Re: [RFC PATCH 09/11] sdhci: dt-bindings: configuration settings

Krzysztof Kozlowski
2024-05-07T06:37:38Z

On 07/05/2024 00:51, Krishna Yarlagadda wrote:
> SDHCI vendor tuning registers are configured using config setting
> framework. Document available config for Tegra SDHCI controllers.
>
> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> ---
> .../bindings/mmc/nvidia,tegra20-sdhci.yaml | 36 +++++++++++++++++++
> 1 file changed, 36 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml
> index 72987f0326a1..002bc1ffc156 100644
> --- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml
> +++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml
> @@ -177,6 +177,37 @@ properties:
> operates at a 1.8 V fixed I/O voltage.
> $ref: /schemas/types.yaml#/definitions/flag
>
> + config:

No. This node does not re

> + description: Config settings for SDHCI devices.
> + Config setting is the configuration based on chip/board/system
> + characterization on interface/controller settings. This is needed for
> + - making the controller internal configuration to better perform
> + - making the interface to work proper by setting drive strength, slew
> + rates etc
> + - making the low power leakage.
> + SDHCI has configuration based on device speed modes.
> + - common is set on all speeds and can be overridden by speed mode.
> + - List of speed modes and their config name
> + "default", /* MMC_TIMING_LEGACY */
> + "sd-mmc-highspeed", /* MMC_TIMING_MMC_HS */
> + "sd-mmc-highspeed", /* MMC_TIMING_SD_HS */
> + "uhs-sdr12", /* MMC_TIMING_UHS_SDR12 */
> + "uhs-sdr25", /* MMC_TIMING_UHS_SDR25 */
> + "uhs-sdr50", /* MMC_TIMING_UHS_SDR50 */
> + "uhs-sdr104", /* MMC_TIMING_UHS_SDR104 */
> + "uhs-ddr52", /* MMC_TIMING_UHS_DDR50 */
> + "uhs-ddr52", /* MMC_TIMING_MMC_DDR52 */
> + "mmc-hs200", /* MMC_TIMING_MMC_HS200 */
> + "mmc-hs400", /* MMC_TIMING_MMC_HS400 */
> + type: object
> + unevaluatedProperties: true

NAK.

> + properties:
> + nvidia,num-tuning-iter:
> + description: Specify DQS trim value for HS400 timing.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 0
> + maximum: 0xffff

"iterations" is decimal value. How it can be 0? 0 tries to time?

Best regards,
Krzysztof