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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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