ps3fb: round up video modes

Round up arbitrary video modes until they fit (if possible)

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 113 insertions, 45 deletions

diff --git a/drivers/video/ps3fb.c b/drivers/video/ps3fb.c
index d61e321dc90b..d552610603b2 100644
--- a/drivers/video/ps3fb.c
+++ b/drivers/video/ps3fb.c
@@ -276,29 +276,49 @@ static char *mode_option __devinitdata;
 static int ps3fb_cmp_mode(const struct fb_videomode *vmode,
                           const struct fb_var_screeninfo *var)
 {
-        /* resolution + black border must match a native resolution */
-        if (vmode->left_margin + vmode->xres + vmode->right_margin !=
-            var->left_margin + var->xres + var->right_margin ||
-            vmode->upper_margin + vmode->yres + vmode->lower_margin !=
-            var->upper_margin + var->yres + var->lower_margin)
+        long xres, yres, left_margin, right_margin, upper_margin, lower_margin;
+        long dx, dy;
+
+        /* maximum values */
+        if (var->xres > vmode->xres || var->yres > vmode->yres ||
+            var->pixclock > vmode->pixclock ||
+            var->hsync_len > vmode->hsync_len ||
+            var->vsync_len > vmode->vsync_len)
                 return -1;
 
-        /* minimum limits for margins */
-        if (vmode->left_margin > var->left_margin ||
-            vmode->right_margin > var->right_margin ||
-            vmode->upper_margin > var->upper_margin ||
-            vmode->lower_margin > var->lower_margin)
+        /* progressive/interlaced must match */
+        if ((var->vmode & FB_VMODE_MASK) != vmode->vmode)
                 return -1;
 
-        /* these fields must match exactly */
-        if (vmode->pixclock != var->pixclock ||
-            vmode->hsync_len != var->hsync_len ||
-            vmode->vsync_len != var->vsync_len ||
-            vmode->sync != var->sync ||
-            vmode->vmode != (var->vmode & FB_VMODE_MASK))
+        /* minimum resolution */
+        xres = max(var->xres, 1U);
+        yres = max(var->yres, 1U);
+
+        /* minimum margins */
+        left_margin = max(var->left_margin, vmode->left_margin);
+        right_margin = max(var->right_margin, vmode->right_margin);
+        upper_margin = max(var->upper_margin, vmode->upper_margin);
+        lower_margin = max(var->lower_margin, vmode->lower_margin);
+
+        /* resolution + margins may not exceed native parameters */
+        dx = ((long)vmode->left_margin + (long)vmode->xres +
+              (long)vmode->right_margin) -
+             (left_margin + xres + right_margin);
+        if (dx < 0)
                 return -1;
 
-        return 0;
+        dy = ((long)vmode->upper_margin + (long)vmode->yres +
+              (long)vmode->lower_margin) -
+             (upper_margin + yres + lower_margin);
+        if (dy < 0)
+                return -1;
+
+        /* exact match */
+        if (!dx && !dy)
+                return 0;
+
+        /* resolution difference */
+        return (vmode->xres - xres) * (vmode->yres - yres);
 }
 
 static const struct fb_videomode *ps3fb_native_vmode(enum ps3av_mode_num id)
@@ -324,33 +344,96 @@ static const struct fb_videomode *ps3fb_vmode(int id)
 static unsigned int ps3fb_find_mode(struct fb_var_screeninfo *var,
                                     u32 *ddr_line_length, u32 *xdr_line_length)
 {
-        unsigned int id;
+        unsigned int id, best_id;
+        int diff, best_diff;
         const struct fb_videomode *vmode;
+        long gap;
 
+        best_id = 0;
+        best_diff = INT_MAX;
+        pr_debug("%s: wanted %u [%u] %u x %u [%u] %u\n", __func__,
+                 var->left_margin, var->xres, var->right_margin,
+                 var->upper_margin, var->yres, var->lower_margin);
         for (id = PS3AV_MODE_480I; id <= PS3AV_MODE_WUXGA; id++) {
                 vmode = ps3fb_native_vmode(id);
-                if (!ps3fb_cmp_mode(vmode, var))
-                        goto found;
+                diff = ps3fb_cmp_mode(vmode, var);
+                pr_debug("%s: mode %u: %u [%u] %u x %u [%u] %u: diff = %d\n",
+                         __func__, id, vmode->left_margin, vmode->xres,
+                         vmode->right_margin, vmode->upper_margin,
+                         vmode->yres, vmode->lower_margin, diff);
+                if (diff < 0)
+                        continue;
+                if (diff < best_diff) {
+                        best_id = id;
+                        if (!diff)
+                                break;
+                        best_diff = diff;
+                }
         }
 
-        pr_debug("%s: mode not found\n", __func__);
-        return 0;
+        if (!best_id) {
+                pr_debug("%s: no suitable mode found\n", __func__);
+                return 0;
+        }
+
+        id = best_id;
+        vmode = ps3fb_native_vmode(id);
 
-found:
         *ddr_line_length = vmode->xres * BPP;
 
-        if (!var->xres) {
+        /* minimum resolution */
+        if (!var->xres)
                 var->xres = 1;
-                var->right_margin--;
-        }
-        if (!var->yres) {
+        if (!var->yres)
                 var->yres = 1;
-                var->lower_margin--;
+
+        /* minimum virtual resolution */
+        if (var->xres_virtual < var->xres)
+                var->xres_virtual = var->xres;
+        if (var->yres_virtual < var->yres)
+                var->yres_virtual = var->yres;
+
+        /* minimum margins */
+        if (var->left_margin < vmode->left_margin)
+                var->left_margin = vmode->left_margin;
+        if (var->right_margin < vmode->right_margin)
+                var->right_margin = vmode->right_margin;
+        if (var->upper_margin < vmode->upper_margin)
+                var->upper_margin = vmode->upper_margin;
+        if (var->lower_margin < vmode->lower_margin)
+                var->lower_margin = vmode->lower_margin;
+
+        /* extra margins */
+        gap = ((long)vmode->left_margin + (long)vmode->xres +
+               (long)vmode->right_margin) -
+              ((long)var->left_margin + (long)var->xres +
+               (long)var->right_margin);
+        if (gap > 0) {
+                var->left_margin += gap/2;
+                var->right_margin += (gap+1)/2;
+                pr_debug("%s: rounded up H to %u [%u] %u\n", __func__,
+                         var->left_margin, var->xres, var->right_margin);
         }
 
+        gap = ((long)vmode->upper_margin + (long)vmode->yres +
+               (long)vmode->lower_margin) -
+              ((long)var->upper_margin + (long)var->yres +
+               (long)var->lower_margin);
+        if (gap > 0) {
+                var->upper_margin += gap/2;
+                var->lower_margin += (gap+1)/2;
+                pr_debug("%s: rounded up V to %u [%u] %u\n", __func__,
+                         var->upper_margin, var->yres, var->lower_margin);
+        }
+
+        /* fixed fields */
+        var->pixclock = vmode->pixclock;
+        var->hsync_len = vmode->hsync_len;
+        var->vsync_len = vmode->vsync_len;
+        var->sync = vmode->sync;
+
         if (ps3_compare_firmware_version(1, 9, 0) >= 0) {
-                *xdr_line_length = GPU_ALIGN_UP(max(var->xres,
-                                                    var->xres_virtual) * BPP);
+                *xdr_line_length = GPU_ALIGN_UP(var->xres_virtual * BPP);
                 if (*xdr_line_length > GPU_MAX_LINE_LENGTH)
                         *xdr_line_length = GPU_MAX_LINE_LENGTH;
         } else
@@ -465,22 +548,11 @@ static int ps3fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
         u32 xdr_line_length, ddr_line_length;
         int mode;
 
-        dev_dbg(info->device, "var->xres:%u info->var.xres:%u\n", var->xres,
-                info->var.xres);
-        dev_dbg(info->device, "var->yres:%u info->var.yres:%u\n", var->yres,
-                info->var.yres);
-
-        /* FIXME For now we do exact matches only */
         mode = ps3fb_find_mode(var, &ddr_line_length, &xdr_line_length);
         if (!mode)
                 return -EINVAL;
 
         /* Virtual screen */
-        if (var->xres_virtual < var->xres)
-                var->xres_virtual = var->xres;
-        if (var->yres_virtual < var->yres)
-                var->yres_virtual = var->yres;
-
         if (var->xres_virtual > xdr_line_length / BPP) {
                 dev_dbg(info->device,
                         "Horizontal virtual screen size too large\n");
@@ -549,10 +621,6 @@ static int ps3fb_set_par(struct fb_info *info)
         const struct fb_videomode *vmode;
         u64 dst;
 
-        dev_dbg(info->device, "xres:%d xv:%d yres:%d yv:%d clock:%d\n",
-                info->var.xres, info->var.xres_virtual,
-                info->var.yres, info->var.yres_virtual, info->var.pixclock);
-
         mode = ps3fb_find_mode(&info->var, &ddr_line_length, &xdr_line_length);
         if (!mode)
                 return -EINVAL;