From ac65caf514ec3e55e8d3d510ee37f80dd97418fe Mon Sep 17 00:00:00 2001 From: Pekon Gupta Date: Thu, 24 Oct 2013 18:20:17 +0530 Subject: ARM: OMAP2+: cleaned-up DT support of various ECC schemes OMAP NAND driver support multiple ECC scheme, which can used in different flavours, depending on in-build Hardware engines present on SoC. This patch updates following in DT bindings related to sectionion of ecc-schemes - ti,elm-id: replaces elm_id (maintains backward compatibility) - ti,nand-ecc-opts: selection of h/w or s/w implementation of an ecc-scheme depends on ti,elm-id. (supported values ham1, bch4, and bch8) - maintain backward compatibility to deprecated DT bindings (sw, hw, hw-romcode) Below table shows different flavours of ecc-schemes supported by OMAP devices +---------------------------------------+---------------+---------------+ | ECC scheme |ECC calculation|Error detection| +---------------------------------------+---------------+---------------+ |OMAP_ECC_HAM1_CODE_HW |H/W (GPMC) |S/W | +---------------------------------------+---------------+---------------+ |OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W | |(requires CONFIG_MTD_NAND_ECC_BCH) | | | +---------------------------------------+---------------+---------------+ |OMAP_ECC_BCH8_CODE_HW |H/W (GPMC) |H/W (ELM) | |(requires CONFIG_MTD_NAND_OMAP_BCH && | | | | ti,elm-id in DT) | | | +---------------------------------------+---------------+---------------+ To optimize footprint of omap2-nand driver, selection of some ECC schemes also require enabling following Kconfigs, in addition to setting appropriate DT bindings - Kconfig:CONFIG_MTD_NAND_ECC_BCH error detection done in software - Kconfig:CONFIG_MTD_NAND_OMAP_BCH error detection done by h/w engine Signed-off-by: Pekon Gupta Reviewed-by: Felipe Balbi Acked-by: Tony Lindgren Tested-by: Ezequiel Garcia Signed-off-by: Brian Norris --- arch/arm/mach-omap2/gpmc.c | 48 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 34 insertions(+), 14 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index 579697adaae..c877129142b 100644 --- a/arch/arm/mach-omap2/gpmc.c +++ b/arch/arm/mach-omap2/gpmc.c @@ -1341,14 +1341,6 @@ static void __maybe_unused gpmc_read_timings_dt(struct device_node *np, #ifdef CONFIG_MTD_NAND -static const char * const nand_ecc_opts[] = { - [OMAP_ECC_HAMMING_CODE_DEFAULT] = "sw", - [OMAP_ECC_HAMMING_CODE_HW] = "hw", - [OMAP_ECC_HAMMING_CODE_HW_ROMCODE] = "hw-romcode", - [OMAP_ECC_BCH4_CODE_HW] = "bch4", - [OMAP_ECC_BCH8_CODE_HW] = "bch8", -}; - static const char * const nand_xfer_types[] = { [NAND_OMAP_PREFETCH_POLLED] = "prefetch-polled", [NAND_OMAP_POLLED] = "polled", @@ -1378,13 +1370,41 @@ static int gpmc_probe_nand_child(struct platform_device *pdev, gpmc_nand_data->cs = val; gpmc_nand_data->of_node = child; - if (!of_property_read_string(child, "ti,nand-ecc-opt", &s)) - for (val = 0; val < ARRAY_SIZE(nand_ecc_opts); val++) - if (!strcasecmp(s, nand_ecc_opts[val])) { - gpmc_nand_data->ecc_opt = val; - break; - } + /* Detect availability of ELM module */ + gpmc_nand_data->elm_of_node = of_parse_phandle(child, "ti,elm-id", 0); + if (gpmc_nand_data->elm_of_node == NULL) + gpmc_nand_data->elm_of_node = + of_parse_phandle(child, "elm_id", 0); + if (gpmc_nand_data->elm_of_node == NULL) + pr_warn("%s: ti,elm-id property not found\n", __func__); + + /* select ecc-scheme for NAND */ + if (of_property_read_string(child, "ti,nand-ecc-opt", &s)) { + pr_err("%s: ti,nand-ecc-opt not found\n", __func__); + return -ENODEV; + } + if (!strcmp(s, "ham1") || !strcmp(s, "sw") || + !strcmp(s, "hw") || !strcmp(s, "hw-romcode")) + gpmc_nand_data->ecc_opt = + OMAP_ECC_HAM1_CODE_HW; + else if (!strcmp(s, "bch4")) + if (gpmc_nand_data->elm_of_node) + gpmc_nand_data->ecc_opt = + OMAP_ECC_BCH4_CODE_HW; + else + gpmc_nand_data->ecc_opt = + OMAP_ECC_BCH4_CODE_HW_DETECTION_SW; + else if (!strcmp(s, "bch8")) + if (gpmc_nand_data->elm_of_node) + gpmc_nand_data->ecc_opt = + OMAP_ECC_BCH8_CODE_HW; + else + gpmc_nand_data->ecc_opt = + OMAP_ECC_BCH8_CODE_HW_DETECTION_SW; + else + pr_err("%s: ti,nand-ecc-opt invalid value\n", __func__); + /* select data transfer mode for NAND controller */ if (!of_property_read_string(child, "ti,nand-xfer-type", &s)) for (val = 0; val < ARRAY_SIZE(nand_xfer_types); val++) if (!strcasecmp(s, nand_xfer_types[val])) { -- cgit v1.2.3 From c66d039197e42af8867e5d0d9b904daf0fb9e6bc Mon Sep 17 00:00:00 2001 From: Pekon Gupta Date: Thu, 24 Oct 2013 18:20:18 +0530 Subject: mtd: nand: omap: combine different flavours of 1-bit hamming ecc schemes OMAP NAND driver currently supports multiple flavours of 1-bit Hamming ecc-scheme, like: - OMAP_ECC_HAMMING_CODE_DEFAULT 1-bit hamming ecc code using software library - OMAP_ECC_HAMMING_CODE_HW 1-bit hamming ecc-code using GPMC h/w engine - OMAP_ECC_HAMMING_CODE_HW_ROMCODE 1-bit hamming ecc-code using GPMC h/w engin with ecc-layout compatible to ROM code. This patch combines above multiple ecc-schemes into single implementation: - OMAP_ECC_HAM1_CODE_HW 1-bit hamming ecc-code using GPMC h/w engine with ROM-code compatible ecc-layout. Signed-off-by: Pekon Gupta Reviewed-by: Felipe Balbi Acked-by: Tony Lindgren Tested-by: Ezequiel Garcia Signed-off-by: Brian Norris --- Documentation/devicetree/bindings/mtd/gpmc-nand.txt | 8 ++++---- arch/arm/mach-omap2/board-flash.c | 2 +- drivers/mtd/nand/omap2.c | 9 +++------ include/linux/platform_data/mtd-nand-omap2.h | 7 +------ 4 files changed, 9 insertions(+), 17 deletions(-) (limited to 'arch/arm') diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt index bfe07e15273..5e1f31b5ff7 100644 --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt +++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt @@ -22,10 +22,10 @@ Optional properties: width of 8 is assumed. - ti,nand-ecc-opt: A string setting the ECC layout to use. One of: - - "sw" Software method (default) - "hw" Hardware method - "hw-romcode" gpmc hamming mode method & romcode layout + "sw" use "ham1" instead + "hw" use "ham1" instead + "hw-romcode" use "ham1" instead + "ham1" 1-bit Hamming ecc code "bch4" 4-bit BCH ecc code "bch8" 8-bit BCH ecc code diff --git a/arch/arm/mach-omap2/board-flash.c b/arch/arm/mach-omap2/board-flash.c index fc20a61f6b2..ac82512b9c8 100644 --- a/arch/arm/mach-omap2/board-flash.c +++ b/arch/arm/mach-omap2/board-flash.c @@ -142,7 +142,7 @@ __init board_nand_init(struct mtd_partition *nand_parts, u8 nr_parts, u8 cs, board_nand_data.nr_parts = nr_parts; board_nand_data.devsize = nand_type; - board_nand_data.ecc_opt = OMAP_ECC_HAMMING_CODE_DEFAULT; + board_nand_data.ecc_opt = OMAP_ECC_BCH8_CODE_HW; gpmc_nand_init(&board_nand_data, gpmc_t); } #endif /* CONFIG_MTD_NAND_OMAP2 || CONFIG_MTD_NAND_OMAP2_MODULE */ diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 4ecf0e5fd48..8d521aa001c 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -1993,10 +1993,7 @@ static int omap_nand_probe(struct platform_device *pdev) } /* select the ecc type */ - if (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_DEFAULT) - info->nand.ecc.mode = NAND_ECC_SOFT; - else if ((pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW) || - (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW_ROMCODE)) { + if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) { info->nand.ecc.bytes = 3; info->nand.ecc.size = 512; info->nand.ecc.strength = 1; @@ -2025,7 +2022,7 @@ static int omap_nand_probe(struct platform_device *pdev) } /* rom code layout */ - if (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW_ROMCODE) { + if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) { if (info->nand.options & NAND_BUSWIDTH_16) offset = 2; @@ -2033,7 +2030,7 @@ static int omap_nand_probe(struct platform_device *pdev) offset = 1; info->nand.badblock_pattern = &bb_descrip_flashbased; } - omap_oobinfo.eccbytes = 3 * (info->mtd.oobsize/16); + omap_oobinfo.eccbytes = 3 * (info->mtd.writesize / 512); for (i = 0; i < omap_oobinfo.eccbytes; i++) omap_oobinfo.eccpos[i] = i+offset; diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h index e4128f1510b..4da5bfa2147 100644 --- a/include/linux/platform_data/mtd-nand-omap2.h +++ b/include/linux/platform_data/mtd-nand-omap2.h @@ -23,13 +23,8 @@ enum nand_io { }; enum omap_ecc { - /* 1-bit ecc: stored at end of spare area */ - OMAP_ECC_HAMMING_CODE_DEFAULT = 0, /* Default, s/w method */ - OMAP_ECC_HAMMING_CODE_HW, /* gpmc to detect the error */ - /* 1-bit ecc: stored at beginning of spare area as romcode */ - OMAP_ECC_HAMMING_CODE_HW_ROMCODE, /* gpmc method & romcode layout */ /* 1-bit ECC calculation by GPMC, Error detection by Software */ - OMAP_ECC_HAM1_CODE_HW, + OMAP_ECC_HAM1_CODE_HW = 0, /* 4-bit ECC calculation by GPMC, Error detection by Software */ OMAP_ECC_BCH4_CODE_HW_DETECTION_SW, /* 4-bit ECC calculation by GPMC, Error detection by ELM */ -- cgit v1.2.3