[PATCH V3 1/3] dt-bindings: mmc: tegra: Add pinctrl for pad drive strength config

[PATCH V3 1/3] dt-bindings: mmc: tegra: Add pinctrl for pad drive strength config

[Sowjanya Komatineni]

Add pinctrl for 3V3 and 1V8 pad drive strength configuration for
Tegra210 sdmmc which has pad configuration registers in the pinmux
reigster domain.
Pad drive strengths for Tegra186 and Later are
part of SDMMC device node itself.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
 Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
index 32b4b4e41923..2cecdc71d94c 100644
--- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
+++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
@@ -39,12 +39,16 @@ sdhci@c8000200 {
 	bus-width = <8>;
 };
 
-Optional properties for Tegra210 and Tegra186:
+Optional properties for Tegra210, Tegra186 and Tegra194:
 - pinctrl-names, pinctrl-0, pinctrl-1 : Specify pad voltage
   configurations. Valid pinctrl-names are "sdmmc-3v3" and "sdmmc-1v8"
   for controllers supporting multiple voltage levels. The order of names
   should correspond to the pin configuration states in pinctrl-0 and
   pinctrl-1.
+- pinctrl-names : "sdmmc-3v3-drv" and "sdmmc-1v8-drv" are applicable for
+  Tegra210 where pad config registers are in the pinmux register domain
+  for pull-up-strength and pull-down-strength values configuration when
+  using pads at 3V3 and 1V8 levels.
 - nvidia,only-1-8-v : The presence of this property indicates that the
   controller operates at a 1.8 V fixed I/O voltage.
 - nvidia,pad-autocal-pull-up-offset-3v3,
-- 
2.7.4

[PATCH V3 2/3] arm64: dts: tegra: Add SDMMC Auto-cal settings

[Sowjanya Komatineni]

Add SDMMC initial pad offsets used by auto calibration process.

Add SDMMC fixed drive strengths for Tegra210 and above which are
used when calibration timeouts.
Fixed drive strengths are based on Pre SI Analysis of the pads.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
 arch/arm64/boot/dts/nvidia/tegra186.dtsi |  2 ++
 arch/arm64/boot/dts/nvidia/tegra194.dtsi | 34 +++++++++++++++++++
 arch/arm64/boot/dts/nvidia/tegra210.dtsi | 57 ++++++++++++++++++++++++++++++--
 3 files changed, 91 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/nvidia/tegra186.dtsi b/arch/arm64/boot/dts/nvidia/tegra186.dtsi
index 2f3c8e29520d..0631bb9bfcc3 100644
--- a/arch/arm64/boot/dts/nvidia/tegra186.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra186.dtsi
@@ -311,6 +311,8 @@
 		nvidia,pad-autocal-pull-down-offset-hs400 = <0x05>;
 		nvidia,pad-autocal-pull-up-offset-1v8-timeout = <0x0a>;
 		nvidia,pad-autocal-pull-down-offset-1v8-timeout = <0x0a>;
+		nvidia,pad-autocal-pull-up-offset-3v3-timeout = <0x0a>;
+		nvidia,pad-autocal-pull-down-offset-3v3-timeout = <0x0a>;
 		nvidia,default-tap = <0x5>;
 		nvidia,default-trim = <0x9>;
 		nvidia,dqs-trim = <63>;
diff --git a/arch/arm64/boot/dts/nvidia/tegra194.dtsi b/arch/arm64/boot/dts/nvidia/tegra194.dtsi
index c2091bb16546..3fab6802c335 100644
--- a/arch/arm64/boot/dts/nvidia/tegra194.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra194.dtsi
@@ -301,6 +301,17 @@
 			clock-names = "sdhci";
 			resets = <&bpmp TEGRA194_RESET_SDMMC1>;
 			reset-names = "sdhci";
+			nvidia,pad-autocal-pull-up-offset-3v3-timeout =
+									<0x07>;
+			nvidia,pad-autocal-pull-down-offset-3v3-timeout =
+									<0x07>;
+			nvidia,pad-autocal-pull-up-offset-1v8-timeout = <0x06>;
+			nvidia,pad-autocal-pull-down-offset-1v8-timeout =
+									<0x07>;
+			nvidia,pad-autocal-pull-up-offset-sdr104 = <0x00>;
+			nvidia,pad-autocal-pull-down-offset-sdr104 = <0x00>;
+			nvidia,default-tap = <0x9>;
+			nvidia,default-trim = <0x5>;
 			status = "disabled";
 		};
 
@@ -312,6 +323,18 @@
 			clock-names = "sdhci";
 			resets = <&bpmp TEGRA194_RESET_SDMMC3>;
 			reset-names = "sdhci";
+			nvidia,pad-autocal-pull-up-offset-1v8 = <0x00>;
+			nvidia,pad-autocal-pull-down-offset-1v8 = <0x7a>;
+			nvidia,pad-autocal-pull-up-offset-3v3-timeout = <0x07>;
+			nvidia,pad-autocal-pull-down-offset-3v3-timeout =
+									<0x07>;
+			nvidia,pad-autocal-pull-up-offset-1v8-timeout = <0x06>;
+			nvidia,pad-autocal-pull-down-offset-1v8-timeout =
+									<0x07>;
+			nvidia,pad-autocal-pull-up-offset-sdr104 = <0x00>;
+			nvidia,pad-autocal-pull-down-offset-sdr104 = <0x00>;
+			nvidia,default-tap = <0x9>;
+			nvidia,default-trim = <0x5>;
 			status = "disabled";
 		};
 
@@ -323,6 +346,17 @@
 			clock-names = "sdhci";
 			resets = <&bpmp TEGRA194_RESET_SDMMC4>;
 			reset-names = "sdhci";
+			nvidia,pad-autocal-pull-up-offset-hs400 = <0x00>;
+			nvidia,pad-autocal-pull-down-offset-hs400 = <0x00>;
+			nvidia,pad-autocal-pull-up-offset-1v8-timeout = <0x0a>;
+			nvidia,pad-autocal-pull-down-offset-1v8-timeout =
+									<0x0a>;
+			nvidia,pad-autocal-pull-up-offset-3v3-timeout = <0x0a>;
+			nvidia,pad-autocal-pull-down-offset-3v3-timeout =
+									<0x0a>;
+			nvidia,default-tap = <0x8>;
+			nvidia,default-trim = <0x14>;
+			nvidia,dqs-trim = <40>;
 			status = "disabled";
 		};
 
diff --git a/arch/arm64/boot/dts/nvidia/tegra210.dtsi b/arch/arm64/boot/dts/nvidia/tegra210.dtsi
index 2205d66b0443..41408df9d4e9 100644
--- a/arch/arm64/boot/dts/nvidia/tegra210.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra210.dtsi
@@ -476,6 +476,48 @@
 		compatible = "nvidia,tegra210-pinmux";
 		reg = <0x0 0x700008d4 0x0 0x29c>, /* Pad control registers */
 		      <0x0 0x70003000 0x0 0x294>; /* Mux registers */
+		sdmmc1_3v3_drv: sdmmc1-3v3-drv {
+			sdmmc1 {
+				nvidia,pins = "drive_sdmmc1";
+				nvidia,pull-down-strength = <0x8>;
+				nvidia,pull-up-strength = <0x8>;
+			};
+		};
+		sdmmc1_1v8_drv: sdmmc1-1v8-drv {
+			sdmmc1 {
+				nvidia,pins = "drive_sdmmc1";
+				nvidia,pull-down-strength = <0x4>;
+				nvidia,pull-up-strength = <0x3>;
+			};
+		};
+		sdmmc2_1v8_drv: sdmmc2-1v8-drv {
+			sdmmc2 {
+				nvidia,pins = "drive_sdmmc2";
+				nvidia,pull-down-strength = <0x10>;
+				nvidia,pull-up-strength = <0x10>;
+			};
+		};
+		sdmmc3_3v3_drv: sdmmc3-3v3-drv {
+			sdmmc3 {
+				nvidia,pins = "drive_sdmmc3";
+				nvidia,pull-down-strength = <0x8>;
+				nvidia,pull-up-strength = <0x8>;
+			};
+		};
+		sdmmc3_1v8_drv: sdmmc3-1v8-drv {
+			sdmmc3 {
+				nvidia,pins = "drive_sdmmc3";
+				nvidia,pull-down-strength = <0x4>;
+				nvidia,pull-up-strength = <0x3>;
+			};
+		};
+		sdmmc4_1v8_drv: sdmmc4-1v8-drv {
+			sdmmc4 {
+				nvidia,pins = "drive_sdmmc4";
+				nvidia,pull-down-strength = <0x10>;
+				nvidia,pull-up-strength = <0x10>;
+			};
+		};
 	};
 
 	/*
@@ -1050,9 +1092,12 @@
 		clock-names = "sdhci";
 		resets = <&tegra_car 14>;
 		reset-names = "sdhci";
-		pinctrl-names = "sdmmc-3v3", "sdmmc-1v8";
+		pinctrl-names = "sdmmc-3v3", "sdmmc-1v8",
+				"sdmmc-3v3-drv", "sdmmc-1v8-drv";
 		pinctrl-0 = <&sdmmc1_3v3>;
 		pinctrl-1 = <&sdmmc1_1v8>;
+		pinctrl-2 = <&sdmmc1_3v3_drv>;
+		pinctrl-3 = <&sdmmc1_1v8_drv>;
 		nvidia,pad-autocal-pull-up-offset-3v3 = <0x00>;
 		nvidia,pad-autocal-pull-down-offset-3v3 = <0x7d>;
 		nvidia,pad-autocal-pull-up-offset-1v8 = <0x7b>;
@@ -1075,6 +1120,8 @@
 		clock-names = "sdhci";
 		resets = <&tegra_car 9>;
 		reset-names = "sdhci";
+		pinctrl-names = "sdmmc-1v8-drv";
+		pinctrl-0 = <&sdmmc2_1v8_drv>;
 		nvidia,pad-autocal-pull-up-offset-1v8 = <0x05>;
 		nvidia,pad-autocal-pull-down-offset-1v8 = <0x05>;
 		nvidia,default-tap = <0x8>;
@@ -1090,9 +1137,12 @@
 		clock-names = "sdhci";
 		resets = <&tegra_car 69>;
 		reset-names = "sdhci";
-		pinctrl-names = "sdmmc-3v3", "sdmmc-1v8";
+		pinctrl-names = "sdmmc-3v3", "sdmmc-1v8",
+				"sdmmc-3v3-drv", "sdmmc-1v8-drv";
 		pinctrl-0 = <&sdmmc3_3v3>;
 		pinctrl-1 = <&sdmmc3_1v8>;
+		pinctrl-2 = <&sdmmc3_3v3_drv>;
+		pinctrl-3 = <&sdmmc3_1v8_drv>;
 		nvidia,pad-autocal-pull-up-offset-3v3 = <0x00>;
 		nvidia,pad-autocal-pull-down-offset-3v3 = <0x7d>;
 		nvidia,pad-autocal-pull-up-offset-1v8 = <0x7b>;
@@ -1110,6 +1160,9 @@
 		clock-names = "sdhci";
 		resets = <&tegra_car 15>;
 		reset-names = "sdhci";
+		pinctrl-names = "sdmmc-3v3-drv", "sdmmc-1v8-drv";
+		pinctrl-0 = <&sdmmc4_1v8_drv>;
+		pinctrl-1 = <&sdmmc4_1v8_drv>;
 		nvidia,pad-autocal-pull-up-offset-1v8 = <0x05>;
 		nvidia,pad-autocal-pull-down-offset-1v8 = <0x05>;
 		nvidia,default-tap = <0x8>;
-- 
2.7.4

[PATCH V3 3/3] mmc: tegra: SDMMC pads auto-calibration

[Sowjanya Komatineni]

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 | 107 +++++++++++++++++++++++++++++++----------
 1 file changed, 81 insertions(+), 26 deletions(-)

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 7b95d088fdef..f8361249cf57 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)
@@ -805,6 +854,12 @@ static int tegra_sdhci_init_pinctrl_info(struct device *dev,
 		return -1;
 	}
 
+	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)) {
-- 
2.7.4

Re: [PATCH V3 1/3] dt-bindings: mmc: tegra: Add pinctrl for pad drive strength config

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 1883 bytes --]

On Wed, Jan 02, 2019 at 12:57:52PM -0800, Sowjanya Komatineni wrote:
> Add pinctrl for 3V3 and 1V8 pad drive strength configuration for
> Tegra210 sdmmc which has pad configuration registers in the pinmux
> reigster domain.
> Pad drive strengths for Tegra186 and Later are
> part of SDMMC device node itself.
> 
> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> ---
>  Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)

Hi Rob,

any chance you could take a look at this?

Thanks,
Thierry

> diff --git a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
> index 32b4b4e41923..2cecdc71d94c 100644
> --- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
> +++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
> @@ -39,12 +39,16 @@ sdhci@c8000200 {
>  	bus-width = <8>;
>  };
>  
> -Optional properties for Tegra210 and Tegra186:
> +Optional properties for Tegra210, Tegra186 and Tegra194:
>  - pinctrl-names, pinctrl-0, pinctrl-1 : Specify pad voltage
>    configurations. Valid pinctrl-names are "sdmmc-3v3" and "sdmmc-1v8"
>    for controllers supporting multiple voltage levels. The order of names
>    should correspond to the pin configuration states in pinctrl-0 and
>    pinctrl-1.
> +- pinctrl-names : "sdmmc-3v3-drv" and "sdmmc-1v8-drv" are applicable for
> +  Tegra210 where pad config registers are in the pinmux register domain
> +  for pull-up-strength and pull-down-strength values configuration when
> +  using pads at 3V3 and 1V8 levels.
>  - nvidia,only-1-8-v : The presence of this property indicates that the
>    controller operates at a 1.8 V fixed I/O voltage.
>  - nvidia,pad-autocal-pull-up-offset-3v3,
> -- 
> 2.7.4
> 

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Re: [PATCH V3 3/3] mmc: tegra: SDMMC pads auto-calibration

[Thierry Reding]

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On Wed, Jan 02, 2019 at 12:57:54PM -0800, Sowjanya Komatineni wrote:
> 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 | 107 +++++++++++++++++++++++++++++++----------
>  1 file changed, 81 insertions(+), 26 deletions(-)

Hi Sowjanya,

this looks really good. Some minor comments below.

> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index 7b95d088fdef..f8361249cf57 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);
> +

You're rewriting most of that function anyway, so might as well move it
up here. The diff should be about the same in terms of readability, so
you don't need the forward declaration.

>  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));

It's customary to align the first argument on subsequent lines with the
first argument on the first line. Also, I find it more readable to have
a ':' separating the error code:

			dev_err(mmc_dev(host->mmc),
				"Setting drive strengths failed: %d\n", ret);

Also note how you don't need to cast the ret value because it is already
an integer.

>  	}
>  }
>  
> @@ -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)

Same as above, make sure the bool state_drvupdn argument aligns with
struct sdhc_host *host.

>  {
>  	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;

Perhaps make this a pointer to avoid copying the whole structure? You
could even make it const if you want to be very explicit that you're
only referencing the autocalibration 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)) {

Perhaps:

	IS_ERR_OR_NULL(tegra_host->pinctrl_state_1v8_drv)?

but then, do we actually need this? It looks like pinctrl_lookup_state()
will always return either an ERR_PTR() encoded error code or a valid
pointer. Under what circumstances would pinctrl_state_1v8_drv be 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)
> @@ -805,6 +854,12 @@ static int tegra_sdhci_init_pinctrl_info(struct device *dev,
>  		return -1;
>  	}
>  
> +	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");

If this truly is optional, then I suggest we do something like this
instead:

	tegra_host->pinctrl_state_1v8_drv = pinctrl_lookup_state(...);
	if (IS_ERR(tegra_host->pinctrl_state_1v8_drv)) {
		err = PTR_ERR(tegra_host->pinctrl_state_1v8_drv);

		if (err == -ENODEV)
			tegra_host->pinctrl_state_1v8_drv = NULL;
		else
			return err;
	}

With that we can use the much simpler condition everywhere:

	if (tegra_host->pinctrl_state_1v8_drv)
		...

Thierry

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RE: [PATCH V3 3/3] mmc: tegra: SDMMC pads auto-calibration

[Sowjanya Komatineni]

>> @@ -805,6 +854,12 @@ static int tegra_sdhci_init_pinctrl_info(struct device *dev,
>>  		return -1;
>>  	}
>>  
>> +	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");
>
>If this truly is optional, then I suggest we do something like this
>instead:

On tegra210, these settings are part of pinmux so using pinctrl to pinmux device node with existing properties pull-up and pull-down strength to configure timeout values.
On tegra186 and later, these settings are part of sdmmc controller itself so using existing pullup and pulldown timeout properties within sdmmc device node itself.

From sdhci driver perspective, if pinctrl state exists (which is the case of tegra210), it uses it to configure drive settings otherwise (tegra186 & tegra194) it configures drive settings in pad register with in sdmmc domain itself.
So in away presence of sdmmc-1v8-drv and sdmmc-3v3-drv state is optional as they apply only for tegra210.
From sdhci-tegra drive perspective,  it shouldn't return error on absence of these states as these states are not used for tegra186 and tegra194 and instead use drive strengths time out properties.
Will add check in drive to return error on absence of both sdmmc-3v3-drv, sdmmc-1v8-drv pinctrl states along with drive settings properties with in sdmmc device node...

>
>	tegra_host->pinctrl_state_1v8_drv = pinctrl_lookup_state(...);
>	if (IS_ERR(tegra_host->pinctrl_state_1v8_drv)) {
>		err = PTR_ERR(tegra_host->pinctrl_state_1v8_drv);
>
>		if (err == -ENODEV)
>			tegra_host->pinctrl_state_1v8_drv = NULL;
>		else
>			return err;
>	}
>
>With that we can use the much simpler condition everywhere:
>
>	if (tegra_host->pinctrl_state_1v8_drv)
>		...
>
>Thierry

Re: [PATCH V3 1/3] dt-bindings: mmc: tegra: Add pinctrl for pad drive strength config

[Rob Herring]

On Wed, 2 Jan 2019 12:57:52 -0800, Sowjanya Komatineni wrote:
> Add pinctrl for 3V3 and 1V8 pad drive strength configuration for
> Tegra210 sdmmc which has pad configuration registers in the pinmux
> reigster domain.
> Pad drive strengths for Tegra186 and Later are
> part of SDMMC device node itself.
> 
> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> ---
>  Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>