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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>
Subject: [PATCH 09/14] cpufreq: cpu0: Move per-cluster initialization code to ->init()
Date: Tue,  1 Jul 2014 22:02:38 +0530	[thread overview]
Message-ID: <b26946cc4573904cd1ef0212ad053a983b547c23.1404231535.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>

Currently this driver only support platforms on which all CPUs share clock &
voltage lines and there is requirement to support platforms which have separate
clock & voltage lines for CPUs, like Qualcomm's Krait and ARM's big LITTLE.

Each group of CPUs sharing clock/voltage lines are represented by 'struct
cpufreq_policy' in cpufreq framework. And core calls ->init() once for each
policy.

Currently we do all initialization/allocation from probe() which wouldn't work
for above scenario. To make it work for these platforms, the first step is to
move all initialization/allocation to ->init() and add ->exit() to do the
reverse of it.

Also, remove all global variables and allocate space for them at runtime.

This patch creates 'struct private_data' for keeping all such information and
a pointer to that would be stored in policy->driver_data.

The changed probe() routine now tries to see if regulator/clocks are available
or we need to defer probe. In case they are available, it registers cpufreq
driver. Otherwise, returns with -EPROBE_DEFER.

We still *don't* support platforms with separate clock/voltage lines for CPUs.
This would be done in a separate patch.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/cpufreq-cpu0.c | 189 +++++++++++++++++++++++++++++------------
 1 file changed, 136 insertions(+), 53 deletions(-)

diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
index 2b7b0ea..15b8e7a 100644
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ b/drivers/cpufreq/cpufreq-cpu0.c
@@ -28,18 +28,21 @@
 #include <linux/slab.h>
 #include <linux/thermal.h>
 
-static unsigned int transition_latency;
-static unsigned int voltage_tolerance; /* in percentage */
-
-static struct device *cpu_dev;
-static struct clk *cpu_clk;
-static struct regulator *cpu_reg;
-static struct cpufreq_frequency_table *freq_table;
-static struct thermal_cooling_device *cdev;
+struct private_data {
+	struct device *cpu_dev;
+	struct regulator *cpu_reg;
+	struct thermal_cooling_device *cdev;
+	unsigned int voltage_tolerance; /* in percentage */
+};
 
 static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index)
 {
 	struct dev_pm_opp *opp;
+	struct cpufreq_frequency_table *freq_table = policy->freq_table;
+	struct clk *cpu_clk = policy->clk;
+	struct private_data *priv = policy->driver_data;
+	struct device *cpu_dev = priv->cpu_dev;
+	struct regulator *cpu_reg = priv->cpu_reg;
 	unsigned long volt = 0, volt_old = 0, tol = 0;
 	unsigned int old_freq, new_freq;
 	long freq_Hz, freq_exact;
@@ -64,7 +67,7 @@ static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index)
 		}
 		volt = dev_pm_opp_get_voltage(opp);
 		rcu_read_unlock();
-		tol = volt * voltage_tolerance / 100;
+		tol = volt * priv->voltage_tolerance / 100;
 		volt_old = regulator_get_voltage(cpu_reg);
 	}
 
@@ -103,26 +106,13 @@ static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index)
 	return ret;
 }
 
-static int cpu0_cpufreq_init(struct cpufreq_policy *policy)
-{
-	policy->clk = cpu_clk;
-	return cpufreq_generic_init(policy, freq_table, transition_latency);
-}
-
-static struct cpufreq_driver cpu0_cpufreq_driver = {
-	.flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
-	.verify = cpufreq_generic_frequency_table_verify,
-	.target_index = cpu0_set_target,
-	.get = cpufreq_generic_get,
-	.init = cpu0_cpufreq_init,
-	.name = "generic_cpu0",
-	.attr = cpufreq_generic_attr,
-};
-
-static int cpu0_cpufreq_probe(struct platform_device *pdev)
+static int allocate_resources(struct device **cdev,
+			      struct regulator **creg, struct clk **cclk)
 {
-	struct device_node *np;
-	int ret;
+	struct device *cpu_dev;
+	struct regulator *cpu_reg;
+	struct clk *cpu_clk;
+	int ret = 0;
 
 	cpu_dev = get_cpu_device(0);
 	if (!cpu_dev) {
@@ -130,12 +120,6 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	np = of_node_get(cpu_dev->of_node);
-	if (!np) {
-		dev_err(cpu_dev, "failed to find cpu0 node\n");
-		return -ENOENT;
-	}
-
 	cpu_reg = regulator_get_optional(cpu_dev, "cpu0");
 	if (IS_ERR(cpu_reg)) {
 		/*
@@ -144,8 +128,7 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 		 */
 		if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) {
 			dev_err(cpu_dev, "cpu0 regulator not ready, retry\n");
-			ret = -EPROBE_DEFER;
-			goto out_put_node;
+			return -EPROBE_DEFER;
 		}
 		dev_warn(cpu_dev, "failed to get cpu0 regulator: %ld\n",
 			 PTR_ERR(cpu_reg));
@@ -153,6 +136,10 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 
 	cpu_clk = clk_get(cpu_dev, NULL);
 	if (IS_ERR(cpu_clk)) {
+		/* put regulator */
+		if (!IS_ERR(cpu_reg))
+			regulator_put(cpu_reg);
+
 		/*
 		 * If cpu's clk node is present, but clock is not yet
 		 * registered, we should try defering probe.
@@ -164,7 +151,39 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 			ret = PTR_ERR(cpu_clk);
 			dev_err(cpu_dev, "failed to get cpu0 clock: %d\n", ret);
 		}
-		goto out_put_reg;
+	} else {
+		*cdev = cpu_dev;
+		*creg = cpu_reg;
+		*cclk = cpu_clk;
+	}
+
+	return ret;
+}
+
+static int cpu0_cpufreq_init(struct cpufreq_policy *policy)
+{
+	struct cpufreq_frequency_table *freq_table;
+	struct thermal_cooling_device *cdev;
+	struct device_node *np;
+	struct private_data *priv;
+	struct device *cpu_dev;
+	struct regulator *cpu_reg;
+	struct clk *cpu_clk;
+	unsigned int transition_latency;
+	int ret;
+
+	/* We only support cpu0 currently */
+	ret = allocate_resources(&cpu_dev, &cpu_reg, &cpu_clk);
+	if (ret) {
+		pr_err("%s: Failed to allocate resources\n: %d", __func__, ret);
+		return ret;
+	}
+
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		dev_err(cpu_dev, "failed to find cpu%d node\n", policy->cpu);
+		ret = -ENOENT;
+		goto out_put_reg_clk;
 	}
 
 	/* OPPs might be populated at runtime, don't check for error here */
@@ -173,10 +192,16 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
 	if (ret) {
 		dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
-		goto out_put_clk;
+		goto out_put_node;
+	}
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		ret = -ENOMEM;
+		goto out_free_table;
 	}
 
-	of_property_read_u32(np, "voltage-tolerance", &voltage_tolerance);
+	of_property_read_u32(np, "voltage-tolerance", &priv->voltage_tolerance);
 
 	if (of_property_read_u32(np, "clock-latency", &transition_latency))
 		transition_latency = CPUFREQ_ETERNAL;
@@ -206,12 +231,6 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 			transition_latency += ret * 1000;
 	}
 
-	ret = cpufreq_register_driver(&cpu0_cpufreq_driver);
-	if (ret) {
-		dev_err(cpu_dev, "failed to register driver: %d\n", ret);
-		goto out_free_table;
-	}
-
 	/*
 	 * For now, just loading the cooling device;
 	 * thermal DT code takes care of matching them.
@@ -223,28 +242,92 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 				"running cpufreq without cooling device: %ld\n",
 				PTR_ERR(cdev));
 	}
-
 	of_node_put(np);
+
+	priv->cdev = cdev;
+	priv->cpu_dev = cpu_dev;
+	priv->cpu_reg = cpu_reg;
+	policy->driver_data = priv;
+
+	policy->clk = cpu_clk;
+	ret = cpufreq_generic_init(policy, freq_table, transition_latency);
+	if (ret)
+		goto out_cooling_unregister;
+
 	return 0;
 
+out_cooling_unregister:
+	cpufreq_cooling_unregister(priv->cdev);
+	kfree(priv);
 out_free_table:
 	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
-out_put_clk:
+out_put_node:
+	of_node_put(np);
+out_put_reg_clk:
 	clk_put(cpu_clk);
-out_put_reg:
 	if (!IS_ERR(cpu_reg))
 		regulator_put(cpu_reg);
-out_put_node:
-	of_node_put(np);
+
+	return ret;
+}
+
+static int cpu0_cpufreq_exit(struct cpufreq_policy *policy)
+{
+	struct private_data *priv = policy->driver_data;
+
+	cpufreq_cooling_unregister(priv->cdev);
+	dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
+	clk_put(policy->clk);
+	if (!IS_ERR(priv->cpu_reg))
+		regulator_put(priv->cpu_reg);
+	kfree(priv);
+
+	return 0;
+}
+
+static struct cpufreq_driver cpu0_cpufreq_driver = {
+	.flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+	.verify = cpufreq_generic_frequency_table_verify,
+	.target_index = cpu0_set_target,
+	.get = cpufreq_generic_get,
+	.init = cpu0_cpufreq_init,
+	.exit = cpu0_cpufreq_exit,
+	.name = "generic_cpu0",
+	.attr = cpufreq_generic_attr,
+};
+
+static int cpu0_cpufreq_probe(struct platform_device *pdev)
+{
+	struct device *cpu_dev;
+	struct regulator *cpu_reg;
+	struct clk *cpu_clk;
+	int ret;
+
+	/*
+	 * All per-cluster (CPUs sharing clock/voltages) initialization is done
+	 * from ->init(). In probe(), we just need to make sure that clk and
+	 * regulators are available. Else defer probe and retry.
+	 *
+	 * FIXME: Is checking this only for CPU0 sufficient ?
+	 */
+	ret = allocate_resources(&cpu_dev, &cpu_reg, &cpu_clk);
+	if (ret)
+		return ret;
+
+	clk_put(cpu_clk);
+	if (!IS_ERR(cpu_reg))
+		regulator_put(cpu_reg);
+
+	ret = cpufreq_register_driver(&cpu0_cpufreq_driver);
+	if (ret)
+		dev_err(cpu_dev, "failed register driver: %d\n", ret);
+
 	return ret;
 }
 
 static int cpu0_cpufreq_remove(struct platform_device *pdev)
 {
-	cpufreq_cooling_unregister(cdev);
 	cpufreq_unregister_driver(&cpu0_cpufreq_driver);
-	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
-
 	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 ` Viresh Kumar [this message]
2014-07-03  0:43   ` [PATCH 09/14] cpufreq: cpu0: Move per-cluster initialization code to ->init() 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 ` [PATCH 12/14] cpufreq: cpu0: Extend support beyond CPU0 Viresh Kumar
2014-07-02  4:03   ` [PATCH V2 Resend " 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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