xref: /linux/drivers/spi/spi-orion.c (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Marvell Orion SPI controller driver
4  *
5  * Author: Shadi Ammouri <shadi@marvell.com>
6  * Copyright (C) 2007-2008 Marvell Ltd.
7  */
8 
9 #include <linux/interrupt.h>
10 #include <linux/delay.h>
11 #include <linux/platform_device.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/spi/spi.h>
15 #include <linux/module.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/of_device.h>
20 #include <linux/clk.h>
21 #include <linux/sizes.h>
22 #include <asm/unaligned.h>
23 
24 #define DRIVER_NAME			"orion_spi"
25 
26 /* Runtime PM autosuspend timeout: PM is fairly light on this driver */
27 #define SPI_AUTOSUSPEND_TIMEOUT		200
28 
29 /* Some SoCs using this driver support up to 8 chip selects.
30  * It is up to the implementer to only use the chip selects
31  * that are available.
32  */
33 #define ORION_NUM_CHIPSELECTS		8
34 
35 #define ORION_SPI_WAIT_RDY_MAX_LOOP	2000 /* in usec */
36 
37 #define ORION_SPI_IF_CTRL_REG		0x00
38 #define ORION_SPI_IF_CONFIG_REG		0x04
39 #define ORION_SPI_IF_RXLSBF		BIT(14)
40 #define ORION_SPI_IF_TXLSBF		BIT(13)
41 #define ORION_SPI_DATA_OUT_REG		0x08
42 #define ORION_SPI_DATA_IN_REG		0x0c
43 #define ORION_SPI_INT_CAUSE_REG		0x10
44 #define ORION_SPI_TIMING_PARAMS_REG	0x18
45 
46 /* Register for the "Direct Mode" */
47 #define SPI_DIRECT_WRITE_CONFIG_REG	0x20
48 
49 #define ORION_SPI_TMISO_SAMPLE_MASK	(0x3 << 6)
50 #define ORION_SPI_TMISO_SAMPLE_1	(1 << 6)
51 #define ORION_SPI_TMISO_SAMPLE_2	(2 << 6)
52 
53 #define ORION_SPI_MODE_CPOL		(1 << 11)
54 #define ORION_SPI_MODE_CPHA		(1 << 12)
55 #define ORION_SPI_IF_8_16_BIT_MODE	(1 << 5)
56 #define ORION_SPI_CLK_PRESCALE_MASK	0x1F
57 #define ARMADA_SPI_CLK_PRESCALE_MASK	0xDF
58 #define ORION_SPI_MODE_MASK		(ORION_SPI_MODE_CPOL | \
59 					 ORION_SPI_MODE_CPHA)
60 #define ORION_SPI_CS_MASK	0x1C
61 #define ORION_SPI_CS_SHIFT	2
62 #define ORION_SPI_CS(cs)	((cs << ORION_SPI_CS_SHIFT) & \
63 					ORION_SPI_CS_MASK)
64 
65 enum orion_spi_type {
66 	ORION_SPI,
67 	ARMADA_SPI,
68 };
69 
70 struct orion_spi_dev {
71 	enum orion_spi_type	typ;
72 	/*
73 	 * min_divisor and max_hz should be exclusive, the only we can
74 	 * have both is for managing the armada-370-spi case with old
75 	 * device tree
76 	 */
77 	unsigned long		max_hz;
78 	unsigned int		min_divisor;
79 	unsigned int		max_divisor;
80 	u32			prescale_mask;
81 	bool			is_errata_50mhz_ac;
82 };
83 
84 struct orion_direct_acc {
85 	void __iomem		*vaddr;
86 	u32			size;
87 };
88 
89 struct orion_child_options {
90 	struct orion_direct_acc direct_access;
91 };
92 
93 struct orion_spi {
94 	struct spi_master	*master;
95 	void __iomem		*base;
96 	struct clk              *clk;
97 	struct clk              *axi_clk;
98 	const struct orion_spi_dev *devdata;
99 	struct device		*dev;
100 
101 	struct orion_child_options	child[ORION_NUM_CHIPSELECTS];
102 };
103 
104 #ifdef CONFIG_PM
105 static int orion_spi_runtime_suspend(struct device *dev);
106 static int orion_spi_runtime_resume(struct device *dev);
107 #endif
108 
109 static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
110 {
111 	return orion_spi->base + reg;
112 }
113 
114 static inline void
115 orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
116 {
117 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
118 	u32 val;
119 
120 	val = readl(reg_addr);
121 	val |= mask;
122 	writel(val, reg_addr);
123 }
124 
125 static inline void
126 orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
127 {
128 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
129 	u32 val;
130 
131 	val = readl(reg_addr);
132 	val &= ~mask;
133 	writel(val, reg_addr);
134 }
135 
136 static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
137 {
138 	u32 tclk_hz;
139 	u32 rate;
140 	u32 prescale;
141 	u32 reg;
142 	struct orion_spi *orion_spi;
143 	const struct orion_spi_dev *devdata;
144 
145 	orion_spi = spi_master_get_devdata(spi->master);
146 	devdata = orion_spi->devdata;
147 
148 	tclk_hz = clk_get_rate(orion_spi->clk);
149 
150 	if (devdata->typ == ARMADA_SPI) {
151 		/*
152 		 * Given the core_clk (tclk_hz) and the target rate (speed) we
153 		 * determine the best values for SPR (in [0 .. 15]) and SPPR (in
154 		 * [0..7]) such that
155 		 *
156 		 * 	core_clk / (SPR * 2 ** SPPR)
157 		 *
158 		 * is as big as possible but not bigger than speed.
159 		 */
160 
161 		/* best integer divider: */
162 		unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
163 		unsigned spr, sppr;
164 
165 		if (divider < 16) {
166 			/* This is the easy case, divider is less than 16 */
167 			spr = divider;
168 			sppr = 0;
169 
170 		} else {
171 			unsigned two_pow_sppr;
172 			/*
173 			 * Find the highest bit set in divider. This and the
174 			 * three next bits define SPR (apart from rounding).
175 			 * SPPR is then the number of zero bits that must be
176 			 * appended:
177 			 */
178 			sppr = fls(divider) - 4;
179 
180 			/*
181 			 * As SPR only has 4 bits, we have to round divider up
182 			 * to the next multiple of 2 ** sppr.
183 			 */
184 			two_pow_sppr = 1 << sppr;
185 			divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
186 
187 			/*
188 			 * recalculate sppr as rounding up divider might have
189 			 * increased it enough to change the position of the
190 			 * highest set bit. In this case the bit that now
191 			 * doesn't make it into SPR is 0, so there is no need to
192 			 * round again.
193 			 */
194 			sppr = fls(divider) - 4;
195 			spr = divider >> sppr;
196 
197 			/*
198 			 * Now do range checking. SPR is constructed to have a
199 			 * width of 4 bits, so this is fine for sure. So we
200 			 * still need to check for sppr to fit into 3 bits:
201 			 */
202 			if (sppr > 7)
203 				return -EINVAL;
204 		}
205 
206 		prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
207 	} else {
208 		/*
209 		 * the supported rates are: 4,6,8...30
210 		 * round up as we look for equal or less speed
211 		 */
212 		rate = DIV_ROUND_UP(tclk_hz, speed);
213 		rate = roundup(rate, 2);
214 
215 		/* check if requested speed is too small */
216 		if (rate > 30)
217 			return -EINVAL;
218 
219 		if (rate < 4)
220 			rate = 4;
221 
222 		/* Convert the rate to SPI clock divisor value.	*/
223 		prescale = 0x10 + rate/2;
224 	}
225 
226 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
227 	reg = ((reg & ~devdata->prescale_mask) | prescale);
228 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
229 
230 	return 0;
231 }
232 
233 static void
234 orion_spi_mode_set(struct spi_device *spi)
235 {
236 	u32 reg;
237 	struct orion_spi *orion_spi;
238 
239 	orion_spi = spi_master_get_devdata(spi->master);
240 
241 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
242 	reg &= ~ORION_SPI_MODE_MASK;
243 	if (spi->mode & SPI_CPOL)
244 		reg |= ORION_SPI_MODE_CPOL;
245 	if (spi->mode & SPI_CPHA)
246 		reg |= ORION_SPI_MODE_CPHA;
247 	if (spi->mode & SPI_LSB_FIRST)
248 		reg |= ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF;
249 	else
250 		reg &= ~(ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF);
251 
252 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
253 }
254 
255 static void
256 orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
257 {
258 	u32 reg;
259 	struct orion_spi *orion_spi;
260 
261 	orion_spi = spi_master_get_devdata(spi->master);
262 
263 	/*
264 	 * Erratum description: (Erratum NO. FE-9144572) The device
265 	 * SPI interface supports frequencies of up to 50 MHz.
266 	 * However, due to this erratum, when the device core clock is
267 	 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
268 	 * clock and CPOL=CPHA=1 there might occur data corruption on
269 	 * reads from the SPI device.
270 	 * Erratum Workaround:
271 	 * Work in one of the following configurations:
272 	 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
273 	 * Register".
274 	 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
275 	 * Register" before setting the interface.
276 	 */
277 	reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
278 	reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
279 
280 	if (clk_get_rate(orion_spi->clk) == 250000000 &&
281 			speed == 50000000 && spi->mode & SPI_CPOL &&
282 			spi->mode & SPI_CPHA)
283 		reg |= ORION_SPI_TMISO_SAMPLE_2;
284 	else
285 		reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
286 
287 	writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
288 }
289 
290 /*
291  * called only when no transfer is active on the bus
292  */
293 static int
294 orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
295 {
296 	struct orion_spi *orion_spi;
297 	unsigned int speed = spi->max_speed_hz;
298 	unsigned int bits_per_word = spi->bits_per_word;
299 	int	rc;
300 
301 	orion_spi = spi_master_get_devdata(spi->master);
302 
303 	if ((t != NULL) && t->speed_hz)
304 		speed = t->speed_hz;
305 
306 	if ((t != NULL) && t->bits_per_word)
307 		bits_per_word = t->bits_per_word;
308 
309 	orion_spi_mode_set(spi);
310 
311 	if (orion_spi->devdata->is_errata_50mhz_ac)
312 		orion_spi_50mhz_ac_timing_erratum(spi, speed);
313 
314 	rc = orion_spi_baudrate_set(spi, speed);
315 	if (rc)
316 		return rc;
317 
318 	if (bits_per_word == 16)
319 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
320 				  ORION_SPI_IF_8_16_BIT_MODE);
321 	else
322 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
323 				  ORION_SPI_IF_8_16_BIT_MODE);
324 
325 	return 0;
326 }
327 
328 static void orion_spi_set_cs(struct spi_device *spi, bool enable)
329 {
330 	struct orion_spi *orion_spi;
331 	void __iomem *ctrl_reg;
332 	u32 val;
333 
334 	orion_spi = spi_master_get_devdata(spi->master);
335 	ctrl_reg = spi_reg(orion_spi, ORION_SPI_IF_CTRL_REG);
336 
337 	val = readl(ctrl_reg);
338 
339 	/* Clear existing chip-select and assertion state */
340 	val &= ~(ORION_SPI_CS_MASK | 0x1);
341 
342 	/*
343 	 * If this line is using a GPIO to control chip select, this internal
344 	 * .set_cs() function will still be called, so we clear any previous
345 	 * chip select. The CS we activate will not have any elecrical effect,
346 	 * as it is handled by a GPIO, but that doesn't matter. What we need
347 	 * is to deassert the old chip select and assert some other chip select.
348 	 */
349 	val |= ORION_SPI_CS(spi->chip_select);
350 
351 	/*
352 	 * Chip select logic is inverted from spi_set_cs(). For lines using a
353 	 * GPIO to do chip select SPI_CS_HIGH is enforced and inversion happens
354 	 * in the GPIO library, but we don't care about that, because in those
355 	 * cases we are dealing with an unused native CS anyways so the polarity
356 	 * doesn't matter.
357 	 */
358 	if (!enable)
359 		val |= 0x1;
360 
361 	/*
362 	 * To avoid toggling unwanted chip selects update the register
363 	 * with a single write.
364 	 */
365 	writel(val, ctrl_reg);
366 }
367 
368 static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
369 {
370 	int i;
371 
372 	for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
373 		if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
374 			return 1;
375 
376 		udelay(1);
377 	}
378 
379 	return -1;
380 }
381 
382 static inline int
383 orion_spi_write_read_8bit(struct spi_device *spi,
384 			  const u8 **tx_buf, u8 **rx_buf)
385 {
386 	void __iomem *tx_reg, *rx_reg, *int_reg;
387 	struct orion_spi *orion_spi;
388 	bool cs_single_byte;
389 
390 	cs_single_byte = spi->mode & SPI_CS_WORD;
391 
392 	orion_spi = spi_master_get_devdata(spi->master);
393 
394 	if (cs_single_byte)
395 		orion_spi_set_cs(spi, 0);
396 
397 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
398 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
399 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
400 
401 	/* clear the interrupt cause register */
402 	writel(0x0, int_reg);
403 
404 	if (tx_buf && *tx_buf)
405 		writel(*(*tx_buf)++, tx_reg);
406 	else
407 		writel(0, tx_reg);
408 
409 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
410 		if (cs_single_byte) {
411 			orion_spi_set_cs(spi, 1);
412 			/* Satisfy some SLIC devices requirements */
413 			udelay(4);
414 		}
415 		dev_err(&spi->dev, "TXS timed out\n");
416 		return -1;
417 	}
418 
419 	if (rx_buf && *rx_buf)
420 		*(*rx_buf)++ = readl(rx_reg);
421 
422 	if (cs_single_byte) {
423 		orion_spi_set_cs(spi, 1);
424 		/* Satisfy some SLIC devices requirements */
425 		udelay(4);
426 	}
427 
428 	return 1;
429 }
430 
431 static inline int
432 orion_spi_write_read_16bit(struct spi_device *spi,
433 			   const u16 **tx_buf, u16 **rx_buf)
434 {
435 	void __iomem *tx_reg, *rx_reg, *int_reg;
436 	struct orion_spi *orion_spi;
437 
438 	if (spi->mode & SPI_CS_WORD) {
439 		dev_err(&spi->dev, "SPI_CS_WORD is only supported for 8 bit words\n");
440 		return -1;
441 	}
442 
443 	orion_spi = spi_master_get_devdata(spi->master);
444 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
445 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
446 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
447 
448 	/* clear the interrupt cause register */
449 	writel(0x0, int_reg);
450 
451 	if (tx_buf && *tx_buf)
452 		writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
453 	else
454 		writel(0, tx_reg);
455 
456 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
457 		dev_err(&spi->dev, "TXS timed out\n");
458 		return -1;
459 	}
460 
461 	if (rx_buf && *rx_buf)
462 		put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
463 
464 	return 1;
465 }
466 
467 static unsigned int
468 orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
469 {
470 	unsigned int count;
471 	int word_len;
472 	struct orion_spi *orion_spi;
473 	int cs = spi->chip_select;
474 	void __iomem *vaddr;
475 
476 	word_len = spi->bits_per_word;
477 	count = xfer->len;
478 
479 	orion_spi = spi_master_get_devdata(spi->master);
480 
481 	/*
482 	 * Use SPI direct write mode if base address is available
483 	 * and SPI_CS_WORD flag is not set.
484 	 * Otherwise fall back to PIO mode for this transfer.
485 	 */
486 	vaddr = orion_spi->child[cs].direct_access.vaddr;
487 
488 	if (vaddr && xfer->tx_buf && word_len == 8 && (spi->mode & SPI_CS_WORD) == 0) {
489 		unsigned int cnt = count / 4;
490 		unsigned int rem = count % 4;
491 
492 		/*
493 		 * Send the TX-data to the SPI device via the direct
494 		 * mapped address window
495 		 */
496 		iowrite32_rep(vaddr, xfer->tx_buf, cnt);
497 		if (rem) {
498 			u32 *buf = (u32 *)xfer->tx_buf;
499 
500 			iowrite8_rep(vaddr, &buf[cnt], rem);
501 		}
502 
503 		return count;
504 	}
505 
506 	if (word_len == 8) {
507 		const u8 *tx = xfer->tx_buf;
508 		u8 *rx = xfer->rx_buf;
509 
510 		do {
511 			if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
512 				goto out;
513 			count--;
514 			spi_delay_exec(&xfer->word_delay, xfer);
515 		} while (count);
516 	} else if (word_len == 16) {
517 		const u16 *tx = xfer->tx_buf;
518 		u16 *rx = xfer->rx_buf;
519 
520 		do {
521 			if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
522 				goto out;
523 			count -= 2;
524 			spi_delay_exec(&xfer->word_delay, xfer);
525 		} while (count);
526 	}
527 
528 out:
529 	return xfer->len - count;
530 }
531 
532 static int orion_spi_transfer_one(struct spi_master *master,
533 					struct spi_device *spi,
534 					struct spi_transfer *t)
535 {
536 	int status = 0;
537 
538 	status = orion_spi_setup_transfer(spi, t);
539 	if (status < 0)
540 		return status;
541 
542 	if (t->len)
543 		orion_spi_write_read(spi, t);
544 
545 	return status;
546 }
547 
548 static int orion_spi_setup(struct spi_device *spi)
549 {
550 	int ret;
551 #ifdef CONFIG_PM
552 	struct orion_spi *orion_spi = spi_master_get_devdata(spi->master);
553 	struct device *dev = orion_spi->dev;
554 
555 	orion_spi_runtime_resume(dev);
556 #endif
557 
558 	ret = orion_spi_setup_transfer(spi, NULL);
559 
560 #ifdef CONFIG_PM
561 	orion_spi_runtime_suspend(dev);
562 #endif
563 
564 	return ret;
565 }
566 
567 static int orion_spi_reset(struct orion_spi *orion_spi)
568 {
569 	/* Verify that the CS is deasserted */
570 	orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
571 
572 	/* Don't deassert CS between the direct mapped SPI transfers */
573 	writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG));
574 
575 	return 0;
576 }
577 
578 static const struct orion_spi_dev orion_spi_dev_data = {
579 	.typ = ORION_SPI,
580 	.min_divisor = 4,
581 	.max_divisor = 30,
582 	.prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
583 };
584 
585 static const struct orion_spi_dev armada_370_spi_dev_data = {
586 	.typ = ARMADA_SPI,
587 	.min_divisor = 4,
588 	.max_divisor = 1920,
589 	.max_hz = 50000000,
590 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
591 };
592 
593 static const struct orion_spi_dev armada_xp_spi_dev_data = {
594 	.typ = ARMADA_SPI,
595 	.max_hz = 50000000,
596 	.max_divisor = 1920,
597 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
598 };
599 
600 static const struct orion_spi_dev armada_375_spi_dev_data = {
601 	.typ = ARMADA_SPI,
602 	.min_divisor = 15,
603 	.max_divisor = 1920,
604 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
605 };
606 
607 static const struct orion_spi_dev armada_380_spi_dev_data = {
608 	.typ = ARMADA_SPI,
609 	.max_hz = 50000000,
610 	.max_divisor = 1920,
611 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
612 	.is_errata_50mhz_ac = true,
613 };
614 
615 static const struct of_device_id orion_spi_of_match_table[] = {
616 	{
617 		.compatible = "marvell,orion-spi",
618 		.data = &orion_spi_dev_data,
619 	},
620 	{
621 		.compatible = "marvell,armada-370-spi",
622 		.data = &armada_370_spi_dev_data,
623 	},
624 	{
625 		.compatible = "marvell,armada-375-spi",
626 		.data = &armada_375_spi_dev_data,
627 	},
628 	{
629 		.compatible = "marvell,armada-380-spi",
630 		.data = &armada_380_spi_dev_data,
631 	},
632 	{
633 		.compatible = "marvell,armada-390-spi",
634 		.data = &armada_xp_spi_dev_data,
635 	},
636 	{
637 		.compatible = "marvell,armada-xp-spi",
638 		.data = &armada_xp_spi_dev_data,
639 	},
640 
641 	{}
642 };
643 MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
644 
645 static int orion_spi_probe(struct platform_device *pdev)
646 {
647 	const struct orion_spi_dev *devdata;
648 	struct spi_master *master;
649 	struct orion_spi *spi;
650 	struct resource *r;
651 	unsigned long tclk_hz;
652 	int status = 0;
653 	struct device_node *np;
654 
655 	master = spi_alloc_master(&pdev->dev, sizeof(*spi));
656 	if (master == NULL) {
657 		dev_dbg(&pdev->dev, "master allocation failed\n");
658 		return -ENOMEM;
659 	}
660 
661 	if (pdev->id != -1)
662 		master->bus_num = pdev->id;
663 	if (pdev->dev.of_node) {
664 		u32 cell_index;
665 
666 		if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
667 					  &cell_index))
668 			master->bus_num = cell_index;
669 	}
670 
671 	/* we support all 4 SPI modes and LSB first option */
672 	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST | SPI_CS_WORD;
673 	master->set_cs = orion_spi_set_cs;
674 	master->transfer_one = orion_spi_transfer_one;
675 	master->num_chipselect = ORION_NUM_CHIPSELECTS;
676 	master->setup = orion_spi_setup;
677 	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
678 	master->auto_runtime_pm = true;
679 	master->use_gpio_descriptors = true;
680 	master->flags = SPI_MASTER_GPIO_SS;
681 
682 	platform_set_drvdata(pdev, master);
683 
684 	spi = spi_master_get_devdata(master);
685 	spi->master = master;
686 	spi->dev = &pdev->dev;
687 
688 	devdata = device_get_match_data(&pdev->dev);
689 	devdata = devdata ? devdata : &orion_spi_dev_data;
690 	spi->devdata = devdata;
691 
692 	spi->clk = devm_clk_get(&pdev->dev, NULL);
693 	if (IS_ERR(spi->clk)) {
694 		status = PTR_ERR(spi->clk);
695 		goto out;
696 	}
697 
698 	status = clk_prepare_enable(spi->clk);
699 	if (status)
700 		goto out;
701 
702 	/* The following clock is only used by some SoCs */
703 	spi->axi_clk = devm_clk_get(&pdev->dev, "axi");
704 	if (PTR_ERR(spi->axi_clk) == -EPROBE_DEFER) {
705 		status = -EPROBE_DEFER;
706 		goto out_rel_clk;
707 	}
708 	if (!IS_ERR(spi->axi_clk))
709 		clk_prepare_enable(spi->axi_clk);
710 
711 	tclk_hz = clk_get_rate(spi->clk);
712 
713 	/*
714 	 * With old device tree, armada-370-spi could be used with
715 	 * Armada XP, however for this SoC the maximum frequency is
716 	 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
717 	 * higher than 200MHz. So, in order to be able to handle both
718 	 * SoCs, we can take the minimum of 50MHz and tclk/4.
719 	 */
720 	if (of_device_is_compatible(pdev->dev.of_node,
721 					"marvell,armada-370-spi"))
722 		master->max_speed_hz = min(devdata->max_hz,
723 				DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
724 	else if (devdata->min_divisor)
725 		master->max_speed_hz =
726 			DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
727 	else
728 		master->max_speed_hz = devdata->max_hz;
729 	master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
730 
731 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
732 	spi->base = devm_ioremap_resource(&pdev->dev, r);
733 	if (IS_ERR(spi->base)) {
734 		status = PTR_ERR(spi->base);
735 		goto out_rel_axi_clk;
736 	}
737 
738 	for_each_available_child_of_node(pdev->dev.of_node, np) {
739 		struct orion_direct_acc *dir_acc;
740 		u32 cs;
741 
742 		/* Get chip-select number from the "reg" property */
743 		status = of_property_read_u32(np, "reg", &cs);
744 		if (status) {
745 			dev_err(&pdev->dev,
746 				"%pOF has no valid 'reg' property (%d)\n",
747 				np, status);
748 			continue;
749 		}
750 
751 		/*
752 		 * Check if an address is configured for this SPI device. If
753 		 * not, the MBus mapping via the 'ranges' property in the 'soc'
754 		 * node is not configured and this device should not use the
755 		 * direct mode. In this case, just continue with the next
756 		 * device.
757 		 */
758 		status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
759 		if (status)
760 			continue;
761 
762 		/*
763 		 * Only map one page for direct access. This is enough for the
764 		 * simple TX transfer which only writes to the first word.
765 		 * This needs to get extended for the direct SPI NOR / SPI NAND
766 		 * support, once this gets implemented.
767 		 */
768 		dir_acc = &spi->child[cs].direct_access;
769 		dir_acc->vaddr = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
770 		if (!dir_acc->vaddr) {
771 			status = -ENOMEM;
772 			of_node_put(np);
773 			goto out_rel_axi_clk;
774 		}
775 		dir_acc->size = PAGE_SIZE;
776 
777 		dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
778 	}
779 
780 	pm_runtime_set_active(&pdev->dev);
781 	pm_runtime_use_autosuspend(&pdev->dev);
782 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
783 	pm_runtime_enable(&pdev->dev);
784 
785 	status = orion_spi_reset(spi);
786 	if (status < 0)
787 		goto out_rel_pm;
788 
789 	master->dev.of_node = pdev->dev.of_node;
790 	status = spi_register_master(master);
791 	if (status < 0)
792 		goto out_rel_pm;
793 
794 	return status;
795 
796 out_rel_pm:
797 	pm_runtime_disable(&pdev->dev);
798 out_rel_axi_clk:
799 	clk_disable_unprepare(spi->axi_clk);
800 out_rel_clk:
801 	clk_disable_unprepare(spi->clk);
802 out:
803 	spi_master_put(master);
804 	return status;
805 }
806 
807 
808 static int orion_spi_remove(struct platform_device *pdev)
809 {
810 	struct spi_master *master = platform_get_drvdata(pdev);
811 	struct orion_spi *spi = spi_master_get_devdata(master);
812 
813 	pm_runtime_get_sync(&pdev->dev);
814 	clk_disable_unprepare(spi->axi_clk);
815 	clk_disable_unprepare(spi->clk);
816 
817 	spi_unregister_master(master);
818 	pm_runtime_disable(&pdev->dev);
819 
820 	return 0;
821 }
822 
823 MODULE_ALIAS("platform:" DRIVER_NAME);
824 
825 #ifdef CONFIG_PM
826 static int orion_spi_runtime_suspend(struct device *dev)
827 {
828 	struct spi_master *master = dev_get_drvdata(dev);
829 	struct orion_spi *spi = spi_master_get_devdata(master);
830 
831 	clk_disable_unprepare(spi->axi_clk);
832 	clk_disable_unprepare(spi->clk);
833 	return 0;
834 }
835 
836 static int orion_spi_runtime_resume(struct device *dev)
837 {
838 	struct spi_master *master = dev_get_drvdata(dev);
839 	struct orion_spi *spi = spi_master_get_devdata(master);
840 
841 	if (!IS_ERR(spi->axi_clk))
842 		clk_prepare_enable(spi->axi_clk);
843 	return clk_prepare_enable(spi->clk);
844 }
845 #endif
846 
847 static const struct dev_pm_ops orion_spi_pm_ops = {
848 	SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
849 			   orion_spi_runtime_resume,
850 			   NULL)
851 };
852 
853 static struct platform_driver orion_spi_driver = {
854 	.driver = {
855 		.name	= DRIVER_NAME,
856 		.pm	= &orion_spi_pm_ops,
857 		.of_match_table = of_match_ptr(orion_spi_of_match_table),
858 	},
859 	.probe		= orion_spi_probe,
860 	.remove		= orion_spi_remove,
861 };
862 
863 module_platform_driver(orion_spi_driver);
864 
865 MODULE_DESCRIPTION("Orion SPI driver");
866 MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
867 MODULE_LICENSE("GPL");
868