[PATCH v8 2/2] scsi: ufs: core: Add support for static TX Equalization settings

[PATCH v8 2/2] scsi: ufs: core: Add support for static TX Equalization settings

[Can Guo]

Parse board-specific static TX Equalization settings from Device Tree for
each HS gear and store them in hba->tx_eq_params.

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

For HS-G6, parse optional tx-precode-enable-g6 using the same per-lane
Host/Device tuple format. If provided, it must contain values for all
active lanes, and each value must be 0 or 1.

Introduce from_dt in struct ufshcd_tx_eq_params to track whether TX EQ
values came from static Device Tree data.

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 Device Tree settings.
- If retrieval is not available/valid, TX EQTR runs and trained settings
  override static Device Tree settings.

So static Device Tree settings are a fallback for cases where adaptive TX
Equalization is not enabled or not used. Adaptive TX Equalization remains
the primary path when enabled.

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

Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
---
 drivers/ufs/core/ufs-txeq.c      |  15 ++-
 drivers/ufs/host/ufshcd-pltfrm.c | 156 +++++++++++++++++++++++++++++++
 include/ufs/ufshcd.h             |   2 +
 3 files changed, 172 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufs-txeq.c b/drivers/ufs/core/ufs-txeq.c
index 4b264adfdf49..63616f8c2f74 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 from Device Tree.
+	 * 3. TX EQTR procedure is forced.
+	 */
+	if (!params->is_valid || params->from_dt || force_tx_eqtr) {
 		int ret;
 
 		ret = ufshcd_tx_eqtr(hba, params, pwr_mode);
@@ -1310,6 +1316,8 @@ int ufshcd_config_tx_eq_settings(struct ufs_hba *hba,
 		/* Mark TX Equalization settings as valid */
 		params->is_valid = true;
 		params->is_trained = true;
+		/* TX EQTR succeeds, clear from_dt flag */
+		params->from_dt = false;
 		params->is_applied = false;
 	}
 
@@ -1495,6 +1503,11 @@ static void ufshcd_extract_tx_eq_settings_attrs(struct ufs_hba *hba, u8 gear)
 	}
 
 	params->is_valid = true;
+	/*
+	 * Optimal TX EQ settings are retrieved from UFS device attributes,
+	 * clear from_dt flag to avoid TX EQTR procedure.
+	 */
+	params->from_dt = 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..5cf934bf10d0 100644
--- a/drivers/ufs/host/ufshcd-pltfrm.c
+++ b/drivers/ufs/host/ufshcd-pltfrm.c
@@ -210,6 +210,160 @@ static void ufshcd_init_lanes_per_dir(struct ufs_hba *hba)
 	}
 }
 
+static int ufshcd_parse_tx_precode_enable(struct ufs_hba *hba,
+					  bool host_precode_en[UFS_MAX_LANES],
+					  bool device_precode_en[UFS_MAX_LANES])
+{
+	const char *prop_name = "tx-precode-enable-g6";
+	u32 num_elems = 2 * hba->lanes_per_direction;
+	const u32 lpd = hba->lanes_per_direction;
+	u32 precode[UFS_MAX_LANES * 2];
+	struct device *dev = hba->dev;
+	struct property *prop;
+	int count, err, i;
+
+	prop = of_find_property(dev->of_node, prop_name, NULL);
+	if (!prop)
+		return 0;
+
+	count = of_property_count_u32_elems(dev->of_node, prop_name);
+	if (count < 0)
+		return count;
+
+	if (count != num_elems) {
+		dev_err(dev, "Property %s has invalid count (%d), expecting %u\n",
+			prop_name, count, num_elems);
+		return -EINVAL;
+	}
+
+	err = of_property_read_u32_array(dev->of_node, prop_name, precode, num_elems);
+	if (err) {
+		dev_err(dev, "Failed to read %s property, %d\n", prop_name, err);
+		return err;
+	}
+
+	for (i = 0; i < num_elems; i++) {
+		if (precode[i] > 1) {
+			dev_err(dev, "Invalid TX precode value (%u) in %s property\n",
+				precode[i], prop_name);
+			return -EINVAL;
+		}
+	}
+
+	for (i = 0; i < lpd; i++) {
+		host_precode_en[i] = precode[i * 2];
+		device_precode_en[i] = precode[i * 2 + 1];
+	}
+
+	return 0;
+}
+
+static int ufshcd_parse_tx_eq_value_array(struct ufs_hba *hba,
+					  const char *prop_name,
+					  const u32 max_value,
+					  u32 values[UFS_MAX_LANES * 2])
+{
+	u32 num_elems = 2 * hba->lanes_per_direction;
+	struct device *dev = hba->dev;
+	int count, err, i;
+
+	count = of_property_count_u32_elems(dev->of_node, prop_name);
+	if (count < 0)
+		return count;
+
+	if (count != num_elems) {
+		dev_err(dev, "Property %s has invalid count (%d), expecting %u\n",
+			prop_name, count, num_elems);
+		return -EINVAL;
+	}
+
+	err = of_property_read_u32_array(dev->of_node, prop_name, values, num_elems);
+	if (err) {
+		dev_err(dev, "Failed to read %s property, %d\n", prop_name, err);
+		return err;
+	}
+
+	for (i = 0; i < num_elems; i++) {
+		if (values[i] >= max_value) {
+			dev_err(dev, "Invalid TX EQ value (%u) in %s property\n",
+				values[i], prop_name);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * ufshcd_parse_tx_eq_settings_for_gear - Parse static TX EQ DT settings for one gear
+ * @hba: per adapter instance
+ * @gear: target HS gear
+ *
+ * Reads the txeq-preshoot-gN, txeq-deemphasis-gN, and (for G6)
+ * tx-precode-enable-g6 device-tree properties.
+ * If all present values 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)
+{
+	bool device_precode_en[UFS_MAX_LANES] = { false };
+	bool host_precode_en[UFS_MAX_LANES] = { false };
+	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];
+	char prop_name[MAX_PROP_SIZE];
+	int err, lane;
+
+	snprintf(prop_name, MAX_PROP_SIZE, "txeq-preshoot-g%d", gear);
+	err = ufshcd_parse_tx_eq_value_array(hba, prop_name, TX_HS_NUM_PRESHOOT, preshoot);
+	if (err)
+		return;
+
+	snprintf(prop_name, MAX_PROP_SIZE, "txeq-deemphasis-g%d", gear);
+	err = ufshcd_parse_tx_eq_value_array(hba, prop_name, TX_HS_NUM_DEEMPHASIS, deemphasis);
+	if (err)
+		return;
+
+	if (gear == UFS_HS_G6) {
+		err = ufshcd_parse_tx_precode_enable(hba, host_precode_en, device_precode_en);
+		if (err)
+			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 = host_precode_en[lane];
+
+		params->device[lane].preshoot = preshoot[lane * 2 + 1];
+		params->device[lane].deemphasis = deemphasis[lane * 2 + 1];
+		params->device[lane].precode_en = device_precode_en[lane];
+	}
+
+	params->is_valid = true;
+	params->from_dt = true;
+}
+
+static void ufshcd_parse_static_tx_eq_settings(struct ufs_hba *hba)
+{
+	const u32 lpd = hba->lanes_per_direction;
+	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);
+}
+
 /**
  * ufshcd_parse_clock_min_max_freq  - Parse MIN and MAX clocks freq
  * @hba: per adapter instance
@@ -528,6 +682,8 @@ 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..0f87b081b2ff 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
+ * @from_dt: True if settings are from Device Tree
  */
 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 from_dt;
 };
 
 /**
-- 
2.34.1

Re: [PATCH v8 2/2] scsi: ufs: core: Add support for static TX Equalization settings

[kernel test robot]

:::::: 
:::::: Manual check reason: "dtcheck: binding changes may go via different trees"
:::::: 

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <20260615085027.2102882-3-can.guo@oss.qualcomm.com>
References: <20260615085027.2102882-3-can.guo@oss.qualcomm.com>
TO: Can Guo <can.guo@oss.qualcomm.com>
TO: krzk@kernel.org
TO: bvanassche@acm.org
TO: beanhuo@micron.com
TO: peter.wang@mediatek.com
TO: martin.petersen@oracle.com
TO: mani@kernel.org
CC: linux-scsi@vger.kernel.org
CC: Can Guo <can.guo@oss.qualcomm.com>
CC: Alim Akhtar <alim.akhtar@samsung.com>
CC: Avri Altman <avri.altman@wdc.com>
CC: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
CC: Nitin Rawat <quic_nitirawa@quicinc.com>
CC: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
CC: linux-kernel@vger.kernel.org

Hi Can,

kernel test robot noticed the following build warnings:

[auto build test WARNING on mkp-scsi/for-next]
[also build test WARNING on jejb-scsi/for-next krzk-dt/for-next linus/master v7.1 next-20260615]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Can-Guo/dt-bindings-ufs-Document-static-TX-Equalization-settings-properties/20260615-170015
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
patch link:    https://lore.kernel.org/r/20260615085027.2102882-3-can.guo%40oss.qualcomm.com
patch subject: [PATCH v8 2/2] scsi: ufs: core: Add support for static TX Equalization settings
:::::: branch date: 12 hours ago
:::::: commit date: 12 hours ago
config: microblaze-randconfig-2051-20260615 (https://download.01.org/0day-ci/archive/20260615/202606152309.d4ZWI89u-lkp@intel.com/config)
compiler: microblaze-linux-gcc (GCC) 8.5.0
dtschema: 2026.5.dev10+g5d839523d
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260615/202606152309.d4ZWI89u-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/r/202606152309.d4ZWI89u-lkp@intel.com/

dtcheck warnings: (new ones prefixed by >>)
   Documentation/devicetree/bindings/mmc/hisilicon,hi3798cv200-dw-mshc.yaml: properties:hisilicon,sap-dll-reg:items:0: 'anyOf' conditional failed, one must be fixed:
   	'items' is a required property
   	'minItems' is a required property
   	'maxItems' is a required property
   	from schema $id: http://devicetree.org/meta-schemas/items.yaml
   Documentation/devicetree/bindings/mmc/hisilicon,hi3798cv200-dw-mshc.yaml: properties:hisilicon,sap-dll-reg:items:1: 'anyOf' conditional failed, one must be fixed:
   	'items' is a required property
   	'minItems' is a required property
   	'maxItems' is a required property
   	from schema $id: http://devicetree.org/meta-schemas/items.yaml
>> Documentation/devicetree/bindings/ufs/ufs-common.yaml: patternProperties:^txeq-preshoot-g[1-6]$:items: 'anyOf' conditional failed, one must be fixed:
   	'items' is a required property
   	'minItems' is a required property
   	'maxItems' is a required property
   	from schema $id: http://devicetree.org/meta-schemas/items.yaml
>> Documentation/devicetree/bindings/ufs/ufs-common.yaml: patternProperties:^txeq-deemphasis-g[1-6]$:items: 'anyOf' conditional failed, one must be fixed:
   	'items' is a required property
   	'minItems' is a required property
   	'maxItems' is a required property
   	from schema $id: http://devicetree.org/meta-schemas/items.yaml
>> Documentation/devicetree/bindings/ufs/ufs-common.yaml: properties:tx-precode-enable-g6:items: 'anyOf' conditional failed, one must be fixed:
   	'items' is a required property
   	'minItems' is a required property
   	'maxItems' is a required property
   	from schema $id: http://devicetree.org/meta-schemas/items.yaml
   Documentation/devicetree/bindings/spi/st,stm32mp25-ospi.yaml: properties:st,syscfg-dlyb:items:0: 'anyOf' conditional failed, one must be fixed:
   	'items' is a required property
   	'minItems' is a required property
   	'maxItems' is a required property
   	from schema $id: http://devicetree.org/meta-schemas/items.yaml
   Documentation/devicetree/bindings/spi/st,stm32mp25-ospi.yaml: properties:st,syscfg-dlyb:items:1: 'anyOf' conditional failed, one must be fixed:

--
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