I believe this is correct. I have redone the patch as two patches. The first patch fixes the 8-bit addressing and has been tested with both 8 and 16-bit support with Spansion. The second patch adds a 1us delay after every reset call. In my email correspondence with Spansion they said that at least some devices require a 500ns delay after the reset command.
-Aaron
On Monday, April 04, 2011 03:14:17 AM Stefan Roese wrote:
Hi Aaron,
On Saturday 02 April 2011 09:17:01 Aaron Williams wrote:
This patch corrects the addresses used when working with Spansion/AMD FLASH chips. Addressing for 8 and 16 bits is almost identical except in the 16-bit case the LSB of the address is always 0. The confusion arose because the addresses in the datasheet for 16-bit mode are word addresses but this code assumed it was byte addresses.
I have only been able to test this on our Octeon boards which use either an 8-bit or 16-bit bus. I have not tested the case where there's an 8-bit part on a 16-bit bus.
This patch also adds some delays as suggested by Spansion.
If a part can be both 8 and 16-bits, it forces it to work in 8-bit mode if an 8-bit bus is detected.
Thanks.
Apart from the comments from Albert and Rogan, here some further notes:
Please explain why the delay() calls are added. If really needed, please move them into a separate patch, as this seems unrelated to the 8/16 bit issue.
Please add a short description and rationale to the commit text (and perhaps to cfi_flash.h), why the offsets for the CFI data are now changed (e.g. 0x10 -> 0x20).
And one further comment below:
@@ -1043,6 +1049,8 @@ int flash_erase (flash_info_t * info, int s_first, int s_last) int prot;
flash_sect_t sect; int st;
debug("%s: erasing sectors %d to %d\n", __func__, s_first, s_last);
if (info->flash_id != FLASH_MAN_CFI) {
puts ("Can't erase unknown flash type - aborted\n");
@@ -1082,6 +1090,7 @@ int flash_erase (flash_info_t * info, int s_first, int s_last) break;
case CFI_CMDSET_AMD_STANDARD: case CFI_CMDSET_AMD_EXTENDED:
flash_write_cmd (info, 0, 0, AMD_CMD_RESET);Is this correct? A reset command in every flash_erase() call?
Thanks.
Cheers, Stefan