| /* |
| * 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; |
| |
| spi_message_init(&m); |
| memset(t, 0, (sizeof t)); |
| |
| t[0].tx_buf = flash->command; |
| t[0].len = sizeof(flash->command); |
| spi_message_add_tail(&t[0], &m); |
| |
| t[1].rx_buf = buf; |
| t[1].len = len; |
| spi_message_add_tail(&t[1], &m); |
| |
| /* Byte count starts at zero. */ |
| if (retlen) |
| *retlen = 0; |
| |
| down(&flash->lock); |
| |
| /* Wait till previous write/erase is done. */ |
| if (wait_till_ready(flash)) { |
| /* REVISIT status return?? */ |
| up(&flash->lock); |
| return 1; |
| } |
| |
| /* 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; |
| |
| 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; |
| |
| spi_message_init(&m); |
| memset(t, 0, (sizeof t)); |
| |
| t[0].tx_buf = flash->command; |
| t[0].len = sizeof(flash->command); |
| spi_message_add_tail(&t[0], &m); |
| |
| t[1].tx_buf = buf; |
| spi_message_add_tail(&t[1], &m); |
| |
| down(&flash->lock); |
| |
| /* Wait until finished previous write command. */ |
| if (wait_till_ready(flash)) |
| return 1; |
| |
| write_enable(flash); |
| |
| /* 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; |
| |
| /* 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].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].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"); |