[PATCH v2 0/2] regulator: richtek,rt4801: use existing ena_gpiod feature

[PATCH v2 0/2] regulator: richtek,rt4801: use existing ena_gpiod feature

[Krzysztof Kozlowski]

Hi,

Not tested.

Follow up of discussion:
https://lore.kernel.org/all/2d124d53-1f36-5315-3877-af8f8ad5f824@linaro.org/#t

Changes since v1
================
Patch 1: add review tag.
Patch 2: Check for ena_gpio_state before accessing I2C (issue pointed out by
         ChiYuan Huang).

Best regards,
Krzysztof

Krzysztof Kozlowski (2):
  regulator: dt-bindings: richtek,rt4801: use existing ena_gpiod feature
  regulator: richtek,rt4801: use existing ena_gpiod feature

 .../regulator/richtek,rt4801-regulator.yaml   | 14 +++-
 drivers/regulator/rt4801-regulator.c          | 68 ++++++++++++++++---
 2 files changed, 71 insertions(+), 11 deletions(-)

-- 
2.32.0

[PATCH v2 1/2] regulator: dt-bindings: richtek,rt4801: use existing ena_gpiod feature

[Krzysztof Kozlowski]

The binding and driver duplicated regulator core feature of controlling
regulators with GPIOs (of_parse_cb + ena_gpiod) and created its own
enable-gpios property with multiple GPIOs.

This is a less preferred way, because enable-gpios should enable only one
element, not multiple. It also duplicates existing solution.

Deprecate the original 'enable-gpios' and add per-regulator property.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../regulator/richtek,rt4801-regulator.yaml        | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/regulator/richtek,rt4801-regulator.yaml b/Documentation/devicetree/bindings/regulator/richtek,rt4801-regulator.yaml
index 4a4dfa7d9d09..091150c4e579 100644
--- a/Documentation/devicetree/bindings/regulator/richtek,rt4801-regulator.yaml
+++ b/Documentation/devicetree/bindings/regulator/richtek,rt4801-regulator.yaml
@@ -32,8 +32,11 @@ properties:
       If only one gpio is specified, only one gpio used to control ENP/ENM.
       Else if both are specified, DSVP/DSVN could be controlled individually.
       If this property not specified, treat both as always-on regulators.
+
+      Property is deprecated. Use enable-gpios in each regulator.
     minItems: 1
     maxItems: 2
+    deprecated: true
 
 patternProperties:
   "^DSV(P|N)$":
@@ -42,6 +45,14 @@ patternProperties:
     description:
       Properties for single display bias regulator.
 
+    properties:
+      enable-gpios:
+        description:
+          GPIO to use to enable DSVP/DSVN regulator. One GPIO can be configured
+          for controlling both regulators.  If this property not specified for
+          any regulator, treat both as always-on regulators.
+        maxItems: 1
+
 required:
   - compatible
   - reg
@@ -57,19 +68,20 @@ examples:
         rt4801@73 {
             compatible = "richtek,rt4801";
             reg = <0x73>;
-            enable-gpios = <&gpio26 2 0>, <&gpio26 3 0>;
 
             dsvp: DSVP {
                 regulator-name = "rt4801,dsvp";
                 regulator-min-microvolt = <4000000>;
                 regulator-max-microvolt = <6000000>;
                 regulator-boot-on;
+                enable-gpios = <&gpio26 2 0>;
             };
             dsvn: DSVN {
                 regulator-name = "rt4801,dsvn";
                 regulator-min-microvolt = <4000000>;
                 regulator-max-microvolt = <6000000>;
                 regulator-boot-on;
+                enable-gpios = <&gpio26 3 0>;
             };
 
         };
-- 
2.32.0

[PATCH v2 2/2] regulator: richtek,rt4801: use existing ena_gpiod feature

[Krzysztof Kozlowski]

The driver duplicated regulator core feature of controlling
regulators with GPIOs (of_parse_cb + ena_gpiod) and created its own
enable-gpios property with multiple GPIOs.

The core already does it. Keep old method for backwards compatibility.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 drivers/regulator/rt4801-regulator.c | 68 ++++++++++++++++++++++++----
 1 file changed, 58 insertions(+), 10 deletions(-)

diff --git a/drivers/regulator/rt4801-regulator.c b/drivers/regulator/rt4801-regulator.c
index 7a87788d3f09..22efe44cd3a0 100644
--- a/drivers/regulator/rt4801-regulator.c
+++ b/drivers/regulator/rt4801-regulator.c
@@ -29,17 +29,71 @@
 
 struct rt4801_priv {
 	struct device *dev;
+	/*
+	 * Driver supports enable GPIOs in two ways:
+	 * 1. Legacy enable-gpios property with multiple entries and enable
+	 *    control handled by the driver.
+	 * 2. Per-regulator enable-gpios property with enable control handled by
+	 *    the regulator core.
+	 *
+	 * The enable_gpios and enable_flag properties are for the (1) case.
+	 */
 	struct gpio_descs *enable_gpios;
 	unsigned int enable_flag;
 	unsigned int volt_sel[DSV_OUT_MAX];
 };
 
+static int rt4801_of_parse_cb(struct device_node *np,
+			      const struct regulator_desc *desc,
+			      struct regulator_config *config)
+{
+	struct rt4801_priv *priv = config->driver_data;
+
+	if (priv->enable_gpios) {
+		dev_warn(priv->dev, "duplicated enable-gpios property\n");
+		return 0;
+	}
+	config->ena_gpiod = fwnode_gpiod_get_index(of_fwnode_handle(np),
+						   "enable-gpios",
+						   0,
+						   GPIOD_OUT_HIGH |
+						   GPIOD_FLAGS_BIT_NONEXCLUSIVE,
+						   "rt4801");
+	if (IS_ERR(config->ena_gpiod))
+		config->ena_gpiod = NULL;
+
+	return 0;
+}
+
+/*
+ * regulator_ops->is_enabled() implementation
+ */
+static int rt4801_is_enabled(struct regulator_dev *rdev)
+{
+	struct rt4801_priv *priv = rdev_get_drvdata(rdev);
+	int id = rdev_get_id(rdev);
+
+	return !!(priv->enable_flag & BIT(id));
+}
+
+/*
+ * Internally used only is_enabled() implementation using also ena_pin from
+ * regulator core.
+ */
+static bool rt4801_is_enabled_ena_pin(struct regulator_dev *rdev)
+{
+	if (rdev->ena_pin)
+		return rdev->ena_gpio_state;
+
+	return rt4801_is_enabled(rdev);
+}
+
 static int rt4801_set_voltage_sel(struct regulator_dev *rdev, unsigned int selector)
 {
 	struct rt4801_priv *priv = rdev_get_drvdata(rdev);
 	int id = rdev_get_id(rdev), ret;
 
-	if (priv->enable_flag & BIT(id)) {
+	if (rt4801_is_enabled_ena_pin(rdev)) {
 		ret = regulator_set_voltage_sel_regmap(rdev, selector);
 		if (ret)
 			return ret;
@@ -54,7 +108,7 @@ static int rt4801_get_voltage_sel(struct regulator_dev *rdev)
 	struct rt4801_priv *priv = rdev_get_drvdata(rdev);
 	int id = rdev_get_id(rdev);
 
-	if (priv->enable_flag & BIT(id))
+	if (rt4801_is_enabled_ena_pin(rdev))
 		return regulator_get_voltage_sel_regmap(rdev);
 
 	return priv->volt_sel[id];
@@ -100,14 +154,6 @@ static int rt4801_disable(struct regulator_dev *rdev)
 	return 0;
 }
 
-static int rt4801_is_enabled(struct regulator_dev *rdev)
-{
-	struct rt4801_priv *priv = rdev_get_drvdata(rdev);
-	int id = rdev_get_id(rdev);
-
-	return !!(priv->enable_flag & BIT(id));
-}
-
 static const struct regulator_ops rt4801_regulator_ops = {
 	.list_voltage = regulator_list_voltage_linear,
 	.set_voltage_sel = rt4801_set_voltage_sel,
@@ -122,6 +168,7 @@ static const struct regulator_desc rt4801_regulator_descs[] = {
 		.name = "DSVP",
 		.ops = &rt4801_regulator_ops,
 		.of_match = of_match_ptr("DSVP"),
+		.of_parse_cb = rt4801_of_parse_cb,
 		.type = REGULATOR_VOLTAGE,
 		.id = DSV_OUT_POS,
 		.min_uV = MIN_UV,
@@ -135,6 +182,7 @@ static const struct regulator_desc rt4801_regulator_descs[] = {
 		.name = "DSVN",
 		.ops = &rt4801_regulator_ops,
 		.of_match = of_match_ptr("DSVN"),
+		.of_parse_cb = rt4801_of_parse_cb,
 		.type = REGULATOR_VOLTAGE,
 		.id = DSV_OUT_NEG,
 		.min_uV = MIN_UV,
-- 
2.32.0

Re: [PATCH v2 2/2] regulator: richtek,rt4801: use existing ena_gpiod feature

[ChiYuan Huang]

On Sat, Apr 23, 2022 at 08:14:19PM +0200, Krzysztof Kozlowski wrote:
> The driver duplicated regulator core feature of controlling
> regulators with GPIOs (of_parse_cb + ena_gpiod) and created its own
> enable-gpios property with multiple GPIOs.
> 
> The core already does it. Keep old method for backwards compatibility.
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---
>  drivers/regulator/rt4801-regulator.c | 68 ++++++++++++++++++++++++----
>  1 file changed, 58 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/regulator/rt4801-regulator.c b/drivers/regulator/rt4801-regulator.c
> index 7a87788d3f09..22efe44cd3a0 100644
> --- a/drivers/regulator/rt4801-regulator.c
> +++ b/drivers/regulator/rt4801-regulator.c
> @@ -29,17 +29,71 @@
>  
>  struct rt4801_priv {
>  	struct device *dev;
> +	/*
> +	 * Driver supports enable GPIOs in two ways:
> +	 * 1. Legacy enable-gpios property with multiple entries and enable
> +	 *    control handled by the driver.
> +	 * 2. Per-regulator enable-gpios property with enable control handled by
> +	 *    the regulator core.
> +	 *
> +	 * The enable_gpios and enable_flag properties are for the (1) case.
> +	 */
>  	struct gpio_descs *enable_gpios;
>  	unsigned int enable_flag;
>  	unsigned int volt_sel[DSV_OUT_MAX];
>  };
>  
> +static int rt4801_of_parse_cb(struct device_node *np,
> +			      const struct regulator_desc *desc,
> +			      struct regulator_config *config)
> +{
> +	struct rt4801_priv *priv = config->driver_data;
> +
> +	if (priv->enable_gpios) {
> +		dev_warn(priv->dev, "duplicated enable-gpios property\n");
> +		return 0;
> +	}
> +	config->ena_gpiod = fwnode_gpiod_get_index(of_fwnode_handle(np),
> +						   "enable-gpios",
'enable' only, gpiod API will automatically concat it to 'enable-gpios'.
> +						   0,
> +						   GPIOD_OUT_HIGH |
> +						   GPIOD_FLAGS_BIT_NONEXCLUSIVE,
> +						   "rt4801");
> +	if (IS_ERR(config->ena_gpiod))
> +		config->ena_gpiod = NULL;
> +
> +	return 0;
> +}
> +
> +/*
> + * regulator_ops->is_enabled() implementation
> + */
> +static int rt4801_is_enabled(struct regulator_dev *rdev)
> +{
> +	struct rt4801_priv *priv = rdev_get_drvdata(rdev);
> +	int id = rdev_get_id(rdev);
> +
> +	return !!(priv->enable_flag & BIT(id));
> +}
> +
> +/*
> + * Internally used only is_enabled() implementation using also ena_pin from
> + * regulator core.
> + */
> +static bool rt4801_is_enabled_ena_pin(struct regulator_dev *rdev)
> +{
> +	if (rdev->ena_pin)
> +		return rdev->ena_gpio_state;
> +
> +	return rt4801_is_enabled(rdev);
> +}
> +
>  static int rt4801_set_voltage_sel(struct regulator_dev *rdev, unsigned int selector)
>  {
>  	struct rt4801_priv *priv = rdev_get_drvdata(rdev);
>  	int id = rdev_get_id(rdev), ret;
>  
> -	if (priv->enable_flag & BIT(id)) {
> +	if (rt4801_is_enabled_ena_pin(rdev)) {
>  		ret = regulator_set_voltage_sel_regmap(rdev, selector);
>  		if (ret)
>  			return ret;
> @@ -54,7 +108,7 @@ static int rt4801_get_voltage_sel(struct regulator_dev *rdev)
>  	struct rt4801_priv *priv = rdev_get_drvdata(rdev);
>  	int id = rdev_get_id(rdev);
>  
> -	if (priv->enable_flag & BIT(id))
> +	if (rt4801_is_enabled_ena_pin(rdev))
>  		return regulator_get_voltage_sel_regmap(rdev);
>  
>  	return priv->volt_sel[id];
> @@ -100,14 +154,6 @@ static int rt4801_disable(struct regulator_dev *rdev)
>  	return 0;
>  }
>  
> -static int rt4801_is_enabled(struct regulator_dev *rdev)
> -{
> -	struct rt4801_priv *priv = rdev_get_drvdata(rdev);
> -	int id = rdev_get_id(rdev);
> -
> -	return !!(priv->enable_flag & BIT(id));
> -}
> -
>  static const struct regulator_ops rt4801_regulator_ops = {
>  	.list_voltage = regulator_list_voltage_linear,
>  	.set_voltage_sel = rt4801_set_voltage_sel,
> @@ -122,6 +168,7 @@ static const struct regulator_desc rt4801_regulator_descs[] = {
>  		.name = "DSVP",
>  		.ops = &rt4801_regulator_ops,
>  		.of_match = of_match_ptr("DSVP"),
> +		.of_parse_cb = rt4801_of_parse_cb,
>  		.type = REGULATOR_VOLTAGE,
>  		.id = DSV_OUT_POS,
>  		.min_uV = MIN_UV,
> @@ -135,6 +182,7 @@ static const struct regulator_desc rt4801_regulator_descs[] = {
>  		.name = "DSVN",
>  		.ops = &rt4801_regulator_ops,
>  		.of_match = of_match_ptr("DSVN"),
> +		.of_parse_cb = rt4801_of_parse_cb,
>  		.type = REGULATOR_VOLTAGE,
>  		.id = DSV_OUT_NEG,
>  		.min_uV = MIN_UV,

There's one problem.
If 'ena_gpiod' is specified, it cannot be conexisted with ops
'enable/disable/is_enabled' by regulator framework.
It will cause no one to recover the voltage back.
You can check the original 'enable' ops.

How about to only parse gpio in 'of_parse_cb' and put it all into the
driver data, not to use regulator framework 'ena_gpiod'?

Best regards,
ChiYuan Huang.
> -- 
> 2.32.0
> 

Re: [PATCH v2 2/2] regulator: richtek,rt4801: use existing ena_gpiod feature

[Krzysztof Kozlowski]

On 25/04/2022 07:49, ChiYuan Huang wrote:
>> +static int rt4801_of_parse_cb(struct device_node *np,
>> +			      const struct regulator_desc *desc,
>> +			      struct regulator_config *config)
>> +{
>> +	struct rt4801_priv *priv = config->driver_data;
>> +
>> +	if (priv->enable_gpios) {
>> +		dev_warn(priv->dev, "duplicated enable-gpios property\n");
>> +		return 0;
>> +	}
>> +	config->ena_gpiod = fwnode_gpiod_get_index(of_fwnode_handle(np),
>> +						   "enable-gpios",
> 'enable' only, gpiod API will automatically concat it to 'enable-gpios'.

Right.

>> +						   0,
>> +						   GPIOD_OUT_HIGH |
>> +						   GPIOD_FLAGS_BIT_NONEXCLUSIVE,
>> +						   "rt4801");

(...)

>>  static const struct regulator_ops rt4801_regulator_ops = {
>>  	.list_voltage = regulator_list_voltage_linear,
>>  	.set_voltage_sel = rt4801_set_voltage_sel,
>> @@ -122,6 +168,7 @@ static const struct regulator_desc rt4801_regulator_descs[] = {
>>  		.name = "DSVP",
>>  		.ops = &rt4801_regulator_ops,
>>  		.of_match = of_match_ptr("DSVP"),
>> +		.of_parse_cb = rt4801_of_parse_cb,
>>  		.type = REGULATOR_VOLTAGE,
>>  		.id = DSV_OUT_POS,
>>  		.min_uV = MIN_UV,
>> @@ -135,6 +182,7 @@ static const struct regulator_desc rt4801_regulator_descs[] = {
>>  		.name = "DSVN",
>>  		.ops = &rt4801_regulator_ops,
>>  		.of_match = of_match_ptr("DSVN"),
>> +		.of_parse_cb = rt4801_of_parse_cb,
>>  		.type = REGULATOR_VOLTAGE,
>>  		.id = DSV_OUT_NEG,
>>  		.min_uV = MIN_UV,
> 
> There's one problem.
> If 'ena_gpiod' is specified, it cannot be conexisted with ops
> 'enable/disable/is_enabled' by regulator framework.
> It will cause no one to recover the voltage back.
> You can check the original 'enable' ops.

You mean that regulator voltage is being reset after disabling it?

> 
> How about to only parse gpio in 'of_parse_cb' and put it all into the
> driver data, not to use regulator framework 'ena_gpiod'?

In such case that's the only option. Thanks for the review.


Best regards,
Krzysztof