ENGR00318895-1 mtd: spi-nor: read 6 bytes for the ID

Currently, we read 5 bytes for ID, but s25fl128s has the same ext_id(0x4d01)
with s25fl129p1. The s25fl128s can support the DDR Quad read, while s25fl129p1
does not. So we have to distinguish the two NOR flashs.

This patch reads out 6 bytes for the ID, and use the 6 bytes ID to search the
right flash_info.

The detail of the patch is:
  [1] change the "ext_id" from u16 to u32.
      We can store two bytes or three bytes with the @ext_id now.

  [2] search the right flash_info with the 6byte ID and the new @ext_id.
      We use "matched" variable to track the legacy two bytes @ext_id.
      If the flash_info's @ext_id is three bytes, we will use the
      sixth byte of the ID to check it.

  [3] add the new item to spi_nor_ids for s25fl128s.

Signed-off-by: Huang Shijie <b32955@freescale.com>

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index c713c865671026a220332263e3086eb7c10674a4..ca1c354e42fd9cd1af304590da9ff5c1c69477e9 100644 (file)
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -3,7 +3,7 @@
  * influence from lart.c (Abraham Van Der Merwe) and mtd_dataflash.c
  *
  * Copyright (C) 2005, Intec Automation Inc.
- * Copyright (C) 2014, Freescale Semiconductor, Inc.
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
  *
  * This code is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -383,7 +383,7 @@ struct flash_info {
         * then a two byte device id.
         */
        u32             jedec_id;
-       u16             ext_id;
+       u32             ext_id;
 
        /* The size listed here is what works with SPINOR_OP_SE, which isn't
         * necessarily called a "sector" by the vendor.
@@ -505,6 +505,7 @@ const struct spi_device_id spi_nor_ids[] = {
        { "s70fl01gs",  INFO(0x010221, 0x4d00, 256 * 1024, 256, 0) },
        { "s25sl12800", INFO(0x012018, 0x0300, 256 * 1024,  64, 0) },
        { "s25sl12801", INFO(0x012018, 0x0301,  64 * 1024, 256, 0) },
+       { "s25fl128s",  INFO(0x012018, 0x4d0180, 64 * 1024, 256, SPI_NOR_QUAD_READ) },
        { "s25fl129p0", INFO(0x012018, 0x4d00, 256 * 1024,  64, 0) },
        { "s25fl129p1", INFO(0x012018, 0x4d01,  64 * 1024, 256, 0) },
        { "s25sl004a",  INFO(0x010212,      0,  64 * 1024,   8, 0) },
@@ -593,12 +594,13 @@ EXPORT_SYMBOL_GPL(spi_nor_ids);
 static const struct spi_device_id *spi_nor_read_id(struct spi_nor *nor)
 {
        int                     tmp;
-       u8                      id[5];
+       u8                      id[6];
        u32                     jedec;
-       u16                     ext_jedec;
+       u32                     ext_jedec;
        struct flash_info       *info;
+       int                     matched = -1;
 
-       tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, 5);
+       tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, 6);
        if (tmp < 0) {
                dev_dbg(nor->dev, " error %d reading JEDEC ID\n", tmp);
                return ERR_PTR(tmp);
@@ -614,8 +616,26 @@ static const struct spi_device_id *spi_nor_read_id(struct spi_nor *nor)
        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->ext_id == 0)
                                return &spi_nor_ids[tmp];
+
+                       /* the legacy two bytes ext_id */
+                       if ((info->ext_id >> 16) == 0) {
+                               if (info->ext_id == ext_jedec)
+                                       matched = tmp;
+                       } else {
+                               /* check the sixth byte now */
+                               ext_jedec = ext_jedec << 8 | id[5];
+                               if (info->ext_id == ext_jedec)
+                                       return &spi_nor_ids[tmp];
+
+                               /* reset back the ext_jedec */
+                               ext_jedec >>= 8;
+                       }
+               } else {
+                       /* shortcut */
+                       if (matched != -1)
+                               return &spi_nor_ids[matched];
                }
        }
        dev_err(nor->dev, "unrecognized JEDEC id %06x\n", jedec);