2019-07-31 09:04:26

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH 1/7] mtd: spi-nor: Add default_init() hook to tweak flash parameters

From: Tudor Ambarus <[email protected]>

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 legacy flash parameters init:
spi_nor_default_init_params()

2/ MFR-based manufacturer flash parameters init:
nor->manufacturer->fixups->default_init()

3/ specific flash_info tweeks done when decisions can not be done just on
MFR:
nor->info->fixups->default_init()

4/ SFDP tables flash parameters init - SFDP knows better:
spi_nor_sfdp_init_params()

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 <[email protected]>
---
drivers/mtd/spi-nor/spi-nor.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 28a64dbdaea9..ac00f90ebaa9 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -219,12 +219,17 @@ 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,
+ struct spi_nor_flash_parameter *params);
int (*post_bfpt)(struct spi_nor *nor,
const struct sfdp_parameter_header *bfpt_header,
const struct sfdp_bfpt *bfpt,
@@ -4267,6 +4272,14 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
return err;
}

+static void
+spi_nor_manufacturer_init_params(struct spi_nor *nor,
+ struct spi_nor_flash_parameter *params)
+{
+ if (nor->info->fixups && nor->info->fixups->default_init)
+ return nor->info->fixups->default_init(nor, params);
+}
+
static int spi_nor_init_params(struct spi_nor *nor,
struct spi_nor_flash_parameter *params)
{
@@ -4370,6 +4383,8 @@ static int spi_nor_init_params(struct spi_nor *nor,
params->quad_enable = info->quad_enable;
}

+ spi_nor_manufacturer_init_params(nor, params);
+
if ((info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
!(info->flags & SPI_NOR_SKIP_SFDP)) {
struct spi_nor_flash_parameter sfdp_params;
--
2.9.5


2019-08-01 07:28:34

by Boris Brezillon

[permalink] [raw]
Subject: Re: [PATCH 1/7] mtd: spi-nor: Add default_init() hook to tweak flash parameters

On Wed, 31 Jul 2019 09:03:27 +0000
<[email protected]> wrote:

> From: Tudor Ambarus <[email protected]>
>
> 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 legacy flash parameters init:
> spi_nor_default_init_params()
>
> 2/ MFR-based manufacturer flash parameters init:
> nor->manufacturer->fixups->default_init()
>
> 3/ specific flash_info tweeks done when decisions can not be done just on
> MFR:
> nor->info->fixups->default_init()
>
> 4/ SFDP tables flash parameters init - SFDP knows better:
> spi_nor_sfdp_init_params()
>
> 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 <[email protected]>

Reviewed-by: Boris Brezillon <[email protected]>

> ---
> drivers/mtd/spi-nor/spi-nor.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 28a64dbdaea9..ac00f90ebaa9 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -219,12 +219,17 @@ 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,
> + struct spi_nor_flash_parameter *params);
> int (*post_bfpt)(struct spi_nor *nor,
> const struct sfdp_parameter_header *bfpt_header,
> const struct sfdp_bfpt *bfpt,
> @@ -4267,6 +4272,14 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
> return err;
> }
>
> +static void
> +spi_nor_manufacturer_init_params(struct spi_nor *nor,
> + struct spi_nor_flash_parameter *params)
> +{
> + if (nor->info->fixups && nor->info->fixups->default_init)
> + return nor->info->fixups->default_init(nor, params);
> +}
> +
> static int spi_nor_init_params(struct spi_nor *nor,
> struct spi_nor_flash_parameter *params)
> {
> @@ -4370,6 +4383,8 @@ static int spi_nor_init_params(struct spi_nor *nor,
> params->quad_enable = info->quad_enable;
> }
>
> + spi_nor_manufacturer_init_params(nor, params);
> +
> if ((info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
> !(info->flags & SPI_NOR_SKIP_SFDP)) {
> struct spi_nor_flash_parameter sfdp_params;