| /* |
| * 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 <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"); |