1 files changed, 93 insertions, 0 deletions
diff --git a/arch/unicore32/kernel/cpu-ucv2.c b/arch/unicore32/kernel/cpu-ucv2.c
new file mode 100644
index 000000000000..4a99f62584c7
--- /dev/null
+++ b/arch/unicore32/kernel/cpu-ucv2.c
@@ -0,0 +1,93 @@
+/*
+ * linux/arch/unicore32/kernel/cpu-ucv2.c: 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/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.
+ */
+int ucv2_verify_speed(struct cpufreq_policy *policy)
+{
+	if (policy->cpu)
+		return -EINVAL;
+
+	cpufreq_verify_within_limits(policy,
+			policy->cpuinfo.min_freq, policy->cpuinfo.max_freq);
+
+	return 0;
+}
+
+static unsigned int ucv2_getspeed(unsigned int cpu)
+{
+	struct clk *mclk = clk_get(NULL, "MAIN_CLK");
+
+	if (cpu)
+		return 0;
+	return clk_get_rate(mclk)/1000;
+}
+
+static int ucv2_target(struct cpufreq_policy *policy,
+			 unsigned int target_freq,
+			 unsigned int relation)
+{
+	unsigned int cur = ucv2_getspeed(0);
+	struct cpufreq_freqs freqs;
+	struct clk *mclk = clk_get(NULL, "MAIN_CLK");
+
+	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+	if (!clk_set_rate(mclk, target_freq * 1000)) {
+		freqs.old = cur;
+		freqs.new = target_freq;
+		freqs.cpu = 0;
+	}
+
+	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+	return 0;
+}
+
+static int __init ucv2_cpu_init(struct cpufreq_policy *policy)
+{
+	if (policy->cpu != 0)
+		return -EINVAL;
+	policy->cur = ucv2_getspeed(0);
+	policy->min = policy->cpuinfo.min_freq = 250000;
+	policy->max = policy->cpuinfo.max_freq = 1000000;
+	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+	return 0;
+}
+
+static struct cpufreq_driver ucv2_driver = {
+	.flags		= CPUFREQ_STICKY,
+	.verify		= ucv2_verify_speed,
+	.target		= ucv2_target,
+	.get		= ucv2_getspeed,
+	.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);