From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= Subject: Re: [PATCH 6/8] ARM: dts: axp209: Add usb_power_supply child node to the ax209 node Date: Fri, 31 Jul 2015 08:35:41 +0200 Message-ID: <20150731083541.5f2c683a@pluto.restena.lu> References: <1433885881-19809-1-git-send-email-hdegoede@redhat.com> <1433885881-19809-7-git-send-email-hdegoede@redhat.com> <20150731075104.48c467e6@pluto.restena.lu> Reply-To: bonbons-ud5FBsm0p/xEiooADzr8i9i2O/JbrIOy@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Chen-Yu Tsai Cc: Hans De Goede , Lee Jones , Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse , Kishon Vijay Abraham I , Felipe Balbi , Maxime Ripard , linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel , devicetree , linux-sunxi List-Id: linux-pm@vger.kernel.org On Fri, 31 Jul 2015 14:14:28 +0800 Chen-Yu Tsai wrote: > On Fri, Jul 31, 2015 at 1:51 PM, Bruno Pr=C3=A9mont wrote: > > Hi ChenYu, > > > > On Fri, 31 Jul 2015 13:31:53 +0800 Chen-Yu Tsai wrote: > >> Hi Hans, > >> > >> On Wed, Jun 10, 2015 at 5:37 AM, Hans de Goede wrote: > >> > Add a node representing the usb power supply part of the axp209 pmic= , note > >> > that the usb power supply and the (to be added later) ac power suppl= y will > >> > each have their own child-node, so that they can be separately speci= fied > >> > as power-supply for other nodes using a power-supply property with a > >> > phandle pointing to the right axp209 child-node. > >> > > >> > Signed-off-by: Hans de Goede > >> > --- > >> > arch/arm/boot/dts/axp209.dtsi | 5 +++++ > >> > 1 file changed, 5 insertions(+) > >> > > >> > diff --git a/arch/arm/boot/dts/axp209.dtsi b/arch/arm/boot/dts/axp20= 9.dtsi > >> > index 24c935c..051ab3b 100644 > >> > --- a/arch/arm/boot/dts/axp209.dtsi > >> > +++ b/arch/arm/boot/dts/axp209.dtsi > >> > @@ -89,4 +89,9 @@ > >> > regulator-name =3D "ldo5"; > >> > }; > >> > }; > >> > + > >> > + usb_power_supply: usb_power_supply { > >> > + compatible =3D "x-powers,axp202-usb-power-supply"; > >> > + status =3D "disabled"; > >> > >> Is there any reason to have this disabled by default? > >> AFAIK this is not something configurable in hardware, > >> and the driver just gives readouts and status updates. > > > > There are some devices that only have 'AC-IN' instead of usb/otg power > > (set-top boxes) so having the devices tell what power sources they > > have makes sense (otherwise those that have ac-in instead of otg would > > have to disable usb_power_supply) and avoids confusion by explicitly > > stating presence in device dts. >=20 > That's true. But this is a bit of hardware inside the AXP. > If it's power isn't routed, it should report it, shouldn't it? If the device does not use the input there are two cases: - ac-in and usb/otg in short-circuited (there is a bit in AXP registers to provide this indication) - the unused one is just not connected/connectable In either case the voltage of the unused/unusable branch is not really useful, nor is it useful to have it show up in sysfs. > And normal users would probably expect to read the input > voltage/current/status through sysfs (or maybe hwmon?), > instead of not finding the device and having to look through > the DTS. Only those supplies effectively present (in-use or with connectors to eventually use them) should be visible in sysfs. Having more of them will just confuse the users, they would be searching how they can connect the supply while there is no means to do so except soldering to the tiny AXP pins. hwmon makes more sense for output voltages of the AXP or temperature of AXP chip itself, not so much for the input side if that side is covered by power_supply devices (otherwise the information is being duplicated and if so should only be via power_supply class, not individual drivers). > If you're using a distro, you might not have the kernel sources > around, and digging through the in-system device tree isn't that > straightforward if you don't know where to look. If the dts is incomplete that's another issue. > > NB: I should hopefully get my battery supply driver ported this WE, > > ac-in/rtc are done, this WE. I'm going to default-off for them as well > > (note that for some extra details should be provided in dts). >=20 > I'm guessing we won't be using the axp288 one? In a first step I won't be using it. There are a few reasons for that: - axp288 is based on ACPI/platform to provide configuration information instead of dts - it makes extensive use of OCV and registers that are possibly present on axp20x but undocumented there. Bruno --=20 You received this message because you are subscribed to the Google Groups "= linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an e= mail to linux-sunxi+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit https://groups.google.com/d/optout. From mboxrd@z Thu Jan 1 00:00:00 1970 From: bonbons@linux-vserver.org (Bruno =?UTF-8?B?UHLDqW1vbnQ=?=) Date: Fri, 31 Jul 2015 08:35:41 +0200 Subject: [linux-sunxi] [PATCH 6/8] ARM: dts: axp209: Add usb_power_supply child node to the ax209 node In-Reply-To: References: <1433885881-19809-1-git-send-email-hdegoede@redhat.com> <1433885881-19809-7-git-send-email-hdegoede@redhat.com> <20150731075104.48c467e6@pluto.restena.lu> Message-ID: <20150731083541.5f2c683a@pluto.restena.lu> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 31 Jul 2015 14:14:28 +0800 Chen-Yu Tsai wrote: > On Fri, Jul 31, 2015 at 1:51 PM, Bruno Pr?mont wrote: > > Hi ChenYu, > > > > On Fri, 31 Jul 2015 13:31:53 +0800 Chen-Yu Tsai wrote: > >> Hi Hans, > >> > >> On Wed, Jun 10, 2015 at 5:37 AM, Hans de Goede wrote: > >> > Add a node representing the usb power supply part of the axp209 pmic, note > >> > that the usb power supply and the (to be added later) ac power supply will > >> > each have their own child-node, so that they can be separately specified > >> > as power-supply for other nodes using a power-supply property with a > >> > phandle pointing to the right axp209 child-node. > >> > > >> > Signed-off-by: Hans de Goede > >> > --- > >> > arch/arm/boot/dts/axp209.dtsi | 5 +++++ > >> > 1 file changed, 5 insertions(+) > >> > > >> > diff --git a/arch/arm/boot/dts/axp209.dtsi b/arch/arm/boot/dts/axp209.dtsi > >> > index 24c935c..051ab3b 100644 > >> > --- a/arch/arm/boot/dts/axp209.dtsi > >> > +++ b/arch/arm/boot/dts/axp209.dtsi > >> > @@ -89,4 +89,9 @@ > >> > regulator-name = "ldo5"; > >> > }; > >> > }; > >> > + > >> > + usb_power_supply: usb_power_supply { > >> > + compatible = "x-powers,axp202-usb-power-supply"; > >> > + status = "disabled"; > >> > >> Is there any reason to have this disabled by default? > >> AFAIK this is not something configurable in hardware, > >> and the driver just gives readouts and status updates. > > > > There are some devices that only have 'AC-IN' instead of usb/otg power > > (set-top boxes) so having the devices tell what power sources they > > have makes sense (otherwise those that have ac-in instead of otg would > > have to disable usb_power_supply) and avoids confusion by explicitly > > stating presence in device dts. > > That's true. But this is a bit of hardware inside the AXP. > If it's power isn't routed, it should report it, shouldn't it? If the device does not use the input there are two cases: - ac-in and usb/otg in short-circuited (there is a bit in AXP registers to provide this indication) - the unused one is just not connected/connectable In either case the voltage of the unused/unusable branch is not really useful, nor is it useful to have it show up in sysfs. > And normal users would probably expect to read the input > voltage/current/status through sysfs (or maybe hwmon?), > instead of not finding the device and having to look through > the DTS. Only those supplies effectively present (in-use or with connectors to eventually use them) should be visible in sysfs. Having more of them will just confuse the users, they would be searching how they can connect the supply while there is no means to do so except soldering to the tiny AXP pins. hwmon makes more sense for output voltages of the AXP or temperature of AXP chip itself, not so much for the input side if that side is covered by power_supply devices (otherwise the information is being duplicated and if so should only be via power_supply class, not individual drivers). > If you're using a distro, you might not have the kernel sources > around, and digging through the in-system device tree isn't that > straightforward if you don't know where to look. If the dts is incomplete that's another issue. > > NB: I should hopefully get my battery supply driver ported this WE, > > ac-in/rtc are done, this WE. I'm going to default-off for them as well > > (note that for some extra details should be provided in dts). > > I'm guessing we won't be using the axp288 one? In a first step I won't be using it. There are a few reasons for that: - axp288 is based on ACPI/platform to provide configuration information instead of dts - it makes extensive use of OCV and registers that are possibly present on axp20x but undocumented there. Bruno