diff options
Diffstat (limited to 'src/northbridge/intel/gm45/gma.c')
| -rw-r--r-- | src/northbridge/intel/gm45/gma.c | 84 |
1 files changed, 42 insertions, 42 deletions
diff --git a/src/northbridge/intel/gm45/gma.c b/src/northbridge/intel/gm45/gma.c index 7e834e6fca..9707d2f9cc 100644 --- a/src/northbridge/intel/gm45/gma.c +++ b/src/northbridge/intel/gm45/gma.c @@ -36,7 +36,7 @@ #include <pc80/vga.h> #include <pc80/vga_io.h> -#define BASE_FREQUECY 96000 +#define BASE_FREQUENCY 96000 static struct resource *gtt_res = NULL; @@ -61,13 +61,13 @@ static void gma_init_lvds(const struct northbridge_intel_gm45_config *info, u32 hactive, vactive, right_border, bottom_border; int hpolarity, vpolarity; u32 vsync, hsync, vblank, hblank, hfront_porch, vfront_porch; - u32 candp1, candn; - u32 best_delta = 0xffffffff; + u32 smallest_err = 0xffffffff; u32 target_frequency; u32 pixel_p1 = 1; u32 pixel_n = 1; u32 pixel_m1 = 1; u32 pixel_m2 = 1; + u32 pixel_p2; u32 link_frequency = info->gfx.link_frequency_270_mhz ? 270000 : 162000; u32 data_m1; u32 data_n1 = 0x00800000; @@ -121,8 +121,6 @@ static void gma_init_lvds(const struct northbridge_intel_gm45_config *info, hfront_porch = mode->hso; vfront_porch = mode->vso; - target_frequency = mode->lvds_dual_channel ? mode->pixel_clock - : (2 * mode->pixel_clock); if (IS_ENABLED(CONFIG_FRAMEBUFFER_KEEP_VESA_MODE)) { vga_sr_write(1, 1); vga_sr_write(0x2, 0xf); @@ -151,40 +149,42 @@ static void gma_init_lvds(const struct northbridge_intel_gm45_config *info, vga_textmode_init(); } - /* Find suitable divisors. */ - for (candp1 = 1; candp1 <= 8; candp1++) { - for (candn = 5; candn <= 10; candn++) { - u32 cur_frequency; - u32 m; /* 77 - 131. */ - u32 denom; /* 35 - 560. */ - u32 current_delta; - - denom = candn * candp1 * 7; - /* Doesnt overflow for up to - 5000000 kHz = 5 GHz. */ - m = (target_frequency * denom + 60000) / 120000; - - if (m < 77 || m > 131) - continue; - - cur_frequency = (120000 * m) / denom; - if (target_frequency > cur_frequency) - current_delta = target_frequency - cur_frequency; - else - current_delta = cur_frequency - target_frequency; - - - if (best_delta > current_delta) { - best_delta = current_delta; - pixel_n = candn; - pixel_p1 = candp1; - pixel_m2 = ((m + 3) % 5) + 7; - pixel_m1 = (m - pixel_m2) / 5; + target_frequency = mode->pixel_clock; + /* + * p2 divisor must 7 for dual channel LVDS + * and 14 for single channel LVDS + */ + pixel_p2 = mode->lvds_dual_channel ? 7 : 14; + + /* + * Find suitable divisors, m1, m2, p1, n. + * refclock * (5 * (m1 + 2) + (m1 + 2)) / (n + 2) / p1 / p2 + * should be closest to target frequency as possible + */ + u32 candn, candm1, candm2, candp1; + for (candn = 1; candn <= 3; candn++) { + for (candm1 = 23; candm1 >= 17; candm1--) { + for (candm2 = 11; candm2 >= 5; candm2--) { + for (candp1 = mode->lvds_dual_channel ? 6 : 8; + candp1 >= 2; candp1--) { + u32 m = 5 * (candm1 + 2) + (candm2 + 2); + u32 p = candp1 * pixel_p2; + u32 vco = DIV_ROUND_CLOSEST(BASE_FREQUENCY * m, candn + 2); + u32 dot = DIV_ROUND_CLOSEST(vco, p); + u32 this_err = ABS(dot - target_frequency); + if (this_err < smallest_err) { + smallest_err = this_err; + pixel_n = candn; + pixel_m1 = candm1; + pixel_m2 = candm2; + pixel_p1 = candp1; + } + } } } } - if (best_delta == 0xffffffff) { + if (smallest_err == 0xffffffff) { printk (BIOS_ERR, "Couldn't find GFX clock divisors\n"); return; } @@ -218,8 +218,8 @@ static void gma_init_lvds(const struct northbridge_intel_gm45_config *info, printk(BIOS_DEBUG, "Pixel N=%d, M1=%d, M2=%d, P1=%d\n", pixel_n, pixel_m1, pixel_m2, pixel_p1); printk(BIOS_DEBUG, "Pixel clock %d kHz\n", - 120000 * (5 * pixel_m1 + pixel_m2) / pixel_n - / (pixel_p1 * 7)); + BASE_FREQUENCY * (5 * (pixel_m1 + 2) + (pixel_m2 + 2) / + (pixel_n + 2) / (pixel_p1 * pixel_p2))); write32(mmio + LVDS, (hpolarity << 20) | (vpolarity << 21) @@ -232,8 +232,8 @@ static void gma_init_lvds(const struct northbridge_intel_gm45_config *info, write32(mmio + PP_CONTROL, PANEL_UNLOCK_REGS | (read32(mmio + PP_CONTROL) & ~PANEL_UNLOCK_MASK)); write32(mmio + FP0(0), - ((pixel_n - 2) << 16) - | ((pixel_m1 - 2) << 8) | (pixel_m2 - 2)); + (pixel_n << 16) + | (pixel_m1 << 8) | (pixel_m2)); write32(mmio + DPLL(0), DPLL_VCO_ENABLE | DPLLB_MODE_LVDS | DPLL_VGA_MODE_DIS @@ -472,7 +472,7 @@ static void gma_init_vga(const struct northbridge_intel_gm45_config *info, for (candp1 = 8; candp1 >= 1; candp1--) { u32 m = 5 * (candm1 + 2) + (candm2 + 2); u32 p = candp1 * 10; /* 10 == p2 */ - u32 vco = DIV_ROUND_CLOSEST(BASE_FREQUECY * m, candn + 2); + u32 vco = DIV_ROUND_CLOSEST(BASE_FREQUENCY * m, candn + 2); u32 dot = DIV_ROUND_CLOSEST(vco, p); u32 this_err = ABS(dot - target_frequency); if (this_err < smallest_err) { @@ -519,8 +519,8 @@ static void gma_init_vga(const struct northbridge_intel_gm45_config *info, printk(BIOS_SPEW, "Pixel N=%d, M1=%d, M2=%d, P1=%d\n", pixel_n, pixel_m1, pixel_m2, pixel_p1); printk(BIOS_SPEW, "Pixel clock %d kHz\n", - BASE_FREQUECY * (5 * (pixel_m1 + 2) + (pixel_m2 + 2) / (pixel_n + 2) - / (pixel_p1 * 10))); + BASE_FREQUENCY * (5 * (pixel_m1 + 2) + (pixel_m2 + 2) / + (pixel_n + 2) / (pixel_p1 * 10))); mdelay(1); write32(mmio + FP0(0), (pixel_n << 16) |