[PATCH 7/9] dt-bindings: mmc: sprd: Add PHY DLL delay documentation

From: Baolin Wang <baolin.wang@linaro.org>
To: adrian.hunter@intel.com, ulf.hansson@linaro.org,
	zhang.lyra@gmail.com, orsonzhai@gmail.com, robh+dt@kernel.org,
	mark.rutland@arm.com, arnd@arndb.de, olof@lixom.net
Cc: baolin.wang@linaro.org, vincent.guittot@linaro.org,
	arm@kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org
Subject: [PATCH 7/9] dt-bindings: mmc: sprd: Add PHY DLL delay documentation
Date: Mon, 20 May 2019 18:12:00 +0800	[thread overview]
Message-ID: <96f4304c001c0cf81ecc6bec69665d239203b9b7.1558346019.git.baolin.wang@linaro.org> (raw)
In-Reply-To: <cover.1558346019.git.baolin.wang@linaro.org>
In-Reply-To: <cover.1558346019.git.baolin.wang@linaro.org>

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

