xref: /openbmc/linux/drivers/spi/spi-ti-qspi.c (revision 78700c0a)
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 
37 #include <linux/spi/spi.h>
38 
39 struct ti_qspi_regs {
40 	u32 clkctrl;
41 };
42 
43 struct ti_qspi {
44 	/* list synchronization */
45 	struct mutex            list_lock;
46 
47 	struct spi_master	*master;
48 	void __iomem            *base;
49 	void __iomem            *mmap_base;
50 	struct regmap		*ctrl_base;
51 	unsigned int		ctrl_reg;
52 	struct clk		*fclk;
53 	struct device           *dev;
54 
55 	struct ti_qspi_regs     ctx_reg;
56 
57 	u32 spi_max_frequency;
58 	u32 cmd;
59 	u32 dc;
60 
61 	bool mmap_enabled;
62 };
63 
64 #define QSPI_PID			(0x0)
65 #define QSPI_SYSCONFIG			(0x10)
66 #define QSPI_SPI_CLOCK_CNTRL_REG	(0x40)
67 #define QSPI_SPI_DC_REG			(0x44)
68 #define QSPI_SPI_CMD_REG		(0x48)
69 #define QSPI_SPI_STATUS_REG		(0x4c)
70 #define QSPI_SPI_DATA_REG		(0x50)
71 #define QSPI_SPI_SETUP_REG(n)		((0x54 + 4 * n))
72 #define QSPI_SPI_SWITCH_REG		(0x64)
73 #define QSPI_SPI_DATA_REG_1		(0x68)
74 #define QSPI_SPI_DATA_REG_2		(0x6c)
75 #define QSPI_SPI_DATA_REG_3		(0x70)
76 
77 #define QSPI_COMPLETION_TIMEOUT		msecs_to_jiffies(2000)
78 
79 #define QSPI_FCLK			192000000
80 
81 /* Clock Control */
82 #define QSPI_CLK_EN			(1 << 31)
83 #define QSPI_CLK_DIV_MAX		0xffff
84 
85 /* Command */
86 #define QSPI_EN_CS(n)			(n << 28)
87 #define QSPI_WLEN(n)			((n - 1) << 19)
88 #define QSPI_3_PIN			(1 << 18)
89 #define QSPI_RD_SNGL			(1 << 16)
90 #define QSPI_WR_SNGL			(2 << 16)
91 #define QSPI_RD_DUAL			(3 << 16)
92 #define QSPI_RD_QUAD			(7 << 16)
93 #define QSPI_INVAL			(4 << 16)
94 #define QSPI_FLEN(n)			((n - 1) << 0)
95 #define QSPI_WLEN_MAX_BITS		128
96 #define QSPI_WLEN_MAX_BYTES		16
97 #define QSPI_WLEN_MASK			QSPI_WLEN(QSPI_WLEN_MAX_BITS)
98 
99 /* STATUS REGISTER */
100 #define BUSY				0x01
101 #define WC				0x02
102 
103 /* Device Control */
104 #define QSPI_DD(m, n)			(m << (3 + n * 8))
105 #define QSPI_CKPHA(n)			(1 << (2 + n * 8))
106 #define QSPI_CSPOL(n)			(1 << (1 + n * 8))
107 #define QSPI_CKPOL(n)			(1 << (n * 8))
108 
109 #define	QSPI_FRAME			4096
110 
111 #define QSPI_AUTOSUSPEND_TIMEOUT         2000
112 
113 #define MEM_CS_EN(n)			((n + 1) << 8)
114 #define MEM_CS_MASK			(7 << 8)
115 
116 #define MM_SWITCH			0x1
117 
118 #define QSPI_SETUP_RD_NORMAL		(0x0 << 12)
119 #define QSPI_SETUP_RD_DUAL		(0x1 << 12)
120 #define QSPI_SETUP_RD_QUAD		(0x3 << 12)
121 #define QSPI_SETUP_ADDR_SHIFT		8
122 #define QSPI_SETUP_DUMMY_SHIFT		10
123 
124 static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
125 		unsigned long reg)
126 {
127 	return readl(qspi->base + reg);
128 }
129 
130 static inline void ti_qspi_write(struct ti_qspi *qspi,
131 		unsigned long val, unsigned long reg)
132 {
133 	writel(val, qspi->base + reg);
134 }
135 
136 static int ti_qspi_setup(struct spi_device *spi)
137 {
138 	struct ti_qspi	*qspi = spi_master_get_devdata(spi->master);
139 	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
140 	int clk_div = 0, ret;
141 	u32 clk_ctrl_reg, clk_rate, clk_mask;
142 
143 	if (spi->master->busy) {
144 		dev_dbg(qspi->dev, "master busy doing other trasnfers\n");
145 		return -EBUSY;
146 	}
147 
148 	if (!qspi->spi_max_frequency) {
149 		dev_err(qspi->dev, "spi max frequency not defined\n");
150 		return -EINVAL;
151 	}
152 
153 	clk_rate = clk_get_rate(qspi->fclk);
154 
155 	clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1;
156 
157 	if (clk_div < 0) {
158 		dev_dbg(qspi->dev, "clock divider < 0, using /1 divider\n");
159 		return -EINVAL;
160 	}
161 
162 	if (clk_div > QSPI_CLK_DIV_MAX) {
163 		dev_dbg(qspi->dev, "clock divider >%d , using /%d divider\n",
164 				QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
165 		return -EINVAL;
166 	}
167 
168 	dev_dbg(qspi->dev, "hz: %d, clock divider %d\n",
169 			qspi->spi_max_frequency, clk_div);
170 
171 	ret = pm_runtime_get_sync(qspi->dev);
172 	if (ret < 0) {
173 		dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
174 		return ret;
175 	}
176 
177 	clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
178 
179 	clk_ctrl_reg &= ~QSPI_CLK_EN;
180 
181 	/* disable SCLK */
182 	ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
183 
184 	/* enable SCLK */
185 	clk_mask = QSPI_CLK_EN | clk_div;
186 	ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG);
187 	ctx_reg->clkctrl = clk_mask;
188 
189 	pm_runtime_mark_last_busy(qspi->dev);
190 	ret = pm_runtime_put_autosuspend(qspi->dev);
191 	if (ret < 0) {
192 		dev_err(qspi->dev, "pm_runtime_put_autosuspend() failed\n");
193 		return ret;
194 	}
195 
196 	return 0;
197 }
198 
199 static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
200 {
201 	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
202 
203 	ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
204 }
205 
206 static inline u32 qspi_is_busy(struct ti_qspi *qspi)
207 {
208 	u32 stat;
209 	unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
210 
211 	stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
212 	while ((stat & BUSY) && time_after(timeout, jiffies)) {
213 		cpu_relax();
214 		stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
215 	}
216 
217 	WARN(stat & BUSY, "qspi busy\n");
218 	return stat & BUSY;
219 }
220 
221 static inline int ti_qspi_poll_wc(struct ti_qspi *qspi)
222 {
223 	u32 stat;
224 	unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
225 
226 	do {
227 		stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
228 		if (stat & WC)
229 			return 0;
230 		cpu_relax();
231 	} while (time_after(timeout, jiffies));
232 
233 	stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
234 	if (stat & WC)
235 		return 0;
236 	return  -ETIMEDOUT;
237 }
238 
239 static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t,
240 			  int count)
241 {
242 	int wlen, xfer_len;
243 	unsigned int cmd;
244 	const u8 *txbuf;
245 	u32 data;
246 
247 	txbuf = t->tx_buf;
248 	cmd = qspi->cmd | QSPI_WR_SNGL;
249 	wlen = t->bits_per_word >> 3;	/* in bytes */
250 	xfer_len = wlen;
251 
252 	while (count) {
253 		if (qspi_is_busy(qspi))
254 			return -EBUSY;
255 
256 		switch (wlen) {
257 		case 1:
258 			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
259 					cmd, qspi->dc, *txbuf);
260 			if (count >= QSPI_WLEN_MAX_BYTES) {
261 				u32 *txp = (u32 *)txbuf;
262 
263 				data = cpu_to_be32(*txp++);
264 				writel(data, qspi->base +
265 				       QSPI_SPI_DATA_REG_3);
266 				data = cpu_to_be32(*txp++);
267 				writel(data, qspi->base +
268 				       QSPI_SPI_DATA_REG_2);
269 				data = cpu_to_be32(*txp++);
270 				writel(data, qspi->base +
271 				       QSPI_SPI_DATA_REG_1);
272 				data = cpu_to_be32(*txp++);
273 				writel(data, qspi->base +
274 				       QSPI_SPI_DATA_REG);
275 				xfer_len = QSPI_WLEN_MAX_BYTES;
276 				cmd |= QSPI_WLEN(QSPI_WLEN_MAX_BITS);
277 			} else {
278 				writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
279 				cmd = qspi->cmd | QSPI_WR_SNGL;
280 				xfer_len = wlen;
281 				cmd |= QSPI_WLEN(wlen);
282 			}
283 			break;
284 		case 2:
285 			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n",
286 					cmd, qspi->dc, *txbuf);
287 			writew(*((u16 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
288 			break;
289 		case 4:
290 			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %08x\n",
291 					cmd, qspi->dc, *txbuf);
292 			writel(*((u32 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
293 			break;
294 		}
295 
296 		ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
297 		if (ti_qspi_poll_wc(qspi)) {
298 			dev_err(qspi->dev, "write timed out\n");
299 			return -ETIMEDOUT;
300 		}
301 		txbuf += xfer_len;
302 		count -= xfer_len;
303 	}
304 
305 	return 0;
306 }
307 
308 static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t,
309 			 int count)
310 {
311 	int wlen;
312 	unsigned int cmd;
313 	u8 *rxbuf;
314 
315 	rxbuf = t->rx_buf;
316 	cmd = qspi->cmd;
317 	switch (t->rx_nbits) {
318 	case SPI_NBITS_DUAL:
319 		cmd |= QSPI_RD_DUAL;
320 		break;
321 	case SPI_NBITS_QUAD:
322 		cmd |= QSPI_RD_QUAD;
323 		break;
324 	default:
325 		cmd |= QSPI_RD_SNGL;
326 		break;
327 	}
328 	wlen = t->bits_per_word >> 3;	/* in bytes */
329 
330 	while (count) {
331 		dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
332 		if (qspi_is_busy(qspi))
333 			return -EBUSY;
334 
335 		ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
336 		if (ti_qspi_poll_wc(qspi)) {
337 			dev_err(qspi->dev, "read timed out\n");
338 			return -ETIMEDOUT;
339 		}
340 		switch (wlen) {
341 		case 1:
342 			*rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG);
343 			break;
344 		case 2:
345 			*((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG);
346 			break;
347 		case 4:
348 			*((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG);
349 			break;
350 		}
351 		rxbuf += wlen;
352 		count -= wlen;
353 	}
354 
355 	return 0;
356 }
357 
358 static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t,
359 			     int count)
360 {
361 	int ret;
362 
363 	if (t->tx_buf) {
364 		ret = qspi_write_msg(qspi, t, count);
365 		if (ret) {
366 			dev_dbg(qspi->dev, "Error while writing\n");
367 			return ret;
368 		}
369 	}
370 
371 	if (t->rx_buf) {
372 		ret = qspi_read_msg(qspi, t, count);
373 		if (ret) {
374 			dev_dbg(qspi->dev, "Error while reading\n");
375 			return ret;
376 		}
377 	}
378 
379 	return 0;
380 }
381 
382 static void ti_qspi_enable_memory_map(struct spi_device *spi)
383 {
384 	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
385 
386 	ti_qspi_write(qspi, MM_SWITCH, QSPI_SPI_SWITCH_REG);
387 	if (qspi->ctrl_base) {
388 		regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
389 				   MEM_CS_EN(spi->chip_select),
390 				   MEM_CS_MASK);
391 	}
392 	qspi->mmap_enabled = true;
393 }
394 
395 static void ti_qspi_disable_memory_map(struct spi_device *spi)
396 {
397 	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
398 
399 	ti_qspi_write(qspi, 0, QSPI_SPI_SWITCH_REG);
400 	if (qspi->ctrl_base)
401 		regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
402 				   0, MEM_CS_MASK);
403 	qspi->mmap_enabled = false;
404 }
405 
406 static void ti_qspi_setup_mmap_read(struct spi_device *spi,
407 				    struct spi_flash_read_message *msg)
408 {
409 	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
410 	u32 memval = msg->read_opcode;
411 
412 	switch (msg->data_nbits) {
413 	case SPI_NBITS_QUAD:
414 		memval |= QSPI_SETUP_RD_QUAD;
415 		break;
416 	case SPI_NBITS_DUAL:
417 		memval |= QSPI_SETUP_RD_DUAL;
418 		break;
419 	default:
420 		memval |= QSPI_SETUP_RD_NORMAL;
421 		break;
422 	}
423 	memval |= ((msg->addr_width - 1) << QSPI_SETUP_ADDR_SHIFT |
424 		   msg->dummy_bytes << QSPI_SETUP_DUMMY_SHIFT);
425 	ti_qspi_write(qspi, memval,
426 		      QSPI_SPI_SETUP_REG(spi->chip_select));
427 }
428 
429 static int ti_qspi_spi_flash_read(struct  spi_device *spi,
430 				  struct spi_flash_read_message *msg)
431 {
432 	struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
433 	int ret = 0;
434 
435 	mutex_lock(&qspi->list_lock);
436 
437 	if (!qspi->mmap_enabled)
438 		ti_qspi_enable_memory_map(spi);
439 	ti_qspi_setup_mmap_read(spi, msg);
440 	memcpy_fromio(msg->buf, qspi->mmap_base + msg->from, msg->len);
441 	msg->retlen = msg->len;
442 
443 	mutex_unlock(&qspi->list_lock);
444 
445 	return ret;
446 }
447 
448 static int ti_qspi_start_transfer_one(struct spi_master *master,
449 		struct spi_message *m)
450 {
451 	struct ti_qspi *qspi = spi_master_get_devdata(master);
452 	struct spi_device *spi = m->spi;
453 	struct spi_transfer *t;
454 	int status = 0, ret;
455 	unsigned int frame_len_words, transfer_len_words;
456 	int wlen;
457 
458 	/* setup device control reg */
459 	qspi->dc = 0;
460 
461 	if (spi->mode & SPI_CPHA)
462 		qspi->dc |= QSPI_CKPHA(spi->chip_select);
463 	if (spi->mode & SPI_CPOL)
464 		qspi->dc |= QSPI_CKPOL(spi->chip_select);
465 	if (spi->mode & SPI_CS_HIGH)
466 		qspi->dc |= QSPI_CSPOL(spi->chip_select);
467 
468 	frame_len_words = 0;
469 	list_for_each_entry(t, &m->transfers, transfer_list)
470 		frame_len_words += t->len / (t->bits_per_word >> 3);
471 	frame_len_words = min_t(unsigned int, frame_len_words, QSPI_FRAME);
472 
473 	/* setup command reg */
474 	qspi->cmd = 0;
475 	qspi->cmd |= QSPI_EN_CS(spi->chip_select);
476 	qspi->cmd |= QSPI_FLEN(frame_len_words);
477 
478 	ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG);
479 
480 	mutex_lock(&qspi->list_lock);
481 
482 	if (qspi->mmap_enabled)
483 		ti_qspi_disable_memory_map(spi);
484 
485 	list_for_each_entry(t, &m->transfers, transfer_list) {
486 		qspi->cmd = ((qspi->cmd & ~QSPI_WLEN_MASK) |
487 			     QSPI_WLEN(t->bits_per_word));
488 
489 		wlen = t->bits_per_word >> 3;
490 		transfer_len_words = min(t->len / wlen, frame_len_words);
491 
492 		ret = qspi_transfer_msg(qspi, t, transfer_len_words * wlen);
493 		if (ret) {
494 			dev_dbg(qspi->dev, "transfer message failed\n");
495 			mutex_unlock(&qspi->list_lock);
496 			return -EINVAL;
497 		}
498 
499 		m->actual_length += transfer_len_words * wlen;
500 		frame_len_words -= transfer_len_words;
501 		if (frame_len_words == 0)
502 			break;
503 	}
504 
505 	mutex_unlock(&qspi->list_lock);
506 
507 	ti_qspi_write(qspi, qspi->cmd | QSPI_INVAL, QSPI_SPI_CMD_REG);
508 	m->status = status;
509 	spi_finalize_current_message(master);
510 
511 	return status;
512 }
513 
514 static int ti_qspi_runtime_resume(struct device *dev)
515 {
516 	struct ti_qspi      *qspi;
517 
518 	qspi = dev_get_drvdata(dev);
519 	ti_qspi_restore_ctx(qspi);
520 
521 	return 0;
522 }
523 
524 static const struct of_device_id ti_qspi_match[] = {
525 	{.compatible = "ti,dra7xxx-qspi" },
526 	{.compatible = "ti,am4372-qspi" },
527 	{},
528 };
529 MODULE_DEVICE_TABLE(of, ti_qspi_match);
530 
531 static int ti_qspi_probe(struct platform_device *pdev)
532 {
533 	struct  ti_qspi *qspi;
534 	struct spi_master *master;
535 	struct resource         *r, *res_mmap;
536 	struct device_node *np = pdev->dev.of_node;
537 	u32 max_freq;
538 	int ret = 0, num_cs, irq;
539 
540 	master = spi_alloc_master(&pdev->dev, sizeof(*qspi));
541 	if (!master)
542 		return -ENOMEM;
543 
544 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD;
545 
546 	master->flags = SPI_MASTER_HALF_DUPLEX;
547 	master->setup = ti_qspi_setup;
548 	master->auto_runtime_pm = true;
549 	master->transfer_one_message = ti_qspi_start_transfer_one;
550 	master->dev.of_node = pdev->dev.of_node;
551 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
552 				     SPI_BPW_MASK(8);
553 
554 	if (!of_property_read_u32(np, "num-cs", &num_cs))
555 		master->num_chipselect = num_cs;
556 
557 	qspi = spi_master_get_devdata(master);
558 	qspi->master = master;
559 	qspi->dev = &pdev->dev;
560 	platform_set_drvdata(pdev, qspi);
561 
562 	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base");
563 	if (r == NULL) {
564 		r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
565 		if (r == NULL) {
566 			dev_err(&pdev->dev, "missing platform data\n");
567 			return -ENODEV;
568 		}
569 	}
570 
571 	res_mmap = platform_get_resource_byname(pdev,
572 			IORESOURCE_MEM, "qspi_mmap");
573 	if (res_mmap == NULL) {
574 		res_mmap = platform_get_resource(pdev, IORESOURCE_MEM, 1);
575 		if (res_mmap == NULL) {
576 			dev_err(&pdev->dev,
577 				"memory mapped resource not required\n");
578 		}
579 	}
580 
581 	irq = platform_get_irq(pdev, 0);
582 	if (irq < 0) {
583 		dev_err(&pdev->dev, "no irq resource?\n");
584 		return irq;
585 	}
586 
587 	mutex_init(&qspi->list_lock);
588 
589 	qspi->base = devm_ioremap_resource(&pdev->dev, r);
590 	if (IS_ERR(qspi->base)) {
591 		ret = PTR_ERR(qspi->base);
592 		goto free_master;
593 	}
594 
595 	if (res_mmap) {
596 		qspi->mmap_base = devm_ioremap_resource(&pdev->dev,
597 							res_mmap);
598 		master->spi_flash_read = ti_qspi_spi_flash_read;
599 		if (IS_ERR(qspi->mmap_base)) {
600 			dev_err(&pdev->dev,
601 				"falling back to PIO mode\n");
602 			master->spi_flash_read = NULL;
603 		}
604 	}
605 	qspi->mmap_enabled = false;
606 
607 	if (of_property_read_bool(np, "syscon-chipselects")) {
608 		qspi->ctrl_base =
609 		syscon_regmap_lookup_by_phandle(np,
610 						"syscon-chipselects");
611 		if (IS_ERR(qspi->ctrl_base))
612 			return PTR_ERR(qspi->ctrl_base);
613 		ret = of_property_read_u32_index(np,
614 						 "syscon-chipselects",
615 						 1, &qspi->ctrl_reg);
616 		if (ret) {
617 			dev_err(&pdev->dev,
618 				"couldn't get ctrl_mod reg index\n");
619 			return ret;
620 		}
621 	}
622 
623 	qspi->fclk = devm_clk_get(&pdev->dev, "fck");
624 	if (IS_ERR(qspi->fclk)) {
625 		ret = PTR_ERR(qspi->fclk);
626 		dev_err(&pdev->dev, "could not get clk: %d\n", ret);
627 	}
628 
629 	pm_runtime_use_autosuspend(&pdev->dev);
630 	pm_runtime_set_autosuspend_delay(&pdev->dev, QSPI_AUTOSUSPEND_TIMEOUT);
631 	pm_runtime_enable(&pdev->dev);
632 
633 	if (!of_property_read_u32(np, "spi-max-frequency", &max_freq))
634 		qspi->spi_max_frequency = max_freq;
635 
636 	ret = devm_spi_register_master(&pdev->dev, master);
637 	if (ret)
638 		goto free_master;
639 
640 	return 0;
641 
642 free_master:
643 	spi_master_put(master);
644 	return ret;
645 }
646 
647 static int ti_qspi_remove(struct platform_device *pdev)
648 {
649 	pm_runtime_put_sync(&pdev->dev);
650 	pm_runtime_disable(&pdev->dev);
651 
652 	return 0;
653 }
654 
655 static const struct dev_pm_ops ti_qspi_pm_ops = {
656 	.runtime_resume = ti_qspi_runtime_resume,
657 };
658 
659 static struct platform_driver ti_qspi_driver = {
660 	.probe	= ti_qspi_probe,
661 	.remove = ti_qspi_remove,
662 	.driver = {
663 		.name	= "ti-qspi",
664 		.pm =   &ti_qspi_pm_ops,
665 		.of_match_table = ti_qspi_match,
666 	}
667 };
668 
669 module_platform_driver(ti_qspi_driver);
670 
671 MODULE_AUTHOR("Sourav Poddar <sourav.poddar@ti.com>");
672 MODULE_LICENSE("GPL v2");
673 MODULE_DESCRIPTION("TI QSPI controller driver");
674 MODULE_ALIAS("platform:ti-qspi");
675