From: Doug Anderson <dianders@chromium.org>
To: Rajeev Nandan <rajeevny@codeaurora.org>
Cc: y@qualcomm.com, dri-devel <dri-devel@lists.freedesktop.org>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
freedreno <freedreno@lists.freedesktop.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>,
Thierry Reding <thierry.reding@gmail.com>,
Sam Ravnborg <sam@ravnborg.org>, Rob Clark <robdclark@gmail.com>,
Lyude Paul <lyude@redhat.com>,
Jani Nikula <jani.nikula@intel.com>,
Rob Herring <robh@kernel.org>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Andrzej Hajda <a.hajda@samsung.com>,
Daniel Thompson <daniel.thompson@linaro.org>,
"Kristian H. Kristensen" <hoegsberg@chromium.org>,
Abhinav Kumar <abhinavk@codeaurora.org>,
Sean Paul <seanpaul@chromium.org>,
Kalyan Thota <kalyan_t@codeaurora.org>,
mkrishn@codeaurora.org
Subject: Re: [v4 2/4] drm/panel-simple: Support for delays between GPIO & regulator
Date: Tue, 25 May 2021 10:18:39 -0700 [thread overview]
Message-ID: <CAD=FV=WBLUqR1BqC_LO87s+4Cf5mEq=ODG_TDdm=YPYJvf7NyA@mail.gmail.com> (raw)
In-Reply-To: <1621927831-29471-3-git-send-email-rajeevny@codeaurora.org>
Hi,
On Tue, May 25, 2021 at 12:31 AM Rajeev Nandan <rajeevny@codeaurora.org> wrote:
>
> Some panels datasheets may specify a delay between the enable GPIO and
> the regulator. Support this in panel-simple.
>
> Signed-off-by: Rajeev Nandan <rajeevny@codeaurora.org>
> ---
>
> Changes in v4:
> - New
>
> drivers/gpu/drm/panel/panel-simple.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index f9e4e60..caed71b 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -134,6 +134,22 @@ struct panel_desc {
> unsigned int prepare_to_enable;
>
> /**
> + * @delay.power_to_enable: Time for the power to enable the display on.
> + *
> + * The time (in milliseconds) that it takes for the panel to
> + * turn the display on.
Maybe a slightly better description:
The time (in milliseconds) to wait after powering up the display
before asserting its enable pin.
> + */
> + unsigned int power_to_enable;
> +
> + /**
> + * @delay.disable_to_power_off: Time for the disable to power the display off.
> + *
> + * The time (in milliseconds) that it takes for the panel to
> + * turn the display off.
Maybe a slightly better description:
The time (in milliseconds) to wait after disabling the display before
deasserting its enable pin.
> + */
> + unsigned int disable_to_power_off;
> +
> + /**
> * @delay.enable: Time for the panel to display a valid frame.
> *
> * The time (in milliseconds) that it takes for the panel to
> @@ -367,6 +383,10 @@ static int panel_simple_suspend(struct device *dev)
> struct panel_simple *p = dev_get_drvdata(dev);
>
> gpiod_set_value_cansleep(p->enable_gpio, 0);
> +
> + if (p->desc->delay.disable_to_power_off)
> + msleep(p->desc->delay.disable_to_power_off);
> +
I wonder if it's worth a warning if
"p->desc->delay.disable_to_power_off" is non-zero and p->enable_gpio
is NULL? I guess in theory it'd also be nice to confirm that p->supply
wasn't a dummy regulator, but that's slightly harder.
> regulator_disable(p->supply);
> p->unprepared_time = ktime_get();
>
> @@ -427,6 +447,9 @@ static int panel_simple_prepare_once(struct panel_simple *p)
> return err;
> }
>
> + if (p->desc->delay.power_to_enable)
> + msleep(p->desc->delay.power_to_enable);
> +
Similar to above: I wonder if it's worth a warning if
"p->desc->delay.power_to_enable" is non-zero and p->enable_gpio is
NULL?
-Doug
next prev parent reply other threads:[~2021-05-25 17:19 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-25 7:30 [v4 0/4] drm: Support basic DPCD backlight in panel-simple and add a new panel ATNA33XC20 Rajeev Nandan
2021-05-25 7:30 ` [v4 1/4] drm/panel-simple: Add basic DPCD backlight support Rajeev Nandan
2021-05-25 11:41 ` kernel test robot
2021-05-25 17:18 ` Doug Anderson
2021-05-27 12:21 ` rajeevny
2021-05-27 21:41 ` Doug Anderson
2021-06-01 18:28 ` Lyude Paul
2021-06-01 22:20 ` Lyude Paul
2021-06-02 5:38 ` rajeevny
2021-06-08 21:02 ` Doug Anderson
2021-05-25 7:30 ` [v4 2/4] drm/panel-simple: Support for delays between GPIO & regulator Rajeev Nandan
2021-05-25 17:18 ` Doug Anderson [this message]
2021-05-25 7:30 ` [v4 3/4] dt-bindings: display: simple: Add Samsung ATNA33XC20 Rajeev Nandan
2021-05-25 17:19 ` Doug Anderson
2021-05-25 7:30 ` [v4 4/4] drm/panel-simple: " Rajeev Nandan
2021-05-25 17:19 ` Doug Anderson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAD=FV=WBLUqR1BqC_LO87s+4Cf5mEq=ODG_TDdm=YPYJvf7NyA@mail.gmail.com' \
--to=dianders@chromium.org \
--cc=a.hajda@samsung.com \
--cc=abhinavk@codeaurora.org \
--cc=daniel.thompson@linaro.org \
--cc=devicetree@vger.kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=freedreno@lists.freedesktop.org \
--cc=hoegsberg@chromium.org \
--cc=jani.nikula@intel.com \
--cc=kalyan_t@codeaurora.org \
--cc=laurent.pinchart@ideasonboard.com \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lyude@redhat.com \
--cc=mkrishn@codeaurora.org \
--cc=rajeevny@codeaurora.org \
--cc=robdclark@gmail.com \
--cc=robh@kernel.org \
--cc=sam@ravnborg.org \
--cc=seanpaul@chromium.org \
--cc=thierry.reding@gmail.com \
--cc=y@qualcomm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).