Messages in this thread | | | Date | Wed, 24 Jul 2019 10:22:53 +0200 | From | Pavel Machek <> | Subject | Re: Backlight in motorola Droid 4 |
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On Tue 2019-07-23 10:53:16, Dan Murphy wrote: > Pavel > > On 7/22/19 3:59 PM, Pavel Machek wrote: > >Hi! > > > >So now the backlight LED can be controlled. Good. (And thanks!) > > > >But I seem to remember that backlight had range from "is it really on?" > >to "very bright"; now it seems to have range from "bright" to "very > >bright". > > > >Any ideas what goes on there? > > In the LM3552 driver we are changing the Full scale brightness registers for > the > > specific control bank. > > #define LM3532_REG_CTRL_A_BRT 0x17 > #define LM3532_REG_CTRL_B_BRT 0x19 > #define LM3532_REG_CTRL_C_BRT 0x1b
Yep, and those registers are 5-bit linear...
> In the ti-lmu code the ALS zones were being modified not the control bank > brightness. > > #define LM3532_REG_BRT_A 0x70 /* zone 0 */ > #define LM3532_REG_BRT_B 0x76 /* zone 1 */ > #define LM3532_REG_BRT_C 0x7C /* zone 2 */
...while these allow 14-bits of control.
That explains very limited range of backlight control.
Do you have any plans to change that?
Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html [unhandled content-type:application/pgp-signature] | |