[PATCH v3 0/2] MIPS: Augment CPC support

[PATCH v3 0/2] MIPS: Augment CPC support

[Aleksandar Markovic]

From: Aleksandar Markovic <aleksandar.markovic@mips.com>

v2->v3:

    - changed documentation file location from
        devicetree/bindings/misc to devicetree/bindings/power
    - minor commit message improvements
    - rebased to the latest code

v1->v2:

    - corrected wording in commit messages and documentation text
    - expanded cover letter to better explain the context of proposed
        changes
    - rebased to the latest code

This series is based on two patches from the larger series submitted
some time ago (30 Aug 2016):

https://www.linux-mips.org/archives/linux-mips/2016-08/msg00456.html

Both patches deal with MIPS Cluster Power Controller (CPC) support.
More specifically, they add device tree related functionalities to
that support.

This functionality is needed for further development of kernel support
for generic-based MIPS platforms that must be DT-based and will at the
same time make more extensive use of CPC.

This series is reviewed by the original author of the above-mentioned
larger series:

Reviewed-by: Paul Burton <paul.burton@mips.com>

Paul Burton (2):
  dt-bindings: Document mti,mips-cpc binding
  MIPS: CPC: Map registers using DT in mips_cpc_default_phys_base()

 Documentation/devicetree/bindings/power/mti,mips-cpc.txt |  8 ++++++++
 arch/mips/kernel/mips-cpc.c                              | 13 +++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/mti,mips-cpc.txt

-- 
2.7.4

[PATCH v3 1/2] dt-bindings: Document mti,mips-cpc binding

[Aleksandar Markovic]

From: Paul Burton <paul.burton@mips.com>

Document a binding for the MIPS Cluster Power Controller (CPC) that
allows the device tree to specify where the CPC registers are located.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
---
 Documentation/devicetree/bindings/power/mti,mips-cpc.txt | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/mti,mips-cpc.txt

diff --git a/Documentation/devicetree/bindings/power/mti,mips-cpc.txt b/Documentation/devicetree/bindings/power/mti,mips-cpc.txt
new file mode 100644
index 0000000..c6b8251
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/mti,mips-cpc.txt
@@ -0,0 +1,8 @@
+Binding for MIPS Cluster Power Controller (CPC).
+
+This binding allows a system to specify where the CPC registers are
+located.
+
+Required properties:
+compatible : Should be "mti,mips-cpc".
+regs: Should describe the address & size of the CPC register region.
-- 
2.7.4

[PATCH v3 2/2] MIPS: CPC: Map registers using DT in mips_cpc_default_phys_base()

[Aleksandar Markovic]

From: Paul Burton <paul.burton@mips.com>

Reading mips_cpc_base value from the DT allows each platform to
define it according to its needs. This is especially convenient
for MIPS_GENERIC kernel where this kind of information should be
determined in runtime.

Use mti,mips-cpc compatible string with just a reg property to
specify the register location for your platform.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@mips.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
---
 arch/mips/kernel/mips-cpc.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c
index 19c88d7..fcf9af4 100644
--- a/arch/mips/kernel/mips-cpc.c
+++ b/arch/mips/kernel/mips-cpc.c
@@ -10,6 +10,8 @@
 
 #include <linux/errno.h>
 #include <linux/percpu.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/spinlock.h>
 
 #include <asm/mips-cps.h>
@@ -22,6 +24,17 @@ static DEFINE_PER_CPU_ALIGNED(unsigned long, cpc_core_lock_flags);
 
 phys_addr_t __weak mips_cpc_default_phys_base(void)
 {
+	struct device_node *cpc_node;
+	struct resource res;
+	int err;
+
+	cpc_node = of_find_compatible_node(of_root, NULL, "mti,mips-cpc");
+	if (cpc_node) {
+		err = of_address_to_resource(cpc_node, 0, &res);
+		if (!err)
+			return res.start;
+	}
+
 	return 0;
 }
 
-- 
2.7.4

Re: [PATCH v3 1/2] dt-bindings: Document mti,mips-cpc binding

[Rob Herring]

On Wed, Dec 27, 2017 at 03:37:51PM +0100, Aleksandar Markovic wrote:
> From: Paul Burton <paul.burton@mips.com>
> 
> Document a binding for the MIPS Cluster Power Controller (CPC) that
> allows the device tree to specify where the CPC registers are located.
> 
> Signed-off-by: Paul Burton <paul.burton@mips.com>
> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
> ---
>  Documentation/devicetree/bindings/power/mti,mips-cpc.txt | 8 ++++++++
>  1 file changed, 8 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/power/mti,mips-cpc.txt

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v3 1/2] dt-bindings: Document mti,mips-cpc binding

[James Hogan]

[-- Attachment #1: Type: text/plain, Size: 1312 bytes --]

On Wed, Dec 27, 2017 at 03:37:51PM +0100, Aleksandar Markovic wrote:
> From: Paul Burton <paul.burton@mips.com>
> 
> Document a binding for the MIPS Cluster Power Controller (CPC) that
> allows the device tree to specify where the CPC registers are located.
> 
> Signed-off-by: Paul Burton <paul.burton@mips.com>
> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
> ---
>  Documentation/devicetree/bindings/power/mti,mips-cpc.txt | 8 ++++++++
>  1 file changed, 8 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/power/mti,mips-cpc.txt
> 
> diff --git a/Documentation/devicetree/bindings/power/mti,mips-cpc.txt b/Documentation/devicetree/bindings/power/mti,mips-cpc.txt
> new file mode 100644

Is it worth adding to the MIPS GENERIC PLATFORM entry of MAINTAINERS,
given that it directly benefits it?

Cheers
James

> index 0000000..c6b8251
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/mti,mips-cpc.txt
> @@ -0,0 +1,8 @@
> +Binding for MIPS Cluster Power Controller (CPC).
> +
> +This binding allows a system to specify where the CPC registers are
> +located.
> +
> +Required properties:
> +compatible : Should be "mti,mips-cpc".
> +regs: Should describe the address & size of the CPC register region.
> -- 
> 2.7.4
> 

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RE: [PATCH v3 1/2] dt-bindings: Document mti,mips-cpc binding

[Aleksandar Markovic]

> On Wed, Dec 27, 2017 at 03:37:51PM +0100, Aleksandar Markovic wrote:
> > From: Paul Burton <paul.burton@mips.com>
> >
> > Document a binding for the MIPS Cluster Power Controller (CPC) that
> > allows the device tree to specify where the CPC registers are located.
> >
> > Signed-off-by: Paul Burton <paul.burton@mips.com>
> > Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
> > ---
> >  Documentation/devicetree/bindings/power/mti,mips-cpc.txt | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/power/mti,mips-cpc.txt
> >
> > diff --git a/Documentation/devicetree/bindings/power/mti,mips-cpc.txt b/Documentation/devicetree/bindings/power/mti,mips-cpc.txt
> > new file mode 100644
> 
> Is it worth adding to the MIPS GENERIC PLATFORM entry of MAINTAINERS,
> given that it directly benefits it?
> 
> Cheers
> James

If nobody objects, in the v4 of this series, as a part of this particular patch, I am going to add the line:

F:       Documentation/devicetree/bindings/power/mti,mips-cpc.txt

to the following segment in MAINTAINERS file:

MIPS GENERIC PLATFORM
M:      Paul Burton <paul.burton@mips.com>
L:      linux-mips@linux-mips.org
S:      Supported
F:      arch/mips/generic/
F:      arch/mips/tools/generic-board-config.sh

v4 is planned to be sent by the end of the day.

Thanks,
Aleksandar