cirrusfb: drop clock fields from cirrusfb_regs structure

Move call to pixclock calculation into the cirrusfb_set_par_foo().  It
makes copy of clock registers redundant.

Simplify clock calculations further.

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

1 files changed, 21 insertions, 29 deletions

diff --git a/drivers/video/cirrusfb.c b/drivers/video/cirrusfb.c
index 573bd456e5ab..30c47f167608 100644
--- a/drivers/video/cirrusfb.c
+++ b/drivers/video/cirrusfb.c
@@ -327,10 +327,6 @@ static const struct {
 #endif /* CONFIG_ZORRO */
 
 struct cirrusfb_regs {
-        long freq;
-        long nom;
-        long den;
-        long div;
         long multiplexing;
         long mclk;
         long divMCLK;
@@ -429,9 +425,7 @@ static void cirrusfb_RectFill(u8 __iomem *regbase, int bits_per_pixel,
                               u_short width, u_short height,
                               u_char color, u_short line_length);
 
-static void bestclock(long freq, long *best,
-                      long *nom, long *den,
-                      long *div, long maxfreq);
+static void bestclock(long freq, int *nom, int *den, int *div);
 
 #ifdef CIRRUSFB_DEBUG
 static void cirrusfb_dump(void);
@@ -711,9 +705,6 @@ static int cirrusfb_decode_var(const struct fb_var_screeninfo *var,
                 break;
         }
 #endif
-
-        bestclock(freq, &regs->freq, &regs->nom, &regs->den, &regs->div,
-                  maxclock);
         regs->mclk = cirrusfb_get_mclk(freq, var->bits_per_pixel,
                                         &regs->divMCLK);
 
@@ -756,6 +747,8 @@ static int cirrusfb_set_par_foo(struct fb_info *info)
         const struct cirrusfb_board_info_rec *bi;
         int hdispend, hsyncstart, hsyncend, htotal;
         int yres, vdispend, vsyncstart, vsyncend, vtotal;
+        long freq;
+        int nom, den, div;
 
         DPRINTK("ENTER\n");
         DPRINTK("Requested mode: %dx%dx%d\n",
@@ -903,14 +896,17 @@ static int cirrusfb_set_par_foo(struct fb_info *info)
         DPRINTK("CRT1a: %d\n", tmp);
         vga_wcrt(regbase, CL_CRT1A, tmp);
 
+        freq = PICOS2KHZ(var->pixclock);
+        bestclock(freq, &nom, &den, &div);
+
         /* set VCLK0 */
         /* hardware RefClock: 14.31818 MHz */
         /* formula: VClk = (OSC * N) / (D * (1+P)) */
         /* Example: VClk = (14.31818 * 91) / (23 * (1+1)) = 28.325 MHz */
 
-        vga_wseq(regbase, CL_SEQRB, regs.nom);
-        tmp = regs.den << 1;
-        if (regs.div != 0)
+        vga_wseq(regbase, CL_SEQRB, nom);
+        tmp = den << 1;
+        if (div != 0)
                 tmp |= 1;
 
         /* 6 bit denom; ONLY 5434!!! (bugged me 10 days) */
@@ -2923,16 +2919,14 @@ static void cirrusfb_RectFill(u8 __iomem *regbase, int bits_per_pixel,
  * bestclock() - determine closest possible clock lower(?) than the
  * desired pixel clock
  **************************************************************************/
-static void bestclock(long freq, long *best, long *nom,
-                       long *den, long *div, long maxfreq)
+static void bestclock(long freq, int *nom, int *den, int *div)
 {
-        long n, h, d, f;
+        int n, d;
+        long h, diff;
 
-        assert(best != NULL);
         assert(nom != NULL);
         assert(den != NULL);
         assert(div != NULL);
-        assert(maxfreq > 0);
 
         *nom = 0;
         *den = 0;
@@ -2943,16 +2937,12 @@ static void bestclock(long freq, long *best, long *nom,
         if (freq < 8000)
                 freq = 8000;
 
-        if (freq > maxfreq)
-                freq = maxfreq;
-
-        *best = 0;
-        f = freq * 10;
+        diff = freq;
 
         for (n = 32; n < 128; n++) {
                 int s = 0;
 
-                d = (143181 * n) / f;
+                d = (14318 * n) / freq;
                 if ((d >= 7) && (d <= 63)) {
                         int temp = d;
 
@@ -2961,8 +2951,9 @@ static void bestclock(long freq, long *best, long *nom,
                                 temp >>= 1;
                         }
                         h = ((14318 * n) / temp) >> s;
-                        if (abs(h - freq) < abs(*best - freq)) {
-                                *best = h;
+                        h = h > freq ? h - freq : freq - h;
+                        if (h < diff) {
+                                diff = h;
                                 *nom = n;
                                 *den = temp;
                                 *div = s;
@@ -2975,8 +2966,9 @@ static void bestclock(long freq, long *best, long *nom,
                                 d >>= 1;
                         }
                         h = ((14318 * n) / d) >> s;
-                        if (abs(h - freq) < abs(*best - freq)) {
-                                *best = h;
+                        h = h > freq ? h - freq : freq - h;
+                        if (h < diff) {
+                                diff = h;
                                 *nom = n;
                                 *den = d;
                                 *div = s;
@@ -2985,7 +2977,7 @@ static void bestclock(long freq, long *best, long *nom,
         }
 
         DPRINTK("Best possible values for given frequency:\n");
-        DPRINTK("       best: %ld kHz  nom: %ld  den: %ld  div: %ld\n",
+        DPRINTK("       freq: %ld kHz  nom: %d  den: %d  div: %d\n",
                 freq, *nom, *den, *div);
 
         DPRINTK("EXIT\n");