Re: [PATCH v4 3/3] Documentation: power: rt9471: Document exported sysfs entries

From: Sebastian Reichel
Date: Mon Sep 12 2022 - 07:12:11 EST


Hi,

On Mon, Aug 29, 2022 at 11:06:31AM +0800, cy_huang wrote:
> From: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
>
> Document the settings exported by rt9471 charger driver through sysfs entries:
> - sysoff_enable
> - charge_term_enable
> - port_detect_enable
>
> Signed-off-by: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-class-power | 44 +++++++++++++++++++++++++++++
> 1 file changed, 44 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power
> index a9ce63c..1f8afe5 100644
> --- a/Documentation/ABI/testing/sysfs-class-power
> +++ b/Documentation/ABI/testing/sysfs-class-power
> @@ -768,3 +768,47 @@ Description:
>
> Access: Read
> Valid values: 1-31
> +
> +What: /sys/class/power_supply/rt9471-*/sysoff_enable
> +Date: Sep 2022
> +KernelVersion: 6.1
> +Contact: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
> +Description:
> + This entry allows enabling the sysoff mode of rt9471 charger devices.
> + If enabled and the input is removed, the internal battery FET is turned
> + off to reduce the leakage from the BAT pin. See device datasheet for details.
> +
> + Access: Read, Write
> + Valid values:
> + - 1: enabled
> + - 0: disabled

This is not a very good description of what the control does. When
do you expect users to control this?

> +What: /sys/class/power_supply/rt9471-*/charge_term_enable
> +Date: Sep 2022
> +KernelVersion: 6.1
> +Contact: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
> +Description:
> + This entry allows enabling the charge termination function of rt9471 charger
> + devices. If enabled, the battery charging current, and the battery voltage
> + reachs charge termination condition, the internal battery FET will be turned off
> + to optimize the battery life. See device datasheet for details.
> +
> + Access: Read, Write
> + Valid values:
> + - 1: enabled
> + - 0: disabled

Just write 0 to .../charge_term_current to disable it.
No need for a custom property.

> +What: /sys/class/power_supply/rt9471-*/port_detect_enable
> +Date: Sep 2022
> +KernelVersion: 6.1
> +Contact: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
> +Description:
> + This entry allows enabling the USB BC12 port detect function of rt9471 charger
> + devices. If enabled and VBUS is inserted, device will start to do the BC12
> + port detect and report the usb port type when port detect is done. See
> + datasheet for details.
> +
> + Access: Read, Write
> + Valid values:
> + - 1: enabled
> + - 0: disabled

Why would one want to disable this?
Can't the driver just enable it unconditionally?

-- Sebastian

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