[PATCH 0/4] PM / Domains: DT bindings for domain idle states and doc updates

[PATCH 0/4] PM / Domains: DT bindings for domain idle states and doc updates

[Lina Iyer]

Hi Rafael,

This patchset adds the following on top of the patches [0-7] of v3[1], that you
have already queued up for linux-next.

- New DT compatible for PM Domain idle states.
- Update documentation for PM domain idle state
(Pls. note that this new compatible is yet to be approved by DT reviewers)
- Update device/domain documentation per your suggestion

Thanks,
Lina

[1]. http://www.spinics.net/lists/arm-kernel/msg536181.html

Lina Iyer (4):
  PM / doc: Update device documentation for devices in IRQ safe PM
    domains
  dt-bindings: add domain-idle-state compatible to arm,idle-state
  dt-bindings: Update domain-idle-state binding to use correct
    compatibles
  PM / Domains: Use domain-idle-state compatible

 Documentation/devicetree/bindings/arm/idle-states.txt    |  3 +++
 Documentation/devicetree/bindings/power/power_domain.txt |  9 +++++----
 Documentation/power/devices.txt                          | 14 +++++++++++++-
 drivers/base/power/domain.c                              |  2 +-
 4 files changed, 22 insertions(+), 6 deletions(-)

-- 
2.7.4

[PATCH 1/4] PM / doc: Update device documentation for devices in IRQ safe PM domains

[Lina Iyer]

Update documentation to reflect the changes made to support IRQ safe PM
domains.

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
---
 Documentation/power/devices.txt | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt
index 8ba6625..73ddea3 100644
--- a/Documentation/power/devices.txt
+++ b/Documentation/power/devices.txt
@@ -607,7 +607,9 @@ individually.  Instead, a set of devices sharing a power resource can be put
 into a low-power state together at the same time by turning off the shared
 power resource.  Of course, they also need to be put into the full-power state
 together, by turning the shared power resource on.  A set of devices with this
-property is often referred to as a power domain.
+property is often referred to as a power domain. A power domain may also be
+nested inside another power domain. The nested domain is referred to as the
+sub-domain of the parent domain.
 
 Support for power domains is provided through the pm_domain field of struct
 device.  This field is a pointer to an object of type struct dev_pm_domain,
@@ -629,6 +631,16 @@ support for power domains into subsystem-level callbacks, for example by
 modifying the platform bus type.  Other platforms need not implement it or take
 it into account in any way.
 
+Devices may be defined as IRQ-safe which indicates to the PM core that their
+runtime PM callbacks may be invoked with disabled interrupts (see
+Documentation/power/runtime_pm.txt for more information).  If an IRQ-safe
+device belongs to a PM domain, the runtime PM of the domain will be
+disallowed, unless the domain itself is defined as IRQ-safe. However, it
+makes sense to define a PM domain as IRQ-safe only if all the devices in it
+are IRQ-safe. Moreover, if an IRQ-safe domain has a parent domain, the runtime
+PM of the parent is only allowed if the parent itself is IRQ-safe too with the
+additional restriction that all child domains of an IRQ-safe parent must also
+be IRQ-safe.
 
 Device Low Power (suspend) States
 ---------------------------------
-- 
2.7.4

[PATCH 1/4] PM / doc: Update device documentation for devices in IRQ safe PM domains

[Rafael J. Wysocki]

On Tuesday, October 25, 2016 08:26:36 AM Lina Iyer wrote:
> Update documentation to reflect the changes made to support IRQ safe PM
> domains.
> 
> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>

This one is in my tree already.

Thanks,
Rafael

[PATCH 2/4] dt-bindings: add domain-idle-state compatible to arm, idle-state

[Lina Iyer]

CPU's idle states are defined by the arm,idle-state compatible flag. PM
domains that can contains devices and other domains also has similar
definition for its idle state. Reuse the definition of arm,idle-state
for PM domains by allowing an addition compatible string
("domain-idle-state") to denote idle states that are specific to PM
Domains.

Cc: <devicetree@vger.kernel.org>
Cc: Rob Herring <robh@kernel.org>
Suggested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
---
 Documentation/devicetree/bindings/arm/idle-states.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/idle-states.txt b/Documentation/devicetree/bindings/arm/idle-states.txt
index b8e41c1..4b0ff59 100644
--- a/Documentation/devicetree/bindings/arm/idle-states.txt
+++ b/Documentation/devicetree/bindings/arm/idle-states.txt
@@ -271,6 +271,9 @@ follows:
 		Usage: Required
 		Value type: <stringlist>
 		Definition: Must be "arm,idle-state".
+			    Additionally, nodes that are used to describe a
+			    idle-state of PM domain must also define
+			    "domain-idle-state" as compatible string.
 
 	- local-timer-stop
 		Usage: See definition
-- 
2.7.4

[PATCH 3/4] dt-bindings: Update domain-idle-state binding to use correct compatibles

[Lina Iyer]

Update domain-idle-state binding to use "domain-idle-state" compatible
from Documentation/devicetree/bindings/arm/idle-states.txt.

Cc: <devicetree@vger.kernel.org>
Cc: Rob Herring <robh@kernel.org>
Suggested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
---
 Documentation/devicetree/bindings/power/power_domain.txt | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
index e165036..6fb53a3 100644
--- a/Documentation/devicetree/bindings/power/power_domain.txt
+++ b/Documentation/devicetree/bindings/power/power_domain.txt
@@ -30,8 +30,9 @@ Optional properties:
    available in the next section.
 
 - domain-idle-states : A phandle of an idle-state that shall be soaked into a
-                generic domain power state. The idle state definitions are
-                compatible with arm,idle-state specified in [1].
+                generic domain power state. The idle state definitions must be
+                compatible with "domain-idle-state" as well as
+                "arm,idle-state" as defined in [1].
   The domain-idle-state property reflects the idle state of this PM domain and
   not the idle states of the devices or sub-domains in the PM domain. Devices
   and sub-domains have their own idle-states independent of the parent
@@ -85,7 +86,7 @@ Example 3:
 	};
 
 	DOMAIN_RET: state at 0 {
-		compatible = "arm,idle-state";
+		compatible = "domain-idle-state", "arm,idle-state";
 		reg = <0x0>;
 		entry-latency-us = <1000>;
 		exit-latency-us = <2000>;
@@ -93,7 +94,7 @@ Example 3:
 	};
 
 	DOMAIN_PWR_DN: state at 1 {
-		compatible = "arm,idle-state";
+		compatible = "domain-idle-state", "arm,idle-state";
 		reg = <0x1>;
 		entry-latency-us = <5000>;
 		exit-latency-us = <8000>;
-- 
2.7.4

[PATCH 3/4] dt-bindings: Update domain-idle-state binding to use correct compatibles

[Sudeep Holla]

On 25/10/16 16:26, Lina Iyer wrote:
> Update domain-idle-state binding to use "domain-idle-state" compatible
> from Documentation/devicetree/bindings/arm/idle-states.txt.
>
> Cc: <devicetree@vger.kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Suggested-by: Sudeep Holla <sudeep.holla@arm.com>
> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
> ---
>  Documentation/devicetree/bindings/power/power_domain.txt | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
> index e165036..6fb53a3 100644
> --- a/Documentation/devicetree/bindings/power/power_domain.txt
> +++ b/Documentation/devicetree/bindings/power/power_domain.txt
> @@ -30,8 +30,9 @@ Optional properties:
>     available in the next section.
>
>  - domain-idle-states : A phandle of an idle-state that shall be soaked into a
> -                generic domain power state. The idle state definitions are
> -                compatible with arm,idle-state specified in [1].
> +                generic domain power state. The idle state definitions must be
> +                compatible with "domain-idle-state"

I would reword the below a bit different so that it's flexible to be
reused without "arm,idle-state".

> as well as
> +                "arm,idle-state" as defined in [1].

'Idle states that are "arm,idle-state" compatible are generally
"domain-idle-state" compatible as well if it's a PM domain.'

or something like that in line with what's in patch 2/4.

That would give us the scope of reuse of "domain-idle-state" in device
for future. Also it aligns with your patch 4/4.

Otherwise, it looks good.

-- 
Regards,
Sudeep

[PATCH 3/4] dt-bindings: Update domain-idle-state binding to use correct compatibles

[Lina Iyer]

On Tue, Oct 25 2016 at 09:59 -0600, Sudeep Holla wrote:
>
>
>On 25/10/16 16:26, Lina Iyer wrote:
>>Update domain-idle-state binding to use "domain-idle-state" compatible
>>from Documentation/devicetree/bindings/arm/idle-states.txt.
>>
>>Cc: <devicetree@vger.kernel.org>
>>Cc: Rob Herring <robh@kernel.org>
>>Suggested-by: Sudeep Holla <sudeep.holla@arm.com>
>>Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
>>---
>> Documentation/devicetree/bindings/power/power_domain.txt | 9 +++++----
>> 1 file changed, 5 insertions(+), 4 deletions(-)
>>
>>diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
>>index e165036..6fb53a3 100644
>>--- a/Documentation/devicetree/bindings/power/power_domain.txt
>>+++ b/Documentation/devicetree/bindings/power/power_domain.txt
>>@@ -30,8 +30,9 @@ Optional properties:
>>    available in the next section.
>>
>> - domain-idle-states : A phandle of an idle-state that shall be soaked into a
>>-                generic domain power state. The idle state definitions are
>>-                compatible with arm,idle-state specified in [1].
>>+                generic domain power state. The idle state definitions must be
>>+                compatible with "domain-idle-state"
>
>I would reword the below a bit different so that it's flexible to be
>reused without "arm,idle-state".
>
>>as well as
>>+                "arm,idle-state" as defined in [1].
>
>'Idle states that are "arm,idle-state" compatible are generally
>"domain-idle-state" compatible as well if it's a PM domain.'
>
I believe we should have both compatible strings. Per [1], any CPU that
follows the idle state compatible *must* have "arm,idle-state" as a
compatible. Since we are re-using the same compatible, its only correct
that we retain what is already spec'd up in [1] and in addition provide
this new compatible.

Thanks,
Lina

>or something like that in line with what's in patch 2/4.
>
>That would give us the scope of reuse of "domain-idle-state" in device
>for future. Also it aligns with your patch 4/4.
>
>Otherwise, it looks good.
>
>-- 
>Regards,
>Sudeep

[PATCH 3/4] dt-bindings: Update domain-idle-state binding to use correct compatibles

[Sudeep Holla]

On 25/10/16 17:24, Lina Iyer wrote:
> On Tue, Oct 25 2016 at 09:59 -0600, Sudeep Holla wrote:
>>
>>
>> On 25/10/16 16:26, Lina Iyer wrote:
>>> Update domain-idle-state binding to use "domain-idle-state" compatible
>>> from Documentation/devicetree/bindings/arm/idle-states.txt.
>>>
>>> Cc: <devicetree@vger.kernel.org>
>>> Cc: Rob Herring <robh@kernel.org>
>>> Suggested-by: Sudeep Holla <sudeep.holla@arm.com>
>>> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
>>> ---
>>> Documentation/devicetree/bindings/power/power_domain.txt | 9 +++++----
>>> 1 file changed, 5 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/power/power_domain.txt
>>> b/Documentation/devicetree/bindings/power/power_domain.txt
>>> index e165036..6fb53a3 100644
>>> --- a/Documentation/devicetree/bindings/power/power_domain.txt
>>> +++ b/Documentation/devicetree/bindings/power/power_domain.txt
>>> @@ -30,8 +30,9 @@ Optional properties:
>>>    available in the next section.
>>>
>>> - domain-idle-states : A phandle of an idle-state that shall be
>>> soaked into a
>>> -                generic domain power state. The idle state
>>> definitions are
>>> -                compatible with arm,idle-state specified in [1].
>>> +                generic domain power state. The idle state
>>> definitions must be
>>> +                compatible with "domain-idle-state"
>>
>> I would reword the below a bit different so that it's flexible to be
>> reused without "arm,idle-state".
>>
>>> as well as
>>> +                "arm,idle-state" as defined in [1].
>>
>> 'Idle states that are "arm,idle-state" compatible are generally
>> "domain-idle-state" compatible as well if it's a PM domain.'
>>
> I believe we should have both compatible strings. Per [1], any CPU that
> follows the idle state compatible *must* have "arm,idle-state" as a
> compatible.

Yes that's implicit for a CPU device. But generic power domain bindings
should not have that explicitly as it *can be* used for non CPU device.

> Since we are re-using the same compatible, its only correct
> that we retain what is already spec'd up in [1] and in addition provide
> this new compatible.
>

Yes [1] applies for *CPUs only* while this applies for *any device* and
*any power domain*, so I would drop *must have* "arm,idle-state" here
to keep this generic based on my understanding on how compatibles work.

-- 
Regards,
Sudeep

[PATCH 3/4] dt-bindings: Update domain-idle-state binding to use correct compatibles

[Kevin Hilman]

Lina Iyer <lina.iyer@linaro.org> writes:

> Update domain-idle-state binding to use "domain-idle-state" compatible
> from Documentation/devicetree/bindings/arm/idle-states.txt.
>
> Cc: <devicetree@vger.kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Suggested-by: Sudeep Holla <sudeep.holla@arm.com>
> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
> ---
>  Documentation/devicetree/bindings/power/power_domain.txt | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)

With no current users for this, I don't see the point of adding a
compatible now.

IMO, this should wait and be added with the identified user we can
discuss it then.

Kevin

[PATCH 3/4] dt-bindings: Update domain-idle-state binding to use correct compatibles

[Sudeep Holla]

On 25/10/16 21:49, Kevin Hilman wrote:
> Lina Iyer <lina.iyer@linaro.org> writes:
>
>> Update domain-idle-state binding to use "domain-idle-state" compatible
>> from Documentation/devicetree/bindings/arm/idle-states.txt.
>>
>> Cc: <devicetree@vger.kernel.org>
>> Cc: Rob Herring <robh@kernel.org>
>> Suggested-by: Sudeep Holla <sudeep.holla@arm.com>
>> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
>> ---
>>  Documentation/devicetree/bindings/power/power_domain.txt | 9 +++++----
>>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> With no current users for this, I don't see the point of adding a
> compatible now.
>
> IMO, this should wait and be added with the identified user we can
> discuss it then.
>

No, IMO it needs to be used for the proposed SoC idle/genpd solution.

I understand the nodes that are "arm,idle-state" compatible can be used
for this new SoC hierarchical idle management, but it was never defined
for that use originally. So this new feature must be advertised by the 
firmware with the presence of "domain-idle-state".

Yes we might have other ways to detect that but I have already seen that 
broken on the reference platform, so we need alternate/DT way to specify 
that.

Not all existing "arm,idle-state" compatible nodes will be capable of
supporting this new SoC idle feature. It's just better and safer for a
new feature getting added that relies on DT to have a new compatible.

-- 
Regards,
Sudeep

[PATCH 3/4] dt-bindings: Update domain-idle-state binding to use correct compatibles

[Rob Herring]

On Wed, Oct 26, 2016 at 09:57:35AM +0100, Sudeep Holla wrote:
> 
> 
> On 25/10/16 21:49, Kevin Hilman wrote:
> > Lina Iyer <lina.iyer@linaro.org> writes:
> > 
> > > Update domain-idle-state binding to use "domain-idle-state" compatible
> > > from Documentation/devicetree/bindings/arm/idle-states.txt.
> > > 
> > > Cc: <devicetree@vger.kernel.org>
> > > Cc: Rob Herring <robh@kernel.org>
> > > Suggested-by: Sudeep Holla <sudeep.holla@arm.com>
> > > Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
> > > ---
> > >  Documentation/devicetree/bindings/power/power_domain.txt | 9 +++++----
> > >  1 file changed, 5 insertions(+), 4 deletions(-)
> > 
> > With no current users for this, I don't see the point of adding a
> > compatible now.
> > 
> > IMO, this should wait and be added with the identified user we can
> > discuss it then.
> > 
> 
> No, IMO it needs to be used for the proposed SoC idle/genpd solution.
> 
> I understand the nodes that are "arm,idle-state" compatible can be used
> for this new SoC hierarchical idle management, but it was never defined
> for that use originally. So this new feature must be advertised by the
> firmware with the presence of "domain-idle-state".
> 
> Yes we might have other ways to detect that but I have already seen that
> broken on the reference platform, so we need alternate/DT way to specify
> that.
> 
> Not all existing "arm,idle-state" compatible nodes will be capable of
> supporting this new SoC idle feature. It's just better and safer for a
> new feature getting added that relies on DT to have a new compatible.

Or perhaps you should describe something new rather than trying to 
graft in what's there. This combination of compatible strings looks a 
bit odd to me. Though, I've not really spent much time thinking about 
this.

Rob

[PATCH 4/4] PM / Domains: Use domain-idle-state compatible

[Lina Iyer]

Use the more specific "domain-idle-states" compatible property to read
idle state properties from DT.

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
---
 drivers/base/power/domain.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index aac656a..07ed835 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2048,7 +2048,7 @@ out:
 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
 
 static const struct of_device_id idle_state_match[] = {
-	{ .compatible = "arm,idle-state", },
+	{ .compatible = "domain-idle-state", },
 	{ }
 };
 
-- 
2.7.4