[mirror_ubuntu-artful-kernel.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/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;

	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>
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;
	55
	56	int partitioned;
	57	};
	58
	59	struct flash_info {
	60	const char *name;
	61	uint16_t device_id;
	62	unsigned page_size;
	63	unsigned nr_pages;
	64	unsigned erase_size;
	65	};
	66
	67	#define to_sst25l_flash(x) container_of(x, struct sst25l_flash, mtd)
	68
	69	static struct flash_info __initdata sst25l_flash_info[] = {
	70	{"sst25lf020a", 0xbf43, 256, 1024, 4096},
	71	{"sst25lf040a", 0xbf44, 256, 2048, 4096},
	72	};
	73
	74	static int sst25l_status(struct sst25l_flash flash, int status)
	75	{
	76	unsigned char command, response;
	77	int err;
	78
	79	command = SST25L_CMD_RDSR;
	80	err = spi_write_then_read(flash->spi, &command, 1, &response, 1);
	81	if (err < 0)
	82	return err;
	83
	84	*status = response;
	85	return 0;
	86	}
	87
	88	static int sst25l_write_enable(struct sst25l_flash *flash, int enable)
89	{
90	unsigned char command[2];
91	int status, err;
92
93	command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI;
94	err = spi_write(flash->spi, command, 1);
95	if (err)
96	return err;
97
98	command[0] = SST25L_CMD_EWSR;
99	err = spi_write(flash->spi, command, 1);
100	if (err)
101	return err;
102
103	command[0] = SST25L_CMD_WRSR;
104	command[1] = enable ? 0 : SST25L_STATUS_BP0 \| SST25L_STATUS_BP1;
105	err = spi_write(flash->spi, command, 2);
106	if (err)
107	return err;
108
109	if (enable) {
110	err = sst25l_status(flash, &status);
111	if (err)
112	return err;
113	if (!(status & SST25L_STATUS_WREN))
114	return -EROFS;
115	}
116
117	return 0;
118	}
119
120	static int sst25l_wait_till_ready(struct sst25l_flash *flash)
121	{
122	unsigned long deadline;
123	int status, err;
124
125	deadline = jiffies + MAX_READY_WAIT_JIFFIES;
126	do {
127	err = sst25l_status(flash, &status);
128	if (err)
129	return err;
130	if (!(status & SST25L_STATUS_BUSY))
131	return 0;
132
133	cond_resched();
134	} while (!time_after_eq(jiffies, deadline));
135
136	return -ETIMEDOUT;
137	}
138
139	static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset)
140	{
141	unsigned char command[4];
142	int err;
143
144	err = sst25l_write_enable(flash, 1);
145	if (err)
146	return err;
147
148	command[0] = SST25L_CMD_SECTOR_ERASE;
149	command[1] = offset >> 16;
150	command[2] = offset >> 8;
151	command[3] = offset;
152	err = spi_write(flash->spi, command, 4);
153	if (err)
154	return err;
155
156	err = sst25l_wait_till_ready(flash);
157	if (err)
158	return err;
159
160	return sst25l_write_enable(flash, 0);
161	}
162
163	static int sst25l_erase(struct mtd_info mtd, struct erase_info instr)
164	{
165	struct sst25l_flash *flash = to_sst25l_flash(mtd);
166	uint32_t addr, end;
167	int err;
168
169	/* Sanity checks */
170	if (instr->addr + instr->len > flash->mtd.size)
171	return -EINVAL;
172
173	if ((uint32_t)instr->len % mtd->erasesize)
174	return -EINVAL;
175
176	if ((uint32_t)instr->addr % mtd->erasesize)
177	return -EINVAL;
178
179	addr = instr->addr;
180	end = addr + instr->len;
181
182	mutex_lock(&flash->lock);
183
184	err = sst25l_wait_till_ready(flash);
2eaaa5ff JS	185	if (err) {
2eaaa5ff JS	186	mutex_unlock(&flash->lock);
ec77e21b	187	return err;
2eaaa5ff	188	}
ec77e21b RM	189
	190	while (addr < end) {
	191	err = sst25l_erase_sector(flash, addr);
	192	if (err) {
	193	mutex_unlock(&flash->lock);
	194	instr->state = MTD_ERASE_FAILED;
	195	dev_err(&flash->spi->dev, "Erase failed\n");
	196	return err;
	197	}
	198
	199	addr += mtd->erasesize;
	200	}
	201
	202	mutex_unlock(&flash->lock);
	203
	204	instr->state = MTD_ERASE_DONE;
	205	mtd_erase_callback(instr);
	206	return 0;
	207	}
	208
	209	static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len,
	210	size_t retlen, unsigned char buf)
	211	{
	212	struct sst25l_flash *flash = to_sst25l_flash(mtd);
	213	struct spi_transfer transfer[2];
	214	struct spi_message message;
	215	unsigned char command[4];
	216	int ret;
	217
	218	/* Sanity checking */
	219	if (len == 0)
	220	return 0;
	221
	222	if (from + len > flash->mtd.size)
	223	return -EINVAL;
	224
	225	if (retlen)
	226	*retlen = 0;
	227
	228	spi_message_init(&message);
	229	memset(&transfer, 0, sizeof(transfer));
	230
	231	command[0] = SST25L_CMD_READ;
	232	command[1] = from >> 16;
	233	command[2] = from >> 8;
	234	command[3] = from;
	235
	236	transfer[0].tx_buf = command;
	237	transfer[0].len = sizeof(command);
	238	spi_message_add_tail(&transfer[0], &message);
	239
	240	transfer[1].rx_buf = buf;
	241	transfer[1].len = len;
	242	spi_message_add_tail(&transfer[1], &message);
	243
	244	mutex_lock(&flash->lock);
	245
	246	/* Wait for previous write/erase to complete */
	247	ret = sst25l_wait_till_ready(flash);
	248	if (ret) {
	249	mutex_unlock(&flash->lock);
	250	return ret;
	251	}
	252
253	spi_sync(flash->spi, &message);
254
255	if (retlen && message.actual_length > sizeof(command))
256	*retlen += message.actual_length - sizeof(command);
257
258	mutex_unlock(&flash->lock);
259	return 0;
260	}
261
262	static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len,
263	size_t retlen, const unsigned char buf)
264	{
265	struct sst25l_flash *flash = to_sst25l_flash(mtd);
266	int i, j, ret, bytes, copied = 0;
267	unsigned char command[5];
268
269	/* Sanity checks */
270	if (!len)
271	return 0;
272
273	if (to + len > flash->mtd.size)
274	return -EINVAL;
275
276	if ((uint32_t)to % mtd->writesize)
277	return -EINVAL;
278
279	mutex_lock(&flash->lock);
280
281	ret = sst25l_write_enable(flash, 1);
282	if (ret)
283	goto out;
284
285	for (i = 0; i < len; i += mtd->writesize) {
286	ret = sst25l_wait_till_ready(flash);
287	if (ret)
288	goto out;
289
290	/* Write the first byte of the page */
291	command[0] = SST25L_CMD_AAI_PROGRAM;
292	command[1] = (to + i) >> 16;
293	command[2] = (to + i) >> 8;
294	command[3] = (to + i);
295	command[4] = buf[i];
296	ret = spi_write(flash->spi, command, 5);
297	if (ret < 0)
298	goto out;
299	copied++;
300
301	/*
302	* Write the remaining bytes using auto address
303	* increment mode
304	*/
305	bytes = min_t(uint32_t, mtd->writesize, len - i);
306	for (j = 1; j < bytes; j++, copied++) {
307	ret = sst25l_wait_till_ready(flash);
308	if (ret)
309	goto out;
310
311	command[1] = buf[i + j];
312	ret = spi_write(flash->spi, command, 2);
313	if (ret)
314	goto out;
315	}
316	}
317
318	out:
319	ret = sst25l_write_enable(flash, 0);
320
321	if (retlen)
322	*retlen = copied;
323
324	mutex_unlock(&flash->lock);
325	return ret;
326	}
327
328	static struct flash_info __init sst25l_match_device(struct spi_device spi)
329	{
330	struct flash_info *flash_info = NULL;
331	unsigned char command[4], response;
332	int i, err;
333	uint16_t id;
334
335	command[0] = SST25L_CMD_READ_ID;
336	command[1] = 0;
337	command[2] = 0;
338	command[3] = 0;
339	err = spi_write_then_read(spi, command, sizeof(command), &response, 1);
340	if (err < 0) {
341	dev_err(&spi->dev, "error reading device id msb\n");
342	return NULL;
343	}
344
345	id = response << 8;
346
347	command[0] = SST25L_CMD_READ_ID;
348	command[1] = 0;
349	command[2] = 0;
350	command[3] = 1;
351	err = spi_write_then_read(spi, command, sizeof(command), &response, 1);
352	if (err < 0) {
353	dev_err(&spi->dev, "error reading device id lsb\n");
354	return NULL;
355	}
356
357	id \|= response;
358
359	for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++)
360	if (sst25l_flash_info[i].device_id == id)
361	flash_info = &sst25l_flash_info[i];
362
363	if (!flash_info)
364	dev_err(&spi->dev, "unknown id %.4x\n", id);
365
366	return flash_info;
367	}
368
369	static int __init sst25l_probe(struct spi_device *spi)
370	{
371	struct flash_info *flash_info;
372	struct sst25l_flash *flash;
373	struct flash_platform_data *data;
374	int ret, i;
375
376	flash_info = sst25l_match_device(spi);
377	if (!flash_info)
378	return -ENODEV;
379
380	flash = kzalloc(sizeof(struct sst25l_flash), GFP_KERNEL);
381	if (!flash)
382	return -ENOMEM;
383
384	flash->spi = spi;
385	mutex_init(&flash->lock);
386	dev_set_drvdata(&spi->dev, flash);
387
388	data = spi->dev.platform_data;
389	if (data && data->name)
390	flash->mtd.name = data->name;
391	else
392	flash->mtd.name = dev_name(&spi->dev);
393
394	flash->mtd.type = MTD_NORFLASH;
395	flash->mtd.flags = MTD_CAP_NORFLASH;
396	flash->mtd.erasesize = flash_info->erase_size;
397	flash->mtd.writesize = flash_info->page_size;
398	flash->mtd.size = flash_info->page_size * flash_info->nr_pages;
399	flash->mtd.erase = sst25l_erase;
400	flash->mtd.read = sst25l_read;
401	flash->mtd.write = sst25l_write;
402
403	dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name,
404	(long long)flash->mtd.size >> 10);
405
406	DEBUG(MTD_DEBUG_LEVEL2,
407	"mtd .name = %s, .size = 0x%llx (%lldMiB) "
408	".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
409	flash->mtd.name,
410	(long long)flash->mtd.size, (long long)(flash->mtd.size >> 20),
411	flash->mtd.erasesize, flash->mtd.erasesize / 1024,
412	flash->mtd.numeraseregions);
413
414	if (flash->mtd.numeraseregions)
415	for (i = 0; i < flash->mtd.numeraseregions; i++)
416	DEBUG(MTD_DEBUG_LEVEL2,
417	"mtd.eraseregions[%d] = { .offset = 0x%llx, "
418	".erasesize = 0x%.8x (%uKiB), "
419	".numblocks = %d }\n",
420	i, (long long)flash->mtd.eraseregions[i].offset,
421	flash->mtd.eraseregions[i].erasesize,
422	flash->mtd.eraseregions[i].erasesize / 1024,
423	flash->mtd.eraseregions[i].numblocks);
424
425	if (mtd_has_partitions()) {
426	struct mtd_partition *parts = NULL;
427	int nr_parts = 0;
428
429	if (mtd_has_cmdlinepart()) {
430	static const char *part_probes[] =
431	{"cmdlinepart", NULL};
432
433	nr_parts = parse_mtd_partitions(&flash->mtd,
434	part_probes,
435	&parts, 0);
436	}
437
438	if (nr_parts <= 0 && data && data->parts) {
439	parts = data->parts;
440	nr_parts = data->nr_parts;
441	}
442
443	if (nr_parts > 0) {
444	for (i = 0; i < nr_parts; i++) {
445	DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "
446	"{.name = %s, .offset = 0x%llx, "
447	".size = 0x%llx (%lldKiB) }\n",
448	i, parts[i].name,
449	(long long)parts[i].offset,
450	(long long)parts[i].size,
451	(long long)(parts[i].size >> 10));
452	}
453
454	flash->partitioned = 1;
455	return add_mtd_partitions(&flash->mtd,
456	parts, nr_parts);
457	}
458
459	} else if (data->nr_parts) {
460	dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
461	data->nr_parts, data->name);
462	}
463
464	ret = add_mtd_device(&flash->mtd);
465	if (ret == 1) {
466	kfree(flash);
467	dev_set_drvdata(&spi->dev, NULL);
468	return -ENODEV;
469	}
470
471	return 0;
472	}
473
474	static int __exit sst25l_remove(struct spi_device *spi)
475	{
476	struct sst25l_flash *flash = dev_get_drvdata(&spi->dev);
477	int ret;
478
479	if (mtd_has_partitions() && flash->partitioned)
480	ret = del_mtd_partitions(&flash->mtd);
481	else
482	ret = del_mtd_device(&flash->mtd);
483	if (ret == 0)
484	kfree(flash);
485	return ret;
486	}
487
488	static struct spi_driver sst25l_driver = {
489	.driver = {
490	.name = "sst25l",
491	.bus = &spi_bus_type,
492	.owner = THIS_MODULE,
493	},
494	.probe = sst25l_probe,
495	.remove = __exit_p(sst25l_remove),
496	};
497
498	static int __init sst25l_init(void)
499	{
500	return spi_register_driver(&sst25l_driver);
501	}
502
503	static void __exit sst25l_exit(void)
504	{
505	spi_unregister_driver(&sst25l_driver);
506	}
507
508	module_init(sst25l_init);
509	module_exit(sst25l_exit);
510
511	MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
512	MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
513	"Ryan Mallon <ryan@bluewatersys.com>");
514	MODULE_LICENSE("GPL");