Re: [PATCH v3 1/2] leds: mt6360: Add LED driver for MT6360

From: Jacek Anaszewski
Date: Thu Sep 10 2020 - 16:36:58 EST

On 9/10/20 10:25 PM, Pavel Machek wrote:

1. set FLED1 brightness
# echo 1 > /sys/class/leds/white:flash1/flash_brightness
2. enable FLED1 strobe
# echo 1 > /sys/class/leds/white:flash1/flash_strobe
3 . turn off FLED1 strobe (just used to gaurantee the strobe mode
flash leds must be turned off)
# echo 0 > /sys/class/leds/white:flash1/flash_strobe

I believe I'd preffer only exposing torch functionality in
/sys/class/leds. .. strobe can be supported using v4l2 APIs.

Actually having LED flash class without strobe is pointless.
If you looked at led_classdev_flash_register_ext() you would see that
it fails with uninitialized strobe_set op. And V4L2 API for strobing
flash calls strobe_set from LED flash class beneath.

That was the idea behind LED and V4L2 flash API unification - there
is one hardware driver needed, the V4L2 Flash layer just takes over
control over it when needed.

I agree that one driver is enough.

But we should not need flash_strobe file in sysfs. Simply use V4L2 for

Apart from the fact that we can't remove it from LED flash class ABI
now, why would you like to prevent the user from exploiting main feature
of the hardware?

Best regards,
Jacek Anaszewski