Thread (11 messages) read the whole thread 11 messages, 3 authors, 2020-08-17

Re: [PATCH v2 2/3] media: i2c: ov772x: Add support for BT656 mode

From: Jacopo Mondi <jacopo@jmondi.org>
Date: 2020-08-06 17:14:30
Also in: linux-media, linux-renesas-soc, lkml

On Mon, Aug 03, 2020 at 12:39:12PM +0100, Lad Prabhakar wrote:
quoted hunk ↗ jump to hunk
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@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
---
 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;
}

quoted hunk ↗ jump to hunk
 	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
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help