[linux.git] / drivers / spi / spi-oc-tiny.c

/*
 * OpenCores tiny SPI master driver
 *
 * http://opencores.org/project,tiny_spi
 *
 * Copyright (C) 2011 Thomas Chou <[email protected]>
 *
 * Based on spi_s3c24xx.c, which is:
 * Copyright (c) 2006 Ben Dooks
 * Copyright (c) 2006 Simtec Electronics
 *	Ben Dooks <[email protected]>
 *
 * 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/interrupt.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/spi/spi_oc_tiny.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/of.h>

#define DRV_NAME "spi_oc_tiny"

#define TINY_SPI_RXDATA 0
#define TINY_SPI_TXDATA 4
#define TINY_SPI_STATUS 8
#define TINY_SPI_CONTROL 12
#define TINY_SPI_BAUD 16

#define TINY_SPI_STATUS_TXE 0x1
#define TINY_SPI_STATUS_TXR 0x2

struct tiny_spi {
	/* bitbang has to be first */
	struct spi_bitbang bitbang;
	struct completion done;

	void __iomem *base;
	int irq;
	unsigned int freq;
	unsigned int baudwidth;
	unsigned int baud;
	unsigned int speed_hz;
	unsigned int mode;
	unsigned int len;
	unsigned int txc, rxc;
	const u8 *txp;
	u8 *rxp;
	int gpio_cs_count;
	int *gpio_cs;
};

static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev)
{
	return spi_master_get_devdata(sdev->master);
}

static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
{
	struct tiny_spi *hw = tiny_spi_to_hw(spi);

	return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
}

static void tiny_spi_chipselect(struct spi_device *spi, int is_active)
{
	struct tiny_spi *hw = tiny_spi_to_hw(spi);

	if (hw->gpio_cs_count > 0) {
		gpio_set_value(hw->gpio_cs[spi->chip_select],
			(spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
	}
}

static int tiny_spi_setup_transfer(struct spi_device *spi,
				   struct spi_transfer *t)
{
	struct tiny_spi *hw = tiny_spi_to_hw(spi);
	unsigned int baud = hw->baud;

	if (t) {
		if (t->speed_hz && t->speed_hz != hw->speed_hz)
			baud = tiny_spi_baud(spi, t->speed_hz);
	}
	writel(baud, hw->base + TINY_SPI_BAUD);
	writel(hw->mode, hw->base + TINY_SPI_CONTROL);
	return 0;
}

static int tiny_spi_setup(struct spi_device *spi)
{
	struct tiny_spi *hw = tiny_spi_to_hw(spi);

	if (spi->max_speed_hz != hw->speed_hz) {
		hw->speed_hz = spi->max_speed_hz;
		hw->baud = tiny_spi_baud(spi, hw->speed_hz);
	}
	hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA);
	return 0;
}

static inline void tiny_spi_wait_txr(struct tiny_spi *hw)
{
	while (!(readb(hw->base + TINY_SPI_STATUS) &
		 TINY_SPI_STATUS_TXR))
		cpu_relax();
}

static inline void tiny_spi_wait_txe(struct tiny_spi *hw)
{
	while (!(readb(hw->base + TINY_SPI_STATUS) &
		 TINY_SPI_STATUS_TXE))
		cpu_relax();
}

static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
{
	struct tiny_spi *hw = tiny_spi_to_hw(spi);
	const u8 *txp = t->tx_buf;
	u8 *rxp = t->rx_buf;
	unsigned int i;

	if (hw->irq >= 0) {
		/* use interrupt driven data transfer */
		hw->len = t->len;
		hw->txp = t->tx_buf;
		hw->rxp = t->rx_buf;
		hw->txc = 0;
		hw->rxc = 0;

		/* send the first byte */
		if (t->len > 1) {
			writeb(hw->txp ? *hw->txp++ : 0,
			       hw->base + TINY_SPI_TXDATA);
			hw->txc++;
			writeb(hw->txp ? *hw->txp++ : 0,
			       hw->base + TINY_SPI_TXDATA);
			hw->txc++;
			writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
		} else {
			writeb(hw->txp ? *hw->txp++ : 0,
			       hw->base + TINY_SPI_TXDATA);
			hw->txc++;
			writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
		}

		wait_for_completion(&hw->done);
	} else {
		/* we need to tighten the transfer loop */
		writeb(txp ? *txp++ : 0, hw->base + TINY_SPI_TXDATA);
		for (i = 1; i < t->len; i++) {
			writeb(txp ? *txp++ : 0, hw->base + TINY_SPI_TXDATA);

			if (rxp || (i != t->len - 1))
				tiny_spi_wait_txr(hw);
			if (rxp)
				*rxp++ = readb(hw->base + TINY_SPI_TXDATA);
		}
		tiny_spi_wait_txe(hw);
		if (rxp)
			*rxp++ = readb(hw->base + TINY_SPI_RXDATA);
	}

	return t->len;
}

static irqreturn_t tiny_spi_irq(int irq, void *dev)
{
	struct tiny_spi *hw = dev;

	writeb(0, hw->base + TINY_SPI_STATUS);
	if (hw->rxc + 1 == hw->len) {
		if (hw->rxp)
			*hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA);
		hw->rxc++;
		complete(&hw->done);
	} else {
		if (hw->rxp)
			*hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA);
		hw->rxc++;
		if (hw->txc < hw->len) {
			writeb(hw->txp ? *hw->txp++ : 0,
			       hw->base + TINY_SPI_TXDATA);
			hw->txc++;
			writeb(TINY_SPI_STATUS_TXR,
			       hw->base + TINY_SPI_STATUS);
		} else {
			writeb(TINY_SPI_STATUS_TXE,
			       hw->base + TINY_SPI_STATUS);
		}
	}
	return IRQ_HANDLED;
}

#ifdef CONFIG_OF
#include <linux/of_gpio.h>

static int tiny_spi_of_probe(struct platform_device *pdev)
{
	struct tiny_spi *hw = platform_get_drvdata(pdev);
	struct device_node *np = pdev->dev.of_node;
	unsigned int i;
	u32 val;

	if (!np)
		return 0;
	hw->gpio_cs_count = of_gpio_count(np);
	if (hw->gpio_cs_count > 0) {
		hw->gpio_cs = devm_kcalloc(&pdev->dev,
				hw->gpio_cs_count, sizeof(unsigned int),
				GFP_KERNEL);
		if (!hw->gpio_cs)
			return -ENOMEM;
	}
	for (i = 0; i < hw->gpio_cs_count; i++) {
		hw->gpio_cs[i] = of_get_gpio_flags(np, i, NULL);
		if (hw->gpio_cs[i] < 0)
			return -ENODEV;
	}
	hw->bitbang.master->dev.of_node = pdev->dev.of_node;
	if (!of_property_read_u32(np, "clock-frequency", &val))
		hw->freq = val;
	if (!of_property_read_u32(np, "baud-width", &val))
		hw->baudwidth = val;
	return 0;
}
#else /* !CONFIG_OF */
static int tiny_spi_of_probe(struct platform_device *pdev)
{
	return 0;
}
#endif /* CONFIG_OF */

static int tiny_spi_probe(struct platform_device *pdev)
{
	struct tiny_spi_platform_data *platp = dev_get_platdata(&pdev->dev);
	struct tiny_spi *hw;
	struct spi_master *master;
	struct resource *res;
	unsigned int i;
	int err = -ENODEV;

	master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
	if (!master)
		return err;

	/* setup the master state. */
	master->bus_num = pdev->id;
	master->num_chipselect = 255;
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
	master->setup = tiny_spi_setup;

	hw = spi_master_get_devdata(master);
	platform_set_drvdata(pdev, hw);

	/* setup the state for the bitbang driver */
	hw->bitbang.master = master;
	hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
	hw->bitbang.chipselect = tiny_spi_chipselect;
	hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;

	/* find and map our resources */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	hw->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(hw->base)) {
		err = PTR_ERR(hw->base);
		goto exit;
	}
	/* irq is optional */
	hw->irq = platform_get_irq(pdev, 0);
	if (hw->irq >= 0) {
		init_completion(&hw->done);
		err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
				       pdev->name, hw);
		if (err)
			goto exit;
	}
	/* find platform data */
	if (platp) {
		hw->gpio_cs_count = platp->gpio_cs_count;
		hw->gpio_cs = platp->gpio_cs;
		if (platp->gpio_cs_count && !platp->gpio_cs) {
			err = -EBUSY;
			goto exit;
		}
		hw->freq = platp->freq;
		hw->baudwidth = platp->baudwidth;
	} else {
		err = tiny_spi_of_probe(pdev);
		if (err)
			goto exit;
	}
	for (i = 0; i < hw->gpio_cs_count; i++) {
		err = gpio_request(hw->gpio_cs[i], dev_name(&pdev->dev));
		if (err)
			goto exit_gpio;
		gpio_direction_output(hw->gpio_cs[i], 1);
	}
	hw->bitbang.master->num_chipselect = max(1, hw->gpio_cs_count);

	/* register our spi controller */
	err = spi_bitbang_start(&hw->bitbang);
	if (err)
		goto exit;
	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);

	return 0;

exit_gpio:
	while (i-- > 0)
		gpio_free(hw->gpio_cs[i]);
exit:
	spi_master_put(master);
	return err;
}

static int tiny_spi_remove(struct platform_device *pdev)
{
	struct tiny_spi *hw = platform_get_drvdata(pdev);
	struct spi_master *master = hw->bitbang.master;
	unsigned int i;

	spi_bitbang_stop(&hw->bitbang);
	for (i = 0; i < hw->gpio_cs_count; i++)
		gpio_free(hw->gpio_cs[i]);
	spi_master_put(master);
	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id tiny_spi_match[] = {
	{ .compatible = "opencores,tiny-spi-rtlsvn2", },
	{},
};
MODULE_DEVICE_TABLE(of, tiny_spi_match);
#endif /* CONFIG_OF */

static struct platform_driver tiny_spi_driver = {
	.probe = tiny_spi_probe,
	.remove = tiny_spi_remove,
	.driver = {
		.name = DRV_NAME,
		.pm = NULL,
		.of_match_table = of_match_ptr(tiny_spi_match),
	},
};
module_platform_driver(tiny_spi_driver);

MODULE_DESCRIPTION("OpenCores tiny SPI driver");
MODULE_AUTHOR("Thomas Chou <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);
Commit	Line	Data
ce792580 TC	1	/*
	2	* OpenCores tiny SPI master driver
	3	*
	4	* http://opencores.org/project,tiny_spi
	5	*
	6	* Copyright (C) 2011 Thomas Chou <[email protected]>
	7	*
	8	* Based on spi_s3c24xx.c, which is:
	9	* Copyright (c) 2006 Ben Dooks
	10	* Copyright (c) 2006 Simtec Electronics
	11	* Ben Dooks <[email protected]>
	12	*
	13	* This program is free software; you can redistribute it and/or modify
	14	* it under the terms of the GNU General Public License version 2 as
	15	* published by the Free Software Foundation.
	16	*/
	17
ce792580 TC	18	#include <linux/interrupt.h>
ce792580 TC	19	#include <linux/errno.h>
d7614de4	20	#include <linux/module.h>
ce792580 TC	21	#include <linux/platform_device.h>
	22	#include <linux/spi/spi.h>
	23	#include <linux/spi/spi_bitbang.h>
	24	#include <linux/spi/spi_oc_tiny.h>
	25	#include <linux/io.h>
	26	#include <linux/gpio.h>
	27	#include <linux/of.h>
	28
	29	#define DRV_NAME "spi_oc_tiny"
	30
	31	#define TINY_SPI_RXDATA 0
	32	#define TINY_SPI_TXDATA 4
	33	#define TINY_SPI_STATUS 8
	34	#define TINY_SPI_CONTROL 12
	35	#define TINY_SPI_BAUD 16
	36
	37	#define TINY_SPI_STATUS_TXE 0x1
	38	#define TINY_SPI_STATUS_TXR 0x2
	39
	40	struct tiny_spi {
	41	/* bitbang has to be first */
	42	struct spi_bitbang bitbang;
	43	struct completion done;
	44
	45	void __iomem *base;
	46	int irq;
	47	unsigned int freq;
	48	unsigned int baudwidth;
	49	unsigned int baud;
	50	unsigned int speed_hz;
	51	unsigned int mode;
	52	unsigned int len;
	53	unsigned int txc, rxc;
	54	const u8 *txp;
	55	u8 *rxp;
e80beb27	56	int gpio_cs_count;
ce792580 TC	57	int *gpio_cs;
	58	};
	59
	60	static inline struct tiny_spi tiny_spi_to_hw(struct spi_device sdev)
	61	{
	62	return spi_master_get_devdata(sdev->master);
	63	}
	64
	65	static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
	66	{
	67	struct tiny_spi *hw = tiny_spi_to_hw(spi);
	68
	69	return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
	70	}
	71
	72	static void tiny_spi_chipselect(struct spi_device *spi, int is_active)
	73	{
	74	struct tiny_spi *hw = tiny_spi_to_hw(spi);
	75
e80beb27	76	if (hw->gpio_cs_count > 0) {
ce792580 TC	77	gpio_set_value(hw->gpio_cs[spi->chip_select],
	78	(spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
	79	}
	80	}
	81
	82	static int tiny_spi_setup_transfer(struct spi_device *spi,
	83	struct spi_transfer *t)
	84	{
	85	struct tiny_spi *hw = tiny_spi_to_hw(spi);
	86	unsigned int baud = hw->baud;
	87
	88	if (t) {
	89	if (t->speed_hz && t->speed_hz != hw->speed_hz)
	90	baud = tiny_spi_baud(spi, t->speed_hz);
	91	}
	92	writel(baud, hw->base + TINY_SPI_BAUD);
	93	writel(hw->mode, hw->base + TINY_SPI_CONTROL);
	94	return 0;
	95	}
	96
	97	static int tiny_spi_setup(struct spi_device *spi)
	98	{
	99	struct tiny_spi *hw = tiny_spi_to_hw(spi);
	100
	101	if (spi->max_speed_hz != hw->speed_hz) {
	102	hw->speed_hz = spi->max_speed_hz;
	103	hw->baud = tiny_spi_baud(spi, hw->speed_hz);
	104	}
	105	hw->mode = spi->mode & (SPI_CPOL \| SPI_CPHA);
	106	return 0;
	107	}
	108
	109	static inline void tiny_spi_wait_txr(struct tiny_spi *hw)
	110	{
	111	while (!(readb(hw->base + TINY_SPI_STATUS) &
	112	TINY_SPI_STATUS_TXR))
	113	cpu_relax();
	114	}
	115
	116	static inline void tiny_spi_wait_txe(struct tiny_spi *hw)
	117	{
	118	while (!(readb(hw->base + TINY_SPI_STATUS) &
	119	TINY_SPI_STATUS_TXE))
	120	cpu_relax();
	121	}
	122
	123	static int tiny_spi_txrx_bufs(struct spi_device spi, struct spi_transfer t)
	124	{
	125	struct tiny_spi *hw = tiny_spi_to_hw(spi);
	126	const u8 *txp = t->tx_buf;
	127	u8 *rxp = t->rx_buf;
	128	unsigned int i;
	129
	130	if (hw->irq >= 0) {
886db6ac	131	/* use interrupt driven data transfer */
ce792580 TC	132	hw->len = t->len;
	133	hw->txp = t->tx_buf;
	134	hw->rxp = t->rx_buf;
	135	hw->txc = 0;
	136	hw->rxc = 0;
	137
	138	/* send the first byte */
	139	if (t->len > 1) {
	140	writeb(hw->txp ? *hw->txp++ : 0,
	141	hw->base + TINY_SPI_TXDATA);
	142	hw->txc++;
	143	writeb(hw->txp ? *hw->txp++ : 0,
	144	hw->base + TINY_SPI_TXDATA);
	145	hw->txc++;
	146	writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
	147	} else {
	148	writeb(hw->txp ? *hw->txp++ : 0,
	149	hw->base + TINY_SPI_TXDATA);
	150	hw->txc++;
	151	writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
	152	}
	153
	154	wait_for_completion(&hw->done);
ce792580	155	} else {
e826a7ff AL	156	/* we need to tighten the transfer loop */
	157	writeb(txp ? *txp++ : 0, hw->base + TINY_SPI_TXDATA);
	158	for (i = 1; i < t->len; i++) {
	159	writeb(txp ? *txp++ : 0, hw->base + TINY_SPI_TXDATA);
	160
	161	if (rxp \|\| (i != t->len - 1))
ce792580	162	tiny_spi_wait_txr(hw);
e826a7ff AL	163	if (rxp)
e826a7ff AL	164	*rxp++ = readb(hw->base + TINY_SPI_TXDATA);
ce792580 TC	165	}
ce792580 TC	166	tiny_spi_wait_txe(hw);
e826a7ff AL	167	if (rxp)
e826a7ff AL	168	*rxp++ = readb(hw->base + TINY_SPI_RXDATA);
ce792580	169	}
e826a7ff	170
ce792580 TC	171	return t->len;
	172	}
	173
	174	static irqreturn_t tiny_spi_irq(int irq, void *dev)
	175	{
	176	struct tiny_spi *hw = dev;
	177
	178	writeb(0, hw->base + TINY_SPI_STATUS);
	179	if (hw->rxc + 1 == hw->len) {
	180	if (hw->rxp)
	181	*hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA);
	182	hw->rxc++;
	183	complete(&hw->done);
	184	} else {
	185	if (hw->rxp)
	186	*hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA);
	187	hw->rxc++;
	188	if (hw->txc < hw->len) {
	189	writeb(hw->txp ? *hw->txp++ : 0,
	190	hw->base + TINY_SPI_TXDATA);
	191	hw->txc++;
	192	writeb(TINY_SPI_STATUS_TXR,
	193	hw->base + TINY_SPI_STATUS);
	194	} else {
	195	writeb(TINY_SPI_STATUS_TXE,
	196	hw->base + TINY_SPI_STATUS);
	197	}
	198	}
	199	return IRQ_HANDLED;
	200	}
	201
	202	#ifdef CONFIG_OF
	203	#include <linux/of_gpio.h>
	204
fd4a319b	205	static int tiny_spi_of_probe(struct platform_device *pdev)
ce792580 TC	206	{
	207	struct tiny_spi *hw = platform_get_drvdata(pdev);
	208	struct device_node *np = pdev->dev.of_node;
	209	unsigned int i;
45a3e771	210	u32 val;
ce792580 TC	211
	212	if (!np)
	213	return 0;
	214	hw->gpio_cs_count = of_gpio_count(np);
e80beb27	215	if (hw->gpio_cs_count > 0) {
a86854d0 KC	216	hw->gpio_cs = devm_kcalloc(&pdev->dev,
a86854d0 KC	217	hw->gpio_cs_count, sizeof(unsigned int),
ce792580 TC	218	GFP_KERNEL);
	219	if (!hw->gpio_cs)
	220	return -ENOMEM;
	221	}
	222	for (i = 0; i < hw->gpio_cs_count; i++) {
	223	hw->gpio_cs[i] = of_get_gpio_flags(np, i, NULL);
	224	if (hw->gpio_cs[i] < 0)
	225	return -ENODEV;
	226	}
	227	hw->bitbang.master->dev.of_node = pdev->dev.of_node;
45a3e771 TK	228	if (!of_property_read_u32(np, "clock-frequency", &val))
	229	hw->freq = val;
	230	if (!of_property_read_u32(np, "baud-width", &val))
	231	hw->baudwidth = val;
ce792580 TC	232	return 0;
	233	}
	234	#else /* !CONFIG_OF */
fd4a319b	235	static int tiny_spi_of_probe(struct platform_device *pdev)
ce792580 TC	236	{
	237	return 0;
	238	}
	239	#endif /* CONFIG_OF */
	240
fd4a319b	241	static int tiny_spi_probe(struct platform_device *pdev)
ce792580	242	{
8074cf06	243	struct tiny_spi_platform_data *platp = dev_get_platdata(&pdev->dev);
ce792580 TC	244	struct tiny_spi *hw;
	245	struct spi_master *master;
	246	struct resource *res;
	247	unsigned int i;
	248	int err = -ENODEV;
	249
	250	master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
	251	if (!master)
	252	return err;
	253
	254	/* setup the master state. */
	255	master->bus_num = pdev->id;
	256	master->num_chipselect = 255;
	257	master->mode_bits = SPI_CPOL \| SPI_CPHA \| SPI_CS_HIGH;
	258	master->setup = tiny_spi_setup;
	259
	260	hw = spi_master_get_devdata(master);
	261	platform_set_drvdata(pdev, hw);
	262
	263	/* setup the state for the bitbang driver */
94c69f76	264	hw->bitbang.master = master;
ce792580 TC	265	hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
	266	hw->bitbang.chipselect = tiny_spi_chipselect;
	267	hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;
	268
	269	/* find and map our resources */
	270	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
b3136f8f JL	271	hw->base = devm_ioremap_resource(&pdev->dev, res);
	272	if (IS_ERR(hw->base)) {
	273	err = PTR_ERR(hw->base);
	274	goto exit;
	275	}
ce792580 TC	276	/* irq is optional */
	277	hw->irq = platform_get_irq(pdev, 0);
	278	if (hw->irq >= 0) {
	279	init_completion(&hw->done);
	280	err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
	281	pdev->name, hw);
	282	if (err)
	283	goto exit;
	284	}
	285	/* find platform data */
	286	if (platp) {
	287	hw->gpio_cs_count = platp->gpio_cs_count;
	288	hw->gpio_cs = platp->gpio_cs;
b3136f8f JL	289	if (platp->gpio_cs_count && !platp->gpio_cs) {
	290	err = -EBUSY;
	291	goto exit;
	292	}
ce792580 TC	293	hw->freq = platp->freq;
	294	hw->baudwidth = platp->baudwidth;
	295	} else {
	296	err = tiny_spi_of_probe(pdev);
	297	if (err)
	298	goto exit;
	299	}
	300	for (i = 0; i < hw->gpio_cs_count; i++) {
	301	err = gpio_request(hw->gpio_cs[i], dev_name(&pdev->dev));
	302	if (err)
	303	goto exit_gpio;
	304	gpio_direction_output(hw->gpio_cs[i], 1);
	305	}
e80beb27	306	hw->bitbang.master->num_chipselect = max(1, hw->gpio_cs_count);
ce792580 TC	307
	308	/* register our spi controller */
	309	err = spi_bitbang_start(&hw->bitbang);
	310	if (err)
	311	goto exit;
	312	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
	313
	314	return 0;
	315
	316	exit_gpio:
	317	while (i-- > 0)
	318	gpio_free(hw->gpio_cs[i]);
ce792580	319	exit:
ce792580 TC	320	spi_master_put(master);
	321	return err;
	322	}
	323
fd4a319b	324	static int tiny_spi_remove(struct platform_device *pdev)
ce792580 TC	325	{
	326	struct tiny_spi *hw = platform_get_drvdata(pdev);
	327	struct spi_master *master = hw->bitbang.master;
	328	unsigned int i;
	329
	330	spi_bitbang_stop(&hw->bitbang);
	331	for (i = 0; i < hw->gpio_cs_count; i++)
	332	gpio_free(hw->gpio_cs[i]);
ce792580 TC	333	spi_master_put(master);
	334	return 0;
	335	}
	336
	337	#ifdef CONFIG_OF
	338	static const struct of_device_id tiny_spi_match[] = {
	339	{ .compatible = "opencores,tiny-spi-rtlsvn2", },
	340	{},
	341	};
	342	MODULE_DEVICE_TABLE(of, tiny_spi_match);
ce792580 TC	343	#endif /* CONFIG_OF */
	344
	345	static struct platform_driver tiny_spi_driver = {
	346	.probe = tiny_spi_probe,
fd4a319b	347	.remove = tiny_spi_remove,
ce792580 TC	348	.driver = {
ce792580 TC	349	.name = DRV_NAME,
ce792580	350	.pm = NULL,
9547acce	351	.of_match_table = of_match_ptr(tiny_spi_match),
ce792580 TC	352	},
ce792580 TC	353	};
940ab889	354	module_platform_driver(tiny_spi_driver);
ce792580 TC	355
	356	MODULE_DESCRIPTION("OpenCores tiny SPI driver");
	357	MODULE_AUTHOR("Thomas Chou <[email protected]>");
	358	MODULE_LICENSE("GPL");
	359	MODULE_ALIAS("platform:" DRV_NAME);