Merge back cpufreq material for v3.18.

13 files changed, 425 insertions, 266 deletions

diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index ffe350f86bca..3489f8f5fada 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -183,14 +183,14 @@ config CPU_FREQ_GOV_CONSERVATIVE
 
 	  If in doubt, say N.
 
-config GENERIC_CPUFREQ_CPU0
-	tristate "Generic CPU0 cpufreq driver"
+config CPUFREQ_DT
+	tristate "Generic DT based cpufreq driver"
 	depends on HAVE_CLK && OF
-	# if CPU_THERMAL is on and THERMAL=m, CPU0 cannot be =y:
+	# if CPU_THERMAL is on and THERMAL=m, CPUFREQ_DT cannot be =y:
 	depends on !CPU_THERMAL || THERMAL
 	select PM_OPP
 	help
-	  This adds a generic cpufreq driver for CPU0 frequency management.
+	  This adds a generic DT based cpufreq driver for frequency management.
 	  It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
 	  systems which share clock and voltage across all CPUs.
 
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 7364a538e056..48ed28b789f7 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -92,7 +92,7 @@ config ARM_EXYNOS_CPU_FREQ_BOOST_SW
 
 config ARM_HIGHBANK_CPUFREQ
 	tristate "Calxeda Highbank-based"
-	depends on ARCH_HIGHBANK && GENERIC_CPUFREQ_CPU0 && REGULATOR
+	depends on ARCH_HIGHBANK && CPUFREQ_DT && REGULATOR
 	default m
 	help
 	  This adds the CPUFreq driver for Calxeda Highbank SoC
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index db6d9a2fea4d..40c53dc1937e 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -13,7 +13,7 @@ obj-$(CONFIG_CPU_FREQ_GOV_ONDEMAND)	+= cpufreq_ondemand.o
 obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE)	+= cpufreq_conservative.o
 obj-$(CONFIG_CPU_FREQ_GOV_COMMON)		+= cpufreq_governor.o
 
-obj-$(CONFIG_GENERIC_CPUFREQ_CPU0)	+= cpufreq-cpu0.o
+obj-$(CONFIG_CPUFREQ_DT)		+= cpufreq-dt.o
 
 ##################################################################################
 # x86 drivers.
diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
deleted file mode 100644
index 0d2172b07765..000000000000
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ /dev/null
@@ -1,248 +0,0 @@
-/*
- * Copyright (C) 2012 Freescale Semiconductor, Inc.
- *
- * The OPP code in function cpu0_set_target() is reused from
- * drivers/cpufreq/omap-cpufreq.c
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
-
-#include <linux/clk.h>
-#include <linux/cpu.h>
-#include <linux/cpu_cooling.h>
-#include <linux/cpufreq.h>
-#include <linux/cpumask.h>
-#include <linux/err.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/pm_opp.h>
-#include <linux/platform_device.h>
-#include <linux/regulator/consumer.h>
-#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;
-
-static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index)
-{
-	struct dev_pm_opp *opp;
-	unsigned long volt = 0, volt_old = 0, tol = 0;
-	unsigned int old_freq, new_freq;
-	long freq_Hz, freq_exact;
-	int ret;
-
-	freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000);
-	if (freq_Hz <= 0)
-		freq_Hz = freq_table[index].frequency * 1000;
-
-	freq_exact = freq_Hz;
-	new_freq = freq_Hz / 1000;
-	old_freq = clk_get_rate(cpu_clk) / 1000;
-
-	if (!IS_ERR(cpu_reg)) {
-		rcu_read_lock();
-		opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz);
-		if (IS_ERR(opp)) {
-			rcu_read_unlock();
-			pr_err("failed to find OPP for %ld\n", freq_Hz);
-			return PTR_ERR(opp);
-		}
-		volt = dev_pm_opp_get_voltage(opp);
-		rcu_read_unlock();
-		tol = volt * voltage_tolerance / 100;
-		volt_old = regulator_get_voltage(cpu_reg);
-	}
-
-	pr_debug("%u MHz, %ld mV --> %u MHz, %ld mV\n",
-		 old_freq / 1000, volt_old ? volt_old / 1000 : -1,
-		 new_freq / 1000, volt ? volt / 1000 : -1);
-
-	/* scaling up?  scale voltage before frequency */
-	if (!IS_ERR(cpu_reg) && new_freq > old_freq) {
-		ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
-		if (ret) {
-			pr_err("failed to scale voltage up: %d\n", ret);
-			return ret;
-		}
-	}
-
-	ret = clk_set_rate(cpu_clk, freq_exact);
-	if (ret) {
-		pr_err("failed to set clock rate: %d\n", ret);
-		if (!IS_ERR(cpu_reg))
-			regulator_set_voltage_tol(cpu_reg, volt_old, tol);
-		return ret;
-	}
-
-	/* scaling down?  scale voltage after frequency */
-	if (!IS_ERR(cpu_reg) && new_freq < old_freq) {
-		ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
-		if (ret) {
-			pr_err("failed to scale voltage down: %d\n", ret);
-			clk_set_rate(cpu_clk, old_freq * 1000);
-		}
-	}
-
-	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)
-{
-	struct device_node *np;
-	int ret;
-
-	cpu_dev = get_cpu_device(0);
-	if (!cpu_dev) {
-		pr_err("failed to get cpu0 device\n");
-		return -ENODEV;
-	}
-
-	np = of_node_get(cpu_dev->of_node);
-	if (!np) {
-		pr_err("failed to find cpu0 node\n");
-		return -ENOENT;
-	}
-
-	cpu_reg = regulator_get_optional(cpu_dev, "cpu0");
-	if (IS_ERR(cpu_reg)) {
-		/*
-		 * If cpu0 regulator supply node is present, but regulator is
-		 * not yet registered, we should try defering probe.
-		 */
-		if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) {
-			dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n");
-			ret = -EPROBE_DEFER;
-			goto out_put_node;
-		}
-		pr_warn("failed to get cpu0 regulator: %ld\n",
-			PTR_ERR(cpu_reg));
-	}
-
-	cpu_clk = clk_get(cpu_dev, NULL);
-	if (IS_ERR(cpu_clk)) {
-		ret = PTR_ERR(cpu_clk);
-		pr_err("failed to get cpu0 clock: %d\n", ret);
-		goto out_put_reg;
-	}
-
-	/* OPPs might be populated at runtime, don't check for error here */
-	of_init_opp_table(cpu_dev);
-
-	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
-	if (ret) {
-		pr_err("failed to init cpufreq table: %d\n", ret);
-		goto out_put_clk;
-	}
-
-	of_property_read_u32(np, "voltage-tolerance", &voltage_tolerance);
-
-	if (of_property_read_u32(np, "clock-latency", &transition_latency))
-		transition_latency = CPUFREQ_ETERNAL;
-
-	if (!IS_ERR(cpu_reg)) {
-		struct dev_pm_opp *opp;
-		unsigned long min_uV, max_uV;
-		int i;
-
-		/*
-		 * OPP is maintained in order of increasing frequency, and
-		 * freq_table initialised from OPP is therefore sorted in the
-		 * same order.
-		 */
-		for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
-			;
-		rcu_read_lock();
-		opp = dev_pm_opp_find_freq_exact(cpu_dev,
-				freq_table[0].frequency * 1000, true);
-		min_uV = dev_pm_opp_get_voltage(opp);
-		opp = dev_pm_opp_find_freq_exact(cpu_dev,
-				freq_table[i-1].frequency * 1000, true);
-		max_uV = dev_pm_opp_get_voltage(opp);
-		rcu_read_unlock();
-		ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV);
-		if (ret > 0)
-			transition_latency += ret * 1000;
-	}
-
-	ret = cpufreq_register_driver(&cpu0_cpufreq_driver);
-	if (ret) {
-		pr_err("failed register driver: %d\n", ret);
-		goto out_free_table;
-	}
-
-	/*
-	 * For now, just loading the cooling device;
-	 * thermal DT code takes care of matching them.
-	 */
-	if (of_find_property(np, "#cooling-cells", NULL)) {
-		cdev = of_cpufreq_cooling_register(np, cpu_present_mask);
-		if (IS_ERR(cdev))
-			pr_err("running cpufreq without cooling device: %ld\n",
-			       PTR_ERR(cdev));
-	}
-
-	of_node_put(np);
-	return 0;
-
-out_free_table:
-	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
-out_put_clk:
-	if (!IS_ERR(cpu_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_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;
-}
-
-static struct platform_driver cpu0_cpufreq_platdrv = {
-	.driver = {
-		.name	= "cpufreq-cpu0",
-		.owner	= THIS_MODULE,
-	},
-	.probe		= cpu0_cpufreq_probe,
-	.remove		= cpu0_cpufreq_remove,
-};
-module_platform_driver(cpu0_cpufreq_platdrv);
-
-MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
-MODULE_DESCRIPTION("Generic CPU0 cpufreq driver");
-MODULE_LICENSE("GPL");
diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
new file mode 100644
index 000000000000..6bbb8b913446
--- /dev/null
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -0,0 +1,364 @@
+/*
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ *
+ * Copyright (C) 2014 Linaro.
+ * Viresh Kumar <viresh.kumar@linaro.org>
+ *
+ * The OPP code in function set_target() is reused from
+ * drivers/cpufreq/omap-cpufreq.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/clk.h>
+#include <linux/cpu.h>
+#include <linux/cpu_cooling.h>
+#include <linux/cpufreq.h>
+#include <linux/cpumask.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm_opp.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/thermal.h>
+
+struct private_data {
+	struct device *cpu_dev;
+	struct regulator *cpu_reg;
+	struct thermal_cooling_device *cdev;
+	unsigned int voltage_tolerance; /* in percentage */
+};
+
+static int 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;
+	int ret;
+
+	freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000);
+	if (freq_Hz <= 0)
+		freq_Hz = freq_table[index].frequency * 1000;
+
+	freq_exact = freq_Hz;
+	new_freq = freq_Hz / 1000;
+	old_freq = clk_get_rate(cpu_clk) / 1000;
+
+	if (!IS_ERR(cpu_reg)) {
+		rcu_read_lock();
+		opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz);
+		if (IS_ERR(opp)) {
+			rcu_read_unlock();
+			dev_err(cpu_dev, "failed to find OPP for %ld\n",
+				freq_Hz);
+			return PTR_ERR(opp);
+		}
+		volt = dev_pm_opp_get_voltage(opp);
+		rcu_read_unlock();
+		tol = volt * priv->voltage_tolerance / 100;
+		volt_old = regulator_get_voltage(cpu_reg);
+	}
+
+	dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n",
+		old_freq / 1000, volt_old ? volt_old / 1000 : -1,
+		new_freq / 1000, volt ? volt / 1000 : -1);
+
+	/* scaling up?  scale voltage before frequency */
+	if (!IS_ERR(cpu_reg) && new_freq > old_freq) {
+		ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
+		if (ret) {
+			dev_err(cpu_dev, "failed to scale voltage up: %d\n",
+				ret);
+			return ret;
+		}
+	}
+
+	ret = clk_set_rate(cpu_clk, freq_exact);
+	if (ret) {
+		dev_err(cpu_dev, "failed to set clock rate: %d\n", ret);
+		if (!IS_ERR(cpu_reg))
+			regulator_set_voltage_tol(cpu_reg, volt_old, tol);
+		return ret;
+	}
+
+	/* scaling down?  scale voltage after frequency */
+	if (!IS_ERR(cpu_reg) && new_freq < old_freq) {
+		ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
+		if (ret) {
+			dev_err(cpu_dev, "failed to scale voltage down: %d\n",
+				ret);
+			clk_set_rate(cpu_clk, old_freq * 1000);
+		}
+	}
+
+	return ret;
+}
+
+static int allocate_resources(int cpu, struct device **cdev,
+			      struct regulator **creg, struct clk **cclk)
+{
+	struct device *cpu_dev;
+	struct regulator *cpu_reg;
+	struct clk *cpu_clk;
+	int ret = 0;
+	char *reg_cpu0 = "cpu0", *reg_cpu = "cpu", *reg;
+
+	cpu_dev = get_cpu_device(cpu);
+	if (!cpu_dev) {
+		pr_err("failed to get cpu%d device\n", cpu);
+		return -ENODEV;
+	}
+
+	/* Try "cpu0" for older DTs */
+	if (!cpu)
+		reg = reg_cpu0;
+	else
+		reg = reg_cpu;
+
+try_again:
+	cpu_reg = regulator_get_optional(cpu_dev, reg);
+	if (IS_ERR(cpu_reg)) {
+		/*
+		 * If cpu's regulator supply node is present, but regulator is
+		 * not yet registered, we should try defering probe.
+		 */
+		if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) {
+			dev_dbg(cpu_dev, "cpu%d regulator not ready, retry\n",
+				cpu);
+			return -EPROBE_DEFER;
+		}
+
+		/* Try with "cpu-supply" */
+		if (reg == reg_cpu0) {
+			reg = reg_cpu;
+			goto try_again;
+		}
+
+		dev_warn(cpu_dev, "failed to get cpu%d regulator: %ld\n",
+			 cpu, PTR_ERR(cpu_reg));
+	}
+
+	cpu_clk = clk_get(cpu_dev, NULL);
+	if (IS_ERR(cpu_clk)) {
+		/* put regulator */
+		if (!IS_ERR(cpu_reg))
+			regulator_put(cpu_reg);
+
+		ret = PTR_ERR(cpu_clk);
+
+		/*
+		 * If cpu's clk node is present, but clock is not yet
+		 * registered, we should try defering probe.
+		 */
+		if (ret == -EPROBE_DEFER)
+			dev_dbg(cpu_dev, "cpu%d clock not ready, retry\n", cpu);
+		else
+			dev_err(cpu_dev, "failed to get cpu%d clock: %d\n", ret,
+				cpu);
+	} else {
+		*cdev = cpu_dev;
+		*creg = cpu_reg;
+		*cclk = cpu_clk;
+	}
+
+	return ret;
+}
+
+static int 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;
+
+	ret = allocate_resources(policy->cpu, &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 */
+	of_init_opp_table(cpu_dev);
+
+	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_node;
+	}
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		ret = -ENOMEM;
+		goto out_free_table;
+	}
+
+	of_property_read_u32(np, "voltage-tolerance", &priv->voltage_tolerance);
+
+	if (of_property_read_u32(np, "clock-latency", &transition_latency))
+		transition_latency = CPUFREQ_ETERNAL;
+
+	if (!IS_ERR(cpu_reg)) {
+		struct dev_pm_opp *opp;
+		unsigned long min_uV, max_uV;
+		int i;
+
+		/*
+		 * OPP is maintained in order of increasing frequency, and
+		 * freq_table initialised from OPP is therefore sorted in the
+		 * same order.
+		 */
+		for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
+			;
+		rcu_read_lock();
+		opp = dev_pm_opp_find_freq_exact(cpu_dev,
+				freq_table[0].frequency * 1000, true);
+		min_uV = dev_pm_opp_get_voltage(opp);
+		opp = dev_pm_opp_find_freq_exact(cpu_dev,
+				freq_table[i-1].frequency * 1000, true);
+		max_uV = dev_pm_opp_get_voltage(opp);
+		rcu_read_unlock();
+		ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV);
+		if (ret > 0)
+			transition_latency += ret * 1000;
+	}
+
+	/*
+	 * For now, just loading the cooling device;
+	 * thermal DT code takes care of matching them.
+	 */
+	if (of_find_property(np, "#cooling-cells", NULL)) {
+		cdev = of_cpufreq_cooling_register(np, cpu_present_mask);
+		if (IS_ERR(cdev))
+			dev_err(cpu_dev,
+				"running cpufreq without cooling device: %ld\n",
+				PTR_ERR(cdev));
+		else
+			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;
+
+	of_node_put(np);
+
+	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_node:
+	of_node_put(np);
+out_put_reg_clk:
+	clk_put(cpu_clk);
+	if (!IS_ERR(cpu_reg))
+		regulator_put(cpu_reg);
+
+	return ret;
+}
+
+static int 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 dt_cpufreq_driver = {
+	.flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+	.verify = cpufreq_generic_frequency_table_verify,
+	.target_index = set_target,
+	.get = cpufreq_generic_get,
+	.init = cpufreq_init,
+	.exit = cpufreq_exit,
+	.name = "cpufreq-dt",
+	.attr = cpufreq_generic_attr,
+};
+
+static int dt_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(0, &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(&dt_cpufreq_driver);
+	if (ret)
+		dev_err(cpu_dev, "failed register driver: %d\n", ret);
+
+	return ret;
+}
+
+static int dt_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_driver(&dt_cpufreq_driver);
+	return 0;
+}
+
+static struct platform_driver dt_cpufreq_platdrv = {
+	.driver = {
+		.name	= "cpufreq-dt",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= dt_cpufreq_probe,
+	.remove		= dt_cpufreq_remove,
+};
+module_platform_driver(dt_cpufreq_platdrv);
+
+MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
+MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
+MODULE_DESCRIPTION("Generic cpufreq driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 61190f6b4829..24bf76fba141 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -437,7 +437,7 @@ static struct cpufreq_governor *__find_governor(const char *str_governor)
 	struct cpufreq_governor *t;
 
 	list_for_each_entry(t, &cpufreq_governor_list, governor_list)
-		if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN))
+		if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
 			return t;
 
 	return NULL;
@@ -455,10 +455,10 @@ static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
 		goto out;
 
 	if (cpufreq_driver->setpolicy) {
-		if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
+		if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
 			*policy = CPUFREQ_POLICY_PERFORMANCE;
 			err = 0;
-		} else if (!strnicmp(str_governor, "powersave",
+		} else if (!strncasecmp(str_governor, "powersave",
 						CPUFREQ_NAME_LEN)) {
 			*policy = CPUFREQ_POLICY_POWERSAVE;
 			err = 0;
@@ -1382,7 +1382,7 @@ static int __cpufreq_remove_dev_prepare(struct device *dev,
 		if (!cpufreq_suspended)
 			pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n",
 				 __func__, new_cpu, cpu);
-	} else if (cpufreq_driver->stop_cpu && cpufreq_driver->setpolicy) {
+	} else if (cpufreq_driver->stop_cpu) {
 		cpufreq_driver->stop_cpu(policy);
 	}
 
diff --git a/drivers/cpufreq/exynos4210-cpufreq.c b/drivers/cpufreq/exynos4210-cpufreq.c
index 61a54310a1b9..843ec824fd91 100644
--- a/drivers/cpufreq/exynos4210-cpufreq.c
+++ b/drivers/cpufreq/exynos4210-cpufreq.c
@@ -127,7 +127,7 @@ int exynos4210_cpufreq_init(struct exynos_dvfs_info *info)
 	 * dependencies on platform headers. It is necessary to enable
 	 * Exynos multi-platform support and will be removed together with
 	 * this whole driver as soon as Exynos gets migrated to use
-	 * cpufreq-cpu0 driver.
+	 * cpufreq-dt driver.
 	 */
 	np = of_find_compatible_node(NULL, NULL, "samsung,exynos4210-clock");
 	if (!np) {
diff --git a/drivers/cpufreq/exynos4x12-cpufreq.c b/drivers/cpufreq/exynos4x12-cpufreq.c
index 351a2074cfea..9e78a850e29f 100644
--- a/drivers/cpufreq/exynos4x12-cpufreq.c
+++ b/drivers/cpufreq/exynos4x12-cpufreq.c
@@ -174,7 +174,7 @@ int exynos4x12_cpufreq_init(struct exynos_dvfs_info *info)
 	 * dependencies on platform headers. It is necessary to enable
 	 * Exynos multi-platform support and will be removed together with
 	 * this whole driver as soon as Exynos gets migrated to use
-	 * cpufreq-cpu0 driver.
+	 * cpufreq-dt driver.
 	 */
 	np = of_find_compatible_node(NULL, NULL, "samsung,exynos4412-clock");
 	if (!np) {
diff --git a/drivers/cpufreq/exynos5250-cpufreq.c b/drivers/cpufreq/exynos5250-cpufreq.c
index c91ce69dc631..3eafdc7ba787 100644
--- a/drivers/cpufreq/exynos5250-cpufreq.c
+++ b/drivers/cpufreq/exynos5250-cpufreq.c
@@ -153,7 +153,7 @@ int exynos5250_cpufreq_init(struct exynos_dvfs_info *info)
 	 * dependencies on platform headers. It is necessary to enable
 	 * Exynos multi-platform support and will be removed together with
 	 * this whole driver as soon as Exynos gets migrated to use
-	 * cpufreq-cpu0 driver.
+	 * cpufreq-dt driver.
 	 */
 	np = of_find_compatible_node(NULL, NULL, "samsung,exynos5250-clock");
 	if (!np) {
diff --git a/drivers/cpufreq/highbank-cpufreq.c b/drivers/cpufreq/highbank-cpufreq.c
index bf8902a0866d..ec399ad2f059 100644
--- a/drivers/cpufreq/highbank-cpufreq.c
+++ b/drivers/cpufreq/highbank-cpufreq.c
@@ -6,7 +6,7 @@
  * published by the Free Software Foundation.
  *
  * This driver provides the clk notifier callbacks that are used when
- * the cpufreq-cpu0 driver changes to frequency to alert the highbank
+ * the cpufreq-dt driver changes to frequency to alert the highbank
  * EnergyCore Management Engine (ECME) about the need to change
  * voltage. The ECME interfaces with the actual voltage regulators.
  */
@@ -60,7 +60,7 @@ static struct notifier_block hb_cpufreq_clk_nb = {
 
 static int hb_cpufreq_driver_init(void)
 {
-	struct platform_device_info devinfo = { .name = "cpufreq-cpu0", };
+	struct platform_device_info devinfo = { .name = "cpufreq-dt", };
 	struct device *cpu_dev;
 	struct clk *cpu_clk;
 	struct device_node *np;
@@ -95,7 +95,7 @@ static int hb_cpufreq_driver_init(void)
 		goto out_put_node;
 	}
 
-	/* Instantiate cpufreq-cpu0 */
+	/* Instantiate cpufreq-dt */
 	platform_device_register_full(&devinfo);
 
 out_put_node:
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 379c0837f5a9..2dfd4fdb5a52 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -26,6 +26,7 @@
 #include <linux/cpufreq.h>
 #include <linux/smp.h>
 #include <linux/of.h>
+#include <linux/reboot.h>
 
 #include <asm/cputhreads.h>
 #include <asm/firmware.h>
@@ -35,6 +36,7 @@
 #define POWERNV_MAX_PSTATES	256
 
 static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
+static bool rebooting;
 
 /*
  * Note: The set of pstates consists of contiguous integers, the
@@ -284,6 +286,15 @@ static void set_pstate(void *freq_data)
 }
 
 /*
+ * get_nominal_index: Returns the index corresponding to the nominal
+ * pstate in the cpufreq table
+ */
+static inline unsigned int get_nominal_index(void)
+{
+	return powernv_pstate_info.max - powernv_pstate_info.nominal;
+}
+
+/*
  * powernv_cpufreq_target_index: Sets the frequency corresponding to
  * the cpufreq table entry indexed by new_index on the cpus in the
  * mask policy->cpus
@@ -293,6 +304,9 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
 {
 	struct powernv_smp_call_data freq_data;
 
+	if (unlikely(rebooting) && new_index != get_nominal_index())
+		return 0;
+
 	freq_data.pstate_id = powernv_freqs[new_index].driver_data;
 
 	/*
@@ -317,6 +331,33 @@ static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	return cpufreq_table_validate_and_show(policy, powernv_freqs);
 }
 
+static int powernv_cpufreq_reboot_notifier(struct notifier_block *nb,
+				unsigned long action, void *unused)
+{
+	int cpu;
+	struct cpufreq_policy cpu_policy;
+
+	rebooting = true;
+	for_each_online_cpu(cpu) {
+		cpufreq_get_policy(&cpu_policy, cpu);
+		powernv_cpufreq_target_index(&cpu_policy, get_nominal_index());
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block powernv_cpufreq_reboot_nb = {
+	.notifier_call = powernv_cpufreq_reboot_notifier,
+};
+
+static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy)
+{
+	struct powernv_smp_call_data freq_data;
+
+	freq_data.pstate_id = powernv_pstate_info.min;
+	smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1);
+}
+
 static struct cpufreq_driver powernv_cpufreq_driver = {
 	.name		= "powernv-cpufreq",
 	.flags		= CPUFREQ_CONST_LOOPS,
@@ -324,6 +365,7 @@ static struct cpufreq_driver powernv_cpufreq_driver = {
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= powernv_cpufreq_target_index,
 	.get		= powernv_cpufreq_get,
+	.stop_cpu	= powernv_cpufreq_stop_cpu,
 	.attr		= powernv_cpu_freq_attr,
 };
 
@@ -342,12 +384,14 @@ static int __init powernv_cpufreq_init(void)
 		return rc;
 	}
 
+	register_reboot_notifier(&powernv_cpufreq_reboot_nb);
 	return cpufreq_register_driver(&powernv_cpufreq_driver);
 }
 module_init(powernv_cpufreq_init);
 
 static void __exit powernv_cpufreq_exit(void)
 {
+	unregister_reboot_notifier(&powernv_cpufreq_reboot_nb);
 	cpufreq_unregister_driver(&powernv_cpufreq_driver);
 }
 module_exit(powernv_cpufreq_exit);
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c
index 3607070797af..bee5df7794d3 100644
--- a/drivers/cpufreq/ppc-corenet-cpufreq.c
+++ b/drivers/cpufreq/ppc-corenet-cpufreq.c
@@ -199,7 +199,6 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	}
 
 	data->table = table;
-	per_cpu(cpu_data, cpu) = data;
 
 	/* update ->cpus if we have cluster, no harm if not */
 	cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
index 3f9791f07b8e..567caa6313ff 100644
--- a/drivers/cpufreq/s5pv210-cpufreq.c
+++ b/drivers/cpufreq/s5pv210-cpufreq.c
@@ -597,7 +597,7 @@ static int s5pv210_cpufreq_probe(struct platform_device *pdev)
 	 * and dependencies on platform headers. It is necessary to enable
 	 * S5PV210 multi-platform support and will be removed together with
 	 * this whole driver as soon as S5PV210 gets migrated to use
-	 * cpufreq-cpu0 driver.
+	 * cpufreq-dt driver.
 	 */
 	np = of_find_compatible_node(NULL, NULL, "samsung,s5pv210-clock");
 	if (!np) {