Control USB Vbus

mohamed-ali_fod — Fri, 03 Sep 2021 06:55:08 GMT

Hello,

I am working on i.MX6 Quad. I want to set vbus on/off through libusb, but it seems that chipidea driver doesn't allow this because it check for CI_HDRC_TURN_VBUS_EARLY_ON in host_start function so the priv->reg_vbus is always NULL

priv->reg_vbus = NULL;

if (ci->platdata->reg_vbus && !ci_otg_is_fsm_mode(ci)) {
if (ci->platdata->flags & CI_HDRC_TURN_VBUS_EARLY_ON) {
ret = regulator_enable(ci->platdata->reg_vbus);
if (ret) {
dev_err(ci->dev,
"Failed to enable vbus regulator, ret=%d\n",ret);
goto put_hcd;
}
} else {
priv->reg_vbus = ci->platdata->reg_vbus;
}
}

because priv->reg_vbus = NULL the following condition is not satisfied in ehci_ci_portpower function:

if (priv->reg_vbus && enable != priv->enabled)

So the regulator_enable(priv->reg_vbus)/regulator_disable(priv->reg_vbus) are not called.

The question is: it is safe to do always priv->reg_vbus =ci->platdata->reg_vbus in host_start ?

if (ci->platdata->reg_vbus && !ci_otg_is_fsm_mode(ci)) {
if (ci->platdata->flags & CI_HDRC_TURN_VBUS_EARLY_ON) {

priv->reg_vbus = ci->platdata->reg_vbus;
ret = regulator_enable(ci->platdata->reg_vbus);
if (ret) {
dev_err(ci->dev,
"Failed to enable vbus regulator, ret=%d\n",ret);
goto put_hcd;
}
}
}

So the condition if (priv->reg_vbus && enable != priv->enabled) in ehci_ci_portpower is true and regulator_disable/regulator_enable can be called.

Best Regards

Re: Control USB Vbus

mohamed-ali_fod — Wed, 08 Sep 2021 09:07:43 GMT

Hello,

The purpose is to disable Vbus in case of over-current from user space or is it already managed in the driver?

Thanks,

Mohamed Ali

Re: Control USB Vbus

Rita_Wang — Fri, 17 Sep 2021 02:17:27 GMT

You can refer to this https://community.nxp.com/t5/i-MX-Processors/Disable-USB-VBUS-power-supply/m-p/884711

topic Control USB Vbus in i.MX Processors

Control USB Vbus

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Re: Control USB Vbus