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/mach-omap2') diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index 579697adaae7..c877129142ba 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 v1.2.2