[PATCH 0/2] ARM: topology: Allow to set the frequency through a clock

[PATCH 0/2] ARM: topology: Allow to set the frequency through a clock

[Maxime Ripard]

Hi,

This patch series add the possibility for the topology code to get the
CPU frequency through a DT clock handle instead of needing a
clock-frequency property.

Indeed, this information can be quite redundant if the clock tree
defined in the DT is already describing the CPU parent clock.

Maxime

Maxime Ripard (2):
  ARM: topology: Use a clock if possible to get the CPU frequency
  ARM: sunxi: Add clocks node to the CPU nodes

 arch/arm/boot/dts/sun6i-a31.dtsi |  4 ++++
 arch/arm/boot/dts/sun7i-a20.dtsi |  2 ++
 arch/arm/kernel/topology.c       | 24 +++++++++++++++++-------
 3 files changed, 23 insertions(+), 7 deletions(-)

-- 
1.9.3

[PATCH 1/2] ARM: topology: Use a clock if possible to get the CPU frequency

[Maxime Ripard]

The Cortex-A7 and Cortex-A15 based SoCs need a clock-frequency property in the
topology code.

Allow to use a clock to provide the same information.

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 arch/arm/kernel/topology.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 0bc94b1fd1ae..2885993ccf53 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -11,6 +11,7 @@
  * for more details.
  */
 
+#include <linux/clk.h>
 #include <linux/cpu.h>
 #include <linux/cpumask.h>
 #include <linux/export.h>
@@ -100,8 +101,8 @@ static void __init parse_dt_topology(void)
 	__cpu_capacity = kzalloc(alloc_size, GFP_NOWAIT);
 
 	for_each_possible_cpu(cpu) {
-		const u32 *rate;
-		int len;
+		struct clk *clk;
+		u32 rate = 0;
 
 		/* too early to use cpu->of_node */
 		cn = of_get_cpu_node(cpu, NULL);
@@ -117,14 +118,23 @@ static void __init parse_dt_topology(void)
 		if (cpu_eff->compatible == NULL)
 			continue;
 
-		rate = of_get_property(cn, "clock-frequency", &len);
-		if (!rate || len != 4) {
-			pr_err("%s missing clock-frequency property\n",
-				cn->full_name);
+		clk = of_clk_get(cn, 0);
+		if (!IS_ERR(clk)) {
+			rate = clk_get_rate(clk);
+		} else {
+			if (of_property_read_u32(cn, "clock-frequency", &rate)) {
+				pr_err("%s missing clocks or clock-frequency properties\n",
+				       cn->full_name);
+				continue;
+			}
+		}
+
+		if (!rate) {
+			pr_err("%s invalid CPU frequency", cn->full_name);
 			continue;
 		}
 
-		capacity = ((be32_to_cpup(rate)) >> 20) * cpu_eff->efficiency;
+		capacity = ((rate) >> 20) * cpu_eff->efficiency;
 
 		/* Save min capacity of the system */
 		if (capacity < min_capacity)
-- 
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH 2/2] ARM: sunxi: Add clocks node to the CPU nodes

[Maxime Ripard]

Setting the clock will make the topology code work, and will remove the
following error at boot

[    0.097194] /cpus/cpu@0 missing clock-frequency property
[    0.103657] /cpus/cpu@1 missing clock-frequency property
[    0.110698] /cpus/cpu@2 missing clock-frequency property
[    0.117132] /cpus/cpu@3 missing clock-frequency property

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 arch/arm/boot/dts/sun6i-a31.dtsi | 4 ++++
 arch/arm/boot/dts/sun7i-a20.dtsi | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
index 4155fc43ecff..6814a1c4759b 100644
--- a/arch/arm/boot/dts/sun6i-a31.dtsi
+++ b/arch/arm/boot/dts/sun6i-a31.dtsi
@@ -34,24 +34,28 @@
 		cpu@0 {
 			compatible = "arm,cortex-a7";
 			device_type = "cpu";
+			clocks = <&cpu>;
 			reg = <0>;
 		};
 
 		cpu@1 {
 			compatible = "arm,cortex-a7";
 			device_type = "cpu";
+			clocks = <&cpu>;
 			reg = <1>;
 		};
 
 		cpu@2 {
 			compatible = "arm,cortex-a7";
 			device_type = "cpu";
+			clocks = <&cpu>;
 			reg = <2>;
 		};
 
 		cpu@3 {
 			compatible = "arm,cortex-a7";
 			device_type = "cpu";
+			clocks = <&cpu>;
 			reg = <3>;
 		};
 	};
diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
index 385933bac114..8402f33158bf 100644
--- a/arch/arm/boot/dts/sun7i-a20.dtsi
+++ b/arch/arm/boot/dts/sun7i-a20.dtsi
@@ -35,12 +35,14 @@
 		cpu@0 {
 			compatible = "arm,cortex-a7";
 			device_type = "cpu";
+			clocks = <&cpu>;
 			reg = <0>;
 		};
 
 		cpu@1 {
 			compatible = "arm,cortex-a7";
 			device_type = "cpu";
+			clocks = <&cpu>;
 			reg = <1>;
 		};
 	};
-- 
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 0/2] ARM: topology: Allow to set the frequency through a clock

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 502 bytes --]

On Wed, May 21, 2014 at 09:33:14PM +0200, Maxime Ripard wrote:
> Hi,
> 
> This patch series add the possibility for the topology code to get the
> CPU frequency through a DT clock handle instead of needing a
> clock-frequency property.
> 
> Indeed, this information can be quite redundant if the clock tree
> defined in the DT is already describing the CPU parent clock.

Ping?

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]