xref: /openbmc/linux/drivers/spi/spi-fsl-dspi.c (revision be709d48)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright 2013 Freescale Semiconductor, Inc.
4 //
5 // Freescale DSPI driver
6 // This file contains a driver for the Freescale DSPI
7 
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/dmaengine.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/err.h>
13 #include <linux/errno.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/math64.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_device.h>
21 #include <linux/pinctrl/consumer.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/regmap.h>
25 #include <linux/sched.h>
26 #include <linux/spi/spi.h>
27 #include <linux/spi/spi-fsl-dspi.h>
28 #include <linux/spi/spi_bitbang.h>
29 #include <linux/time.h>
30 
31 #define DRIVER_NAME "fsl-dspi"
32 
33 #ifdef CONFIG_M5441x
34 #define DSPI_FIFO_SIZE			16
35 #else
36 #define DSPI_FIFO_SIZE			4
37 #endif
38 #define DSPI_DMA_BUFSIZE		(DSPI_FIFO_SIZE * 1024)
39 
40 #define SPI_MCR		0x00
41 #define SPI_MCR_MASTER		(1 << 31)
42 #define SPI_MCR_PCSIS		(0x3F << 16)
43 #define SPI_MCR_CLR_TXF	(1 << 11)
44 #define SPI_MCR_CLR_RXF	(1 << 10)
45 #define SPI_MCR_XSPI		(1 << 3)
46 
47 #define SPI_TCR			0x08
48 #define SPI_TCR_GET_TCNT(x)	(((x) & 0xffff0000) >> 16)
49 
50 #define SPI_CTAR(x)		(0x0c + (((x) & 0x3) * 4))
51 #define SPI_CTAR_FMSZ(x)	(((x) & 0x0000000f) << 27)
52 #define SPI_CTAR_CPOL(x)	((x) << 26)
53 #define SPI_CTAR_CPHA(x)	((x) << 25)
54 #define SPI_CTAR_LSBFE(x)	((x) << 24)
55 #define SPI_CTAR_PCSSCK(x)	(((x) & 0x00000003) << 22)
56 #define SPI_CTAR_PASC(x)	(((x) & 0x00000003) << 20)
57 #define SPI_CTAR_PDT(x)	(((x) & 0x00000003) << 18)
58 #define SPI_CTAR_PBR(x)	(((x) & 0x00000003) << 16)
59 #define SPI_CTAR_CSSCK(x)	(((x) & 0x0000000f) << 12)
60 #define SPI_CTAR_ASC(x)	(((x) & 0x0000000f) << 8)
61 #define SPI_CTAR_DT(x)		(((x) & 0x0000000f) << 4)
62 #define SPI_CTAR_BR(x)		((x) & 0x0000000f)
63 #define SPI_CTAR_SCALE_BITS	0xf
64 
65 #define SPI_CTAR0_SLAVE	0x0c
66 
67 #define SPI_SR			0x2c
68 #define SPI_SR_EOQF		0x10000000
69 #define SPI_SR_TCFQF		0x80000000
70 #define SPI_SR_CLEAR		0x9aaf0000
71 
72 #define SPI_RSER_TFFFE		BIT(25)
73 #define SPI_RSER_TFFFD		BIT(24)
74 #define SPI_RSER_RFDFE		BIT(17)
75 #define SPI_RSER_RFDFD		BIT(16)
76 
77 #define SPI_RSER		0x30
78 #define SPI_RSER_EOQFE		0x10000000
79 #define SPI_RSER_TCFQE		0x80000000
80 
81 #define SPI_PUSHR		0x34
82 #define SPI_PUSHR_CMD_CONT	(1 << 15)
83 #define SPI_PUSHR_CONT		(SPI_PUSHR_CMD_CONT << 16)
84 #define SPI_PUSHR_CMD_CTAS(x)	(((x) & 0x0003) << 12)
85 #define SPI_PUSHR_CTAS(x)	(SPI_PUSHR_CMD_CTAS(x) << 16)
86 #define SPI_PUSHR_CMD_EOQ	(1 << 11)
87 #define SPI_PUSHR_EOQ		(SPI_PUSHR_CMD_EOQ << 16)
88 #define SPI_PUSHR_CMD_CTCNT	(1 << 10)
89 #define SPI_PUSHR_CTCNT		(SPI_PUSHR_CMD_CTCNT << 16)
90 #define SPI_PUSHR_CMD_PCS(x)	((1 << x) & 0x003f)
91 #define SPI_PUSHR_PCS(x)	(SPI_PUSHR_CMD_PCS(x) << 16)
92 #define SPI_PUSHR_TXDATA(x)	((x) & 0x0000ffff)
93 
94 #define SPI_PUSHR_SLAVE	0x34
95 
96 #define SPI_POPR		0x38
97 #define SPI_POPR_RXDATA(x)	((x) & 0x0000ffff)
98 
99 #define SPI_TXFR0		0x3c
100 #define SPI_TXFR1		0x40
101 #define SPI_TXFR2		0x44
102 #define SPI_TXFR3		0x48
103 #define SPI_RXFR0		0x7c
104 #define SPI_RXFR1		0x80
105 #define SPI_RXFR2		0x84
106 #define SPI_RXFR3		0x88
107 
108 #define SPI_CTARE(x)		(0x11c + (((x) & 0x3) * 4))
109 #define SPI_CTARE_FMSZE(x)	(((x) & 0x1) << 16)
110 #define SPI_CTARE_DTCP(x)	((x) & 0x7ff)
111 
112 #define SPI_SREX		0x13c
113 
114 #define SPI_FRAME_BITS(bits)	SPI_CTAR_FMSZ((bits) - 1)
115 #define SPI_FRAME_BITS_MASK	SPI_CTAR_FMSZ(0xf)
116 #define SPI_FRAME_BITS_16	SPI_CTAR_FMSZ(0xf)
117 #define SPI_FRAME_BITS_8	SPI_CTAR_FMSZ(0x7)
118 
119 #define SPI_FRAME_EBITS(bits)	SPI_CTARE_FMSZE(((bits) - 1) >> 4)
120 #define SPI_FRAME_EBITS_MASK	SPI_CTARE_FMSZE(1)
121 
122 /* Register offsets for regmap_pushr */
123 #define PUSHR_CMD		0x0
124 #define PUSHR_TX		0x2
125 
126 #define SPI_CS_INIT		0x01
127 #define SPI_CS_ASSERT		0x02
128 #define SPI_CS_DROP		0x04
129 
130 #define DMA_COMPLETION_TIMEOUT	msecs_to_jiffies(3000)
131 
132 struct chip_data {
133 	u32 ctar_val;
134 	u16 void_write_data;
135 };
136 
137 enum dspi_trans_mode {
138 	DSPI_EOQ_MODE = 0,
139 	DSPI_TCFQ_MODE,
140 	DSPI_DMA_MODE,
141 };
142 
143 struct fsl_dspi_devtype_data {
144 	enum dspi_trans_mode trans_mode;
145 	u8 max_clock_factor;
146 	bool xspi_mode;
147 };
148 
149 static const struct fsl_dspi_devtype_data vf610_data = {
150 	.trans_mode = DSPI_DMA_MODE,
151 	.max_clock_factor = 2,
152 };
153 
154 static const struct fsl_dspi_devtype_data ls1021a_v1_data = {
155 	.trans_mode = DSPI_TCFQ_MODE,
156 	.max_clock_factor = 8,
157 	.xspi_mode = true,
158 };
159 
160 static const struct fsl_dspi_devtype_data ls2085a_data = {
161 	.trans_mode = DSPI_TCFQ_MODE,
162 	.max_clock_factor = 8,
163 };
164 
165 static const struct fsl_dspi_devtype_data coldfire_data = {
166 	.trans_mode = DSPI_EOQ_MODE,
167 	.max_clock_factor = 8,
168 };
169 
170 struct fsl_dspi_dma {
171 	/* Length of transfer in words of DSPI_FIFO_SIZE */
172 	u32 curr_xfer_len;
173 
174 	u32 *tx_dma_buf;
175 	struct dma_chan *chan_tx;
176 	dma_addr_t tx_dma_phys;
177 	struct completion cmd_tx_complete;
178 	struct dma_async_tx_descriptor *tx_desc;
179 
180 	u32 *rx_dma_buf;
181 	struct dma_chan *chan_rx;
182 	dma_addr_t rx_dma_phys;
183 	struct completion cmd_rx_complete;
184 	struct dma_async_tx_descriptor *rx_desc;
185 };
186 
187 struct fsl_dspi {
188 	struct spi_master	*master;
189 	struct platform_device	*pdev;
190 
191 	struct regmap		*regmap;
192 	struct regmap		*regmap_pushr;
193 	int			irq;
194 	struct clk		*clk;
195 
196 	struct spi_transfer	*cur_transfer;
197 	struct spi_message	*cur_msg;
198 	struct chip_data	*cur_chip;
199 	size_t			len;
200 	const void		*tx;
201 	void			*rx;
202 	void			*rx_end;
203 	u16			void_write_data;
204 	u16			tx_cmd;
205 	u8			bits_per_word;
206 	u8			bytes_per_word;
207 	const struct fsl_dspi_devtype_data *devtype_data;
208 
209 	wait_queue_head_t	waitq;
210 	u32			waitflags;
211 
212 	struct fsl_dspi_dma	*dma;
213 };
214 
215 static u32 dspi_pop_tx(struct fsl_dspi *dspi)
216 {
217 	u32 txdata = 0;
218 
219 	if (dspi->tx) {
220 		if (dspi->bytes_per_word == 1)
221 			txdata = *(u8 *)dspi->tx;
222 		else if (dspi->bytes_per_word == 2)
223 			txdata = *(u16 *)dspi->tx;
224 		else  /* dspi->bytes_per_word == 4 */
225 			txdata = *(u32 *)dspi->tx;
226 		dspi->tx += dspi->bytes_per_word;
227 	}
228 	dspi->len -= dspi->bytes_per_word;
229 	return txdata;
230 }
231 
232 static u32 dspi_pop_tx_pushr(struct fsl_dspi *dspi)
233 {
234 	u16 cmd = dspi->tx_cmd, data = dspi_pop_tx(dspi);
235 
236 	if (spi_controller_is_slave(dspi->master))
237 		return data;
238 
239 	if (dspi->len > 0)
240 		cmd |= SPI_PUSHR_CMD_CONT;
241 	return cmd << 16 | data;
242 }
243 
244 static void dspi_push_rx(struct fsl_dspi *dspi, u32 rxdata)
245 {
246 	if (!dspi->rx)
247 		return;
248 
249 	/* Mask of undefined bits */
250 	rxdata &= (1 << dspi->bits_per_word) - 1;
251 
252 	if (dspi->bytes_per_word == 1)
253 		*(u8 *)dspi->rx = rxdata;
254 	else if (dspi->bytes_per_word == 2)
255 		*(u16 *)dspi->rx = rxdata;
256 	else /* dspi->bytes_per_word == 4 */
257 		*(u32 *)dspi->rx = rxdata;
258 	dspi->rx += dspi->bytes_per_word;
259 }
260 
261 static void dspi_tx_dma_callback(void *arg)
262 {
263 	struct fsl_dspi *dspi = arg;
264 	struct fsl_dspi_dma *dma = dspi->dma;
265 
266 	complete(&dma->cmd_tx_complete);
267 }
268 
269 static void dspi_rx_dma_callback(void *arg)
270 {
271 	struct fsl_dspi *dspi = arg;
272 	struct fsl_dspi_dma *dma = dspi->dma;
273 	int i;
274 
275 	if (dspi->rx) {
276 		for (i = 0; i < dma->curr_xfer_len; i++)
277 			dspi_push_rx(dspi, dspi->dma->rx_dma_buf[i]);
278 	}
279 
280 	complete(&dma->cmd_rx_complete);
281 }
282 
283 static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi)
284 {
285 	struct fsl_dspi_dma *dma = dspi->dma;
286 	struct device *dev = &dspi->pdev->dev;
287 	int time_left;
288 	int i;
289 
290 	for (i = 0; i < dma->curr_xfer_len; i++)
291 		dspi->dma->tx_dma_buf[i] = dspi_pop_tx_pushr(dspi);
292 
293 	dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx,
294 					dma->tx_dma_phys,
295 					dma->curr_xfer_len *
296 					DMA_SLAVE_BUSWIDTH_4_BYTES,
297 					DMA_MEM_TO_DEV,
298 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
299 	if (!dma->tx_desc) {
300 		dev_err(dev, "Not able to get desc for DMA xfer\n");
301 		return -EIO;
302 	}
303 
304 	dma->tx_desc->callback = dspi_tx_dma_callback;
305 	dma->tx_desc->callback_param = dspi;
306 	if (dma_submit_error(dmaengine_submit(dma->tx_desc))) {
307 		dev_err(dev, "DMA submit failed\n");
308 		return -EINVAL;
309 	}
310 
311 	dma->rx_desc = dmaengine_prep_slave_single(dma->chan_rx,
312 					dma->rx_dma_phys,
313 					dma->curr_xfer_len *
314 					DMA_SLAVE_BUSWIDTH_4_BYTES,
315 					DMA_DEV_TO_MEM,
316 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
317 	if (!dma->rx_desc) {
318 		dev_err(dev, "Not able to get desc for DMA xfer\n");
319 		return -EIO;
320 	}
321 
322 	dma->rx_desc->callback = dspi_rx_dma_callback;
323 	dma->rx_desc->callback_param = dspi;
324 	if (dma_submit_error(dmaengine_submit(dma->rx_desc))) {
325 		dev_err(dev, "DMA submit failed\n");
326 		return -EINVAL;
327 	}
328 
329 	reinit_completion(&dspi->dma->cmd_rx_complete);
330 	reinit_completion(&dspi->dma->cmd_tx_complete);
331 
332 	dma_async_issue_pending(dma->chan_rx);
333 	dma_async_issue_pending(dma->chan_tx);
334 
335 	if (spi_controller_is_slave(dspi->master)) {
336 		wait_for_completion_interruptible(&dspi->dma->cmd_rx_complete);
337 		return 0;
338 	}
339 
340 	time_left = wait_for_completion_timeout(&dspi->dma->cmd_tx_complete,
341 					DMA_COMPLETION_TIMEOUT);
342 	if (time_left == 0) {
343 		dev_err(dev, "DMA tx timeout\n");
344 		dmaengine_terminate_all(dma->chan_tx);
345 		dmaengine_terminate_all(dma->chan_rx);
346 		return -ETIMEDOUT;
347 	}
348 
349 	time_left = wait_for_completion_timeout(&dspi->dma->cmd_rx_complete,
350 					DMA_COMPLETION_TIMEOUT);
351 	if (time_left == 0) {
352 		dev_err(dev, "DMA rx timeout\n");
353 		dmaengine_terminate_all(dma->chan_tx);
354 		dmaengine_terminate_all(dma->chan_rx);
355 		return -ETIMEDOUT;
356 	}
357 
358 	return 0;
359 }
360 
361 static int dspi_dma_xfer(struct fsl_dspi *dspi)
362 {
363 	struct fsl_dspi_dma *dma = dspi->dma;
364 	struct device *dev = &dspi->pdev->dev;
365 	struct spi_message *message = dspi->cur_msg;
366 	int curr_remaining_bytes;
367 	int bytes_per_buffer;
368 	int ret = 0;
369 
370 	curr_remaining_bytes = dspi->len;
371 	bytes_per_buffer = DSPI_DMA_BUFSIZE / DSPI_FIFO_SIZE;
372 	while (curr_remaining_bytes) {
373 		/* Check if current transfer fits the DMA buffer */
374 		dma->curr_xfer_len = curr_remaining_bytes
375 			/ dspi->bytes_per_word;
376 		if (dma->curr_xfer_len > bytes_per_buffer)
377 			dma->curr_xfer_len = bytes_per_buffer;
378 
379 		ret = dspi_next_xfer_dma_submit(dspi);
380 		if (ret) {
381 			dev_err(dev, "DMA transfer failed\n");
382 			goto exit;
383 
384 		} else {
385 			const int len =
386 				dma->curr_xfer_len * dspi->bytes_per_word;
387 			curr_remaining_bytes -= len;
388 			message->actual_length += len;
389 			if (curr_remaining_bytes < 0)
390 				curr_remaining_bytes = 0;
391 		}
392 	}
393 
394 exit:
395 	return ret;
396 }
397 
398 static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr)
399 {
400 	struct fsl_dspi_dma *dma;
401 	struct dma_slave_config cfg;
402 	struct device *dev = &dspi->pdev->dev;
403 	int ret;
404 
405 	dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
406 	if (!dma)
407 		return -ENOMEM;
408 
409 	dma->chan_rx = dma_request_slave_channel(dev, "rx");
410 	if (!dma->chan_rx) {
411 		dev_err(dev, "rx dma channel not available\n");
412 		ret = -ENODEV;
413 		return ret;
414 	}
415 
416 	dma->chan_tx = dma_request_slave_channel(dev, "tx");
417 	if (!dma->chan_tx) {
418 		dev_err(dev, "tx dma channel not available\n");
419 		ret = -ENODEV;
420 		goto err_tx_channel;
421 	}
422 
423 	dma->tx_dma_buf = dma_alloc_coherent(dev, DSPI_DMA_BUFSIZE,
424 					&dma->tx_dma_phys, GFP_KERNEL);
425 	if (!dma->tx_dma_buf) {
426 		ret = -ENOMEM;
427 		goto err_tx_dma_buf;
428 	}
429 
430 	dma->rx_dma_buf = dma_alloc_coherent(dev, DSPI_DMA_BUFSIZE,
431 					&dma->rx_dma_phys, GFP_KERNEL);
432 	if (!dma->rx_dma_buf) {
433 		ret = -ENOMEM;
434 		goto err_rx_dma_buf;
435 	}
436 
437 	cfg.src_addr = phy_addr + SPI_POPR;
438 	cfg.dst_addr = phy_addr + SPI_PUSHR;
439 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
440 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
441 	cfg.src_maxburst = 1;
442 	cfg.dst_maxburst = 1;
443 
444 	cfg.direction = DMA_DEV_TO_MEM;
445 	ret = dmaengine_slave_config(dma->chan_rx, &cfg);
446 	if (ret) {
447 		dev_err(dev, "can't configure rx dma channel\n");
448 		ret = -EINVAL;
449 		goto err_slave_config;
450 	}
451 
452 	cfg.direction = DMA_MEM_TO_DEV;
453 	ret = dmaengine_slave_config(dma->chan_tx, &cfg);
454 	if (ret) {
455 		dev_err(dev, "can't configure tx dma channel\n");
456 		ret = -EINVAL;
457 		goto err_slave_config;
458 	}
459 
460 	dspi->dma = dma;
461 	init_completion(&dma->cmd_tx_complete);
462 	init_completion(&dma->cmd_rx_complete);
463 
464 	return 0;
465 
466 err_slave_config:
467 	dma_free_coherent(dev, DSPI_DMA_BUFSIZE,
468 			dma->rx_dma_buf, dma->rx_dma_phys);
469 err_rx_dma_buf:
470 	dma_free_coherent(dev, DSPI_DMA_BUFSIZE,
471 			dma->tx_dma_buf, dma->tx_dma_phys);
472 err_tx_dma_buf:
473 	dma_release_channel(dma->chan_tx);
474 err_tx_channel:
475 	dma_release_channel(dma->chan_rx);
476 
477 	devm_kfree(dev, dma);
478 	dspi->dma = NULL;
479 
480 	return ret;
481 }
482 
483 static void dspi_release_dma(struct fsl_dspi *dspi)
484 {
485 	struct fsl_dspi_dma *dma = dspi->dma;
486 	struct device *dev = &dspi->pdev->dev;
487 
488 	if (dma) {
489 		if (dma->chan_tx) {
490 			dma_unmap_single(dev, dma->tx_dma_phys,
491 					DSPI_DMA_BUFSIZE, DMA_TO_DEVICE);
492 			dma_release_channel(dma->chan_tx);
493 		}
494 
495 		if (dma->chan_rx) {
496 			dma_unmap_single(dev, dma->rx_dma_phys,
497 					DSPI_DMA_BUFSIZE, DMA_FROM_DEVICE);
498 			dma_release_channel(dma->chan_rx);
499 		}
500 	}
501 }
502 
503 static void hz_to_spi_baud(char *pbr, char *br, int speed_hz,
504 		unsigned long clkrate)
505 {
506 	/* Valid baud rate pre-scaler values */
507 	int pbr_tbl[4] = {2, 3, 5, 7};
508 	int brs[16] = {	2,	4,	6,	8,
509 		16,	32,	64,	128,
510 		256,	512,	1024,	2048,
511 		4096,	8192,	16384,	32768 };
512 	int scale_needed, scale, minscale = INT_MAX;
513 	int i, j;
514 
515 	scale_needed = clkrate / speed_hz;
516 	if (clkrate % speed_hz)
517 		scale_needed++;
518 
519 	for (i = 0; i < ARRAY_SIZE(brs); i++)
520 		for (j = 0; j < ARRAY_SIZE(pbr_tbl); j++) {
521 			scale = brs[i] * pbr_tbl[j];
522 			if (scale >= scale_needed) {
523 				if (scale < minscale) {
524 					minscale = scale;
525 					*br = i;
526 					*pbr = j;
527 				}
528 				break;
529 			}
530 		}
531 
532 	if (minscale == INT_MAX) {
533 		pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld, we use the max prescaler value.\n",
534 			speed_hz, clkrate);
535 		*pbr = ARRAY_SIZE(pbr_tbl) - 1;
536 		*br =  ARRAY_SIZE(brs) - 1;
537 	}
538 }
539 
540 static void ns_delay_scale(char *psc, char *sc, int delay_ns,
541 		unsigned long clkrate)
542 {
543 	int pscale_tbl[4] = {1, 3, 5, 7};
544 	int scale_needed, scale, minscale = INT_MAX;
545 	int i, j;
546 	u32 remainder;
547 
548 	scale_needed = div_u64_rem((u64)delay_ns * clkrate, NSEC_PER_SEC,
549 			&remainder);
550 	if (remainder)
551 		scale_needed++;
552 
553 	for (i = 0; i < ARRAY_SIZE(pscale_tbl); i++)
554 		for (j = 0; j <= SPI_CTAR_SCALE_BITS; j++) {
555 			scale = pscale_tbl[i] * (2 << j);
556 			if (scale >= scale_needed) {
557 				if (scale < minscale) {
558 					minscale = scale;
559 					*psc = i;
560 					*sc = j;
561 				}
562 				break;
563 			}
564 		}
565 
566 	if (minscale == INT_MAX) {
567 		pr_warn("Cannot find correct scale values for %dns delay at clkrate %ld, using max prescaler value",
568 			delay_ns, clkrate);
569 		*psc = ARRAY_SIZE(pscale_tbl) - 1;
570 		*sc = SPI_CTAR_SCALE_BITS;
571 	}
572 }
573 
574 static void fifo_write(struct fsl_dspi *dspi)
575 {
576 	regmap_write(dspi->regmap, SPI_PUSHR, dspi_pop_tx_pushr(dspi));
577 }
578 
579 static void cmd_fifo_write(struct fsl_dspi *dspi)
580 {
581 	u16 cmd = dspi->tx_cmd;
582 
583 	if (dspi->len > 0)
584 		cmd |= SPI_PUSHR_CMD_CONT;
585 	regmap_write(dspi->regmap_pushr, PUSHR_CMD, cmd);
586 }
587 
588 static void tx_fifo_write(struct fsl_dspi *dspi, u16 txdata)
589 {
590 	regmap_write(dspi->regmap_pushr, PUSHR_TX, txdata);
591 }
592 
593 static void dspi_tcfq_write(struct fsl_dspi *dspi)
594 {
595 	/* Clear transfer count */
596 	dspi->tx_cmd |= SPI_PUSHR_CMD_CTCNT;
597 
598 	if (dspi->devtype_data->xspi_mode && dspi->bits_per_word > 16) {
599 		/* Write two TX FIFO entries first, and then the corresponding
600 		 * CMD FIFO entry.
601 		 */
602 		u32 data = dspi_pop_tx(dspi);
603 
604 		if (dspi->cur_chip->ctar_val & SPI_CTAR_LSBFE(1)) {
605 			/* LSB */
606 			tx_fifo_write(dspi, data & 0xFFFF);
607 			tx_fifo_write(dspi, data >> 16);
608 		} else {
609 			/* MSB */
610 			tx_fifo_write(dspi, data >> 16);
611 			tx_fifo_write(dspi, data & 0xFFFF);
612 		}
613 		cmd_fifo_write(dspi);
614 	} else {
615 		/* Write one entry to both TX FIFO and CMD FIFO
616 		 * simultaneously.
617 		 */
618 		fifo_write(dspi);
619 	}
620 }
621 
622 static u32 fifo_read(struct fsl_dspi *dspi)
623 {
624 	u32 rxdata = 0;
625 
626 	regmap_read(dspi->regmap, SPI_POPR, &rxdata);
627 	return rxdata;
628 }
629 
630 static void dspi_tcfq_read(struct fsl_dspi *dspi)
631 {
632 	dspi_push_rx(dspi, fifo_read(dspi));
633 }
634 
635 static void dspi_eoq_write(struct fsl_dspi *dspi)
636 {
637 	int fifo_size = DSPI_FIFO_SIZE;
638 	u16 xfer_cmd = dspi->tx_cmd;
639 
640 	/* Fill TX FIFO with as many transfers as possible */
641 	while (dspi->len && fifo_size--) {
642 		dspi->tx_cmd = xfer_cmd;
643 		/* Request EOQF for last transfer in FIFO */
644 		if (dspi->len == dspi->bytes_per_word || fifo_size == 0)
645 			dspi->tx_cmd |= SPI_PUSHR_CMD_EOQ;
646 		/* Clear transfer count for first transfer in FIFO */
647 		if (fifo_size == (DSPI_FIFO_SIZE - 1))
648 			dspi->tx_cmd |= SPI_PUSHR_CMD_CTCNT;
649 		/* Write combined TX FIFO and CMD FIFO entry */
650 		fifo_write(dspi);
651 	}
652 }
653 
654 static void dspi_eoq_read(struct fsl_dspi *dspi)
655 {
656 	int fifo_size = DSPI_FIFO_SIZE;
657 
658 	/* Read one FIFO entry at and push to rx buffer */
659 	while ((dspi->rx < dspi->rx_end) && fifo_size--)
660 		dspi_push_rx(dspi, fifo_read(dspi));
661 }
662 
663 static int dspi_transfer_one_message(struct spi_master *master,
664 		struct spi_message *message)
665 {
666 	struct fsl_dspi *dspi = spi_master_get_devdata(master);
667 	struct spi_device *spi = message->spi;
668 	struct spi_transfer *transfer;
669 	int status = 0;
670 	enum dspi_trans_mode trans_mode;
671 
672 	message->actual_length = 0;
673 
674 	list_for_each_entry(transfer, &message->transfers, transfer_list) {
675 		dspi->cur_transfer = transfer;
676 		dspi->cur_msg = message;
677 		dspi->cur_chip = spi_get_ctldata(spi);
678 		/* Prepare command word for CMD FIFO */
679 		dspi->tx_cmd = SPI_PUSHR_CMD_CTAS(0) |
680 			SPI_PUSHR_CMD_PCS(spi->chip_select);
681 		if (list_is_last(&dspi->cur_transfer->transfer_list,
682 				 &dspi->cur_msg->transfers)) {
683 			/* Leave PCS activated after last transfer when
684 			 * cs_change is set.
685 			 */
686 			if (transfer->cs_change)
687 				dspi->tx_cmd |= SPI_PUSHR_CMD_CONT;
688 		} else {
689 			/* Keep PCS active between transfers in same message
690 			 * when cs_change is not set, and de-activate PCS
691 			 * between transfers in the same message when
692 			 * cs_change is set.
693 			 */
694 			if (!transfer->cs_change)
695 				dspi->tx_cmd |= SPI_PUSHR_CMD_CONT;
696 		}
697 
698 		dspi->void_write_data = dspi->cur_chip->void_write_data;
699 
700 		dspi->tx = transfer->tx_buf;
701 		dspi->rx = transfer->rx_buf;
702 		dspi->rx_end = dspi->rx + transfer->len;
703 		dspi->len = transfer->len;
704 		/* Validated transfer specific frame size (defaults applied) */
705 		dspi->bits_per_word = transfer->bits_per_word;
706 		if (transfer->bits_per_word <= 8)
707 			dspi->bytes_per_word = 1;
708 		else if (transfer->bits_per_word <= 16)
709 			dspi->bytes_per_word = 2;
710 		else
711 			dspi->bytes_per_word = 4;
712 
713 		regmap_update_bits(dspi->regmap, SPI_MCR,
714 				   SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF,
715 				   SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF);
716 		regmap_write(dspi->regmap, SPI_CTAR(0),
717 			     dspi->cur_chip->ctar_val |
718 			     SPI_FRAME_BITS(transfer->bits_per_word));
719 		if (dspi->devtype_data->xspi_mode)
720 			regmap_write(dspi->regmap, SPI_CTARE(0),
721 				     SPI_FRAME_EBITS(transfer->bits_per_word)
722 				     | SPI_CTARE_DTCP(1));
723 
724 		trans_mode = dspi->devtype_data->trans_mode;
725 		switch (trans_mode) {
726 		case DSPI_EOQ_MODE:
727 			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
728 			dspi_eoq_write(dspi);
729 			break;
730 		case DSPI_TCFQ_MODE:
731 			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_TCFQE);
732 			dspi_tcfq_write(dspi);
733 			break;
734 		case DSPI_DMA_MODE:
735 			regmap_write(dspi->regmap, SPI_RSER,
736 				SPI_RSER_TFFFE | SPI_RSER_TFFFD |
737 				SPI_RSER_RFDFE | SPI_RSER_RFDFD);
738 			status = dspi_dma_xfer(dspi);
739 			break;
740 		default:
741 			dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n",
742 				trans_mode);
743 			status = -EINVAL;
744 			goto out;
745 		}
746 
747 		if (trans_mode != DSPI_DMA_MODE) {
748 			if (wait_event_interruptible(dspi->waitq,
749 						dspi->waitflags))
750 				dev_err(&dspi->pdev->dev,
751 					"wait transfer complete fail!\n");
752 			dspi->waitflags = 0;
753 		}
754 
755 		if (transfer->delay_usecs)
756 			udelay(transfer->delay_usecs);
757 	}
758 
759 out:
760 	message->status = status;
761 	spi_finalize_current_message(master);
762 
763 	return status;
764 }
765 
766 static int dspi_setup(struct spi_device *spi)
767 {
768 	struct chip_data *chip;
769 	struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
770 	struct fsl_dspi_platform_data *pdata;
771 	u32 cs_sck_delay = 0, sck_cs_delay = 0;
772 	unsigned char br = 0, pbr = 0, pcssck = 0, cssck = 0;
773 	unsigned char pasc = 0, asc = 0;
774 	unsigned long clkrate;
775 
776 	/* Only alloc on first setup */
777 	chip = spi_get_ctldata(spi);
778 	if (chip == NULL) {
779 		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
780 		if (!chip)
781 			return -ENOMEM;
782 	}
783 
784 	pdata = dev_get_platdata(&dspi->pdev->dev);
785 
786 	if (!pdata) {
787 		of_property_read_u32(spi->dev.of_node, "fsl,spi-cs-sck-delay",
788 				&cs_sck_delay);
789 
790 		of_property_read_u32(spi->dev.of_node, "fsl,spi-sck-cs-delay",
791 				&sck_cs_delay);
792 	} else {
793 		cs_sck_delay = pdata->cs_sck_delay;
794 		sck_cs_delay = pdata->sck_cs_delay;
795 	}
796 
797 	chip->void_write_data = 0;
798 
799 	clkrate = clk_get_rate(dspi->clk);
800 	hz_to_spi_baud(&pbr, &br, spi->max_speed_hz, clkrate);
801 
802 	/* Set PCS to SCK delay scale values */
803 	ns_delay_scale(&pcssck, &cssck, cs_sck_delay, clkrate);
804 
805 	/* Set After SCK delay scale values */
806 	ns_delay_scale(&pasc, &asc, sck_cs_delay, clkrate);
807 
808 	chip->ctar_val = SPI_CTAR_CPOL(spi->mode & SPI_CPOL ? 1 : 0)
809 		| SPI_CTAR_CPHA(spi->mode & SPI_CPHA ? 1 : 0);
810 
811 	if (!spi_controller_is_slave(dspi->master)) {
812 		chip->ctar_val |= SPI_CTAR_LSBFE(spi->mode &
813 						 SPI_LSB_FIRST ? 1 : 0)
814 			| SPI_CTAR_PCSSCK(pcssck)
815 			| SPI_CTAR_CSSCK(cssck)
816 			| SPI_CTAR_PASC(pasc)
817 			| SPI_CTAR_ASC(asc)
818 			| SPI_CTAR_PBR(pbr)
819 			| SPI_CTAR_BR(br);
820 	}
821 
822 	spi_set_ctldata(spi, chip);
823 
824 	return 0;
825 }
826 
827 static void dspi_cleanup(struct spi_device *spi)
828 {
829 	struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
830 
831 	dev_dbg(&spi->dev, "spi_device %u.%u cleanup\n",
832 			spi->master->bus_num, spi->chip_select);
833 
834 	kfree(chip);
835 }
836 
837 static irqreturn_t dspi_interrupt(int irq, void *dev_id)
838 {
839 	struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id;
840 	struct spi_message *msg = dspi->cur_msg;
841 	enum dspi_trans_mode trans_mode;
842 	u32 spi_sr, spi_tcr;
843 	u16 spi_tcnt;
844 
845 	regmap_read(dspi->regmap, SPI_SR, &spi_sr);
846 	regmap_write(dspi->regmap, SPI_SR, spi_sr);
847 
848 
849 	if (spi_sr & (SPI_SR_EOQF | SPI_SR_TCFQF)) {
850 		/* Get transfer counter (in number of SPI transfers). It was
851 		 * reset to 0 when transfer(s) were started.
852 		 */
853 		regmap_read(dspi->regmap, SPI_TCR, &spi_tcr);
854 		spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr);
855 		/* Update total number of bytes that were transferred */
856 		msg->actual_length += spi_tcnt * dspi->bytes_per_word;
857 
858 		trans_mode = dspi->devtype_data->trans_mode;
859 		switch (trans_mode) {
860 		case DSPI_EOQ_MODE:
861 			dspi_eoq_read(dspi);
862 			break;
863 		case DSPI_TCFQ_MODE:
864 			dspi_tcfq_read(dspi);
865 			break;
866 		default:
867 			dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n",
868 				trans_mode);
869 				return IRQ_HANDLED;
870 		}
871 
872 		if (!dspi->len) {
873 			dspi->waitflags = 1;
874 			wake_up_interruptible(&dspi->waitq);
875 		} else {
876 			switch (trans_mode) {
877 			case DSPI_EOQ_MODE:
878 				dspi_eoq_write(dspi);
879 				break;
880 			case DSPI_TCFQ_MODE:
881 				dspi_tcfq_write(dspi);
882 				break;
883 			default:
884 				dev_err(&dspi->pdev->dev,
885 					"unsupported trans_mode %u\n",
886 					trans_mode);
887 			}
888 		}
889 	}
890 
891 	return IRQ_HANDLED;
892 }
893 
894 static const struct of_device_id fsl_dspi_dt_ids[] = {
895 	{ .compatible = "fsl,vf610-dspi", .data = &vf610_data, },
896 	{ .compatible = "fsl,ls1021a-v1.0-dspi", .data = &ls1021a_v1_data, },
897 	{ .compatible = "fsl,ls2085a-dspi", .data = &ls2085a_data, },
898 	{ /* sentinel */ }
899 };
900 MODULE_DEVICE_TABLE(of, fsl_dspi_dt_ids);
901 
902 #ifdef CONFIG_PM_SLEEP
903 static int dspi_suspend(struct device *dev)
904 {
905 	struct spi_master *master = dev_get_drvdata(dev);
906 	struct fsl_dspi *dspi = spi_master_get_devdata(master);
907 
908 	spi_master_suspend(master);
909 	clk_disable_unprepare(dspi->clk);
910 
911 	pinctrl_pm_select_sleep_state(dev);
912 
913 	return 0;
914 }
915 
916 static int dspi_resume(struct device *dev)
917 {
918 	struct spi_master *master = dev_get_drvdata(dev);
919 	struct fsl_dspi *dspi = spi_master_get_devdata(master);
920 	int ret;
921 
922 	pinctrl_pm_select_default_state(dev);
923 
924 	ret = clk_prepare_enable(dspi->clk);
925 	if (ret)
926 		return ret;
927 	spi_master_resume(master);
928 
929 	return 0;
930 }
931 #endif /* CONFIG_PM_SLEEP */
932 
933 static SIMPLE_DEV_PM_OPS(dspi_pm, dspi_suspend, dspi_resume);
934 
935 static const struct regmap_range dspi_volatile_ranges[] = {
936 	regmap_reg_range(SPI_MCR, SPI_TCR),
937 	regmap_reg_range(SPI_SR, SPI_SR),
938 	regmap_reg_range(SPI_PUSHR, SPI_RXFR3),
939 };
940 
941 static const struct regmap_access_table dspi_volatile_table = {
942 	.yes_ranges     = dspi_volatile_ranges,
943 	.n_yes_ranges   = ARRAY_SIZE(dspi_volatile_ranges),
944 };
945 
946 static const struct regmap_config dspi_regmap_config = {
947 	.reg_bits = 32,
948 	.val_bits = 32,
949 	.reg_stride = 4,
950 	.max_register = 0x88,
951 	.volatile_table = &dspi_volatile_table,
952 };
953 
954 static const struct regmap_range dspi_xspi_volatile_ranges[] = {
955 	regmap_reg_range(SPI_MCR, SPI_TCR),
956 	regmap_reg_range(SPI_SR, SPI_SR),
957 	regmap_reg_range(SPI_PUSHR, SPI_RXFR3),
958 	regmap_reg_range(SPI_SREX, SPI_SREX),
959 };
960 
961 static const struct regmap_access_table dspi_xspi_volatile_table = {
962 	.yes_ranges     = dspi_xspi_volatile_ranges,
963 	.n_yes_ranges   = ARRAY_SIZE(dspi_xspi_volatile_ranges),
964 };
965 
966 static const struct regmap_config dspi_xspi_regmap_config[] = {
967 	{
968 		.reg_bits = 32,
969 		.val_bits = 32,
970 		.reg_stride = 4,
971 		.max_register = 0x13c,
972 		.volatile_table = &dspi_xspi_volatile_table,
973 	},
974 	{
975 		.name = "pushr",
976 		.reg_bits = 16,
977 		.val_bits = 16,
978 		.reg_stride = 2,
979 		.max_register = 0x2,
980 	},
981 };
982 
983 static void dspi_init(struct fsl_dspi *dspi)
984 {
985 	unsigned int mcr = SPI_MCR_PCSIS |
986 		(dspi->devtype_data->xspi_mode ? SPI_MCR_XSPI : 0);
987 
988 	if (!spi_controller_is_slave(dspi->master))
989 		mcr |= SPI_MCR_MASTER;
990 
991 	regmap_write(dspi->regmap, SPI_MCR, mcr);
992 	regmap_write(dspi->regmap, SPI_SR, SPI_SR_CLEAR);
993 	if (dspi->devtype_data->xspi_mode)
994 		regmap_write(dspi->regmap, SPI_CTARE(0),
995 			     SPI_CTARE_FMSZE(0) | SPI_CTARE_DTCP(1));
996 }
997 
998 static int dspi_probe(struct platform_device *pdev)
999 {
1000 	struct device_node *np = pdev->dev.of_node;
1001 	struct spi_master *master;
1002 	struct fsl_dspi *dspi;
1003 	struct resource *res;
1004 	const struct regmap_config *regmap_config;
1005 	void __iomem *base;
1006 	struct fsl_dspi_platform_data *pdata;
1007 	int ret = 0, cs_num, bus_num;
1008 
1009 	master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
1010 	if (!master)
1011 		return -ENOMEM;
1012 
1013 	dspi = spi_master_get_devdata(master);
1014 	dspi->pdev = pdev;
1015 	dspi->master = master;
1016 
1017 	master->transfer = NULL;
1018 	master->setup = dspi_setup;
1019 	master->transfer_one_message = dspi_transfer_one_message;
1020 	master->dev.of_node = pdev->dev.of_node;
1021 
1022 	master->cleanup = dspi_cleanup;
1023 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
1024 
1025 	pdata = dev_get_platdata(&pdev->dev);
1026 	if (pdata) {
1027 		master->num_chipselect = pdata->cs_num;
1028 		master->bus_num = pdata->bus_num;
1029 
1030 		dspi->devtype_data = &coldfire_data;
1031 	} else {
1032 
1033 		ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num);
1034 		if (ret < 0) {
1035 			dev_err(&pdev->dev, "can't get spi-num-chipselects\n");
1036 			goto out_master_put;
1037 		}
1038 		master->num_chipselect = cs_num;
1039 
1040 		ret = of_property_read_u32(np, "bus-num", &bus_num);
1041 		if (ret < 0) {
1042 			dev_err(&pdev->dev, "can't get bus-num\n");
1043 			goto out_master_put;
1044 		}
1045 		master->bus_num = bus_num;
1046 
1047 		if (of_property_read_bool(np, "spi-slave"))
1048 			master->slave = true;
1049 
1050 		dspi->devtype_data = of_device_get_match_data(&pdev->dev);
1051 		if (!dspi->devtype_data) {
1052 			dev_err(&pdev->dev, "can't get devtype_data\n");
1053 			ret = -EFAULT;
1054 			goto out_master_put;
1055 		}
1056 	}
1057 
1058 	if (dspi->devtype_data->xspi_mode)
1059 		master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1060 	else
1061 		master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
1062 
1063 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1064 	base = devm_ioremap_resource(&pdev->dev, res);
1065 	if (IS_ERR(base)) {
1066 		ret = PTR_ERR(base);
1067 		goto out_master_put;
1068 	}
1069 
1070 	if (dspi->devtype_data->xspi_mode)
1071 		regmap_config = &dspi_xspi_regmap_config[0];
1072 	else
1073 		regmap_config = &dspi_regmap_config;
1074 	dspi->regmap = devm_regmap_init_mmio(&pdev->dev, base, regmap_config);
1075 	if (IS_ERR(dspi->regmap)) {
1076 		dev_err(&pdev->dev, "failed to init regmap: %ld\n",
1077 				PTR_ERR(dspi->regmap));
1078 		ret = PTR_ERR(dspi->regmap);
1079 		goto out_master_put;
1080 	}
1081 
1082 	if (dspi->devtype_data->xspi_mode) {
1083 		dspi->regmap_pushr = devm_regmap_init_mmio(
1084 			&pdev->dev, base + SPI_PUSHR,
1085 			&dspi_xspi_regmap_config[1]);
1086 		if (IS_ERR(dspi->regmap_pushr)) {
1087 			dev_err(&pdev->dev,
1088 				"failed to init pushr regmap: %ld\n",
1089 				PTR_ERR(dspi->regmap_pushr));
1090 			ret = PTR_ERR(dspi->regmap_pushr);
1091 			goto out_master_put;
1092 		}
1093 	}
1094 
1095 	dspi->clk = devm_clk_get(&pdev->dev, "dspi");
1096 	if (IS_ERR(dspi->clk)) {
1097 		ret = PTR_ERR(dspi->clk);
1098 		dev_err(&pdev->dev, "unable to get clock\n");
1099 		goto out_master_put;
1100 	}
1101 	ret = clk_prepare_enable(dspi->clk);
1102 	if (ret)
1103 		goto out_master_put;
1104 
1105 	dspi_init(dspi);
1106 	dspi->irq = platform_get_irq(pdev, 0);
1107 	if (dspi->irq < 0) {
1108 		dev_err(&pdev->dev, "can't get platform irq\n");
1109 		ret = dspi->irq;
1110 		goto out_clk_put;
1111 	}
1112 
1113 	ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt,
1114 			       IRQF_SHARED, pdev->name, dspi);
1115 	if (ret < 0) {
1116 		dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
1117 		goto out_clk_put;
1118 	}
1119 
1120 	if (dspi->devtype_data->trans_mode == DSPI_DMA_MODE) {
1121 		ret = dspi_request_dma(dspi, res->start);
1122 		if (ret < 0) {
1123 			dev_err(&pdev->dev, "can't get dma channels\n");
1124 			goto out_clk_put;
1125 		}
1126 	}
1127 
1128 	master->max_speed_hz =
1129 		clk_get_rate(dspi->clk) / dspi->devtype_data->max_clock_factor;
1130 
1131 	init_waitqueue_head(&dspi->waitq);
1132 	platform_set_drvdata(pdev, master);
1133 
1134 	ret = spi_register_master(master);
1135 	if (ret != 0) {
1136 		dev_err(&pdev->dev, "Problem registering DSPI master\n");
1137 		goto out_clk_put;
1138 	}
1139 
1140 	return ret;
1141 
1142 out_clk_put:
1143 	clk_disable_unprepare(dspi->clk);
1144 out_master_put:
1145 	spi_master_put(master);
1146 
1147 	return ret;
1148 }
1149 
1150 static int dspi_remove(struct platform_device *pdev)
1151 {
1152 	struct spi_master *master = platform_get_drvdata(pdev);
1153 	struct fsl_dspi *dspi = spi_master_get_devdata(master);
1154 
1155 	/* Disconnect from the SPI framework */
1156 	dspi_release_dma(dspi);
1157 	clk_disable_unprepare(dspi->clk);
1158 	spi_unregister_master(dspi->master);
1159 
1160 	return 0;
1161 }
1162 
1163 static struct platform_driver fsl_dspi_driver = {
1164 	.driver.name    = DRIVER_NAME,
1165 	.driver.of_match_table = fsl_dspi_dt_ids,
1166 	.driver.owner   = THIS_MODULE,
1167 	.driver.pm = &dspi_pm,
1168 	.probe          = dspi_probe,
1169 	.remove		= dspi_remove,
1170 };
1171 module_platform_driver(fsl_dspi_driver);
1172 
1173 MODULE_DESCRIPTION("Freescale DSPI Controller Driver");
1174 MODULE_LICENSE("GPL");
1175 MODULE_ALIAS("platform:" DRIVER_NAME);
1176