The common CFI driver provides this weak default implementation for
|
flash_cmd_reset():
|
|
static void __flash_cmd_reset(flash_info_t *info)
|
{
|
/*
|
* We do not yet know what kind of commandset to use, so we issue
|
* the reset command in both Intel and AMD variants, in the hope
|
* that AMD flash roms ignore the Intel command.
|
*/
|
flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
|
udelay(1);
|
flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
|
}
|
void flash_cmd_reset(flash_info_t *info)
|
__attribute__((weak,alias("__flash_cmd_reset")));
|
|
Some flash chips seem to have trouble with this reset sequence.
|
In this case, board-specific code can override this weak default
|
version with a board-specific function.
|
|
At the time of writing, there are two boards that define their own
|
routine for this.
|
|
First, the digsy_mtc board equipped with the M29W128GH from Numonyx
|
needs this version to function properly:
|
|
void flash_cmd_reset(flash_info_t *info)
|
{
|
flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
|
}
|
|
In addition, the t3corp board defines the routine thusly:
|
|
void flash_cmd_reset(flash_info_t *info)
|
{
|
/*
|
* FLASH at address CONFIG_SYS_FLASH_BASE is a Spansion chip and
|
* needs the Spansion type reset commands. The other flash chip
|
* is located behind a FPGA (Xilinx DS617) and needs the Intel type
|
* reset command.
|
*/
|
if (info->start[0] == CONFIG_SYS_FLASH_BASE)
|
flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
|
else
|
flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
|
}
|
|
see also:
|
http://www.mail-archive.com/u-boot@lists.denx.de/msg24368.html
|
|
|
Config Option
|
|
CONFIG_SYS_MAX_FLASH_SECT: Number of sectors available on Flash device
|
|
CONFIG_SYS_FLASH_CFI_WIDTH: Data-width of the flash device
|
|
CONFIG_CMD_FLASH: Enables Flash command library
|
|
CONFIG_FLASH_CFI_DRIVER: Enables CFI Flash driver
|
|
CONFIG_FLASH_CFI_MTD: Enables MTD frame work for NOR Flash devices
|
