[media] V4L: sh_mobile_csi2: verify client compatibility

Switch the meaning of the .lanes platform data parameter to specify
the number of used lanes instead of a bitmask. Verify bus configuration
compatibility with client's capabilities.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/sh_mobile_csi2.c

@@ -19,6 +19,7 @@
 #include <media/sh_mobile_ceu.h>
 #include <media/sh_mobile_csi2.h>
 #include <media/soc_camera.h>
+#include <media/soc_mediabus.h>
 #include <media/v4l2-common.h>
 #include <media/v4l2-dev.h>
 #include <media/v4l2-device.h>
@@ -144,11 +145,21 @@ static void sh_csi2_hwinit(struct sh_csi2 *priv)
 	udelay(5);
 	iowrite32(0x00000000, priv->base + SH_CSI2_SRST);
 
-	if (priv->client->lanes & 3)
-		tmp |= priv->client->lanes & 3;
-	else
-		/* Default - both lanes */
-		tmp |= 3;
+	switch (pdata->type) {
+	case SH_CSI2C:
+		if (priv->client->lanes == 1)
+			tmp |= 1;
+		else
+			/* Default - both lanes */
+			tmp |= 3;
+		break;
+	case SH_CSI2I:
+		if (!priv->client->lanes || priv->client->lanes > 4)
+			/* Default - all 4 lanes */
+			tmp |= 0xf;
+		else
+			tmp |= (1 << priv->client->lanes) - 1;
+	}
 
 	if (priv->client->phy == SH_CSI2_PHY_MAIN)
 		tmp |= 0x8000;
@@ -185,7 +196,9 @@ static int sh_csi2_client_connect(struct sh_csi2 *priv)
 	struct v4l2_subdev *sd, *csi2_sd = &priv->subdev;
 	struct soc_camera_device *icd = NULL;
 	struct device *dev = v4l2_get_subdevdata(&priv->subdev);
-	int i;
+	struct v4l2_mbus_config cfg;
+	unsigned long common_flags, csi2_flags;
+	int i, ret;
 
 	v4l2_device_for_each_subdev(sd, csi2_sd->v4l2_dev)
 		if (sd->grp_id) {
@@ -205,6 +218,39 @@ static int sh_csi2_client_connect(struct sh_csi2 *priv)
 	if (i == pdata->num_clients)
 		return -ENODEV;
 
+	/* Check if we can support this camera */
+	csi2_flags = V4L2_MBUS_CSI2_CONTINUOUS_CLOCK | V4L2_MBUS_CSI2_1_LANE;
+
+	switch (pdata->type) {
+	case SH_CSI2C:
+		if (pdata->clients[i].lanes != 1)
+			csi2_flags |= V4L2_MBUS_CSI2_2_LANE;
+		break;
+	case SH_CSI2I:
+		switch (pdata->clients[i].lanes) {
+		default:
+			csi2_flags |= V4L2_MBUS_CSI2_4_LANE;
+		case 3:
+			csi2_flags |= V4L2_MBUS_CSI2_3_LANE;
+		case 2:
+			csi2_flags |= V4L2_MBUS_CSI2_2_LANE;
+		}
+	}
+
+	cfg.type = V4L2_MBUS_CSI2;
+	ret = v4l2_subdev_call(sd, video, g_mbus_config, &cfg);
+	if (ret == -ENOIOCTLCMD)
+		common_flags = csi2_flags;
+	else if (!ret)
+		common_flags = soc_mbus_config_compatible(&cfg,
+							  csi2_flags);
+	else
+		common_flags = 0;
+
+	if (!common_flags)
+		return -EINVAL;
+
+	/* All good: camera MIPI configuration supported */
 	priv->client = pdata->clients + i;
 
 	priv->set_bus_param		= icd->ops->set_bus_param;