diff options
Diffstat (limited to 'drivers/mtd/spi/atmel.c')
| -rw-r--r-- | drivers/mtd/spi/atmel.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/drivers/mtd/spi/atmel.c b/drivers/mtd/spi/atmel.c new file mode 100644 index 0000000..fb7a4a9 --- /dev/null +++ b/drivers/mtd/spi/atmel.c @@ -0,0 +1,362 @@ +/* + * Atmel SPI DataFlash support + * + * Copyright (C) 2008 Atmel Corporation + */ +#define DEBUG +#include <common.h> +#include <malloc.h> +#include <spi_flash.h> + +#include "spi_flash_internal.h" + +/* AT45-specific commands */ +#define CMD_AT45_READ_STATUS 0xd7 +#define CMD_AT45_ERASE_PAGE 0x81 +#define CMD_AT45_LOAD_PROG_BUF1 0x82 +#define CMD_AT45_LOAD_BUF1 0x84 +#define CMD_AT45_LOAD_PROG_BUF2 0x85 +#define CMD_AT45_LOAD_BUF2 0x87 +#define CMD_AT45_PROG_BUF1 0x88 +#define CMD_AT45_PROG_BUF2 0x89 + +/* AT45 status register bits */ +#define AT45_STATUS_P2_PAGE_SIZE (1 << 0) +#define AT45_STATUS_READY (1 << 7) + +/* DataFlash family IDs, as obtained from the second idcode byte */ +#define DF_FAMILY_AT26F 0 +#define DF_FAMILY_AT45 1 +#define DF_FAMILY_AT26DF 2 /* AT25DF and AT26DF */ + +struct atmel_spi_flash_params { + u8 idcode1; + /* Log2 of page size in power-of-two mode */ + u8 l2_page_size; + u8 pages_per_block; + u8 blocks_per_sector; + u8 nr_sectors; + const char *name; +}; + +struct atmel_spi_flash { + const struct atmel_spi_flash_params *params; + struct spi_flash flash; +}; + +static inline struct atmel_spi_flash * +to_atmel_spi_flash(struct spi_flash *flash) +{ + return container_of(flash, struct atmel_spi_flash, flash); +} + +static const struct atmel_spi_flash_params atmel_spi_flash_table[] = { + { + .idcode1 = 0x28, + .l2_page_size = 10, + .pages_per_block = 8, + .blocks_per_sector = 32, + .nr_sectors = 32, + .name = "AT45DB642D", + }, +}; + +static int at45_wait_ready(struct spi_flash *flash, unsigned long timeout) +{ + struct spi_slave *spi = flash->spi; + unsigned long timebase; + int ret; + u8 cmd = CMD_AT45_READ_STATUS; + u8 status; + + timebase = get_timer(0); + + ret = spi_xfer(spi, 8, &cmd, NULL, SPI_XFER_BEGIN); + if (ret) + return -1; + + do { + ret = spi_xfer(spi, 8, NULL, &status, 0); + if (ret) + return -1; + + if (status & AT45_STATUS_READY) + break; + } while (get_timer(timebase) < timeout); + + /* Deactivate CS */ + spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END); + + if (status & AT45_STATUS_READY) + return 0; + + /* Timed out */ + return -1; +} + +/* + * Assemble the address part of a command for AT45 devices in + * non-power-of-two page size mode. + */ +static void at45_build_address(struct atmel_spi_flash *asf, u8 *cmd, u32 offset) +{ + unsigned long page_addr; + unsigned long byte_addr; + unsigned long page_size; + unsigned int page_shift; + + /* + * The "extra" space per page is the power-of-two page size + * divided by 32. + */ + page_shift = asf->params->l2_page_size; + page_size = (1 << page_shift) + (1 << (page_shift - 5)); + page_shift++; + page_addr = offset / page_size; + byte_addr = offset % page_size; + + cmd[0] = page_addr >> (16 - page_shift); + cmd[1] = page_addr << (page_shift - 8) | (byte_addr >> 8); + cmd[2] = byte_addr; +} + +static int dataflash_read_fast_p2(struct spi_flash *flash, + u32 offset, size_t len, void *buf) +{ + u8 cmd[5]; + + cmd[0] = CMD_READ_ARRAY_FAST; + cmd[1] = offset >> 16; + cmd[2] = offset >> 8; + cmd[3] = offset; + cmd[4] = 0x00; + + return spi_flash_read_common(flash, cmd, sizeof(cmd), buf, len); +} + +static int dataflash_read_fast_at45(struct spi_flash *flash, + u32 offset, size_t len, void *buf) +{ + struct atmel_spi_flash *asf = to_atmel_spi_flash(flash); + u8 cmd[5]; + + cmd[0] = CMD_READ_ARRAY_FAST; + at45_build_address(asf, cmd + 1, offset); + cmd[4] = 0x00; + + return spi_flash_read_common(flash, cmd, sizeof(cmd), buf, len); +} + +static int dataflash_write_at45(struct spi_flash *flash, + u32 offset, size_t len, const void *buf) +{ + struct atmel_spi_flash *asf = to_atmel_spi_flash(flash); + unsigned long page_addr; + unsigned long byte_addr; + unsigned long page_size; + unsigned int page_shift; + size_t chunk_len; + size_t actual; + int ret; + u8 cmd[4]; + + page_shift = asf->params->l2_page_size; + page_size = (1 << page_shift) + (1 << (page_shift - 5)); + page_shift++; + page_addr = offset / page_size; + byte_addr = offset % page_size; + + ret = spi_claim_bus(flash->spi); + if (ret) { + debug("SF: Unable to claim SPI bus\n"); + return ret; + } + + for (actual = 0; actual < len; actual += chunk_len) { + chunk_len = min(len - actual, page_size - byte_addr); + + /* Use the same address bits for both commands */ + cmd[0] = CMD_AT45_LOAD_BUF1; + cmd[1] = page_addr >> (16 - page_shift); + cmd[2] = page_addr << (page_shift - 8) | (byte_addr >> 8); + cmd[3] = byte_addr; + + ret = spi_flash_cmd_write(flash->spi, cmd, 4, + buf + actual, chunk_len); + if (ret < 0) { + debug("SF: Loading AT45 buffer failed\n"); + goto out; + } + + cmd[0] = CMD_AT45_PROG_BUF1; + ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0); + if (ret < 0) { + debug("SF: AT45 page programming failed\n"); + goto out; + } + + ret = at45_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT); + if (ret < 0) { + debug("SF: AT45 page programming timed out\n"); + goto out; + } + + page_addr++; + byte_addr = 0; + } + + debug("SF: AT45: Successfully programmed %u bytes @ 0x%x\n", + len, offset); + ret = 0; + +out: + spi_release_bus(flash->spi); + return ret; +} + +int dataflash_erase_at45(struct spi_flash *flash, u32 offset, size_t len) +{ + struct atmel_spi_flash *asf = to_atmel_spi_flash(flash); + unsigned long page_addr; + unsigned long page_size; + unsigned int page_shift; + size_t actual; + int ret; + u8 cmd[4]; + + /* + * TODO: This function currently uses page erase only. We can + * probably speed things up by using block and/or sector erase + * when possible. + */ + + page_shift = asf->params->l2_page_size; + page_size = (1 << page_shift) + (1 << (page_shift - 5)); + page_shift++; + page_addr = offset / page_size; + + if (offset % page_size || len % page_size) { + debug("SF: Erase offset/length not multiple of page size\n"); + return -1; + } + + cmd[0] = CMD_AT45_ERASE_PAGE; + cmd[3] = 0x00; + + ret = spi_claim_bus(flash->spi); + if (ret) { + debug("SF: Unable to claim SPI bus\n"); + return ret; + } + + for (actual = 0; actual < len; actual += page_size) { + cmd[1] = page_addr >> (16 - page_shift); + cmd[2] = page_addr << (page_shift - 8); + + ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0); + if (ret < 0) { + debug("SF: AT45 page erase failed\n"); + goto out; + } + + ret = at45_wait_ready(flash, SPI_FLASH_PAGE_ERASE_TIMEOUT); + if (ret < 0) { + debug("SF: AT45 page erase timed out\n"); + goto out; + } + + page_addr++; + } + + debug("SF: AT45: Successfully erased %u bytes @ 0x%x\n", + len, offset); + ret = 0; + +out: + spi_release_bus(flash->spi); + return ret; +} + +struct spi_flash *spi_flash_probe_atmel(struct spi_slave *spi, u8 *idcode) +{ + const struct atmel_spi_flash_params *params; + unsigned long page_size; + unsigned int family; + struct atmel_spi_flash *asf; + unsigned int i; + int ret; + u8 status; + + for (i = 0; i < ARRAY_SIZE(atmel_spi_flash_table); i++) { + params = &atmel_spi_flash_table[i]; + if (params->idcode1 == idcode[1]) + break; + } + + if (i == ARRAY_SIZE(atmel_spi_flash_table)) { + debug("SF: Unsupported DataFlash ID %02x\n", + idcode[1]); + return NULL; + } + + asf = malloc(sizeof(struct atmel_spi_flash)); + if (!asf) { + debug("SF: Failed to allocate memory\n"); + return NULL; + } + + asf->params = params; + asf->flash.spi = spi; + asf->flash.name = params->name; + + /* Assuming power-of-two page size initially. */ + page_size = 1 << params->l2_page_size; + + family = idcode[1] >> 5; + + switch (family) { + case DF_FAMILY_AT45: + /* + * AT45 chips have configurable page size. The status + * register indicates which configuration is active. + */ + ret = spi_flash_cmd(spi, CMD_AT45_READ_STATUS, &status, 1); + if (ret) + goto err; + + debug("SF: AT45 status register: %02x\n", status); + + if (!(status & AT45_STATUS_P2_PAGE_SIZE)) { + asf->flash.read = dataflash_read_fast_at45; + asf->flash.write = dataflash_write_at45; + asf->flash.erase = dataflash_erase_at45; + page_size += 1 << (params->l2_page_size - 5); + } else { + asf->flash.read = dataflash_read_fast_p2; + } + + break; + + case DF_FAMILY_AT26F: + case DF_FAMILY_AT26DF: + asf->flash.read = dataflash_read_fast_p2; + break; + + default: + debug("SF: Unsupported DataFlash family %u\n", family); + goto err; + } + + asf->flash.size = page_size * params->pages_per_block + * params->blocks_per_sector + * params->nr_sectors; + + debug("SF: Detected %s with page size %u, total %u bytes\n", + params->name, page_size, asf->flash.size); + + return &asf->flash; + +err: + free(asf); + return NULL; +} |