Hi Scott and Stefano,

You will find below the newest patch for the NAND flash access problem on the 
TX25 module.
I hope this version is fulfilling all your expectations.

Cordially,

Daniel

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index 936186f..08fbb12 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -48,6 +48,17 @@
  *     Reading or writing a 2K or 4K page requires only 1 FDI/FDO cycle.
  *      Also some of registers are moved and/or changed meaning as seen below.
  */
+/*
+ * NAND Flash access mode on MX25
+ *
+ * The MX25 NAND Flash Controller supports two modes to access the Flash:
+ *   a) symmetric mode (one Flash clock cycle per access) or
+ *   b) asymmetric mode (two Flash clock cycles per access)
+ *
+ * By default the NAND Flash Controller is configured in the symmetric mode.
+ * To select the asymmetric mode, the configuration option
+ * CONFIG_SYS_NAND_MXC_NFC_TWO_CYCLES has to be selected.
+ */
 #if defined(CONFIG_MX31) || defined(CONFIG_MX27)
 #define MXC_NFC_V1
 #elif defined(CONFIG_MX25) || defined(CONFIG_MX35)
@@ -1290,7 +1301,9 @@ static void mxc_setup_config1(void)
        uint16_t tmp;
 
        tmp = readw(&host->regs->nfc_config1);
+#ifndef CONFIG_SYS_NAND_MXC_NFC_TWO_CYCLES
        tmp |= NFC_ONE_CYCLE;
+#endif
        tmp |= NFC_4_8N_ECC;
        writew(tmp, &host->regs->nfc_config1);
        if (host->pagesize_2k)
diff --git a/include/configs/tx25.h b/include/configs/tx25.h
index 6821528..8fa51cb 100644
--- a/include/configs/tx25.h
+++ b/include/configs/tx25.h
@@ -109,6 +109,7 @@
 /* NAND */
 #define CONFIG_NAND_MXC
 #define CONFIG_NAND_MXC_V1_1
+#define CONFIG_SYS_NAND_MXC_NFC_TWO_CYCLES /* 2 cycles to access NAND Flash */
 #define CONFIG_MXC_NAND_REGS_BASE      (0xBB000000)
 #define CONFIG_SYS_MAX_NAND_DEVICE     1
 #define CONFIG_SYS_NAND_BASE           (0xBB000000)



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