[PATCH 0/1] power: supply: gpio-charger: Support to disable charger

[PATCH 0/1] power: supply: gpio-charger: Support to disable charger

[Stefan Raufhake]

From: Stefan Raufhake <s.raufhake@beckhoff.com>

Hello,
We have a device with a simple built-in UPS, which
is controlled by GPIOs. For the control of the UPS,
we used the “gpio-charger” driver module from the
power-supply. For our usecase we want to support 
enabing and disabling the ups. When the UPS is 
disabled, the device turns off immediately if the
supply power is switched off. When the UPS is
enabled, the device has power as long as the UPS
has enough energy for the device. Now, we are
looking for the best way to implement this
function. This patch contains our first proposal.

Stefan Raufhake (1):
  power: supply: gpio-charger: Support to disable charger

 .../bindings/power/supply/gpio-charger.yaml   |  6 +++
 drivers/power/supply/gpio-charger.c           | 43 +++++++++++++++++++
 2 files changed, 49 insertions(+)

-- 
2.25.1

[PATCH 1/1] power: supply: gpio-charger: Support to disable charger

[Stefan Raufhake]

From: Stefan Raufhake <s.raufhake@beckhoff.de>

We want to disable the built-in UPS in our device
so that we can switch off the supply power of the
device with and without the support of the UPS.
This commit will allow us to disable the ups by
using the command echo 1 > /sys/class/power_supply/xxx/charge_type
(1 = POWER_SUPPLY_CHARGE_TYPE_NONE) and enable the
charger by setting it to 4 (POWER_SUPPLY_CHARGE_TYPE_STANDARD).

Signed-off-by: Stefan Raufhake <s.raufhake@beckhoff.de>
---
 .../bindings/power/supply/gpio-charger.yaml   |  6 +++
 drivers/power/supply/gpio-charger.c           | 43 +++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml b/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml
index 89f8e2bcb2d7..b2658b0b20e4 100644
--- a/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml
+++ b/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml
@@ -44,6 +44,10 @@ properties:
     maxItems: 32
     description: GPIOs used for current limiting
 
+  charge-disable-gpios:
+    maxItems: 1
+    description: GPIO to disable the charger
+
   charge-current-limit-mapping:
     description: List of tuples with current in uA and a GPIO bitmap (in
       this order). The tuples must be provided in descending order of the
@@ -68,6 +72,8 @@ anyOf:
       - charge-status-gpios
   - required:
       - charge-current-limit-gpios
+  - required:
+      - charge-type-gpios
 
 dependencies:
   charge-current-limit-gpios: [ charge-current-limit-mapping ]
diff --git a/drivers/power/supply/gpio-charger.c b/drivers/power/supply/gpio-charger.c
index 68212b39785b..24cabb2cb111 100644
--- a/drivers/power/supply/gpio-charger.c
+++ b/drivers/power/supply/gpio-charger.c
@@ -32,6 +32,7 @@ struct gpio_charger {
 	struct power_supply_desc charger_desc;
 	struct gpio_desc *gpiod;
 	struct gpio_desc *charge_status;
+	struct gpio_desc *charge_type;
 
 	struct gpio_descs *current_limit_gpios;
 	struct gpio_mapping *current_limit_map;
@@ -82,6 +83,26 @@ static int set_charge_current_limit(struct gpio_charger *gpio_charger, int val)
 	return 0;
 }
 
+static int gpio_charger_set_charge_type(struct gpio_desc *gpio_charger, int type)
+{
+	int chg_config = 0;
+
+	switch (type) {
+	case POWER_SUPPLY_CHARGE_TYPE_STANDARD:
+		chg_config = 0;
+		break;
+	case POWER_SUPPLY_CHARGE_TYPE_NONE:
+		chg_config = 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	gpiod_set_value_cansleep(gpio_charger, chg_config);
+
+	return 0;
+}
+
 static int gpio_charger_get_property(struct power_supply *psy,
 		enum power_supply_property psp, union power_supply_propval *val)
 {
@@ -100,6 +121,13 @@ static int gpio_charger_get_property(struct power_supply *psy,
 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
 		val->intval = gpio_charger->charge_current_limit;
 		break;
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		if (gpiod_get_value_cansleep(gpio_charger->charge_type))
+			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
+		else
+			val->intval = POWER_SUPPLY_CHARGE_TYPE_STANDARD;
+		break;
+
 	default:
 		return -EINVAL;
 	}
@@ -115,6 +143,9 @@ static int gpio_charger_set_property(struct power_supply *psy,
 	switch (psp) {
 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
 		return set_charge_current_limit(gpio_charger, val->intval);
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		return gpio_charger_set_charge_type(gpio_charger->charge_type, val->intval);
+	break;
 	default:
 		return -EINVAL;
 	}
@@ -126,6 +157,7 @@ static int gpio_charger_property_is_writeable(struct power_supply *psy,
 					      enum power_supply_property psp)
 {
 	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
 		return 1;
 	default:
@@ -246,6 +278,7 @@ static enum power_supply_property gpio_charger_properties[] = {
 	POWER_SUPPLY_PROP_ONLINE,
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
+	POWER_SUPPLY_PROP_CHARGE_TYPE,
 };
 
 static int gpio_charger_probe(struct platform_device *pdev)
@@ -256,6 +289,7 @@ static int gpio_charger_probe(struct platform_device *pdev)
 	struct gpio_charger *gpio_charger;
 	struct power_supply_desc *charger_desc;
 	struct gpio_desc *charge_status;
+	struct gpio_desc *charge_type;
 	int charge_status_irq;
 	int ret;
 	int num_props = 0;
@@ -304,6 +338,15 @@ static int gpio_charger_probe(struct platform_device *pdev)
 		num_props++;
 	}
 
+	charge_type = devm_gpiod_get_optional(dev, "charge-disable", GPIOD_OUT_LOW);
+	if (IS_ERR(charge_type))
+		return PTR_ERR(charge_type);
+	if (charge_type) {
+		gpio_charger->charge_type = charge_type;
+		gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_CHARGE_TYPE;
+		num_props++;
+	}
+
 	charger_desc = &gpio_charger->charger_desc;
 	charger_desc->properties = gpio_charger_properties;
 	charger_desc->num_properties = num_props;
-- 
2.25.1

Re: [PATCH 1/1] power: supply: gpio-charger: Support to disable charger

[Krzysztof Kozlowski]

On 29/11/2024 11:38, Stefan Raufhake wrote:
> From: Stefan Raufhake <s.raufhake@beckhoff.de>
> 
> We want to disable the built-in UPS in our device

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


> so that we can switch off the supply power of the
> device with and without the support of the UPS.

Please wrap commit message according to Linux coding style / submission
process (neither too early nor over the limit):
https://elixir.bootlin.com/linux/v6.4-rc1/source/Documentation/process/submitting-patches.rst#L597

> This commit will allow us to disable the ups by
> using the command echo 1 > /sys/class/power_supply/xxx/charge_type
> (1 = POWER_SUPPLY_CHARGE_TYPE_NONE) and enable the
> charger by setting it to 4 (POWER_SUPPLY_CHARGE_TYPE_STANDARD).

Please describe the hardware, not OS.

> 
> Signed-off-by: Stefan Raufhake <s.raufhake@beckhoff.de>
> ---
>  .../bindings/power/supply/gpio-charger.yaml   |  6 +++
>  drivers/power/supply/gpio-charger.c           | 43 +++++++++++++++++++

Please run scripts/checkpatch.pl and fix reported warnings. Then please
run `scripts/checkpatch.pl --strict` and (probably) fix more warnings.
Some warnings can be ignored, especially from --strict run, but the code
here looks like it needs a fix. Feel free to get in touch if the warning
is not clear.

>  2 files changed, 49 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml b/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml
> index 89f8e2bcb2d7..b2658b0b20e4 100644
> --- a/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml
> +++ b/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml
> @@ -44,6 +44,10 @@ properties:
>      maxItems: 32
>      description: GPIOs used for current limiting
>  
> +  charge-disable-gpios:
> +    maxItems: 1
> +    description: GPIO to disable the charger

You just inverted existing "gpios" property, so no.

Best regards,
Krzysztof