1 files changed, 149 insertions, 0 deletions

diff --git a/drivers/mtd/nand/nand_bcm_umi.c b/drivers/mtd/nand/nand_bcm_umi.c
new file mode 100644
index 00000000000..46a6bc9c4b7
--- /dev/null
+++ b/drivers/mtd/nand/nand_bcm_umi.c
@@ -0,0 +1,149 @@
+/*****************************************************************************
+* Copyright 2004 - 2009 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+
+/* ---- Include Files ---------------------------------------------------- */
+#include <mach/reg_umi.h>
+#include "nand_bcm_umi.h"
+#ifdef BOOT0_BUILD
+#include <uart.h>
+#endif
+
+/* ---- External Variable Declarations ----------------------------------- */
+/* ---- External Function Prototypes ------------------------------------- */
+/* ---- Public Variables ------------------------------------------------- */
+/* ---- Private Constants and Types -------------------------------------- */
+/* ---- Private Function Prototypes -------------------------------------- */
+/* ---- Private Variables ------------------------------------------------ */
+/* ---- Private Functions ------------------------------------------------ */
+
+#if NAND_ECC_BCH
+/****************************************************************************
+*  nand_bch_ecc_flip_bit - Routine to flip an errored bit
+*
+*  PURPOSE:
+*     This is a helper routine that flips the bit (0 -> 1 or 1 -> 0) of the
+*     errored bit specified
+*
+*  PARAMETERS:
+*     datap - Container that holds the 512 byte data
+*     errorLocation - Location of the bit that needs to be flipped
+*
+*  RETURNS:
+*     None
+****************************************************************************/
+static void nand_bcm_umi_bch_ecc_flip_bit(uint8_t *datap, int errorLocation)
+{
+        int locWithinAByte = (errorLocation & REG_UMI_BCH_ERR_LOC_BYTE) >> 0;
+        int locWithinAWord = (errorLocation & REG_UMI_BCH_ERR_LOC_WORD) >> 3;
+        int locWithinAPage = (errorLocation & REG_UMI_BCH_ERR_LOC_PAGE) >> 5;
+
+        uint8_t errorByte = 0;
+        uint8_t byteMask = 1 << locWithinAByte;
+
+        /* BCH uses big endian, need to change the location
+         * bits to little endian */
+        locWithinAWord = 3 - locWithinAWord;
+
+        errorByte = datap[locWithinAPage * sizeof(uint32_t) + locWithinAWord];
+
+#ifdef BOOT0_BUILD
+        puthexs("\nECC Correct Offset: ",
+                locWithinAPage * sizeof(uint32_t) + locWithinAWord);
+        puthexs(" errorByte:", errorByte);
+        puthex8(" Bit: ", locWithinAByte);
+#endif
+
+        if (errorByte & byteMask) {
+                /* bit needs to be cleared */
+                errorByte &= ~byteMask;
+        } else {
+                /* bit needs to be set */
+                errorByte |= byteMask;
+        }
+
+        /* write back the value with the fixed bit */
+        datap[locWithinAPage * sizeof(uint32_t) + locWithinAWord] = errorByte;
+}
+
+/****************************************************************************
+*  nand_correct_page_bch - Routine to correct bit errors when reading NAND
+*
+*  PURPOSE:
+*     This routine reads the BCH registers to determine if there are any bit
+*     errors during the read of the last 512 bytes of data + ECC bytes.  If
+*     errors exists, the routine fixes it.
+*
+*  PARAMETERS:
+*     datap - Container that holds the 512 byte data
+*
+*  RETURNS:
+*     0 or greater = Number of errors corrected
+*                    (No errors are found or errors have been fixed)
+*    -1 = Error(s) cannot be fixed
+****************************************************************************/
+int nand_bcm_umi_bch_correct_page(uint8_t *datap, uint8_t *readEccData,
+                                  int numEccBytes)
+{
+        int numErrors;
+        int errorLocation;
+        int idx;
+        uint32_t regValue;
+
+        /* wait for read ECC to be valid */
+        regValue = nand_bcm_umi_bch_poll_read_ecc_calc();
+
+        /*
+         * read the control status register to determine if there
+         * are error'ed bits
+         * see if errors are correctible
+         */
+        if ((regValue & REG_UMI_BCH_CTRL_STATUS_UNCORR_ERR) > 0) {
+                int i;
+
+                for (i = 0; i < numEccBytes; i++) {
+                        if (readEccData[i] != 0xff) {
+                                /* errors cannot be fixed, return -1 */
+                                return -1;
+                        }
+                }
+                /* If ECC is unprogrammed then we can't correct,
+                 * assume everything OK */
+                return 0;
+        }
+
+        if ((regValue & REG_UMI_BCH_CTRL_STATUS_CORR_ERR) == 0) {
+                /* no errors */
+                return 0;
+        }
+
+        /*
+         * Fix errored bits by doing the following:
+         * 1. Read the number of errors in the control and status register
+         * 2. Read the error location registers that corresponds to the number
+         *    of errors reported
+         * 3. Invert the bit in the data
+         */
+        numErrors = (regValue & REG_UMI_BCH_CTRL_STATUS_NB_CORR_ERROR) >> 20;
+
+        for (idx = 0; idx < numErrors; idx++) {
+                errorLocation =
+                    REG_UMI_BCH_ERR_LOC_ADDR(idx) & REG_UMI_BCH_ERR_LOC_MASK;
+
+                /* Flip bit */
+                nand_bcm_umi_bch_ecc_flip_bit(datap, errorLocation);
+        }
+        /* Errors corrected */
+        return numErrors;
+}
+#endif