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authorArthur Heymans <arthur@aheymans.xyz>2016-10-12 00:05:00 +0200
committerMartin Roth <martinroth@google.com>2016-10-19 16:59:34 +0200
commit063cd5f6eee0ad9416e62eac4a168591220f53d0 (patch)
tree7f9196330bbae483274cfcb93b14a8f094b0e173 /src/northbridge/intel/x4x
parentf2b8d7cbd6d92adac26cbd639bb51f29b237fbc0 (diff)
nb/gm45,x4x/gma.c: Compute p2 in VGA init instead of hardcoding it
According to: "Intel ® 965 Express Chipset Family and Intel ® G35 Express Chipset Graphics Controller PR" the p2 divisor needs to be 10 when the dotclock is below 225MHz and 5 when its above 225MHz. Change-Id: I363039b6fd92051c4be4fdc88788f27527645944 Signed-off-by: Arthur Heymans <arthur@aheymans.xyz> Reviewed-on: https://review.coreboot.org/16991 Tested-by: build bot (Jenkins) Reviewed-by: Nico Huber <nico.h@gmx.de>
Diffstat (limited to 'src/northbridge/intel/x4x')
-rw-r--r--src/northbridge/intel/x4x/gma.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/src/northbridge/intel/x4x/gma.c b/src/northbridge/intel/x4x/gma.c
index e950386d3c..eb419c9f7d 100644
--- a/src/northbridge/intel/x4x/gma.c
+++ b/src/northbridge/intel/x4x/gma.c
@@ -70,6 +70,7 @@ static void intel_gma_init(const struct northbridge_intel_x4x_config *info,
u32 err_most = 0xffffffff;
u32 pixel_p1 = 1;
+ u32 pixel_p2;
u32 pixel_n = 1;
u32 pixel_m1 = 1;
u32 pixel_m2 = 1;
@@ -178,13 +179,15 @@ static void intel_gma_init(const struct northbridge_intel_x4x_config *info,
vga_textmode_init();
}
+ pixel_p2 = target_frequency <= 225000 ? 10 : 5;
+
u32 candn, candm1, candm2, candp1;
for (candn = 1; candn <= 4; candn++) {
for (candm1 = 23; candm1 >= 16; candm1--) {
for (candm2 = 11; candm2 >= 5; candm2--) {
for (candp1 = 8; candp1 >= 1; candp1--) {
u32 m = 5 * (candm1 + 2) + (candm2 + 2);
- u32 p = candp1 * 10; /* 10 == p2 */
+ u32 p = candp1 * pixel_p2;
u32 vco = DIV_ROUND_CLOSEST(
BASE_FREQUENCY * m, candn + 2);
u32 dot = DIV_ROUND_CLOSEST(vco, p);
@@ -230,23 +233,27 @@ static void intel_gma_init(const struct northbridge_intel_x4x_config *info,
link_frequency);
printk(BIOS_DEBUG, "Link M1=%d, N1=%d\n",
link_m1, link_n1);
- 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 N=%d, M1=%d, M2=%d, P1=%d, P2=%d\n",
+ pixel_n, pixel_m1, pixel_m2, pixel_p1, pixel_p2);
printk(BIOS_DEBUG, "Pixel clock %d kHz\n",
BASE_FREQUENCY * (5 * (pixel_m1 + 2) + (pixel_m2 + 2)) /
- (pixel_n + 2) / (pixel_p1 * 10));
+ (pixel_n + 2) / (pixel_p1 * pixel_p2));
mdelay(1);
write32(mmio + FP0(0), (pixel_n << 16)
| (pixel_m1 << 8) | pixel_m2);
write32(mmio + DPLL(0), DPLL_VCO_ENABLE
| DPLL_VGA_MODE_DIS | DPLLB_MODE_DAC_SERIAL
+ | (pixel_p2 == 10 ? DPLL_DAC_SERIAL_P2_CLOCK_DIV_10 :
+ DPLL_DAC_SERIAL_P2_CLOCK_DIV_5)
| (0x10000 << (pixel_p1 - 1))
| (6 << 9));
mdelay(1);
write32(mmio + DPLL(0), DPLL_VCO_ENABLE
| DPLL_VGA_MODE_DIS | DPLLB_MODE_DAC_SERIAL
+ | (pixel_p2 == 10 ? DPLL_DAC_SERIAL_P2_CLOCK_DIV_10 :
+ DPLL_DAC_SERIAL_P2_CLOCK_DIV_5)
| (0x10000 << (pixel_p1 - 1))
| (6 << 9));