[PATCH v10 2/2] scsi: ufs: core: Add support for static TX Equalization settings
Can Guo
can.guo at oss.qualcomm.com
Tue Jun 16 04:33:48 PDT 2026
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.
Reviewed-by: Manivannan Sadhasivam <mani at kernel.org>
Reviewed-by: Peter Wang <peter.wang at mediatek.com>
Signed-off-by: Can Guo <can.guo at oss.qualcomm.com>
---
drivers/ufs/core/ufs-txeq.c | 15 ++-
drivers/ufs/host/ufshcd-pltfrm.c | 154 +++++++++++++++++++++++++++++++
include/ufs/ufshcd.h | 2 +
3 files changed, 170 insertions(+), 1 deletion(-)
diff --git a/drivers/ufs/core/ufs-txeq.c b/drivers/ufs/core/ufs-txeq.c
index 3a2fb5329d27..3c94b94dd7b7 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..5ac7afe75934 100644
--- a/drivers/ufs/host/ufshcd-pltfrm.c
+++ b/drivers/ufs/host/ufshcd-pltfrm.c
@@ -210,6 +210,158 @@ 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;
+ int count, err, i;
+
+ count = of_property_count_u32_elems(dev->of_node, prop_name);
+ if (count == -EINVAL || count == -ENODATA)
+ return 0;
+
+ 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 +680,8 @@ 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
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