[PATCH V3] mtd: move support for struct flash_platform_data into m25p80

["Rafał Miłecki" <zajec5@gmail.com>]

This "type" seems to be an extra hint for m25p80 about the flash. Some
archs register flash_platform_data with "name" set to "m25p80" and then
with a real flash name set in "type". It seems to be a trick specific
to the m25p80 so let's move it out of spi-nor.
Btw switch to the spi_nor_match_id instead of iterating spi_nor_ids.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
---
V2: Comment usage of data->type
    Set mtd.name in m25p80
V3: Fix "respect" spelling in the comment

Brian: do you think this comment about "name" and "type" is clear
enough now? If so, could you pick this patch, please?
---
 drivers/mtd/devices/m25p80.c  | 22 ++++++++++++++++++++--
 drivers/mtd/spi-nor/spi-nor.c | 28 +---------------------------
 2 files changed, 21 insertions(+), 29 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index ed7e0a1b..dcda628 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -193,11 +193,14 @@ static int m25p_probe(struct spi_device *spi)
 {
 	struct mtd_part_parser_data	ppdata;
 	struct flash_platform_data	*data;
+	const struct spi_device_id *id = NULL;
 	struct m25p *flash;
 	struct spi_nor *nor;
 	enum read_mode mode = SPI_NOR_NORMAL;
 	int ret;
 
+	data = dev_get_platdata(&spi->dev);
+
 	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
 	if (!flash)
 		return -ENOMEM;
@@ -223,11 +226,26 @@ static int m25p_probe(struct spi_device *spi)
 		mode = SPI_NOR_QUAD;
 	else if (spi->mode & SPI_RX_DUAL)
 		mode = SPI_NOR_DUAL;
-	ret = spi_nor_scan(nor, spi_get_device_id(spi), mode);
+
+	if (data && data->name)
+		flash->mtd.name = data->name;
+
+	/* For some (historical?) reason many platforms provide two different
+	 * names in flash_platform_data: "name" and "type". Quite often name is
+	 * set to "m25p80" and then "type" provides a real chip name.
+	 * If that's the case, respect "type" and ignore a "name".
+	 */
+	if (data && data->type)
+		id = spi_nor_match_id(data->type);
+
+	/* If we didn't get name from platform, simply use "modalias". */
+	if (!id)
+		id = spi_get_device_id(spi);
+
+	ret = spi_nor_scan(nor, id, mode);
 	if (ret)
 		return ret;
 
-	data = dev_get_platdata(&spi->dev);
 	ppdata.of_node = spi->dev.of_node;
 
 	return mtd_device_parse_register(&flash->mtd, NULL, &ppdata,
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 11459f6..ae16aa2 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -915,7 +915,6 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
 			enum read_mode mode)
 {
 	struct flash_info		*info;
-	struct flash_platform_data	*data;
 	struct device *dev = nor->dev;
 	struct mtd_info *mtd = nor->mtd;
 	struct device_node *np = dev->of_node;
@@ -926,28 +925,6 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
 	if (ret)
 		return ret;
 
-	/* Platform data helps sort out which chip type we have, as
-	 * well as how this board partitions it.  If we don't have
-	 * a chip ID, try the JEDEC id commands; they'll work for most
-	 * newer chips, even if we don't recognize the particular chip.
-	 */
-	data = dev_get_platdata(dev);
-	if (data && data->type) {
-		const struct spi_device_id *plat_id;
-
-		for (i = 0; i < ARRAY_SIZE(spi_nor_ids) - 1; i++) {
-			plat_id = &spi_nor_ids[i];
-			if (strcmp(data->type, plat_id->name))
-				continue;
-			break;
-		}
-
-		if (i < ARRAY_SIZE(spi_nor_ids) - 1)
-			id = plat_id;
-		else
-			dev_warn(dev, "unrecognized id %s\n", data->type);
-	}
-
 	info = (void *)id->driver_data;
 
 	if (info->jedec_id) {
@@ -985,11 +962,8 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
 		write_sr(nor, 0);
 	}
 
-	if (data && data->name)
-		mtd->name = data->name;
-	else
+	if (!mtd->name)
 		mtd->name = dev_name(dev);
-
 	mtd->type = MTD_NORFLASH;
 	mtd->writesize = 1;
 	mtd->flags = MTD_CAP_NORFLASH;
-- 
1.8.4.5