[U-Boot] [PATCH v2] doc/README.cfi: Update code snippet, and add example.

[Robert P. J. Day]

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 at crashcourse.ca>

---

  figured since i was there, and there were only two boards in the
entire code base that defined their own flash_cmd_reset(), might as
well show them both. anything else worth adding to this README?

  or is there any code simplification that could be done to remove
even these exceptional cases?

diff --git a/doc/README.cfi b/doc/README.cfi
index 81e7cf1..ad52850 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


-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================