[linux-block.git] / drivers / mtd / devices / sst25l.c

/*
 * sst25l.c
 *
 * Driver for SST25L SPI Flash chips
 *
 * Copyright © 2009 Bluewater Systems Ltd
 * Author: Andre Renaud <andre@bluewatersys.com>
 * Author: Ryan Mallon
 *
 * Based on m25p80.c
 *
 * This code 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/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/sched.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>

#include <linux/spi/spi.h>
#include <linux/spi/flash.h>

/* Erases can take up to 3 seconds! */
#define MAX_READY_WAIT_JIFFIES	msecs_to_jiffies(3000)

#define SST25L_CMD_WRSR		0x01	/* Write status register */
#define SST25L_CMD_WRDI		0x04	/* Write disable */
#define SST25L_CMD_RDSR		0x05	/* Read status register */
#define SST25L_CMD_WREN		0x06	/* Write enable */
#define SST25L_CMD_READ		0x03	/* High speed read */

#define SST25L_CMD_EWSR		0x50	/* Enable write status register */
#define SST25L_CMD_SECTOR_ERASE	0x20	/* Erase sector */
#define SST25L_CMD_READ_ID	0x90	/* Read device ID */
#define SST25L_CMD_AAI_PROGRAM	0xaf	/* Auto address increment */

#define SST25L_STATUS_BUSY	(1 << 0)	/* Chip is busy */
#define SST25L_STATUS_WREN	(1 << 1)	/* Write enabled */
#define SST25L_STATUS_BP0	(1 << 2)	/* Block protection 0 */
#define SST25L_STATUS_BP1	(1 << 3)	/* Block protection 1 */

struct sst25l_flash {
	struct spi_device	*spi;
	struct mutex		lock;
	struct mtd_info		mtd;
};

struct flash_info {
	const char		*name;
	uint16_t		device_id;
	unsigned		page_size;
	unsigned		nr_pages;
	unsigned		erase_size;
};

#define to_sst25l_flash(x) container_of(x, struct sst25l_flash, mtd)

static struct flash_info __devinitdata sst25l_flash_info[] = {
	{"sst25lf020a", 0xbf43, 256, 1024, 4096},
	{"sst25lf040a",	0xbf44,	256, 2048, 4096},
};

static int sst25l_status(struct sst25l_flash *flash, int *status)
{
	struct spi_message m;
	struct spi_transfer t;
	unsigned char cmd_resp[2];
	int err;

	spi_message_init(&m);
	memset(&t, 0, sizeof(struct spi_transfer));

	cmd_resp[0] = SST25L_CMD_RDSR;
	cmd_resp[1] = 0xff;
	t.tx_buf = cmd_resp;
	t.rx_buf = cmd_resp;
	t.len = sizeof(cmd_resp);
	spi_message_add_tail(&t, &m);
	err = spi_sync(flash->spi, &m);
	if (err < 0)
		return err;

	*status = cmd_resp[1];
	return 0;
}

static int sst25l_write_enable(struct sst25l_flash *flash, int enable)
{
	unsigned char command[2];
	int status, err;

	command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI;
	err = spi_write(flash->spi, command, 1);
	if (err)
		return err;

	command[0] = SST25L_CMD_EWSR;
	err = spi_write(flash->spi, command, 1);
	if (err)
		return err;

	command[0] = SST25L_CMD_WRSR;
	command[1] = enable ? 0 : SST25L_STATUS_BP0 | SST25L_STATUS_BP1;
	err = spi_write(flash->spi, command, 2);
	if (err)
		return err;

	if (enable) {
		err = sst25l_status(flash, &status);
		if (err)
			return err;
		if (!(status & SST25L_STATUS_WREN))
			return -EROFS;
	}

	return 0;
}

static int sst25l_wait_till_ready(struct sst25l_flash *flash)
{
	unsigned long deadline;
	int status, err;

	deadline = jiffies + MAX_READY_WAIT_JIFFIES;
	do {
		err = sst25l_status(flash, &status);
		if (err)
			return err;
		if (!(status & SST25L_STATUS_BUSY))
			return 0;

		cond_resched();
	} while (!time_after_eq(jiffies, deadline));

	return -ETIMEDOUT;
}

static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset)
{
	unsigned char command[4];
	int err;

	err = sst25l_write_enable(flash, 1);
	if (err)
		return err;

	command[0] = SST25L_CMD_SECTOR_ERASE;
	command[1] = offset >> 16;
	command[2] = offset >> 8;
	command[3] = offset;
	err = spi_write(flash->spi, command, 4);
	if (err)
		return err;

	err = sst25l_wait_till_ready(flash);
	if (err)
		return err;

	return sst25l_write_enable(flash, 0);
}

static int sst25l_erase(struct mtd_info *mtd, struct erase_info *instr)
{
	struct sst25l_flash *flash = to_sst25l_flash(mtd);
	uint32_t addr, end;
	int err;

	/* Sanity checks */
	if ((uint32_t)instr->len % mtd->erasesize)
		return -EINVAL;

	if ((uint32_t)instr->addr % mtd->erasesize)
		return -EINVAL;

	addr = instr->addr;
	end = addr + instr->len;

	mutex_lock(&flash->lock);

	err = sst25l_wait_till_ready(flash);
	if (err) {
		mutex_unlock(&flash->lock);
		return err;
	}

	while (addr < end) {
		err = sst25l_erase_sector(flash, addr);
		if (err) {
			mutex_unlock(&flash->lock);
			instr->state = MTD_ERASE_FAILED;
			dev_err(&flash->spi->dev, "Erase failed\n");
			return err;
		}

		addr += mtd->erasesize;
	}

	mutex_unlock(&flash->lock);

	instr->state = MTD_ERASE_DONE;
	mtd_erase_callback(instr);
	return 0;
}

static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len,
		       size_t *retlen, unsigned char *buf)
{
	struct sst25l_flash *flash = to_sst25l_flash(mtd);
	struct spi_transfer transfer[2];
	struct spi_message message;
	unsigned char command[4];
	int ret;

	spi_message_init(&message);
	memset(&transfer, 0, sizeof(transfer));

	command[0] = SST25L_CMD_READ;
	command[1] = from >> 16;
	command[2] = from >> 8;
	command[3] = from;

	transfer[0].tx_buf = command;
	transfer[0].len = sizeof(command);
	spi_message_add_tail(&transfer[0], &message);

	transfer[1].rx_buf = buf;
	transfer[1].len = len;
	spi_message_add_tail(&transfer[1], &message);

	mutex_lock(&flash->lock);

	/* Wait for previous write/erase to complete */
	ret = sst25l_wait_till_ready(flash);
	if (ret) {
		mutex_unlock(&flash->lock);
		return ret;
	}

	spi_sync(flash->spi, &message);

	if (retlen && message.actual_length > sizeof(command))
		*retlen += message.actual_length - sizeof(command);

	mutex_unlock(&flash->lock);
	return 0;
}

static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len,
			size_t *retlen, const unsigned char *buf)
{
	struct sst25l_flash *flash = to_sst25l_flash(mtd);
	int i, j, ret, bytes, copied = 0;
	unsigned char command[5];

	if ((uint32_t)to % mtd->writesize)
		return -EINVAL;

	mutex_lock(&flash->lock);

	ret = sst25l_write_enable(flash, 1);
	if (ret)
		goto out;

	for (i = 0; i < len; i += mtd->writesize) {
		ret = sst25l_wait_till_ready(flash);
		if (ret)
			goto out;

		/* Write the first byte of the page */
		command[0] = SST25L_CMD_AAI_PROGRAM;
		command[1] = (to + i) >> 16;
		command[2] = (to + i) >> 8;
		command[3] = (to + i);
		command[4] = buf[i];
		ret = spi_write(flash->spi, command, 5);
		if (ret < 0)
			goto out;
		copied++;

		/*
		 * Write the remaining bytes using auto address
		 * increment mode
		 */
		bytes = min_t(uint32_t, mtd->writesize, len - i);
		for (j = 1; j < bytes; j++, copied++) {
			ret = sst25l_wait_till_ready(flash);
			if (ret)
				goto out;

			command[1] = buf[i + j];
			ret = spi_write(flash->spi, command, 2);
			if (ret)
				goto out;
		}
	}

out:
	ret = sst25l_write_enable(flash, 0);

	if (retlen)
		*retlen = copied;

	mutex_unlock(&flash->lock);
	return ret;
}

static struct flash_info *__devinit sst25l_match_device(struct spi_device *spi)
{
	struct flash_info *flash_info = NULL;
	struct spi_message m;
	struct spi_transfer t;
	unsigned char cmd_resp[6];
	int i, err;
	uint16_t id;

	spi_message_init(&m);
	memset(&t, 0, sizeof(struct spi_transfer));

	cmd_resp[0] = SST25L_CMD_READ_ID;
	cmd_resp[1] = 0;
	cmd_resp[2] = 0;
	cmd_resp[3] = 0;
	cmd_resp[4] = 0xff;
	cmd_resp[5] = 0xff;
	t.tx_buf = cmd_resp;
	t.rx_buf = cmd_resp;
	t.len = sizeof(cmd_resp);
	spi_message_add_tail(&t, &m);
	err = spi_sync(spi, &m);
	if (err < 0) {
		dev_err(&spi->dev, "error reading device id\n");
		return NULL;
	}

	id = (cmd_resp[4] << 8) | cmd_resp[5];

	for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++)
		if (sst25l_flash_info[i].device_id == id)
			flash_info = &sst25l_flash_info[i];

	if (!flash_info)
		dev_err(&spi->dev, "unknown id %.4x\n", id);

	return flash_info;
}

static int __devinit sst25l_probe(struct spi_device *spi)
{
	struct flash_info *flash_info;
	struct sst25l_flash *flash;
	struct flash_platform_data *data;
	int ret;

	flash_info = sst25l_match_device(spi);
	if (!flash_info)
		return -ENODEV;

	flash = kzalloc(sizeof(struct sst25l_flash), GFP_KERNEL);
	if (!flash)
		return -ENOMEM;

	flash->spi = spi;
	mutex_init(&flash->lock);
	dev_set_drvdata(&spi->dev, flash);

	data = spi->dev.platform_data;
	if (data && data->name)
		flash->mtd.name = data->name;
	else
		flash->mtd.name = dev_name(&spi->dev);

	flash->mtd.type		= MTD_NORFLASH;
	flash->mtd.flags	= MTD_CAP_NORFLASH;
	flash->mtd.erasesize	= flash_info->erase_size;
	flash->mtd.writesize	= flash_info->page_size;
	flash->mtd.writebufsize	= flash_info->page_size;
	flash->mtd.size		= flash_info->page_size * flash_info->nr_pages;
	flash->mtd._erase	= sst25l_erase;
	flash->mtd._read		= sst25l_read;
	flash->mtd._write 	= sst25l_write;

	dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name,
		 (long long)flash->mtd.size >> 10);

	pr_debug("mtd .name = %s, .size = 0x%llx (%lldMiB) "
	      ".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
	      flash->mtd.name,
	      (long long)flash->mtd.size, (long long)(flash->mtd.size >> 20),
	      flash->mtd.erasesize, flash->mtd.erasesize / 1024,
	      flash->mtd.numeraseregions);


	ret = mtd_device_parse_register(&flash->mtd, NULL, NULL,
					data ? data->parts : NULL,
					data ? data->nr_parts : 0);
	if (ret) {
		kfree(flash);
		dev_set_drvdata(&spi->dev, NULL);
		return -ENODEV;
	}

	return 0;
}

static int __devexit sst25l_remove(struct spi_device *spi)
{
	struct sst25l_flash *flash = dev_get_drvdata(&spi->dev);
	int ret;

	ret = mtd_device_unregister(&flash->mtd);
	if (ret == 0)
		kfree(flash);
	return ret;
}

static struct spi_driver sst25l_driver = {
	.driver = {
		.name	= "sst25l",
		.owner	= THIS_MODULE,
	},
	.probe		= sst25l_probe,
	.remove		= sst25l_remove,
};

module_spi_driver(sst25l_driver);

MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
	      "Ryan Mallon");
MODULE_LICENSE("GPL");
Commit	Line	Data
ec77e21b RM	1	/*
	2	* sst25l.c
	3	*
	4	* Driver for SST25L SPI Flash chips
	5	*
	6	* Copyright © 2009 Bluewater Systems Ltd
	7	* Author: Andre Renaud <andre@bluewatersys.com>
1c5454ee	8	* Author: Ryan Mallon
ec77e21b RM	9	*
	10	* Based on m25p80.c
	11	*
	12	* This code is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2 as
	14	* published by the Free Software Foundation.
	15	*
	16	*/
	17
	18	#include <linux/init.h>
	19	#include <linux/module.h>
	20	#include <linux/device.h>
	21	#include <linux/mutex.h>
	22	#include <linux/interrupt.h>
5a0e3ad6	23	#include <linux/slab.h>
d43c36dc	24	#include <linux/sched.h>
ec77e21b RM	25
	26	#include <linux/mtd/mtd.h>
	27	#include <linux/mtd/partitions.h>
	28
	29	#include <linux/spi/spi.h>
	30	#include <linux/spi/flash.h>
	31
	32	/* Erases can take up to 3 seconds! */
	33	#define MAX_READY_WAIT_JIFFIES msecs_to_jiffies(3000)
	34
	35	#define SST25L_CMD_WRSR 0x01 /* Write status register */
	36	#define SST25L_CMD_WRDI 0x04 /* Write disable */
	37	#define SST25L_CMD_RDSR 0x05 /* Read status register */
	38	#define SST25L_CMD_WREN 0x06 /* Write enable */
	39	#define SST25L_CMD_READ 0x03 /* High speed read */
	40
	41	#define SST25L_CMD_EWSR 0x50 /* Enable write status register */
	42	#define SST25L_CMD_SECTOR_ERASE 0x20 /* Erase sector */
	43	#define SST25L_CMD_READ_ID 0x90 /* Read device ID */
	44	#define SST25L_CMD_AAI_PROGRAM 0xaf /* Auto address increment */
	45
	46	#define SST25L_STATUS_BUSY (1 << 0) /* Chip is busy */
	47	#define SST25L_STATUS_WREN (1 << 1) /* Write enabled */
	48	#define SST25L_STATUS_BP0 (1 << 2) /* Block protection 0 */
	49	#define SST25L_STATUS_BP1 (1 << 3) /* Block protection 1 */
	50
	51	struct sst25l_flash {
	52	struct spi_device *spi;
	53	struct mutex lock;
	54	struct mtd_info mtd;
ec77e21b RM	55	};
	56
	57	struct flash_info {
	58	const char *name;
	59	uint16_t device_id;
	60	unsigned page_size;
	61	unsigned nr_pages;
	62	unsigned erase_size;
	63	};
	64
	65	#define to_sst25l_flash(x) container_of(x, struct sst25l_flash, mtd)
	66
61cc8276	67	static struct flash_info __devinitdata sst25l_flash_info[] = {
ec77e21b RM	68	{"sst25lf020a", 0xbf43, 256, 1024, 4096},
	69	{"sst25lf040a", 0xbf44, 256, 2048, 4096},
	70	};
	71
	72	static int sst25l_status(struct sst25l_flash flash, int status)
	73	{
0ffe0ce3 HS	74	struct spi_message m;
	75	struct spi_transfer t;
	76	unsigned char cmd_resp[2];
ec77e21b RM	77	int err;
ec77e21b RM	78
0ffe0ce3 HS	79	spi_message_init(&m);
	80	memset(&t, 0, sizeof(struct spi_transfer));
	81
	82	cmd_resp[0] = SST25L_CMD_RDSR;
	83	cmd_resp[1] = 0xff;
	84	t.tx_buf = cmd_resp;
	85	t.rx_buf = cmd_resp;
	86	t.len = sizeof(cmd_resp);
	87	spi_message_add_tail(&t, &m);
	88	err = spi_sync(flash->spi, &m);
ec77e21b RM	89	if (err < 0)
	90	return err;
	91
0ffe0ce3	92	*status = cmd_resp[1];
ec77e21b RM	93	return 0;
	94	}
	95
	96	static int sst25l_write_enable(struct sst25l_flash *flash, int enable)
	97	{
	98	unsigned char command[2];
	99	int status, err;
	100
	101	command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI;
	102	err = spi_write(flash->spi, command, 1);
	103	if (err)
	104	return err;
	105
	106	command[0] = SST25L_CMD_EWSR;
	107	err = spi_write(flash->spi, command, 1);
	108	if (err)
	109	return err;
	110
	111	command[0] = SST25L_CMD_WRSR;
	112	command[1] = enable ? 0 : SST25L_STATUS_BP0 \| SST25L_STATUS_BP1;
	113	err = spi_write(flash->spi, command, 2);
	114	if (err)
	115	return err;
	116
	117	if (enable) {
	118	err = sst25l_status(flash, &status);
	119	if (err)
	120	return err;
	121	if (!(status & SST25L_STATUS_WREN))
	122	return -EROFS;
	123	}
	124
	125	return 0;
	126	}
	127
	128	static int sst25l_wait_till_ready(struct sst25l_flash *flash)
	129	{
	130	unsigned long deadline;
	131	int status, err;
	132
	133	deadline = jiffies + MAX_READY_WAIT_JIFFIES;
	134	do {
	135	err = sst25l_status(flash, &status);
	136	if (err)
	137	return err;
	138	if (!(status & SST25L_STATUS_BUSY))
	139	return 0;
	140
	141	cond_resched();
	142	} while (!time_after_eq(jiffies, deadline));
	143
	144	return -ETIMEDOUT;
	145	}
	146
	147	static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset)
	148	{
	149	unsigned char command[4];
	150	int err;
	151
	152	err = sst25l_write_enable(flash, 1);
	153	if (err)
	154	return err;
	155
	156	command[0] = SST25L_CMD_SECTOR_ERASE;
157	command[1] = offset >> 16;
158	command[2] = offset >> 8;
159	command[3] = offset;
160	err = spi_write(flash->spi, command, 4);
161	if (err)
162	return err;
163
164	err = sst25l_wait_till_ready(flash);
165	if (err)
166	return err;
167
168	return sst25l_write_enable(flash, 0);
169	}
170
171	static int sst25l_erase(struct mtd_info mtd, struct erase_info instr)
172	{
173	struct sst25l_flash *flash = to_sst25l_flash(mtd);
174	uint32_t addr, end;
175	int err;
176
177	/* Sanity checks */
ec77e21b RM	178	if ((uint32_t)instr->len % mtd->erasesize)
	179	return -EINVAL;
	180
	181	if ((uint32_t)instr->addr % mtd->erasesize)
	182	return -EINVAL;
	183
	184	addr = instr->addr;
	185	end = addr + instr->len;
	186
	187	mutex_lock(&flash->lock);
	188
	189	err = sst25l_wait_till_ready(flash);
2eaaa5ff JS	190	if (err) {
2eaaa5ff JS	191	mutex_unlock(&flash->lock);
ec77e21b	192	return err;
2eaaa5ff	193	}
ec77e21b RM	194
	195	while (addr < end) {
	196	err = sst25l_erase_sector(flash, addr);
	197	if (err) {
	198	mutex_unlock(&flash->lock);
	199	instr->state = MTD_ERASE_FAILED;
	200	dev_err(&flash->spi->dev, "Erase failed\n");
	201	return err;
	202	}
	203
	204	addr += mtd->erasesize;
	205	}
	206
	207	mutex_unlock(&flash->lock);
	208
	209	instr->state = MTD_ERASE_DONE;
	210	mtd_erase_callback(instr);
	211	return 0;
	212	}
	213
	214	static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len,
	215	size_t retlen, unsigned char buf)
	216	{
	217	struct sst25l_flash *flash = to_sst25l_flash(mtd);
	218	struct spi_transfer transfer[2];
	219	struct spi_message message;
	220	unsigned char command[4];
	221	int ret;
	222
ec77e21b RM	223	spi_message_init(&message);
	224	memset(&transfer, 0, sizeof(transfer));
	225
	226	command[0] = SST25L_CMD_READ;
	227	command[1] = from >> 16;
	228	command[2] = from >> 8;
	229	command[3] = from;
	230
	231	transfer[0].tx_buf = command;
	232	transfer[0].len = sizeof(command);
	233	spi_message_add_tail(&transfer[0], &message);
	234
	235	transfer[1].rx_buf = buf;
	236	transfer[1].len = len;
	237	spi_message_add_tail(&transfer[1], &message);
	238
	239	mutex_lock(&flash->lock);
	240
	241	/* Wait for previous write/erase to complete */
	242	ret = sst25l_wait_till_ready(flash);
	243	if (ret) {
	244	mutex_unlock(&flash->lock);
	245	return ret;
	246	}
	247
	248	spi_sync(flash->spi, &message);
	249
	250	if (retlen && message.actual_length > sizeof(command))
	251	*retlen += message.actual_length - sizeof(command);
	252
	253	mutex_unlock(&flash->lock);
	254	return 0;
	255	}
	256
	257	static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len,
	258	size_t retlen, const unsigned char buf)
	259	{
	260	struct sst25l_flash *flash = to_sst25l_flash(mtd);
	261	int i, j, ret, bytes, copied = 0;
	262	unsigned char command[5];
	263
ec77e21b RM	264	if ((uint32_t)to % mtd->writesize)
	265	return -EINVAL;
	266
	267	mutex_lock(&flash->lock);
	268
	269	ret = sst25l_write_enable(flash, 1);
	270	if (ret)
	271	goto out;
	272
	273	for (i = 0; i < len; i += mtd->writesize) {
	274	ret = sst25l_wait_till_ready(flash);
	275	if (ret)
	276	goto out;
	277
	278	/* Write the first byte of the page */
	279	command[0] = SST25L_CMD_AAI_PROGRAM;
	280	command[1] = (to + i) >> 16;
	281	command[2] = (to + i) >> 8;
	282	command[3] = (to + i);
	283	command[4] = buf[i];
	284	ret = spi_write(flash->spi, command, 5);
	285	if (ret < 0)
	286	goto out;
	287	copied++;
	288
	289	/*
	290	* Write the remaining bytes using auto address
	291	* increment mode
	292	*/
	293	bytes = min_t(uint32_t, mtd->writesize, len - i);
	294	for (j = 1; j < bytes; j++, copied++) {
	295	ret = sst25l_wait_till_ready(flash);
	296	if (ret)
	297	goto out;
	298
	299	command[1] = buf[i + j];
	300	ret = spi_write(flash->spi, command, 2);
	301	if (ret)
	302	goto out;
	303	}
	304	}
	305
	306	out:
	307	ret = sst25l_write_enable(flash, 0);
	308
	309	if (retlen)
	310	*retlen = copied;
	311
	312	mutex_unlock(&flash->lock);
	313	return ret;
	314	}
	315
6b2995b6	316	static struct flash_info __devinit sst25l_match_device(struct spi_device spi)
ec77e21b RM	317	{
ec77e21b RM	318	struct flash_info *flash_info = NULL;
0ffe0ce3 HS	319	struct spi_message m;
	320	struct spi_transfer t;
	321	unsigned char cmd_resp[6];
ec77e21b RM	322	int i, err;
	323	uint16_t id;
	324
0ffe0ce3 HS	325	spi_message_init(&m);
	326	memset(&t, 0, sizeof(struct spi_transfer));
	327
	328	cmd_resp[0] = SST25L_CMD_READ_ID;
	329	cmd_resp[1] = 0;
	330	cmd_resp[2] = 0;
	331	cmd_resp[3] = 0;
	332	cmd_resp[4] = 0xff;
	333	cmd_resp[5] = 0xff;
	334	t.tx_buf = cmd_resp;
	335	t.rx_buf = cmd_resp;
	336	t.len = sizeof(cmd_resp);
	337	spi_message_add_tail(&t, &m);
	338	err = spi_sync(spi, &m);
ec77e21b	339	if (err < 0) {
0ffe0ce3	340	dev_err(&spi->dev, "error reading device id\n");
ec77e21b RM	341	return NULL;
	342	}
	343
0ffe0ce3	344	id = (cmd_resp[4] << 8) \| cmd_resp[5];
ec77e21b RM	345
	346	for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++)
	347	if (sst25l_flash_info[i].device_id == id)
	348	flash_info = &sst25l_flash_info[i];
	349
	350	if (!flash_info)
	351	dev_err(&spi->dev, "unknown id %.4x\n", id);
	352
	353	return flash_info;
	354	}
	355
6b2995b6	356	static int __devinit sst25l_probe(struct spi_device *spi)
ec77e21b RM	357	{
	358	struct flash_info *flash_info;
	359	struct sst25l_flash *flash;
	360	struct flash_platform_data *data;
d81a32f2	361	int ret;
ec77e21b RM	362
	363	flash_info = sst25l_match_device(spi);
	364	if (!flash_info)
	365	return -ENODEV;
	366
	367	flash = kzalloc(sizeof(struct sst25l_flash), GFP_KERNEL);
	368	if (!flash)
	369	return -ENOMEM;
	370
	371	flash->spi = spi;
	372	mutex_init(&flash->lock);
	373	dev_set_drvdata(&spi->dev, flash);
	374
	375	data = spi->dev.platform_data;
	376	if (data && data->name)
	377	flash->mtd.name = data->name;
	378	else
	379	flash->mtd.name = dev_name(&spi->dev);
	380
	381	flash->mtd.type = MTD_NORFLASH;
	382	flash->mtd.flags = MTD_CAP_NORFLASH;
	383	flash->mtd.erasesize = flash_info->erase_size;
	384	flash->mtd.writesize = flash_info->page_size;
c4cc625e	385	flash->mtd.writebufsize = flash_info->page_size;
ec77e21b	386	flash->mtd.size = flash_info->page_size * flash_info->nr_pages;
3c3c10bb AB	387	flash->mtd._erase = sst25l_erase;
	388	flash->mtd._read = sst25l_read;
	389	flash->mtd._write = sst25l_write;
ec77e21b RM	390
	391	dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name,
	392	(long long)flash->mtd.size >> 10);
	393
289c0522	394	pr_debug("mtd .name = %s, .size = 0x%llx (%lldMiB) "
ec77e21b RM	395	".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
	396	flash->mtd.name,
	397	(long long)flash->mtd.size, (long long)(flash->mtd.size >> 20),
	398	flash->mtd.erasesize, flash->mtd.erasesize / 1024,
	399	flash->mtd.numeraseregions);
	400
ec77e21b	401
42d7fbe2 AB	402	ret = mtd_device_parse_register(&flash->mtd, NULL, NULL,
	403	data ? data->parts : NULL,
	404	data ? data->nr_parts : 0);
81939afc	405	if (ret) {
ec77e21b RM	406	kfree(flash);
	407	dev_set_drvdata(&spi->dev, NULL);
	408	return -ENODEV;
	409	}
	410
	411	return 0;
	412	}
	413
61cc8276	414	static int __devexit sst25l_remove(struct spi_device *spi)
ec77e21b RM	415	{
	416	struct sst25l_flash *flash = dev_get_drvdata(&spi->dev);
	417	int ret;
	418
98b3979b	419	ret = mtd_device_unregister(&flash->mtd);
ec77e21b RM	420	if (ret == 0)
	421	kfree(flash);
	422	return ret;
	423	}
	424
	425	static struct spi_driver sst25l_driver = {
	426	.driver = {
	427	.name = "sst25l",
ec77e21b RM	428	.owner = THIS_MODULE,
	429	},
	430	.probe = sst25l_probe,
5153b88c	431	.remove = sst25l_remove,
ec77e21b RM	432	};
ec77e21b RM	433
c9d1b752	434	module_spi_driver(sst25l_driver);
ec77e21b RM	435
	436	MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
	437	MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
1c5454ee	438	"Ryan Mallon");
ec77e21b	439	MODULE_LICENSE("GPL");