[PATCH v6 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[PATCH v6 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Can Guo]

UFS v5.0/UFSHCI v5.0 add HS-G6 support (46.6 Gbps/lane) via UniPro v3.0
and M-PHY v6.0. In these specs, TX Equalization is defined for all High
Speed Gears (not only HS-G6) to compensate channel loss and improve signal
integrity at high speed operation.

For HS-G6, M-PHY uses PAM4 1b1b line coding, Pre-Coding may also be
required depending on channel characteristics.

Add vendor-neutral DT properties:

- patternProperties for txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6]
- fixed property tx-precode-enable-g6

Each property is a uint32 array of per-lane tuples:
<Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]

Accept 2 or 4 values (x1/x2 lane configs). PreShoot and DeEmphasis values
are 0..7. Precode enable values are 0/1 and only applicable to HS-G6.

Acked-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
---
 .../devicetree/bindings/ufs/ufs-common.yaml   | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
index ed97f5682509..d90cf25adfa5 100644
--- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
+++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
@@ -105,6 +105,51 @@ properties:
       Restricts the UFS controller to rate-a or rate-b for both TX and
       RX directions.
 
+  tx-precode-enable-g6:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    oneOf:
+      - minItems: 2
+        maxItems: 2
+      - minItems: 4
+        maxItems: 4
+    items:
+      enum: [0, 1]
+    description: |
+      Static TX Precode enable values for HS-G6 only.
+      Values are specified as per-lane tuples:
+      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].
+
+patternProperties:
+  "^txeq-preshoot-g[1-6]$":
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    oneOf:
+      - minItems: 2
+        maxItems: 2
+      - minItems: 4
+        maxItems: 4
+    items:
+      minimum: 0
+      maximum: 7
+    description: |
+      Static TX Equalization PreShoot values for High Speed Gears.
+      Values are specified as per-lane tuples:
+      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].
+
+  "^txeq-deemphasis-g[1-6]$":
+    $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 values for High Speed Gears.
+      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

[PATCH v6 2/2] scsi: ufs: core: Add support for static TX Equalization settings

[Can Guo]

Static TX Equalization settings and TX Precode enable indication from DT
properties txeq-preshoot-g[1-6], txeq-deemphasis-g[1-6], and
tx-precode-enable-g6 are board-specific baseline values. Values are
provided as per-lane tuples:

<Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]

Parse DT u32 properties with explicit range checks by using
of_property_count_u32_elems()/of_property_read_u32_array().

When adaptive TX Equalization is used, these static settings are not final:

- If valid settings are retrieved from qTxEQGnSettings/wTxEQGnSettingsExt,
  those retrieved settings override static DT settings.
- If retrieval is not available/valid, TX EQTR runs and trained settings
  override static DT settings.

So static DT settings are a fallback and are intended for cases where
adaptive TX Equalization is not enabled/used. Adaptive TX Equalization
remains the primary path when enabled.

No behavior changes for platforms that do not provide these properties.

Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
---
 drivers/ufs/core/ufs-txeq.c      |  10 ++-
 drivers/ufs/host/ufshcd-pltfrm.c | 139 +++++++++++++++++++++++++++++++
 include/ufs/ufshcd.h             |   2 +
 3 files changed, 150 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufs-txeq.c b/drivers/ufs/core/ufs-txeq.c
index 4b264adfdf49..b645fe5f6d95 100644
--- a/drivers/ufs/core/ufs-txeq.c
+++ b/drivers/ufs/core/ufs-txeq.c
@@ -1297,7 +1297,13 @@ int ufshcd_config_tx_eq_settings(struct ufs_hba *hba,
 	}
 
 	params = &hba->tx_eq_params[gear - 1];
-	if (!params->is_valid || force_tx_eqtr) {
+	/*
+	 * TX EQTR must run for the following cases:
+	 * 1. TX EQ settings are invalid.
+	 * 2. TX EQ settings are valid but static, i.e., populated from DT.
+	 * 3. TX EQTR procedure is forced.
+	 */
+	if (!params->is_valid || params->is_static || force_tx_eqtr) {
 		int ret;
 
 		ret = ufshcd_tx_eqtr(hba, params, pwr_mode);
@@ -1310,6 +1316,7 @@ int ufshcd_config_tx_eq_settings(struct ufs_hba *hba,
 		/* Mark TX Equalization settings as valid */
 		params->is_valid = true;
 		params->is_trained = true;
+		params->is_static = false;
 		params->is_applied = false;
 	}
 
@@ -1495,6 +1502,7 @@ static void ufshcd_extract_tx_eq_settings_attrs(struct ufs_hba *hba, u8 gear)
 	}
 
 	params->is_valid = true;
+	params->is_static = false;
 }
 
 void ufshcd_retrieve_tx_eq_settings(struct ufs_hba *hba)
diff --git a/drivers/ufs/host/ufshcd-pltfrm.c b/drivers/ufs/host/ufshcd-pltfrm.c
index c2dafb583cf5..fc6aa91b6210 100644
--- a/drivers/ufs/host/ufshcd-pltfrm.c
+++ b/drivers/ufs/host/ufshcd-pltfrm.c
@@ -210,6 +210,143 @@ static void ufshcd_init_lanes_per_dir(struct ufs_hba *hba)
 	}
 }
 
+/**
+ * ufshcd_parse_tx_eq_settings_for_gear - Parse static TX EQ DT settings for one gear
+ * @hba: per adapter instance
+ * @gear: target HS gear
+ * @num_elems: expected number of elements per property
+ *
+ * Reads the txeq-preshoot-gN, txeq-deemphasis-gN, and (for G6)
+ * tx-precode-enable-gN device-tree properties and, if all are valid, stores
+ * them as static TX Equalization settings for the given gear.
+ */
+static void ufshcd_parse_tx_eq_settings_for_gear(struct ufs_hba *hba,
+						 int gear, const u32 num_elems)
+{
+	u32 precode_en[UFS_MAX_LANES * 2] = { 0 };
+	const u32 lpd = hba->lanes_per_direction;
+	struct ufshcd_tx_eq_params *params;
+	u32 deemphasis[UFS_MAX_LANES * 2];
+	u32 preshoot[UFS_MAX_LANES * 2];
+	struct device *dev = hba->dev;
+	char prop_name[MAX_PROP_SIZE];
+	int i, err, lane, count;
+
+	snprintf(prop_name, MAX_PROP_SIZE, "txeq-preshoot-g%d", gear);
+	count = of_property_count_u32_elems(dev->of_node, prop_name);
+	if (count <= 0)
+		return;
+
+	if (count != num_elems) {
+		dev_err(dev, "Property %s has invalid count (%d), expecting %u\n",
+			prop_name, count, num_elems);
+		return;
+	}
+
+	err = of_property_read_u32_array(dev->of_node, prop_name, preshoot, num_elems);
+	if (err) {
+		dev_err(dev, "Failed to read %s property, %d\n", prop_name, err);
+		return;
+	}
+
+	for (i = 0; i < num_elems; i++) {
+		if (preshoot[i] >= TX_HS_NUM_PRESHOOT) {
+			dev_err(dev, "An invalid TX EQ PreShoot (%d) provided in %s property\n",
+				preshoot[i], prop_name);
+			return;
+		}
+	}
+
+	snprintf(prop_name, MAX_PROP_SIZE, "txeq-deemphasis-g%d", gear);
+	count = of_property_count_u32_elems(dev->of_node, prop_name);
+	if (count <= 0) {
+		dev_err(dev, "Missing required %s property\n", prop_name);
+		return;
+	}
+
+	if (count != num_elems) {
+		dev_err(dev, "Property %s has invalid count (%d), expecting %u\n",
+			prop_name, count, num_elems);
+		return;
+	}
+
+	err = of_property_read_u32_array(dev->of_node, prop_name, deemphasis, num_elems);
+	if (err) {
+		dev_err(dev, "Failed to read %s property, %d\n", prop_name, err);
+		return;
+	}
+
+	for (i = 0; i < num_elems; i++) {
+		if (deemphasis[i] >= TX_HS_NUM_DEEMPHASIS) {
+			dev_err(dev, "An invalid TX EQ DeEmphasis (%d) provided in %s property\n",
+				deemphasis[i], prop_name);
+			return;
+		}
+	}
+
+	if (gear == UFS_HS_G6) {
+		snprintf(prop_name, MAX_PROP_SIZE, "tx-precode-enable-g%d", gear);
+		count = of_property_count_u32_elems(dev->of_node, prop_name);
+		if (count > 0) {
+			if (count != num_elems) {
+				dev_err(dev, "Property %s has invalid count (%d), expecting %u\n",
+					prop_name, count, num_elems);
+				return;
+			}
+
+			err = of_property_read_u32_array(dev->of_node, prop_name,
+							 precode_en, num_elems);
+			if (err) {
+				dev_err(dev, "Failed to read %s property, %d\n",
+					prop_name, err);
+				return;
+			}
+
+			for (i = 0; i < num_elems; i++) {
+				if (precode_en[i] > 1) {
+					dev_err(dev, "An invalid PrecodeEn (%d) provided in %s property\n",
+						precode_en[i], prop_name);
+					return;
+				}
+			}
+		}
+	}
+
+	params = &hba->tx_eq_params[gear - 1];
+	for (lane = 0; lane < lpd; lane++) {
+		params->host[lane].preshoot = preshoot[lane * 2];
+		params->host[lane].deemphasis = deemphasis[lane * 2];
+		params->host[lane].precode_en = precode_en[lane * 2];
+
+		params->device[lane].preshoot = preshoot[lane * 2 + 1];
+		params->device[lane].deemphasis = deemphasis[lane * 2 + 1];
+		params->device[lane].precode_en = precode_en[lane * 2 + 1];
+	}
+
+	params->is_valid = true;
+	params->is_static = true;
+}
+
+static void ufshcd_parse_static_tx_eq_settings(struct ufs_hba *hba)
+{
+	const u32 lpd = hba->lanes_per_direction;
+	const u32 num_elems = lpd * 2;
+	int gear;
+
+	if (!lpd) {
+		return;
+	}
+
+	if (lpd > UFS_MAX_LANES) {
+		dev_warn(hba->dev, "lanes_per_direction (%u) exceeds UFS_MAX_LANES (%u)\n",
+			 lpd, UFS_MAX_LANES);
+		return;
+	}
+
+	for (gear = UFS_HS_G1; gear <= UFS_HS_GEAR_MAX; gear++)
+		ufshcd_parse_tx_eq_settings_for_gear(hba, gear, num_elems);
+}
+
 /**
  * ufshcd_parse_clock_min_max_freq  - Parse MIN and MAX clocks freq
  * @hba: per adapter instance
@@ -528,6 +665,8 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
 
 	ufshcd_init_lanes_per_dir(hba);
 
+	ufshcd_parse_static_tx_eq_settings(hba);
+
 	err = ufshcd_parse_operating_points(hba);
 	if (err) {
 		dev_err(dev, "%s: OPP parse failed %d\n", __func__, err);
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index f48d6416e299..c01824576472 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -359,6 +359,7 @@ struct ufshcd_tx_eqtr_record {
  * @is_valid: True if parameter contains valid TX Equalization settings
  * @is_applied: True if settings have been applied to UniPro of both sides
  * @is_trained: True if parameters obtained from TX EQTR procedure
+ * @is_static: True if settings are static
  */
 struct ufshcd_tx_eq_params {
 	struct ufshcd_tx_eq_settings host[UFS_MAX_LANES];
@@ -367,6 +368,7 @@ struct ufshcd_tx_eq_params {
 	bool is_valid;
 	bool is_applied;
 	bool is_trained;
+	bool is_static;
 };
 
 /**
-- 
2.34.1

Re: [PATCH v6 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Krzysztof Kozlowski]

On Fri, May 29, 2026 at 04:33:37AM -0700, Can Guo wrote:
> UFS v5.0/UFSHCI v5.0 add HS-G6 support (46.6 Gbps/lane) via UniPro v3.0
> and M-PHY v6.0. In these specs, TX Equalization is defined for all High
> Speed Gears (not only HS-G6) to compensate channel loss and improve signal
> integrity at high speed operation.
> 
> For HS-G6, M-PHY uses PAM4 1b1b line coding, Pre-Coding may also be
> required depending on channel characteristics.
> 
> Add vendor-neutral DT properties:
> 
> - patternProperties for txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6]
> - fixed property tx-precode-enable-g6
> 
> Each property is a uint32 array of per-lane tuples:
> <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
> 
> Accept 2 or 4 values (x1/x2 lane configs). PreShoot and DeEmphasis values
> are 0..7. Precode enable values are 0/1 and only applicable to HS-G6.
> 
> Acked-by: Manivannan Sadhasivam <mani@kernel.org>
> Reviewed-by: Bean Huo <beanhuo@micron.com>
> Reviewed-by: Peter Wang <peter.wang@mediatek.com>
> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
> ---
>  .../devicetree/bindings/ufs/ufs-common.yaml   | 45 +++++++++++++++++++
>  1 file changed, 45 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
> index ed97f5682509..d90cf25adfa5 100644
> --- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
> +++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
> @@ -105,6 +105,51 @@ properties:
>        Restricts the UFS controller to rate-a or rate-b for both TX and
>        RX directions.
>  
> +  tx-precode-enable-g6:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    oneOf:
> +      - minItems: 2
> +        maxItems: 2
> +      - minItems: 4
> +        maxItems: 4
> +    items:
> +      enum: [0, 1]
> +    description: |
> +      Static TX Precode enable values for HS-G6 only.
> +      Values are specified as per-lane tuples:
> +      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].

You need to include them in any of applicable examples, otherwise
nothing here is validated.

Why values cannot be on or off? Or even better: why you cannot just list
all the lanes which has it enabled, assuming disabled is by default?

> +
> +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

What is the meaning of values? Nothing here refers to the spec, so is
this driver specific?

Best regards,
Krzysztof

Re: [PATCH v6 2/2] scsi: ufs: core: Add support for static TX Equalization settings

[Manivannan Sadhasivam]

On Fri, May 29, 2026 at 04:33:38AM -0700, Can Guo wrote:
> Static TX Equalization settings and TX Precode enable indication from DT
> properties txeq-preshoot-g[1-6], txeq-deemphasis-g[1-6], and
> tx-precode-enable-g6 are board-specific baseline values. Values are
> provided as per-lane tuples:
> 
> <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
> 
> Parse DT u32 properties with explicit range checks by using
> of_property_count_u32_elems()/of_property_read_u32_array().
> 
> When adaptive TX Equalization is used, these static settings are not final:
> 
> - If valid settings are retrieved from qTxEQGnSettings/wTxEQGnSettingsExt,
>   those retrieved settings override static DT settings.
> - If retrieval is not available/valid, TX EQTR runs and trained settings
>   override static DT settings.
> 
> So static DT settings are a fallback and are intended for cases where
> adaptive TX Equalization is not enabled/used. Adaptive TX Equalization
> remains the primary path when enabled.
> 
> No behavior changes for platforms that do not provide these properties.
> 
> Reviewed-by: Bean Huo <beanhuo@micron.com>
> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

A couple of nits below.

> ---
>  drivers/ufs/core/ufs-txeq.c      |  10 ++-
>  drivers/ufs/host/ufshcd-pltfrm.c | 139 +++++++++++++++++++++++++++++++
>  include/ufs/ufshcd.h             |   2 +
>  3 files changed, 150 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ufs/core/ufs-txeq.c b/drivers/ufs/core/ufs-txeq.c
> index 4b264adfdf49..b645fe5f6d95 100644
> --- a/drivers/ufs/core/ufs-txeq.c
> +++ b/drivers/ufs/core/ufs-txeq.c
> @@ -1297,7 +1297,13 @@ int ufshcd_config_tx_eq_settings(struct ufs_hba *hba,
>  	}
>  
>  	params = &hba->tx_eq_params[gear - 1];
> -	if (!params->is_valid || force_tx_eqtr) {
> +	/*
> +	 * TX EQTR must run for the following cases:
> +	 * 1. TX EQ settings are invalid.
> +	 * 2. TX EQ settings are valid but static, i.e., populated from DT.
> +	 * 3. TX EQTR procedure is forced.
> +	 */
> +	if (!params->is_valid || params->is_static || force_tx_eqtr) {
>  		int ret;
>  
>  		ret = ufshcd_tx_eqtr(hba, params, pwr_mode);
> @@ -1310,6 +1316,7 @@ int ufshcd_config_tx_eq_settings(struct ufs_hba *hba,
>  		/* Mark TX Equalization settings as valid */
>  		params->is_valid = true;
>  		params->is_trained = true;
> +		params->is_static = false;
>  		params->is_applied = false;
>  	}
>  
> @@ -1495,6 +1502,7 @@ static void ufshcd_extract_tx_eq_settings_attrs(struct ufs_hba *hba, u8 gear)
>  	}
>  
>  	params->is_valid = true;
> +	params->is_static = false;
>  }
>  
>  void ufshcd_retrieve_tx_eq_settings(struct ufs_hba *hba)
> diff --git a/drivers/ufs/host/ufshcd-pltfrm.c b/drivers/ufs/host/ufshcd-pltfrm.c
> index c2dafb583cf5..fc6aa91b6210 100644
> --- a/drivers/ufs/host/ufshcd-pltfrm.c
> +++ b/drivers/ufs/host/ufshcd-pltfrm.c
> @@ -210,6 +210,143 @@ static void ufshcd_init_lanes_per_dir(struct ufs_hba *hba)
>  	}
>  }
>  
> +/**
> + * ufshcd_parse_tx_eq_settings_for_gear - Parse static TX EQ DT settings for one gear
> + * @hba: per adapter instance
> + * @gear: target HS gear
> + * @num_elems: expected number of elements per property
> + *
> + * Reads the txeq-preshoot-gN, txeq-deemphasis-gN, and (for G6)
> + * tx-precode-enable-gN device-tree properties and, if all are valid, stores
> + * them as static TX Equalization settings for the given gear.
> + */
> +static void ufshcd_parse_tx_eq_settings_for_gear(struct ufs_hba *hba,
> +						 int gear, const u32 num_elems)

ufshcd_parse_tx_eq_settings_per_gear()?

> +{
> +	u32 precode_en[UFS_MAX_LANES * 2] = { 0 };
> +	const u32 lpd = hba->lanes_per_direction;
> +	struct ufshcd_tx_eq_params *params;
> +	u32 deemphasis[UFS_MAX_LANES * 2];
> +	u32 preshoot[UFS_MAX_LANES * 2];
> +	struct device *dev = hba->dev;
> +	char prop_name[MAX_PROP_SIZE];
> +	int i, err, lane, count;
> +
> +	snprintf(prop_name, MAX_PROP_SIZE, "txeq-preshoot-g%d", gear);
> +	count = of_property_count_u32_elems(dev->of_node, prop_name);
> +	if (count <= 0)
> +		return;
> +
> +	if (count != num_elems) {
> +		dev_err(dev, "Property %s has invalid count (%d), expecting %u\n",
> +			prop_name, count, num_elems);
> +		return;
> +	}
> +
> +	err = of_property_read_u32_array(dev->of_node, prop_name, preshoot, num_elems);
> +	if (err) {
> +		dev_err(dev, "Failed to read %s property, %d\n", prop_name, err);
> +		return;
> +	}
> +
> +	for (i = 0; i < num_elems; i++) {
> +		if (preshoot[i] >= TX_HS_NUM_PRESHOOT) {
> +			dev_err(dev, "An invalid TX EQ PreShoot (%d) provided in %s property\n",
> +				preshoot[i], prop_name);
> +			return;
> +		}
> +	}
> +
> +	snprintf(prop_name, MAX_PROP_SIZE, "txeq-deemphasis-g%d", gear);
> +	count = of_property_count_u32_elems(dev->of_node, prop_name);
> +	if (count <= 0) {
> +		dev_err(dev, "Missing required %s property\n", prop_name);
> +		return;
> +	}
> +
> +	if (count != num_elems) {
> +		dev_err(dev, "Property %s has invalid count (%d), expecting %u\n",
> +			prop_name, count, num_elems);
> +		return;
> +	}
> +
> +	err = of_property_read_u32_array(dev->of_node, prop_name, deemphasis, num_elems);
> +	if (err) {
> +		dev_err(dev, "Failed to read %s property, %d\n", prop_name, err);
> +		return;
> +	}
> +
> +	for (i = 0; i < num_elems; i++) {
> +		if (deemphasis[i] >= TX_HS_NUM_DEEMPHASIS) {
> +			dev_err(dev, "An invalid TX EQ DeEmphasis (%d) provided in %s property\n",
> +				deemphasis[i], prop_name);
> +			return;
> +		}
> +	}
> +
> +	if (gear == UFS_HS_G6) {
> +		snprintf(prop_name, MAX_PROP_SIZE, "tx-precode-enable-g%d", gear);
> +		count = of_property_count_u32_elems(dev->of_node, prop_name);
> +		if (count > 0) {
> +			if (count != num_elems) {
> +				dev_err(dev, "Property %s has invalid count (%d), expecting %u\n",
> +					prop_name, count, num_elems);
> +				return;
> +			}
> +
> +			err = of_property_read_u32_array(dev->of_node, prop_name,
> +							 precode_en, num_elems);
> +			if (err) {
> +				dev_err(dev, "Failed to read %s property, %d\n",
> +					prop_name, err);
> +				return;
> +			}
> +
> +			for (i = 0; i < num_elems; i++) {
> +				if (precode_en[i] > 1) {
> +					dev_err(dev, "An invalid PrecodeEn (%d) provided in %s property\n",
> +						precode_en[i], prop_name);
> +					return;
> +				}
> +			}
> +		}
> +	}
> +
> +	params = &hba->tx_eq_params[gear - 1];
> +	for (lane = 0; lane < lpd; lane++) {
> +		params->host[lane].preshoot = preshoot[lane * 2];
> +		params->host[lane].deemphasis = deemphasis[lane * 2];
> +		params->host[lane].precode_en = precode_en[lane * 2];
> +
> +		params->device[lane].preshoot = preshoot[lane * 2 + 1];
> +		params->device[lane].deemphasis = deemphasis[lane * 2 + 1];
> +		params->device[lane].precode_en = precode_en[lane * 2 + 1];
> +	}
> +
> +	params->is_valid = true;
> +	params->is_static = true;
> +}
> +
> +static void ufshcd_parse_static_tx_eq_settings(struct ufs_hba *hba)
> +{
> +	const u32 lpd = hba->lanes_per_direction;
> +	const u32 num_elems = lpd * 2;
> +	int gear;
> +
> +	if (!lpd) {
> +		return;
> +	}

Redundant braces.

- Mani

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v6 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Can Guo]

On 5/30/2026 12:58 AM, Krzysztof Kozlowski wrote:
> On Fri, May 29, 2026 at 04:33:37AM -0700, Can Guo wrote:
>> UFS v5.0/UFSHCI v5.0 add HS-G6 support (46.6 Gbps/lane) via UniPro v3.0
>> and M-PHY v6.0. In these specs, TX Equalization is defined for all High
>> Speed Gears (not only HS-G6) to compensate channel loss and improve signal
>> integrity at high speed operation.
>>
>> For HS-G6, M-PHY uses PAM4 1b1b line coding, Pre-Coding may also be
>> required depending on channel characteristics.
>>
>> Add vendor-neutral DT properties:
>>
>> - patternProperties for txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6]
>> - fixed property tx-precode-enable-g6
>>
>> Each property is a uint32 array of per-lane tuples:
>> <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
>>
>> Accept 2 or 4 values (x1/x2 lane configs). PreShoot and DeEmphasis values
>> are 0..7. Precode enable values are 0/1 and only applicable to HS-G6.
>>
>> Acked-by: Manivannan Sadhasivam <mani@kernel.org>
>> Reviewed-by: Bean Huo <beanhuo@micron.com>
>> Reviewed-by: Peter Wang <peter.wang@mediatek.com>
>> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
>> ---
>>   .../devicetree/bindings/ufs/ufs-common.yaml   | 45 +++++++++++++++++++
>>   1 file changed, 45 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>> index ed97f5682509..d90cf25adfa5 100644
>> --- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>> +++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>> @@ -105,6 +105,51 @@ properties:
>>         Restricts the UFS controller to rate-a or rate-b for both TX and
>>         RX directions.
>>   
>> +  tx-precode-enable-g6:
>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>> +    oneOf:
>> +      - minItems: 2
>> +        maxItems: 2
>> +      - minItems: 4
>> +        maxItems: 4
>> +    items:
>> +      enum: [0, 1]
>> +    description: |
>> +      Static TX Precode enable values for HS-G6 only.
>> +      Values are specified as per-lane tuples:
>> +      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].
> You need to include them in any of applicable examples, otherwise
> nothing here is validated.
Hi Krzysztof,

Thanks for the review.

Since no UFS5-capable SoC binding exists upstream yet (the target SoC is
still pre-CS), there is no vendor-specific YAML to attach the example to.

Is a synthetic example directly in ufs-common.yaml OK to you?
>
> Why values cannot be on or off? Or even better: why you cannot just list
> all the lanes which has it enabled, assuming disabled is by default?
Thanks for the suggestions.

For the "just list enabled lanes" suggestion: precode must be configured
independently for the Host-side TX and Device-side TX transceivers within
the same physical lane. A lane index list alone cannot capture this
two-dimensional per-lane state. The tuple format <Host_LaneN Device_LaneN>
is the minimal encoding that covers both.

For the "on/off" suggestion: the on/off string pattern is used with
single-value properties (e.g. LED default-state) read via
of_property_read_string(). I am not aware of precedent for on/off as a
string array for per-lane tuples.
>
>> +
>> +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
> What is the meaning of values? Nothing here refers to the spec, so is
> this driver specific?
These are not driver-specific. PreShoot and DeEmphasis are standard
features of the MIPI M-PHY / UniPro stack. The range [0, 7] is defined
in the UniPro specification for the relevant PA layer attributes, and each
value maps to a specific dB level as defined in the M-PHY specification.
I will add the value-to-dB mapping table to the property descriptions in v7.

Thanks,
Can Guo.
>
> Best regards,
> Krzysztof
>

Re: [PATCH v6 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Can Guo]

On 5/30/2026 8:45 PM, Can Guo wrote:
>
>
> On 5/30/2026 12:58 AM, Krzysztof Kozlowski wrote:
>> On Fri, May 29, 2026 at 04:33:37AM -0700, Can Guo wrote:
>>> UFS v5.0/UFSHCI v5.0 add HS-G6 support (46.6 Gbps/lane) via UniPro v3.0
>>> and M-PHY v6.0. In these specs, TX Equalization is defined for all High
>>> Speed Gears (not only HS-G6) to compensate channel loss and improve 
>>> signal
>>> integrity at high speed operation.
>>>
>>> For HS-G6, M-PHY uses PAM4 1b1b line coding, Pre-Coding may also be
>>> required depending on channel characteristics.
>>>
>>> Add vendor-neutral DT properties:
>>>
>>> - patternProperties for txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6]
>>> - fixed property tx-precode-enable-g6
>>>
>>> Each property is a uint32 array of per-lane tuples:
>>> <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
>>>
>>> Accept 2 or 4 values (x1/x2 lane configs). PreShoot and DeEmphasis 
>>> values
>>> are 0..7. Precode enable values are 0/1 and only applicable to HS-G6.
>>>
>>> Acked-by: Manivannan Sadhasivam <mani@kernel.org>
>>> Reviewed-by: Bean Huo <beanhuo@micron.com>
>>> Reviewed-by: Peter Wang <peter.wang@mediatek.com>
>>> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
>>> ---
>>>   .../devicetree/bindings/ufs/ufs-common.yaml   | 45 
>>> +++++++++++++++++++
>>>   1 file changed, 45 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml 
>>> b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>> index ed97f5682509..d90cf25adfa5 100644
>>> --- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>> +++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>> @@ -105,6 +105,51 @@ properties:
>>>         Restricts the UFS controller to rate-a or rate-b for both TX 
>>> and
>>>         RX directions.
>>>   +  tx-precode-enable-g6:
>>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>>> +    oneOf:
>>> +      - minItems: 2
>>> +        maxItems: 2
>>> +      - minItems: 4
>>> +        maxItems: 4
>>> +    items:
>>> +      enum: [0, 1]
>>> +    description: |
>>> +      Static TX Precode enable values for HS-G6 only.
>>> +      Values are specified as per-lane tuples:
>>> +      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].
>> You need to include them in any of applicable examples, otherwise
>> nothing here is validated.
> Hi Krzysztof,
>
> Thanks for the review.
>
> Since no UFS5-capable SoC binding exists upstream yet (the target SoC is
> still pre-CS), there is no vendor-specific YAML to attach the example to.
>
> Is a synthetic example directly in ufs-common.yaml OK to you?
Let me update qcom,sm8650-ufshc.yaml as it includes sm8650 and others.

Thanks,
Can Guo.
>>
>> Why values cannot be on or off? Or even better: why you cannot just list
>> all the lanes which has it enabled, assuming disabled is by default?
> Thanks for the suggestions.
>
> For the "just list enabled lanes" suggestion: precode must be configured
> independently for the Host-side TX and Device-side TX transceivers within
> the same physical lane. A lane index list alone cannot capture this
> two-dimensional per-lane state. The tuple format <Host_LaneN 
> Device_LaneN>
> is the minimal encoding that covers both.
>
> For the "on/off" suggestion: the on/off string pattern is used with
> single-value properties (e.g. LED default-state) read via
> of_property_read_string(). I am not aware of precedent for on/off as a
> string array for per-lane tuples.
>>
>>> +
>>> +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
>> What is the meaning of values? Nothing here refers to the spec, so is
>> this driver specific?
> These are not driver-specific. PreShoot and DeEmphasis are standard
> features of the MIPI M-PHY / UniPro stack. The range [0, 7] is defined
> in the UniPro specification for the relevant PA layer attributes, and 
> each
> value maps to a specific dB level as defined in the M-PHY specification.
> I will add the value-to-dB mapping table to the property descriptions 
> in v7.
>
> Thanks,
> Can Guo.
>>
>> Best regards,
>> Krzysztof
>>
>

Re: [PATCH v6 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Krzysztof Kozlowski]

On 30/05/2026 14:45, Can Guo wrote:
> 
> 
> On 5/30/2026 12:58 AM, Krzysztof Kozlowski wrote:
>> On Fri, May 29, 2026 at 04:33:37AM -0700, Can Guo wrote:
>>> UFS v5.0/UFSHCI v5.0 add HS-G6 support (46.6 Gbps/lane) via UniPro v3.0
>>> and M-PHY v6.0. In these specs, TX Equalization is defined for all High
>>> Speed Gears (not only HS-G6) to compensate channel loss and improve signal
>>> integrity at high speed operation.
>>>
>>> For HS-G6, M-PHY uses PAM4 1b1b line coding, Pre-Coding may also be
>>> required depending on channel characteristics.
>>>
>>> Add vendor-neutral DT properties:
>>>
>>> - patternProperties for txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6]
>>> - fixed property tx-precode-enable-g6
>>>
>>> Each property is a uint32 array of per-lane tuples:
>>> <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
>>>
>>> Accept 2 or 4 values (x1/x2 lane configs). PreShoot and DeEmphasis values
>>> are 0..7. Precode enable values are 0/1 and only applicable to HS-G6.
>>>
>>> Acked-by: Manivannan Sadhasivam <mani@kernel.org>
>>> Reviewed-by: Bean Huo <beanhuo@micron.com>
>>> Reviewed-by: Peter Wang <peter.wang@mediatek.com>
>>> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
>>> ---
>>>   .../devicetree/bindings/ufs/ufs-common.yaml   | 45 +++++++++++++++++++
>>>   1 file changed, 45 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>> index ed97f5682509..d90cf25adfa5 100644
>>> --- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>> +++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>> @@ -105,6 +105,51 @@ properties:
>>>         Restricts the UFS controller to rate-a or rate-b for both TX and
>>>         RX directions.
>>>   
>>> +  tx-precode-enable-g6:
>>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>>> +    oneOf:
>>> +      - minItems: 2
>>> +        maxItems: 2
>>> +      - minItems: 4
>>> +        maxItems: 4
>>> +    items:
>>> +      enum: [0, 1]
>>> +    description: |
>>> +      Static TX Precode enable values for HS-G6 only.
>>> +      Values are specified as per-lane tuples:
>>> +      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].
>> You need to include them in any of applicable examples, otherwise
>> nothing here is validated.
> Hi Krzysztof,
> 
> Thanks for the review.
> 
> Since no UFS5-capable SoC binding exists upstream yet (the target SoC is

I would imagine cover letter or commit msg would briefly mention that.

> still pre-CS), there is no vendor-specific YAML to attach the example to.
> 
> Is a synthetic example directly in ufs-common.yaml OK to you?

Skip example in such case.

>>
>> Why values cannot be on or off? Or even better: why you cannot just list
>> all the lanes which has it enabled, assuming disabled is by default?
> Thanks for the suggestions.
> 
> For the "just list enabled lanes" suggestion: precode must be configured
> independently for the Host-side TX and Device-side TX transceivers within
> the same physical lane. A lane index list alone cannot capture this
> two-dimensional per-lane state. The tuple format <Host_LaneN Device_LaneN>
> is the minimal encoding that covers both.

Again, why do you need to encode '0'?

> 
> For the "on/off" suggestion: the on/off string pattern is used with
> single-value properties (e.g. LED default-state) read via
> of_property_read_string(). I am not aware of precedent for on/off as a
> string array for per-lane tuples.

git grep string-array. Plenty of precedents.

Best regards,
Krzysztof

Re: [PATCH v6 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Can Guo]

On 5/31/2026 1:33 AM, Krzysztof Kozlowski wrote:
> On 30/05/2026 14:45, Can Guo wrote:
>>
>> On 5/30/2026 12:58 AM, Krzysztof Kozlowski wrote:
>>> On Fri, May 29, 2026 at 04:33:37AM -0700, Can Guo wrote:
>>>> UFS v5.0/UFSHCI v5.0 add HS-G6 support (46.6 Gbps/lane) via UniPro v3.0
>>>> and M-PHY v6.0. In these specs, TX Equalization is defined for all High
>>>> Speed Gears (not only HS-G6) to compensate channel loss and improve signal
>>>> integrity at high speed operation.
>>>>
>>>> For HS-G6, M-PHY uses PAM4 1b1b line coding, Pre-Coding may also be
>>>> required depending on channel characteristics.
>>>>
>>>> Add vendor-neutral DT properties:
>>>>
>>>> - patternProperties for txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6]
>>>> - fixed property tx-precode-enable-g6
>>>>
>>>> Each property is a uint32 array of per-lane tuples:
>>>> <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
>>>>
>>>> Accept 2 or 4 values (x1/x2 lane configs). PreShoot and DeEmphasis values
>>>> are 0..7. Precode enable values are 0/1 and only applicable to HS-G6.
>>>>
>>>> Acked-by: Manivannan Sadhasivam <mani@kernel.org>
>>>> Reviewed-by: Bean Huo <beanhuo@micron.com>
>>>> Reviewed-by: Peter Wang <peter.wang@mediatek.com>
>>>> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
>>>> ---
>>>>    .../devicetree/bindings/ufs/ufs-common.yaml   | 45 +++++++++++++++++++
>>>>    1 file changed, 45 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>>> index ed97f5682509..d90cf25adfa5 100644
>>>> --- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>>> +++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>>> @@ -105,6 +105,51 @@ properties:
>>>>          Restricts the UFS controller to rate-a or rate-b for both TX and
>>>>          RX directions.
>>>>    
>>>> +  tx-precode-enable-g6:
>>>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>>>> +    oneOf:
>>>> +      - minItems: 2
>>>> +        maxItems: 2
>>>> +      - minItems: 4
>>>> +        maxItems: 4
>>>> +    items:
>>>> +      enum: [0, 1]
>>>> +    description: |
>>>> +      Static TX Precode enable values for HS-G6 only.
>>>> +      Values are specified as per-lane tuples:
>>>> +      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].
>>> You need to include them in any of applicable examples, otherwise
>>> nothing here is validated.
>> Hi Krzysztof,
>>
>> Thanks for the review.
>>
>> Since no UFS5-capable SoC binding exists upstream yet (the target SoC is
> I would imagine cover letter or commit msg would briefly mention that.
Thanks for the clarification. Will do.
>
>> still pre-CS), there is no vendor-specific YAML to attach the example to.
>>
>> Is a synthetic example directly in ufs-common.yaml OK to you?
> Skip example in such case.
>
>>> Why values cannot be on or off? Or even better: why you cannot just list
>>> all the lanes which has it enabled, assuming disabled is by default?
>> Thanks for the suggestions.
>>
>> For the "just list enabled lanes" suggestion: precode must be configured
>> independently for the Host-side TX and Device-side TX transceivers within
>> the same physical lane. A lane index list alone cannot capture this
>> two-dimensional per-lane state. The tuple format <Host_LaneN Device_LaneN>
>> is the minimal encoding that covers both.
> Again, why do you need to encode '0'?
The tuple is still needed because Precoding is configured per 
transmitter-receiver pair,
so each lane has two independent states:
- Host_TX -> Device_RX
- Device_TX -> Host_RX
A lane-only enabled list cannot represent directional combinations like 
lane0 =
(on, off) vs (off, on).
>
>> For the "on/off" suggestion: the on/off string pattern is used with
>> single-value properties (e.g. LED default-state) read via
>> of_property_read_string(). I am not aware of precedent for on/off as a
>> string array for per-lane tuples.
> git grep string-array. Plenty of precedents.
I will keep the per-lane tuple model but switch tx-precode-enable-g6 
from 0/1 to
"on"/"off" (string array) in v7.

Thanks,
Can Guo.
>
> Best regards,
> Krzysztof

Re: [PATCH v6 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Can Guo]

On 5/31/2026 9:41 AM, Can Guo wrote:
>
>
> On 5/31/2026 1:33 AM, Krzysztof Kozlowski wrote:
>> On 30/05/2026 14:45, Can Guo wrote:
>>>
>>> On 5/30/2026 12:58 AM, Krzysztof Kozlowski wrote:
>>>> On Fri, May 29, 2026 at 04:33:37AM -0700, Can Guo wrote:
>>>>> UFS v5.0/UFSHCI v5.0 add HS-G6 support (46.6 Gbps/lane) via UniPro 
>>>>> v3.0
>>>>> and M-PHY v6.0. In these specs, TX Equalization is defined for all 
>>>>> High
>>>>> Speed Gears (not only HS-G6) to compensate channel loss and 
>>>>> improve signal
>>>>> integrity at high speed operation.
>>>>>
>>>>> For HS-G6, M-PHY uses PAM4 1b1b line coding, Pre-Coding may also be
>>>>> required depending on channel characteristics.
>>>>>
>>>>> Add vendor-neutral DT properties:
>>>>>
>>>>> - patternProperties for txeq-preshoot-g[1-6] and 
>>>>> txeq-deemphasis-g[1-6]
>>>>> - fixed property tx-precode-enable-g6
>>>>>
>>>>> Each property is a uint32 array of per-lane tuples:
>>>>> <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
>>>>>
>>>>> Accept 2 or 4 values (x1/x2 lane configs). PreShoot and DeEmphasis 
>>>>> values
>>>>> are 0..7. Precode enable values are 0/1 and only applicable to HS-G6.
>>>>>
>>>>> Acked-by: Manivannan Sadhasivam <mani@kernel.org>
>>>>> Reviewed-by: Bean Huo <beanhuo@micron.com>
>>>>> Reviewed-by: Peter Wang <peter.wang@mediatek.com>
>>>>> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
>>>>> ---
>>>>>    .../devicetree/bindings/ufs/ufs-common.yaml   | 45 
>>>>> +++++++++++++++++++
>>>>>    1 file changed, 45 insertions(+)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml 
>>>>> b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>>>> index ed97f5682509..d90cf25adfa5 100644
>>>>> --- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>>>> +++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
>>>>> @@ -105,6 +105,51 @@ properties:
>>>>>          Restricts the UFS controller to rate-a or rate-b for both 
>>>>> TX and
>>>>>          RX directions.
>>>>>    +  tx-precode-enable-g6:
>>>>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>>>>> +    oneOf:
>>>>> +      - minItems: 2
>>>>> +        maxItems: 2
>>>>> +      - minItems: 4
>>>>> +        maxItems: 4
>>>>> +    items:
>>>>> +      enum: [0, 1]
>>>>> +    description: |
>>>>> +      Static TX Precode enable values for HS-G6 only.
>>>>> +      Values are specified as per-lane tuples:
>>>>> +      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].
>>>> You need to include them in any of applicable examples, otherwise
>>>> nothing here is validated.
>>> Hi Krzysztof,
>>>
>>> Thanks for the review.
>>>
>>> Since no UFS5-capable SoC binding exists upstream yet (the target 
>>> SoC is
>> I would imagine cover letter or commit msg would briefly mention that.
> Thanks for the clarification. Will do.
>>
>>> still pre-CS), there is no vendor-specific YAML to attach the 
>>> example to.
>>>
>>> Is a synthetic example directly in ufs-common.yaml OK to you?
>> Skip example in such case.
>>
>>>> Why values cannot be on or off? Or even better: why you cannot just 
>>>> list
>>>> all the lanes which has it enabled, assuming disabled is by default?
>>> Thanks for the suggestions.
>>>
>>> For the "just list enabled lanes" suggestion: precode must be 
>>> configured
>>> independently for the Host-side TX and Device-side TX transceivers 
>>> within
>>> the same physical lane. A lane index list alone cannot capture this
>>> two-dimensional per-lane state. The tuple format <Host_LaneN 
>>> Device_LaneN>
>>> is the minimal encoding that covers both.
>> Again, why do you need to encode '0'?
> The tuple is still needed because Precoding is configured per 
> transmitter-receiver pair,
> so each lane has two independent states:
> - Host_TX -> Device_RX
> - Device_TX -> Host_RX
> A lane-only enabled list cannot represent directional combinations 
> like lane0 =
> (on, off) vs (off, on).
How about we split into two properties, something like below?
tx-precode-enable-g6-host-lanes = <0 1>
tx-precode-enable-g6-device-lanes = <1>

Only listed lanes are enabled; unlisted lanes are disabled by default.

Are you OK with this approach?

Thanks,
Can Guo.
>>
>>> For the "on/off" suggestion: the on/off string pattern is used with
>>> single-value properties (e.g. LED default-state) read via
>>> of_property_read_string(). I am not aware of precedent for on/off as a
>>> string array for per-lane tuples.
>> git grep string-array. Plenty of precedents.
> I will keep the per-lane tuple model but switch tx-precode-enable-g6 
> from 0/1 to
> "on"/"off" (string array) in v7.
>
> Thanks,
> Can Guo.
>>
>> Best regards,
>> Krzysztof
>

Re: [PATCH v6 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Krzysztof Kozlowski]

On 31/05/2026 06:48, Can Guo wrote:
>>>> is the minimal encoding that covers both.
>>> Again, why do you need to encode '0'?
>> The tuple is still needed because Precoding is configured per 
>> transmitter-receiver pair,
>> so each lane has two independent states:
>> - Host_TX -> Device_RX
>> - Device_TX -> Host_RX
>> A lane-only enabled list cannot represent directional combinations 
>> like lane0 =
>> (on, off) vs (off, on).
> How about we split into two properties, something like below?
> tx-precode-enable-g6-host-lanes = <0 1>
> tx-precode-enable-g6-device-lanes = <1>
> 
> Only listed lanes are enabled; unlisted lanes are disabled by default.
> 
> Are you OK with this approach?

Yes, I do prefer this, because we don't have empty entries (<0, 0>, <0,
1> ....).

Best regards,
Krzysztof

Re: [PATCH v6 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Can Guo]

On 6/9/2026 3:08 PM, Krzysztof Kozlowski wrote:
> On 31/05/2026 06:48, Can Guo wrote:
>>>>> is the minimal encoding that covers both.
>>>> Again, why do you need to encode '0'?
>>> The tuple is still needed because Precoding is configured per
>>> transmitter-receiver pair,
>>> so each lane has two independent states:
>>> - Host_TX -> Device_RX
>>> - Device_TX -> Host_RX
>>> A lane-only enabled list cannot represent directional combinations
>>> like lane0 =
>>> (on, off) vs (off, on).
>> How about we split into two properties, something like below?
>> tx-precode-enable-g6-host-lanes = <0 1>
>> tx-precode-enable-g6-device-lanes = <1>
>>
>> Only listed lanes are enabled; unlisted lanes are disabled by default.
>>
>> Are you OK with this approach?
> Yes, I do prefer this, because we don't have empty entries (<0, 0>, <0,
> 1> ....).
Thank you for coming back. Sure, I will use this format in next version.

Best Regards,
Can Guo.
>
> Best regards,
> Krzysztof