From deb9eec69662f14818e68c6a4e65c6c71a1789c2 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Sat, 10 Feb 2018 10:28:38 -0500 Subject: [PATCH] media: ov2640: make s_ctrl() work in power-down mode 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: Mauro Carvalho Chehab Signed-off-by: Akinobu Mita Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- 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