diff mbox series

[1/2] power: supply: add input voltage limit property.

Message ID 20181121153444.24747-1-enric.balletbo@collabora.com (mailing list archive)
State Not Applicable, archived
Headers show
Series [1/2] power: supply: add input voltage limit property. | expand

Commit Message

Enric Balletbo i Serra Nov. 21, 2018, 3:34 p.m. UTC 
We have a problem with USBPD chargers which under certain conditions
can result in system overheating if the voltage provided by the USBPD
port is too high. While the preferred means to control this would be
through devicetree or ACPI settings, this is not always possible, and
we need to have a means to set a voltage limit.

This patch exposes a new property, similar to input current limit, to
re-configure the maximum voltage from the external supply at runtime
based on system-level knowledge or user input.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
---

 Documentation/power/power_supply_class.txt | 2 ++
 drivers/power/supply/power_supply_sysfs.c  | 1 +
 include/linux/power_supply.h               | 1 +
 3 files changed, 4 insertions(+)

Comments

Guenter Roeck Nov. 21, 2018, 7 p.m. UTC | #1 
On Wed, Nov 21, 2018 at 7:34 AM Enric Balletbo i Serra
<enric.balletbo@collabora.com> wrote:
>
> We have a problem with USBPD chargers which under certain conditions
> can result in system overheating if the voltage provided by the USBPD
> port is too high. While the preferred means to control this would be
> through devicetree or ACPI settings, this is not always possible, and
> we need to have a means to set a voltage limit.
>
> This patch exposes a new property, similar to input current limit, to
> re-configure the maximum voltage from the external supply at runtime
> based on system-level knowledge or user input.
>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>


Reviewed-by: Guenter Roeck <groeck@chromium.org>

>
> ---
>
>  Documentation/power/power_supply_class.txt | 2 ++
>  drivers/power/supply/power_supply_sysfs.c  | 1 +
>  include/linux/power_supply.h               | 1 +
>  3 files changed, 4 insertions(+)
>
> diff --git a/Documentation/power/power_supply_class.txt b/Documentation/power/power_supply_class.txt
> index 300d37896e51..7b4be615b4f8 100644
> --- a/Documentation/power/power_supply_class.txt
> +++ b/Documentation/power/power_supply_class.txt
> @@ -137,6 +137,8 @@ power supply object.
>
>  INPUT_CURRENT_LIMIT - input current limit programmed by charger. Indicates
>  the current drawn from a charging source.
> +INPUT_VOLTAGE_LIMIT - input voltage limit programmed by charger. Indicates
> +the voltage limit from a charging source.
>
>  CHARGE_CONTROL_LIMIT - current charge control limit setting
>  CHARGE_CONTROL_LIMIT_MAX - maximum charge control limit setting
> diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
> index dce24f596160..5848742ebb59 100644
> --- a/drivers/power/supply/power_supply_sysfs.c
> +++ b/drivers/power/supply/power_supply_sysfs.c
> @@ -275,6 +275,7 @@ static struct device_attribute power_supply_attrs[] = {
>         POWER_SUPPLY_ATTR(charge_control_limit),
>         POWER_SUPPLY_ATTR(charge_control_limit_max),
>         POWER_SUPPLY_ATTR(input_current_limit),
> +       POWER_SUPPLY_ATTR(input_voltage_limit),
>         POWER_SUPPLY_ATTR(energy_full_design),
>         POWER_SUPPLY_ATTR(energy_empty_design),
>         POWER_SUPPLY_ATTR(energy_full),
> diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
> index f80769175c56..608ba88e32ee 100644
> --- a/include/linux/power_supply.h
> +++ b/include/linux/power_supply.h
> @@ -122,6 +122,7 @@ enum power_supply_property {
>         POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT,
>         POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX,
>         POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
> +       POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT,
>         POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
>         POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN,
>         POWER_SUPPLY_PROP_ENERGY_FULL,
> --
> 2.19.1
>
Adam Thomson Nov. 21, 2018, 10:11 p.m. UTC | #2 
On 21 November 2018 15:35, Enric Balletbo i Serra wrote:

> We have a problem with USBPD chargers which under certain conditions 
> can result in system overheating if the voltage provided by the USBPD 
> port is too high. While the preferred means to control this would be 
> through devicetree or ACPI settings, this is not always possible, and 
> we need to have a means to set a voltage limit.
> 
> This patch exposes a new property, similar to input current limit, to 
> re-configure the maximum voltage from the external supply at runtime 
> based on system-level knowledge or user input.

I think we should be adding new documentation to the following file for any property changes:

Documentation/ABI/testing/sysfs-class-power

Sebastian can maybe comment further though. 
 
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> ---
> 
>  Documentation/power/power_supply_class.txt | 2 ++ 
> drivers/power/supply/power_supply_sysfs.c  | 1 +
>  include/linux/power_supply.h               | 1 +
>  3 files changed, 4 insertions(+)
> 
> diff --git a/Documentation/power/power_supply_class.txt
> b/Documentation/power/power_supply_class.txt
> index 300d37896e51..7b4be615b4f8 100644
> --- a/Documentation/power/power_supply_class.txt
> +++ b/Documentation/power/power_supply_class.txt
> @@ -137,6 +137,8 @@ power supply object.
> 
>  INPUT_CURRENT_LIMIT - input current limit programmed by charger. 
> Indicates the current drawn from a charging source.
> +INPUT_VOLTAGE_LIMIT - input voltage limit programmed by charger.
> +Indicates the voltage limit from a charging source.
> 
>  CHARGE_CONTROL_LIMIT - current charge control limit setting 
> CHARGE_CONTROL_LIMIT_MAX - maximum charge control limit setting diff 
> --git a/drivers/power/supply/power_supply_sysfs.c
> b/drivers/power/supply/power_supply_sysfs.c
> index dce24f596160..5848742ebb59 100644
> --- a/drivers/power/supply/power_supply_sysfs.c
> +++ b/drivers/power/supply/power_supply_sysfs.c
> @@ -275,6 +275,7 @@ static struct device_attribute power_supply_attrs[] = {
>  	POWER_SUPPLY_ATTR(charge_control_limit),
>  	POWER_SUPPLY_ATTR(charge_control_limit_max),
>  	POWER_SUPPLY_ATTR(input_current_limit),
> +	POWER_SUPPLY_ATTR(input_voltage_limit),
>  	POWER_SUPPLY_ATTR(energy_full_design),
>  	POWER_SUPPLY_ATTR(energy_empty_design),
>  	POWER_SUPPLY_ATTR(energy_full),
> diff --git a/include/linux/power_supply.h 
> b/include/linux/power_supply.h index f80769175c56..608ba88e32ee 100644
> --- a/include/linux/power_supply.h
> +++ b/include/linux/power_supply.h
> @@ -122,6 +122,7 @@ enum power_supply_property {
>  	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT,
>  	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX,
>  	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
> +	POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT,
>  	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
>  	POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN,
>  	POWER_SUPPLY_PROP_ENERGY_FULL,
> --
> 2.19.1
diff mbox series

Patch

diff --git a/Documentation/power/power_supply_class.txt b/Documentation/power/power_supply_class.txt
index 300d37896e51..7b4be615b4f8 100644
--- a/Documentation/power/power_supply_class.txt
+++ b/Documentation/power/power_supply_class.txt
@@ -137,6 +137,8 @@  power supply object.
 
 INPUT_CURRENT_LIMIT - input current limit programmed by charger. Indicates
 the current drawn from a charging source.
+INPUT_VOLTAGE_LIMIT - input voltage limit programmed by charger. Indicates
+the voltage limit from a charging source.
 
 CHARGE_CONTROL_LIMIT - current charge control limit setting
 CHARGE_CONTROL_LIMIT_MAX - maximum charge control limit setting
diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index dce24f596160..5848742ebb59 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -275,6 +275,7 @@  static struct device_attribute power_supply_attrs[] = {
 	POWER_SUPPLY_ATTR(charge_control_limit),
 	POWER_SUPPLY_ATTR(charge_control_limit_max),
 	POWER_SUPPLY_ATTR(input_current_limit),
+	POWER_SUPPLY_ATTR(input_voltage_limit),
 	POWER_SUPPLY_ATTR(energy_full_design),
 	POWER_SUPPLY_ATTR(energy_empty_design),
 	POWER_SUPPLY_ATTR(energy_full),
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index f80769175c56..608ba88e32ee 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -122,6 +122,7 @@  enum power_supply_property {
 	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT,
 	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX,
 	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
+	POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT,
 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
 	POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN,
 	POWER_SUPPLY_PROP_ENERGY_FULL,