[U-Boot] [PATCH 1/2 v1] sf: probe: Add support Atmel AT45DB series devices special commands

[Haikun.Wang at freescale.com]

On 3/25/2015 10:10 PM, Fan Peng-B51431 wrote:
> Hi Haikun,
>
> On 3/25/2015 8:35 PM, Haikun Wang wrote:
>> From: Haikun Wang <Haikun.Wang at freescale.com>
>>
>> Atmel AT45DB series devices commands is different from common spi flash
>> commands. This patch add support for AT45DB special commands.
>> Add a flag AT45DB_CMD to control whether use those commands.
>>
>> Signed-off-by: Haikun Wang <Haikun.Wang at freescale.com>
>> ---
>>
>> Changes in v1: None
>>
>>    drivers/mtd/spi/sf_internal.h |  7 +++++++
>>    drivers/mtd/spi/sf_ops.c      |  2 +-
>>    drivers/mtd/spi/sf_probe.c    | 10 ++++++++++
>>    3 files changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
>> index 785f7a9..234af21 100644
>> --- a/drivers/mtd/spi/sf_internal.h
>> +++ b/drivers/mtd/spi/sf_internal.h
>> @@ -43,6 +43,7 @@ enum {
>>    	SST_BP		= 1 << 3,
>>    	SST_WP		= 1 << 4,
>>    	WR_QPP		= 1 << 5,
>> +	AT45DB_CMD	= 1 << 6,
>>    };
>>
>>    #define SST_WR		(SST_BP | SST_WP)
>> @@ -106,6 +107,12 @@ enum {
>>    #define SPI_FLASH_PAGE_ERASE_TIMEOUT		(5 * CONFIG_SYS_HZ)
>>    #define SPI_FLASH_SECTOR_ERASE_TIMEOUT	(10 * CONFIG_SYS_HZ)
>>
>> +/* Atmel AT45DB specific */
>> +#define CMD_ATMEL_PAGE_PROGRAM		0x82
> Why not use 0x2 to align with current mtd/spi framework?
I didn't find the program command '0x2' in AT45DB021D datasheet.
Do you ever use it in AT45DBxxxx flash chip?
>> +#define CMD_ATMEL_READ_STATUS		0xd7
>> +#define CMD_ATMEL_FLAG_STATUS		0xd7
>> +#define CMD_ATMEL_BLK_ERASE	        0x50
>> +
>>    /* SST specific */
>>    #ifdef CONFIG_SPI_FLASH_SST
>>    # define CMD_SST_BP		0x02    /* Byte Program */
>> diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c
>> index 34bc54e..27ce5f9 100644
>> --- a/drivers/mtd/spi/sf_ops.c
>> +++ b/drivers/mtd/spi/sf_ops.c
>> @@ -165,7 +165,7 @@ int spi_flash_cmd_wait_ready(struct spi_flash *flash, unsigned long timeout)
>>    	u8 poll_bit = STATUS_WIP;
>>    	u8 cmd = flash->poll_cmd;
>>
>> -	if (cmd == CMD_FLAG_STATUS) {
>> +	if (cmd == CMD_FLAG_STATUS || cmd == CMD_ATMEL_FLAG_STATUS) {
>>    		poll_bit = STATUS_PEC;
>>    		check_status = poll_bit;
>>    	}
>> diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
>> index 4103723..2ccddf2 100644
>> --- a/drivers/mtd/spi/sf_probe.c
>> +++ b/drivers/mtd/spi/sf_probe.c
>> @@ -226,6 +226,16 @@ static int spi_flash_validate_params(struct spi_slave *spi, u8 *idcode,
>>    		flash->poll_cmd = CMD_FLAG_STATUS;
>>    #endif
>>
>> +#ifdef CONFIG_SPI_FLASH_ATMEL
>> +	if (params->flags & AT45DB_CMD) {
>> +		flash->poll_cmd = CMD_ATMEL_READ_STATUS;
>> +		flash->write_cmd = CMD_ATMEL_PAGE_PROGRAM;
>> +		/* use block-erase command, eight pages */
>> +		flash->erase_cmd = CMD_ATMEL_BLK_ERASE;
>> +		flash->erase_size = flash->page_size * 8;
>> +	}
>> +#endif
>> +
> The SPI Flash's default page size is 264 bytes, but mtd/spi framework
> supports 256 and 512 bytes for one page. In your patch, you does not
> handle such case, can your driver works as expected?
Fine, I know mtd/spi framework doesn't support page-size of 264bytes.
In fact we change the chip's page-size to 256bytes before using it.
It is a big work to adjust the framework support 264bytes.
So how about add a check here, if the chip has a page-size of 264bytes, 
we just return an error.
Or I will add a AT45DB special flash driver under Driver Model.
-- 

Best regards,
Wang Haikun
>>    	/* Configure the BAR - discover bank cmds and read current bank */
>>    #ifdef CONFIG_SPI_FLASH_BAR
>>    	u8 curr_bank = 0;
> Regards,
> Peng.
>