cpufreq: sh: move cpufreq driver to drivers/cpufreq

This patch moves cpufreq driver of SUPERH architecture to drivers/cpufreq.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

3 files changed, 208 insertions, 0 deletions

diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index 5030df5cd3eb..602d5dbc4345 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -258,5 +258,23 @@ depends on PPC32 || PPC64
 source "drivers/cpufreq/Kconfig.powerpc"
 endmenu
 
+menu "SH CPU Frequency scaling"
+depends on SUPERH
+config SH_CPU_FREQ
+	tristate "SuperH CPU Frequency driver"
+	select CPU_FREQ_TABLE
+	help
+	  This adds the cpufreq driver for SuperH. Any CPU that supports
+	  clock rate rounding through the clock framework can use this
+	  driver. While it will make the kernel slightly larger, this is
+	  harmless for CPUs that don't support rate rounding. The driver
+	  will also generate a notice in the boot log before disabling
+	  itself if the CPU in question is not capable of rate rounding.
+
+	  For details, take a look at <file:Documentation/cpu-freq>.
+
+	  If unsure, say N.
+endmenu
+
 endif
 endmenu
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 9659cbbad25e..3930d2e6a664 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -83,3 +83,4 @@ obj-$(CONFIG_CRIS_MACH_ARTPEC3)		+= cris-artpec3-cpufreq.o
 obj-$(CONFIG_ETRAXFS)			+= cris-etraxfs-cpufreq.o
 obj-$(CONFIG_IA64_ACPI_CPUFREQ)		+= ia64-acpi-cpufreq.o
 obj-$(CONFIG_LOONGSON2_CPUFREQ)		+= loongson2_cpufreq.o
+obj-$(CONFIG_SH_CPU_FREQ)		+= sh-cpufreq.o
diff --git a/drivers/cpufreq/sh-cpufreq.c b/drivers/cpufreq/sh-cpufreq.c
new file mode 100644
index 000000000000..73adb64651e8
--- /dev/null
+++ b/drivers/cpufreq/sh-cpufreq.c
@@ -0,0 +1,189 @@
+/*
+ * cpufreq driver for the SuperH processors.
+ *
+ * Copyright (C) 2002 - 2012 Paul Mundt
+ * Copyright (C) 2002 M. R. Brown
+ *
+ * Clock framework bits from arch/avr32/mach-at32ap/cpufreq.c
+ *
+ *   Copyright (C) 2004-2007 Atmel Corporation
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#define pr_fmt(fmt) "cpufreq: " fmt
+
+#include <linux/types.h>
+#include <linux/cpufreq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/cpumask.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/sched.h>	/* set_cpus_allowed() */
+#include <linux/clk.h>
+#include <linux/percpu.h>
+#include <linux/sh_clk.h>
+
+static DEFINE_PER_CPU(struct clk, sh_cpuclk);
+
+static unsigned int sh_cpufreq_get(unsigned int cpu)
+{
+	return (clk_get_rate(&per_cpu(sh_cpuclk, cpu)) + 500) / 1000;
+}
+
+/*
+ * Here we notify other drivers of the proposed change and the final change.
+ */
+static int sh_cpufreq_target(struct cpufreq_policy *policy,
+			     unsigned int target_freq,
+			     unsigned int relation)
+{
+	unsigned int cpu = policy->cpu;
+	struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
+	cpumask_t cpus_allowed;
+	struct cpufreq_freqs freqs;
+	struct device *dev;
+	long freq;
+
+	cpus_allowed = current->cpus_allowed;
+	set_cpus_allowed_ptr(current, cpumask_of(cpu));
+
+	BUG_ON(smp_processor_id() != cpu);
+
+	dev = get_cpu_device(cpu);
+
+	/* Convert target_freq from kHz to Hz */
+	freq = clk_round_rate(cpuclk, target_freq * 1000);
+
+	if (freq < (policy->min * 1000) || freq > (policy->max * 1000))
+		return -EINVAL;
+
+	dev_dbg(dev, "requested frequency %u Hz\n", target_freq * 1000);
+
+	freqs.old	= sh_cpufreq_get(cpu);
+	freqs.new	= (freq + 500) / 1000;
+	freqs.flags	= 0;
+
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	set_cpus_allowed_ptr(current, &cpus_allowed);
+	clk_set_rate(cpuclk, freq);
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+
+	dev_dbg(dev, "set frequency %lu Hz\n", freq);
+
+	return 0;
+}
+
+static int sh_cpufreq_verify(struct cpufreq_policy *policy)
+{
+	struct clk *cpuclk = &per_cpu(sh_cpuclk, policy->cpu);
+	struct cpufreq_frequency_table *freq_table;
+
+	freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
+	if (freq_table)
+		return cpufreq_frequency_table_verify(policy, freq_table);
+
+	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
+				     policy->cpuinfo.max_freq);
+
+	policy->min = (clk_round_rate(cpuclk, 1) + 500) / 1000;
+	policy->max = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
+
+	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
+				     policy->cpuinfo.max_freq);
+
+	return 0;
+}
+
+static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	unsigned int cpu = policy->cpu;
+	struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
+	struct cpufreq_frequency_table *freq_table;
+	struct device *dev;
+
+	dev = get_cpu_device(cpu);
+
+	cpuclk = clk_get(dev, "cpu_clk");
+	if (IS_ERR(cpuclk)) {
+		dev_err(dev, "couldn't get CPU clk\n");
+		return PTR_ERR(cpuclk);
+	}
+
+	policy->cur = sh_cpufreq_get(cpu);
+
+	freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
+	if (freq_table) {
+		int result;
+
+		result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
+		if (!result)
+			cpufreq_frequency_table_get_attr(freq_table, cpu);
+	} else {
+		dev_notice(dev, "no frequency table found, falling back "
+			   "to rate rounding.\n");
+
+		policy->min = policy->cpuinfo.min_freq =
+			(clk_round_rate(cpuclk, 1) + 500) / 1000;
+		policy->max = policy->cpuinfo.max_freq =
+			(clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
+	}
+
+	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+
+	dev_info(dev, "CPU Frequencies - Minimum %u.%03u MHz, "
+	       "Maximum %u.%03u MHz.\n",
+	       policy->min / 1000, policy->min % 1000,
+	       policy->max / 1000, policy->max % 1000);
+
+	return 0;
+}
+
+static int sh_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+	unsigned int cpu = policy->cpu;
+	struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
+
+	cpufreq_frequency_table_put_attr(cpu);
+	clk_put(cpuclk);
+
+	return 0;
+}
+
+static struct freq_attr *sh_freq_attr[] = {
+	&cpufreq_freq_attr_scaling_available_freqs,
+	NULL,
+};
+
+static struct cpufreq_driver sh_cpufreq_driver = {
+	.owner		= THIS_MODULE,
+	.name		= "sh",
+	.get		= sh_cpufreq_get,
+	.target		= sh_cpufreq_target,
+	.verify		= sh_cpufreq_verify,
+	.init		= sh_cpufreq_cpu_init,
+	.exit		= sh_cpufreq_cpu_exit,
+	.attr		= sh_freq_attr,
+};
+
+static int __init sh_cpufreq_module_init(void)
+{
+	pr_notice("SuperH CPU frequency driver.\n");
+	return cpufreq_register_driver(&sh_cpufreq_driver);
+}
+
+static void __exit sh_cpufreq_module_exit(void)
+{
+	cpufreq_unregister_driver(&sh_cpufreq_driver);
+}
+
+module_init(sh_cpufreq_module_init);
+module_exit(sh_cpufreq_module_exit);
+
+MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
+MODULE_DESCRIPTION("cpufreq driver for SuperH");
+MODULE_LICENSE("GPL");