Thread (45 messages) 45 messages, 4 authors, 2018-08-31
STALE2826d REVIEWED: 1 (0M)
Revisions (3)
  1. v1 [diff vs current]
  2. v2 [diff vs current]
  3. v3 current

[PATCH v3 04/38] dt-bindings: mmc: Add Tegra SDHCI sampling trimmer values

From: Aapo Vienamo <hidden>
Date: 2018-08-30 15:07:00
Also in: linux-mmc, linux-tegra, lkml
Subsystem: multimedia card (mmc), secure digital (sd) and sdio subsystem, open firmware and flattened device tree bindings, the rest · Maintainers: Ulf Hansson, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds

Document the Tegra SDHCI inbound and outbound sampling trimmer values.

Signed-off-by: Aapo Vienamo <redacted>
Acked-by: Thierry Reding <redacted>
---
 .../devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt  | 11 +++++++++++
 1 file changed, 11 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
index 9713e052f736..edecf97231b9 100644
--- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
+++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
@@ -67,6 +67,10 @@ Optional properties for Tegra210 and Tegra186:
 - nvidia,pad-autocal-pull-up-offset-hs400,
   nvidia,pad-autocal-pull-down-offset-hs400 : Specify drive strength
   calibration offsets for HS400 mode.
+- nvidia,default-tap : Specify the default inbound sampling clock
+  trimmer value for non-tunable modes.
+- nvidia,default-trim : Specify the default outbound clock trimmer
+  value.
 
   Notes on the pad calibration pull up and pulldown offset values:
     - The property values are drive codes which are programmed into the
@@ -77,6 +81,13 @@ Optional properties for Tegra210 and Tegra186:
     - The SDR104 and HS400 timing specific values are used in
       corresponding modes if specified.
 
+  Notes on tap and trim values:
+    - The values are used for compensating trace length differences
+      by adjusting the sampling point.
+    - The values are programmed to the Vendor Clock Control Register.
+      Please refer to the reference manual of the SoC for correct
+      values.
+
 Example:
 sdhci@700b0000 {
 	compatible = "nvidia,tegra210-sdhci", "nvidia,tegra124-sdhci";
-- 
2.18.0
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