[PATCH 2/2] media: ov7670: Add the s_power operation

[Wenyou Yang]

Add the s_power operation which is responsible for manipulating the
power dowm mode through the PWDN pin and the reset operation through
the RESET pin.

Signed-off-by: Wenyou Yang <wenyou.yang at microchip.com>
---

 drivers/media/i2c/ov7670.c | 30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
index 5c8460ee65c3..5ed79ccfaf91 100644
--- a/drivers/media/i2c/ov7670.c
+++ b/drivers/media/i2c/ov7670.c
@@ -1506,6 +1506,22 @@ static int ov7670_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_regis
 }
 #endif
 
+static int ov7670_s_power(struct v4l2_subdev *sd, int on)
+{
+	struct ov7670_info *info = to_state(sd);
+
+	if (info->pwdn_gpio)
+		gpiod_direction_output(info->pwdn_gpio, !on);
+	if (on && info->resetb_gpio) {
+		gpiod_set_value(info->resetb_gpio, 1);
+		usleep_range(500, 1000);
+		gpiod_set_value(info->resetb_gpio, 0);
+		usleep_range(3000, 5000);
+	}
+
+	return 0;
+}
+
 /* ----------------------------------------------------------------------- */
 
 static const struct v4l2_subdev_core_ops ov7670_core_ops = {
@@ -1515,6 +1531,7 @@ static const struct v4l2_subdev_core_ops ov7670_core_ops = {
 	.g_register = ov7670_g_register,
 	.s_register = ov7670_s_register,
 #endif
+	.s_power = ov7670_s_power,
 };
 
 static const struct v4l2_subdev_video_ops ov7670_video_ops = {
@@ -1568,8 +1585,6 @@ static int ov7670_init_gpio(struct i2c_client *client, struct ov7670_info *info)
 		return PTR_ERR(info->resetb_gpio);
 	}
 
-	usleep_range(3000, 5000);
-
 	return 0;
 }
 
@@ -1630,13 +1645,19 @@ static int ov7670_probe(struct i2c_client *client,
 		goto clk_disable;
 	}
 
+	ret = ov7670_init_gpio(client, info);
+	if (ret)
+		goto clk_disable;
+
+	ov7670_s_power(sd, 1);
+
 	/* Make sure it's an ov7670 */
 	ret = ov7670_detect(sd);
 	if (ret) {
 		v4l_dbg(1, debug, client,
 			"chip found @ 0x%x (%s) is not an ov7670 chip.\n",
 			client->addr << 1, client->adapter->name);
-		goto clk_disable;
+		goto power_off;
 	}
 	v4l_info(client, "chip found @ 0x%02x (%s)\n",
 			client->addr << 1, client->adapter->name);
@@ -1708,6 +1729,8 @@ static int ov7670_probe(struct i2c_client *client,
 	media_entity_cleanup(&info->sd.entity);
 hdl_free:
 	v4l2_ctrl_handler_free(&info->hdl);
+power_off:
+	ov7670_s_power(sd, 0);
 clk_disable:
 	clk_disable_unprepare(info->clk);
 	return ret;
@@ -1723,6 +1746,7 @@ static int ov7670_remove(struct i2c_client *client)
 	v4l2_ctrl_handler_free(&info->hdl);
 	clk_disable_unprepare(info->clk);
 	media_entity_cleanup(&info->sd.entity);
+	ov7670_s_power(sd, 0);
 	return 0;
 }
 
-- 
2.13.0