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-rw-r--r--drivers/mtd/nand/nand_bcm_umi.c149
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
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--- /dev/null
+++ b/drivers/mtd/nand/nand_bcm_umi.c
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+/*****************************************************************************
+* 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
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