xref: /openbmc/linux/drivers/spi/spi-orion.c (revision d2ba09c1)
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 <linux/gpio.h>
26 #include <asm/unaligned.h>
27 
28 #define DRIVER_NAME			"orion_spi"
29 
30 /* Runtime PM autosuspend timeout: PM is fairly light on this driver */
31 #define SPI_AUTOSUSPEND_TIMEOUT		200
32 
33 /* Some SoCs using this driver support up to 8 chip selects.
34  * It is up to the implementer to only use the chip selects
35  * that are available.
36  */
37 #define ORION_NUM_CHIPSELECTS		8
38 
39 #define ORION_SPI_WAIT_RDY_MAX_LOOP	2000 /* in usec */
40 
41 #define ORION_SPI_IF_CTRL_REG		0x00
42 #define ORION_SPI_IF_CONFIG_REG		0x04
43 #define ORION_SPI_IF_RXLSBF		BIT(14)
44 #define ORION_SPI_IF_TXLSBF		BIT(13)
45 #define ORION_SPI_DATA_OUT_REG		0x08
46 #define ORION_SPI_DATA_IN_REG		0x0c
47 #define ORION_SPI_INT_CAUSE_REG		0x10
48 #define ORION_SPI_TIMING_PARAMS_REG	0x18
49 
50 /* Register for the "Direct Mode" */
51 #define SPI_DIRECT_WRITE_CONFIG_REG	0x20
52 
53 #define ORION_SPI_TMISO_SAMPLE_MASK	(0x3 << 6)
54 #define ORION_SPI_TMISO_SAMPLE_1	(1 << 6)
55 #define ORION_SPI_TMISO_SAMPLE_2	(2 << 6)
56 
57 #define ORION_SPI_MODE_CPOL		(1 << 11)
58 #define ORION_SPI_MODE_CPHA		(1 << 12)
59 #define ORION_SPI_IF_8_16_BIT_MODE	(1 << 5)
60 #define ORION_SPI_CLK_PRESCALE_MASK	0x1F
61 #define ARMADA_SPI_CLK_PRESCALE_MASK	0xDF
62 #define ORION_SPI_MODE_MASK		(ORION_SPI_MODE_CPOL | \
63 					 ORION_SPI_MODE_CPHA)
64 #define ORION_SPI_CS_MASK	0x1C
65 #define ORION_SPI_CS_SHIFT	2
66 #define ORION_SPI_CS(cs)	((cs << ORION_SPI_CS_SHIFT) & \
67 					ORION_SPI_CS_MASK)
68 
69 enum orion_spi_type {
70 	ORION_SPI,
71 	ARMADA_SPI,
72 };
73 
74 struct orion_spi_dev {
75 	enum orion_spi_type	typ;
76 	/*
77 	 * min_divisor and max_hz should be exclusive, the only we can
78 	 * have both is for managing the armada-370-spi case with old
79 	 * device tree
80 	 */
81 	unsigned long		max_hz;
82 	unsigned int		min_divisor;
83 	unsigned int		max_divisor;
84 	u32			prescale_mask;
85 	bool			is_errata_50mhz_ac;
86 };
87 
88 struct orion_direct_acc {
89 	void __iomem		*vaddr;
90 	u32			size;
91 };
92 
93 struct orion_child_options {
94 	struct orion_direct_acc direct_access;
95 };
96 
97 struct orion_spi {
98 	struct spi_master	*master;
99 	void __iomem		*base;
100 	struct clk              *clk;
101 	struct clk              *axi_clk;
102 	const struct orion_spi_dev *devdata;
103 	int			unused_hw_gpio;
104 
105 	struct orion_child_options	child[ORION_NUM_CHIPSELECTS];
106 };
107 
108 static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
109 {
110 	return orion_spi->base + reg;
111 }
112 
113 static inline void
114 orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
115 {
116 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
117 	u32 val;
118 
119 	val = readl(reg_addr);
120 	val |= mask;
121 	writel(val, reg_addr);
122 }
123 
124 static inline void
125 orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
126 {
127 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
128 	u32 val;
129 
130 	val = readl(reg_addr);
131 	val &= ~mask;
132 	writel(val, reg_addr);
133 }
134 
135 static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
136 {
137 	u32 tclk_hz;
138 	u32 rate;
139 	u32 prescale;
140 	u32 reg;
141 	struct orion_spi *orion_spi;
142 	const struct orion_spi_dev *devdata;
143 
144 	orion_spi = spi_master_get_devdata(spi->master);
145 	devdata = orion_spi->devdata;
146 
147 	tclk_hz = clk_get_rate(orion_spi->clk);
148 
149 	if (devdata->typ == ARMADA_SPI) {
150 		/*
151 		 * Given the core_clk (tclk_hz) and the target rate (speed) we
152 		 * determine the best values for SPR (in [0 .. 15]) and SPPR (in
153 		 * [0..7]) such that
154 		 *
155 		 * 	core_clk / (SPR * 2 ** SPPR)
156 		 *
157 		 * is as big as possible but not bigger than speed.
158 		 */
159 
160 		/* best integer divider: */
161 		unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
162 		unsigned spr, sppr;
163 
164 		if (divider < 16) {
165 			/* This is the easy case, divider is less than 16 */
166 			spr = divider;
167 			sppr = 0;
168 
169 		} else {
170 			unsigned two_pow_sppr;
171 			/*
172 			 * Find the highest bit set in divider. This and the
173 			 * three next bits define SPR (apart from rounding).
174 			 * SPPR is then the number of zero bits that must be
175 			 * appended:
176 			 */
177 			sppr = fls(divider) - 4;
178 
179 			/*
180 			 * As SPR only has 4 bits, we have to round divider up
181 			 * to the next multiple of 2 ** sppr.
182 			 */
183 			two_pow_sppr = 1 << sppr;
184 			divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
185 
186 			/*
187 			 * recalculate sppr as rounding up divider might have
188 			 * increased it enough to change the position of the
189 			 * highest set bit. In this case the bit that now
190 			 * doesn't make it into SPR is 0, so there is no need to
191 			 * round again.
192 			 */
193 			sppr = fls(divider) - 4;
194 			spr = divider >> sppr;
195 
196 			/*
197 			 * Now do range checking. SPR is constructed to have a
198 			 * width of 4 bits, so this is fine for sure. So we
199 			 * still need to check for sppr to fit into 3 bits:
200 			 */
201 			if (sppr > 7)
202 				return -EINVAL;
203 		}
204 
205 		prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
206 	} else {
207 		/*
208 		 * the supported rates are: 4,6,8...30
209 		 * round up as we look for equal or less speed
210 		 */
211 		rate = DIV_ROUND_UP(tclk_hz, speed);
212 		rate = roundup(rate, 2);
213 
214 		/* check if requested speed is too small */
215 		if (rate > 30)
216 			return -EINVAL;
217 
218 		if (rate < 4)
219 			rate = 4;
220 
221 		/* Convert the rate to SPI clock divisor value.	*/
222 		prescale = 0x10 + rate/2;
223 	}
224 
225 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
226 	reg = ((reg & ~devdata->prescale_mask) | prescale);
227 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
228 
229 	return 0;
230 }
231 
232 static void
233 orion_spi_mode_set(struct spi_device *spi)
234 {
235 	u32 reg;
236 	struct orion_spi *orion_spi;
237 
238 	orion_spi = spi_master_get_devdata(spi->master);
239 
240 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
241 	reg &= ~ORION_SPI_MODE_MASK;
242 	if (spi->mode & SPI_CPOL)
243 		reg |= ORION_SPI_MODE_CPOL;
244 	if (spi->mode & SPI_CPHA)
245 		reg |= ORION_SPI_MODE_CPHA;
246 	if (spi->mode & SPI_LSB_FIRST)
247 		reg |= ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF;
248 	else
249 		reg &= ~(ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF);
250 
251 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
252 }
253 
254 static void
255 orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
256 {
257 	u32 reg;
258 	struct orion_spi *orion_spi;
259 
260 	orion_spi = spi_master_get_devdata(spi->master);
261 
262 	/*
263 	 * Erratum description: (Erratum NO. FE-9144572) The device
264 	 * SPI interface supports frequencies of up to 50 MHz.
265 	 * However, due to this erratum, when the device core clock is
266 	 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
267 	 * clock and CPOL=CPHA=1 there might occur data corruption on
268 	 * reads from the SPI device.
269 	 * Erratum Workaround:
270 	 * Work in one of the following configurations:
271 	 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
272 	 * Register".
273 	 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
274 	 * Register" before setting the interface.
275 	 */
276 	reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
277 	reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
278 
279 	if (clk_get_rate(orion_spi->clk) == 250000000 &&
280 			speed == 50000000 && spi->mode & SPI_CPOL &&
281 			spi->mode & SPI_CPHA)
282 		reg |= ORION_SPI_TMISO_SAMPLE_2;
283 	else
284 		reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
285 
286 	writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
287 }
288 
289 /*
290  * called only when no transfer is active on the bus
291  */
292 static int
293 orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
294 {
295 	struct orion_spi *orion_spi;
296 	unsigned int speed = spi->max_speed_hz;
297 	unsigned int bits_per_word = spi->bits_per_word;
298 	int	rc;
299 
300 	orion_spi = spi_master_get_devdata(spi->master);
301 
302 	if ((t != NULL) && t->speed_hz)
303 		speed = t->speed_hz;
304 
305 	if ((t != NULL) && t->bits_per_word)
306 		bits_per_word = t->bits_per_word;
307 
308 	orion_spi_mode_set(spi);
309 
310 	if (orion_spi->devdata->is_errata_50mhz_ac)
311 		orion_spi_50mhz_ac_timing_erratum(spi, speed);
312 
313 	rc = orion_spi_baudrate_set(spi, speed);
314 	if (rc)
315 		return rc;
316 
317 	if (bits_per_word == 16)
318 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
319 				  ORION_SPI_IF_8_16_BIT_MODE);
320 	else
321 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
322 				  ORION_SPI_IF_8_16_BIT_MODE);
323 
324 	return 0;
325 }
326 
327 static void orion_spi_set_cs(struct spi_device *spi, bool enable)
328 {
329 	struct orion_spi *orion_spi;
330 	int cs;
331 
332 	orion_spi = spi_master_get_devdata(spi->master);
333 
334 	if (gpio_is_valid(spi->cs_gpio))
335 		cs = orion_spi->unused_hw_gpio;
336 	else
337 		cs = spi->chip_select;
338 
339 	orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
340 	orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
341 				ORION_SPI_CS(cs));
342 
343 	/* Chip select logic is inverted from spi_set_cs */
344 	if (!enable)
345 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
346 	else
347 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
348 }
349 
350 static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
351 {
352 	int i;
353 
354 	for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
355 		if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
356 			return 1;
357 
358 		udelay(1);
359 	}
360 
361 	return -1;
362 }
363 
364 static inline int
365 orion_spi_write_read_8bit(struct spi_device *spi,
366 			  const u8 **tx_buf, u8 **rx_buf)
367 {
368 	void __iomem *tx_reg, *rx_reg, *int_reg;
369 	struct orion_spi *orion_spi;
370 
371 	orion_spi = spi_master_get_devdata(spi->master);
372 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
373 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
374 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
375 
376 	/* clear the interrupt cause register */
377 	writel(0x0, int_reg);
378 
379 	if (tx_buf && *tx_buf)
380 		writel(*(*tx_buf)++, tx_reg);
381 	else
382 		writel(0, tx_reg);
383 
384 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
385 		dev_err(&spi->dev, "TXS timed out\n");
386 		return -1;
387 	}
388 
389 	if (rx_buf && *rx_buf)
390 		*(*rx_buf)++ = readl(rx_reg);
391 
392 	return 1;
393 }
394 
395 static inline int
396 orion_spi_write_read_16bit(struct spi_device *spi,
397 			   const u16 **tx_buf, u16 **rx_buf)
398 {
399 	void __iomem *tx_reg, *rx_reg, *int_reg;
400 	struct orion_spi *orion_spi;
401 
402 	orion_spi = spi_master_get_devdata(spi->master);
403 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
404 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
405 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
406 
407 	/* clear the interrupt cause register */
408 	writel(0x0, int_reg);
409 
410 	if (tx_buf && *tx_buf)
411 		writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
412 	else
413 		writel(0, tx_reg);
414 
415 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
416 		dev_err(&spi->dev, "TXS timed out\n");
417 		return -1;
418 	}
419 
420 	if (rx_buf && *rx_buf)
421 		put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
422 
423 	return 1;
424 }
425 
426 static unsigned int
427 orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
428 {
429 	unsigned int count;
430 	int word_len;
431 	struct orion_spi *orion_spi;
432 	int cs = spi->chip_select;
433 
434 	word_len = spi->bits_per_word;
435 	count = xfer->len;
436 
437 	orion_spi = spi_master_get_devdata(spi->master);
438 
439 	/*
440 	 * Use SPI direct write mode if base address is available. Otherwise
441 	 * fall back to PIO mode for this transfer.
442 	 */
443 	if ((orion_spi->child[cs].direct_access.vaddr) && (xfer->tx_buf) &&
444 	    (word_len == 8)) {
445 		unsigned int cnt = count / 4;
446 		unsigned int rem = count % 4;
447 
448 		/*
449 		 * Send the TX-data to the SPI device via the direct
450 		 * mapped address window
451 		 */
452 		iowrite32_rep(orion_spi->child[cs].direct_access.vaddr,
453 			      xfer->tx_buf, cnt);
454 		if (rem) {
455 			u32 *buf = (u32 *)xfer->tx_buf;
456 
457 			iowrite8_rep(orion_spi->child[cs].direct_access.vaddr,
458 				     &buf[cnt], rem);
459 		}
460 
461 		return count;
462 	}
463 
464 	if (word_len == 8) {
465 		const u8 *tx = xfer->tx_buf;
466 		u8 *rx = xfer->rx_buf;
467 
468 		do {
469 			if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
470 				goto out;
471 			count--;
472 		} while (count);
473 	} else if (word_len == 16) {
474 		const u16 *tx = xfer->tx_buf;
475 		u16 *rx = xfer->rx_buf;
476 
477 		do {
478 			if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
479 				goto out;
480 			count -= 2;
481 		} while (count);
482 	}
483 
484 out:
485 	return xfer->len - count;
486 }
487 
488 static int orion_spi_transfer_one(struct spi_master *master,
489 					struct spi_device *spi,
490 					struct spi_transfer *t)
491 {
492 	int status = 0;
493 
494 	status = orion_spi_setup_transfer(spi, t);
495 	if (status < 0)
496 		return status;
497 
498 	if (t->len)
499 		orion_spi_write_read(spi, t);
500 
501 	return status;
502 }
503 
504 static int orion_spi_setup(struct spi_device *spi)
505 {
506 	if (gpio_is_valid(spi->cs_gpio)) {
507 		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
508 	}
509 	return orion_spi_setup_transfer(spi, NULL);
510 }
511 
512 static int orion_spi_reset(struct orion_spi *orion_spi)
513 {
514 	/* Verify that the CS is deasserted */
515 	orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
516 
517 	/* Don't deassert CS between the direct mapped SPI transfers */
518 	writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG));
519 
520 	return 0;
521 }
522 
523 static const struct orion_spi_dev orion_spi_dev_data = {
524 	.typ = ORION_SPI,
525 	.min_divisor = 4,
526 	.max_divisor = 30,
527 	.prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
528 };
529 
530 static const struct orion_spi_dev armada_370_spi_dev_data = {
531 	.typ = ARMADA_SPI,
532 	.min_divisor = 4,
533 	.max_divisor = 1920,
534 	.max_hz = 50000000,
535 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
536 };
537 
538 static const struct orion_spi_dev armada_xp_spi_dev_data = {
539 	.typ = ARMADA_SPI,
540 	.max_hz = 50000000,
541 	.max_divisor = 1920,
542 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
543 };
544 
545 static const struct orion_spi_dev armada_375_spi_dev_data = {
546 	.typ = ARMADA_SPI,
547 	.min_divisor = 15,
548 	.max_divisor = 1920,
549 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
550 };
551 
552 static const struct orion_spi_dev armada_380_spi_dev_data = {
553 	.typ = ARMADA_SPI,
554 	.max_hz = 50000000,
555 	.max_divisor = 1920,
556 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
557 	.is_errata_50mhz_ac = true,
558 };
559 
560 static const struct of_device_id orion_spi_of_match_table[] = {
561 	{
562 		.compatible = "marvell,orion-spi",
563 		.data = &orion_spi_dev_data,
564 	},
565 	{
566 		.compatible = "marvell,armada-370-spi",
567 		.data = &armada_370_spi_dev_data,
568 	},
569 	{
570 		.compatible = "marvell,armada-375-spi",
571 		.data = &armada_375_spi_dev_data,
572 	},
573 	{
574 		.compatible = "marvell,armada-380-spi",
575 		.data = &armada_380_spi_dev_data,
576 	},
577 	{
578 		.compatible = "marvell,armada-390-spi",
579 		.data = &armada_xp_spi_dev_data,
580 	},
581 	{
582 		.compatible = "marvell,armada-xp-spi",
583 		.data = &armada_xp_spi_dev_data,
584 	},
585 
586 	{}
587 };
588 MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
589 
590 static int orion_spi_probe(struct platform_device *pdev)
591 {
592 	const struct of_device_id *of_id;
593 	const struct orion_spi_dev *devdata;
594 	struct spi_master *master;
595 	struct orion_spi *spi;
596 	struct resource *r;
597 	unsigned long tclk_hz;
598 	int status = 0;
599 	struct device_node *np;
600 
601 	master = spi_alloc_master(&pdev->dev, sizeof(*spi));
602 	if (master == NULL) {
603 		dev_dbg(&pdev->dev, "master allocation failed\n");
604 		return -ENOMEM;
605 	}
606 
607 	if (pdev->id != -1)
608 		master->bus_num = pdev->id;
609 	if (pdev->dev.of_node) {
610 		u32 cell_index;
611 
612 		if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
613 					  &cell_index))
614 			master->bus_num = cell_index;
615 	}
616 
617 	/* we support all 4 SPI modes and LSB first option */
618 	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;
619 	master->set_cs = orion_spi_set_cs;
620 	master->transfer_one = orion_spi_transfer_one;
621 	master->num_chipselect = ORION_NUM_CHIPSELECTS;
622 	master->setup = orion_spi_setup;
623 	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
624 	master->auto_runtime_pm = true;
625 	master->flags = SPI_MASTER_GPIO_SS;
626 
627 	platform_set_drvdata(pdev, master);
628 
629 	spi = spi_master_get_devdata(master);
630 	spi->master = master;
631 	spi->unused_hw_gpio = -1;
632 
633 	of_id = of_match_device(orion_spi_of_match_table, &pdev->dev);
634 	devdata = (of_id) ? of_id->data : &orion_spi_dev_data;
635 	spi->devdata = devdata;
636 
637 	spi->clk = devm_clk_get(&pdev->dev, NULL);
638 	if (IS_ERR(spi->clk)) {
639 		status = PTR_ERR(spi->clk);
640 		goto out;
641 	}
642 
643 	status = clk_prepare_enable(spi->clk);
644 	if (status)
645 		goto out;
646 
647 	/* The following clock is only used by some SoCs */
648 	spi->axi_clk = devm_clk_get(&pdev->dev, "axi");
649 	if (IS_ERR(spi->axi_clk) &&
650 	    PTR_ERR(spi->axi_clk) == -EPROBE_DEFER) {
651 		status = -EPROBE_DEFER;
652 		goto out_rel_clk;
653 	}
654 	if (!IS_ERR(spi->axi_clk))
655 		clk_prepare_enable(spi->axi_clk);
656 
657 	tclk_hz = clk_get_rate(spi->clk);
658 
659 	/*
660 	 * With old device tree, armada-370-spi could be used with
661 	 * Armada XP, however for this SoC the maximum frequency is
662 	 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
663 	 * higher than 200MHz. So, in order to be able to handle both
664 	 * SoCs, we can take the minimum of 50MHz and tclk/4.
665 	 */
666 	if (of_device_is_compatible(pdev->dev.of_node,
667 					"marvell,armada-370-spi"))
668 		master->max_speed_hz = min(devdata->max_hz,
669 				DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
670 	else if (devdata->min_divisor)
671 		master->max_speed_hz =
672 			DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
673 	else
674 		master->max_speed_hz = devdata->max_hz;
675 	master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
676 
677 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
678 	spi->base = devm_ioremap_resource(&pdev->dev, r);
679 	if (IS_ERR(spi->base)) {
680 		status = PTR_ERR(spi->base);
681 		goto out_rel_axi_clk;
682 	}
683 
684 	/* Scan all SPI devices of this controller for direct mapped devices */
685 	for_each_available_child_of_node(pdev->dev.of_node, np) {
686 		u32 cs;
687 
688 		/* Get chip-select number from the "reg" property */
689 		status = of_property_read_u32(np, "reg", &cs);
690 		if (status) {
691 			dev_err(&pdev->dev,
692 				"%pOF has no valid 'reg' property (%d)\n",
693 				np, status);
694 			continue;
695 		}
696 
697 		/*
698 		 * Check if an address is configured for this SPI device. If
699 		 * not, the MBus mapping via the 'ranges' property in the 'soc'
700 		 * node is not configured and this device should not use the
701 		 * direct mode. In this case, just continue with the next
702 		 * device.
703 		 */
704 		status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
705 		if (status)
706 			continue;
707 
708 		/*
709 		 * Only map one page for direct access. This is enough for the
710 		 * simple TX transfer which only writes to the first word.
711 		 * This needs to get extended for the direct SPI-NOR / SPI-NAND
712 		 * support, once this gets implemented.
713 		 */
714 		spi->child[cs].direct_access.vaddr = devm_ioremap(&pdev->dev,
715 							    r->start,
716 							    PAGE_SIZE);
717 		if (!spi->child[cs].direct_access.vaddr) {
718 			status = -ENOMEM;
719 			goto out_rel_axi_clk;
720 		}
721 		spi->child[cs].direct_access.size = PAGE_SIZE;
722 
723 		dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
724 	}
725 
726 	pm_runtime_set_active(&pdev->dev);
727 	pm_runtime_use_autosuspend(&pdev->dev);
728 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
729 	pm_runtime_enable(&pdev->dev);
730 
731 	status = orion_spi_reset(spi);
732 	if (status < 0)
733 		goto out_rel_pm;
734 
735 	pm_runtime_mark_last_busy(&pdev->dev);
736 	pm_runtime_put_autosuspend(&pdev->dev);
737 
738 	master->dev.of_node = pdev->dev.of_node;
739 	status = spi_register_master(master);
740 	if (status < 0)
741 		goto out_rel_pm;
742 
743 	if (master->cs_gpios) {
744 		int i;
745 		for (i = 0; i < master->num_chipselect; ++i) {
746 			char *gpio_name;
747 
748 			if (!gpio_is_valid(master->cs_gpios[i])) {
749 				continue;
750 			}
751 
752 			gpio_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
753 					"%s-CS%d", dev_name(&pdev->dev), i);
754 			if (!gpio_name) {
755 				status = -ENOMEM;
756 				goto out_rel_master;
757 			}
758 
759 			status = devm_gpio_request(&pdev->dev,
760 					master->cs_gpios[i], gpio_name);
761 			if (status) {
762 				dev_err(&pdev->dev,
763 					"Can't request GPIO for CS %d\n",
764 					master->cs_gpios[i]);
765 				goto out_rel_master;
766 			}
767 			if (spi->unused_hw_gpio == -1) {
768 				dev_info(&pdev->dev,
769 					"Selected unused HW CS#%d for any GPIO CSes\n",
770 					i);
771 				spi->unused_hw_gpio = i;
772 			}
773 		}
774 	}
775 
776 
777 	return status;
778 
779 out_rel_master:
780 	spi_unregister_master(master);
781 out_rel_pm:
782 	pm_runtime_disable(&pdev->dev);
783 out_rel_axi_clk:
784 	clk_disable_unprepare(spi->axi_clk);
785 out_rel_clk:
786 	clk_disable_unprepare(spi->clk);
787 out:
788 	spi_master_put(master);
789 	return status;
790 }
791 
792 
793 static int orion_spi_remove(struct platform_device *pdev)
794 {
795 	struct spi_master *master = platform_get_drvdata(pdev);
796 	struct orion_spi *spi = spi_master_get_devdata(master);
797 
798 	pm_runtime_get_sync(&pdev->dev);
799 	clk_disable_unprepare(spi->axi_clk);
800 	clk_disable_unprepare(spi->clk);
801 
802 	spi_unregister_master(master);
803 	pm_runtime_disable(&pdev->dev);
804 
805 	return 0;
806 }
807 
808 MODULE_ALIAS("platform:" DRIVER_NAME);
809 
810 #ifdef CONFIG_PM
811 static int orion_spi_runtime_suspend(struct device *dev)
812 {
813 	struct spi_master *master = dev_get_drvdata(dev);
814 	struct orion_spi *spi = spi_master_get_devdata(master);
815 
816 	clk_disable_unprepare(spi->axi_clk);
817 	clk_disable_unprepare(spi->clk);
818 	return 0;
819 }
820 
821 static int orion_spi_runtime_resume(struct device *dev)
822 {
823 	struct spi_master *master = dev_get_drvdata(dev);
824 	struct orion_spi *spi = spi_master_get_devdata(master);
825 
826 	if (!IS_ERR(spi->axi_clk))
827 		clk_prepare_enable(spi->axi_clk);
828 	return clk_prepare_enable(spi->clk);
829 }
830 #endif
831 
832 static const struct dev_pm_ops orion_spi_pm_ops = {
833 	SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
834 			   orion_spi_runtime_resume,
835 			   NULL)
836 };
837 
838 static struct platform_driver orion_spi_driver = {
839 	.driver = {
840 		.name	= DRIVER_NAME,
841 		.pm	= &orion_spi_pm_ops,
842 		.of_match_table = of_match_ptr(orion_spi_of_match_table),
843 	},
844 	.probe		= orion_spi_probe,
845 	.remove		= orion_spi_remove,
846 };
847 
848 module_platform_driver(orion_spi_driver);
849 
850 MODULE_DESCRIPTION("Orion SPI driver");
851 MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
852 MODULE_LICENSE("GPL");
853