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Subject[PATCH v2 7/9] dt-bindings: mmc: sprd: Add PHY DLL delay documentation
Date
Introduce some PHY DLL delays properties to help to sample the PHY clock.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
.../devicetree/bindings/mmc/sdhci-sprd.txt | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/sdhci-sprd.txt b/Documentation/devicetree/bindings/mmc/sdhci-sprd.txt
index a285c77..e675397 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-sprd.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-sprd.txt
@@ -20,6 +20,23 @@ Optional properties:
- assigned-clocks: the same with "sdio" clock
- assigned-clock-parents: the default parent of "sdio" clock

+PHY DLL delays are used to delay the data valid window, and align the window
+to sampling clock. PHY DLL delays can be configured by following properties,
+and each property contains 4 cells which are used to configure the clock data
+write line delay value, clock read command line delay value, clock read data
+positive edge delay value and clock read data negative edge delay value.
+Each cell's delay value unit is cycle of the PHY clock.
+
+- sprd,phy-delay-legacy: Delay value for legacy timing.
+- sprd,phy-delay-sd-highspeed: Delay value for SD high-speed timing.
+- sprd,phy-delay-sd-uhs-sdr50: Delay value for SD UHS SDR50 timing.
+- sprd,phy-delay-sd-uhs-sdr104: Delay value for SD UHS SDR50 timing.
+- sprd,phy-delay-mmc-highspeed: Delay value for MMC high-speed timing.
+- sprd,phy-delay-mmc-ddr52: Delay value for MMC DDR52 timing.
+- sprd,phy-delay-mmc-hs200: Delay value for MMC HS200 timing.
+- sprd,phy-delay-mmc-hs400: Delay value for MMC HS400 timing.
+- sprd,phy-delay-mmc-hs400es: Delay value for MMC HS400 enhanced strobe timing.
+
Examples:

sdio0: sdio@20600000 {
@@ -33,6 +50,7 @@ sdio0: sdio@20600000 {
assigned-clocks = <&ap_clk CLK_EMMC_2X>;
assigned-clock-parents = <&rpll CLK_RPLL_390M>;

+ sprd,phy-delay-sd-uhs-sdr104 = <0x3f 0x7f 0x2e 0x2e>;
bus-width = <8>;
non-removable;
no-sdio;
--
1.7.9.5
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