mtd: spi-nor: core: Introduce the late_init() hook

Flash parameters init is done in a spaghetti way right now.
There is the init based on the flash_info data, then there is the
default_init() hook, then SFDP init, an intermediary post_bft(),
then post_sfdp() and a spi_nor_late_init_params(). Each method can
overwrite previuosly initialized parameters.

We want to separate what is SFDP and non-SFDP specific. late_init()
will replace the default_init() hook and will be used only to initialize
flash parameters that are not declared in the JESD216 SFDP standard, or
where SFDP tables are not defined at all.
We cut a member in the chain of initializing parameters by getting rid
of the default_init() hook, and we make it clear that everything that is
in late_init() is not covered by the SFDP tables defined by the flash.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20211029172633.886453-6-tudor.ambarus@microchip.com

drivers/mtd/spi-nor/core.c

@@ -2666,11 +2666,19 @@ static void spi_nor_post_sfdp_fixups(struct spi_nor *nor)
  * spi_nor_late_init_params() - Late initialization of default flash parameters.
  * @nor:	pointer to a 'struct spi_nor'
  *
- * Used to set default flash parameters and settings when the ->default_init()
+ * Used to initialize flash parameters that are not declared in the JESD216
- * hook or the SFDP parser let voids.
+ * SFDP standard, or where SFDP tables are not defined at all.
+ * Will replace the spi_nor_manufacturer_init_params() method.
  */
 static void spi_nor_late_init_params(struct spi_nor *nor)
 {
+	if (nor->manufacturer && nor->manufacturer->fixups &&
+	    nor->manufacturer->fixups->late_init)
+		nor->manufacturer->fixups->late_init(nor);
+
+	if (nor->info->fixups && nor->info->fixups->late_init)
+		nor->info->fixups->late_init(nor);
+
 	/*
 	 * NOR protection support. When locking_ops are not provided, we pick
 	 * the default ones.
@@ -2712,8 +2720,9 @@ static void spi_nor_late_init_params(struct spi_nor *nor)
  *    wrong).
  *		spi_nor_post_sfdp_fixups()
  *
- * 5/ Late default flash parameters initialization, used when the
+ * 5/ Late flash parameters initialization, used to initialize flash
- * ->default_init() hook or the SFDP parser do not set specific params.
+ * parameters that are not declared in the JESD216 SFDP standard, or where SFDP
+ * tables are not defined at all.
  *		spi_nor_late_init_params()
  */
 static int spi_nor_init_params(struct spi_nor *nor)

drivers/mtd/spi-nor/core.h

@@ -297,6 +297,9 @@ struct spi_nor_flash_parameter {
  *             parameters that could not be extracted by other means (i.e.
  *             when information provided by the SFDP/flash_info tables are
  *             incomplete or wrong).
+ * @late_init: used to initialize flash parameters that are not declared in the
+ *             JESD216 SFDP standard, or where SFDP tables not defined at all.
+ *             Will replace the default_init() hook.
  *
  * Those hooks can be used to tweak the SPI NOR configuration when the SFDP
  * table is broken or not available.
@@ -307,6 +310,7 @@ struct spi_nor_fixups {
 			 const struct sfdp_parameter_header *bfpt_header,
 			 const struct sfdp_bfpt *bfpt);
 	void (*post_sfdp)(struct spi_nor *nor);
+	void (*late_init)(struct spi_nor *nor);
 };
 
 struct flash_info {