[Intel-gfx] [PATCH 47/53] drm/i915/dg2: Wait for SNPS PHY calibration during display init

Matt Roper
2021-07-01T20:27:11Z

Initialization of the PHY is handled by the hardware/firmware, but the
driver should wait up to 25ms for the PHY to report that its calibration
has completed.

Bspec: 49189
Bspec: 50107
Cc: Matt Atwood <matthew.s.atwood@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
---
.../gpu/drm/i915/display/intel_display_power.c | 5 +++++
drivers/gpu/drm/i915/display/intel_snps_phy.c | 15 +++++++++++++++
drivers/gpu/drm/i915/display/intel_snps_phy.h | 3 +++
drivers/gpu/drm/i915/i915_reg.h | 1 +
4 files changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index df6358638fee..83bc2e691560 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -18,6 +18,7 @@
#include "intel_pm.h"
#include "intel_pps.h"
#include "intel_sideband.h"
+#include "intel_snps_phy.h"
#include "intel_tc.h"
#include "intel_vga.h"

@@ -5899,6 +5900,10 @@ static void icl_display_core_init(struct drm_i915_private *dev_priv,
if (DISPLAY_VER(dev_priv) >= 12)
tgl_bw_buddy_init(dev_priv);

+ /* 8. Ensure PHYs have completed calibration and adaptation */
+ if (IS_DG2(dev_priv))
+ intel_snps_phy_wait_for_calibration(dev_priv);
+
if (resume && intel_dmc_has_payload(dev_priv))
intel_dmc_load_program(dev_priv);

diff --git a/drivers/gpu/drm/i915/display/intel_snps_phy.c b/drivers/gpu/drm/i915/display/intel_snps_phy.c
index 77759bda98a4..f0c30d3d2dfb 100644
--- a/drivers/gpu/drm/i915/display/intel_snps_phy.c
+++ b/drivers/gpu/drm/i915/display/intel_snps_phy.c
@@ -21,6 +21,21 @@
* since it is not handled by the shared DPLL framework as on other platforms.
*/

+void intel_snps_phy_wait_for_calibration(struct drm_i915_private *dev_priv)
+{
+ enum phy phy;
+
+ for_each_phy_masked(phy, ~0) {
+ if (!intel_phy_is_snps(dev_priv, phy))
+ continue;
+
+ if (intel_de_wait_for_clear(dev_priv, ICL_PHY_MISC(phy),
+ DG2_PHY_DP_TX_ACK_MASK, 25))
+ DRM_ERROR("SNPS PHY %c failed to calibrate after 25ms.\n",
+ phy);
+ }
+}
+
static const u32 dg2_ddi_translations[] = {
/* VS 0, pre-emph 0 */
REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 26),
diff --git a/drivers/gpu/drm/i915/display/intel_snps_phy.h b/drivers/gpu/drm/i915/display/intel_snps_phy.h
index 3ce92d424f66..6aa33ff729ec 100644
--- a/drivers/gpu/drm/i915/display/intel_snps_phy.h
+++ b/drivers/gpu/drm/i915/display/intel_snps_phy.h
@@ -8,10 +8,13 @@

#include <linux/types.h>

+struct drm_i915_private;
struct intel_encoder;
struct intel_crtc_state;
struct intel_mpllb_state;

+void intel_snps_phy_wait_for_calibration(struct drm_i915_private *dev_priv);
+
int intel_mpllb_calc_state(struct intel_crtc_state *crtc_state,
struct intel_encoder *encoder);
void intel_mpllb_enable(struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 203056b9f02c..e3a165eb4fb6 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -12442,6 +12442,7 @@ enum skl_power_gate {
_ICL_PHY_MISC_B)
#define ICL_PHY_MISC_MUX_DDID (1 << 28)
#define ICL_PHY_MISC_DE_IO_COMP_PWR_DOWN (1 << 23)
+#define DG2_PHY_DP_TX_ACK_MASK REG_GENMASK(23, 20)

/* Icelake Display Stream Compression Registers */
#define DSCA_PICTURE_PARAMETER_SET_0 _MMIO(0x6B200)