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mtd: cfi: Fix PPB lock status readout 

According to S26KL512S datasheet [1] and S29GL01GS datasheet [2],
the procedure to read out PPB lock bits is to send the PPB Entry,
PPB Read, Reset/ASO Exit. Currently, the code does send incorrect
PPB Entry, PPB Read and Reset/ASO Exit is completely missing.

The PPB Entry sent is implemented by sending flash_unlock_seq()
and flash_write_cmd(..., FLASH_CMD_READ_ID). This translates to
sequence 0x555:0xaa, 0x2aa:0x55, 0x555:0x90=FLASH_CMD_READ_ID.
However, both [1] and [2] specify the last byte of PPB Entry as
0xc0=AMD_CMD_SET_PPB_ENTRY instead of 0x90=FLASH_CMD_READ_ID,
that is  0x555:0xaa, 0x2aa:0x55, 0x555:0xc0=AMD_CMD_SET_PPB_ENTRY.
Since this does make sense, this patch fixes it and thus also
aligns the code in flash_get_size() with flash_real_protect().

The PPB Read returns 00h in case of Protected state and 01h in case
of Unprotected state, according to [1] Note 83 and [2] Note 17, so
invert the result. Moreover, align the arguments with similar code
in flash_real_protect().

Finally, Reset/ASO Exit command should be executed to exit the PPB
mode, so add the missing reset.

[1] https://www.cypress.com/file/213346/download
    Document Number: 001-99198 Rev. *M
    Table 40. Command Definitions, Nonvolatile Sector Protection
    Command Set Definitions
[2] https://www.cypress.com/file/177976/download
    Document Number: 001-98285 Rev. *R
    Table 7.1 Command Definitions, Nonvolatile Sector Protection
    Command Set Definitions

Fixes: 03deff433e ("cfi_flash: Read PPB sector protection from device for AMD/Spansion chips")
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Stefan Roese <sr@denx.de>
Reviewed-by: Stefan Roese <sr@denx.de>
This commit is contained in:
Marek Vasut 2021-04-11 20:47:45 +02:00 committed by Stefan Roese
parent 79b0f08d6a
commit 94657482f3
1 changed files with 5 additions and 5 deletions
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10
drivers/mtd/cfi_flash.c
View File

@ -2276,12 +2276,12 @@ ulong flash_get_size(phys_addr_t base, int banknum)
flash_unlock_seq(info, 0);
flash_write_cmd(info, 0,
info->addr_unlock1,
FLASH_CMD_READ_ID);
AMD_CMD_SET_PPB_ENTRY);
info->protect[sect_cnt] =
flash_isset(
info, sect_cnt,
FLASH_OFFSET_PROTECT,
FLASH_STATUS_PROTECT);
!flash_isset(info, sect_cnt,
0, 0x01);
flash_write_cmd(info, 0, 0,
info->cmd_reset);
break;
default:
/* default: not protected */