Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752553AbaAXSok (ORCPT ); Fri, 24 Jan 2014 13:44:40 -0500 Received: from exprod5og119.obsmtp.com ([64.18.0.189]:59859 "HELO exprod5og119.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752167AbaAXSoi (ORCPT ); Fri, 24 Jan 2014 13:44:38 -0500 MIME-Version: 1.0 In-Reply-To: <20140124182355.GF4758@e106331-lin.cambridge.arm.com> References: <1390504801-24483-1-git-send-email-fkan@apm.com> <1390504801-24483-6-git-send-email-fkan@apm.com> <20140124113920.GF814@e106331-lin.cambridge.arm.com> <20140124182355.GF4758@e106331-lin.cambridge.arm.com> Date: Fri, 24 Jan 2014 10:44:37 -0800 Message-ID: Subject: Re: [PATCH V4 5/5] Documentation: power: reset: Add documentation for generic SYSCON reboot driver From: Feng Kan To: Mark Rutland Cc: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 24, 2014 at 10:23 AM, Mark Rutland wrote: > On Fri, Jan 24, 2014 at 06:03:10PM +0000, Feng Kan wrote: >> On Fri, Jan 24, 2014 at 3:39 AM, Mark Rutland wrote: >> > On Thu, Jan 23, 2014 at 07:20:01PM +0000, Feng Kan wrote: >> >> Add documentation for generic SYSCON reboot driver. >> >> >> >> Signed-off-by: Feng Kan >> >> --- >> >> .../bindings/power/reset/syscon-reboot.txt | 16 ++++++++++++++++ >> >> 1 files changed, 16 insertions(+), 0 deletions(-) >> >> create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot.txt >> >> >> >> diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt b/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt >> >> new file mode 100644 >> >> index 0000000..e9eb1fe >> >> --- /dev/null >> >> +++ b/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt >> >> @@ -0,0 +1,16 @@ >> >> +Generic SYSCON mapped register reset driver >> > >> > Bindings should describe hardware, not drivers. >> > >> > What precisely does this binding describe? >> > >> >> + >> >> +Required properties: >> >> +- compatible: should contain "syscon-reboot" >> >> +- regmap: this is phandle to the register map node >> >> +- offset: offset in the register map for the reboot register >> >> +- mask: the reset value written to the reboot register >> >> + >> >> +Examples: >> >> + >> >> +reboot { >> >> + compatible = "syscon-reboot"; >> >> + regmap = <®mapnode>; >> >> + offset = <0x0>; >> >> + mask = <0x1>; >> >> +}; >> > >> > Access size? Endianness? >> FKAN: are you asking for documentation? I don't see alot of example of >> support for these. > > If I used the enippet in the example, what endianness and access size > should I expect an OS to perform? That should be documented. > > If this doesn't match the general case, we can add properties later to > adjust the access size and/or endianness. We just need to document what > the binding actually describes currently, or it's not possible to > implement anything based off of the binding documentation. > > I should be able to read a binding document and write a dts. I shouldn't > have to read the code to figure out what the binding describes. > >> >> > >> > Why can we not have a binding for the register bank this exists in, and >> > have that pass on the appropriate details to a syscon-reboot driver? >> >> FKAN: Thats a good idea. But the hardware in this case (SCU) system >> clock unit has a bunch of registers used for different functions. If syscon is >> used alot in this case and we pile more attribute into it. It would get kinda >> messy after a while. > > Huh? > > What's wrong with having a system clock unit binding, that the kernel > can decompose as appropriate? > > I don't get your syscon argument. FKAN: I do have a SCU binding, I thought you wanted to move the offset and mask to the SCU binding. The only issue I see in that case is when we use more such methods, the SCU binding would look rather crowded. If this is not the case, I am a bit confused at what I should do next. > > Thanks, > Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/