[PATCH v1 0/3] mfd: aat2870: Convert to use OF bindings

[PATCH v1 0/3] mfd: aat2870: Convert to use OF bindings

[Svyatoslav Ryhel]

Document Skyworks AAT2870 into schema, convert existing driver to
use OF bindings and remove platform data, add support for
in-supplies.

Svyatoslav Ryhel (3):
  dt-bindings: mfd: Document Skyworks AAT2870
  mfd: aat2870: Convert to use OF bindings
  mfd: aat2870: Add support for VIN and IN-LDO power supplies

 .../bindings/leds/skyworks,aat2870.yaml       | 127 ++++++++++++++++++
 drivers/mfd/aat2870-core.c                    | 120 +++++------------
 drivers/regulator/aat2870-regulator.c         |  71 +++++++---
 drivers/video/backlight/aat2870_bl.c          |  54 ++++----
 include/linux/mfd/aat2870.h                   |  95 +------------
 5 files changed, 237 insertions(+), 230 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/leds/skyworks,aat2870.yaml

-- 
2.53.0

[PATCH v1 1/3] dt-bindings: mfd: Document Skyworks AAT2870

[Svyatoslav Ryhel]

Document Skyworks AAT2870 LED Backlight Driver and Multiple LDO Lighting
Management Unit.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 .../bindings/leds/skyworks,aat2870.yaml       | 127 ++++++++++++++++++
 1 file changed, 127 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/skyworks,aat2870.yaml

diff --git a/Documentation/devicetree/bindings/leds/skyworks,aat2870.yaml b/Documentation/devicetree/bindings/leds/skyworks,aat2870.yaml
new file mode 100644
index 0000000000000..6dfcd1fa399ca
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/skyworks,aat2870.yaml
@@ -0,0 +1,127 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/skyworks,aat2870.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AAT2870 LED Backlight Driver and Multiple LDO Lighting Management Unit
+
+maintainers:
+  - Svyatoslav Ryhel <clamor95@gmail.com>
+
+properties:
+  compatible:
+    const: skyworks,aat2870
+
+  reg:
+    maxItems: 1
+
+  enable-gpios:
+    description: GPIO connected to EN pin.
+    maxItems: 1
+
+  vin-supply:
+    description: Regulator providing power to the "IN" pin.
+
+  backlight:
+    $ref: /schemas/leds/backlight/common.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      compatible:
+        const: skyworks,aat2870-backlight
+
+      led-max-microamp:
+        minimum: 450000
+        maximum: 27900000
+        default: 450000
+
+      max-brightness:
+        default: 255
+
+      skyworks,channels:
+        description: layout of active channels, where each bit represents
+          one of 8 channels.
+        $ref: /schemas/types.yaml#/definitions/uint8
+        default: 0xff
+
+    required:
+      - compatible
+
+  regulators:
+    type: object
+    additionalProperties: false
+
+    properties:
+      compatible:
+        const: skyworks,aat2870-regulator
+
+      in-ldo-supply:
+        description: Phandle to parent supply of regulators populated under
+          regulators node. They all share same parent.
+
+    patternProperties:
+      "^(ldo-(a|b|c|d))$":
+        $ref: /schemas/regulator/regulator.yaml#
+        unevaluatedProperties: false
+
+    required:
+      - compatible
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        led-controller@60 {
+            compatible = "skyworks,aat2870";
+            reg = <0x60>;
+
+            enable-gpios = <&gpio 139 GPIO_ACTIVE_HIGH>;
+            vin-supply = <&vdd_3v3_vbat>;
+
+            backlight {
+                compatible = "skyworks,aat2870-backlight";
+
+                skyworks,channels = /bits/ 8 <0xff>;
+                led-max-microamp = <27900000>;
+            };
+
+            regulators {
+                compatible = "skyworks,aat2870-regulator";
+
+                in-ldo-supply = <&vdd_3v3_vbat>;
+
+                ldo-a {
+                    regulator-min-microvolt = <1200000>;
+                    regulator-max-microvolt = <1200000>;
+                };
+
+                ldo-b {
+                    regulator-min-microvolt = <3300000>;
+                    regulator-max-microvolt = <3300000>;
+                    regulator-always-on;
+                };
+
+                ldo-c {
+                    regulator-min-microvolt = <1800000>;
+                    regulator-max-microvolt = <3300000>;
+                    regulator-boot-on;
+                };
+
+                ldo-d {
+                    regulator-min-microvolt = <2700000>;
+                    regulator-max-microvolt = <2800000>;
+                };
+            };
+        };
+    };
-- 
2.53.0

[PATCH v1 2/3] mfd: aat2870: Convert to use OF bindings

[Svyatoslav Ryhel]

Conversion of the AAT2870 driver to use OF bindings requires a few complex
changes that should be done simultaneously.

The AAT2870 essentially provides two functions via child devices:
backlight and regulators. Both functions are fairly self-sufficient and
may not be populated on the final board. Consequently, the MFD
registration API was replaced with of_platform_populate(), and each
sub-device was given its own compatible string.

Additionally, aat2870-core utilizes an enable GPIO. Obtaining this GPIO
was converted to use modern gpiod/OF helpers, allowing the redundant
aat2870_enable() and aat2870_disable() helpers to be removed.

The aat2870-regulator driver was updated to register each of the four LDOs
from a dedicated OF node.

The aat2870-backlight driver was changed to populate all required
properties from a dedicated Device Tree node. Its channel map was updated
to use u8 instead of int. Furthermore, because the maximum current is now
parsed as an absolute value rather than an enum entry, the calculation and
application of the maximum current were updated accordingly.

All of the changes above allow platform data to be removed entirely.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 drivers/mfd/aat2870-core.c            | 115 ++++++--------------------
 drivers/regulator/aat2870-regulator.c |  70 +++++++++++-----
 drivers/video/backlight/aat2870_bl.c  |  54 ++++++------
 include/linux/mfd/aat2870.h           |  95 +--------------------
 4 files changed, 104 insertions(+), 230 deletions(-)

diff --git a/drivers/mfd/aat2870-core.c b/drivers/mfd/aat2870-core.c
index 0d56cd6fbc6a5..8f6d7956e79b2 100644
--- a/drivers/mfd/aat2870-core.c
+++ b/drivers/mfd/aat2870-core.c
@@ -16,8 +16,15 @@
 #include <linux/gpio/legacy.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/aat2870.h>
+#include <linux/of_platform.h>
 #include <linux/regulator/machine.h>
 
+struct aat2870_register {
+	bool readable;
+	bool writeable;
+	u8 value;
+};
+
 static struct aat2870_register aat2870_regs[AAT2870_REG_NUM] = {
 	/* readable, writeable, value */
 	{ 0, 1, 0x00 },	/* 0x00 AAT2870_BL_CH_EN */
@@ -61,34 +68,6 @@ static struct aat2870_register aat2870_regs[AAT2870_REG_NUM] = {
 	{ 0, 1, 0x00 },	/* 0x26 AAT2870_LDO_EN */
 };
 
-static struct mfd_cell aat2870_devs[] = {
-	{
-		.name = "aat2870-backlight",
-		.id = AAT2870_ID_BL,
-		.pdata_size = sizeof(struct aat2870_bl_platform_data),
-	},
-	{
-		.name = "aat2870-regulator",
-		.id = AAT2870_ID_LDOA,
-		.pdata_size = sizeof(struct regulator_init_data),
-	},
-	{
-		.name = "aat2870-regulator",
-		.id = AAT2870_ID_LDOB,
-		.pdata_size = sizeof(struct regulator_init_data),
-	},
-	{
-		.name = "aat2870-regulator",
-		.id = AAT2870_ID_LDOC,
-		.pdata_size = sizeof(struct regulator_init_data),
-	},
-	{
-		.name = "aat2870-regulator",
-		.id = AAT2870_ID_LDOD,
-		.pdata_size = sizeof(struct regulator_init_data),
-	},
-};
-
 static int __aat2870_read(struct aat2870_data *aat2870, u8 addr, u8 *val)
 {
 	int ret;
@@ -196,22 +175,6 @@ static int aat2870_update(struct aat2870_data *aat2870, u8 addr, u8 mask,
 	return ret;
 }
 
-static inline void aat2870_enable(struct aat2870_data *aat2870)
-{
-	if (aat2870->en_pin >= 0)
-		gpio_set_value(aat2870->en_pin, 1);
-
-	aat2870->is_enable = 1;
-}
-
-static inline void aat2870_disable(struct aat2870_data *aat2870)
-{
-	if (aat2870->en_pin >= 0)
-		gpio_set_value(aat2870->en_pin, 0);
-
-	aat2870->is_enable = 0;
-}
-
 #ifdef CONFIG_DEBUG_FS
 static ssize_t aat2870_dump_reg(struct aat2870_data *aat2870, char *buf)
 {
@@ -332,9 +295,7 @@ static inline void aat2870_init_debugfs(struct aat2870_data *aat2870)
 
 static int aat2870_i2c_probe(struct i2c_client *client)
 {
-	struct aat2870_platform_data *pdata = dev_get_platdata(&client->dev);
 	struct aat2870_data *aat2870;
-	int i, j;
 	int ret = 0;
 
 	aat2870 = devm_kzalloc(&client->dev, sizeof(struct aat2870_data),
@@ -348,60 +309,29 @@ static int aat2870_i2c_probe(struct i2c_client *client)
 
 	aat2870->reg_cache = aat2870_regs;
 
-	if (pdata->en_pin < 0)
-		aat2870->en_pin = -1;
-	else
-		aat2870->en_pin = pdata->en_pin;
+	aat2870->en_pin = devm_gpiod_get_optional(&client->dev, "enable",
+						  GPIOD_OUT_HIGH);
+	if (IS_ERR(aat2870->en_pin))
+		return dev_err_probe(&client->dev, PTR_ERR(aat2870->en_pin),
+				     "Failed to get EN GPIO\n");
 
-	aat2870->init = pdata->init;
-	aat2870->uninit = pdata->uninit;
 	aat2870->read = aat2870_read;
 	aat2870->write = aat2870_write;
 	aat2870->update = aat2870_update;
 
 	mutex_init(&aat2870->io_lock);
 
-	if (aat2870->init)
-		aat2870->init(aat2870);
-
-	if (aat2870->en_pin >= 0) {
-		ret = devm_gpio_request_one(&client->dev, aat2870->en_pin,
-					GPIOF_OUT_INIT_HIGH, "aat2870-en");
-		if (ret < 0) {
-			dev_err(&client->dev,
-				"Failed to request GPIO %d\n", aat2870->en_pin);
-			return ret;
-		}
-	}
-
-	aat2870_enable(aat2870);
-
-	for (i = 0; i < pdata->num_subdevs; i++) {
-		for (j = 0; j < ARRAY_SIZE(aat2870_devs); j++) {
-			if ((pdata->subdevs[i].id == aat2870_devs[j].id) &&
-					!strcmp(pdata->subdevs[i].name,
-						aat2870_devs[j].name)) {
-				aat2870_devs[j].platform_data =
-					pdata->subdevs[i].platform_data;
-				break;
-			}
-		}
-	}
+	gpiod_set_value(aat2870->en_pin, 1);
 
-	ret = mfd_add_devices(aat2870->dev, 0, aat2870_devs,
-			      ARRAY_SIZE(aat2870_devs), NULL, 0, NULL);
-	if (ret != 0) {
-		dev_err(aat2870->dev, "Failed to add subdev: %d\n", ret);
-		goto out_disable;
+	ret = of_platform_populate(client->dev.of_node, NULL, NULL, &client->dev);
+	if (ret) {
+		gpiod_set_value(aat2870->en_pin, 0);
+		return dev_err_probe(&client->dev, ret, "Failed to populate cells\n");
 	}
 
 	aat2870_init_debugfs(aat2870);
 
 	return 0;
-
-out_disable:
-	aat2870_disable(aat2870);
-	return ret;
 }
 
 static int aat2870_i2c_suspend(struct device *dev)
@@ -409,7 +339,7 @@ static int aat2870_i2c_suspend(struct device *dev)
 	struct i2c_client *client = to_i2c_client(dev);
 	struct aat2870_data *aat2870 = i2c_get_clientdata(client);
 
-	aat2870_disable(aat2870);
+	gpiod_set_value(aat2870->en_pin, 0);
 
 	return 0;
 }
@@ -421,7 +351,7 @@ static int aat2870_i2c_resume(struct device *dev)
 	struct aat2870_register *reg = NULL;
 	int i;
 
-	aat2870_enable(aat2870);
+	gpiod_set_value(aat2870->en_pin, 1);
 
 	/* restore registers */
 	for (i = 0; i < AAT2870_REG_NUM; i++) {
@@ -436,6 +366,12 @@ static int aat2870_i2c_resume(struct device *dev)
 static DEFINE_SIMPLE_DEV_PM_OPS(aat2870_pm_ops, aat2870_i2c_suspend,
 				aat2870_i2c_resume);
 
+static const struct of_device_id aat2870_match_table[] = {
+	{ .compatible = "skyworks,aat2870" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, aat2870_match_table);
+
 static const struct i2c_device_id aat2870_i2c_id_table[] = {
 	{ "aat2870" },
 	{ }
@@ -444,6 +380,7 @@ static const struct i2c_device_id aat2870_i2c_id_table[] = {
 static struct i2c_driver aat2870_i2c_driver = {
 	.driver = {
 		.name			= "aat2870",
+		.of_match_table		= aat2870_match_table,
 		.pm			= pm_sleep_ptr(&aat2870_pm_ops),
 		.suppress_bind_attrs	= true,
 	},
diff --git a/drivers/regulator/aat2870-regulator.c b/drivers/regulator/aat2870-regulator.c
index 970d86f2bbb81..4d399d0486d19 100644
--- a/drivers/regulator/aat2870-regulator.c
+++ b/drivers/regulator/aat2870-regulator.c
@@ -15,6 +15,15 @@
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/mfd/aat2870.h>
+#include <linux/regulator/of_regulator.h>
+
+/* Device IDs */
+enum aat2870_regulator_id {
+	AAT2870_ID_LDOA,
+	AAT2870_ID_LDOB,
+	AAT2870_ID_LDOC,
+	AAT2870_ID_LDOD
+};
 
 struct aat2870_regulator {
 	struct aat2870_data *aat2870;
@@ -121,6 +130,13 @@ static struct aat2870_regulator aat2870_regulators[] = {
 	AAT2870_LDO(LDOD),
 };
 
+static struct of_regulator_match aat2870_regulator_matches[] = {
+	{ .name = "ldo-a" },
+	{ .name = "ldo-b" },
+	{ .name = "ldo-c" },
+	{ .name = "ldo-d" },
+};
+
 static struct aat2870_regulator *aat2870_get_regulator(int id)
 {
 	struct aat2870_regulator *ri = NULL;
@@ -136,12 +152,11 @@ static struct aat2870_regulator *aat2870_get_regulator(int id)
 		return NULL;
 
 	ri->enable_addr = AAT2870_LDO_EN;
-	ri->enable_shift = id - AAT2870_ID_LDOA;
+	ri->enable_shift = id;
 	ri->enable_mask = 0x1 << ri->enable_shift;
 
-	ri->voltage_addr = (id - AAT2870_ID_LDOA) / 2 ?
-			   AAT2870_LDO_CD : AAT2870_LDO_AB;
-	ri->voltage_shift = (id - AAT2870_ID_LDOA) % 2 ? 0 : 4;
+	ri->voltage_addr = id / 2 ? AAT2870_LDO_CD : AAT2870_LDO_AB;
+	ri->voltage_shift = id % 2 ? 0 : 4;
 	ri->voltage_mask = 0xF << ri->voltage_shift;
 
 	return ri;
@@ -152,33 +167,50 @@ static int aat2870_regulator_probe(struct platform_device *pdev)
 	struct aat2870_regulator *ri;
 	struct regulator_config config = { };
 	struct regulator_dev *rdev;
+	int ret;
 
-	ri = aat2870_get_regulator(pdev->id);
-	if (!ri) {
-		dev_err(&pdev->dev, "Invalid device ID, %d\n", pdev->id);
-		return -EINVAL;
-	}
-	ri->aat2870 = dev_get_drvdata(pdev->dev.parent);
+	ret = of_regulator_match(&pdev->dev, pdev->dev.of_node,
+				 aat2870_regulator_matches,
+				 ARRAY_SIZE(aat2870_regulator_matches));
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret,
+				     "Parsing of regulator node failed\n");
 
-	config.dev = &pdev->dev;
-	config.driver_data = ri;
-	config.init_data = dev_get_platdata(&pdev->dev);
+	for (int idx = 0; idx < ARRAY_SIZE(aat2870_regulator_matches); idx++) {
+		if (!aat2870_regulator_matches[idx].of_node)
+			continue;
 
-	rdev = devm_regulator_register(&pdev->dev, &ri->desc, &config);
-	if (IS_ERR(rdev)) {
-		dev_err(&pdev->dev, "Failed to register regulator %s\n",
-			ri->desc.name);
-		return PTR_ERR(rdev);
+		ri = aat2870_get_regulator(idx);
+		if (!ri)
+			return dev_err_probe(&pdev->dev, -EINVAL,
+					     "Invalid device ID, %d\n", idx);
+
+		ri->aat2870 = dev_get_drvdata(pdev->dev.parent);
+
+		config.dev = &pdev->dev;
+		config.driver_data = ri;
+
+		rdev = devm_regulator_register(&pdev->dev, &ri->desc, &config);
+		if (IS_ERR(rdev))
+			return dev_err_probe(&pdev->dev, PTR_ERR(rdev),
+					     "Failed to register regulator %s\n",
+					     ri->desc.name);
 	}
-	platform_set_drvdata(pdev, rdev);
 
 	return 0;
 }
 
+static const struct of_device_id aat2870_regulator_match_table[] = {
+	{ .compatible = "skyworks,aat2870-regulator" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, aat2870_regulator_match_table);
+
 static struct platform_driver aat2870_regulator_driver = {
 	.driver = {
 		.name	= "aat2870-regulator",
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = aat2870_regulator_match_table,
 	},
 	.probe	= aat2870_regulator_probe,
 };
diff --git a/drivers/video/backlight/aat2870_bl.c b/drivers/video/backlight/aat2870_bl.c
index 8b790df1e842b..bb4c5f9e5af2e 100644
--- a/drivers/video/backlight/aat2870_bl.c
+++ b/drivers/video/backlight/aat2870_bl.c
@@ -15,11 +15,19 @@
 #include <linux/backlight.h>
 #include <linux/mfd/aat2870.h>
 
+/* Backlight has 8 channels, each bit represents one channel */
+#define AAT2870_BL_CH_ALL	0xFF
+
+/* Backlight current magnitude (mA) */
+#define AAT2870_CURRENT_MIN	450000
+#define AAT2870_CURRENT_MAX	27900000
+#define AAT2870_CURRENT_STEP	900000
+
 struct aat2870_bl_driver_data {
 	struct platform_device *pdev;
 	struct backlight_device *bd;
 
-	int channels;
+	u8 channels;
 	int max_current;
 	int brightness; /* current brightness */
 };
@@ -30,7 +38,7 @@ static inline int aat2870_brightness(struct aat2870_bl_driver_data *aat2870_bl,
 	struct backlight_device *bd = aat2870_bl->bd;
 	int val;
 
-	val = brightness * (aat2870_bl->max_current - 1);
+	val = brightness * aat2870_bl->max_current;
 	val /= bd->props.max_brightness;
 
 	return val;
@@ -42,7 +50,7 @@ static inline int aat2870_bl_enable(struct aat2870_bl_driver_data *aat2870_bl)
 			= dev_get_drvdata(aat2870_bl->pdev->dev.parent);
 
 	return aat2870->write(aat2870, AAT2870_BL_CH_EN,
-			      (u8)aat2870_bl->channels);
+			      aat2870_bl->channels);
 }
 
 static inline int aat2870_bl_disable(struct aat2870_bl_driver_data *aat2870_bl)
@@ -96,24 +104,11 @@ static const struct backlight_ops aat2870_bl_ops = {
 
 static int aat2870_bl_probe(struct platform_device *pdev)
 {
-	struct aat2870_bl_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct aat2870_bl_driver_data *aat2870_bl;
 	struct backlight_device *bd;
 	struct backlight_properties props;
 	int ret = 0;
 
-	if (!pdata) {
-		dev_err(&pdev->dev, "No platform data\n");
-		ret = -ENXIO;
-		goto out;
-	}
-
-	if (pdev->id != AAT2870_ID_BL) {
-		dev_err(&pdev->dev, "Invalid device ID, %d\n", pdev->id);
-		ret = -EINVAL;
-		goto out;
-	}
-
 	aat2870_bl = devm_kzalloc(&pdev->dev,
 				  sizeof(struct aat2870_bl_driver_data),
 				  GFP_KERNEL);
@@ -140,20 +135,16 @@ static int aat2870_bl_probe(struct platform_device *pdev)
 
 	aat2870_bl->bd = bd;
 
-	if (pdata->channels > 0)
-		aat2870_bl->channels = pdata->channels;
-	else
-		aat2870_bl->channels = AAT2870_BL_CH_ALL;
+	aat2870_bl->channels = AAT2870_BL_CH_ALL;
+	device_property_read_u8(&pdev->dev, "skyworks,channels", &aat2870_bl->channels);
 
-	if (pdata->max_current > 0)
-		aat2870_bl->max_current = pdata->max_current;
-	else
-		aat2870_bl->max_current = AAT2870_CURRENT_27_9;
+	device_property_read_u32(&pdev->dev, "led-max-microamp", &aat2870_bl->max_current);
+	aat2870_bl->max_current = clamp(aat2870_bl->max_current, AAT2870_CURRENT_MIN,
+					AAT2870_CURRENT_MAX);
+	aat2870_bl->max_current /= AAT2870_CURRENT_STEP;
 
-	if (pdata->max_brightness > 0)
-		bd->props.max_brightness = pdata->max_brightness;
-	else
-		bd->props.max_brightness = 255;
+	bd->props.max_brightness = 255;
+	device_property_read_u32(&pdev->dev, "max-brightness", &bd->props.max_brightness);
 
 	aat2870_bl->brightness = 0;
 	bd->props.power = BACKLIGHT_POWER_ON;
@@ -181,9 +172,16 @@ static void aat2870_bl_remove(struct platform_device *pdev)
 	backlight_update_status(bd);
 }
 
+static const struct of_device_id aat2870_bl_match_table[] = {
+	{ .compatible = "skyworks,aat2870-backlight" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, aat2870_bl_match_table);
+
 static struct platform_driver aat2870_bl_driver = {
 	.driver = {
 		.name	= "aat2870-backlight",
+		.of_match_table = aat2870_bl_match_table,
 	},
 	.probe		= aat2870_bl_probe,
 	.remove		= aat2870_bl_remove,
diff --git a/include/linux/mfd/aat2870.h b/include/linux/mfd/aat2870.h
index c7a3c53eba681..a7b482b790b4e 100644
--- a/include/linux/mfd/aat2870.h
+++ b/include/linux/mfd/aat2870.h
@@ -54,80 +54,13 @@
 #define AAT2870_LDO_EN		0x26
 #define AAT2870_REG_NUM		0x27
 
-/* Device IDs */
-enum aat2870_id {
-	AAT2870_ID_BL,
-	AAT2870_ID_LDOA,
-	AAT2870_ID_LDOB,
-	AAT2870_ID_LDOC,
-	AAT2870_ID_LDOD
-};
-
-/* Backlight channels */
-#define AAT2870_BL_CH1		0x01
-#define AAT2870_BL_CH2		0x02
-#define AAT2870_BL_CH3		0x04
-#define AAT2870_BL_CH4		0x08
-#define AAT2870_BL_CH5		0x10
-#define AAT2870_BL_CH6		0x20
-#define AAT2870_BL_CH7		0x40
-#define AAT2870_BL_CH8		0x80
-#define AAT2870_BL_CH_ALL	0xFF
-
-/* Backlight current magnitude (mA) */
-enum aat2870_current {
-	AAT2870_CURRENT_0_45 = 1,
-	AAT2870_CURRENT_0_90,
-	AAT2870_CURRENT_1_80,
-	AAT2870_CURRENT_2_70,
-	AAT2870_CURRENT_3_60,
-	AAT2870_CURRENT_4_50,
-	AAT2870_CURRENT_5_40,
-	AAT2870_CURRENT_6_30,
-	AAT2870_CURRENT_7_20,
-	AAT2870_CURRENT_8_10,
-	AAT2870_CURRENT_9_00,
-	AAT2870_CURRENT_9_90,
-	AAT2870_CURRENT_10_8,
-	AAT2870_CURRENT_11_7,
-	AAT2870_CURRENT_12_6,
-	AAT2870_CURRENT_13_5,
-	AAT2870_CURRENT_14_4,
-	AAT2870_CURRENT_15_3,
-	AAT2870_CURRENT_16_2,
-	AAT2870_CURRENT_17_1,
-	AAT2870_CURRENT_18_0,
-	AAT2870_CURRENT_18_9,
-	AAT2870_CURRENT_19_8,
-	AAT2870_CURRENT_20_7,
-	AAT2870_CURRENT_21_6,
-	AAT2870_CURRENT_22_5,
-	AAT2870_CURRENT_23_4,
-	AAT2870_CURRENT_24_3,
-	AAT2870_CURRENT_25_2,
-	AAT2870_CURRENT_26_1,
-	AAT2870_CURRENT_27_0,
-	AAT2870_CURRENT_27_9
-};
-
-struct aat2870_register {
-	bool readable;
-	bool writeable;
-	u8 value;
-};
-
 struct aat2870_data {
 	struct device *dev;
 	struct i2c_client *client;
 
 	struct mutex io_lock;
 	struct aat2870_register *reg_cache; /* register cache */
-	int en_pin; /* enable GPIO pin (if < 0, ignore this value) */
-	bool is_enable;
-
-	/* init and uninit for platform specified */
-	int (*init)(struct aat2870_data *aat2870);
-	void (*uninit)(struct aat2870_data *aat2870);
+	struct gpio_desc *en_pin;
 
 	/* i2c io funcntions */
 	int (*read)(struct aat2870_data *aat2870, u8 addr, u8 *val);
@@ -135,30 +68,4 @@ struct aat2870_data {
 	int (*update)(struct aat2870_data *aat2870, u8 addr, u8 mask, u8 val);
 };
 
-struct aat2870_subdev_info {
-	int id;
-	const char *name;
-	void *platform_data;
-};
-
-struct aat2870_platform_data {
-	int en_pin; /* enable GPIO pin (if < 0, ignore this value) */
-
-	struct aat2870_subdev_info *subdevs;
-	int num_subdevs;
-
-	/* init and uninit for platform specified */
-	int (*init)(struct aat2870_data *aat2870);
-	void (*uninit)(struct aat2870_data *aat2870);
-};
-
-struct aat2870_bl_platform_data {
-	/* backlight channels, default is AAT2870_BL_CH_ALL */
-	int channels;
-	/* backlight current magnitude, default is AAT2870_CURRENT_27_9 */
-	int max_current;
-	/* maximum brightness, default is 255 */
-	int max_brightness;
-};
-
 #endif /* __LINUX_MFD_AAT2870_H */
-- 
2.53.0

[PATCH v1 3/3] mfd: aat2870: Add support for VIN and IN-LDO power supplies

[Svyatoslav Ryhel]

The AAT2870 supports a dedicated main power supply input alongside parent
power supply for its internal regulators.

Add support for retrieving and managing these supply regulators
(vin-supply and in-ldo-supply) using the regulator framework to ensure
proper power supply dependencies and power-up sequencing.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 drivers/mfd/aat2870-core.c            | 5 +++++
 drivers/regulator/aat2870-regulator.c | 1 +
 2 files changed, 6 insertions(+)

diff --git a/drivers/mfd/aat2870-core.c b/drivers/mfd/aat2870-core.c
index 8f6d7956e79b2..a9a11be373916 100644
--- a/drivers/mfd/aat2870-core.c
+++ b/drivers/mfd/aat2870-core.c
@@ -17,6 +17,7 @@
 #include <linux/mfd/core.h>
 #include <linux/mfd/aat2870.h>
 #include <linux/of_platform.h>
+#include <linux/regulator/consumer.h>
 #include <linux/regulator/machine.h>
 
 struct aat2870_register {
@@ -309,6 +310,10 @@ static int aat2870_i2c_probe(struct i2c_client *client)
 
 	aat2870->reg_cache = aat2870_regs;
 
+	ret = devm_regulator_get_enable(&client->dev, "vin");
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "Failed to enable regulator\n");
+
 	aat2870->en_pin = devm_gpiod_get_optional(&client->dev, "enable",
 						  GPIOD_OUT_HIGH);
 	if (IS_ERR(aat2870->en_pin))
diff --git a/drivers/regulator/aat2870-regulator.c b/drivers/regulator/aat2870-regulator.c
index 4d399d0486d19..4cbcb277ff20d 100644
--- a/drivers/regulator/aat2870-regulator.c
+++ b/drivers/regulator/aat2870-regulator.c
@@ -114,6 +114,7 @@ static const unsigned int aat2870_ldo_voltages[] = {
 	{						\
 		.desc = {				\
 			.name = #ids,			\
+			.supply_name = "in-ldo",	\
 			.id = AAT2870_ID_##ids,		\
 			.n_voltages = ARRAY_SIZE(aat2870_ldo_voltages),	\
 			.volt_table = aat2870_ldo_voltages, \
-- 
2.53.0

Re: [PATCH v1 3/3] mfd: aat2870: Add support for VIN and IN-LDO power supplies

[sashiko-bot]

> The AAT2870 supports a dedicated main power supply input alongside parent
> power supply for its internal regulators.
> 
> Add support for retrieving and managing these supply regulators
> (vin-supply and in-ldo-supply) using the regulator framework to ensure
> proper power supply dependencies and power-up sequencing.
> 
> Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260930071513.54697-1-clamor95@gmail.com?part=3

Re: [PATCH v1 1/3] dt-bindings: mfd: Document Skyworks AAT2870

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] leds: incorrect scaling for led-max-microamp constraints
--

commit 629a67ba3ff0e9f6e02a0fa733445881d67a7d0c
Author: Svyatoslav Ryhel <clamor95@gmail.com>

dt-bindings: mfd: Document Skyworks AAT2870
    
Document Skyworks AAT2870 LED Backlight Driver and Multiple LDO Lighting
Management Unit.

> diff --git a/Documentation/devicetree/bindings/leds/skyworks,aat2870.yaml b/Documentation/devicetree/bindings/leds/skyworks,aat2870.yaml
> new file mode 100644
> index 0000000000000..6dfcd1fa399ca
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/skyworks,aat2870.yaml
> @@ -0,0 +1,127 @@
[ ... ]
> +  backlight:
> +    $ref: /schemas/leds/backlight/common.yaml#
> +    unevaluatedProperties: false
> +
> +    properties:
> +      compatible:
> +        const: skyworks,aat2870-backlight
> +
> +      led-max-microamp:
> +        minimum: 450000
> +        maximum: 27900000
> +        default: 450000

[Severity: Medium]
Are these constraints for led-max-microamp mathematically correct? The values
range from 450,000 to 27,900,000 uA, which corresponds to 450 mA to 27.9 Amps.

Real hardware limits appear to be 0.45 mA to 27.9 mA, which would be 450 to
27,900 uA. Defining a physically correct value (e.g., <27900>) in a device
tree will fail schema validation.

> +
> +      max-brightness:
> +        default: 255
[ ... ]
> +            backlight {
> +                compatible = "skyworks,aat2870-backlight";
> +
> +                skyworks,channels = /bits/ 8 <0xff>;
> +                led-max-microamp = <27900000>;

[Severity: Medium]
Does this example propagate the erroneous 27.9 Amps value?

The follow-up driver patch (commit mfd: aat2870: Convert to use OF bindings)
propagates this incorrect scaling, meaning correct values will be wrongly
clamped to minimum brightness.

> +            };

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260930071513.54697-1-clamor95@gmail.com?part=1

Re: [PATCH v1 2/3] mfd: aat2870: Convert to use OF bindings

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 7 potential issue(s) to consider:
- [High] regulator: Missing DT Configuration for aat2870
- [High] regulator: Global state corruption causing UAF via of_regulator_match
- [High] backlight: Logic error scales max_current to zero due to unit mismatch
- [High] backlight: Missing default initialization causes max_current truncation to zero
- [High] mfd: Resource Leak and UAF due to unmanaged of_platform_populate
- [High] backlight: Divide by zero in aat2870_brightness()
- [Low] backlight: Type mismatch passing int pointer to u32 reader
--

commit fb76177a0777d443ea10abf629ceb4bbf320d8b9
Author: Svyatoslav Ryhel <clamor95@gmail.com>

mfd: aat2870: Convert to use OF bindings

This commit converts the AAT2870 driver to use OF bindings, replacing the
MFD registration API with of_platform_populate(). It updates the backlight
and regulator child drivers to parse device tree properties directly and
removes the legacy platform data initialization.

> diff --git a/drivers/mfd/aat2870-core.c b/drivers/mfd/aat2870-core.c
> --- a/drivers/mfd/aat2870-core.c
> +++ b/drivers/mfd/aat2870-core.c
[ ... ]
> @@ -348,60 +309,29 @@ static int aat2870_i2c_probe(struct i2c_client *client)
[ ... ]
> -	ret = mfd_add_devices(aat2870->dev, 0, aat2870_devs,
> -			      ARRAY_SIZE(aat2870_devs), NULL, 0, NULL);
> -	if (ret != 0) {
> -		dev_err(aat2870->dev, "Failed to add subdev: %d\n", ret);
> -		goto out_disable;
> +	gpiod_set_value(aat2870->en_pin, 1);
>  
> -	}
> +	ret = of_platform_populate(client->dev.of_node, NULL, NULL, &client->dev);
> +	if (ret) {

[Severity: High]
Are we missing an of_platform_depopulate() call here?

Since of_platform_populate() creates unmanaged child devices, if the parent
I2C driver unbinds, the child devices will remain active. If a child device
is accessed after the parent is removed, wouldn't it result in a
use-after-free when dereferencing the freed parent driver data? Using
devm_of_platform_populate() might resolve this leak.

> +		gpiod_set_value(aat2870->en_pin, 0);
> +		return dev_err_probe(&client->dev, ret, "Failed to populate cells\n");
>  	}
>  
>  	aat2870_init_debugfs(aat2870);
[ ... ]
> diff --git a/drivers/regulator/aat2870-regulator.c b/drivers/regulator/aat2870-regulator.c
> --- a/drivers/regulator/aat2870-regulator.c
> +++ b/drivers/regulator/aat2870-regulator.c
[ ... ]
> @@ -121,6 +130,13 @@ static struct aat2870_regulator aat2870_regulators[] = {
>  	AAT2870_LDO(LDOD),
>  };
>  
> +static struct of_regulator_match aat2870_regulator_matches[] = {
> +	{ .name = "ldo-a" },
> +	{ .name = "ldo-b" },
> +	{ .name = "ldo-c" },
> +	{ .name = "ldo-d" },
> +};

[Severity: High]
Does of_regulator_match() mutate this static array?

of_regulator_match() typically writes device-specific of_node and init_data
pointers into the matched array. If multiple AAT2870 devices are probed,
wouldn't the second probe overwrite the pointers from the first, leading to
data corruption and a potential use-after-free during devres cleanup?

> +
>  static struct aat2870_regulator *aat2870_get_regulator(int id)
>  {
[ ... ]
> @@ -152,33 +167,50 @@ static int aat2870_regulator_probe(struct platform_device *pdev)
[ ... ]
> +	for (int idx = 0; idx < ARRAY_SIZE(aat2870_regulator_matches); idx++) {
> +		if (!aat2870_regulator_matches[idx].of_node)
> +			continue;
>  
> -		return PTR_ERR(rdev);
> +		ri = aat2870_get_regulator(idx);
> +		if (!ri)
> +			return dev_err_probe(&pdev->dev, -EINVAL,
> +					     "Invalid device ID, %d\n", idx);
> +
> +		ri->aat2870 = dev_get_drvdata(pdev->dev.parent);
> +
> +		config.dev = &pdev->dev;
> +		config.driver_data = ri;
> +
> +		rdev = devm_regulator_register(&pdev->dev, &ri->desc, &config);

[Severity: High]
Is there a missing assignment for the Device Tree configuration?

of_regulator_match() parses the DT constraints into the match array, but
config.init_data and config.of_node don't seem to be populated from
aat2870_regulator_matches[idx] before calling devm_regulator_register().
Without these, do the regulators get registered without their DT constraints?

> +		if (IS_ERR(rdev))
> +			return dev_err_probe(&pdev->dev, PTR_ERR(rdev),
> +					     "Failed to register regulator %s\n",
> +					     ri->desc.name);
>  	}
[ ... ]
> diff --git a/drivers/video/backlight/aat2870_bl.c b/drivers/video/backlight/aat2870_bl.c
> --- a/drivers/video/backlight/aat2870_bl.c
> +++ b/drivers/video/backlight/aat2870_bl.c
[ ... ]
> @@ -140,20 +135,16 @@ static int aat2870_bl_probe(struct platform_device *pdev)
>  
>  	aat2870_bl->bd = bd;
>  
> -	if (pdata->channels > 0)
> -		aat2870_bl->channels = pdata->channels;
> -	else
> -		aat2870_bl->channels = AAT2870_BL_CH_ALL;
> +	aat2870_bl->channels = AAT2870_BL_CH_ALL;
> +	device_property_read_u8(&pdev->dev, "skyworks,channels", &aat2870_bl->channels);
>  
> -	if (pdata->max_current > 0)
> -		aat2870_bl->max_current = pdata->max_current;
> -	else
> -		aat2870_bl->max_current = AAT2870_CURRENT_27_9;
> +	device_property_read_u32(&pdev->dev, "led-max-microamp", &aat2870_bl->max_current);
> +	aat2870_bl->max_current = clamp(aat2870_bl->max_current, AAT2870_CURRENT_MIN,
> +					AAT2870_CURRENT_MAX);
> +	aat2870_bl->max_current /= AAT2870_CURRENT_STEP;

[Severity: High]
Can this sequence cause the max current to evaluate to 0?

If the led-max-microamp property is missing, aat2870_bl->max_current starts at
0 (due to devm_kzalloc) before entering the clamp logic.

Also, the clamp and divide logic seems to mix units. If the DT provides a
microamp value like 27900, it gets clamped up to AAT2870_CURRENT_MIN
(450,000) and then integer-divided by AAT2870_CURRENT_STEP (900,000). This
results in 0, which would lock the brightness at 0 when calculating
aat2870_brightness(). Does this need scaling adjustments?

>  
> -	if (pdata->max_brightness > 0)
> -		bd->props.max_brightness = pdata->max_brightness;
> -	else
> -		bd->props.max_brightness = 255;
> +	bd->props.max_brightness = 255;
> +	device_property_read_u32(&pdev->dev, "max-brightness", &bd->props.max_brightness);

[Severity: Low]
Is it safe to pass a pointer to a signed int here? bd->props.max_brightness
is an int, but device_property_read_u32() expects a u32 pointer. This might
cause signedness mismatch issues.

[Severity: High]
Could this lead to a division by zero in aat2870_brightness()?

If the device tree configures max-brightness = <0>, this property reader will
directly overwrite the default 255 with 0. Later, aat2870_brightness()
executes val /= bd->props.max_brightness, which would cause a kernel panic.

>  
>  	aat2870_bl->brightness = 0;
>  	bd->props.power = BACKLIGHT_POWER_ON;

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260930071513.54697-1-clamor95@gmail.com?part=2