Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / cpufreq / unicore2-cpufreq.c

diff --git a/kernel/drivers/cpufreq/unicore2-cpufreq.c b/kernel/drivers/cpufreq/unicore2-cpufreq.c
new file mode 100644 (file)
index 0000000..6f9dfa8
--- /dev/null
+++ b/kernel/drivers/cpufreq/unicore2-cpufreq.c
@@ -0,0 +1,80 @@
+/*
+ * clock scaling for the UniCore-II
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ *     Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
+ *     Copyright (C) 2001-2010 Guan Xuetao
+ *
+ * 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.
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+
+#include <mach/hardware.h>
+
+static struct cpufreq_driver ucv2_driver;
+
+/* make sure that only the "userspace" governor is run
+ * -- anything else wouldn't make sense on this platform, anyway.
+ */
+static int ucv2_verify_speed(struct cpufreq_policy *policy)
+{
+       if (policy->cpu)
+               return -EINVAL;
+
+       cpufreq_verify_within_cpu_limits(policy);
+       return 0;
+}
+
+static int ucv2_target(struct cpufreq_policy *policy,
+                        unsigned int target_freq,
+                        unsigned int relation)
+{
+       struct cpufreq_freqs freqs;
+       int ret;
+
+       freqs.old = policy->cur;
+       freqs.new = target_freq;
+
+       cpufreq_freq_transition_begin(policy, &freqs);
+       ret = clk_set_rate(policy->clk, target_freq * 1000);
+       cpufreq_freq_transition_end(policy, &freqs, ret);
+
+       return ret;
+}
+
+static int __init ucv2_cpu_init(struct cpufreq_policy *policy)
+{
+       if (policy->cpu != 0)
+               return -EINVAL;
+
+       policy->min = policy->cpuinfo.min_freq = 250000;
+       policy->max = policy->cpuinfo.max_freq = 1000000;
+       policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+       policy->clk = clk_get(NULL, "MAIN_CLK");
+       return PTR_ERR_OR_ZERO(policy->clk);
+}
+
+static struct cpufreq_driver ucv2_driver = {
+       .flags          = CPUFREQ_STICKY,
+       .verify         = ucv2_verify_speed,
+       .target         = ucv2_target,
+       .get            = cpufreq_generic_get,
+       .init           = ucv2_cpu_init,
+       .name           = "UniCore-II",
+};
+
+static int __init ucv2_cpufreq_init(void)
+{
+       return cpufreq_register_driver(&ucv2_driver);
+}
+
+arch_initcall(ucv2_cpufreq_init);