drm/i915/bios: Refactor panel_type code

Make the panel type code a bit more abstract along the
lines of the source of the panel type. For the moment
we have three classes: OpRegion, VBT, fallback.
Well introduce another one shortly.

We can now also print out all the different panel types,
and indicate which one we ultimately selected. Could help
with debugging.

v2: Add .get_panel_type() vfunc (Jani)

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220504150440.13748-8-ville.syrjala@linux.intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index 5248ca4..92de16f 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -594,6 +594,11 @@ get_lfp_data_tail(const struct bdb_lvds_lfp_data *data,
                return NULL;
 }
 
+static int opregion_get_panel_type(struct drm_i915_private *i915)
+{
+       return intel_opregion_get_panel_type(i915);
+}
+
 static int vbt_get_panel_type(struct drm_i915_private *i915)
 {
        const struct bdb_lvds_options *lvds_options;
@@ -611,25 +616,60 @@ static int vbt_get_panel_type(struct drm_i915_private *i915)
        return lvds_options->panel_type;
 }
 
+static int fallback_get_panel_type(struct drm_i915_private *i915)
+{
+       return 0;
+}
+
+enum panel_type {
+       PANEL_TYPE_OPREGION,
+       PANEL_TYPE_VBT,
+       PANEL_TYPE_FALLBACK,
+};
+
 static int get_panel_type(struct drm_i915_private *i915)
 {
-       int ret;
+       struct {
+               const char *name;
+               int (*get_panel_type)(struct drm_i915_private *i915);
+               int panel_type;
+       } panel_types[] = {
+               [PANEL_TYPE_OPREGION] = {
+                       .name = "OpRegion",
+                       .get_panel_type = opregion_get_panel_type,
+               },
+               [PANEL_TYPE_VBT] = {
+                       .name = "VBT",
+                       .get_panel_type = vbt_get_panel_type,
+               },
+               [PANEL_TYPE_FALLBACK] = {
+                       .name = "fallback",
+                       .get_panel_type = fallback_get_panel_type,
+               },
+       };
+       int i;
 
-       ret = intel_opregion_get_panel_type(i915);
-       if (ret >= 0) {
-               drm_WARN_ON(&i915->drm, ret > 0xf);
-               drm_dbg_kms(&i915->drm, "Panel type: %d (OpRegion)\n", ret);
-               return ret;
-       }
+       for (i = 0; i < ARRAY_SIZE(panel_types); i++) {
+               panel_types[i].panel_type = panel_types[i].get_panel_type(i915);
 
-       ret = vbt_get_panel_type(i915);
-       if (ret >= 0) {
-               drm_WARN_ON(&i915->drm, ret > 0xf);
-               drm_dbg_kms(&i915->drm, "Panel type: %d (VBT)\n", ret);
-               return ret;
+               drm_WARN_ON(&i915->drm, panel_types[i].panel_type > 0xf);
+
+               if (panel_types[i].panel_type >= 0)
+                       drm_dbg_kms(&i915->drm, "Panel type (%s): %d\n",
+                                   panel_types[i].name, panel_types[i].panel_type);
        }
 
-       return 0; /* fallback */
+       if (panel_types[PANEL_TYPE_OPREGION].panel_type >= 0)
+               i = PANEL_TYPE_OPREGION;
+       else if (panel_types[PANEL_TYPE_VBT].panel_type >= 0)
+               i = PANEL_TYPE_VBT;
+       else
+               i = PANEL_TYPE_FALLBACK;
+
+       drm_dbg_kms(&i915->drm, "Selected panel type (%s): %d\n",
+                   panel_types[i].name, panel_types[i].panel_type);
+
+       return panel_types[i].panel_type;
 }
 
 /* Parse general panel options */