xref: /openbmc/linux/drivers/spi/spi-ti-qspi.c (revision 0c874100)
1 /*
2  * TI QSPI driver
3  *
4  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
5  * Author: Sourav Poddar <sourav.poddar@ti.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GPLv2.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/interrupt.h>
19 #include <linux/module.h>
20 #include <linux/device.h>
21 #include <linux/delay.h>
22 #include <linux/dma-mapping.h>
23 #include <linux/dmaengine.h>
24 #include <linux/omap-dma.h>
25 #include <linux/platform_device.h>
26 #include <linux/err.h>
27 #include <linux/clk.h>
28 #include <linux/io.h>
29 #include <linux/slab.h>
30 #include <linux/pm_runtime.h>
31 #include <linux/of.h>
32 #include <linux/of_device.h>
33 #include <linux/pinctrl/consumer.h>
34 #include <linux/mfd/syscon.h>
35 #include <linux/regmap.h>
36 #include <linux/sizes.h>
37 
38 #include <linux/spi/spi.h>
39 #include <linux/spi/spi-mem.h>
40 
41 struct ti_qspi_regs {
42 	u32 clkctrl;
43 };
44 
45 struct ti_qspi {
46 	struct completion	transfer_complete;
47 
48 	/* list synchronization */
49 	struct mutex            list_lock;
50 
51 	struct spi_master	*master;
52 	void __iomem            *base;
53 	void __iomem            *mmap_base;
54 	size_t			mmap_size;
55 	struct regmap		*ctrl_base;
56 	unsigned int		ctrl_reg;
57 	struct clk		*fclk;
58 	struct device           *dev;
59 
60 	struct ti_qspi_regs     ctx_reg;
61 
62 	dma_addr_t		mmap_phys_base;
63 	dma_addr_t		rx_bb_dma_addr;
64 	void			*rx_bb_addr;
65 	struct dma_chan		*rx_chan;
66 
67 	u32 spi_max_frequency;
68 	u32 cmd;
69 	u32 dc;
70 
71 	bool mmap_enabled;
72 };
73 
74 #define QSPI_PID			(0x0)
75 #define QSPI_SYSCONFIG			(0x10)
76 #define QSPI_SPI_CLOCK_CNTRL_REG	(0x40)
77 #define QSPI_SPI_DC_REG			(0x44)
78 #define QSPI_SPI_CMD_REG		(0x48)
79 #define QSPI_SPI_STATUS_REG		(0x4c)
80 #define QSPI_SPI_DATA_REG		(0x50)
81 #define QSPI_SPI_SETUP_REG(n)		((0x54 + 4 * n))
82 #define QSPI_SPI_SWITCH_REG		(0x64)
83 #define QSPI_SPI_DATA_REG_1		(0x68)
84 #define QSPI_SPI_DATA_REG_2		(0x6c)
85 #define QSPI_SPI_DATA_REG_3		(0x70)
86 
87 #define QSPI_COMPLETION_TIMEOUT		msecs_to_jiffies(2000)
88 
89 #define QSPI_FCLK			192000000
90 
91 /* Clock Control */
92 #define QSPI_CLK_EN			(1 << 31)
93 #define QSPI_CLK_DIV_MAX		0xffff
94 
95 /* Command */
96 #define QSPI_EN_CS(n)			(n << 28)
97 #define QSPI_WLEN(n)			((n - 1) << 19)
98 #define QSPI_3_PIN			(1 << 18)
99 #define QSPI_RD_SNGL			(1 << 16)
100 #define QSPI_WR_SNGL			(2 << 16)
101 #define QSPI_RD_DUAL			(3 << 16)
102 #define QSPI_RD_QUAD			(7 << 16)
103 #define QSPI_INVAL			(4 << 16)
104 #define QSPI_FLEN(n)			((n - 1) << 0)
105 #define QSPI_WLEN_MAX_BITS		128
106 #define QSPI_WLEN_MAX_BYTES		16
107 #define QSPI_WLEN_MASK			QSPI_WLEN(QSPI_WLEN_MAX_BITS)
108 
109 /* STATUS REGISTER */
110 #define BUSY				0x01
111 #define WC				0x02
112 
113 /* Device Control */
114 #define QSPI_DD(m, n)			(m << (3 + n * 8))
115 #define QSPI_CKPHA(n)			(1 << (2 + n * 8))
116 #define QSPI_CSPOL(n)			(1 << (1 + n * 8))
117 #define QSPI_CKPOL(n)			(1 << (n * 8))
118 
119 #define	QSPI_FRAME			4096
120 
121 #define QSPI_AUTOSUSPEND_TIMEOUT         2000
122 
123 #define MEM_CS_EN(n)			((n + 1) << 8)
124 #define MEM_CS_MASK			(7 << 8)
125 
126 #define MM_SWITCH			0x1
127 
128 #define QSPI_SETUP_RD_NORMAL		(0x0 << 12)
129 #define QSPI_SETUP_RD_DUAL		(0x1 << 12)
130 #define QSPI_SETUP_RD_QUAD		(0x3 << 12)
131 #define QSPI_SETUP_ADDR_SHIFT		8
132 #define QSPI_SETUP_DUMMY_SHIFT		10
133 
134 #define QSPI_DMA_BUFFER_SIZE            SZ_64K
135 
136 static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
137 		unsigned long reg)
138 {
139 	return readl(qspi->base + reg);
140 }
141 
142 static inline void ti_qspi_write(struct ti_qspi *qspi,
143 		unsigned long val, unsigned long reg)
144 {
145 	writel(val, qspi->base + reg);
146 }
147 
148 static int ti_qspi_setup(struct spi_device *spi)
149 {
150 	struct ti_qspi	*qspi = spi_master_get_devdata(spi->master);
151 	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
152 	int clk_div = 0, ret;
153 	u32 clk_ctrl_reg, clk_rate, clk_mask;
154 
155 	if (spi->master->busy) {
156 		dev_dbg(qspi->dev, "master busy doing other transfers\n");
157 		return -EBUSY;
158 	}
159 
160 	if (!qspi->spi_max_frequency) {
161 		dev_err(qspi->dev, "spi max frequency not defined\n");
162 		return -EINVAL;
163 	}
164 
165 	clk_rate = clk_get_rate(qspi->fclk);
166 
167 	clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1;
168 
169 	if (clk_div < 0) {
170 		dev_dbg(qspi->dev, "clock divider < 0, using /1 divider\n");
171 		return -EINVAL;
172 	}
173 
174 	if (clk_div > QSPI_CLK_DIV_MAX) {
175 		dev_dbg(qspi->dev, "clock divider >%d , using /%d divider\n",
176 				QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
177 		return -EINVAL;
178 	}
179 
180 	dev_dbg(qspi->dev, "hz: %d, clock divider %d\n",
181 			qspi->spi_max_frequency, clk_div);
182 
183 	ret = pm_runtime_get_sync(qspi->dev);
184 	if (ret < 0) {
185 		dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
186 		return ret;
187 	}
188 
189 	clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
190 
191 	clk_ctrl_reg &= ~QSPI_CLK_EN;
192 
193 	/* disable SCLK */
194 	ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
195 
196 	/* enable SCLK */
197 	clk_mask = QSPI_CLK_EN | clk_div;
198 	ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG);
199 	ctx_reg->clkctrl = clk_mask;
200 
201 	pm_runtime_mark_last_busy(qspi->dev);
202 	ret = pm_runtime_put_autosuspend(qspi->dev);
203 	if (ret < 0) {
204 		dev_err(qspi->dev, "pm_runtime_put_autosuspend() failed\n");
205 		return ret;
206 	}
207 
208 	return 0;
209 }
210 
211 static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
212 {
213 	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
214 
215 	ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
216 }
217 
218 static inline u32 qspi_is_busy(struct ti_qspi *qspi)
219 {
220 	u32 stat;
221 	unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
222 
223 	stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
224 	while ((stat & BUSY) && time_after(timeout, jiffies)) {
225 		cpu_relax();
226 		stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
227 	}
228 
229 	WARN(stat & BUSY, "qspi busy\n");
230 	return stat & BUSY;
231 }
232 
233 static inline int ti_qspi_poll_wc(struct ti_qspi *qspi)
234 {
235 	u32 stat;
236 	unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
237 
238 	do {
239 		stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
240 		if (stat & WC)
241 			return 0;
242 		cpu_relax();
243 	} while (time_after(timeout, jiffies));
244 
245 	stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
246 	if (stat & WC)
247 		return 0;
248 	return  -ETIMEDOUT;
249 }
250 
251 static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t,
252 			  int count)
253 {
254 	int wlen, xfer_len;
255 	unsigned int cmd;
256 	const u8 *txbuf;
257 	u32 data;
258 
259 	txbuf = t->tx_buf;
260 	cmd = qspi->cmd | QSPI_WR_SNGL;
261 	wlen = t->bits_per_word >> 3;	/* in bytes */
262 	xfer_len = wlen;
263 
264 	while (count) {
265 		if (qspi_is_busy(qspi))
266 			return -EBUSY;
267 
268 		switch (wlen) {
269 		case 1:
270 			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
271 					cmd, qspi->dc, *txbuf);
272 			if (count >= QSPI_WLEN_MAX_BYTES) {
273 				u32 *txp = (u32 *)txbuf;
274 
275 				data = cpu_to_be32(*txp++);
276 				writel(data, qspi->base +
277 				       QSPI_SPI_DATA_REG_3);
278 				data = cpu_to_be32(*txp++);
279 				writel(data, qspi->base +
280 				       QSPI_SPI_DATA_REG_2);
281 				data = cpu_to_be32(*txp++);
282 				writel(data, qspi->base +
283 				       QSPI_SPI_DATA_REG_1);
284 				data = cpu_to_be32(*txp++);
285 				writel(data, qspi->base +
286 				       QSPI_SPI_DATA_REG);
287 				xfer_len = QSPI_WLEN_MAX_BYTES;
288 				cmd |= QSPI_WLEN(QSPI_WLEN_MAX_BITS);
289 			} else {
290 				writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
291 				cmd = qspi->cmd | QSPI_WR_SNGL;
292 				xfer_len = wlen;
293 				cmd |= QSPI_WLEN(wlen);
294 			}
295 			break;
296 		case 2:
297 			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n",
298 					cmd, qspi->dc, *txbuf);
299 			writew(*((u16 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
300 			break;
301 		case 4:
302 			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %08x\n",
303 					cmd, qspi->dc, *txbuf);
304 			writel(*((u32 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
305 			break;
306 		}
307 
308 		ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
309 		if (ti_qspi_poll_wc(qspi)) {
310 			dev_err(qspi->dev, "write timed out\n");
311 			return -ETIMEDOUT;
312 		}
313 		txbuf += xfer_len;
314 		count -= xfer_len;
315 	}
316 
317 	return 0;
318 }
319 
320 static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t,
321 			 int count)
322 {
323 	int wlen;
324 	unsigned int cmd;
325 	u8 *rxbuf;
326 
327 	rxbuf = t->rx_buf;
328 	cmd = qspi->cmd;
329 	switch (t->rx_nbits) {
330 	case SPI_NBITS_DUAL:
331 		cmd |= QSPI_RD_DUAL;
332 		break;
333 	case SPI_NBITS_QUAD:
334 		cmd |= QSPI_RD_QUAD;
335 		break;
336 	default:
337 		cmd |= QSPI_RD_SNGL;
338 		break;
339 	}
340 	wlen = t->bits_per_word >> 3;	/* in bytes */
341 
342 	while (count) {
343 		dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
344 		if (qspi_is_busy(qspi))
345 			return -EBUSY;
346 
347 		ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
348 		if (ti_qspi_poll_wc(qspi)) {
349 			dev_err(qspi->dev, "read timed out\n");
350 			return -ETIMEDOUT;
351 		}
352 		switch (wlen) {
353 		case 1:
354 			*rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG);
355 			break;
356 		case 2:
357 			*((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG);
358 			break;
359 		case 4:
360 			*((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG);
361 			break;
362 		}
363 		rxbuf += wlen;
364 		count -= wlen;
365 	}
366 
367 	return 0;
368 }
369 
370 static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t,
371 			     int count)
372 {
373 	int ret;
374 
375 	if (t->tx_buf) {
376 		ret = qspi_write_msg(qspi, t, count);
377 		if (ret) {
378 			dev_dbg(qspi->dev, "Error while writing\n");
379 			return ret;
380 		}
381 	}
382 
383 	if (t->rx_buf) {
384 		ret = qspi_read_msg(qspi, t, count);
385 		if (ret) {
386 			dev_dbg(qspi->dev, "Error while reading\n");
387 			return ret;
388 		}
389 	}
390 
391 	return 0;
392 }
393 
394 static void ti_qspi_dma_callback(void *param)
395 {
396 	struct ti_qspi *qspi = param;
397 
398 	complete(&qspi->transfer_complete);
399 }
400 
401 static int ti_qspi_dma_xfer(struct ti_qspi *qspi, dma_addr_t dma_dst,
402 			    dma_addr_t dma_src, size_t len)
403 {
404 	struct dma_chan *chan = qspi->rx_chan;
405 	dma_cookie_t cookie;
406 	enum dma_ctrl_flags flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
407 	struct dma_async_tx_descriptor *tx;
408 	int ret;
409 
410 	tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags);
411 	if (!tx) {
412 		dev_err(qspi->dev, "device_prep_dma_memcpy error\n");
413 		return -EIO;
414 	}
415 
416 	tx->callback = ti_qspi_dma_callback;
417 	tx->callback_param = qspi;
418 	cookie = tx->tx_submit(tx);
419 	reinit_completion(&qspi->transfer_complete);
420 
421 	ret = dma_submit_error(cookie);
422 	if (ret) {
423 		dev_err(qspi->dev, "dma_submit_error %d\n", cookie);
424 		return -EIO;
425 	}
426 
427 	dma_async_issue_pending(chan);
428 	ret = wait_for_completion_timeout(&qspi->transfer_complete,
429 					  msecs_to_jiffies(len));
430 	if (ret <= 0) {
431 		dmaengine_terminate_sync(chan);
432 		dev_err(qspi->dev, "DMA wait_for_completion_timeout\n");
433 		return -ETIMEDOUT;
434 	}
435 
436 	return 0;
437 }
438 
439 static int ti_qspi_dma_bounce_buffer(struct ti_qspi *qspi, loff_t offs,
440 				     void *to, size_t readsize)
441 {
442 	dma_addr_t dma_src = qspi->mmap_phys_base + offs;
443 	int ret = 0;
444 
445 	/*
446 	 * Use bounce buffer as FS like jffs2, ubifs may pass
447 	 * buffers that does not belong to kernel lowmem region.
448 	 */
449 	while (readsize != 0) {
450 		size_t xfer_len = min_t(size_t, QSPI_DMA_BUFFER_SIZE,
451 					readsize);
452 
453 		ret = ti_qspi_dma_xfer(qspi, qspi->rx_bb_dma_addr,
454 				       dma_src, xfer_len);
455 		if (ret != 0)
456 			return ret;
457 		memcpy(to, qspi->rx_bb_addr, xfer_len);
458 		readsize -= xfer_len;
459 		dma_src += xfer_len;
460 		to += xfer_len;
461 	}
462 
463 	return ret;
464 }
465 
466 static int ti_qspi_dma_xfer_sg(struct ti_qspi *qspi, struct sg_table rx_sg,
467 			       loff_t from)
468 {
469 	struct scatterlist *sg;
470 	dma_addr_t dma_src = qspi->mmap_phys_base + from;
471 	dma_addr_t dma_dst;
472 	int i, len, ret;
473 
474 	for_each_sg(rx_sg.sgl, sg, rx_sg.nents, i) {
475 		dma_dst = sg_dma_address(sg);
476 		len = sg_dma_len(sg);
477 		ret = ti_qspi_dma_xfer(qspi, dma_dst, dma_src, len);
478 		if (ret)
479 			return ret;
480 		dma_src += len;
481 	}
482 
483 	return 0;
484 }
485 
486 static void ti_qspi_enable_memory_map(struct spi_device *spi)
487 {
488 	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
489 
490 	ti_qspi_write(qspi, MM_SWITCH, QSPI_SPI_SWITCH_REG);
491 	if (qspi->ctrl_base) {
492 		regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
493 				   MEM_CS_EN(spi->chip_select),
494 				   MEM_CS_MASK);
495 	}
496 	qspi->mmap_enabled = true;
497 }
498 
499 static void ti_qspi_disable_memory_map(struct spi_device *spi)
500 {
501 	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
502 
503 	ti_qspi_write(qspi, 0, QSPI_SPI_SWITCH_REG);
504 	if (qspi->ctrl_base)
505 		regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
506 				   0, MEM_CS_MASK);
507 	qspi->mmap_enabled = false;
508 }
509 
510 static void ti_qspi_setup_mmap_read(struct spi_device *spi, u8 opcode,
511 				    u8 data_nbits, u8 addr_width,
512 				    u8 dummy_bytes)
513 {
514 	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
515 	u32 memval = opcode;
516 
517 	switch (data_nbits) {
518 	case SPI_NBITS_QUAD:
519 		memval |= QSPI_SETUP_RD_QUAD;
520 		break;
521 	case SPI_NBITS_DUAL:
522 		memval |= QSPI_SETUP_RD_DUAL;
523 		break;
524 	default:
525 		memval |= QSPI_SETUP_RD_NORMAL;
526 		break;
527 	}
528 	memval |= ((addr_width - 1) << QSPI_SETUP_ADDR_SHIFT |
529 		   dummy_bytes << QSPI_SETUP_DUMMY_SHIFT);
530 	ti_qspi_write(qspi, memval,
531 		      QSPI_SPI_SETUP_REG(spi->chip_select));
532 }
533 
534 static int ti_qspi_exec_mem_op(struct spi_mem *mem,
535 			       const struct spi_mem_op *op)
536 {
537 	struct ti_qspi *qspi = spi_master_get_devdata(mem->spi->master);
538 	u32 from = 0;
539 	int ret = 0;
540 
541 	/* Only optimize read path. */
542 	if (!op->data.nbytes || op->data.dir != SPI_MEM_DATA_IN ||
543 	    !op->addr.nbytes || op->addr.nbytes > 4)
544 		return -ENOTSUPP;
545 
546 	/* Address exceeds MMIO window size, fall back to regular mode. */
547 	from = op->addr.val;
548 	if (from + op->data.nbytes > qspi->mmap_size)
549 		return -ENOTSUPP;
550 
551 	mutex_lock(&qspi->list_lock);
552 
553 	if (!qspi->mmap_enabled)
554 		ti_qspi_enable_memory_map(mem->spi);
555 	ti_qspi_setup_mmap_read(mem->spi, op->cmd.opcode, op->data.buswidth,
556 				op->addr.nbytes, op->dummy.nbytes);
557 
558 	if (qspi->rx_chan) {
559 		struct sg_table sgt;
560 
561 		if (virt_addr_valid(op->data.buf.in) &&
562 		    !spi_controller_dma_map_mem_op_data(mem->spi->master, op,
563 							&sgt)) {
564 			ret = ti_qspi_dma_xfer_sg(qspi, sgt, from);
565 			spi_controller_dma_unmap_mem_op_data(mem->spi->master,
566 							     op, &sgt);
567 		} else {
568 			ret = ti_qspi_dma_bounce_buffer(qspi, from,
569 							op->data.buf.in,
570 							op->data.nbytes);
571 		}
572 	} else {
573 		memcpy_fromio(op->data.buf.in, qspi->mmap_base + from,
574 			      op->data.nbytes);
575 	}
576 
577 	mutex_unlock(&qspi->list_lock);
578 
579 	return ret;
580 }
581 
582 static const struct spi_controller_mem_ops ti_qspi_mem_ops = {
583 	.exec_op = ti_qspi_exec_mem_op,
584 };
585 
586 static int ti_qspi_start_transfer_one(struct spi_master *master,
587 		struct spi_message *m)
588 {
589 	struct ti_qspi *qspi = spi_master_get_devdata(master);
590 	struct spi_device *spi = m->spi;
591 	struct spi_transfer *t;
592 	int status = 0, ret;
593 	unsigned int frame_len_words, transfer_len_words;
594 	int wlen;
595 
596 	/* setup device control reg */
597 	qspi->dc = 0;
598 
599 	if (spi->mode & SPI_CPHA)
600 		qspi->dc |= QSPI_CKPHA(spi->chip_select);
601 	if (spi->mode & SPI_CPOL)
602 		qspi->dc |= QSPI_CKPOL(spi->chip_select);
603 	if (spi->mode & SPI_CS_HIGH)
604 		qspi->dc |= QSPI_CSPOL(spi->chip_select);
605 
606 	frame_len_words = 0;
607 	list_for_each_entry(t, &m->transfers, transfer_list)
608 		frame_len_words += t->len / (t->bits_per_word >> 3);
609 	frame_len_words = min_t(unsigned int, frame_len_words, QSPI_FRAME);
610 
611 	/* setup command reg */
612 	qspi->cmd = 0;
613 	qspi->cmd |= QSPI_EN_CS(spi->chip_select);
614 	qspi->cmd |= QSPI_FLEN(frame_len_words);
615 
616 	ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG);
617 
618 	mutex_lock(&qspi->list_lock);
619 
620 	if (qspi->mmap_enabled)
621 		ti_qspi_disable_memory_map(spi);
622 
623 	list_for_each_entry(t, &m->transfers, transfer_list) {
624 		qspi->cmd = ((qspi->cmd & ~QSPI_WLEN_MASK) |
625 			     QSPI_WLEN(t->bits_per_word));
626 
627 		wlen = t->bits_per_word >> 3;
628 		transfer_len_words = min(t->len / wlen, frame_len_words);
629 
630 		ret = qspi_transfer_msg(qspi, t, transfer_len_words * wlen);
631 		if (ret) {
632 			dev_dbg(qspi->dev, "transfer message failed\n");
633 			mutex_unlock(&qspi->list_lock);
634 			return -EINVAL;
635 		}
636 
637 		m->actual_length += transfer_len_words * wlen;
638 		frame_len_words -= transfer_len_words;
639 		if (frame_len_words == 0)
640 			break;
641 	}
642 
643 	mutex_unlock(&qspi->list_lock);
644 
645 	ti_qspi_write(qspi, qspi->cmd | QSPI_INVAL, QSPI_SPI_CMD_REG);
646 	m->status = status;
647 	spi_finalize_current_message(master);
648 
649 	return status;
650 }
651 
652 static int ti_qspi_runtime_resume(struct device *dev)
653 {
654 	struct ti_qspi      *qspi;
655 
656 	qspi = dev_get_drvdata(dev);
657 	ti_qspi_restore_ctx(qspi);
658 
659 	return 0;
660 }
661 
662 static const struct of_device_id ti_qspi_match[] = {
663 	{.compatible = "ti,dra7xxx-qspi" },
664 	{.compatible = "ti,am4372-qspi" },
665 	{},
666 };
667 MODULE_DEVICE_TABLE(of, ti_qspi_match);
668 
669 static int ti_qspi_probe(struct platform_device *pdev)
670 {
671 	struct  ti_qspi *qspi;
672 	struct spi_master *master;
673 	struct resource         *r, *res_mmap;
674 	struct device_node *np = pdev->dev.of_node;
675 	u32 max_freq;
676 	int ret = 0, num_cs, irq;
677 	dma_cap_mask_t mask;
678 
679 	master = spi_alloc_master(&pdev->dev, sizeof(*qspi));
680 	if (!master)
681 		return -ENOMEM;
682 
683 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD;
684 
685 	master->flags = SPI_MASTER_HALF_DUPLEX;
686 	master->setup = ti_qspi_setup;
687 	master->auto_runtime_pm = true;
688 	master->transfer_one_message = ti_qspi_start_transfer_one;
689 	master->dev.of_node = pdev->dev.of_node;
690 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
691 				     SPI_BPW_MASK(8);
692 	master->mem_ops = &ti_qspi_mem_ops;
693 
694 	if (!of_property_read_u32(np, "num-cs", &num_cs))
695 		master->num_chipselect = num_cs;
696 
697 	qspi = spi_master_get_devdata(master);
698 	qspi->master = master;
699 	qspi->dev = &pdev->dev;
700 	platform_set_drvdata(pdev, qspi);
701 
702 	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base");
703 	if (r == NULL) {
704 		r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
705 		if (r == NULL) {
706 			dev_err(&pdev->dev, "missing platform data\n");
707 			ret = -ENODEV;
708 			goto free_master;
709 		}
710 	}
711 
712 	res_mmap = platform_get_resource_byname(pdev,
713 			IORESOURCE_MEM, "qspi_mmap");
714 	if (res_mmap == NULL) {
715 		res_mmap = platform_get_resource(pdev, IORESOURCE_MEM, 1);
716 		if (res_mmap == NULL) {
717 			dev_err(&pdev->dev,
718 				"memory mapped resource not required\n");
719 		}
720 	}
721 
722 	if (res_mmap)
723 		qspi->mmap_size = resource_size(res_mmap);
724 
725 	irq = platform_get_irq(pdev, 0);
726 	if (irq < 0) {
727 		dev_err(&pdev->dev, "no irq resource?\n");
728 		ret = irq;
729 		goto free_master;
730 	}
731 
732 	mutex_init(&qspi->list_lock);
733 
734 	qspi->base = devm_ioremap_resource(&pdev->dev, r);
735 	if (IS_ERR(qspi->base)) {
736 		ret = PTR_ERR(qspi->base);
737 		goto free_master;
738 	}
739 
740 
741 	if (of_property_read_bool(np, "syscon-chipselects")) {
742 		qspi->ctrl_base =
743 		syscon_regmap_lookup_by_phandle(np,
744 						"syscon-chipselects");
745 		if (IS_ERR(qspi->ctrl_base)) {
746 			ret = PTR_ERR(qspi->ctrl_base);
747 			goto free_master;
748 		}
749 		ret = of_property_read_u32_index(np,
750 						 "syscon-chipselects",
751 						 1, &qspi->ctrl_reg);
752 		if (ret) {
753 			dev_err(&pdev->dev,
754 				"couldn't get ctrl_mod reg index\n");
755 			goto free_master;
756 		}
757 	}
758 
759 	qspi->fclk = devm_clk_get(&pdev->dev, "fck");
760 	if (IS_ERR(qspi->fclk)) {
761 		ret = PTR_ERR(qspi->fclk);
762 		dev_err(&pdev->dev, "could not get clk: %d\n", ret);
763 	}
764 
765 	pm_runtime_use_autosuspend(&pdev->dev);
766 	pm_runtime_set_autosuspend_delay(&pdev->dev, QSPI_AUTOSUSPEND_TIMEOUT);
767 	pm_runtime_enable(&pdev->dev);
768 
769 	if (!of_property_read_u32(np, "spi-max-frequency", &max_freq))
770 		qspi->spi_max_frequency = max_freq;
771 
772 	dma_cap_zero(mask);
773 	dma_cap_set(DMA_MEMCPY, mask);
774 
775 	qspi->rx_chan = dma_request_chan_by_mask(&mask);
776 	if (IS_ERR(qspi->rx_chan)) {
777 		dev_err(qspi->dev,
778 			"No Rx DMA available, trying mmap mode\n");
779 		qspi->rx_chan = NULL;
780 		ret = 0;
781 		goto no_dma;
782 	}
783 	qspi->rx_bb_addr = dma_alloc_coherent(qspi->dev,
784 					      QSPI_DMA_BUFFER_SIZE,
785 					      &qspi->rx_bb_dma_addr,
786 					      GFP_KERNEL | GFP_DMA);
787 	if (!qspi->rx_bb_addr) {
788 		dev_err(qspi->dev,
789 			"dma_alloc_coherent failed, using PIO mode\n");
790 		dma_release_channel(qspi->rx_chan);
791 		goto no_dma;
792 	}
793 	master->dma_rx = qspi->rx_chan;
794 	init_completion(&qspi->transfer_complete);
795 	if (res_mmap)
796 		qspi->mmap_phys_base = (dma_addr_t)res_mmap->start;
797 
798 no_dma:
799 	if (!qspi->rx_chan && res_mmap) {
800 		qspi->mmap_base = devm_ioremap_resource(&pdev->dev, res_mmap);
801 		if (IS_ERR(qspi->mmap_base)) {
802 			dev_info(&pdev->dev,
803 				 "mmap failed with error %ld using PIO mode\n",
804 				 PTR_ERR(qspi->mmap_base));
805 			qspi->mmap_base = NULL;
806 			master->mem_ops = NULL;
807 		}
808 	}
809 	qspi->mmap_enabled = false;
810 
811 	ret = devm_spi_register_master(&pdev->dev, master);
812 	if (!ret)
813 		return 0;
814 
815 	pm_runtime_disable(&pdev->dev);
816 free_master:
817 	spi_master_put(master);
818 	return ret;
819 }
820 
821 static int ti_qspi_remove(struct platform_device *pdev)
822 {
823 	struct ti_qspi *qspi = platform_get_drvdata(pdev);
824 	int rc;
825 
826 	rc = spi_master_suspend(qspi->master);
827 	if (rc)
828 		return rc;
829 
830 	pm_runtime_put_sync(&pdev->dev);
831 	pm_runtime_disable(&pdev->dev);
832 
833 	if (qspi->rx_bb_addr)
834 		dma_free_coherent(qspi->dev, QSPI_DMA_BUFFER_SIZE,
835 				  qspi->rx_bb_addr,
836 				  qspi->rx_bb_dma_addr);
837 	if (qspi->rx_chan)
838 		dma_release_channel(qspi->rx_chan);
839 
840 	return 0;
841 }
842 
843 static const struct dev_pm_ops ti_qspi_pm_ops = {
844 	.runtime_resume = ti_qspi_runtime_resume,
845 };
846 
847 static struct platform_driver ti_qspi_driver = {
848 	.probe	= ti_qspi_probe,
849 	.remove = ti_qspi_remove,
850 	.driver = {
851 		.name	= "ti-qspi",
852 		.pm =   &ti_qspi_pm_ops,
853 		.of_match_table = ti_qspi_match,
854 	}
855 };
856 
857 module_platform_driver(ti_qspi_driver);
858 
859 MODULE_AUTHOR("Sourav Poddar <sourav.poddar@ti.com>");
860 MODULE_LICENSE("GPL v2");
861 MODULE_DESCRIPTION("TI QSPI controller driver");
862 MODULE_ALIAS("platform:ti-qspi");
863