[PATCH v2 0/2] power: supply: gpio-charger: add support for default charge current limit

[PATCH v2 0/2] power: supply: gpio-charger: add support for default charge current limit

[Dimitri Fedrau via B4 Relay]

With DT properties charge-current-limit-gpios and
charge-current-limit-mapping one can define charge current limits in uA
using up to 32 GPIOs. At the moment the driver defaults to smallest charge
current limitation for safety reasons. When disabling charging is
supported, which should be common, the driver defaults to non charging on
probe. By having a default, charging can be enabled on probe for such
devices.

Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
---
Changes in v2:
- renamed DT property charge-current-limit-default to
  charge-current-limit-default-microamp
- Added dependency on charge-current-limit-mapping
- Added intention and use case to commit descriptions
- Added charge-current-limit-default-microamp in bindings example
- Link to v1: https://lore.kernel.org/r/20241211-default-charge-current-limit-v1-0-7819ba06ee2a@liebherr.com

---
Dimitri Fedrau (2):
      dt-bindings: power: supply: gpio-charger: add support for default charge current limit
      power: supply: gpio-charger: add support for default charge current limit

 .../devicetree/bindings/power/supply/gpio-charger.yaml      |  6 ++++++
 drivers/power/supply/gpio-charger.c                         | 13 +++++++++++++
 2 files changed, 19 insertions(+)
---
base-commit: 57cb041f61d4abcf8dfa41259df27d081ab4cb6a
change-id: 20241209-default-charge-current-limit-69ae7945061a

Best regards,
-- 
Dimitri Fedrau <dimitri.fedrau@liebherr.com>

[PATCH v2 1/2] dt-bindings: power: supply: gpio-charger: add support for default charge current limit

[Dimitri Fedrau via B4 Relay]

From: Dimitri Fedrau <dimitri.fedrau@liebherr.com>

With DT properties charge-current-limit-gpios and
charge-current-limit-mapping one can define charge current limits in uA
using up to 32 GPIOs. Add property charge-current-limit-default-microamp
which selects a default charge current limit that must be listed in
charge-current-limit-mapping.

Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
---
 Documentation/devicetree/bindings/power/supply/gpio-charger.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml b/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml
index 89f8e2bcb2d7836c6a4308aff51721bd83fa3ba1..25826bfc289c1c00c338fd0cee2ae6932529cfc3 100644
--- a/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml
+++ b/Documentation/devicetree/bindings/power/supply/gpio-charger.yaml
@@ -58,6 +58,10 @@ properties:
             charge-current-limit-gpios property. Bit 1 second to last
             GPIO and so on.
 
+  charge-current-limit-default-microamp:
+    description: Default charge current limit. Must be listed in
+      charge-current-limit-mapping.
+
 required:
   - compatible
 
@@ -72,6 +76,7 @@ anyOf:
 dependencies:
   charge-current-limit-gpios: [ charge-current-limit-mapping ]
   charge-current-limit-mapping: [ charge-current-limit-gpios ]
+  charge-current-limit-default-microamp: [charge-current-limit-mapping]
 
 additionalProperties: false
 
@@ -91,4 +96,5 @@ examples:
       charge-current-limit-mapping = <2500000 0x00>, // 2.5 A => both GPIOs low
                                      <700000 0x01>, // 700 mA => GPIO A.12 high
                                      <0 0x02>; // 0 mA => GPIO A.11 high
+      charge-current-limit-default-microamp = <700000>;
     };

-- 
2.39.5

[PATCH v2 2/2] power: supply: gpio-charger: add support for default charge current limit

[Dimitri Fedrau via B4 Relay]

From: Dimitri Fedrau <dimitri.fedrau@liebherr.com>

With DT properties charge-current-limit-gpios and
charge-current-limit-mapping one can define charge current limits in uA
using up to 32 GPIOs. At the moment the driver defaults to smallest charge
current limitation for safety reasons. When disabling charging is
supported, which should be common, the driver defaults to non charging on
probe. By having a default, charging can be enabled on probe for such
devices.

Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
---
 drivers/power/supply/gpio-charger.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/power/supply/gpio-charger.c b/drivers/power/supply/gpio-charger.c
index 68212b39785beabfe5536a18fa15bc249f7b1eea..56149545a1dc6004b474cec44984c6dfad3413b5 100644
--- a/drivers/power/supply/gpio-charger.c
+++ b/drivers/power/supply/gpio-charger.c
@@ -187,6 +187,8 @@ static int init_charge_current_limit(struct device *dev,
 {
 	int i, len;
 	u32 cur_limit = U32_MAX;
+	bool set_def_limit;
+	u32 def_limit;
 
 	gpio_charger->current_limit_gpios = devm_gpiod_get_array_optional(dev,
 		"charge-current-limit", GPIOD_OUT_LOW);
@@ -220,6 +222,9 @@ static int init_charge_current_limit(struct device *dev,
 	if (len < 0)
 		return len;
 
+	set_def_limit = !device_property_read_u32(dev,
+						  "charge-current-limit-default-microamp",
+						  &def_limit);
 	for (i=0; i < gpio_charger->current_limit_map_size; i++) {
 		if (gpio_charger->current_limit_map[i].limit_ua > cur_limit) {
 			dev_err(dev, "charge-current-limit-mapping not sorted by current in descending order\n");
@@ -227,8 +232,16 @@ static int init_charge_current_limit(struct device *dev,
 		}
 
 		cur_limit = gpio_charger->current_limit_map[i].limit_ua;
+		if (set_def_limit && def_limit == cur_limit) {
+			set_charge_current_limit(gpio_charger, cur_limit);
+			return 0;
+		}
 	}
 
+	if (set_def_limit)
+		dev_warn(dev, "charge-current-limit-default-microamp %u not listed in charge-current-limit-mapping\n",
+			 def_limit);
+
 	/* default to smallest current limitation for safety reasons */
 	len = gpio_charger->current_limit_map_size - 1;
 	set_charge_current_limit(gpio_charger,

-- 
2.39.5

Re: [PATCH v2 1/2] dt-bindings: power: supply: gpio-charger: add support for default charge current limit

[Krzysztof Kozlowski]

On Fri, Dec 13, 2024 at 08:32:33PM +0100, Dimitri Fedrau wrote:
> With DT properties charge-current-limit-gpios and
> charge-current-limit-mapping one can define charge current limits in uA
> using up to 32 GPIOs. Add property charge-current-limit-default-microamp
> which selects a default charge current limit that must be listed in
> charge-current-limit-mapping.

Last time you wrote the point of it is to avoid defaulting to 0 A for
charging, because existing implementation uses smallest possible value.
This is supposed to be here in commit msg.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH v2 1/2] dt-bindings: power: supply: gpio-charger: add support for default charge current limit

[Dimitri Fedrau]

Am Mon, Dec 16, 2024 at 11:04:40AM +0100 schrieb Krzysztof Kozlowski:
> On Fri, Dec 13, 2024 at 08:32:33PM +0100, Dimitri Fedrau wrote:
> > With DT properties charge-current-limit-gpios and
> > charge-current-limit-mapping one can define charge current limits in uA
> > using up to 32 GPIOs. Add property charge-current-limit-default-microamp
> > which selects a default charge current limit that must be listed in
> > charge-current-limit-mapping.
> 
> Last time you wrote the point of it is to avoid defaulting to 0 A for
> charging, because existing implementation uses smallest possible value.
> This is supposed to be here in commit msg.
>
Will add it. Thanks for reviewing.

Best regards,
Dimitri