Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756302Ab2JCOxw (ORCPT ); Wed, 3 Oct 2012 10:53:52 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:41339 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753764Ab2JCOxv (ORCPT ); Wed, 3 Oct 2012 10:53:51 -0400 From: "Philip, Avinash" To: , , CC: , , , , , , , , "Philip, Avinash" Subject: [PATCH 3/4] ARM: OMAP2: gpmc: Add support for BCH ECC scheme Date: Wed, 3 Oct 2012 19:59:48 +0530 Message-ID: <1349274589-11389-4-git-send-email-avinashphilip@ti.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1349274589-11389-1-git-send-email-avinashphilip@ti.com> References: <1349274589-11389-1-git-send-email-avinashphilip@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7397 Lines: 208 Add support for BCH ECC scheme to gpmc driver and also enabling multi sector read/write. This helps in doing single shot NAND page read and write. ECC engine configurations BCH 4 bit support 1. write => ECC engine configured in wrap mode 6 and with ecc_size0 as 32. 2. read => ECC engine configured in wrap mode 1 and with ecc_size0 as 13 and ecc_size1 as 1. BCH 8 bit support 1. write => ECC engine configured in wrap mode 6 and with ecc_size0 as 32. 2. read => ECC engine configured in wrap mode 1 and with ecc_size0 as 26 and ecc_size1 as 2. Note: For BCH8 ECC bytes set to 14 to make compatible with RBL. Signed-off-by: Philip, Avinash --- :100644 100644 72428bd... c9bc3cf... M arch/arm/mach-omap2/gpmc.c :100644 100644 2e6e259... c916510... M arch/arm/plat-omap/include/plat/gpmc.h arch/arm/mach-omap2/gpmc.c | 120 +++++++++++++++++++++++++++++--- arch/arm/plat-omap/include/plat/gpmc.h | 1 + 2 files changed, 112 insertions(+), 9 deletions(-) diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index 72428bd..c9bc3cf 100644 --- a/arch/arm/mach-omap2/gpmc.c +++ b/arch/arm/mach-omap2/gpmc.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -83,6 +84,18 @@ #define ENABLE_PREFETCH (0x1 << 7) #define DMA_MPU_MODE 2 +/* GPMC ecc engine settings for read */ +#define BCH_WRAPMODE_1 1 /* BCH wrap mode 6 */ +#define BCH8R_ECC_SIZE0 0x1a /* ecc_size0 = 26 */ +#define BCH8R_ECC_SIZE1 0x2 /* ecc_size1 = 2 */ +#define BCH4R_ECC_SIZE0 0xd /* ecc_size0 = 13 */ +#define BCH4R_ECC_SIZE1 0x1 /* ecc_size1 = 1 4bit padding in BCH4 */ + +/* GPMC ecc engine settings for write */ +#define BCH_WRAPMODE_6 6 /* BCH wrap mode 6 */ +#define BCH_ECC_SIZE0 0x0 /* ecc_size0 = 0, no oob protection */ +#define BCH_ECC_SIZE1 0x20 /* ecc_size1 = 32 */ + /* XXX: Only NAND irq has been considered,currently these are the only ones used */ #define GPMC_NR_IRQ 2 @@ -1119,7 +1132,8 @@ EXPORT_SYMBOL_GPL(gpmc_init_hwecc_bch); int gpmc_enable_hwecc_bch(int cs, int mode, int dev_width, int nsectors, int nerrors) { - unsigned int val; + unsigned int val, wr_mode; + unsigned int ecc_size1, ecc_size0; /* check if ecc module is in use */ if (gpmc_ecc_used != -EINVAL) @@ -1130,18 +1144,35 @@ int gpmc_enable_hwecc_bch(int cs, int mode, int dev_width, int nsectors, /* clear ecc and enable bits */ gpmc_write_reg(GPMC_ECC_CONTROL, 0x1); - /* - * When using BCH, sector size is hardcoded to 512 bytes. - * Here we are using wrapping mode 6 both for reading and writing, with: - * size0 = 0 (no additional protected byte in spare area) - * size1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area) - */ - gpmc_write_reg(GPMC_ECC_SIZE_CONFIG, (32 << 22) | (0 << 12)); + /* When using BCH, sector size is hard coded to 512 bytes. */ + if ((mode == NAND_ECC_READ) && (nsectors != 1)) { + /* + * Here we are using wrapping mode 1 for reading, for + * supporting multi sector reading. + * Read mode, ECC engine enabled for valid ecc_size0 nibbles + * & disabled for ecc_size1 nibbles. + */ + ecc_size0 = (nerrors == 8) ? BCH8R_ECC_SIZE0 : BCH4R_ECC_SIZE0; + ecc_size1 = (nerrors == 8) ? BCH8R_ECC_SIZE1 : BCH4R_ECC_SIZE1; + wr_mode = BCH_WRAPMODE_1; + } else { + /* + * Here we are using wrapping mode 6 for writing, + * ECC engine enabled for valid ecc_size0 nibbles + * & disabled for ecc_size1 nibbles. + */ + ecc_size0 = BCH_ECC_SIZE0; + ecc_size1 = BCH_ECC_SIZE1; + wr_mode = BCH_WRAPMODE_6; + } + + gpmc_write_reg(GPMC_ECC_SIZE_CONFIG, (ecc_size1 << 22) | + (ecc_size0 << 12)); /* BCH configuration */ val = ((1 << 16) | /* enable BCH */ (((nerrors == 8) ? 1 : 0) << 12) | /* 8 or 4 bits */ - (0x06 << 8) | /* wrap mode = 6 */ + (wr_mode << 8) | /* wrap mode = 6 or 1 */ (dev_width << 7) | /* bus width */ (((nsectors-1) & 0x7) << 4) | /* number of sectors */ (cs << 1) | /* ECC CS */ @@ -1154,6 +1185,77 @@ int gpmc_enable_hwecc_bch(int cs, int mode, int dev_width, int nsectors, EXPORT_SYMBOL_GPL(gpmc_enable_hwecc_bch); /** + * gpmc_calculate_ecc_bch - Generate ecc bytes per block of 512 data bytes for entire page + * @cs: chip select number + * @dat: The pointer to data on which ECC is computed + * @ecc: The ECC output buffer + */ +int gpmc_calculate_ecc_bch(int cs, const u_char *dat, u_char *ecc) +{ + int i, eccbchtsel; + u32 nsectors, reg, bch_val1, bch_val2, bch_val3, bch_val4; + + if (gpmc_ecc_used != cs) + return -EINVAL; + + /* read number of sectors for ecc to be calculated */ + nsectors = ((gpmc_read_reg(GPMC_ECC_CONFIG) >> 4) & 0x7) + 1; + /* + * find BCH scheme used + * 0 -> BCH4 + * 1 -> BCH8 + */ + eccbchtsel = ((gpmc_read_reg(GPMC_ECC_CONFIG) >> 12) & 0x3); + + /* update ecc bytes for entire page */ + for (i = 0; i < nsectors; i++) { + + reg = GPMC_ECC_BCH_RESULT_0 + 16 * i; + + /* Read hw-computed remainder */ + bch_val1 = gpmc_read_reg(reg + 0); + bch_val2 = gpmc_read_reg(reg + 4); + if (eccbchtsel) { + bch_val3 = gpmc_read_reg(reg + 8); + bch_val4 = gpmc_read_reg(reg + 12); + } + + if (eccbchtsel) { + /* BCH8 ecc scheme */ + *ecc++ = (bch_val4 & 0xFF); + *ecc++ = ((bch_val3 >> 24) & 0xFF); + *ecc++ = ((bch_val3 >> 16) & 0xFF); + *ecc++ = ((bch_val3 >> 8) & 0xFF); + *ecc++ = (bch_val3 & 0xFF); + *ecc++ = ((bch_val2 >> 24) & 0xFF); + *ecc++ = ((bch_val2 >> 16) & 0xFF); + *ecc++ = ((bch_val2 >> 8) & 0xFF); + *ecc++ = (bch_val2 & 0xFF); + *ecc++ = ((bch_val1 >> 24) & 0xFF); + *ecc++ = ((bch_val1 >> 16) & 0xFF); + *ecc++ = ((bch_val1 >> 8) & 0xFF); + *ecc++ = (bch_val1 & 0xFF); + /* 14th byte of ecc not used */ + *ecc++ = 0; + } else { + /* BCH4 ecc scheme */ + *ecc++ = ((bch_val2 >> 12) & 0xFF); + *ecc++ = ((bch_val2 >> 4) & 0xFF); + *ecc++ = (((bch_val2 & 0xF) << 4) | + ((bch_val1 >> 28) & 0xF)); + *ecc++ = ((bch_val1 >> 20) & 0xFF); + *ecc++ = ((bch_val1 >> 12) & 0xFF); + *ecc++ = ((bch_val1 >> 4) & 0xFF); + *ecc++ = ((bch_val1 & 0xF) << 4); + } + } + + gpmc_ecc_used = -EINVAL; + return 0; +} +EXPORT_SYMBOL_GPL(gpmc_calculate_ecc_bch); + +/** * gpmc_calculate_ecc_bch4 - Generate 7 ecc bytes per sector of 512 data bytes * @cs: chip select number * @dat: The pointer to data on which ecc is computed diff --git a/arch/arm/plat-omap/include/plat/gpmc.h b/arch/arm/plat-omap/include/plat/gpmc.h index 2e6e259..c916510 100644 --- a/arch/arm/plat-omap/include/plat/gpmc.h +++ b/arch/arm/plat-omap/include/plat/gpmc.h @@ -185,6 +185,7 @@ int gpmc_enable_hwecc_bch(int cs, int mode, int dev_width, int nsectors, int nerrors); int gpmc_calculate_ecc_bch4(int cs, const u_char *dat, u_char *ecc); int gpmc_calculate_ecc_bch8(int cs, const u_char *dat, u_char *ecc); +int gpmc_calculate_ecc_bch(int cs, const u_char *dat, u_char *ecc); #endif /* CONFIG_ARCH_OMAP3 */ #endif -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/