Re: [PATCH v4 3/3] regulator: bd9571mwv: Document "backup_mode" sysfs file

From: Niklas Söderlund
Date: Tue Jul 17 2018 - 07:53:11 EST


Hi Geert,

Thanks for your work.

On 2018-07-16 17:30:52 +0200, Geert Uytterhoeven wrote:
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Acked-by: Pavel Machek <pavel@xxxxxx>

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>

> ---
> v4:
> - Add Acked-by,
>
> v3:
> - New.
> ---
> .../testing/sysfs-driver-bd9571mwv-regulator | 27 +++++++++++++++++++
> 1 file changed, 27 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-driver-bd9571mwv-regulator
>
> diff --git a/Documentation/ABI/testing/sysfs-driver-bd9571mwv-regulator b/Documentation/ABI/testing/sysfs-driver-bd9571mwv-regulator
> new file mode 100644
> index 0000000000000000..4d63a7904b94a993
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-driver-bd9571mwv-regulator
> @@ -0,0 +1,27 @@
> +What: /sys/bus/i2c/devices/.../bd9571mwv-regulator.*.auto/backup_mode
> +Date: Jul 2018
> +KernelVersion: 4.19
> +Contact: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> +Description: Read/write the current state of DDR Backup Mode, which controls
> + if DDR power rails will be kept powered during system suspend.
> + ("on"/"1" = enabled, "off"/"0" = disabled).
> + Two types of power switches (or control signals) can be used:
> + A. With a momentary power switch (or pulse signal), DDR
> + Backup Mode is enabled by default when available, as the
> + PMIC will be configured only during system suspend.
> + B. With a toggle power switch (or level signal), the
> + following steps must be followed exactly:
> + 1. Configure PMIC for backup mode, to change the role of
> + the accessory power switch from a power switch to a
> + wake-up switch,
> + 2. Switch accessory power switch off, to prepare for
> + system suspend, which is a manual step not controlled
> + by software,
> + 3. Suspend system,
> + 4. Switch accessory power switch on, to resume the
> + system.
> + DDR Backup Mode must be explicitly enabled by the user,
> + to invoke step 1.
> + See also Documentation/devicetree/bindings/mfd/bd9571mwv.txt.
> +Users: User space applications for embedded boards equipped with a
> + BD9571MWV PMIC.
> --
> 2.17.1
>

--
Regards,
Niklas Söderlund