[Intel-gfx] [PATCH 10/16] drm/i915: Query the vswing levels per-lane for tgl dkl phy

Ville Syrjala
2021-10-06T20:50:20Z

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Prepare for per-lane drive settings by querying the desired vswing
level per-lane.

Note that the code only does two loops, with each one writing the
levels for two TX lanes. The register offsets also look a bit funny
because each time through the loop we write to the exact same
register offsets. The crucial bit is the HIP_INDEX_REG
write that steers the same mmio window into different places.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/display/intel_ddi.c | 33 ++++++++++++++----------
1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 1874a2ca8f3b..85247744e9dd 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -1295,9 +1295,7 @@ static void tgl_dkl_phy_set_signal_levels(struct intel_encoder *encoder,
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
enum tc_port tc_port = intel_port_to_tc(dev_priv, encoder->port);
- int level = intel_ddi_level(encoder, crtc_state, 0);
const struct intel_ddi_buf_trans *trans;
- u32 val, dpcnt_mask, dpcnt_val;
int n_entries, ln;

if (intel_tc_port_in_tbt_alt_mode(enc_to_dig_port(encoder)))
@@ -1307,28 +1305,35 @@ static void tgl_dkl_phy_set_signal_levels(struct intel_encoder *encoder,
if (drm_WARN_ON_ONCE(&dev_priv->drm, !trans))
return;

- dpcnt_mask = (DKL_TX_PRESHOOT_COEFF_MASK |
- DKL_TX_DE_EMPAHSIS_COEFF_MASK |
- DKL_TX_VSWING_CONTROL_MASK);
- dpcnt_val = DKL_TX_VSWING_CONTROL(trans->entries[level].dkl.vswing);
- dpcnt_val |= DKL_TX_DE_EMPHASIS_COEFF(trans->entries[level].dkl.de_emphasis);
- dpcnt_val |= DKL_TX_PRESHOOT_COEFF(trans->entries[level].dkl.preshoot);
-
for (ln = 0; ln < 2; ln++) {
+ int level;
+ u32 val;
+
intel_de_write(dev_priv, HIP_INDEX_REG(tc_port),
HIP_INDEX_VAL(tc_port, ln));

intel_de_write(dev_priv, DKL_TX_PMD_LANE_SUS(tc_port), 0);

- /* All the registers are RMW */
+ level = intel_ddi_level(encoder, crtc_state, 2*ln+0);
+
val = intel_de_read(dev_priv, DKL_TX_DPCNTL0(tc_port));
- val &= ~dpcnt_mask;
- val |= dpcnt_val;
+ val &= ~(DKL_TX_PRESHOOT_COEFF_MASK |
+ DKL_TX_DE_EMPAHSIS_COEFF_MASK |
+ DKL_TX_VSWING_CONTROL_MASK);
+ val |= DKL_TX_VSWING_CONTROL(trans->entries[level].dkl.vswing) |
+ DKL_TX_DE_EMPHASIS_COEFF(trans->entries[level].dkl.de_emphasis) |
+ DKL_TX_PRESHOOT_COEFF(trans->entries[level].dkl.preshoot);
intel_de_write(dev_priv, DKL_TX_DPCNTL0(tc_port), val);

+ level = intel_ddi_level(encoder, crtc_state, 2*ln+1);
+
val = intel_de_read(dev_priv, DKL_TX_DPCNTL1(tc_port));
- val &= ~dpcnt_mask;
- val |= dpcnt_val;
+ val &= ~(DKL_TX_PRESHOOT_COEFF_MASK |
+ DKL_TX_DE_EMPAHSIS_COEFF_MASK |
+ DKL_TX_VSWING_CONTROL_MASK);
+ val |= DKL_TX_VSWING_CONTROL(trans->entries[level].dkl.vswing) |
+ DKL_TX_DE_EMPHASIS_COEFF(trans->entries[level].dkl.de_emphasis) |
+ DKL_TX_PRESHOOT_COEFF(trans->entries[level].dkl.preshoot);
intel_de_write(dev_priv, DKL_TX_DPCNTL1(tc_port), val);

val = intel_de_read(dev_priv, DKL_TX_DPCNTL2(tc_port));
--
2.32.0