[PATCH RESEND v2] mfd: syscon: add child device support

[PATCH RESEND v2] mfd: syscon: add child device support

[Philipp Zabel]

For devices which have a complete register for themselves, it is possible to
place them next to the syscon device with overlapping reg ranges. The same is
not possible for devices which only occupy bitfields in registers shared with
other users.
For devices that are completely controlled by bitfields in the syscon address
range, such as multiplexers or voltage regulators, allow to put child devices
into the syscon device node.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
Changes since v1:
 - Reworded binding documentation to allow #size-cells = <1>, which is useful
   for syscon children that are controlled through a (possibly shared) register
   range.
---
 Documentation/devicetree/bindings/mfd/syscon.txt | 13 +++++++++++++
 drivers/mfd/syscon.c                             |  3 +++
 2 files changed, 16 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt
index fe8150b..0c6b497 100644
--- a/Documentation/devicetree/bindings/mfd/syscon.txt
+++ b/Documentation/devicetree/bindings/mfd/syscon.txt
@@ -9,12 +9,25 @@ using a specific compatible value), interrogate the node (or associated
 OS driver) to determine the location of the registers, and access the
 registers directly.
 
+Optionally, devices that are controlled exclusively through syscon registers,
+or even bitfields in shared syscon registers, can also be added as child nodes
+to the syscon device node. These devices can implicitly assume their parent
+node is a syscon provider without referencing it explicitly via phandle.
+In this case, the syscon node should have #address-cells = <1> and
+#size-cells = <0> or <1> and no ranges property.
+
 Required properties:
 - compatible: Should contain "syscon".
 - reg: the register region can be accessed from syscon
 
+Optional properties:
+- #address-cells: Should be 1.
+- #size-cells: Should be 0 or 1.
+
 Examples:
 gpr: iomuxc-gpr@020e0000 {
+	#address-cells = <1>;
+	#size-cells = <0>;
 	compatible = "fsl,imx6q-iomuxc-gpr", "syscon";
 	reg = <0x020e0000 0x38>;
 };
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index ca15878..38da178 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -155,6 +155,9 @@ static int syscon_probe(struct platform_device *pdev)
 
 	dev_dbg(dev, "regmap %pR registered\n", res);
 
+	if (!of_device_is_compatible(pdev->dev.of_node, "simple-bus"))
+		of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
+
 	return 0;
 }
 
-- 
2.1.1

Re: [PATCH RESEND v2] mfd: syscon: add child device support

[Philipp Zabel]

Hi,

Am Montag, den 01.12.2014, 17:25 +0100 schrieb Philipp Zabel:
> For devices which have a complete register for themselves, it is possible to
> place them next to the syscon device with overlapping reg ranges. The same is
> not possible for devices which only occupy bitfields in registers shared with
> other users.
> For devices that are completely controlled by bitfields in the syscon address
> range, such as multiplexers or voltage regulators, allow to put child devices
> into the syscon device node.

What is the status of this patch?
Is this ok to be applied after the merge window closes?

For reference, these are the previous threads:
https://lkml.org/lkml/2014/5/27/422
https://lkml.org/lkml/2014/11/3/134

regards
Philipp

> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> ---
> Changes since v1:
>  - Reworded binding documentation to allow #size-cells = <1>, which is useful
>    for syscon children that are controlled through a (possibly shared) register
>    range.
> ---
>  Documentation/devicetree/bindings/mfd/syscon.txt | 13 +++++++++++++
>  drivers/mfd/syscon.c                             |  3 +++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt
> index fe8150b..0c6b497 100644
> --- a/Documentation/devicetree/bindings/mfd/syscon.txt
> +++ b/Documentation/devicetree/bindings/mfd/syscon.txt
> @@ -9,12 +9,25 @@ using a specific compatible value), interrogate the node (or associated
>  OS driver) to determine the location of the registers, and access the
>  registers directly.
>  
> +Optionally, devices that are controlled exclusively through syscon registers,
> +or even bitfields in shared syscon registers, can also be added as child nodes
> +to the syscon device node. These devices can implicitly assume their parent
> +node is a syscon provider without referencing it explicitly via phandle.
> +In this case, the syscon node should have #address-cells = <1> and
> +#size-cells = <0> or <1> and no ranges property.
> +
>  Required properties:
>  - compatible: Should contain "syscon".
>  - reg: the register region can be accessed from syscon
>  
> +Optional properties:
> +- #address-cells: Should be 1.
> +- #size-cells: Should be 0 or 1.
> +
>  Examples:
>  gpr: iomuxc-gpr@020e0000 {
> +	#address-cells = <1>;
> +	#size-cells = <0>;
>  	compatible = "fsl,imx6q-iomuxc-gpr", "syscon";
>  	reg = <0x020e0000 0x38>;
>  };
> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> index ca15878..38da178 100644
> --- a/drivers/mfd/syscon.c
> +++ b/drivers/mfd/syscon.c
> @@ -155,6 +155,9 @@ static int syscon_probe(struct platform_device *pdev)
>  
>  	dev_dbg(dev, "regmap %pR registered\n", res);
>  
> +	if (!of_device_is_compatible(pdev->dev.of_node, "simple-bus"))
> +		of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
> +
>  	return 0;
>  }
>  

Re: [PATCH RESEND v2] mfd: syscon: add child device support

[Lee Jones]

On Mon, 15 Dec 2014, Philipp Zabel wrote:
> Am Montag, den 01.12.2014, 17:25 +0100 schrieb Philipp Zabel:
> > For devices which have a complete register for themselves, it is possible to
> > place them next to the syscon device with overlapping reg ranges. The same is
> > not possible for devices which only occupy bitfields in registers shared with
> > other users.
> > For devices that are completely controlled by bitfields in the syscon address
> > range, such as multiplexers or voltage regulators, allow to put child devices
> > into the syscon device node.
> 
> What is the status of this patch?
> Is this ok to be applied after the merge window closes?
> 
> For reference, these are the previous threads:
> https://lkml.org/lkml/2014/5/27/422
> https://lkml.org/lkml/2014/11/3/134

As this is such an important driver I need more Acks for users/testers
and senior reviewers before applying.

> > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> > ---
> > Changes since v1:
> >  - Reworded binding documentation to allow #size-cells = <1>, which is useful
> >    for syscon children that are controlled through a (possibly shared) register
> >    range.
> > ---
> >  Documentation/devicetree/bindings/mfd/syscon.txt | 13 +++++++++++++
> >  drivers/mfd/syscon.c                             |  3 +++
> >  2 files changed, 16 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt
> > index fe8150b..0c6b497 100644
> > --- a/Documentation/devicetree/bindings/mfd/syscon.txt
> > +++ b/Documentation/devicetree/bindings/mfd/syscon.txt
> > @@ -9,12 +9,25 @@ using a specific compatible value), interrogate the node (or associated
> >  OS driver) to determine the location of the registers, and access the
> >  registers directly.
> >  
> > +Optionally, devices that are controlled exclusively through syscon registers,
> > +or even bitfields in shared syscon registers, can also be added as child nodes
> > +to the syscon device node. These devices can implicitly assume their parent
> > +node is a syscon provider without referencing it explicitly via phandle.
> > +In this case, the syscon node should have #address-cells = <1> and
> > +#size-cells = <0> or <1> and no ranges property.
> > +
> >  Required properties:
> >  - compatible: Should contain "syscon".
> >  - reg: the register region can be accessed from syscon
> >  
> > +Optional properties:
> > +- #address-cells: Should be 1.
> > +- #size-cells: Should be 0 or 1.
> > +
> >  Examples:
> >  gpr: iomuxc-gpr@020e0000 {
> > +	#address-cells = <1>;
> > +	#size-cells = <0>;
> >  	compatible = "fsl,imx6q-iomuxc-gpr", "syscon";
> >  	reg = <0x020e0000 0x38>;
> >  };
> > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> > index ca15878..38da178 100644
> > --- a/drivers/mfd/syscon.c
> > +++ b/drivers/mfd/syscon.c
> > @@ -155,6 +155,9 @@ static int syscon_probe(struct platform_device *pdev)
> >  
> >  	dev_dbg(dev, "regmap %pR registered\n", res);
> >  
> > +	if (!of_device_is_compatible(pdev->dev.of_node, "simple-bus"))
> > +		of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
> > +
> >  	return 0;
> >  }
> >  
> 
> 

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH RESEND v2] mfd: syscon: add child device support

[Flora Fu]

Hi,

The patch set is used to implement reset controller in
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/299141.html

Tested-by: Flora Fu <flora.fu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>

Thanks,
Flora

On Mon, 2014-12-15 at 09:58 +0000, Lee Jones wrote:
> On Mon, 15 Dec 2014, Philipp Zabel wrote:
> > Am Montag, den 01.12.2014, 17:25 +0100 schrieb Philipp Zabel:
> > > For devices which have a complete register for themselves, it is possible to
> > > place them next to the syscon device with overlapping reg ranges. The same is
> > > not possible for devices which only occupy bitfields in registers shared with
> > > other users.
> > > For devices that are completely controlled by bitfields in the syscon address
> > > range, such as multiplexers or voltage regulators, allow to put child devices
> > > into the syscon device node.
> > 
> > What is the status of this patch?
> > Is this ok to be applied after the merge window closes?
> > 
> > For reference, these are the previous threads:
> > https://lkml.org/lkml/2014/5/27/422
> > https://lkml.org/lkml/2014/11/3/134
> 
> As this is such an important driver I need more Acks for users/testers
> and senior reviewers before applying.
> 
> > > Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> > > ---
> > > Changes since v1:
> > >  - Reworded binding documentation to allow #size-cells = <1>, which is useful
> > >    for syscon children that are controlled through a (possibly shared) register
> > >    range.
> > > ---
> > >  Documentation/devicetree/bindings/mfd/syscon.txt | 13 +++++++++++++
> > >  drivers/mfd/syscon.c                             |  3 +++
> > >  2 files changed, 16 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt
> > > index fe8150b..0c6b497 100644
> > > --- a/Documentation/devicetree/bindings/mfd/syscon.txt
> > > +++ b/Documentation/devicetree/bindings/mfd/syscon.txt
> > > @@ -9,12 +9,25 @@ using a specific compatible value), interrogate the node (or associated
> > >  OS driver) to determine the location of the registers, and access the
> > >  registers directly.
> > >  
> > > +Optionally, devices that are controlled exclusively through syscon registers,
> > > +or even bitfields in shared syscon registers, can also be added as child nodes
> > > +to the syscon device node. These devices can implicitly assume their parent
> > > +node is a syscon provider without referencing it explicitly via phandle.
> > > +In this case, the syscon node should have #address-cells = <1> and
> > > +#size-cells = <0> or <1> and no ranges property.
> > > +
> > >  Required properties:
> > >  - compatible: Should contain "syscon".
> > >  - reg: the register region can be accessed from syscon
> > >  
> > > +Optional properties:
> > > +- #address-cells: Should be 1.
> > > +- #size-cells: Should be 0 or 1.
> > > +
> > >  Examples:
> > >  gpr: iomuxc-gpr@020e0000 {
> > > +	#address-cells = <1>;
> > > +	#size-cells = <0>;
> > >  	compatible = "fsl,imx6q-iomuxc-gpr", "syscon";
> > >  	reg = <0x020e0000 0x38>;
> > >  };
> > > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> > > index ca15878..38da178 100644
> > > --- a/drivers/mfd/syscon.c
> > > +++ b/drivers/mfd/syscon.c
> > > @@ -155,6 +155,9 @@ static int syscon_probe(struct platform_device *pdev)
> > >  
> > >  	dev_dbg(dev, "regmap %pR registered\n", res);
> > >  
> > > +	if (!of_device_is_compatible(pdev->dev.of_node, "simple-bus"))
> > > +		of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
> > > +
> > >  	return 0;
> > >  }
> > >  
> > 
> > 
> 


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