[PATCH 1/2] dt-bindings: leds: Document rohm,bd65b60 bindings

[PATCH 1/2] dt-bindings: leds: Document rohm,bd65b60 bindings

[Bogdan Ionescu]

Hi all,

This is my first patch to the kernel, so I expect to have made
some mistakes. I did my best to follow the documentation and
submitting patches guidelines, but if I missed something, please
let me know.

I wasn't sure if I had to add myself to the MAINTAINERS file for such a
small patch, so I didn't.

Patch begins here:

Added devicetree bindings documentation for the rohm,bd65b60
led driver.

Signed-off-by: Bogdan Ionescu <bogdan.ionescu.work@gmail.com>
---
 .../bindings/leds/rohm,bd65b60-leds.yaml      | 77 +++++++++++++++++++
 include/dt-bindings/leds/leds-bd65b60.h       | 20 +++++
 2 files changed, 97 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.yaml
 create mode 100644 include/dt-bindings/leds/leds-bd65b60.h

diff --git a/Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.yaml b/Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.yaml
new file mode 100644
index 000000000000..f69d7acd39c8
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/rohm,bd65b60-leds.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ROHM BD65B60 device tree bindings
+
+maintainers:
+  - Bogdan Ionescu <bogdan.ionescu.work+kernel@gmail.com>
+
+description: |
+  BD65B60 is a white LED driver IC that integrates PWM
+  step-up DC/DC converter with boost-capability of up to
+  maximum 28.5V and current driver with drive capability of up
+  to 25mA(Typ.) maximum setting. Precise brightness can be
+  controlled at wide ranges through the external PWM pulse
+  input.
+
+properties:
+  compatible:
+    const: rohm,bd65b60
+
+  reg:
+    maxItems: 1
+
+  led:
+    type: object
+    $ref: common.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      rohm,enable-outputs:
+        description:
+          Select which leds are being controlled.
+          Values defined in <dt-bindings/leds/leds-bd65b60.h>
+        $ref: "/schemas/types.yaml#/definitions/uint32"
+        enum: [ 0, 1, 4, 5 ]
+
+      rohm,ovp:
+        description:
+          Select Over-Voltage-Portection level.
+          Values defined in <dt-bindings/leds/leds-bd65b60.h>
+        $ref: "/schemas/types.yaml#/definitions/uint32"
+        enum: [ 0, 8, 16 ]
+        default: 16
+
+    required:
+      - rohm,enable-outputs
+
+required:
+  - compatible
+  - reg
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/leds/common.h>
+    #include <dt-bindings/leds/leds-bd65b60.h>
+
+    i2c {
+
+        led_controler@64 {
+            compatible = "rohm,bd65b60";
+            reg = <0x64>;
+
+            backlight_led: led {
+                function = LED_FUNCTION_BACKLIGHT;
+                color = <LED_COLOR_ID_WHITE>;
+                rohm,enable-outputs = <BD65B60_ENABLE_LED1>;
+                default-state = "keep";
+                linux,default-trigger = "backlight";
+            };
+        };
+    };
+
+...
diff --git a/include/dt-bindings/leds/leds-bd65b60.h b/include/dt-bindings/leds/leds-bd65b60.h
new file mode 100644
index 000000000000..8634faae58f4
--- /dev/null
+++ b/include/dt-bindings/leds/leds-bd65b60.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * This header provides macros for the ROHM BD65B60 device tree bindings.
+ *
+ * Copyright (C) 2023 Bogdan Ionescu <bogdan.ionescu.work+kernel@gmail.com>
+ */
+
+#ifndef _DT_BINDINGS_LEDS_BD65B60_H
+#define _DT_BINDINGS_LEDS_BD65B60_H
+
+#define BD65B60_ENABLE_NONE 0
+#define BD65B60_ENABLE_LED1 1
+#define BD65B60_ENABLE_LED2 4
+#define BD65B60_ENABLE_BOTH (BD65B60_ENABLE_LED1 | BD65B60_ENABLE_LED2)
+
+#define BD65B60_OVP_25V 0
+#define BD65B60_OVP_30V 0x08
+#define BD65B60_OVP_35V 0x10
+
+#endif /* _DT_BINDINGS_LEDS_BD65B60_H */
-- 
2.39.2

[PATCH 2/2] leds: Add support for rohm,bd65b60 led driver

[Bogdan Ionescu]

This commit adds support for ROHM BD65B60 led driver.
The chip supports 2 outpus sharing the same current setting
and is controlled over I2C.

Signed-off-by: Bogdan Ionescu <bogdan.ionescu.work@gmail.com>
---
 drivers/leds/Kconfig        |  11 ++
 drivers/leds/Makefile       |   1 +
 drivers/leds/leds-bd65b60.c | 287 ++++++++++++++++++++++++++++++++++++
 3 files changed, 299 insertions(+)
 create mode 100644 drivers/leds/leds-bd65b60.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index aaa9140bc351..8c5090ac5cba 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -717,6 +717,17 @@ config LEDS_BLINKM
 	  This option enables support for the BlinkM RGB LED connected
 	  through I2C. Say Y to enable support for the BlinkM LED.
 
+config LEDS_BD65B60
+	tristate "LED Driver for BD65B60"
+	depends on LEDS_CLASS
+	depends on I2C
+	help
+	  If you have a LCD backlight connected to the ROHM BD65B60,
+	  say Y here to enable this driver.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called leds-bd65b60.
+
 config LEDS_POWERNV
 	tristate "LED support for PowerNV Platform"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index d30395d11fd8..9f85642a2c79 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_LEDS_AW2013)		+= leds-aw2013.o
 obj-$(CONFIG_LEDS_BCM6328)		+= leds-bcm6328.o
 obj-$(CONFIG_LEDS_BCM6358)		+= leds-bcm6358.o
 obj-$(CONFIG_LEDS_BD2802)		+= leds-bd2802.o
+obj-$(CONFIG_LEDS_BD65B60)		+= leds-bd65b60.o
 obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
 obj-$(CONFIG_LEDS_CLEVO_MAIL)		+= leds-clevo-mail.o
 obj-$(CONFIG_LEDS_COBALT_QUBE)		+= leds-cobalt-qube.o
diff --git a/drivers/leds/leds-bd65b60.c b/drivers/leds/leds-bd65b60.c
new file mode 100644
index 000000000000..9843e20369d3
--- /dev/null
+++ b/drivers/leds/leds-bd65b60.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Simple driver for ROHM Semiconductor BD65B60GWL Backlight driver chip
+ *
+ * Copyright (C) 2014 ROHM Semiconductor.com
+ * Copyright (C) 2014 MMI
+ * Copyright (C) 2023 Bogdan Ionescu <bogdan.ionescu.work+kernel@gmail.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define BD65B60_MAX_BRIGHTNESS 255
+#define BD65B60_DEFAULT_BRIGHTNESS 255
+#define BD65B60_DEFAULT_TRIGGER "bkl-trigger"
+#define BD65B60_DEFAULT_NAME "white"
+#define BD65B60_DEFAULT_OVP_VAL BD65B60_35V_OVP
+
+#define INT_DEBOUNCE_MSEC 10
+
+#define PWMEN_MASK 0x20
+#define OVP_MASK 0x18
+#define LEDSEL_MASK 0x05
+
+enum bd65b60_regs {
+	REG_SFTRST = 0x00,
+	REG_COMSET1 = 0x01,
+	REG_COMSET2 = 0x02,
+	REG_LEDSEL = 0x03,
+	REG_ILED = 0x05,
+	REG_CTRLSET = 0x07,
+	REG_SLEWSET = 0x08,
+	REG_PON = 0x0E,
+	REG_MAX = REG_PON,
+};
+
+enum bd65b60_ovp {
+	BD65B60_25V_OVP = 0x00,
+	BD65B60_30V_OVP = 0x08,
+	BD65B60_35V_OVP = 0x10,
+};
+
+enum bd65b60_ledsel {
+	BD65B60_DISABLE = 0x00,
+	BD65B60_LED1SEL = 0x01,
+	BD65B60_LED2SEL = 0x04,
+	BD65B60_LED12SEL = 0x05,
+};
+
+enum bd65b60_pwm_ctrl {
+	BD65B60_PWM_DISABLE = 0x00,
+	BD65B60_PWM_ENABLE = 0x20,
+};
+
+enum bd65b60_state {
+	BD65B60_OFF = 0,
+	BD65B60_ON = 1,
+	BD65B60_KEEP = 2,
+};
+
+struct bd65b60_led {
+	struct led_classdev cdev;
+	struct i2c_client *client;
+	struct regmap *regmap;
+	struct mutex lock; /* Held when writing to registers */
+	enum bd65b60_ledsel enable;
+	enum bd65b60_state state;
+	enum bd65b60_ovp ovp;
+};
+
+static const struct regmap_config bd65b60_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = REG_MAX,
+};
+
+static void bd65b60_brightness_set(struct led_classdev *cdev,
+				   enum led_brightness brightness)
+{
+	int ret;
+	enum bd65b60_state new_state;
+	struct bd65b60_led *led = container_of(cdev, struct bd65b60_led, cdev);
+
+	mutex_lock(&led->lock);
+
+	ret = regmap_write(led->regmap, REG_ILED, brightness);
+
+	new_state = (brightness) ? BD65B60_ON : BD65B60_OFF;
+
+	if (new_state != led->state) {
+		ret |= regmap_write(led->regmap, REG_PON, new_state);
+		led->state = new_state;
+	}
+
+	mutex_unlock(&led->lock);
+
+	if (ret)
+		dev_err(&led->client->dev, "Failed to set brightness: %d", ret);
+}
+
+static int bd65b60_init(struct bd65b60_led *led)
+{
+	int ret;
+
+	mutex_lock(&led->lock);
+
+	if (led->state != BD65B60_KEEP) {
+		/* Reset the chip */
+		ret = regmap_write(led->regmap, REG_SFTRST, 0x01);
+	}
+
+	ret |= regmap_update_bits(led->regmap, REG_COMSET1, OVP_MASK, led->ovp);
+	ret |= regmap_update_bits(led->regmap, REG_LEDSEL, LEDSEL_MASK,
+				  led->enable);
+	ret |= regmap_update_bits(led->regmap, REG_CTRLSET, PWMEN_MASK,
+				  BD65B60_PWM_ENABLE);
+	ret |= regmap_write(led->regmap, REG_PON,
+			    led->state ? BD65B60_ON : BD65B60_OFF);
+
+	mutex_unlock(&led->lock);
+
+	return ret;
+}
+
+static int bd65b60_parse_dt(struct bd65b60_led *led,
+			    struct fwnode_handle **fwnode)
+{
+	struct device *dev = &led->client->dev;
+	struct fwnode_handle *child = NULL;
+	char default_state[] = "keep";
+	int ret;
+
+	child = device_get_next_child_node(dev, child);
+	if (!child) {
+		dev_err(dev, "No led child node found");
+		return -ENODEV;
+	}
+
+	/* Check required properties */
+	if (!fwnode_property_present(child, "rohm,enable-outputs")) {
+		dev_err(dev, "No rohm,enable-outputs property found");
+		return -ENOENT;
+	}
+
+	ret = fwnode_property_read_u32(child, "rohm,enable-outputs", &led->enable);
+	if (ret || (led->enable & LEDSEL_MASK) != led->enable) {
+		dev_err(dev, "Failed to read rohm,enable-outputs property");
+		return ret;
+	}
+
+	/* Check optional properties */
+	led->state = BD65B60_OFF;
+	if (!fwnode_property_present(child, "default-state")) {
+		ret = fwnode_property_read_string(child, "default-state",
+						(const char **)&default_state);
+		if (ret) {
+			dev_err(dev, "Failed to read default-state property");
+			return ret;
+		}
+
+		if (strcmp(default_state, "keep") == 0) {
+			led->state = BD65B60_KEEP;
+		} else if (strcmp(default_state, "on") == 0) {
+			led->state = BD65B60_ON;
+		} else if (strcmp(default_state, "off") == 0) {
+			led->state = BD65B60_OFF;
+		} else {
+			dev_err(dev, "Invalid default-state property");
+			return -EINVAL;
+		}
+	}
+
+	led->ovp = BD65B60_DEFAULT_OVP_VAL;
+	if (fwnode_property_present(child, "rohm,ovp")) {
+		ret = fwnode_property_read_u32(child, "rohm,ovp", &led->ovp);
+
+		if (ret || (led->ovp & OVP_MASK) != led->ovp) {
+			dev_err(dev, "Failed to read rohm,ovp property");
+			return ret;
+		}
+	}
+
+	*fwnode = child;
+
+	return 0;
+}
+
+static int bd65b60_probe(struct i2c_client *client)
+{
+	struct bd65b60_led *led;
+	struct led_init_data init_data = {};
+	struct fwnode_handle *fwnode = NULL;
+	int ret;
+
+	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	led->client = client;
+	i2c_set_clientdata(client, led);
+
+	ret = bd65b60_parse_dt(led, &fwnode);
+	if (ret)
+		return ret;
+
+	led->cdev.name = BD65B60_DEFAULT_NAME;
+	led->cdev.brightness_set = bd65b60_brightness_set;
+	led->cdev.brightness = BD65B60_DEFAULT_BRIGHTNESS;
+	led->cdev.max_brightness = BD65B60_MAX_BRIGHTNESS;
+	led->cdev.default_trigger = BD65B60_DEFAULT_TRIGGER;
+	led->client = client;
+
+	led->regmap = devm_regmap_init_i2c(client, &bd65b60_regmap_config);
+	if (IS_ERR(led->regmap)) {
+		ret = PTR_ERR(led->regmap);
+		dev_err(&client->dev, "Failed to allocate register map: %d",
+			ret);
+		return ret;
+	}
+
+	mutex_init(&led->lock);
+
+	ret = bd65b60_init(led);
+	if (ret) {
+		dev_err(&client->dev, "Failed to initialize led: %d", ret);
+		mutex_destroy(&led->lock);
+		return ret;
+	}
+
+	init_data.fwnode = fwnode;
+	init_data.devicename = led->client->name;
+	init_data.default_label = ":";
+	ret = devm_led_classdev_register_ext(&client->dev, &led->cdev,
+					     &init_data);
+	if (ret) {
+		dev_err(&client->dev, "Failed to register led: %d", ret);
+		mutex_destroy(&led->lock);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void bd65b60_remove(struct i2c_client *client)
+{
+	int ret;
+	struct bd65b60_led *led = i2c_get_clientdata(client);
+
+	ret = regmap_write(led->regmap, REG_PON, BD65B60_OFF);
+	if (ret)
+		dev_err(&client->dev, "Failed to turn off led: %d", ret);
+
+	mutex_destroy(&led->lock);
+}
+
+static const struct i2c_device_id bd65b60_id[] = {
+	{ "bd65b60", 0 },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, bd65b60_id);
+
+static const struct of_device_id of_bd65b60_leds_match[] = {
+	{ .compatible = "rohm,bd65b60" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_bd65b60_leds_match);
+
+static struct i2c_driver bd65b60_i2c_driver = {
+	.driver = {
+		.name = "bd65b60",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(of_bd65b60_leds_match),
+		  },
+	.probe_new = bd65b60_probe,
+	.remove = bd65b60_remove,
+	.id_table = bd65b60_id,
+};
+
+module_i2c_driver(bd65b60_i2c_driver);
+
+MODULE_AUTHOR("Bogdan Ionescu <bogdan.ionescu.work+kernel@gmail.com>");
+MODULE_DESCRIPTION("ROHM Semiconductor led driver for bd65b60");
+MODULE_LICENSE("GPL");
-- 
2.39.2

Re: [PATCH 2/2] leds: Add support for rohm,bd65b60 led driver

[Krzysztof Kozlowski]

On 08/03/2023 21:14, Bogdan Ionescu wrote:
> This commit adds support for ROHM BD65B60 led driver.

Do not use "This commit/patch".
https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95

> The chip supports 2 outpus sharing the same current setting
> and is controlled over I2C.
> 
> Signed-off-by: Bogdan Ionescu <bogdan.ionescu.work@gmail.com>
> ---

Thank you for your patch. There is something to discuss/improve.

> +
> +	/* Check required properties */
> +	if (!fwnode_property_present(child, "rohm,enable-outputs")) {
> +		dev_err(dev, "No rohm,enable-outputs property found");
> +		return -ENOENT;

The property is not required by your binding, so you cannot bail here.

> +	}
> +
> +	ret = fwnode_property_read_u32(child, "rohm,enable-outputs", &led->enable);
> +	if (ret || (led->enable & LEDSEL_MASK) != led->enable) {
> +		dev_err(dev, "Failed to read rohm,enable-outputs property");

No need to check for properties twice...

> +		return ret;
> +	}
> +
> +	/* Check optional properties */
> +	led->state = BD65B60_OFF;
> +	if (!fwnode_property_present(child, "default-state")) {
> +		ret = fwnode_property_read_string(child, "default-state",
> +						(const char **)&default_state);
> +		if (ret) {
> +			dev_err(dev, "Failed to read default-state property");
> +			return ret;
> +		}
> +
> +		if (strcmp(default_state, "keep") == 0) {
> +			led->state = BD65B60_KEEP;
> +		} else if (strcmp(default_state, "on") == 0) {
> +			led->state = BD65B60_ON;
> +		} else if (strcmp(default_state, "off") == 0) {
> +			led->state = BD65B60_OFF;
> +		} else {
> +			dev_err(dev, "Invalid default-state property");
> +			return -EINVAL;
> +		}
> +	}
> +
> +	led->ovp = BD65B60_DEFAULT_OVP_VAL;
> +	if (fwnode_property_present(child, "rohm,ovp")) {
> +		ret = fwnode_property_read_u32(child, "rohm,ovp", &led->ovp);
> +
> +		if (ret || (led->ovp & OVP_MASK) != led->ovp) {
> +			dev_err(dev, "Failed to read rohm,ovp property");
> +			return ret;
> +		}
> +	}
> +
> +	*fwnode = child;
> +
> +	return 0;
> +}
> +
> +static int bd65b60_probe(struct i2c_client *client)
> +{
> +	struct bd65b60_led *led;
> +	struct led_init_data init_data = {};
> +	struct fwnode_handle *fwnode = NULL;
> +	int ret;
> +
> +	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	led->client = client;
> +	i2c_set_clientdata(client, led);
> +
> +	ret = bd65b60_parse_dt(led, &fwnode);
> +	if (ret)
> +		return ret;
> +
> +	led->cdev.name = BD65B60_DEFAULT_NAME;
> +	led->cdev.brightness_set = bd65b60_brightness_set;
> +	led->cdev.brightness = BD65B60_DEFAULT_BRIGHTNESS;
> +	led->cdev.max_brightness = BD65B60_MAX_BRIGHTNESS;
> +	led->cdev.default_trigger = BD65B60_DEFAULT_TRIGGER;
> +	led->client = client;
> +
> +	led->regmap = devm_regmap_init_i2c(client, &bd65b60_regmap_config);
> +	if (IS_ERR(led->regmap)) {
> +		ret = PTR_ERR(led->regmap);
> +		dev_err(&client->dev, "Failed to allocate register map: %d",
> +			ret);

return dev_err_probe

> +		return ret;
> +	}
> +
> +	mutex_init(&led->lock);
> +
> +	ret = bd65b60_init(led);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to initialize led: %d", ret);

return dev_err_probe

> +		mutex_destroy(&led->lock);

or ret = dev_err_probe and goto to common cleanup part

> +		return ret;
> +	}
> +
> +	init_data.fwnode = fwnode;
> +	init_data.devicename = led->client->name;
> +	init_data.default_label = ":";
> +	ret = devm_led_classdev_register_ext(&client->dev, &led->cdev,
> +					     &init_data);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to register led: %d", ret);

return dev_err_probe

> +		mutex_destroy(&led->lock);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void bd65b60_remove(struct i2c_client *client)
> +{
> +	int ret;
> +	struct bd65b60_led *led = i2c_get_clientdata(client);
> +
> +	ret = regmap_write(led->regmap, REG_PON, BD65B60_OFF);
> +	if (ret)
> +		dev_err(&client->dev, "Failed to turn off led: %d", ret);
> +
> +	mutex_destroy(&led->lock);
> +}
> +
> +static const struct i2c_device_id bd65b60_id[] = {
> +	{ "bd65b60", 0 },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(i2c, bd65b60_id);
> +
> +static const struct of_device_id of_bd65b60_leds_match[] = {
> +	{ .compatible = "rohm,bd65b60" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, of_bd65b60_leds_match);
> +
> +static struct i2c_driver bd65b60_i2c_driver = {
> +	.driver = {
> +		.name = "bd65b60",
> +		.owner = THIS_MODULE,
> +		.of_match_table = of_match_ptr(of_bd65b60_leds_match),

Drop of_match_ptr. It requires maybe_unused which you do not have, so
this will cause warnings.

Best regards,
Krzysztof

Re: [PATCH 2/2] leds: Add support for rohm,bd65b60 led driver

[Krzysztof Kozlowski]

On 10/03/2023 11:44, Bogdan Ionescu wrote:
>>> + /* Check required properties */
>>> + if (!fwnode_property_present(child, "rohm,enable-outputs")) {
>>> + dev_err(dev, "No rohm,enable-outputs property found");
>>> + return -ENOENT;
>>> + }
>>> +
>>> + ret = fwnode_property_read_u32(child, "rohm,enable-outputs",
> &led->enable);
>>> + if (ret || (led->enable & LEDSEL_MASK) != led->enable) {
>>> + dev_err(dev, "Failed to read rohm,enable-outputs property");
>>
>> No need to check for properties twice...
> 
> I understand that you can just check the return value, but what is then
> the point of the fwnode_property_present() function? Where is it otherwise
> supposed to be used?
> 
> I am happy to remove the first check, but I would like to understand the
> reasoning behind it. I found value in separating a value not found error
> from an incorrect value error.

ENOENT is not valid code  -  No such file or directory. Thus you cannot
return different codes. The code should be simple and printing error on
fwnode_property_read_u32() is enough to report it to the developer.



Best regards,
Krzysztof

Re: [PATCH 2/2] leds: Add support for rohm,bd65b60 led driver

[kernel test robot]

Hi Bogdan,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on lee-leds/for-leds-next]
[also build test WARNING on robh/for-next pavel-leds/for-next linus/master v6.3-rc2 next-20230317]
[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/Bogdan-Ionescu/leds-Add-support-for-rohm-bd65b60-led-driver/20230309-041730
base:   https://git.kernel.org/pub/scm/linux/kernel/git/lee/leds.git for-leds-next
patch link:    https://lore.kernel.org/r/20230308201451.11629-2-bogdan.ionescu.work%40gmail.com
patch subject: [PATCH 2/2] leds: Add support for rohm,bd65b60 led driver
config: s390-randconfig-r003-20230318 (https://download.01.org/0day-ci/archive/20230318/202303181228.ZP7Ig92k-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 67409911353323ca5edf2049ef0df54132fa1ca7)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/72417c0228f115628b1ad307be9d8e53532de6a6
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Bogdan-Ionescu/leds-Add-support-for-rohm-bd65b60-led-driver/20230309-041730
        git checkout 72417c0228f115628b1ad307be9d8e53532de6a6
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/leds/ drivers/net/usb/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303181228.ZP7Ig92k-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/leds/leds-bd65b60.c:14:
   In file included from include/linux/regmap.h:20:
   In file included from include/linux/iopoll.h:14:
   In file included from include/linux/io.h:13:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __raw_readb(PCI_IOBASE + addr);
                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
                                                           ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu'
   #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
                                                             ^
   include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
   #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
                                                        ^
   In file included from drivers/leds/leds-bd65b60.c:14:
   In file included from include/linux/regmap.h:20:
   In file included from include/linux/iopoll.h:14:
   In file included from include/linux/io.h:13:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
                                                           ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu'
   #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
                                                             ^
   include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
   #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
                                                        ^
   In file included from drivers/leds/leds-bd65b60.c:14:
   In file included from include/linux/regmap.h:20:
   In file included from include/linux/iopoll.h:14:
   In file included from include/linux/io.h:13:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writeb(value, PCI_IOBASE + addr);
                               ~~~~~~~~~~ ^
   include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
                                                         ~~~~~~~~~~ ^
   include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
                                                         ~~~~~~~~~~ ^
   include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           readsb(PCI_IOBASE + addr, buffer, count);
                  ~~~~~~~~~~ ^
   include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           readsw(PCI_IOBASE + addr, buffer, count);
                  ~~~~~~~~~~ ^
   include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           readsl(PCI_IOBASE + addr, buffer, count);
                  ~~~~~~~~~~ ^
   include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           writesb(PCI_IOBASE + addr, buffer, count);
                   ~~~~~~~~~~ ^
   include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           writesw(PCI_IOBASE + addr, buffer, count);
                   ~~~~~~~~~~ ^
   include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           writesl(PCI_IOBASE + addr, buffer, count);
                   ~~~~~~~~~~ ^
   drivers/leds/leds-bd65b60.c:111:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
           if (led->state != BD65B60_KEEP) {
               ^~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/leds/leds-bd65b60.c:116:2: note: uninitialized use occurs here
           ret |= regmap_update_bits(led->regmap, REG_COMSET1, OVP_MASK, led->ovp);
           ^~~
   drivers/leds/leds-bd65b60.c:111:2: note: remove the 'if' if its condition is always true
           if (led->state != BD65B60_KEEP) {
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/leds/leds-bd65b60.c:107:9: note: initialize the variable 'ret' to silence this warning
           int ret;
                  ^
                   = 0
>> drivers/leds/leds-bd65b60.c:266:34: warning: unused variable 'of_bd65b60_leds_match' [-Wunused-const-variable]
   static const struct of_device_id of_bd65b60_leds_match[] = {
                                    ^
   14 warnings generated.


vim +/of_bd65b60_leds_match +266 drivers/leds/leds-bd65b60.c

   265	
 > 266	static const struct of_device_id of_bd65b60_leds_match[] = {
   267		{ .compatible = "rohm,bd65b60" },
   268		{},
   269	};
   270	MODULE_DEVICE_TABLE(of, of_bd65b60_leds_match);
   271	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

Re: [PATCH 1/2] dt-bindings: leds: Document rohm,bd65b60 bindings

[Rob Herring]

On Wed, 08 Mar 2023 20:14:50 +0000, Bogdan Ionescu wrote:
> Hi all,
> 
> This is my first patch to the kernel, so I expect to have made
> some mistakes. I did my best to follow the documentation and
> submitting patches guidelines, but if I missed something, please
> let me know.
> 
> I wasn't sure if I had to add myself to the MAINTAINERS file for such a
> small patch, so I didn't.
> 
> Patch begins here:
> 
> Added devicetree bindings documentation for the rohm,bd65b60
> led driver.
> 
> Signed-off-by: Bogdan Ionescu <bogdan.ionescu.work@gmail.com>
> ---
>  .../bindings/leds/rohm,bd65b60-leds.yaml      | 77 +++++++++++++++++++
>  include/dt-bindings/leds/leds-bd65b60.h       | 20 +++++
>  2 files changed, 97 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.yaml
>  create mode 100644 include/dt-bindings/leds/leds-bd65b60.h
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:

dtschema/dtc warnings/errors:
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dts:25.17-30: Warning (reg_format): /example-0/i2c/led_controler@64:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dtb: Warning (pci_device_reg): Failed prerequisite 'reg_format'
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dtb: Warning (pci_device_bus_num): Failed prerequisite 'reg_format'
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dtb: Warning (simple_bus_reg): Failed prerequisite 'reg_format'
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dts:21.13-35.11: Warning (i2c_bus_bridge): /example-0/i2c: incorrect #address-cells for I2C bus
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dts:21.13-35.11: Warning (i2c_bus_bridge): /example-0/i2c: incorrect #size-cells for I2C bus
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dtb: Warning (i2c_bus_reg): Failed prerequisite 'reg_format'
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dtb: Warning (i2c_bus_reg): Failed prerequisite 'i2c_bus_bridge'
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dtb: Warning (spi_bus_reg): Failed prerequisite 'reg_format'
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dts:23.30-34.15: Warning (avoid_default_addr_size): /example-0/i2c/led_controler@64: Relying on default #address-cells value
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dts:23.30-34.15: Warning (avoid_default_addr_size): /example-0/i2c/led_controler@64: Relying on default #size-cells value
Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.example.dtb: Warning (unique_unit_address_if_enabled): Failed prerequisite 'avoid_default_addr_size'

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20230308201451.11629-1-bogdan.ionescu.work@gmail.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH 1/2] dt-bindings: leds: Document rohm,bd65b60 bindings

[Krzysztof Kozlowski]

On 08/03/2023 21:14, Bogdan Ionescu wrote:
> Hi all,
> 
> This is my first patch to the kernel, so I expect to have made
> some mistakes. I did my best to follow the documentation and
> submitting patches guidelines, but if I missed something, please
> let me know.
> 
> I wasn't sure if I had to add myself to the MAINTAINERS file for such a
> small patch, so I didn't.
> 
> Patch begins here:

This all goes to cover letter. Patch begins with first line. `git am`
this patch so you will see the issues.

> 
> Added devicetree bindings documentation for the rohm,bd65b60
> led driver.
> 
> Signed-off-by: Bogdan Ionescu <bogdan.ionescu.work@gmail.com>

Subject: drop second/last, redundant "bindings". The "dt-bindings"
prefix is already stating that these are bindings.

> ---
>  .../bindings/leds/rohm,bd65b60-leds.yaml      | 77 +++++++++++++++++++
>  include/dt-bindings/leds/leds-bd65b60.h       | 20 +++++
>  2 files changed, 97 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.yaml
>  create mode 100644 include/dt-bindings/leds/leds-bd65b60.h
> 
> diff --git a/Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.yaml b/Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.yaml
> new file mode 100644
> index 000000000000..f69d7acd39c8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/rohm,bd65b60-leds.yaml

Drop "-leds". This should match compatible.

> @@ -0,0 +1,77 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/rohm,bd65b60-leds.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ROHM BD65B60 device tree bindings

Drop "device tree bindings"

> +
> +maintainers:
> +  - Bogdan Ionescu <bogdan.ionescu.work+kernel@gmail.com>
> +
> +description: |
> +  BD65B60 is a white LED driver IC that integrates PWM
> +  step-up DC/DC converter with boost-capability of up to
> +  maximum 28.5V and current driver with drive capability of up
> +  to 25mA(Typ.) maximum setting. Precise brightness can be
> +  controlled at wide ranges through the external PWM pulse
> +  input.
> +
> +properties:
> +  compatible:
> +    const: rohm,bd65b60
> +
> +  reg:
> +    maxItems: 1
> +
> +  led:

Drop led object. There is no real need for it, is it?

> +    type: object
> +    $ref: common.yaml#
> +    unevaluatedProperties: false
> +
> +    properties:
> +      rohm,enable-outputs:
> +        description:
> +          Select which leds are being controlled.
> +          Values defined in <dt-bindings/leds/leds-bd65b60.h>

I don't understand why do you need this property. You should use
generic/existing properties, if possible.

> +        $ref: "/schemas/types.yaml#/definitions/uint32"

Drop quotes

> +        enum: [ 0, 1, 4, 5 ]
> +
> +      rohm,ovp:
> +        description:
> +          Select Over-Voltage-Portection level.
> +          Values defined in <dt-bindings/leds/leds-bd65b60.h>
> +        $ref: "/schemas/types.yaml#/definitions/uint32"

Drop quotes

> +        enum: [ 0, 8, 16 ]
> +        default: 16

What are the units? percent? Volts? Then use unit suffix in property
name. Your other file suggests volts so make it microvolts.

https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml


> +
> +    required:
> +      - rohm,enable-outputs
> +
> +required:
> +  - compatible
> +  - reg
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/leds/common.h>
> +    #include <dt-bindings/leds/leds-bd65b60.h>
> +
> +    i2c {
> +

Drop blank line

Does not look like you tested the bindings. Please run `make
dt_binding_check` (see
Documentation/devicetree/bindings/writing-schema.rst for instructions).

> +        led_controler@64 {

No underscores in node names

> +            compatible = "rohm,bd65b60";
> +            reg = <0x64>;
> +
> +            backlight_led: led {
> +                function = LED_FUNCTION_BACKLIGHT;
> +                color = <LED_COLOR_ID_WHITE>;
> +                rohm,enable-outputs = <BD65B60_ENABLE_LED1>;
> +                default-state = "keep";
> +                linux,default-trigger = "backlight";
> +            };
> +        };
> +    };
> +
> +...
> diff --git a/include/dt-bindings/leds/leds-bd65b60.h b/include/dt-bindings/leds/leds-bd65b60.h
> new file mode 100644
> index 000000000000..8634faae58f4
> --- /dev/null
> +++ b/include/dt-bindings/leds/leds-bd65b60.h

Filename matching binding, but I think entire file will be gone.

> @@ -0,0 +1,20 @@
> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
> +/*
> + * This header provides macros for the ROHM BD65B60 device tree bindings.
> + *
> + * Copyright (C) 2023 Bogdan Ionescu <bogdan.ionescu.work+kernel@gmail.com>
> + */
> +
> +#ifndef _DT_BINDINGS_LEDS_BD65B60_H
> +#define _DT_BINDINGS_LEDS_BD65B60_H
> +
> +#define BD65B60_ENABLE_NONE 0
> +#define BD65B60_ENABLE_LED1 1
> +#define BD65B60_ENABLE_LED2 4
> +#define BD65B60_ENABLE_BOTH (BD65B60_ENABLE_LED1 | BD65B60_ENABLE_LED2)

I don't understand this.

> +
> +#define BD65B60_OVP_25V 0
> +#define BD65B60_OVP_30V 0x08
> +#define BD65B60_OVP_35V 0x10

Drop, register values are not bindings.

> +
> +#endif /* _DT_BINDINGS_LEDS_BD65B60_H */

Best regards,
Krzysztof

Re: [PATCH 1/2] dt-bindings: leds: Document rohm,bd65b60 bindings

[Krzysztof Kozlowski]

On 10/03/2023 11:41, Bogdan Ionescu wrote:
> Thanks for the feedback, I am working on addressing the issues you have
> raised. If I haven't mentioned something, please assume I am implementing
> your suggestion.
> 
>>> +    properties:
>>> +      rohm,enable-outputs:
>>
>> I don't understand why do you need this property. You should use
>> generic/existing properties, if possible.
> 
>> Drop led object. There is no real need for it, is it?
> 
> Would this structure be more appropriate:
> 
> + led-controler@64 {
> +     compatible = "rohm,bd65b60";
> +     reg = <0x64>;
> +     default-state = "keep";
> +     linux,default-trigger = "backlight";
> +
> +     led@1 {
> +         reg = <1>;
> +         function = LED_FUNCTION_BACKLIGHT;
> +         color = <LED_COLOR_ID_WHITE>;
> +     };
> +
> +     led@2 {
> +         reg = <2>;
> +         function = LED_FUNCTION_BACKLIGHT;
> +         color = <LED_COLOR_ID_WHITE>;
> +     };
> + };
> 
> Can I have 2 led nodes if they share the same brightness?

I think yes, but what about LED on/off? Is it also shared or separate?
Because if it is shared, then basically it is just one LED...

> 
>>> +        enum: [ 0, 8, 16 ]
>>> +        default: 16
>>
>> What are the units? percent? Volts? Then use unit suffix in property
>> name. Your other file suggests volts so make it microvolts.
> 
> The chip has 3 possible values 25V, 30V and 35V. How should the driver
>  handle a value that is not exactly that?
> Should it round down for safety or return an error?

Then use -microvolt and real units
https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml


> 
> This was the reason for creating the bindings header file.
> Is it possible to reference defines from the bindings header file?
> 
> + enum:
> +   - BD65B60_OVP_25V
> +   - BD65B60_OVP_30V
> +   - BD65B60_OVP_35V
> + default: BD65B60_OVP_35V
> 
> I would prefer it if I didn't have to expose the weird bitmasks that ROHM
> have decided to use and instead use the actual values.
> 
> Apologies for the long email, but I wanted to make sure I was clear.




Best regards,
Krzysztof

Re: [PATCH 1/2] dt-bindings: leds: Document rohm,bd65b60 bindings

[Krzysztof Kozlowski]

On 12/03/2023 21:34, Bogdan Ionescu wrote:
>> I think yes, but what about LED on/off? Is it also shared or separate?
>> Because if it is shared, then basically it is just one LED...
> No, the outputs can be enabled independently, but I don't see any
> function in the led_classdev to do that.
> The led-sources property looks like the right thing to use for this.
> If I have effectively only one led per device, do I still need an led
> child node or is this sufficient:
> 
> +   #include <dt-bindings/leds/common.h>
> +   i2c {
> +     backlight@64 {

First of all, backlight is something a bit different/more specific - see
Documentation/devicetree/bindings/leds/backlight/

Anyway for led-sources and everything in one node, I think you do not
need any children. But this will allow you only one function and one
color...

> +       compatible = "rohm,bd65b60";
> +       reg = <0x64>;
> +
> +       led-sources = <1>, <2>;
> +       function = LED_FUNCTION_BACKLIGHT;
> +       color = <LED_COLOR_ID_WHITE>;
> +
> +       rohm,ovp = <30000000>;
> +     };
> +   };
> 
> Best regards,
> Bogdan Ionescu
> 

Best regards,
Krzysztof