Re: [PATCH v2 08/10] hikey960: Support usb functionality of Hikey960

[Chunfeng Yun <chunfeng.yun@mediatek.com>]

On Tue, 2019-02-19 at 11:20 +0800, Chen Yu wrote:
> Hi,
> 
> On 2019/2/19 10:50, Chunfeng Yun wrote:
> >> +	if (ret)
> >> +		hisi_hikey_usb->typec_vbus_enable_val = 1;
> >> +
> >> +	hisi_hikey_usb->typec_vbus = devm_gpiod_get(dev, "typec-vbus",
> >> +			hisi_hikey_usb->typec_vbus_enable_val ?
> >> +			GPIOD_OUT_LOW : GPIOD_OUT_HIGH);
> >> +	if (!hisi_hikey_usb->typec_vbus)
> >> +		return -ENOENT;
> >> +	else if (IS_ERR(hisi_hikey_usb->typec_vbus))
> >> +		return PTR_ERR(hisi_hikey_usb->typec_vbus);
> >> +
> >> +	gpiod_direction_output(hisi_hikey_usb->typec_vbus,
> >> +			!hisi_hikey_usb->typec_vbus_enable_val);
> > maybe a simple way if use fixed regulator?
> > 
> The hardware of the Hikey960 board has been fixed, and the type-c
> port can act as UFP. So it is better to close the vbus when Hikey960
> connect to host(e.g PC).
I guess you misunderstand what I mean?
Please refer to bindings/regulator/fixed-regulator.txt
If you control vbus by gpio, you can use fixed-regulator, it will be
easy to make compatible with other cases, think about using a LDO to
control vbus
> >> +
> >> +	hisi_hikey_usb->otg_switch = devm_gpiod_get(dev, "otg-switch", GPIOD_IN);
> >> +	if (!hisi_hikey_usb->otg_switch)
> >> +		return -ENOENT;
> >> +	else if (IS_ERR(hisi_hikey_usb->otg_switch))
> >> +		return PTR_ERR(hisi_hikey_usb->otg_switch);
> >> +
> >> +	gpiod_direction_output(hisi_hikey_usb->otg_switch, USB_SWITCH_TO_HUB);
> >> +
> >> +	/* hub-vdd33-en is optional */
> >> +	hisi_hikey_usb->hub_vbus = devm_gpiod_get(dev, "hub-vdd33-en",
> >> +			GPIOD_OUT_LOW);
> >> +	if (IS_ERR(hisi_hikey_usb->hub_vbus))
> >> +		return PTR_ERR(hisi_hikey_usb->hub_vbus);
> >> +
> >> +	gpiod_direction_output(hisi_hikey_usb->hub_vbus, HUB_VBUS_POWER_ON);
> > ditto
> >> +
> >> +	hisi_hikey_usb->role_sw = usb_role_switch_get(dev);
> >> +	if (!hisi_hikey_usb->role_sw)
> >> +		return -EPROBE_DEFER;
> >> +	else if (IS_ERR(hisi_hikey_usb->role_sw))
> >> +		return PTR_ERR(hisi_hikey_usb->role_sw);
> >> +
> 
> Thanks
> Yu Chen
>