From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: Backlight in motorola Droid 4 Date: Wed, 24 Jul 2019 10:22:53 +0200 Message-ID: <20190724082253.GA23552@amd> References: <20181219162626.12297-1-dmurphy@ti.com> <20190722205921.GA24787@amd> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="HlL+5n6rz5pIUxbD" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Dan Murphy Cc: linux-omap@vger.kernel.org, tony@atomide.com, sre@kernel.org, nekit1000@gmail.com, mpartap@gmx.net, merlijn@wizzup.org, jacek.anaszewski@gmail.com, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org List-Id: linux-omap@vger.kernel.org --HlL+5n6rz5pIUxbD Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue 2019-07-23 10:53:16, Dan Murphy wrote: > Pavel >=20 > 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? >=20 > In the LM3552 driver we are changing the Full scale brightness registers = for > the >=20 > specific control bank. >=20 > #define LM3532_REG_CTRL_A_BRT=A0=A0=A0 0x17 > #define LM3532_REG_CTRL_B_BRT=A0=A0=A0 0x19 > #define LM3532_REG_CTRL_C_BRT=A0=A0=A0 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. >=20 > #define LM3532_REG_BRT_A=A0=A0=A0 =A0=A0=A0 =A0=A0=A0 0x70=A0=A0=A0 /* zo= ne 0 */ > #define LM3532_REG_BRT_B=A0=A0=A0 =A0=A0=A0 =A0=A0=A0 0x76=A0=A0=A0 /* zo= ne 1 */ > #define LM3532_REG_BRT_C=A0=A0=A0 =A0=A0=A0 =A0=A0=A0 0x7C=A0=A0=A0 /* zo= ne 2 */ =2E..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 --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --HlL+5n6rz5pIUxbD Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAl04FV0ACgkQMOfwapXb+vI3tgCguRG0MY2FC+hQMV0vAg4QyYGf mJ8Anix5g0Mp6MVJSUSJhX7Bk6dJOX2a =0ZJs -----END PGP SIGNATURE----- --HlL+5n6rz5pIUxbD--