Unverified Commit ce0b6f3f authored Aug 24, 2019 by Tudor Ambarus

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>

parent c4687217

drivers/mtd/spi-nor/spi-nor.c

+17 −0

Original line number	Diff line number	Diff line
		@@ -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;

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