diff options
| author | Robert P. J. Day <rpjday@crashcourse.ca> | 2016-12-29 05:23:19 -0500 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2017-01-02 11:14:01 -0500 |
| commit | 66723eda4ebbb53a0708aa0cbb1853f2b86fb117 (patch) | |
| tree | 05f2ba3838040c87b606484f666c2d25288f3d53 /doc | |
| parent | b352548890c2d7d937d156727905b906aaa7eebd (diff) | |
doc/README.cfi: Update code snippet, and add example.
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>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.cfi | 31 |
1 files changed, 26 insertions, 5 deletions
diff --git a/doc/README.cfi b/doc/README.cfi index 81e7cf1d7e..ad52850818 100644 --- a/doc/README.cfi +++ b/doc/README.cfi @@ -1,7 +1,7 @@ The common CFI driver provides this weak default implementation for flash_cmd_reset(): -void __flash_cmd_reset(flash_info_t *info) +static void __flash_cmd_reset(flash_info_t *info) { /* * We do not yet know what kind of commandset to use, so we issue @@ -9,22 +9,43 @@ void __flash_cmd_reset(flash_info_t *info) * 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. -Some flash chips seems to have trouble with this reset sequence. In this case -the board specific code can override this weak default version with a board -specific function. For example the digsy_mtc board equipped with the M29W128GH -from Numonyx needs this version to function properly: +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 |