xref: /linux/drivers/spi/spi-ti-qspi.c (revision b0f84a84fff180718995b1269da2988e5b28be42)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * TI QSPI driver
4  *
5  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
6  * Author: Sourav Poddar <sourav.poddar@ti.com>
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/init.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/omap-dma.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/pinctrl/consumer.h>
27 #include <linux/mfd/syscon.h>
28 #include <linux/regmap.h>
29 #include <linux/sizes.h>
30 
31 #include <linux/spi/spi.h>
32 #include <linux/spi/spi-mem.h>
33 
34 struct ti_qspi_regs {
35 	u32 clkctrl;
36 };
37 
38 struct ti_qspi {
39 	struct completion	transfer_complete;
40 
41 	/* list synchronization */
42 	struct mutex            list_lock;
43 
44 	struct spi_master	*master;
45 	void __iomem            *base;
46 	void __iomem            *mmap_base;
47 	size_t			mmap_size;
48 	struct regmap		*ctrl_base;
49 	unsigned int		ctrl_reg;
50 	struct clk		*fclk;
51 	struct device           *dev;
52 
53 	struct ti_qspi_regs     ctx_reg;
54 
55 	dma_addr_t		mmap_phys_base;
56 	dma_addr_t		rx_bb_dma_addr;
57 	void			*rx_bb_addr;
58 	struct dma_chan		*rx_chan;
59 
60 	u32 spi_max_frequency;
61 	u32 cmd;
62 	u32 dc;
63 
64 	bool mmap_enabled;
65 };
66 
67 #define QSPI_PID			(0x0)
68 #define QSPI_SYSCONFIG			(0x10)
69 #define QSPI_SPI_CLOCK_CNTRL_REG	(0x40)
70 #define QSPI_SPI_DC_REG			(0x44)
71 #define QSPI_SPI_CMD_REG		(0x48)
72 #define QSPI_SPI_STATUS_REG		(0x4c)
73 #define QSPI_SPI_DATA_REG		(0x50)
74 #define QSPI_SPI_SETUP_REG(n)		((0x54 + 4 * n))
75 #define QSPI_SPI_SWITCH_REG		(0x64)
76 #define QSPI_SPI_DATA_REG_1		(0x68)
77 #define QSPI_SPI_DATA_REG_2		(0x6c)
78 #define QSPI_SPI_DATA_REG_3		(0x70)
79 
80 #define QSPI_COMPLETION_TIMEOUT		msecs_to_jiffies(2000)
81 
82 #define QSPI_FCLK			192000000
83 
84 /* Clock Control */
85 #define QSPI_CLK_EN			(1 << 31)
86 #define QSPI_CLK_DIV_MAX		0xffff
87 
88 /* Command */
89 #define QSPI_EN_CS(n)			(n << 28)
90 #define QSPI_WLEN(n)			((n - 1) << 19)
91 #define QSPI_3_PIN			(1 << 18)
92 #define QSPI_RD_SNGL			(1 << 16)
93 #define QSPI_WR_SNGL			(2 << 16)
94 #define QSPI_RD_DUAL			(3 << 16)
95 #define QSPI_RD_QUAD			(7 << 16)
96 #define QSPI_INVAL			(4 << 16)
97 #define QSPI_FLEN(n)			((n - 1) << 0)
98 #define QSPI_WLEN_MAX_BITS		128
99 #define QSPI_WLEN_MAX_BYTES		16
100 #define QSPI_WLEN_MASK			QSPI_WLEN(QSPI_WLEN_MAX_BITS)
101 
102 /* STATUS REGISTER */
103 #define BUSY				0x01
104 #define WC				0x02
105 
106 /* Device Control */
107 #define QSPI_DD(m, n)			(m << (3 + n * 8))
108 #define QSPI_CKPHA(n)			(1 << (2 + n * 8))
109 #define QSPI_CSPOL(n)			(1 << (1 + n * 8))
110 #define QSPI_CKPOL(n)			(1 << (n * 8))
111 
112 #define	QSPI_FRAME			4096
113 
114 #define QSPI_AUTOSUSPEND_TIMEOUT         2000
115 
116 #define MEM_CS_EN(n)			((n + 1) << 8)
117 #define MEM_CS_MASK			(7 << 8)
118 
119 #define MM_SWITCH			0x1
120 
121 #define QSPI_SETUP_RD_NORMAL		(0x0 << 12)
122 #define QSPI_SETUP_RD_DUAL		(0x1 << 12)
123 #define QSPI_SETUP_RD_QUAD		(0x3 << 12)
124 #define QSPI_SETUP_ADDR_SHIFT		8
125 #define QSPI_SETUP_DUMMY_SHIFT		10
126 
127 #define QSPI_DMA_BUFFER_SIZE            SZ_64K
128 
129 static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
130 		unsigned long reg)
131 {
132 	return readl(qspi->base + reg);
133 }
134 
135 static inline void ti_qspi_write(struct ti_qspi *qspi,
136 		unsigned long val, unsigned long reg)
137 {
138 	writel(val, qspi->base + reg);
139 }
140 
141 static int ti_qspi_setup(struct spi_device *spi)
142 {
143 	struct ti_qspi	*qspi = spi_master_get_devdata(spi->master);
144 	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
145 	int clk_div = 0, ret;
146 	u32 clk_ctrl_reg, clk_rate, clk_mask;
147 
148 	if (spi->master->busy) {
149 		dev_dbg(qspi->dev, "master busy doing other transfers\n");
150 		return -EBUSY;
151 	}
152 
153 	if (!qspi->spi_max_frequency) {
154 		dev_err(qspi->dev, "spi max frequency not defined\n");
155 		return -EINVAL;
156 	}
157 
158 	clk_rate = clk_get_rate(qspi->fclk);
159 
160 	clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1;
161 
162 	if (clk_div < 0) {
163 		dev_dbg(qspi->dev, "clock divider < 0, using /1 divider\n");
164 		return -EINVAL;
165 	}
166 
167 	if (clk_div > QSPI_CLK_DIV_MAX) {
168 		dev_dbg(qspi->dev, "clock divider >%d , using /%d divider\n",
169 				QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
170 		return -EINVAL;
171 	}
172 
173 	dev_dbg(qspi->dev, "hz: %d, clock divider %d\n",
174 			qspi->spi_max_frequency, clk_div);
175 
176 	ret = pm_runtime_get_sync(qspi->dev);
177 	if (ret < 0) {
178 		dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
179 		return ret;
180 	}
181 
182 	clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
183 
184 	clk_ctrl_reg &= ~QSPI_CLK_EN;
185 
186 	/* disable SCLK */
187 	ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
188 
189 	/* enable SCLK */
190 	clk_mask = QSPI_CLK_EN | clk_div;
191 	ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG);
192 	ctx_reg->clkctrl = clk_mask;
193 
194 	pm_runtime_mark_last_busy(qspi->dev);
195 	ret = pm_runtime_put_autosuspend(qspi->dev);
196 	if (ret < 0) {
197 		dev_err(qspi->dev, "pm_runtime_put_autosuspend() failed\n");
198 		return ret;
199 	}
200 
201 	return 0;
202 }
203 
204 static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
205 {
206 	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
207 
208 	ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
209 }
210 
211 static inline u32 qspi_is_busy(struct ti_qspi *qspi)
212 {
213 	u32 stat;
214 	unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
215 
216 	stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
217 	while ((stat & BUSY) && time_after(timeout, jiffies)) {
218 		cpu_relax();
219 		stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
220 	}
221 
222 	WARN(stat & BUSY, "qspi busy\n");
223 	return stat & BUSY;
224 }
225 
226 static inline int ti_qspi_poll_wc(struct ti_qspi *qspi)
227 {
228 	u32 stat;
229 	unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
230 
231 	do {
232 		stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
233 		if (stat & WC)
234 			return 0;
235 		cpu_relax();
236 	} while (time_after(timeout, jiffies));
237 
238 	stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
239 	if (stat & WC)
240 		return 0;
241 	return  -ETIMEDOUT;
242 }
243 
244 static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t,
245 			  int count)
246 {
247 	int wlen, xfer_len;
248 	unsigned int cmd;
249 	const u8 *txbuf;
250 	u32 data;
251 
252 	txbuf = t->tx_buf;
253 	cmd = qspi->cmd | QSPI_WR_SNGL;
254 	wlen = t->bits_per_word >> 3;	/* in bytes */
255 	xfer_len = wlen;
256 
257 	while (count) {
258 		if (qspi_is_busy(qspi))
259 			return -EBUSY;
260 
261 		switch (wlen) {
262 		case 1:
263 			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
264 					cmd, qspi->dc, *txbuf);
265 			if (count >= QSPI_WLEN_MAX_BYTES) {
266 				u32 *txp = (u32 *)txbuf;
267 
268 				data = cpu_to_be32(*txp++);
269 				writel(data, qspi->base +
270 				       QSPI_SPI_DATA_REG_3);
271 				data = cpu_to_be32(*txp++);
272 				writel(data, qspi->base +
273 				       QSPI_SPI_DATA_REG_2);
274 				data = cpu_to_be32(*txp++);
275 				writel(data, qspi->base +
276 				       QSPI_SPI_DATA_REG_1);
277 				data = cpu_to_be32(*txp++);
278 				writel(data, qspi->base +
279 				       QSPI_SPI_DATA_REG);
280 				xfer_len = QSPI_WLEN_MAX_BYTES;
281 				cmd |= QSPI_WLEN(QSPI_WLEN_MAX_BITS);
282 			} else {
283 				writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
284 				cmd = qspi->cmd | QSPI_WR_SNGL;
285 				xfer_len = wlen;
286 				cmd |= QSPI_WLEN(wlen);
287 			}
288 			break;
289 		case 2:
290 			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n",
291 					cmd, qspi->dc, *txbuf);
292 			writew(*((u16 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
293 			break;
294 		case 4:
295 			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %08x\n",
296 					cmd, qspi->dc, *txbuf);
297 			writel(*((u32 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
298 			break;
299 		}
300 
301 		ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
302 		if (ti_qspi_poll_wc(qspi)) {
303 			dev_err(qspi->dev, "write timed out\n");
304 			return -ETIMEDOUT;
305 		}
306 		txbuf += xfer_len;
307 		count -= xfer_len;
308 	}
309 
310 	return 0;
311 }
312 
313 static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t,
314 			 int count)
315 {
316 	int wlen;
317 	unsigned int cmd;
318 	u8 *rxbuf;
319 
320 	rxbuf = t->rx_buf;
321 	cmd = qspi->cmd;
322 	switch (t->rx_nbits) {
323 	case SPI_NBITS_DUAL:
324 		cmd |= QSPI_RD_DUAL;
325 		break;
326 	case SPI_NBITS_QUAD:
327 		cmd |= QSPI_RD_QUAD;
328 		break;
329 	default:
330 		cmd |= QSPI_RD_SNGL;
331 		break;
332 	}
333 	wlen = t->bits_per_word >> 3;	/* in bytes */
334 
335 	while (count) {
336 		dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
337 		if (qspi_is_busy(qspi))
338 			return -EBUSY;
339 
340 		ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
341 		if (ti_qspi_poll_wc(qspi)) {
342 			dev_err(qspi->dev, "read timed out\n");
343 			return -ETIMEDOUT;
344 		}
345 		switch (wlen) {
346 		case 1:
347 			*rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG);
348 			break;
349 		case 2:
350 			*((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG);
351 			break;
352 		case 4:
353 			*((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG);
354 			break;
355 		}
356 		rxbuf += wlen;
357 		count -= wlen;
358 	}
359 
360 	return 0;
361 }
362 
363 static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t,
364 			     int count)
365 {
366 	int ret;
367 
368 	if (t->tx_buf) {
369 		ret = qspi_write_msg(qspi, t, count);
370 		if (ret) {
371 			dev_dbg(qspi->dev, "Error while writing\n");
372 			return ret;
373 		}
374 	}
375 
376 	if (t->rx_buf) {
377 		ret = qspi_read_msg(qspi, t, count);
378 		if (ret) {
379 			dev_dbg(qspi->dev, "Error while reading\n");
380 			return ret;
381 		}
382 	}
383 
384 	return 0;
385 }
386 
387 static void ti_qspi_dma_callback(void *param)
388 {
389 	struct ti_qspi *qspi = param;
390 
391 	complete(&qspi->transfer_complete);
392 }
393 
394 static int ti_qspi_dma_xfer(struct ti_qspi *qspi, dma_addr_t dma_dst,
395 			    dma_addr_t dma_src, size_t len)
396 {
397 	struct dma_chan *chan = qspi->rx_chan;
398 	dma_cookie_t cookie;
399 	enum dma_ctrl_flags flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
400 	struct dma_async_tx_descriptor *tx;
401 	int ret;
402 
403 	tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags);
404 	if (!tx) {
405 		dev_err(qspi->dev, "device_prep_dma_memcpy error\n");
406 		return -EIO;
407 	}
408 
409 	tx->callback = ti_qspi_dma_callback;
410 	tx->callback_param = qspi;
411 	cookie = tx->tx_submit(tx);
412 	reinit_completion(&qspi->transfer_complete);
413 
414 	ret = dma_submit_error(cookie);
415 	if (ret) {
416 		dev_err(qspi->dev, "dma_submit_error %d\n", cookie);
417 		return -EIO;
418 	}
419 
420 	dma_async_issue_pending(chan);
421 	ret = wait_for_completion_timeout(&qspi->transfer_complete,
422 					  msecs_to_jiffies(len));
423 	if (ret <= 0) {
424 		dmaengine_terminate_sync(chan);
425 		dev_err(qspi->dev, "DMA wait_for_completion_timeout\n");
426 		return -ETIMEDOUT;
427 	}
428 
429 	return 0;
430 }
431 
432 static int ti_qspi_dma_bounce_buffer(struct ti_qspi *qspi, loff_t offs,
433 				     void *to, size_t readsize)
434 {
435 	dma_addr_t dma_src = qspi->mmap_phys_base + offs;
436 	int ret = 0;
437 
438 	/*
439 	 * Use bounce buffer as FS like jffs2, ubifs may pass
440 	 * buffers that does not belong to kernel lowmem region.
441 	 */
442 	while (readsize != 0) {
443 		size_t xfer_len = min_t(size_t, QSPI_DMA_BUFFER_SIZE,
444 					readsize);
445 
446 		ret = ti_qspi_dma_xfer(qspi, qspi->rx_bb_dma_addr,
447 				       dma_src, xfer_len);
448 		if (ret != 0)
449 			return ret;
450 		memcpy(to, qspi->rx_bb_addr, xfer_len);
451 		readsize -= xfer_len;
452 		dma_src += xfer_len;
453 		to += xfer_len;
454 	}
455 
456 	return ret;
457 }
458 
459 static int ti_qspi_dma_xfer_sg(struct ti_qspi *qspi, struct sg_table rx_sg,
460 			       loff_t from)
461 {
462 	struct scatterlist *sg;
463 	dma_addr_t dma_src = qspi->mmap_phys_base + from;
464 	dma_addr_t dma_dst;
465 	int i, len, ret;
466 
467 	for_each_sg(rx_sg.sgl, sg, rx_sg.nents, i) {
468 		dma_dst = sg_dma_address(sg);
469 		len = sg_dma_len(sg);
470 		ret = ti_qspi_dma_xfer(qspi, dma_dst, dma_src, len);
471 		if (ret)
472 			return ret;
473 		dma_src += len;
474 	}
475 
476 	return 0;
477 }
478 
479 static void ti_qspi_enable_memory_map(struct spi_device *spi)
480 {
481 	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
482 
483 	ti_qspi_write(qspi, MM_SWITCH, QSPI_SPI_SWITCH_REG);
484 	if (qspi->ctrl_base) {
485 		regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
486 				   MEM_CS_MASK,
487 				   MEM_CS_EN(spi->chip_select));
488 	}
489 	qspi->mmap_enabled = true;
490 }
491 
492 static void ti_qspi_disable_memory_map(struct spi_device *spi)
493 {
494 	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
495 
496 	ti_qspi_write(qspi, 0, QSPI_SPI_SWITCH_REG);
497 	if (qspi->ctrl_base)
498 		regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
499 				   MEM_CS_MASK, 0);
500 	qspi->mmap_enabled = false;
501 }
502 
503 static void ti_qspi_setup_mmap_read(struct spi_device *spi, u8 opcode,
504 				    u8 data_nbits, u8 addr_width,
505 				    u8 dummy_bytes)
506 {
507 	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
508 	u32 memval = opcode;
509 
510 	switch (data_nbits) {
511 	case SPI_NBITS_QUAD:
512 		memval |= QSPI_SETUP_RD_QUAD;
513 		break;
514 	case SPI_NBITS_DUAL:
515 		memval |= QSPI_SETUP_RD_DUAL;
516 		break;
517 	default:
518 		memval |= QSPI_SETUP_RD_NORMAL;
519 		break;
520 	}
521 	memval |= ((addr_width - 1) << QSPI_SETUP_ADDR_SHIFT |
522 		   dummy_bytes << QSPI_SETUP_DUMMY_SHIFT);
523 	ti_qspi_write(qspi, memval,
524 		      QSPI_SPI_SETUP_REG(spi->chip_select));
525 }
526 
527 static int ti_qspi_exec_mem_op(struct spi_mem *mem,
528 			       const struct spi_mem_op *op)
529 {
530 	struct ti_qspi *qspi = spi_master_get_devdata(mem->spi->master);
531 	u32 from = 0;
532 	int ret = 0;
533 
534 	/* Only optimize read path. */
535 	if (!op->data.nbytes || op->data.dir != SPI_MEM_DATA_IN ||
536 	    !op->addr.nbytes || op->addr.nbytes > 4)
537 		return -ENOTSUPP;
538 
539 	/* Address exceeds MMIO window size, fall back to regular mode. */
540 	from = op->addr.val;
541 	if (from + op->data.nbytes > qspi->mmap_size)
542 		return -ENOTSUPP;
543 
544 	mutex_lock(&qspi->list_lock);
545 
546 	if (!qspi->mmap_enabled)
547 		ti_qspi_enable_memory_map(mem->spi);
548 	ti_qspi_setup_mmap_read(mem->spi, op->cmd.opcode, op->data.buswidth,
549 				op->addr.nbytes, op->dummy.nbytes);
550 
551 	if (qspi->rx_chan) {
552 		struct sg_table sgt;
553 
554 		if (virt_addr_valid(op->data.buf.in) &&
555 		    !spi_controller_dma_map_mem_op_data(mem->spi->master, op,
556 							&sgt)) {
557 			ret = ti_qspi_dma_xfer_sg(qspi, sgt, from);
558 			spi_controller_dma_unmap_mem_op_data(mem->spi->master,
559 							     op, &sgt);
560 		} else {
561 			ret = ti_qspi_dma_bounce_buffer(qspi, from,
562 							op->data.buf.in,
563 							op->data.nbytes);
564 		}
565 	} else {
566 		memcpy_fromio(op->data.buf.in, qspi->mmap_base + from,
567 			      op->data.nbytes);
568 	}
569 
570 	mutex_unlock(&qspi->list_lock);
571 
572 	return ret;
573 }
574 
575 static const struct spi_controller_mem_ops ti_qspi_mem_ops = {
576 	.exec_op = ti_qspi_exec_mem_op,
577 };
578 
579 static int ti_qspi_start_transfer_one(struct spi_master *master,
580 		struct spi_message *m)
581 {
582 	struct ti_qspi *qspi = spi_master_get_devdata(master);
583 	struct spi_device *spi = m->spi;
584 	struct spi_transfer *t;
585 	int status = 0, ret;
586 	unsigned int frame_len_words, transfer_len_words;
587 	int wlen;
588 
589 	/* setup device control reg */
590 	qspi->dc = 0;
591 
592 	if (spi->mode & SPI_CPHA)
593 		qspi->dc |= QSPI_CKPHA(spi->chip_select);
594 	if (spi->mode & SPI_CPOL)
595 		qspi->dc |= QSPI_CKPOL(spi->chip_select);
596 	if (spi->mode & SPI_CS_HIGH)
597 		qspi->dc |= QSPI_CSPOL(spi->chip_select);
598 
599 	frame_len_words = 0;
600 	list_for_each_entry(t, &m->transfers, transfer_list)
601 		frame_len_words += t->len / (t->bits_per_word >> 3);
602 	frame_len_words = min_t(unsigned int, frame_len_words, QSPI_FRAME);
603 
604 	/* setup command reg */
605 	qspi->cmd = 0;
606 	qspi->cmd |= QSPI_EN_CS(spi->chip_select);
607 	qspi->cmd |= QSPI_FLEN(frame_len_words);
608 
609 	ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG);
610 
611 	mutex_lock(&qspi->list_lock);
612 
613 	if (qspi->mmap_enabled)
614 		ti_qspi_disable_memory_map(spi);
615 
616 	list_for_each_entry(t, &m->transfers, transfer_list) {
617 		qspi->cmd = ((qspi->cmd & ~QSPI_WLEN_MASK) |
618 			     QSPI_WLEN(t->bits_per_word));
619 
620 		wlen = t->bits_per_word >> 3;
621 		transfer_len_words = min(t->len / wlen, frame_len_words);
622 
623 		ret = qspi_transfer_msg(qspi, t, transfer_len_words * wlen);
624 		if (ret) {
625 			dev_dbg(qspi->dev, "transfer message failed\n");
626 			mutex_unlock(&qspi->list_lock);
627 			return -EINVAL;
628 		}
629 
630 		m->actual_length += transfer_len_words * wlen;
631 		frame_len_words -= transfer_len_words;
632 		if (frame_len_words == 0)
633 			break;
634 	}
635 
636 	mutex_unlock(&qspi->list_lock);
637 
638 	ti_qspi_write(qspi, qspi->cmd | QSPI_INVAL, QSPI_SPI_CMD_REG);
639 	m->status = status;
640 	spi_finalize_current_message(master);
641 
642 	return status;
643 }
644 
645 static int ti_qspi_runtime_resume(struct device *dev)
646 {
647 	struct ti_qspi      *qspi;
648 
649 	qspi = dev_get_drvdata(dev);
650 	ti_qspi_restore_ctx(qspi);
651 
652 	return 0;
653 }
654 
655 static const struct of_device_id ti_qspi_match[] = {
656 	{.compatible = "ti,dra7xxx-qspi" },
657 	{.compatible = "ti,am4372-qspi" },
658 	{},
659 };
660 MODULE_DEVICE_TABLE(of, ti_qspi_match);
661 
662 static int ti_qspi_probe(struct platform_device *pdev)
663 {
664 	struct  ti_qspi *qspi;
665 	struct spi_master *master;
666 	struct resource         *r, *res_mmap;
667 	struct device_node *np = pdev->dev.of_node;
668 	u32 max_freq;
669 	int ret = 0, num_cs, irq;
670 	dma_cap_mask_t mask;
671 
672 	master = spi_alloc_master(&pdev->dev, sizeof(*qspi));
673 	if (!master)
674 		return -ENOMEM;
675 
676 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD;
677 
678 	master->flags = SPI_MASTER_HALF_DUPLEX;
679 	master->setup = ti_qspi_setup;
680 	master->auto_runtime_pm = true;
681 	master->transfer_one_message = ti_qspi_start_transfer_one;
682 	master->dev.of_node = pdev->dev.of_node;
683 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
684 				     SPI_BPW_MASK(8);
685 	master->mem_ops = &ti_qspi_mem_ops;
686 
687 	if (!of_property_read_u32(np, "num-cs", &num_cs))
688 		master->num_chipselect = num_cs;
689 
690 	qspi = spi_master_get_devdata(master);
691 	qspi->master = master;
692 	qspi->dev = &pdev->dev;
693 	platform_set_drvdata(pdev, qspi);
694 
695 	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base");
696 	if (r == NULL) {
697 		r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
698 		if (r == NULL) {
699 			dev_err(&pdev->dev, "missing platform data\n");
700 			ret = -ENODEV;
701 			goto free_master;
702 		}
703 	}
704 
705 	res_mmap = platform_get_resource_byname(pdev,
706 			IORESOURCE_MEM, "qspi_mmap");
707 	if (res_mmap == NULL) {
708 		res_mmap = platform_get_resource(pdev, IORESOURCE_MEM, 1);
709 		if (res_mmap == NULL) {
710 			dev_err(&pdev->dev,
711 				"memory mapped resource not required\n");
712 		}
713 	}
714 
715 	if (res_mmap)
716 		qspi->mmap_size = resource_size(res_mmap);
717 
718 	irq = platform_get_irq(pdev, 0);
719 	if (irq < 0) {
720 		dev_err(&pdev->dev, "no irq resource?\n");
721 		ret = irq;
722 		goto free_master;
723 	}
724 
725 	mutex_init(&qspi->list_lock);
726 
727 	qspi->base = devm_ioremap_resource(&pdev->dev, r);
728 	if (IS_ERR(qspi->base)) {
729 		ret = PTR_ERR(qspi->base);
730 		goto free_master;
731 	}
732 
733 
734 	if (of_property_read_bool(np, "syscon-chipselects")) {
735 		qspi->ctrl_base =
736 		syscon_regmap_lookup_by_phandle(np,
737 						"syscon-chipselects");
738 		if (IS_ERR(qspi->ctrl_base)) {
739 			ret = PTR_ERR(qspi->ctrl_base);
740 			goto free_master;
741 		}
742 		ret = of_property_read_u32_index(np,
743 						 "syscon-chipselects",
744 						 1, &qspi->ctrl_reg);
745 		if (ret) {
746 			dev_err(&pdev->dev,
747 				"couldn't get ctrl_mod reg index\n");
748 			goto free_master;
749 		}
750 	}
751 
752 	qspi->fclk = devm_clk_get(&pdev->dev, "fck");
753 	if (IS_ERR(qspi->fclk)) {
754 		ret = PTR_ERR(qspi->fclk);
755 		dev_err(&pdev->dev, "could not get clk: %d\n", ret);
756 	}
757 
758 	pm_runtime_use_autosuspend(&pdev->dev);
759 	pm_runtime_set_autosuspend_delay(&pdev->dev, QSPI_AUTOSUSPEND_TIMEOUT);
760 	pm_runtime_enable(&pdev->dev);
761 
762 	if (!of_property_read_u32(np, "spi-max-frequency", &max_freq))
763 		qspi->spi_max_frequency = max_freq;
764 
765 	dma_cap_zero(mask);
766 	dma_cap_set(DMA_MEMCPY, mask);
767 
768 	qspi->rx_chan = dma_request_chan_by_mask(&mask);
769 	if (IS_ERR(qspi->rx_chan)) {
770 		dev_err(qspi->dev,
771 			"No Rx DMA available, trying mmap mode\n");
772 		qspi->rx_chan = NULL;
773 		ret = 0;
774 		goto no_dma;
775 	}
776 	qspi->rx_bb_addr = dma_alloc_coherent(qspi->dev,
777 					      QSPI_DMA_BUFFER_SIZE,
778 					      &qspi->rx_bb_dma_addr,
779 					      GFP_KERNEL | GFP_DMA);
780 	if (!qspi->rx_bb_addr) {
781 		dev_err(qspi->dev,
782 			"dma_alloc_coherent failed, using PIO mode\n");
783 		dma_release_channel(qspi->rx_chan);
784 		goto no_dma;
785 	}
786 	master->dma_rx = qspi->rx_chan;
787 	init_completion(&qspi->transfer_complete);
788 	if (res_mmap)
789 		qspi->mmap_phys_base = (dma_addr_t)res_mmap->start;
790 
791 no_dma:
792 	if (!qspi->rx_chan && res_mmap) {
793 		qspi->mmap_base = devm_ioremap_resource(&pdev->dev, res_mmap);
794 		if (IS_ERR(qspi->mmap_base)) {
795 			dev_info(&pdev->dev,
796 				 "mmap failed with error %ld using PIO mode\n",
797 				 PTR_ERR(qspi->mmap_base));
798 			qspi->mmap_base = NULL;
799 			master->mem_ops = NULL;
800 		}
801 	}
802 	qspi->mmap_enabled = false;
803 
804 	ret = devm_spi_register_master(&pdev->dev, master);
805 	if (!ret)
806 		return 0;
807 
808 	pm_runtime_disable(&pdev->dev);
809 free_master:
810 	spi_master_put(master);
811 	return ret;
812 }
813 
814 static int ti_qspi_remove(struct platform_device *pdev)
815 {
816 	struct ti_qspi *qspi = platform_get_drvdata(pdev);
817 	int rc;
818 
819 	rc = spi_master_suspend(qspi->master);
820 	if (rc)
821 		return rc;
822 
823 	pm_runtime_put_sync(&pdev->dev);
824 	pm_runtime_disable(&pdev->dev);
825 
826 	if (qspi->rx_bb_addr)
827 		dma_free_coherent(qspi->dev, QSPI_DMA_BUFFER_SIZE,
828 				  qspi->rx_bb_addr,
829 				  qspi->rx_bb_dma_addr);
830 	if (qspi->rx_chan)
831 		dma_release_channel(qspi->rx_chan);
832 
833 	return 0;
834 }
835 
836 static const struct dev_pm_ops ti_qspi_pm_ops = {
837 	.runtime_resume = ti_qspi_runtime_resume,
838 };
839 
840 static struct platform_driver ti_qspi_driver = {
841 	.probe	= ti_qspi_probe,
842 	.remove = ti_qspi_remove,
843 	.driver = {
844 		.name	= "ti-qspi",
845 		.pm =   &ti_qspi_pm_ops,
846 		.of_match_table = ti_qspi_match,
847 	}
848 };
849 
850 module_platform_driver(ti_qspi_driver);
851 
852 MODULE_AUTHOR("Sourav Poddar <sourav.poddar@ti.com>");
853 MODULE_LICENSE("GPL v2");
854 MODULE_DESCRIPTION("TI QSPI controller driver");
855 MODULE_ALIAS("platform:ti-qspi");
856