diff options
| -rw-r--r-- | drivers/video/cirrusfb.c | 119 |
1 files changed, 53 insertions, 66 deletions
diff --git a/drivers/video/cirrusfb.c b/drivers/video/cirrusfb.c index 9e0a1c58fde..048b139f0e5 100644 --- a/drivers/video/cirrusfb.c +++ b/drivers/video/cirrusfb.c @@ -327,9 +327,7 @@ static const struct { #endif /* CONFIG_ZORRO */ struct cirrusfb_regs { - long multiplexing; - long mclk; - long divMCLK; + int multiplexing; }; #ifdef CIRRUSFB_DEBUG @@ -461,45 +459,28 @@ static int cirrusfb_release(struct fb_info *info, int user) /****************************************************************************/ /**** BEGIN Hardware specific Routines **************************************/ -/* Get a good MCLK value */ -static long cirrusfb_get_mclk(long freq, int bpp, long *div) +/* Check if the MCLK is not a better clock source */ +static int cirrusfb_check_mclk(struct cirrusfb_info *cinfo, long freq) { - long mclk; + long mclk = vga_rseq(cinfo->regbase, CL_SEQR1F) & 0x3f; - assert(div != NULL); - - /* Calculate MCLK, in case VCLK is high enough to require > 50MHz. - * Assume a 64-bit data path for now. The formula is: - * ((B * PCLK * 2)/W) * 1.2 - * B = bytes per pixel, PCLK = pixclock, W = data width in bytes */ - mclk = ((bpp / 8) * freq * 2) / 4; - mclk = (mclk * 12) / 10; - if (mclk < 50000) - mclk = 50000; - DPRINTK("Use MCLK of %ld kHz\n", mclk); - - /* Calculate value for SR1F. Multiply by 2 so we can round up. */ - mclk = ((mclk * 16) / 14318); - mclk = (mclk + 1) / 2; - DPRINTK("Set SR1F[5:0] to 0x%lx\n", mclk); + /* Read MCLK value */ + mclk = (14318 * mclk) >> 3; + DPRINTK("Read MCLK of %ld kHz\n", mclk); /* Determine if we should use MCLK instead of VCLK, and if so, what we - * should divide it by to get VCLK */ - switch (freq) { - case 24751 ... 25249: - *div = 2; - DPRINTK("Using VCLK = MCLK/2\n"); - break; - case 49501 ... 50499: - *div = 1; + * should divide it by to get VCLK + */ + + if (abs(freq - mclk) < 250) { DPRINTK("Using VCLK = MCLK\n"); - break; - default: - *div = 0; - break; + return 1; + } else if (abs(freq - (mclk / 2)) < 250) { + DPRINTK("Using VCLK = MCLK/2\n"); + return 2; } - return mclk; + return 0; } static int cirrusfb_check_var(struct fb_var_screeninfo *var, @@ -705,30 +686,27 @@ static int cirrusfb_decode_var(const struct fb_var_screeninfo *var, break; } #endif - regs->mclk = cirrusfb_get_mclk(freq, var->bits_per_pixel, - ®s->divMCLK); - return 0; } -static void cirrusfb_set_mclk(const struct cirrusfb_info *cinfo, int val, - int div) +static void cirrusfb_set_mclk_as_source(const struct cirrusfb_info *cinfo, + int div) { + unsigned char old1f, old1e; assert(cinfo != NULL); + old1f = vga_rseq(cinfo->regbase, CL_SEQR1F) & ~0x40; - if (div == 2) { - /* VCLK = MCLK/2 */ - unsigned char old = vga_rseq(cinfo->regbase, CL_SEQR1E); - vga_wseq(cinfo->regbase, CL_SEQR1E, old | 0x1); - vga_wseq(cinfo->regbase, CL_SEQR1F, 0x40 | (val & 0x3f)); - } else if (div == 1) { - /* VCLK = MCLK */ - unsigned char old = vga_rseq(cinfo->regbase, CL_SEQR1E); - vga_wseq(cinfo->regbase, CL_SEQR1E, old & ~0x1); - vga_wseq(cinfo->regbase, CL_SEQR1F, 0x40 | (val & 0x3f)); - } else { - vga_wseq(cinfo->regbase, CL_SEQR1F, val & 0x3f); + if (div) { + DPRINTK("Set %s as pixclock source.\n", + (div == 2) ? "MCLK/2" : "MCLK"); + old1f |= 0x40; + old1e = vga_rseq(cinfo->regbase, CL_SEQR1E) & ~0x1; + if (div == 2) + old1e |= 1; + + vga_wseq(cinfo->regbase, CL_SEQR1E, old1e); } + vga_wseq(cinfo->regbase, CL_SEQR1F, old1f); } /************************************************************************* @@ -904,19 +882,31 @@ static int cirrusfb_set_par_foo(struct fb_info *info) /* formula: VClk = (OSC * N) / (D * (1+P)) */ /* Example: VClk = (14.31818 * 91) / (23 * (1+1)) = 28.325 MHz */ - vga_wseq(regbase, CL_SEQRB, nom); - tmp = den << 1; - if (div != 0) - tmp |= 1; + if (cinfo->btype == BT_ALPINE) { + /* if freq is close to mclk or mclk/2 select mclk + * as clock source + */ + int divMCLK = cirrusfb_check_mclk(cinfo, freq); + if (divMCLK) { + nom = 0; + cirrusfb_set_mclk_as_source(cinfo, divMCLK); + } + } + if (nom) { + vga_wseq(regbase, CL_SEQRB, nom); + tmp = den << 1; + if (div != 0) + tmp |= 1; - /* 6 bit denom; ONLY 5434!!! (bugged me 10 days) */ - if ((cinfo->btype == BT_SD64) || - (cinfo->btype == BT_ALPINE) || - (cinfo->btype == BT_GD5480)) - tmp |= 0x80; + /* 6 bit denom; ONLY 5434!!! (bugged me 10 days) */ + if ((cinfo->btype == BT_SD64) || + (cinfo->btype == BT_ALPINE) || + (cinfo->btype == BT_GD5480)) + tmp |= 0x80; - DPRINTK("CL_SEQR1B: %ld\n", (long) tmp); - vga_wseq(regbase, CL_SEQR1B, tmp); + DPRINTK("CL_SEQR1B: %ld\n", (long) tmp); + vga_wseq(regbase, CL_SEQR1B, tmp); + } if (yres >= 1024) /* 1280x1024 */ @@ -1106,7 +1096,6 @@ static int cirrusfb_set_par_foo(struct fb_info *info) case BT_ALPINE: DPRINTK(" (for GD543x)\n"); - cirrusfb_set_mclk(cinfo, regs.mclk, regs.divMCLK); /* We already set SRF and SR1F */ break; @@ -1179,7 +1168,6 @@ static int cirrusfb_set_par_foo(struct fb_info *info) case BT_ALPINE: DPRINTK(" (for GD543x)\n"); vga_wseq(regbase, CL_SEQR7, 0xa7); - cirrusfb_set_mclk(cinfo, regs.mclk, regs.divMCLK); break; case BT_GD5480: @@ -1257,7 +1245,6 @@ static int cirrusfb_set_par_foo(struct fb_info *info) case BT_ALPINE: DPRINTK(" (for GD543x)\n"); vga_wseq(regbase, CL_SEQR7, 0xa9); - cirrusfb_set_mclk(cinfo, regs.mclk, regs.divMCLK); break; case BT_GD5480: |