Messages in this thread | | | Subject | Re: [PATCH v3 1/5] leds: lm3532: Fix brightness control for i2c mode | From | Dan Murphy <> | Date | Tue, 27 Aug 2019 07:44:09 -0500 |
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Tony
On 8/27/19 7:18 AM, Pavel Machek wrote: > On Mon 2019-08-26 15:44:37, Tony Lindgren wrote: >> * Pavel Machek <pavel@ucw.cz> [190826 22:14]: >>> On Mon 2019-08-26 14:58:22, Tony Lindgren wrote: >>>> Hi, >>>> >>>> * Dan Murphy <dmurphy@ti.com> [190820 19:53]: >>>>> Fix the brightness control for I2C mode. Instead of >>>>> changing the full scale current register update the ALS target >>>>> register for the appropriate banks. >>>>> >>>>> In addition clean up some code errors and random misspellings found >>>>> during coding. >>>>> >>>>> Tested on Droid4 as well as LM3532 EVM connected to a BeagleBoneBlack >>>>> >>>>> Fixes: e37a7f8d77e1 ("leds: lm3532: Introduce the lm3532 LED driver") >>>>> Reported-by: Pavel Machek <pavel@ucw.cz> >>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com> >>>>> --- >>>>> >>>>> v3 - Removed register define updates - https://lore.kernel.org/patchwork/patch/1114542/ >>>> Looks like starting with this patch in Linux next the LCD on droid4 >>>> is so dim it's unreadable even with brightness set to 255. Setting >>>> brightness to 0 does blank it completely though. >>>> >>>> Did something maybe break with the various patch revisions or are >>>> we now missing some dts patch? >>> Maybe missing dts patch. We should provide maximum current the LED can >>> handle... >> Or i2c control is somehow broken and only als control now works?
With only setting CONFIG_LEDS_LM3532=m to the next branch I get full brightness with 255.
I also see half brightness at 128 with the ramp down working.
I am not able to reproduce this issue on my device.
> Well, max current led is obviously missing. Plus code does not check > the return from reading led-max-microamp.
led-max-microamp is optional so there is no need to check the return.
full_scale_current should be 0 if not populated and in the init only if this variable is set does
the code program the register otherwise it is default of 20.2 mA.
Dan
> > ret = fwnode_property_read_u32(child, "led-max-microamp", > &led->full_scale_current); > > Untested, but something like this is neccessary according to code > review. > > Signed-off-by: Pavel Machek <pavel@ucw.cz> > Pavel > > diff --git a/arch/arm/boot/dts/omap4-droid4-xt894.dts b/arch/arm/boot/dts/omap4-droid4-xt894.dts > index 4454449..b883b84 100644 > --- a/arch/arm/boot/dts/omap4-droid4-xt894.dts > +++ b/arch/arm/boot/dts/omap4-droid4-xt894.dts > @@ -395,6 +395,7 @@ > ti,led-mode = <0>; > label = ":backlight"; > linux,default-trigger = "backlight"; > + led-max-microamp = 29800; > }; > > led@1 { > @@ -402,6 +403,7 @@ > led-sources = <1>; > ti,led-mode = <0>; > label = ":kbd_backlight"; > + led-max-microamp = 29800; > }; > }; > }; > >
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