[PATCH v2 0/2] regulator: Add driver for Maxim MAX20086-MAX20089

[PATCH v2 0/2] regulator: Add driver for Maxim MAX20086-MAX20089

[Laurent Pinchart]

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Hello,

This small series adds a new driver (along with DT bindings) for the
Maxim MAX20086-MAX20089 camera power protectors.

Compared to v1, this version takes all review comments into account
(assuming I've understood them correctly :-)).

The code originates from initial work done by Avnet, which I have
reworked extensively. Watson, I've kept your authorship on patch 2/2.
Would you like to be listed as a maintainer for the driver and the DT
bindings ?

Laurent Pinchart (1):
  dt-bindings: regulators: Add bindings for Maxim MAX20086-MAX20089

Watson Chow (1):
  regulator: Add MAX20086-MAX20089 driver

 .../bindings/regulator/maxim,max20086.yaml    | 106 ++++++
 MAINTAINERS                                   |   7 +
 drivers/regulator/Kconfig                     |  10 +-
 drivers/regulator/Makefile                    |   1 +
 drivers/regulator/max20086-regulator.c        | 332 ++++++++++++++++++
 5 files changed, 455 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/regulator/maxim,max20086.yaml
 create mode 100644 drivers/regulator/max20086-regulator.c

-- 
Regards,

Laurent Pinchart

[PATCH v2 1/2] dt-bindings: regulators: Add bindings for Maxim MAX20086-MAX20089

[Laurent Pinchart]

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The MAX20086-MAX20089 are dual/quad power protectors for cameras. Add
corresponding DT bindings.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v1:

- Make OUT nodes optional
---
 .../bindings/regulator/maxim,max20086.yaml    | 106 ++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/maxim,max20086.yaml

diff --git a/Documentation/devicetree/bindings/regulator/maxim,max20086.yaml b/Documentation/devicetree/bindings/regulator/maxim,max20086.yaml
new file mode 100644
index 000000000000..05f72391185e
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/maxim,max20086.yaml
@@ -0,0 +1,106 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/maxim,max20086.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim Integrated MAX20086-MAX20089 Camera Power Protector
+
+maintainers:
+  - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+
+description: |
+  The MAX20086-MAX20089 are dual/quad camera power protectors, designed to
+  deliver power over coax for radar and camera modules. They support
+  software-configurable output switching and monitoring. The output voltage and
+  current limit are fixed by the hardware design.
+
+properties:
+  compatible:
+    enum:
+      - maxim,max20086
+      - maxim,max20087
+      - maxim,max20088
+      - maxim,max20089
+
+  reg:
+    maxItems: 1
+
+  enable-gpios:
+    maxItems: 1
+    description: GPIO connected to the EN pin, active high
+
+  in-supply:
+    description: Input supply for the camera outputs (IN pin, 3.0V to 15.0V)
+
+  vdd-supply:
+    description: Input supply for the device (VDD pin, 3.0V to 5.5V)
+
+  regulators:
+    type: object
+
+    patternProperties:
+      "^OUT[1-4]$":
+        type: object
+        $ref: regulator.yaml#
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - in-supply
+  - vdd-supply
+  - regulators
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - maxim,max20088
+              - maxim,max20089
+    then:
+      properties:
+        regulators:
+          properties:
+            OUT3: false
+            OUT4: false
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        regulator@28 {
+            compatible = "maxim,max20087";
+            reg = <0x28>;
+
+            in-supply = <&reg_12v0>;
+            vdd-supply = <&reg_3v3>;
+
+            enable-gpios = <&gpio 108 GPIO_ACTIVE_HIGH>;
+
+            regulators {
+                OUT1 {
+                    regulator-name = "VOUT1";
+                };
+                OUT2 {
+                    regulator-name = "VOUT2";
+                };
+                OUT3 {
+                    regulator-name = "VOUT3";
+                };
+                OUT4 {
+                    regulator-name = "VOUT4";
+                };
+            };
+        };
+    };
+...
-- 
Regards,

Laurent Pinchart

[PATCH v2 2/2] regulator: Add MAX20086-MAX20089 driver

[Laurent Pinchart]

From: Watson Chow <watson.chow@avnet.com>

The MAX20086-MAX20089 are dual/quad power protectors for cameras. Add a
driver that supports controlling the outputs individually. Additional
features, such as overcurrent detection, may be added later if needed.

Signed-off-by: Watson Chow <watson.chow@avnet.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v1:

- Use C++ comment style for top header
- Unconditionally register all outputs
- Fix W=1 warning
- Don't disable all outputs at probe time
- Wire up enable GPIO to regulators
---
 MAINTAINERS                            |   7 +
 drivers/regulator/Kconfig              |  10 +-
 drivers/regulator/Makefile             |   1 +
 drivers/regulator/max20086-regulator.c | 332 +++++++++++++++++++++++++
 4 files changed, 349 insertions(+), 1 deletion(-)
 create mode 100644 drivers/regulator/max20086-regulator.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 79fd8a012893..2891e71c0b9e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11577,6 +11577,13 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/power/supply/maxim,max17042.yaml
 F:	drivers/power/supply/max17042_battery.c
 
+MAXIM MAX20086 CAMERA POWER PROTECTOR DRIVER
+M:	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/regulator/maxim,max20086.yaml
+F:	drivers/regulator/max20086-regulator.c
+
 MAXIM MAX77650 PMIC MFD DRIVER
 M:	Bartosz Golaszewski <brgl@bgdev.pl>
 L:	linux-kernel@vger.kernel.org
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 6be9b1c8a615..dd5c70fe7438 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -636,6 +636,15 @@ config REGULATOR_MAX8998
 	  via I2C bus. The provided regulator is suitable for S3C6410
 	  and S5PC1XX chips to control VCC_CORE and VCC_USIM voltages.
 
+config REGULATOR_MAX20086
+	tristate "Maxim MAX20086-MAX20089 Camera Power Protectors"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  This driver controls a Maxim MAX20086-MAX20089 camera power
+	  protectorvia I2C bus. The regulator has 2 or 4 outputs depending on
+	  the device model. This driver is only capable to turn on/off them.
+
 config REGULATOR_MAX77686
 	tristate "Maxim 77686 regulator"
 	depends on MFD_MAX77686 || COMPILE_TEST
@@ -1415,4 +1424,3 @@ config REGULATOR_QCOM_LABIBB
 	  for LCD display panel.
 
 endif
-
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index b07d2a22df0b..a9e986231eb8 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -78,6 +78,7 @@ obj-$(CONFIG_REGULATOR_MAX8952) += max8952.o
 obj-$(CONFIG_REGULATOR_MAX8973) += max8973-regulator.o
 obj-$(CONFIG_REGULATOR_MAX8997) += max8997-regulator.o
 obj-$(CONFIG_REGULATOR_MAX8998) += max8998.o
+obj-$(CONFIG_REGULATOR_MAX20086) += max20086-regulator.o
 obj-$(CONFIG_REGULATOR_MAX77686) += max77686-regulator.o
 obj-$(CONFIG_REGULATOR_MAX77693) += max77693-regulator.o
 obj-$(CONFIG_REGULATOR_MAX77802) += max77802-regulator.o
diff --git a/drivers/regulator/max20086-regulator.c b/drivers/regulator/max20086-regulator.c
new file mode 100644
index 000000000000..fbc56b043071
--- /dev/null
+++ b/drivers/regulator/max20086-regulator.c
@@ -0,0 +1,332 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// max20086-regulator.c - MAX20086-MAX20089 camera power protector driver
+//
+// Copyright (C) 2022 Laurent Pinchart <laurent.pinchart@idesonboard.com>
+// Copyright (C) 2018 Avnet, Inc.
+
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/slab.h>
+
+/* Register Offset */
+#define MAX20086_REG_MASK		0x00
+#define MAX20086_REG_CONFIG		0x01
+#define	MAX20086_REG_ID			0x02
+#define	MAX20086_REG_STAT1		0x03
+#define	MAX20086_REG_STAT2_L		0x04
+#define	MAX20086_REG_STAT2_H		0x05
+#define	MAX20086_REG_ADC1		0x06
+#define	MAX20086_REG_ADC2		0x07
+#define	MAX20086_REG_ADC3		0x08
+#define	MAX20086_REG_ADC4		0x09
+
+/* DEVICE IDs */
+#define MAX20086_DEVICE_ID_MAX20086	0x40
+#define MAX20086_DEVICE_ID_MAX20087	0x20
+#define MAX20086_DEVICE_ID_MAX20088	0x10
+#define MAX20086_DEVICE_ID_MAX20089	0x00
+#define DEVICE_ID_MASK			0xf0
+
+/* Register bits */
+#define MAX20086_EN_MASK		0x0f
+#define MAX20086_EN_OUT1		0x01
+#define MAX20086_EN_OUT2		0x02
+#define MAX20086_EN_OUT3		0x04
+#define MAX20086_EN_OUT4		0x08
+#define MAX20086_INT_DISABLE_ALL	0x3f
+
+#define MAX20086_MAX_REGULATORS		4
+
+struct max20086_chip_info {
+	u8 id;
+	unsigned int num_outputs;
+};
+
+struct max20086_regulator {
+	struct device_node *of_node;
+	struct regulator_init_data *init_data;
+	const struct regulator_desc *desc;
+	struct regulator_dev *rdev;
+};
+
+struct max20086 {
+	struct device *dev;
+	struct regmap *regmap;
+	struct gpio_desc *ena_gpiod;
+
+	const struct max20086_chip_info *info;
+
+	struct max20086_regulator regulators[MAX20086_MAX_REGULATORS];
+};
+
+static const struct regulator_ops max20086_buck_ops = {
+	.enable = regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = regulator_is_enabled_regmap,
+};
+
+#define MAX20086_REGULATOR_DESC(n)		\
+{						\
+	.name = "OUT"#n,			\
+	.supply_name = "in",			\
+	.id = (n) - 1,				\
+	.ops = &max20086_buck_ops,		\
+	.type = REGULATOR_VOLTAGE,		\
+	.owner = THIS_MODULE,			\
+	.enable_reg = MAX20086_REG_CONFIG,	\
+	.enable_mask = 1 << ((n) - 1),		\
+	.enable_val = 1 << ((n) - 1),		\
+	.disable_val = 0,			\
+}
+
+static const char * const max20086_output_names[] = {
+	"OUT1",
+	"OUT2",
+	"OUT3",
+	"OUT4",
+};
+
+static const struct regulator_desc max20086_regulators[] = {
+	MAX20086_REGULATOR_DESC(1),
+	MAX20086_REGULATOR_DESC(2),
+	MAX20086_REGULATOR_DESC(3),
+	MAX20086_REGULATOR_DESC(4),
+};
+
+static int max20086_regulators_register(struct max20086 *chip)
+{
+	unsigned int i;
+
+	for (i = 0; i < chip->info->num_outputs; i++) {
+		struct max20086_regulator *reg = &chip->regulators[i];
+		struct regulator_config config = { };
+		struct regulator_dev *rdev;
+
+		config.dev = chip->dev;
+		config.init_data = reg->init_data;
+		config.driver_data = chip;
+		config.of_node = reg->of_node;
+		config.regmap = chip->regmap;
+		config.ena_gpiod = chip->ena_gpiod;
+
+		rdev = devm_regulator_register(chip->dev, reg->desc, &config);
+		if (IS_ERR(rdev)) {
+			dev_err(chip->dev,
+				"Failed to register regulator output %s\n",
+				reg->desc->name);
+			return PTR_ERR(rdev);
+		}
+
+		reg->rdev = rdev;
+	}
+
+	return 0;
+}
+
+static int max20086_parse_regulators_dt(struct max20086 *chip, bool *boot_on)
+{
+	struct of_regulator_match matches[MAX20086_MAX_REGULATORS] = { };
+	struct device_node *node;
+	unsigned int i;
+	int ret;
+
+	node = of_get_child_by_name(chip->dev->of_node, "regulators");
+	if (!node) {
+		dev_err(chip->dev, "regulators node not found\n");
+		return PTR_ERR(node);
+	}
+
+	for (i = 0; i < chip->info->num_outputs; ++i)
+		matches[i].name = max20086_output_names[i];
+
+	ret = of_regulator_match(chip->dev, node, matches,
+				 chip->info->num_outputs);
+	of_node_put(node);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to match regulators\n");
+		return -EINVAL;
+	}
+
+	*boot_on = false;
+
+	for (i = 0; i < chip->info->num_outputs; i++) {
+		struct max20086_regulator *reg = &chip->regulators[i];
+
+		reg->init_data = matches[i].init_data;
+		reg->of_node = matches[i].of_node;
+		reg->desc = &max20086_regulators[i];
+
+		if (reg->init_data) {
+			if (reg->init_data->constraints.always_on ||
+			    reg->init_data->constraints.boot_on)
+				*boot_on = true;
+		}
+	}
+
+	return 0;
+}
+
+static int max20086_detect(struct max20086 *chip)
+{
+	unsigned int data;
+	int ret;
+
+	ret = regmap_read(chip->regmap, MAX20086_REG_ID, &data);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to read DEVICE_ID reg: %d\n", ret);
+		return ret;
+	}
+
+	if ((data & DEVICE_ID_MASK) != chip->info->id) {
+		dev_err(chip->dev, "Invalid device ID 0x%02x\n", data);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+static bool max20086_gen_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MAX20086_REG_MASK:
+	case MAX20086_REG_CONFIG:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config max20086_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.writeable_reg = max20086_gen_is_writeable_reg,
+	.max_register = 0x9,
+	.cache_type = REGCACHE_NONE,
+};
+
+static int max20086_i2c_probe(struct i2c_client *i2c)
+{
+	struct max20086 *chip;
+	enum gpiod_flags flags;
+	bool boot_on;
+	int ret;
+
+	chip = devm_kzalloc(&i2c->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = &i2c->dev;
+	chip->info = device_get_match_data(chip->dev);
+
+	i2c_set_clientdata(i2c, chip);
+
+	chip->regmap = devm_regmap_init_i2c(i2c, &max20086_regmap_config);
+	if (IS_ERR(chip->regmap)) {
+		ret = PTR_ERR(chip->regmap);
+		dev_err(chip->dev, "Failed to allocate register map: %d\n", ret);
+		return ret;
+	}
+
+	ret = max20086_parse_regulators_dt(chip, &boot_on);
+	if (ret < 0)
+		return ret;
+
+	ret = max20086_detect(chip);
+	if (ret < 0)
+		return ret;
+
+	/* Until IRQ support is added, just disable all interrupts. */
+	ret = regmap_update_bits(chip->regmap, MAX20086_REG_MASK,
+				 MAX20086_INT_DISABLE_ALL,
+				 MAX20086_INT_DISABLE_ALL);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to disable interrupts: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Get the enable GPIO. If any of the outputs is marked as being
+	 * enabled at boot, request the GPIO with an initial high state to
+	 * avoid disabling outputs that may have been turned on by the boot
+	 * loader. Otherwise, request it with a low state to enter lower-power
+	 * shutdown.
+	 */
+	flags = boot_on ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+	chip->ena_gpiod = devm_gpiod_get(chip->dev, "enable", flags);
+	if (IS_ERR(chip->ena_gpiod)) {
+		ret = PTR_ERR(chip->ena_gpiod);
+		dev_err(chip->dev, "Failed to get enable GPIO: %d\n", ret);
+		return ret;
+	}
+
+	ret = max20086_regulators_register(chip);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to register regulators: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct i2c_device_id max20086_i2c_id[] = {
+	{ "max20086" },
+	{ "max20087" },
+	{ "max20088" },
+	{ "max20089" },
+	{ /* Sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(i2c, max20086_i2c_id);
+
+static const struct of_device_id max20086_dt_ids[] = {
+	{
+		.compatible = "maxim,max20086",
+		.data = &(const struct max20086_chip_info) {
+			.id = MAX20086_DEVICE_ID_MAX20086,
+			.num_outputs = 4,
+		}
+	}, {
+		.compatible = "maxim,max20087",
+		.data = &(const struct max20086_chip_info) {
+			.id = MAX20086_DEVICE_ID_MAX20087,
+			.num_outputs = 4,
+		}
+	}, {
+		.compatible = "maxim,max20088",
+		.data = &(const struct max20086_chip_info) {
+			.id = MAX20086_DEVICE_ID_MAX20088,
+			.num_outputs = 2,
+		}
+	}, {
+		.compatible = "maxim,max20089",
+		.data = &(const struct max20086_chip_info) {
+			.id = MAX20086_DEVICE_ID_MAX20089,
+			.num_outputs = 2,
+		}
+	},
+	{ /* Sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(of, max20086_dt_ids);
+
+static struct i2c_driver max20086_regulator_driver = {
+	.driver = {
+		.name = "max20086",
+		.of_match_table = of_match_ptr(max20086_dt_ids),
+	},
+	.probe_new = max20086_i2c_probe,
+	.id_table = max20086_i2c_id,
+};
+
+module_i2c_driver(max20086_regulator_driver);
+
+MODULE_AUTHOR("Watson Chow <watson.chow@avnet.com>");
+MODULE_DESCRIPTION("MAX20086-MAX20089 Camera Power Protector Driver");
+MODULE_LICENSE("GPL");
-- 
Regards,

Laurent Pinchart

Re: [PATCH v2 0/2] regulator: Add driver for Maxim MAX20086-MAX20089

[Mark Brown]

On Fri, 7 Jan 2022 00:43:48 +0200, Laurent Pinchart wrote:
> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> Hello,
> 
> This small series adds a new driver (along with DT bindings) for the
> Maxim MAX20086-MAX20089 camera power protectors.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next

Thanks!

[1/2] dt-bindings: regulators: Add bindings for Maxim MAX20086-MAX20089
      commit: 764aaa4e031a9acd26babc622cabe652f57bbb04
[2/2] regulator: Add MAX20086-MAX20089 driver
      commit: bfff546aae50ae68ed395bf0e0848188d27b0ba3

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark