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Diffstat (limited to 'kernel/drivers/macintosh/windfarm_cpufreq_clamp.c')
-rw-r--r--kernel/drivers/macintosh/windfarm_cpufreq_clamp.c106
1 files changed, 106 insertions, 0 deletions
diff --git a/kernel/drivers/macintosh/windfarm_cpufreq_clamp.c b/kernel/drivers/macintosh/windfarm_cpufreq_clamp.c
new file mode 100644
index 000000000..72d1fdfe0
--- /dev/null
+++ b/kernel/drivers/macintosh/windfarm_cpufreq_clamp.c
@@ -0,0 +1,106 @@
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/cpufreq.h>
+
+#include <asm/prom.h>
+
+#include "windfarm.h"
+
+#define VERSION "0.3"
+
+static int clamped;
+static struct wf_control *clamp_control;
+
+static int clamp_notifier_call(struct notifier_block *self,
+ unsigned long event, void *data)
+{
+ struct cpufreq_policy *p = data;
+ unsigned long max_freq;
+
+ if (event != CPUFREQ_ADJUST)
+ return 0;
+
+ max_freq = clamped ? (p->cpuinfo.min_freq) : (p->cpuinfo.max_freq);
+ cpufreq_verify_within_limits(p, 0, max_freq);
+
+ return 0;
+}
+
+static struct notifier_block clamp_notifier = {
+ .notifier_call = clamp_notifier_call,
+};
+
+static int clamp_set(struct wf_control *ct, s32 value)
+{
+ if (value)
+ printk(KERN_INFO "windfarm: Clamping CPU frequency to "
+ "minimum !\n");
+ else
+ printk(KERN_INFO "windfarm: CPU frequency unclamped !\n");
+ clamped = value;
+ cpufreq_update_policy(0);
+ return 0;
+}
+
+static int clamp_get(struct wf_control *ct, s32 *value)
+{
+ *value = clamped;
+ return 0;
+}
+
+static s32 clamp_min(struct wf_control *ct)
+{
+ return 0;
+}
+
+static s32 clamp_max(struct wf_control *ct)
+{
+ return 1;
+}
+
+static struct wf_control_ops clamp_ops = {
+ .set_value = clamp_set,
+ .get_value = clamp_get,
+ .get_min = clamp_min,
+ .get_max = clamp_max,
+ .owner = THIS_MODULE,
+};
+
+static int __init wf_cpufreq_clamp_init(void)
+{
+ struct wf_control *clamp;
+
+ clamp = kmalloc(sizeof(struct wf_control), GFP_KERNEL);
+ if (clamp == NULL)
+ return -ENOMEM;
+ cpufreq_register_notifier(&clamp_notifier, CPUFREQ_POLICY_NOTIFIER);
+ clamp->ops = &clamp_ops;
+ clamp->name = "cpufreq-clamp";
+ if (wf_register_control(clamp))
+ goto fail;
+ clamp_control = clamp;
+ return 0;
+ fail:
+ kfree(clamp);
+ return -ENODEV;
+}
+
+static void __exit wf_cpufreq_clamp_exit(void)
+{
+ if (clamp_control)
+ wf_unregister_control(clamp_control);
+}
+
+
+module_init(wf_cpufreq_clamp_init);
+module_exit(wf_cpufreq_clamp_exit);
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("CPU frequency clamp for PowerMacs thermal control");
+MODULE_LICENSE("GPL");
+