[PATCH v2 0/8] arm64: qcom: enable display card support on SM8150 HDK

[PATCH v2 0/8] arm64: qcom: enable display card support on SM8150 HDK

[Dmitry Baryshkov]

The Qualcomm SM8150 HDK can be equipped with an optional display card
having the same panel as the display card for SDM845 HDK. Reuse the
driver submitted at [1] and enable display card support on this HDK.

Unlike SDM845, this also requires a new LCDB driver, providing voltage
for the panel and several fixes in the WLED driver. The FSA4480 address
fix is independent and can be applied earlier.

[1] https://lore.kernel.org/dri-devel/20261014-sdm845-hdk-v2-0-6d0b4b42f267@oss.qualcomm.com/

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
Changes in v2:
- Dropped WLED patch, duplicating one of the applied patches (Konrad)
- Rework the WLED auto-calibration patch, also dropping the reviews.
- Tighten voltages in LCDB example (Konrad) and in the DTSO.
- Renamed the node to regulator@ (Krzysztof)
- In LCDB driver, fixed handling of pull-down on disable, fixed caching
  of the state, added REGULATOR_EVENT_FAIL and fixesd short-circuit
  recovery (Sashiko)
- Link to v1: https://patch.msgid.link/20261015-sm8150-display-card-v1-0-5c14928cef29@oss.qualcomm.com

---
Dmitry Baryshkov (8):
      backlight: qcom-wled: fix string detection brightness on WLED5
      regulator: dt-bindings: add Qualcomm LCDB regulator
      dt-bindings: mfd: qcom,spmi-pmic: add LCDB
      regulator: add Qualcomm LCDB driver
      arm64: dts: qcom: pm8150l: add LCDB regulators
      arm64: dts: qcom: sm8150: add MDSS reset
      arm64: dts: qcom: sm8150-hdk: fix FSA4480 address
      arm64: dts: qcom: sm8150-hdk: add display card overlay

 .../devicetree/bindings/mfd/qcom,spmi-pmic.yaml    |   4 +
 .../bindings/regulator/qcom,pm8150l-lcdb.yaml      |  81 ++++
 arch/arm64/boot/dts/qcom/Makefile                  |   4 +
 arch/arm64/boot/dts/qcom/pm8150l.dtsi              |  14 +
 .../boot/dts/qcom/sm8150-hdk-display-card.dtso     | 113 +++++
 arch/arm64/boot/dts/qcom/sm8150-hdk.dts            |   4 +-
 arch/arm64/boot/dts/qcom/sm8150.dtsi               |   1 +
 drivers/regulator/Kconfig                          |   8 +
 drivers/regulator/Makefile                         |   1 +
 drivers/regulator/qcom-lcdb-regulator.c            | 494 +++++++++++++++++++++
 drivers/video/backlight/qcom-wled.c                |  56 +--
 11 files changed, 746 insertions(+), 34 deletions(-)
---
base-commit: 2efb7a11f1aa4d2dc285fe2680cca22cb9f72f64
change-id: 20261014-sm8150-display-card-e43ee5b08c61
prerequisite-change-id: 20260122-sdm845-hdk-9466530c4267:v5
prerequisite-patch-id: cb272273cdb260eb5049ba5cfffe13e7904e7a70
prerequisite-patch-id: de7bcd02cfa3baa997e973220d71791b4e74b4cf
prerequisite-patch-id: efe1cd41bd8c1ddf7c9491a6fca5aec877afce3d
prerequisite-patch-id: 98360ae85418d09598608b3a6337aabd76eff717
prerequisite-patch-id: e46e47c4d158362a382efc455438ef1fd5c95f42
prerequisite-change-id: 20260908-qcom-wled-backlight-fd9574027353:v4
prerequisite-patch-id: ad71f17b07fe258da495c7df319d77c63ab9db7a
prerequisite-patch-id: 0403e028ec3ecac35344dbd6dfa430abb71d45f5
prerequisite-patch-id: 2294f3f59a928fb80b92ff9f1ea57d7eb47365cd
prerequisite-patch-id: 74b7c8ba3cc2e3d9475f4f219a8e8d10fc381d44

Best regards,
--  
With best wishes
Dmitry

[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@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 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

[PATCH v2 2/8] regulator: dt-bindings: add Qualcomm LCDB regulator

[Dmitry Baryshkov]

Several Qualcomm PMICs have an LCDB block providing the positive and
negative bias rails for LCD panels. It is not supported by Linux, so
boards using it either model the rails as dummy fixed regulators and
depend on the state left by the bootloader.

Describe the LCDB regulator present on the PM8150L. Use it as a fallback
compatible for LCDB blocks on PMI632 and PM6150L. PM660L has a different
version of LCDB block, so it's not being covered.

Assisted-by: LLM
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 .../bindings/regulator/qcom,pm8150l-lcdb.yaml      | 81 ++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/Documentation/devicetree/bindings/regulator/qcom,pm8150l-lcdb.yaml b/Documentation/devicetree/bindings/regulator/qcom,pm8150l-lcdb.yaml
new file mode 100644
index 000000000000..d3cba1aa0c2e
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/qcom,pm8150l-lcdb.yaml
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/qcom,pm8150l-lcdb.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm LCDB (LCD Bias) regulator
+
+maintainers:
+  - Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
+
+description:
+  LCDB is the LCD panel bias supply found on Qualcomm PMICs such as PMI632,
+  PM6150L and PM8150L. It consists of a boost converter feeding an LDO, which
+  provides the positive bias rail, and an inverting charge pump (NCP), which
+  provides the negative one. Both rails are switched together by a single
+  module enable.
+
+properties:
+  compatible:
+    oneOf:
+      - const: qcom,pm8150l-lcdb
+      - items:
+          - enum:
+              - qcom,pm6150l-lcdb
+              - qcom,pmi632-lcdb
+          - const: qcom,pm8150l-lcdb
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    items:
+      - description: short circuit on one of the outputs
+
+  ldo:
+    type: object
+    $ref: regulator.yaml#
+    unevaluatedProperties: false
+    description: Positive bias rail.
+
+  ncp:
+    type: object
+    $ref: regulator.yaml#
+    unevaluatedProperties: false
+    description:
+      Negative bias rail. The voltage is specified as an absolute value.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    pmic {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        regulator@ec00 {
+            compatible = "qcom,pm8150l-lcdb";
+            reg = <0xec00>;
+            interrupts = <0x5 0xec 0x1 IRQ_TYPE_EDGE_RISING>;
+
+            ldo {
+                regulator-min-microvolt = <5500000>;
+                regulator-max-microvolt = <5500000>;
+            };
+
+            ncp {
+                regulator-min-microvolt = <5500000>;
+                regulator-max-microvolt = <5500000>;
+            };
+        };
+    };
+
+...

-- 
2.47.3

[PATCH v2 3/8] dt-bindings: mfd: qcom,spmi-pmic: add LCDB

[Dmitry Baryshkov]

Allow the LCDB regulator block as a child of the SPMI PMIC node.

Assisted-by: LLM
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 Documentation/devicetree/bindings/mfd/qcom,spmi-pmic.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/qcom,spmi-pmic.yaml b/Documentation/devicetree/bindings/mfd/qcom,spmi-pmic.yaml
index f6534e9e9912..3ca32d741e68 100644
--- a/Documentation/devicetree/bindings/mfd/qcom,spmi-pmic.yaml
+++ b/Documentation/devicetree/bindings/mfd/qcom,spmi-pmic.yaml
@@ -191,6 +191,10 @@ patternProperties:
     type: object
     $ref: /schemas/power/reset/qcom,pon.yaml#
 
+  "^regulator@[0-9a-f]+$":
+    type: object
+    $ref: /schemas/regulator/qcom,pm8150l-lcdb.yaml#
+
   "^rtc@[0-9a-f]+$":
     type: object
     $ref: /schemas/rtc/qcom-pm8xxx-rtc.yaml#

-- 
2.47.3

[PATCH v2 4/8] regulator: add Qualcomm LCDB driver

[Dmitry Baryshkov]

LCD panels on boards with PMI632, PM6150L or PM8150L take their bias
rails from the LCDB block. Without a driver they only work as long as
the bootloader has enabled it and nothing turns it off.

Both rails sit behind a single module enable, so the module is kept on
while at least one of them is in use. The boost output is not exposed:
it follows the higher of the two rails plus the headroom. Enabling
starts at a lower voltage and ramps up in steps, and the LDO pull-down
is forced while disabling, both as done by the vendor driver.

On a short circuit the module is restarted, up to ten times within a
second. After that the outputs are kept off and the consumers are
notified.

Touch-to-wake and the current limit and soft start tuning are not
supported. Neither is PM660L, whose boost is programmed differently.

Assisted-by: LLM
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/regulator/Kconfig               |   8 +
 drivers/regulator/Makefile              |   1 +
 drivers/regulator/qcom-lcdb-regulator.c | 494 ++++++++++++++++++++++++++++++++
 3 files changed, 503 insertions(+)

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index be6b72daa76f..9fd3f2c7e365 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1915,4 +1915,12 @@ config REGULATOR_QCOM_LABIBB
 	  boost regulator and IBB can be used as a negative boost regulator
 	  for LCD display panel.
 
+config REGULATOR_QCOM_LCDB
+	tristate "Qualcomm LCDB regulator support"
+	depends on SPMI || COMPILE_TEST
+	help
+	  This driver supports the LCDB (LCD bias) block found on Qualcomm
+	  PMICs such as PMI632, PM6150L and PM8150L. It provides the positive
+	  (LDO) and negative (NCP) bias rails for LCD panels.
+
 endif
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 6aabcc54382a..84164d2b6c45 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -123,6 +123,7 @@ obj-$(CONFIG_REGULATOR_MT6397)	+= mt6397-regulator.o
 obj-$(CONFIG_REGULATOR_MTK_DVFSRC) += mtk-dvfsrc-regulator.o
 obj-$(CONFIG_REGULATOR_NEX10000UB) += nex10000ub-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_LABIBB) += qcom-labibb-regulator.o
+obj-$(CONFIG_REGULATOR_QCOM_LCDB) += qcom-lcdb-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_PM8008) += qcom-pm8008-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_REFGEN) += qcom-refgen-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_RPM) += qcom_rpm-regulator.o
diff --git a/drivers/regulator/qcom-lcdb-regulator.c b/drivers/regulator/qcom-lcdb-regulator.c
new file mode 100644
index 000000000000..bb2d4ee23ad5
--- /dev/null
+++ b/drivers/regulator/qcom-lcdb-regulator.c
@@ -0,0 +1,494 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/ktime.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+
+#define LCDB_INT_RT_STS			0x10
+#define  LCDB_VREG_OK_RT_STS		BIT(0)
+#define  LCDB_SC_ERROR_RT_STS		BIT(1)
+
+#define LCDB_BST_OUTPUT_VOLTAGE		0x41
+#define  LCDB_BST_OUTPUT_VOLTAGE_MASK	GENMASK(5, 0)
+
+#define LCDB_MODULE_RDY			0x45
+#define  LCDB_MODULE_RDY_BIT		BIT(7)
+
+#define LCDB_ENABLE_CTL1		0x46
+#define  LCDB_MODULE_EN			BIT(7)
+
+#define LCDB_LDO_OUTPUT_VOLTAGE		0x71
+#define LCDB_LDO_FORCE_PD_CTL		0x79
+#define  LCDB_LDO_FORCE_PD_EN		BIT(0)
+#define  LCDB_LDO_FORCE_PD_MODE		BIT(7)
+
+#define LCDB_NCP_OUTPUT_VOLTAGE		0x81
+
+#define LCDB_OUTPUT_VOLTAGE_MASK	GENMASK(4, 0)
+
+#define LCDB_MIN_UV			4000000
+#define LCDB_STEP_100MV_UV		100000
+#define LCDB_50MV_MIN_UV		4950000
+#define LCDB_STEP_50MV_UV		50000
+#define LCDB_50MV_MIN_SEL		10
+#define LCDB_N_VOLTAGES			32
+
+#define LCDB_BST_MIN_UV			4700000
+#define LCDB_BST_MAX_UV			6275000
+#define LCDB_BST_STEP_UV		25000
+#define LCDB_BST_HEADROOM_UV		150000
+
+#define LCDB_RAMP_START_UV		4500000
+#define LCDB_RAMP_STEP_UV		500000
+
+#define LCDB_OFF_ON_DELAY_US		20000
+#define LCDB_VREG_OK_TIMEOUT_US		50000
+
+#define LCDB_SC_RESET_CNT_DLY_US	1000000
+#define LCDB_SC_CNT_MAX			10
+
+enum {
+	LCDB_LDO,
+	LCDB_NCP,
+	LCDB_NUM_RAILS,
+};
+
+struct qcom_lcdb {
+	struct device *dev;
+	struct regmap *regmap;
+	u32 base;
+
+	struct mutex lock;
+	struct regulator_dev *rdev[LCDB_NUM_RAILS];
+	int uV[LCDB_NUM_RAILS];
+	unsigned int enabled_mask;
+	ktime_t off_time;
+
+	bool sc_disabled;
+	int sc_count;
+	ktime_t sc_time;
+};
+
+static const u8 qcom_lcdb_vreg[LCDB_NUM_RAILS] = {
+	[LCDB_LDO] = LCDB_LDO_OUTPUT_VOLTAGE,
+	[LCDB_NCP] = LCDB_NCP_OUTPUT_VOLTAGE,
+};
+
+static unsigned int qcom_lcdb_uV_to_sel(int uV)
+{
+	if (uV < LCDB_50MV_MIN_UV)
+		return (uV - LCDB_MIN_UV) / LCDB_STEP_100MV_UV;
+
+	return LCDB_50MV_MIN_SEL + (uV - LCDB_50MV_MIN_UV) / LCDB_STEP_50MV_UV;
+}
+
+static int qcom_lcdb_sel_to_uV(unsigned int sel)
+{
+	if (sel < LCDB_50MV_MIN_SEL)
+		return LCDB_MIN_UV + sel * LCDB_STEP_100MV_UV;
+
+	return LCDB_50MV_MIN_UV + (sel - LCDB_50MV_MIN_SEL) * LCDB_STEP_50MV_UV;
+}
+
+static int qcom_lcdb_write_voltages(struct qcom_lcdb *lcdb, int ldo_uV, int ncp_uV)
+{
+	const int uV[LCDB_NUM_RAILS] = { ldo_uV, ncp_uV };
+	unsigned int bst_sel, cur_sel;
+	int bst_uV, ret, i;
+
+	bst_uV = clamp(max(ldo_uV, ncp_uV) + LCDB_BST_HEADROOM_UV,
+		       LCDB_BST_MIN_UV, LCDB_BST_MAX_UV);
+	bst_sel = DIV_ROUND_UP(bst_uV - LCDB_BST_MIN_UV, LCDB_BST_STEP_UV);
+
+	ret = regmap_read(lcdb->regmap, lcdb->base + LCDB_BST_OUTPUT_VOLTAGE, &cur_sel);
+	if (ret)
+		return ret;
+	cur_sel &= LCDB_BST_OUTPUT_VOLTAGE_MASK;
+
+	/* The boost has to stay above both outputs while they are changing */
+	if (bst_sel > cur_sel) {
+		ret = regmap_update_bits(lcdb->regmap,
+					 lcdb->base + LCDB_BST_OUTPUT_VOLTAGE,
+					 LCDB_BST_OUTPUT_VOLTAGE_MASK, bst_sel);
+		if (ret)
+			return ret;
+	}
+
+	for (i = 0; i < LCDB_NUM_RAILS; i++) {
+		ret = regmap_update_bits(lcdb->regmap,
+					 lcdb->base + qcom_lcdb_vreg[i],
+					 LCDB_OUTPUT_VOLTAGE_MASK,
+					 qcom_lcdb_uV_to_sel(uV[i]));
+		if (ret)
+			return ret;
+	}
+
+	if (bst_sel < cur_sel)
+		ret = regmap_update_bits(lcdb->regmap,
+					 lcdb->base + LCDB_BST_OUTPUT_VOLTAGE,
+					 LCDB_BST_OUTPUT_VOLTAGE_MASK, bst_sel);
+
+	return ret;
+}
+
+static int qcom_lcdb_write_limited(struct qcom_lcdb *lcdb, int limit_uV)
+{
+	return qcom_lcdb_write_voltages(lcdb,
+					min(lcdb->uV[LCDB_LDO], limit_uV),
+					min(lcdb->uV[LCDB_NCP], limit_uV));
+}
+
+static int qcom_lcdb_module_disable(struct qcom_lcdb *lcdb)
+{
+	int ret, pd_ret;
+
+	/* Force the LDO pull-down to discharge the output quickly */
+	ret = regmap_write(lcdb->regmap, lcdb->base + LCDB_LDO_FORCE_PD_CTL,
+			   LCDB_LDO_FORCE_PD_EN | LCDB_LDO_FORCE_PD_MODE);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(lcdb->regmap, lcdb->base + LCDB_ENABLE_CTL1, 0);
+	if (!ret) {
+		lcdb->off_time = ktime_get();
+		usleep_range(10000, 11000);
+	}
+
+	pd_ret = regmap_write(lcdb->regmap, lcdb->base + LCDB_LDO_FORCE_PD_CTL, 0);
+
+	return ret ?: pd_ret;
+}
+
+static int qcom_lcdb_module_enable(struct qcom_lcdb *lcdb)
+{
+	int target_uV = max(lcdb->uV[LCDB_LDO], lcdb->uV[LCDB_NCP]);
+	int uV = LCDB_RAMP_START_UV;
+	unsigned int val;
+	s64 off_us;
+	int ret;
+
+	off_us = ktime_us_delta(ktime_get(), lcdb->off_time);
+	if (off_us < LCDB_OFF_ON_DELAY_US)
+		usleep_range(LCDB_OFF_ON_DELAY_US - off_us,
+			     LCDB_OFF_ON_DELAY_US - off_us + 1000);
+
+	/* Start low and ramp the outputs up in steps to limit the inrush current */
+	ret = qcom_lcdb_write_limited(lcdb, uV);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(lcdb->regmap, lcdb->base + LCDB_ENABLE_CTL1,
+			   LCDB_MODULE_EN);
+	if (ret)
+		return ret;
+
+	ret = regmap_read_poll_timeout(lcdb->regmap,
+				       lcdb->base + LCDB_INT_RT_STS, val,
+				       val & LCDB_VREG_OK_RT_STS,
+				       1000, LCDB_VREG_OK_TIMEOUT_US);
+	if (ret) {
+		dev_err(lcdb->dev, "outputs failed to come up: %d\n", ret);
+		goto err_disable;
+	}
+
+	usleep_range(10000, 11000);
+
+	while (uV < target_uV) {
+		uV += LCDB_RAMP_STEP_UV;
+
+		ret = qcom_lcdb_write_limited(lcdb, uV);
+		if (ret)
+			goto err_disable;
+
+		usleep_range(1000, 1100);
+	}
+
+	return 0;
+
+err_disable:
+	qcom_lcdb_module_disable(lcdb);
+
+	return ret;
+}
+
+static int qcom_lcdb_enable(struct regulator_dev *rdev)
+{
+	struct qcom_lcdb *lcdb = rdev_get_drvdata(rdev);
+	int ret = 0;
+
+	guard(mutex)(&lcdb->lock);
+
+	if (lcdb->sc_disabled)
+		return -EIO;
+
+	if (!lcdb->enabled_mask)
+		ret = qcom_lcdb_module_enable(lcdb);
+	if (ret)
+		return ret;
+
+	lcdb->enabled_mask |= BIT(rdev_get_id(rdev));
+
+	return 0;
+}
+
+static int qcom_lcdb_disable(struct regulator_dev *rdev)
+{
+	struct qcom_lcdb *lcdb = rdev_get_drvdata(rdev);
+	unsigned int mask;
+	int ret;
+
+	guard(mutex)(&lcdb->lock);
+
+	mask = lcdb->enabled_mask & ~BIT(rdev_get_id(rdev));
+	if (!mask && !lcdb->sc_disabled) {
+		ret = qcom_lcdb_module_disable(lcdb);
+		if (ret)
+			return ret;
+	}
+
+	lcdb->enabled_mask = mask;
+
+	return 0;
+}
+
+static int qcom_lcdb_is_enabled(struct regulator_dev *rdev)
+{
+	struct qcom_lcdb *lcdb = rdev_get_drvdata(rdev);
+
+	guard(mutex)(&lcdb->lock);
+
+	return !lcdb->sc_disabled && (lcdb->enabled_mask & BIT(rdev_get_id(rdev)));
+}
+
+static int qcom_lcdb_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
+{
+	struct qcom_lcdb *lcdb = rdev_get_drvdata(rdev);
+	int id = rdev_get_id(rdev);
+	int uV[LCDB_NUM_RAILS];
+	int ret;
+
+	guard(mutex)(&lcdb->lock);
+
+	memcpy(uV, lcdb->uV, sizeof(uV));
+	uV[id] = qcom_lcdb_sel_to_uV(sel);
+
+	ret = qcom_lcdb_write_voltages(lcdb, uV[LCDB_LDO], uV[LCDB_NCP]);
+	if (ret)
+		return ret;
+
+	lcdb->uV[id] = uV[id];
+
+	return 0;
+}
+
+static int qcom_lcdb_get_voltage_sel(struct regulator_dev *rdev)
+{
+	struct qcom_lcdb *lcdb = rdev_get_drvdata(rdev);
+
+	guard(mutex)(&lcdb->lock);
+
+	return qcom_lcdb_uV_to_sel(lcdb->uV[rdev_get_id(rdev)]);
+}
+
+static const struct regulator_ops qcom_lcdb_ops = {
+	.enable			= qcom_lcdb_enable,
+	.disable		= qcom_lcdb_disable,
+	.is_enabled		= qcom_lcdb_is_enabled,
+	.set_voltage_sel	= qcom_lcdb_set_voltage_sel,
+	.get_voltage_sel	= qcom_lcdb_get_voltage_sel,
+	.list_voltage		= regulator_list_voltage_linear_range,
+	.map_voltage		= regulator_map_voltage_linear_range,
+};
+
+static const struct linear_range qcom_lcdb_ranges[] = {
+	REGULATOR_LINEAR_RANGE(LCDB_MIN_UV, 0, LCDB_50MV_MIN_SEL - 1,
+			       LCDB_STEP_100MV_UV),
+	REGULATOR_LINEAR_RANGE(LCDB_50MV_MIN_UV, LCDB_50MV_MIN_SEL,
+			       LCDB_N_VOLTAGES - 1, LCDB_STEP_50MV_UV),
+};
+
+static const struct regulator_desc qcom_lcdb_descs[LCDB_NUM_RAILS] = {
+	[LCDB_LDO] = {
+		.name			= "lcdb_ldo",
+		.of_match		= "ldo",
+		.id			= LCDB_LDO,
+		.ops			= &qcom_lcdb_ops,
+		.type			= REGULATOR_VOLTAGE,
+		.linear_ranges		= qcom_lcdb_ranges,
+		.n_linear_ranges	= ARRAY_SIZE(qcom_lcdb_ranges),
+		.n_voltages		= LCDB_N_VOLTAGES,
+		.owner			= THIS_MODULE,
+	},
+	[LCDB_NCP] = {
+		.name			= "lcdb_ncp",
+		.of_match		= "ncp",
+		.id			= LCDB_NCP,
+		.ops			= &qcom_lcdb_ops,
+		.type			= REGULATOR_VOLTAGE,
+		.linear_ranges		= qcom_lcdb_ranges,
+		.n_linear_ranges	= ARRAY_SIZE(qcom_lcdb_ranges),
+		.n_voltages		= LCDB_N_VOLTAGES,
+		.owner			= THIS_MODULE,
+	},
+};
+
+static bool qcom_lcdb_handle_sc(struct qcom_lcdb *lcdb)
+{
+	guard(mutex)(&lcdb->lock);
+
+	if (!lcdb->enabled_mask || lcdb->sc_disabled)
+		return false;
+
+	qcom_lcdb_module_disable(lcdb);
+
+	if (ktime_us_delta(ktime_get(), lcdb->sc_time) > LCDB_SC_RESET_CNT_DLY_US) {
+		lcdb->sc_count = 0;
+	} else if (lcdb->sc_count > LCDB_SC_CNT_MAX) {
+		dev_err(lcdb->dev, "persistent short circuit, keeping the outputs off\n");
+		lcdb->sc_disabled = true;
+		return true;
+	}
+
+	lcdb->sc_count++;
+	lcdb->sc_time = ktime_get();
+
+	if (qcom_lcdb_module_enable(lcdb)) {
+		dev_err(lcdb->dev, "failed to recover from a short circuit\n");
+		lcdb->sc_disabled = true;
+		return true;
+	}
+
+	return false;
+}
+
+static irqreturn_t qcom_lcdb_sc_irq(int irq, void *data)
+{
+	struct qcom_lcdb *lcdb = data;
+	unsigned int val;
+	int ret, i;
+
+	ret = regmap_read(lcdb->regmap, lcdb->base + LCDB_INT_RT_STS, &val);
+	if (ret || !(val & LCDB_SC_ERROR_RT_STS))
+		return IRQ_HANDLED;
+
+	/* Blanking time, a real short circuit is still reported afterwards */
+	usleep_range(2000, 2100);
+
+	ret = regmap_read(lcdb->regmap, lcdb->base + LCDB_INT_RT_STS, &val);
+	if (ret || !(val & LCDB_SC_ERROR_RT_STS))
+		return IRQ_HANDLED;
+
+	if (qcom_lcdb_handle_sc(lcdb)) {
+		for (i = 0; i < LCDB_NUM_RAILS; i++)
+			regulator_notifier_call_chain(lcdb->rdev[i],
+						      REGULATOR_EVENT_FAIL, NULL);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int qcom_lcdb_hw_init(struct qcom_lcdb *lcdb)
+{
+	unsigned int val;
+	int ret, i;
+
+	for (i = 0; i < LCDB_NUM_RAILS; i++) {
+		ret = regmap_read(lcdb->regmap, lcdb->base + qcom_lcdb_vreg[i], &val);
+		if (ret)
+			return ret;
+
+		lcdb->uV[i] = qcom_lcdb_sel_to_uV(val & LCDB_OUTPUT_VOLTAGE_MASK);
+	}
+
+	ret = regmap_read(lcdb->regmap, lcdb->base + LCDB_ENABLE_CTL1, &val);
+	if (ret)
+		return ret;
+
+	if (val & LCDB_MODULE_EN) {
+		lcdb->enabled_mask = GENMASK(LCDB_NUM_RAILS - 1, 0);
+		return 0;
+	}
+
+	return regmap_set_bits(lcdb->regmap, lcdb->base + LCDB_MODULE_RDY,
+			       LCDB_MODULE_RDY_BIT);
+}
+
+static int qcom_lcdb_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct regulator_config cfg = {};
+	struct qcom_lcdb *lcdb;
+	int irq, ret, i;
+
+	lcdb = devm_kzalloc(dev, sizeof(*lcdb), GFP_KERNEL);
+	if (!lcdb)
+		return -ENOMEM;
+
+	lcdb->dev = dev;
+
+	lcdb->regmap = dev_get_regmap(dev->parent, NULL);
+	if (!lcdb->regmap)
+		return dev_err_probe(dev, -ENODEV, "failed to get the parent regmap\n");
+
+	ret = device_property_read_u32(dev, "reg", &lcdb->base);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to get the base address\n");
+
+	ret = devm_mutex_init(dev, &lcdb->lock);
+	if (ret)
+		return ret;
+
+	ret = qcom_lcdb_hw_init(lcdb);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to read the initial state\n");
+
+	cfg.dev = dev;
+	cfg.regmap = lcdb->regmap;
+	cfg.driver_data = lcdb;
+
+	for (i = 0; i < LCDB_NUM_RAILS; i++) {
+		lcdb->rdev[i] = devm_regulator_register(dev, &qcom_lcdb_descs[i], &cfg);
+		if (IS_ERR(lcdb->rdev[i]))
+			return dev_err_probe(dev, PTR_ERR(lcdb->rdev[i]),
+					     "failed to register %s\n",
+					     qcom_lcdb_descs[i].name);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	return devm_request_threaded_irq(dev, irq, NULL, qcom_lcdb_sc_irq,
+					 IRQF_ONESHOT, "lcdb-sc", lcdb);
+}
+
+static const struct of_device_id qcom_lcdb_match[] = {
+	{ .compatible = "qcom,pm8150l-lcdb" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, qcom_lcdb_match);
+
+static struct platform_driver qcom_lcdb_driver = {
+	.driver = {
+		.name = "qcom-lcdb-regulator",
+		.of_match_table = qcom_lcdb_match,
+	},
+	.probe = qcom_lcdb_probe,
+};
+module_platform_driver(qcom_lcdb_driver);
+
+MODULE_DESCRIPTION("Qualcomm LCDB (LCD bias) regulator driver");
+MODULE_LICENSE("GPL");

-- 
2.47.3

[PATCH v2 5/8] arm64: dts: qcom: pm8150l: add LCDB regulators

[Dmitry Baryshkov]

Describe the LCDB block providing the LCD bias rails. Leave empty
regulator nodes, forcing board files to provide correct voltage.

Assisted-by: LLM
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/pm8150l.dtsi | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/pm8150l.dtsi b/arch/arm64/boot/dts/qcom/pm8150l.dtsi
index 3911d6d0d2e2..8d2136d165b1 100644
--- a/arch/arm64/boot/dts/qcom/pm8150l.dtsi
+++ b/arch/arm64/boot/dts/qcom/pm8150l.dtsi
@@ -141,5 +141,19 @@ pm8150l_wled: leds@d800 {
 
 			status = "disabled";
 		};
+
+		pm8150l_lcdb: regulator@ec00 {
+			compatible = "qcom,pm8150l-lcdb";
+			reg = <0xec00>;
+			interrupts = <0x5 0xec 0x1 IRQ_TYPE_EDGE_RISING>;
+
+			status = "disabled";
+
+			pm8150l_lcdb_ldo: ldo {
+			};
+
+			pm8150l_lcdb_ncp: ncp {
+			};
+		};
 	};
 };

-- 
2.47.3

[PATCH v2 6/8] arm64: dts: qcom: sm8150: add MDSS reset

[Dmitry Baryshkov]

The bootloader can leave the display running, as it does on the SM8150
HDK with the display card attached. Describe the MDSS reset so that the
driver can bring the hardware into a known state before using it.

Assisted-by: LLM
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/sm8150.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/qcom/sm8150.dtsi b/arch/arm64/boot/dts/qcom/sm8150.dtsi
index 293fcbacff34..a2d6e6947c4c 100644
--- a/arch/arm64/boot/dts/qcom/sm8150.dtsi
+++ b/arch/arm64/boot/dts/qcom/sm8150.dtsi
@@ -3817,6 +3817,7 @@ mdss: display-subsystem@ae00000 {
 
 			iommus = <&apps_smmu 0x800 0x420>;
 
+			resets = <&dispcc DISP_CC_MDSS_CORE_BCR>;
 			status = "disabled";
 
 			#address-cells = <2>;

-- 
2.47.3

[PATCH v2 7/8] arm64: dts: qcom: sm8150-hdk: fix FSA4480 address

[Dmitry Baryshkov]

The FSA4480 on the SM8150 HDK responds at 0x43 rather than 0x42. With
the wrong address the mux driver fails to probe, the Type-C controller
and the DisplayPort controller keep waiting for it and the display
subsystem never binds.

Fixes: ba712fd55c7b ("arm64: dts: qcom: sm8150-hdk: enable DisplayPort and USB-C altmode")
Assisted-by: LLM
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/sm8150-hdk.dts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sm8150-hdk.dts b/arch/arm64/boot/dts/qcom/sm8150-hdk.dts
index cdced5c848d3..8f4ea981bb89 100644
--- a/arch/arm64/boot/dts/qcom/sm8150-hdk.dts
+++ b/arch/arm64/boot/dts/qcom/sm8150-hdk.dts
@@ -434,9 +434,9 @@ &i2c4 {
 
 	status = "okay";
 
-	typec-mux@42 {
+	typec-mux@43 {
 		compatible = "fcs,fsa4480";
-		reg = <0x42>;
+		reg = <0x43>;
 
 		interrupts-extended = <&tlmm 152 IRQ_TYPE_LEVEL_LOW>;
 

-- 
2.47.3

[PATCH v2 8/8] arm64: dts: qcom: sm8150-hdk: add display card overlay

[Dmitry Baryshkov]

The SM8150 HDK can be fitted with a display card carrying a Truly
NT36850 WQHD dual-DSI panel. It uses the PM8150L WLED for the backlight
and LCDB for the bias rails, and it is mutually exclusive with the
on-board LT9611 HDMI bridge.

Only two of the three WLED strings are connected on the card: the
backlight stays dark and the boost runs into the overvoltage limit if
only the third string is driven.

Assisted-by: LLM
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/Makefile                  |   4 +
 .../boot/dts/qcom/sm8150-hdk-display-card.dtso     | 113 +++++++++++++++++++++
 2 files changed, 117 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/Makefile b/arch/arm64/boot/dts/qcom/Makefile
index 85d06a950b4a..571bda210d63 100644
--- a/arch/arm64/boot/dts/qcom/Makefile
+++ b/arch/arm64/boot/dts/qcom/Makefile
@@ -409,6 +409,10 @@ dtb-$(CONFIG_ARCH_QCOM)	+= sm7325-nothing-spacewar.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sm7325-xiaomi-lisa.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sm7325-xiaomi-taoyao.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sm8150-hdk.dtb
+
+sm8150-hdk-display-card-dtbs	:= sm8150-hdk.dtb sm8150-hdk-display-card.dtbo
+
+dtb-$(CONFIG_ARCH_QCOM)	+= sm8150-hdk-display-card.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sm8150-microsoft-surface-duo.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sm8150-mtp.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sm8150-sony-xperia-kumano-bahamut.dtb
diff --git a/arch/arm64/boot/dts/qcom/sm8150-hdk-display-card.dtso b/arch/arm64/boot/dts/qcom/sm8150-hdk-display-card.dtso
new file mode 100644
index 000000000000..bd57459f9c86
--- /dev/null
+++ b/arch/arm64/boot/dts/qcom/sm8150-hdk-display-card.dtso
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+/*
+ * Display Card kit overlay.
+ */
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+
+/dts-v1/;
+/plugin/;
+
+/* Disable HDMI bridge related nodes (mutually exclusive with the display card) */
+&lt9611_codec {
+	status = "disabled";
+};
+
+&mdss_dsi0 {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	panel@0 {
+		compatible = "truly,wqhd60-nt36850";
+		reg = <0>;
+
+		reset-gpios = <&tlmm 6 GPIO_ACTIVE_LOW>;
+
+		vddio-supply = <&vreg_l14a_1p8>;
+		avdd-supply = <&pm8150l_lcdb_ldo>;
+		avee-supply = <&pm8150l_lcdb_ncp>;
+
+		backlight = <&pm8150l_wled>;
+
+		pinctrl-0 = <&disp0_reset_n_active>, <&mdp_vsync>;
+		pinctrl-1 = <&disp0_reset_n_suspend>, <&mdp_vsync>;
+		pinctrl-names = "default", "sleep";
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				reg = <0>;
+
+				panel0_in: endpoint {
+					remote-endpoint = <&mdss_dsi0_out>;
+				};
+			};
+
+			port@1 {
+				reg = <1>;
+
+				panel1_in: endpoint {
+					remote-endpoint = <&mdss_dsi1_out>;
+				};
+			};
+		};
+	};
+};
+
+&mdss_dsi0_out {
+	remote-endpoint = <&panel0_in>;
+};
+
+&mdss_dsi1_out {
+	remote-endpoint = <&panel1_in>;
+};
+
+&pm8150l_lcdb {
+	status = "okay";
+};
+
+&pm8150l_lcdb_ldo {
+	regulator-min-microvolt = <5500000>;
+	regulator-max-microvolt = <5500000>;
+};
+
+&pm8150l_lcdb_ncp {
+	regulator-min-microvolt = <5500000>;
+	regulator-max-microvolt = <5500000>;
+};
+
+&pm8150l_wled {
+	qcom,num-strings = <2>;
+
+	status = "okay";
+};
+
+&tlmm {
+	disp0_reset_n_active: disp0-reset-n-active-state {
+		pins = "gpio6";
+		function = "gpio";
+		drive-strength = <8>;
+		bias-disable;
+	};
+
+	disp0_reset_n_suspend: disp0-reset-n-suspend-state {
+		pins = "gpio6";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-pull-down;
+	};
+
+	mdp_vsync: mdp-vsync-state {
+		pins = "gpio8";
+		function = "mdp_vsync";
+		drive-strength = <2>;
+		bias-pull-down;
+	};
+};

-- 
2.47.3

Re: [PATCH v2 0/8] arm64: qcom: enable display card support on SM8150 HDK

[Konrad Dybcio]

On 10/19/26 1:25 PM, Dmitry Baryshkov wrote:
> The Qualcomm SM8150 HDK can be equipped with an optional display card
> having the same panel as the display card for SDM845 HDK. Reuse the
> driver submitted at [1] and enable display card support on this HDK.
> 
> Unlike SDM845, this also requires a new LCDB driver, providing voltage
> for the panel and several fixes in the WLED driver. The FSA4480 address
> fix is independent and can be applied earlier.
> 
> [1] https://lore.kernel.org/dri-devel/20261014-sdm845-hdk-v2-0-6d0b4b42f267@oss.qualcomm.com/
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> ---
> Changes in v2:
> - Dropped WLED patch, duplicating one of the applied patches (Konrad)
> - Rework the WLED auto-calibration patch, also dropping the reviews.

The latter failed to complete

Konrad

Re: [PATCH v2 7/8] arm64: dts: qcom: sm8150-hdk: fix FSA4480 address

[Abel Vesa]

On 26-10-19 14:25:43, Dmitry Baryshkov wrote:
> The FSA4480 on the SM8150 HDK responds at 0x43 rather than 0x42. With
> the wrong address the mux driver fails to probe, the Type-C controller
> and the DisplayPort controller keep waiting for it and the display
> subsystem never binds.
> 
> Fixes: ba712fd55c7b ("arm64: dts: qcom: sm8150-hdk: enable DisplayPort and USB-C altmode")
> Assisted-by: LLM
> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Reviewed-by: Abel Vesa <abel.vesa@oss.qualcomm.com>

Re: [PATCH v2 6/8] arm64: dts: qcom: sm8150: add MDSS reset

[Abel Vesa]

On 26-10-19 14:25:42, Dmitry Baryshkov wrote:
> The bootloader can leave the display running, as it does on the SM8150
> HDK with the display card attached. Describe the MDSS reset so that the
> driver can bring the hardware into a known state before using it.
> 
> Assisted-by: LLM
> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Reviewed-by: Abel Vesa <abel.vesa@oss.qualcomm.com>

Re: [PATCH v2 5/8] arm64: dts: qcom: pm8150l: add LCDB regulators

[Abel Vesa]

On 26-10-19 14:25:41, Dmitry Baryshkov wrote:
> Describe the LCDB block providing the LCD bias rails. Leave empty
> regulator nodes, forcing board files to provide correct voltage.
> 
> Assisted-by: LLM
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Reviewed-by: Abel Vesa <abel.vesa@oss.qualcomm.com>

Re: [PATCH v2 8/8] arm64: dts: qcom: sm8150-hdk: add display card overlay

[Konrad Dybcio]

On 10/19/26 1:25 PM, Dmitry Baryshkov wrote:
> The SM8150 HDK can be fitted with a display card carrying a Truly
> NT36850 WQHD dual-DSI panel. It uses the PM8150L WLED for the backlight
> and LCDB for the bias rails, and it is mutually exclusive with the
> on-board LT9611 HDMI bridge.
> 
> Only two of the three WLED strings are connected on the card: the
> backlight stays dark and the boost runs into the overvoltage limit if
> only the third string is driven.
> 
> Assisted-by: LLM
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad

Re: [PATCH v2 8/8] arm64: dts: qcom: sm8150-hdk: add display card overlay

[Abel Vesa]

On 26-10-19 14:25:44, Dmitry Baryshkov wrote:
> The SM8150 HDK can be fitted with a display card carrying a Truly
> NT36850 WQHD dual-DSI panel. It uses the PM8150L WLED for the backlight
> and LCDB for the bias rails, and it is mutually exclusive with the
> on-board LT9611 HDMI bridge.
> 
> Only two of the three WLED strings are connected on the card: the
> backlight stays dark and the boost runs into the overvoltage limit if
> only the third string is driven.
> 
> Assisted-by: LLM
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Reviewed-by: Abel Vesa <abel.vesa@oss.qualcomm.com>

Re: [PATCH v2 5/8] arm64: dts: qcom: pm8150l: add LCDB regulators

[Konrad Dybcio]

On 10/19/26 1:25 PM, Dmitry Baryshkov wrote:
> Describe the LCDB block providing the LCD bias rails. Leave empty
> regulator nodes, forcing board files to provide correct voltage.
> 
> Assisted-by: LLM
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad

Re: [PATCH v2 4/8] regulator: add Qualcomm LCDB driver

[Konrad Dybcio]

On 10/19/26 1:25 PM, Dmitry Baryshkov wrote:
> LCD panels on boards with PMI632, PM6150L or PM8150L take their bias
> rails from the LCDB block. Without a driver they only work as long as
> the bootloader has enabled it and nothing turns it off.

[...]

> +static bool qcom_lcdb_handle_sc(struct qcom_lcdb *lcdb)
> +{
> +	guard(mutex)(&lcdb->lock);
> +
> +	if (!lcdb->enabled_mask || lcdb->sc_disabled)
> +		return false;
> +
> +	qcom_lcdb_module_disable(lcdb);
> +
> +	if (ktime_us_delta(ktime_get(), lcdb->sc_time) > LCDB_SC_RESET_CNT_DLY_US) {
> +		lcdb->sc_count = 0;
> +	} else if (lcdb->sc_count > LCDB_SC_CNT_MAX) {
> +		dev_err(lcdb->dev, "persistent short circuit, keeping the outputs off\n");
> +		lcdb->sc_disabled = true;
> +		return true;
> +	}
> +
> +	lcdb->sc_count++;
> +	lcdb->sc_time = ktime_get();


GPT:

The commit message says to restart up to ten times within one second,
but sc_time is updated on every fault.

Konrad

> +
> +	if (qcom_lcdb_module_enable(lcdb)) {
> +		dev_err(lcdb->dev, "failed to recover from a short circuit\n");
> +		lcdb->sc_disabled = true;
> +		return true;
> +	}
> +
> +	return false;
> +}
> +
> +static irqreturn_t qcom_lcdb_sc_irq(int irq, void *data)
> +{
> +	struct qcom_lcdb *lcdb = data;
> +	unsigned int val;
> +	int ret, i;
> +
> +	ret = regmap_read(lcdb->regmap, lcdb->base + LCDB_INT_RT_STS, &val);
> +	if (ret || !(val & LCDB_SC_ERROR_RT_STS))
> +		return IRQ_HANDLED;
> +
> +	/* Blanking time, a real short circuit is still reported afterwards */
> +	usleep_range(2000, 2100);
> +
> +	ret = regmap_read(lcdb->regmap, lcdb->base + LCDB_INT_RT_STS, &val);
> +	if (ret || !(val & LCDB_SC_ERROR_RT_STS))
> +		return IRQ_HANDLED;
> +
> +	if (qcom_lcdb_handle_sc(lcdb)) {
> +		for (i = 0; i < LCDB_NUM_RAILS; i++)
> +			regulator_notifier_call_chain(lcdb->rdev[i],
> +						      REGULATOR_EVENT_FAIL, NULL);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int qcom_lcdb_hw_init(struct qcom_lcdb *lcdb)
> +{
> +	unsigned int val;
> +	int ret, i;
> +
> +	for (i = 0; i < LCDB_NUM_RAILS; i++) {
> +		ret = regmap_read(lcdb->regmap, lcdb->base + qcom_lcdb_vreg[i], &val);
> +		if (ret)
> +			return ret;
> +
> +		lcdb->uV[i] = qcom_lcdb_sel_to_uV(val & LCDB_OUTPUT_VOLTAGE_MASK);
> +	}
> +
> +	ret = regmap_read(lcdb->regmap, lcdb->base + LCDB_ENABLE_CTL1, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (val & LCDB_MODULE_EN) {
> +		lcdb->enabled_mask = GENMASK(LCDB_NUM_RAILS - 1, 0);
> +		return 0;
> +	}
> +
> +	return regmap_set_bits(lcdb->regmap, lcdb->base + LCDB_MODULE_RDY,
> +			       LCDB_MODULE_RDY_BIT);
> +}
> +
> +static int qcom_lcdb_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct regulator_config cfg = {};
> +	struct qcom_lcdb *lcdb;
> +	int irq, ret, i;
> +
> +	lcdb = devm_kzalloc(dev, sizeof(*lcdb), GFP_KERNEL);
> +	if (!lcdb)
> +		return -ENOMEM;
> +
> +	lcdb->dev = dev;
> +
> +	lcdb->regmap = dev_get_regmap(dev->parent, NULL);
> +	if (!lcdb->regmap)
> +		return dev_err_probe(dev, -ENODEV, "failed to get the parent regmap\n");
> +
> +	ret = device_property_read_u32(dev, "reg", &lcdb->base);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to get the base address\n");
> +
> +	ret = devm_mutex_init(dev, &lcdb->lock);
> +	if (ret)
> +		return ret;
> +
> +	ret = qcom_lcdb_hw_init(lcdb);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to read the initial state\n");
> +
> +	cfg.dev = dev;
> +	cfg.regmap = lcdb->regmap;
> +	cfg.driver_data = lcdb;
> +
> +	for (i = 0; i < LCDB_NUM_RAILS; i++) {
> +		lcdb->rdev[i] = devm_regulator_register(dev, &qcom_lcdb_descs[i], &cfg);
> +		if (IS_ERR(lcdb->rdev[i]))
> +			return dev_err_probe(dev, PTR_ERR(lcdb->rdev[i]),
> +					     "failed to register %s\n",
> +					     qcom_lcdb_descs[i].name);
> +	}
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;
> +
> +	return devm_request_threaded_irq(dev, irq, NULL, qcom_lcdb_sc_irq,
> +					 IRQF_ONESHOT, "lcdb-sc", lcdb);
> +}
> +
> +static const struct of_device_id qcom_lcdb_match[] = {
> +	{ .compatible = "qcom,pm8150l-lcdb" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, qcom_lcdb_match);
> +
> +static struct platform_driver qcom_lcdb_driver = {
> +	.driver = {
> +		.name = "qcom-lcdb-regulator",
> +		.of_match_table = qcom_lcdb_match,
> +	},
> +	.probe = qcom_lcdb_probe,
> +};
> +module_platform_driver(qcom_lcdb_driver);
> +
> +MODULE_DESCRIPTION("Qualcomm LCDB (LCD bias) regulator driver");
> +MODULE_LICENSE("GPL");
>