From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javier Martinez Canillas Subject: Re: [PATCH 6/8] regulator: max77686: Add external GPIO control Date: Wed, 29 Oct 2014 11:49:31 +0100 Message-ID: <5450C63B.3000602@collabora.co.uk> References: <1414422226-10948-1-git-send-email-k.kozlowski@samsung.com> <1414422226-10948-7-git-send-email-k.kozlowski@samsung.com> <544EA4FA.6040704@collabora.co.uk> <1414486356.24949.19.camel@AMDC1943> <1414498308.24949.32.camel@AMDC1943> <1414579362.18868.11.camel@AMDC1943> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1414579362.18868.11.camel@AMDC1943> Sender: linux-kernel-owner@vger.kernel.org To: Krzysztof Kozlowski Cc: Samuel Ortiz , Lee Jones , Liam Girdwood , Mark Brown , linux-kernel@vger.kernel.org, Ben Dooks , Kukjin Kim , Russell King , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org, Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz , Chanwoo Choi , Linus Walleij , Alexandre Courbot List-Id: devicetree@vger.kernel.org [adding Linus and Alexandre to the cc list] Hello Krzysztof, On 10/29/2014 11:42 AM, Krzysztof Kozlowski wrote: > On wto, 2014-10-28 at 13:11 +0100, Krzysztof Kozlowski wrote: >> On wto, 2014-10-28 at 09:52 +0100, Krzysztof Kozlowski wrote: >> > On pon, 2014-10-27 at 21:03 +0100, Javier Martinez Canillas wrote: >> > > Hello Krzysztof, >> > > >> > > On 10/27/2014 04:03 PM, Krzysztof Kozlowski wrote: >> > > > @@ -85,6 +91,9 @@ struct max77686_data { >> > > > struct max77686_regulator_data *regulators; >> > > > int num_regulators; >> > > > >> > > > + /* Array of size num_regulators with GPIOs for external control. */ >> > > > + int *ext_control_gpio; >> > > > + >> > > >> > > The integer-based GPIO API is deprecated in favor of the descriptor-based GPIO >> > > interface (Documentation/gpio/consumer.txt). Could you please use the later? >> > >> > Sure, I can. Please have in mind that regulator core still accepts old >> > GPIO so I will have to use desc_to_gpio(). That should work... and >> > should be future-ready. >> >> It seems I was too hasty... I think usage of the new gpiod API implies >> completely different bindings. >> >> The gpiod_get() gets GPIO from a device level, not from given sub-node >> pointer. This means that you cannot have DTS like this: >> ldo21_reg: ldo21 { >> regulator-compatible = "LDO21"; >> regulator-name = "VTF_2.8V"; >> regulator-min-microvolt = <2800000>; >> regulator-max-microvolt = <2800000>; >> ec-gpio = <&gpy2 0 0>; >> }; >> >> ldo22_reg: ldo22 { >> regulator-compatible = "LDO22"; >> regulator-name = "VMEM_VDD_2.8V"; >> regulator-min-microvolt = <2800000>; >> regulator-max-microvolt = <2800000>; >> ec-gpio = <&gpk0 2 0>; >> }; >> >> >> I could put GPIOs in device node: >> >> max77686_pmic@09 { >> compatible = "maxim,max77686"; >> interrupt-parent = <&gpx0>; >> interrupts = <7 0>; >> reg = <0x09>; >> #clock-cells = <1>; >> ldo21-gpio = <&gpy2 0 0>; >> ldo22-gpio = <&gpk0 2 0>; >> >> ldo21_reg: ldo21 { >> regulator-compatible = "LDO21"; >> regulator-name = "VTF_2.8V"; >> regulator-min-microvolt = <2800000>; >> regulator-max-microvolt = <2800000>; >> }; >> >> ldo22_reg: ldo22 { >> regulator-compatible = "LDO22"; >> regulator-name = "VMEM_VDD_2.8V"; >> regulator-min-microvolt = <2800000>; >> regulator-max-microvolt = <2800000>; >> }; >> >> This would work but I don't like it. The properties of a regulator are >> above the node configuring that regulator. >> >> Any ideas? >> > > Continuing talking to myself... I found another problem - GPIO cannot be > requested more than once (-EBUSY). In case of this driver (and board: > Trats2) one GPIO is connected to regulators. The legacy GPIO API and > regulator core handle this. > > With new GPIO API I would have to implement some additional steps in > such case... > > So there are 2 issues: > 1. Cannot put GPIO property in regulator node. > 2. Cannot request some GPIO more than once. > > I'm going back to legacy API for now. > I've added the GPIO maintainers as cc so hopefully they can comment on this. > Best regards, > Krzysztof > Best regards, Javier