[U-Boot] [PATCH] Revert "spi: add config option to enable the WP pin function on st micron flashes"

[Heiko Schocher <hs@denx.de>]

Hello Jagan,

Am 22.12.2014 09:58, schrieb Jagan Teki:
> On 18 December 2014 at 19:21, Jagannadha Sutradharudu Teki
> <jagannadh.teki@gmail.com> wrote:
>> This reverts commit 562f8df18da62ae02c4ace1e530451fe82c3312d.
>>
>> Never see the issue with N25Q128 flash without need of W#/Vpp signal
>> during probe.
>>
>> Signed-off-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
>> Cc: Heiko Schocher <hs@denx.de>
>> ---
>>   README                        | 11 -----------
>>   drivers/mtd/spi/sf_internal.h |  4 ----
>>   drivers/mtd/spi/sf_probe.c    | 30 ------------------------------
>>   3 files changed, 45 deletions(-)

I found this issue on the aristainetos board, there the "W#/Vpp" signal
is connected to a gpio pin.

bye,
Heiko

BTW: What is with the patchset:

[U-Boot] [PATCH v3 0/3] spi, sf: add mtdparts feature to spi and sf commands
http://lists.denx.de/pipermail/u-boot/2014-September/188098.html

Patchwork [U-Boot,v3,1/3] mtd, spi: add MTD layer driver
http://patchwork.ozlabs.org/patch/386102/

Patchwork [U-Boot,v3,2/3] mtd, nand: move common functions from cmd_nand.c to common place
http://patchwork.ozlabs.org/patch/386103/

Patchwork [U-Boot,v3,3/3] spi, sf: use offset and size in sf cmd from mtdpartition
http://patchwork.ozlabs.org/patch/386101/


>>
>> diff --git a/README b/README
>> index 4ca04d0..908646f 100644
>> --- a/README
>> +++ b/README
>> @@ -3090,17 +3090,6 @@ CBFS (Coreboot Filesystem) support
>>                  memories can be connected with a given cs line.
>>                  currently Xilinx Zynq qspi support these type of connections.
>>
>> -               CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
>> -               enable the W#/Vpp signal to disable writing to the status
>> -               register on ST MICRON flashes like the N25Q128.
>> -               The status register write enable/disable bit, combined with
>> -               the W#/VPP signal provides hardware data protection for the
>> -               device as follows: When the enable/disable bit is set to 1,
>> -               and the W#/VPP signal is driven LOW, the status register
>> -               nonvolatile bits become read-only and the WRITE STATUS REGISTER
>> -               operation will not execute. The only way to exit this
>> -               hardware-protected mode is to drive W#/VPP HIGH.
>> -
>>   - SystemACE Support:
>>                  CONFIG_SYSTEMACE
>>
>> diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
>> index 785f7a9..bd834dc 100644
>> --- a/drivers/mtd/spi/sf_internal.h
>> +++ b/drivers/mtd/spi/sf_internal.h
>> @@ -97,10 +97,6 @@ enum {
>>   #define STATUS_QEB_MXIC                (1 << 6)
>>   #define STATUS_PEC                     (1 << 7)
>>
>> -#ifdef CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
>> -#define STATUS_SRWD                    (1 << 7) /* SR write protect */
>> -#endif
>> -
>>   /* Flash timeout values */
>>   #define SPI_FLASH_PROG_TIMEOUT         (2 * CONFIG_SYS_HZ)
>>   #define SPI_FLASH_PAGE_ERASE_TIMEOUT           (5 * CONFIG_SYS_HZ)
>> diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
>> index ce9987f..3b0e652 100644
>> --- a/drivers/mtd/spi/sf_probe.c
>> +++ b/drivers/mtd/spi/sf_probe.c
>> @@ -287,34 +287,6 @@ int spi_flash_decode_fdt(const void *blob, struct spi_flash *flash)
>>   }
>>   #endif /* CONFIG_OF_CONTROL */
>>
>> -#ifdef CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
>> -/* enable the W#/Vpp signal to disable writing to the status register */
>> -static int spi_enable_wp_pin(struct spi_flash *flash)
>> -{
>> -       u8 status;
>> -       int ret;
>> -
>> -       ret = spi_flash_cmd_read_status(flash, &status);
>> -       if (ret < 0)
>> -               return ret;
>> -
>> -       ret = spi_flash_cmd_write_status(flash, STATUS_SRWD);
>> -       if (ret < 0)
>> -               return ret;
>> -
>> -       ret = spi_flash_cmd_write_disable(flash);
>> -       if (ret < 0)
>> -               return ret;
>> -
>> -       return 0;
>> -}
>> -#else
>> -static int spi_enable_wp_pin(struct spi_flash *flash)
>> -{
>> -       return 0;
>> -}
>> -#endif
>> -
>>   /**
>>    * spi_flash_probe_slave() - Probe for a SPI flash device on a bus
>>    *
>> @@ -393,8 +365,6 @@ int spi_flash_probe_slave(struct spi_slave *spi, struct spi_flash *flash)
>>                  puts(" Full access #define CONFIG_SPI_FLASH_BAR\n");
>>          }
>>   #endif
>> -       if (spi_enable_wp_pin(flash))
>> -               puts("Enable WP pin failed\n");
>>
>>          /* Release spi bus */
>>          spi_release_bus(spi);
>> --
>> 1.9.1
>>
>
> Ping!
>
> thanks!
>

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