xref: /openbmc/linux/drivers/spi/spi-omap2-mcspi.c (revision dbf563ee)
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 
31 #include <linux/platform_data/spi-omap2-mcspi.h>
32 
33 #define OMAP2_MCSPI_MAX_FREQ		48000000
34 #define OMAP2_MCSPI_MAX_DIVIDER		4096
35 #define OMAP2_MCSPI_MAX_FIFODEPTH	64
36 #define OMAP2_MCSPI_MAX_FIFOWCNT	0xFFFF
37 #define SPI_AUTOSUSPEND_TIMEOUT		2000
38 
39 #define OMAP2_MCSPI_REVISION		0x00
40 #define OMAP2_MCSPI_SYSSTATUS		0x14
41 #define OMAP2_MCSPI_IRQSTATUS		0x18
42 #define OMAP2_MCSPI_IRQENABLE		0x1c
43 #define OMAP2_MCSPI_WAKEUPENABLE	0x20
44 #define OMAP2_MCSPI_SYST		0x24
45 #define OMAP2_MCSPI_MODULCTRL		0x28
46 #define OMAP2_MCSPI_XFERLEVEL		0x7c
47 
48 /* per-channel banks, 0x14 bytes each, first is: */
49 #define OMAP2_MCSPI_CHCONF0		0x2c
50 #define OMAP2_MCSPI_CHSTAT0		0x30
51 #define OMAP2_MCSPI_CHCTRL0		0x34
52 #define OMAP2_MCSPI_TX0			0x38
53 #define OMAP2_MCSPI_RX0			0x3c
54 
55 /* per-register bitmasks: */
56 #define OMAP2_MCSPI_IRQSTATUS_EOW	BIT(17)
57 
58 #define OMAP2_MCSPI_MODULCTRL_SINGLE	BIT(0)
59 #define OMAP2_MCSPI_MODULCTRL_MS	BIT(2)
60 #define OMAP2_MCSPI_MODULCTRL_STEST	BIT(3)
61 
62 #define OMAP2_MCSPI_CHCONF_PHA		BIT(0)
63 #define OMAP2_MCSPI_CHCONF_POL		BIT(1)
64 #define OMAP2_MCSPI_CHCONF_CLKD_MASK	(0x0f << 2)
65 #define OMAP2_MCSPI_CHCONF_EPOL		BIT(6)
66 #define OMAP2_MCSPI_CHCONF_WL_MASK	(0x1f << 7)
67 #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY	BIT(12)
68 #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY	BIT(13)
69 #define OMAP2_MCSPI_CHCONF_TRM_MASK	(0x03 << 12)
70 #define OMAP2_MCSPI_CHCONF_DMAW		BIT(14)
71 #define OMAP2_MCSPI_CHCONF_DMAR		BIT(15)
72 #define OMAP2_MCSPI_CHCONF_DPE0		BIT(16)
73 #define OMAP2_MCSPI_CHCONF_DPE1		BIT(17)
74 #define OMAP2_MCSPI_CHCONF_IS		BIT(18)
75 #define OMAP2_MCSPI_CHCONF_TURBO	BIT(19)
76 #define OMAP2_MCSPI_CHCONF_FORCE	BIT(20)
77 #define OMAP2_MCSPI_CHCONF_FFET		BIT(27)
78 #define OMAP2_MCSPI_CHCONF_FFER		BIT(28)
79 #define OMAP2_MCSPI_CHCONF_CLKG		BIT(29)
80 
81 #define OMAP2_MCSPI_CHSTAT_RXS		BIT(0)
82 #define OMAP2_MCSPI_CHSTAT_TXS		BIT(1)
83 #define OMAP2_MCSPI_CHSTAT_EOT		BIT(2)
84 #define OMAP2_MCSPI_CHSTAT_TXFFE	BIT(3)
85 
86 #define OMAP2_MCSPI_CHCTRL_EN		BIT(0)
87 #define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK	(0xff << 8)
88 
89 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN	BIT(0)
90 
91 /* We have 2 DMA channels per CS, one for RX and one for TX */
92 struct omap2_mcspi_dma {
93 	struct dma_chan *dma_tx;
94 	struct dma_chan *dma_rx;
95 
96 	struct completion dma_tx_completion;
97 	struct completion dma_rx_completion;
98 
99 	char dma_rx_ch_name[14];
100 	char dma_tx_ch_name[14];
101 };
102 
103 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
104  * cache operations; better heuristics consider wordsize and bitrate.
105  */
106 #define DMA_MIN_BYTES			160
107 
108 
109 /*
110  * Used for context save and restore, structure members to be updated whenever
111  * corresponding registers are modified.
112  */
113 struct omap2_mcspi_regs {
114 	u32 modulctrl;
115 	u32 wakeupenable;
116 	struct list_head cs;
117 };
118 
119 struct omap2_mcspi {
120 	struct completion	txdone;
121 	struct spi_master	*master;
122 	/* Virtual base address of the controller */
123 	void __iomem		*base;
124 	unsigned long		phys;
125 	/* SPI1 has 4 channels, while SPI2 has 2 */
126 	struct omap2_mcspi_dma	*dma_channels;
127 	struct device		*dev;
128 	struct omap2_mcspi_regs ctx;
129 	int			fifo_depth;
130 	bool			slave_aborted;
131 	unsigned int		pin_dir:1;
132 	size_t			max_xfer_len;
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 	struct dma_async_tx_descriptor *tx;
401 
402 	mcspi = spi_master_get_devdata(spi->master);
403 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
404 
405 	dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
406 
407 	tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl,
408 				     xfer->tx_sg.nents,
409 				     DMA_MEM_TO_DEV,
410 				     DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
411 	if (tx) {
412 		tx->callback = omap2_mcspi_tx_callback;
413 		tx->callback_param = spi;
414 		dmaengine_submit(tx);
415 	} else {
416 		/* FIXME: fall back to PIO? */
417 	}
418 	dma_async_issue_pending(mcspi_dma->dma_tx);
419 	omap2_mcspi_set_dma_req(spi, 0, 1);
420 }
421 
422 static unsigned
423 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
424 				struct dma_slave_config cfg,
425 				unsigned es)
426 {
427 	struct omap2_mcspi	*mcspi;
428 	struct omap2_mcspi_dma  *mcspi_dma;
429 	unsigned int		count, transfer_reduction = 0;
430 	struct scatterlist	*sg_out[2];
431 	int			nb_sizes = 0, out_mapped_nents[2], ret, x;
432 	size_t			sizes[2];
433 	u32			l;
434 	int			elements = 0;
435 	int			word_len, element_count;
436 	struct omap2_mcspi_cs	*cs = spi->controller_state;
437 	void __iomem		*chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
438 	struct dma_async_tx_descriptor *tx;
439 
440 	mcspi = spi_master_get_devdata(spi->master);
441 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
442 	count = xfer->len;
443 
444 	/*
445 	 *  In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM
446 	 *  it mentions reducing DMA transfer length by one element in master
447 	 *  normal mode.
448 	 */
449 	if (mcspi->fifo_depth == 0)
450 		transfer_reduction = es;
451 
452 	word_len = cs->word_len;
453 	l = mcspi_cached_chconf0(spi);
454 
455 	if (word_len <= 8)
456 		element_count = count;
457 	else if (word_len <= 16)
458 		element_count = count >> 1;
459 	else /* word_len <= 32 */
460 		element_count = count >> 2;
461 
462 
463 	dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
464 
465 	/*
466 	 *  Reduce DMA transfer length by one more if McSPI is
467 	 *  configured in turbo mode.
468 	 */
469 	if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
470 		transfer_reduction += es;
471 
472 	if (transfer_reduction) {
473 		/* Split sgl into two. The second sgl won't be used. */
474 		sizes[0] = count - transfer_reduction;
475 		sizes[1] = transfer_reduction;
476 		nb_sizes = 2;
477 	} else {
478 		/*
479 		 * Don't bother splitting the sgl. This essentially
480 		 * clones the original sgl.
481 		 */
482 		sizes[0] = count;
483 		nb_sizes = 1;
484 	}
485 
486 	ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents, 0, nb_sizes,
487 		       sizes, sg_out, out_mapped_nents, GFP_KERNEL);
488 
489 	if (ret < 0) {
490 		dev_err(&spi->dev, "sg_split failed\n");
491 		return 0;
492 	}
493 
494 	tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, sg_out[0],
495 				     out_mapped_nents[0], DMA_DEV_TO_MEM,
496 				     DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
497 	if (tx) {
498 		tx->callback = omap2_mcspi_rx_callback;
499 		tx->callback_param = spi;
500 		dmaengine_submit(tx);
501 	} else {
502 		/* FIXME: fall back to PIO? */
503 	}
504 
505 	dma_async_issue_pending(mcspi_dma->dma_rx);
506 	omap2_mcspi_set_dma_req(spi, 1, 1);
507 
508 	ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_rx_completion);
509 	if (ret || mcspi->slave_aborted) {
510 		dmaengine_terminate_sync(mcspi_dma->dma_rx);
511 		omap2_mcspi_set_dma_req(spi, 1, 0);
512 		return 0;
513 	}
514 
515 	for (x = 0; x < nb_sizes; x++)
516 		kfree(sg_out[x]);
517 
518 	if (mcspi->fifo_depth > 0)
519 		return count;
520 
521 	/*
522 	 *  Due to the DMA transfer length reduction the missing bytes must
523 	 *  be read manually to receive all of the expected data.
524 	 */
525 	omap2_mcspi_set_enable(spi, 0);
526 
527 	elements = element_count - 1;
528 
529 	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
530 		elements--;
531 
532 		if (!mcspi_wait_for_reg_bit(chstat_reg,
533 					    OMAP2_MCSPI_CHSTAT_RXS)) {
534 			u32 w;
535 
536 			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
537 			if (word_len <= 8)
538 				((u8 *)xfer->rx_buf)[elements++] = w;
539 			else if (word_len <= 16)
540 				((u16 *)xfer->rx_buf)[elements++] = w;
541 			else /* word_len <= 32 */
542 				((u32 *)xfer->rx_buf)[elements++] = w;
543 		} else {
544 			int bytes_per_word = mcspi_bytes_per_word(word_len);
545 			dev_err(&spi->dev, "DMA RX penultimate word empty\n");
546 			count -= (bytes_per_word << 1);
547 			omap2_mcspi_set_enable(spi, 1);
548 			return count;
549 		}
550 	}
551 	if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) {
552 		u32 w;
553 
554 		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
555 		if (word_len <= 8)
556 			((u8 *)xfer->rx_buf)[elements] = w;
557 		else if (word_len <= 16)
558 			((u16 *)xfer->rx_buf)[elements] = w;
559 		else /* word_len <= 32 */
560 			((u32 *)xfer->rx_buf)[elements] = w;
561 	} else {
562 		dev_err(&spi->dev, "DMA RX last word empty\n");
563 		count -= mcspi_bytes_per_word(word_len);
564 	}
565 	omap2_mcspi_set_enable(spi, 1);
566 	return count;
567 }
568 
569 static unsigned
570 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
571 {
572 	struct omap2_mcspi	*mcspi;
573 	struct omap2_mcspi_cs	*cs = spi->controller_state;
574 	struct omap2_mcspi_dma  *mcspi_dma;
575 	unsigned int		count;
576 	u8			*rx;
577 	const u8		*tx;
578 	struct dma_slave_config	cfg;
579 	enum dma_slave_buswidth width;
580 	unsigned es;
581 	void __iomem		*chstat_reg;
582 	void __iomem            *irqstat_reg;
583 	int			wait_res;
584 
585 	mcspi = spi_master_get_devdata(spi->master);
586 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
587 
588 	if (cs->word_len <= 8) {
589 		width = DMA_SLAVE_BUSWIDTH_1_BYTE;
590 		es = 1;
591 	} else if (cs->word_len <= 16) {
592 		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
593 		es = 2;
594 	} else {
595 		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
596 		es = 4;
597 	}
598 
599 	count = xfer->len;
600 
601 	memset(&cfg, 0, sizeof(cfg));
602 	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
603 	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
604 	cfg.src_addr_width = width;
605 	cfg.dst_addr_width = width;
606 	cfg.src_maxburst = 1;
607 	cfg.dst_maxburst = 1;
608 
609 	rx = xfer->rx_buf;
610 	tx = xfer->tx_buf;
611 
612 	mcspi->slave_aborted = false;
613 	reinit_completion(&mcspi_dma->dma_tx_completion);
614 	reinit_completion(&mcspi_dma->dma_rx_completion);
615 	reinit_completion(&mcspi->txdone);
616 	if (tx) {
617 		/* Enable EOW IRQ to know end of tx in slave mode */
618 		if (spi_controller_is_slave(spi->master))
619 			mcspi_write_reg(spi->master,
620 					OMAP2_MCSPI_IRQENABLE,
621 					OMAP2_MCSPI_IRQSTATUS_EOW);
622 		omap2_mcspi_tx_dma(spi, xfer, cfg);
623 	}
624 
625 	if (rx != NULL)
626 		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
627 
628 	if (tx != NULL) {
629 		int ret;
630 
631 		ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_tx_completion);
632 		if (ret || mcspi->slave_aborted) {
633 			dmaengine_terminate_sync(mcspi_dma->dma_tx);
634 			omap2_mcspi_set_dma_req(spi, 0, 0);
635 			return 0;
636 		}
637 
638 		if (spi_controller_is_slave(mcspi->master)) {
639 			ret = mcspi_wait_for_completion(mcspi, &mcspi->txdone);
640 			if (ret || mcspi->slave_aborted)
641 				return 0;
642 		}
643 
644 		if (mcspi->fifo_depth > 0) {
645 			irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
646 
647 			if (mcspi_wait_for_reg_bit(irqstat_reg,
648 						OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
649 				dev_err(&spi->dev, "EOW timed out\n");
650 
651 			mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
652 					OMAP2_MCSPI_IRQSTATUS_EOW);
653 		}
654 
655 		/* for TX_ONLY mode, be sure all words have shifted out */
656 		if (rx == NULL) {
657 			chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
658 			if (mcspi->fifo_depth > 0) {
659 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
660 						OMAP2_MCSPI_CHSTAT_TXFFE);
661 				if (wait_res < 0)
662 					dev_err(&spi->dev, "TXFFE timed out\n");
663 			} else {
664 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
665 						OMAP2_MCSPI_CHSTAT_TXS);
666 				if (wait_res < 0)
667 					dev_err(&spi->dev, "TXS timed out\n");
668 			}
669 			if (wait_res >= 0 &&
670 				(mcspi_wait_for_reg_bit(chstat_reg,
671 					OMAP2_MCSPI_CHSTAT_EOT) < 0))
672 				dev_err(&spi->dev, "EOT timed out\n");
673 		}
674 	}
675 	return count;
676 }
677 
678 static unsigned
679 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
680 {
681 	struct omap2_mcspi_cs	*cs = spi->controller_state;
682 	unsigned int		count, c;
683 	u32			l;
684 	void __iomem		*base = cs->base;
685 	void __iomem		*tx_reg;
686 	void __iomem		*rx_reg;
687 	void __iomem		*chstat_reg;
688 	int			word_len;
689 
690 	count = xfer->len;
691 	c = count;
692 	word_len = cs->word_len;
693 
694 	l = mcspi_cached_chconf0(spi);
695 
696 	/* We store the pre-calculated register addresses on stack to speed
697 	 * up the transfer loop. */
698 	tx_reg		= base + OMAP2_MCSPI_TX0;
699 	rx_reg		= base + OMAP2_MCSPI_RX0;
700 	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
701 
702 	if (c < (word_len>>3))
703 		return 0;
704 
705 	if (word_len <= 8) {
706 		u8		*rx;
707 		const u8	*tx;
708 
709 		rx = xfer->rx_buf;
710 		tx = xfer->tx_buf;
711 
712 		do {
713 			c -= 1;
714 			if (tx != NULL) {
715 				if (mcspi_wait_for_reg_bit(chstat_reg,
716 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
717 					dev_err(&spi->dev, "TXS timed out\n");
718 					goto out;
719 				}
720 				dev_vdbg(&spi->dev, "write-%d %02x\n",
721 						word_len, *tx);
722 				writel_relaxed(*tx++, tx_reg);
723 			}
724 			if (rx != NULL) {
725 				if (mcspi_wait_for_reg_bit(chstat_reg,
726 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
727 					dev_err(&spi->dev, "RXS timed out\n");
728 					goto out;
729 				}
730 
731 				if (c == 1 && tx == NULL &&
732 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
733 					omap2_mcspi_set_enable(spi, 0);
734 					*rx++ = readl_relaxed(rx_reg);
735 					dev_vdbg(&spi->dev, "read-%d %02x\n",
736 						    word_len, *(rx - 1));
737 					if (mcspi_wait_for_reg_bit(chstat_reg,
738 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
739 						dev_err(&spi->dev,
740 							"RXS timed out\n");
741 						goto out;
742 					}
743 					c = 0;
744 				} else if (c == 0 && tx == NULL) {
745 					omap2_mcspi_set_enable(spi, 0);
746 				}
747 
748 				*rx++ = readl_relaxed(rx_reg);
749 				dev_vdbg(&spi->dev, "read-%d %02x\n",
750 						word_len, *(rx - 1));
751 			}
752 		} while (c);
753 	} else if (word_len <= 16) {
754 		u16		*rx;
755 		const u16	*tx;
756 
757 		rx = xfer->rx_buf;
758 		tx = xfer->tx_buf;
759 		do {
760 			c -= 2;
761 			if (tx != NULL) {
762 				if (mcspi_wait_for_reg_bit(chstat_reg,
763 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
764 					dev_err(&spi->dev, "TXS timed out\n");
765 					goto out;
766 				}
767 				dev_vdbg(&spi->dev, "write-%d %04x\n",
768 						word_len, *tx);
769 				writel_relaxed(*tx++, tx_reg);
770 			}
771 			if (rx != NULL) {
772 				if (mcspi_wait_for_reg_bit(chstat_reg,
773 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
774 					dev_err(&spi->dev, "RXS timed out\n");
775 					goto out;
776 				}
777 
778 				if (c == 2 && tx == NULL &&
779 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
780 					omap2_mcspi_set_enable(spi, 0);
781 					*rx++ = readl_relaxed(rx_reg);
782 					dev_vdbg(&spi->dev, "read-%d %04x\n",
783 						    word_len, *(rx - 1));
784 					if (mcspi_wait_for_reg_bit(chstat_reg,
785 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
786 						dev_err(&spi->dev,
787 							"RXS timed out\n");
788 						goto out;
789 					}
790 					c = 0;
791 				} else if (c == 0 && tx == NULL) {
792 					omap2_mcspi_set_enable(spi, 0);
793 				}
794 
795 				*rx++ = readl_relaxed(rx_reg);
796 				dev_vdbg(&spi->dev, "read-%d %04x\n",
797 						word_len, *(rx - 1));
798 			}
799 		} while (c >= 2);
800 	} else if (word_len <= 32) {
801 		u32		*rx;
802 		const u32	*tx;
803 
804 		rx = xfer->rx_buf;
805 		tx = xfer->tx_buf;
806 		do {
807 			c -= 4;
808 			if (tx != NULL) {
809 				if (mcspi_wait_for_reg_bit(chstat_reg,
810 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
811 					dev_err(&spi->dev, "TXS timed out\n");
812 					goto out;
813 				}
814 				dev_vdbg(&spi->dev, "write-%d %08x\n",
815 						word_len, *tx);
816 				writel_relaxed(*tx++, tx_reg);
817 			}
818 			if (rx != NULL) {
819 				if (mcspi_wait_for_reg_bit(chstat_reg,
820 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
821 					dev_err(&spi->dev, "RXS timed out\n");
822 					goto out;
823 				}
824 
825 				if (c == 4 && tx == NULL &&
826 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
827 					omap2_mcspi_set_enable(spi, 0);
828 					*rx++ = readl_relaxed(rx_reg);
829 					dev_vdbg(&spi->dev, "read-%d %08x\n",
830 						    word_len, *(rx - 1));
831 					if (mcspi_wait_for_reg_bit(chstat_reg,
832 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
833 						dev_err(&spi->dev,
834 							"RXS timed out\n");
835 						goto out;
836 					}
837 					c = 0;
838 				} else if (c == 0 && tx == NULL) {
839 					omap2_mcspi_set_enable(spi, 0);
840 				}
841 
842 				*rx++ = readl_relaxed(rx_reg);
843 				dev_vdbg(&spi->dev, "read-%d %08x\n",
844 						word_len, *(rx - 1));
845 			}
846 		} while (c >= 4);
847 	}
848 
849 	/* for TX_ONLY mode, be sure all words have shifted out */
850 	if (xfer->rx_buf == NULL) {
851 		if (mcspi_wait_for_reg_bit(chstat_reg,
852 				OMAP2_MCSPI_CHSTAT_TXS) < 0) {
853 			dev_err(&spi->dev, "TXS timed out\n");
854 		} else if (mcspi_wait_for_reg_bit(chstat_reg,
855 				OMAP2_MCSPI_CHSTAT_EOT) < 0)
856 			dev_err(&spi->dev, "EOT timed out\n");
857 
858 		/* disable chan to purge rx datas received in TX_ONLY transfer,
859 		 * otherwise these rx datas will affect the direct following
860 		 * RX_ONLY transfer.
861 		 */
862 		omap2_mcspi_set_enable(spi, 0);
863 	}
864 out:
865 	omap2_mcspi_set_enable(spi, 1);
866 	return count - c;
867 }
868 
869 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
870 {
871 	u32 div;
872 
873 	for (div = 0; div < 15; div++)
874 		if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
875 			return div;
876 
877 	return 15;
878 }
879 
880 /* called only when no transfer is active to this device */
881 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
882 		struct spi_transfer *t)
883 {
884 	struct omap2_mcspi_cs *cs = spi->controller_state;
885 	struct omap2_mcspi *mcspi;
886 	u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
887 	u8 word_len = spi->bits_per_word;
888 	u32 speed_hz = spi->max_speed_hz;
889 
890 	mcspi = spi_master_get_devdata(spi->master);
891 
892 	if (t != NULL && t->bits_per_word)
893 		word_len = t->bits_per_word;
894 
895 	cs->word_len = word_len;
896 
897 	if (t && t->speed_hz)
898 		speed_hz = t->speed_hz;
899 
900 	speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
901 	if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
902 		clkd = omap2_mcspi_calc_divisor(speed_hz);
903 		speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
904 		clkg = 0;
905 	} else {
906 		div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
907 		speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
908 		clkd = (div - 1) & 0xf;
909 		extclk = (div - 1) >> 4;
910 		clkg = OMAP2_MCSPI_CHCONF_CLKG;
911 	}
912 
913 	l = mcspi_cached_chconf0(spi);
914 
915 	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
916 	 * REVISIT: this controller could support SPI_3WIRE mode.
917 	 */
918 	if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
919 		l &= ~OMAP2_MCSPI_CHCONF_IS;
920 		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
921 		l |= OMAP2_MCSPI_CHCONF_DPE0;
922 	} else {
923 		l |= OMAP2_MCSPI_CHCONF_IS;
924 		l |= OMAP2_MCSPI_CHCONF_DPE1;
925 		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
926 	}
927 
928 	/* wordlength */
929 	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
930 	l |= (word_len - 1) << 7;
931 
932 	/* set chipselect polarity; manage with FORCE */
933 	if (!(spi->mode & SPI_CS_HIGH))
934 		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
935 	else
936 		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
937 
938 	/* set clock divisor */
939 	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
940 	l |= clkd << 2;
941 
942 	/* set clock granularity */
943 	l &= ~OMAP2_MCSPI_CHCONF_CLKG;
944 	l |= clkg;
945 	if (clkg) {
946 		cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
947 		cs->chctrl0 |= extclk << 8;
948 		mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
949 	}
950 
951 	/* set SPI mode 0..3 */
952 	if (spi->mode & SPI_CPOL)
953 		l |= OMAP2_MCSPI_CHCONF_POL;
954 	else
955 		l &= ~OMAP2_MCSPI_CHCONF_POL;
956 	if (spi->mode & SPI_CPHA)
957 		l |= OMAP2_MCSPI_CHCONF_PHA;
958 	else
959 		l &= ~OMAP2_MCSPI_CHCONF_PHA;
960 
961 	mcspi_write_chconf0(spi, l);
962 
963 	cs->mode = spi->mode;
964 
965 	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
966 			speed_hz,
967 			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
968 			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
969 
970 	return 0;
971 }
972 
973 /*
974  * Note that we currently allow DMA only if we get a channel
975  * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
976  */
977 static int omap2_mcspi_request_dma(struct omap2_mcspi *mcspi,
978 				   struct omap2_mcspi_dma *mcspi_dma)
979 {
980 	int ret = 0;
981 
982 	mcspi_dma->dma_rx = dma_request_chan(mcspi->dev,
983 					     mcspi_dma->dma_rx_ch_name);
984 	if (IS_ERR(mcspi_dma->dma_rx)) {
985 		ret = PTR_ERR(mcspi_dma->dma_rx);
986 		mcspi_dma->dma_rx = NULL;
987 		goto no_dma;
988 	}
989 
990 	mcspi_dma->dma_tx = dma_request_chan(mcspi->dev,
991 					     mcspi_dma->dma_tx_ch_name);
992 	if (IS_ERR(mcspi_dma->dma_tx)) {
993 		ret = PTR_ERR(mcspi_dma->dma_tx);
994 		mcspi_dma->dma_tx = NULL;
995 		dma_release_channel(mcspi_dma->dma_rx);
996 		mcspi_dma->dma_rx = NULL;
997 	}
998 
999 	init_completion(&mcspi_dma->dma_rx_completion);
1000 	init_completion(&mcspi_dma->dma_tx_completion);
1001 
1002 no_dma:
1003 	return ret;
1004 }
1005 
1006 static void omap2_mcspi_release_dma(struct spi_master *master)
1007 {
1008 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1009 	struct omap2_mcspi_dma	*mcspi_dma;
1010 	int i;
1011 
1012 	for (i = 0; i < master->num_chipselect; i++) {
1013 		mcspi_dma = &mcspi->dma_channels[i];
1014 
1015 		if (mcspi_dma->dma_rx) {
1016 			dma_release_channel(mcspi_dma->dma_rx);
1017 			mcspi_dma->dma_rx = NULL;
1018 		}
1019 		if (mcspi_dma->dma_tx) {
1020 			dma_release_channel(mcspi_dma->dma_tx);
1021 			mcspi_dma->dma_tx = NULL;
1022 		}
1023 	}
1024 }
1025 
1026 static int omap2_mcspi_setup(struct spi_device *spi)
1027 {
1028 	int			ret;
1029 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(spi->master);
1030 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1031 	struct omap2_mcspi_cs	*cs = spi->controller_state;
1032 
1033 	if (!cs) {
1034 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
1035 		if (!cs)
1036 			return -ENOMEM;
1037 		cs->base = mcspi->base + spi->chip_select * 0x14;
1038 		cs->phys = mcspi->phys + spi->chip_select * 0x14;
1039 		cs->mode = 0;
1040 		cs->chconf0 = 0;
1041 		cs->chctrl0 = 0;
1042 		spi->controller_state = cs;
1043 		/* Link this to context save list */
1044 		list_add_tail(&cs->node, &ctx->cs);
1045 	}
1046 
1047 	ret = pm_runtime_get_sync(mcspi->dev);
1048 	if (ret < 0) {
1049 		pm_runtime_put_noidle(mcspi->dev);
1050 
1051 		return ret;
1052 	}
1053 
1054 	ret = omap2_mcspi_setup_transfer(spi, NULL);
1055 	pm_runtime_mark_last_busy(mcspi->dev);
1056 	pm_runtime_put_autosuspend(mcspi->dev);
1057 
1058 	return ret;
1059 }
1060 
1061 static void omap2_mcspi_cleanup(struct spi_device *spi)
1062 {
1063 	struct omap2_mcspi_cs	*cs;
1064 
1065 	if (spi->controller_state) {
1066 		/* Unlink controller state from context save list */
1067 		cs = spi->controller_state;
1068 		list_del(&cs->node);
1069 
1070 		kfree(cs);
1071 	}
1072 }
1073 
1074 static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data)
1075 {
1076 	struct omap2_mcspi *mcspi = data;
1077 	u32 irqstat;
1078 
1079 	irqstat	= mcspi_read_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS);
1080 	if (!irqstat)
1081 		return IRQ_NONE;
1082 
1083 	/* Disable IRQ and wakeup slave xfer task */
1084 	mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQENABLE, 0);
1085 	if (irqstat & OMAP2_MCSPI_IRQSTATUS_EOW)
1086 		complete(&mcspi->txdone);
1087 
1088 	return IRQ_HANDLED;
1089 }
1090 
1091 static int omap2_mcspi_slave_abort(struct spi_master *master)
1092 {
1093 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1094 	struct omap2_mcspi_dma *mcspi_dma = mcspi->dma_channels;
1095 
1096 	mcspi->slave_aborted = true;
1097 	complete(&mcspi_dma->dma_rx_completion);
1098 	complete(&mcspi_dma->dma_tx_completion);
1099 	complete(&mcspi->txdone);
1100 
1101 	return 0;
1102 }
1103 
1104 static int omap2_mcspi_transfer_one(struct spi_master *master,
1105 				    struct spi_device *spi,
1106 				    struct spi_transfer *t)
1107 {
1108 
1109 	/* We only enable one channel at a time -- the one whose message is
1110 	 * -- although this controller would gladly
1111 	 * arbitrate among multiple channels.  This corresponds to "single
1112 	 * channel" master mode.  As a side effect, we need to manage the
1113 	 * chipselect with the FORCE bit ... CS != channel enable.
1114 	 */
1115 
1116 	struct omap2_mcspi		*mcspi;
1117 	struct omap2_mcspi_dma		*mcspi_dma;
1118 	struct omap2_mcspi_cs		*cs;
1119 	struct omap2_mcspi_device_config *cd;
1120 	int				par_override = 0;
1121 	int				status = 0;
1122 	u32				chconf;
1123 
1124 	mcspi = spi_master_get_devdata(master);
1125 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1126 	cs = spi->controller_state;
1127 	cd = spi->controller_data;
1128 
1129 	/*
1130 	 * The slave driver could have changed spi->mode in which case
1131 	 * it will be different from cs->mode (the current hardware setup).
1132 	 * If so, set par_override (even though its not a parity issue) so
1133 	 * omap2_mcspi_setup_transfer will be called to configure the hardware
1134 	 * with the correct mode on the first iteration of the loop below.
1135 	 */
1136 	if (spi->mode != cs->mode)
1137 		par_override = 1;
1138 
1139 	omap2_mcspi_set_enable(spi, 0);
1140 
1141 	if (spi->cs_gpiod)
1142 		omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH);
1143 
1144 	if (par_override ||
1145 	    (t->speed_hz != spi->max_speed_hz) ||
1146 	    (t->bits_per_word != spi->bits_per_word)) {
1147 		par_override = 1;
1148 		status = omap2_mcspi_setup_transfer(spi, t);
1149 		if (status < 0)
1150 			goto out;
1151 		if (t->speed_hz == spi->max_speed_hz &&
1152 		    t->bits_per_word == spi->bits_per_word)
1153 			par_override = 0;
1154 	}
1155 	if (cd && cd->cs_per_word) {
1156 		chconf = mcspi->ctx.modulctrl;
1157 		chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1158 		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1159 		mcspi->ctx.modulctrl =
1160 			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1161 	}
1162 
1163 	chconf = mcspi_cached_chconf0(spi);
1164 	chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1165 	chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1166 
1167 	if (t->tx_buf == NULL)
1168 		chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1169 	else if (t->rx_buf == NULL)
1170 		chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1171 
1172 	if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1173 		/* Turbo mode is for more than one word */
1174 		if (t->len > ((cs->word_len + 7) >> 3))
1175 			chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1176 	}
1177 
1178 	mcspi_write_chconf0(spi, chconf);
1179 
1180 	if (t->len) {
1181 		unsigned	count;
1182 
1183 		if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1184 		    master->cur_msg_mapped &&
1185 		    master->can_dma(master, spi, t))
1186 			omap2_mcspi_set_fifo(spi, t, 1);
1187 
1188 		omap2_mcspi_set_enable(spi, 1);
1189 
1190 		/* RX_ONLY mode needs dummy data in TX reg */
1191 		if (t->tx_buf == NULL)
1192 			writel_relaxed(0, cs->base
1193 					+ OMAP2_MCSPI_TX0);
1194 
1195 		if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1196 		    master->cur_msg_mapped &&
1197 		    master->can_dma(master, spi, t))
1198 			count = omap2_mcspi_txrx_dma(spi, t);
1199 		else
1200 			count = omap2_mcspi_txrx_pio(spi, t);
1201 
1202 		if (count != t->len) {
1203 			status = -EIO;
1204 			goto out;
1205 		}
1206 	}
1207 
1208 	omap2_mcspi_set_enable(spi, 0);
1209 
1210 	if (mcspi->fifo_depth > 0)
1211 		omap2_mcspi_set_fifo(spi, t, 0);
1212 
1213 out:
1214 	/* Restore defaults if they were overriden */
1215 	if (par_override) {
1216 		par_override = 0;
1217 		status = omap2_mcspi_setup_transfer(spi, NULL);
1218 	}
1219 
1220 	if (cd && cd->cs_per_word) {
1221 		chconf = mcspi->ctx.modulctrl;
1222 		chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1223 		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1224 		mcspi->ctx.modulctrl =
1225 			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1226 	}
1227 
1228 	omap2_mcspi_set_enable(spi, 0);
1229 
1230 	if (spi->cs_gpiod)
1231 		omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH));
1232 
1233 	if (mcspi->fifo_depth > 0 && t)
1234 		omap2_mcspi_set_fifo(spi, t, 0);
1235 
1236 	return status;
1237 }
1238 
1239 static int omap2_mcspi_prepare_message(struct spi_master *master,
1240 				       struct spi_message *msg)
1241 {
1242 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1243 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1244 	struct omap2_mcspi_cs	*cs;
1245 
1246 	/* Only a single channel can have the FORCE bit enabled
1247 	 * in its chconf0 register.
1248 	 * Scan all channels and disable them except the current one.
1249 	 * A FORCE can remain from a last transfer having cs_change enabled
1250 	 */
1251 	list_for_each_entry(cs, &ctx->cs, node) {
1252 		if (msg->spi->controller_state == cs)
1253 			continue;
1254 
1255 		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
1256 			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1257 			writel_relaxed(cs->chconf0,
1258 					cs->base + OMAP2_MCSPI_CHCONF0);
1259 			readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
1260 		}
1261 	}
1262 
1263 	return 0;
1264 }
1265 
1266 static bool omap2_mcspi_can_dma(struct spi_master *master,
1267 				struct spi_device *spi,
1268 				struct spi_transfer *xfer)
1269 {
1270 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
1271 	struct omap2_mcspi_dma *mcspi_dma =
1272 		&mcspi->dma_channels[spi->chip_select];
1273 
1274 	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx)
1275 		return false;
1276 
1277 	if (spi_controller_is_slave(master))
1278 		return true;
1279 
1280 	master->dma_rx = mcspi_dma->dma_rx;
1281 	master->dma_tx = mcspi_dma->dma_tx;
1282 
1283 	return (xfer->len >= DMA_MIN_BYTES);
1284 }
1285 
1286 static size_t omap2_mcspi_max_xfer_size(struct spi_device *spi)
1287 {
1288 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
1289 	struct omap2_mcspi_dma *mcspi_dma =
1290 		&mcspi->dma_channels[spi->chip_select];
1291 
1292 	if (mcspi->max_xfer_len && mcspi_dma->dma_rx)
1293 		return mcspi->max_xfer_len;
1294 
1295 	return SIZE_MAX;
1296 }
1297 
1298 static int omap2_mcspi_controller_setup(struct omap2_mcspi *mcspi)
1299 {
1300 	struct spi_master	*master = mcspi->master;
1301 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1302 	int			ret = 0;
1303 
1304 	ret = pm_runtime_get_sync(mcspi->dev);
1305 	if (ret < 0) {
1306 		pm_runtime_put_noidle(mcspi->dev);
1307 
1308 		return ret;
1309 	}
1310 
1311 	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1312 			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1313 	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1314 
1315 	omap2_mcspi_set_mode(master);
1316 	pm_runtime_mark_last_busy(mcspi->dev);
1317 	pm_runtime_put_autosuspend(mcspi->dev);
1318 	return 0;
1319 }
1320 
1321 /*
1322  * When SPI wake up from off-mode, CS is in activate state. If it was in
1323  * inactive state when driver was suspend, then force it to inactive state at
1324  * wake up.
1325  */
1326 static int omap_mcspi_runtime_resume(struct device *dev)
1327 {
1328 	struct spi_master *master = dev_get_drvdata(dev);
1329 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1330 	struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1331 	struct omap2_mcspi_cs *cs;
1332 
1333 	/* McSPI: context restore */
1334 	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
1335 	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
1336 
1337 	list_for_each_entry(cs, &ctx->cs, node) {
1338 		/*
1339 		 * We need to toggle CS state for OMAP take this
1340 		 * change in account.
1341 		 */
1342 		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1343 			cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1344 			writel_relaxed(cs->chconf0,
1345 				       cs->base + OMAP2_MCSPI_CHCONF0);
1346 			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1347 			writel_relaxed(cs->chconf0,
1348 				       cs->base + OMAP2_MCSPI_CHCONF0);
1349 		} else {
1350 			writel_relaxed(cs->chconf0,
1351 				       cs->base + OMAP2_MCSPI_CHCONF0);
1352 		}
1353 	}
1354 
1355 	return 0;
1356 }
1357 
1358 static struct omap2_mcspi_platform_config omap2_pdata = {
1359 	.regs_offset = 0,
1360 };
1361 
1362 static struct omap2_mcspi_platform_config omap4_pdata = {
1363 	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1364 };
1365 
1366 static struct omap2_mcspi_platform_config am654_pdata = {
1367 	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1368 	.max_xfer_len = SZ_4K - 1,
1369 };
1370 
1371 static const struct of_device_id omap_mcspi_of_match[] = {
1372 	{
1373 		.compatible = "ti,omap2-mcspi",
1374 		.data = &omap2_pdata,
1375 	},
1376 	{
1377 		.compatible = "ti,omap4-mcspi",
1378 		.data = &omap4_pdata,
1379 	},
1380 	{
1381 		.compatible = "ti,am654-mcspi",
1382 		.data = &am654_pdata,
1383 	},
1384 	{ },
1385 };
1386 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1387 
1388 static int omap2_mcspi_probe(struct platform_device *pdev)
1389 {
1390 	struct spi_master	*master;
1391 	const struct omap2_mcspi_platform_config *pdata;
1392 	struct omap2_mcspi	*mcspi;
1393 	struct resource		*r;
1394 	int			status = 0, i;
1395 	u32			regs_offset = 0;
1396 	struct device_node	*node = pdev->dev.of_node;
1397 	const struct of_device_id *match;
1398 
1399 	if (of_property_read_bool(node, "spi-slave"))
1400 		master = spi_alloc_slave(&pdev->dev, sizeof(*mcspi));
1401 	else
1402 		master = spi_alloc_master(&pdev->dev, sizeof(*mcspi));
1403 	if (!master)
1404 		return -ENOMEM;
1405 
1406 	/* the spi->mode bits understood by this driver: */
1407 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1408 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1409 	master->setup = omap2_mcspi_setup;
1410 	master->auto_runtime_pm = true;
1411 	master->prepare_message = omap2_mcspi_prepare_message;
1412 	master->can_dma = omap2_mcspi_can_dma;
1413 	master->transfer_one = omap2_mcspi_transfer_one;
1414 	master->set_cs = omap2_mcspi_set_cs;
1415 	master->cleanup = omap2_mcspi_cleanup;
1416 	master->slave_abort = omap2_mcspi_slave_abort;
1417 	master->dev.of_node = node;
1418 	master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1419 	master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1420 	master->use_gpio_descriptors = true;
1421 
1422 	platform_set_drvdata(pdev, master);
1423 
1424 	mcspi = spi_master_get_devdata(master);
1425 	mcspi->master = master;
1426 
1427 	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1428 	if (match) {
1429 		u32 num_cs = 1; /* default number of chipselect */
1430 		pdata = match->data;
1431 
1432 		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1433 		master->num_chipselect = num_cs;
1434 		if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1435 			mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1436 	} else {
1437 		pdata = dev_get_platdata(&pdev->dev);
1438 		master->num_chipselect = pdata->num_cs;
1439 		mcspi->pin_dir = pdata->pin_dir;
1440 	}
1441 	regs_offset = pdata->regs_offset;
1442 	if (pdata->max_xfer_len) {
1443 		mcspi->max_xfer_len = pdata->max_xfer_len;
1444 		master->max_transfer_size = omap2_mcspi_max_xfer_size;
1445 	}
1446 
1447 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1448 	mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1449 	if (IS_ERR(mcspi->base)) {
1450 		status = PTR_ERR(mcspi->base);
1451 		goto free_master;
1452 	}
1453 	mcspi->phys = r->start + regs_offset;
1454 	mcspi->base += regs_offset;
1455 
1456 	mcspi->dev = &pdev->dev;
1457 
1458 	INIT_LIST_HEAD(&mcspi->ctx.cs);
1459 
1460 	mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1461 					   sizeof(struct omap2_mcspi_dma),
1462 					   GFP_KERNEL);
1463 	if (mcspi->dma_channels == NULL) {
1464 		status = -ENOMEM;
1465 		goto free_master;
1466 	}
1467 
1468 	for (i = 0; i < master->num_chipselect; i++) {
1469 		sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
1470 		sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
1471 
1472 		status = omap2_mcspi_request_dma(mcspi,
1473 						 &mcspi->dma_channels[i]);
1474 		if (status == -EPROBE_DEFER)
1475 			goto free_master;
1476 	}
1477 
1478 	status = platform_get_irq(pdev, 0);
1479 	if (status == -EPROBE_DEFER)
1480 		goto free_master;
1481 	if (status < 0) {
1482 		dev_err(&pdev->dev, "no irq resource found\n");
1483 		goto free_master;
1484 	}
1485 	init_completion(&mcspi->txdone);
1486 	status = devm_request_irq(&pdev->dev, status,
1487 				  omap2_mcspi_irq_handler, 0, pdev->name,
1488 				  mcspi);
1489 	if (status) {
1490 		dev_err(&pdev->dev, "Cannot request IRQ");
1491 		goto free_master;
1492 	}
1493 
1494 	pm_runtime_use_autosuspend(&pdev->dev);
1495 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1496 	pm_runtime_enable(&pdev->dev);
1497 
1498 	status = omap2_mcspi_controller_setup(mcspi);
1499 	if (status < 0)
1500 		goto disable_pm;
1501 
1502 	status = devm_spi_register_controller(&pdev->dev, master);
1503 	if (status < 0)
1504 		goto disable_pm;
1505 
1506 	return status;
1507 
1508 disable_pm:
1509 	pm_runtime_dont_use_autosuspend(&pdev->dev);
1510 	pm_runtime_put_sync(&pdev->dev);
1511 	pm_runtime_disable(&pdev->dev);
1512 free_master:
1513 	omap2_mcspi_release_dma(master);
1514 	spi_master_put(master);
1515 	return status;
1516 }
1517 
1518 static int omap2_mcspi_remove(struct platform_device *pdev)
1519 {
1520 	struct spi_master *master = platform_get_drvdata(pdev);
1521 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1522 
1523 	omap2_mcspi_release_dma(master);
1524 
1525 	pm_runtime_dont_use_autosuspend(mcspi->dev);
1526 	pm_runtime_put_sync(mcspi->dev);
1527 	pm_runtime_disable(&pdev->dev);
1528 
1529 	return 0;
1530 }
1531 
1532 /* work with hotplug and coldplug */
1533 MODULE_ALIAS("platform:omap2_mcspi");
1534 
1535 static int __maybe_unused omap2_mcspi_suspend(struct device *dev)
1536 {
1537 	struct spi_master *master = dev_get_drvdata(dev);
1538 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1539 	int error;
1540 
1541 	error = pinctrl_pm_select_sleep_state(dev);
1542 	if (error)
1543 		dev_warn(mcspi->dev, "%s: failed to set pins: %i\n",
1544 			 __func__, error);
1545 
1546 	error = spi_master_suspend(master);
1547 	if (error)
1548 		dev_warn(mcspi->dev, "%s: master suspend failed: %i\n",
1549 			 __func__, error);
1550 
1551 	return pm_runtime_force_suspend(dev);
1552 }
1553 
1554 static int __maybe_unused omap2_mcspi_resume(struct device *dev)
1555 {
1556 	struct spi_master *master = dev_get_drvdata(dev);
1557 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1558 	int error;
1559 
1560 	error = pinctrl_pm_select_default_state(dev);
1561 	if (error)
1562 		dev_warn(mcspi->dev, "%s: failed to set pins: %i\n",
1563 			 __func__, error);
1564 
1565 	error = spi_master_resume(master);
1566 	if (error)
1567 		dev_warn(mcspi->dev, "%s: master resume failed: %i\n",
1568 			 __func__, error);
1569 
1570 	return pm_runtime_force_resume(dev);
1571 }
1572 
1573 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1574 	SET_SYSTEM_SLEEP_PM_OPS(omap2_mcspi_suspend,
1575 				omap2_mcspi_resume)
1576 	.runtime_resume	= omap_mcspi_runtime_resume,
1577 };
1578 
1579 static struct platform_driver omap2_mcspi_driver = {
1580 	.driver = {
1581 		.name =		"omap2_mcspi",
1582 		.pm =		&omap2_mcspi_pm_ops,
1583 		.of_match_table = omap_mcspi_of_match,
1584 	},
1585 	.probe =	omap2_mcspi_probe,
1586 	.remove =	omap2_mcspi_remove,
1587 };
1588 
1589 module_platform_driver(omap2_mcspi_driver);
1590 MODULE_LICENSE("GPL");
1591