[deliverable/linux.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 <ryan@bluewatersys.com>
 *
 * 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/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;

	int 			partitioned;
};

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 __initdata sst25l_flash_info[] = {
	{"sst25lf020a", 0xbf43, 256, 1024, 4096},
	{"sst25lf040a",	0xbf44,	256, 2048, 4096},
};

static int sst25l_status(struct sst25l_flash *flash, int *status)
{
	unsigned char command, response;
	int err;

	command = SST25L_CMD_RDSR;
	err = spi_write_then_read(flash->spi, &command, 1, &response, 1);
	if (err < 0)
		return err;

	*status = response;
	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 (instr->addr + instr->len > flash->mtd.size)
		return -EINVAL;

	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;

	/* Sanity checking */
	if (len == 0)
		return 0;

	if (from + len > flash->mtd.size)
		return -EINVAL;

	if (retlen)
		*retlen = 0;

	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];

	/* Sanity checks */
	if (!len)
		return 0;

	if (to + len > flash->mtd.size)
		return -EINVAL;

	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 *__init sst25l_match_device(struct spi_device *spi)
{
	struct flash_info *flash_info = NULL;
	unsigned char command[4], response;
	int i, err;
	uint16_t id;

	command[0] = SST25L_CMD_READ_ID;
	command[1] = 0;
	command[2] = 0;
	command[3] = 0;
	err = spi_write_then_read(spi, command, sizeof(command), &response, 1);
	if (err < 0) {
		dev_err(&spi->dev, "error reading device id msb\n");
		return NULL;
	}

	id = response << 8;

	command[0] = SST25L_CMD_READ_ID;
	command[1] = 0;
	command[2] = 0;
	command[3] = 1;
	err = spi_write_then_read(spi, command, sizeof(command), &response, 1);
	if (err < 0) {
		dev_err(&spi->dev, "error reading device id lsb\n");
		return NULL;
	}

	id |= response;

	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 __init sst25l_probe(struct spi_device *spi)
{
	struct flash_info *flash_info;
	struct sst25l_flash *flash;
	struct flash_platform_data *data;
	int ret, i;

	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.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);

	DEBUG(MTD_DEBUG_LEVEL2,
	      "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);

	if (flash->mtd.numeraseregions)
		for (i = 0; i < flash->mtd.numeraseregions; i++)
			DEBUG(MTD_DEBUG_LEVEL2,
			      "mtd.eraseregions[%d] = { .offset = 0x%llx, "
			      ".erasesize = 0x%.8x (%uKiB), "
			      ".numblocks = %d }\n",
			      i, (long long)flash->mtd.eraseregions[i].offset,
			      flash->mtd.eraseregions[i].erasesize,
			      flash->mtd.eraseregions[i].erasesize / 1024,
			      flash->mtd.eraseregions[i].numblocks);

	if (mtd_has_partitions()) {
		struct mtd_partition *parts = NULL;
		int nr_parts = 0;

		if (mtd_has_cmdlinepart()) {
			static const char *part_probes[] =
				{"cmdlinepart", NULL};

			nr_parts = parse_mtd_partitions(&flash->mtd,
							part_probes,
							&parts, 0);
		}

		if (nr_parts <= 0 && data && data->parts) {
			parts = data->parts;
			nr_parts = data->nr_parts;
		}

		if (nr_parts > 0) {
			for (i = 0; i < nr_parts; i++) {
				DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "
				      "{.name = %s, .offset = 0x%llx, "
				      ".size = 0x%llx (%lldKiB) }\n",
				      i, parts[i].name,
				      (long long)parts[i].offset,
				      (long long)parts[i].size,
				      (long long)(parts[i].size >> 10));
			}

			flash->partitioned = 1;
			return add_mtd_partitions(&flash->mtd,
						  parts, nr_parts);
		}

	} else if (data->nr_parts) {
		dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
			 data->nr_parts, data->name);
	}

	ret = add_mtd_device(&flash->mtd);
	if (ret == 1) {
		kfree(flash);
		dev_set_drvdata(&spi->dev, NULL);
		return -ENODEV;
	}

	return 0;
}

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

	if (mtd_has_partitions() && flash->partitioned)
		ret = del_mtd_partitions(&flash->mtd);
	else
		ret = del_mtd_device(&flash->mtd);
	if (ret == 0)
		kfree(flash);
	return ret;
}

static struct spi_driver sst25l_driver = {
	.driver = {
		.name	= "sst25l",
		.bus	= &spi_bus_type,
		.owner	= THIS_MODULE,
	},
	.probe		= sst25l_probe,
	.remove		= __exit_p(sst25l_remove),
};

static int __init sst25l_init(void)
{
	return spi_register_driver(&sst25l_driver);
}

static void __exit sst25l_exit(void)
{
	spi_unregister_driver(&sst25l_driver);
}

module_init(sst25l_init);
module_exit(sst25l_exit);

MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
	      "Ryan Mallon <ryan@bluewatersys.com>");
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>
	8	* Author: Ryan Mallon <ryan@bluewatersys.com>
	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>
	23
	24	#include <linux/mtd/mtd.h>
	25	#include <linux/mtd/partitions.h>
	26
	27	#include <linux/spi/spi.h>
	28	#include <linux/spi/flash.h>
	29
	30	/* Erases can take up to 3 seconds! */
	31	#define MAX_READY_WAIT_JIFFIES msecs_to_jiffies(3000)
	32
	33	#define SST25L_CMD_WRSR 0x01 /* Write status register */
	34	#define SST25L_CMD_WRDI 0x04 /* Write disable */
	35	#define SST25L_CMD_RDSR 0x05 /* Read status register */
	36	#define SST25L_CMD_WREN 0x06 /* Write enable */
	37	#define SST25L_CMD_READ 0x03 /* High speed read */
	38
	39	#define SST25L_CMD_EWSR 0x50 /* Enable write status register */
	40	#define SST25L_CMD_SECTOR_ERASE 0x20 /* Erase sector */
	41	#define SST25L_CMD_READ_ID 0x90 /* Read device ID */
	42	#define SST25L_CMD_AAI_PROGRAM 0xaf /* Auto address increment */
	43
	44	#define SST25L_STATUS_BUSY (1 << 0) /* Chip is busy */
	45	#define SST25L_STATUS_WREN (1 << 1) /* Write enabled */
	46	#define SST25L_STATUS_BP0 (1 << 2) /* Block protection 0 */
	47	#define SST25L_STATUS_BP1 (1 << 3) /* Block protection 1 */
	48
	49	struct sst25l_flash {
	50	struct spi_device *spi;
	51	struct mutex lock;
	52	struct mtd_info mtd;
	53
	54	int partitioned;
	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
67	static struct flash_info __initdata sst25l_flash_info[] = {
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	{
74	unsigned char command, response;
75	int err;
76
77	command = SST25L_CMD_RDSR;
78	err = spi_write_then_read(flash->spi, &command, 1, &response, 1);
79	if (err < 0)
80	return err;
81
82	*status = response;
83	return 0;
84	}
85
86	static int sst25l_write_enable(struct sst25l_flash *flash, int enable)
87	{
88	unsigned char command[2];
89	int status, err;
90
91	command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI;
92	err = spi_write(flash->spi, command, 1);
93	if (err)
94	return err;
95
96	command[0] = SST25L_CMD_EWSR;
97	err = spi_write(flash->spi, command, 1);
98	if (err)
99	return err;
100
101	command[0] = SST25L_CMD_WRSR;
102	command[1] = enable ? 0 : SST25L_STATUS_BP0 \| SST25L_STATUS_BP1;
103	err = spi_write(flash->spi, command, 2);
104	if (err)
105	return err;
106
107	if (enable) {
108	err = sst25l_status(flash, &status);
109	if (err)
110	return err;
111	if (!(status & SST25L_STATUS_WREN))
112	return -EROFS;
113	}
114
115	return 0;
116	}
117
118	static int sst25l_wait_till_ready(struct sst25l_flash *flash)
119	{
120	unsigned long deadline;
121	int status, err;
122
123	deadline = jiffies + MAX_READY_WAIT_JIFFIES;
124	do {
125	err = sst25l_status(flash, &status);
126	if (err)
127	return err;
128	if (!(status & SST25L_STATUS_BUSY))
129	return 0;
130
131	cond_resched();
132	} while (!time_after_eq(jiffies, deadline));
133
134	return -ETIMEDOUT;
135	}
136
137	static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset)
138	{
139	unsigned char command[4];
140	int err;
141
142	err = sst25l_write_enable(flash, 1);
143	if (err)
144	return err;
145
146	command[0] = SST25L_CMD_SECTOR_ERASE;
147	command[1] = offset >> 16;
148	command[2] = offset >> 8;
149	command[3] = offset;
150	err = spi_write(flash->spi, command, 4);
151	if (err)
152	return err;
153
154	err = sst25l_wait_till_ready(flash);
155	if (err)
156	return err;
157
158	return sst25l_write_enable(flash, 0);
159	}
160
161	static int sst25l_erase(struct mtd_info mtd, struct erase_info instr)
162	{
163	struct sst25l_flash *flash = to_sst25l_flash(mtd);
164	uint32_t addr, end;
165	int err;
166
167	/* Sanity checks */
168	if (instr->addr + instr->len > flash->mtd.size)
169	return -EINVAL;
170
171	if ((uint32_t)instr->len % mtd->erasesize)
172	return -EINVAL;
173
174	if ((uint32_t)instr->addr % mtd->erasesize)
175	return -EINVAL;
176
177	addr = instr->addr;
178	end = addr + instr->len;
179
180	mutex_lock(&flash->lock);
181
182	err = sst25l_wait_till_ready(flash);
2eaaa5ff JS	183	if (err) {
2eaaa5ff JS	184	mutex_unlock(&flash->lock);
ec77e21b	185	return err;
2eaaa5ff	186	}
ec77e21b RM	187
	188	while (addr < end) {
	189	err = sst25l_erase_sector(flash, addr);
	190	if (err) {
	191	mutex_unlock(&flash->lock);
	192	instr->state = MTD_ERASE_FAILED;
	193	dev_err(&flash->spi->dev, "Erase failed\n");
	194	return err;
	195	}
	196
	197	addr += mtd->erasesize;
	198	}
	199
	200	mutex_unlock(&flash->lock);
	201
	202	instr->state = MTD_ERASE_DONE;
	203	mtd_erase_callback(instr);
	204	return 0;
	205	}
	206
	207	static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len,
	208	size_t retlen, unsigned char buf)
	209	{
	210	struct sst25l_flash *flash = to_sst25l_flash(mtd);
	211	struct spi_transfer transfer[2];
	212	struct spi_message message;
	213	unsigned char command[4];
	214	int ret;
	215
	216	/* Sanity checking */
	217	if (len == 0)
	218	return 0;
	219
	220	if (from + len > flash->mtd.size)
	221	return -EINVAL;
	222
	223	if (retlen)
	224	*retlen = 0;
	225
	226	spi_message_init(&message);
	227	memset(&transfer, 0, sizeof(transfer));
	228
	229	command[0] = SST25L_CMD_READ;
	230	command[1] = from >> 16;
	231	command[2] = from >> 8;
	232	command[3] = from;
	233
	234	transfer[0].tx_buf = command;
	235	transfer[0].len = sizeof(command);
	236	spi_message_add_tail(&transfer[0], &message);
	237
	238	transfer[1].rx_buf = buf;
	239	transfer[1].len = len;
	240	spi_message_add_tail(&transfer[1], &message);
	241
	242	mutex_lock(&flash->lock);
	243
	244	/* Wait for previous write/erase to complete */
	245	ret = sst25l_wait_till_ready(flash);
	246	if (ret) {
	247	mutex_unlock(&flash->lock);
	248	return ret;
	249	}
	250
251	spi_sync(flash->spi, &message);
252
253	if (retlen && message.actual_length > sizeof(command))
254	*retlen += message.actual_length - sizeof(command);
255
256	mutex_unlock(&flash->lock);
257	return 0;
258	}
259
260	static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len,
261	size_t retlen, const unsigned char buf)
262	{
263	struct sst25l_flash *flash = to_sst25l_flash(mtd);
264	int i, j, ret, bytes, copied = 0;
265	unsigned char command[5];
266
267	/* Sanity checks */
268	if (!len)
269	return 0;
270
271	if (to + len > flash->mtd.size)
272	return -EINVAL;
273
274	if ((uint32_t)to % mtd->writesize)
275	return -EINVAL;
276
277	mutex_lock(&flash->lock);
278
279	ret = sst25l_write_enable(flash, 1);
280	if (ret)
281	goto out;
282
283	for (i = 0; i < len; i += mtd->writesize) {
284	ret = sst25l_wait_till_ready(flash);
285	if (ret)
286	goto out;
287
288	/* Write the first byte of the page */
289	command[0] = SST25L_CMD_AAI_PROGRAM;
290	command[1] = (to + i) >> 16;
291	command[2] = (to + i) >> 8;
292	command[3] = (to + i);
293	command[4] = buf[i];
294	ret = spi_write(flash->spi, command, 5);
295	if (ret < 0)
296	goto out;
297	copied++;
298
299	/*
300	* Write the remaining bytes using auto address
301	* increment mode
302	*/
303	bytes = min_t(uint32_t, mtd->writesize, len - i);
304	for (j = 1; j < bytes; j++, copied++) {
305	ret = sst25l_wait_till_ready(flash);
306	if (ret)
307	goto out;
308
309	command[1] = buf[i + j];
310	ret = spi_write(flash->spi, command, 2);
311	if (ret)
312	goto out;
313	}
314	}
315
316	out:
317	ret = sst25l_write_enable(flash, 0);
318
319	if (retlen)
320	*retlen = copied;
321
322	mutex_unlock(&flash->lock);
323	return ret;
324	}
325
326	static struct flash_info __init sst25l_match_device(struct spi_device spi)
327	{
328	struct flash_info *flash_info = NULL;
329	unsigned char command[4], response;
330	int i, err;
331	uint16_t id;
332
333	command[0] = SST25L_CMD_READ_ID;
334	command[1] = 0;
335	command[2] = 0;
336	command[3] = 0;
337	err = spi_write_then_read(spi, command, sizeof(command), &response, 1);
338	if (err < 0) {
339	dev_err(&spi->dev, "error reading device id msb\n");
340	return NULL;
341	}
342
343	id = response << 8;
344
345	command[0] = SST25L_CMD_READ_ID;
346	command[1] = 0;
347	command[2] = 0;
348	command[3] = 1;
349	err = spi_write_then_read(spi, command, sizeof(command), &response, 1);
350	if (err < 0) {
351	dev_err(&spi->dev, "error reading device id lsb\n");
352	return NULL;
353	}
354
355	id \|= response;
356
357	for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++)
358	if (sst25l_flash_info[i].device_id == id)
359	flash_info = &sst25l_flash_info[i];
360
361	if (!flash_info)
362	dev_err(&spi->dev, "unknown id %.4x\n", id);
363
364	return flash_info;
365	}
366
367	static int __init sst25l_probe(struct spi_device *spi)
368	{
369	struct flash_info *flash_info;
370	struct sst25l_flash *flash;
371	struct flash_platform_data *data;
372	int ret, i;
373
374	flash_info = sst25l_match_device(spi);
375	if (!flash_info)
376	return -ENODEV;
377
378	flash = kzalloc(sizeof(struct sst25l_flash), GFP_KERNEL);
379	if (!flash)
380	return -ENOMEM;
381
382	flash->spi = spi;
383	mutex_init(&flash->lock);
384	dev_set_drvdata(&spi->dev, flash);
385
386	data = spi->dev.platform_data;
387	if (data && data->name)
388	flash->mtd.name = data->name;
389	else
390	flash->mtd.name = dev_name(&spi->dev);
391
392	flash->mtd.type = MTD_NORFLASH;
393	flash->mtd.flags = MTD_CAP_NORFLASH;
394	flash->mtd.erasesize = flash_info->erase_size;
395	flash->mtd.writesize = flash_info->page_size;
396	flash->mtd.size = flash_info->page_size * flash_info->nr_pages;
397	flash->mtd.erase = sst25l_erase;
398	flash->mtd.read = sst25l_read;
399	flash->mtd.write = sst25l_write;
400
401	dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name,
402	(long long)flash->mtd.size >> 10);
403
404	DEBUG(MTD_DEBUG_LEVEL2,
405	"mtd .name = %s, .size = 0x%llx (%lldMiB) "
406	".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
407	flash->mtd.name,
408	(long long)flash->mtd.size, (long long)(flash->mtd.size >> 20),
409	flash->mtd.erasesize, flash->mtd.erasesize / 1024,
410	flash->mtd.numeraseregions);
411
412	if (flash->mtd.numeraseregions)
413	for (i = 0; i < flash->mtd.numeraseregions; i++)
414	DEBUG(MTD_DEBUG_LEVEL2,
415	"mtd.eraseregions[%d] = { .offset = 0x%llx, "
416	".erasesize = 0x%.8x (%uKiB), "
417	".numblocks = %d }\n",
418	i, (long long)flash->mtd.eraseregions[i].offset,
419	flash->mtd.eraseregions[i].erasesize,
420	flash->mtd.eraseregions[i].erasesize / 1024,
421	flash->mtd.eraseregions[i].numblocks);
422
423	if (mtd_has_partitions()) {
424	struct mtd_partition *parts = NULL;
425	int nr_parts = 0;
426
427	if (mtd_has_cmdlinepart()) {
428	static const char *part_probes[] =
429	{"cmdlinepart", NULL};
430
431	nr_parts = parse_mtd_partitions(&flash->mtd,
432	part_probes,
433	&parts, 0);
434	}
435
436	if (nr_parts <= 0 && data && data->parts) {
437	parts = data->parts;
438	nr_parts = data->nr_parts;
439	}
440
441	if (nr_parts > 0) {
442	for (i = 0; i < nr_parts; i++) {
443	DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "
444	"{.name = %s, .offset = 0x%llx, "
445	".size = 0x%llx (%lldKiB) }\n",
446	i, parts[i].name,
447	(long long)parts[i].offset,
448	(long long)parts[i].size,
449	(long long)(parts[i].size >> 10));
450	}
451
452	flash->partitioned = 1;
453	return add_mtd_partitions(&flash->mtd,
454	parts, nr_parts);
455	}
456
457	} else if (data->nr_parts) {
458	dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
459	data->nr_parts, data->name);
460	}
461
462	ret = add_mtd_device(&flash->mtd);
463	if (ret == 1) {
464	kfree(flash);
465	dev_set_drvdata(&spi->dev, NULL);
466	return -ENODEV;
467	}
468
469	return 0;
470	}
471
472	static int __exit sst25l_remove(struct spi_device *spi)
473	{
474	struct sst25l_flash *flash = dev_get_drvdata(&spi->dev);
475	int ret;
476
477	if (mtd_has_partitions() && flash->partitioned)
478	ret = del_mtd_partitions(&flash->mtd);
479	else
480	ret = del_mtd_device(&flash->mtd);
481	if (ret == 0)
482	kfree(flash);
483	return ret;
484	}
485
486	static struct spi_driver sst25l_driver = {
487	.driver = {
488	.name = "sst25l",
489	.bus = &spi_bus_type,
490	.owner = THIS_MODULE,
491	},
492	.probe = sst25l_probe,
493	.remove = __exit_p(sst25l_remove),
494	};
495
496	static int __init sst25l_init(void)
497	{
498	return spi_register_driver(&sst25l_driver);
499	}
500
501	static void __exit sst25l_exit(void)
502	{
503	spi_unregister_driver(&sst25l_driver);
504	}
505
506	module_init(sst25l_init);
507	module_exit(sst25l_exit);
508
509	MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
510	MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
511	"Ryan Mallon <ryan@bluewatersys.com>");
512	MODULE_LICENSE("GPL");