[Intel-gfx] [PATCH 44/53] drm/i915/dg2: Add vswing programming for SNPS phys

Matt Roper
2021-07-01T20:26:58Z

Vswing programming for SNPS PHYs is just a single step -- look up the
value that corresponds to the voltage level from a table and program it
into the SNPS_PHY_TX_EQ register.

Bspec: 53920
Cc: Matt Atwood <matthew.s.atwood@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
drivers/gpu/drm/i915/display/intel_ddi.c | 23 ++++++--
drivers/gpu/drm/i915/display/intel_snps_phy.c | 54 +++++++++++++++++++
drivers/gpu/drm/i915/display/intel_snps_phy.h | 4 ++
drivers/gpu/drm/i915/i915_reg.h | 5 ++
4 files changed, 83 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 929a95ddb316..ade03cf41caa 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -1496,6 +1496,16 @@ static int intel_ddi_dp_level(struct intel_dp *intel_dp)
return translate_signal_level(intel_dp, signal_levels);
}

+static void
+dg2_set_signal_levels(struct intel_dp *intel_dp,
+ const struct intel_crtc_state *crtc_state)
+{
+ struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
+ int level = intel_ddi_dp_level(intel_dp);
+
+ intel_snps_phy_ddi_vswing_sequence(encoder, level);
+}
+
static void
tgl_set_signal_levels(struct intel_dp *intel_dp,
const struct intel_crtc_state *crtc_state)
@@ -2563,7 +2573,10 @@ static void tgl_ddi_pre_enable_dp(struct intel_atomic_state *state,
*/

/* 7.e Configure voltage swing and related IO settings */
- tgl_ddi_vswing_sequence(encoder, crtc_state, level);
+ if (IS_DG2(dev_priv))
+ intel_snps_phy_ddi_vswing_sequence(encoder, level);
+ else
+ tgl_ddi_vswing_sequence(encoder, crtc_state, level);

/*
* 7.f Combo PHY: Configure PORT_CL_DW10 Static Power Down to power up
@@ -3102,7 +3115,9 @@ static void intel_enable_ddi_hdmi(struct intel_atomic_state *state,
"[CONNECTOR:%d:%s] Failed to configure sink scrambling/TMDS bit clock ratio\n",
connector->base.id, connector->name);

- if (DISPLAY_VER(dev_priv) >= 12)
+ if (IS_DG2(dev_priv))
+ intel_snps_phy_ddi_vswing_sequence(encoder, U32_MAX);
+ else if (DISPLAY_VER(dev_priv) >= 12)
tgl_ddi_vswing_sequence(encoder, crtc_state, level);
else if (DISPLAY_VER(dev_priv) == 11)
icl_ddi_vswing_sequence(encoder, crtc_state, level);
@@ -4075,7 +4090,9 @@ intel_ddi_init_dp_connector(struct intel_digital_port *dig_port)
dig_port->dp.set_link_train = intel_ddi_set_link_train;
dig_port->dp.set_idle_link_train = intel_ddi_set_idle_link_train;

- if (DISPLAY_VER(dev_priv) >= 12)
+ if (IS_DG2(dev_priv))
+ dig_port->dp.set_signal_levels = dg2_set_signal_levels;
+ else if (DISPLAY_VER(dev_priv) >= 12)
dig_port->dp.set_signal_levels = tgl_set_signal_levels;
else if (DISPLAY_VER(dev_priv) >= 11)
dig_port->dp.set_signal_levels = icl_set_signal_levels;
diff --git a/drivers/gpu/drm/i915/display/intel_snps_phy.c b/drivers/gpu/drm/i915/display/intel_snps_phy.c
index 1317b4e94b50..77759bda98a4 100644
--- a/drivers/gpu/drm/i915/display/intel_snps_phy.c
+++ b/drivers/gpu/drm/i915/display/intel_snps_phy.c
@@ -21,6 +21,60 @@
* since it is not handled by the shared DPLL framework as on other platforms.
*/

+static const u32 dg2_ddi_translations[] = {
+ /* VS 0, pre-emph 0 */
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 26),
+
+ /* VS 0, pre-emph 1 */
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 33) |
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 6),
+
+ /* VS 0, pre-emph 2 */
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 38) |
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 12),
+
+ /* VS 0, pre-emph 3 */
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 43) |
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 19),
+
+ /* VS 1, pre-emph 0 */
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 39),
+
+ /* VS 1, pre-emph 1 */
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 44) |
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 8),
+
+ /* VS 1, pre-emph 2 */
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 47) |
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 15),
+
+ /* VS 2, pre-emph 0 */
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 52),
+
+ /* VS 2, pre-emph 1 */
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 51) |
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 10),
+
+ /* VS 3, pre-emph 0 */
+ REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 62),
+};
+
+void intel_snps_phy_ddi_vswing_sequence(struct intel_encoder *encoder,
+ u32 level)
+{
+ struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+ enum phy phy = intel_port_to_phy(dev_priv, encoder->port);
+ int n_entries, ln;
+
+ n_entries = ARRAY_SIZE(dg2_ddi_translations);
+ if (level >= n_entries)
+ level = n_entries - 1;
+
+ for (ln = 0; ln < 4; ln++)
+ intel_de_write(dev_priv, SNPS_PHY_TX_EQ(ln, phy),
+ dg2_ddi_translations[level]);
+}
+
/*
* Basic DP link rates with 100 MHz reference clock.
*/
diff --git a/drivers/gpu/drm/i915/display/intel_snps_phy.h b/drivers/gpu/drm/i915/display/intel_snps_phy.h
index ca4c2a25182b..3ce92d424f66 100644
--- a/drivers/gpu/drm/i915/display/intel_snps_phy.h
+++ b/drivers/gpu/drm/i915/display/intel_snps_phy.h
@@ -6,6 +6,8 @@
#ifndef __INTEL_SNPS_PHY_H__
#define __INTEL_SNPS_PHY_H__

+#include <linux/types.h>
+
struct intel_encoder;
struct intel_crtc_state;
struct intel_mpllb_state;
@@ -21,5 +23,7 @@ int intel_mpllb_calc_port_clock(struct intel_encoder *encoder,
const struct intel_mpllb_state *pll_state);

int intel_snps_phy_check_hdmi_link_rate(int clock);
+void intel_snps_phy_ddi_vswing_sequence(struct intel_encoder *encoder,
+ u32 level);

#endif /* __INTEL_SNPS_PHY_H__ */
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 15465f9cf9ab..203056b9f02c 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2340,6 +2340,11 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
#define SNPS_PHY_REF_CONTROL(phy) _MMIO_SNPS(phy, 0x168188)
#define SNPS_PHY_REF_CONTROL_REF_RANGE REG_GENMASK(31, 27)

+#define SNPS_PHY_TX_EQ(ln, phy) _MMIO_SNPS_LN(ln, phy, 0x168300)
+#define SNPS_PHY_TX_EQ_MAIN REG_GENMASK(23, 18)
+#define SNPS_PHY_TX_EQ_POST REG_GENMASK(15, 10)
+#define SNPS_PHY_TX_EQ_PRE REG_GENMASK(7, 2)
+
/* The spec defines this only for BXT PHY0, but lets assume that this
* would exist for PHY1 too if it had a second channel.
*/