[PATCH v7 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Can Guo]

UFS v5.0/UFSHCI v5.0 add HS-G6 support via UniPro v3.0 and M-PHY v6.0.
These specs define TX Equalization for all High Speed Gears, and HS-G6 may
also require TX precode depending on channel characteristics.

Document vendor-neutral DT properties in ufs-common.yaml:

- patternProperties for txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6]
- tx-precode-g6-host-lanes
- tx-precode-g6-device-lanes

txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6] accept per-lane tuples:
<Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]

PreShoot and DeEmphasis values are 0..7 and accept 2 or 4 values for x1/x2
lane configurations.

tx-precode-g6-host-lanes and tx-precode-g6-device-lanes list lane indices
where precode is enabled on host and device sides.

Signed-off-by: Can Guo <can.guo@xxxxxxxxxxxxxxxx>
---
 .../devicetree/bindings/ufs/ufs-common.yaml   | 61 +++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
index ed97f5682509..2d53bbbe5865 100644
--- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
+++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
@@ -105,6 +105,67 @@ properties:
       Restricts the UFS controller to rate-a or rate-b for both TX and
       RX directions.
 
+  tx-precode-g6-host-lanes:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    maxItems: 2
+    uniqueItems: true
+    items:
+      minimum: 0
+      maximum: 1
+    description: |
+      Lane indices for static Host-side TX precode enable settings for HS-G6
+      only. Listed lanes have precode enabled; unlisted lanes are disabled.
+
+  tx-precode-g6-device-lanes:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    maxItems: 2
+    uniqueItems: true
+    items:
+      minimum: 0
+      maximum: 1
+    description: |
+      Lane indices for static Device-side TX precode enable settings for HS-G6
+      only. Listed lanes have precode enabled; unlisted lanes are disabled.
+
+patternProperties:
+  "^txeq-preshoot-g[1-6]$":
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    oneOf:
+      - minItems: 2
+        maxItems: 2
+      - minItems: 4
+        maxItems: 4
+    items:
+      minimum: 0
+      maximum: 7
+    description: |
+      Static TX Equalization PreShoot settings for High Speed Gears. These
+      values are programmed to the corresponding UniPro PA layer attribute
+      PA_TxEQG[1-6]Setting. Each value selects a Pre-Shoot level as defined
+      by the MIPI M-PHY specification (TX_HS_PreShoot_Setting).
+      Values are specified as per-lane tuples:
+      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
+
+  "^txeq-deemphasis-g[1-6]$":
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    oneOf:
+      - minItems: 2
+        maxItems: 2
+      - minItems: 4
+        maxItems: 4
+    items:
+      minimum: 0
+      maximum: 7
+    description: |
+      Static TX Equalization DeEmphasis settings for High Speed Gears. These
+      values are programmed to the corresponding UniPro PA layer attribute
+      PA_TxEQG[1-6]Setting. Each value selects a De-Emphasis level as defined
+      by the MIPI M-PHY specification (TX_HS_DeEmphasis_Setting).
+      Values are specified as per-lane tuples:
+      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
+
 dependencies:
   freq-table-hz: [ clocks ]
   operating-points-v2: [ clocks, clock-names ]
-- 
2.34.1