[PATCH v2 3/4] media: i2c: ov2659: Add clk_prepare_enable(), clk_disable_unprepare() to handle xvclk

[dillon . minfei]

From: dillon min <dillon.min...@gmail.com>

For power save purpose, xvclk might not be always on.
need add clk_prepare_enable(), clk_disable_unprepare() at driver
side to set xvclk on/off at proper stage.

Add following changes:
- add 'struct clk *clk' in 'struct ov2659'
- enable xvclk in ov2659_power_on()
- disable xvclk in ov2659_power_off()

Signed-off-by: dillon min <dillon.min...@gmail.com>
---
v2: no changes

 drivers/media/i2c/ov2659.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/media/i2c/ov2659.c b/drivers/media/i2c/ov2659.c
index 42f64175a6df..fb78a1cedc03 100644
--- a/drivers/media/i2c/ov2659.c
+++ b/drivers/media/i2c/ov2659.c
@@ -204,6 +204,7 @@ struct ov2659 {
        struct i2c_client *client;
        struct v4l2_ctrl_handler ctrls;
        struct v4l2_ctrl *link_frequency;
+       struct clk *clk;
        const struct ov2659_framesize *frame_size;
        struct sensor_register *format_ctrl_regs;
        struct ov2659_pll_ctrl pll;
@@ -1270,6 +1271,8 @@ static int ov2659_power_off(struct device *dev)
 
        gpiod_set_value(ov2659->pwdn_gpio, 1);
 
+       clk_disable_unprepare(ov2659->clk);
+
        return 0;
 }
 
@@ -1278,9 +1281,17 @@ static int ov2659_power_on(struct device *dev)
        struct i2c_client *client = to_i2c_client(dev);
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct ov2659 *ov2659 = to_ov2659(sd);
+       int ret;
 
        dev_dbg(&client->dev, "%s:\n", __func__);
 
+       ret = clk_prepare_enable(ov2659->clk);
+       if (ret) {
+               dev_err(&client->dev, "%s: failed to enable clock\n",
+                       __func__);
+               return ret;
+       }
+
        gpiod_set_value(ov2659->pwdn_gpio, 0);
 
        if (ov2659->resetb_gpio) {
@@ -1425,7 +1436,6 @@ static int ov2659_probe(struct i2c_client *client)
        const struct ov2659_platform_data *pdata = ov2659_get_pdata(client);
        struct v4l2_subdev *sd;
        struct ov2659 *ov2659;
-       struct clk *clk;
        int ret;
 
        if (!pdata) {
@@ -1440,11 +1450,11 @@ static int ov2659_probe(struct i2c_client *client)
        ov2659->pdata = pdata;
        ov2659->client = client;
 
-       clk = devm_clk_get(&client->dev, "xvclk");
-       if (IS_ERR(clk))
-               return PTR_ERR(clk);
+       ov2659->clk = devm_clk_get(&client->dev, "xvclk");
+       if (IS_ERR(ov2659->clk))
+               return PTR_ERR(ov2659->clk);
 
-       ov2659->xvclk_frequency = clk_get_rate(clk);
+       ov2659->xvclk_frequency = clk_get_rate(ov2659->clk);
        if (ov2659->xvclk_frequency < 6000000 ||
            ov2659->xvclk_frequency > 27000000)
                return -EINVAL;
@@ -1506,7 +1516,9 @@ static int ov2659_probe(struct i2c_client *client)
        ov2659->frame_size = &ov2659_framesizes[2];
        ov2659->format_ctrl_regs = ov2659_formats[0].format_ctrl_regs;
 
-       ov2659_power_on(&client->dev);
+       ret = ov2659_power_on(&client->dev);
+       if (ret < 0)
+               goto error;
 
        ret = ov2659_detect(sd);
        if (ret < 0)
-- 
2.7.4