diff options
Diffstat (limited to 'drivers/mtd/devices/m25p80.c')
| -rw-r--r-- | drivers/mtd/devices/m25p80.c | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c new file mode 100644 index 00000000000..71a072103a7 --- /dev/null +++ b/drivers/mtd/devices/m25p80.c @@ -0,0 +1,580 @@ +/* + * MTD SPI driver for ST M25Pxx flash chips + * + * Author: Mike Lavender, mike@steroidmicros.com + * + * Copyright (c) 2005, Intec Automation Inc. + * + * Some parts are based on lart.c by Abraham Van Der Merwe + * + * Cleaned up and generalized based on mtd_dataflash.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/interrupt.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> + +#include <asm/semaphore.h> + + +/* NOTE: AT 25F and SST 25LF series are very similar, + * but commands for sector erase and chip id differ... + */ + +#define FLASH_PAGESIZE 256 + +/* Flash opcodes. */ +#define OPCODE_WREN 6 /* Write enable */ +#define OPCODE_RDSR 5 /* Read status register */ +#define OPCODE_READ 3 /* Read data bytes */ +#define OPCODE_PP 2 /* Page program */ +#define OPCODE_SE 0xd8 /* Sector erase */ +#define OPCODE_RES 0xab /* Read Electronic Signature */ +#define OPCODE_RDID 0x9f /* Read JEDEC ID */ + +/* Status Register bits. */ +#define SR_WIP 1 /* Write in progress */ +#define SR_WEL 2 /* Write enable latch */ +#define SR_BP0 4 /* Block protect 0 */ +#define SR_BP1 8 /* Block protect 1 */ +#define SR_BP2 0x10 /* Block protect 2 */ +#define SR_SRWD 0x80 /* SR write protect */ + +/* Define max times to check status register before we give up. */ +#define MAX_READY_WAIT_COUNT 100000 + + +#ifdef CONFIG_MTD_PARTITIONS +#define mtd_has_partitions() (1) +#else +#define mtd_has_partitions() (0) +#endif + +/****************************************************************************/ + +struct m25p { + struct spi_device *spi; + struct semaphore lock; + struct mtd_info mtd; + unsigned partitioned; + u8 command[4]; +}; + +static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd) +{ + return container_of(mtd, struct m25p, mtd); +} + +/****************************************************************************/ + +/* + * Internal helper functions + */ + +/* + * Read the status register, returning its value in the location + * Return the status register value. + * Returns negative if error occurred. + */ +static int read_sr(struct m25p *flash) +{ + ssize_t retval; + u8 code = OPCODE_RDSR; + u8 val; + + retval = spi_write_then_read(flash->spi, &code, 1, &val, 1); + + if (retval < 0) { + dev_err(&flash->spi->dev, "error %d reading SR\n", + (int) retval); + return retval; + } + + return val; +} + + +/* + * Set write enable latch with Write Enable command. + * Returns negative if error occurred. + */ +static inline int write_enable(struct m25p *flash) +{ + u8 code = OPCODE_WREN; + + return spi_write_then_read(flash->spi, &code, 1, NULL, 0); +} + + +/* + * Service routine to read status register until ready, or timeout occurs. + * Returns non-zero if error. + */ +static int wait_till_ready(struct m25p *flash) +{ + int count; + int sr; + + /* one chip guarantees max 5 msec wait here after page writes, + * but potentially three seconds (!) after page erase. + */ + for (count = 0; count < MAX_READY_WAIT_COUNT; count++) { + if ((sr = read_sr(flash)) < 0) + break; + else if (!(sr & SR_WIP)) + return 0; + + /* REVISIT sometimes sleeping would be best */ + } + + return 1; +} + + +/* + * Erase one sector of flash memory at offset ``offset'' which is any + * address within the sector which should be erased. + * + * Returns 0 if successful, non-zero otherwise. + */ +static int erase_sector(struct m25p *flash, u32 offset) +{ + DEBUG(MTD_DEBUG_LEVEL3, "%s: %s at 0x%08x\n", flash->spi->dev.bus_id, + __FUNCTION__, offset); + + /* Wait until finished previous write command. */ + if (wait_till_ready(flash)) + return 1; + + /* Send write enable, then erase commands. */ + write_enable(flash); + + /* Set up command buffer. */ + flash->command[0] = OPCODE_SE; + flash->command[1] = offset >> 16; + flash->command[2] = offset >> 8; + flash->command[3] = offset; + + spi_write(flash->spi, flash->command, sizeof(flash->command)); + + return 0; +} + +/****************************************************************************/ + +/* + * MTD implementation + */ + +/* + * Erase an address range on the flash chip. The address range may extend + * one or more erase sectors. Return an error is there is a problem erasing. + */ +static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr) +{ + struct m25p *flash = mtd_to_m25p(mtd); + u32 addr,len; + + DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n", + flash->spi->dev.bus_id, __FUNCTION__, "at", + (u32)instr->addr, instr->len); + + /* sanity checks */ + if (instr->addr + instr->len > flash->mtd.size) + return -EINVAL; + if ((instr->addr % mtd->erasesize) != 0 + || (instr->len % mtd->erasesize) != 0) { + return -EINVAL; + } + + addr = instr->addr; + len = instr->len; + + down(&flash->lock); + + /* now erase those sectors */ + while (len) { + if (erase_sector(flash, addr)) { + instr->state = MTD_ERASE_FAILED; + up(&flash->lock); + return -EIO; + } + + addr += mtd->erasesize; + len -= mtd->erasesize; + } + + up(&flash->lock); + + instr->state = MTD_ERASE_DONE; + mtd_erase_callback(instr); + + return 0; +} + +/* + * Read an address range from the flash chip. The address range + * may be any size provided it is within the physical boundaries. + */ +static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, u_char *buf) +{ + struct m25p *flash = mtd_to_m25p(mtd); + struct spi_transfer t[2]; + struct spi_message m; + + DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n", + flash->spi->dev.bus_id, __FUNCTION__, "from", + (u32)from, len); + + /* sanity checks */ + if (!len) + return 0; + + if (from + len > flash->mtd.size) + return -EINVAL; + + down(&flash->lock); + + /* Wait till previous write/erase is done. */ + if (wait_till_ready(flash)) { + /* REVISIT status return?? */ + up(&flash->lock); + return 1; + } + + memset(t, 0, (sizeof t)); + + /* NOTE: OPCODE_FAST_READ (if available) is faster... */ + + /* Set up the write data buffer. */ + flash->command[0] = OPCODE_READ; + flash->command[1] = from >> 16; + flash->command[2] = from >> 8; + flash->command[3] = from; + + /* Byte count starts at zero. */ + if (retlen) + *retlen = 0; + + t[0].tx_buf = flash->command; + t[0].len = sizeof(flash->command); + + t[1].rx_buf = buf; + t[1].len = len; + + m.transfers = t; + m.n_transfer = 2; + + spi_sync(flash->spi, &m); + + *retlen = m.actual_length - sizeof(flash->command); + + up(&flash->lock); + + return 0; +} + +/* + * Write an address range to the flash chip. Data must be written in + * FLASH_PAGESIZE chunks. The address range may be any size provided + * it is within the physical boundaries. + */ +static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len, + size_t *retlen, const u_char *buf) +{ + struct m25p *flash = mtd_to_m25p(mtd); + u32 page_offset, page_size; + struct spi_transfer t[2]; + struct spi_message m; + + DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n", + flash->spi->dev.bus_id, __FUNCTION__, "to", + (u32)to, len); + + if (retlen) + *retlen = 0; + + /* sanity checks */ + if (!len) + return(0); + + if (to + len > flash->mtd.size) + return -EINVAL; + + down(&flash->lock); + + /* Wait until finished previous write command. */ + if (wait_till_ready(flash)) + return 1; + + write_enable(flash); + + memset(t, 0, (sizeof t)); + + /* Set up the opcode in the write buffer. */ + flash->command[0] = OPCODE_PP; + flash->command[1] = to >> 16; + flash->command[2] = to >> 8; + flash->command[3] = to; + + t[0].tx_buf = flash->command; + t[0].len = sizeof(flash->command); + + m.transfers = t; + m.n_transfer = 2; + + /* what page do we start with? */ + page_offset = to % FLASH_PAGESIZE; + + /* do all the bytes fit onto one page? */ + if (page_offset + len <= FLASH_PAGESIZE) { + t[1].tx_buf = buf; + t[1].len = len; + + spi_sync(flash->spi, &m); + + *retlen = m.actual_length - sizeof(flash->command); + } else { + u32 i; + + /* the size of data remaining on the first page */ + page_size = FLASH_PAGESIZE - page_offset; + + t[1].tx_buf = buf; + t[1].len = page_size; + spi_sync(flash->spi, &m); + + *retlen = m.actual_length - sizeof(flash->command); + + /* write everything in PAGESIZE chunks */ + for (i = page_size; i < len; i += page_size) { + page_size = len - i; + if (page_size > FLASH_PAGESIZE) + page_size = FLASH_PAGESIZE; + + /* write the next page to flash */ + flash->command[1] = (to + i) >> 16; + flash->command[2] = (to + i) >> 8; + flash->command[3] = (to + i); + + t[1].tx_buf = buf + i; + t[1].len = page_size; + + wait_till_ready(flash); + + write_enable(flash); + + spi_sync(flash->spi, &m); + + *retlen += m.actual_length - sizeof(flash->command); + } + } + + up(&flash->lock); + + return 0; +} + + +/****************************************************************************/ + +/* + * SPI device driver setup and teardown + */ + +struct flash_info { + char *name; + u8 id; + u16 jedec_id; + unsigned sector_size; + unsigned n_sectors; +}; + +static struct flash_info __devinitdata m25p_data [] = { + /* REVISIT: fill in JEDEC ids, for parts that have them */ + { "m25p05", 0x05, 0x0000, 32 * 1024, 2 }, + { "m25p10", 0x10, 0x0000, 32 * 1024, 4 }, + { "m25p20", 0x11, 0x0000, 64 * 1024, 4 }, + { "m25p40", 0x12, 0x0000, 64 * 1024, 8 }, + { "m25p80", 0x13, 0x0000, 64 * 1024, 16 }, + { "m25p16", 0x14, 0x0000, 64 * 1024, 32 }, + { "m25p32", 0x15, 0x0000, 64 * 1024, 64 }, + { "m25p64", 0x16, 0x2017, 64 * 1024, 128 }, +}; + +/* + * board specific setup should have ensured the SPI clock used here + * matches what the READ command supports, at least until this driver + * understands FAST_READ (for clocks over 25 MHz). + */ +static int __devinit m25p_probe(struct spi_device *spi) +{ + struct flash_platform_data *data; + struct m25p *flash; + struct flash_info *info; + unsigned i; + + /* Platform data helps sort out which chip type we have, as + * well as how this board partitions it. + */ + data = spi->dev.platform_data; + if (!data || !data->type) { + /* FIXME some chips can identify themselves with RES + * or JEDEC get-id commands. Try them ... + */ + DEBUG(MTD_DEBUG_LEVEL1, "%s: no chip id\n", + flash->spi->dev.bus_id); + return -ENODEV; + } + + for (i = 0, info = m25p_data; i < ARRAY_SIZE(m25p_data); i++, info++) { + if (strcmp(data->type, info->name) == 0) + break; + } + if (i == ARRAY_SIZE(m25p_data)) { + DEBUG(MTD_DEBUG_LEVEL1, "%s: unrecognized id %s\n", + flash->spi->dev.bus_id, data->type); + return -ENODEV; + } + + flash = kzalloc(sizeof *flash, SLAB_KERNEL); + if (!flash) + return -ENOMEM; + + flash->spi = spi; + init_MUTEX(&flash->lock); + dev_set_drvdata(&spi->dev, flash); + + if (data->name) + flash->mtd.name = data->name; + else + flash->mtd.name = spi->dev.bus_id; + + flash->mtd.type = MTD_NORFLASH; + flash->mtd.flags = MTD_CAP_NORFLASH; + flash->mtd.size = info->sector_size * info->n_sectors; + flash->mtd.erasesize = info->sector_size; + flash->mtd.erase = m25p80_erase; + flash->mtd.read = m25p80_read; + flash->mtd.write = m25p80_write; + + dev_info(&spi->dev, "%s (%d Kbytes)\n", info->name, + flash->mtd.size / 1024); + + DEBUG(MTD_DEBUG_LEVEL2, + "mtd .name = %s, .size = 0x%.8x (%uM) " + ".erasesize = 0x%.8x (%uK) .numeraseregions = %d\n", + flash->mtd.name, + flash->mtd.size, flash->mtd.size / (1024*1024), + 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%.8x, " + ".erasesize = 0x%.8x (%uK), " + ".numblocks = %d }\n", + i, flash->mtd.eraseregions[i].offset, + flash->mtd.eraseregions[i].erasesize, + flash->mtd.eraseregions[i].erasesize / 1024, + flash->mtd.eraseregions[i].numblocks); + + + /* partitions should match sector boundaries; and it may be good to + * use readonly partitions for writeprotected sectors (BP2..BP0). + */ + if (mtd_has_partitions()) { + struct mtd_partition *parts = NULL; + int nr_parts = 0; + +#ifdef CONFIG_MTD_CMDLINE_PARTS + static const char *part_probes[] = { "cmdlinepart", NULL, }; + + nr_parts = parse_mtd_partitions(&flash->mtd, + part_probes, &parts, 0); +#endif + + if (nr_parts <= 0 && data && data->parts) { + parts = data->parts; + nr_parts = data->nr_parts; + } + + if (nr_parts > 0) { + for (i = 0; i < data->nr_parts; i++) { + DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = " + "{.name = %s, .offset = 0x%.8x, " + ".size = 0x%.8x (%uK) }\n", + i, data->parts[i].name, + data->parts[i].offset, + data->parts[i].size, + data->parts[i].size / 1024); + } + 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 __devexit m25p_remove(struct spi_device *spi) +{ + struct m25p *flash = dev_get_drvdata(&spi->dev); + int status; + + /* Clean up MTD stuff. */ + if (mtd_has_partitions() && flash->partitioned) + status = del_mtd_partitions(&flash->mtd); + else + status = del_mtd_device(&flash->mtd); + if (status == 0) + kfree(flash); + return 0; +} + + +static struct spi_driver m25p80_driver = { + .driver = { + .name = "m25p80", + .bus = &spi_bus_type, + .owner = THIS_MODULE, + }, + .probe = m25p_probe, + .remove = __devexit_p(m25p_remove), +}; + + +static int m25p80_init(void) +{ + return spi_register_driver(&m25p80_driver); +} + + +static void m25p80_exit(void) +{ + spi_unregister_driver(&m25p80_driver); +} + + +module_init(m25p80_init); +module_exit(m25p80_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Mike Lavender"); +MODULE_DESCRIPTION("MTD SPI driver for ST M25Pxx flash chips"); |