Re: [PATCH] power: reset: ltc2952: make trigger delay configurable

[Marek Czerski <ma.czerski@gmail.com>]

Hi Sebastian,

Thanks for the review. I will send fixed patch as v2 to the correct
list of recipients afer I test it on my hardware this week.

Best regards,
Marek Czerski.

sob., 16 sty 2021 o 16:04 Sebastian Reichel <sre@kernel.org> napisał(a):
>
> Hi,
>
> On Mon, Dec 07, 2020 at 11:28:29PM +0100, Marek Czerski wrote:
> > Make trigger delay configurable through device tree with
> > trigger-delay-ms property.
> >
> > Trigger delay is the time to wait before starting shutdown
> > sequence after trigger line assertion.
> > Trigger delay must take into account the OFFT time configured
> > with the capacitor connected to OFFT pin of the LTC2952 chip.
> > Basically, the higher the capacitance connected to OFFT pin,
> > the larger trigger delay must be.
> >
> > Signed-off-by: Marek Czerski <ma.czerski@gmail.com>
> > ---
> >  .../devicetree/bindings/power/reset/ltc2952-poweroff.txt  | 4 ++++
> >  drivers/power/reset/ltc2952-poweroff.c                    | 8 ++++++++
> >  2 files changed, 12 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/power/reset/ltc2952-poweroff.txt b/Documentation/devicetree/bindings/power/reset/ltc2952-poweroff.txt
> > index cd2d7f58a..881f15a78 100644
> > --- a/Documentation/devicetree/bindings/power/reset/ltc2952-poweroff.txt
> > +++ b/Documentation/devicetree/bindings/power/reset/ltc2952-poweroff.txt
>
> Please additionally Cc DT binding maintainer:
>
> OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS
> M:      Rob Herring <robh+dt@kernel.org>
> L:      devicetree@vger.kernel.org
>
> > @@ -17,6 +17,9 @@ Optional properties:
> >                       chip's trigger line. If this property is not set, the
> >                       trigger function is ignored and the chip is kept alive
> >                       until an explicit kill signal is received
> > +- trigger-delay-ms   The number of milliseconds to wait after trigger line
> > +                     assertion before executing shut down procedure.
> > +                     The default is 2500ms.
> >
> >  Example:
> >
> > @@ -24,6 +27,7 @@ ltc2952 {
> >       compatible = "lltc,ltc2952";
> >
> >       trigger-gpios = <&gpio0 1 GPIO_ACTIVE_LOW>;
> > +        trigger-delay-ms = <2000>;
>
> please use tab instead of spaces
>
> >       watchdog-gpios = <&gpio1 2 GPIO_ACTIVE_HIGH>;
> >       kill-gpios = <&gpio0 2 GPIO_ACTIVE_LOW>;
> >  };
> > diff --git a/drivers/power/reset/ltc2952-poweroff.c b/drivers/power/reset/ltc2952-poweroff.c
> > index 318927938..243811541 100644
> > --- a/drivers/power/reset/ltc2952-poweroff.c
> > +++ b/drivers/power/reset/ltc2952-poweroff.c
> > @@ -55,6 +55,7 @@
> >  #include <linux/mod_devicetable.h>
> >  #include <linux/gpio/consumer.h>
> >  #include <linux/reboot.h>
> > +#include <linux/of.h>
> >
> >  struct ltc2952_poweroff {
> >       struct hrtimer timer_trigger;
> > @@ -172,10 +173,17 @@ static void ltc2952_poweroff_default(struct ltc2952_poweroff *data)
> >  static int ltc2952_poweroff_init(struct platform_device *pdev)
> >  {
> >       int ret;
> > +     u32 trigger_delay_ms;
> >       struct ltc2952_poweroff *data = platform_get_drvdata(pdev);
> >
> >       ltc2952_poweroff_default(data);
> >
> > +     if (!of_property_read_u32(pdev->dev.of_node, "trigger-delay-ms",
> > +                               &trigger_delay_ms)) {
>
> please use device_property_read_u32() from <linux/property.h>.
>
> > +             data->trigger_delay = ktime_set(trigger_delay_ms / MSEC_PER_SEC,
> > +                     (trigger_delay_ms % MSEC_PER_SEC) * NSEC_PER_MSEC);
> > +     }
> > +
> >       data->gpio_watchdog = devm_gpiod_get(&pdev->dev, "watchdog",
> >                                            GPIOD_OUT_LOW);
> >       if (IS_ERR(data->gpio_watchdog)) {
>
> Thanks and sorry for delayed response,
>
> -- Sebastian



-- 
mgr inż. Marek Czerski
+48 696 842 686