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From: Viresh Kumar <viresh.kumar@linaro.org>
To: rjw@rjwysocki.net, shawn.guo@linaro.org
Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org, arvind.chauhan@arm.com,
	sboyd@codeaurora.org, linux-arm-msm@vger.kernel.org,
	spk.linux@gmail.com, thomas.ab@samsung.com, nm@ti.com,
	t.figa@samsung.com, Viresh Kumar <viresh.kumar@linaro.org>,
	devicetree@vger.kernel.org
Subject: [PATCH 12/14] cpufreq: cpu0: Extend support beyond CPU0
Date: Tue,  1 Jul 2014 22:02:41 +0530	[thread overview]
Message-ID: <89da404a3b8f545774f5782d901b8381caf02c07.1404231535.git.viresh.kumar@linaro.org> (raw)
In-Reply-To: <cover.1404231535.git.viresh.kumar@linaro.org>
In-Reply-To: <cover.1404231535.git.viresh.kumar@linaro.org>

Most of the infrastructure is in place now, with only little left. How to find
siblings ?

Stephen Boyd suggested to compare "clocks" properties from CPU's DT node and
siblings should match. This patch adds another routine find_siblings() which
calls of_clk_shared_by_cpus() to find if CPUs share clock line or not.

If of_clk_shared_by_cpus() returns error, we fallback to all CPUs sharing clock
line assumption as existing platforms don't have "clocks" property in all CPU
nodes and would fail from of_clk_shared_by_cpus().

Cc: devicetree@vger.kernel.org
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 .../devicetree/bindings/cpufreq/cpufreq-cpu0.txt   | 72 ++++++++++++++++++++--
 drivers/cpufreq/cpufreq-cpu0.c                     | 35 ++++++++++-
 2 files changed, 101 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
index f055515..4b83c1a 100644
--- a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
@@ -1,11 +1,11 @@
-Generic CPU0 cpufreq driver
+Generic cpufreq driver
 
-It is a generic cpufreq driver for CPU0 frequency management.  It
+It is a generic cpufreq driver for frequency management.  It
 supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
-systems which share clock and voltage across all CPUs.
+systems which may or maynot share clock and voltage across all CPUs.
 
 Both required and optional properties listed below must be defined
-under node /cpus/cpu@0.
+under node /cpus/cpu@x. Where x is the first cpu inside a cluster.
 
 Required properties:
 - operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt
@@ -19,9 +19,16 @@ Optional properties:
 - cooling-min-level:
 - cooling-max-level:
      Please refer to Documentation/devicetree/bindings/thermal/thermal.txt.
+- clocks: If CPU clock is populated from DT, "clocks" property must be copied to
+  every cpu node sharing clock with cpu@x. Generic cpufreq driver compares
+  "clocks" to find siblings, i.e. to see which CPUs share clock/voltages. If
+  only cpu@0 contains "clocks" property it is assumed that all CPUs share clock
+  line.
 
 Examples:
 
+1. All CPUs share clock/voltages
+
 cpus {
 	#address-cells = <1>;
 	#size-cells = <0>;
@@ -36,6 +43,8 @@ cpus {
 			396000  950000
 			198000  850000
 		>;
+		clocks = <&clock CLK_ARM_CLK>;
+		clock-names = "cpu";
 		clock-latency = <61036>; /* two CLK32 periods */
 		#cooling-cells = <2>;
 		cooling-min-level = <0>;
@@ -46,17 +55,72 @@ cpus {
 		compatible = "arm,cortex-a9";
 		reg = <1>;
 		next-level-cache = <&L2>;
+		clocks = <&clock CLK_ARM_CLK>;
 	};
 
 	cpu@2 {
 		compatible = "arm,cortex-a9";
 		reg = <2>;
 		next-level-cache = <&L2>;
+		clocks = <&clock CLK_ARM_CLK>;
 	};
 
 	cpu@3 {
 		compatible = "arm,cortex-a9";
 		reg = <3>;
 		next-level-cache = <&L2>;
+		clocks = <&clock CLK_ARM_CLK>;
+	};
+};
+
+
+2. All CPUs inside a cluster share clock/voltages, there are multiple clusters.
+
+cpus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	cpu@0 {
+		compatible = "arm,cortex-a15";
+		reg = <0>;
+		next-level-cache = <&L2>;
+		operating-points = <
+			/* kHz    uV */
+			792000  1100000
+			396000  950000
+			198000  850000
+		>;
+		clocks = <&clock CLK_ARM1_CLK>;
+		clock-names = "cpu";
+		clock-latency = <61036>; /* two CLK32 periods */
+	};
+
+	cpu@1 {
+		compatible = "arm,cortex-a15";
+		reg = <1>;
+		next-level-cache = <&L2>;
+		clocks = <&clock CLK_ARM1_CLK>;
+	};
+
+	cpu@100 {
+		compatible = "arm,cortex-a7";
+		reg = <100>;
+		next-level-cache = <&L2>;
+		operating-points = <
+			/* kHz    uV */
+			792000  950000
+			396000  750000
+			198000  450000
+		>;
+		clocks = <&clock CLK_ARM2_CLK>;
+		clock-names = "cpu";
+		clock-latency = <61036>; /* two CLK32 periods */
+	};
+
+	cpu@101 {
+		compatible = "arm,cortex-a7";
+		reg = <101>;
+		next-level-cache = <&L2>;
+		clocks = <&clock CLK_ARM2_CLK>;
 	};
 };
diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
index 44633f6..b3f2bf0 100644
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ b/drivers/cpufreq/cpufreq-cpu0.c
@@ -177,6 +177,30 @@ try_again:
 	return ret;
 }
 
+/*
+ * Sets all CPUs as sibling if any cpu doesn't have a "clocks" property,
+ * Otherwise it matches "clocks" property to find siblings.
+ */
+static void find_siblings(struct cpufreq_policy *policy)
+{
+	int cpu, ret;
+
+	for_each_possible_cpu(cpu) {
+		if (cpu == policy->cpu)
+			continue;
+
+		ret = of_clk_shared_by_cpus(policy->cpu, cpu);
+
+		/* Error while parsing nodes, fallback to set-all */
+		if (ret < 0) {
+			cpumask_setall(policy->cpus);
+			return;
+		} else if (ret == 1) {
+			cpumask_set_cpu(cpu, policy->cpus);
+		}
+	}
+}
+
 static int cpu0_cpufreq_init(struct cpufreq_policy *policy)
 {
 	struct cpufreq_frequency_table *freq_table;
@@ -266,9 +290,16 @@ static int cpu0_cpufreq_init(struct cpufreq_policy *policy)
 	policy->driver_data = priv;
 
 	policy->clk = cpu_clk;
-	ret = cpufreq_generic_init(policy, freq_table, transition_latency);
-	if (ret)
+
+	find_siblings(policy);
+	ret = cpufreq_table_validate_and_show(policy, freq_table);
+	if (ret) {
+		dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__,
+			ret);
 		goto out_cooling_unregister;
+	}
+
+	policy->cpuinfo.transition_latency = transition_latency;
 
 	return 0;
 
-- 
2.0.0.rc2

  parent reply	other threads:[~2014-07-01 16:32 UTC|newest]

Thread overview: 83+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-01 16:32 [PATCH 00/14] cpufreq: cpu0: Extend support beyond CPU0, V2 Viresh Kumar
2014-07-01 16:32 ` [PATCH 01/14] of: Create of_property_match() Viresh Kumar
2014-07-01 16:32 ` [PATCH 02/14] clk: Create of_clk_shared_by_cpus() Viresh Kumar
2014-07-01 18:00   ` Stephen Boyd
2014-07-02  1:57     ` Viresh Kumar
2014-07-09 14:38   ` Santosh Shilimkar
2014-07-09 14:38     ` Santosh Shilimkar
2014-07-09 15:20     ` Viresh Kumar
     [not found]   ` <5f7164d789e87c62d722b575980c92dfd0504334.1404231535.git.viresh.kumar@linar o.org>
2014-07-28 14:01     ` Grant Likely
2014-07-28 14:01       ` Grant Likely
2014-07-01 16:32 ` [PATCH 03/14] cpufreq: Add support for per-policy driver data Viresh Kumar
2014-07-09 14:33   ` Santosh Shilimkar
2014-07-09 14:33     ` Santosh Shilimkar
2014-07-09 15:07     ` Viresh Kumar
2014-07-01 16:32 ` [PATCH 04/14] cpufreq: cpu0: Add Module Author Viresh Kumar
2014-07-09 14:42   ` Santosh Shilimkar
2014-07-09 14:42     ` Santosh Shilimkar
2014-07-09 15:08     ` Viresh Kumar
2014-07-09 15:24       ` Santosh Shilimkar
2014-07-01 16:32 ` [PATCH 05/14] cpufreq: cpu0: don't validate clock on clk_put() Viresh Kumar
2014-07-09 14:42   ` Santosh Shilimkar
2014-07-09 14:42     ` Santosh Shilimkar
2014-07-01 16:32 ` [PATCH 06/14] cpufreq: cpu0: defer probe if clock isn't registered yet Viresh Kumar
2014-07-02  5:53   ` Shawn Guo
2014-07-02  5:53     ` Shawn Guo
2014-07-02  5:55     ` Viresh Kumar
2014-07-02 11:32       ` Viresh Kumar
2014-07-03  0:38         ` Stephen Boyd
2014-07-03  2:19           ` Viresh Kumar
2014-07-09 14:43             ` Santosh Shilimkar
2014-07-09 14:43               ` Santosh Shilimkar
2014-07-01 16:32 ` [PATCH 07/14] cpufreq: cpu0: OPPs can be populated at runtime Viresh Kumar
2014-07-01 18:02   ` Stephen Boyd
2014-07-02  2:03     ` Viresh Kumar
2014-07-02  4:03   ` [PATCH V2 Resend " Viresh Kumar
2014-07-09 14:44   ` [PATCH " Santosh Shilimkar
2014-07-09 14:44     ` Santosh Shilimkar
2014-07-09 15:09     ` Viresh Kumar
2014-07-10 11:19     ` Viresh Kumar
2014-07-10 12:39       ` Nishanth Menon
2014-07-10 13:31         ` Santosh Shilimkar
2014-07-10 13:36           ` Viresh Kumar
2014-07-01 16:32 ` [PATCH 08/14] cpufreq: cpu0: use dev_{err|warn|dbg} instead of pr_{err|warn|debug} Viresh Kumar
2014-07-09 14:45   ` Santosh Shilimkar
2014-07-09 14:45     ` Santosh Shilimkar
2014-07-01 16:32 ` [PATCH 09/14] cpufreq: cpu0: Move per-cluster initialization code to ->init() Viresh Kumar
2014-07-03  0:43   ` Stephen Boyd
2014-07-03  2:11     ` Viresh Kumar
2014-07-09 14:53   ` Santosh Shilimkar
2014-07-09 14:53     ` Santosh Shilimkar
2014-07-09 15:17     ` Viresh Kumar
2014-07-09 15:26       ` Santosh Shilimkar
2014-07-09 15:27         ` Viresh Kumar
2014-07-09 15:29           ` Santosh Shilimkar
2014-07-09 15:33             ` Viresh Kumar
2014-07-01 16:32 ` [PATCH 10/14] cpufreq: cpu0: try regulators with name "cpu-supply" Viresh Kumar
2014-07-01 16:32 ` [PATCH 11/14] cpufreq: cpu0: Make allocate_resources() work for any CPU Viresh Kumar
2014-07-01 16:32 ` Viresh Kumar [this message]
2014-07-02  4:03   ` [PATCH V2 Resend 12/14] cpufreq: cpu0: Extend support beyond CPU0 Viresh Kumar
2014-07-01 16:32 ` [PATCH 13/14] cpufreq: cpu0: rename driver and internals to 'cpufreq_generic' Viresh Kumar
2014-07-01 16:32 ` [PATCH 14/14] cpufreq: generic: set platform_{driver|device} '.name' to 'cpufreq-generic' Viresh Kumar
2014-07-02  4:12 ` [PATCH 00/14] cpufreq: cpu0: Extend support beyond CPU0, V2 Viresh Kumar
2014-07-03  1:24   ` Stephen Boyd
2014-07-03  2:44     ` Viresh Kumar
2014-07-03 22:16       ` Mike Turquette
2014-07-04  4:21         ` Viresh Kumar
2014-07-08  4:50           ` Viresh Kumar
2014-07-09 17:41             ` Stephen Boyd
2014-07-16 16:01             ` Viresh Kumar
2014-07-16 17:28               ` Thomas Petazzoni
2014-07-16 21:17                 ` Rafael J. Wysocki
2014-07-16 21:18               ` Rafael J. Wysocki
2014-07-17  0:28                 ` Viresh Kumar
2014-07-17  7:35                   ` Thomas Petazzoni
2014-07-17  7:41                     ` Viresh Kumar
2014-07-18  1:02                       ` Rafael J. Wysocki
2014-07-18  4:17                         ` Viresh Kumar
     [not found]                           ` <CAKohpomKzK8pMJs1gv+uXxhd17HtCQyfjSnVYw9KpGz6FwbgDA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-07-24 10:48                             ` Viresh Kumar
2014-07-24 10:48                               ` Viresh Kumar
2014-07-25 14:29                               ` Rob Herring
     [not found]                                 ` <CAL_JsqKqCeU0zs+rS1vxsOeh=Kuw_-gaVHtGU76Lb6TchCTytw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-07-25 14:34                                   ` Viresh Kumar
2014-07-25 14:34                                     ` Viresh Kumar
2014-07-25 15:41                                 ` Thomas Petazzoni

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