mtd: spi-nor: Add default_init() hook to tweak flash parameters

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>
This commit is contained in:
Tudor Ambarus 2019-08-24 12:00:37 +00:00
parent c46872170a
commit ce0b6f3f3c
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@ -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 @@ exit:
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;