[media] soc_camera: add support for dt binding soc_camera drivers

Add initial support for OF based soc-camera devices that may be used
by any of the soc-camera drivers. The driver itself will need converting
to use OF.

These changes allow the soc-camera driver to do the connecting of any
async capable v4l2 device to the soc-camera driver. This has currently
been tested on the Renesas Lager board.

It currently only supports one input device per driver as this seems
to be the standard connection for these devices.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
[g.liakhovetski@gmx.de add check for multiple subdevices]
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Tested-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/platform/soc_camera/soc_camera.c

@@ -36,6 +36,7 @@
 #include <media/v4l2-common.h>
 #include <media/v4l2-ioctl.h>
 #include <media/v4l2-dev.h>
+#include <media/v4l2-of.h>
 #include <media/videobuf-core.h>
 #include <media/videobuf2-core.h>
 
@@ -1585,6 +1586,130 @@ static void scan_async_host(struct soc_camera_host *ici)
 #define scan_async_host(ici)		do {} while (0)
 #endif
 
+#ifdef CONFIG_OF
+
+struct soc_of_info {
+	struct soc_camera_async_subdev	sasd;
+	struct soc_camera_async_client	sasc;
+	struct v4l2_async_subdev	*subdev;
+};
+
+static int soc_of_bind(struct soc_camera_host *ici,
+		       struct device_node *ep,
+		       struct device_node *remote)
+{
+	struct soc_camera_device *icd;
+	struct soc_camera_desc sdesc = {.host_desc.bus_id = ici->nr,};
+	struct soc_camera_async_client *sasc;
+	struct soc_of_info *info;
+	struct i2c_client *client;
+	char clk_name[V4L2_SUBDEV_NAME_SIZE];
+	int ret;
+
+	/* allocate a new subdev and add match info to it */
+	info = devm_kzalloc(ici->v4l2_dev.dev, sizeof(struct soc_of_info),
+			    GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->sasd.asd.match.of.node = remote;
+	info->sasd.asd.match_type = V4L2_ASYNC_MATCH_OF;
+	info->subdev = &info->sasd.asd;
+
+	/* Or shall this be managed by the soc-camera device? */
+	sasc = &info->sasc;
+
+	/* HACK: just need a != NULL */
+	sdesc.host_desc.board_info = ERR_PTR(-ENODATA);
+
+	ret = soc_camera_dyn_pdev(&sdesc, sasc);
+	if (ret < 0)
+		goto eallocpdev;
+
+	sasc->sensor = &info->sasd.asd;
+
+	icd = soc_camera_add_pdev(sasc);
+	if (!icd) {
+		ret = -ENOMEM;
+		goto eaddpdev;
+	}
+
+	sasc->notifier.subdevs = &info->subdev;
+	sasc->notifier.num_subdevs = 1;
+	sasc->notifier.bound = soc_camera_async_bound;
+	sasc->notifier.unbind = soc_camera_async_unbind;
+	sasc->notifier.complete = soc_camera_async_complete;
+
+	icd->sasc = sasc;
+	icd->parent = ici->v4l2_dev.dev;
+
+	client = of_find_i2c_device_by_node(remote);
+
+	if (client)
+		snprintf(clk_name, sizeof(clk_name), "%d-%04x",
+			 client->adapter->nr, client->addr);
+	else
+		snprintf(clk_name, sizeof(clk_name), "of-%s",
+			 of_node_full_name(remote));
+
+	icd->clk = v4l2_clk_register(&soc_camera_clk_ops, clk_name, "mclk", icd);
+	if (IS_ERR(icd->clk)) {
+		ret = PTR_ERR(icd->clk);
+		goto eclkreg;
+	}
+
+	ret = v4l2_async_notifier_register(&ici->v4l2_dev, &sasc->notifier);
+	if (!ret)
+		return 0;
+eclkreg:
+	icd->clk = NULL;
+	platform_device_del(sasc->pdev);
+eaddpdev:
+	platform_device_put(sasc->pdev);
+eallocpdev:
+	devm_kfree(ici->v4l2_dev.dev, sasc);
+	dev_err(ici->v4l2_dev.dev, "group probe failed: %d\n", ret);
+
+	return ret;
+}
+
+static void scan_of_host(struct soc_camera_host *ici)
+{
+	struct device *dev = ici->v4l2_dev.dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *epn = NULL, *ren;
+	unsigned int i;
+
+	for (i = 0; ; i++) {
+		epn = of_graph_get_next_endpoint(np, epn);
+		if (!epn)
+			break;
+
+		ren = of_graph_get_remote_port(epn);
+		if (!ren) {
+			dev_notice(dev, "no remote for %s\n",
+				   of_node_full_name(epn));
+			continue;
+		}
+
+		/* so we now have a remote node to connect */
+		if (!i)
+			soc_of_bind(ici, epn, ren->parent);
+
+		of_node_put(epn);
+		of_node_put(ren);
+
+		if (i) {
+			dev_err(dev, "multiple subdevices aren't supported yet!\n");
+			break;
+		}
+	}
+}
+
+#else
+static inline void scan_of_host(struct soc_camera_host *ici) { }
+#endif
+
 /* Called during host-driver probe */
 static int soc_camera_probe(struct soc_camera_host *ici,
 			    struct soc_camera_device *icd)
@@ -1836,7 +1961,9 @@ int soc_camera_host_register(struct soc_camera_host *ici)
 	mutex_init(&ici->host_lock);
 	mutex_init(&ici->clk_lock);
 
-	if (ici->asd_sizes)
+	if (ici->v4l2_dev.dev->of_node)
+		scan_of_host(ici);
+	else if (ici->asd_sizes)
 		/*
 		 * No OF, host with a list of subdevices. Don't try to mix
 		 * modes by initialising some groups statically and some