[linux.git] / drivers / spi / spi_sh_msiof.c

/*
 * SuperH MSIOF SPI Master Interface
 *
 * Copyright (c) 2009 Magnus Damm
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/bitmap.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>

#include <linux/spi/sh_msiof.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>

#include <asm/unaligned.h>

struct sh_msiof_spi_priv {
	struct spi_bitbang bitbang; /* must be first for spi_bitbang.c */
	void __iomem *mapbase;
	struct clk *clk;
	struct platform_device *pdev;
	struct sh_msiof_spi_info *info;
	struct completion done;
	unsigned long flags;
	int tx_fifo_size;
	int rx_fifo_size;
};

#define TMDR1	0x00
#define TMDR2	0x04
#define TMDR3	0x08
#define RMDR1	0x10
#define RMDR2	0x14
#define RMDR3	0x18
#define TSCR	0x20
#define RSCR	0x22
#define CTR	0x28
#define FCTR	0x30
#define STR	0x40
#define IER	0x44
#define TDR1	0x48
#define TDR2	0x4c
#define TFDR	0x50
#define RDR1	0x58
#define RDR2	0x5c
#define RFDR	0x60

#define CTR_TSCKE (1 << 15)
#define CTR_TFSE  (1 << 14)
#define CTR_TXE   (1 << 9)
#define CTR_RXE   (1 << 8)

#define STR_TEOF  (1 << 23)
#define STR_REOF  (1 << 7)

static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
{
	switch (reg_offs) {
	case TSCR:
	case RSCR:
		return ioread16(p->mapbase + reg_offs);
	default:
		return ioread32(p->mapbase + reg_offs);
	}
}

static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
			   u32 value)
{
	switch (reg_offs) {
	case TSCR:
	case RSCR:
		iowrite16(value, p->mapbase + reg_offs);
		break;
	default:
		iowrite32(value, p->mapbase + reg_offs);
		break;
	}
}

static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
				    u32 clr, u32 set)
{
	u32 mask = clr | set;
	u32 data;
	int k;

	data = sh_msiof_read(p, CTR);
	data &= ~clr;
	data |= set;
	sh_msiof_write(p, CTR, data);

	for (k = 100; k > 0; k--) {
		if ((sh_msiof_read(p, CTR) & mask) == set)
			break;

		udelay(10);
	}

	return k > 0 ? 0 : -ETIMEDOUT;
}

static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
{
	struct sh_msiof_spi_priv *p = data;

	/* just disable the interrupt and wake up */
	sh_msiof_write(p, IER, 0);
	complete(&p->done);

	return IRQ_HANDLED;
}

static struct {
	unsigned short div;
	unsigned short scr;
} const sh_msiof_spi_clk_table[] = {
	{ 1, 0x0007 },
	{ 2, 0x0000 },
	{ 4, 0x0001 },
	{ 8, 0x0002 },
	{ 16, 0x0003 },
	{ 32, 0x0004 },
	{ 64, 0x1f00 },
	{ 128, 0x1f01 },
	{ 256, 0x1f02 },
	{ 512, 0x1f03 },
	{ 1024, 0x1f04 },
};

static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
				      unsigned long parent_rate,
				      unsigned long spi_hz)
{
	unsigned long div = 1024;
	size_t k;

	if (!WARN_ON(!spi_hz || !parent_rate))
		div = parent_rate / spi_hz;

	/* TODO: make more fine grained */

	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_clk_table); k++) {
		if (sh_msiof_spi_clk_table[k].div >= div)
			break;
	}

	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_clk_table) - 1);

	sh_msiof_write(p, TSCR, sh_msiof_spi_clk_table[k].scr);
	sh_msiof_write(p, RSCR, sh_msiof_spi_clk_table[k].scr);
}

static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
				      u32 cpol, u32 cpha,
				      u32 tx_hi_z, u32 lsb_first)
{
	u32 tmp;
	int edge;

	/*
	 * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
	 *    0    0         10     10    1    1
	 *    0    1         10     10    0    0
	 *    1    0         11     11    0    0
	 *    1    1         11     11    1    1
	 */
	sh_msiof_write(p, FCTR, 0);
	sh_msiof_write(p, TMDR1, 0xe2000005 | (lsb_first << 24));
	sh_msiof_write(p, RMDR1, 0x22000005 | (lsb_first << 24));

	tmp = 0xa0000000;
	tmp |= cpol << 30; /* TSCKIZ */
	tmp |= cpol << 28; /* RSCKIZ */

	edge = cpol ^ !cpha;

	tmp |= edge << 27; /* TEDG */
	tmp |= edge << 26; /* REDG */
	tmp |= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */
	sh_msiof_write(p, CTR, tmp);
}

static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
				       const void *tx_buf, void *rx_buf,
				       u32 bits, u32 words)
{
	u32 dr2 = ((bits - 1) << 24) | ((words - 1) << 16);

	if (tx_buf)
		sh_msiof_write(p, TMDR2, dr2);
	else
		sh_msiof_write(p, TMDR2, dr2 | 1);

	if (rx_buf)
		sh_msiof_write(p, RMDR2, dr2);

	sh_msiof_write(p, IER, STR_TEOF | STR_REOF);
}

static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
{
	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
}

static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
				      const void *tx_buf, int words, int fs)
{
	const u8 *buf_8 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, buf_8[k] << fs);
}

static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
				       const void *tx_buf, int words, int fs)
{
	const u16 *buf_16 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, buf_16[k] << fs);
}

static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
					const void *tx_buf, int words, int fs)
{
	const u16 *buf_16 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
}

static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
				       const void *tx_buf, int words, int fs)
{
	const u32 *buf_32 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, buf_32[k] << fs);
}

static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
					const void *tx_buf, int words, int fs)
{
	const u32 *buf_32 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
}

static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
					const void *tx_buf, int words, int fs)
{
	const u32 *buf_32 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
}

static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
					 const void *tx_buf, int words, int fs)
{
	const u32 *buf_32 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
}

static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
				     void *rx_buf, int words, int fs)
{
	u8 *buf_8 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
}

static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
				      void *rx_buf, int words, int fs)
{
	u16 *buf_16 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
}

static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
				       void *rx_buf, int words, int fs)
{
	u16 *buf_16 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
}

static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
				      void *rx_buf, int words, int fs)
{
	u32 *buf_32 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
}

static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
				       void *rx_buf, int words, int fs)
{
	u32 *buf_32 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
}

static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
				       void *rx_buf, int words, int fs)
{
	u32 *buf_32 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
}

static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
				       void *rx_buf, int words, int fs)
{
	u32 *buf_32 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
}

static int sh_msiof_spi_bits(struct spi_device *spi, struct spi_transfer *t)
{
	int bits;

	bits = t ? t->bits_per_word : 0;
	if (!bits)
		bits = spi->bits_per_word;
	return bits;
}

static unsigned long sh_msiof_spi_hz(struct spi_device *spi,
				     struct spi_transfer *t)
{
	unsigned long hz;

	hz = t ? t->speed_hz : 0;
	if (!hz)
		hz = spi->max_speed_hz;
	return hz;
}

static int sh_msiof_spi_setup_transfer(struct spi_device *spi,
				       struct spi_transfer *t)
{
	int bits;

	/* noting to check hz values against since parent clock is disabled */

	bits = sh_msiof_spi_bits(spi, t);
	if (bits < 8)
		return -EINVAL;
	if (bits > 32)
		return -EINVAL;

	return spi_bitbang_setup_transfer(spi, t);
}

static void sh_msiof_spi_chipselect(struct spi_device *spi, int is_on)
{
	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
	int value;

	/* chip select is active low unless SPI_CS_HIGH is set */
	if (spi->mode & SPI_CS_HIGH)
		value = (is_on == BITBANG_CS_ACTIVE) ? 1 : 0;
	else
		value = (is_on == BITBANG_CS_ACTIVE) ? 0 : 1;

	if (is_on == BITBANG_CS_ACTIVE) {
		if (!test_and_set_bit(0, &p->flags)) {
			pm_runtime_get_sync(&p->pdev->dev);
			clk_enable(p->clk);
		}

		/* Configure pins before asserting CS */
		sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
					  !!(spi->mode & SPI_CPHA),
					  !!(spi->mode & SPI_3WIRE),
					  !!(spi->mode & SPI_LSB_FIRST));
	}

	/* use spi->controller data for CS (same strategy as spi_gpio) */
	gpio_set_value((unsigned)spi->controller_data, value);

	if (is_on == BITBANG_CS_INACTIVE) {
		if (test_and_clear_bit(0, &p->flags)) {
			clk_disable(p->clk);
			pm_runtime_put(&p->pdev->dev);
		}
	}
}

static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
						  const void *, int, int),
				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
						  void *, int, int),
				  const void *tx_buf, void *rx_buf,
				  int words, int bits)
{
	int fifo_shift;
	int ret;

	/* limit maximum word transfer to rx/tx fifo size */
	if (tx_buf)
		words = min_t(int, words, p->tx_fifo_size);
	if (rx_buf)
		words = min_t(int, words, p->rx_fifo_size);

	/* the fifo contents need shifting */
	fifo_shift = 32 - bits;

	/* setup msiof transfer mode registers */
	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);

	/* write tx fifo */
	if (tx_buf)
		tx_fifo(p, tx_buf, words, fifo_shift);

	/* setup clock and rx/tx signals */
	ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
	if (rx_buf)
		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);

	/* start by setting frame bit */
	INIT_COMPLETION(p->done);
	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
	if (ret) {
		dev_err(&p->pdev->dev, "failed to start hardware\n");
		goto err;
	}

	/* wait for tx fifo to be emptied / rx fifo to be filled */
	wait_for_completion(&p->done);

	/* read rx fifo */
	if (rx_buf)
		rx_fifo(p, rx_buf, words, fifo_shift);

	/* clear status bits */
	sh_msiof_reset_str(p);

	/* shut down frame, tx/tx and clock signals */
	ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
	if (rx_buf)
		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
	if (ret) {
		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
		goto err;
	}

	return words;

 err:
	sh_msiof_write(p, IER, 0);
	return ret;
}

static int sh_msiof_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
{
	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
	int bits;
	int bytes_per_word;
	int bytes_done;
	int words;
	int n;
	bool swab;

	bits = sh_msiof_spi_bits(spi, t);

	if (bits <= 8 && t->len > 15 && !(t->len & 3)) {
		bits = 32;
		swab = true;
	} else {
		swab = false;
	}

	/* setup bytes per word and fifo read/write functions */
	if (bits <= 8) {
		bytes_per_word = 1;
		tx_fifo = sh_msiof_spi_write_fifo_8;
		rx_fifo = sh_msiof_spi_read_fifo_8;
	} else if (bits <= 16) {
		bytes_per_word = 2;
		if ((unsigned long)t->tx_buf & 0x01)
			tx_fifo = sh_msiof_spi_write_fifo_16u;
		else
			tx_fifo = sh_msiof_spi_write_fifo_16;

		if ((unsigned long)t->rx_buf & 0x01)
			rx_fifo = sh_msiof_spi_read_fifo_16u;
		else
			rx_fifo = sh_msiof_spi_read_fifo_16;
	} else if (swab) {
		bytes_per_word = 4;
		if ((unsigned long)t->tx_buf & 0x03)
			tx_fifo = sh_msiof_spi_write_fifo_s32u;
		else
			tx_fifo = sh_msiof_spi_write_fifo_s32;

		if ((unsigned long)t->rx_buf & 0x03)
			rx_fifo = sh_msiof_spi_read_fifo_s32u;
		else
			rx_fifo = sh_msiof_spi_read_fifo_s32;
	} else {
		bytes_per_word = 4;
		if ((unsigned long)t->tx_buf & 0x03)
			tx_fifo = sh_msiof_spi_write_fifo_32u;
		else
			tx_fifo = sh_msiof_spi_write_fifo_32;

		if ((unsigned long)t->rx_buf & 0x03)
			rx_fifo = sh_msiof_spi_read_fifo_32u;
		else
			rx_fifo = sh_msiof_spi_read_fifo_32;
	}

	/* setup clocks (clock already enabled in chipselect()) */
	sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk),
				  sh_msiof_spi_hz(spi, t));

	/* transfer in fifo sized chunks */
	words = t->len / bytes_per_word;
	bytes_done = 0;

	while (bytes_done < t->len) {
		void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
		const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
					   tx_buf,
					   rx_buf,
					   words, bits);
		if (n < 0)
			break;

		bytes_done += n * bytes_per_word;
		words -= n;
	}

	return bytes_done;
}

static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
				  u32 word, u8 bits)
{
	BUG(); /* unused but needed by bitbang code */
	return 0;
}

static int sh_msiof_spi_probe(struct platform_device *pdev)
{
	struct resource	*r;
	struct spi_master *master;
	struct sh_msiof_spi_priv *p;
	char clk_name[16];
	int i;
	int ret;

	master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
	if (master == NULL) {
		dev_err(&pdev->dev, "failed to allocate spi master\n");
		ret = -ENOMEM;
		goto err0;
	}

	p = spi_master_get_devdata(master);

	platform_set_drvdata(pdev, p);
	p->info = pdev->dev.platform_data;
	init_completion(&p->done);

	snprintf(clk_name, sizeof(clk_name), "msiof%d", pdev->id);
	p->clk = clk_get(&pdev->dev, clk_name);
	if (IS_ERR(p->clk)) {
		dev_err(&pdev->dev, "cannot get clock \"%s\"\n", clk_name);
		ret = PTR_ERR(p->clk);
		goto err1;
	}

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	i = platform_get_irq(pdev, 0);
	if (!r || i < 0) {
		dev_err(&pdev->dev, "cannot get platform resources\n");
		ret = -ENOENT;
		goto err2;
	}
	p->mapbase = ioremap_nocache(r->start, resource_size(r));
	if (!p->mapbase) {
		dev_err(&pdev->dev, "unable to ioremap\n");
		ret = -ENXIO;
		goto err2;
	}

	ret = request_irq(i, sh_msiof_spi_irq, IRQF_DISABLED,
			  dev_name(&pdev->dev), p);
	if (ret) {
		dev_err(&pdev->dev, "unable to request irq\n");
		goto err3;
	}

	p->pdev = pdev;
	pm_runtime_enable(&pdev->dev);

	/* The standard version of MSIOF use 64 word FIFOs */
	p->tx_fifo_size = 64;
	p->rx_fifo_size = 64;

	/* Platform data may override FIFO sizes */
	if (p->info->tx_fifo_override)
		p->tx_fifo_size = p->info->tx_fifo_override;
	if (p->info->rx_fifo_override)
		p->rx_fifo_size = p->info->rx_fifo_override;

	/* init master and bitbang code */
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
	master->flags = 0;
	master->bus_num = pdev->id;
	master->num_chipselect = p->info->num_chipselect;
	master->setup = spi_bitbang_setup;
	master->cleanup = spi_bitbang_cleanup;

	p->bitbang.master = master;
	p->bitbang.chipselect = sh_msiof_spi_chipselect;
	p->bitbang.setup_transfer = sh_msiof_spi_setup_transfer;
	p->bitbang.txrx_bufs = sh_msiof_spi_txrx;
	p->bitbang.txrx_word[SPI_MODE_0] = sh_msiof_spi_txrx_word;
	p->bitbang.txrx_word[SPI_MODE_1] = sh_msiof_spi_txrx_word;
	p->bitbang.txrx_word[SPI_MODE_2] = sh_msiof_spi_txrx_word;
	p->bitbang.txrx_word[SPI_MODE_3] = sh_msiof_spi_txrx_word;

	ret = spi_bitbang_start(&p->bitbang);
	if (ret == 0)
		return 0;

	pm_runtime_disable(&pdev->dev);
 err3:
	iounmap(p->mapbase);
 err2:
	clk_put(p->clk);
 err1:
	spi_master_put(master);
 err0:
	return ret;
}

static int sh_msiof_spi_remove(struct platform_device *pdev)
{
	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
	int ret;

	ret = spi_bitbang_stop(&p->bitbang);
	if (!ret) {
		pm_runtime_disable(&pdev->dev);
		free_irq(platform_get_irq(pdev, 0), p);
		iounmap(p->mapbase);
		clk_put(p->clk);
		spi_master_put(p->bitbang.master);
	}
	return ret;
}

static int sh_msiof_spi_runtime_nop(struct device *dev)
{
	/* Runtime PM callback shared between ->runtime_suspend()
	 * and ->runtime_resume(). Simply returns success.
	 *
	 * This driver re-initializes all registers after
	 * pm_runtime_get_sync() anyway so there is no need
	 * to save and restore registers here.
	 */
	return 0;
}

static struct dev_pm_ops sh_msiof_spi_dev_pm_ops = {
	.runtime_suspend = sh_msiof_spi_runtime_nop,
	.runtime_resume = sh_msiof_spi_runtime_nop,
};

static struct platform_driver sh_msiof_spi_drv = {
	.probe		= sh_msiof_spi_probe,
	.remove		= sh_msiof_spi_remove,
	.driver		= {
		.name		= "spi_sh_msiof",
		.owner		= THIS_MODULE,
		.pm		= &sh_msiof_spi_dev_pm_ops,
	},
};

static int __init sh_msiof_spi_init(void)
{
	return platform_driver_register(&sh_msiof_spi_drv);
}
module_init(sh_msiof_spi_init);

static void __exit sh_msiof_spi_exit(void)
{
	platform_driver_unregister(&sh_msiof_spi_drv);
}
module_exit(sh_msiof_spi_exit);

MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
MODULE_AUTHOR("Magnus Damm");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:spi_sh_msiof");
Commit	Line	Data
8051effc MD	1	/*
	2	* SuperH MSIOF SPI Master Interface
	3	*
	4	* Copyright (c) 2009 Magnus Damm
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	*/
	11
e2dbf5eb GL	12	#include <linux/bitmap.h>
	13	#include <linux/clk.h>
	14	#include <linux/completion.h>
8051effc	15	#include <linux/delay.h>
e2dbf5eb GL	16	#include <linux/err.h>
	17	#include <linux/gpio.h>
	18	#include <linux/init.h>
8051effc	19	#include <linux/interrupt.h>
e2dbf5eb GL	20	#include <linux/io.h>
e2dbf5eb GL	21	#include <linux/kernel.h>
8051effc	22	#include <linux/platform_device.h>
8051effc	23	#include <linux/pm_runtime.h>
8051effc	24
e2dbf5eb	25	#include <linux/spi/sh_msiof.h>
8051effc MD	26	#include <linux/spi/spi.h>
8051effc MD	27	#include <linux/spi/spi_bitbang.h>
8051effc	28
8051effc MD	29	#include <asm/unaligned.h>
	30
	31	struct sh_msiof_spi_priv {
	32	struct spi_bitbang bitbang; /* must be first for spi_bitbang.c */
	33	void __iomem *mapbase;
	34	struct clk *clk;
	35	struct platform_device *pdev;
	36	struct sh_msiof_spi_info *info;
	37	struct completion done;
	38	unsigned long flags;
	39	int tx_fifo_size;
	40	int rx_fifo_size;
	41	};
	42
	43	#define TMDR1 0x00
	44	#define TMDR2 0x04
	45	#define TMDR3 0x08
	46	#define RMDR1 0x10
	47	#define RMDR2 0x14
	48	#define RMDR3 0x18
	49	#define TSCR 0x20
	50	#define RSCR 0x22
	51	#define CTR 0x28
	52	#define FCTR 0x30
	53	#define STR 0x40
	54	#define IER 0x44
	55	#define TDR1 0x48
	56	#define TDR2 0x4c
	57	#define TFDR 0x50
	58	#define RDR1 0x58
	59	#define RDR2 0x5c
	60	#define RFDR 0x60
	61
	62	#define CTR_TSCKE (1 << 15)
	63	#define CTR_TFSE (1 << 14)
	64	#define CTR_TXE (1 << 9)
	65	#define CTR_RXE (1 << 8)
	66
	67	#define STR_TEOF (1 << 23)
	68	#define STR_REOF (1 << 7)
	69
e2dbf5eb	70	static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
8051effc MD	71	{
	72	switch (reg_offs) {
	73	case TSCR:
	74	case RSCR:
	75	return ioread16(p->mapbase + reg_offs);
	76	default:
	77	return ioread32(p->mapbase + reg_offs);
	78	}
	79	}
	80
	81	static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
e2dbf5eb	82	u32 value)
8051effc MD	83	{
	84	switch (reg_offs) {
	85	case TSCR:
	86	case RSCR:
	87	iowrite16(value, p->mapbase + reg_offs);
	88	break;
	89	default:
	90	iowrite32(value, p->mapbase + reg_offs);
	91	break;
	92	}
	93	}
	94
	95	static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
e2dbf5eb	96	u32 clr, u32 set)
8051effc	97	{
e2dbf5eb GL	98	u32 mask = clr \| set;
e2dbf5eb GL	99	u32 data;
8051effc MD	100	int k;
	101
	102	data = sh_msiof_read(p, CTR);
	103	data &= ~clr;
	104	data \|= set;
	105	sh_msiof_write(p, CTR, data);
	106
	107	for (k = 100; k > 0; k--) {
	108	if ((sh_msiof_read(p, CTR) & mask) == set)
	109	break;
	110
	111	udelay(10);
	112	}
	113
	114	return k > 0 ? 0 : -ETIMEDOUT;
	115	}
	116
	117	static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
	118	{
	119	struct sh_msiof_spi_priv *p = data;
	120
	121	/* just disable the interrupt and wake up */
	122	sh_msiof_write(p, IER, 0);
	123	complete(&p->done);
	124
	125	return IRQ_HANDLED;
	126	}
	127
	128	static struct {
	129	unsigned short div;
	130	unsigned short scr;
	131	} const sh_msiof_spi_clk_table[] = {
	132	{ 1, 0x0007 },
	133	{ 2, 0x0000 },
	134	{ 4, 0x0001 },
	135	{ 8, 0x0002 },
	136	{ 16, 0x0003 },
	137	{ 32, 0x0004 },
	138	{ 64, 0x1f00 },
	139	{ 128, 0x1f01 },
	140	{ 256, 0x1f02 },
	141	{ 512, 0x1f03 },
	142	{ 1024, 0x1f04 },
	143	};
	144
	145	static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
	146	unsigned long parent_rate,
	147	unsigned long spi_hz)
	148	{
	149	unsigned long div = 1024;
	150	size_t k;
	151
	152	if (!WARN_ON(!spi_hz \|\| !parent_rate))
	153	div = parent_rate / spi_hz;
	154
	155	/* TODO: make more fine grained */
	156
	157	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_clk_table); k++) {
	158	if (sh_msiof_spi_clk_table[k].div >= div)
	159	break;
	160	}
	161
	162	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_clk_table) - 1);
	163
164	sh_msiof_write(p, TSCR, sh_msiof_spi_clk_table[k].scr);
165	sh_msiof_write(p, RSCR, sh_msiof_spi_clk_table[k].scr);
166	}
167
168	static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
e2dbf5eb GL	169	u32 cpol, u32 cpha,
e2dbf5eb GL	170	u32 tx_hi_z, u32 lsb_first)
8051effc	171	{
e2dbf5eb	172	u32 tmp;
8051effc MD	173	int edge;
	174
	175	/*
e8708ef7 MP	176	* CPOL CPHA TSCKIZ RSCKIZ TEDG REDG
	177	* 0 0 10 10 1 1
	178	* 0 1 10 10 0 0
	179	* 1 0 11 11 0 0
	180	* 1 1 11 11 1 1
8051effc	181	*/
8051effc MD	182	sh_msiof_write(p, FCTR, 0);
	183	sh_msiof_write(p, TMDR1, 0xe2000005 \| (lsb_first << 24));
	184	sh_msiof_write(p, RMDR1, 0x22000005 \| (lsb_first << 24));
	185
	186	tmp = 0xa0000000;
	187	tmp \|= cpol << 30; /* TSCKIZ */
	188	tmp \|= cpol << 28; /* RSCKIZ */
	189
e2dbf5eb	190	edge = cpol ^ !cpha;
8051effc MD	191
8051effc MD	192	tmp \|= edge << 27; /* TEDG */
e8708ef7	193	tmp \|= edge << 26; /* REDG */
8051effc MD	194	tmp \|= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */
	195	sh_msiof_write(p, CTR, tmp);
	196	}
	197
	198	static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
	199	const void tx_buf, void rx_buf,
e2dbf5eb	200	u32 bits, u32 words)
8051effc	201	{
e2dbf5eb	202	u32 dr2 = ((bits - 1) << 24) \| ((words - 1) << 16);
8051effc MD	203
	204	if (tx_buf)
	205	sh_msiof_write(p, TMDR2, dr2);
	206	else
	207	sh_msiof_write(p, TMDR2, dr2 \| 1);
	208
	209	if (rx_buf)
	210	sh_msiof_write(p, RMDR2, dr2);
	211
	212	sh_msiof_write(p, IER, STR_TEOF \| STR_REOF);
	213	}
	214
	215	static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
	216	{
	217	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
	218	}
	219
	220	static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
	221	const void *tx_buf, int words, int fs)
	222	{
e2dbf5eb	223	const u8 *buf_8 = tx_buf;
8051effc MD	224	int k;
	225
	226	for (k = 0; k < words; k++)
	227	sh_msiof_write(p, TFDR, buf_8[k] << fs);
	228	}
	229
	230	static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
	231	const void *tx_buf, int words, int fs)
	232	{
e2dbf5eb	233	const u16 *buf_16 = tx_buf;
8051effc MD	234	int k;
	235
	236	for (k = 0; k < words; k++)
	237	sh_msiof_write(p, TFDR, buf_16[k] << fs);
	238	}
	239
	240	static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
	241	const void *tx_buf, int words, int fs)
	242	{
e2dbf5eb	243	const u16 *buf_16 = tx_buf;
8051effc MD	244	int k;
	245
	246	for (k = 0; k < words; k++)
	247	sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
	248	}
	249
	250	static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
	251	const void *tx_buf, int words, int fs)
	252	{
e2dbf5eb	253	const u32 *buf_32 = tx_buf;
8051effc MD	254	int k;
	255
	256	for (k = 0; k < words; k++)
	257	sh_msiof_write(p, TFDR, buf_32[k] << fs);
	258	}
	259
	260	static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
	261	const void *tx_buf, int words, int fs)
	262	{
e2dbf5eb	263	const u32 *buf_32 = tx_buf;
8051effc MD	264	int k;
	265
	266	for (k = 0; k < words; k++)
	267	sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
	268	}
	269
9dabb3f3 GL	270	static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
	271	const void *tx_buf, int words, int fs)
	272	{
	273	const u32 *buf_32 = tx_buf;
	274	int k;
	275
	276	for (k = 0; k < words; k++)
	277	sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
	278	}
	279
	280	static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
	281	const void *tx_buf, int words, int fs)
	282	{
	283	const u32 *buf_32 = tx_buf;
	284	int k;
	285
	286	for (k = 0; k < words; k++)
	287	sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
	288	}
	289
8051effc MD	290	static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
	291	void *rx_buf, int words, int fs)
	292	{
e2dbf5eb	293	u8 *buf_8 = rx_buf;
8051effc MD	294	int k;
	295
	296	for (k = 0; k < words; k++)
	297	buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
	298	}
	299
	300	static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
	301	void *rx_buf, int words, int fs)
	302	{
e2dbf5eb	303	u16 *buf_16 = rx_buf;
8051effc MD	304	int k;
	305
	306	for (k = 0; k < words; k++)
	307	buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
	308	}
	309
	310	static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
	311	void *rx_buf, int words, int fs)
	312	{
e2dbf5eb	313	u16 *buf_16 = rx_buf;
8051effc MD	314	int k;
	315
	316	for (k = 0; k < words; k++)
	317	put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
	318	}
	319
	320	static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
	321	void *rx_buf, int words, int fs)
	322	{
e2dbf5eb	323	u32 *buf_32 = rx_buf;
8051effc MD	324	int k;
	325
	326	for (k = 0; k < words; k++)
	327	buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
	328	}
	329
	330	static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
	331	void *rx_buf, int words, int fs)
	332	{
e2dbf5eb	333	u32 *buf_32 = rx_buf;
8051effc MD	334	int k;
	335
	336	for (k = 0; k < words; k++)
	337	put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
	338	}
	339
9dabb3f3 GL	340	static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
	341	void *rx_buf, int words, int fs)
	342	{
	343	u32 *buf_32 = rx_buf;
	344	int k;
	345
	346	for (k = 0; k < words; k++)
	347	buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
	348	}
	349
	350	static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
	351	void *rx_buf, int words, int fs)
	352	{
	353	u32 *buf_32 = rx_buf;
	354	int k;
	355
	356	for (k = 0; k < words; k++)
	357	put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
	358	}
	359
8051effc MD	360	static int sh_msiof_spi_bits(struct spi_device spi, struct spi_transfer t)
	361	{
	362	int bits;
	363
	364	bits = t ? t->bits_per_word : 0;
e2dbf5eb GL	365	if (!bits)
e2dbf5eb GL	366	bits = spi->bits_per_word;
8051effc MD	367	return bits;
	368	}
	369
	370	static unsigned long sh_msiof_spi_hz(struct spi_device *spi,
	371	struct spi_transfer *t)
	372	{
	373	unsigned long hz;
	374
	375	hz = t ? t->speed_hz : 0;
e2dbf5eb GL	376	if (!hz)
e2dbf5eb GL	377	hz = spi->max_speed_hz;
8051effc MD	378	return hz;
	379	}
	380
	381	static int sh_msiof_spi_setup_transfer(struct spi_device *spi,
	382	struct spi_transfer *t)
	383	{
	384	int bits;
	385
	386	/* noting to check hz values against since parent clock is disabled */
	387
	388	bits = sh_msiof_spi_bits(spi, t);
	389	if (bits < 8)
	390	return -EINVAL;
	391	if (bits > 32)
	392	return -EINVAL;
	393
	394	return spi_bitbang_setup_transfer(spi, t);
	395	}
	396
	397	static void sh_msiof_spi_chipselect(struct spi_device *spi, int is_on)
	398	{
	399	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
	400	int value;
	401
	402	/* chip select is active low unless SPI_CS_HIGH is set */
	403	if (spi->mode & SPI_CS_HIGH)
	404	value = (is_on == BITBANG_CS_ACTIVE) ? 1 : 0;
	405	else
	406	value = (is_on == BITBANG_CS_ACTIVE) ? 0 : 1;
	407
	408	if (is_on == BITBANG_CS_ACTIVE) {
	409	if (!test_and_set_bit(0, &p->flags)) {
	410	pm_runtime_get_sync(&p->pdev->dev);
	411	clk_enable(p->clk);
	412	}
	413
	414	/* Configure pins before asserting CS */
	415	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
	416	!!(spi->mode & SPI_CPHA),
	417	!!(spi->mode & SPI_3WIRE),
	418	!!(spi->mode & SPI_LSB_FIRST));
	419	}
	420
	421	/* use spi->controller data for CS (same strategy as spi_gpio) */
	422	gpio_set_value((unsigned)spi->controller_data, value);
	423
	424	if (is_on == BITBANG_CS_INACTIVE) {
	425	if (test_and_clear_bit(0, &p->flags)) {
	426	clk_disable(p->clk);
	427	pm_runtime_put(&p->pdev->dev);
	428	}
	429	}
	430	}
	431
	432	static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
	433	void (tx_fifo)(struct sh_msiof_spi_priv ,
	434	const void *, int, int),
	435	void (rx_fifo)(struct sh_msiof_spi_priv ,
	436	void *, int, int),
	437	const void tx_buf, void rx_buf,
	438	int words, int bits)
	439	{
	440	int fifo_shift;
	441	int ret;
442
443	/* limit maximum word transfer to rx/tx fifo size */
444	if (tx_buf)
445	words = min_t(int, words, p->tx_fifo_size);
446	if (rx_buf)
447	words = min_t(int, words, p->rx_fifo_size);
448
449	/* the fifo contents need shifting */
450	fifo_shift = 32 - bits;
451
452	/* setup msiof transfer mode registers */
453	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
454
455	/* write tx fifo */
456	if (tx_buf)
457	tx_fifo(p, tx_buf, words, fifo_shift);
458
459	/* setup clock and rx/tx signals */
460	ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
461	if (rx_buf)
462	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
463	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
464
465	/* start by setting frame bit */
466	INIT_COMPLETION(p->done);
467	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
468	if (ret) {
469	dev_err(&p->pdev->dev, "failed to start hardware\n");
470	goto err;
471	}
472
473	/* wait for tx fifo to be emptied / rx fifo to be filled */
474	wait_for_completion(&p->done);
475
476	/* read rx fifo */
477	if (rx_buf)
478	rx_fifo(p, rx_buf, words, fifo_shift);
479
480	/* clear status bits */
481	sh_msiof_reset_str(p);
482
483	/* shut down frame, tx/tx and clock signals */
484	ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
485	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
486	if (rx_buf)
487	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
488	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
489	if (ret) {
490	dev_err(&p->pdev->dev, "failed to shut down hardware\n");
491	goto err;
492	}
493
494	return words;
495
496	err:
497	sh_msiof_write(p, IER, 0);
498	return ret;
499	}
500
501	static int sh_msiof_spi_txrx(struct spi_device spi, struct spi_transfer t)
502	{
503	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
504	void (tx_fifo)(struct sh_msiof_spi_priv , const void *, int, int);
505	void (rx_fifo)(struct sh_msiof_spi_priv , void *, int, int);
506	int bits;
507	int bytes_per_word;
508	int bytes_done;
509	int words;
510	int n;
9dabb3f3	511	bool swab;
8051effc MD	512
	513	bits = sh_msiof_spi_bits(spi, t);
	514
9dabb3f3 GL	515	if (bits <= 8 && t->len > 15 && !(t->len & 3)) {
	516	bits = 32;
	517	swab = true;
	518	} else {
	519	swab = false;
	520	}
	521
8051effc MD	522	/* setup bytes per word and fifo read/write functions */
	523	if (bits <= 8) {
	524	bytes_per_word = 1;
	525	tx_fifo = sh_msiof_spi_write_fifo_8;
	526	rx_fifo = sh_msiof_spi_read_fifo_8;
	527	} else if (bits <= 16) {
	528	bytes_per_word = 2;
	529	if ((unsigned long)t->tx_buf & 0x01)
	530	tx_fifo = sh_msiof_spi_write_fifo_16u;
	531	else
	532	tx_fifo = sh_msiof_spi_write_fifo_16;
	533
	534	if ((unsigned long)t->rx_buf & 0x01)
	535	rx_fifo = sh_msiof_spi_read_fifo_16u;
	536	else
	537	rx_fifo = sh_msiof_spi_read_fifo_16;
9dabb3f3 GL	538	} else if (swab) {
	539	bytes_per_word = 4;
	540	if ((unsigned long)t->tx_buf & 0x03)
	541	tx_fifo = sh_msiof_spi_write_fifo_s32u;
	542	else
	543	tx_fifo = sh_msiof_spi_write_fifo_s32;
	544
	545	if ((unsigned long)t->rx_buf & 0x03)
	546	rx_fifo = sh_msiof_spi_read_fifo_s32u;
	547	else
	548	rx_fifo = sh_msiof_spi_read_fifo_s32;
8051effc MD	549	} else {
	550	bytes_per_word = 4;
	551	if ((unsigned long)t->tx_buf & 0x03)
	552	tx_fifo = sh_msiof_spi_write_fifo_32u;
	553	else
	554	tx_fifo = sh_msiof_spi_write_fifo_32;
	555
	556	if ((unsigned long)t->rx_buf & 0x03)
	557	rx_fifo = sh_msiof_spi_read_fifo_32u;
	558	else
	559	rx_fifo = sh_msiof_spi_read_fifo_32;
	560	}
	561
	562	/* setup clocks (clock already enabled in chipselect()) */
	563	sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk),
	564	sh_msiof_spi_hz(spi, t));
	565
	566	/* transfer in fifo sized chunks */
	567	words = t->len / bytes_per_word;
	568	bytes_done = 0;
	569
	570	while (bytes_done < t->len) {
8a6afb9a GL	571	void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
8a6afb9a GL	572	const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
8051effc	573	n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
8a6afb9a GL	574	tx_buf,
8a6afb9a GL	575	rx_buf,
8051effc MD	576	words, bits);
	577	if (n < 0)
	578	break;
	579
	580	bytes_done += n * bytes_per_word;
	581	words -= n;
	582	}
	583
	584	return bytes_done;
	585	}
	586
	587	static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
	588	u32 word, u8 bits)
	589	{
	590	BUG(); /* unused but needed by bitbang code */
	591	return 0;
	592	}
	593
	594	static int sh_msiof_spi_probe(struct platform_device *pdev)
	595	{
	596	struct resource *r;
	597	struct spi_master *master;
	598	struct sh_msiof_spi_priv *p;
	599	char clk_name[16];
	600	int i;
	601	int ret;
	602
	603	master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
	604	if (master == NULL) {
	605	dev_err(&pdev->dev, "failed to allocate spi master\n");
	606	ret = -ENOMEM;
	607	goto err0;
	608	}
	609
	610	p = spi_master_get_devdata(master);
	611
	612	platform_set_drvdata(pdev, p);
	613	p->info = pdev->dev.platform_data;
	614	init_completion(&p->done);
	615
	616	snprintf(clk_name, sizeof(clk_name), "msiof%d", pdev->id);
	617	p->clk = clk_get(&pdev->dev, clk_name);
	618	if (IS_ERR(p->clk)) {
	619	dev_err(&pdev->dev, "cannot get clock \"%s\"\n", clk_name);
	620	ret = PTR_ERR(p->clk);
	621	goto err1;
	622	}
	623
	624	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	625	i = platform_get_irq(pdev, 0);
	626	if (!r \|\| i < 0) {
	627	dev_err(&pdev->dev, "cannot get platform resources\n");
	628	ret = -ENOENT;
	629	goto err2;
	630	}
	631	p->mapbase = ioremap_nocache(r->start, resource_size(r));
	632	if (!p->mapbase) {
	633	dev_err(&pdev->dev, "unable to ioremap\n");
	634	ret = -ENXIO;
	635	goto err2;
	636	}
	637
	638	ret = request_irq(i, sh_msiof_spi_irq, IRQF_DISABLED,
	639	dev_name(&pdev->dev), p);
640	if (ret) {
641	dev_err(&pdev->dev, "unable to request irq\n");
642	goto err3;
643	}
644
645	p->pdev = pdev;
646	pm_runtime_enable(&pdev->dev);
647
648	/* The standard version of MSIOF use 64 word FIFOs */
649	p->tx_fifo_size = 64;
650	p->rx_fifo_size = 64;
651
652	/* Platform data may override FIFO sizes */
653	if (p->info->tx_fifo_override)
654	p->tx_fifo_size = p->info->tx_fifo_override;
655	if (p->info->rx_fifo_override)
656	p->rx_fifo_size = p->info->rx_fifo_override;
657
658	/* init master and bitbang code */
659	master->mode_bits = SPI_CPOL \| SPI_CPHA \| SPI_CS_HIGH;
660	master->mode_bits \|= SPI_LSB_FIRST \| SPI_3WIRE;
661	master->flags = 0;
662	master->bus_num = pdev->id;
663	master->num_chipselect = p->info->num_chipselect;
664	master->setup = spi_bitbang_setup;
665	master->cleanup = spi_bitbang_cleanup;
666
667	p->bitbang.master = master;
668	p->bitbang.chipselect = sh_msiof_spi_chipselect;
669	p->bitbang.setup_transfer = sh_msiof_spi_setup_transfer;
670	p->bitbang.txrx_bufs = sh_msiof_spi_txrx;
671	p->bitbang.txrx_word[SPI_MODE_0] = sh_msiof_spi_txrx_word;
672	p->bitbang.txrx_word[SPI_MODE_1] = sh_msiof_spi_txrx_word;
673	p->bitbang.txrx_word[SPI_MODE_2] = sh_msiof_spi_txrx_word;
674	p->bitbang.txrx_word[SPI_MODE_3] = sh_msiof_spi_txrx_word;
675
676	ret = spi_bitbang_start(&p->bitbang);
677	if (ret == 0)
678	return 0;
679
680	pm_runtime_disable(&pdev->dev);
681	err3:
682	iounmap(p->mapbase);
683	err2:
684	clk_put(p->clk);
685	err1:
686	spi_master_put(master);
687	err0:
688	return ret;
689	}
690
691	static int sh_msiof_spi_remove(struct platform_device *pdev)
692	{
693	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
694	int ret;
695
696	ret = spi_bitbang_stop(&p->bitbang);
697	if (!ret) {
698	pm_runtime_disable(&pdev->dev);
d95defac	699	free_irq(platform_get_irq(pdev, 0), p);
8051effc MD	700	iounmap(p->mapbase);
	701	clk_put(p->clk);
	702	spi_master_put(p->bitbang.master);
	703	}
	704	return ret;
	705	}
	706
	707	static int sh_msiof_spi_runtime_nop(struct device *dev)
	708	{
	709	/* Runtime PM callback shared between ->runtime_suspend()
	710	* and ->runtime_resume(). Simply returns success.
	711	*
	712	* This driver re-initializes all registers after
	713	* pm_runtime_get_sync() anyway so there is no need
	714	* to save and restore registers here.
	715	*/
	716	return 0;
	717	}
	718
	719	static struct dev_pm_ops sh_msiof_spi_dev_pm_ops = {
	720	.runtime_suspend = sh_msiof_spi_runtime_nop,
	721	.runtime_resume = sh_msiof_spi_runtime_nop,
	722	};
	723
	724	static struct platform_driver sh_msiof_spi_drv = {
	725	.probe = sh_msiof_spi_probe,
	726	.remove = sh_msiof_spi_remove,
	727	.driver = {
	728	.name = "spi_sh_msiof",
	729	.owner = THIS_MODULE,
	730	.pm = &sh_msiof_spi_dev_pm_ops,
	731	},
	732	};
	733
	734	static int __init sh_msiof_spi_init(void)
	735	{
	736	return platform_driver_register(&sh_msiof_spi_drv);
	737	}
	738	module_init(sh_msiof_spi_init);
	739
	740	static void __exit sh_msiof_spi_exit(void)
	741	{
	742	platform_driver_unregister(&sh_msiof_spi_drv);
	743	}
	744	module_exit(sh_msiof_spi_exit);
	745
	746	MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
	747	MODULE_AUTHOR("Magnus Damm");
	748	MODULE_LICENSE("GPL v2");
	749	MODULE_ALIAS("platform:spi_sh_msiof");