From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [RESEND] [PATCH v2 2/4] dt-bindings: Add jdi lt070me05000 panel bindings Date: Wed, 24 Aug 2016 14:32:46 +0200 Message-ID: <20160824123246.GA3714@ulmo.ba.sec> References: <1469978126-925-1-git-send-email-simhavcs@gmail.com> <1469978126-925-2-git-send-email-simhavcs@gmail.com> <20160824114534.GA3169@ulmo.ba.sec> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="pWyiEgJYm5f9v55/" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Vinay Simha Cc: Archit Taneja , John Stultz , Sumit Semwal , David Airlie , Rob Herring , Mark Rutland , "open list:DRM PANEL DRIVERS" , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list List-Id: devicetree@vger.kernel.org --pWyiEgJYm5f9v55/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 24, 2016 at 05:34:55PM +0530, Vinay Simha wrote: > thierry, >=20 > this is the reference pinouts of the panel > http://www.tonylabs.com/wp-content/uploads/LT070ME05000-pinouts.jpg I can't open that file. > as you suggest , i will change the vcc-supply, >=20 > - iovcc-supply: phandle of the regulator that supplies power to > the IOVCC voltage input (1.8 V) >=20 > will keep the other two(vddp-supply, dcdc_en-supply) remaining same. "dcdc_en" sounds to me like it should be a GPIO rather than a regulator. According to this datasheet: http://kb.52solution.com/data/uploads/2016/04/07/3172846545705cc22d050e.pdf the input voltages are indeed VDD, VDDp and IOVCC, though with slightly larger tolerances than the previous datasheet. VDD and VDDp can both go =66rom 3.0 V to 5.0 V. DCDC_EN is indeed an additional GPIO to enable the VDDp supply. I think you'd need something along these lines: - vdd-supply: LED power supply (3.0-5.0 V) - vddp-supply: power IC supply (3.0-5.0 V) - iovcc-supply: LCM power supply (1.8 V) - dcdc-en-gpios: power IC supply enable - led-en-gpios: LED backlight enable Or perhaps your vddp-supply should be a regulator that's controlled by the GPIO that you'd put in dcdc-en-gpios. That might work better. That would leave only led-en-gpios as the only enable GPIOs property, so it would be okay to keep the name "enable-gpios", I guess. Thierry > On Wed, Aug 24, 2016 at 5:15 PM, Thierry Reding > wrote: > > On Sun, Jul 31, 2016 at 08:45:21PM +0530, Vinay Simha BN wrote: > >> Add documentation for lt070me05000 panel > >> > >> Cc: Archit Taneja > >> Cc: John Stultz > >> Cc: Thierry Reding > >> Cc: Sumit Semwal > >> Signed-off-by: Vinay Simha BN > >> Acked-by: Rob Herring > >> > >> --- > >> v2: > >> * incorporated rob herring and thierry reviews > >> gpio to gpios, gpio to regulator using fixed regulators > >> and pwm backlight is removed, since it is controlled by > >> dcs commands > >> --- > >> .../bindings/display/panel/jdi,lt070me05000.txt | 57 +++++++++++++= +++++++++ > >> 1 file changed, 57 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/display/panel/jd= i,lt070me05000.txt > >> > >> diff --git a/Documentation/devicetree/bindings/display/panel/jdi,lt070= me05000.txt b/Documentation/devicetree/bindings/display/panel/jdi,lt070me05= 000.txt > >> new file mode 100644 > >> index 0000000..613b76f > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000= =2Etxt > >> @@ -0,0 +1,57 @@ > >> +JDI model LT070ME05000 1200x1920 7" DSI Panel > >> + > >> +Required properties: > >> +- compatible: should be "jdi,lt070me05000" > >> +- vddp-supply: phandle of the regulator that provides the supply volt= age > >> + Power IC supply (3-5V) > >> +- dcdc_en-supply: phandle of the regulator that provides the supply v= oltage > >> + Power IC supply enable, High active > >> +- vcc-supply: phandle of the regulator that provides the supply volta= ge > >> + IOVCC , power supply for LCM (1.8V) > > > > I was just going to apply this and wanted to add some information about > > how many lanes the panel uses, so I looked at the datasheet linked to in > > patch 4/4: > > > > http://panelone.net/en/7-0-inch/JDI_LT070ME05000_7.0_inch-datas= heet > > > > and noticed that the power supplies in the binding here don't match the > > ones listed in the datasheet. Granted, the datasheet is somewhat meager, > > but it lists the following three input voltages: > > > > - IOVCC at 1.8 V > > - VDD at 3.0 V > > - VDDP at 3.0 V > > > > This matches in part what the above binding describes, but it's not > > quite right, so I'm wondering if the name for dcdc_en-supply came from > > the board schematics and reflects the name of the rail on the board > > design that provides this rather than the input voltage on the panel. > > > > I think we should follow the names in the panel datasheet so that people > > can more easily reference the correct regulators when using this panel > > on a different board. I'd suggest: > > > > - iovcc-supply: phandle of the regulator that supplies power to > > the IOVCC voltage input (1.8 V) > > - vdd-supply: phandle of the regulator that supplies power to > > the VDD voltage input (3.0 V) > > - vddp-supply: phandle of the regulator that supplies power to > > the VDDP voltage input (3.0 V) > > > > Any objections? > > > > Thierry >=20 >=20 >=20 > --=20 > regards, > vinaysimha --pWyiEgJYm5f9v55/ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJXvZPsAAoJEN0jrNd/PrOhZsoP/jf8If5+EBAouj9ULwD0Mfum O9JCRyD7JUJOxbgzmOn2LI0uwovZHKQfBDk2tGqFkxG+uYPqniosfNq3AWGg7OqW DYpNQmXWbMyKxTe1m7Rwz7byikhZvXNWpHDBKYQXRTMQvNH6CunAsiU2JhoHznVh ag05fLEuH/s5iQrW4T63GBpiMSUDnQ6HxCfi6ieSzpqZEy72Gm8CxHjEN1mx5Vof Xkyvzodf127sRSp463Y8RYs6XtOhSzseIV7uNWzBd9hqfimPeqzooY+5gTDfV6BR l7BgKazDqQJrm121Iy1WuX/Uo22WjxdCjhyMBbdLrJrPfjpgaEPSQM3hN3LjLhr+ /D9XJVLGM6K68AkVh6RiHlS2Alp1O8OxptJRt2HQbxdnKqx2aQT03s7mkH+DJXdf aSskmyQmr738QdwEFSi3lhUM/HL1W/3rEsmei7HVt1znzUjwow2xX69lSmIu9Gze ywFQYMz5UC82atn9yk8c1e/aSyFYNilsTrDMMz8y8b5FazZhXAH4T+82GfNxEV7+ nrTzXz6q/fCzh1IRNuDRuPCzYitHZJqvd5sL43At/gYZnLLW23CZHXf6Q4B75yen UA6Lx5jFn8hDZBfw+6sIcpqsmXLMiVN4C7XC1NOHimSalIOTaHOHbBZJLFRFHu4R tJexLWNsGazZTGF66YcD =gvSc -----END PGP SIGNATURE----- --pWyiEgJYm5f9v55/--