tdfxfb: make use of DDC information about connected monitor

Read DDC information from a connected monitor and use it to select initial
mode (if the mode is not specified).

Also, use the information to protect against modes outside the monitor
specs.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Tested-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 63 insertions, 4 deletions

diff --git a/drivers/video/tdfxfb.c b/drivers/video/tdfxfb.c
index bc6f916c53be..89f231dc443f 100644
--- a/drivers/video/tdfxfb.c
+++ b/drivers/video/tdfxfb.c
@@ -487,6 +487,12 @@ static int tdfxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
                 return -EINVAL;
         }
 
+        if (info->monspecs.hfmax && info->monspecs.vfmax &&
+            info->monspecs.dclkmax && fb_validate_mode(var, info) < 0) {
+                DPRINTK("mode outside monitor's specs\n");
+                return -EINVAL;
+        }
+
         var->xres = (var->xres + 15) & ~15; /* could sometimes be 8 */
         lpitch = var->xres * ((var->bits_per_pixel + 7) >> 3);
 
@@ -1355,6 +1361,23 @@ static void tdfxfb_delete_i2c_busses(struct tdfx_par *par)
                 i2c_del_adapter(&par->chan[1].adapter);
         par->chan[1].par = NULL;
 }
+
+static int tdfxfb_probe_i2c_connector(struct tdfx_par *par,
+                                      struct fb_monspecs *specs)
+{
+        u8 *edid = NULL;
+
+        DPRINTK("Probe DDC Bus\n");
+        if (par->chan[0].par)
+                edid = fb_ddc_read(&par->chan[0].adapter);
+
+        if (edid) {
+                fb_edid_to_monspecs(edid, specs);
+                kfree(edid);
+                return 0;
+        }
+        return 1;
+}
 #endif /* CONFIG_FB_3DFX_I2C */
 
 /**
@@ -1372,6 +1395,8 @@ static int __devinit tdfxfb_probe(struct pci_dev *pdev,
         struct tdfx_par *default_par;
         struct fb_info *info;
         int err, lpitch;
+        struct fb_monspecs *specs;
+        bool found;
 
         err = pci_enable_device(pdev);
         if (err) {
@@ -1474,15 +1499,49 @@ static int __devinit tdfxfb_probe(struct pci_dev *pdev,
         if (hwcursor)
                 info->fix.smem_len = (info->fix.smem_len - 1024) &
                                         (PAGE_MASK << 1);
+        specs = &info->monspecs;
+        found = false;
+        info->var.bits_per_pixel = 8;
 #ifdef CONFIG_FB_3DFX_I2C
         tdfxfb_create_i2c_busses(info);
+        err = tdfxfb_probe_i2c_connector(default_par, specs);
+
+        if (!err) {
+                if (specs->modedb == NULL)
+                        DPRINTK("Unable to get Mode Database\n");
+                else {
+                        const struct fb_videomode *m;
+
+                        fb_videomode_to_modelist(specs->modedb,
+                                                 specs->modedb_len,
+                                                 &info->modelist);
+                        m = fb_find_best_display(specs, &info->modelist);
+                        if (m) {
+                                fb_videomode_to_var(&info->var, m);
+                                /* fill all other info->var's fields */
+                                if (tdfxfb_check_var(&info->var, info) < 0)
+                                        info->var = tdfx_var;
+                                else
+                                        found = true;
+                        }
+                }
+        }
 #endif
-        if (!mode_option)
+        if (!mode_option && !found)
                 mode_option = "640x480@60";
 
-        err = fb_find_mode(&info->var, info, mode_option, NULL, 0, NULL, 8);
-        if (!err || err == 4)
-                info->var = tdfx_var;
+        if (mode_option) {
+                err = fb_find_mode(&info->var, info, mode_option,
+                                   specs->modedb, specs->modedb_len,
+                                   NULL, info->var.bits_per_pixel);
+                if (!err || err == 4)
+                        info->var = tdfx_var;
+        }
+
+        if (found) {
+                fb_destroy_modedb(specs->modedb);
+                specs->modedb = NULL;
+        }
 
         /* maximize virtual vertical length */
         lpitch = info->var.xres_virtual * ((info->var.bits_per_pixel + 7) >> 3);