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1The common CFI driver provides this weak default implementation for
2flash_cmd_reset():
3
66723eda 4static void __flash_cmd_reset(flash_info_t *info)
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5{
6 /*
7 * We do not yet know what kind of commandset to use, so we issue
8 * the reset command in both Intel and AMD variants, in the hope
9 * that AMD flash roms ignore the Intel command.
10 */
11 flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
66723eda 12 udelay(1);
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13 flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
14}
15void flash_cmd_reset(flash_info_t *info)
16 __attribute__((weak,alias("__flash_cmd_reset")));
17
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18Some flash chips seem to have trouble with this reset sequence.
19In this case, board-specific code can override this weak default
20version with a board-specific function.
466f0137 21
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22At the time of writing, there are two boards that define their own
23routine for this.
24
25First, the digsy_mtc board equipped with the M29W128GH from Numonyx
26needs this version to function properly:
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27
28void flash_cmd_reset(flash_info_t *info)
29{
30 flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
31}
32
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33In addition, the t3corp board defines the routine thusly:
34
35void flash_cmd_reset(flash_info_t *info)
36{
37 /*
38 * FLASH at address CONFIG_SYS_FLASH_BASE is a Spansion chip and
39 * needs the Spansion type reset commands. The other flash chip
40 * is located behind a FPGA (Xilinx DS617) and needs the Intel type
41 * reset command.
42 */
43 if (info->start[0] == CONFIG_SYS_FLASH_BASE)
44 flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
45 else
46 flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
47}
48
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49see also:
50http://www.mail-archive.com/u-boot@lists.denx.de/msg24368.html
3df3bc1e 51
52
53Config Option
54
55 CONFIG_SYS_MAX_FLASH_SECT: Number of sectors available on Flash device
56
57 CONFIG_SYS_FLASH_CFI_WIDTH: Data-width of the flash device
58
59 CONFIG_CMD_FLASH: Enables Flash command library
60
61 CONFIG_FLASH_CFI_DRIVER: Enables CFI Flash driver
62
63 CONFIG_FLASH_CFI_MTD: Enables MTD frame work for NOR Flash devices