[U-Boot] [V4 2/2] sf: Turn SPI flash into 3-Byte address mode on Micron chips

[Jagan Teki]

On 10 August 2015 at 08:28, Hou Zhiqiang <B48286 at freescale.com> wrote:
> Hi Jagan,
>
> Do you have any feedback?
>
>> -----Original Message-----
>> From: Zhiqiang Hou [mailto:B48286 at freescale.com]
>> Sent: 2015年7月23日 17:54
>> To: u-boot at lists.denx.de; jteki at openedev.com
>> Cc: Sun York-R58495; Hu Mingkai-B21284; Hou Zhiqiang-B48286
>> Subject: [V4 2/2] sf: Turn SPI flash into 3-Byte address mode on Micron
>> chips
>>
>> From: Hou Zhiqiang <B48286 at freescale.com>
>>
>> For more than 16MiB Micron chips, there are 3-Byte and 4-Byte address
>> mode, and only the 3-Byte address mode is supported in u-boot.
>> So, reset the SPI flash to 3-Byte address mode in probe to ensure the SPI
>> flash work correctly, because it may be in 4-Byte address mode after warm
>> boot.
>>
>> Signed-off-by: Hou Zhiqiang <B48286 at freescale.com>
>> ---
>>  drivers/mtd/spi/sf_internal.h |  8 ++++++++
>>  drivers/mtd/spi/sf_ops.c      | 24 ++++++++++++++++++++++++
>>  drivers/mtd/spi/sf_probe.c    |  5 +++++
>>  3 files changed, 37 insertions(+)
>>
>> diff --git a/drivers/mtd/spi/sf_internal.h
>> b/drivers/mtd/spi/sf_internal.h index 703d4a7..3d7ed24 100644
>> --- a/drivers/mtd/spi/sf_internal.h
>> +++ b/drivers/mtd/spi/sf_internal.h
>> @@ -75,6 +75,10 @@ enum {
>>  #define CMD_FLAG_STATUS                      0x70
>>  #define CMD_CLEAR_FLAG_STATUS                0x50
>>
>> +/* Used for Macronix and Winbond flashes */
>> +#define      CMD_ENTER_4B_ADDR               0xB7
>> +#define      CMD_EXIT_4B_ADDR                0xE9
>> +
>>  /* Read commands */
>>  #define CMD_READ_ARRAY_SLOW          0x03
>>  #define CMD_READ_ARRAY_FAST          0x0b
>> @@ -227,6 +231,10 @@ int spi_flash_read_common(struct spi_flash *flash,
>> const u8 *cmd,  int spi_flash_cmd_read_ops(struct spi_flash *flash, u32
>> offset,
>>               size_t len, void *data);
>>
>> +#if defined(CONFIG_SPI_FLASH_STMICRO)
>> +int spi_flash_cmd_4B_addr_switch(struct spi_flash *flash, int enable);
>> +#endif
>> +
>>  #ifdef CONFIG_SPI_FLASH_MTD
>>  int spi_flash_mtd_register(struct spi_flash *flash);  void
>> spi_flash_mtd_unregister(void); diff --git a/drivers/mtd/spi/sf_ops.c
>> b/drivers/mtd/spi/sf_ops.c index cbb9f00..1ce14d1 100644
>> --- a/drivers/mtd/spi/sf_ops.c
>> +++ b/drivers/mtd/spi/sf_ops.c
>> @@ -93,6 +93,30 @@ int spi_flash_cmd_write_config(struct spi_flash *flash,
>> u8 wc)  }  #endif
>>
>> +#if defined(CONFIG_SPI_FLASH_STMICRO)
>> +int spi_flash_cmd_4B_addr_switch(struct spi_flash *flash, int enable) {
>> +     int ret;
>> +     u8 cmd;
>> +
>> +     cmd = enable ? CMD_ENTER_4B_ADDR : CMD_EXIT_4B_ADDR;
>> +
>> +     ret = spi_claim_bus(flash->spi);
>> +     if (ret) {
>> +             debug("SF: unable to claim SPI bus\n");
>> +             return ret;
>> +     }
>> +
>> +     ret = spi_flash_cmd_write_enable(flash);
>> +     if (ret < 0) {
>> +             debug("SF: enabling write failed\n");
>> +             return ret;
>> +     }
>> +
>> +     return spi_flash_cmd(flash->spi, cmd, NULL, 0); } #endif
>> +
>>  #ifdef CONFIG_SPI_FLASH_BAR
>>  static int spi_flash_cmd_bankaddr_write(struct spi_flash *flash, u8
>> bank_sel)  { diff --git a/drivers/mtd/spi/sf_probe.c
>> b/drivers/mtd/spi/sf_probe.c index e0283dc..5ba7dde 100644
>> --- a/drivers/mtd/spi/sf_probe.c
>> +++ b/drivers/mtd/spi/sf_probe.c
>> @@ -231,6 +231,11 @@ static int spi_flash_validate_params(struct
>> spi_slave *spi, u8 *idcode,  #ifdef CONFIG_SPI_FLASH_STMICRO
>>       if (params->flags & E_FSR)
>>               flash->poll_cmd = CMD_FLAG_STATUS;
>> +
>> +     if (flash->size > SPI_FLASH_16MB_BOUN) {
>> +             if (spi_flash_cmd_4B_addr_switch(flash, 0) < 0)
>> +                     debug("SF: enter 3B address mode failed\n");
>> +     }

Don't add STMICRO specific macro, add something like
1. define a macro CONFIG_SF_EN4B
2. probe check for size > 16MiB, and try to set the 4byte addressing.

>>  #endif
>>
>>       /* Configure the BAR - discover bank cmds and read current bank */
>> --
>> 2.1.0.27.g96db324
>

thanks!
-- 
Jagan | openedev.