From af51079e68d4759e458b0592df5d1fab373c43ae Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Mon, 21 Jan 2013 19:02:28 +0800 Subject: [PATCH] mmc: sdhci-esdhc-imx: support 8bit mode The i.MX esdhc has a nonstandard bit layout for the SDHCI_HOST_CONTROL register. To support 8bit bus width on i.MX populate the platform_bus_width callback. This is tested on an i.MX25, but should according to the datasheets work on the other i.MX using this hardware aswell. The i.MX6, while having a SDHCI_SPEC_300 controller, still uses the same nonstandard register layout. Signed-off-by: Sascha Hauer Signed-off-by: Shawn Guo Tested-by: Dirk Behme Signed-off-by: Chris Ball --- drivers/mmc/host/sdhci-esdhc-imx.c | 56 ++++++++++++++++++++- include/linux/platform_data/mmc-esdhc-imx.h | 1 + 2 files changed, 55 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 24daaf4e20ba..f7ee5e67516c 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -40,6 +40,13 @@ /* Bits 3 and 6 are not SDHCI standard definitions */ #define ESDHC_MIX_CTRL_SDHCI_MASK 0xb7 +/* + * Our interpretation of the SDHCI_HOST_CONTROL register + */ +#define ESDHC_CTRL_4BITBUS (0x1 << 1) +#define ESDHC_CTRL_8BITBUS (0x2 << 1) +#define ESDHC_CTRL_BUSWIDTH_MASK (0x3 << 1) + /* * There is an INT DMA ERR mis-match between eSDHC and STD SDHC SPEC: * Bit25 is used in STD SPEC, and is reserved in fsl eSDHC design, @@ -294,6 +301,7 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg) struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct pltfm_imx_data *imx_data = pltfm_host->priv; u32 new_val; + u32 mask; switch (reg) { case SDHCI_POWER_CONTROL: @@ -304,7 +312,7 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg) return; case SDHCI_HOST_CONTROL: /* FSL messed up here, so we need to manually compose it. */ - new_val = val & (SDHCI_CTRL_LED | SDHCI_CTRL_4BITBUS); + new_val = val & SDHCI_CTRL_LED; /* ensure the endianness */ new_val |= ESDHC_HOST_CONTROL_LE; /* bits 8&9 are reserved on mx25 */ @@ -313,7 +321,13 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg) new_val |= (val & SDHCI_CTRL_DMA_MASK) << 5; } - esdhc_clrset_le(host, 0xffff, new_val, reg); + /* + * Do not touch buswidth bits here. This is done in + * esdhc_pltfm_bus_width. + */ + mask = 0xffff & ~ESDHC_CTRL_BUSWIDTH_MASK; + + esdhc_clrset_le(host, mask, new_val, reg); return; } esdhc_clrset_le(host, 0xff, val, reg); @@ -370,6 +384,28 @@ static unsigned int esdhc_pltfm_get_ro(struct sdhci_host *host) return -ENOSYS; } +static int esdhc_pltfm_bus_width(struct sdhci_host *host, int width) +{ + u32 ctrl; + + switch (width) { + case MMC_BUS_WIDTH_8: + ctrl = ESDHC_CTRL_8BITBUS; + break; + case MMC_BUS_WIDTH_4: + ctrl = ESDHC_CTRL_4BITBUS; + break; + default: + ctrl = 0; + break; + } + + esdhc_clrset_le(host, ESDHC_CTRL_BUSWIDTH_MASK, ctrl, + SDHCI_HOST_CONTROL); + + return 0; +} + static struct sdhci_ops sdhci_esdhc_ops = { .read_l = esdhc_readl_le, .read_w = esdhc_readw_le, @@ -380,6 +416,7 @@ static struct sdhci_ops sdhci_esdhc_ops = { .get_max_clock = esdhc_pltfm_get_max_clock, .get_min_clock = esdhc_pltfm_get_min_clock, .get_ro = esdhc_pltfm_get_ro, + .platform_bus_width = esdhc_pltfm_bus_width, }; static struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = { @@ -417,6 +454,8 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev, if (gpio_is_valid(boarddata->wp_gpio)) boarddata->wp_type = ESDHC_WP_GPIO; + of_property_read_u32(np, "bus-width", &boarddata->max_bus_width); + return 0; } #else @@ -548,6 +587,19 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev) break; } + switch (boarddata->max_bus_width) { + case 8: + host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA; + break; + case 4: + host->mmc->caps |= MMC_CAP_4_BIT_DATA; + break; + case 1: + default: + host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA; + break; + } + err = sdhci_add_host(host); if (err) goto disable_clk; diff --git a/include/linux/platform_data/mmc-esdhc-imx.h b/include/linux/platform_data/mmc-esdhc-imx.h index aaf97481f413..b4a0521ce411 100644 --- a/include/linux/platform_data/mmc-esdhc-imx.h +++ b/include/linux/platform_data/mmc-esdhc-imx.h @@ -39,5 +39,6 @@ struct esdhc_platform_data { unsigned int cd_gpio; enum wp_types wp_type; enum cd_types cd_type; + int max_bus_width; }; #endif /* __ASM_ARCH_IMX_ESDHC_H */ -- 2.30.2