| Message ID | 1571254641-13626-7-git-send-email-thara.gopinath@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce Power domain based warming device driver | expand |
On Thu, 17 Oct 2019 at 17:28, Thara Gopinath <thara.gopinath@linaro.org> wrote: > > Hello Ulf, > Thanks for the review! > > On 10/17/2019 05:04 AM, Ulf Hansson wrote: > > On Wed, 16 Oct 2019 at 21:37, Thara Gopinath <thara.gopinath@linaro.org> wrote: > >> > >> RPMh power controller hosts mx domain that can be used as thermal > >> warming device. Add a sub-node to specify this. > >> > >> Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org> > >> --- > >> Documentation/devicetree/bindings/power/qcom,rpmpd.txt | 10 ++++++++++ > >> 1 file changed, 10 insertions(+) > >> > >> diff --git a/Documentation/devicetree/bindings/power/qcom,rpmpd.txt b/Documentation/devicetree/bindings/power/qcom,rpmpd.txt > >> index eb35b22..fff695d 100644 > >> --- a/Documentation/devicetree/bindings/power/qcom,rpmpd.txt > >> +++ b/Documentation/devicetree/bindings/power/qcom,rpmpd.txt > >> @@ -18,6 +18,16 @@ Required Properties: > >> Refer to <dt-bindings/power/qcom-rpmpd.h> for the level values for > >> various OPPs for different platforms as well as Power domain indexes > >> > >> += SUBNODES > >> +RPMh alsp hosts power domains that can behave as thermal warming device. > >> +These are expressed as subnodes of the RPMh. The name of the node is used > >> +to identify the power domain and must therefor be "mx". > >> + > >> +- #cooling-cells: > >> + Usage: optional > >> + Value type: <u32> > >> + Definition: must be 2 > >> + > > > > Just wanted to express a minor thought about this. In general we use > > subnodes of PM domain providers to represent the topology of PM > > domains (subdomains), this is something different, which I guess is > > fine. > > > > I assume the #cooling-cells is here tells us this is not a PM domain > > provider, but a "cooling device provider"? > Yep. > > > > Also, I wonder if it would be fine to specify "power-domains" here, > > rather than using "name" as I think that is kind of awkward!? > Do you mean "power-domain-names" ? I am using this to match against the > genpd names defined in the provider driver. No. If you are using "power-domains" it means that you allow to describe the specifier for the provider. From Linux point of view, it means you can use dev_pm_domain_attach() to hook up the corresponding device with the PM domain. Using "power-domain-names" is just to allow to specify a name rather than an index, which makes sense if there is more than one index. Perhaps you can state that the "power-domain-names" should be there anyway, to be a little bit future proof if ever multiple index (multiple PM domains). Kind regards Uffe
On 10/17/2019 11:43 AM, Ulf Hansson wrote: > On Thu, 17 Oct 2019 at 17:28, Thara Gopinath <thara.gopinath@linaro.org> wrote: >> >> Hello Ulf, >> Thanks for the review! >> >> On 10/17/2019 05:04 AM, Ulf Hansson wrote: >>> On Wed, 16 Oct 2019 at 21:37, Thara Gopinath <thara.gopinath@linaro.org> wrote: >>>> >>>> RPMh power controller hosts mx domain that can be used as thermal >>>> warming device. Add a sub-node to specify this. >>>> >>>> Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org> >>>> --- >>>> Documentation/devicetree/bindings/power/qcom,rpmpd.txt | 10 ++++++++++ >>>> 1 file changed, 10 insertions(+) >>>> >>>> diff --git a/Documentation/devicetree/bindings/power/qcom,rpmpd.txt b/Documentation/devicetree/bindings/power/qcom,rpmpd.txt >>>> index eb35b22..fff695d 100644 >>>> --- a/Documentation/devicetree/bindings/power/qcom,rpmpd.txt >>>> +++ b/Documentation/devicetree/bindings/power/qcom,rpmpd.txt >>>> @@ -18,6 +18,16 @@ Required Properties: >>>> Refer to <dt-bindings/power/qcom-rpmpd.h> for the level values for >>>> various OPPs for different platforms as well as Power domain indexes >>>> >>>> += SUBNODES >>>> +RPMh alsp hosts power domains that can behave as thermal warming device. >>>> +These are expressed as subnodes of the RPMh. The name of the node is used >>>> +to identify the power domain and must therefor be "mx". >>>> + >>>> +- #cooling-cells: >>>> + Usage: optional >>>> + Value type: <u32> >>>> + Definition: must be 2 >>>> + >>> >>> Just wanted to express a minor thought about this. In general we use >>> subnodes of PM domain providers to represent the topology of PM >>> domains (subdomains), this is something different, which I guess is >>> fine. >>> >>> I assume the #cooling-cells is here tells us this is not a PM domain >>> provider, but a "cooling device provider"? >> Yep. >>> >>> Also, I wonder if it would be fine to specify "power-domains" here, >>> rather than using "name" as I think that is kind of awkward!? >> Do you mean "power-domain-names" ? I am using this to match against the >> genpd names defined in the provider driver. > > No. If you are using "power-domains" it means that you allow to > describe the specifier for the provider. Yep. But won't this look funny in DT ? The provider node will have a sub node with a power domain referencing to itself Like below: Is this ok ? rpmhpd: power-controller { compatible = "qcom,sdm845-rpmhpd"; #power-domain-cells = <1>; ... ... mx_cdev: mx { #cooling-cells = <2>; power-domains = <&rpmhpd SDM845_MX>; }; > > From Linux point of view, it means you can use dev_pm_domain_attach() > to hook up the corresponding device with the PM domain. Yes. Only the thermal framework does not populate cdev->dev->of_node. But it should be a trivial thing to fix it. Also if I end up creating a separate device, it should not matter. > > Using "power-domain-names" is just to allow to specify a name rather > than an index, which makes sense if there is more than one index. > Perhaps you can state that the "power-domain-names" should be there > anyway, to be a little bit future proof if ever multiple index > (multiple PM domains). > > Kind regards > Uffe > -- Warm Regards Thara
On Tue, Oct 29, 2019 at 5:07 AM Ulf Hansson <ulf.hansson@linaro.org> wrote: > > On Tue, 29 Oct 2019 at 02:36, Rob Herring <robh@kernel.org> wrote: > > > > On Thu, Oct 17, 2019 at 12:10:15PM -0400, Thara Gopinath wrote: > > > On 10/17/2019 11:43 AM, Ulf Hansson wrote: > > > > On Thu, 17 Oct 2019 at 17:28, Thara Gopinath <thara.gopinath@linaro.org> wrote: > > > >> > > > >> Hello Ulf, > > > >> Thanks for the review! > > > >> > > > >> On 10/17/2019 05:04 AM, Ulf Hansson wrote: > > > >>> On Wed, 16 Oct 2019 at 21:37, Thara Gopinath <thara.gopinath@linaro.org> wrote: > > > >>>> > > > >>>> RPMh power controller hosts mx domain that can be used as thermal > > > >>>> warming device. Add a sub-node to specify this. > > > >>>> > > > >>>> Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org> > > > >>>> --- > > > >>>> Documentation/devicetree/bindings/power/qcom,rpmpd.txt | 10 ++++++++++ > > > >>>> 1 file changed, 10 insertions(+) > > > >>>> > > > >>>> diff --git a/Documentation/devicetree/bindings/power/qcom,rpmpd.txt b/Documentation/devicetree/bindings/power/qcom,rpmpd.txt > > > >>>> index eb35b22..fff695d 100644 > > > >>>> --- a/Documentation/devicetree/bindings/power/qcom,rpmpd.txt > > > >>>> +++ b/Documentation/devicetree/bindings/power/qcom,rpmpd.txt > > > >>>> @@ -18,6 +18,16 @@ Required Properties: > > > >>>> Refer to <dt-bindings/power/qcom-rpmpd.h> for the level values for > > > >>>> various OPPs for different platforms as well as Power domain indexes > > > >>>> > > > >>>> += SUBNODES > > > >>>> +RPMh alsp hosts power domains that can behave as thermal warming device. > > > >>>> +These are expressed as subnodes of the RPMh. The name of the node is used > > > >>>> +to identify the power domain and must therefor be "mx". > > > >>>> + > > > >>>> +- #cooling-cells: > > > >>>> + Usage: optional > > > >>>> + Value type: <u32> > > > >>>> + Definition: must be 2 > > > >>>> + > > > >>> > > > >>> Just wanted to express a minor thought about this. In general we use > > > >>> subnodes of PM domain providers to represent the topology of PM > > > >>> domains (subdomains), this is something different, which I guess is > > > >>> fine. > > > >>> > > > >>> I assume the #cooling-cells is here tells us this is not a PM domain > > > >>> provider, but a "cooling device provider"? > > > >> Yep. > > > >>> > > > >>> Also, I wonder if it would be fine to specify "power-domains" here, > > > >>> rather than using "name" as I think that is kind of awkward!? > > > >> Do you mean "power-domain-names" ? I am using this to match against the > > > >> genpd names defined in the provider driver. > > > > > > > > No. If you are using "power-domains" it means that you allow to > > > > describe the specifier for the provider. > > > Yep. But won't this look funny in DT ? The provider node will have a sub > > > node with a power domain referencing to itself Like below: Is this ok ? > > > > > > rpmhpd: power-controller { > > > compatible = "qcom,sdm845-rpmhpd"; > > > #power-domain-cells = <1>; > > > > > > ... > > > ... > > > mx_cdev: mx { > > > #cooling-cells = <2>; > > > power-domains = <&rpmhpd SDM845_MX>; > > > }; > > > > > > > The whole concept here seems all wrong to me. Isn't it what's in the > > power domain that's the cooling device. A CPU power domain is not a > > cooling device, the CPU is. Or we wouldn't make a clock a cooling > > device, but what the clock drives. > > Well, I don't think that's entirely correct description either. > > As I see it, it's really the actual PM domain (that manages voltages > for a power island), that needs to stay in full power state and > increase its voltage level, as to warm up some of the silicon. It's > not a regular device, but more a characteristics of how the PM domain > can be used. First I've heard of Si needing warming... I think I'd just expect the power domain provider to know which domains to power on then. Rob
diff --git a/Documentation/devicetree/bindings/power/qcom,rpmpd.txt b/Documentation/devicetree/bindings/power/qcom,rpmpd.txt index eb35b22..fff695d 100644 --- a/Documentation/devicetree/bindings/power/qcom,rpmpd.txt +++ b/Documentation/devicetree/bindings/power/qcom,rpmpd.txt @@ -18,6 +18,16 @@ Required Properties: Refer to <dt-bindings/power/qcom-rpmpd.h> for the level values for various OPPs for different platforms as well as Power domain indexes += SUBNODES +RPMh alsp hosts power domains that can behave as thermal warming device. +These are expressed as subnodes of the RPMh. The name of the node is used +to identify the power domain and must therefor be "mx". + +- #cooling-cells: + Usage: optional + Value type: <u32> + Definition: must be 2 + Example: rpmh power domain controller and OPP table #include <dt-bindings/power/qcom-rpmhpd.h>
RPMh power controller hosts mx domain that can be used as thermal warming device. Add a sub-node to specify this. Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org> --- Documentation/devicetree/bindings/power/qcom,rpmpd.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) -- 2.1.4