From dfc9700cef771fbafd654c93327d930585b9e44c Mon Sep 17 00:00:00 2001 From: Aapo Vienamo Date: Fri, 10 Aug 2018 21:14:00 +0300 Subject: [PATCH] mmc: tegra: Implement HS400 enhanced strobe Implement eMMC HS400 enhanced strobe. Enhanced strobe is an alternative mechanism to the HS400 tuning procedure. Signed-off-by: Aapo Vienamo Acked-by: Adrian Hunter Acked-by: Thierry Reding Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci-tegra.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c index b102edc..a3f4452 100644 --- a/drivers/mmc/host/sdhci-tegra.c +++ b/drivers/mmc/host/sdhci-tegra.c @@ -43,6 +43,9 @@ #define SDHCI_CLOCK_CTRL_PADPIPE_CLKEN_OVERRIDE BIT(3) #define SDHCI_CLOCK_CTRL_SPI_MODE_CLKEN_OVERRIDE BIT(2) +#define SDHCI_TEGRA_VENDOR_SYS_SW_CTRL 0x104 +#define SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE BIT(31) + #define SDHCI_TEGRA_VENDOR_CAP_OVERRIDES 0x10c #define SDHCI_TEGRA_CAP_OVERRIDES_DQS_TRIM_MASK 0x00003f00 #define SDHCI_TEGRA_CAP_OVERRIDES_DQS_TRIM_SHIFT 8 @@ -294,6 +297,23 @@ static void tegra_sdhci_set_tap(struct sdhci_host *host, unsigned int tap) } } +static void tegra_sdhci_hs400_enhanced_strobe(struct mmc_host *mmc, + struct mmc_ios *ios) +{ + struct sdhci_host *host = mmc_priv(mmc); + u32 val; + + val = sdhci_readl(host, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL); + + if (ios->enhanced_strobe) + val |= SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE; + else + val &= ~SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE; + + sdhci_writel(host, val, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL); + +} + static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); @@ -996,6 +1016,9 @@ static int sdhci_tegra_probe(struct platform_device *pdev) sdhci_tegra_start_signal_voltage_switch; } + host->mmc_host_ops.hs400_enhanced_strobe = + tegra_sdhci_hs400_enhanced_strobe; + rc = mmc_of_parse(host->mmc); if (rc) goto err_parse_dt; -- 2.7.4