| Message ID | 1392737687-25003-2-git-send-email-p.zabel@pengutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tuesday 18 February 2014 16:34:41 Philipp Zabel wrote: > + > +Example of a device that is part of a power domain: > + > + vpu: vpu@02040000 { > + reg = <0x02040000 0x3c000>; > + /* ... */ > + fsl,power-domain = <&pd_pu>; > + /* ... */ > + }; > + I'm really not too happy about platforms starting to add random bindings for power domains. Unfortunately I didn't catch exynos doing this first, but I don't want to see another platform like that. Can we please come up with a proper generic power domain binding first and then add platform specific users? Arnd
Hi Arnd, [adding Samsung guys into the loop] Am Dienstag, den 18.02.2014, 19:10 +0100 schrieb Arnd Bergmann: > On Tuesday 18 February 2014 16:34:41 Philipp Zabel wrote: > > + > > +Example of a device that is part of a power domain: > > + > > + vpu: vpu@02040000 { > > + reg = <0x02040000 0x3c000>; > > + /* ... */ > > + fsl,power-domain = <&pd_pu>; > > + /* ... */ > > + }; > > + > > I'm really not too happy about platforms starting to add random > bindings for power domains. Unfortunately I didn't catch exynos > doing this first, but I don't want to see another platform like > that. > > Can we please come up with a proper generic power domain binding > first and then add platform specific users? what is the process here? I've seen the samsung bindings and copied the pattern. I guess the Exynos bindings are set in stone, and the i.MX power domains can be handled using the same bindings. regards Philipp
On Wednesday 19 February 2014, Philipp Zabel wrote: > Am Dienstag, den 18.02.2014, 19:10 +0100 schrieb Arnd Bergmann: > > On Tuesday 18 February 2014 16:34:41 Philipp Zabel wrote: > > > + > > > +Example of a device that is part of a power domain: > > > + > > > + vpu: vpu@02040000 { > > > + reg = <0x02040000 0x3c000>; > > > + /* ... */ > > > + fsl,power-domain = <&pd_pu>; > > > + /* ... */ > > > + }; > > > + > > > > I'm really not too happy about platforms starting to add random > > bindings for power domains. Unfortunately I didn't catch exynos > > doing this first, but I don't want to see another platform like > > that. > > > > Can we please come up with a proper generic power domain binding > > first and then add platform specific users? > > what is the process here? I've seen the samsung bindings and copied the > pattern. I guess the Exynos bindings are set in stone, and the i.MX > power domains can be handled using the same bindings. * First of all, get the pm domain maintainers into the loop, then make sure all other users of pm domains are aware of what you are doing. * Come up with a way to describe a pm_domain in a sufficiently generic way. It's possible you just need a phandle, but experience on other subsystems suggests that it helps to allow arguments, as we do for clocks, dmas, mailboxes, etc. * Draft a generic binding that can work on all platforms * Implement support for the generic binding in the platform independent code. * Add a specific binding for your hardware. * Implement support for your hardware binding on top of the generic code. * Get everyone involved to Ack the generic binding and implementation. Arnd
On 19.02.2014 15:38, Arnd Bergmann wrote: > On Wednesday 19 February 2014, Philipp Zabel wrote: > >> Am Dienstag, den 18.02.2014, 19:10 +0100 schrieb Arnd Bergmann: >>> On Tuesday 18 February 2014 16:34:41 Philipp Zabel wrote: >>>> + >>>> +Example of a device that is part of a power domain: >>>> + >>>> + vpu: vpu@02040000 { >>>> + reg = <0x02040000 0x3c000>; >>>> + /* ... */ >>>> + fsl,power-domain = <&pd_pu>; >>>> + /* ... */ >>>> + }; >>>> + >>> >>> I'm really not too happy about platforms starting to add random >>> bindings for power domains. Unfortunately I didn't catch exynos >>> doing this first, but I don't want to see another platform like >>> that. >>> >>> Can we please come up with a proper generic power domain binding >>> first and then add platform specific users? >> >> what is the process here? I've seen the samsung bindings and copied the >> pattern. I guess the Exynos bindings are set in stone, and the i.MX >> power domains can be handled using the same bindings. > > * First of all, get the pm domain maintainers into the loop, then make > sure all other users of pm domains are aware of what you are doing. > > * Come up with a way to describe a pm_domain in a sufficiently generic > way. It's possible you just need a phandle, but experience on other > subsystems suggests that it helps to allow arguments, as we do for > clocks, dmas, mailboxes, etc. > > * Draft a generic binding that can work on all platforms > > * Implement support for the generic binding in the platform independent > code. > > * Add a specific binding for your hardware. > > * Implement support for your hardware binding on top of the generic > code. > > * Get everyone involved to Ack the generic binding and implementation. > > Arnd > Just wanted to share a link with you. ;) http://www.spinics.net/lists/devicetree/msg18051.html Best regards, Tomasz
On Wednesday 19 February 2014 15:51:21 Tomasz Figa wrote: > > Just wanted to share a link with you. > > http://www.spinics.net/lists/devicetree/msg18051.html Excellent, thanks for the heads-up. Philipp, please review that patch and see if you can build on top of that for your work. Arnd
Am Mittwoch, den 19.02.2014, 15:56 +0100 schrieb Arnd Bergmann: > On Wednesday 19 February 2014 15:51:21 Tomasz Figa wrote: > > > > Just wanted to share a link with you. > > > > http://www.spinics.net/lists/devicetree/msg18051.html > > Excellent, thanks for the heads-up. > > Philipp, please review that patch and see if you can build on top of that > for your work. Thanks, I'll do that. regards Philipp
diff --git a/Documentation/devicetree/bindings/power/fsl,imx-gpc.txt b/Documentation/devicetree/bindings/power/fsl,imx-gpc.txt new file mode 100644 index 0000000..05927a7 --- /dev/null +++ b/Documentation/devicetree/bindings/power/fsl,imx-gpc.txt @@ -0,0 +1,58 @@ +Freescale i.MX General Power Controller +======================================= + +The i.MX6Q General Power Control (GPC) block contains DVFS load tracking +counters and Power Gating Control (PGC) for the CPU and PU (GPU/VPU) power +domains. + +Required properties: +- compatible: Should be "fsl,imx6q-gpc" +- reg: should be register base and length as documented in the + datasheet +- interrupts: Should contain GPC interrupt request 1 +- pu-supply: Link to the LDO regulator powering the PU power domain + +The gpc node should contain a 'pu-power-domain' subnode that serves as a +phandle target for devices belonging to the PU power domain: + +Power domains controlled by a PGC register set +============================================== + +Required properties: +- compatible: Should be "fsl,imx6q-power-domain" +- reg: should be register base and length as documented in the + datasheet + +Specifying power domain for IP modules +====================================== + +IP cores belonging to a power domain should contain a 'power-domain' property +that is a phandle pointing to the power-domain subnode of the gpc device node. + +Required properties: +- fsl,power-domain: A phandle pointing to the power-domain device tree node + + +Example: + + gpc: gpc@020dc000 { + compatible = "fsl,imx6q-gpc"; + reg = <0x020dc000 0x4000>; + interrupts = <0 89 0x04 0 90 0x04>; + pu-supply = <®_pu>; + + pd_pu: pu-power-domain@020dc260 { + compatible = "fsl,imx6q-power-domain"; + reg = <0x020dc260 0x10>; + }; + }; + +Example of a device that is part of a power domain: + + vpu: vpu@02040000 { + reg = <0x02040000 0x3c000>; + /* ... */ + fsl,power-domain = <&pd_pu>; + /* ... */ + }; +
The i.MX6 contains a power controller that controls power gating and sequencing for the SoC's power domains. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> --- Changes since v3: - Updated documentation to use fsl,power-domain property name and pu-power-domain as node name. - Removed address-cells/size-cells --- .../devicetree/bindings/power/fsl,imx-gpc.txt | 58 ++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/fsl,imx-gpc.txt