xref: /linux/drivers/spi/spi-bcm63xx.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Broadcom BCM63xx SPI controller support
4  *
5  * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
6  * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/clk.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/delay.h>
15 #include <linux/interrupt.h>
16 #include <linux/spi/spi.h>
17 #include <linux/completion.h>
18 #include <linux/err.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/of.h>
21 #include <linux/reset.h>
22 
23 /* BCM 6338/6348 SPI core */
24 #define SPI_6348_RSET_SIZE		64
25 #define SPI_6348_CMD			0x00	/* 16-bits register */
26 #define SPI_6348_INT_STATUS		0x02
27 #define SPI_6348_INT_MASK_ST		0x03
28 #define SPI_6348_INT_MASK		0x04
29 #define SPI_6348_ST			0x05
30 #define SPI_6348_CLK_CFG		0x06
31 #define SPI_6348_FILL_BYTE		0x07
32 #define SPI_6348_MSG_TAIL		0x09
33 #define SPI_6348_RX_TAIL		0x0b
34 #define SPI_6348_MSG_CTL		0x40	/* 8-bits register */
35 #define SPI_6348_MSG_CTL_WIDTH		8
36 #define SPI_6348_MSG_DATA		0x41
37 #define SPI_6348_MSG_DATA_SIZE		0x3f
38 #define SPI_6348_RX_DATA		0x80
39 #define SPI_6348_RX_DATA_SIZE		0x3f
40 
41 /* BCM 3368/6358/6262/6368 SPI core */
42 #define SPI_6358_RSET_SIZE		1804
43 #define SPI_6358_MSG_CTL		0x00	/* 16-bits register */
44 #define SPI_6358_MSG_CTL_WIDTH		16
45 #define SPI_6358_MSG_DATA		0x02
46 #define SPI_6358_MSG_DATA_SIZE		0x21e
47 #define SPI_6358_RX_DATA		0x400
48 #define SPI_6358_RX_DATA_SIZE		0x220
49 #define SPI_6358_CMD			0x700	/* 16-bits register */
50 #define SPI_6358_INT_STATUS		0x702
51 #define SPI_6358_INT_MASK_ST		0x703
52 #define SPI_6358_INT_MASK		0x704
53 #define SPI_6358_ST			0x705
54 #define SPI_6358_CLK_CFG		0x706
55 #define SPI_6358_FILL_BYTE		0x707
56 #define SPI_6358_MSG_TAIL		0x709
57 #define SPI_6358_RX_TAIL		0x70B
58 
59 /* Shared SPI definitions */
60 
61 /* Message configuration */
62 #define SPI_FD_RW			0x00
63 #define SPI_HD_W			0x01
64 #define SPI_HD_R			0x02
65 #define SPI_BYTE_CNT_SHIFT		0
66 #define SPI_6348_MSG_TYPE_SHIFT		6
67 #define SPI_6358_MSG_TYPE_SHIFT		14
68 
69 /* Command */
70 #define SPI_CMD_NOOP			0x00
71 #define SPI_CMD_SOFT_RESET		0x01
72 #define SPI_CMD_HARD_RESET		0x02
73 #define SPI_CMD_START_IMMEDIATE		0x03
74 #define SPI_CMD_COMMAND_SHIFT		0
75 #define SPI_CMD_COMMAND_MASK		0x000f
76 #define SPI_CMD_DEVICE_ID_SHIFT		4
77 #define SPI_CMD_PREPEND_BYTE_CNT_SHIFT	8
78 #define SPI_CMD_ONE_BYTE_SHIFT		11
79 #define SPI_CMD_ONE_WIRE_SHIFT		12
80 #define SPI_DEV_ID_0			0
81 #define SPI_DEV_ID_1			1
82 #define SPI_DEV_ID_2			2
83 #define SPI_DEV_ID_3			3
84 
85 /* Interrupt mask */
86 #define SPI_INTR_CMD_DONE		0x01
87 #define SPI_INTR_RX_OVERFLOW		0x02
88 #define SPI_INTR_TX_UNDERFLOW		0x04
89 #define SPI_INTR_TX_OVERFLOW		0x08
90 #define SPI_INTR_RX_UNDERFLOW		0x10
91 #define SPI_INTR_CLEAR_ALL		0x1f
92 
93 /* Status */
94 #define SPI_RX_EMPTY			0x02
95 #define SPI_CMD_BUSY			0x04
96 #define SPI_SERIAL_BUSY			0x08
97 
98 /* Clock configuration */
99 #define SPI_CLK_20MHZ			0x00
100 #define SPI_CLK_0_391MHZ		0x01
101 #define SPI_CLK_0_781MHZ		0x02	/* default */
102 #define SPI_CLK_1_563MHZ		0x03
103 #define SPI_CLK_3_125MHZ		0x04
104 #define SPI_CLK_6_250MHZ		0x05
105 #define SPI_CLK_12_50MHZ		0x06
106 #define SPI_CLK_MASK			0x07
107 #define SPI_SSOFFTIME_MASK		0x38
108 #define SPI_SSOFFTIME_SHIFT		3
109 #define SPI_BYTE_SWAP			0x80
110 
111 enum bcm63xx_regs_spi {
112 	SPI_CMD,
113 	SPI_INT_STATUS,
114 	SPI_INT_MASK_ST,
115 	SPI_INT_MASK,
116 	SPI_ST,
117 	SPI_CLK_CFG,
118 	SPI_FILL_BYTE,
119 	SPI_MSG_TAIL,
120 	SPI_RX_TAIL,
121 	SPI_MSG_CTL,
122 	SPI_MSG_DATA,
123 	SPI_RX_DATA,
124 	SPI_MSG_TYPE_SHIFT,
125 	SPI_MSG_CTL_WIDTH,
126 	SPI_MSG_DATA_SIZE,
127 };
128 
129 #define BCM63XX_SPI_MAX_PREPEND		7
130 
131 #define BCM63XX_SPI_MAX_CS		8
132 #define BCM63XX_SPI_BUS_NUM		0
133 
134 struct bcm63xx_spi {
135 	struct completion	done;
136 
137 	void __iomem		*regs;
138 	int			irq;
139 
140 	/* Platform data */
141 	const unsigned long	*reg_offsets;
142 	unsigned int		fifo_size;
143 	unsigned int		msg_type_shift;
144 	unsigned int		msg_ctl_width;
145 
146 	/* data iomem */
147 	u8 __iomem		*tx_io;
148 	const u8 __iomem	*rx_io;
149 
150 	struct clk		*clk;
151 	struct platform_device	*pdev;
152 };
153 
154 static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs,
155 			       unsigned int offset)
156 {
157 	return readb(bs->regs + bs->reg_offsets[offset]);
158 }
159 
160 static inline void bcm_spi_writeb(struct bcm63xx_spi *bs,
161 				  u8 value, unsigned int offset)
162 {
163 	writeb(value, bs->regs + bs->reg_offsets[offset]);
164 }
165 
166 static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
167 				  u16 value, unsigned int offset)
168 {
169 #ifdef CONFIG_CPU_BIG_ENDIAN
170 	iowrite16be(value, bs->regs + bs->reg_offsets[offset]);
171 #else
172 	writew(value, bs->regs + bs->reg_offsets[offset]);
173 #endif
174 }
175 
176 static const unsigned int bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
177 	{ 20000000, SPI_CLK_20MHZ },
178 	{ 12500000, SPI_CLK_12_50MHZ },
179 	{  6250000, SPI_CLK_6_250MHZ },
180 	{  3125000, SPI_CLK_3_125MHZ },
181 	{  1563000, SPI_CLK_1_563MHZ },
182 	{   781000, SPI_CLK_0_781MHZ },
183 	{   391000, SPI_CLK_0_391MHZ }
184 };
185 
186 static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
187 				      struct spi_transfer *t)
188 {
189 	struct bcm63xx_spi *bs = spi_controller_get_devdata(spi->controller);
190 	u8 clk_cfg, reg;
191 	int i;
192 
193 	/* Default to lowest clock configuration */
194 	clk_cfg = SPI_CLK_0_391MHZ;
195 
196 	/* Find the closest clock configuration */
197 	for (i = 0; i < SPI_CLK_MASK; i++) {
198 		if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) {
199 			clk_cfg = bcm63xx_spi_freq_table[i][1];
200 			break;
201 		}
202 	}
203 
204 	/* clear existing clock configuration bits of the register */
205 	reg = bcm_spi_readb(bs, SPI_CLK_CFG);
206 	reg &= ~SPI_CLK_MASK;
207 	reg |= clk_cfg;
208 
209 	bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
210 	dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
211 		clk_cfg, t->speed_hz);
212 }
213 
214 /* the spi->mode bits understood by this driver: */
215 #define MODEBITS (SPI_CPOL | SPI_CPHA)
216 
217 static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first,
218 				unsigned int num_transfers)
219 {
220 	struct bcm63xx_spi *bs = spi_controller_get_devdata(spi->controller);
221 	u16 msg_ctl;
222 	u16 cmd;
223 	unsigned int i, timeout = 0, prepend_len = 0, len = 0;
224 	struct spi_transfer *t = first;
225 	bool do_rx = false;
226 	bool do_tx = false;
227 
228 	/* Disable the CMD_DONE interrupt */
229 	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
230 
231 	dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
232 		t->tx_buf, t->rx_buf, t->len);
233 
234 	if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND)
235 		prepend_len = t->len;
236 
237 	/* prepare the buffer */
238 	for (i = 0; i < num_transfers; i++) {
239 		if (t->tx_buf) {
240 			do_tx = true;
241 			memcpy_toio(bs->tx_io + len, t->tx_buf, t->len);
242 
243 			/* don't prepend more than one tx */
244 			if (t != first)
245 				prepend_len = 0;
246 		}
247 
248 		if (t->rx_buf) {
249 			do_rx = true;
250 			/* prepend is half-duplex write only */
251 			if (t == first)
252 				prepend_len = 0;
253 		}
254 
255 		len += t->len;
256 
257 		t = list_entry(t->transfer_list.next, struct spi_transfer,
258 			       transfer_list);
259 	}
260 
261 	reinit_completion(&bs->done);
262 
263 	/* Fill in the Message control register */
264 	msg_ctl = (len << SPI_BYTE_CNT_SHIFT);
265 
266 	if (do_rx && do_tx && prepend_len == 0)
267 		msg_ctl |= (SPI_FD_RW << bs->msg_type_shift);
268 	else if (do_rx)
269 		msg_ctl |= (SPI_HD_R << bs->msg_type_shift);
270 	else if (do_tx)
271 		msg_ctl |= (SPI_HD_W << bs->msg_type_shift);
272 
273 	switch (bs->msg_ctl_width) {
274 	case 8:
275 		bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL);
276 		break;
277 	case 16:
278 		bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
279 		break;
280 	}
281 
282 	/* Issue the transfer */
283 	cmd = SPI_CMD_START_IMMEDIATE;
284 	cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
285 	cmd |= (spi_get_chipselect(spi, 0) << SPI_CMD_DEVICE_ID_SHIFT);
286 	bcm_spi_writew(bs, cmd, SPI_CMD);
287 
288 	/* Enable the CMD_DONE interrupt */
289 	bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
290 
291 	timeout = wait_for_completion_timeout(&bs->done, HZ);
292 	if (!timeout)
293 		return -ETIMEDOUT;
294 
295 	if (!do_rx)
296 		return 0;
297 
298 	len = 0;
299 	t = first;
300 	/* Read out all the data */
301 	for (i = 0; i < num_transfers; i++) {
302 		if (t->rx_buf)
303 			memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len);
304 
305 		if (t != first || prepend_len == 0)
306 			len += t->len;
307 
308 		t = list_entry(t->transfer_list.next, struct spi_transfer,
309 			       transfer_list);
310 	}
311 
312 	return 0;
313 }
314 
315 static int bcm63xx_spi_transfer_one(struct spi_controller *host,
316 					struct spi_message *m)
317 {
318 	struct bcm63xx_spi *bs = spi_controller_get_devdata(host);
319 	struct spi_transfer *t, *first = NULL;
320 	struct spi_device *spi = m->spi;
321 	int status = 0;
322 	unsigned int n_transfers = 0, total_len = 0;
323 	bool can_use_prepend = false;
324 
325 	/*
326 	 * This SPI controller does not support keeping CS active after a
327 	 * transfer.
328 	 * Work around this by merging as many transfers we can into one big
329 	 * full-duplex transfers.
330 	 */
331 	list_for_each_entry(t, &m->transfers, transfer_list) {
332 		if (!first)
333 			first = t;
334 
335 		n_transfers++;
336 		total_len += t->len;
337 
338 		if (n_transfers == 2 && !first->rx_buf && !t->tx_buf &&
339 		    first->len <= BCM63XX_SPI_MAX_PREPEND)
340 			can_use_prepend = true;
341 		else if (can_use_prepend && t->tx_buf)
342 			can_use_prepend = false;
343 
344 		/* we can only transfer one fifo worth of data */
345 		if ((can_use_prepend &&
346 		     total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) ||
347 		    (!can_use_prepend && total_len > bs->fifo_size)) {
348 			dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
349 				total_len, bs->fifo_size);
350 			status = -EINVAL;
351 			goto exit;
352 		}
353 
354 		/* all combined transfers have to have the same speed */
355 		if (t->speed_hz != first->speed_hz) {
356 			dev_err(&spi->dev, "unable to change speed between transfers\n");
357 			status = -EINVAL;
358 			goto exit;
359 		}
360 
361 		/* CS will be deasserted directly after transfer */
362 		if (t->delay.value) {
363 			dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
364 			status = -EINVAL;
365 			goto exit;
366 		}
367 
368 		if (t->cs_change ||
369 		    list_is_last(&t->transfer_list, &m->transfers)) {
370 			/* configure adapter for a new transfer */
371 			bcm63xx_spi_setup_transfer(spi, first);
372 
373 			/* send the data */
374 			status = bcm63xx_txrx_bufs(spi, first, n_transfers);
375 			if (status)
376 				goto exit;
377 
378 			m->actual_length += total_len;
379 
380 			first = NULL;
381 			n_transfers = 0;
382 			total_len = 0;
383 			can_use_prepend = false;
384 		}
385 	}
386 exit:
387 	m->status = status;
388 	spi_finalize_current_message(host);
389 
390 	return 0;
391 }
392 
393 /* This driver supports single host mode only. Hence
394  * CMD_DONE is the only interrupt we care about
395  */
396 static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
397 {
398 	struct spi_controller *host = (struct spi_controller *)dev_id;
399 	struct bcm63xx_spi *bs = spi_controller_get_devdata(host);
400 	u8 intr;
401 
402 	/* Read interupts and clear them immediately */
403 	intr = bcm_spi_readb(bs, SPI_INT_STATUS);
404 	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
405 	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
406 
407 	/* A transfer completed */
408 	if (intr & SPI_INTR_CMD_DONE)
409 		complete(&bs->done);
410 
411 	return IRQ_HANDLED;
412 }
413 
414 static size_t bcm63xx_spi_max_length(struct spi_device *spi)
415 {
416 	struct bcm63xx_spi *bs = spi_controller_get_devdata(spi->controller);
417 
418 	return bs->fifo_size;
419 }
420 
421 static const unsigned long bcm6348_spi_reg_offsets[] = {
422 	[SPI_CMD]		= SPI_6348_CMD,
423 	[SPI_INT_STATUS]	= SPI_6348_INT_STATUS,
424 	[SPI_INT_MASK_ST]	= SPI_6348_INT_MASK_ST,
425 	[SPI_INT_MASK]		= SPI_6348_INT_MASK,
426 	[SPI_ST]		= SPI_6348_ST,
427 	[SPI_CLK_CFG]		= SPI_6348_CLK_CFG,
428 	[SPI_FILL_BYTE]		= SPI_6348_FILL_BYTE,
429 	[SPI_MSG_TAIL]		= SPI_6348_MSG_TAIL,
430 	[SPI_RX_TAIL]		= SPI_6348_RX_TAIL,
431 	[SPI_MSG_CTL]		= SPI_6348_MSG_CTL,
432 	[SPI_MSG_DATA]		= SPI_6348_MSG_DATA,
433 	[SPI_RX_DATA]		= SPI_6348_RX_DATA,
434 	[SPI_MSG_TYPE_SHIFT]	= SPI_6348_MSG_TYPE_SHIFT,
435 	[SPI_MSG_CTL_WIDTH]	= SPI_6348_MSG_CTL_WIDTH,
436 	[SPI_MSG_DATA_SIZE]	= SPI_6348_MSG_DATA_SIZE,
437 };
438 
439 static const unsigned long bcm6358_spi_reg_offsets[] = {
440 	[SPI_CMD]		= SPI_6358_CMD,
441 	[SPI_INT_STATUS]	= SPI_6358_INT_STATUS,
442 	[SPI_INT_MASK_ST]	= SPI_6358_INT_MASK_ST,
443 	[SPI_INT_MASK]		= SPI_6358_INT_MASK,
444 	[SPI_ST]		= SPI_6358_ST,
445 	[SPI_CLK_CFG]		= SPI_6358_CLK_CFG,
446 	[SPI_FILL_BYTE]		= SPI_6358_FILL_BYTE,
447 	[SPI_MSG_TAIL]		= SPI_6358_MSG_TAIL,
448 	[SPI_RX_TAIL]		= SPI_6358_RX_TAIL,
449 	[SPI_MSG_CTL]		= SPI_6358_MSG_CTL,
450 	[SPI_MSG_DATA]		= SPI_6358_MSG_DATA,
451 	[SPI_RX_DATA]		= SPI_6358_RX_DATA,
452 	[SPI_MSG_TYPE_SHIFT]	= SPI_6358_MSG_TYPE_SHIFT,
453 	[SPI_MSG_CTL_WIDTH]	= SPI_6358_MSG_CTL_WIDTH,
454 	[SPI_MSG_DATA_SIZE]	= SPI_6358_MSG_DATA_SIZE,
455 };
456 
457 static const struct platform_device_id bcm63xx_spi_dev_match[] = {
458 	{
459 		.name = "bcm6348-spi",
460 		.driver_data = (unsigned long)bcm6348_spi_reg_offsets,
461 	},
462 	{
463 		.name = "bcm6358-spi",
464 		.driver_data = (unsigned long)bcm6358_spi_reg_offsets,
465 	},
466 	{
467 	},
468 };
469 MODULE_DEVICE_TABLE(platform, bcm63xx_spi_dev_match);
470 
471 static const struct of_device_id bcm63xx_spi_of_match[] = {
472 	{ .compatible = "brcm,bcm6348-spi", .data = &bcm6348_spi_reg_offsets },
473 	{ .compatible = "brcm,bcm6358-spi", .data = &bcm6358_spi_reg_offsets },
474 	{ },
475 };
476 MODULE_DEVICE_TABLE(of, bcm63xx_spi_of_match);
477 
478 static int bcm63xx_spi_probe(struct platform_device *pdev)
479 {
480 	struct resource *r;
481 	const unsigned long *bcm63xx_spireg;
482 	struct device *dev = &pdev->dev;
483 	int irq, bus_num;
484 	struct spi_controller *host;
485 	struct clk *clk;
486 	struct bcm63xx_spi *bs;
487 	int ret;
488 	u32 num_cs = BCM63XX_SPI_MAX_CS;
489 	struct reset_control *reset;
490 
491 	if (dev->of_node) {
492 		const struct of_device_id *match;
493 
494 		match = of_match_node(bcm63xx_spi_of_match, dev->of_node);
495 		if (!match)
496 			return -EINVAL;
497 		bcm63xx_spireg = match->data;
498 
499 		of_property_read_u32(dev->of_node, "num-cs", &num_cs);
500 		if (num_cs > BCM63XX_SPI_MAX_CS) {
501 			dev_warn(dev, "unsupported number of cs (%i), reducing to 8\n",
502 				 num_cs);
503 			num_cs = BCM63XX_SPI_MAX_CS;
504 		}
505 
506 		bus_num = -1;
507 	} else if (pdev->id_entry->driver_data) {
508 		const struct platform_device_id *match = pdev->id_entry;
509 
510 		bcm63xx_spireg = (const unsigned long *)match->driver_data;
511 		bus_num = BCM63XX_SPI_BUS_NUM;
512 	} else {
513 		return -EINVAL;
514 	}
515 
516 	irq = platform_get_irq(pdev, 0);
517 	if (irq < 0)
518 		return irq;
519 
520 	clk = devm_clk_get(dev, "spi");
521 	if (IS_ERR(clk)) {
522 		dev_err(dev, "no clock for device\n");
523 		return PTR_ERR(clk);
524 	}
525 
526 	reset = devm_reset_control_get_optional_exclusive(dev, NULL);
527 	if (IS_ERR(reset))
528 		return PTR_ERR(reset);
529 
530 	host = spi_alloc_host(dev, sizeof(*bs));
531 	if (!host) {
532 		dev_err(dev, "out of memory\n");
533 		return -ENOMEM;
534 	}
535 
536 	bs = spi_controller_get_devdata(host);
537 	init_completion(&bs->done);
538 
539 	platform_set_drvdata(pdev, host);
540 	bs->pdev = pdev;
541 
542 	bs->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &r);
543 	if (IS_ERR(bs->regs)) {
544 		ret = PTR_ERR(bs->regs);
545 		goto out_err;
546 	}
547 
548 	bs->irq = irq;
549 	bs->clk = clk;
550 	bs->reg_offsets = bcm63xx_spireg;
551 	bs->fifo_size = bs->reg_offsets[SPI_MSG_DATA_SIZE];
552 
553 	ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
554 			       pdev->name, host);
555 	if (ret) {
556 		dev_err(dev, "unable to request irq\n");
557 		goto out_err;
558 	}
559 
560 	host->dev.of_node = dev->of_node;
561 	host->bus_num = bus_num;
562 	host->num_chipselect = num_cs;
563 	host->transfer_one_message = bcm63xx_spi_transfer_one;
564 	host->mode_bits = MODEBITS;
565 	host->bits_per_word_mask = SPI_BPW_MASK(8);
566 	host->max_transfer_size = bcm63xx_spi_max_length;
567 	host->max_message_size = bcm63xx_spi_max_length;
568 	host->auto_runtime_pm = true;
569 	bs->msg_type_shift = bs->reg_offsets[SPI_MSG_TYPE_SHIFT];
570 	bs->msg_ctl_width = bs->reg_offsets[SPI_MSG_CTL_WIDTH];
571 	bs->tx_io = (u8 *)(bs->regs + bs->reg_offsets[SPI_MSG_DATA]);
572 	bs->rx_io = (const u8 *)(bs->regs + bs->reg_offsets[SPI_RX_DATA]);
573 
574 	/* Initialize hardware */
575 	ret = clk_prepare_enable(bs->clk);
576 	if (ret)
577 		goto out_err;
578 
579 	ret = reset_control_reset(reset);
580 	if (ret) {
581 		dev_err(dev, "unable to reset device: %d\n", ret);
582 		goto out_clk_disable;
583 	}
584 
585 	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
586 
587 	ret = devm_pm_runtime_enable(&pdev->dev);
588 	if (ret)
589 		goto out_clk_disable;
590 
591 	/* register and we are done */
592 	ret = devm_spi_register_controller(dev, host);
593 	if (ret) {
594 		dev_err(dev, "spi register failed\n");
595 		goto out_clk_disable;
596 	}
597 
598 	dev_info(dev, "at %pr (irq %d, FIFOs size %d)\n",
599 		 r, irq, bs->fifo_size);
600 
601 	return 0;
602 
603 out_clk_disable:
604 	clk_disable_unprepare(clk);
605 out_err:
606 	spi_controller_put(host);
607 	return ret;
608 }
609 
610 static void bcm63xx_spi_remove(struct platform_device *pdev)
611 {
612 	struct spi_controller *host = platform_get_drvdata(pdev);
613 	struct bcm63xx_spi *bs = spi_controller_get_devdata(host);
614 
615 	/* reset spi block */
616 	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
617 
618 	/* HW shutdown */
619 	clk_disable_unprepare(bs->clk);
620 }
621 
622 static int bcm63xx_spi_suspend(struct device *dev)
623 {
624 	struct spi_controller *host = dev_get_drvdata(dev);
625 	struct bcm63xx_spi *bs = spi_controller_get_devdata(host);
626 
627 	spi_controller_suspend(host);
628 
629 	clk_disable_unprepare(bs->clk);
630 
631 	return 0;
632 }
633 
634 static int bcm63xx_spi_resume(struct device *dev)
635 {
636 	struct spi_controller *host = dev_get_drvdata(dev);
637 	struct bcm63xx_spi *bs = spi_controller_get_devdata(host);
638 	int ret;
639 
640 	ret = clk_prepare_enable(bs->clk);
641 	if (ret)
642 		return ret;
643 
644 	spi_controller_resume(host);
645 
646 	return 0;
647 }
648 
649 static DEFINE_SIMPLE_DEV_PM_OPS(bcm63xx_spi_pm_ops, bcm63xx_spi_suspend, bcm63xx_spi_resume);
650 
651 static struct platform_driver bcm63xx_spi_driver = {
652 	.driver = {
653 		.name	= "bcm63xx-spi",
654 		.pm	= &bcm63xx_spi_pm_ops,
655 		.of_match_table = bcm63xx_spi_of_match,
656 	},
657 	.id_table	= bcm63xx_spi_dev_match,
658 	.probe		= bcm63xx_spi_probe,
659 	.remove		= bcm63xx_spi_remove,
660 };
661 
662 module_platform_driver(bcm63xx_spi_driver);
663 
664 MODULE_ALIAS("platform:bcm63xx_spi");
665 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
666 MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>");
667 MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
668 MODULE_LICENSE("GPL");
669