drm/dsi: Use mipi_dsi_device_register_full() for DSI device creation

Use mipi_dsi_device_register_full() for device creation. This takes in
a struct mipi_dsi_device_info as a template to populate the DSI device
information.

The reason to introduce this is to have a way to create DSI devices not
available via DT. Drivers that want to create a DSI device can populate
a struct mipi_dsi_device_info and call this function. For DSI devices
available via DT, of_mipi_dsi_device_add() is used as before, but this
now calls mipi_dsi_device_register_full() internally.
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/drm_mipi_dsi.c

@@ -133,8 +133,8 @@ static int mipi_dsi_device_add(struct mipi_dsi_device *dsi)
 static struct mipi_dsi_device *
 of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 {
-	struct mipi_dsi_device *dsi;
 	struct device *dev = host->dev;
+	struct mipi_dsi_device_info info = { };
 	int ret;
 	u32 reg;
 
@@ -145,39 +145,69 @@ of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 		return ERR_PTR(-EINVAL);
 	}
 
-	if (reg > 3) {
-		dev_err(dev, "device node %s has invalid reg property: %u\n",
-			node->full_name, reg);
+	info.channel = reg;
+	info.node = of_node_get(node);
+
+	return mipi_dsi_device_register_full(host, &info);
+}
+#else
+static struct mipi_dsi_device *
+of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
+{
+	return ERR_PTR(-ENODEV);
+}
+#endif
+
+/**
+ * mipi_dsi_device_register_full - create a MIPI DSI device
+ * @host: DSI host to which this device is connected
+ * @info: pointer to template containing DSI device information
+ *
+ * Create a MIPI DSI device by using the device information provided by
+ * mipi_dsi_device_info template
+ *
+ * Returns:
+ * A pointer to the newly created MIPI DSI device, or, a pointer encoded
+ * with an error
+ */
+struct mipi_dsi_device *
+mipi_dsi_device_register_full(struct mipi_dsi_host *host,
+			      const struct mipi_dsi_device_info *info)
+{
+	struct mipi_dsi_device *dsi;
+	struct device *dev = host->dev;
+	int ret;
+
+	if (!info) {
+		dev_err(dev, "invalid mipi_dsi_device_info pointer\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (info->channel > 3) {
+		dev_err(dev, "invalid virtual channel: %u\n", info->channel);
 		return ERR_PTR(-EINVAL);
 	}
 
 	dsi = mipi_dsi_device_alloc(host);
 	if (IS_ERR(dsi)) {
-		dev_err(dev, "failed to allocate DSI device %s: %ld\n",
-			node->full_name, PTR_ERR(dsi));
+		dev_err(dev, "failed to allocate DSI device %ld\n",
+			PTR_ERR(dsi));
 		return dsi;
 	}
 
-	dsi->dev.of_node = of_node_get(node);
-	dsi->channel = reg;
+	dsi->dev.of_node = info->node;
+	dsi->channel = info->channel;
 
 	ret = mipi_dsi_device_add(dsi);
 	if (ret) {
-		dev_err(dev, "failed to add DSI device %s: %d\n",
-			node->full_name, ret);
+		dev_err(dev, "failed to add DSI device %d\n", ret);
 		kfree(dsi);
 		return ERR_PTR(ret);
 	}
 
 	return dsi;
 }
-#else
-static struct mipi_dsi_device *
-of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
-{
-	return ERR_PTR(-ENODEV);
-}
-#endif
+EXPORT_SYMBOL(mipi_dsi_device_register_full);
 
 int mipi_dsi_host_register(struct mipi_dsi_host *host)
 {

include/drm/drm_mipi_dsi.h

@@ -139,6 +139,19 @@ enum mipi_dsi_pixel_format {
 	MIPI_DSI_FMT_RGB565,
 };
 
+ /**
+ * struct mipi_dsi_device_info - template for creating a mipi_dsi_device
+ * @channel: DSI virtual channel assigned to peripheral
+ * @node: pointer to OF device node
+ *
+ * This is populated and passed to mipi_dsi_device_new to create a new
+ * DSI device
+ */
+struct mipi_dsi_device_info {
+	u32 channel;
+	struct device_node *node;
+};
+
 /**
  * struct mipi_dsi_device - DSI peripheral device
  * @host: DSI host for this peripheral
@@ -188,6 +201,9 @@ static inline int mipi_dsi_pixel_format_to_bpp(enum mipi_dsi_pixel_format fmt)
 	return -EINVAL;
 }
 
+struct mipi_dsi_device *
+mipi_dsi_device_register_full(struct mipi_dsi_host *host,
+			      const struct mipi_dsi_device_info *info);
 struct mipi_dsi_device *of_find_mipi_dsi_device_by_node(struct device_node *np);
 int mipi_dsi_attach(struct mipi_dsi_device *dsi);
 int mipi_dsi_detach(struct mipi_dsi_device *dsi);