Re: [PATCH v3 1/2] media: i2c: ov772x: Add support for BT656 mode

From: Laurent Pinchart
Date: Thu Sep 03 2020 - 21:20:40 EST


Hi Prabhakar,

Thank you for the patch.

On Mon, Aug 24, 2020 at 08:04:05PM +0100, Lad Prabhakar wrote:
> Add support to read the bus-type and enable BT656 mode if needed.
>
> Also fail probe if unsupported bus_type is detected.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> ---
> drivers/media/i2c/ov772x.c | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/drivers/media/i2c/ov772x.c b/drivers/media/i2c/ov772x.c
> index 2cc6a678069a..67764d647526 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;
> };
>
> /*
> @@ -581,6 +583,13 @@ 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) {
> + ret = regmap_update_bits(priv->regmap, COM7, ITU656_ON_OFF,
> + enable ? ITU656_ON_OFF : ~ITU656_ON_OFF);
> + if (ret)
> + goto done;
> + }
> +
> ret = regmap_update_bits(priv->regmap, COM2, SOFT_SLEEP_MODE,
> enable ? 0 : SOFT_SLEEP_MODE);
> if (ret)
> @@ -1354,6 +1363,7 @@ 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 +1425,28 @@ 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);

v4l2_fwnode_endpoint_parse() is deprecated for new drivers,
v4l2_fwnode_endpoint_alloc_parse() is recommended instead. Please note
that v4l2_fwnode_endpoint_free() then needs to be called in the error
path and in remove().

On the other hand, not setting .bus_type and letting the parse()
function determine the but type automatically is also deprecated, and I
don't think forcing drivers to call v4l2_fwnode_endpoint_alloc_parse()
once for each bus type until one succeeds is a good API. As change will
be needed in that API, you can ignore v4l2_fwnode_endpoint_alloc_parse()
for the time being if you want.

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

> + fwnode_handle_put(endpoint);
> + if (ret) {
> + dev_err(&client->dev, "Could not parse endpoint\n");
> + goto error_clk_put;
> + }
> +
> + if (priv->ep.bus_type != V4L2_MBUS_PARALLEL &&
> + priv->ep.bus_type != V4L2_MBUS_BT656) {
> + dev_err(&client->dev, "Unsupported bus type %d\n",
> + priv->ep.bus_type);
> + goto error_clk_put;
> + }
> +
> ret = ov772x_video_probe(priv);
> if (ret < 0)
> goto error_gpio_put;

--
Regards,

Laurent Pinchart