Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753402AbcKZSJC (ORCPT ); Sat, 26 Nov 2016 13:09:02 -0500 Received: from conuserg-11.nifty.com ([210.131.2.78]:48025 "EHLO conuserg-11.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753152AbcKZSIP (ORCPT ); Sat, 26 Nov 2016 13:08:15 -0500 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-11.nifty.com uAQI6Uen018512 X-Nifty-SrcIP: [111.169.71.157] From: Masahiro Yamada To: linux-mtd@lists.infradead.org Cc: Masahiro Yamada , linux-kernel@vger.kernel.org, Boris Brezillon , Marek Vasut , Brian Norris , Richard Weinberger , David Woodhouse , Cyrille Pitchen Subject: [PATCH 17/39] mtd: nand: denali: support HW_ECC_FIXUP capability Date: Sun, 27 Nov 2016 03:06:03 +0900 Message-Id: <1480183585-592-18-git-send-email-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1480183585-592-1-git-send-email-yamada.masahiro@socionext.com> References: <1480183585-592-1-git-send-email-yamada.masahiro@socionext.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5581 Lines: 168 Some old versions of the Denali IP (perhaps used only for Intel?) detects ECC errors and provides correct data via a register, but does not touch the transferred data. So, the software must fixup the data in the buffer according to the provided ECC correction information. Newer versions perform ECC correction before transferring the data. No more software intervention is needed. The ECC_ERROR_ADDRESS and ECC_CORRECTION_INFO registers were deprecated. Instead, the number of corrected bit-flips can be read from the ECC_COR_INFO register. When an uncorrectable ECC error happens, a status flag is set to the INTR_STATUS and ECC_COR_INFO registers. As is often the case with this IP, the register view of INTR_STATUS had broken compatibility. For older versions (SW ECC fixup): bit 0: ECC_TRANSACTION_DONE bit 1: ECC_ERR For newer versions (HW ECC fixup): bit 0: ECC_UNCOR_ERR bit 1: Reserved Due to this difference, the irq_mask must be fixed too. The comment block in the denali_sw_ecc_fixup() has been moved to the common part because the comment applies to both cases. The U-Boot port of this driver already supports the HW ECC fixup. I borrowed the comment "Some versions of ..." in denali.h from U-Boot. Signed-off-by: Masahiro Yamada --- drivers/mtd/nand/denali.c | 44 ++++++++++++++++++++++++++++++++++---------- drivers/mtd/nand/denali.h | 14 ++++++++++++++ 2 files changed, 48 insertions(+), 10 deletions(-) diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c index 271b41a..c101e7f 100644 --- a/drivers/mtd/nand/denali.c +++ b/drivers/mtd/nand/denali.c @@ -894,6 +894,25 @@ static bool is_erased(u8 *buf, int len) return false; return true; } + +static bool denali_hw_ecc_fixup(struct denali_nand_info *denali, + unsigned int *max_bitflips) +{ + int bank = denali->flash_bank; + u32 ecc_cor; + + ecc_cor = ioread32(denali->flash_reg + ECC_COR_INFO(bank)); + ecc_cor >>= ECC_COR_INFO_SHIFT(bank); + + if (ecc_cor & ECC_COR_INFO__UNCOR_ERR) { + *max_bitflips = 0; + return true; + } + + *max_bitflips = ecc_cor & ECC_COR_INFO__MAX_ERRORS; + return false; +} + #define ECC_SECTOR_SIZE 512 #define ECC_SECTOR(x) (((x) & ECC_ERROR_ADDRESS__SECTOR_NR) >> 12) @@ -949,11 +968,6 @@ static bool denali_sw_ecc_fixup(struct denali_nand_info *denali, u8 *buf, bitflips++; } } else { - /* - * if the error is not correctable, need to look at the - * page to see if it is an erased page. if so, then - * it's not a real ECC error - */ check_erased_page = true; } } while (!ECC_LAST_ERR(err_correction_info)); @@ -1109,12 +1123,12 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip, { unsigned int max_bitflips; struct denali_nand_info *denali = mtd_to_denali(mtd); - dma_addr_t addr = denali->buf.dma_buf; size_t size = mtd->writesize + mtd->oobsize; - u32 irq_status; - u32 irq_mask = INTR_STATUS__ECC_TRANSACTION_DONE | INTR_STATUS__ECC_ERR; + u32 irq_mask = denali->caps & DENALI_CAPS_HW_ECC_FIXUP ? + INTR_STATUS__DMA_CMD_COMP | INTR_STATUS__ECC_UNCOR_ERR : + INTR_STATUS__ECC_TRANSACTION_DONE | INTR_STATUS__ECC_ERR; bool check_erased_page = false; if (page != denali->page) { @@ -1139,11 +1153,21 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip, memcpy(buf, denali->buf.buf, mtd->writesize); - check_erased_page = denali_sw_ecc_fixup(denali, buf, irq_status, - &max_bitflips); + if (denali->caps & DENALI_CAPS_HW_ECC_FIXUP) + check_erased_page = denali_hw_ecc_fixup(denali, &max_bitflips); + else + check_erased_page = denali_sw_ecc_fixup(denali, buf, irq_status, + &max_bitflips); + denali_enable_dma(denali, false); if (check_erased_page) { + /* + * If the error is not correctable, need to look at the page to + * see if it is an erased page. If so, then it's not a real ECC + * error. + */ + read_oob_data(mtd, chip->oob_poi, denali->page); /* check ECC failures that may have occurred on erased pages */ diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h index 69314d0..beadc8a 100644 --- a/drivers/mtd/nand/denali.h +++ b/drivers/mtd/nand/denali.h @@ -20,6 +20,7 @@ #ifndef __DENALI_H__ #define __DENALI_H__ +#include #include #define DEVICE_RESET 0x0 @@ -219,6 +220,13 @@ #define INTR_STATUS(__bank) (0x410 + ((__bank) * 0x50)) #define INTR_EN(__bank) (0x420 + ((__bank) * 0x50)) +/* + * Some versions of the IP have the ECC fixup handled in hardware. In this + * configuration we only get interrupted when the error is uncorrectable. + * Unfortunately this bit replaces INTR_STATUS__ECC_TRANSACTION_DONE from the + * old IP. + */ +#define INTR_STATUS__ECC_UNCOR_ERR 0x0001 #define INTR_STATUS__ECC_TRANSACTION_DONE 0x0001 #define INTR_STATUS__ECC_ERR 0x0002 #define INTR_STATUS__DMA_CMD_COMP 0x0004 @@ -297,6 +305,11 @@ #define ERR_CORRECTION_INFO__ERROR_TYPE 0x4000 #define ERR_CORRECTION_INFO__LAST_ERR_INFO 0x8000 +#define ECC_COR_INFO(__bank) (0x650 + (__bank) / 2 * 0x10) +#define ECC_COR_INFO_SHIFT(__bank) ((__bank) % 2 * 8) +#define ECC_COR_INFO__MAX_ERRORS 0x007f +#define ECC_COR_INFO__UNCOR_ERR 0x0080 + #define DMA_ENABLE 0x700 #define DMA_ENABLE__FLAG 0x0001 @@ -421,6 +434,7 @@ struct denali_nand_info { u32 bbtskipbytes; u32 max_banks; unsigned int caps; +#define DENALI_CAPS_HW_ECC_FIXUP BIT(0) }; extern int denali_init(struct denali_nand_info *denali); -- 2.7.4