xref: /openbmc/linux/drivers/spi/spi-orion.c (revision 4f6cce39)
1 /*
2  * Marvell Orion SPI controller driver
3  *
4  * Author: Shadi Ammouri <shadi@marvell.com>
5  * Copyright (C) 2007-2008 Marvell Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/interrupt.h>
13 #include <linux/delay.h>
14 #include <linux/platform_device.h>
15 #include <linux/err.h>
16 #include <linux/io.h>
17 #include <linux/spi/spi.h>
18 #include <linux/module.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/of.h>
21 #include <linux/of_address.h>
22 #include <linux/of_device.h>
23 #include <linux/clk.h>
24 #include <linux/sizes.h>
25 #include <asm/unaligned.h>
26 
27 #define DRIVER_NAME			"orion_spi"
28 
29 /* Runtime PM autosuspend timeout: PM is fairly light on this driver */
30 #define SPI_AUTOSUSPEND_TIMEOUT		200
31 
32 /* Some SoCs using this driver support up to 8 chip selects.
33  * It is up to the implementer to only use the chip selects
34  * that are available.
35  */
36 #define ORION_NUM_CHIPSELECTS		8
37 
38 #define ORION_SPI_WAIT_RDY_MAX_LOOP	2000 /* in usec */
39 
40 #define ORION_SPI_IF_CTRL_REG		0x00
41 #define ORION_SPI_IF_CONFIG_REG		0x04
42 #define ORION_SPI_DATA_OUT_REG		0x08
43 #define ORION_SPI_DATA_IN_REG		0x0c
44 #define ORION_SPI_INT_CAUSE_REG		0x10
45 #define ORION_SPI_TIMING_PARAMS_REG	0x18
46 
47 /* Register for the "Direct Mode" */
48 #define SPI_DIRECT_WRITE_CONFIG_REG	0x20
49 
50 #define ORION_SPI_TMISO_SAMPLE_MASK	(0x3 << 6)
51 #define ORION_SPI_TMISO_SAMPLE_1	(1 << 6)
52 #define ORION_SPI_TMISO_SAMPLE_2	(2 << 6)
53 
54 #define ORION_SPI_MODE_CPOL		(1 << 11)
55 #define ORION_SPI_MODE_CPHA		(1 << 12)
56 #define ORION_SPI_IF_8_16_BIT_MODE	(1 << 5)
57 #define ORION_SPI_CLK_PRESCALE_MASK	0x1F
58 #define ARMADA_SPI_CLK_PRESCALE_MASK	0xDF
59 #define ORION_SPI_MODE_MASK		(ORION_SPI_MODE_CPOL | \
60 					 ORION_SPI_MODE_CPHA)
61 #define ORION_SPI_CS_MASK	0x1C
62 #define ORION_SPI_CS_SHIFT	2
63 #define ORION_SPI_CS(cs)	((cs << ORION_SPI_CS_SHIFT) & \
64 					ORION_SPI_CS_MASK)
65 
66 enum orion_spi_type {
67 	ORION_SPI,
68 	ARMADA_SPI,
69 };
70 
71 struct orion_spi_dev {
72 	enum orion_spi_type	typ;
73 	/*
74 	 * min_divisor and max_hz should be exclusive, the only we can
75 	 * have both is for managing the armada-370-spi case with old
76 	 * device tree
77 	 */
78 	unsigned long		max_hz;
79 	unsigned int		min_divisor;
80 	unsigned int		max_divisor;
81 	u32			prescale_mask;
82 	bool			is_errata_50mhz_ac;
83 };
84 
85 struct orion_direct_acc {
86 	void __iomem		*vaddr;
87 	u32			size;
88 };
89 
90 struct orion_spi {
91 	struct spi_master	*master;
92 	void __iomem		*base;
93 	struct clk              *clk;
94 	const struct orion_spi_dev *devdata;
95 
96 	struct orion_direct_acc	direct_access[ORION_NUM_CHIPSELECTS];
97 };
98 
99 static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
100 {
101 	return orion_spi->base + reg;
102 }
103 
104 static inline void
105 orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
106 {
107 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
108 	u32 val;
109 
110 	val = readl(reg_addr);
111 	val |= mask;
112 	writel(val, reg_addr);
113 }
114 
115 static inline void
116 orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
117 {
118 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
119 	u32 val;
120 
121 	val = readl(reg_addr);
122 	val &= ~mask;
123 	writel(val, reg_addr);
124 }
125 
126 static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
127 {
128 	u32 tclk_hz;
129 	u32 rate;
130 	u32 prescale;
131 	u32 reg;
132 	struct orion_spi *orion_spi;
133 	const struct orion_spi_dev *devdata;
134 
135 	orion_spi = spi_master_get_devdata(spi->master);
136 	devdata = orion_spi->devdata;
137 
138 	tclk_hz = clk_get_rate(orion_spi->clk);
139 
140 	if (devdata->typ == ARMADA_SPI) {
141 		/*
142 		 * Given the core_clk (tclk_hz) and the target rate (speed) we
143 		 * determine the best values for SPR (in [0 .. 15]) and SPPR (in
144 		 * [0..7]) such that
145 		 *
146 		 * 	core_clk / (SPR * 2 ** SPPR)
147 		 *
148 		 * is as big as possible but not bigger than speed.
149 		 */
150 
151 		/* best integer divider: */
152 		unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
153 		unsigned spr, sppr;
154 
155 		if (divider < 16) {
156 			/* This is the easy case, divider is less than 16 */
157 			spr = divider;
158 			sppr = 0;
159 
160 		} else {
161 			unsigned two_pow_sppr;
162 			/*
163 			 * Find the highest bit set in divider. This and the
164 			 * three next bits define SPR (apart from rounding).
165 			 * SPPR is then the number of zero bits that must be
166 			 * appended:
167 			 */
168 			sppr = fls(divider) - 4;
169 
170 			/*
171 			 * As SPR only has 4 bits, we have to round divider up
172 			 * to the next multiple of 2 ** sppr.
173 			 */
174 			two_pow_sppr = 1 << sppr;
175 			divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
176 
177 			/*
178 			 * recalculate sppr as rounding up divider might have
179 			 * increased it enough to change the position of the
180 			 * highest set bit. In this case the bit that now
181 			 * doesn't make it into SPR is 0, so there is no need to
182 			 * round again.
183 			 */
184 			sppr = fls(divider) - 4;
185 			spr = divider >> sppr;
186 
187 			/*
188 			 * Now do range checking. SPR is constructed to have a
189 			 * width of 4 bits, so this is fine for sure. So we
190 			 * still need to check for sppr to fit into 3 bits:
191 			 */
192 			if (sppr > 7)
193 				return -EINVAL;
194 		}
195 
196 		prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
197 	} else {
198 		/*
199 		 * the supported rates are: 4,6,8...30
200 		 * round up as we look for equal or less speed
201 		 */
202 		rate = DIV_ROUND_UP(tclk_hz, speed);
203 		rate = roundup(rate, 2);
204 
205 		/* check if requested speed is too small */
206 		if (rate > 30)
207 			return -EINVAL;
208 
209 		if (rate < 4)
210 			rate = 4;
211 
212 		/* Convert the rate to SPI clock divisor value.	*/
213 		prescale = 0x10 + rate/2;
214 	}
215 
216 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
217 	reg = ((reg & ~devdata->prescale_mask) | prescale);
218 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
219 
220 	return 0;
221 }
222 
223 static void
224 orion_spi_mode_set(struct spi_device *spi)
225 {
226 	u32 reg;
227 	struct orion_spi *orion_spi;
228 
229 	orion_spi = spi_master_get_devdata(spi->master);
230 
231 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
232 	reg &= ~ORION_SPI_MODE_MASK;
233 	if (spi->mode & SPI_CPOL)
234 		reg |= ORION_SPI_MODE_CPOL;
235 	if (spi->mode & SPI_CPHA)
236 		reg |= ORION_SPI_MODE_CPHA;
237 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
238 }
239 
240 static void
241 orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
242 {
243 	u32 reg;
244 	struct orion_spi *orion_spi;
245 
246 	orion_spi = spi_master_get_devdata(spi->master);
247 
248 	/*
249 	 * Erratum description: (Erratum NO. FE-9144572) The device
250 	 * SPI interface supports frequencies of up to 50 MHz.
251 	 * However, due to this erratum, when the device core clock is
252 	 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
253 	 * clock and CPOL=CPHA=1 there might occur data corruption on
254 	 * reads from the SPI device.
255 	 * Erratum Workaround:
256 	 * Work in one of the following configurations:
257 	 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
258 	 * Register".
259 	 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
260 	 * Register" before setting the interface.
261 	 */
262 	reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
263 	reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
264 
265 	if (clk_get_rate(orion_spi->clk) == 250000000 &&
266 			speed == 50000000 && spi->mode & SPI_CPOL &&
267 			spi->mode & SPI_CPHA)
268 		reg |= ORION_SPI_TMISO_SAMPLE_2;
269 	else
270 		reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
271 
272 	writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
273 }
274 
275 /*
276  * called only when no transfer is active on the bus
277  */
278 static int
279 orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
280 {
281 	struct orion_spi *orion_spi;
282 	unsigned int speed = spi->max_speed_hz;
283 	unsigned int bits_per_word = spi->bits_per_word;
284 	int	rc;
285 
286 	orion_spi = spi_master_get_devdata(spi->master);
287 
288 	if ((t != NULL) && t->speed_hz)
289 		speed = t->speed_hz;
290 
291 	if ((t != NULL) && t->bits_per_word)
292 		bits_per_word = t->bits_per_word;
293 
294 	orion_spi_mode_set(spi);
295 
296 	if (orion_spi->devdata->is_errata_50mhz_ac)
297 		orion_spi_50mhz_ac_timing_erratum(spi, speed);
298 
299 	rc = orion_spi_baudrate_set(spi, speed);
300 	if (rc)
301 		return rc;
302 
303 	if (bits_per_word == 16)
304 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
305 				  ORION_SPI_IF_8_16_BIT_MODE);
306 	else
307 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
308 				  ORION_SPI_IF_8_16_BIT_MODE);
309 
310 	return 0;
311 }
312 
313 static void orion_spi_set_cs(struct spi_device *spi, bool enable)
314 {
315 	struct orion_spi *orion_spi;
316 
317 	orion_spi = spi_master_get_devdata(spi->master);
318 
319 	orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
320 	orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
321 				ORION_SPI_CS(spi->chip_select));
322 
323 	/* Chip select logic is inverted from spi_set_cs */
324 	if (!enable)
325 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
326 	else
327 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
328 }
329 
330 static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
331 {
332 	int i;
333 
334 	for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
335 		if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
336 			return 1;
337 
338 		udelay(1);
339 	}
340 
341 	return -1;
342 }
343 
344 static inline int
345 orion_spi_write_read_8bit(struct spi_device *spi,
346 			  const u8 **tx_buf, u8 **rx_buf)
347 {
348 	void __iomem *tx_reg, *rx_reg, *int_reg;
349 	struct orion_spi *orion_spi;
350 
351 	orion_spi = spi_master_get_devdata(spi->master);
352 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
353 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
354 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
355 
356 	/* clear the interrupt cause register */
357 	writel(0x0, int_reg);
358 
359 	if (tx_buf && *tx_buf)
360 		writel(*(*tx_buf)++, tx_reg);
361 	else
362 		writel(0, tx_reg);
363 
364 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
365 		dev_err(&spi->dev, "TXS timed out\n");
366 		return -1;
367 	}
368 
369 	if (rx_buf && *rx_buf)
370 		*(*rx_buf)++ = readl(rx_reg);
371 
372 	return 1;
373 }
374 
375 static inline int
376 orion_spi_write_read_16bit(struct spi_device *spi,
377 			   const u16 **tx_buf, u16 **rx_buf)
378 {
379 	void __iomem *tx_reg, *rx_reg, *int_reg;
380 	struct orion_spi *orion_spi;
381 
382 	orion_spi = spi_master_get_devdata(spi->master);
383 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
384 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
385 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
386 
387 	/* clear the interrupt cause register */
388 	writel(0x0, int_reg);
389 
390 	if (tx_buf && *tx_buf)
391 		writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
392 	else
393 		writel(0, tx_reg);
394 
395 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
396 		dev_err(&spi->dev, "TXS timed out\n");
397 		return -1;
398 	}
399 
400 	if (rx_buf && *rx_buf)
401 		put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
402 
403 	return 1;
404 }
405 
406 static unsigned int
407 orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
408 {
409 	unsigned int count;
410 	int word_len;
411 	struct orion_spi *orion_spi;
412 	int cs = spi->chip_select;
413 
414 	word_len = spi->bits_per_word;
415 	count = xfer->len;
416 
417 	orion_spi = spi_master_get_devdata(spi->master);
418 
419 	/*
420 	 * Use SPI direct write mode if base address is available. Otherwise
421 	 * fall back to PIO mode for this transfer.
422 	 */
423 	if ((orion_spi->direct_access[cs].vaddr) && (xfer->tx_buf) &&
424 	    (word_len == 8)) {
425 		unsigned int cnt = count / 4;
426 		unsigned int rem = count % 4;
427 
428 		/*
429 		 * Send the TX-data to the SPI device via the direct
430 		 * mapped address window
431 		 */
432 		iowrite32_rep(orion_spi->direct_access[cs].vaddr,
433 			      xfer->tx_buf, cnt);
434 		if (rem) {
435 			u32 *buf = (u32 *)xfer->tx_buf;
436 
437 			iowrite8_rep(orion_spi->direct_access[cs].vaddr,
438 				     &buf[cnt], rem);
439 		}
440 
441 		return count;
442 	}
443 
444 	if (word_len == 8) {
445 		const u8 *tx = xfer->tx_buf;
446 		u8 *rx = xfer->rx_buf;
447 
448 		do {
449 			if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
450 				goto out;
451 			count--;
452 		} while (count);
453 	} else if (word_len == 16) {
454 		const u16 *tx = xfer->tx_buf;
455 		u16 *rx = xfer->rx_buf;
456 
457 		do {
458 			if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
459 				goto out;
460 			count -= 2;
461 		} while (count);
462 	}
463 
464 out:
465 	return xfer->len - count;
466 }
467 
468 static int orion_spi_transfer_one(struct spi_master *master,
469 					struct spi_device *spi,
470 					struct spi_transfer *t)
471 {
472 	int status = 0;
473 
474 	status = orion_spi_setup_transfer(spi, t);
475 	if (status < 0)
476 		return status;
477 
478 	if (t->len)
479 		orion_spi_write_read(spi, t);
480 
481 	return status;
482 }
483 
484 static int orion_spi_setup(struct spi_device *spi)
485 {
486 	return orion_spi_setup_transfer(spi, NULL);
487 }
488 
489 static int orion_spi_reset(struct orion_spi *orion_spi)
490 {
491 	/* Verify that the CS is deasserted */
492 	orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
493 
494 	/* Don't deassert CS between the direct mapped SPI transfers */
495 	writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG));
496 
497 	return 0;
498 }
499 
500 static const struct orion_spi_dev orion_spi_dev_data = {
501 	.typ = ORION_SPI,
502 	.min_divisor = 4,
503 	.max_divisor = 30,
504 	.prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
505 };
506 
507 static const struct orion_spi_dev armada_370_spi_dev_data = {
508 	.typ = ARMADA_SPI,
509 	.min_divisor = 4,
510 	.max_divisor = 1920,
511 	.max_hz = 50000000,
512 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
513 };
514 
515 static const struct orion_spi_dev armada_xp_spi_dev_data = {
516 	.typ = ARMADA_SPI,
517 	.max_hz = 50000000,
518 	.max_divisor = 1920,
519 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
520 };
521 
522 static const struct orion_spi_dev armada_375_spi_dev_data = {
523 	.typ = ARMADA_SPI,
524 	.min_divisor = 15,
525 	.max_divisor = 1920,
526 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
527 };
528 
529 static const struct orion_spi_dev armada_380_spi_dev_data = {
530 	.typ = ARMADA_SPI,
531 	.max_hz = 50000000,
532 	.max_divisor = 1920,
533 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
534 	.is_errata_50mhz_ac = true,
535 };
536 
537 static const struct of_device_id orion_spi_of_match_table[] = {
538 	{
539 		.compatible = "marvell,orion-spi",
540 		.data = &orion_spi_dev_data,
541 	},
542 	{
543 		.compatible = "marvell,armada-370-spi",
544 		.data = &armada_370_spi_dev_data,
545 	},
546 	{
547 		.compatible = "marvell,armada-375-spi",
548 		.data = &armada_375_spi_dev_data,
549 	},
550 	{
551 		.compatible = "marvell,armada-380-spi",
552 		.data = &armada_380_spi_dev_data,
553 	},
554 	{
555 		.compatible = "marvell,armada-390-spi",
556 		.data = &armada_xp_spi_dev_data,
557 	},
558 	{
559 		.compatible = "marvell,armada-xp-spi",
560 		.data = &armada_xp_spi_dev_data,
561 	},
562 
563 	{}
564 };
565 MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
566 
567 static int orion_spi_probe(struct platform_device *pdev)
568 {
569 	const struct of_device_id *of_id;
570 	const struct orion_spi_dev *devdata;
571 	struct spi_master *master;
572 	struct orion_spi *spi;
573 	struct resource *r;
574 	unsigned long tclk_hz;
575 	int status = 0;
576 	struct device_node *np;
577 
578 	master = spi_alloc_master(&pdev->dev, sizeof(*spi));
579 	if (master == NULL) {
580 		dev_dbg(&pdev->dev, "master allocation failed\n");
581 		return -ENOMEM;
582 	}
583 
584 	if (pdev->id != -1)
585 		master->bus_num = pdev->id;
586 	if (pdev->dev.of_node) {
587 		u32 cell_index;
588 
589 		if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
590 					  &cell_index))
591 			master->bus_num = cell_index;
592 	}
593 
594 	/* we support only mode 0, and no options */
595 	master->mode_bits = SPI_CPHA | SPI_CPOL;
596 	master->set_cs = orion_spi_set_cs;
597 	master->transfer_one = orion_spi_transfer_one;
598 	master->num_chipselect = ORION_NUM_CHIPSELECTS;
599 	master->setup = orion_spi_setup;
600 	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
601 	master->auto_runtime_pm = true;
602 
603 	platform_set_drvdata(pdev, master);
604 
605 	spi = spi_master_get_devdata(master);
606 	spi->master = master;
607 
608 	of_id = of_match_device(orion_spi_of_match_table, &pdev->dev);
609 	devdata = (of_id) ? of_id->data : &orion_spi_dev_data;
610 	spi->devdata = devdata;
611 
612 	spi->clk = devm_clk_get(&pdev->dev, NULL);
613 	if (IS_ERR(spi->clk)) {
614 		status = PTR_ERR(spi->clk);
615 		goto out;
616 	}
617 
618 	status = clk_prepare_enable(spi->clk);
619 	if (status)
620 		goto out;
621 
622 	tclk_hz = clk_get_rate(spi->clk);
623 
624 	/*
625 	 * With old device tree, armada-370-spi could be used with
626 	 * Armada XP, however for this SoC the maximum frequency is
627 	 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
628 	 * higher than 200MHz. So, in order to be able to handle both
629 	 * SoCs, we can take the minimum of 50MHz and tclk/4.
630 	 */
631 	if (of_device_is_compatible(pdev->dev.of_node,
632 					"marvell,armada-370-spi"))
633 		master->max_speed_hz = min(devdata->max_hz,
634 				DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
635 	else if (devdata->min_divisor)
636 		master->max_speed_hz =
637 			DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
638 	else
639 		master->max_speed_hz = devdata->max_hz;
640 	master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
641 
642 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
643 	spi->base = devm_ioremap_resource(&pdev->dev, r);
644 	if (IS_ERR(spi->base)) {
645 		status = PTR_ERR(spi->base);
646 		goto out_rel_clk;
647 	}
648 
649 	/* Scan all SPI devices of this controller for direct mapped devices */
650 	for_each_available_child_of_node(pdev->dev.of_node, np) {
651 		u32 cs;
652 
653 		/* Get chip-select number from the "reg" property */
654 		status = of_property_read_u32(np, "reg", &cs);
655 		if (status) {
656 			dev_err(&pdev->dev,
657 				"%s has no valid 'reg' property (%d)\n",
658 				np->full_name, status);
659 			status = 0;
660 			continue;
661 		}
662 
663 		/*
664 		 * Check if an address is configured for this SPI device. If
665 		 * not, the MBus mapping via the 'ranges' property in the 'soc'
666 		 * node is not configured and this device should not use the
667 		 * direct mode. In this case, just continue with the next
668 		 * device.
669 		 */
670 		status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
671 		if (status)
672 			continue;
673 
674 		/*
675 		 * Only map one page for direct access. This is enough for the
676 		 * simple TX transfer which only writes to the first word.
677 		 * This needs to get extended for the direct SPI-NOR / SPI-NAND
678 		 * support, once this gets implemented.
679 		 */
680 		spi->direct_access[cs].vaddr = devm_ioremap(&pdev->dev,
681 							    r->start,
682 							    PAGE_SIZE);
683 		if (!spi->direct_access[cs].vaddr) {
684 			status = -ENOMEM;
685 			goto out_rel_clk;
686 		}
687 		spi->direct_access[cs].size = PAGE_SIZE;
688 
689 		dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
690 	}
691 
692 	pm_runtime_set_active(&pdev->dev);
693 	pm_runtime_use_autosuspend(&pdev->dev);
694 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
695 	pm_runtime_enable(&pdev->dev);
696 
697 	status = orion_spi_reset(spi);
698 	if (status < 0)
699 		goto out_rel_pm;
700 
701 	pm_runtime_mark_last_busy(&pdev->dev);
702 	pm_runtime_put_autosuspend(&pdev->dev);
703 
704 	master->dev.of_node = pdev->dev.of_node;
705 	status = spi_register_master(master);
706 	if (status < 0)
707 		goto out_rel_pm;
708 
709 	return status;
710 
711 out_rel_pm:
712 	pm_runtime_disable(&pdev->dev);
713 out_rel_clk:
714 	clk_disable_unprepare(spi->clk);
715 out:
716 	spi_master_put(master);
717 	return status;
718 }
719 
720 
721 static int orion_spi_remove(struct platform_device *pdev)
722 {
723 	struct spi_master *master = platform_get_drvdata(pdev);
724 	struct orion_spi *spi = spi_master_get_devdata(master);
725 
726 	pm_runtime_get_sync(&pdev->dev);
727 	clk_disable_unprepare(spi->clk);
728 
729 	spi_unregister_master(master);
730 	pm_runtime_disable(&pdev->dev);
731 
732 	return 0;
733 }
734 
735 MODULE_ALIAS("platform:" DRIVER_NAME);
736 
737 #ifdef CONFIG_PM
738 static int orion_spi_runtime_suspend(struct device *dev)
739 {
740 	struct spi_master *master = dev_get_drvdata(dev);
741 	struct orion_spi *spi = spi_master_get_devdata(master);
742 
743 	clk_disable_unprepare(spi->clk);
744 	return 0;
745 }
746 
747 static int orion_spi_runtime_resume(struct device *dev)
748 {
749 	struct spi_master *master = dev_get_drvdata(dev);
750 	struct orion_spi *spi = spi_master_get_devdata(master);
751 
752 	return clk_prepare_enable(spi->clk);
753 }
754 #endif
755 
756 static const struct dev_pm_ops orion_spi_pm_ops = {
757 	SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
758 			   orion_spi_runtime_resume,
759 			   NULL)
760 };
761 
762 static struct platform_driver orion_spi_driver = {
763 	.driver = {
764 		.name	= DRIVER_NAME,
765 		.pm	= &orion_spi_pm_ops,
766 		.of_match_table = of_match_ptr(orion_spi_of_match_table),
767 	},
768 	.probe		= orion_spi_probe,
769 	.remove		= orion_spi_remove,
770 };
771 
772 module_platform_driver(orion_spi_driver);
773 
774 MODULE_DESCRIPTION("Orion SPI driver");
775 MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
776 MODULE_LICENSE("GPL");
777