[PATCH 48/49] drm/i915/bxt: VSwing programming sequence

Imre Deak
2015-03-17T09:41:06Z

From: Vandana Kannan <vandana.kannan@intel.com>

VSwing programming sequence as specified in the updated BXT BSpec

v2: Satheesh's review comments addressed.
- clear value before setting into registers
- move print statement to bxt function
Other changes
- since signal level will not be set into DDI_BUF_CTL, the value need
not be returned to intel_dp_set_signal_levels(). Making the bxt
specific function to return void and setting signal_levels = 0 for
bxt inside intel_dp_set_signal_levels()
- instead of signal levels, printing vswing level and pre-emphasis
level
- in case none of the pre-emphasis levels or vswing levels are set,
setting default of 400mV + 0dB

v3: Satheesh's review comments
- Check for mask before printing signal_levels.
- Removing redundant register writes
- Call intel_prepare_ddi_buffers only for HAS_PCH_SPLIT
- Making register write part generic as it will be required for HDMI as
well.

Re-structure the code to include an array for vswing related values, set
signal levels

v4: Satheesh's review comments
- Rebase over latest renaming patches
- use hsw_signal_levels for HAS_DDI
Other changes
- Modified vswing_sequence() func definition
- Rebased on top of register macro definitions

v5: Satheesh's review comments
- Check ddi translation table size

v6: Imre's review comments
- removed comments in vswing sequence
- added vswing, pre-emphasis prints in intel_dp_set_signal_levels
- added comment explaining use of DP vswing values for eDP
- initialize n_entries and ddi_transaltion table based on encoder type
- create bxt_ddi_buf_trans structure and use decimal values
- adding a flag in bxt buffer translation table to indicate def entry

v7: (imre)
- squash in Vandana's "VSwing register definition",
"HDMI VSwing programming", "Re-enable vswing programming",
"Fix vswing sequence" patches
- use BXT_PORT_* regs directly instead of via a temp var
- simplify BXT_PORT_* macro definitions
- add code comment why we read lane while write group registers
- fix readout of DP_TRAIN_PRE_EMPHASIS in debug message

Signed-off-by: Vandana Kannan <vandana.kannan@intel.com> (v6)
Signed-off-by: Imre Deak <imre.deak@intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 61 ++++++++++++++++++++
drivers/gpu/drm/i915/intel_ddi.c | 120 ++++++++++++++++++++++++++++++++++++++-
drivers/gpu/drm/i915/intel_dp.c | 64 ++++++++++++++++++++-
drivers/gpu/drm/i915/intel_drv.h | 2 +
4 files changed, 244 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 2e72283c..545b7cf 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1269,6 +1269,21 @@ enum bxt_phy {
_PORT_REF_DW8_BC)

/* BXT PHY PCS registers */
+#define _PORT_PCS_DW10_LN01_A 0x162428
+#define _PORT_PCS_DW10_LN01_B 0x6C428
+#define _PORT_PCS_DW10_LN01_C 0x6C828
+#define _PORT_PCS_DW10_GRP_A 0x162C28
+#define _PORT_PCS_DW10_GRP_B 0x6CC28
+#define _PORT_PCS_DW10_GRP_C 0x6CE28
+#define BXT_PORT_PCS_DW10_LN01(port) _PORT3(port, _PORT_PCS_DW10_LN01_A, \
+ _PORT_PCS_DW10_LN01_B, \
+ _PORT_PCS_DW10_LN01_C)
+#define BXT_PORT_PCS_DW10_GRP(port) _PORT3(port, _PORT_PCS_DW10_GRP_A, \
+ _PORT_PCS_DW10_GRP_B, \
+ _PORT_PCS_DW10_GRP_C)
+#define TX2_SWING_CALC_INIT (1 << 31)
+#define TX1_SWING_CALC_INIT (1 << 30)
+
#define _PORT_PCS_DW12_LN01_A 0x162430
#define _PORT_PCS_DW12_LN01_B 0x6C430
#define _PORT_PCS_DW12_LN01_C 0x6C830
@@ -1294,6 +1309,52 @@ enum bxt_phy {
#define BXT_LANE_OFFSET(lane) (((lane) >> 1) * 0x200 + \
((lane) & 1) * 0x80)

+#define _PORT_TX_DW2_LN0_A 0x162508
+#define _PORT_TX_DW2_LN0_B 0x6C508
+#define _PORT_TX_DW2_LN0_C 0x6C908
+#define _PORT_TX_DW2_GRP_A 0x162D08
+#define _PORT_TX_DW2_GRP_B 0x6CD08
+#define _PORT_TX_DW2_GRP_C 0x6CF08
+#define BXT_PORT_TX_DW2_GRP(port) _PORT3(port, _PORT_TX_DW2_GRP_A, \
+ _PORT_TX_DW2_GRP_B, \
+ _PORT_TX_DW2_GRP_C)
+#define BXT_PORT_TX_DW2_LN0(port) _PORT3(port, _PORT_TX_DW2_LN0_A, \
+ _PORT_TX_DW2_LN0_B, \
+ _PORT_TX_DW2_LN0_C)
+#define MARGIN_000_SHIFT 16
+#define MARGIN_000 (0xFF << MARGIN_000_SHIFT)
+#define UNIQ_TRANS_SCALE_SHIFT 8
+#define UNIQ_TRANS_SCALE (0xFF << UNIQ_TRANS_SCALE_SHIFT)
+
+#define _PORT_TX_DW3_LN0_A 0x16250C
+#define _PORT_TX_DW3_LN0_B 0x6C50C
+#define _PORT_TX_DW3_LN0_C 0x6C90C
+#define _PORT_TX_DW3_GRP_A 0x162D0C
+#define _PORT_TX_DW3_GRP_B 0x6CD0C
+#define _PORT_TX_DW3_GRP_C 0x6CF0C
+#define BXT_PORT_TX_DW3_GRP(port) _PORT3(port, _PORT_TX_DW3_GRP_A, \
+ _PORT_TX_DW3_GRP_B, \
+ _PORT_TX_DW3_GRP_C)
+#define BXT_PORT_TX_DW3_LN0(port) _PORT3(port, _PORT_TX_DW3_LN0_A, \
+ _PORT_TX_DW3_LN0_B, \
+ _PORT_TX_DW3_LN0_C)
+#define UNIQE_TRANGE_EN_METHOD (1 << 27)
+
+#define _PORT_TX_DW4_LN0_A 0x162510
+#define _PORT_TX_DW4_LN0_B 0x6C510
+#define _PORT_TX_DW4_LN0_C 0x6C910
+#define _PORT_TX_DW4_GRP_A 0x162D10
+#define _PORT_TX_DW4_GRP_B 0x6CD10
+#define _PORT_TX_DW4_GRP_C 0x6CF10
+#define BXT_PORT_TX_DW4_LN0(port) _PORT3(port, _PORT_TX_DW4_LN0_A, \
+ _PORT_TX_DW4_LN0_B, \
+ _PORT_TX_DW4_LN0_C)
+#define BXT_PORT_TX_DW4_GRP(port) _PORT3(port, _PORT_TX_DW4_GRP_A, \
+ _PORT_TX_DW4_GRP_B, \
+ _PORT_TX_DW4_GRP_C)
+#define DEEMPH_SHIFT 24
+#define DE_EMPHASIS (0xFF << DEEMPH_SHIFT)
+
#define _PORT_TX_DW14_LN0_A 0x162538
#define _PORT_TX_DW14_LN0_B 0x6C538
#define _PORT_TX_DW14_LN0_C 0x6C938
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 5aa4dab..799f9fc 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -159,6 +159,48 @@ static const struct ddi_buf_trans skl_ddi_translations_hdmi[] = {
{ 0x00004014, 0x00000087 }, /* 0: 800 1000 2 */
};

+struct bxt_ddi_buf_trans {
+ u32 margin; /* swing value */
+ u32 scale; /* scale value */
+ u32 enable; /* scale enable */
+ u32 deemphasis;
+ bool default_index; /* true if the entry represents default value */
+};
+
+/* BSpec does not define separate vswing/pre-emphasis values for eDP.
+ * Using DP values for eDP as well.
+ */
+static const struct bxt_ddi_buf_trans bxt_ddi_translations_dp[] = {
+ /* Idx NT mV diff db */
+ { 52, 0, 0, 128, true }, /* 0: 400 0 */
+ { 78, 0, 0, 85, false }, /* 1: 400 3.5 */
+ { 104, 0, 0, 64, false }, /* 2: 400 6 */
+ { 154, 0, 0, 43, false }, /* 3: 400 9.5 */
+ { 77, 0, 0, 128, false }, /* 4: 600 0 */
+ { 116, 0, 0, 85, false }, /* 5: 600 3.5 */
+ { 154, 0, 0, 64, false }, /* 6: 600 6 */
+ { 102, 0, 0, 128, false }, /* 7: 800 0 */
+ { 154, 0, 0, 85, false }, /* 8: 800 3.5 */
+ { 154, 0x9A, 1, 128, false }, /* 9: 1200 0 */
+};
+
+/* BSpec has 2 recommended values - entries 0 and 8.
+ * Using the entry with higher vswing.
+ */
+static const struct bxt_ddi_buf_trans bxt_ddi_translations_hdmi[] = {
+ /* Idx NT mV diff db */
+ { 52, 0, 0, 128, false }, /* 0: 400 0 */
+ { 52, 0, 0, 85, false }, /* 1: 400 3.5 */
+ { 52, 0, 0, 64, false }, /* 2: 400 6 */
+ { 42, 0, 0, 43, false }, /* 3: 400 9.5 */
+ { 77, 0, 0, 128, false }, /* 4: 600 0 */
+ { 77, 0, 0, 85, false }, /* 5: 600 3.5 */
+ { 77, 0, 0, 64, false }, /* 6: 600 6 */
+ { 102, 0, 0, 128, false }, /* 7: 800 0 */
+ { 102, 0, 0, 85, false }, /* 8: 800 3.5 */
+ { 154, 0x9A, 1, 128, true }, /* 9: 1200 0 */
+};
+
enum port intel_ddi_get_encoder_port(struct intel_encoder *intel_encoder)
{
struct drm_encoder *encoder = &intel_encoder->base;
@@ -210,7 +252,15 @@ static void intel_prepare_ddi_buffers(struct drm_device *dev,
const struct ddi_buf_trans *ddi_translations_hdmi;
const struct ddi_buf_trans *ddi_translations;

- if (IS_SKYLAKE(dev)) {
+ if (IS_BROXTON(dev)) {
+ if (!intel_dig_port_supports_hdmi(intel_dig_port))
+ return;
+
+ /* Vswing programming for HDMI */
+ bxt_ddi_vswing_sequence(dev, hdmi_level, port,
+ INTEL_OUTPUT_HDMI);
+ return;
+ } else if (IS_SKYLAKE(dev)) {
ddi_translations_fdi = NULL;
ddi_translations_dp = skl_ddi_translations_dp;
n_dp_entries = ARRAY_SIZE(skl_ddi_translations_dp);
@@ -1666,6 +1716,67 @@ void intel_ddi_disable_pipe_clock(struct intel_crtc *intel_crtc)
TRANS_CLK_SEL_DISABLED);
}

+void bxt_ddi_vswing_sequence(struct drm_device *dev, u32 level,
+ enum port port, int type)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ const struct bxt_ddi_buf_trans *ddi_translations;
+ u32 n_entries, i;
+ uint32_t val;
+
+ if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
+ n_entries = ARRAY_SIZE(bxt_ddi_translations_dp);
+ ddi_translations = bxt_ddi_translations_dp;
+ } else if (type == INTEL_OUTPUT_HDMI) {
+ n_entries = ARRAY_SIZE(bxt_ddi_translations_hdmi);
+ ddi_translations = bxt_ddi_translations_hdmi;
+ } else {
+ DRM_DEBUG_KMS("Vswing programming not done for encoder %d\n",
+ type);
+ return;
+ }
+
+ /* Check if default value has to be used */
+ if (level >= n_entries ||
+ (type == INTEL_OUTPUT_HDMI && level == HDMI_LEVEL_SHIFT_UNKNOWN)) {
+ for (i = 0; i < n_entries; i++) {
+ if (ddi_translations[i].default_index) {
+ level = i;
+ break;
+ }
+ }
+ }
+
+ /*
+ * While we write to the group register to program all lanes at once we
+ * can read only lane registers and we pick lanes 0/1 for that.
+ */
+ val = I915_READ(BXT_PORT_PCS_DW10_LN01(port));
+ val &= ~(TX2_SWING_CALC_INIT | TX1_SWING_CALC_INIT);
+ I915_WRITE(BXT_PORT_PCS_DW10_GRP(port), val);
+
+ val = I915_READ(BXT_PORT_TX_DW2_LN0(port));
+ val &= ~(MARGIN_000 | UNIQ_TRANS_SCALE);
+ val |= ddi_translations[level].margin << MARGIN_000_SHIFT |
+ ddi_translations[level].scale << UNIQ_TRANS_SCALE_SHIFT;
+ I915_WRITE(BXT_PORT_TX_DW2_GRP(port), val);
+
+ val = I915_READ(BXT_PORT_TX_DW3_LN0(port));
+ val &= ~UNIQE_TRANGE_EN_METHOD;
+ if (ddi_translations[level].enable)
+ val |= UNIQE_TRANGE_EN_METHOD;
+ I915_WRITE(BXT_PORT_TX_DW3_GRP(port), val);
+
+ val = I915_READ(BXT_PORT_TX_DW4_LN0(port));
+ val &= ~DE_EMPHASIS;
+ val |= ddi_translations[level].deemphasis << DEEMPH_SHIFT;
+ I915_WRITE(BXT_PORT_TX_DW4_GRP(port), val);
+
+ val = I915_READ(BXT_PORT_PCS_DW10_LN01(port));
+ val |= TX2_SWING_CALC_INIT | TX1_SWING_CALC_INIT;
+ I915_WRITE(BXT_PORT_PCS_DW10_GRP(port), val);
+}
+
static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
{
struct drm_encoder *encoder = &intel_encoder->base;
@@ -1674,6 +1785,7 @@ static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
struct intel_crtc *crtc = to_intel_crtc(encoder->crtc);
enum port port = intel_ddi_get_encoder_port(intel_encoder);
int type = intel_encoder->type;
+ int hdmi_level;

if (type == INTEL_OUTPUT_EDP) {
struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
@@ -1730,6 +1842,12 @@ static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
} else if (type == INTEL_OUTPUT_HDMI) {
struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);

+ if (IS_BROXTON(dev)) {
+ hdmi_level = dev_priv->vbt.
+ ddi_port_info[port].hdmi_level_shift;
+ bxt_ddi_vswing_sequence(dev, hdmi_level, port,
+ INTEL_OUTPUT_HDMI);
+ }
intel_hdmi->set_infoframes(encoder,
crtc->config->has_hdmi_sink,
&crtc->config->base.adjusted_mode);
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 4bfbeed..1cb6eb0 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3354,6 +3354,55 @@ intel_hsw_signal_levels(uint8_t train_set)
}
}

+static void intel_bxt_signal_levels(struct intel_dp *intel_dp)
+{
+ struct intel_digital_port *dport = dp_to_dig_port(intel_dp);
+ enum port port = dport->port;
+ struct drm_device *dev = dport->base.base.dev;
+ struct intel_encoder *encoder = &dport->base;
+ uint8_t train_set = intel_dp->train_set[0];
+ uint32_t level = 0;
+
+ int signal_levels = train_set & (DP_TRAIN_VOLTAGE_SWING_MASK |
+ DP_TRAIN_PRE_EMPHASIS_MASK);
+ switch (signal_levels) {
+ default:
+ DRM_DEBUG_KMS("Unsupported voltage swing/pre-emph level\n");
+ case DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | DP_TRAIN_PRE_EMPH_LEVEL_0:
+ level = 0;
+ break;
+ case DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | DP_TRAIN_PRE_EMPH_LEVEL_1:
+ level = 1;
+ break;
+ case DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | DP_TRAIN_PRE_EMPH_LEVEL_2:
+ level = 2;
+ break;
+ case DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | DP_TRAIN_PRE_EMPH_LEVEL_3:
+ level = 3;
+ break;
+ case DP_TRAIN_VOLTAGE_SWING_LEVEL_1 | DP_TRAIN_PRE_EMPH_LEVEL_0:
+ level = 4;
+ break;
+ case DP_TRAIN_VOLTAGE_SWING_LEVEL_1 | DP_TRAIN_PRE_EMPH_LEVEL_1:
+ level = 5;
+ break;
+ case DP_TRAIN_VOLTAGE_SWING_LEVEL_1 | DP_TRAIN_PRE_EMPH_LEVEL_2:
+ level = 6;
+ break;
+ case DP_TRAIN_VOLTAGE_SWING_LEVEL_2 | DP_TRAIN_PRE_EMPH_LEVEL_0:
+ level = 7;
+ break;
+ case DP_TRAIN_VOLTAGE_SWING_LEVEL_2 | DP_TRAIN_PRE_EMPH_LEVEL_1:
+ level = 8;
+ break;
+ case DP_TRAIN_VOLTAGE_SWING_LEVEL_3 | DP_TRAIN_PRE_EMPH_LEVEL_0:
+ level = 9;
+ break;
+ }
+
+ bxt_ddi_vswing_sequence(dev, level, port, encoder->type);
+}
+
/* Properly updates "DP" with the correct signal levels. */
static void
intel_dp_set_signal_levels(struct intel_dp *intel_dp, uint32_t *DP)
@@ -3364,7 +3413,11 @@ intel_dp_set_signal_levels(struct intel_dp *intel_dp, uint32_t *DP)
uint32_t signal_levels, mask;
uint8_t train_set = intel_dp->train_set[0];

- if (IS_HASWELL(dev) || IS_BROADWELL(dev) || INTEL_INFO(dev)->gen >= 9) {
+ if (IS_BROXTON(dev)) {
+ signal_levels = 0;
+ intel_bxt_signal_levels(intel_dp);
+ mask = 0;
+ } else if (HAS_DDI(dev)) {
signal_levels = intel_hsw_signal_levels(train_set);
mask = DDI_BUF_EMP_MASK;
} else if (IS_CHERRYVIEW(dev)) {
@@ -3384,7 +3437,14 @@ intel_dp_set_signal_levels(struct intel_dp *intel_dp, uint32_t *DP)
mask = DP_VOLTAGE_MASK | DP_PRE_EMPHASIS_MASK;
}

- DRM_DEBUG_KMS("Using signal levels %08x\n", signal_levels);
+ if (mask)
+ DRM_DEBUG_KMS("Using signal levels %08x\n", signal_levels);
+
+ DRM_DEBUG_KMS("Using vswing level %d\n",
+ train_set & DP_TRAIN_VOLTAGE_SWING_MASK);
+ DRM_DEBUG_KMS("Using pre-emphasis level %d\n",
+ (train_set & DP_TRAIN_PRE_EMPHASIS_MASK) >>
+ DP_TRAIN_PRE_EMPHASIS_SHIFT);

*DP = (*DP & ~mask) | signal_levels;
}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 097fb85..f07a14a 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -874,6 +874,8 @@ void intel_ddi_clock_get(struct intel_encoder *encoder,
struct intel_crtc_state *pipe_config);
void intel_ddi_set_vc_payload_alloc(struct drm_crtc *crtc, bool state);
void bxt_select_cdclk_freq(struct drm_device *dev, u32 frequency);
+void bxt_ddi_vswing_sequence(struct drm_device *dev, u32 level,
+ enum port port, int type);

/* intel_frontbuffer.c */
void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
--
2.1.0