linux/drivers/mtd/devices/sst25l.c

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/*
* sst25l.c
*
* Driver for SST25L SPI Flash chips
*
* Copyright © 2009 Bluewater Systems Ltd
* Author: Andre Renaud <andre@bluewatersys.com>
* Author: Ryan Mallon
*
* Based on m25p80.c
*
* This code is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/spi/spi.h>
#include <linux/spi/flash.h>
/* Erases can take up to 3 seconds! */
#define MAX_READY_WAIT_JIFFIES msecs_to_jiffies(3000)
#define SST25L_CMD_WRSR 0x01 /* Write status register */
#define SST25L_CMD_WRDI 0x04 /* Write disable */
#define SST25L_CMD_RDSR 0x05 /* Read status register */
#define SST25L_CMD_WREN 0x06 /* Write enable */
#define SST25L_CMD_READ 0x03 /* High speed read */
#define SST25L_CMD_EWSR 0x50 /* Enable write status register */
#define SST25L_CMD_SECTOR_ERASE 0x20 /* Erase sector */
#define SST25L_CMD_READ_ID 0x90 /* Read device ID */
#define SST25L_CMD_AAI_PROGRAM 0xaf /* Auto address increment */
#define SST25L_STATUS_BUSY (1 << 0) /* Chip is busy */
#define SST25L_STATUS_WREN (1 << 1) /* Write enabled */
#define SST25L_STATUS_BP0 (1 << 2) /* Block protection 0 */
#define SST25L_STATUS_BP1 (1 << 3) /* Block protection 1 */
struct sst25l_flash {
struct spi_device *spi;
struct mutex lock;
struct mtd_info mtd;
};
struct flash_info {
const char *name;
uint16_t device_id;
unsigned page_size;
unsigned nr_pages;
unsigned erase_size;
};
#define to_sst25l_flash(x) container_of(x, struct sst25l_flash, mtd)
static struct flash_info sst25l_flash_info[] = {
{"sst25lf020a", 0xbf43, 256, 1024, 4096},
{"sst25lf040a", 0xbf44, 256, 2048, 4096},
};
static int sst25l_status(struct sst25l_flash *flash, int *status)
{
struct spi_message m;
struct spi_transfer t;
unsigned char cmd_resp[2];
int err;
spi_message_init(&m);
memset(&t, 0, sizeof(struct spi_transfer));
cmd_resp[0] = SST25L_CMD_RDSR;
cmd_resp[1] = 0xff;
t.tx_buf = cmd_resp;
t.rx_buf = cmd_resp;
t.len = sizeof(cmd_resp);
spi_message_add_tail(&t, &m);
err = spi_sync(flash->spi, &m);
if (err < 0)
return err;
*status = cmd_resp[1];
return 0;
}
static int sst25l_write_enable(struct sst25l_flash *flash, int enable)
{
unsigned char command[2];
int status, err;
command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI;
err = spi_write(flash->spi, command, 1);
if (err)
return err;
command[0] = SST25L_CMD_EWSR;
err = spi_write(flash->spi, command, 1);
if (err)
return err;
command[0] = SST25L_CMD_WRSR;
command[1] = enable ? 0 : SST25L_STATUS_BP0 | SST25L_STATUS_BP1;
err = spi_write(flash->spi, command, 2);
if (err)
return err;
if (enable) {
err = sst25l_status(flash, &status);
if (err)
return err;
if (!(status & SST25L_STATUS_WREN))
return -EROFS;
}
return 0;
}
static int sst25l_wait_till_ready(struct sst25l_flash *flash)
{
unsigned long deadline;
int status, err;
deadline = jiffies + MAX_READY_WAIT_JIFFIES;
do {
err = sst25l_status(flash, &status);
if (err)
return err;
if (!(status & SST25L_STATUS_BUSY))
return 0;
cond_resched();
} while (!time_after_eq(jiffies, deadline));
return -ETIMEDOUT;
}
static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset)
{
unsigned char command[4];
int err;
err = sst25l_write_enable(flash, 1);
if (err)
return err;
command[0] = SST25L_CMD_SECTOR_ERASE;
command[1] = offset >> 16;
command[2] = offset >> 8;
command[3] = offset;
err = spi_write(flash->spi, command, 4);
if (err)
return err;
err = sst25l_wait_till_ready(flash);
if (err)
return err;
return sst25l_write_enable(flash, 0);
}
static int sst25l_erase(struct mtd_info *mtd, struct erase_info *instr)
{
struct sst25l_flash *flash = to_sst25l_flash(mtd);
uint32_t addr, end;
int err;
/* Sanity checks */
if ((uint32_t)instr->len % mtd->erasesize)
return -EINVAL;
if ((uint32_t)instr->addr % mtd->erasesize)
return -EINVAL;
addr = instr->addr;
end = addr + instr->len;
mutex_lock(&flash->lock);
err = sst25l_wait_till_ready(flash);
if (err) {
mutex_unlock(&flash->lock);
return err;
}
while (addr < end) {
err = sst25l_erase_sector(flash, addr);
if (err) {
mutex_unlock(&flash->lock);
instr->state = MTD_ERASE_FAILED;
dev_err(&flash->spi->dev, "Erase failed\n");
return err;
}
addr += mtd->erasesize;
}
mutex_unlock(&flash->lock);
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
return 0;
}
static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, unsigned char *buf)
{
struct sst25l_flash *flash = to_sst25l_flash(mtd);
struct spi_transfer transfer[2];
struct spi_message message;
unsigned char command[4];
int ret;
spi_message_init(&message);
memset(&transfer, 0, sizeof(transfer));
command[0] = SST25L_CMD_READ;
command[1] = from >> 16;
command[2] = from >> 8;
command[3] = from;
transfer[0].tx_buf = command;
transfer[0].len = sizeof(command);
spi_message_add_tail(&transfer[0], &message);
transfer[1].rx_buf = buf;
transfer[1].len = len;
spi_message_add_tail(&transfer[1], &message);
mutex_lock(&flash->lock);
/* Wait for previous write/erase to complete */
ret = sst25l_wait_till_ready(flash);
if (ret) {
mutex_unlock(&flash->lock);
return ret;
}
spi_sync(flash->spi, &message);
if (retlen && message.actual_length > sizeof(command))
*retlen += message.actual_length - sizeof(command);
mutex_unlock(&flash->lock);
return 0;
}
static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const unsigned char *buf)
{
struct sst25l_flash *flash = to_sst25l_flash(mtd);
int i, j, ret, bytes, copied = 0;
unsigned char command[5];
if ((uint32_t)to % mtd->writesize)
return -EINVAL;
mutex_lock(&flash->lock);
ret = sst25l_write_enable(flash, 1);
if (ret)
goto out;
for (i = 0; i < len; i += mtd->writesize) {
ret = sst25l_wait_till_ready(flash);
if (ret)
goto out;
/* Write the first byte of the page */
command[0] = SST25L_CMD_AAI_PROGRAM;
command[1] = (to + i) >> 16;
command[2] = (to + i) >> 8;
command[3] = (to + i);
command[4] = buf[i];
ret = spi_write(flash->spi, command, 5);
if (ret < 0)
goto out;
copied++;
/*
* Write the remaining bytes using auto address
* increment mode
*/
bytes = min_t(uint32_t, mtd->writesize, len - i);
for (j = 1; j < bytes; j++, copied++) {
ret = sst25l_wait_till_ready(flash);
if (ret)
goto out;
command[1] = buf[i + j];
ret = spi_write(flash->spi, command, 2);
if (ret)
goto out;
}
}
out:
ret = sst25l_write_enable(flash, 0);
if (retlen)
*retlen = copied;
mutex_unlock(&flash->lock);
return ret;
}
static struct flash_info *sst25l_match_device(struct spi_device *spi)
{
struct flash_info *flash_info = NULL;
struct spi_message m;
struct spi_transfer t;
unsigned char cmd_resp[6];
int i, err;
uint16_t id;
spi_message_init(&m);
memset(&t, 0, sizeof(struct spi_transfer));
cmd_resp[0] = SST25L_CMD_READ_ID;
cmd_resp[1] = 0;
cmd_resp[2] = 0;
cmd_resp[3] = 0;
cmd_resp[4] = 0xff;
cmd_resp[5] = 0xff;
t.tx_buf = cmd_resp;
t.rx_buf = cmd_resp;
t.len = sizeof(cmd_resp);
spi_message_add_tail(&t, &m);
err = spi_sync(spi, &m);
if (err < 0) {
dev_err(&spi->dev, "error reading device id\n");
return NULL;
}
id = (cmd_resp[4] << 8) | cmd_resp[5];
for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++)
if (sst25l_flash_info[i].device_id == id)
flash_info = &sst25l_flash_info[i];
if (!flash_info)
dev_err(&spi->dev, "unknown id %.4x\n", id);
return flash_info;
}
static int sst25l_probe(struct spi_device *spi)
{
struct flash_info *flash_info;
struct sst25l_flash *flash;
struct flash_platform_data *data;
int ret;
flash_info = sst25l_match_device(spi);
if (!flash_info)
return -ENODEV;
flash = kzalloc(sizeof(struct sst25l_flash), GFP_KERNEL);
if (!flash)
return -ENOMEM;
flash->spi = spi;
mutex_init(&flash->lock);
spi_set_drvdata(spi, flash);
data = dev_get_platdata(&spi->dev);
if (data && data->name)
flash->mtd.name = data->name;
else
flash->mtd.name = dev_name(&spi->dev);
flash->mtd.type = MTD_NORFLASH;
flash->mtd.flags = MTD_CAP_NORFLASH;
flash->mtd.erasesize = flash_info->erase_size;
flash->mtd.writesize = flash_info->page_size;
flash->mtd.writebufsize = flash_info->page_size;
flash->mtd.size = flash_info->page_size * flash_info->nr_pages;
flash->mtd._erase = sst25l_erase;
flash->mtd._read = sst25l_read;
flash->mtd._write = sst25l_write;
dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name,
(long long)flash->mtd.size >> 10);
pr_debug("mtd .name = %s, .size = 0x%llx (%lldMiB) "
".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
flash->mtd.name,
(long long)flash->mtd.size, (long long)(flash->mtd.size >> 20),
flash->mtd.erasesize, flash->mtd.erasesize / 1024,
flash->mtd.numeraseregions);
ret = mtd_device_parse_register(&flash->mtd, NULL, NULL,
data ? data->parts : NULL,
data ? data->nr_parts : 0);
if (ret) {
kfree(flash);
spi_set_drvdata(spi, NULL);
return -ENODEV;
}
return 0;
}
static int sst25l_remove(struct spi_device *spi)
{
struct sst25l_flash *flash = spi_get_drvdata(spi);
int ret;
ret = mtd_device_unregister(&flash->mtd);
if (ret == 0)
kfree(flash);
return ret;
}
static struct spi_driver sst25l_driver = {
.driver = {
.name = "sst25l",
.owner = THIS_MODULE,
},
.probe = sst25l_probe,
.remove = sst25l_remove,
};
module_spi_driver(sst25l_driver);
MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
"Ryan Mallon");
MODULE_LICENSE("GPL");