clk: cs2000: add Suspend/Resume feature

CS2000 needs re-setup when redume, otherwise, it can't
handle correct clock rate.

Signed-off-by: Khiem Nguyen <khiem.nguyen.xt@rvc.renesas.com>
[Kuninori: cleanup original patch]
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

diff --git a/drivers/clk/clk-cs2000-cp.c b/drivers/clk/clk-cs2000-cp.c
index 021f3daf34e140edef6b678fd99d2de0f5eee3b6..3fca0526d940af68fc2a9b550b5951014f2a7dcc 100644 (file)
--- a/drivers/clk/clk-cs2000-cp.c
+++ b/drivers/clk/clk-cs2000-cp.c
@@ -59,6 +59,10 @@ struct cs2000_priv {
        struct i2c_client *client;
        struct clk *clk_in;
        struct clk *ref_clk;
+
+       /* suspend/resume */
+       unsigned long saved_rate;
+       unsigned long saved_parent_rate;
 };
 
 static const struct of_device_id cs2000_of_match[] = {
@@ -286,6 +290,9 @@ static int __cs2000_set_rate(struct cs2000_priv *priv, int ch,
        if (ret < 0)
                return ret;
 
+       priv->saved_rate        = rate;
+       priv->saved_parent_rate = parent_rate;
+
        return 0;
 }
 
@@ -489,9 +496,24 @@ probe_err:
        return ret;
 }
 
+static int cs2000_resume(struct device *dev)
+{
+       struct cs2000_priv *priv = dev_get_drvdata(dev);
+       int ch = 0; /* it uses ch0 only at this point */
+
+       return __cs2000_set_rate(priv, ch,
+                                priv->saved_rate,
+                                priv->saved_parent_rate);
+}
+
+static const struct dev_pm_ops cs2000_pm_ops = {
+       .resume_early   = cs2000_resume,
+};
+
 static struct i2c_driver cs2000_driver = {
        .driver = {
                .name = "cs2000-cp",
+               .pm     = &cs2000_pm_ops,
                .of_match_table = cs2000_of_match,
        },
        .probe          = cs2000_probe,