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>

diff --git a/drivers/video/cirrusfb.c b/drivers/video/cirrusfb.c
index 573bd45..30c47f1 100644 (file)
--- 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");