Re: [RFC v5 07/15] usb: ehci: add vbus-gpio parameter

From: Antony Pavlov
Date: Thu Feb 18 2016 - 16:45:58 EST


On Thu, 18 Feb 2016 21:31:20 +0300
Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx> wrote:

> On 02/18/2016 09:06 PM, Antony Pavlov wrote:
[...]
> > so I use regulator in the TL-MR3020 board dts file:
> >
> > reg_usb_vbus: reg_usb_vbus {
> > compatible = "regulator-fixed";
> > regulator-name = "usb_vbus";
> > regulator-min-microvolt = <5000000>;
>
> Not 0?
>
> > regulator-max-microvolt = <5000000>;
> > gpio = <&gpio 8 GPIO_ACTIVE_HIGH>;
>
> Where's the switch if both voltages are equal?

Here is a quote from linux/Documentation/devicetree/bindings/regulator/fixed-regulator.txt

Any property defined as part of the core regulator
binding, defined in regulator.txt, can also be used.
However a fixed voltage regulator is expected to have the
regulator-min-microvolt and regulator-max-microvolt
to be the same.

Moreover please see this of_get_fixed_voltage_config() code fragment
(please see linux/drivers/regulator/fixed.c for details):

if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
config->microvolts = init_data->constraints.min_uV;
} else {
dev_err(dev,
"Fixed regulator specified with variable voltages\n");
return ERR_PTR(-EINVAL);
}

-- 
Best regards,
  Antony Pavlov