[PATCH v2 1/8] backlight: qcom-wled: fix string detection brightness on WLED5

[Dmitry Baryshkov]

The string detection sets the test brightness through
wled4_set_brightness(). On WLED5 that writes to unrelated registers and
the detection runs with whatever brightness has been programmed before.

Use the per-version callback. A WLED5 brightness write also only takes
effect once the module sync bit is toggled, which so far was done by
wled_update_status() alone. Toggle it in wled5_set_brightness() instead,
so that every caller of the callback gets the new value.

Fixes: 62a1d3f623ac ("backlight: qcom-wled: Add support for WLED5 peripheral that is present on PM8150L PMICs")
Assisted-by: LLM
Reviewed-by: Daniel Thompson (RISCstar) <danielt@xxxxxxxxxx>
Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
---
 drivers/video/backlight/qcom-wled.c | 56 ++++++++++++++++---------------------
 1 file changed, 24 insertions(+), 32 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index ca350f320e17..c5243a6d547e 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -269,6 +269,24 @@ static int wled4_set_brightness(struct wled *wled, u16 brightness)
 	return 0;
 }
 
+static int wled5_mod_sync_toggle(struct wled *wled)
+{
+	int rc;
+	u8 val;
+
+	rc = regmap_update_bits(wled->regmap,
+				wled->sink_addr + WLED5_SINK_REG_MOD_SYNC_BIT,
+				WLED5_SINK_REG_SYNC_MASK, 0);
+	if (rc < 0)
+		return rc;
+
+	val = (wled->cfg.mod_sel == MOD_A) ? WLED5_SINK_REG_SYNC_MOD_A_BIT :
+					     WLED5_SINK_REG_SYNC_MOD_B_BIT;
+	return regmap_update_bits(wled->regmap,
+				  wled->sink_addr + WLED5_SINK_REG_MOD_SYNC_BIT,
+				  WLED5_SINK_REG_SYNC_MASK, val);
+}
+
 static int wled5_set_brightness(struct wled *wled, u16 brightness)
 {
 	int rc, offset;
@@ -287,7 +305,10 @@ static int wled5_set_brightness(struct wled *wled, u16 brightness)
 
 	rc = regmap_bulk_write(wled->regmap, wled->sink_addr + offset,
 			       &v, sizeof(v));
-	return rc;
+	if (rc < 0)
+		return rc;
+
+	return wled5_mod_sync_toggle(wled);
 }
 
 static int wled_read_brightness(struct wled *wled)
@@ -391,24 +412,6 @@ static int wled3_sync_toggle(struct wled *wled)
 	return rc;
 }
 
-static int wled5_mod_sync_toggle(struct wled *wled)
-{
-	int rc;
-	u8 val;
-
-	rc = regmap_update_bits(wled->regmap,
-				wled->sink_addr + WLED5_SINK_REG_MOD_SYNC_BIT,
-				WLED5_SINK_REG_SYNC_MASK, 0);
-	if (rc < 0)
-		return rc;
-
-	val = (wled->cfg.mod_sel == MOD_A) ? WLED5_SINK_REG_SYNC_MOD_A_BIT :
-					     WLED5_SINK_REG_SYNC_MOD_B_BIT;
-	return regmap_update_bits(wled->regmap,
-				  wled->sink_addr + WLED5_SINK_REG_MOD_SYNC_BIT,
-				  WLED5_SINK_REG_SYNC_MASK, val);
-}
-
 static int wled_ovp_fault_status(struct wled *wled, bool *fault_set)
 {
 	int rc;
@@ -494,17 +497,6 @@ static int wled_update_status(struct backlight_device *bl)
 				dev_err(wled->dev, "wled sync failed rc:%d\n", rc);
 				goto unlock_mutex;
 			}
-		} else {
-			/*
-			 * For WLED5 toggling the MOD_SYNC_BIT updates the
-			 * brightness
-			 */
-			rc = wled5_mod_sync_toggle(wled);
-			if (rc < 0) {
-				dev_err(wled->dev, "wled mod sync failed rc:%d\n",
-					rc);
-				goto unlock_mutex;
-			}
 		}
 	}
 
@@ -651,7 +643,7 @@ static void wled_auto_string_detection(struct wled *wled)
 	}
 
 	/* Set low brightness across all sinks */
-	rc = wled4_set_brightness(wled, AUTO_DETECT_BRIGHTNESS);
+	rc = wled->wled_set_brightness(wled, AUTO_DETECT_BRIGHTNESS);
 	if (rc < 0) {
 		dev_err(wled->dev, "Failed to set brightness for auto detection rc=%d\n",
 			rc);
@@ -791,7 +783,7 @@ static void wled_auto_string_detection(struct wled *wled)
 	}
 
 	/* Restore brightness */
-	rc = wled4_set_brightness(wled, wled->brightness);
+	rc = wled->wled_set_brightness(wled, wled->brightness);
 	if (rc < 0) {
 		dev_err(wled->dev, "Failed to set brightness after auto detection rc=%d\n",
 			rc);

-- 
2.47.3