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>

1 files changed, 64 insertions, 0 deletions

diff --git a/arch/sh/kernel/cpu/clock.c b/arch/sh/kernel/cpu/clock.c
index 332a1798547c..3209a8740fa4 100644
--- a/arch/sh/kernel/cpu/clock.c
+++ b/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;