From mboxrd@z Thu Jan 1 00:00:00 1970 From: Timur Tabi Subject: Re: [PATCH 4/4] [v4] pinctrl: qcom: qdf2xxx: add support for new ACPI HID QCOM8002 Date: Tue, 12 Dec 2017 14:27:10 -0600 Message-ID: <88349f2e-5243-8061-cc72-d01fa70e6f2e@codeaurora.org> References: <1512170904-4749-1-git-send-email-timur@codeaurora.org> <1512170904-4749-5-git-send-email-timur@codeaurora.org> <1513076836.25007.641.camel@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1513076836.25007.641.camel@linux.intel.com> Content-Language: en-US Sender: linux-gpio-owner@vger.kernel.org To: Andy Shevchenko , Linus Walleij , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" Cc: linux-arm-msm@vger.kernel.org, Linux ARM , linux-gpio@vger.kernel.org, Mika Westerberg , "thierry.reding@gmail.com" , Stephen Boyd , David Brown , Andy Gross , Bjorn Andersson , Varadarajan Narayanan , Archit Taneja List-Id: devicetree@vger.kernel.org On 12/12/2017 05:07 AM, Andy Shevchenko wrote: > Not ACPI standards as of my knowledge. ACPI standard defines a common > scheme how to define properties, it doesn't tell anything about property > names or any mappings between names to values or names to "OS > subsystem"). There was an attempt a while back to standardize this like we do for device tree, but it fell apart. Device-specific ACPI-only properties are not standarized. This driver is initialized only on ACPI systems. It has no device tree binding. > As for GPIO we just follow *de facto* what DT has right now, i.e. "xxx- > gpio" or "xxx-gpios" pattern is used to map ACPI standard resource to a > GPIO name. That's how GPIO ACPI lib is being developed. GPIOs in device tree are defined completely differently than in ACPI. On DT, the kernel controls the pin muxing. On ACPI, pins are muxed by firmware and never re-muxed by the operating system. So all this driver does is expose a few pins as simple GPIOs. -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.