From 266dead21675aeb89407b1213788cd924353d5e1 Mon Sep 17 00:00:00 2001 From: "Leo (Hao) Chen" Date: Fri, 9 Oct 2009 19:13:08 -0700 Subject: mtd: add bcmring nand driver Signed-off-by: Leo Hao Chen Signed-off-by: David Woodhouse --- drivers/mtd/nand/nand_bcm_umi.c | 149 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 149 insertions(+) create mode 100644 drivers/mtd/nand/nand_bcm_umi.c (limited to 'drivers/mtd/nand/nand_bcm_umi.c') 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 +#include "nand_bcm_umi.h" +#ifdef BOOT0_BUILD +#include +#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 -- cgit v1.2.3