[Intel-gfx] [PATCH] drm/i915/tgl: Add Wa_1409371443

[Aditya Swarup]

Set GMBUS0 Pin Pair Select to 1 at boot and each FLR exit.
Return GMBUS0 Pin Pair Select to 1 after GMBUS transactions are done.

Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski at intel.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
Cc: Jose Souza <jose.souza at intel.com>
Signed-off-by: Aditya Swarup <aditya.swarup at intel.com>
---
 drivers/gpu/drm/i915/display/intel_gmbus.c | 16 ++++++++++++++++
 drivers/gpu/drm/i915/i915_reg.h            |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_gmbus.c b/drivers/gpu/drm/i915/display/intel_gmbus.c
index a8d119b6b45c..8dd5aa025c3f 100644
--- a/drivers/gpu/drm/i915/display/intel_gmbus.c
+++ b/drivers/gpu/drm/i915/display/intel_gmbus.c
@@ -139,11 +139,19 @@ to_intel_gmbus(struct i2c_adapter *i2c)
 	return container_of(i2c, struct intel_gmbus, adapter);
 }
 
+static void gmbus0_wa_reset(struct drm_i915_private *dev_priv)
+{
+	intel_de_write(dev_priv, GMBUS0, 0 | GMBUS_PIN_PAIR_1);
+}
+
 void
 intel_gmbus_reset(struct drm_i915_private *dev_priv)
 {
 	intel_de_write(dev_priv, GMBUS0, 0);
 	intel_de_write(dev_priv, GMBUS4, 0);
+	/* Wa_1409371443: tgl[a0] */
+	if (IS_TGL_REVID(dev_priv, TGL_REVID_A0, TGL_REVID_A0))
+		gmbus0_wa_reset(dev_priv);
 }
 
 static void pnv_gmbus_clock_gating(struct drm_i915_private *dev_priv,
@@ -299,6 +307,10 @@ intel_gpio_post_xfer(struct i2c_adapter *adapter)
 
 	if (IS_PINEVIEW(dev_priv))
 		pnv_gmbus_clock_gating(dev_priv, true);
+
+	/* Wa_1409371443: tgl[a0] */
+	if (IS_TGL_REVID(dev_priv, TGL_REVID_A0, TGL_REVID_A0))
+		gmbus0_wa_reset(dev_priv);
 }
 
 static void
@@ -955,4 +967,8 @@ void intel_gmbus_teardown(struct drm_i915_private *dev_priv)
 		bus = &dev_priv->gmbus[pin];
 		i2c_del_adapter(&bus->adapter);
 	}
+
+	/* Wa_1409371443: tgl[a0] */
+	if (IS_TGL_REVID(dev_priv, TGL_REVID_A0, TGL_REVID_A0))
+		gmbus0_wa_reset(dev_priv);
 }
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 578cfe11cbb9..a1640476cefb 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3337,6 +3337,8 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define   GMBUS_RATE_1MHZ	(3 << 8) /* reserved on Pineview */
 #define   GMBUS_HOLD_EXT	(1 << 7) /* 300ns hold time, rsvd on Pineview */
 #define   GMBUS_BYTE_CNT_OVERRIDE (1 << 6)
+#define   GMBUS_PIN_PAIR_MASK	REG_GENMASK(4, 0)
+#define   GMBUS_PIN_PAIR_1	REG_FIELD_PREP(GMBUS_PIN_PAIR_MASK, 1)
 
 #define GMBUS1			_MMIO(dev_priv->gpio_mmio_base + 0x5104) /* command/status */
 #define   GMBUS_SW_CLR_INT	(1 << 31)
-- 
2.26.2