Refactor the function to easaly construct error paths later on. The
error handling gets dirty if we don't refactor the code yet. While on it
I fixed a missing i2c_put_adapter() if the bind() fails.

Signed-off-by: Marco Felsch <m.fel...@pengutronix.de>
---
 drivers/gpu/drm/imx/imx-ldb.c | 246 ++++++++++++++++++----------------
 1 file changed, 132 insertions(+), 114 deletions(-)

diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c
index 0e5a3c84df10..5e6c1b09dbfa 100644
--- a/drivers/gpu/drm/imx/imx-ldb.c
+++ b/drivers/gpu/drm/imx/imx-ldb.c
@@ -441,64 +441,6 @@ static int imx_ldb_get_clk(struct imx_ldb *ldb, int chno)
        return PTR_ERR_OR_ZERO(ldb->clk_pll[chno]);
 }
 
-static int imx_ldb_register_channel(struct drm_device *drm,
-                                   struct imx_ldb_channel *imx_ldb_ch,
-                                   struct imx_ldb_connector *imx_ldb_con)
-{
-       struct imx_ldb *ldb = imx_ldb_ch->ldb;
-       struct drm_encoder *encoder = &imx_ldb_ch->encoder;
-       struct drm_connector *connector = &imx_ldb_con->connector;
-       int ret;
-
-       ret = imx_drm_encoder_parse_of(drm, encoder, imx_ldb_ch->child);
-       if (ret)
-               return ret;
-
-       ret = imx_ldb_get_clk(ldb, imx_ldb_ch->chno);
-       if (ret)
-               return ret;
-
-       if (imx_ldb_is_dual(ldb)) {
-               ret = imx_ldb_get_clk(ldb, 1);
-               if (ret)
-                       return ret;
-       }
-
-       drm_encoder_helper_add(encoder, &imx_ldb_encoder_helper_funcs);
-       drm_encoder_init(drm, encoder, &imx_ldb_encoder_funcs,
-                        DRM_MODE_ENCODER_LVDS, NULL);
-
-       if (imx_ldb_ch->bridge) {
-               ret = drm_bridge_attach(encoder, imx_ldb_ch->bridge, NULL);
-               if (ret) {
-                       DRM_ERROR("Failed to initialize bridge with drm\n");
-                       return ret;
-               }
-       } else {
-               /*
-                * We want to add the connector whenever there is no bridge
-                * that brings its own, not only when there is a panel. For
-                * historical reasons, the ldb driver can also work without
-                * a panel.
-                */
-               drm_connector_helper_add(connector,
-                                        &imx_ldb_connector_helper_funcs);
-               drm_connector_init_with_ddc(drm, connector,
-                                           &imx_ldb_connector_funcs,
-                                           DRM_MODE_CONNECTOR_LVDS,
-                                           imx_ldb_con->ddc);
-               drm_connector_attach_encoder(connector, encoder);
-       }
-
-       if (imx_ldb_ch->panel) {
-               ret = drm_panel_attach(imx_ldb_ch->panel, connector);
-               if (ret)
-                       return ret;
-       }
-
-       return 0;
-}
-
 struct imx_ldb_bit_mapping {
        u32 bus_format;
        u32 datawidth;
@@ -576,6 +518,136 @@ static int imx_ldb_panel_ddc(struct device *dev,
        return 0;
 }
 
+static int imx_ldb_setup_channel(struct device *dev,
+                                struct device_node *child,
+                                struct drm_device *drm,
+                                struct imx_ldb *ldb,
+                                int channel_number)
+{
+       struct imx_ldb_channel *channel;
+       struct imx_ldb_connector *imx_ldb_con;
+       struct drm_encoder *encoder;
+       struct drm_connector *connector = NULL;
+       int bus_format;
+       int ret;
+
+       /*
+        * 1) Parse all available data and alloc needed structs
+        * 2) Setup the HW
+        * 3) Register it with the DRM framework
+        * 4) Attach bridge or connector to encoder
+        */
+       channel = devm_kzalloc(dev, sizeof(*channel), GFP_KERNEL);
+       if (!channel)
+               return -ENOMEM;
+
+       channel->ldb = ldb;
+       channel->chno = channel_number;
+       channel->child = child;
+       encoder = &channel->encoder;
+
+       /*
+        * The output port is port@4 with an external 4-port mux or
+        * port@2 with the internal 2-port mux.
+        */
+       ret = drm_of_find_panel_or_bridge(child,
+                                         ldb->lvds_mux ? 4 : 2, 0,
+                                         &channel->panel, &channel->bridge);
+       if (ret && ret != -ENODEV)
+               return ret;
+
+       /* panel ddc only if there is no bridge */
+       if (!channel->bridge) {
+               imx_ldb_con = devm_kzalloc(dev, sizeof(*connector), GFP_KERNEL);
+               if (!imx_ldb_con)
+                       return -ENOMEM;
+
+               ret = imx_ldb_panel_ddc(dev, channel, imx_ldb_con, child);
+               if (ret)
+                       return ret;
+
+               imx_ldb_con->ldb_channel = channel;
+               connector = &imx_ldb_con->connector;
+       }
+
+       bus_format = of_get_bus_format(dev, child);
+       if (bus_format == -EINVAL) {
+               /*
+                * If no bus format was specified in the device tree,
+                * we can still get it from the connected panel later.
+                */
+               if (channel->panel && channel->panel->funcs &&
+                   channel->panel->funcs->get_modes)
+                       bus_format = 0;
+       }
+       if (bus_format < 0) {
+               dev_err(dev, "could not determine data mapping: %d\n",
+                       bus_format);
+               ret = bus_format;
+               goto err_put_ddc;
+       }
+       channel->bus_format = bus_format;
+
+       /* 2) Setup the HW */
+       ret = imx_ldb_get_clk(channel->ldb, channel->chno);
+       if (ret)
+               goto err_put_ddc;
+
+       if (imx_ldb_is_dual(ldb)) {
+               ret = imx_ldb_get_clk(ldb, 1);
+               if (ret)
+                       goto err_put_ddc;
+       }
+
+       /* 3) Register it with the DRM framework */
+       ret = imx_drm_encoder_parse_of(drm, encoder, channel->child);
+       if (ret)
+               goto err_put_ddc;
+
+       drm_encoder_helper_add(encoder, &imx_ldb_encoder_helper_funcs);
+       drm_encoder_init(drm, encoder, &imx_ldb_encoder_funcs,
+                        DRM_MODE_ENCODER_LVDS, NULL);
+
+       if (!channel->bridge) {
+               /*
+                * We want to add the connector whenever there is no bridge
+                * that brings its own, not only when there is a panel. For
+                * historical reasons, the ldb driver can also work without
+                * a panel.
+                */
+               drm_connector_helper_add(connector,
+                                        &imx_ldb_connector_helper_funcs);
+               drm_connector_init_with_ddc(drm, connector,
+                                           &imx_ldb_connector_funcs,
+                                           DRM_MODE_CONNECTOR_LVDS,
+                                           imx_ldb_con->ddc);
+       }
+
+       /* 4) Attach bridge or connector to encoder */
+       if (channel->bridge) {
+               ret = drm_bridge_attach(encoder, channel->bridge, NULL);
+               if (ret) {
+                       DRM_ERROR("Failed to initialize bridge with drm\n");
+                       goto err_put_ddc;
+               }
+       } else {
+               drm_connector_attach_encoder(connector, encoder);
+       }
+
+       if (channel->panel) {
+               ret = drm_panel_attach(channel->panel, connector);
+               if (ret)
+                       goto err_put_ddc;
+       }
+
+       return 0;
+
+err_put_ddc:
+       if (imx_ldb_con)
+               i2c_put_adapter(imx_ldb_con->ddc);
+       return ret;
+}
+
 static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
 {
        struct drm_device *drm = data;
@@ -587,9 +659,6 @@ static int imx_ldb_bind(struct device *dev, struct device 
*master, void *data)
        int i;
 
        for_each_child_of_node(np, child) {
-               struct imx_ldb_channel *channel;
-               struct imx_ldb_connector *connector;
-               int bus_format;
 
                ret = of_property_read_u32(child, "reg", &i);
                if (ret || i < 0 || i > 1) {
@@ -605,60 +674,9 @@ static int imx_ldb_bind(struct device *dev, struct device 
*master, void *data)
                        continue;
                }
 
-               channel = devm_kzalloc(dev, sizeof(*channel), GFP_KERNEL);
-               if (!channel)
-                       return -ENOMEM;
-
-               channel->ldb = imx_ldb;
-               channel->chno = i;
-
-               /*
-                * The output port is port@4 with an external 4-port mux or
-                * port@2 with the internal 2-port mux.
-                */
-               ret = drm_of_find_panel_or_bridge(child,
-                                                 imx_ldb->lvds_mux ? 4 : 2, 0,
-                                                 &channel->panel, 
&channel->bridge);
-               if (ret && ret != -ENODEV)
-                       goto free_child;
-
-               /* panel ddc only if there is no bridge */
-               if (!channel->bridge) {
-                       connector = devm_kzalloc(dev, sizeof(*connector), 
GFP_KERNEL);
-                       if (!connector)
-                               return -ENOMEM;
-
-                       ret = imx_ldb_panel_ddc(dev, channel, connector, child);
-                       if (ret)
-                               goto free_child;
-
-                       connector->ldb_channel = channel;
-               }
-
-               bus_format = of_get_bus_format(dev, child);
-               if (bus_format == -EINVAL) {
-                       /*
-                        * If no bus format was specified in the device tree,
-                        * we can still get it from the connected panel later.
-                        */
-                       if (channel->panel && channel->panel->funcs &&
-                           channel->panel->funcs->get_modes)
-                               bus_format = 0;
-               }
-               if (bus_format < 0) {
-                       dev_err(dev, "could not determine data mapping: %d\n",
-                               bus_format);
-                       ret = bus_format;
-                       goto free_child;
-               }
-               channel->bus_format = bus_format;
-               channel->child = child;
-
-               ret = imx_ldb_register_channel(drm, channel, connector);
-               if (ret) {
-                       channel->child = NULL;
+               ret = imx_ldb_setup_channel(dev, child, drm, imx_ldb, i);
+               if (ret)
                        goto free_child;
-               }
        }
 
        return 0;
-- 
2.20.1

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