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From:   Eugen Hristev <eugen.hristev@microchip.com>
To:     <leonl@leopardimaging.com>, <linux-media@vger.kernel.org>
CC:     <skomatineni@nvidia.com>, <sakari.ailus@linux.intel.com>,
        <luca@lucaceresoli.net>, <linux-kernel@vger.kernel.org>,
        Eugen Hristev <eugen.hristev@microchip.com>
Subject: [PATCH 2/2] media: i2c: imx274: implement fwnode parsing
Date:   Tue, 23 Nov 2021 13:15:21 +0200
Message-ID: <20211123111521.593863-2-eugen.hristev@microchip.com>
In-Reply-To: <20211123111521.593863-1-eugen.hristev@microchip.com>
References: <20211123111521.593863-1-eugen.hristev@microchip.com>
MIME-Version: 1.0
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Precedence: bulk

Implement fwnode parsing at probe time.
Check if the bus and number of lanes are supported.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
---
 drivers/media/i2c/imx274.c | 40 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
index e31f006b10d9..774912f44efe 100644
--- a/drivers/media/i2c/imx274.c
+++ b/drivers/media/i2c/imx274.c
@@ -27,6 +27,7 @@
 
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
 #include <media/v4l2-subdev.h>
 
 /*
@@ -1957,6 +1958,41 @@ static const struct i2c_device_id imx274_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, imx274_id);
 
+static int imx274_fwnode_parse(struct device *dev)
+{
+	struct fwnode_handle *endpoint;
+	/* Only CSI2 is supported */
+	struct v4l2_fwnode_endpoint ep = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY
+	};
+	int ret;
+
+	endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(dev), NULL);
+	if (!endpoint) {
+		dev_err(dev, "Endpoint node not found\n");
+		return -EINVAL;
+	}
+
+	ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &ep);
+	fwnode_handle_put(endpoint);
+	if (ret == -ENXIO) {
+		dev_err(dev, "Unsupported bus type, should be CSI2\n");
+		return ret;
+	} else if (ret) {
+		dev_err(dev, "Parsing endpoint node failed %d\n", ret);
+		return ret;
+	}
+
+	/* Check number of data lanes, only 4 lanes supported */
+	if (ep.bus.mipi_csi2.num_data_lanes != 4) {
+		dev_err(dev, "Invalid data lanes: %d\n",
+			ep.bus.mipi_csi2.num_data_lanes);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int imx274_probe(struct i2c_client *client)
 {
 	struct v4l2_subdev *sd;
@@ -1971,6 +2007,10 @@ static int imx274_probe(struct i2c_client *client)
 
 	mutex_init(&imx274->lock);
 
+	ret = imx274_fwnode_parse(dev);
+	if (ret)
+		return ret;
+
 	imx274->inck = devm_clk_get_optional(dev, "inck");
 	if (IS_ERR(imx274->inck))
 		return PTR_ERR(imx274->inck);
-- 
2.25.1