xref: /openbmc/linux/drivers/spi/spi-orion.c (revision e1cd7b80)
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/of_gpio.h>
21 #include <linux/clk.h>
22 #include <linux/sizes.h>
23 #include <linux/gpio.h>
24 #include <asm/unaligned.h>
25 
26 #define DRIVER_NAME			"orion_spi"
27 
28 /* Runtime PM autosuspend timeout: PM is fairly light on this driver */
29 #define SPI_AUTOSUSPEND_TIMEOUT		200
30 
31 /* Some SoCs using this driver support up to 8 chip selects.
32  * It is up to the implementer to only use the chip selects
33  * that are available.
34  */
35 #define ORION_NUM_CHIPSELECTS		8
36 
37 #define ORION_SPI_WAIT_RDY_MAX_LOOP	2000 /* in usec */
38 
39 #define ORION_SPI_IF_CTRL_REG		0x00
40 #define ORION_SPI_IF_CONFIG_REG		0x04
41 #define ORION_SPI_IF_RXLSBF		BIT(14)
42 #define ORION_SPI_IF_TXLSBF		BIT(13)
43 #define ORION_SPI_DATA_OUT_REG		0x08
44 #define ORION_SPI_DATA_IN_REG		0x0c
45 #define ORION_SPI_INT_CAUSE_REG		0x10
46 #define ORION_SPI_TIMING_PARAMS_REG	0x18
47 
48 /* Register for the "Direct Mode" */
49 #define SPI_DIRECT_WRITE_CONFIG_REG	0x20
50 
51 #define ORION_SPI_TMISO_SAMPLE_MASK	(0x3 << 6)
52 #define ORION_SPI_TMISO_SAMPLE_1	(1 << 6)
53 #define ORION_SPI_TMISO_SAMPLE_2	(2 << 6)
54 
55 #define ORION_SPI_MODE_CPOL		(1 << 11)
56 #define ORION_SPI_MODE_CPHA		(1 << 12)
57 #define ORION_SPI_IF_8_16_BIT_MODE	(1 << 5)
58 #define ORION_SPI_CLK_PRESCALE_MASK	0x1F
59 #define ARMADA_SPI_CLK_PRESCALE_MASK	0xDF
60 #define ORION_SPI_MODE_MASK		(ORION_SPI_MODE_CPOL | \
61 					 ORION_SPI_MODE_CPHA)
62 #define ORION_SPI_CS_MASK	0x1C
63 #define ORION_SPI_CS_SHIFT	2
64 #define ORION_SPI_CS(cs)	((cs << ORION_SPI_CS_SHIFT) & \
65 					ORION_SPI_CS_MASK)
66 
67 enum orion_spi_type {
68 	ORION_SPI,
69 	ARMADA_SPI,
70 };
71 
72 struct orion_spi_dev {
73 	enum orion_spi_type	typ;
74 	/*
75 	 * min_divisor and max_hz should be exclusive, the only we can
76 	 * have both is for managing the armada-370-spi case with old
77 	 * device tree
78 	 */
79 	unsigned long		max_hz;
80 	unsigned int		min_divisor;
81 	unsigned int		max_divisor;
82 	u32			prescale_mask;
83 	bool			is_errata_50mhz_ac;
84 };
85 
86 struct orion_direct_acc {
87 	void __iomem		*vaddr;
88 	u32			size;
89 };
90 
91 struct orion_child_options {
92 	struct orion_direct_acc direct_access;
93 };
94 
95 struct orion_spi {
96 	struct spi_master	*master;
97 	void __iomem		*base;
98 	struct clk              *clk;
99 	struct clk              *axi_clk;
100 	const struct orion_spi_dev *devdata;
101 	int			unused_hw_gpio;
102 
103 	struct orion_child_options	child[ORION_NUM_CHIPSELECTS];
104 };
105 
106 static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
107 {
108 	return orion_spi->base + reg;
109 }
110 
111 static inline void
112 orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
113 {
114 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
115 	u32 val;
116 
117 	val = readl(reg_addr);
118 	val |= mask;
119 	writel(val, reg_addr);
120 }
121 
122 static inline void
123 orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
124 {
125 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
126 	u32 val;
127 
128 	val = readl(reg_addr);
129 	val &= ~mask;
130 	writel(val, reg_addr);
131 }
132 
133 static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
134 {
135 	u32 tclk_hz;
136 	u32 rate;
137 	u32 prescale;
138 	u32 reg;
139 	struct orion_spi *orion_spi;
140 	const struct orion_spi_dev *devdata;
141 
142 	orion_spi = spi_master_get_devdata(spi->master);
143 	devdata = orion_spi->devdata;
144 
145 	tclk_hz = clk_get_rate(orion_spi->clk);
146 
147 	if (devdata->typ == ARMADA_SPI) {
148 		/*
149 		 * Given the core_clk (tclk_hz) and the target rate (speed) we
150 		 * determine the best values for SPR (in [0 .. 15]) and SPPR (in
151 		 * [0..7]) such that
152 		 *
153 		 * 	core_clk / (SPR * 2 ** SPPR)
154 		 *
155 		 * is as big as possible but not bigger than speed.
156 		 */
157 
158 		/* best integer divider: */
159 		unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
160 		unsigned spr, sppr;
161 
162 		if (divider < 16) {
163 			/* This is the easy case, divider is less than 16 */
164 			spr = divider;
165 			sppr = 0;
166 
167 		} else {
168 			unsigned two_pow_sppr;
169 			/*
170 			 * Find the highest bit set in divider. This and the
171 			 * three next bits define SPR (apart from rounding).
172 			 * SPPR is then the number of zero bits that must be
173 			 * appended:
174 			 */
175 			sppr = fls(divider) - 4;
176 
177 			/*
178 			 * As SPR only has 4 bits, we have to round divider up
179 			 * to the next multiple of 2 ** sppr.
180 			 */
181 			two_pow_sppr = 1 << sppr;
182 			divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
183 
184 			/*
185 			 * recalculate sppr as rounding up divider might have
186 			 * increased it enough to change the position of the
187 			 * highest set bit. In this case the bit that now
188 			 * doesn't make it into SPR is 0, so there is no need to
189 			 * round again.
190 			 */
191 			sppr = fls(divider) - 4;
192 			spr = divider >> sppr;
193 
194 			/*
195 			 * Now do range checking. SPR is constructed to have a
196 			 * width of 4 bits, so this is fine for sure. So we
197 			 * still need to check for sppr to fit into 3 bits:
198 			 */
199 			if (sppr > 7)
200 				return -EINVAL;
201 		}
202 
203 		prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
204 	} else {
205 		/*
206 		 * the supported rates are: 4,6,8...30
207 		 * round up as we look for equal or less speed
208 		 */
209 		rate = DIV_ROUND_UP(tclk_hz, speed);
210 		rate = roundup(rate, 2);
211 
212 		/* check if requested speed is too small */
213 		if (rate > 30)
214 			return -EINVAL;
215 
216 		if (rate < 4)
217 			rate = 4;
218 
219 		/* Convert the rate to SPI clock divisor value.	*/
220 		prescale = 0x10 + rate/2;
221 	}
222 
223 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
224 	reg = ((reg & ~devdata->prescale_mask) | prescale);
225 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
226 
227 	return 0;
228 }
229 
230 static void
231 orion_spi_mode_set(struct spi_device *spi)
232 {
233 	u32 reg;
234 	struct orion_spi *orion_spi;
235 
236 	orion_spi = spi_master_get_devdata(spi->master);
237 
238 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
239 	reg &= ~ORION_SPI_MODE_MASK;
240 	if (spi->mode & SPI_CPOL)
241 		reg |= ORION_SPI_MODE_CPOL;
242 	if (spi->mode & SPI_CPHA)
243 		reg |= ORION_SPI_MODE_CPHA;
244 	if (spi->mode & SPI_LSB_FIRST)
245 		reg |= ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF;
246 	else
247 		reg &= ~(ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF);
248 
249 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
250 }
251 
252 static void
253 orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
254 {
255 	u32 reg;
256 	struct orion_spi *orion_spi;
257 
258 	orion_spi = spi_master_get_devdata(spi->master);
259 
260 	/*
261 	 * Erratum description: (Erratum NO. FE-9144572) The device
262 	 * SPI interface supports frequencies of up to 50 MHz.
263 	 * However, due to this erratum, when the device core clock is
264 	 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
265 	 * clock and CPOL=CPHA=1 there might occur data corruption on
266 	 * reads from the SPI device.
267 	 * Erratum Workaround:
268 	 * Work in one of the following configurations:
269 	 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
270 	 * Register".
271 	 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
272 	 * Register" before setting the interface.
273 	 */
274 	reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
275 	reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
276 
277 	if (clk_get_rate(orion_spi->clk) == 250000000 &&
278 			speed == 50000000 && spi->mode & SPI_CPOL &&
279 			spi->mode & SPI_CPHA)
280 		reg |= ORION_SPI_TMISO_SAMPLE_2;
281 	else
282 		reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
283 
284 	writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
285 }
286 
287 /*
288  * called only when no transfer is active on the bus
289  */
290 static int
291 orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
292 {
293 	struct orion_spi *orion_spi;
294 	unsigned int speed = spi->max_speed_hz;
295 	unsigned int bits_per_word = spi->bits_per_word;
296 	int	rc;
297 
298 	orion_spi = spi_master_get_devdata(spi->master);
299 
300 	if ((t != NULL) && t->speed_hz)
301 		speed = t->speed_hz;
302 
303 	if ((t != NULL) && t->bits_per_word)
304 		bits_per_word = t->bits_per_word;
305 
306 	orion_spi_mode_set(spi);
307 
308 	if (orion_spi->devdata->is_errata_50mhz_ac)
309 		orion_spi_50mhz_ac_timing_erratum(spi, speed);
310 
311 	rc = orion_spi_baudrate_set(spi, speed);
312 	if (rc)
313 		return rc;
314 
315 	if (bits_per_word == 16)
316 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
317 				  ORION_SPI_IF_8_16_BIT_MODE);
318 	else
319 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
320 				  ORION_SPI_IF_8_16_BIT_MODE);
321 
322 	return 0;
323 }
324 
325 static void orion_spi_set_cs(struct spi_device *spi, bool enable)
326 {
327 	struct orion_spi *orion_spi;
328 	int cs;
329 
330 	orion_spi = spi_master_get_devdata(spi->master);
331 
332 	if (gpio_is_valid(spi->cs_gpio))
333 		cs = orion_spi->unused_hw_gpio;
334 	else
335 		cs = spi->chip_select;
336 
337 	orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
338 	orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
339 				ORION_SPI_CS(cs));
340 
341 	/* Chip select logic is inverted from spi_set_cs */
342 	if (!enable)
343 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
344 	else
345 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
346 }
347 
348 static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
349 {
350 	int i;
351 
352 	for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
353 		if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
354 			return 1;
355 
356 		udelay(1);
357 	}
358 
359 	return -1;
360 }
361 
362 static inline int
363 orion_spi_write_read_8bit(struct spi_device *spi,
364 			  const u8 **tx_buf, u8 **rx_buf)
365 {
366 	void __iomem *tx_reg, *rx_reg, *int_reg;
367 	struct orion_spi *orion_spi;
368 
369 	orion_spi = spi_master_get_devdata(spi->master);
370 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
371 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
372 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
373 
374 	/* clear the interrupt cause register */
375 	writel(0x0, int_reg);
376 
377 	if (tx_buf && *tx_buf)
378 		writel(*(*tx_buf)++, tx_reg);
379 	else
380 		writel(0, tx_reg);
381 
382 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
383 		dev_err(&spi->dev, "TXS timed out\n");
384 		return -1;
385 	}
386 
387 	if (rx_buf && *rx_buf)
388 		*(*rx_buf)++ = readl(rx_reg);
389 
390 	return 1;
391 }
392 
393 static inline int
394 orion_spi_write_read_16bit(struct spi_device *spi,
395 			   const u16 **tx_buf, u16 **rx_buf)
396 {
397 	void __iomem *tx_reg, *rx_reg, *int_reg;
398 	struct orion_spi *orion_spi;
399 
400 	orion_spi = spi_master_get_devdata(spi->master);
401 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
402 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
403 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
404 
405 	/* clear the interrupt cause register */
406 	writel(0x0, int_reg);
407 
408 	if (tx_buf && *tx_buf)
409 		writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
410 	else
411 		writel(0, tx_reg);
412 
413 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
414 		dev_err(&spi->dev, "TXS timed out\n");
415 		return -1;
416 	}
417 
418 	if (rx_buf && *rx_buf)
419 		put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
420 
421 	return 1;
422 }
423 
424 static unsigned int
425 orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
426 {
427 	unsigned int count;
428 	int word_len;
429 	struct orion_spi *orion_spi;
430 	int cs = spi->chip_select;
431 	void __iomem *vaddr;
432 
433 	word_len = spi->bits_per_word;
434 	count = xfer->len;
435 
436 	orion_spi = spi_master_get_devdata(spi->master);
437 
438 	/*
439 	 * Use SPI direct write mode if base address is available. Otherwise
440 	 * fall back to PIO mode for this transfer.
441 	 */
442 	vaddr = orion_spi->child[cs].direct_access.vaddr;
443 
444 	if (vaddr && xfer->tx_buf && 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(vaddr, xfer->tx_buf, cnt);
453 		if (rem) {
454 			u32 *buf = (u32 *)xfer->tx_buf;
455 
456 			iowrite8_rep(vaddr, &buf[cnt], rem);
457 		}
458 
459 		return count;
460 	}
461 
462 	if (word_len == 8) {
463 		const u8 *tx = xfer->tx_buf;
464 		u8 *rx = xfer->rx_buf;
465 
466 		do {
467 			if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
468 				goto out;
469 			count--;
470 			spi_delay_exec(&xfer->word_delay, xfer);
471 		} while (count);
472 	} else if (word_len == 16) {
473 		const u16 *tx = xfer->tx_buf;
474 		u16 *rx = xfer->rx_buf;
475 
476 		do {
477 			if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
478 				goto out;
479 			count -= 2;
480 			spi_delay_exec(&xfer->word_delay, xfer);
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 	for_each_available_child_of_node(pdev->dev.of_node, np) {
685 		struct orion_direct_acc *dir_acc;
686 		u32 cs;
687 		int cs_gpio;
688 
689 		/* Get chip-select number from the "reg" property */
690 		status = of_property_read_u32(np, "reg", &cs);
691 		if (status) {
692 			dev_err(&pdev->dev,
693 				"%pOF has no valid 'reg' property (%d)\n",
694 				np, status);
695 			continue;
696 		}
697 
698 		/*
699 		 * Initialize the CS GPIO:
700 		 * - properly request the actual GPIO signal
701 		 * - de-assert the logical signal so that all GPIO CS lines
702 		 *   are inactive when probing for slaves
703 		 * - find an unused physical CS which will be driven for any
704 		 *   slave which uses a CS GPIO
705 		 */
706 		cs_gpio = of_get_named_gpio(pdev->dev.of_node, "cs-gpios", cs);
707 		if (cs_gpio > 0) {
708 			char *gpio_name;
709 			int cs_flags;
710 
711 			if (spi->unused_hw_gpio == -1) {
712 				dev_info(&pdev->dev,
713 					"Selected unused HW CS#%d for any GPIO CSes\n",
714 					cs);
715 				spi->unused_hw_gpio = cs;
716 			}
717 
718 			gpio_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
719 					"%s-CS%d", dev_name(&pdev->dev), cs);
720 			if (!gpio_name) {
721 				status = -ENOMEM;
722 				goto out_rel_axi_clk;
723 			}
724 
725 			cs_flags = of_property_read_bool(np, "spi-cs-high") ?
726 				GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH;
727 			status = devm_gpio_request_one(&pdev->dev, cs_gpio,
728 					cs_flags, gpio_name);
729 			if (status) {
730 				dev_err(&pdev->dev,
731 					"Can't request GPIO for CS %d\n", cs);
732 				goto out_rel_axi_clk;
733 			}
734 		}
735 
736 		/*
737 		 * Check if an address is configured for this SPI device. If
738 		 * not, the MBus mapping via the 'ranges' property in the 'soc'
739 		 * node is not configured and this device should not use the
740 		 * direct mode. In this case, just continue with the next
741 		 * device.
742 		 */
743 		status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
744 		if (status)
745 			continue;
746 
747 		/*
748 		 * Only map one page for direct access. This is enough for the
749 		 * simple TX transfer which only writes to the first word.
750 		 * This needs to get extended for the direct SPI-NOR / SPI-NAND
751 		 * support, once this gets implemented.
752 		 */
753 		dir_acc = &spi->child[cs].direct_access;
754 		dir_acc->vaddr = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
755 		if (!dir_acc->vaddr) {
756 			status = -ENOMEM;
757 			goto out_rel_axi_clk;
758 		}
759 		dir_acc->size = PAGE_SIZE;
760 
761 		dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
762 	}
763 
764 	pm_runtime_set_active(&pdev->dev);
765 	pm_runtime_use_autosuspend(&pdev->dev);
766 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
767 	pm_runtime_enable(&pdev->dev);
768 
769 	status = orion_spi_reset(spi);
770 	if (status < 0)
771 		goto out_rel_pm;
772 
773 	master->dev.of_node = pdev->dev.of_node;
774 	status = spi_register_master(master);
775 	if (status < 0)
776 		goto out_rel_pm;
777 
778 	return status;
779 
780 out_rel_pm:
781 	pm_runtime_disable(&pdev->dev);
782 out_rel_axi_clk:
783 	clk_disable_unprepare(spi->axi_clk);
784 out_rel_clk:
785 	clk_disable_unprepare(spi->clk);
786 out:
787 	spi_master_put(master);
788 	return status;
789 }
790 
791 
792 static int orion_spi_remove(struct platform_device *pdev)
793 {
794 	struct spi_master *master = platform_get_drvdata(pdev);
795 	struct orion_spi *spi = spi_master_get_devdata(master);
796 
797 	pm_runtime_get_sync(&pdev->dev);
798 	clk_disable_unprepare(spi->axi_clk);
799 	clk_disable_unprepare(spi->clk);
800 
801 	spi_unregister_master(master);
802 	pm_runtime_disable(&pdev->dev);
803 
804 	return 0;
805 }
806 
807 MODULE_ALIAS("platform:" DRIVER_NAME);
808 
809 #ifdef CONFIG_PM
810 static int orion_spi_runtime_suspend(struct device *dev)
811 {
812 	struct spi_master *master = dev_get_drvdata(dev);
813 	struct orion_spi *spi = spi_master_get_devdata(master);
814 
815 	clk_disable_unprepare(spi->axi_clk);
816 	clk_disable_unprepare(spi->clk);
817 	return 0;
818 }
819 
820 static int orion_spi_runtime_resume(struct device *dev)
821 {
822 	struct spi_master *master = dev_get_drvdata(dev);
823 	struct orion_spi *spi = spi_master_get_devdata(master);
824 
825 	if (!IS_ERR(spi->axi_clk))
826 		clk_prepare_enable(spi->axi_clk);
827 	return clk_prepare_enable(spi->clk);
828 }
829 #endif
830 
831 static const struct dev_pm_ops orion_spi_pm_ops = {
832 	SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
833 			   orion_spi_runtime_resume,
834 			   NULL)
835 };
836 
837 static struct platform_driver orion_spi_driver = {
838 	.driver = {
839 		.name	= DRIVER_NAME,
840 		.pm	= &orion_spi_pm_ops,
841 		.of_match_table = of_match_ptr(orion_spi_of_match_table),
842 	},
843 	.probe		= orion_spi_probe,
844 	.remove		= orion_spi_remove,
845 };
846 
847 module_platform_driver(orion_spi_driver);
848 
849 MODULE_DESCRIPTION("Orion SPI driver");
850 MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
851 MODULE_LICENSE("GPL");
852