mtd: spi-nor: core: set mtd->eraseregions for non-uniform erase map

Some of Infineon SPI NOR flash devices support hybrid sector layout that
overlays 4KB sectors on a 256KB sector and SPI NOR framework recognizes
that by parsing SMPT and construct params->erase_map. The hybrid sector
layout is similar to CFI flash devices that have small sectors on top
and/or bottom address. In case of CFI flash devices, the erase map
information is parsed through CFI table and populated into
mtd->eraseregions so that users can create MTD partitions that aligned
with small sector boundaries. This patch provides the same capability to
SPI NOR flash devices that have non-uniform erase map.

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Reviewed-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/35d0962986e493b06c13bdf7ada8130a9966dc02.1708404584.git.Takahiro.Kuwano@infineon.com
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 898472538dae7447f6423c6cca7c87779e7f4adf..65b32ea59afc67acc09bc7182058dfc63c0ab46d 100644 (file)
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3369,7 +3369,54 @@ static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor,
        return info;
 }
 
-static void spi_nor_set_mtd_info(struct spi_nor *nor)
+static u32
+spi_nor_get_region_erasesize(const struct spi_nor_erase_region *region,
+                            const struct spi_nor_erase_type *erase_type)
+{
+       u8 i;
+
+       if (region->overlaid)
+               return region->size;
+
+       for (i = SNOR_ERASE_TYPE_MAX - 1; i >= 0; i--) {
+               if (region->erase_mask & BIT(i))
+                       return erase_type[i].size;
+       }
+
+       return 0;
+}
+
+static int spi_nor_set_mtd_eraseregions(struct spi_nor *nor)
+{
+       const struct spi_nor_erase_map *map = &nor->params->erase_map;
+       const struct spi_nor_erase_region *region = map->regions;
+       struct mtd_erase_region_info *mtd_region;
+       struct mtd_info *mtd = &nor->mtd;
+       u32 erasesize, i;
+
+       mtd_region = devm_kcalloc(nor->dev, map->n_regions, sizeof(*mtd_region),
+                                 GFP_KERNEL);
+       if (!mtd_region)
+               return -ENOMEM;
+
+       for (i = 0; i < map->n_regions; i++) {
+               erasesize = spi_nor_get_region_erasesize(&region[i],
+                                                        map->erase_type);
+               if (!erasesize)
+                       return -EINVAL;
+
+               mtd_region[i].erasesize = erasesize;
+               mtd_region[i].numblocks = div64_ul(region[i].size, erasesize);
+               mtd_region[i].offset = region[i].offset;
+       }
+
+       mtd->numeraseregions = map->n_regions;
+       mtd->eraseregions = mtd_region;
+
+       return 0;
+}
+
+static int spi_nor_set_mtd_info(struct spi_nor *nor)
 {
        struct mtd_info *mtd = &nor->mtd;
        struct device *dev = nor->dev;
@@ -3400,6 +3447,11 @@ static void spi_nor_set_mtd_info(struct spi_nor *nor)
        mtd->_resume = spi_nor_resume;
        mtd->_get_device = spi_nor_get_device;
        mtd->_put_device = spi_nor_put_device;
+
+       if (!spi_nor_has_uniform_erase(nor))
+               return spi_nor_set_mtd_eraseregions(nor);
+
+       return 0;
 }
 
 static int spi_nor_hw_reset(struct spi_nor *nor)
@@ -3490,7 +3542,9 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
                return ret;
 
        /* No mtd_info fields should be used up to this point. */
-       spi_nor_set_mtd_info(nor);
+       ret = spi_nor_set_mtd_info(nor);
+       if (ret)
+               return ret;
 
        dev_dbg(dev, "Manufacturer and device ID: %*phN\n",
                SPI_NOR_MAX_ID_LEN, nor->id);