Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Mime-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain; charset=UTF-8
Date:   Mon, 12 Dec 2022 14:59:07 +0100
Message-Id: <COZW5FAXA36Z.175ARPIESQSLL@otso>
To:     "Pavel Machek" <pavel@ucw.cz>
Cc:     "Andy Gross" <agross@kernel.org>,
        "Bjorn Andersson" <andersson@kernel.org>,
        "Konrad Dybcio" <konrad.dybcio@linaro.org>,
        "Rob Herring" <robh+dt@kernel.org>,
        "Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
        "Fenglin Wu" <quic_fenglinw@quicinc.com>,
        <linux-arm-msm@vger.kernel.org>, <linux-leds@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/3] arm64: dts: qcom: sm7225-fairphone-fp4: configure
 flash LED
From:   "Luca Weiss" <luca.weiss@fairphone.com>
References: <20221209-fp4-pm6150l-flash-v1-0-531521eb2a72@fairphone.com>
 <20221209-fp4-pm6150l-flash-v1-3-531521eb2a72@fairphone.com>
 <Y5S+6j1yJ62RJU/v@duo.ucw.cz>
In-Reply-To: <Y5S+6j1yJ62RJU/v@duo.ucw.cz>
Precedence: bulk

On Sat Dec 10, 2022 at 6:16 PM CET, Pavel Machek wrote:
> Hi!
>
> > Configure the pm6150l flash node for the dual flash LEDs found on FP4.
>
> > +&pm6150l_flash {
> > +	status =3D "okay";
> > +
> > +	led-0 {
> > +		function =3D LED_FUNCTION_FLASH;
> > +		color =3D <LED_COLOR_ID_YELLOW>;
> > +		led-sources =3D <1>;
> > +		led-max-microamp =3D <180000>;
> > +		flash-max-microamp =3D <1000000>;
> > +		flash-max-timeout-us =3D <1280000>;
> > +	};

Hi Pavel,

>
> I'm pretty sure the flash is not yellow.

The marketing term is Dual LED flash or Dual-tone flash, one LED is a
blue-ish white and one is a yellow-ish white, but from what I can tell,
in the original code it's always referred to as white and yellow so I
also followed that here.

Also the LEDs are right next to each other so in practise for torch just
both go on, and for camera flash I cannot really tell you but I guess
it's doing something there with the camera tuning.

See also this picture:
https://shop.fairphone.com/media/catalog/product/cache/b752d78484639b19641a=
8560800d919d/p/_/p_5b_main_camera_back.jpg

>
> Plus, how is the node in /sys/class/leds called? Can you make an entry
> in Documentation/leds/well-known-leds.txt and ensure the name stays
> consistent across devices?

/ # ls -al /sys/class/leds/white:flash/
total 0
drwxr-xr-x    3 0        0                0 Jan  1 00:00 .
drwxr-xr-x    4 0        0                0 Jan  1 00:00 ..
-rw-r--r--    1 0        0             4096 Jan  1 00:00 brightness
lrwxrwxrwx    1 0        0                0 Jan  1 00:00 device -> ../../..=
/c440000.spmi:pmic@5:led-controller@d300
-rw-r--r--    1 0        0             4096 Jan  1 00:00 flash_brightness
-r--r--r--    1 0        0             4096 Jan  1 00:00 flash_fault
-rw-r--r--    1 0        0             4096 Jan  1 00:00 flash_strobe
-rw-r--r--    1 0        0             4096 Jan  1 00:00 flash_timeout
-r--r--r--    1 0        0             4096 Jan  1 00:00 max_brightness
-r--r--r--    1 0        0             4096 Jan  1 00:00 max_flash_brightne=
ss
-r--r--r--    1 0        0             4096 Jan  1 00:00 max_flash_timeout
drwxr-xr-x    2 0        0                0 Jan  1 00:00 power
lrwxrwxrwx    1 0        0                0 Jan  1 00:00 subsystem -> ../..=
/../../../../../../../class/leds
-rw-r--r--    1 0        0             4096 Jan  1 00:00 uevent
/ # ls -al /sys/class/leds/yellow:flash/
total 0
drwxr-xr-x    3 0        0                0 Jan  1 00:00 .
drwxr-xr-x    4 0        0                0 Jan  1 00:00 ..
-rw-r--r--    1 0        0             4096 Jan  1 00:00 brightness
lrwxrwxrwx    1 0        0                0 Jan  1 00:00 device -> ../../..=
/c440000.spmi:pmic@5:led-controller@d300
-rw-r--r--    1 0        0             4096 Jan  1 00:00 flash_brightness
-r--r--r--    1 0        0             4096 Jan  1 00:00 flash_fault
-rw-r--r--    1 0        0             4096 Jan  1 00:00 flash_strobe
-rw-r--r--    1 0        0             4096 Jan  1 00:00 flash_timeout
-r--r--r--    1 0        0             4096 Jan  1 00:00 max_brightness
-r--r--r--    1 0        0             4096 Jan  1 00:00 max_flash_brightne=
ss
-r--r--r--    1 0        0             4096 Jan  1 00:00 max_flash_timeout
drwxr-xr-x    2 0        0                0 Jan  1 00:00 power
lrwxrwxrwx    1 0        0                0 Jan  1 00:00 subsystem -> ../..=
/../../../../../../../class/leds
-rw-r--r--    1 0        0             4096 Jan  1 00:00 uevent

There's also already flash LED on PinePhone and some MSM8916 devices,
but I think they also have white:flash based on the dt.

>
> Best regards,
> 								Pavel
> --=20
> People of Russia, stop Putin before his war on Ukraine escalates.