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66723eda4e
First, update the code snippet referenced in the README file. And since there are only two boards that override flash_cmd_reset(), might as well show them both. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
63 lines
1.8 KiB
Text
63 lines
1.8 KiB
Text
The common CFI driver provides this weak default implementation for
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flash_cmd_reset():
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static void __flash_cmd_reset(flash_info_t *info)
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{
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/*
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* We do not yet know what kind of commandset to use, so we issue
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* the reset command in both Intel and AMD variants, in the hope
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* that AMD flash roms ignore the Intel command.
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*/
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flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
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udelay(1);
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flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
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}
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void flash_cmd_reset(flash_info_t *info)
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__attribute__((weak,alias("__flash_cmd_reset")));
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Some flash chips seem to have trouble with this reset sequence.
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In this case, board-specific code can override this weak default
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version with a board-specific function.
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At the time of writing, there are two boards that define their own
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routine for this.
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First, the digsy_mtc board equipped with the M29W128GH from Numonyx
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needs this version to function properly:
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void flash_cmd_reset(flash_info_t *info)
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{
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flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
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}
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In addition, the t3corp board defines the routine thusly:
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void flash_cmd_reset(flash_info_t *info)
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{
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/*
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* FLASH at address CONFIG_SYS_FLASH_BASE is a Spansion chip and
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* needs the Spansion type reset commands. The other flash chip
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* is located behind a FPGA (Xilinx DS617) and needs the Intel type
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* reset command.
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*/
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if (info->start[0] == CONFIG_SYS_FLASH_BASE)
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flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
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else
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flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
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}
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see also:
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http://www.mail-archive.com/u-boot@lists.denx.de/msg24368.html
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Config Option
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CONFIG_SYS_MAX_FLASH_SECT: Number of sectors available on Flash device
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CONFIG_SYS_FLASH_CFI_WIDTH: Data-width of the flash device
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CONFIG_CMD_FLASH: Enables Flash command library
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CONFIG_FLASH_CFI_DRIVER: Enables CFI Flash driver
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CONFIG_FLASH_CFI_MTD: Enables MTD frame work for NOR Flash devices
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