused omap2_mcspi_resume(struct device *dev)
1554 {
1555 	struct spi_master *master = dev_get_drvdata(dev);
1556 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1557 	int error;
1558 
1559 	error = pinctrl_pm_select_default_state(dev);
1560 	if (error)
1561 		dev_warn(mcspi->dev, "%s: failed to set pins: %i\n",
1562 			 __func__, error);
1563 
1564 	error = spi_master_resume(master);
1565 	if (error)
1566 		dev_warn(mcspi->dev, "%s: master resume failed: %i\n",
1567 			 __func__, error);
1568 
1569 	return pm_runtime_force_resume(dev);
1570 }
1571 
1572 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1573 	SET_SYSTEM_SLEEP_PM_OPS(omap2_mcspi_suspend,
1574 				omap2_mcspi_resume)
1575 	.runtime_resume	= omap_mcspi_runtime_resume,
1576 };
1577 
1578 static struct platform_driver omap2_mcspi_driver = {
1579 	.driver = {
1580 		.name =		"omap2_mcspi",
1581 		.pm =		&omap2_mcspi_pm_ops,
1582 		.of_match_table = omap_mcspi_of_match,
1583 	},
1584 	.probe =	omap2_mcspi_probe,
1585 	.remove =	omap2_mcspi_remove,
1586 };
1587 
1588 module_platform_driver(omap2_mcspi_driver);
1589 MODULE_LICENSE("GPL");
1590