summaryrefslogtreecommitdiffstats
path: root/kernel/Documentation/block/switching-sched.txt
blob: 3b2612e342f184664d0bb9d5a4cb941f21326825 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
To choose IO schedulers at boot time, use the argument 'elevator=deadline'.
'noop' and 'cfq' (the default) are also available. IO schedulers are assigned
globally at boot time only presently.

Each io queue has a set of io scheduler tunables associated with it. These
tunables control how the io scheduler works. You can find these entries
in:

/sys/block/<device>/queue/iosched

assuming that you have sysfs mounted on /sys. If you don't have sysfs mounted,
you can do so by typing:

# mount none /sys -t sysfs

As of the Linux 2.6.10 kernel, it is now possible to change the
IO scheduler for a given block device on the fly (thus making it possible,
for instance, to set the CFQ scheduler for the system default, but
set a specific device to use the deadline or noop schedulers - which
can improve that device's throughput).

To set a specific scheduler, simply do this:

echo SCHEDNAME > /sys/block/DEV/queue/scheduler

where SCHEDNAME is the name of a defined IO scheduler, and DEV is the
device name (hda, hdb, sga, or whatever you happen to have).

The list of defined schedulers can be found by simply doing
a "cat /sys/block/DEV/queue/scheduler" - the list of valid names
will be displayed, with the currently selected scheduler in brackets:

# cat /sys/block/hda/queue/scheduler
noop deadline [cfq]
# echo deadline > /sys/block/hda/queue/scheduler
# cat /sys/block/hda/queue/scheduler
noop [deadline] cfq
ref='#n388'>388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640
/*
 * Broadcom BCM63xx SPI controller support
 *
 * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
 * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/spi/spi.h>
#include <linux/completion.h>
#include <linux/err.h>
#include <linux/pm_runtime.h>

/* BCM 6338/6348 SPI core */
#define SPI_6348_RSET_SIZE		64
#define SPI_6348_CMD			0x00	/* 16-bits register */
#define SPI_6348_INT_STATUS		0x02
#define SPI_6348_INT_MASK_ST		0x03
#define SPI_6348_INT_MASK		0x04
#define SPI_6348_ST			0x05
#define SPI_6348_CLK_CFG		0x06
#define SPI_6348_FILL_BYTE		0x07
#define SPI_6348_MSG_TAIL		0x09
#define SPI_6348_RX_TAIL		0x0b
#define SPI_6348_MSG_CTL		0x40	/* 8-bits register */
#define SPI_6348_MSG_CTL_WIDTH		8
#define SPI_6348_MSG_DATA		0x41
#define SPI_6348_MSG_DATA_SIZE		0x3f
#define SPI_6348_RX_DATA		0x80
#define SPI_6348_RX_DATA_SIZE		0x3f

/* BCM 3368/6358/6262/6368 SPI core */
#define SPI_6358_RSET_SIZE		1804
#define SPI_6358_MSG_CTL		0x00	/* 16-bits register */
#define SPI_6358_MSG_CTL_WIDTH		16
#define SPI_6358_MSG_DATA		0x02
#define SPI_6358_MSG_DATA_SIZE		0x21e
#define SPI_6358_RX_DATA		0x400
#define SPI_6358_RX_DATA_SIZE		0x220
#define SPI_6358_CMD			0x700	/* 16-bits register */
#define SPI_6358_INT_STATUS		0x702
#define SPI_6358_INT_MASK_ST		0x703
#define SPI_6358_INT_MASK		0x704
#define SPI_6358_ST			0x705
#define SPI_6358_CLK_CFG		0x706
#define SPI_6358_FILL_BYTE		0x707
#define SPI_6358_MSG_TAIL		0x709
#define SPI_6358_RX_TAIL		0x70B

/* Shared SPI definitions */

/* Message configuration */
#define SPI_FD_RW			0x00
#define SPI_HD_W			0x01
#define SPI_HD_R			0x02
#define SPI_BYTE_CNT_SHIFT		0
#define SPI_6348_MSG_TYPE_SHIFT		6
#define SPI_6358_MSG_TYPE_SHIFT		14

/* Command */
#define SPI_CMD_NOOP			0x00
#define SPI_CMD_SOFT_RESET		0x01
#define SPI_CMD_HARD_RESET		0x02
#define SPI_CMD_START_IMMEDIATE		0x03
#define SPI_CMD_COMMAND_SHIFT		0
#define SPI_CMD_COMMAND_MASK		0x000f
#define SPI_CMD_DEVICE_ID_SHIFT		4
#define SPI_CMD_PREPEND_BYTE_CNT_SHIFT	8
#define SPI_CMD_ONE_BYTE_SHIFT		11
#define SPI_CMD_ONE_WIRE_SHIFT		12
#define SPI_DEV_ID_0			0
#define SPI_DEV_ID_1			1
#define SPI_DEV_ID_2			2
#define SPI_DEV_ID_3			3

/* Interrupt mask */
#define SPI_INTR_CMD_DONE		0x01
#define SPI_INTR_RX_OVERFLOW		0x02
#define SPI_INTR_TX_UNDERFLOW		0x04
#define SPI_INTR_TX_OVERFLOW		0x08
#define SPI_INTR_RX_UNDERFLOW		0x10
#define SPI_INTR_CLEAR_ALL		0x1f

/* Status */
#define SPI_RX_EMPTY			0x02
#define SPI_CMD_BUSY			0x04
#define SPI_SERIAL_BUSY			0x08

/* Clock configuration */
#define SPI_CLK_20MHZ			0x00
#define SPI_CLK_0_391MHZ		0x01
#define SPI_CLK_0_781MHZ		0x02	/* default */
#define SPI_CLK_1_563MHZ		0x03
#define SPI_CLK_3_125MHZ		0x04
#define SPI_CLK_6_250MHZ		0x05
#define SPI_CLK_12_50MHZ		0x06
#define SPI_CLK_MASK			0x07
#define SPI_SSOFFTIME_MASK		0x38
#define SPI_SSOFFTIME_SHIFT		3
#define SPI_BYTE_SWAP			0x80

enum bcm63xx_regs_spi {
	SPI_CMD,
	SPI_INT_STATUS,
	SPI_INT_MASK_ST,
	SPI_INT_MASK,
	SPI_ST,
	SPI_CLK_CFG,
	SPI_FILL_BYTE,
	SPI_MSG_TAIL,
	SPI_RX_TAIL,
	SPI_MSG_CTL,
	SPI_MSG_DATA,
	SPI_RX_DATA,
	SPI_MSG_TYPE_SHIFT,
	SPI_MSG_CTL_WIDTH,
	SPI_MSG_DATA_SIZE,
};

#define BCM63XX_SPI_MAX_PREPEND		15

#define BCM63XX_SPI_MAX_CS		8
#define BCM63XX_SPI_BUS_NUM		0

struct bcm63xx_spi {
	struct completion	done;

	void __iomem		*regs;
	int			irq;

	/* Platform data */
	const unsigned long	*reg_offsets;
	unsigned		fifo_size;
	unsigned int		msg_type_shift;
	unsigned int		msg_ctl_width;

	/* data iomem */
	u8 __iomem		*tx_io;
	const u8 __iomem	*rx_io;

	struct clk		*clk;
	struct platform_device	*pdev;
};

static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs,
			       unsigned int offset)
{
	return readb(bs->regs + bs->reg_offsets[offset]);
}

static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs,
				unsigned int offset)
{
#ifdef CONFIG_CPU_BIG_ENDIAN
	return ioread16be(bs->regs + bs->reg_offsets[offset]);
#else
	return readw(bs->regs + bs->reg_offsets[offset]);
#endif
}

static inline void bcm_spi_writeb(struct bcm63xx_spi *bs,
				  u8 value, unsigned int offset)
{
	writeb(value, bs->regs + bs->reg_offsets[offset]);
}

static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
				  u16 value, unsigned int offset)
{
#ifdef CONFIG_CPU_BIG_ENDIAN
	iowrite16be(value, bs->regs + bs->reg_offsets[offset]);
#else
	writew(value, bs->regs + bs->reg_offsets[offset]);
#endif
}

static const unsigned bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
	{ 20000000, SPI_CLK_20MHZ },
	{ 12500000, SPI_CLK_12_50MHZ },
	{  6250000, SPI_CLK_6_250MHZ },
	{  3125000, SPI_CLK_3_125MHZ },
	{  1563000, SPI_CLK_1_563MHZ },
	{   781000, SPI_CLK_0_781MHZ },
	{   391000, SPI_CLK_0_391MHZ }
};

static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
				      struct spi_transfer *t)
{
	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
	u8 clk_cfg, reg;
	int i;

	/* Find the closest clock configuration */
	for (i = 0; i < SPI_CLK_MASK; i++) {
		if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) {
			clk_cfg = bcm63xx_spi_freq_table[i][1];
			break;
		}
	}

	/* No matching configuration found, default to lowest */
	if (i == SPI_CLK_MASK)
		clk_cfg = SPI_CLK_0_391MHZ;

	/* clear existing clock configuration bits of the register */
	reg = bcm_spi_readb(bs, SPI_CLK_CFG);
	reg &= ~SPI_CLK_MASK;
	reg |= clk_cfg;

	bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
	dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
		clk_cfg, t->speed_hz);
}

/* the spi->mode bits understood by this driver: */
#define MODEBITS (SPI_CPOL | SPI_CPHA)

static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first,
				unsigned int num_transfers)
{
	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
	u16 msg_ctl;
	u16 cmd;
	unsigned int i, timeout = 0, prepend_len = 0, len = 0;
	struct spi_transfer *t = first;
	bool do_rx = false;
	bool do_tx = false;

	/* Disable the CMD_DONE interrupt */
	bcm_spi_writeb(bs, 0, SPI_INT_MASK);

	dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
		t->tx_buf, t->rx_buf, t->len);

	if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND)
		prepend_len = t->len;

	/* prepare the buffer */
	for (i = 0; i < num_transfers; i++) {
		if (t->tx_buf) {
			do_tx = true;
			memcpy_toio(bs->tx_io + len, t->tx_buf, t->len);

			/* don't prepend more than one tx */
			if (t != first)
				prepend_len = 0;
		}

		if (t->rx_buf) {
			do_rx = true;
			/* prepend is half-duplex write only */
			if (t == first)
				prepend_len = 0;
		}

		len += t->len;

		t = list_entry(t->transfer_list.next, struct spi_transfer,
			       transfer_list);
	}

	reinit_completion(&bs->done);

	/* Fill in the Message control register */
	msg_ctl = (len << SPI_BYTE_CNT_SHIFT);

	if (do_rx && do_tx && prepend_len == 0)
		msg_ctl |= (SPI_FD_RW << bs->msg_type_shift);
	else if (do_rx)
		msg_ctl |= (SPI_HD_R << bs->msg_type_shift);
	else if (do_tx)
		msg_ctl |= (SPI_HD_W << bs->msg_type_shift);

	switch (bs->msg_ctl_width) {
	case 8:
		bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL);
		break;
	case 16:
		bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
		break;
	}

	/* Issue the transfer */
	cmd = SPI_CMD_START_IMMEDIATE;
	cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
	cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
	bcm_spi_writew(bs, cmd, SPI_CMD);

	/* Enable the CMD_DONE interrupt */
	bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);

	timeout = wait_for_completion_timeout(&bs->done, HZ);
	if (!timeout)
		return -ETIMEDOUT;

	if (!do_rx)
		return 0;

	len = 0;
	t = first;
	/* Read out all the data */
	for (i = 0; i < num_transfers; i++) {
		if (t->rx_buf)
			memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len);

		if (t != first || prepend_len == 0)
			len += t->len;

		t = list_entry(t->transfer_list.next, struct spi_transfer,
			       transfer_list);
	}

	return 0;
}

static int bcm63xx_spi_transfer_one(struct spi_master *master,
					struct spi_message *m)
{
	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
	struct spi_transfer *t, *first = NULL;
	struct spi_device *spi = m->spi;
	int status = 0;
	unsigned int n_transfers = 0, total_len = 0;
	bool can_use_prepend = false;

	/*
	 * This SPI controller does not support keeping CS active after a
	 * transfer.
	 * Work around this by merging as many transfers we can into one big
	 * full-duplex transfers.
	 */
	list_for_each_entry(t, &m->transfers, transfer_list) {
		if (!first)
			first = t;

		n_transfers++;
		total_len += t->len;

		if (n_transfers == 2 && !first->rx_buf && !t->tx_buf &&
		    first->len <= BCM63XX_SPI_MAX_PREPEND)
			can_use_prepend = true;
		else if (can_use_prepend && t->tx_buf)
			can_use_prepend = false;

		/* we can only transfer one fifo worth of data */
		if ((can_use_prepend &&
		     total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) ||
		    (!can_use_prepend && total_len > bs->fifo_size)) {
			dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
				total_len, bs->fifo_size);
			status = -EINVAL;
			goto exit;
		}

		/* all combined transfers have to have the same speed */
		if (t->speed_hz != first->speed_hz) {
			dev_err(&spi->dev, "unable to change speed between transfers\n");
			status = -EINVAL;
			goto exit;
		}

		/* CS will be deasserted directly after transfer */
		if (t->delay_usecs) {
			dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
			status = -EINVAL;
			goto exit;
		}

		if (t->cs_change ||
		    list_is_last(&t->transfer_list, &m->transfers)) {
			/* configure adapter for a new transfer */
			bcm63xx_spi_setup_transfer(spi, first);

			/* send the data */
			status = bcm63xx_txrx_bufs(spi, first, n_transfers);
			if (status)
				goto exit;

			m->actual_length += total_len;

			first = NULL;
			n_transfers = 0;
			total_len = 0;
			can_use_prepend = false;
		}
	}
exit:
	m->status = status;
	spi_finalize_current_message(master);

	return 0;
}

/* This driver supports single master mode only. Hence
 * CMD_DONE is the only interrupt we care about
 */
static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
{
	struct spi_master *master = (struct spi_master *)dev_id;
	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
	u8 intr;

	/* Read interupts and clear them immediately */
	intr = bcm_spi_readb(bs, SPI_INT_STATUS);
	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
	bcm_spi_writeb(bs, 0, SPI_INT_MASK);

	/* A transfer completed */
	if (intr & SPI_INTR_CMD_DONE)
		complete(&bs->done);

	return IRQ_HANDLED;
}

static const unsigned long bcm6348_spi_reg_offsets[] = {
	[SPI_CMD]		= SPI_6348_CMD,
	[SPI_INT_STATUS]	= SPI_6348_INT_STATUS,
	[SPI_INT_MASK_ST]	= SPI_6348_INT_MASK_ST,
	[SPI_INT_MASK]		= SPI_6348_INT_MASK,
	[SPI_ST]		= SPI_6348_ST,
	[SPI_CLK_CFG]		= SPI_6348_CLK_CFG,
	[SPI_FILL_BYTE]		= SPI_6348_FILL_BYTE,
	[SPI_MSG_TAIL]		= SPI_6348_MSG_TAIL,
	[SPI_RX_TAIL]		= SPI_6348_RX_TAIL,
	[SPI_MSG_CTL]		= SPI_6348_MSG_CTL,
	[SPI_MSG_DATA]		= SPI_6348_MSG_DATA,
	[SPI_RX_DATA]		= SPI_6348_RX_DATA,
	[SPI_MSG_TYPE_SHIFT]	= SPI_6348_MSG_TYPE_SHIFT,
	[SPI_MSG_CTL_WIDTH]	= SPI_6348_MSG_CTL_WIDTH,
	[SPI_MSG_DATA_SIZE]	= SPI_6348_MSG_DATA_SIZE,
};

static const unsigned long bcm6358_spi_reg_offsets[] = {
	[SPI_CMD]		= SPI_6358_CMD,
	[SPI_INT_STATUS]	= SPI_6358_INT_STATUS,
	[SPI_INT_MASK_ST]	= SPI_6358_INT_MASK_ST,
	[SPI_INT_MASK]		= SPI_6358_INT_MASK,
	[SPI_ST]		= SPI_6358_ST,
	[SPI_CLK_CFG]		= SPI_6358_CLK_CFG,
	[SPI_FILL_BYTE]		= SPI_6358_FILL_BYTE,
	[SPI_MSG_TAIL]		= SPI_6358_MSG_TAIL,
	[SPI_RX_TAIL]		= SPI_6358_RX_TAIL,
	[SPI_MSG_CTL]		= SPI_6358_MSG_CTL,
	[SPI_MSG_DATA]		= SPI_6358_MSG_DATA,
	[SPI_RX_DATA]		= SPI_6358_RX_DATA,
	[SPI_MSG_TYPE_SHIFT]	= SPI_6358_MSG_TYPE_SHIFT,
	[SPI_MSG_CTL_WIDTH]	= SPI_6358_MSG_CTL_WIDTH,
	[SPI_MSG_DATA_SIZE]	= SPI_6358_MSG_DATA_SIZE,
};

static const struct platform_device_id bcm63xx_spi_dev_match[] = {
	{
		.name = "bcm6348-spi",
		.driver_data = (unsigned long)bcm6348_spi_reg_offsets,
	},
	{
		.name = "bcm6358-spi",
		.driver_data = (unsigned long)bcm6358_spi_reg_offsets,
	},
	{
	},
};

static int bcm63xx_spi_probe(struct platform_device *pdev)
{
	struct resource *r;
	const unsigned long *bcm63xx_spireg;
	struct device *dev = &pdev->dev;
	int irq;
	struct spi_master *master;
	struct clk *clk;
	struct bcm63xx_spi *bs;
	int ret;

	if (!pdev->id_entry->driver_data)
		return -EINVAL;

	bcm63xx_spireg = (const unsigned long *)pdev->id_entry->driver_data;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(dev, "no irq\n");
		return -ENXIO;
	}

	clk = devm_clk_get(dev, "spi");
	if (IS_ERR(clk)) {
		dev_err(dev, "no clock for device\n");
		return PTR_ERR(clk);
	}

	master = spi_alloc_master(dev, sizeof(*bs));
	if (!master) {
		dev_err(dev, "out of memory\n");
		return -ENOMEM;
	}

	bs = spi_master_get_devdata(master);
	init_completion(&bs->done);

	platform_set_drvdata(pdev, master);
	bs->pdev = pdev;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	bs->regs = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(bs->regs)) {
		ret = PTR_ERR(bs->regs);
		goto out_err;
	}

	bs->irq = irq;
	bs->clk = clk;
	bs->reg_offsets = bcm63xx_spireg;
	bs->fifo_size = bs->reg_offsets[SPI_MSG_DATA_SIZE];

	ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
							pdev->name, master);
	if (ret) {
		dev_err(dev, "unable to request irq\n");
		goto out_err;
	}

	master->bus_num = BCM63XX_SPI_BUS_NUM;
	master->num_chipselect = BCM63XX_SPI_MAX_CS;
	master->transfer_one_message = bcm63xx_spi_transfer_one;
	master->mode_bits = MODEBITS;
	master->bits_per_word_mask = SPI_BPW_MASK(8);
	master->auto_runtime_pm = true;
	bs->msg_type_shift = bs->reg_offsets[SPI_MSG_TYPE_SHIFT];
	bs->msg_ctl_width = bs->reg_offsets[SPI_MSG_CTL_WIDTH];
	bs->tx_io = (u8 *)(bs->regs + bs->reg_offsets[SPI_MSG_DATA]);
	bs->rx_io = (const u8 *)(bs->regs + bs->reg_offsets[SPI_RX_DATA]);

	/* Initialize hardware */
	ret = clk_prepare_enable(bs->clk);
	if (ret)
		goto out_err;

	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);

	/* register and we are done */
	ret = devm_spi_register_master(dev, master);
	if (ret) {
		dev_err(dev, "spi register failed\n");
		goto out_clk_disable;
	}

	dev_info(dev, "at %pr (irq %d, FIFOs size %d)\n",
		 r, irq, bs->fifo_size);

	return 0;

out_clk_disable:
	clk_disable_unprepare(clk);
out_err:
	spi_master_put(master);
	return ret;
}

static int bcm63xx_spi_remove(struct platform_device *pdev)
{
	struct spi_master *master = platform_get_drvdata(pdev);
	struct bcm63xx_spi *bs = spi_master_get_devdata(master);

	/* reset spi block */
	bcm_spi_writeb(bs, 0, SPI_INT_MASK);

	/* HW shutdown */
	clk_disable_unprepare(bs->clk);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int bcm63xx_spi_suspend(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct bcm63xx_spi *bs = spi_master_get_devdata(master);

	spi_master_suspend(master);

	clk_disable_unprepare(bs->clk);

	return 0;
}

static int bcm63xx_spi_resume(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
	int ret;

	ret = clk_prepare_enable(bs->clk);
	if (ret)
		return ret;

	spi_master_resume(master);

	return 0;
}
#endif

static const struct dev_pm_ops bcm63xx_spi_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(bcm63xx_spi_suspend, bcm63xx_spi_resume)
};

static struct platform_driver bcm63xx_spi_driver = {
	.driver = {
		.name	= "bcm63xx-spi",
		.pm	= &bcm63xx_spi_pm_ops,
	},
	.id_table	= bcm63xx_spi_dev_match,
	.probe		= bcm63xx_spi_probe,
	.remove		= bcm63xx_spi_remove,
};

module_platform_driver(bcm63xx_spi_driver);

MODULE_ALIAS("platform:bcm63xx_spi");
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>");
MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
MODULE_LICENSE("GPL");