On Thu, Jul 26, 2018 at 03:26:51PM +0300, Aapo Vienamo wrote:
> Add bindings documentation for pad pull up and pull down offset values to be
> programmed before executing automatic pad drive strength calibration.
>
> Signed-off-by: Aapo Vienamo <avienamo@xxxxxxxxxx>
> ---
> .../bindings/mmc/nvidia,tegra20-sdhci.txt | 34 ++++++++++++++++++++++
> 1 file changed, 34 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
> index 95010cf..c3d8a15 100644
> --- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
> +++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
> @@ -24,6 +24,7 @@ Required properties:
> Optional properties:
> - power-gpios : Specify GPIOs for power control
>
> +Optional properties for Tegra210 and Tegra186:
> Example:
>
> sdhci@c8000200 {
> @@ -47,6 +48,35 @@ Optional properties for Tegra210 and Tegra186:
> pinctrl-1.
> - 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,
> + nvidia,pad-autocal-pull-down-offset-3v3 : Specify drive strength
> + calibration offsets for 3.3 V signaling modes.
Perhaps a single property with 2 values?
> +- nvidia,pad-autocal-pull-up-offset-1v8,
> + nvidia,pad-autocal-pull-down-offset-1v8 : Specify drive strength
> + calibration offsets for 1.8 V signaling modes.
> +- nvidia,pad-autocal-pull-up-offset-3v3-timeout,
> + nvidia,pad-autocal-pull-down-offset-3v3-timeout : Specify drive
> + strength used as a fallback in case the automatic calibration times
> + out on a 3.3 V signaling mode.
> +- nvidia,pad-autocal-pull-up-offset-1v8-timeout,
> + nvidia,pad-autocal-pull-down-offset-1v8-timeout : Specify drive
> + strength used as a fallback in case the automatic calibration times
> + out on a 1.8 V signaling mode.
> +- nvidia,pad-autocal-pull-up-offset-sdr104,
> + nvidia,pad-autocal-pull-down-offset-sdr104 : Specify drive strength
> + calibration offsets for SDR104 mode.
> +- nvidia,pad-autocal-pull-up-offset-hs400,
> + nvidia,pad-autocal-pull-down-offset-hs400 : Specify drive strength
> + calibration offsets for HS400 mode.
> +
> + Notes on the pad calibration pull up and pulldown offset values:
> + - The property values are drive codes which are programmed into the
> + PD_OFFSET and PU_OFFSET sections of the
> + SDHCI_TEGRA_AUTO_CAL_CONFIG register.
> + - A higher value corresponds to higher drive strength. Please refer
> + to the reference manual of the SoC for correct values.
> + - The SDR104 and HS400 timing specific values are used in
> + corresponding modes if specified.
>
> Example:
> sdhci@700b0000 {
> @@ -60,5 +90,9 @@ sdhci@700b0000 {
> pinctrl-names = "sdmmc-3v3", "sdmmc-1v8";
> pinctrl-0 = <&sdmmc1_3v3>;
> pinctrl-1 = <&sdmmc1_1v8>;
> + pad-autocal-pull-up-offset-3v3 = <0x00>;
> + pad-autocal-pull-down-offset-3v3 = <0x7d>;
> + pad-autocal-pull-up-offset-1v8 = <0x7b>;
> + pad-autocal-pull-down-offset-1v8 = <0x7b>;
Doesn't match the doc.
> status = "disabled";
> };
> --
> 2.7.4
>
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