[PATCH] SST25L (non JEDEC) SPI Flash driver

[PATCH] SST25L (non JEDEC) SPI Flash driver

[Ryan Mallon]

Hi Andrew,

It was suggested I send the following patch via you as David Woodhouse
is currently busy.

Thanks,
~Ryan

----
Add support for the non JEDEC SST25L SPI Flash devices.

Signed-off-by: Andre Renaud <andre@bluewatersys.com>
Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
----

diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index 325fab9..c222514 100644
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -104,6 +104,16 @@ config M25PXX_USE_FAST_READ
 	help
 	  This option enables FAST_READ access supported by ST M25Pxx.
 
+config MTD_SST25L
+	tristate "Support SST25L (non JEDEC) SPI Flash chips"
+	depends on SPI_MASTER
+	help
+	  This enables access to the non JEDEC SST25L SPI flash chips, used
+	  for program and data storage.
+
+	  Set up your spi devices with the right board-specific platform data,
+	  if you want to specify device partitioning.
+
 config MTD_SLRAM
 	tristate "Uncached system RAM"
 	help
diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile
index 0993d5c..ab5c9b9 100644
--- a/drivers/mtd/devices/Makefile
+++ b/drivers/mtd/devices/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_MTD_LART)		+= lart.o
 obj-$(CONFIG_MTD_BLOCK2MTD)	+= block2mtd.o
 obj-$(CONFIG_MTD_DATAFLASH)	+= mtd_dataflash.o
 obj-$(CONFIG_MTD_M25P80)	+= m25p80.o
+obj-$(CONFIG_MTD_SST25L)	+= sst25l.o
diff --git a/drivers/mtd/devices/sst25l.c b/drivers/mtd/devices/sst25l.c
new file mode 100644
index 0000000..30658f6
--- /dev/null
+++ b/drivers/mtd/devices/sst25l.c
@@ -0,0 +1,503 @@
+/*
+ * drivers/mtd/sst25l.c
+ *
+ * Driver for SST25L SPI Flash chips
+ *
+ * Copyright (C) 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_BLOCK_ERASE	0x52	/* 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;
+	u16			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, 32 * 1024},
+	{"sst25lf040a",	0xbf44,	256, 2048, 32 * 1024},
+};
+
+static int sst25l_status(struct sst25l_flash *flash, int *status)
+{
+	u8 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)
+{
+	u8 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_block(struct sst25l_flash *flash, u32 offset)
+{
+	u8 command[4];
+	int err;
+
+	err = sst25l_write_enable(flash, 1);
+	if (err)
+		return err;
+
+	command[0] = SST25L_CMD_BLOCK_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);
+	u32 addr, end;
+	int err;
+
+	/* Sanity checks */
+	if (instr->addr + instr->len > flash->mtd.size)
+		return -EINVAL;
+
+	if ((u32)instr->len % mtd->erasesize)
+		return -EINVAL;
+
+	if ((u32)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)
+		return err;
+
+	while (addr < end) {
+		err = sst25l_erase_block(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, u_char *buf)
+{
+	struct sst25l_flash *flash = to_sst25l_flash(mtd);
+	struct spi_transfer transfer[2];
+	struct spi_message message;
+	u8 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 u_char *buf)
+{
+	struct sst25l_flash *flash = to_sst25l_flash(mtd);
+	int i, j, ret, bytes, copied = 0;
+	u8 command[5];
+
+	/* Sanity checks */
+	if (!len)
+		return 0;
+
+	if (to + len > flash->mtd.size)
+		return -EINVAL;
+
+	if ((u32)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(mtd->writesize, (u32)(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;
+	u8 command[4], response;
+	int i, err;
+	u16 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 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 Kbytes)\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);
+	}
+
+	return add_mtd_device(&flash->mtd) == 1 ? -ENODEV : 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");

Re: [PATCH] SST25L (non JEDEC) SPI Flash driver

[Linus Walleij]

2009/6/25 Ryan Mallon <ryan@bluewatersys.com>:

> It was suggested I send the following patch via you as David Woodhouse
> is currently busy.

Actually it was David Brownell (the SPI maintainer) I was thinking of
that was sort of busy lately, perhaps Woodhouse (the MTD maintainer)
is less busy ... let's see.

Linus Walleij

Re: [PATCH] SST25L (non JEDEC) SPI Flash driver

[Andrew Morton]

On Thu, 25 Jun 2009 11:59:47 +1200 Ryan Mallon <ryan@bluewatersys.com> wrote:

> Add support for the non JEDEC SST25L SPI Flash devices.
> 
> Signed-off-by: Andre Renaud <andre@bluewatersys.com>
> Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
> Acked-by: Linus Walleij <linus.walleij@stericsson.com>

It looks OK to my inexperienced eye.

> ...
>
> +		bytes = min(mtd->writesize, (u32)(len - i));

The conventional way of suppressing the warning is min_t().

> +static int __init sst25l_probe(struct spi_device *spi)
> +{
> +	struct flash_info *flash_info;
> +	struct sst25l_flash *flash;
> +	struct flash_platform_data *data;
> +	int 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 Kbytes)\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);
> +	}
> +
> +	return add_mtd_device(&flash->mtd) == 1 ? -ENODEV : 0;

If this returns -ENODEV, did we leak the memory at *flash?

> +}
> +

Re: [PATCH] SST25L (non JEDEC) SPI Flash driver

[Ryan Mallon]

Andrew Morton wrote:
> On Thu, 25 Jun 2009 11:59:47 +1200 Ryan Mallon <ryan@bluewatersys.com> wrote:
>
>   
>> Add support for the non JEDEC SST25L SPI Flash devices.
>>
>> Signed-off-by: Andre Renaud <andre@bluewatersys.com>
>> Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
>> Acked-by: Linus Walleij <linus.walleij@stericsson.com>
>>     
>
> It looks OK to my inexperienced eye.
>
>   
Cool, thanks for picking this up. The patch below fixes the two issues
you pointed out. It will apply on top of
mtd-sst25l-non-jedec-spi-flash-driver-update.patch

----
Fix two issues in the SSTL25 driver:
- Replace min() plus u32 cast with min_t
- Fix memory leak on failed add_mtd_device

Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
----

diff --git a/drivers/mtd/devices/sst25l.c b/drivers/mtd/devices/sst25l.c
index 777fadf..d235067 100644
--- a/drivers/mtd/devices/sst25l.c
+++ b/drivers/mtd/devices/sst25l.c
@@ -298,7 +298,7 @@ static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len,
 		 * Write the remaining bytes using auto address
 		 * increment mode
 		 */
-		bytes = min(mtd->writesize, (u32)(len - i));
+		bytes = min_t(u32, mtd->writesize, len - i);
 		for (j = 1; j < bytes; j++, copied++) {
 			ret = sst25l_wait_till_ready(flash);
 			if (ret)
@@ -367,7 +367,7 @@ static int __init sst25l_probe(struct spi_device *spi)
 	struct flash_info *flash_info;
 	struct sst25l_flash *flash;
 	struct flash_platform_data *data;
-	int i;
+	int ret, i;
 
 	flash_info = sst25l_match_device(spi);
 	if (!flash_info)
@@ -457,7 +457,14 @@ static int __init sst25l_probe(struct spi_device *spi)
 			 data->nr_parts, data->name);
 	}
 
-	return add_mtd_device(&flash->mtd) == 1 ? -ENODEV : 0;
+	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)

Re: [spi-devel-general] [PATCH] SST25L (non JEDEC) SPI Flash driver

[David Brownell]

On Wednesday 24 June 2009, Linus Walleij wrote:
> > It was suggested I send the following patch via you as David Woodhouse
> > is currently busy.
> 
> Actually it was David Brownell (the SPI maintainer) I was thinking of
> that was sort of busy lately, perhaps Woodhouse (the MTD maintainer)
> is less busy ... let's see.

It's an MTD patch so I'd expect it to go through the MTD tree... :)

Re: [spi-devel-general] [PATCH] SST25L (non JEDEC) SPI Flash driver

[Linus Walleij]

2009/6/25 Ryan Mallon <ryan@bluewatersys.com>:

> Linus, is this still okay by you?

I'm a novice in MTD, sorry. But AFAICT yes.

Linus Walleij

Re: [spi-devel-general] [PATCH] SST25L (non JEDEC) SPI Flash driver

[Ryan Mallon]

H Hartley Sweeten wrote:
> On Wednesday, June 24, 2009 7:06 PM, Ryan Mallon wrote:
>> H Hartley Sweeten wrote:
>>> On Sunday, June 21, 2009 8:59 PM, Ryan Mallon wrote:

> I think you could still support the block erase and chip erase internal
> to the driver for performance.  Maybe something like the following?
> 
> static int sst25l_erase(struct mtd_info *mtd, struct erase_info *instr)
> {
...
> 	if (instr->len == mtd->size) {
> 		err = __sst25l_erase(flash, addr, SST25L_CMD_CHIP_ERASE);
> 		if (err) {
> 			mutex_unlock(&flash->lock);
> 			instr->state = MTD_ERASE_FAILED;
> 			dev_err(&flash->spi->dev, "Erase failed\n");
> 			return err;
> 		}
> 	} else {
> 		while (addr < end) {
> 			u32 erasesize;
> 
> 			if (addr % block || addr + block > end) {
> 				erasesize = sector;
> 				err = __sst25l_erase(flash, addr,
> 						SST25L_CMD_SECTOR_ERASE);
> 			} else {
> 				erasesize = block;
> 				err = __sst25l_erase(flash, addr,
> 						SST25L_CMD_BLOCK_ERASE);
> 			}
> 			if (err) {
> 				mutex_unlock(&flash->lock);
> 				instr->state = MTD_ERASE_FAILED;
> 				dev_err(&flash->spi->dev, "Erase failed\n");
> 				return err;
> 			}
> 
> 			addr += erasesize;
> 		}
> 	}

> 
> You would need to add sector_size and block_size to the ss25l_flash
> and flash_info structs and modify flash_info as appropriate.  Then copy
> those over during the probe and use sector_size for mtd.erasesize.
> 
> That way we get the 4K erase size but still get the performance increase
> for block and chip erase.

We discussed this, but it adds additional complexity to what is
otherwise quite a simple driver. The 4K sector erase will work in all
cases, and the speed difference shouldn't be a massive problem. I would
venture a guess that most people using the chips have reasonably
non-volatile storage on them, and don't get erased very often. We use
ours for the Bootloader and boot environment.

~Ryan

-- 
Bluewater Systems Ltd - ARM Technology Solution Centre

       Ryan Mallon                              Unit 5, Amuri Park
       Phone: +64 3 3779127                     404 Barbadoes St
       Fax:   +64 3 3779135                     PO Box 13 889
       Email: ryan@bluewatersys.com             Christchurch, 8013
       Web:   http://www.bluewatersys.com       New Zealand
       Freecall Australia  1800 148 751         USA 1800 261 2934

RE: [spi-devel-general] [PATCH] SST25L (non JEDEC) SPI Flash driver

[H Hartley Sweeten]

On Wednesday, June 24, 2009 7:06 PM, Ryan Mallon wrote:
> H Hartley Sweeten wrote:
>> On Sunday, June 21, 2009 8:59 PM, Ryan Mallon wrote:
>>   
>>> Add support for the non JEDEC SST25L SPI Flash devices.
>>>
>>> Signed-off-by: Andre Renaud <andre@bluewatersys.com>
>>> Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
>>>     
>>
>>   
>>> +struct flash_info {
>>> +	const char		*name;
>>> +	u16			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, 32 * 1024},
>>> +	{"sst25lf040a",	0xbf44,	256, 2048, 32 * 1024},
>>> +};
>>> +
>>>     
>>
>> Ryan,
>>
>> I finally got a chance to test this on my hardware.  Previously
>> I was using a hacked version on the m25p80 driver to access the
>> SST23LF020A on my board.
>>
>> The driver works fine but you are only supporting the block erase,
>> SST25L_CMD_BLOCK_ERASE (opcode 0x52).  The SST25L chips also can do a
>> sector erase (opcode 0x20) and a full chip erase (opcode 0x60).
>>   
> The MTD sub-system doesn't support different types of erases (as far as
> I am aware). We chose to use block erases since they are faster than
> sector erases and the trade-off of having 32k aligned partitions didn't
> seem to bad.

True.  The mtd.erasesize is supposed to be the smallest erasable region
on the chip.  Thus, the sector size should be used.

>> The full chip erase is not that important but might give a slight
>> performance increase on larger devices.  Max block erase time is
>> listed as 25ms at 25MHz in the datasheet.  The SST25LF020A contains
>> 8 blocks so it's "typical" full chip erase time should be around
>> 200ms.  For comparison, the chip erase time is listed as 100ms.
>>
>> The sector erase is a bigger deal.  On the EDB93xx boards one of the
>> SPI flash uses is used to store the MAC address at offset 0x2000 (4K
>> offset).  The board can also be configured to boot from offset 0x0000
>> in the SPI flash.  
>>   
>> Without the sector erase this partition setup results in all of the
>> partitions being forced read-only.
>>   
> The updated patch below uses sector erases instead to allow for smaller
> partition sizes.
>
> Linus, is this still okay by you?

I think you could still support the block erase and chip erase internal
to the driver for performance.  Maybe something like the following?


static int __sst25l_erase(struct sst25l_flash *flash, u32 offset, u8 cmd)
{
	u8 command[4];
	int err;

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

	command[0] = cmd;
	if (cmd != SST25L_CMD_CHIP_ERASE) {
		command[1] = offset >> 16;
		command[2] = offset >> 8;
		command[3] = offset;
	}
	err = spi_write(flash->spi, command,
			cmd == SST25L_CMD_CHIP_ERASE ? 1 : 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);
	u32 block = flash->block_size;
	u32 sector = flash->sector_size;
	u32 addr, end;
	int err;

	/* Sanity checks */
	if (instr->addr + instr->len > flash->mtd.size)
		return -EINVAL;

	if ((u32)instr->len % mtd->erasesize)
		return -EINVAL;

	if ((u32)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)
		return err;

	if (instr->len == mtd->size) {
		err = __sst25l_erase(flash, addr, SST25L_CMD_CHIP_ERASE);
		if (err) {
			mutex_unlock(&flash->lock);
			instr->state = MTD_ERASE_FAILED;
			dev_err(&flash->spi->dev, "Erase failed\n");
			return err;
		}
	} else {
		while (addr < end) {
			u32 erasesize;

			if (addr % block || addr + block > end) {
				erasesize = sector;
				err = __sst25l_erase(flash, addr,
						SST25L_CMD_SECTOR_ERASE);
			} else {
				erasesize = block;
				err = __sst25l_erase(flash, addr,
						SST25L_CMD_BLOCK_ERASE);
			}
			if (err) {
				mutex_unlock(&flash->lock);
				instr->state = MTD_ERASE_FAILED;
				dev_err(&flash->spi->dev, "Erase failed\n");
				return err;
			}

			addr += erasesize;
		}
	}

	mutex_unlock(&flash->lock);

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


You would need to add sector_size and block_size to the ss25l_flash
and flash_info structs and modify flash_info as appropriate.  Then copy
those over during the probe and use sector_size for mtd.erasesize.

That way we get the 4K erase size but still get the performance increase
for block and chip erase.

What do you think?

Regards,
Hartley

Re: [spi-devel-general] [PATCH] SST25L (non JEDEC) SPI Flash driver

[Ryan Mallon]

H Hartley Sweeten wrote:
> On Sunday, June 21, 2009 8:59 PM, Ryan Mallon wrote:
>   
>> Add support for the non JEDEC SST25L SPI Flash devices.
>>
>> Signed-off-by: Andre Renaud <andre@bluewatersys.com>
>> Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
>>     
>
>   
>> +struct flash_info {
>> +	const char		*name;
>> +	u16			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, 32 * 1024},
>> +	{"sst25lf040a",	0xbf44,	256, 2048, 32 * 1024},
>> +};
>> +
>>     
>
> Ryan,
>
> I finally got a chance to test this on my hardware.  Previously
> I was using a hacked version on the m25p80 driver to access the
> SST23LF020A on my board.
>
> The driver works fine but you are only supporting the block erase,
> SST25L_CMD_BLOCK_ERASE (opcode 0x52).  The SST25L chips also can do a
> sector erase (opcode 0x20) and a full chip erase (opcode 0x60).
>   
The MTD sub-system doesn't support different types of erases (as far as
I am aware). We chose to use block erases since they are faster than
sector erases and the trade-off of having 32k aligned partitions didn't
seem to bad.
> The full chip erase is not that important but might give a slight
> performance increase on larger devices.  Max block erase time is
> listed as 25ms at 25MHz in the datasheet.  The SST25LF020A contains
> 8 blocks so it's "typical" full chip erase time should be around
> 200ms.  For comparison, the chip erase time is listed as 100ms.
>
> The sector erase is a bigger deal.  On the EDB93xx boards one of the
> SPI flash uses is used to store the MAC address at offset 0x2000 (4K
> offset).  The board can also be configured to boot from offset 0x0000
> in the SPI flash.  
>   
> Without the sector erase this partition setup results in all of the
> partitions being forced read-only.
>   
The updated patch below uses sector erases instead to allow for smaller
partition sizes.

Linus, is this still okay by you?

~Ryan

----
Add support for SST25L (non JEDEC) SPI Flash chips. Although the SSTL25
chips support a quick 32kb block erase, we use the slower 4k sector
erase to allow for smaller 4kb aligned MTD partitions.

Signed-off-by: Andre Renaud <andre@bluewatersys.com>
Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
----

diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index 325fab9..c222514 100644
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -104,6 +104,16 @@ config M25PXX_USE_FAST_READ
 	help
 	  This option enables FAST_READ access supported by ST M25Pxx.
 
+config MTD_SST25L
+	tristate "Support SST25L (non JEDEC) SPI Flash chips"
+	depends on SPI_MASTER
+	help
+	  This enables access to the non JEDEC SST25L SPI flash chips, used
+	  for program and data storage.
+
+	  Set up your spi devices with the right board-specific platform data,
+	  if you want to specify device partitioning.
+
 config MTD_SLRAM
 	tristate "Uncached system RAM"
 	help
diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile
index 0993d5c..ab5c9b9 100644
--- a/drivers/mtd/devices/Makefile
+++ b/drivers/mtd/devices/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_MTD_LART)		+= lart.o
 obj-$(CONFIG_MTD_BLOCK2MTD)	+= block2mtd.o
 obj-$(CONFIG_MTD_DATAFLASH)	+= mtd_dataflash.o
 obj-$(CONFIG_MTD_M25P80)	+= m25p80.o
+obj-$(CONFIG_MTD_SST25L)	+= sst25l.o
diff --git a/drivers/mtd/devices/sst25l.c b/drivers/mtd/devices/sst25l.c
new file mode 100644
index 0000000..777fadf
--- /dev/null
+++ b/drivers/mtd/devices/sst25l.c
@@ -0,0 +1,503 @@
+/*
+ * drivers/mtd/sst25l.c
+ *
+ * Driver for SST25L SPI Flash chips
+ *
+ * Copyright (C) 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;
+	u16			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)
+{
+	u8 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)
+{
+	u8 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, u32 offset)
+{
+	u8 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);
+	u32 addr, end;
+	int err;
+
+	/* Sanity checks */
+	if (instr->addr + instr->len > flash->mtd.size)
+		return -EINVAL;
+
+	if ((u32)instr->len % mtd->erasesize)
+		return -EINVAL;
+
+	if ((u32)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)
+		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, u_char *buf)
+{
+	struct sst25l_flash *flash = to_sst25l_flash(mtd);
+	struct spi_transfer transfer[2];
+	struct spi_message message;
+	u8 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 u_char *buf)
+{
+	struct sst25l_flash *flash = to_sst25l_flash(mtd);
+	int i, j, ret, bytes, copied = 0;
+	u8 command[5];
+
+	/* Sanity checks */
+	if (!len)
+		return 0;
+
+	if (to + len > flash->mtd.size)
+		return -EINVAL;
+
+	if ((u32)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(mtd->writesize, (u32)(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;
+	u8 command[4], response;
+	int i, err;
+	u16 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 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 Kbytes)\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);
+	}
+
+	return add_mtd_device(&flash->mtd) == 1 ? -ENODEV : 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");

RE: [spi-devel-general] [PATCH] SST25L (non JEDEC) SPI Flash driver

[H Hartley Sweeten]

On Sunday, June 21, 2009 8:59 PM, Ryan Mallon wrote:
>
> Add support for the non JEDEC SST25L SPI Flash devices.
>
> Signed-off-by: Andre Renaud <andre@bluewatersys.com>
> Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>

> +struct flash_info {
> +	const char		*name;
> +	u16			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, 32 * 1024},
> +	{"sst25lf040a",	0xbf44,	256, 2048, 32 * 1024},
> +};
> +

Ryan,

I finally got a chance to test this on my hardware.  Previously
I was using a hacked version on the m25p80 driver to access the
SST23LF020A on my board.

The driver works fine but you are only supporting the block erase,
SST25L_CMD_BLOCK_ERASE (opcode 0x52).  The SST25L chips also can do a
sector erase (opcode 0x20) and a full chip erase (opcode 0x60).

The full chip erase is not that important but might give a slight
performance increase on larger devices.  Max block erase time is
listed as 25ms at 25MHz in the datasheet.  The SST25LF020A contains
8 blocks so it's "typical" full chip erase time should be around
200ms.  For comparison, the chip erase time is listed as 100ms.

The sector erase is a bigger deal.  On the EDB93xx boards one of the
SPI flash uses is used to store the MAC address at offset 0x2000 (4K
offset).  The board can also be configured to boot from offset 0x0000
in the SPI flash.  This basically gives the user a three partition
setup:

static struct mtd_partition edb93xx_spi_flash_partitions[] = {
	{
		.name	= "SPI bootstrap",
		.offset	= 0,
		.size	= SZ_4K,
	}, {
		.name	= "Bootstrap config",
		.offset	= MTDPART_OFS_APPEND,
		.size	= SZ_4K,
	}, {
		.name	= "unallocated",
		.offset	= MTDPART_OFS_APPEND,
		.size	= MTDPART_SIZ_FULL,
	},
};

Without the sector erase this partition setup results in all of the
partitions being forced read-only.

Just my two cents...

Regards,
Hartley

Re: [spi-devel-general] [PATCH] SST25L (non JEDEC) SPI Flash driver

[Ryan Mallon]

Baruch Siach wrote:
> Hi Ryan,
> 
> On Mon, Jun 22, 2009 at 03:58:51PM +1200, Ryan Mallon wrote:
>> +static int sst25l_erase_block(struct sst25l_flash *flash, u32 offset)
>> +{
>> +	u8 command[4];
>> +	int err;
>> +
>> +	err = sst25l_write_enable(flash, 1);
> 
> Is this enable/disable strictly required for each write/erase? Can't we just 
> enable write once?

The datasheet says that prior to any write/erase instruction the write
enable instruction must be sent.

~Ryan

-- 
Bluewater Systems Ltd - ARM Technology Solution Centre

       Ryan Mallon                              Unit 5, Amuri Park
       Phone: +64 3 3779127                     404 Barbadoes St
       Fax:   +64 3 3779135                     PO Box 13 889
       Email: ryan@bluewatersys.com             Christchurch, 8013
       Web:   http://www.bluewatersys.com       New Zealand
       Freecall Australia  1800 148 751         USA 1800 261 2934

Re: [spi-devel-general] [PATCH] SST25L (non JEDEC) SPI Flash driver

[Baruch Siach]

Hi Ryan,

On Mon, Jun 22, 2009 at 03:58:51PM +1200, Ryan Mallon wrote:
> +static int sst25l_erase_block(struct sst25l_flash *flash, u32 offset)
> +{
> +	u8 command[4];
> +	int err;
> +
> +	err = sst25l_write_enable(flash, 1);

Is this enable/disable strictly required for each write/erase? Can't we just 
enable write once?

> +	if (err)
> +		return err;
> +
> +	command[0] = SST25L_CMD_BLOCK_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);
> +}

baruch

-- 
                                                     ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
   - baruch@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -