xref: /linux/drivers/spi/spi-orion.c (revision 109d59b900e78834c66657dd4748fcedb9a1fe8d)
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_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 
100 	struct orion_direct_acc	direct_access[ORION_NUM_CHIPSELECTS];
101 };
102 
103 static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
104 {
105 	return orion_spi->base + reg;
106 }
107 
108 static inline void
109 orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
110 {
111 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
112 	u32 val;
113 
114 	val = readl(reg_addr);
115 	val |= mask;
116 	writel(val, reg_addr);
117 }
118 
119 static inline void
120 orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
121 {
122 	void __iomem *reg_addr = spi_reg(orion_spi, reg);
123 	u32 val;
124 
125 	val = readl(reg_addr);
126 	val &= ~mask;
127 	writel(val, reg_addr);
128 }
129 
130 static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
131 {
132 	u32 tclk_hz;
133 	u32 rate;
134 	u32 prescale;
135 	u32 reg;
136 	struct orion_spi *orion_spi;
137 	const struct orion_spi_dev *devdata;
138 
139 	orion_spi = spi_master_get_devdata(spi->master);
140 	devdata = orion_spi->devdata;
141 
142 	tclk_hz = clk_get_rate(orion_spi->clk);
143 
144 	if (devdata->typ == ARMADA_SPI) {
145 		/*
146 		 * Given the core_clk (tclk_hz) and the target rate (speed) we
147 		 * determine the best values for SPR (in [0 .. 15]) and SPPR (in
148 		 * [0..7]) such that
149 		 *
150 		 * 	core_clk / (SPR * 2 ** SPPR)
151 		 *
152 		 * is as big as possible but not bigger than speed.
153 		 */
154 
155 		/* best integer divider: */
156 		unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
157 		unsigned spr, sppr;
158 
159 		if (divider < 16) {
160 			/* This is the easy case, divider is less than 16 */
161 			spr = divider;
162 			sppr = 0;
163 
164 		} else {
165 			unsigned two_pow_sppr;
166 			/*
167 			 * Find the highest bit set in divider. This and the
168 			 * three next bits define SPR (apart from rounding).
169 			 * SPPR is then the number of zero bits that must be
170 			 * appended:
171 			 */
172 			sppr = fls(divider) - 4;
173 
174 			/*
175 			 * As SPR only has 4 bits, we have to round divider up
176 			 * to the next multiple of 2 ** sppr.
177 			 */
178 			two_pow_sppr = 1 << sppr;
179 			divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
180 
181 			/*
182 			 * recalculate sppr as rounding up divider might have
183 			 * increased it enough to change the position of the
184 			 * highest set bit. In this case the bit that now
185 			 * doesn't make it into SPR is 0, so there is no need to
186 			 * round again.
187 			 */
188 			sppr = fls(divider) - 4;
189 			spr = divider >> sppr;
190 
191 			/*
192 			 * Now do range checking. SPR is constructed to have a
193 			 * width of 4 bits, so this is fine for sure. So we
194 			 * still need to check for sppr to fit into 3 bits:
195 			 */
196 			if (sppr > 7)
197 				return -EINVAL;
198 		}
199 
200 		prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
201 	} else {
202 		/*
203 		 * the supported rates are: 4,6,8...30
204 		 * round up as we look for equal or less speed
205 		 */
206 		rate = DIV_ROUND_UP(tclk_hz, speed);
207 		rate = roundup(rate, 2);
208 
209 		/* check if requested speed is too small */
210 		if (rate > 30)
211 			return -EINVAL;
212 
213 		if (rate < 4)
214 			rate = 4;
215 
216 		/* Convert the rate to SPI clock divisor value.	*/
217 		prescale = 0x10 + rate/2;
218 	}
219 
220 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
221 	reg = ((reg & ~devdata->prescale_mask) | prescale);
222 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
223 
224 	return 0;
225 }
226 
227 static void
228 orion_spi_mode_set(struct spi_device *spi)
229 {
230 	u32 reg;
231 	struct orion_spi *orion_spi;
232 
233 	orion_spi = spi_master_get_devdata(spi->master);
234 
235 	reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
236 	reg &= ~ORION_SPI_MODE_MASK;
237 	if (spi->mode & SPI_CPOL)
238 		reg |= ORION_SPI_MODE_CPOL;
239 	if (spi->mode & SPI_CPHA)
240 		reg |= ORION_SPI_MODE_CPHA;
241 	if (spi->mode & SPI_LSB_FIRST)
242 		reg |= ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF;
243 	else
244 		reg &= ~(ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF);
245 
246 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
247 }
248 
249 static void
250 orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
251 {
252 	u32 reg;
253 	struct orion_spi *orion_spi;
254 
255 	orion_spi = spi_master_get_devdata(spi->master);
256 
257 	/*
258 	 * Erratum description: (Erratum NO. FE-9144572) The device
259 	 * SPI interface supports frequencies of up to 50 MHz.
260 	 * However, due to this erratum, when the device core clock is
261 	 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
262 	 * clock and CPOL=CPHA=1 there might occur data corruption on
263 	 * reads from the SPI device.
264 	 * Erratum Workaround:
265 	 * Work in one of the following configurations:
266 	 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
267 	 * Register".
268 	 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
269 	 * Register" before setting the interface.
270 	 */
271 	reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
272 	reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
273 
274 	if (clk_get_rate(orion_spi->clk) == 250000000 &&
275 			speed == 50000000 && spi->mode & SPI_CPOL &&
276 			spi->mode & SPI_CPHA)
277 		reg |= ORION_SPI_TMISO_SAMPLE_2;
278 	else
279 		reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
280 
281 	writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
282 }
283 
284 /*
285  * called only when no transfer is active on the bus
286  */
287 static int
288 orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
289 {
290 	struct orion_spi *orion_spi;
291 	unsigned int speed = spi->max_speed_hz;
292 	unsigned int bits_per_word = spi->bits_per_word;
293 	int	rc;
294 
295 	orion_spi = spi_master_get_devdata(spi->master);
296 
297 	if ((t != NULL) && t->speed_hz)
298 		speed = t->speed_hz;
299 
300 	if ((t != NULL) && t->bits_per_word)
301 		bits_per_word = t->bits_per_word;
302 
303 	orion_spi_mode_set(spi);
304 
305 	if (orion_spi->devdata->is_errata_50mhz_ac)
306 		orion_spi_50mhz_ac_timing_erratum(spi, speed);
307 
308 	rc = orion_spi_baudrate_set(spi, speed);
309 	if (rc)
310 		return rc;
311 
312 	if (bits_per_word == 16)
313 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
314 				  ORION_SPI_IF_8_16_BIT_MODE);
315 	else
316 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
317 				  ORION_SPI_IF_8_16_BIT_MODE);
318 
319 	return 0;
320 }
321 
322 static void orion_spi_set_cs(struct spi_device *spi, bool enable)
323 {
324 	struct orion_spi *orion_spi;
325 	int cs;
326 
327 	if (gpio_is_valid(spi->cs_gpio))
328 		cs = 0;
329 	else
330 		cs = spi->chip_select;
331 
332 	orion_spi = spi_master_get_devdata(spi->master);
333 
334 	orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
335 	orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
336 				ORION_SPI_CS(cs));
337 
338 	/* Chip select logic is inverted from spi_set_cs */
339 	if (!enable)
340 		orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
341 	else
342 		orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
343 }
344 
345 static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
346 {
347 	int i;
348 
349 	for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
350 		if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
351 			return 1;
352 
353 		udelay(1);
354 	}
355 
356 	return -1;
357 }
358 
359 static inline int
360 orion_spi_write_read_8bit(struct spi_device *spi,
361 			  const u8 **tx_buf, u8 **rx_buf)
362 {
363 	void __iomem *tx_reg, *rx_reg, *int_reg;
364 	struct orion_spi *orion_spi;
365 
366 	orion_spi = spi_master_get_devdata(spi->master);
367 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
368 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
369 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
370 
371 	/* clear the interrupt cause register */
372 	writel(0x0, int_reg);
373 
374 	if (tx_buf && *tx_buf)
375 		writel(*(*tx_buf)++, tx_reg);
376 	else
377 		writel(0, tx_reg);
378 
379 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
380 		dev_err(&spi->dev, "TXS timed out\n");
381 		return -1;
382 	}
383 
384 	if (rx_buf && *rx_buf)
385 		*(*rx_buf)++ = readl(rx_reg);
386 
387 	return 1;
388 }
389 
390 static inline int
391 orion_spi_write_read_16bit(struct spi_device *spi,
392 			   const u16 **tx_buf, u16 **rx_buf)
393 {
394 	void __iomem *tx_reg, *rx_reg, *int_reg;
395 	struct orion_spi *orion_spi;
396 
397 	orion_spi = spi_master_get_devdata(spi->master);
398 	tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
399 	rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
400 	int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
401 
402 	/* clear the interrupt cause register */
403 	writel(0x0, int_reg);
404 
405 	if (tx_buf && *tx_buf)
406 		writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
407 	else
408 		writel(0, tx_reg);
409 
410 	if (orion_spi_wait_till_ready(orion_spi) < 0) {
411 		dev_err(&spi->dev, "TXS timed out\n");
412 		return -1;
413 	}
414 
415 	if (rx_buf && *rx_buf)
416 		put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
417 
418 	return 1;
419 }
420 
421 static unsigned int
422 orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
423 {
424 	unsigned int count;
425 	int word_len;
426 	struct orion_spi *orion_spi;
427 	int cs = spi->chip_select;
428 
429 	word_len = spi->bits_per_word;
430 	count = xfer->len;
431 
432 	orion_spi = spi_master_get_devdata(spi->master);
433 
434 	/*
435 	 * Use SPI direct write mode if base address is available. Otherwise
436 	 * fall back to PIO mode for this transfer.
437 	 */
438 	if ((orion_spi->direct_access[cs].vaddr) && (xfer->tx_buf) &&
439 	    (word_len == 8)) {
440 		unsigned int cnt = count / 4;
441 		unsigned int rem = count % 4;
442 
443 		/*
444 		 * Send the TX-data to the SPI device via the direct
445 		 * mapped address window
446 		 */
447 		iowrite32_rep(orion_spi->direct_access[cs].vaddr,
448 			      xfer->tx_buf, cnt);
449 		if (rem) {
450 			u32 *buf = (u32 *)xfer->tx_buf;
451 
452 			iowrite8_rep(orion_spi->direct_access[cs].vaddr,
453 				     &buf[cnt], rem);
454 		}
455 
456 		return count;
457 	}
458 
459 	if (word_len == 8) {
460 		const u8 *tx = xfer->tx_buf;
461 		u8 *rx = xfer->rx_buf;
462 
463 		do {
464 			if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
465 				goto out;
466 			count--;
467 		} while (count);
468 	} else if (word_len == 16) {
469 		const u16 *tx = xfer->tx_buf;
470 		u16 *rx = xfer->rx_buf;
471 
472 		do {
473 			if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
474 				goto out;
475 			count -= 2;
476 		} while (count);
477 	}
478 
479 out:
480 	return xfer->len - count;
481 }
482 
483 static int orion_spi_transfer_one(struct spi_master *master,
484 					struct spi_device *spi,
485 					struct spi_transfer *t)
486 {
487 	int status = 0;
488 
489 	status = orion_spi_setup_transfer(spi, t);
490 	if (status < 0)
491 		return status;
492 
493 	if (t->len)
494 		orion_spi_write_read(spi, t);
495 
496 	return status;
497 }
498 
499 static int orion_spi_setup(struct spi_device *spi)
500 {
501 	return orion_spi_setup_transfer(spi, NULL);
502 }
503 
504 static int orion_spi_reset(struct orion_spi *orion_spi)
505 {
506 	/* Verify that the CS is deasserted */
507 	orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
508 
509 	/* Don't deassert CS between the direct mapped SPI transfers */
510 	writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG));
511 
512 	return 0;
513 }
514 
515 static const struct orion_spi_dev orion_spi_dev_data = {
516 	.typ = ORION_SPI,
517 	.min_divisor = 4,
518 	.max_divisor = 30,
519 	.prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
520 };
521 
522 static const struct orion_spi_dev armada_370_spi_dev_data = {
523 	.typ = ARMADA_SPI,
524 	.min_divisor = 4,
525 	.max_divisor = 1920,
526 	.max_hz = 50000000,
527 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
528 };
529 
530 static const struct orion_spi_dev armada_xp_spi_dev_data = {
531 	.typ = ARMADA_SPI,
532 	.max_hz = 50000000,
533 	.max_divisor = 1920,
534 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
535 };
536 
537 static const struct orion_spi_dev armada_375_spi_dev_data = {
538 	.typ = ARMADA_SPI,
539 	.min_divisor = 15,
540 	.max_divisor = 1920,
541 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
542 };
543 
544 static const struct orion_spi_dev armada_380_spi_dev_data = {
545 	.typ = ARMADA_SPI,
546 	.max_hz = 50000000,
547 	.max_divisor = 1920,
548 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
549 	.is_errata_50mhz_ac = true,
550 };
551 
552 static const struct of_device_id orion_spi_of_match_table[] = {
553 	{
554 		.compatible = "marvell,orion-spi",
555 		.data = &orion_spi_dev_data,
556 	},
557 	{
558 		.compatible = "marvell,armada-370-spi",
559 		.data = &armada_370_spi_dev_data,
560 	},
561 	{
562 		.compatible = "marvell,armada-375-spi",
563 		.data = &armada_375_spi_dev_data,
564 	},
565 	{
566 		.compatible = "marvell,armada-380-spi",
567 		.data = &armada_380_spi_dev_data,
568 	},
569 	{
570 		.compatible = "marvell,armada-390-spi",
571 		.data = &armada_xp_spi_dev_data,
572 	},
573 	{
574 		.compatible = "marvell,armada-xp-spi",
575 		.data = &armada_xp_spi_dev_data,
576 	},
577 
578 	{}
579 };
580 MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
581 
582 static int orion_spi_probe(struct platform_device *pdev)
583 {
584 	const struct of_device_id *of_id;
585 	const struct orion_spi_dev *devdata;
586 	struct spi_master *master;
587 	struct orion_spi *spi;
588 	struct resource *r;
589 	unsigned long tclk_hz;
590 	int status = 0;
591 	struct device_node *np;
592 
593 	master = spi_alloc_master(&pdev->dev, sizeof(*spi));
594 	if (master == NULL) {
595 		dev_dbg(&pdev->dev, "master allocation failed\n");
596 		return -ENOMEM;
597 	}
598 
599 	if (pdev->id != -1)
600 		master->bus_num = pdev->id;
601 	if (pdev->dev.of_node) {
602 		u32 cell_index;
603 
604 		if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
605 					  &cell_index))
606 			master->bus_num = cell_index;
607 	}
608 
609 	/* we support all 4 SPI modes and LSB first option */
610 	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;
611 	master->set_cs = orion_spi_set_cs;
612 	master->transfer_one = orion_spi_transfer_one;
613 	master->num_chipselect = ORION_NUM_CHIPSELECTS;
614 	master->setup = orion_spi_setup;
615 	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
616 	master->auto_runtime_pm = true;
617 	master->flags = SPI_MASTER_GPIO_SS;
618 
619 	platform_set_drvdata(pdev, master);
620 
621 	spi = spi_master_get_devdata(master);
622 	spi->master = master;
623 
624 	of_id = of_match_device(orion_spi_of_match_table, &pdev->dev);
625 	devdata = (of_id) ? of_id->data : &orion_spi_dev_data;
626 	spi->devdata = devdata;
627 
628 	spi->clk = devm_clk_get(&pdev->dev, NULL);
629 	if (IS_ERR(spi->clk)) {
630 		status = PTR_ERR(spi->clk);
631 		goto out;
632 	}
633 
634 	status = clk_prepare_enable(spi->clk);
635 	if (status)
636 		goto out;
637 
638 	/* The following clock is only used by some SoCs */
639 	spi->axi_clk = devm_clk_get(&pdev->dev, "axi");
640 	if (IS_ERR(spi->axi_clk) &&
641 	    PTR_ERR(spi->axi_clk) == -EPROBE_DEFER) {
642 		status = -EPROBE_DEFER;
643 		goto out_rel_clk;
644 	}
645 	if (!IS_ERR(spi->axi_clk))
646 		clk_prepare_enable(spi->axi_clk);
647 
648 	tclk_hz = clk_get_rate(spi->clk);
649 
650 	/*
651 	 * With old device tree, armada-370-spi could be used with
652 	 * Armada XP, however for this SoC the maximum frequency is
653 	 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
654 	 * higher than 200MHz. So, in order to be able to handle both
655 	 * SoCs, we can take the minimum of 50MHz and tclk/4.
656 	 */
657 	if (of_device_is_compatible(pdev->dev.of_node,
658 					"marvell,armada-370-spi"))
659 		master->max_speed_hz = min(devdata->max_hz,
660 				DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
661 	else if (devdata->min_divisor)
662 		master->max_speed_hz =
663 			DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
664 	else
665 		master->max_speed_hz = devdata->max_hz;
666 	master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
667 
668 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
669 	spi->base = devm_ioremap_resource(&pdev->dev, r);
670 	if (IS_ERR(spi->base)) {
671 		status = PTR_ERR(spi->base);
672 		goto out_rel_axi_clk;
673 	}
674 
675 	/* Scan all SPI devices of this controller for direct mapped devices */
676 	for_each_available_child_of_node(pdev->dev.of_node, np) {
677 		u32 cs;
678 
679 		/* Get chip-select number from the "reg" property */
680 		status = of_property_read_u32(np, "reg", &cs);
681 		if (status) {
682 			dev_err(&pdev->dev,
683 				"%pOF has no valid 'reg' property (%d)\n",
684 				np, status);
685 			continue;
686 		}
687 
688 		/*
689 		 * Check if an address is configured for this SPI device. If
690 		 * not, the MBus mapping via the 'ranges' property in the 'soc'
691 		 * node is not configured and this device should not use the
692 		 * direct mode. In this case, just continue with the next
693 		 * device.
694 		 */
695 		status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
696 		if (status)
697 			continue;
698 
699 		/*
700 		 * Only map one page for direct access. This is enough for the
701 		 * simple TX transfer which only writes to the first word.
702 		 * This needs to get extended for the direct SPI-NOR / SPI-NAND
703 		 * support, once this gets implemented.
704 		 */
705 		spi->direct_access[cs].vaddr = devm_ioremap(&pdev->dev,
706 							    r->start,
707 							    PAGE_SIZE);
708 		if (!spi->direct_access[cs].vaddr) {
709 			status = -ENOMEM;
710 			goto out_rel_axi_clk;
711 		}
712 		spi->direct_access[cs].size = PAGE_SIZE;
713 
714 		dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
715 	}
716 
717 	pm_runtime_set_active(&pdev->dev);
718 	pm_runtime_use_autosuspend(&pdev->dev);
719 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
720 	pm_runtime_enable(&pdev->dev);
721 
722 	status = orion_spi_reset(spi);
723 	if (status < 0)
724 		goto out_rel_pm;
725 
726 	pm_runtime_mark_last_busy(&pdev->dev);
727 	pm_runtime_put_autosuspend(&pdev->dev);
728 
729 	master->dev.of_node = pdev->dev.of_node;
730 	status = spi_register_master(master);
731 	if (status < 0)
732 		goto out_rel_pm;
733 
734 	return status;
735 
736 out_rel_pm:
737 	pm_runtime_disable(&pdev->dev);
738 out_rel_axi_clk:
739 	clk_disable_unprepare(spi->axi_clk);
740 out_rel_clk:
741 	clk_disable_unprepare(spi->clk);
742 out:
743 	spi_master_put(master);
744 	return status;
745 }
746 
747 
748 static int orion_spi_remove(struct platform_device *pdev)
749 {
750 	struct spi_master *master = platform_get_drvdata(pdev);
751 	struct orion_spi *spi = spi_master_get_devdata(master);
752 
753 	pm_runtime_get_sync(&pdev->dev);
754 	clk_disable_unprepare(spi->axi_clk);
755 	clk_disable_unprepare(spi->clk);
756 
757 	spi_unregister_master(master);
758 	pm_runtime_disable(&pdev->dev);
759 
760 	return 0;
761 }
762 
763 MODULE_ALIAS("platform:" DRIVER_NAME);
764 
765 #ifdef CONFIG_PM
766 static int orion_spi_runtime_suspend(struct device *dev)
767 {
768 	struct spi_master *master = dev_get_drvdata(dev);
769 	struct orion_spi *spi = spi_master_get_devdata(master);
770 
771 	clk_disable_unprepare(spi->axi_clk);
772 	clk_disable_unprepare(spi->clk);
773 	return 0;
774 }
775 
776 static int orion_spi_runtime_resume(struct device *dev)
777 {
778 	struct spi_master *master = dev_get_drvdata(dev);
779 	struct orion_spi *spi = spi_master_get_devdata(master);
780 
781 	if (!IS_ERR(spi->axi_clk))
782 		clk_prepare_enable(spi->axi_clk);
783 	return clk_prepare_enable(spi->clk);
784 }
785 #endif
786 
787 static const struct dev_pm_ops orion_spi_pm_ops = {
788 	SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
789 			   orion_spi_runtime_resume,
790 			   NULL)
791 };
792 
793 static struct platform_driver orion_spi_driver = {
794 	.driver = {
795 		.name	= DRIVER_NAME,
796 		.pm	= &orion_spi_pm_ops,
797 		.of_match_table = of_match_ptr(orion_spi_of_match_table),
798 	},
799 	.probe		= orion_spi_probe,
800 	.remove		= orion_spi_remove,
801 };
802 
803 module_platform_driver(orion_spi_driver);
804 
805 MODULE_DESCRIPTION("Orion SPI driver");
806 MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
807 MODULE_LICENSE("GPL");
808