xref: /openbmc/linux/drivers/spi/spi-bcm63xx.c (revision aad7ebb5)
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 
22 /* BCM 6338/6348 SPI core */
23 #define SPI_6348_RSET_SIZE		64
24 #define SPI_6348_CMD			0x00	/* 16-bits register */
25 #define SPI_6348_INT_STATUS		0x02
26 #define SPI_6348_INT_MASK_ST		0x03
27 #define SPI_6348_INT_MASK		0x04
28 #define SPI_6348_ST			0x05
29 #define SPI_6348_CLK_CFG		0x06
30 #define SPI_6348_FILL_BYTE		0x07
31 #define SPI_6348_MSG_TAIL		0x09
32 #define SPI_6348_RX_TAIL		0x0b
33 #define SPI_6348_MSG_CTL		0x40	/* 8-bits register */
34 #define SPI_6348_MSG_CTL_WIDTH		8
35 #define SPI_6348_MSG_DATA		0x41
36 #define SPI_6348_MSG_DATA_SIZE		0x3f
37 #define SPI_6348_RX_DATA		0x80
38 #define SPI_6348_RX_DATA_SIZE		0x3f
39 
40 /* BCM 3368/6358/6262/6368 SPI core */
41 #define SPI_6358_RSET_SIZE		1804
42 #define SPI_6358_MSG_CTL		0x00	/* 16-bits register */
43 #define SPI_6358_MSG_CTL_WIDTH		16
44 #define SPI_6358_MSG_DATA		0x02
45 #define SPI_6358_MSG_DATA_SIZE		0x21e
46 #define SPI_6358_RX_DATA		0x400
47 #define SPI_6358_RX_DATA_SIZE		0x220
48 #define SPI_6358_CMD			0x700	/* 16-bits register */
49 #define SPI_6358_INT_STATUS		0x702
50 #define SPI_6358_INT_MASK_ST		0x703
51 #define SPI_6358_INT_MASK		0x704
52 #define SPI_6358_ST			0x705
53 #define SPI_6358_CLK_CFG		0x706
54 #define SPI_6358_FILL_BYTE		0x707
55 #define SPI_6358_MSG_TAIL		0x709
56 #define SPI_6358_RX_TAIL		0x70B
57 
58 /* Shared SPI definitions */
59 
60 /* Message configuration */
61 #define SPI_FD_RW			0x00
62 #define SPI_HD_W			0x01
63 #define SPI_HD_R			0x02
64 #define SPI_BYTE_CNT_SHIFT		0
65 #define SPI_6348_MSG_TYPE_SHIFT		6
66 #define SPI_6358_MSG_TYPE_SHIFT		14
67 
68 /* Command */
69 #define SPI_CMD_NOOP			0x00
70 #define SPI_CMD_SOFT_RESET		0x01
71 #define SPI_CMD_HARD_RESET		0x02
72 #define SPI_CMD_START_IMMEDIATE		0x03
73 #define SPI_CMD_COMMAND_SHIFT		0
74 #define SPI_CMD_COMMAND_MASK		0x000f
75 #define SPI_CMD_DEVICE_ID_SHIFT		4
76 #define SPI_CMD_PREPEND_BYTE_CNT_SHIFT	8
77 #define SPI_CMD_ONE_BYTE_SHIFT		11
78 #define SPI_CMD_ONE_WIRE_SHIFT		12
79 #define SPI_DEV_ID_0			0
80 #define SPI_DEV_ID_1			1
81 #define SPI_DEV_ID_2			2
82 #define SPI_DEV_ID_3			3
83 
84 /* Interrupt mask */
85 #define SPI_INTR_CMD_DONE		0x01
86 #define SPI_INTR_RX_OVERFLOW		0x02
87 #define SPI_INTR_TX_UNDERFLOW		0x04
88 #define SPI_INTR_TX_OVERFLOW		0x08
89 #define SPI_INTR_RX_UNDERFLOW		0x10
90 #define SPI_INTR_CLEAR_ALL		0x1f
91 
92 /* Status */
93 #define SPI_RX_EMPTY			0x02
94 #define SPI_CMD_BUSY			0x04
95 #define SPI_SERIAL_BUSY			0x08
96 
97 /* Clock configuration */
98 #define SPI_CLK_20MHZ			0x00
99 #define SPI_CLK_0_391MHZ		0x01
100 #define SPI_CLK_0_781MHZ		0x02	/* default */
101 #define SPI_CLK_1_563MHZ		0x03
102 #define SPI_CLK_3_125MHZ		0x04
103 #define SPI_CLK_6_250MHZ		0x05
104 #define SPI_CLK_12_50MHZ		0x06
105 #define SPI_CLK_MASK			0x07
106 #define SPI_SSOFFTIME_MASK		0x38
107 #define SPI_SSOFFTIME_SHIFT		3
108 #define SPI_BYTE_SWAP			0x80
109 
110 enum bcm63xx_regs_spi {
111 	SPI_CMD,
112 	SPI_INT_STATUS,
113 	SPI_INT_MASK_ST,
114 	SPI_INT_MASK,
115 	SPI_ST,
116 	SPI_CLK_CFG,
117 	SPI_FILL_BYTE,
118 	SPI_MSG_TAIL,
119 	SPI_RX_TAIL,
120 	SPI_MSG_CTL,
121 	SPI_MSG_DATA,
122 	SPI_RX_DATA,
123 	SPI_MSG_TYPE_SHIFT,
124 	SPI_MSG_CTL_WIDTH,
125 	SPI_MSG_DATA_SIZE,
126 };
127 
128 #define BCM63XX_SPI_MAX_PREPEND		15
129 
130 #define BCM63XX_SPI_MAX_CS		8
131 #define BCM63XX_SPI_BUS_NUM		0
132 
133 struct bcm63xx_spi {
134 	struct completion	done;
135 
136 	void __iomem		*regs;
137 	int			irq;
138 
139 	/* Platform data */
140 	const unsigned long	*reg_offsets;
141 	unsigned int		fifo_size;
142 	unsigned int		msg_type_shift;
143 	unsigned int		msg_ctl_width;
144 
145 	/* data iomem */
146 	u8 __iomem		*tx_io;
147 	const u8 __iomem	*rx_io;
148 
149 	struct clk		*clk;
150 	struct platform_device	*pdev;
151 };
152 
153 static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs,
154 			       unsigned int offset)
155 {
156 	return readb(bs->regs + bs->reg_offsets[offset]);
157 }
158 
159 static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs,
160 				unsigned int offset)
161 {
162 #ifdef CONFIG_CPU_BIG_ENDIAN
163 	return ioread16be(bs->regs + bs->reg_offsets[offset]);
164 #else
165 	return readw(bs->regs + bs->reg_offsets[offset]);
166 #endif
167 }
168 
169 static inline void bcm_spi_writeb(struct bcm63xx_spi *bs,
170 				  u8 value, unsigned int offset)
171 {
172 	writeb(value, bs->regs + bs->reg_offsets[offset]);
173 }
174 
175 static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
176 				  u16 value, unsigned int offset)
177 {
178 #ifdef CONFIG_CPU_BIG_ENDIAN
179 	iowrite16be(value, bs->regs + bs->reg_offsets[offset]);
180 #else
181 	writew(value, bs->regs + bs->reg_offsets[offset]);
182 #endif
183 }
184 
185 static const unsigned int bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
186 	{ 20000000, SPI_CLK_20MHZ },
187 	{ 12500000, SPI_CLK_12_50MHZ },
188 	{  6250000, SPI_CLK_6_250MHZ },
189 	{  3125000, SPI_CLK_3_125MHZ },
190 	{  1563000, SPI_CLK_1_563MHZ },
191 	{   781000, SPI_CLK_0_781MHZ },
192 	{   391000, SPI_CLK_0_391MHZ }
193 };
194 
195 static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
196 				      struct spi_transfer *t)
197 {
198 	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
199 	u8 clk_cfg, reg;
200 	int i;
201 
202 	/* Default to lowest clock configuration */
203 	clk_cfg = SPI_CLK_0_391MHZ;
204 
205 	/* Find the closest clock configuration */
206 	for (i = 0; i < SPI_CLK_MASK; i++) {
207 		if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) {
208 			clk_cfg = bcm63xx_spi_freq_table[i][1];
209 			break;
210 		}
211 	}
212 
213 	/* clear existing clock configuration bits of the register */
214 	reg = bcm_spi_readb(bs, SPI_CLK_CFG);
215 	reg &= ~SPI_CLK_MASK;
216 	reg |= clk_cfg;
217 
218 	bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
219 	dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
220 		clk_cfg, t->speed_hz);
221 }
222 
223 /* the spi->mode bits understood by this driver: */
224 #define MODEBITS (SPI_CPOL | SPI_CPHA)
225 
226 static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first,
227 				unsigned int num_transfers)
228 {
229 	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
230 	u16 msg_ctl;
231 	u16 cmd;
232 	unsigned int i, timeout = 0, prepend_len = 0, len = 0;
233 	struct spi_transfer *t = first;
234 	bool do_rx = false;
235 	bool do_tx = false;
236 
237 	/* Disable the CMD_DONE interrupt */
238 	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
239 
240 	dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
241 		t->tx_buf, t->rx_buf, t->len);
242 
243 	if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND)
244 		prepend_len = t->len;
245 
246 	/* prepare the buffer */
247 	for (i = 0; i < num_transfers; i++) {
248 		if (t->tx_buf) {
249 			do_tx = true;
250 			memcpy_toio(bs->tx_io + len, t->tx_buf, t->len);
251 
252 			/* don't prepend more than one tx */
253 			if (t != first)
254 				prepend_len = 0;
255 		}
256 
257 		if (t->rx_buf) {
258 			do_rx = true;
259 			/* prepend is half-duplex write only */
260 			if (t == first)
261 				prepend_len = 0;
262 		}
263 
264 		len += t->len;
265 
266 		t = list_entry(t->transfer_list.next, struct spi_transfer,
267 			       transfer_list);
268 	}
269 
270 	reinit_completion(&bs->done);
271 
272 	/* Fill in the Message control register */
273 	msg_ctl = (len << SPI_BYTE_CNT_SHIFT);
274 
275 	if (do_rx && do_tx && prepend_len == 0)
276 		msg_ctl |= (SPI_FD_RW << bs->msg_type_shift);
277 	else if (do_rx)
278 		msg_ctl |= (SPI_HD_R << bs->msg_type_shift);
279 	else if (do_tx)
280 		msg_ctl |= (SPI_HD_W << bs->msg_type_shift);
281 
282 	switch (bs->msg_ctl_width) {
283 	case 8:
284 		bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL);
285 		break;
286 	case 16:
287 		bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
288 		break;
289 	}
290 
291 	/* Issue the transfer */
292 	cmd = SPI_CMD_START_IMMEDIATE;
293 	cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
294 	cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
295 	bcm_spi_writew(bs, cmd, SPI_CMD);
296 
297 	/* Enable the CMD_DONE interrupt */
298 	bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
299 
300 	timeout = wait_for_completion_timeout(&bs->done, HZ);
301 	if (!timeout)
302 		return -ETIMEDOUT;
303 
304 	if (!do_rx)
305 		return 0;
306 
307 	len = 0;
308 	t = first;
309 	/* Read out all the data */
310 	for (i = 0; i < num_transfers; i++) {
311 		if (t->rx_buf)
312 			memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len);
313 
314 		if (t != first || prepend_len == 0)
315 			len += t->len;
316 
317 		t = list_entry(t->transfer_list.next, struct spi_transfer,
318 			       transfer_list);
319 	}
320 
321 	return 0;
322 }
323 
324 static int bcm63xx_spi_transfer_one(struct spi_master *master,
325 					struct spi_message *m)
326 {
327 	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
328 	struct spi_transfer *t, *first = NULL;
329 	struct spi_device *spi = m->spi;
330 	int status = 0;
331 	unsigned int n_transfers = 0, total_len = 0;
332 	bool can_use_prepend = false;
333 
334 	/*
335 	 * This SPI controller does not support keeping CS active after a
336 	 * transfer.
337 	 * Work around this by merging as many transfers we can into one big
338 	 * full-duplex transfers.
339 	 */
340 	list_for_each_entry(t, &m->transfers, transfer_list) {
341 		if (!first)
342 			first = t;
343 
344 		n_transfers++;
345 		total_len += t->len;
346 
347 		if (n_transfers == 2 && !first->rx_buf && !t->tx_buf &&
348 		    first->len <= BCM63XX_SPI_MAX_PREPEND)
349 			can_use_prepend = true;
350 		else if (can_use_prepend && t->tx_buf)
351 			can_use_prepend = false;
352 
353 		/* we can only transfer one fifo worth of data */
354 		if ((can_use_prepend &&
355 		     total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) ||
356 		    (!can_use_prepend && total_len > bs->fifo_size)) {
357 			dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
358 				total_len, bs->fifo_size);
359 			status = -EINVAL;
360 			goto exit;
361 		}
362 
363 		/* all combined transfers have to have the same speed */
364 		if (t->speed_hz != first->speed_hz) {
365 			dev_err(&spi->dev, "unable to change speed between transfers\n");
366 			status = -EINVAL;
367 			goto exit;
368 		}
369 
370 		/* CS will be deasserted directly after transfer */
371 		if (t->delay_usecs || t->delay.value) {
372 			dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
373 			status = -EINVAL;
374 			goto exit;
375 		}
376 
377 		if (t->cs_change ||
378 		    list_is_last(&t->transfer_list, &m->transfers)) {
379 			/* configure adapter for a new transfer */
380 			bcm63xx_spi_setup_transfer(spi, first);
381 
382 			/* send the data */
383 			status = bcm63xx_txrx_bufs(spi, first, n_transfers);
384 			if (status)
385 				goto exit;
386 
387 			m->actual_length += total_len;
388 
389 			first = NULL;
390 			n_transfers = 0;
391 			total_len = 0;
392 			can_use_prepend = false;
393 		}
394 	}
395 exit:
396 	m->status = status;
397 	spi_finalize_current_message(master);
398 
399 	return 0;
400 }
401 
402 /* This driver supports single master mode only. Hence
403  * CMD_DONE is the only interrupt we care about
404  */
405 static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
406 {
407 	struct spi_master *master = (struct spi_master *)dev_id;
408 	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
409 	u8 intr;
410 
411 	/* Read interupts and clear them immediately */
412 	intr = bcm_spi_readb(bs, SPI_INT_STATUS);
413 	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
414 	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
415 
416 	/* A transfer completed */
417 	if (intr & SPI_INTR_CMD_DONE)
418 		complete(&bs->done);
419 
420 	return IRQ_HANDLED;
421 }
422 
423 static size_t bcm63xx_spi_max_length(struct spi_device *spi)
424 {
425 	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
426 
427 	return bs->fifo_size;
428 }
429 
430 static const unsigned long bcm6348_spi_reg_offsets[] = {
431 	[SPI_CMD]		= SPI_6348_CMD,
432 	[SPI_INT_STATUS]	= SPI_6348_INT_STATUS,
433 	[SPI_INT_MASK_ST]	= SPI_6348_INT_MASK_ST,
434 	[SPI_INT_MASK]		= SPI_6348_INT_MASK,
435 	[SPI_ST]		= SPI_6348_ST,
436 	[SPI_CLK_CFG]		= SPI_6348_CLK_CFG,
437 	[SPI_FILL_BYTE]		= SPI_6348_FILL_BYTE,
438 	[SPI_MSG_TAIL]		= SPI_6348_MSG_TAIL,
439 	[SPI_RX_TAIL]		= SPI_6348_RX_TAIL,
440 	[SPI_MSG_CTL]		= SPI_6348_MSG_CTL,
441 	[SPI_MSG_DATA]		= SPI_6348_MSG_DATA,
442 	[SPI_RX_DATA]		= SPI_6348_RX_DATA,
443 	[SPI_MSG_TYPE_SHIFT]	= SPI_6348_MSG_TYPE_SHIFT,
444 	[SPI_MSG_CTL_WIDTH]	= SPI_6348_MSG_CTL_WIDTH,
445 	[SPI_MSG_DATA_SIZE]	= SPI_6348_MSG_DATA_SIZE,
446 };
447 
448 static const unsigned long bcm6358_spi_reg_offsets[] = {
449 	[SPI_CMD]		= SPI_6358_CMD,
450 	[SPI_INT_STATUS]	= SPI_6358_INT_STATUS,
451 	[SPI_INT_MASK_ST]	= SPI_6358_INT_MASK_ST,
452 	[SPI_INT_MASK]		= SPI_6358_INT_MASK,
453 	[SPI_ST]		= SPI_6358_ST,
454 	[SPI_CLK_CFG]		= SPI_6358_CLK_CFG,
455 	[SPI_FILL_BYTE]		= SPI_6358_FILL_BYTE,
456 	[SPI_MSG_TAIL]		= SPI_6358_MSG_TAIL,
457 	[SPI_RX_TAIL]		= SPI_6358_RX_TAIL,
458 	[SPI_MSG_CTL]		= SPI_6358_MSG_CTL,
459 	[SPI_MSG_DATA]		= SPI_6358_MSG_DATA,
460 	[SPI_RX_DATA]		= SPI_6358_RX_DATA,
461 	[SPI_MSG_TYPE_SHIFT]	= SPI_6358_MSG_TYPE_SHIFT,
462 	[SPI_MSG_CTL_WIDTH]	= SPI_6358_MSG_CTL_WIDTH,
463 	[SPI_MSG_DATA_SIZE]	= SPI_6358_MSG_DATA_SIZE,
464 };
465 
466 static const struct platform_device_id bcm63xx_spi_dev_match[] = {
467 	{
468 		.name = "bcm6348-spi",
469 		.driver_data = (unsigned long)bcm6348_spi_reg_offsets,
470 	},
471 	{
472 		.name = "bcm6358-spi",
473 		.driver_data = (unsigned long)bcm6358_spi_reg_offsets,
474 	},
475 	{
476 	},
477 };
478 
479 static const struct of_device_id bcm63xx_spi_of_match[] = {
480 	{ .compatible = "brcm,bcm6348-spi", .data = &bcm6348_spi_reg_offsets },
481 	{ .compatible = "brcm,bcm6358-spi", .data = &bcm6358_spi_reg_offsets },
482 	{ },
483 };
484 
485 static int bcm63xx_spi_probe(struct platform_device *pdev)
486 {
487 	struct resource *r;
488 	const unsigned long *bcm63xx_spireg;
489 	struct device *dev = &pdev->dev;
490 	int irq, bus_num;
491 	struct spi_master *master;
492 	struct clk *clk;
493 	struct bcm63xx_spi *bs;
494 	int ret;
495 	u32 num_cs = BCM63XX_SPI_MAX_CS;
496 
497 	if (dev->of_node) {
498 		const struct of_device_id *match;
499 
500 		match = of_match_node(bcm63xx_spi_of_match, dev->of_node);
501 		if (!match)
502 			return -EINVAL;
503 		bcm63xx_spireg = match->data;
504 
505 		of_property_read_u32(dev->of_node, "num-cs", &num_cs);
506 		if (num_cs > BCM63XX_SPI_MAX_CS) {
507 			dev_warn(dev, "unsupported number of cs (%i), reducing to 8\n",
508 				 num_cs);
509 			num_cs = BCM63XX_SPI_MAX_CS;
510 		}
511 
512 		bus_num = -1;
513 	} else if (pdev->id_entry->driver_data) {
514 		const struct platform_device_id *match = pdev->id_entry;
515 
516 		bcm63xx_spireg = (const unsigned long *)match->driver_data;
517 		bus_num = BCM63XX_SPI_BUS_NUM;
518 	} else {
519 		return -EINVAL;
520 	}
521 
522 	irq = platform_get_irq(pdev, 0);
523 	if (irq < 0)
524 		return irq;
525 
526 	clk = devm_clk_get(dev, "spi");
527 	if (IS_ERR(clk)) {
528 		dev_err(dev, "no clock for device\n");
529 		return PTR_ERR(clk);
530 	}
531 
532 	master = spi_alloc_master(dev, sizeof(*bs));
533 	if (!master) {
534 		dev_err(dev, "out of memory\n");
535 		return -ENOMEM;
536 	}
537 
538 	bs = spi_master_get_devdata(master);
539 	init_completion(&bs->done);
540 
541 	platform_set_drvdata(pdev, master);
542 	bs->pdev = pdev;
543 
544 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
545 	bs->regs = devm_ioremap_resource(&pdev->dev, r);
546 	if (IS_ERR(bs->regs)) {
547 		ret = PTR_ERR(bs->regs);
548 		goto out_err;
549 	}
550 
551 	bs->irq = irq;
552 	bs->clk = clk;
553 	bs->reg_offsets = bcm63xx_spireg;
554 	bs->fifo_size = bs->reg_offsets[SPI_MSG_DATA_SIZE];
555 
556 	ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
557 							pdev->name, master);
558 	if (ret) {
559 		dev_err(dev, "unable to request irq\n");
560 		goto out_err;
561 	}
562 
563 	master->dev.of_node = dev->of_node;
564 	master->bus_num = bus_num;
565 	master->num_chipselect = num_cs;
566 	master->transfer_one_message = bcm63xx_spi_transfer_one;
567 	master->mode_bits = MODEBITS;
568 	master->bits_per_word_mask = SPI_BPW_MASK(8);
569 	master->max_transfer_size = bcm63xx_spi_max_length;
570 	master->max_message_size = bcm63xx_spi_max_length;
571 	master->auto_runtime_pm = true;
572 	bs->msg_type_shift = bs->reg_offsets[SPI_MSG_TYPE_SHIFT];
573 	bs->msg_ctl_width = bs->reg_offsets[SPI_MSG_CTL_WIDTH];
574 	bs->tx_io = (u8 *)(bs->regs + bs->reg_offsets[SPI_MSG_DATA]);
575 	bs->rx_io = (const u8 *)(bs->regs + bs->reg_offsets[SPI_RX_DATA]);
576 
577 	/* Initialize hardware */
578 	ret = clk_prepare_enable(bs->clk);
579 	if (ret)
580 		goto out_err;
581 
582 	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
583 
584 	/* register and we are done */
585 	ret = devm_spi_register_master(dev, master);
586 	if (ret) {
587 		dev_err(dev, "spi register failed\n");
588 		goto out_clk_disable;
589 	}
590 
591 	dev_info(dev, "at %pr (irq %d, FIFOs size %d)\n",
592 		 r, irq, bs->fifo_size);
593 
594 	return 0;
595 
596 out_clk_disable:
597 	clk_disable_unprepare(clk);
598 out_err:
599 	spi_master_put(master);
600 	return ret;
601 }
602 
603 static int bcm63xx_spi_remove(struct platform_device *pdev)
604 {
605 	struct spi_master *master = platform_get_drvdata(pdev);
606 	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
607 
608 	/* reset spi block */
609 	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
610 
611 	/* HW shutdown */
612 	clk_disable_unprepare(bs->clk);
613 
614 	return 0;
615 }
616 
617 #ifdef CONFIG_PM_SLEEP
618 static int bcm63xx_spi_suspend(struct device *dev)
619 {
620 	struct spi_master *master = dev_get_drvdata(dev);
621 	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
622 
623 	spi_master_suspend(master);
624 
625 	clk_disable_unprepare(bs->clk);
626 
627 	return 0;
628 }
629 
630 static int bcm63xx_spi_resume(struct device *dev)
631 {
632 	struct spi_master *master = dev_get_drvdata(dev);
633 	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
634 	int ret;
635 
636 	ret = clk_prepare_enable(bs->clk);
637 	if (ret)
638 		return ret;
639 
640 	spi_master_resume(master);
641 
642 	return 0;
643 }
644 #endif
645 
646 static const struct dev_pm_ops bcm63xx_spi_pm_ops = {
647 	SET_SYSTEM_SLEEP_PM_OPS(bcm63xx_spi_suspend, bcm63xx_spi_resume)
648 };
649 
650 static struct platform_driver bcm63xx_spi_driver = {
651 	.driver = {
652 		.name	= "bcm63xx-spi",
653 		.pm	= &bcm63xx_spi_pm_ops,
654 		.of_match_table = bcm63xx_spi_of_match,
655 	},
656 	.id_table	= bcm63xx_spi_dev_match,
657 	.probe		= bcm63xx_spi_probe,
658 	.remove		= bcm63xx_spi_remove,
659 };
660 
661 module_platform_driver(bcm63xx_spi_driver);
662 
663 MODULE_ALIAS("platform:bcm63xx_spi");
664 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
665 MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>");
666 MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
667 MODULE_LICENSE("GPL");
668