The s_ctrl() operation can be called when the device is placed into
power down mode. Then, applying controls to H/W should be postponed at
this time. Instead the controls will be restored when the streaming is
started.
Cc: Sakari Ailus <sakari.ai...@linux.intel.com>
Cc: Mauro Carvalho Chehab <mche...@s-opensource.com>
Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com>
---
drivers/media/i2c/ov2640.c | 43 ++++++++++++++++++++++++++++++++++++-------
1 file changed, 36 insertions(+), 7 deletions(-)
diff --git a/drivers/media/i2c/ov2640.c b/drivers/media/i2c/ov2640.c
index 68a356d..beb7220 100644
--- a/drivers/media/i2c/ov2640.c
+++ b/drivers/media/i2c/ov2640.c
@@ -308,8 +308,9 @@ struct ov2640_priv {
struct gpio_desc *resetb_gpio;
struct gpio_desc *pwdn_gpio;
- struct mutex lock; /* lock to protect streaming */
+ struct mutex lock; /* lock to protect streaming and power_count */
bool streaming;
+ int power_count;
};
/*
@@ -712,9 +713,20 @@ static int ov2640_s_ctrl(struct v4l2_ctrl *ctrl)
struct v4l2_subdev *sd =
&container_of(ctrl->handler, struct ov2640_priv, hdl)->subdev;
struct i2c_client *client = v4l2_get_subdevdata(sd);
+ struct ov2640_priv *priv = to_ov2640(client);
u8 val;
int ret;
+ /* v4l2_ctrl_lock() locks our own mutex */
+
+ /*
+ * If the device is not powered up by the host driver, do not apply any
+ * controls to H/W at this time. Instead the controls will be restored
+ * when the streaming is started.
+ */
+ if (!priv->power_count)
+ return 0;
+
ret = i2c_smbus_write_byte_data(client, BANK_SEL, BANK_SEL_SENS);
if (ret < 0)
return ret;
@@ -766,12 +778,9 @@ static int ov2640_s_register(struct v4l2_subdev *sd,
}
#endif
-static int ov2640_s_power(struct v4l2_subdev *sd, int on)
+static void ov2640_set_power(struct ov2640_priv *priv, int on)
{
#ifdef CONFIG_GPIOLIB
- struct i2c_client *client = v4l2_get_subdevdata(sd);
- struct ov2640_priv *priv = to_ov2640(client);
-
if (priv->pwdn_gpio)
gpiod_direction_output(priv->pwdn_gpio, !on);
if (on && priv->resetb_gpio) {
@@ -781,6 +790,25 @@ static int ov2640_s_power(struct v4l2_subdev *sd, int on)
gpiod_set_value(priv->resetb_gpio, 0);
}
#endif
+}
+
+static int ov2640_s_power(struct v4l2_subdev *sd, int on)
+{
+ struct i2c_client *client = v4l2_get_subdevdata(sd);
+ struct ov2640_priv *priv = to_ov2640(client);
+
+ mutex_lock(&priv->lock);
+
+ /*
+ * If the power count is modified from 0 to != 0 or from != 0 to 0,
+ * update the power state.
+ */
+ if (priv->power_count == !on)
+ ov2640_set_power(priv, on);
+ priv->power_count += on ? 1 : -1;
+ WARN_ON(priv->power_count < 0);
+ mutex_unlock(&priv->lock);
+
return 0;
}
@@ -1005,6 +1033,8 @@ static int ov2640_s_stream(struct v4l2_subdev *sd, int on)
if (on) {
ret = ov2640_set_params(client, priv->win,
priv->cfmt_code);
+ if (!ret)
+ ret = __v4l2_ctrl_handler_setup(&priv->hdl);
}
}
if (!ret)
@@ -1049,8 +1079,6 @@ static int ov2640_video_probe(struct i2c_client *client)
"%s Product ID %0x:%0x Manufacturer ID %x:%x\n",
devname, pid, ver, midh, midl);
- ret = v4l2_ctrl_handler_setup(&priv->hdl);
-
done:
ov2640_s_power(&priv->subdev, 0);
return ret;
@@ -1158,6 +1186,7 @@ static int ov2640_probe(struct i2c_client *client,
priv->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
mutex_init(&priv->lock);
v4l2_ctrl_handler_init(&priv->hdl, 2);
+ priv->hdl.lock = &priv->lock;
v4l2_ctrl_new_std(&priv->hdl, &ov2640_ctrl_ops,
V4L2_CID_VFLIP, 0, 1, 1, 0);
v4l2_ctrl_new_std(&priv->hdl, &ov2640_ctrl_ops,
--
2.7.4
