mmc: tegra: Program pad autocal offsets from dt

Parse the pad drive strength calibration offsets from the device tree.
Program the calibration offsets in accordance with the current signaling
mode.
Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-tegra.c

@@ -50,6 +50,7 @@
 #define SDHCI_TEGRA_AUTO_CAL_CONFIG			0x1e4
 #define SDHCI_AUTO_CAL_START				BIT(31)
 #define SDHCI_AUTO_CAL_ENABLE				BIT(29)
+#define SDHCI_AUTO_CAL_PDPU_OFFSET_MASK			0x0000ffff
 
 #define SDHCI_TEGRA_SDMEM_COMP_PADCTRL			0x1e0
 #define SDHCI_TEGRA_SDMEM_COMP_PADCTRL_VREF_SEL_MASK	0x0000000f
@@ -73,6 +74,22 @@ struct sdhci_tegra_soc_data {
 	u32 nvquirks;
 };
 
+/* Magic pull up and pull down pad calibration offsets */
+struct sdhci_tegra_autocal_offsets {
+	u32 pull_up_3v3;
+	u32 pull_down_3v3;
+	u32 pull_up_3v3_timeout;
+	u32 pull_down_3v3_timeout;
+	u32 pull_up_1v8;
+	u32 pull_down_1v8;
+	u32 pull_up_1v8_timeout;
+	u32 pull_down_1v8_timeout;
+	u32 pull_up_sdr104;
+	u32 pull_down_sdr104;
+	u32 pull_up_hs400;
+	u32 pull_down_hs400;
+};
+
 struct sdhci_tegra {
 	const struct sdhci_tegra_soc_data *soc_data;
 	struct gpio_desc *power_gpio;
@@ -84,6 +101,8 @@ struct sdhci_tegra {
 	struct pinctrl *pinctrl_sdmmc;
 	struct pinctrl_state *pinctrl_state_3v3;
 	struct pinctrl_state *pinctrl_state_1v8;
+
+	struct sdhci_tegra_autocal_offsets autocal_offsets;
 };
 
 static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
@@ -281,12 +300,45 @@ static bool tegra_sdhci_configure_card_clk(struct sdhci_host *host, bool enable)
 	return status;
 }
 
+static void tegra_sdhci_set_pad_autocal_offset(struct sdhci_host *host,
+					       u16 pdpu)
+{
+	u32 reg;
+
+	reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+	reg &= ~SDHCI_AUTO_CAL_PDPU_OFFSET_MASK;
+	reg |= pdpu;
+	sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+}
+
 static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
 {
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
+	struct sdhci_tegra_autocal_offsets offsets =
+			tegra_host->autocal_offsets;
+	struct mmc_ios *ios = &host->mmc->ios;
 	bool card_clk_enabled;
+	u16 pdpu;
 	u32 reg;
 	int ret;
 
+	switch (ios->timing) {
+	case MMC_TIMING_UHS_SDR104:
+		pdpu = offsets.pull_down_sdr104 << 8 | offsets.pull_up_sdr104;
+		break;
+	case MMC_TIMING_MMC_HS400:
+		pdpu = offsets.pull_down_hs400 << 8 | offsets.pull_up_hs400;
+		break;
+	default:
+		if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
+			pdpu = offsets.pull_down_1v8 << 8 | offsets.pull_up_1v8;
+		else
+			pdpu = offsets.pull_down_3v3 << 8 | offsets.pull_up_3v3;
+	}
+
+	tegra_sdhci_set_pad_autocal_offset(host, pdpu);
+
 	card_clk_enabled = tegra_sdhci_configure_card_clk(host, false);
 
 	tegra_sdhci_configure_cal_pad(host, true);
@@ -305,8 +357,104 @@ static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
 
 	tegra_sdhci_configure_card_clk(host, card_clk_enabled);
 
-	if (ret)
+	if (ret) {
 		dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n");
+
+		if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
+			pdpu = offsets.pull_down_1v8_timeout << 8 |
+			       offsets.pull_up_1v8_timeout;
+		else
+			pdpu = offsets.pull_down_3v3_timeout << 8 |
+			       offsets.pull_up_3v3_timeout;
+
+		/* Disable automatic calibration and use fixed offsets */
+		reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+		reg &= ~SDHCI_AUTO_CAL_ENABLE;
+		sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+
+		tegra_sdhci_set_pad_autocal_offset(host, pdpu);
+	}
+}
+
+static void tegra_sdhci_parse_pad_autocal_dt(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
+	struct sdhci_tegra_autocal_offsets *autocal =
+			&tegra_host->autocal_offsets;
+	int err;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-up-offset-3v3",
+			&autocal->pull_up_3v3);
+	if (err)
+		autocal->pull_up_3v3 = 0;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-down-offset-3v3",
+			&autocal->pull_down_3v3);
+	if (err)
+		autocal->pull_down_3v3 = 0;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-up-offset-1v8",
+			&autocal->pull_up_1v8);
+	if (err)
+		autocal->pull_up_1v8 = 0;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-down-offset-1v8",
+			&autocal->pull_down_1v8);
+	if (err)
+		autocal->pull_down_1v8 = 0;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-up-offset-3v3-timeout",
+			&autocal->pull_up_3v3);
+	if (err)
+		autocal->pull_up_3v3_timeout = 0;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-down-offset-3v3-timeout",
+			&autocal->pull_down_3v3);
+	if (err)
+		autocal->pull_down_3v3_timeout = 0;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-up-offset-1v8-timeout",
+			&autocal->pull_up_1v8);
+	if (err)
+		autocal->pull_up_1v8_timeout = 0;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-down-offset-1v8-timeout",
+			&autocal->pull_down_1v8);
+	if (err)
+		autocal->pull_down_1v8_timeout = 0;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-up-offset-sdr104",
+			&autocal->pull_up_sdr104);
+	if (err)
+		autocal->pull_up_sdr104 = autocal->pull_up_1v8;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-down-offset-sdr104",
+			&autocal->pull_down_sdr104);
+	if (err)
+		autocal->pull_down_sdr104 = autocal->pull_down_1v8;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-up-offset-hs400",
+			&autocal->pull_up_hs400);
+	if (err)
+		autocal->pull_up_hs400 = autocal->pull_up_1v8;
+
+	err = device_property_read_u32(host->mmc->parent,
+			"nvidia,pad-autocal-pull-down-offset-hs400",
+			&autocal->pull_down_hs400);
+	if (err)
+		autocal->pull_down_hs400 = autocal->pull_down_1v8;
 }
 
 static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
@@ -698,6 +846,8 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
 	if (tegra_host->soc_data->nvquirks & NVQUIRK_ENABLE_DDR50)
 		host->mmc->caps |= MMC_CAP_1_8V_DDR;
 
+	tegra_sdhci_parse_pad_autocal_dt(host);
+
 	tegra_host->power_gpio = devm_gpiod_get_optional(&pdev->dev, "power",
 							 GPIOD_OUT_HIGH);
 	if (IS_ERR(tegra_host->power_gpio)) {