| Message ID | 20171002120854.5212-1-quentin.schulz@free-electrons.com |
|---|---|
| Headers | show |
| Series | add pinmuxing support for pins in AXP209 and AXP813 PMICs | expand |
On Mon, Oct 02, 2017 at 12:08:43PM +0000, Quentin Schulz wrote: > To prepare the driver for the upcoming pinctrl features, move the GPIO > driver AXP209 from GPIO to pinctrl subsystem. > > Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
On Mon, Oct 02, 2017 at 12:08:49PM +0000, Quentin Schulz wrote: > This board has an AXP813 PMIC so let's include its dtsi. > > Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com> > --- > arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts > index 723641f56a74..4f4db07ca19f 100644 > --- a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts > +++ b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts > @@ -146,7 +146,7 @@ > &r_rsb { > status = "okay"; > > - axp813: pmic@3a3 { > + axp81x: pmic@3a3 { Aren't we going to have an axp813 DTSI? What's your plan here Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
On Tue, Oct 3, 2017 at 4:18 AM, Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > On Mon, Oct 02, 2017 at 12:08:43PM +0000, Quentin Schulz wrote: >> To prepare the driver for the upcoming pinctrl features, move the GPIO >> driver AXP209 from GPIO to pinctrl subsystem. >> >> Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com> > > Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Chen-Yu Tsai <wens@csie.org> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Oct 3, 2017 at 4:38 AM, Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > On Mon, Oct 02, 2017 at 12:08:46PM +0000, Quentin Schulz wrote: >> To prepare for patches that will add support for a new PMIC that has a >> different GPIO input status register, add a gpio_status_offset within >> axp20x_pctl structure and use it. >> >> Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com> > > Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Chen-Yu Tsai <wens@csie.org> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Oct 4, 2017 at 3:35 PM, Quentin Schulz <quentin.schulz@free-electrons.com> wrote: > Hi Chen-Yu, Linus, > > On 03/10/2017 17:08, Chen-Yu Tsai wrote: >> On Tue, Oct 3, 2017 at 10:47 PM, Maxime Ripard >> <maxime.ripard@free-electrons.com> wrote: >>> Hi Linus, >>> >>> On Tue, Oct 03, 2017 at 09:27:17AM +0000, Linus Walleij wrote: >>>> On Mon, Oct 2, 2017 at 2:08 PM, Quentin Schulz >>>> <quentin.schulz@free-electrons.com> wrote: >>>> >>>>> On AXP813/818, GPIO0 and GPIO1 can be used as LDO as (respectively) >>>>> ldo_io0 and ldo_io1. >>>> (...) >>>>> + gpio0_ldo: gpio0_ldo { >>>>> + pins = "GPIO0"; >>>>> + function = "ldo"; >>>>> + }; >>>> (...) >>>>> + pinctrl-names = "default"; >>>>> + pinctrl-0 = <&gpio0_ldo>; >>>>> /* Disable by default to avoid conflicts with GPIO */ >>>>> status = "disabled"; >>>> >>>> So this is still by default disabled, but you make the default >>>> mode something called "ldo". >>>> >>>> And I think that is to be understood as a low-dropout regulator? >>>> >>>> So is the idea that this should be represented as a regulator >>>> in the end? >>>> >>>> Then I think the state name should not be "default" rather >>>> something like "regulator" and "default" should be the GPIO >>>> mode, as I guess something like that exists. >>>> >>>> Activating a regulator using pin control "default" mode is >>>> not very pretty. It would probably be unintuitive and end >>>> up wasting power because people will get confused about >>>> what is going on. >>> >>> That's not really it. The PMIC has pins that can be muxed either to >>> (regular) GPIOs, an ADC or to an LDO regulator. >>> >>> This is just muxing, the regulator will be enabled and disabled >>> separately through another register. If it wasn't the case, it would >>> indeed be very messy. >> >> No. Actually they are controlled in the same register, so it is >> very messy. The muxing options are: >> >> - 0: drive low >> - 1: drive high >> - 2: input with interrupt triggering >> - 3: LDO on >> - 4: LDO off >> - 5~7: floating (or ADC) >> > > Just to be a little more precise, > - 0: drive low > - 1: drive high > - 2: input with interrupt triggering > - 3: LDO on > - 4: LDO off > - 5~7: floating (or ADC) > > for AXP813, and > - 0: drive low > - 1: drive high > - 2: input with interrupt triggering > - 3: LDO on > - 4: ADC > - 5~7: floating > > for AXP209. > > So I think what you suggested Linus is not really relevant here as the > regulator framework will take care of disabling the regulator when > needed (for AXP813 via the ldo_off "muxing" selected by the regulator > framework). Linus is suggesting that we use (switching between) pinctrl states to control the regulator, as opposed to overriding the register value directly. That would be nice, as both subsystems would have the same idea of what's actually happening in the hardware. As Linus mentioned, having the LDO on or off as the default pinctrl state is not pretty. It also means as soon as the device is brought up, the regulator state gets overridden. That would not work well for regulators that have/want the "always-on" or "boot-on" properties. > However, there is no LDO off bit for AXP209 and the LDO can't be set to > 0V in any other register. What's done now in the regulator driver for > AXP209 is to select the floating "muxing" for the pin when wanting to > disable the regulator. So I guess that's a way to handle it. Should we > do it another way? I can't think of one. :) You could have an actual pinmux option for "floating". If there's no "LDO off" state, the regulator driver could use the "floating" state instead. ChenYu > Thanks for raising the issue, I frankly haven't thought about that at all. > > I have to send a v4 to update the support for AXP813 (basically setting > ADC muxing to 0x5 instead of 0x4, for AXP813) as I misread the muxing > register description when adding support for it. > > Thanks, > Quentin > -- > Quentin Schulz, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html