[PATCH v8 1/4] mtd: spi-nor: introduce SPI 1-2-2 and SPI 1-4-4 protocols

Cyrille Pitchen cyrille.pitchen at wedev4u.fr
Tue Apr 25 14:47:31 PDT 2017


Le 25/04/2017 à 22:25, Marek Vasut a écrit :
> On 04/25/2017 10:08 PM, Cyrille Pitchen wrote:
>> From: Cyrille Pitchen <cyrille.pitchen at atmel.com>
>>
>> This patch changes the prototype of spi_nor_scan(): its 3rd parameter
>> is replaced by a 'struct spi_nor_hwcaps' pointer, which tells the spi-nor
>> framework about the actual hardware capabilities supported by the SPI
>> controller and its driver.
>>
>> Besides, this patch also introduces a new 'struct spi_nor_flash_parameter'
>> telling the spi-nor framework about the hardware capabilities supported by
>> the SPI flash memory and the associated settings required to use those
>> hardware caps.
>>
>> Then, to improve the readability of spi_nor_scan(), the discovery of the
>> memory settings and the memory initialization are now split into two
>> dedicated functions.
>>
>> 1 - spi_nor_init_params()
>>
>> The spi_nor_init_params() function is responsible for initializing the
>> 'struct spi_nor_flash_parameter'. Currently this structure is filled with
>> legacy values but further patches will allow to override some parameter
>> values dynamically, for instance by reading the JESD216 Serial Flash
>> Discoverable Parameter (SFDP) tables from the SPI memory.
>> The spi_nor_init_params() function only deals with the hardware
>> capabilities of the SPI flash memory: especially it doesn't care about
>> the hardware capabilities supported by the SPI controller.
>>
>> 2 - spi_nor_setup()
>>
>> The second function is called once the 'struct spi_nor_flash_parameter'
>> has been initialized by spi_nor_init_params().
>> With both 'struct spi_nor_flash_parameter' and 'struct spi_nor_hwcaps',
>> the new argument of spi_nor_scan(), spi_nor_setup() computes the best
>> match between hardware caps supported by both the (Q)SPI memory and
>> controller hence selecting the relevant settings for (Fast) Read and Page
>> Program operations.
>>
>> Signed-off-by: Cyrille Pitchen <cyrille.pitchen at atmel.com>
> 
> Reviewed-by: Marek Vasut <marek.vasut at gmail.com>
> 
> [...]
> 

whole series applied to the 'next' branch of the github/spi-nor tree.


Thanks for your reviews!

Best regards,

Cyrille



More information about the linux-mtd mailing list