Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / cpufreq / sh-cpufreq.c

diff --git a/kernel/drivers/cpufreq/sh-cpufreq.c b/kernel/drivers/cpufreq/sh-cpufreq.c
new file mode 100644 (file)
index 0000000..86628e2
--- /dev/null
+++ b/kernel/drivers/cpufreq/sh-cpufreq.c
@@ -0,0 +1,177 @@
+/*
+ * 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_freq_transition_begin(policy, &freqs);
+       set_cpus_allowed_ptr(current, &cpus_allowed);
+       clk_set_rate(cpuclk, freq);
+       cpufreq_freq_transition_end(policy, &freqs, 0);
+
+       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_cpu_limits(policy);
+
+       policy->min = (clk_round_rate(cpuclk, 1) + 500) / 1000;
+       policy->max = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
+
+       cpufreq_verify_within_cpu_limits(policy);
+       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);
+       }
+
+       freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
+       if (freq_table) {
+               int result;
+
+               result = cpufreq_table_validate_and_show(policy, freq_table);
+               if (result)
+                       return result;
+       } 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);
+
+       clk_put(cpuclk);
+
+       return 0;
+}
+
+static struct cpufreq_driver sh_cpufreq_driver = {
+       .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           = cpufreq_generic_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");