On Mon, Aug 03, 2020 at 12:39:12PM +0100, Lad Prabhakar wrote:
> Add support to read the bus-type and enable BT656 mode if needed.
>
> The driver defaults to parallel mode if bus-type is not specified in DT.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> ---
> drivers/media/i2c/ov772x.c | 40 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/drivers/media/i2c/ov772x.c b/drivers/media/i2c/ov772x.c
> index 2cc6a678069a..2de9248e3689 100644
> --- a/drivers/media/i2c/ov772x.c
> +++ b/drivers/media/i2c/ov772x.c
> @@ -31,6 +31,7 @@
> #include <media/v4l2-ctrls.h>
> #include <media/v4l2-device.h>
> #include <media/v4l2-event.h>
> +#include <media/v4l2-fwnode.h>
> #include <media/v4l2-image-sizes.h>
> #include <media/v4l2-subdev.h>
>
> @@ -434,6 +435,7 @@ struct ov772x_priv {
> #ifdef CONFIG_MEDIA_CONTROLLER
> struct media_pad pad;
> #endif
> + struct v4l2_fwnode_endpoint ep;
> };
>
> /*
> @@ -574,6 +576,7 @@ static int ov772x_s_stream(struct v4l2_subdev *sd, int enable)
> {
> struct i2c_client *client = v4l2_get_subdevdata(sd);
> struct ov772x_priv *priv = to_ov772x(sd);
> + unsigned int val;
> int ret = 0;
>
> mutex_lock(&priv->lock);
> @@ -581,6 +584,22 @@ static int ov772x_s_stream(struct v4l2_subdev *sd, int enable)
> if (priv->streaming == enable)
> goto done;
>
> + if (priv->ep.bus_type == V4L2_MBUS_BT656 && enable) {
> + ret = regmap_read(priv->regmap, COM7, &val);
> + if (ret)
> + goto done;
> + val |= ITU656_ON_OFF;
> + ret = regmap_write(priv->regmap, COM7, val);
> + } else if (priv->ep.bus_type == V4L2_MBUS_BT656 && !enable) {
is the !enable intentional ? (sorry I don't have access to the sensor
manual). If not, see below:
> + ret = regmap_read(priv->regmap, COM7, &val);
> + if (ret)
> + goto done;
> + val &= ~ITU656_ON_OFF;
> + ret = regmap_write(priv->regmap, COM7, val);
> + }
> + if (ret)
> + goto done;
Could you write this as:
static int ov772x_s_stream(struct v4l2_subdev *sd, int enable)
{
struct i2c_client *client = v4l2_get_subdevdata(sd);
struct ov772x_priv *priv = to_ov772x(sd);
int ret = 0;
mutex_lock(&priv->lock);
if (priv->streaming == enable)
goto done;
if (enable) {
ret = regmap_read(priv->regmap, COM7, &val);
if (ret)
goto done;
if (priv->ep.bus_type == V4L2_MBUS_BT656)
val |= ITU656_ON_OFF;
else /* if you accept my suggestion to consider othe
bus types as errors */
val &= ~ITU656_ON_OFF;
ret = regmap_write(priv->regmap, COM7, val);
if (ret)
goto done;
dev_dbg(&client->dev, "format %d, win %s\n",
priv->cfmt->code, priv->win->name);
}
ret = regmap_update_bits(priv->regmap, COM2, SOFT_SLEEP_MODE,
enable ? 0 : SOFT_SLEEP_MODE);
if (ret)
goto done;
priv->streaming = enable;
done:
mutex_unlock(&priv->lock);
return ret;
}
> ret = regmap_update_bits(priv->regmap, COM2, SOFT_SLEEP_MODE,
> enable ? 0 : SOFT_SLEEP_MODE);
> if (ret)
> @@ -1354,6 +1373,7 @@ static const struct v4l2_subdev_ops ov772x_subdev_ops = {
>
> static int ov772x_probe(struct i2c_client *client)
> {
> + struct fwnode_handle *endpoint;
> struct ov772x_priv *priv;
> int ret;
> static const struct regmap_config ov772x_regmap_config = {
> @@ -1415,6 +1435,26 @@ static int ov772x_probe(struct i2c_client *client)
> goto error_clk_put;
> }
>
> + endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(&client->dev),
> + NULL);
> + if (!endpoint) {
> + dev_err(&client->dev, "endpoint node not found\n");
> + ret = -EINVAL;
> + goto error_clk_put;
> + }
> +
> + ret = v4l2_fwnode_endpoint_parse(endpoint, &priv->ep);
> + fwnode_handle_put(endpoint);
> + if (ret) {
> + dev_err(&client->dev, "Could not parse endpoint\n");
> + goto error_clk_put;
> + }
> +
> + /* fallback to parallel mode */
> + if (priv->ep.bus_type != V4L2_MBUS_PARALLEL &&
> + priv->ep.bus_type != V4L2_MBUS_BT656)
> + priv->ep.bus_type = V4L2_MBUS_PARALLEL;
shouldn't this be an error ? It's either the bus type has not been
specified on DT (which is fine, otherwise old DTB without that
properties will fail) and the bus identification routine implemented
in v4l2_fwnode_endpoint_parse() detected a bus type which is not
supported, hence the DT properties are wrong, and this should be an
error. If you plan to expand the parsing routine to support, say
bus-width and pclk polarity please break this out to a new function.
Thanks
j
> +
> ret = ov772x_video_probe(priv);
> if (ret < 0)
> goto error_gpio_put;
> --
> 2.17.1
>
