Hi Laurent, Thanks for the feedback. > Subject: Re: [PATCH v3] ARM: dts: iwg20d-q7-common: Fix touch controller > probe failure > > Hi Biju, > > Thank you for the patch. > > On Mon, Aug 10, 2020 at 06:49:44PM +0100, Biju Das wrote: > > As per the iWave RZ/G1M schematic, the signal LVDS_PPEN controls > > supply voltage for touch panel, LVDS receiver and RGB LCD panel. Add > > regulator for these device nodes and remove powerdown-gpios property > > from lvds-receiver node as it results in touch controller driver probe failure. > > > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx> > > --- > > This patch depend on below patches > > > > 1) https://patchwork.kernel.org/patch/11707595/ > > 2) https://patchwork.kernel.org/patch/11707593/ > > > > v2->v3 : Added the missing part from the patch. removal of powerdown- > gpios property. > > v1->v2 : Add regulator in touch panel, LVDS receiver and RGB LCD panel > > v1->device nodes > > (Ref: https://patchwork.kernel.org/patch/11707559/) > > v1 : https://patchwork.kernel.org/patch/11705819/ > > --- > > arch/arm/boot/dts/iwg20d-q7-common.dtsi | 15 ++++++++++++++- > > 1 file changed, 14 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm/boot/dts/iwg20d-q7-common.dtsi > > b/arch/arm/boot/dts/iwg20d-q7-common.dtsi > > index ebbe1518ef8a..056f93119d8a 100644 > > --- a/arch/arm/boot/dts/iwg20d-q7-common.dtsi > > +++ b/arch/arm/boot/dts/iwg20d-q7-common.dtsi > > @@ -57,7 +57,7 @@ > > > > lvds-receiver { > > compatible = "ti,ds90cf384a", "lvds-decoder"; > > -powerdown-gpios = <&gpio7 25 GPIO_ACTIVE_LOW>; > > +vcc-supply = <&vcc_3v3_tft1>; > > > > ports { > > #address-cells = <1>; > > @@ -81,6 +81,7 @@ > > panel { > > compatible = "edt,etm0700g0dh6"; > > backlight = <&lcd_backlight>; > > +power-supply = <&vcc_3v3_tft1>; > > > > port { > > panel_in: endpoint { > > @@ -113,6 +114,17 @@ > > }; > > }; > > > > +vcc_3v3_tft1: regulator-panel { > > +compatible = "regulator-fixed"; > > + > > +regulator-name = "Panel Vcc"; > > Should this be named vcc-3v3-tft1, to match the hardware ? It's not just the > panel, it's also the power supply to the LVDS receiver and touch screen. Ok. I will change this to vcc-3v3-tft1. > > +regulator-min-microvolt = <3300000>; > > +regulator-max-microvolt = <3300000>; > > +enable-active-high; > > +startup-delay-us = <70000>; > > Where does the 70ms value come from ? The time constant of the VCC_3V3 > -> VCC_3V3_TFT[12] switches circuitry is 0.1ms (RC = 100kΩ * 1nF), so > 0.5ms (5*RC) should be enough there. Are there other delays that need to > be taken into account ? Ok Thanks , I will change it to 0.5 msec. Initially I faced a probe failure, after turning on this regulator, so I chosen a value from the bindings examples and it seems to fix the issue. Now I have changed this value to 0.5 msec and confirms it works fine. Cheers, Biju > With those small issues addressed, > > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > > +gpio = <&gpio7 25 GPIO_ACTIVE_HIGH>; > > +}; > > + > > vcc_sdhi1: regulator-vcc-sdhi1 { > > compatible = "regulator-fixed"; > > > > @@ -207,6 +219,7 @@ > > reg = <0x38>; > > interrupt-parent = <&gpio2>; > > interrupts = <12 IRQ_TYPE_EDGE_FALLING>; > > +vcc-supply = <&vcc_3v3_tft1>; > > }; > > }; > > > > -- > Regards, > > Laurent Pinchart Renesas Electronics Europe GmbH, Geschaeftsfuehrer/President: Carsten Jauch, Sitz der Gesellschaft/Registered office: Duesseldorf, Arcadiastrasse 10, 40472 Duesseldorf, Germany, Handelsregister/Commercial Register: Duesseldorf, HRB 3708 USt-IDNr./Tax identification no.: DE 119353406 WEEE-Reg.-Nr./WEEE reg. no.: DE 14978647