[V1,2/2] mmc: tegra: SDMMC pads auto-calibration

Message ID 1545160787-3157-2-git-send-email-skomatineni@nvidia.com
State New
Headers show
Series
  • [V1,1/2] arm64: dts: tegra210: Add SDMMC Auto-cal settings
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Commit Message

Sowjanya Komatineni Dec. 18, 2018, 7:19 p.m.
Programs initial drive code offsets which will be used by auto
calibration process.

Programs fixed drive strengths for SDMMC pads when auto cal
timeouts. Fixed settings are based on Pre-SI analysis of the
pad design.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
 drivers/mmc/host/sdhci-tegra.c | 112 ++++++++++++++++++++++++++++++-----------
 1 file changed, 84 insertions(+), 28 deletions(-)

Comments

Ulf Hansson Dec. 19, 2018, 11:39 a.m. | #1
[...]

>         if (tegra_host->pad_calib_required)
> @@ -805,8 +854,15 @@ static int tegra_sdhci_init_pinctrl_info(struct device *dev,
>                 return -1;
>         }
>
> -       tegra_host->pinctrl_state_3v3 =
> -               pinctrl_lookup_state(tegra_host->pinctrl_sdmmc, "sdmmc-3v3");
> +       tegra_host->pinctrl_state_1v8_drv = pinctrl_lookup_state(
> +                               tegra_host->pinctrl_sdmmc, "sdmmc-1v8-drv");

This requires and updated DT doc for tegra sdhci. Please make that a
separate patch and put it first in the series. Also don't forget to
include the DT maintainers in the to field for that patch.

> +
> +       tegra_host->pinctrl_state_3v3_drv = pinctrl_lookup_state(
> +                               tegra_host->pinctrl_sdmmc, "sdmmc-3v3-drv");

Ditto.

> +
> +       tegra_host->pinctrl_state_3v3 = pinctrl_lookup_state(
> +                               tegra_host->pinctrl_sdmmc, "sdmmc-3v3");
> +

The above looks like an unnecessary line change. Please just stick to
the existing format and avoid changing code that doesn't need to be
changed.

>         if (IS_ERR(tegra_host->pinctrl_state_3v3)) {
>                 dev_warn(dev, "Missing 3.3V pad state, err: %ld\n",
>                          PTR_ERR(tegra_host->pinctrl_state_3v3));
> --
> 2.7.4
>

Kind regards
Uffe

Patch

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 7b95d088fdef..2524654282d1 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -75,6 +75,7 @@ 
 #define SDHCI_TEGRA_SDMEM_COMP_PADCTRL_VREF_SEL_MASK	0x0000000f
 #define SDHCI_TEGRA_SDMEM_COMP_PADCTRL_VREF_SEL_VAL	0x7
 #define SDHCI_TEGRA_SDMEM_COMP_PADCTRL_E_INPUT_E_PWRD	BIT(31)
+#define SDHCI_COMP_PADCTRL_DRVUPDN_OFFSET_MASK		0x07FFF000
 
 #define SDHCI_TEGRA_AUTO_CAL_STATUS			0x1ec
 #define SDHCI_TEGRA_AUTO_CAL_ACTIVE			BIT(31)
@@ -121,6 +122,8 @@  struct sdhci_tegra {
 	struct pinctrl *pinctrl_sdmmc;
 	struct pinctrl_state *pinctrl_state_3v3;
 	struct pinctrl_state *pinctrl_state_1v8;
+	struct pinctrl_state *pinctrl_state_3v3_drv;
+	struct pinctrl_state *pinctrl_state_1v8_drv;
 
 	struct sdhci_tegra_autocal_offsets autocal_offsets;
 	ktime_t last_calib;
@@ -130,6 +133,9 @@  struct sdhci_tegra {
 	u32 dqs_trim;
 };
 
+static int tegra_sdhci_set_padctrl(struct sdhci_host *host, int voltage,
+							bool state_drvupdn);
+
 static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -437,6 +443,7 @@  static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
 			pdpu = offsets.pull_down_3v3 << 8 | offsets.pull_up_3v3;
 	}
 
+	/* Set initial offset before auto-calibration */
 	tegra_sdhci_set_pad_autocal_offset(host, pdpu);
 
 	card_clk_enabled = tegra_sdhci_configure_card_clk(host, false);
@@ -460,19 +467,15 @@  static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
 	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 */
+		/* Disable automatic cal and use fixed Drive Strengths */
 		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);
+		ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage, false);
+		if (ret < 0)
+			dev_err(mmc_dev(host->mmc),
+			"Setting drive strengths failed %d\n", PTR_ERR(ret));
 	}
 }
 
@@ -743,27 +746,73 @@  static int tegra_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
 	return mmc_send_tuning(host->mmc, opcode, NULL);
 }
 
-static int tegra_sdhci_set_padctrl(struct sdhci_host *host, int voltage)
+static int tegra_sdhci_set_padctrl(struct sdhci_host *host, int voltage,
+							bool state_drvupdn)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
-	int ret;
+	struct sdhci_tegra_autocal_offsets offsets =
+					tegra_host->autocal_offsets;
+	struct pinctrl_state *pinctrl_drvupdn = NULL;
+	int ret = 0;
+	u8 drvup = 0, drvdn = 0;
+	u32 reg;
 
-	if (!tegra_host->pad_control_available)
-		return 0;
+	if (!state_drvupdn) {
+		/* PADS Drive Strength */
+		if (voltage == MMC_SIGNAL_VOLTAGE_180) {
+			if (!IS_ERR(tegra_host->pinctrl_state_1v8_drv) &&
+				(tegra_host->pinctrl_state_1v8_drv != NULL)) {
+				pinctrl_drvupdn =
+					tegra_host->pinctrl_state_1v8_drv;
+			} else {
+				drvup = offsets.pull_up_1v8_timeout;
+				drvdn = offsets.pull_down_1v8_timeout;
+			}
+		} else {
+			if (!IS_ERR(tegra_host->pinctrl_state_3v3_drv) &&
+				(tegra_host->pinctrl_state_3v3_drv != NULL)) {
+				pinctrl_drvupdn =
+					tegra_host->pinctrl_state_3v3_drv;
+			} else {
+				drvup = offsets.pull_up_3v3_timeout;
+				drvdn = offsets.pull_down_3v3_timeout;
+			}
+		}
+
+		if (pinctrl_drvupdn != NULL) {
+			ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
+							pinctrl_drvupdn);
+			if (ret < 0)
+				dev_err(mmc_dev(host->mmc),
+					"failed pads drvupdn, ret: %d\n", ret);
+		} else if ((drvup) || (drvdn)) {
+			reg = sdhci_readl(host,
+					SDHCI_TEGRA_SDMEM_COMP_PADCTRL);
+			reg &= ~SDHCI_COMP_PADCTRL_DRVUPDN_OFFSET_MASK;
+			reg |= (drvup << 20) | (drvdn << 12);
+			sdhci_writel(host, reg,
+					SDHCI_TEGRA_SDMEM_COMP_PADCTRL);
+		}
 
-	if (voltage == MMC_SIGNAL_VOLTAGE_180) {
-		ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
-					   tegra_host->pinctrl_state_1v8);
-		if (ret < 0)
-			dev_err(mmc_dev(host->mmc),
-				"setting 1.8V failed, ret: %d\n", ret);
 	} else {
-		ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
-					   tegra_host->pinctrl_state_3v3);
-		if (ret < 0)
-			dev_err(mmc_dev(host->mmc),
-				"setting 3.3V failed, ret: %d\n", ret);
+		/* Dual Voltage PADS Voltage selection */
+		if (!tegra_host->pad_control_available)
+			return 0;
+
+		if (voltage == MMC_SIGNAL_VOLTAGE_180) {
+			ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
+						tegra_host->pinctrl_state_1v8);
+			if (ret < 0)
+				dev_err(mmc_dev(host->mmc),
+					"setting 1.8V failed, ret: %d\n", ret);
+		} else {
+			ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
+						tegra_host->pinctrl_state_3v3);
+			if (ret < 0)
+				dev_err(mmc_dev(host->mmc),
+					"setting 3.3V failed, ret: %d\n", ret);
+		}
 	}
 
 	return ret;
@@ -778,7 +827,7 @@  static int sdhci_tegra_start_signal_voltage_switch(struct mmc_host *mmc,
 	int ret = 0;
 
 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
-		ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage);
+		ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage, true);
 		if (ret < 0)
 			return ret;
 		ret = sdhci_start_signal_voltage_switch(mmc, ios);
@@ -786,7 +835,7 @@  static int sdhci_tegra_start_signal_voltage_switch(struct mmc_host *mmc,
 		ret = sdhci_start_signal_voltage_switch(mmc, ios);
 		if (ret < 0)
 			return ret;
-		ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage);
+		ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage, true);
 	}
 
 	if (tegra_host->pad_calib_required)
@@ -805,8 +854,15 @@  static int tegra_sdhci_init_pinctrl_info(struct device *dev,
 		return -1;
 	}
 
-	tegra_host->pinctrl_state_3v3 =
-		pinctrl_lookup_state(tegra_host->pinctrl_sdmmc, "sdmmc-3v3");
+	tegra_host->pinctrl_state_1v8_drv = pinctrl_lookup_state(
+				tegra_host->pinctrl_sdmmc, "sdmmc-1v8-drv");
+
+	tegra_host->pinctrl_state_3v3_drv = pinctrl_lookup_state(
+				tegra_host->pinctrl_sdmmc, "sdmmc-3v3-drv");
+
+	tegra_host->pinctrl_state_3v3 = pinctrl_lookup_state(
+				tegra_host->pinctrl_sdmmc, "sdmmc-3v3");
+
 	if (IS_ERR(tegra_host->pinctrl_state_3v3)) {
 		dev_warn(dev, "Missing 3.3V pad state, err: %ld\n",
 			 PTR_ERR(tegra_host->pinctrl_state_3v3));