This patch adds the possibility to (optinally) write to the flash configuration register. The Intel style CFI chips support such a register that can be used to configure the operation mode to a non-default value.

This method will be used by the t3corp board, which needs to configure the DS617 Xilinx flash for async read mode.

Signed-off-by: Stefan Roese sr@denx.de --- drivers/mtd/cfi_flash.c | 43 +++++++++++++++++++++++++++++++++++++++++++ include/mtd/cfi_flash.h | 2 ++ 2 files changed, 45 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c index c17c542..6e617f0 100644 --- a/drivers/mtd/cfi_flash.c +++ b/drivers/mtd/cfi_flash.c @@ -74,6 +74,20 @@ flash_info_t flash_info[CFI_MAX_FLASH_BANKS]; /* FLASH chips info */ #define CONFIG_SYS_FLASH_CFI_WIDTH FLASH_CFI_8BIT #endif

+/* + * 0xffff is an undefined value for the configuration register. When + * this value is returned, the configuration register shall not be + * written at all (default mode). + */ +static u16 cfi_flash_config_reg(int i) +{ +#ifdef CONFIG_SYS_CFI_FLASH_CONFIG_REGS + return ((u16 [])CONFIG_SYS_CFI_FLASH_CONFIG_REGS)[i]; +#else + return 0xffff; +#endif +} + #if defined(CONFIG_SYS_MAX_FLASH_BANKS_DETECT) int cfi_flash_num_flash_banks = CONFIG_SYS_MAX_FLASH_BANKS_DETECT; #endif @@ -2031,6 +2045,31 @@ void flash_set_verbose(uint v) flash_verbose = v; }

+static void cfi_flash_set_config_reg(u32 base, u16 val) +{ +#ifdef CONFIG_SYS_CFI_FLASH_CONFIG_REGS + /* + * Only set this config register if really defined + * to a valid value (0xffff is invalid) + */ + if (val == 0xffff) + return; + + /* + * Set configuration register. Data is "encrypted" in the 16 lower + * address bits. + */ + flash_write16(FLASH_CMD_SETUP, (void *)(base + (val << 1))); + flash_write16(FLASH_CMD_SET_CR_CONFIRM, (void *)(base + (val << 1))); + + /* + * Finally issue reset-command to bring device back to + * read-array mode + */ + flash_write16(FLASH_CMD_RESET, (void *)base); +#endif +} + /*----------------------------------------------------------------------- */ unsigned long flash_init (void) @@ -2054,6 +2093,10 @@ unsigned long flash_init (void) for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; ++i) { flash_info[i].flash_id = FLASH_UNKNOWN;

+ /* Optionally write flash configuration register */ + cfi_flash_set_config_reg(cfi_flash_bank_addr(i), + cfi_flash_config_reg(i)); + if (!flash_detect_legacy(cfi_flash_bank_addr(i), i)) flash_get_size(cfi_flash_bank_addr(i), i, cfi_flash_bank_size(i)); diff --git a/include/mtd/cfi_flash.h b/include/mtd/cfi_flash.h index 2ff00f2..3245b44 100644 --- a/include/mtd/cfi_flash.h +++ b/include/mtd/cfi_flash.h @@ -32,6 +32,8 @@ #define FLASH_CMD_ERASE_CONFIRM 0xD0 #define FLASH_CMD_WRITE 0x40 #define FLASH_CMD_PROTECT 0x60 +#define FLASH_CMD_SETUP 0x60 +#define FLASH_CMD_SET_CR_CONFIRM 0x03 #define FLASH_CMD_PROTECT_SET 0x01 #define FLASH_CMD_PROTECT_CLEAR 0xD0 #define FLASH_CMD_CLEAR_STATUS 0x50