sf: turn probe switch into a lookup table

[karo-tx-uboot.git] / drivers / mtd / spi / spi_flash.c

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index ea875dc812b4bcf34e41af00072ff3c8004207c0..b4ba1dda51dc4fee48116841f702d17787e11787 100644 (file)
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -2,6 +2,8 @@
  * SPI flash interface
  *
  * Copyright (C) 2008 Atmel Corporation
+ * Copyright (C) 2010 Reinhard Meyer, EMK Elektronik
+ *
  * Licensed under the GPL-2 or later.
  */
 
@@ -96,13 +98,68 @@ int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
        return ret;
 }
 
+/*
+ * The following table holds all device probe functions
+ *
+ * shift:  number of continuation bytes before the ID
+ * idcode: the expected IDCODE or 0xff for non JEDEC devices
+ * probe:  the function to call
+ *
+ * Non JEDEC devices should be ordered in the table such that
+ * the probe functions with best detection algorithms come first.
+ *
+ * Several matching entries are permitted, they will be tried
+ * in sequence until a probe function returns non NULL.
+ *
+ * IDCODE_CONT_LEN may be redefined if a device needs to declare a
+ * larger "shift" value.  IDCODE_PART_LEN generally shouldn't be
+ * changed.  This is the max number of bytes probe functions may
+ * examine when looking up part-specific identification info.
+ *
+ * Probe functions will be given the idcode buffer starting at their
+ * manu id byte (the "idcode" in the table below).  In other words,
+ * all of the continuation bytes will be skipped (the "shift" below).
+ */
+#define IDCODE_CONT_LEN 0
+#define IDCODE_PART_LEN 5
+static const struct {
+       const u8 shift;
+       const u8 idcode;
+       struct spi_flash *(*probe) (struct spi_slave *spi, u8 *idcode);
+} flashes[] = {
+       /* Keep it sorted by define name */
+#ifdef CONFIG_SPI_FLASH_ATMEL
+       { 0, 0x1f, spi_flash_probe_atmel, },
+#endif
+#ifdef CONFIG_SPI_FLASH_MACRONIX
+       { 0, 0xc2, spi_flash_probe_macronix, },
+#endif
+#ifdef CONFIG_SPI_FLASH_SPANSION
+       { 0, 0x01, spi_flash_probe_spansion, },
+#endif
+#ifdef CONFIG_SPI_FLASH_SST
+       { 0, 0xbf, spi_flash_probe_sst, },
+#endif
+#ifdef CONFIG_SPI_FLASH_STMICRO
+       { 0, 0x20, spi_flash_probe_stmicro, },
+#endif
+#ifdef CONFIG_SPI_FLASH_WINBOND
+       { 0, 0xef, spi_flash_probe_winbond, },
+#endif
+       /* Keep it sorted by best detection */
+#ifdef CONFIG_SPI_FLASH_STMICRO
+       { 0, 0xff, spi_flash_probe_stmicro, },
+#endif
+};
+#define IDCODE_LEN (IDCODE_CONT_LEN + IDCODE_PART_LEN)
+
 struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
                unsigned int max_hz, unsigned int spi_mode)
 {
        struct spi_slave *spi;
-       struct spi_flash *flash;
-       int ret;
-       u8 idcode[5];
+       struct spi_flash *flash = NULL;
+       int ret, i, shift;
+       u8 idcode[IDCODE_LEN], *idp;
 
        spi = spi_setup_slave(bus, cs, max_hz, spi_mode);
        if (!spi) {
@@ -117,53 +174,34 @@ struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
        }
 
        /* Read the ID codes */
-       ret = spi_flash_cmd(spi, CMD_READ_ID, &idcode, sizeof(idcode));
+       ret = spi_flash_cmd(spi, CMD_READ_ID, idcode, sizeof(idcode));
        if (ret)
                goto err_read_id;
 
-       debug("SF: Got idcode %02x %02x %02x %02x %02x\n", idcode[0],
-                       idcode[1], idcode[2], idcode[3], idcode[4]);
-
-       switch (idcode[0]) {
-#ifdef CONFIG_SPI_FLASH_SPANSION
-       case 0x01:
-               flash = spi_flash_probe_spansion(spi, idcode);
-               break;
+#ifdef DEBUG
+       printf("SF: Got idcodes\n");
+       print_buffer(0, idcode, 1, sizeof(idcode), 0);
 #endif
-#ifdef CONFIG_SPI_FLASH_ATMEL
-       case 0x1F:
-               flash = spi_flash_probe_atmel(spi, idcode);
-               break;
-#endif
-#ifdef CONFIG_SPI_FLASH_MACRONIX
-       case 0xc2:
-               flash = spi_flash_probe_macronix(spi, idcode);
-               break;
-#endif
-#ifdef CONFIG_SPI_FLASH_WINBOND
-       case 0xef:
-               flash = spi_flash_probe_winbond(spi, idcode);
-               break;
-#endif
-#ifdef CONFIG_SPI_FLASH_STMICRO
-       case 0x20:
-       case 0xff: /* Let the stmicro func handle non-JEDEC ids */
-               flash = spi_flash_probe_stmicro(spi, idcode);
-               break;
-#endif
-#ifdef CONFIG_SPI_FLASH_SST
-       case 0xBF:
-               flash = spi_flash_probe_sst(spi, idcode);
-               break;
-#endif
-       default:
-               printf("SF: Unsupported manufacturer %02X\n", idcode[0]);
-               flash = NULL;
-               break;
-       }
 
-       if (!flash)
+       /* count the number of continuation bytes */
+       for (shift = 0, idp = idcode;
+            shift < IDCODE_CONT_LEN && *idp == 0x7f;
+            ++shift, ++idp)
+               continue;
+
+       /* search the table for matches in shift and id */
+       for (i = 0; i < ARRAY_SIZE(flashes); ++i)
+               if (flashes[i].shift == shift && flashes[i].idcode == *idp) {
+                       /* we have a match, call probe */
+                       flash = flashes[i].probe(spi, idp);
+                       if (flash)
+                               break;
+               }
+
+       if (!flash) {
+               printf("SF: Unsupported manufacturer %02x\n", *idp);
                goto err_manufacturer_probe;
+       }
 
        spi_release_bus(spi);