viafb: add initial EDID support

This patch adds support for using EDID data on CRT and DVP1 for
initial configuration if viafb_mode or viafb_mode1 are not present.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

1 files changed, 58 insertions, 1 deletions

diff --git a/drivers/video/via/via_aux_edid.c b/drivers/video/via/via_aux_edid.c
index 547bff53a448..03f7a41c8a3f 100644
--- a/drivers/video/via/via_aux_edid.c
+++ b/drivers/video/via/via_aux_edid.c
@@ -22,18 +22,75 @@
  */
 
 #include <linux/slab.h>
+#include <linux/fb.h>
 #include "via_aux.h"
+#include "../edid.h"
 
 
 static const char *name = "EDID";
 
 
+static void query_edid(struct via_aux_drv *drv)
+{
+        struct fb_monspecs *spec = drv->data;
+        unsigned char edid[EDID_LENGTH];
+        bool valid = false;
+
+        if (spec)
+                fb_destroy_modedb(spec->modedb);
+        else
+                spec = kmalloc(sizeof(*spec), GFP_KERNEL);
+
+        spec->version = spec->revision = 0;
+        if (via_aux_read(drv, 0x00, edid, EDID_LENGTH)) {
+                fb_edid_to_monspecs(edid, spec);
+                valid = spec->version || spec->revision;
+        }
+
+        if (!valid) {
+                kfree(spec);
+                spec = NULL;
+        } else
+                printk(KERN_DEBUG "EDID: %s %s\n", spec->manufacturer, spec->monitor);
+
+        drv->data = spec;
+}
+
+static const struct fb_videomode *get_preferred_mode(struct via_aux_drv *drv)
+{
+        struct fb_monspecs *spec = drv->data;
+        int i;
+
+        if (!spec || !spec->modedb || !(spec->misc & FB_MISC_1ST_DETAIL))
+                return NULL;
+
+        for (i = 0; i < spec->modedb_len; i++) {
+                if (spec->modedb[i].flag & FB_MODE_IS_FIRST &&
+                        spec->modedb[i].flag & FB_MODE_IS_DETAILED)
+                        return &spec->modedb[i];
+        }
+
+        return NULL;
+}
+
+static void cleanup(struct via_aux_drv *drv)
+{
+        struct fb_monspecs *spec = drv->data;
+
+        if (spec)
+                fb_destroy_modedb(spec->modedb);
+}
+
 void via_aux_edid_probe(struct via_aux_bus *bus)
 {
         struct via_aux_drv drv = {
                 .bus    =       bus,
                 .addr   =       0x50,
-                .name   =       name};
+                .name   =       name,
+                .cleanup        =       cleanup,
+                .get_preferred_mode     =       get_preferred_mode};
+
+        query_edid(&drv);
 
         /* as EDID devices can be connected/disconnected just add the driver */
         via_aux_add(&drv);