sh: clkfwk: Add resume from hibernation support.

This patch adds PM support to the clock framework.
With this, resume from hibernation is properly supported.

Signed-off-by: Francesco Virlinzi <francesco.virlinzi@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/cpu/clock.c

@@ -20,6 +20,8 @@
 #include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/kref.h>
+#include <linux/kobject.h>
+#include <linux/sysdev.h>
 #include <linux/seq_file.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
@@ -358,6 +360,68 @@ static int show_clocks(char *buf, char **start, off_t off,
 	return p - buf;
 }
 
+#ifdef CONFIG_PM
+static int clks_sysdev_suspend(struct sys_device *dev, pm_message_t state)
+{
+	static pm_message_t prev_state;
+	struct clk *clkp;
+
+	switch (state.event) {
+	case PM_EVENT_ON:
+		/* Resumeing from hibernation */
+		if (prev_state.event == PM_EVENT_FREEZE) {
+			list_for_each_entry(clkp, &clock_list, node)
+				if (likely(clkp->ops)) {
+					if (likely(clkp->ops->set_parent))
+						clkp->ops->set_parent(clkp,
+							clkp->parent);
+					if (likely(clkp->ops->set_rate))
+						clkp->ops->set_rate(clkp,
+							clkp->rate, NO_CHANGE);
+					else if (likely(clkp->ops->recalc))
+						clkp->ops->recalc(clkp);
+					}
+		}
+		break;
+	case PM_EVENT_FREEZE:
+		break;
+	case PM_EVENT_SUSPEND:
+		break;
+	}
+
+	prev_state = state;
+	return 0;
+}
+
+static int clks_sysdev_resume(struct sys_device *dev)
+{
+	return clks_sysdev_suspend(dev, PMSG_ON);
+}
+
+static struct sysdev_class clks_sysdev_class = {
+	.name = "clks",
+};
+
+static struct sysdev_driver clks_sysdev_driver = {
+	.suspend = clks_sysdev_suspend,
+	.resume = clks_sysdev_resume,
+};
+
+static struct sys_device clks_sysdev_dev = {
+	.cls = &clks_sysdev_class,
+};
+
+static int __init clk_sysdev_init(void)
+{
+	sysdev_class_register(&clks_sysdev_class);
+	sysdev_driver_register(&clks_sysdev_class, &clks_sysdev_driver);
+	sysdev_register(&clks_sysdev_dev);
+
+	return 0;
+}
+subsys_initcall(clk_sysdev_init);
+#endif
+
 int __init clk_init(void)
 {
 	int i, ret = 0;