On Thu, 9 Aug 2018 14:15:00 +0200
Thierry Reding [off-list ref] wrote:

On Wed, Aug 01, 2018 at 07:31:52PM +0300, Aapo Vienamo wrote:

quoted

Document the pinctrl bindings used by the SDHCI driver to reconfigure
pad voltages on controllers supporting multiple voltage levels.

Signed-off-by: Aapo Vienamo <redacted>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/mmc/nvidia,tegra20-sdhci.txt          | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
index 9bce578..90c214d 100644
--- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
+++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt

@@ -38,3 +38,25 @@ sdhci@c8000200 {
 	power-gpios = <&gpio 155 0>; /* gpio PT3 */
 	bus-width = <8>;
 };
+
+Optional properties for Tegra210 and Tegra186:
+- 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.  

Do we also want "sdmmc-off" to allow SDMMC pads to be powered down when
the slot or card is not used?

I don't see a real need for it, at least not in the context of this
series which aims to implement support for HS200 and UHS signaling. I
guess it could be added later if there's an actual case for it, where
turning off the pad would result in measureable change in total power
consumption.

 -Aapo

quoted

+
+Example:
+sdhci@700b0000 {
+	compatible = "nvidia,tegra210-sdhci", "nvidia,tegra124-sdhci";
+	reg = <0x0 0x700b0000 0x0 0x200>;
+	interrupts = <GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&tegra_car TEGRA210_CLK_SDMMC1>;
+	clock-names = "sdhci";
+	resets = <&tegra_car 14>;
+	reset-names = "sdhci";
+	pinctrl-names = "sdmmc-3v3", "sdmmc-1v8";
+	pinctrl-0 = <&sdmmc1_3v3>;
+	pinctrl-1 = <&sdmmc1_1v8>;
+	status = "disabled";
+};
-- 
2.7.4