xref: /openbmc/linux/drivers/spi/spi-orion.c (revision d236d361)
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_IF_RXLSBF		BIT(14)
43 #define ORION_SPI_IF_TXLSBF		BIT(13)
44 #define ORION_SPI_DATA_OUT_REG		0x08
45 #define ORION_SPI_DATA_IN_REG		0x0c
46 #define ORION_SPI_INT_CAUSE_REG		0x10
47 #define ORION_SPI_TIMING_PARAMS_REG	0x18
48 
49 /* Register for the "Direct Mode" */
50 #define SPI_DIRECT_WRITE_CONFIG_REG	0x20
51 
52 #define ORION_SPI_TMISO_SAMPLE_MASK	(0x3 << 6)
53 #define ORION_SPI_TMISO_SAMPLE_1	(1 << 6)
54 #define ORION_SPI_TMISO_SAMPLE_2	(2 << 6)
55 
56 #define ORION_SPI_MODE_CPOL		(1 << 11)
57 #define ORION_SPI_MODE_CPHA		(1 << 12)
58 #define ORION_SPI_IF_8_16_BIT_MODE	(1 << 5)
59 #define ORION_SPI_CLK_PRESCALE_MASK	0x1F
60 #define ARMADA_SPI_CLK_PRESCALE_MASK	0xDF
61 #define ORION_SPI_MODE_MASK		(ORION_SPI_MODE_CPOL | \
62 					 ORION_SPI_MODE_CPHA)
63 #define ORION_SPI_CS_MASK	0x1C
64 #define ORION_SPI_CS_SHIFT	2
65 #define ORION_SPI_CS(cs)	((cs << ORION_SPI_CS_SHIFT) & \
66 					ORION_SPI_CS_MASK)
67 
68 enum orion_spi_type {
69 	ORION_SPI,
70 	ARMADA_SPI,
71 };
72 
73 struct orion_spi_dev {
74 	enum orion_spi_type	typ;
75 	/*
76 	 * min_divisor and max_hz should be exclusive, the only we can
77 	 * have both is for managing the armada-370-spi case with old
78 	 * device tree
79 	 */
80 	unsigned long		max_hz;
81 	unsigned int		min_divisor;
82 	unsigned int		max_divisor;
83 	u32			prescale_mask;
84 	bool			is_errata_50mhz_ac;
85 };
86 
87 struct orion_direct_acc {
88 	void __iomem		*vaddr;
89 	u32			size;
90 };
91 
92 struct orion_spi {
93 	struct spi_master	*master;
94 	void __iomem		*base;
95 	struct clk              *clk;
96 	const struct orion_spi_dev *devdata;
97 
98 	struct orion_direct_acc	direct_access[ORION_NUM_CHIPSELECTS];
99 };
100 
101 static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
102 {
103 	return orion_spi->base + reg;
104 }
105 
106 static inline void
107 orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
108 {
109 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
110 	u32 val;
111 
112 	val = readl(reg_addr);
113 	val |= mask;
114 	writel(val, reg_addr);
115 }
116 
117 static inline void
118 orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
119 {
120 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
121 	u32 val;
122 
123 	val = readl(reg_addr);
124 	val &= ~mask;
125 	writel(val, reg_addr);
126 }
127 
128 static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
129 {
130 	u32 tclk_hz;
131 	u32 rate;
132 	u32 prescale;
133 	u32 reg;
134 	struct orion_spi *orion_spi;
135 	const struct orion_spi_dev *devdata;
136 
137 	orion_spi = spi_master_get_devdata(spi->master);
138 	devdata = orion_spi->devdata;
139 
140 	tclk_hz = clk_get_rate(orion_spi->clk);
141 
142 	if (devdata->typ == ARMADA_SPI) {
143 		/*
144 		 * Given the core_clk (tclk_hz) and the target rate (speed) we
145 		 * determine the best values for SPR (in [0 .. 15]) and SPPR (in
146 		 * [0..7]) such that
147 		 *
148 		 * 	core_clk / (SPR * 2 ** SPPR)
149 		 *
150 		 * is as big as possible but not bigger than speed.
151 		 */
152 
153 		/* best integer divider: */
154 		unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
155 		unsigned spr, sppr;
156 
157 		if (divider < 16) {
158 			/* This is the easy case, divider is less than 16 */
159 			spr = divider;
160 			sppr = 0;
161 
162 		} else {
163 			unsigned two_pow_sppr;
164 			/*
165 			 * Find the highest bit set in divider. This and the
166 			 * three next bits define SPR (apart from rounding).
167 			 * SPPR is then the number of zero bits that must be
168 			 * appended:
169 			 */
170 			sppr = fls(divider) - 4;
171 
172 			/*
173 			 * As SPR only has 4 bits, we have to round divider up
174 			 * to the next multiple of 2 ** sppr.
175 			 */
176 			two_pow_sppr = 1 << sppr;
177 			divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
178 
179 			/*
180 			 * recalculate sppr as rounding up divider might have
181 			 * increased it enough to change the position of the
182 			 * highest set bit. In this case the bit that now
183 			 * doesn't make it into SPR is 0, so there is no need to
184 			 * round again.
185 			 */
186 			sppr = fls(divider) - 4;
187 			spr = divider >> sppr;
188 
189 			/*
190 			 * Now do range checking. SPR is constructed to have a
191 			 * width of 4 bits, so this is fine for sure. So we
192 			 * still need to check for sppr to fit into 3 bits:
193 			 */
194 			if (sppr > 7)
195 				return -EINVAL;
196 		}
197 
198 		prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
199 	} else {
200 		/*
201 		 * the supported rates are: 4,6,8...30
202 		 * round up as we look for equal or less speed
203 		 */
204 		rate = DIV_ROUND_UP(tclk_hz, speed);
205 		rate = roundup(rate, 2);
206 
207 		/* check if requested speed is too small */
208 		if (rate > 30)
209 			return -EINVAL;
210 
211 		if (rate < 4)
212 			rate = 4;
213 
214 		/* Convert the rate to SPI clock divisor value.	*/
215 		prescale = 0x10 + rate/2;
216 	}
217 
218 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
219 	reg = ((reg & ~devdata->prescale_mask) | prescale);
220 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
221 
222 	return 0;
223 }
224 
225 static void
226 orion_spi_mode_set(struct spi_device *spi)
227 {
228 	u32 reg;
229 	struct orion_spi *orion_spi;
230 
231 	orion_spi = spi_master_get_devdata(spi->master);
232 
233 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
234 	reg &= ~ORION_SPI_MODE_MASK;
235 	if (spi->mode & SPI_CPOL)
236 		reg |= ORION_SPI_MODE_CPOL;
237 	if (spi->mode & SPI_CPHA)
238 		reg |= ORION_SPI_MODE_CPHA;
239 	if (spi->mode & SPI_LSB_FIRST)
240 		reg |= ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF;
241 	else
242 		reg &= ~(ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF);
243 
244 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
245 }
246 
247 static void
248 orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
249 {
250 	u32 reg;
251 	struct orion_spi *orion_spi;
252 
253 	orion_spi = spi_master_get_devdata(spi->master);
254 
255 	/*
256 	 * Erratum description: (Erratum NO. FE-9144572) The device
257 	 * SPI interface supports frequencies of up to 50 MHz.
258 	 * However, due to this erratum, when the device core clock is
259 	 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
260 	 * clock and CPOL=CPHA=1 there might occur data corruption on
261 	 * reads from the SPI device.
262 	 * Erratum Workaround:
263 	 * Work in one of the following configurations:
264 	 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
265 	 * Register".
266 	 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
267 	 * Register" before setting the interface.
268 	 */
269 	reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
270 	reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
271 
272 	if (clk_get_rate(orion_spi->clk) == 250000000 &&
273 			speed == 50000000 && spi->mode & SPI_CPOL &&
274 			spi->mode & SPI_CPHA)
275 		reg |= ORION_SPI_TMISO_SAMPLE_2;
276 	else
277 		reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
278 
279 	writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
280 }
281 
282 /*
283  * called only when no transfer is active on the bus
284  */
285 static int
286 orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
287 {
288 	struct orion_spi *orion_spi;
289 	unsigned int speed = spi->max_speed_hz;
290 	unsigned int bits_per_word = spi->bits_per_word;
291 	int	rc;
292 
293 	orion_spi = spi_master_get_devdata(spi->master);
294 
295 	if ((t != NULL) && t->speed_hz)
296 		speed = t->speed_hz;
297 
298 	if ((t != NULL) && t->bits_per_word)
299 		bits_per_word = t->bits_per_word;
300 
301 	orion_spi_mode_set(spi);
302 
303 	if (orion_spi->devdata->is_errata_50mhz_ac)
304 		orion_spi_50mhz_ac_timing_erratum(spi, speed);
305 
306 	rc = orion_spi_baudrate_set(spi, speed);
307 	if (rc)
308 		return rc;
309 
310 	if (bits_per_word == 16)
311 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
312 				  ORION_SPI_IF_8_16_BIT_MODE);
313 	else
314 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
315 				  ORION_SPI_IF_8_16_BIT_MODE);
316 
317 	return 0;
318 }
319 
320 static void orion_spi_set_cs(struct spi_device *spi, bool enable)
321 {
322 	struct orion_spi *orion_spi;
323 
324 	orion_spi = spi_master_get_devdata(spi->master);
325 
326 	orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
327 	orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
328 				ORION_SPI_CS(spi->chip_select));
329 
330 	/* Chip select logic is inverted from spi_set_cs */
331 	if (!enable)
332 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
333 	else
334 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
335 }
336 
337 static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
338 {
339 	int i;
340 
341 	for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
342 		if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
343 			return 1;
344 
345 		udelay(1);
346 	}
347 
348 	return -1;
349 }
350 
351 static inline int
352 orion_spi_write_read_8bit(struct spi_device *spi,
353 			  const u8 **tx_buf, u8 **rx_buf)
354 {
355 	void __iomem *tx_reg, *rx_reg, *int_reg;
356 	struct orion_spi *orion_spi;
357 
358 	orion_spi = spi_master_get_devdata(spi->master);
359 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
360 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
361 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
362 
363 	/* clear the interrupt cause register */
364 	writel(0x0, int_reg);
365 
366 	if (tx_buf && *tx_buf)
367 		writel(*(*tx_buf)++, tx_reg);
368 	else
369 		writel(0, tx_reg);
370 
371 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
372 		dev_err(&spi->dev, "TXS timed out\n");
373 		return -1;
374 	}
375 
376 	if (rx_buf && *rx_buf)
377 		*(*rx_buf)++ = readl(rx_reg);
378 
379 	return 1;
380 }
381 
382 static inline int
383 orion_spi_write_read_16bit(struct spi_device *spi,
384 			   const u16 **tx_buf, u16 **rx_buf)
385 {
386 	void __iomem *tx_reg, *rx_reg, *int_reg;
387 	struct orion_spi *orion_spi;
388 
389 	orion_spi = spi_master_get_devdata(spi->master);
390 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
391 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
392 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
393 
394 	/* clear the interrupt cause register */
395 	writel(0x0, int_reg);
396 
397 	if (tx_buf && *tx_buf)
398 		writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
399 	else
400 		writel(0, tx_reg);
401 
402 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
403 		dev_err(&spi->dev, "TXS timed out\n");
404 		return -1;
405 	}
406 
407 	if (rx_buf && *rx_buf)
408 		put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
409 
410 	return 1;
411 }
412 
413 static unsigned int
414 orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
415 {
416 	unsigned int count;
417 	int word_len;
418 	struct orion_spi *orion_spi;
419 	int cs = spi->chip_select;
420 
421 	word_len = spi->bits_per_word;
422 	count = xfer->len;
423 
424 	orion_spi = spi_master_get_devdata(spi->master);
425 
426 	/*
427 	 * Use SPI direct write mode if base address is available. Otherwise
428 	 * fall back to PIO mode for this transfer.
429 	 */
430 	if ((orion_spi->direct_access[cs].vaddr) && (xfer->tx_buf) &&
431 	    (word_len == 8)) {
432 		unsigned int cnt = count / 4;
433 		unsigned int rem = count % 4;
434 
435 		/*
436 		 * Send the TX-data to the SPI device via the direct
437 		 * mapped address window
438 		 */
439 		iowrite32_rep(orion_spi->direct_access[cs].vaddr,
440 			      xfer->tx_buf, cnt);
441 		if (rem) {
442 			u32 *buf = (u32 *)xfer->tx_buf;
443 
444 			iowrite8_rep(orion_spi->direct_access[cs].vaddr,
445 				     &buf[cnt], rem);
446 		}
447 
448 		return count;
449 	}
450 
451 	if (word_len == 8) {
452 		const u8 *tx = xfer->tx_buf;
453 		u8 *rx = xfer->rx_buf;
454 
455 		do {
456 			if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
457 				goto out;
458 			count--;
459 		} while (count);
460 	} else if (word_len == 16) {
461 		const u16 *tx = xfer->tx_buf;
462 		u16 *rx = xfer->rx_buf;
463 
464 		do {
465 			if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
466 				goto out;
467 			count -= 2;
468 		} while (count);
469 	}
470 
471 out:
472 	return xfer->len - count;
473 }
474 
475 static int orion_spi_transfer_one(struct spi_master *master,
476 					struct spi_device *spi,
477 					struct spi_transfer *t)
478 {
479 	int status = 0;
480 
481 	status = orion_spi_setup_transfer(spi, t);
482 	if (status < 0)
483 		return status;
484 
485 	if (t->len)
486 		orion_spi_write_read(spi, t);
487 
488 	return status;
489 }
490 
491 static int orion_spi_setup(struct spi_device *spi)
492 {
493 	return orion_spi_setup_transfer(spi, NULL);
494 }
495 
496 static int orion_spi_reset(struct orion_spi *orion_spi)
497 {
498 	/* Verify that the CS is deasserted */
499 	orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
500 
501 	/* Don't deassert CS between the direct mapped SPI transfers */
502 	writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG));
503 
504 	return 0;
505 }
506 
507 static const struct orion_spi_dev orion_spi_dev_data = {
508 	.typ = ORION_SPI,
509 	.min_divisor = 4,
510 	.max_divisor = 30,
511 	.prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
512 };
513 
514 static const struct orion_spi_dev armada_370_spi_dev_data = {
515 	.typ = ARMADA_SPI,
516 	.min_divisor = 4,
517 	.max_divisor = 1920,
518 	.max_hz = 50000000,
519 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
520 };
521 
522 static const struct orion_spi_dev armada_xp_spi_dev_data = {
523 	.typ = ARMADA_SPI,
524 	.max_hz = 50000000,
525 	.max_divisor = 1920,
526 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
527 };
528 
529 static const struct orion_spi_dev armada_375_spi_dev_data = {
530 	.typ = ARMADA_SPI,
531 	.min_divisor = 15,
532 	.max_divisor = 1920,
533 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
534 };
535 
536 static const struct orion_spi_dev armada_380_spi_dev_data = {
537 	.typ = ARMADA_SPI,
538 	.max_hz = 50000000,
539 	.max_divisor = 1920,
540 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
541 	.is_errata_50mhz_ac = true,
542 };
543 
544 static const struct of_device_id orion_spi_of_match_table[] = {
545 	{
546 		.compatible = "marvell,orion-spi",
547 		.data = &orion_spi_dev_data,
548 	},
549 	{
550 		.compatible = "marvell,armada-370-spi",
551 		.data = &armada_370_spi_dev_data,
552 	},
553 	{
554 		.compatible = "marvell,armada-375-spi",
555 		.data = &armada_375_spi_dev_data,
556 	},
557 	{
558 		.compatible = "marvell,armada-380-spi",
559 		.data = &armada_380_spi_dev_data,
560 	},
561 	{
562 		.compatible = "marvell,armada-390-spi",
563 		.data = &armada_xp_spi_dev_data,
564 	},
565 	{
566 		.compatible = "marvell,armada-xp-spi",
567 		.data = &armada_xp_spi_dev_data,
568 	},
569 
570 	{}
571 };
572 MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
573 
574 static int orion_spi_probe(struct platform_device *pdev)
575 {
576 	const struct of_device_id *of_id;
577 	const struct orion_spi_dev *devdata;
578 	struct spi_master *master;
579 	struct orion_spi *spi;
580 	struct resource *r;
581 	unsigned long tclk_hz;
582 	int status = 0;
583 	struct device_node *np;
584 
585 	master = spi_alloc_master(&pdev->dev, sizeof(*spi));
586 	if (master == NULL) {
587 		dev_dbg(&pdev->dev, "master allocation failed\n");
588 		return -ENOMEM;
589 	}
590 
591 	if (pdev->id != -1)
592 		master->bus_num = pdev->id;
593 	if (pdev->dev.of_node) {
594 		u32 cell_index;
595 
596 		if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
597 					  &cell_index))
598 			master->bus_num = cell_index;
599 	}
600 
601 	/* we support all 4 SPI modes and LSB first option */
602 	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;
603 	master->set_cs = orion_spi_set_cs;
604 	master->transfer_one = orion_spi_transfer_one;
605 	master->num_chipselect = ORION_NUM_CHIPSELECTS;
606 	master->setup = orion_spi_setup;
607 	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
608 	master->auto_runtime_pm = true;
609 
610 	platform_set_drvdata(pdev, master);
611 
612 	spi = spi_master_get_devdata(master);
613 	spi->master = master;
614 
615 	of_id = of_match_device(orion_spi_of_match_table, &pdev->dev);
616 	devdata = (of_id) ? of_id->data : &orion_spi_dev_data;
617 	spi->devdata = devdata;
618 
619 	spi->clk = devm_clk_get(&pdev->dev, NULL);
620 	if (IS_ERR(spi->clk)) {
621 		status = PTR_ERR(spi->clk);
622 		goto out;
623 	}
624 
625 	status = clk_prepare_enable(spi->clk);
626 	if (status)
627 		goto out;
628 
629 	tclk_hz = clk_get_rate(spi->clk);
630 
631 	/*
632 	 * With old device tree, armada-370-spi could be used with
633 	 * Armada XP, however for this SoC the maximum frequency is
634 	 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
635 	 * higher than 200MHz. So, in order to be able to handle both
636 	 * SoCs, we can take the minimum of 50MHz and tclk/4.
637 	 */
638 	if (of_device_is_compatible(pdev->dev.of_node,
639 					"marvell,armada-370-spi"))
640 		master->max_speed_hz = min(devdata->max_hz,
641 				DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
642 	else if (devdata->min_divisor)
643 		master->max_speed_hz =
644 			DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
645 	else
646 		master->max_speed_hz = devdata->max_hz;
647 	master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
648 
649 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
650 	spi->base = devm_ioremap_resource(&pdev->dev, r);
651 	if (IS_ERR(spi->base)) {
652 		status = PTR_ERR(spi->base);
653 		goto out_rel_clk;
654 	}
655 
656 	/* Scan all SPI devices of this controller for direct mapped devices */
657 	for_each_available_child_of_node(pdev->dev.of_node, np) {
658 		u32 cs;
659 
660 		/* Get chip-select number from the "reg" property */
661 		status = of_property_read_u32(np, "reg", &cs);
662 		if (status) {
663 			dev_err(&pdev->dev,
664 				"%s has no valid 'reg' property (%d)\n",
665 				np->full_name, status);
666 			status = 0;
667 			continue;
668 		}
669 
670 		/*
671 		 * Check if an address is configured for this SPI device. If
672 		 * not, the MBus mapping via the 'ranges' property in the 'soc'
673 		 * node is not configured and this device should not use the
674 		 * direct mode. In this case, just continue with the next
675 		 * device.
676 		 */
677 		status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
678 		if (status)
679 			continue;
680 
681 		/*
682 		 * Only map one page for direct access. This is enough for the
683 		 * simple TX transfer which only writes to the first word.
684 		 * This needs to get extended for the direct SPI-NOR / SPI-NAND
685 		 * support, once this gets implemented.
686 		 */
687 		spi->direct_access[cs].vaddr = devm_ioremap(&pdev->dev,
688 							    r->start,
689 							    PAGE_SIZE);
690 		if (!spi->direct_access[cs].vaddr) {
691 			status = -ENOMEM;
692 			goto out_rel_clk;
693 		}
694 		spi->direct_access[cs].size = PAGE_SIZE;
695 
696 		dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
697 	}
698 
699 	pm_runtime_set_active(&pdev->dev);
700 	pm_runtime_use_autosuspend(&pdev->dev);
701 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
702 	pm_runtime_enable(&pdev->dev);
703 
704 	status = orion_spi_reset(spi);
705 	if (status < 0)
706 		goto out_rel_pm;
707 
708 	pm_runtime_mark_last_busy(&pdev->dev);
709 	pm_runtime_put_autosuspend(&pdev->dev);
710 
711 	master->dev.of_node = pdev->dev.of_node;
712 	status = spi_register_master(master);
713 	if (status < 0)
714 		goto out_rel_pm;
715 
716 	return status;
717 
718 out_rel_pm:
719 	pm_runtime_disable(&pdev->dev);
720 out_rel_clk:
721 	clk_disable_unprepare(spi->clk);
722 out:
723 	spi_master_put(master);
724 	return status;
725 }
726 
727 
728 static int orion_spi_remove(struct platform_device *pdev)
729 {
730 	struct spi_master *master = platform_get_drvdata(pdev);
731 	struct orion_spi *spi = spi_master_get_devdata(master);
732 
733 	pm_runtime_get_sync(&pdev->dev);
734 	clk_disable_unprepare(spi->clk);
735 
736 	spi_unregister_master(master);
737 	pm_runtime_disable(&pdev->dev);
738 
739 	return 0;
740 }
741 
742 MODULE_ALIAS("platform:" DRIVER_NAME);
743 
744 #ifdef CONFIG_PM
745 static int orion_spi_runtime_suspend(struct device *dev)
746 {
747 	struct spi_master *master = dev_get_drvdata(dev);
748 	struct orion_spi *spi = spi_master_get_devdata(master);
749 
750 	clk_disable_unprepare(spi->clk);
751 	return 0;
752 }
753 
754 static int orion_spi_runtime_resume(struct device *dev)
755 {
756 	struct spi_master *master = dev_get_drvdata(dev);
757 	struct orion_spi *spi = spi_master_get_devdata(master);
758 
759 	return clk_prepare_enable(spi->clk);
760 }
761 #endif
762 
763 static const struct dev_pm_ops orion_spi_pm_ops = {
764 	SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
765 			   orion_spi_runtime_resume,
766 			   NULL)
767 };
768 
769 static struct platform_driver orion_spi_driver = {
770 	.driver = {
771 		.name	= DRIVER_NAME,
772 		.pm	= &orion_spi_pm_ops,
773 		.of_match_table = of_match_ptr(orion_spi_of_match_table),
774 	},
775 	.probe		= orion_spi_probe,
776 	.remove		= orion_spi_remove,
777 };
778 
779 module_platform_driver(orion_spi_driver);
780 
781 MODULE_DESCRIPTION("Orion SPI driver");
782 MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
783 MODULE_LICENSE("GPL");
784