Re: [PATCH v3 0/2] Add LED driver for flash module in QCOM PMICs

From: Luca Weiss
Date: Wed Oct 19 2022 - 08:11:23 EST


Hi Fenglin,

On Wed Oct 19, 2022 at 12:17 PM CEST, Fenglin Wu wrote:
>
>
> On 2022/10/19 15:23, Luca Weiss wrote:
> > Hi Fenglin,
> >
> > On Tue Oct 18, 2022 at 3:40 AM CEST, Fenglin Wu wrote:
> >> Initial driver and binding document changes for supporting flash LED
> >> module in Qualcomm Technologies, Inc. PMICs.
> >>
> >
> > Thanks for these patches, it's really nice to see drivers like this
> > being sent upstream!
> >
> > I've just tried these patches on pm6150l which also is compatible with
> > this driver (and used on sm7225-fairphone-fp4).
> >
> > The two different flash LEDs on the device I could adjust as expected
> > using sysfs:
> >
> > $ echo 255 > /sys/class/leds/yellow:flash-0/brightness
> > $ echo 255 > /sys/class/leds/white:flash-0/brightness
> >
> > Also lower brightness values resulted in lower brightness on the LED, so
> > all is good here!
> >
> > But for flash usage, I couldn't figure out how to use it, doing the
> > following resulted in no change on the LED.
> >
> > $ cat /sys/class/leds/white:flash-0/max_flash_brightness
> > 1000000
> > $ echo 1000000 > /sys/class/leds/white:flash-0/flash_brightness
> >
> > Here's my LED definition:
> >
> > led-0 {
> > function = LED_FUNCTION_FLASH;
> > color = <LED_COLOR_ID_YELLOW>;
> > led-sources = <1>;
> > led-max-microamp = <180000>;
> > flash-max-microamp = <1000000>;
> > flash-max-timeout-us = <1280000>;
> > };
> >
> > From values are from msm-4.19 kernel:
> >
> > qcom,flash_0 {
> > qcom,current-ma = <1000>; // => flash-max-microamp
> > qcom,duration-ms = <1280>; // => flash-max-timeout-us
> > qcom,id = <0>; // => led-sources?
> > };
> >
> > qcom,torch_0 {
> > qcom,current-ma = <180>; // => led-max-microamp
> > qcom,id = <0>; // => led-sources?
> > };
> >
> > Could you please let me know how flash is supposed to work or if I
> > maybe have messed up some setting here?
> >
> > Regards
> > Luca
>
> Hi Luca,
>
> Thanks for testing the driver at your end.
> The "brightness" node is for enabling/disable/adjusting brightness when
> the LED is working in torch mode, the nodes for enabling/adjusting the
> LED behavior in flash mode are "flash_brightness" "flash_timeout"
> "flash_strobe".
> You can strobe the flash by "echo 1 > flash_strobe" directly and the
> default brightness/timeout value will be used, or you can update the
> settings with "echo xxx > flash_brightness; echo xxx > flash_timeout"
> then strobe the LED with "echo 1 > flash_strobe". Please remember you
> always need to "echo 0 > flash_strobe" 1st if you want to enable it again.
> Thanks

Indeed with flash_strobe it works as expected!

Tested-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx> # sm7225-fairphone-fp4 + pm6150l

Thanks again,
Luca

>
> Fenglin
> >
> >> Changes in V3:
> >> 1. Updated the driver to use regmap_field for register access.
> >> 2. Adressed the review comments in binding document change.
> >>
> >> Changes in V2:
> >> 1. Addressed review comments in binding change, thanks Krzysztof!
> >> 2. Updated driver to address the compilation issue reported by
> >> kernel test robot.
> >>
> >>
> >> Fenglin Wu (2):
> >> leds: flash: add driver to support flash LED module in QCOM PMICs
> >> dt-bindings: add bindings for QCOM flash LED
> >>
> >> .../bindings/leds/qcom,spmi-flash-led.yaml | 116 +++
> >> drivers/leds/flash/Kconfig | 15 +
> >> drivers/leds/flash/Makefile | 1 +
> >> drivers/leds/flash/leds-qcom-flash.c | 700 ++++++++++++++++++
> >> 4 files changed, 832 insertions(+)
> >> create mode 100644 Documentation/devicetree/bindings/leds/qcom,spmi-flash-led.yaml
> >> create mode 100644 drivers/leds/flash/leds-qcom-flash.c
> >>
> >> --
> >> 2.25.1
> >