drm/omap: Major omap_modeset_init() cleanup

Cleanup overly complex omap_modeset_init(). The function is trying to
support many unusual configuration, that have never been tested and
are not supported by other parts of the dirver.

After cleanup the init function creates exactly one connector,
encoder, crtc, and primary plane per each connected dss-device. Each
connector->encoder->crtc chain is expected to be separate and each
crtc is connect to a single dss-channel. If the configuration does not
match the expectations or exceeds the available resources, the
configuration is rejected.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c
index 4f03f74685f0..dccd03726796 100644
--- a/drivers/gpu/drm/omapdrm/omap_crtc.c
+++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
@@ -573,6 +573,8 @@ static const char *channel_names[] = {
 
 void omap_crtc_pre_init(void)
 {
+        memset(omap_crtcs, 0, sizeof(omap_crtcs));
+
         dss_install_mgr_ops(&mgr_ops);
 }
 
@@ -583,18 +585,28 @@ void omap_crtc_pre_uninit(void)
 
 /* initialize crtc */
 struct drm_crtc *omap_crtc_init(struct drm_device *dev,
-                struct drm_plane *plane, enum omap_channel channel, int id)
+                struct drm_plane *plane, struct omap_dss_device *dssdev)
 {
         struct omap_drm_private *priv = dev->dev_private;
         struct drm_crtc *crtc = NULL;
         struct omap_crtc *omap_crtc;
+        enum omap_channel channel;
+        struct omap_dss_device *out;
         int ret;
 
+        out = omapdss_find_output_from_display(dssdev);
+        channel = out->dispc_channel;
+        omap_dss_put_device(out);
+
         DBG("%s", channel_names[channel]);
 
+        /* Multiple displays on same channel is not allowed */
+        if (WARN_ON(omap_crtcs[channel] != NULL))
+                return ERR_PTR(-EINVAL);
+
         omap_crtc = kzalloc(sizeof(*omap_crtc), GFP_KERNEL);
         if (!omap_crtc)
-                return NULL;
+                return ERR_PTR(-ENOMEM);
 
         crtc = &omap_crtc->base;
 
@@ -606,8 +618,10 @@ struct drm_crtc *omap_crtc_init(struct drm_device *dev,
         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
                                         &omap_crtc_funcs, NULL);
         if (ret < 0) {
+                dev_err(dev->dev, "%s(): could not init crtc for: %s\n",
+                        __func__, dssdev->name);
                 kfree(omap_crtc);
-                return NULL;
+                return ERR_PTR(ret);
         }
 
         drm_crtc_helper_add(crtc, &omap_crtc_helper_funcs);