[PATCH 2/3] i2c/at91: add support for system PM

[Wenyou Yang <wenyou.yang-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>]

Signed-off-by: Wenyou Yang <wenyou.yang-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
---
 drivers/i2c/busses/i2c-at91.c |   30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
index 03b9f48..8f408f8 100644
--- a/drivers/i2c/busses/i2c-at91.c
+++ b/drivers/i2c/busses/i2c-at91.c
@@ -845,6 +845,35 @@ static int at91_twi_remove(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
+static int at91_twi_suspend(struct device *dev)
+{
+	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
+
+	if (!pm_runtime_suspended(dev))
+		clk_disable_unprepare(twi_dev->clk);
+
+	return 0;
+}
+
+static int at91_twi_resume(struct device *dev)
+{
+	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
+	int ret;
+
+	if (!pm_runtime_suspended(dev)) {
+		ret = clk_prepare_enable(twi_dev->clk);
+		if (ret)
+			return ret;
+	}
+
+	pm_runtime_mark_last_busy(dev);
+	pm_request_autosuspend(dev);
+
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_PM_RUNTIME
 static int at91_twi_runtime_suspend(struct device *dev)
 {
@@ -864,6 +893,7 @@ static int at91_twi_runtime_resume(struct device *dev)
 #endif
 
 static const struct dev_pm_ops at91_twi_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(at91_twi_suspend, at91_twi_resume)
 	SET_RUNTIME_PM_OPS(at91_twi_runtime_suspend,
 				at91_twi_runtime_resume, NULL)
 };
-- 
1.7.9.5