On Tue, Jun 27, 2017 at 10:54 PM, Fabio Estevam wrote:
> Hi Gautam,
>
> On Wed, Jun 21, 2017 at 1:18 PM, Gautam Bhat
> wrote:
> > This change sets the VLDO4 settings output to 2.8V in PMIC
> > initialization so that the MIPI DSI and MIPI CSI input voltage
> > is 2.8V as per the schematics.
>
> As we do not have MIPI DSI / MIPI CSI support in U-Boot, it is
> preferable to let the kernel configure the regulator.
>
> You can do this is the device tree like this:
>
> diff --git a/arch/arm/boot/dts/imx7d-sdb.dts
> b/arch/arm/boot/dts/imx7d-sdb.dts
> index 54c4540..923aa755 100644
> --- a/arch/arm/boot/dts/imx7d-sdb.dts
> +++ b/arch/arm/boot/dts/imx7d-sdb.dts
> @@ -285,8 +285,8 @@
> };
>
> vgen6_reg: vldo4 {
> - regulator-min-microvolt = <180>;
> - regulator-max-microvolt = <330>;
> + regulator-min-microvolt = <280>;
> + regulator-max-microvolt = <280>;
> regulator-always-on;
> };
> };
>
> Regards,
>
> Fabio Estevam
>
Hi Fabio,
The patch for the kernel was supposed to be next. Should I send the kernel
patch to mainline or some place else?
Coming to u-boot, the fact that even if there is no MIPI DSI/MIPI CSI
support the voltage would still be 3.3V in those rails. In my case I do not
attach the display after u-boot boots up. I keep the display attached and
sometimes I leave it in u-boot command line without going over to the
kernel. Since this is a development board this is often the case for many
developers and there may be chances of the display getting damaged.
Thanks,
Gautam.
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