[PATCH v3 0/2] Add support for voltage regulator on ChromeOS EC.

[PATCH v3 0/2] Add support for voltage regulator on ChromeOS EC.

[Pi-Hsun Shih]

Add support for controlling voltage regulator that is connected and
controlled by ChromeOS EC. Kernel controls these regulators through
newly added EC host commands.

Changes from v2:
* Add 'depends on OF' to Kconfig.
* Add Kconfig description about compiling as module.

Changes from v1:
* Change compatible string to google,regulator-cros-ec.
* Use reg property in device tree.
* Change license for dt binding according to checkpatch.pl.
* Address comments on code styles.

Pi-Hsun Shih (2):
  dt-bindings: regulator: Add DT binding for cros-ec-regulator
  regulator: Add driver for cros-ec-regulator

 .../bindings/regulator/cros-ec-regulator.yaml |  43 +++
 drivers/regulator/Kconfig                     |  10 +
 drivers/regulator/Makefile                    |   1 +
 drivers/regulator/cros-ec-regulator.c         | 262 ++++++++++++++++++
 .../linux/platform_data/cros_ec_commands.h    |  82 ++++++
 5 files changed, 398 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/cros-ec-regulator.yaml
 create mode 100644 drivers/regulator/cros-ec-regulator.c


base-commit: 5b14671be58d0084e7e2d1cc9c2c36a94467f6e0
-- 
2.27.0.278.ge193c7cf3a9-goog

[PATCH v3 1/2] dt-bindings: regulator: Add DT binding for cros-ec-regulator

[Pi-Hsun Shih]

Add DT binding documentation for cros-ec-regulator, a voltage regulator
controlled by ChromeOS EC.

Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
---
Changes from v2:
* No change

Changes from v1:
* Change compatible string to google,regulator-cros-ec.
* Use reg property in device tree.
* Change license for dt binding according to checkpatch.pl.
---
 .../bindings/regulator/cros-ec-regulator.yaml | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/cros-ec-regulator.yaml

diff --git a/Documentation/devicetree/bindings/regulator/cros-ec-regulator.yaml b/Documentation/devicetree/bindings/regulator/cros-ec-regulator.yaml
new file mode 100644
index 000000000000..e677614dcdf9
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/cros-ec-regulator.yaml
@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/cros-ec-regulator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ChromeOS EC controlled voltage regulators
+
+maintainers:
+  - Pi-Hsun Shih <pihsun@chromium.org>
+
+description:
+  Any property defined as part of the core regulator binding, defined in
+  regulator.yaml, can also be used.
+
+allOf:
+  - $ref: "regulator.yaml#"
+
+properties:
+  compatible:
+    const: google,regulator-cros-ec
+
+  reg:
+    maxItems: 1
+    description: Identifier for the voltage regulator to ChromeOS EC.
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    cros-ec {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      regulator@0 {
+        compatible = "regulator-cros-ec";
+        regulator-min-microvolt = <1800000>;
+        regulator-max-microvolt = <3300000>;
+        reg = <0>;
+      };
+    };
+...
-- 
2.27.0.278.ge193c7cf3a9-goog

Re: [PATCH v3 1/2] dt-bindings: regulator: Add DT binding for cros-ec-regulator

[Enric Balletbo i Serra]

Hi Pi-Hsun,

Thank you for your patch. Some few/trivial comments below

On 10/6/20 11:07, Pi-Hsun Shih wrote:
> Add DT binding documentation for cros-ec-regulator, a voltage regulator
> controlled by ChromeOS EC.
> 
> Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
> ---
> Changes from v2:
> * No change
> 
> Changes from v1:
> * Change compatible string to google,regulator-cros-ec.
> * Use reg property in device tree.
> * Change license for dt binding according to checkpatch.pl.
> ---
>  .../bindings/regulator/cros-ec-regulator.yaml | 43 +++++++++++++++++++


The vendor should be part of the binding name, google,cros-ec-regulator.yaml

>  1 file changed, 43 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/regulator/cros-ec-regulator.yaml
> 
> diff --git a/Documentation/devicetree/bindings/regulator/cros-ec-regulator.yaml b/Documentation/devicetree/bindings/regulator/cros-ec-regulator.yaml
> new file mode 100644
> index 000000000000..e677614dcdf9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/regulator/cros-ec-regulator.yaml
> @@ -0,0 +1,43 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/regulator/cros-ec-regulator.yaml#

Remember also to change the name here.

> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ChromeOS EC controlled voltage regulators
> +
> +maintainers:
> +  - Pi-Hsun Shih <pihsun@chromium.org>
> +
> +description:
> +  Any property defined as part of the core regulator binding, defined in
> +  regulator.yaml, can also be used.
> +
> +allOf:
> +  - $ref: "regulator.yaml#"
> +
> +properties:
> +  compatible:
> +    const: google,regulator-cros-ec
> +
> +  reg:
> +    maxItems: 1
> +    description: Identifier for the voltage regulator to ChromeOS EC.
> +
> +required:
> +  - compatible
> +  - reg
> +
> +examples:
> +  - |

Please use a full example,

    spi0 {
      #address-cells = <1>;
      #size-cells = <0>;

      cros_ec: ec@0 {
        compatible = "google,cros-ec-spi";
        reg = <0>;


> +    cros-ec {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +      regulator@0 {
> +        compatible = "regulator-cros-ec";

The compatible should be "google,cros-ec-regulator"

> +        regulator-min-microvolt = <1800000>;
> +        regulator-max-microvolt = <3300000>;
> +        reg = <0>;
> +      };
> +    };
> +...
> 

[PATCH v3 2/2] regulator: Add driver for cros-ec-regulator

[Pi-Hsun Shih]

Add driver for cros-ec-regulator, representing a voltage regulator that
is connected and controlled by ChromeOS EC, and is controlled by kernel
with EC host commands.

Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
---
Changes from v2:
* Add 'depends on OF' to Kconfig.
* Add Kconfig description about compiling as module.

Changes from v1:
* Change compatible string to google,regulator-cros-ec.
* Use reg property in device tree.
* Address comments on code styles.

This patch contains function cros_ec_cmd that is copied from the series:
https://lore.kernel.org/patchwork/project/lkml/list/?series=428457.

I can't find the first patch in that v2 series, so the function is
modified from v1 of that series according to reviewers comment:
https://lore.kernel.org/patchwork/patch/1188110/

I copied the function instead of depending on that series since I feel
the function is small enough, and the series has stalled for some time.
---
 drivers/regulator/Kconfig                     |  10 +
 drivers/regulator/Makefile                    |   1 +
 drivers/regulator/cros-ec-regulator.c         | 262 ++++++++++++++++++
 .../linux/platform_data/cros_ec_commands.h    |  82 ++++++
 4 files changed, 355 insertions(+)
 create mode 100644 drivers/regulator/cros-ec-regulator.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 8f677f5d79b4..c398e90e0e73 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -238,6 +238,16 @@ config REGULATOR_CPCAP
 	  Say y here for CPCAP regulator found on some Motorola phones
 	  and tablets such as Droid 4.
 
+config REGULATOR_CROS_EC
+	tristate "ChromeOS EC regulators"
+	depends on CROS_EC && OF
+	help
+	  This driver supports voltage regulators that is connected to ChromeOS
+	  EC and controlled through EC host commands.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called cros-ec-regulator.
+
 config REGULATOR_DA903X
 	tristate "Dialog Semiconductor DA9030/DA9034 regulators"
 	depends on PMIC_DA903X
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index e8f163371071..46592c160d22 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_REGULATOR_USERSPACE_CONSUMER) += userspace-consumer.o
 obj-$(CONFIG_REGULATOR_88PG86X) += 88pg86x.o
 obj-$(CONFIG_REGULATOR_88PM800) += 88pm800-regulator.o
 obj-$(CONFIG_REGULATOR_88PM8607) += 88pm8607.o
+obj-$(CONFIG_REGULATOR_CROS_EC) += cros-ec-regulator.o
 obj-$(CONFIG_REGULATOR_CPCAP) += cpcap-regulator.o
 obj-$(CONFIG_REGULATOR_AAT2870) += aat2870-regulator.o
 obj-$(CONFIG_REGULATOR_AB3100) += ab3100.o
diff --git a/drivers/regulator/cros-ec-regulator.c b/drivers/regulator/cros-ec-regulator.c
new file mode 100644
index 000000000000..0af3a397781c
--- /dev/null
+++ b/drivers/regulator/cros-ec-regulator.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright 2020 Google LLC.
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/slab.h>
+
+struct cros_ec_regulator_data {
+	struct regulator_desc desc;
+	struct regulator_dev *dev;
+	struct cros_ec_device *ec_dev;
+
+	u32 index;
+
+	u16 *voltages_mV;
+	u16 num_voltages;
+};
+
+static int cros_ec_cmd(struct cros_ec_device *ec, u32 version, u32 command,
+		       void *outdata, u32 outsize, void *indata, u32 insize)
+{
+	struct cros_ec_command *msg;
+	int ret;
+
+	msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	msg->version = version;
+	msg->command = command;
+	msg->outsize = outsize;
+	msg->insize = insize;
+
+	if (outdata && outsize > 0)
+		memcpy(msg->data, outdata, outsize);
+
+	ret = cros_ec_cmd_xfer_status(ec, msg);
+	if (ret < 0) {
+		dev_warn(ec->dev, "Command failed: %d\n", msg->result);
+		goto cleanup;
+	}
+
+	if (insize)
+		memcpy(indata, msg->data, insize);
+
+cleanup:
+	kfree(msg);
+	return ret;
+}
+
+static int cros_ec_regulator_enable(struct regulator_dev *dev)
+{
+	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+	struct ec_params_regulator_enable cmd = {
+		.index = data->index,
+		.enable = 1,
+	};
+
+	return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd,
+			  sizeof(cmd), NULL, 0);
+}
+
+static int cros_ec_regulator_disable(struct regulator_dev *dev)
+{
+	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+	struct ec_params_regulator_enable cmd = {
+		.index = data->index,
+		.enable = 0,
+	};
+
+	return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd,
+			  sizeof(cmd), NULL, 0);
+}
+
+static int cros_ec_regulator_is_enabled(struct regulator_dev *dev)
+{
+	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+	struct ec_params_regulator_is_enabled cmd = {
+		.index = data->index,
+	};
+	struct ec_response_regulator_is_enabled resp;
+	int ret;
+
+	ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_IS_ENABLED, &cmd,
+			  sizeof(cmd), &resp, sizeof(resp));
+	if (ret < 0)
+		return ret;
+	return resp.enabled;
+}
+
+static int cros_ec_regulator_list_voltage(struct regulator_dev *dev,
+					  unsigned int selector)
+{
+	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+
+	if (selector >= data->num_voltages)
+		return -EINVAL;
+
+	return data->voltages_mV[selector] * 1000;
+}
+
+static int cros_ec_regulator_get_voltage(struct regulator_dev *dev)
+{
+	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+	struct ec_params_regulator_get_voltage cmd = {
+		.index = data->index,
+	};
+	struct ec_response_regulator_get_voltage resp;
+	int ret;
+
+	ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_VOLTAGE, &cmd,
+			  sizeof(cmd), &resp, sizeof(resp));
+	if (ret < 0)
+		return ret;
+	return resp.voltage_mv * 1000;
+}
+
+static int cros_ec_regulator_set_voltage(struct regulator_dev *dev, int min_uV,
+					 int max_uV, unsigned int *selector)
+{
+	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+	int min_mV = DIV_ROUND_UP(min_uV, 1000);
+	int max_mV = max_uV / 1000;
+	struct ec_params_regulator_set_voltage cmd = {
+		.index = data->index,
+		.min_mv = min_mV,
+		.max_mv = max_mV,
+	};
+
+	if (min_mV > max_mV)
+		return -EINVAL;
+	return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_SET_VOLTAGE, &cmd,
+			   sizeof(cmd), NULL, 0);
+}
+
+static struct regulator_ops cros_ec_regulator_voltage_ops = {
+	.enable = cros_ec_regulator_enable,
+	.disable = cros_ec_regulator_disable,
+	.is_enabled = cros_ec_regulator_is_enabled,
+	.list_voltage = cros_ec_regulator_list_voltage,
+	.get_voltage = cros_ec_regulator_get_voltage,
+	.set_voltage = cros_ec_regulator_set_voltage,
+};
+
+static int cros_ec_regulator_init_info(struct device *dev,
+				       struct cros_ec_regulator_data *data)
+{
+	struct ec_params_regulator_get_info cmd = {
+		.index = data->index,
+	};
+	struct ec_response_regulator_get_info resp;
+	int ret;
+
+	ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_INFO, &cmd,
+			   sizeof(cmd), &resp, sizeof(resp));
+	if (ret < 0)
+		return ret;
+
+	data->num_voltages =
+		min_t(u16, ARRAY_SIZE(resp.voltages_mv), resp.num_voltages);
+	data->voltages_mV =
+		devm_kmemdup(dev, resp.voltages_mv,
+			     sizeof(u16) * data->num_voltages, GFP_KERNEL);
+	data->desc.n_voltages = data->num_voltages;
+	data->desc.name = kstrndup(resp.name, sizeof(resp.name), GFP_KERNEL);
+	if (!data->desc.name)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int cros_ec_regulator_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct cros_ec_regulator_data *drvdata;
+	struct regulator_init_data *init_data;
+	struct regulator_config cfg = {};
+	struct regulator_desc *desc;
+	int ret;
+
+	drvdata = devm_kzalloc(
+		&pdev->dev, sizeof(struct cros_ec_regulator_data), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->ec_dev = dev_get_drvdata(dev->parent);
+	desc = &drvdata->desc;
+
+	init_data = of_get_regulator_init_data(dev, np, desc);
+	if (!init_data)
+		return -EINVAL;
+
+	ret = of_property_read_u32(np, "reg", &drvdata->index);
+	if (ret < 0)
+		return ret;
+
+	desc->owner = THIS_MODULE;
+	desc->type = REGULATOR_VOLTAGE;
+	desc->ops = &cros_ec_regulator_voltage_ops;
+
+	ret = cros_ec_regulator_init_info(dev, drvdata);
+	if (ret < 0)
+		return ret;
+
+	cfg.dev = &pdev->dev;
+	cfg.init_data = init_data;
+	cfg.driver_data = drvdata;
+	cfg.of_node = np;
+
+	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
+	if (IS_ERR(drvdata->dev)) {
+		ret = PTR_ERR(drvdata->dev);
+		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
+		goto free_name;
+	}
+
+	platform_set_drvdata(pdev, drvdata);
+
+	return 0;
+
+free_name:
+	kfree(desc->name);
+	return ret;
+}
+
+static int cros_ec_regulator_remove(struct platform_device *pdev)
+{
+	struct cros_ec_regulator_data *drvdata = platform_get_drvdata(pdev);
+
+	kfree(drvdata->desc.name);
+
+	return 0;
+}
+
+#if defined(CONFIG_OF)
+static const struct of_device_id regulator_cros_ec_of_match[] = {
+	{ .compatible = "google,regulator-cros-ec", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, regulator_cros_ec_of_match);
+#endif
+
+static struct platform_driver cros_ec_regulator_driver = {
+	.probe		= cros_ec_regulator_probe,
+	.remove		= cros_ec_regulator_remove,
+	.driver		= {
+		.name		= "cros-ec-regulator",
+		.of_match_table = of_match_ptr(regulator_cros_ec_of_match),
+	},
+};
+
+module_platform_driver(cros_ec_regulator_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ChromeOS EC controlled regulator");
diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index 69210881ebac..a417b51b5764 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -5430,6 +5430,88 @@ struct ec_response_rollback_info {
 /* Issue AP reset */
 #define EC_CMD_AP_RESET 0x0125
 
+/*****************************************************************************/
+/* Voltage regulator controls */
+
+/*
+ * Get basic info of voltage regulator for given index.
+ *
+ * Returns the regulator name and supported voltage list in mV.
+ */
+#define EC_CMD_REGULATOR_GET_INFO 0x012B
+
+/* Maximum length of regulator name */
+#define EC_REGULATOR_NAME_MAX_LEN 16
+
+/* Maximum length of the supported voltage list. */
+#define EC_REGULATOR_VOLTAGE_MAX_COUNT 16
+
+struct ec_params_regulator_get_info {
+	uint32_t index;
+} __ec_align4;
+
+struct ec_response_regulator_get_info {
+	char name[EC_REGULATOR_NAME_MAX_LEN];
+	uint16_t num_voltages;
+	uint16_t voltages_mv[EC_REGULATOR_VOLTAGE_MAX_COUNT];
+} __ec_align1;
+
+/*
+ * Configure the regulator as enabled / disabled.
+ */
+#define EC_CMD_REGULATOR_ENABLE 0x012C
+
+struct ec_params_regulator_enable {
+	uint32_t index;
+	uint8_t enable;
+} __ec_align4;
+
+/*
+ * Query if the regulator is enabled.
+ *
+ * Returns 1 if the regulator is enabled, 0 if not.
+ */
+#define EC_CMD_REGULATOR_IS_ENABLED 0x012D
+
+struct ec_params_regulator_is_enabled {
+	uint32_t index;
+} __ec_align4;
+
+struct ec_response_regulator_is_enabled {
+	uint8_t enabled;
+} __ec_align1;
+
+/*
+ * Set voltage for the voltage regulator within the range specified.
+ *
+ * The driver should select the voltage in range closest to min_mv.
+ *
+ * Also note that this might be called before the regulator is enabled, and the
+ * setting should be in effect after the regulator is enabled.
+ */
+#define EC_CMD_REGULATOR_SET_VOLTAGE 0x012E
+
+struct ec_params_regulator_set_voltage {
+	uint32_t index;
+	uint32_t min_mv;
+	uint32_t max_mv;
+} __ec_align4;
+
+/*
+ * Get the currently configured voltage for the voltage regulator.
+ *
+ * Note that this might be called before the regulator is enabled.
+ */
+#define EC_CMD_REGULATOR_GET_VOLTAGE 0x012F
+
+struct ec_params_regulator_get_voltage {
+	uint32_t index;
+} __ec_align4;
+
+struct ec_response_regulator_get_voltage {
+	uint32_t voltage_mv;
+} __ec_align4;
+
 /*****************************************************************************/
 /* The command range 0x200-0x2FF is reserved for Rotor. */
 
-- 
2.27.0.278.ge193c7cf3a9-goog

Re: [PATCH v3 2/2] regulator: Add driver for cros-ec-regulator

[Enric Balletbo i Serra]

Hi Pi-Hsun,

Thank you for your patch.

On 10/6/20 11:07, Pi-Hsun Shih wrote:
> Add driver for cros-ec-regulator, representing a voltage regulator that
> is connected and controlled by ChromeOS EC, and is controlled by kernel
> with EC host commands.
> 
> Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
> ---
> Changes from v2:
> * Add 'depends on OF' to Kconfig.
> * Add Kconfig description about compiling as module.
> 
> Changes from v1:
> * Change compatible string to google,regulator-cros-ec.
> * Use reg property in device tree.
> * Address comments on code styles.
> 
> This patch contains function cros_ec_cmd that is copied from the series:
> https://lore.kernel.org/patchwork/project/lkml/list/?series=428457.
> 
> I can't find the first patch in that v2 series, so the function is
> modified from v1 of that series according to reviewers comment:
> https://lore.kernel.org/patchwork/patch/1188110/
> 
> I copied the function instead of depending on that series since I feel
> the function is small enough, and the series has stalled for some time.
> ---
>  drivers/regulator/Kconfig                     |  10 +
>  drivers/regulator/Makefile                    |   1 +
>  drivers/regulator/cros-ec-regulator.c         | 262 ++++++++++++++++++
>  .../linux/platform_data/cros_ec_commands.h    |  82 ++++++
>  4 files changed, 355 insertions(+)
>  create mode 100644 drivers/regulator/cros-ec-regulator.c
> 
> diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
> index 8f677f5d79b4..c398e90e0e73 100644
> --- a/drivers/regulator/Kconfig
> +++ b/drivers/regulator/Kconfig
> @@ -238,6 +238,16 @@ config REGULATOR_CPCAP
>  	  Say y here for CPCAP regulator found on some Motorola phones
>  	  and tablets such as Droid 4.
>  
> +config REGULATOR_CROS_EC
> +	tristate "ChromeOS EC regulators"
> +	depends on CROS_EC && OF
> +	help
> +	  This driver supports voltage regulators that is connected to ChromeOS
> +	  EC and controlled through EC host commands.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called cros-ec-regulator.
> +
>  config REGULATOR_DA903X
>  	tristate "Dialog Semiconductor DA9030/DA9034 regulators"
>  	depends on PMIC_DA903X
> diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
> index e8f163371071..46592c160d22 100644
> --- a/drivers/regulator/Makefile
> +++ b/drivers/regulator/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_REGULATOR_USERSPACE_CONSUMER) += userspace-consumer.o
>  obj-$(CONFIG_REGULATOR_88PG86X) += 88pg86x.o
>  obj-$(CONFIG_REGULATOR_88PM800) += 88pm800-regulator.o
>  obj-$(CONFIG_REGULATOR_88PM8607) += 88pm8607.o
> +obj-$(CONFIG_REGULATOR_CROS_EC) += cros-ec-regulator.o
>  obj-$(CONFIG_REGULATOR_CPCAP) += cpcap-regulator.o
>  obj-$(CONFIG_REGULATOR_AAT2870) += aat2870-regulator.o
>  obj-$(CONFIG_REGULATOR_AB3100) += ab3100.o
> diff --git a/drivers/regulator/cros-ec-regulator.c b/drivers/regulator/cros-ec-regulator.c
> new file mode 100644
> index 000000000000..0af3a397781c
> --- /dev/null
> +++ b/drivers/regulator/cros-ec-regulator.c
> @@ -0,0 +1,262 @@
> +// SPDX-License-Identifier: GPL-2.0

You probably want to specify that this is GPL-2.0-only license.

> +//
> +// Copyright 2020 Google LLC.
> +
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_data/cros_ec_proto.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/driver.h>
> +#include <linux/regulator/machine.h>
> +#include <linux/regulator/of_regulator.h>
> +#include <linux/slab.h>
> +
> +struct cros_ec_regulator_data {
> +	struct regulator_desc desc;
> +	struct regulator_dev *dev;
> +	struct cros_ec_device *ec_dev;
> +
> +	u32 index;
> +
> +	u16 *voltages_mV;
> +	u16 num_voltages;
> +};
> +
> +static int cros_ec_cmd(struct cros_ec_device *ec, u32 version, u32 command,
> +		       void *outdata, u32 outsize, void *indata, u32 insize)
> +{
> +	struct cros_ec_command *msg;
> +	int ret;
> +
> +	msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
> +	if (!msg)
> +		return -ENOMEM;
> +
> +	msg->version = version;
> +	msg->command = command;
> +	msg->outsize = outsize;
> +	msg->insize = insize;
> +
> +	if (outdata && outsize > 0)
> +		memcpy(msg->data, outdata, outsize);
> +
> +	ret = cros_ec_cmd_xfer_status(ec, msg);
> +	if (ret < 0) {
> +		dev_warn(ec->dev, "Command failed: %d\n", msg->result);

The cros_ec_cmd_xfer_status() will already print an error if fails, don't need
to do this as is redundant.

> +		goto cleanup;
> +	}
> +
> +	if (insize)
> +		memcpy(indata, msg->data, insize);
> +
> +cleanup:
> +	kfree(msg);
> +	return ret;
> +}
> +
> +static int cros_ec_regulator_enable(struct regulator_dev *dev)
> +{
> +	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
> +	struct ec_params_regulator_enable cmd = {
> +		.index = data->index,
> +		.enable = 1,
> +	};
> +
> +	return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd,
> +			  sizeof(cmd), NULL, 0);
> +}
> +
> +static int cros_ec_regulator_disable(struct regulator_dev *dev)
> +{
> +	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
> +	struct ec_params_regulator_enable cmd = {
> +		.index = data->index,
> +		.enable = 0,
> +	};
> +
> +	return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd,
> +			  sizeof(cmd), NULL, 0);
> +}
> +
> +static int cros_ec_regulator_is_enabled(struct regulator_dev *dev)
> +{
> +	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
> +	struct ec_params_regulator_is_enabled cmd = {
> +		.index = data->index,
> +	};
> +	struct ec_response_regulator_is_enabled resp;
> +	int ret;
> +
> +	ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_IS_ENABLED, &cmd,
> +			  sizeof(cmd), &resp, sizeof(resp));
> +	if (ret < 0)
> +		return ret;
> +	return resp.enabled;
> +}
> +
> +static int cros_ec_regulator_list_voltage(struct regulator_dev *dev,
> +					  unsigned int selector)
> +{
> +	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
> +
> +	if (selector >= data->num_voltages)
> +		return -EINVAL;
> +
> +	return data->voltages_mV[selector] * 1000;
> +}
> +
> +static int cros_ec_regulator_get_voltage(struct regulator_dev *dev)
> +{
> +	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
> +	struct ec_params_regulator_get_voltage cmd = {
> +		.index = data->index,
> +	};
> +	struct ec_response_regulator_get_voltage resp;
> +	int ret;
> +
> +	ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_VOLTAGE, &cmd,
> +			  sizeof(cmd), &resp, sizeof(resp));
> +	if (ret < 0)
> +		return ret;
> +	return resp.voltage_mv * 1000;
> +}
> +
> +static int cros_ec_regulator_set_voltage(struct regulator_dev *dev, int min_uV,
> +					 int max_uV, unsigned int *selector)
> +{
> +	struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
> +	int min_mV = DIV_ROUND_UP(min_uV, 1000);
> +	int max_mV = max_uV / 1000;
> +	struct ec_params_regulator_set_voltage cmd = {
> +		.index = data->index,
> +		.min_mv = min_mV,
> +		.max_mv = max_mV,
> +	};
> +
> +	if (min_mV > max_mV)
> +		return -EINVAL;
> +	return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_SET_VOLTAGE, &cmd,
> +			   sizeof(cmd), NULL, 0);
> +}
> +
> +static struct regulator_ops cros_ec_regulator_voltage_ops = {
> +	.enable = cros_ec_regulator_enable,
> +	.disable = cros_ec_regulator_disable,
> +	.is_enabled = cros_ec_regulator_is_enabled,
> +	.list_voltage = cros_ec_regulator_list_voltage,
> +	.get_voltage = cros_ec_regulator_get_voltage,
> +	.set_voltage = cros_ec_regulator_set_voltage,
> +};
> +
> +static int cros_ec_regulator_init_info(struct device *dev,
> +				       struct cros_ec_regulator_data *data)
> +{
> +	struct ec_params_regulator_get_info cmd = {
> +		.index = data->index,
> +	};
> +	struct ec_response_regulator_get_info resp;
> +	int ret;
> +
> +	ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_INFO, &cmd,
> +			   sizeof(cmd), &resp, sizeof(resp));
> +	if (ret < 0)
> +		return ret;
> +
> +	data->num_voltages =
> +		min_t(u16, ARRAY_SIZE(resp.voltages_mv), resp.num_voltages);
> +	data->voltages_mV =
> +		devm_kmemdup(dev, resp.voltages_mv,
> +			     sizeof(u16) * data->num_voltages, GFP_KERNEL);
> +	data->desc.n_voltages = data->num_voltages;
> +	data->desc.name = kstrndup(resp.name, sizeof(resp.name), GFP_KERNEL);

Can you also use a device managed allocation here, so we can get rid of the
cros_ec_regulator_remove() function?

> +	if (!data->desc.name)
> +		return -ENOMEM;
> +
> +	return 0;
> +}
> +
> +static int cros_ec_regulator_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct cros_ec_regulator_data *drvdata;
> +	struct regulator_init_data *init_data;
> +	struct regulator_config cfg = {};
> +	struct regulator_desc *desc;
> +	int ret;
> +
> +	drvdata = devm_kzalloc(
> +		&pdev->dev, sizeof(struct cros_ec_regulator_data), GFP_KERNEL);
> +	if (!drvdata)
> +		return -ENOMEM;
> +
> +	drvdata->ec_dev = dev_get_drvdata(dev->parent);
> +	desc = &drvdata->desc;
> +
> +	init_data = of_get_regulator_init_data(dev, np, desc);
> +	if (!init_data)
> +		return -EINVAL;
> +
> +	ret = of_property_read_u32(np, "reg", &drvdata->index);
> +	if (ret < 0)
> +		return ret;
> +
> +	desc->owner = THIS_MODULE;
> +	desc->type = REGULATOR_VOLTAGE;
> +	desc->ops = &cros_ec_regulator_voltage_ops;
> +
> +	ret = cros_ec_regulator_init_info(dev, drvdata);
> +	if (ret < 0)
> +		return ret;
> +
> +	cfg.dev = &pdev->dev;
> +	cfg.init_data = init_data;
> +	cfg.driver_data = drvdata;
> +	cfg.of_node = np;
> +
> +	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
> +	if (IS_ERR(drvdata->dev)) {
> +		ret = PTR_ERR(drvdata->dev);
> +		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
> +		goto free_name;
> +	}
> +
> +	platform_set_drvdata(pdev, drvdata);
> +
> +	return 0;
> +
> +free_name:
> +	kfree(desc->name);
> +	return ret;
> +}
> +
> +static int cros_ec_regulator_remove(struct platform_device *pdev)
> +{
> +	struct cros_ec_regulator_data *drvdata = platform_get_drvdata(pdev);
> +
> +	kfree(drvdata->desc.name);
> +
> +	return 0;
> +}
> +
> +#if defined(CONFIG_OF)

This is not really needed as this driver is OF-only.

> +static const struct of_device_id regulator_cros_ec_of_match[] = {
> +	{ .compatible = "google,regulator-cros-ec", },
> +	{},

The sentinel indicates the last item on structure/arrays so no need to add a
comma at the end.

> +};
> +MODULE_DEVICE_TABLE(of, regulator_cros_ec_of_match);
> +#endif
> +
> +static struct platform_driver cros_ec_regulator_driver = {
> +	.probe		= cros_ec_regulator_probe,
> +	.remove		= cros_ec_regulator_remove,
> +	.driver		= {
> +		.name		= "cros-ec-regulator",
> +		.of_match_table = of_match_ptr(regulator_cros_ec_of_match),

Also you can just do .of_match_table = regulator_cros_ec_of_match as this driver
is OF-only.

> +	},
> +};
> +
> +module_platform_driver(cros_ec_regulator_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("ChromeOS EC controlled regulator");

MODULE_AUTHOR? :-)

> diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
> index 69210881ebac..a417b51b5764 100644
> --- a/include/linux/platform_data/cros_ec_commands.h
> +++ b/include/linux/platform_data/cros_ec_commands.h
> @@ -5430,6 +5430,88 @@ struct ec_response_rollback_info {
>  /* Issue AP reset */
>  #define EC_CMD_AP_RESET 0x0125
>  
> +/*****************************************************************************/
> +/* Voltage regulator controls */
> +
> +/*
> + * Get basic info of voltage regulator for given index.
> + *
> + * Returns the regulator name and supported voltage list in mV.
> + */
> +#define EC_CMD_REGULATOR_GET_INFO 0x012B

This introduces a new EC command, while you are here, please also add the
command in drivers/platform/chrome/cros_ec_trace.c, so we can trace properly the
command. Also can you point me to the commit that introduces this command in the
EC firmware?

> +
> +/* Maximum length of regulator name */
> +#define EC_REGULATOR_NAME_MAX_LEN 16
> +
> +/* Maximum length of the supported voltage list. */
> +#define EC_REGULATOR_VOLTAGE_MAX_COUNT 16
> +
> +struct ec_params_regulator_get_info {
> +	uint32_t index;
> +} __ec_align4;
> +
> +struct ec_response_regulator_get_info {
> +	char name[EC_REGULATOR_NAME_MAX_LEN];
> +	uint16_t num_voltages;
> +	uint16_t voltages_mv[EC_REGULATOR_VOLTAGE_MAX_COUNT];
> +} __ec_align1;
> +
> +/*
> + * Configure the regulator as enabled / disabled.
> + */
> +#define EC_CMD_REGULATOR_ENABLE 0x012C
> +

Same comment here and for all the new commands introduced.

> +struct ec_params_regulator_enable {
> +	uint32_t index;
> +	uint8_t enable;
> +} __ec_align4;
> +
> +/*
> + * Query if the regulator is enabled.
> + *
> + * Returns 1 if the regulator is enabled, 0 if not.
> + */
> +#define EC_CMD_REGULATOR_IS_ENABLED 0x012D
> +
> +struct ec_params_regulator_is_enabled {
> +	uint32_t index;
> +} __ec_align4;
> +
> +struct ec_response_regulator_is_enabled {
> +	uint8_t enabled;
> +} __ec_align1;
> +
> +/*
> + * Set voltage for the voltage regulator within the range specified.
> + *
> + * The driver should select the voltage in range closest to min_mv.
> + *
> + * Also note that this might be called before the regulator is enabled, and the
> + * setting should be in effect after the regulator is enabled.
> + */
> +#define EC_CMD_REGULATOR_SET_VOLTAGE 0x012E
> +
> +struct ec_params_regulator_set_voltage {
> +	uint32_t index;
> +	uint32_t min_mv;
> +	uint32_t max_mv;
> +} __ec_align4;
> +
> +/*
> + * Get the currently configured voltage for the voltage regulator.
> + *
> + * Note that this might be called before the regulator is enabled.
> + */
> +#define EC_CMD_REGULATOR_GET_VOLTAGE 0x012F
> +
> +struct ec_params_regulator_get_voltage {
> +	uint32_t index;
> +} __ec_align4;
> +
> +struct ec_response_regulator_get_voltage {
> +	uint32_t voltage_mv;
> +} __ec_align4;
> +
>  /*****************************************************************************/
>  /* The command range 0x200-0x2FF is reserved for Rotor. */
>  
> 

Re: [PATCH v3 2/2] regulator: Add driver for cros-ec-regulator

[Pi-Hsun Shih]

Thanks for the review, would address most of them in v4. An inline
reply as below:

On Thu, Jun 11, 2020 at 12:47 AM Enric Balletbo i Serra
<enric.balletbo@collabora.com> wrote:
>
> Hi Pi-Hsun,
>
> Thank you for your patch.
>
> On 10/6/20 11:07, Pi-Hsun Shih wrote:
> > +/*****************************************************************************/
> > +/* Voltage regulator controls */
> > +
> > +/*
> > + * Get basic info of voltage regulator for given index.
> > + *
> > + * Returns the regulator name and supported voltage list in mV.
> > + */
> > +#define EC_CMD_REGULATOR_GET_INFO 0x012B
>
> This introduces a new EC command, while you are here, please also add the
> command in drivers/platform/chrome/cros_ec_trace.c, so we can trace properly the
> command. Also can you point me to the commit that introduces this command in the
> EC firmware?

The commit that introduces this in EC firmware is at https://crrev.com/c/2100327