linux-kernel - [PATCH v2 4/7] mtd: spi-nor: Split spi_nor_init

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Date:   Sat, 24 Aug 2019 12:00:43 +0000
From:   <Tudor.Ambarus@...rochip.com>
To:     <boris.brezillon@...labora.com>, <marek.vasut@...il.com>,
        <vigneshr@...com>, <miquel.raynal@...tlin.com>, <richard@....at>,
        <linux-mtd@...ts.infradead.org>, <linux-kernel@...r.kernel.org>
CC:     <Tudor.Ambarus@...rochip.com>
Subject: [PATCH v2 4/7] mtd: spi-nor: Split spi_nor_init_params()

From: Tudor Ambarus <tudor.ambarus@...rochip.com>

Add functions to delimit what the chunks of code do:

static void spi_nor_init_params()
{
	spi_nor_legacy_init_params()
	spi_nor_manufacturer_init_params()
	spi_nor_sfdp_init_params()
}

Add descriptions to all methods.

spi_nor_init_params() becomes of type void, as all its children
return void.

Signed-off-by: Tudor Ambarus <tudor.ambarus@...rochip.com>
---
 drivers/mtd/spi-nor/spi-nor.c | 83 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 63 insertions(+), 20 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index c9514dfd7d6d..93424f914159 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -4186,7 +4186,34 @@ static void spi_nor_manufacturer_init_params(struct spi_nor *nor)
 		nor->info->fixups->default_init(nor);
 }
 
-static int spi_nor_init_params(struct spi_nor *nor)
+/**
+ * spi_nor_sfdp_init_params() - Initialize the flash's parameters and settings
+ * based on JESD216 SFDP standard.
+ * @nor:	pointer to a 'struct spi-nor'.
+ *
+ * The method has a roll-back mechanism: in case the SFDP parsing fails, the
+ * legacy flash parameters and settings will be restored.
+ */
+static void spi_nor_sfdp_init_params(struct spi_nor *nor)
+{
+	struct spi_nor_flash_parameter sfdp_params;
+
+	memcpy(&sfdp_params, &nor->params, sizeof(sfdp_params));
+
+	if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
+		nor->addr_width = 0;
+		nor->flags &= ~SNOR_F_4B_OPCODES;
+	} else {
+		memcpy(&nor->params, &sfdp_params, sizeof(nor->params));
+	}
+}
+
+/**
+ * spi_nor_legacy_init_params() - Initialize the flash's parameters and settings
+ * based on nor->info data.
+ * @nor:	pointer to a 'struct spi-nor'.
+ */
+static void spi_nor_legacy_init_params(struct spi_nor *nor)
 {
 	struct spi_nor_flash_parameter *params = &nor->params;
 	struct spi_nor_erase_map *map = &params->erase_map;
@@ -4260,25 +4287,43 @@ static int spi_nor_init_params(struct spi_nor *nor)
 	spi_nor_set_erase_type(&map->erase_type[i], info->sector_size,
 			       SPINOR_OP_SE);
 	spi_nor_init_uniform_erase_map(map, erase_mask, params->size);
+}
 
+/**
+ * spi_nor_init_params() - Initialize the flash's parameters and settings.
+ * @nor:	pointer to a 'struct spi-nor'.
+ *
+ * The flash parameters and settings are initialized based on a sequence of
+ * calls that are ordered by priority:
+ *
+ * 1/ Legacy flash parameters initialization. The initializations are done
+ *    based on nor->info data:
+ *		spi_nor_legacy_init_params()
+ *
+ * which can be overwritten by:
+ * 2/ Manufacturer flash parameters initialization. The initializations are
+ *    done based on MFR register, or when the decisions can not be done solely
+ *    based on MFR, by using specific flash_info tweeks, ->default_init():
+ *		spi_nor_manufacturer_init_params()
+ *
+ * which can be overwritten by:
+ * 3/ SFDP flash parameters initialization. JESD216 SFDP is a standard and
+ *    should be more accurate that the above.
+ *		spi_nor_sfdp_init_params()
+ *
+ *    Please not that there is a ->post_bfpt() fixup hook that can overwrite the
+ *    flash parameters and settings imediately after parsing the Basic Flash
+ *    Parameter Table.
+ */
+static void spi_nor_init_params(struct spi_nor *nor)
+{
+	spi_nor_legacy_init_params(nor);
 
 	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;
-
-		memcpy(&sfdp_params, params, sizeof(sfdp_params));
-
-		if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
-			nor->addr_width = 0;
-			nor->flags &= ~SNOR_F_4B_OPCODES;
-		} else {
-			memcpy(params, &sfdp_params, sizeof(*params));
-		}
-	}
-
-	return 0;
+	if ((nor->info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
+	    !(nor->info->flags & SPI_NOR_SKIP_SFDP))
+		spi_nor_sfdp_init_params(nor);
 }
 
 static int spi_nor_select_read(struct spi_nor *nor,
@@ -4693,10 +4738,8 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
 	    nor->info->flags & SPI_NOR_HAS_LOCK)
 		nor->params.disable_block_protection = spi_nor_clear_sr_bp;
 
-	/* Parse the Serial Flash Discoverable Parameters table. */
-	ret = spi_nor_init_params(nor);
-	if (ret)
-		return ret;
+	/* Init flash parameters based on flash_info struct and SFDP */
+	spi_nor_init_params(nor);
 
 	if (!mtd->name)
 		mtd->name = dev_name(dev);
-- 
2.9.5