i2c: rcar: add suspend/resume support

Because the adapter will be set up before every transaction anyhow, we
just need to mark it as suspended to the I2C core.

Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 254e621..1d6390e 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -1017,10 +1017,35 @@ static int rcar_i2c_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int rcar_i2c_suspend(struct device *dev)
+{
+	struct rcar_i2c_priv *priv = dev_get_drvdata(dev);
+
+	i2c_mark_adapter_suspended(&priv->adap);
+	return 0;
+}
+
+static int rcar_i2c_resume(struct device *dev)
+{
+	struct rcar_i2c_priv *priv = dev_get_drvdata(dev);
+
+	i2c_mark_adapter_resumed(&priv->adap);
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(rcar_i2c_pm_ops, rcar_i2c_suspend, rcar_i2c_resume);
+
+#define DEV_PM_OPS (&rcar_i2c_pm_ops)
+#else
+#define DEV_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
 static struct platform_driver rcar_i2c_driver = {
 	.driver	= {
 		.name	= "i2c-rcar",
 		.of_match_table = rcar_i2c_dt_ids,
+		.pm	= DEV_PM_OPS,
 	},
 	.probe		= rcar_i2c_probe,
 	.remove		= rcar_i2c_remove,