[PATCH v2 1/2] dt-bindings: backlight: Add MPS MP3309C

[PATCH v2 1/2] dt-bindings: backlight: Add MPS MP3309C

[Flavio Suligoi]

The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
programmable switching frequency to optimize efficiency.
The brightness can be controlled either by I2C commands (called "analog"
mode) or by a PWM input signal (PWM mode).
This driver supports both modes.

For device driver details, please refer to:
- drivers/video/backlight/mp3309c_bl.c

The datasheet is available at:
- https://www.monolithicpower.com/en/mp3309c.html

Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
---

v2:
 - remove useless properties (dimming-mode, pinctrl-names, pinctrl-0,
   switch-on-delay-ms, switch-off-delay-ms, reset-gpios, reset-on-delay-ms,
   reset-on-length-ms)
 - add common.yaml#
 - remove already included properties (default-brightness, max-brightness)
 - substitute three boolean properties, used for the overvoltage-protection
   values, with a single enum property
 - remove some conditional definitions
 - remove the 2nd example
v1:
 - first version

 .../bindings/leds/backlight/mps,mp3309c.yaml  | 73 +++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml

diff --git a/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
new file mode 100644
index 000000000000..99ccdba2c08f
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/mps,mp3309c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MPS MP3309C backlight
+
+maintainers:
+  - Flavio Suligoi <f.suligoi@asem.it>
+
+description: |
+  The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
+  programmable switching frequency to optimize efficiency.
+  It supports two different dimming modes:
+
+  - analog mode, via I2C commands (default)
+  - PWM controlled mode.
+
+  The datasheet is available at:
+  https://www.monolithicpower.com/en/mp3309c.html
+
+allOf:
+  - $ref: common.yaml#
+
+properties:
+  compatible:
+    const: mps,mp3309c
+
+  reg:
+    maxItems: 1
+
+  pwms:
+    description: if present, the backlight is controlled in PWM mode.
+    maxItems: 1
+
+  enable-gpios:
+    description: GPIO used to enable the backlight in "analog-i2c" dimming mode.
+    maxItems: 1
+
+  mps,overvoltage-protection-microvolt:
+    description: Overvoltage protection (13.5V, 24V or 35.5V). If missing, the
+      hardware default of 35.5V is used.
+    enum: [ 13500000, 24000000, 35500000 ]
+
+  mps,no-sync-mode:
+    description: disable synchronous rectification mode
+    type: boolean
+
+required:
+  - compatible
+  - reg
+  - max-brightness
+  - default-brightness
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        /* Backlight with PWM control */
+        backlight_pwm: backlight@17 {
+            compatible = "mps,mp3309c-backlight";
+            reg = <0x17>;
+            pwms = <&pwm1 0 3333333 0>; /* 300 Hz --> (1/f) * 1*10^9 */
+            max-brightness = <100>;
+            default-brightness = <80>;
+            overvoltage-protection-microvolt = <24000000>;
+        };
+    };
-- 
2.34.1

[PATCH v2 2/2] backlight: mp3309c: Add support for MPS MP3309C

[Flavio Suligoi]

The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
programmable switching frequency to optimize efficiency.
The brightness can be controlled either by I2C commands (called "analog"
mode) or by a PWM input signal (PWM mode).
This driver supports both modes.

For DT configuration details, please refer to:
- Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml

The datasheet is available at:
- https://www.monolithicpower.com/en/mp3309c.html

Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
---

v2:
 - fix dependecies in Kconfig
 - fix Kconfig MP3309C entry order
 - remove switch-on-delay-ms property
 - remove optional gpio property to reset external devices
 - remove dimming-mode property (the analog-i2c dimming mode is the default; the
   presence of the pwms property, in DT, selects automatically the pwm dimming
   mode)
 - substitute three boolean properties, used for the overvoltage-protection
   values, with a single enum property
 - drop simple tracing messages
 - use dev_err_probe() in probe function
 - change device name from mp3309c_bl to the simple mp3309c
 - remove shutdown function
v1:
 - first version

 MAINTAINERS                       |   6 +
 drivers/video/backlight/Kconfig   |  11 +
 drivers/video/backlight/Makefile  |   1 +
 drivers/video/backlight/mp3309c.c | 395 ++++++++++++++++++++++++++++++
 4 files changed, 413 insertions(+)
 create mode 100644 drivers/video/backlight/mp3309c.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 3be1bdfe8ecc..f779df433af1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14333,6 +14333,12 @@ S:	Maintained
 F:	Documentation/driver-api/tty/moxa-smartio.rst
 F:	drivers/tty/mxser.*
 
+MP3309C BACKLIGHT DRIVER
+M:	Flavio Suligoi <f.suligoi@asem.it>
+S:	Maintained
+F:	Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
+F:	drivers/video/backlight/mp3309c.c
+
 MR800 AVERMEDIA USB FM RADIO DRIVER
 M:	Alexey Klimov <klimov.linux@gmail.com>
 L:	linux-media@vger.kernel.org
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 51387b1ef012..1144a54a35c0 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -402,6 +402,17 @@ config BACKLIGHT_LP8788
 	help
 	  This supports TI LP8788 backlight driver.
 
+config BACKLIGHT_MP3309C
+	tristate "Backlight Driver for MPS MP3309C"
+	depends on I2C && PWM
+	select REGMAP_I2C
+	help
+	  This supports MPS MP3309C backlight WLED driver in both PWM and
+	  analog/I2C dimming modes.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called mp3309c.
+
 config BACKLIGHT_PANDORA
 	tristate "Backlight driver for Pandora console"
 	depends on TWL4030_CORE
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index f72e1c3c59e9..1af583de665b 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_BACKLIGHT_LP855X)		+= lp855x_bl.o
 obj-$(CONFIG_BACKLIGHT_LP8788)		+= lp8788_bl.o
 obj-$(CONFIG_BACKLIGHT_LV5207LP)	+= lv5207lp.o
 obj-$(CONFIG_BACKLIGHT_MAX8925)		+= max8925_bl.o
+obj-$(CONFIG_BACKLIGHT_MP3309C)		+= mp3309c.o
 obj-$(CONFIG_BACKLIGHT_MT6370)		+= mt6370-backlight.o
 obj-$(CONFIG_BACKLIGHT_OMAP1)		+= omap1_bl.o
 obj-$(CONFIG_BACKLIGHT_PANDORA)		+= pandora_bl.o
diff --git a/drivers/video/backlight/mp3309c.c b/drivers/video/backlight/mp3309c.c
new file mode 100644
index 000000000000..470c960d7438
--- /dev/null
+++ b/drivers/video/backlight/mp3309c.c
@@ -0,0 +1,395 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for MPS MP3309C White LED driver with I2C interface
+ *
+ * Copyright (C) 2023 ASEM Srl
+ * Author: Flavio Suligoi <f.suligoi@asem.it>
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+
+#define REG_I2C_0	0x00
+#define REG_I2C_1	0x01
+
+#define REG_I2C_0_EN	0x80
+#define REG_I2C_0_D0	0x40
+#define REG_I2C_0_D1	0x20
+#define REG_I2C_0_D2	0x10
+#define REG_I2C_0_D3	0x08
+#define REG_I2C_0_D4	0x04
+#define REG_I2C_0_RSRV1	0x02
+#define REG_I2C_0_RSRV2	0x01
+
+#define REG_I2C_1_RSRV1	0x80
+#define REG_I2C_1_DIMS	0x40
+#define REG_I2C_1_SYNC	0x20
+#define REG_I2C_1_OVP0	0x10
+#define REG_I2C_1_OVP1	0x08
+#define REG_I2C_1_VOS	0x04
+#define REG_I2C_1_LEDO	0x02
+#define REG_I2C_1_OTP	0x01
+
+#define ANALOG_MAX_VAL	31
+#define ANALOG_REG_MASK 0x7c
+
+enum mp3309c_status_value {
+	FIRST_POWER_ON,
+	BACKLIGHT_OFF,
+	BACKLIGHT_ON,
+};
+
+enum mp3309c_dimming_mode_value {
+	DIMMING_PWM,
+	DIMMING_ANALOG_I2C,
+};
+
+struct mp3309c_platform_data {
+	u32 max_brightness;
+	u32 default_brightness;
+	u8  dimming_mode;
+	u8  over_voltage_protection;
+	bool sync_mode;
+	u8 status;
+};
+
+struct mp3309c_chip {
+	struct device *dev;
+	struct mp3309c_platform_data *pdata;
+	struct backlight_device *bl;
+	struct gpio_desc *enable_gpio;
+	struct regmap *regmap;
+	struct pwm_device *pwmd;
+	int irq;
+	struct gpio_desc *reset_gpio;
+};
+
+static const struct regmap_config mp3309c_regmap = {
+	.name = "mp3309c_regmap",
+	.reg_bits = 8,
+	.reg_stride = 1,
+	.val_bits = 8,
+	.max_register = REG_I2C_1,
+};
+
+static int mp3309c_enable_device(struct mp3309c_chip *chip)
+{
+	u8 reg_val;
+	int ret;
+
+	/* I2C register #0 - Device enable */
+	ret = regmap_update_bits(chip->regmap, REG_I2C_0, REG_I2C_0_EN,
+				 REG_I2C_0_EN);
+	if (ret)
+		return ret;
+
+	/*
+	 * I2C register #1 - Set working mode:
+	 *  - set one of the two dimming mode:
+	 *    - PWM dimming using an external PWM dimming signal
+	 *    - analog dimming using I2C commands
+	 *  - enable/disable synchronous mode
+	 *  - set overvoltage protection (OVP)
+	 */
+	reg_val = 0x00;
+	if (chip->pdata->dimming_mode == DIMMING_PWM)
+		reg_val |= REG_I2C_1_DIMS;
+	if (chip->pdata->sync_mode)
+		reg_val |= REG_I2C_1_SYNC;
+	reg_val |= chip->pdata->over_voltage_protection;
+	ret = regmap_write(chip->regmap, REG_I2C_1, reg_val);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int mp3309c_bl_update_status(struct backlight_device *bl)
+{
+	struct mp3309c_chip *chip = bl_get_data(bl);
+	int brightness = backlight_get_brightness(bl);
+	struct pwm_state pwmstate;
+	unsigned int analog_val, bits_val;
+	int i, ret;
+
+	if (chip->pdata->dimming_mode == DIMMING_PWM) {
+		/*
+		 * PWM dimming mode
+		 */
+		pwm_get_state(chip->pwmd, &pwmstate);
+		pwm_set_relative_duty_cycle(&pwmstate, brightness,
+					    chip->pdata->max_brightness);
+		pwmstate.enabled = true;
+		ret = pwm_apply_state(chip->pwmd, &pwmstate);
+		if (ret)
+			return ret;
+
+		switch (chip->pdata->status) {
+		case FIRST_POWER_ON:
+		case BACKLIGHT_OFF:
+			/*
+			 * After 20ms of pwm off, we must enable the chip again
+			 */
+			if (brightness > 0) {
+				msleep_interruptible(10);
+				mp3309c_enable_device(chip);
+				chip->pdata->status = BACKLIGHT_ON;
+			} else {
+				chip->pdata->status = BACKLIGHT_OFF;
+			}
+			break;
+		case BACKLIGHT_ON:
+			if (brightness == 0)
+				chip->pdata->status = BACKLIGHT_OFF;
+			break;
+		}
+	} else {
+		/*
+		 * Analog dimming (by I2C command) dimming mode
+		 *
+		 * The first time, before setting brightness, we must enable the
+		 * device
+		 */
+		if (chip->pdata->status == FIRST_POWER_ON)
+			mp3309c_enable_device(chip);
+
+		/*
+		 * Dimming mode I2C command
+		 *
+		 * The 5 bits of the dimming analog value D4..D0 is allocated
+		 * in the I2C register #0, in the following way:
+		 *
+		 *     +--+--+--+--+--+--+--+--+
+		 *     |EN|D0|D1|D2|D3|D4|XX|XX|
+		 *     +--+--+--+--+--+--+--+--+
+		 */
+		analog_val = DIV_ROUND_UP(ANALOG_MAX_VAL * brightness,
+					  chip->pdata->max_brightness);
+		bits_val = 0;
+		for (i = 0; i <= 5; i++)
+			bits_val += ((analog_val >> i) & 0x01) << (6 - i);
+		ret = regmap_update_bits(chip->regmap, REG_I2C_0,
+					 ANALOG_REG_MASK, bits_val);
+		if (ret)
+			return ret;
+
+		if (brightness > 0)
+			chip->pdata->status = BACKLIGHT_ON;
+		else
+			chip->pdata->status = BACKLIGHT_OFF;
+	}
+
+	return 0;
+}
+
+static const struct backlight_ops mp3309c_bl_ops = {
+	.update_status = mp3309c_bl_update_status,
+};
+
+static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
+				 struct mp3309c_platform_data *pdata)
+{
+	struct device_node *node = chip->dev->of_node;
+	struct property *prop;
+	int length, ret;
+	unsigned int tmp_value;
+
+	if (!node) {
+		dev_err(chip->dev, "failed to get DT node\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * Dimming mode: the MP3309C provides two dimming control mode:
+	 *
+	 * - PWM mode
+	 * - Analog by I2C control mode (default)
+	 *
+	 * I2C control mode is assumed as default but, if the pwms property is
+	 * found in the backlight node, the mode switches to PWM mode.
+	 */
+	pdata->dimming_mode = DIMMING_ANALOG_I2C;
+	prop = of_find_property(node, "pwms", &length);
+	if (prop) {
+		chip->pwmd = devm_pwm_get(chip->dev, NULL);
+		if (IS_ERR(chip->pwmd))
+			return dev_err_probe(chip->dev, PTR_ERR(chip->pwmd),
+					     "error getting pwm data\n");
+		pdata->dimming_mode = DIMMING_PWM;
+		pwm_apply_args(chip->pwmd);
+	}
+
+	/* Dimming steps (levels): 0 .. max_brightness */
+	ret = of_property_read_u32(node, "max-brightness",
+				   &pdata->max_brightness);
+	if (ret < 0) {
+		dev_err(chip->dev, "failed to get max-brightness from DT\n");
+		return ret;
+	}
+
+	/* Default brightness at startup */
+	ret = of_property_read_u32(node, "default-brightness",
+				   &pdata->default_brightness);
+	if (ret < 0) {
+		dev_err(chip->dev,
+			"failed to get default-brightness from DT\n");
+		return ret;
+	}
+
+	/* Enable GPIO used in I2C dimming mode */
+	if (pdata->dimming_mode == DIMMING_ANALOG_I2C) {
+		chip->enable_gpio = devm_gpiod_get(chip->dev, "enable",
+						   GPIOD_OUT_HIGH);
+		if (IS_ERR(chip->enable_gpio))
+			return dev_err_probe(chip->dev, PTR_ERR(chip->enable_gpio),
+					     "error getting enable gpio\n");
+	}
+
+	/*
+	 * Over-voltage protection (OVP)
+	 *
+	 * This (optional) property values are:
+	 *
+	 *  - 13.5V
+	 *  - 24V
+	 *  - 35.5V (hardware default setting)
+	 *
+	 * If missing, the default value for OVP is 35.5V
+	 */
+	pdata->over_voltage_protection = REG_I2C_1_OVP1;
+	if (!of_property_read_u32(node, "mps,overvoltage-protection-microvolt",
+				  &tmp_value)) {
+		switch (tmp_value) {
+		case 13500000:
+			pdata->over_voltage_protection = 0x00;
+			break;
+		case 24000000:
+			pdata->over_voltage_protection = REG_I2C_1_OVP0;
+			break;
+		case 35500000:
+			pdata->over_voltage_protection = REG_I2C_1_OVP1;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	/* Synchronous (default) and non-synchronous mode */
+	pdata->sync_mode = true;
+	if (of_property_read_bool(node, "mps,no-sync-mode"))
+		pdata->sync_mode = false;
+
+	return 0;
+}
+
+static int mp3309c_probe(struct i2c_client *client)
+{
+	struct mp3309c_platform_data *pdata = dev_get_platdata(&client->dev);
+	struct mp3309c_chip *chip;
+	struct backlight_properties props;
+	struct pwm_state pwmstate;
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(&client->dev, "failed to check i2c functionality\n");
+		return -EOPNOTSUPP;
+	}
+
+	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = &client->dev;
+
+	chip->regmap = devm_regmap_init_i2c(client, &mp3309c_regmap);
+	if (IS_ERR(chip->regmap))
+		return dev_err_probe(&client->dev, PTR_ERR(chip->regmap),
+				     "failed to allocate register map\n");
+
+	i2c_set_clientdata(client, chip);
+
+	if (!pdata) {
+		pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL);
+		if (!pdata)
+			return -ENOMEM;
+
+		ret = pm3309c_parse_dt_node(chip, pdata);
+		if (ret)
+			return ret;
+	}
+	chip->pdata = pdata;
+
+	/* Backlight properties */
+	props.brightness = pdata->default_brightness;
+	props.max_brightness = pdata->max_brightness;
+	props.scale = BACKLIGHT_SCALE_LINEAR;
+	props.type = BACKLIGHT_RAW;
+	props.power = FB_BLANK_UNBLANK;
+	props.fb_blank = FB_BLANK_UNBLANK;
+	chip->bl = devm_backlight_device_register(chip->dev, "mp3309c",
+						  chip->dev, chip, &mp3309c_bl_ops,
+						  &props);
+	if (IS_ERR(chip->bl))
+		return dev_err_probe(chip->dev, PTR_ERR(chip->bl),
+				     "error registering backlight device\n");
+
+	/* In PWM dimming mode, enable pwm device */
+	if (chip->pdata->dimming_mode == DIMMING_PWM) {
+		pwm_init_state(chip->pwmd, &pwmstate);
+		pwm_set_relative_duty_cycle(&pwmstate,
+					    chip->pdata->default_brightness,
+					    chip->pdata->max_brightness);
+		pwmstate.enabled = true;
+		ret = pwm_apply_state(chip->pwmd, &pwmstate);
+		if (ret)
+			return dev_err_probe(chip->dev, ret,
+					     "error setting pwm device\n");
+	}
+
+	chip->pdata->status = FIRST_POWER_ON;
+	backlight_update_status(chip->bl);
+
+	return 0;
+}
+
+static void mp3309c_remove(struct i2c_client *client)
+{
+	struct mp3309c_chip *chip = i2c_get_clientdata(client);
+	struct backlight_device *bl = chip->bl;
+
+	bl->props.power = FB_BLANK_POWERDOWN;
+	bl->props.brightness = 0;
+	backlight_update_status(chip->bl);
+}
+
+static const struct of_device_id mp3309c_match_table[] = {
+	{ .compatible = "mps,mp3309c", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, mp3309c_match_table);
+
+static const struct i2c_device_id mp3309c_id[] = {
+	{ "mp3309c", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mp3309c_id);
+
+static struct i2c_driver mp3309c_i2c_driver = {
+	.driver	= {
+			.name		= KBUILD_MODNAME,
+			.of_match_table	= mp3309c_match_table,
+	},
+	.probe		= mp3309c_probe,
+	.remove		= mp3309c_remove,
+	.id_table	= mp3309c_id,
+};
+
+module_i2c_driver(mp3309c_i2c_driver);
+
+MODULE_DESCRIPTION("Backlight Driver for MPS MP3309C");
+MODULE_AUTHOR("Flavio Suligoi <f.suligoi@asem.it>");
+MODULE_LICENSE("GPL");
-- 
2.34.1

Re: [PATCH v2 1/2] dt-bindings: backlight: Add MPS MP3309C

[Rob Herring]

On Fri, 15 Sep 2023 16:05:15 +0200, Flavio Suligoi wrote:
> The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
> programmable switching frequency to optimize efficiency.
> The brightness can be controlled either by I2C commands (called "analog"
> mode) or by a PWM input signal (PWM mode).
> This driver supports both modes.
> 
> For device driver details, please refer to:
> - drivers/video/backlight/mp3309c_bl.c
> 
> The datasheet is available at:
> - https://www.monolithicpower.com/en/mp3309c.html
> 
> Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
> ---
> 
> v2:
>  - remove useless properties (dimming-mode, pinctrl-names, pinctrl-0,
>    switch-on-delay-ms, switch-off-delay-ms, reset-gpios, reset-on-delay-ms,
>    reset-on-length-ms)
>  - add common.yaml#
>  - remove already included properties (default-brightness, max-brightness)
>  - substitute three boolean properties, used for the overvoltage-protection
>    values, with a single enum property
>  - remove some conditional definitions
>  - remove the 2nd example
> v1:
>  - first version
> 
>  .../bindings/leds/backlight/mps,mp3309c.yaml  | 73 +++++++++++++++++++
>  1 file changed, 73 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> 

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/backlight/mps,mp3309c.example.dtb: /example-0/i2c/backlight@17: failed to match any schema with compatible: ['mps,mp3309c-backlight']

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20230915140516.1294925-1-f.suligoi@asem.it

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 v2 1/2] dt-bindings: backlight: Add MPS MP3309C

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 3963 bytes --]

Yo,

On Fri, Sep 15, 2023 at 04:05:15PM +0200, Flavio Suligoi wrote:
> The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
> programmable switching frequency to optimize efficiency.
> The brightness can be controlled either by I2C commands (called "analog"
> mode) or by a PWM input signal (PWM mode).
> This driver supports both modes.
> 
> For device driver details, please refer to:
> - drivers/video/backlight/mp3309c_bl.c
> 
> The datasheet is available at:
> - https://www.monolithicpower.com/en/mp3309c.html
> 
> Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
> ---
> 
> v2:
>  - remove useless properties (dimming-mode, pinctrl-names, pinctrl-0,
>    switch-on-delay-ms, switch-off-delay-ms, reset-gpios, reset-on-delay-ms,
>    reset-on-length-ms)
>  - add common.yaml#
>  - remove already included properties (default-brightness, max-brightness)
>  - substitute three boolean properties, used for the overvoltage-protection
>    values, with a single enum property
>  - remove some conditional definitions
>  - remove the 2nd example
> v1:
>  - first version
> 
>  .../bindings/leds/backlight/mps,mp3309c.yaml  | 73 +++++++++++++++++++
>  1 file changed, 73 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> 
> diff --git a/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> new file mode 100644
> index 000000000000..99ccdba2c08f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> @@ -0,0 +1,73 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/mps,mp3309c.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MPS MP3309C backlight
> +
> +maintainers:
> +  - Flavio Suligoi <f.suligoi@asem.it>
> +
> +description: |
> +  The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
> +  programmable switching frequency to optimize efficiency.
> +  It supports two different dimming modes:
> +
> +  - analog mode, via I2C commands (default)
> +  - PWM controlled mode.
> +
> +  The datasheet is available at:
> +  https://www.monolithicpower.com/en/mp3309c.html
> +
> +allOf:
> +  - $ref: common.yaml#
> +
> +properties:
> +  compatible:
> +    const: mps,mp3309c
> +
> +  reg:
> +    maxItems: 1
> +
> +  pwms:
> +    description: if present, the backlight is controlled in PWM mode.
> +    maxItems: 1
> +
> +  enable-gpios:
> +    description: GPIO used to enable the backlight in "analog-i2c" dimming mode.
> +    maxItems: 1
> +
> +  mps,overvoltage-protection-microvolt:
> +    description: Overvoltage protection (13.5V, 24V or 35.5V). If missing, the
> +      hardware default of 35.5V is used.
> +    enum: [ 13500000, 24000000, 35500000 ]
You can add "default: 35500000" and drop the free form default as text
in the description.

Cheers,
Conor.

> +
> +  mps,no-sync-mode:
> +    description: disable synchronous rectification mode
> +    type: boolean
> +
> +required:
> +  - compatible
> +  - reg
> +  - max-brightness
> +  - default-brightness
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        /* Backlight with PWM control */
> +        backlight_pwm: backlight@17 {
> +            compatible = "mps,mp3309c-backlight";

As the bot pointed out, the compatible doesn't contain "backlight".

> +            reg = <0x17>;
> +            pwms = <&pwm1 0 3333333 0>; /* 300 Hz --> (1/f) * 1*10^9 */
> +            max-brightness = <100>;
> +            default-brightness = <80>;
> +            overvoltage-protection-microvolt = <24000000>;
> +        };
> +    };
> -- 
> 2.34.1
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

Re: [PATCH v2 1/2] dt-bindings: backlight: Add MPS MP3309C

[Rob Herring]

On Fri, Sep 15, 2023 at 04:05:15PM +0200, Flavio Suligoi wrote:
> The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
> programmable switching frequency to optimize efficiency.
> The brightness can be controlled either by I2C commands (called "analog"
> mode) or by a PWM input signal (PWM mode).
> This driver supports both modes.
> 
> For device driver details, please refer to:
> - drivers/video/backlight/mp3309c_bl.c
> 
> The datasheet is available at:
> - https://www.monolithicpower.com/en/mp3309c.html
> 
> Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
> ---
> 
> v2:
>  - remove useless properties (dimming-mode, pinctrl-names, pinctrl-0,
>    switch-on-delay-ms, switch-off-delay-ms, reset-gpios, reset-on-delay-ms,
>    reset-on-length-ms)
>  - add common.yaml#
>  - remove already included properties (default-brightness, max-brightness)
>  - substitute three boolean properties, used for the overvoltage-protection
>    values, with a single enum property
>  - remove some conditional definitions
>  - remove the 2nd example
> v1:
>  - first version
> 
>  .../bindings/leds/backlight/mps,mp3309c.yaml  | 73 +++++++++++++++++++
>  1 file changed, 73 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> 
> diff --git a/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> new file mode 100644
> index 000000000000..99ccdba2c08f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> @@ -0,0 +1,73 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/mps,mp3309c.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MPS MP3309C backlight
> +
> +maintainers:
> +  - Flavio Suligoi <f.suligoi@asem.it>
> +
> +description: |
> +  The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
> +  programmable switching frequency to optimize efficiency.
> +  It supports two different dimming modes:
> +
> +  - analog mode, via I2C commands (default)
> +  - PWM controlled mode.
> +
> +  The datasheet is available at:
> +  https://www.monolithicpower.com/en/mp3309c.html
> +
> +allOf:
> +  - $ref: common.yaml#
> +
> +properties:
> +  compatible:
> +    const: mps,mp3309c
> +
> +  reg:
> +    maxItems: 1
> +
> +  pwms:
> +    description: if present, the backlight is controlled in PWM mode.
> +    maxItems: 1
> +
> +  enable-gpios:
> +    description: GPIO used to enable the backlight in "analog-i2c" dimming mode.
> +    maxItems: 1
> +
> +  mps,overvoltage-protection-microvolt:
> +    description: Overvoltage protection (13.5V, 24V or 35.5V). If missing, the
> +      hardware default of 35.5V is used.

default: 35500000

instead of prose saying the same thing.

With that,

Reviewed-by: Rob Herring <robh@kernel.org>

> +    enum: [ 13500000, 24000000, 35500000 ]
> +
> +  mps,no-sync-mode:
> +    description: disable synchronous rectification mode
> +    type: boolean
> +
> +required:
> +  - compatible
> +  - reg
> +  - max-brightness
> +  - default-brightness
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        /* Backlight with PWM control */
> +        backlight_pwm: backlight@17 {
> +            compatible = "mps,mp3309c-backlight";
> +            reg = <0x17>;
> +            pwms = <&pwm1 0 3333333 0>; /* 300 Hz --> (1/f) * 1*10^9 */
> +            max-brightness = <100>;
> +            default-brightness = <80>;
> +            overvoltage-protection-microvolt = <24000000>;
> +        };
> +    };
> -- 
> 2.34.1
> 

RE: [PATCH v2 1/2] dt-bindings: backlight: Add MPS MP3309C

[Flavio Suligoi]

Hi Conor,

...


> On Fri, Sep 15, 2023 at 04:05:15PM +0200, Flavio Suligoi wrote:
> > The Monolithic Power (MPS) MP3309C is a WLED step-up converter,
> > featuring a programmable switching frequency to optimize efficiency.
> > The brightness can be controlled either by I2C commands (called "analog"
> > mode) or by a PWM input signal (PWM mode).
> > This driver supports both modes.
> >
> > For device driver details, please refer to:
> > - drivers/video/backlight/mp3309c_bl.c
> >
> > The datasheet is available at:
> > - https://www.monolithicpower.com/en/mp3309c.html
> >
> > Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
> > ---
> >
> > v2:
> >  - remove useless properties (dimming-mode, pinctrl-names, pinctrl-0,
> >    switch-on-delay-ms, switch-off-delay-ms, reset-gpios, reset-on-delay-ms,
> >    reset-on-length-ms)
> >  - add common.yaml#
> >  - remove already included properties (default-brightness,
> > max-brightness)
> >  - substitute three boolean properties, used for the overvoltage-protection
> >    values, with a single enum property
> >  - remove some conditional definitions
> >  - remove the 2nd example
> > v1:
> >  - first version
> >
> >  .../bindings/leds/backlight/mps,mp3309c.yaml  | 73
> > +++++++++++++++++++
> >  1 file changed, 73 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> > b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> > new file mode 100644
> > index 000000000000..99ccdba2c08f
> > --- /dev/null
> > +++
> b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yam
> > +++ l
> > @@ -0,0 +1,73 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/leds/backlight/mps,mp3309c.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: MPS MP3309C backlight
> > +
> > +maintainers:
> > +  - Flavio Suligoi <f.suligoi@asem.it>

...

> > +  mps,overvoltage-protection-microvolt:
> > +    description: Overvoltage protection (13.5V, 24V or 35.5V). If missing, the
> > +      hardware default of 35.5V is used.
> > +    enum: [ 13500000, 24000000, 35500000 ]
> You can add "default: 35500000" and drop the free form default as text in the
> description.

Ok, thanks.

> 
> Cheers,
> Conor.
> 
> > +
> > +  mps,no-sync-mode:
> > +    description: disable synchronous rectification mode
> > +    type: boolean
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - max-brightness
> > +  - default-brightness
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > +  - |
> > +    i2c {
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        /* Backlight with PWM control */
> > +        backlight_pwm: backlight@17 {
> > +            compatible = "mps,mp3309c-backlight";
> 
> As the bot pointed out, the compatible doesn't contain "backlight".

Right, fixed!

Thanks and regards,
Flavio

RE: [PATCH v2 1/2] dt-bindings: backlight: Add MPS MP3309C

[Flavio Suligoi]

HI Rob,

...

> Subject: Re: [PATCH v2 1/2] dt-bindings: backlight: Add MPS MP3309C
> 

...

> > +
> > +  mps,overvoltage-protection-microvolt:
> > +    description: Overvoltage protection (13.5V, 24V or 35.5V). If missing, the
> > +      hardware default of 35.5V is used.
> 
> default: 35500000
> 
> instead of prose saying the same thing.
> 
> With that,
> 
> Reviewed-by: Rob Herring <robh@kernel.org>

Ok, right, I'll fix it in my next version.

I prefer to wait a few days before sending the next version,
to wait if there are other comments on the device driver file as well.

Just a question about the procedure: in my next version, I have to add the sentence:

"Reviewed-by: Rob Herring <robh@kernel.org>"

in my commit or it will be added again by you?

Thanks for your help,
Flavio 

Re: [PATCH v2 2/2] backlight: mp3309c: Add support for MPS MP3309C

[Daniel Thompson]

On Fri, Sep 15, 2023 at 04:05:16PM +0200, Flavio Suligoi wrote:
> The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
> programmable switching frequency to optimize efficiency.
> The brightness can be controlled either by I2C commands (called "analog"
> mode) or by a PWM input signal (PWM mode).
> This driver supports both modes.
>
> For DT configuration details, please refer to:
> - Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
>
> The datasheet is available at:
> - https://www.monolithicpower.com/en/mp3309c.html
>
> Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
> ---
>
> v2:
>  - fix dependecies in Kconfig
>  - fix Kconfig MP3309C entry order
>  - remove switch-on-delay-ms property
>  - remove optional gpio property to reset external devices
>  - remove dimming-mode property (the analog-i2c dimming mode is the default; the
>    presence of the pwms property, in DT, selects automatically the pwm dimming
>    mode)
>  - substitute three boolean properties, used for the overvoltage-protection
>    values, with a single enum property
>  - drop simple tracing messages
>  - use dev_err_probe() in probe function
>  - change device name from mp3309c_bl to the simple mp3309c
>  - remove shutdown function
> v1:
>  - first version
>
>  MAINTAINERS                       |   6 +
>  drivers/video/backlight/Kconfig   |  11 +
>  drivers/video/backlight/Makefile  |   1 +
>  drivers/video/backlight/mp3309c.c | 395 ++++++++++++++++++++++++++++++
>  4 files changed, 413 insertions(+)
>  create mode 100644 drivers/video/backlight/mp3309c.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3be1bdfe8ecc..f779df433af1 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14333,6 +14333,12 @@ S:	Maintained
>  F:	Documentation/driver-api/tty/moxa-smartio.rst
>  F:	drivers/tty/mxser.*
>
> +MP3309C BACKLIGHT DRIVER
> +M:	Flavio Suligoi <f.suligoi@asem.it>
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
> +F:	drivers/video/backlight/mp3309c.c
> +
>  MR800 AVERMEDIA USB FM RADIO DRIVER
>  M:	Alexey Klimov <klimov.linux@gmail.com>
>  L:	linux-media@vger.kernel.org
> diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
> index 51387b1ef012..1144a54a35c0 100644
> --- a/drivers/video/backlight/Kconfig
> +++ b/drivers/video/backlight/Kconfig
> @@ -402,6 +402,17 @@ config BACKLIGHT_LP8788
>  	help
>  	  This supports TI LP8788 backlight driver.
>
> +config BACKLIGHT_MP3309C
> +	tristate "Backlight Driver for MPS MP3309C"
> +	depends on I2C && PWM
> +	select REGMAP_I2C
> +	help
> +	  This supports MPS MP3309C backlight WLED driver in both PWM and
> +	  analog/I2C dimming modes.
> +
> +	  To compile this driver as a module, choose M here: the module will
> +	  be called mp3309c.
> +
>  config BACKLIGHT_PANDORA
>  	tristate "Backlight driver for Pandora console"
>  	depends on TWL4030_CORE
> diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
> index f72e1c3c59e9..1af583de665b 100644
> --- a/drivers/video/backlight/Makefile
> +++ b/drivers/video/backlight/Makefile
> @@ -44,6 +44,7 @@ obj-$(CONFIG_BACKLIGHT_LP855X)		+= lp855x_bl.o
>  obj-$(CONFIG_BACKLIGHT_LP8788)		+= lp8788_bl.o
>  obj-$(CONFIG_BACKLIGHT_LV5207LP)	+= lv5207lp.o
>  obj-$(CONFIG_BACKLIGHT_MAX8925)		+= max8925_bl.o
> +obj-$(CONFIG_BACKLIGHT_MP3309C)		+= mp3309c.o
>  obj-$(CONFIG_BACKLIGHT_MT6370)		+= mt6370-backlight.o
>  obj-$(CONFIG_BACKLIGHT_OMAP1)		+= omap1_bl.o
>  obj-$(CONFIG_BACKLIGHT_PANDORA)		+= pandora_bl.o
> diff --git a/drivers/video/backlight/mp3309c.c b/drivers/video/backlight/mp3309c.c
> new file mode 100644
> index 000000000000..470c960d7438
> --- /dev/null
> +++ b/drivers/video/backlight/mp3309c.c
> @@ -0,0 +1,395 @@
> +// SPDX-License-Identifier: GPL-2.0+

This is an obsolete spelling. Should be:
https://spdx.org/licenses/GPL-2.0-or-later.html


> +static int mp3309c_bl_update_status(struct backlight_device *bl)
> +{
> +	struct mp3309c_chip *chip = bl_get_data(bl);
> +	int brightness = backlight_get_brightness(bl);
> +	struct pwm_state pwmstate;
> +	unsigned int analog_val, bits_val;
> +	int i, ret;
> +
> +	if (chip->pdata->dimming_mode == DIMMING_PWM) {
> +		/*
> +		 * PWM dimming mode
> +		 */
> +		pwm_get_state(chip->pwmd, &pwmstate);
> +		pwm_set_relative_duty_cycle(&pwmstate, brightness,
> +					    chip->pdata->max_brightness);
> +		pwmstate.enabled = true;
> +		ret = pwm_apply_state(chip->pwmd, &pwmstate);
> +		if (ret)
> +			return ret;
> +
> +		switch (chip->pdata->status) {
> +		case FIRST_POWER_ON:
> +		case BACKLIGHT_OFF:
> +			/*
> +			 * After 20ms of pwm off, we must enable the chip again
> +			 */
> +			if (brightness > 0) {
> +				msleep_interruptible(10);

This is either missing a return code check (and working bail-out logic)
or, more likely, shouldn't be interruptible.

Also it looks like the delay time and the comment do not match.

However, when these and the license comment is addressed please add my:
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>


Daniel.