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");