From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754540AbbCQP1c (ORCPT ); Tue, 17 Mar 2015 11:27:32 -0400 Received: from mail-we0-f170.google.com ([74.125.82.170]:33871 "EHLO mail-we0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753618AbbCQP12 (ORCPT ); Tue, 17 Mar 2015 11:27:28 -0400 Date: Tue, 17 Mar 2015 15:27:23 +0000 From: Lee Jones To: Linus Walleij Cc: Samuel Ortiz , linux-kernel@vger.kernel.org, Arnd Bergmann , Devicetree , Rob Herring , Benjamin Herrenschmidt , Grant Likely , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala Subject: Re: [PATCH 1/5 v2] MFD/OF: document MFD devices and handle simple-mfd Message-ID: <20150317152723.GB3318@x1> References: <1426588510-9940-1-git-send-email-linus.walleij@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1426588510-9940-1-git-send-email-linus.walleij@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 17 Mar 2015, Linus Walleij wrote: > This defines a new compatible option for MFD devices "simple-mfd" that will > make the OF core spawn child devices for all subnodes of that MFD device. > It is optional but handy for things like syscon and possibly other > simpler MFD devices. > > Since there was no file to put the documentation in, I took this opportunity > to make a small writeup on MFD devices and add the compatible definition > there. > > Suggested-by: Lee Jones > Cc: Arnd Bergmann > Cc: Devicetree > Cc: Rob Herring > Cc: Benjamin Herrenschmidt > Cc: Grant Likely > Cc: Pawel Moll > Cc: Mark Rutland > Cc: Ian Campbell > Cc: Kumar Gala > Signed-off-by: Linus Walleij > --- > ChangeLog v1->v2: > - Fix spelling, terminology. > > I make the patch to the OF core in this one, it makes much more sense since > it's a oneliner > > Lee: this is a (tested!) implementation of your suggestion for simple-mfd. > If you can eventually ACK this from the MFD side, I think it should be > funneled through the ARM SoC tree. > > Grant/Rob: if either of you can ACK the change to the OF core likewise it can > be taken through ARM SoC. > > DT binings maintainers: there is some background discussion on this here: > http://marc.info/?l=linux-arm-kernel&m=142486676603889&w=2 > http://marc.info/?l=devicetree&m=142166313621469&w=2 > --- > Documentation/devicetree/bindings/mfd/mfd.txt | 41 +++++++++++++++++++++++++++ > drivers/of/platform.c | 1 + > 2 files changed, 42 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mfd/mfd.txt Acked-by: Lee Jones > diff --git a/Documentation/devicetree/bindings/mfd/mfd.txt b/Documentation/devicetree/bindings/mfd/mfd.txt > new file mode 100644 > index 000000000000..af9d6931a1a2 > --- /dev/null > +++ b/Documentation/devicetree/bindings/mfd/mfd.txt > @@ -0,0 +1,41 @@ > +Multi-Function Devices (MFD) > + > +These devices comprise a nexus for heterogeneous hardware blocks containing > +more than one non-unique yet varying hardware functionality. > + > +A typical MFD can be: > + > +- A mixed signal ASIC on an external bus, sometimes a PMIC (Power Management > + Integrated Circuit) that is manufactured in a lower technology node (rough > + silicon) that handles analog drivers for things like audio amplifiers, LED > + drivers, level shifters, PHY (physical interfaces to things like USB or > + ethernet), regulators etc. > + > +- A range of memory registers containing "miscellaneous system registers" also > + known as a system controller "syscon" or any other memory range containing a > + mix of unrelated hardware devices. > + > +Optional properties: > + > +- compatible : "simple-mfd" - this signifies that the operating system should > + consider all subnodes of the MFD device as separate devices akin to how > + "simple-bus" inidicates when to see subnodes as children for a simple > + memory-mapped bus. For more complex devices, when the nexus driver has to > + probe registers to figure out what child devices exist etc, this should not > + be used. In the latter case the child devices will be determined by the > + operating system. > + > +Example: > + > +foo@1000 { > + compatible = "syscon", "simple-mfd"; > + reg = <0x01000 0x1000>; > + > + led@08.0 { > + compatible = "register-bit-led"; > + offset = <0x08>; > + mask = <0x01>; > + label = "myled"; > + default-state = "on"; > + }; > +}; > diff --git a/drivers/of/platform.c b/drivers/of/platform.c > index b189733a1539..969ba4e1460c 100644 > --- a/drivers/of/platform.c > +++ b/drivers/of/platform.c > @@ -26,6 +26,7 @@ > > const struct of_device_id of_default_bus_match_table[] = { > { .compatible = "simple-bus", }, > + { .compatible = "simple-mfd", }, > #ifdef CONFIG_ARM_AMBA > { .compatible = "arm,amba-bus", }, > #endif /* CONFIG_ARM_AMBA */ -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH 1/5 v2] MFD/OF: document MFD devices and handle simple-mfd Date: Tue, 17 Mar 2015 15:27:23 +0000 Message-ID: <20150317152723.GB3318@x1> References: <1426588510-9940-1-git-send-email-linus.walleij@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1426588510-9940-1-git-send-email-linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Linus Walleij Cc: Samuel Ortiz , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Arnd Bergmann , Devicetree , Rob Herring , Benjamin Herrenschmidt , Grant Likely , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala List-Id: devicetree@vger.kernel.org On Tue, 17 Mar 2015, Linus Walleij wrote: > This defines a new compatible option for MFD devices "simple-mfd" tha= t will > make the OF core spawn child devices for all subnodes of that MFD dev= ice. > It is optional but handy for things like syscon and possibly other > simpler MFD devices. >=20 > Since there was no file to put the documentation in, I took this oppo= rtunity > to make a small writeup on MFD devices and add the compatible definit= ion > there. >=20 > Suggested-by: Lee Jones > Cc: Arnd Bergmann > Cc: Devicetree > Cc: Rob Herring > Cc: Benjamin Herrenschmidt > Cc: Grant Likely > Cc: Pawel Moll > Cc: Mark Rutland > Cc: Ian Campbell > Cc: Kumar Gala > Signed-off-by: Linus Walleij > --- > ChangeLog v1->v2: > - Fix spelling, terminology. >=20 > I make the patch to the OF core in this one, it makes much more sense= since > it's a oneliner >=20 > Lee: this is a (tested!) implementation of your suggestion for simple= -mfd. > If you can eventually ACK this from the MFD side, I think it should b= e > funneled through the ARM SoC tree. >=20 > Grant/Rob: if either of you can ACK the change to the OF core likewis= e it can > be taken through ARM SoC. >=20 > DT binings maintainers: there is some background discussion on this h= ere: > http://marc.info/?l=3Dlinux-arm-kernel&m=3D142486676603889&w=3D2 > http://marc.info/?l=3Ddevicetree&m=3D142166313621469&w=3D2 > --- > Documentation/devicetree/bindings/mfd/mfd.txt | 41 +++++++++++++++++= ++++++++++ > drivers/of/platform.c | 1 + > 2 files changed, 42 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mfd/mfd.txt Acked-by: Lee Jones > diff --git a/Documentation/devicetree/bindings/mfd/mfd.txt b/Document= ation/devicetree/bindings/mfd/mfd.txt > new file mode 100644 > index 000000000000..af9d6931a1a2 > --- /dev/null > +++ b/Documentation/devicetree/bindings/mfd/mfd.txt > @@ -0,0 +1,41 @@ > +Multi-Function Devices (MFD) > + > +These devices comprise a nexus for heterogeneous hardware blocks con= taining > +more than one non-unique yet varying hardware functionality. > + > +A typical MFD can be: > + > +- A mixed signal ASIC on an external bus, sometimes a PMIC (Power Ma= nagement > + Integrated Circuit) that is manufactured in a lower technology nod= e (rough > + silicon) that handles analog drivers for things like audio amplifi= ers, LED > + drivers, level shifters, PHY (physical interfaces to things like U= SB or > + ethernet), regulators etc. > + > +- A range of memory registers containing "miscellaneous system regis= ters" also > + known as a system controller "syscon" or any other memory range co= ntaining a > + mix of unrelated hardware devices. > + > +Optional properties: > + > +- compatible : "simple-mfd" - this signifies that the operating syst= em should > + consider all subnodes of the MFD device as separate devices akin t= o how > + "simple-bus" inidicates when to see subnodes as children for a sim= ple > + memory-mapped bus. For more complex devices, when the nexus driver= has to > + probe registers to figure out what child devices exist etc, this s= hould not > + be used. In the latter case the child devices will be determined b= y the > + operating system. > + > +Example: > + > +foo@1000 { > + compatible =3D "syscon", "simple-mfd"; > + reg =3D <0x01000 0x1000>; > + > + led@08.0 { > + compatible =3D "register-bit-led"; > + offset =3D <0x08>; > + mask =3D <0x01>; > + label =3D "myled"; > + default-state =3D "on"; > + }; > +}; > diff --git a/drivers/of/platform.c b/drivers/of/platform.c > index b189733a1539..969ba4e1460c 100644 > --- a/drivers/of/platform.c > +++ b/drivers/of/platform.c > @@ -26,6 +26,7 @@ > =20 > const struct of_device_id of_default_bus_match_table[] =3D { > { .compatible =3D "simple-bus", }, > + { .compatible =3D "simple-mfd", }, > #ifdef CONFIG_ARM_AMBA > { .compatible =3D "arm,amba-bus", }, > #endif /* CONFIG_ARM_AMBA */ --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html