From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH] gpio: exynos4: Add device tree support Date: Tue, 11 Oct 2011 10:30:17 -0500 Message-ID: <4E946109.2000305@gmail.com> References: <1318320974-9879-1-git-send-email-thomas.abraham@linaro.org> <4E945C90.1050601@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-samsung-soc-owner@vger.kernel.org To: Thomas Abraham Cc: devicetree-discuss@lists.ozlabs.org, grant.likely@secretlab.ca, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, kgene.kim@samsung.com List-Id: devicetree@vger.kernel.org On 10/11/2011 10:19 AM, Thomas Abraham wrote: > Hi Rob, > > On 11 October 2011 20:41, Rob Herring wrote: >> Thomas, >> >> On 10/11/2011 03:16 AM, Thomas Abraham wrote: >>> As gpio chips get registered, a device tree node which represents the >>> gpio chip is searched and attached to it. A translate function is also >>> provided to convert the gpio specifier into actual platform settings >>> for pin function selection, pull up/down and driver strength settings. >>> >>> Signed-off-by: Thomas Abraham >>> --- >>> This patch is based on the latest consolidated Samsung GPIO driver available >>> in the following tree: >>> https://github.com/kgene/linux-samsung.git branch: for-next >>> >>> .../devicetree/bindings/gpio/gpio-samsung.txt | 30 +++++++++++ >>> drivers/gpio/gpio-samsung.c | 53 ++++++++++++++++++++ >>> 2 files changed, 83 insertions(+), 0 deletions(-) >>> create mode 100644 Documentation/devicetree/bindings/gpio/gpio-samsung.txt >>> >>> diff --git a/Documentation/devicetree/bindings/gpio/gpio-samsung.txt b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt >>> new file mode 100644 >>> index 0000000..883faeb >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt >>> @@ -0,0 +1,30 @@ >>> +Samsung Exynos4 GPIO Controller >>> + >>> +Required properties: >>> +- compatible: Format of compatible property value should be >>> + "samsung,exynos4-gpio-". Example: For GPA0 controller, the >>> + compatible property value should be "samsung,exynos4-gpio-gpa0". >> >> Isn't gpa0 an instance of the h/w, not a version? > > GPA0 is a instance of the gpio controller. There are several such > instances and there could be differences in those instances such as > the number of GPIO lines managed by that gpio controller instance. > That doesn't seem like a reason to have different compatible strings. Does that affect the programming model of the controller? Unused lines whether at the board level or SOC level shouldn't really matter. Rob