[PATCH 0/2] ARM: sun9i: cubieboard4: Enable USB hosts and LEDs

[PATCH 0/2] ARM: sun9i: cubieboard4: Enable USB hosts and LEDs

[Chen-Yu Tsai]

Hi Maxime,

This small series enables USB host and LED support on the Cubieboard4.
We already support these on the Optimus, so it's just dts stuff.


Regards
ChenYu


Chen-Yu Tsai (2):
  ARM: dts: sun9i: cubieboard4: Enable USB support
  ARM: dts: sun9i: cubieboard4: Enable LEDs

 arch/arm/boot/dts/sun9i-a80-cubieboard4.dts | 83 +++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)

-- 
2.1.4

[PATCH 1/2] ARM: dts: sun9i: cubieboard4: Enable USB support

[Chen-Yu Tsai]

The Cubieboard4 has 4 USB ports. 3 of them are connected to a GL850G
USB hub chip on usb1. The fourth one, the lower port of 2 ports next
to the power barrel, is directly connected to usb3.

2 power enable GPIOs are used between the 2 port groups, 1 for each.
This raises the possibility of having no power for hub-connected port
next to the power barrel, if usb3 is not enabled.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 arch/arm/boot/dts/sun9i-a80-cubieboard4.dts | 60 +++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
index 6484dcf69873..42ddc046213c 100644
--- a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
+++ b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
@@ -62,6 +62,30 @@
 		stdout-path = "serial0:115200n8";
 	};
 
+	reg_usb3_vbus: usb3-vbus {
+		compatible = "regulator-fixed";
+		pinctrl-names = "default";
+		pinctrl-0 = <&usb3_vbus_pin_cubieboard4>;
+		regulator-name = "usb3-vbus";
+		regulator-min-microvolt = <5000000>;
+		regulator-max-microvolt = <5000000>;
+		enable-active-high;
+		gpio = <&pio 7 15 GPIO_ACTIVE_HIGH>; /* PH15 */
+	};
+};
+
+&ehci0 {
+	status = "okay";
+};
+
+&ehci2 {
+	status = "okay";
+};
+
+/* usb1 is connected to a GL850G USB hub chip, so no need to enable OHCI */
+
+&ohci2 {
+	status = "okay";
 };
 
 &pio {
@@ -71,6 +95,20 @@
 		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
 		allwinner,pull = <SUN4I_PINCTRL_PULL_UP>;
 	};
+
+	usb1_vbus_pin_cubieboard4: usb1_vbus_pin at 1 {
+		allwinner,pins = "PH14";
+		allwinner,function = "gpio_out";
+		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+	};
+
+	usb3_vbus_pin_cubieboard4: usb3_vbus_pin at 1 {
+		allwinner,pins = "PH15";
+		allwinner,function = "gpio_out";
+		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+	};
 };
 
 &mmc0 {
@@ -92,8 +130,30 @@
 	status = "okay";
 };
 
+&reg_usb1_vbus {
+	pinctrl-0 = <&usb1_vbus_pin_cubieboard4>;
+	gpio = <&pio 7 14 GPIO_ACTIVE_HIGH>; /* PH14 */
+	status = "okay";
+};
+
 &uart0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart0_pins_a>;
 	status = "okay";
 };
+
+&usbphy1 {
+	phy-supply = <&reg_usb1_vbus>;
+	status = "okay";
+};
+
+/*
+ * Unfortunately reg_usb1_vbus also powers one of the ports from usb3's hub.
+ * One should always make sure both regulators are enabled and working for
+ * all USB ports to have power.
+ */
+
+&usbphy3 {
+	phy-supply = <&reg_usb3_vbus>;
+	status = "okay";
+};
-- 
2.1.4

[PATCH 2/2] ARM: dts: sun9i: cubieboard4: Enable LEDs

[Chen-Yu Tsai]

The Cubieboard4 has 2 controllable LEDs, 1 red and 1 green.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 arch/arm/boot/dts/sun9i-a80-cubieboard4.dts | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
index 42ddc046213c..d63ea4284adf 100644
--- a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
+++ b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
@@ -62,6 +62,22 @@
 		stdout-path = "serial0:115200n8";
 	};
 
+	leds {
+		compatible = "gpio-leds";
+		pinctrl-names = "default";
+		pinctrl-0 = <&led_pins_cubieboard4>;
+
+		green {
+			label = "cubieboard4:green:usr";
+			gpios = <&pio 7 17 GPIO_ACTIVE_HIGH>; /* PH17 */
+		};
+
+		red {
+			label = "cubieboard4:red:usr";
+			gpios = <&pio 7 6 GPIO_ACTIVE_HIGH>; /* PH6 */
+		};
+	};
+
 	reg_usb3_vbus: usb3-vbus {
 		compatible = "regulator-fixed";
 		pinctrl-names = "default";
@@ -89,6 +105,13 @@
 };
 
 &pio {
+	led_pins_cubieboard4: led-pins at 0 {
+		allwinner,pins = "PH6", "PH17";
+		allwinner,function = "gpio_out";
+		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+	};
+
 	mmc0_cd_pin_cubieboard4: mmc0_cd_pin at 0 {
 		allwinner,pins = "PH18";
 		allwinner,function = "gpio_in";
-- 
2.1.4

[PATCH 0/2] ARM: sun9i: cubieboard4: Enable USB hosts and LEDs

[Tyler Baker]

Hi ChenYu,

On 7 May 2015 at 09:43, Chen-Yu Tsai <wens@csie.org> wrote:
> Hi Maxime,
>
> This small series enables USB host and LED support on the Cubieboard4.
> We already support these on the Optimus, so it's just dts stuff.
>
>
> Regards
> ChenYu
>
>
> Chen-Yu Tsai (2):
>   ARM: dts: sun9i: cubieboard4: Enable USB support
>   ARM: dts: sun9i: cubieboard4: Enable LEDs

Thanks for posting these patches. I gave this series a spin on my
cubieboard4 atop next-20150507 both with sunxi_defconfig and
multi_v7_defconfig.  Tested all four USB ports with various USB
devices, and for good measure toggled the LED's :) Everything worked
as expected, so feel free to add my

Tested-by: Tyler Baker <tyler.baker@linaro.org>

>
>  arch/arm/boot/dts/sun9i-a80-cubieboard4.dts | 83 +++++++++++++++++++++++++++++
>  1 file changed, 83 insertions(+)
>
> --
> 2.1.4
>

Cheers,

Tyler

[PATCH 1/2] ARM: dts: sun9i: cubieboard4: Enable USB support

[Maxime Ripard]

Hi,

On Fri, May 08, 2015 at 12:43:56AM +0800, Chen-Yu Tsai wrote:
> The Cubieboard4 has 4 USB ports. 3 of them are connected to a GL850G
> USB hub chip on usb1. The fourth one, the lower port of 2 ports next
> to the power barrel, is directly connected to usb3.
> 
> 2 power enable GPIOs are used between the 2 port groups, 1 for each.
> This raises the possibility of having no power for hub-connected port
> next to the power barrel, if usb3 is not enabled.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
>  arch/arm/boot/dts/sun9i-a80-cubieboard4.dts | 60 +++++++++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
> index 6484dcf69873..42ddc046213c 100644
> --- a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
> +++ b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
> @@ -62,6 +62,30 @@
>  		stdout-path = "serial0:115200n8";
>  	};
>  
> +	reg_usb3_vbus: usb3-vbus {
> +		compatible = "regulator-fixed";
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&usb3_vbus_pin_cubieboard4>;
> +		regulator-name = "usb3-vbus";
> +		regulator-min-microvolt = <5000000>;
> +		regulator-max-microvolt = <5000000>;
> +		enable-active-high;
> +		gpio = <&pio 7 15 GPIO_ACTIVE_HIGH>; /* PH15 */
> +	};
> +};
> +
> +&ehci0 {
> +	status = "okay";
> +};
> +
> +&ehci2 {
> +	status = "okay";
> +};
> +
> +/* usb1 is connected to a GL850G USB hub chip, so no need to enable OHCI */

You're mentionning usb1, but I don't see it enabled anywhere, is that
a typo?

> +
> +&ohci2 {
> +	status = "okay";
>  };
>  
>  &pio {
> @@ -71,6 +95,20 @@
>  		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
>  		allwinner,pull = <SUN4I_PINCTRL_PULL_UP>;
>  	};
> +
> +	usb1_vbus_pin_cubieboard4: usb1_vbus_pin at 1 {
> +		allwinner,pins = "PH14";
> +		allwinner,function = "gpio_out";
> +		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
> +		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
> +	};
> +
> +	usb3_vbus_pin_cubieboard4: usb3_vbus_pin at 1 {
> +		allwinner,pins = "PH15";
> +		allwinner,function = "gpio_out";
> +		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
> +		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
> +	};
>  };
>  
>  &mmc0 {
> @@ -92,8 +130,30 @@
>  	status = "okay";
>  };
>  
> +&reg_usb1_vbus {
> +	pinctrl-0 = <&usb1_vbus_pin_cubieboard4>;
> +	gpio = <&pio 7 14 GPIO_ACTIVE_HIGH>; /* PH14 */
> +	status = "okay";
> +};
> +
>  &uart0 {
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&uart0_pins_a>;
>  	status = "okay";
>  };
> +
> +&usbphy1 {
> +	phy-supply = <&reg_usb1_vbus>;
> +	status = "okay";
> +};
> +
> +/*
> + * Unfortunately reg_usb1_vbus also powers one of the ports from usb3's hub.
> + * One should always make sure both regulators are enabled and working for
> + * all USB ports to have power.
> + */

Can't we just provide the two regulators, and enable both of them so
that we know that we always have the needed regulators enabled,
disregarding which USB port is used?

Thanks,
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH 1/2] ARM: dts: sun9i: cubieboard4: Enable USB support

[Chen-Yu Tsai]

On Fri, May 8, 2015 at 3:46 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Hi,
>
> On Fri, May 08, 2015 at 12:43:56AM +0800, Chen-Yu Tsai wrote:
>> The Cubieboard4 has 4 USB ports. 3 of them are connected to a GL850G
>> USB hub chip on usb1. The fourth one, the lower port of 2 ports next
>> to the power barrel, is directly connected to usb3.
>>
>> 2 power enable GPIOs are used between the 2 port groups, 1 for each.
>> This raises the possibility of having no power for hub-connected port
>> next to the power barrel, if usb3 is not enabled.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> ---
>>  arch/arm/boot/dts/sun9i-a80-cubieboard4.dts | 60 +++++++++++++++++++++++++++++
>>  1 file changed, 60 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
>> index 6484dcf69873..42ddc046213c 100644
>> --- a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
>> +++ b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts
>> @@ -62,6 +62,30 @@
>>               stdout-path = "serial0:115200n8";
>>       };
>>
>> +     reg_usb3_vbus: usb3-vbus {
>> +             compatible = "regulator-fixed";
>> +             pinctrl-names = "default";
>> +             pinctrl-0 = <&usb3_vbus_pin_cubieboard4>;
>> +             regulator-name = "usb3-vbus";
>> +             regulator-min-microvolt = <5000000>;
>> +             regulator-max-microvolt = <5000000>;
>> +             enable-active-high;
>> +             gpio = <&pio 7 15 GPIO_ACTIVE_HIGH>; /* PH15 */
>> +     };
>> +};
>> +
>> +&ehci0 {
>> +     status = "okay";
>> +};
>> +
>> +&ehci2 {
>> +     status = "okay";
>> +};
>> +
>> +/* usb1 is connected to a GL850G USB hub chip, so no need to enable OHCI */
>
> You're mentionning usb1, but I don't see it enabled anywhere, is that
> a typo?

usb1 (or usbphy1) == ehci/ohci0. usb0 is otg.

This numbering matches the fex files, and (mostly) matches the specs.

>> +
>> +&ohci2 {
>> +     status = "okay";
>>  };
>>
>>  &pio {
>> @@ -71,6 +95,20 @@
>>               allwinner,drive = <SUN4I_PINCTRL_10_MA>;
>>               allwinner,pull = <SUN4I_PINCTRL_PULL_UP>;
>>       };
>> +
>> +     usb1_vbus_pin_cubieboard4: usb1_vbus_pin at 1 {
>> +             allwinner,pins = "PH14";
>> +             allwinner,function = "gpio_out";
>> +             allwinner,drive = <SUN4I_PINCTRL_10_MA>;
>> +             allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
>> +     };
>> +
>> +     usb3_vbus_pin_cubieboard4: usb3_vbus_pin at 1 {
>> +             allwinner,pins = "PH15";
>> +             allwinner,function = "gpio_out";
>> +             allwinner,drive = <SUN4I_PINCTRL_10_MA>;
>> +             allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
>> +     };
>>  };
>>
>>  &mmc0 {
>> @@ -92,8 +130,30 @@
>>       status = "okay";
>>  };
>>
>> +&reg_usb1_vbus {
>> +     pinctrl-0 = <&usb1_vbus_pin_cubieboard4>;
>> +     gpio = <&pio 7 14 GPIO_ACTIVE_HIGH>; /* PH14 */
>> +     status = "okay";
>> +};
>> +
>>  &uart0 {
>>       pinctrl-names = "default";
>>       pinctrl-0 = <&uart0_pins_a>;
>>       status = "okay";
>>  };
>> +
>> +&usbphy1 {
>> +     phy-supply = <&reg_usb1_vbus>;
>> +     status = "okay";
>> +};
>> +
>> +/*
>> + * Unfortunately reg_usb1_vbus also powers one of the ports from usb3's hub.
>> + * One should always make sure both regulators are enabled and working for
>> + * all USB ports to have power.
>> + */
>
> Can't we just provide the two regulators, and enable both of them so
> that we know that we always have the needed regulators enabled,
> disregarding which USB port is used?

Would setting "always-on" for both regulators work for you?
Or maybe just the one that's used by both USB hosts?

ChenYu

[PATCH 1/2] ARM: dts: sun9i: cubieboard4: Enable USB support

[Maxime Ripard]

On Fri, May 08, 2015 at 04:01:14PM +0800, Chen-Yu Tsai wrote:
> >> +&ehci0 {
> >> +     status = "okay";
> >> +};
> >> +
> >> +&ehci2 {
> >> +     status = "okay";
> >> +};
> >> +
> >> +/* usb1 is connected to a GL850G USB hub chip, so no need to enable OHCI */
> >
> > You're mentionning usb1, but I don't see it enabled anywhere, is that
> > a typo?
> 
> usb1 (or usbphy1) == ehci/ohci0. usb0 is otg.
> 
> This numbering matches the fex files, and (mostly) matches the
> specs.

Ok, having this comment between ehci2 and ohci2 is confusing then :)

It's not the first board that has a hub, we usually don't really care
as it's kind of obvious. Maybe we can just remove it?

> >>  &mmc0 {
> >> @@ -92,8 +130,30 @@
> >>       status = "okay";
> >>  };
> >>
> >> +&reg_usb1_vbus {
> >> +     pinctrl-0 = <&usb1_vbus_pin_cubieboard4>;
> >> +     gpio = <&pio 7 14 GPIO_ACTIVE_HIGH>; /* PH14 */
> >> +     status = "okay";
> >> +};
> >> +
> >>  &uart0 {
> >>       pinctrl-names = "default";
> >>       pinctrl-0 = <&uart0_pins_a>;
> >>       status = "okay";
> >>  };
> >> +
> >> +&usbphy1 {
> >> +     phy-supply = <&reg_usb1_vbus>;
> >> +     status = "okay";
> >> +};
> >> +
> >> +/*
> >> + * Unfortunately reg_usb1_vbus also powers one of the ports from usb3's hub.
> >> + * One should always make sure both regulators are enabled and working for
> >> + * all USB ports to have power.
> >> + */
> >
> > Can't we just provide the two regulators, and enable both of them so
> > that we know that we always have the needed regulators enabled,
> > disregarding which USB port is used?
> 
> Would setting "always-on" for both regulators work for you?
> Or maybe just the one that's used by both USB hosts?

I was more thinking of giving to the phy an additional regulator, so
that it would enable both the regulators needed to power up all ports.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH 1/2] ARM: dts: sun9i: cubieboard4: Enable USB support

[Chen-Yu Tsai]

On Fri, May 8, 2015 at 7:40 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> On Fri, May 08, 2015 at 04:01:14PM +0800, Chen-Yu Tsai wrote:
>> >> +&ehci0 {
>> >> +     status = "okay";
>> >> +};
>> >> +
>> >> +&ehci2 {
>> >> +     status = "okay";
>> >> +};
>> >> +
>> >> +/* usb1 is connected to a GL850G USB hub chip, so no need to enable OHCI */
>> >
>> > You're mentionning usb1, but I don't see it enabled anywhere, is that
>> > a typo?
>>
>> usb1 (or usbphy1) == ehci/ohci0. usb0 is otg.
>>
>> This numbering matches the fex files, and (mostly) matches the
>> specs.
>
> Ok, having this comment between ehci2 and ohci2 is confusing then :)
>
> It's not the first board that has a hub, we usually don't really care
> as it's kind of obvious. Maybe we can just remove it?

Why not. :)

>> >>  &mmc0 {
>> >> @@ -92,8 +130,30 @@
>> >>       status = "okay";
>> >>  };
>> >>
>> >> +&reg_usb1_vbus {
>> >> +     pinctrl-0 = <&usb1_vbus_pin_cubieboard4>;
>> >> +     gpio = <&pio 7 14 GPIO_ACTIVE_HIGH>; /* PH14 */
>> >> +     status = "okay";
>> >> +};
>> >> +
>> >>  &uart0 {
>> >>       pinctrl-names = "default";
>> >>       pinctrl-0 = <&uart0_pins_a>;
>> >>       status = "okay";
>> >>  };
>> >> +
>> >> +&usbphy1 {
>> >> +     phy-supply = <&reg_usb1_vbus>;
>> >> +     status = "okay";
>> >> +};
>> >> +
>> >> +/*
>> >> + * Unfortunately reg_usb1_vbus also powers one of the ports from usb3's hub.
>> >> + * One should always make sure both regulators are enabled and working for
>> >> + * all USB ports to have power.
>> >> + */
>> >
>> > Can't we just provide the two regulators, and enable both of them so
>> > that we know that we always have the needed regulators enabled,
>> > disregarding which USB port is used?
>>
>> Would setting "always-on" for both regulators work for you?
>> Or maybe just the one that's used by both USB hosts?
>
> I was more thinking of giving to the phy an additional regulator, so
> that it would enable both the regulators needed to power up all ports.

That would require adding back all the regulator-related code I
removed from the phy driver before it was merged. (sigh) It's not
like the regulator bindings takes a list.

I see this as more of a hardware design flaw, and we should label
it as such. And it might still work for self-powered devices even
if VBUS is off. The USB hub chip is always on.


ChenYu

[PATCH 1/2] ARM: dts: sun9i: cubieboard4: Enable USB support

[Maxime Ripard]

On Mon, May 11, 2015 at 04:26:58PM +0800, Chen-Yu Tsai wrote:
> >> >> +&usbphy1 {
> >> >> +     phy-supply = <&reg_usb1_vbus>;
> >> >> +     status = "okay";
> >> >> +};
> >> >> +
> >> >> +/*
> >> >> + * Unfortunately reg_usb1_vbus also powers one of the ports from usb3's hub.
> >> >> + * One should always make sure both regulators are enabled and working for
> >> >> + * all USB ports to have power.
> >> >> + */
> >> >
> >> > Can't we just provide the two regulators, and enable both of them so
> >> > that we know that we always have the needed regulators enabled,
> >> > disregarding which USB port is used?
> >>
> >> Would setting "always-on" for both regulators work for you?
> >> Or maybe just the one that's used by both USB hosts?
> >
> > I was more thinking of giving to the phy an additional regulator, so
> > that it would enable both the regulators needed to power up all ports.
> 
> That would require adding back all the regulator-related code I
> removed from the phy driver before it was merged. (sigh) It's not
> like the regulator bindings takes a list.

Yeah, but maybe we can just add an optional device-supply property or
something like that to power up the devices connected on the bus.

> I see this as more of a hardware design flaw, and we should label
> it as such.

This can be seen as one, and we can debate it for some time I guess,
but if the hardware guys were not making crazy stuff like that, we
would run out of work pretty quickly :)

What we really need to do is find a proper and reliable way to handle
this case. Whether we declare it as a flaw or not is a separate
debate.

> And it might still work for self-powered devices even if VBUS is
> off. The USB hub chip is always on.

That still leaves a significant amount of devices out and non
functional, especially very standard devices like USB keys, keyboards
or headsets that you would expect to just work.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH 1/2] ARM: dts: sun9i: cubieboard4: Enable USB support

[Chen-Yu Tsai]

On Tue, May 12, 2015 at 10:57 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> On Mon, May 11, 2015 at 04:26:58PM +0800, Chen-Yu Tsai wrote:
>> >> >> +&usbphy1 {
>> >> >> +     phy-supply = <&reg_usb1_vbus>;
>> >> >> +     status = "okay";
>> >> >> +};
>> >> >> +
>> >> >> +/*
>> >> >> + * Unfortunately reg_usb1_vbus also powers one of the ports from usb3's hub.
>> >> >> + * One should always make sure both regulators are enabled and working for
>> >> >> + * all USB ports to have power.
>> >> >> + */
>> >> >
>> >> > Can't we just provide the two regulators, and enable both of them so
>> >> > that we know that we always have the needed regulators enabled,
>> >> > disregarding which USB port is used?
>> >>
>> >> Would setting "always-on" for both regulators work for you?
>> >> Or maybe just the one that's used by both USB hosts?
>> >
>> > I was more thinking of giving to the phy an additional regulator, so
>> > that it would enable both the regulators needed to power up all ports.
>>
>> That would require adding back all the regulator-related code I
>> removed from the phy driver before it was merged. (sigh) It's not
>> like the regulator bindings takes a list.
>
> Yeah, but maybe we can just add an optional device-supply property or
> something like that to power up the devices connected on the bus.

(CC-ed Kishon)
Do we think this generic enough to go into the generic phy core?

>> I see this as more of a hardware design flaw, and we should label
>> it as such.
>
> This can be seen as one, and we can debate it for some time I guess,
> but if the hardware guys were not making crazy stuff like that, we
> would run out of work pretty quickly :)

Ah yes, but the users would be happier. :)

> What we really need to do is find a proper and reliable way to handle
> this case. Whether we declare it as a flaw or not is a separate
> debate.
>
>> And it might still work for self-powered devices even if VBUS is
>> off. The USB hub chip is always on.
>
> That still leaves a significant amount of devices out and non
> functional, especially very standard devices like USB keys, keyboards
> or headsets that you would expect to just work.

I agree. So the question is where should this go in.

ChenYu