Re: [RESEND PATCH v3 05/20] mtd: spi-nor: Add default_init() hook to tweak flash parameters

Vignesh Raghavendra
2019-08-27T05:48:13Z

On 26/08/19 5:38 PM, Tudor.Ambarus@microchip.com wrote:
> From: Tudor Ambarus <tudor.ambarus@microchip.com>
>
> As of now, the flash parameters initialization logic is as following:
>
> a/ default flash parameters init in spi_nor_init_params()
> b/ manufacturer specific flash parameters updates, split across entire
> spi-nor core code
> c/ flash parameters updates based on SFDP tables
> d/ post BFPT flash parameter updates
>
> In the quest of removing the manufacturer specific code from the spi-nor
> core, we want to impose a timeline/priority on how the flash parameters
> are updated. The following sequence of calls is pursued:
>
> 1/ spi-nor core parameters init based on 'flash_info' struct:
> spi_nor_info_init_params()
>
> which can be overwritten by:
> 2/ MFR-based manufacturer flash parameters init:
> nor->manufacturer->fixups->default_init()
>
> which can be overwritten by:
> 3/ specific flash_info tweeks done when decisions can not be done just on
> MFR:
> nor->info->fixups->default_init()
>
> which can be overwritten by:
> 4/ SFDP tables flash parameters init - SFDP knows better:
> spi_nor_sfdp_init_params()
>
> which can be overwritten by:
> 5/ post SFDP tables flash parameters updates - in case manufacturers get
> the serial flash tables wrong or incomplete.
> nor->info->fixups->post_sfdp()
> The later can be extended to nor->manufacturer->fixups->post_sfdp() if
> needed.
>
> This patch opens doors for steps 2/ and 3/.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
> ---

Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>

Regards
Vignesh

> v3: reword description
>
> drivers/mtd/spi-nor/spi-nor.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 9dd6cd8cd13c..8fd60e1eebd2 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -154,12 +154,16 @@ struct sfdp_bfpt {
>
> /**
> * struct spi_nor_fixups - SPI NOR fixup hooks
> + * @default_init: called after default flash parameters init. Used to tweak
> + * flash parameters when information provided by the flash_info
> + * table is incomplete or wrong.
> * @post_bfpt: called after the BFPT table has been parsed
> *
> * Those hooks can be used to tweak the SPI NOR configuration when the SFDP
> * table is broken or not available.
> */
> struct spi_nor_fixups {
> + void (*default_init)(struct spi_nor *nor);
> int (*post_bfpt)(struct spi_nor *nor,
> const struct sfdp_parameter_header *bfpt_header,
> const struct sfdp_bfpt *bfpt,
> @@ -4133,6 +4137,17 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
> return err;
> }
>
> +/**
> + * spi_nor_manufacturer_init_params() - Initialize the flash's parameters and
> + * settings based on ->default_init() hook.
> + * @nor: pointer to a 'struct spi-nor'.
> + */
> +static void spi_nor_manufacturer_init_params(struct spi_nor *nor)
> +{
> + if (nor->info->fixups && nor->info->fixups->default_init)
> + nor->info->fixups->default_init(nor);
> +}
> +
> static int spi_nor_init_params(struct spi_nor *nor)
> {
> struct spi_nor_flash_parameter *params = &nor->params;
> @@ -4233,6 +4248,8 @@ static int spi_nor_init_params(struct spi_nor *nor)
> params->quad_enable = info->quad_enable;
> }
>
> + spi_nor_manufacturer_init_params(nor);
> +
> if ((info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
> !(info->flags & SPI_NOR_SKIP_SFDP)) {
> struct spi_nor_flash_parameter sfdp_params;
>

--
Regards
Vignesh