Spread spectrum is a periodic disturbance added to the feedback
divider to change the pixel clock periodically to reduce interference.
Used for LVDS.
I don't have an atom-based laptop at the moment, so it's only been
tested on desktop cards. I'd appreciate feedback from laptop users.
Alex
From 562b4d8c261db106acdd272ab3bdb12c0152649c Mon Sep 17 00:00:00 2001
From: Alex Deucher <[email protected]>
Date: Fri, 16 Oct 2009 11:15:25 -0400
Subject: [PATCH] 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 <[email protected]>
---
drivers/gpu/drm/radeon/atombios.h | 2 +-
drivers/gpu/drm/radeon/atombios_crtc.c | 68 +++++++++++++++++++++++++-----
drivers/gpu/drm/radeon/radeon_atombios.c | 42 ++++++++++++++++++
drivers/gpu/drm/radeon/radeon_mode.h | 11 +++++
4 files changed, 111 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/radeon/atombios.h b/drivers/gpu/drm/radeon/atombios.h
index 5d40208..c11dddd 100644
--- a/drivers/gpu/drm/radeon/atombios.h
+++ b/drivers/gpu/drm/radeon/atombios.h
@@ -2314,7 +2314,7 @@ typedef struct _ATOM_SPREAD_SPECTRUM_ASSIGNMENT {
UCHAR ucSS_Step;
UCHAR ucSS_Delay;
UCHAR ucSS_Id;
- UCHAR ucRecommandedRef_Div;
+ UCHAR ucRecommendedRef_Div;
UCHAR ucSS_Range; /* it was reserved for V11 */
} ATOM_SPREAD_SPECTRUM_ASSIGNMENT;
diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index f7dcb69..0a9df66 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -351,6 +351,61 @@ static void atombios_crtc_set_timing(struct drm_crtc *crtc,
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 @@ void atombios_crtc_set_pll(struct drm_crtc *crtc, struct drm_display_mode *mode)
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 @@ void atombios_crtc_set_pll(struct drm_crtc *crtc, struct drm_display_mode *mode)
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;
@@ -631,7 +675,9 @@ int atombios_crtc_mode_set(struct drm_crtc *crtc,
/* 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))
diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index 79d4b77..0cd992b 100644
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -767,6 +767,46 @@ bool radeon_atombios_get_tmds_info(struct radeon_encoder *encoder,
return false;
}
+static struct radeon_atom_ss *radeon_atombios_get_ss_info(struct
+ radeon_encoder
+ *encoder,
+ int id)
+{
+ struct drm_device *dev = encoder->base.dev;
+ struct radeon_device *rdev = dev->dev_private;
+ struct radeon_mode_info *mode_info = &rdev->mode_info;
+ int index = GetIndexIntoMasterTable(DATA, PPLL_SS_Info);
+ uint16_t data_offset;
+ struct _ATOM_SPREAD_SPECTRUM_INFO *ss_info;
+ uint8_t frev, crev;
+ struct radeon_atom_ss *ss = NULL;
+
+ if (id > ATOM_MAX_SS_ENTRY)
+ return NULL;
+
+ atom_parse_data_header(mode_info->atom_context, index, NULL, &frev,
+ &crev, &data_offset);
+
+ ss_info =
+ (struct _ATOM_SPREAD_SPECTRUM_INFO *)(mode_info->atom_context->bios + data_offset);
+
+ if (ss_info) {
+ ss =
+ kzalloc(sizeof(struct radeon_atom_ss), GFP_KERNEL);
+
+ if (!ss)
+ return NULL;
+
+ ss->percentage = le16_to_cpu(ss_info->asSS_Info[id].usSpreadSpectrumPercentage);
+ ss->type = ss_info->asSS_Info[id].ucSpreadSpectrumType;
+ ss->step = ss_info->asSS_Info[id].ucSS_Step;
+ ss->delay = ss_info->asSS_Info[id].ucSS_Delay;
+ ss->range = ss_info->asSS_Info[id].ucSS_Range;
+ ss->refdiv = ss_info->asSS_Info[id].ucRecommendedRef_Div;
+ }
+ return ss;
+}
+
union lvds_info {
struct _ATOM_LVDS_INFO info;
struct _ATOM_LVDS_INFO_V12 info_12;
@@ -822,6 +862,8 @@ struct radeon_encoder_atom_dig *radeon_atombios_get_lvds_info(struct
/* set crtc values */
drm_mode_set_crtcinfo(&lvds->native_mode, CRTC_INTERLACE_HALVE_V);
+ lvds->ss = radeon_atombios_get_ss_info(encoder, lvds_info->info.ucSS_Id);
+
encoder->native_mode = lvds->native_mode;
}
return lvds;
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index b6868fb..2ea5707 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -260,6 +260,16 @@ struct radeon_encoder_int_tmds {
struct radeon_tmds_pll tmds_pll[4];
};
+/* spread spectrum */
+struct radeon_atom_ss {
+ uint16_t percentage;
+ uint8_t type;
+ uint8_t step;
+ uint8_t delay;
+ uint8_t range;
+ uint8_t refdiv;
+};
+
struct radeon_encoder_atom_dig {
/* atom dig */
bool coherent_mode;
@@ -267,6 +277,7 @@ struct radeon_encoder_atom_dig {
/* atom lvds */
uint32_t lvds_misc;
uint16_t panel_pwr_delay;
+ struct radeon_atom_ss *ss;
/* panel mode */
struct drm_display_mode native_mode;
};
--
1.5.6.3
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