drm/radeon/kms/atom: add support for spread spectrum (v2)
Spread spectrum is a periodic disturbance added
to the feedback divider to change the pixel clock
periodically to reduce interference.
Only enabled on LVDS.
v2: add support for r4xx and fix DCE 3
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 9c26e53..e5a3c30 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -351,6 +351,61 @@
atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
}
+static void atombios_set_ss(struct drm_crtc *crtc, int enable)
+{
+ struct radeon_crtc *radeon_crtc = to_radeon_crtc(crtc);
+ struct drm_device *dev = crtc->dev;
+ struct radeon_device *rdev = dev->dev_private;
+ struct drm_encoder *encoder = NULL;
+ struct radeon_encoder *radeon_encoder = NULL;
+ struct radeon_encoder_atom_dig *dig = NULL;
+ int index = GetIndexIntoMasterTable(COMMAND, EnableSpreadSpectrumOnPPLL);
+ ENABLE_SPREAD_SPECTRUM_ON_PPLL_PS_ALLOCATION args;
+ ENABLE_LVDS_SS_PARAMETERS legacy_args;
+ uint16_t percentage = 0;
+ uint8_t type = 0, step = 0, delay = 0, range = 0;
+
+ list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
+ if (encoder->crtc == crtc) {
+ radeon_encoder = to_radeon_encoder(encoder);
+ dig = radeon_encoder->enc_priv;
+ /* only enable spread spectrum on LVDS */
+ if (dig && dig->ss) {
+ percentage = dig->ss->percentage;
+ type = dig->ss->type;
+ step = dig->ss->step;
+ delay = dig->ss->delay;
+ range = dig->ss->range;
+ } else if (enable)
+ return;
+ break;
+ }
+ }
+
+ if (!radeon_encoder)
+ return;
+
+ if (ASIC_IS_AVIVO(rdev)) {
+ memset(&args, 0, sizeof(args));
+ args.usSpreadSpectrumPercentage = percentage;
+ args.ucSpreadSpectrumType = type;
+ args.ucSpreadSpectrumStep = step;
+ args.ucSpreadSpectrumDelay = delay;
+ args.ucSpreadSpectrumRange = range;
+ args.ucPpll = radeon_crtc->crtc_id ? ATOM_PPLL2 : ATOM_PPLL1;
+ args.ucEnable = enable;
+ atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
+ } else {
+ memset(&legacy_args, 0, sizeof(legacy_args));
+ legacy_args.usSpreadSpectrumPercentage = percentage;
+ legacy_args.ucSpreadSpectrumType = type;
+ legacy_args.ucSpreadSpectrumStepSize_Delay = (step & 3) << 2;
+ legacy_args.ucSpreadSpectrumStepSize_Delay |= (delay & 7) << 4;
+ legacy_args.ucEnable = enable;
+ atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&legacy_args);
+ }
+}
+
void atombios_crtc_set_pll(struct drm_crtc *crtc, struct drm_display_mode *mode)
{
struct radeon_crtc *radeon_crtc = to_radeon_crtc(crtc);
@@ -373,8 +428,6 @@
memset(&args, 0, sizeof(args));
if (ASIC_IS_AVIVO(rdev)) {
- uint32_t ss_cntl;
-
if ((rdev->family == CHIP_RS600) ||
(rdev->family == CHIP_RS690) ||
(rdev->family == CHIP_RS740))
@@ -385,15 +438,6 @@
pll_flags |= RADEON_PLL_PREFER_HIGH_FB_DIV;
else
pll_flags |= RADEON_PLL_PREFER_LOW_REF_DIV;
-
- /* disable spread spectrum clocking for now -- thanks Hedy Lamarr */
- if (radeon_crtc->crtc_id == 0) {
- ss_cntl = RREG32(AVIVO_P1PLL_INT_SS_CNTL);
- WREG32(AVIVO_P1PLL_INT_SS_CNTL, ss_cntl & ~1);
- } else {
- ss_cntl = RREG32(AVIVO_P2PLL_INT_SS_CNTL);
- WREG32(AVIVO_P2PLL_INT_SS_CNTL, ss_cntl & ~1);
- }
} else {
pll_flags |= RADEON_PLL_LEGACY;
@@ -641,7 +685,9 @@
/* TODO color tiling */
+ atombios_set_ss(crtc, 0);
atombios_crtc_set_pll(crtc, adjusted_mode);
+ atombios_set_ss(crtc, 1);
atombios_crtc_set_timing(crtc, adjusted_mode);
if (ASIC_IS_AVIVO(rdev))