mtd: spi-nor: add id/id_len for flash_info{}

This patch adds the id/id_len fields for flash_info{}, and rewrite the
INFO to fill them. And at last, we read out 6 bytes in the spi_nor_read_id(),
and we use these new fields to parse out the correct flash_info.

Signed-off-by: Huang Shijie <shijie.huang@intel.com>
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

1 files changed, 25 insertions, 14 deletions

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 3f2a3ccb37d5..786344f08675 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -418,6 +418,8 @@ err:
         return ret;
 }
 
+#define SPI_NOR_MAX_ID_LEN      6
+
 struct flash_info {
         /* JEDEC id zero means "no ID" (most older chips); otherwise it has
          * a high byte of zero plus three data bytes: the manufacturer id,
@@ -426,6 +428,14 @@ struct flash_info {
         u32             jedec_id;
         u16             ext_id;
 
+        /*
+         * This array stores the ID bytes.
+         * The first three bytes are the JEDIC ID.
+         * JEDEC ID zero means "no ID" (mostly older chips).
+         */
+        u8              id[SPI_NOR_MAX_ID_LEN];
+        u8              id_len;
+
         /* The size listed here is what works with SPINOR_OP_SE, which isn't
          * necessarily called a "sector" by the vendor.
          */
@@ -446,10 +456,19 @@ struct flash_info {
 #define USE_FSR                 0x80    /* use flag status register */
 };
 
+/* Used when the "_ext_id" is two bytes at most */
 #define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags)      \
         ((kernel_ulong_t)&(struct flash_info) {                         \
                 .jedec_id = (_jedec_id),                                \
                 .ext_id = (_ext_id),                                    \
+                .id = {                                                 \
+                        ((_jedec_id) >> 16) & 0xff,                     \
+                        ((_jedec_id) >> 8) & 0xff,                      \
+                        (_jedec_id) & 0xff,                             \
+                        ((_ext_id) >> 8) & 0xff,                        \
+                        (_ext_id) & 0xff,                               \
+                        },                                              \
+                .id_len = (!(_jedec_id) ? 0 : (3 + ((_ext_id) ? 2 : 0))),       \
                 .sector_size = (_sector_size),                          \
                 .n_sectors = (_n_sectors),                              \
                 .page_size = 256,                                       \
@@ -642,32 +661,24 @@ static const struct spi_device_id spi_nor_ids[] = {
 static const struct spi_device_id *spi_nor_read_id(struct spi_nor *nor)
 {
         int                     tmp;
-        u8                      id[5];
-        u32                     jedec;
-        u16                     ext_jedec;
+        u8                      id[SPI_NOR_MAX_ID_LEN];
         struct flash_info       *info;
 
-        tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, 5);
+        tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, SPI_NOR_MAX_ID_LEN);
         if (tmp < 0) {
                 dev_dbg(nor->dev, " error %d reading JEDEC ID\n", tmp);
                 return ERR_PTR(tmp);
         }
-        jedec = id[0];
-        jedec = jedec << 8;
-        jedec |= id[1];
-        jedec = jedec << 8;
-        jedec |= id[2];
-
-        ext_jedec = id[3] << 8 | id[4];
 
         for (tmp = 0; tmp < ARRAY_SIZE(spi_nor_ids) - 1; tmp++) {
                 info = (void *)spi_nor_ids[tmp].driver_data;
-                if (info->jedec_id == jedec) {
-                        if (info->ext_id == 0 || info->ext_id == ext_jedec)
+                if (info->id_len) {
+                        if (!memcmp(info->id, id, info->id_len))
                                 return &spi_nor_ids[tmp];
                 }
         }
-        dev_err(nor->dev, "unrecognized JEDEC id %06x\n", jedec);
+        dev_err(nor->dev, "unrecognized JEDEC id bytes: %02x, %2x, %2x\n",
+                id[0], id[1], id[2]);
         return ERR_PTR(-ENODEV);
 }