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path: root/drivers/video/tdfxfb.c
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Diffstat (limited to 'drivers/video/tdfxfb.c')
-rw-r--r--drivers/video/tdfxfb.c88
1 files changed, 53 insertions, 35 deletions
diff --git a/drivers/video/tdfxfb.c b/drivers/video/tdfxfb.c
index c34ba39b6f7..7044226c5d4 100644
--- a/drivers/video/tdfxfb.c
+++ b/drivers/video/tdfxfb.c
@@ -317,30 +317,49 @@ static inline void do_setpalentry(struct tdfx_par *par, unsigned regno, u32 c)
static u32 do_calc_pll(int freq, int* freq_out)
{
- int m, n, k, best_m, best_n, best_k, f_cur, best_error;
+ int m, n, k, best_m, best_n, best_k, best_error;
int fref = 14318;
- /* this really could be done with more intelligence --
- 255*63*4 = 64260 iterations is silly */
best_error = freq;
best_n = best_m = best_k = 0;
- for (n = 1; n < 256; n++) {
- for (m = 1; m < 64; m++) {
- for (k = 0; k < 4; k++) {
- f_cur = fref*(n + 2)/(m + 2)/(1 << k);
- if (abs(f_cur - freq) < best_error) {
- best_error = abs(f_cur-freq);
- best_n = n;
- best_m = m;
- best_k = k;
+
+ for (k = 3; k >= 0; k--) {
+ for (m = 63; m >= 0; m--) {
+ /*
+ * Estimate value of n that produces target frequency
+ * with current m and k
+ */
+ int n_estimated = (freq * (m + 2) * (1 << k) / fref) - 2;
+
+ /* Search neighborhood of estimated n */
+ for (n = max(0, n_estimated - 1);
+ n <= min(255, n_estimated + 1); n++) {
+ /*
+ * Calculate PLL freqency with current m, k and
+ * estimated n
+ */
+ int f = fref * (n + 2) / (m + 2) / (1 << k);
+ int error = abs (f - freq);
+
+ /*
+ * If this is the closest we've come to the
+ * target frequency then remember n, m and k
+ */
+ if (error < best_error) {
+ best_error = error;
+ best_n = n;
+ best_m = m;
+ best_k = k;
}
}
}
}
+
n = best_n;
m = best_m;
k = best_k;
*freq_out = fref*(n + 2)/(m + 2)/(1 << k);
+
return (n << 8) | (m << 2) | k;
}
@@ -411,36 +430,35 @@ static void do_write_regs(struct fb_info *info, struct banshee_reg* reg)
static unsigned long do_lfb_size(struct tdfx_par *par, unsigned short dev_id)
{
- u32 draminit0 = 0;
- u32 draminit1 = 0;
- u32 miscinit1 = 0;
- u32 lfbsize = 0;
- int sgram_p = 0;
+ u32 draminit0;
+ u32 draminit1;
+ u32 miscinit1;
+
+ int num_chips;
+ int chip_size; /* in MB */
+ u32 lfbsize;
+ int has_sgram;
draminit0 = tdfx_inl(par, DRAMINIT0);
draminit1 = tdfx_inl(par, DRAMINIT1);
+
+ num_chips = (draminit0 & DRAMINIT0_SGRAM_NUM) ? 8 : 4;
- if ((dev_id == PCI_DEVICE_ID_3DFX_BANSHEE) ||
- (dev_id == PCI_DEVICE_ID_3DFX_VOODOO3)) {
- sgram_p = (draminit1 & DRAMINIT1_MEM_SDRAM) ? 0 : 1;
-
- lfbsize = sgram_p ?
- (((draminit0 & DRAMINIT0_SGRAM_NUM) ? 2 : 1) *
- ((draminit0 & DRAMINIT0_SGRAM_TYPE) ? 8 : 4) * 1024 * 1024) :
- 16 * 1024 * 1024;
+ if (dev_id < PCI_DEVICE_ID_3DFX_VOODOO5) {
+ /* Banshee/Voodoo3 */
+ has_sgram = draminit1 & DRAMINIT1_MEM_SDRAM;
+ chip_size = has_sgram ? ((draminit0 & DRAMINIT0_SGRAM_TYPE) ? 2 : 1)
+ : 2;
} else {
/* Voodoo4/5 */
- u32 chips, psize, banks;
-
- chips = ((draminit0 & (1 << 26)) == 0) ? 4 : 8;
- psize = 1 << ((draminit0 & 0x38000000) >> 28);
- banks = ((draminit0 & (1 << 30)) == 0) ? 2 : 4;
- lfbsize = chips * psize * banks;
- lfbsize <<= 20;
- }
- /* disable block writes for SDRAM (why?) */
+ has_sgram = 0;
+ chip_size = 1 << ((draminit0 & DRAMINIT0_SGRAM_TYPE_MASK) >> DRAMINIT0_SGRAM_TYPE_SHIFT);
+ }
+ lfbsize = num_chips * chip_size * 1024 * 1024;
+
+ /* disable block writes for SDRAM */
miscinit1 = tdfx_inl(par, MISCINIT1);
- miscinit1 |= sgram_p ? 0 : MISCINIT1_2DBLOCK_DIS;
+ miscinit1 |= has_sgram ? 0 : MISCINIT1_2DBLOCK_DIS;
miscinit1 |= MISCINIT1_CLUT_INV;
banshee_make_room(par, 1);