drm/i915/mtl/display: Implement DisplayPort sequences

The differences between MTL and TGL DP sequences are big enough to
MTL have its own functions.

Also it is much easier to follow MTL sequences against spec with
its own functions.

One change worthy to mention is the move of
'intel_display_power_get(dev_priv, dig_port->ddi_io_power_domain)'.
This call is not necessary for MTL but we have _put() counter part in
intel_ddi_post_disable_dp() that needs to balanced.
We could add a display version check on it but instead here it is
moving it to intel_ddi_pre_enable_dp() so it is executed for all
platforms in a single place and this will not cause any harm in MTL
and newer platforms.

v2:
 - Fix logic to wait for buf idle.
 - Use the right register to wait for ddi active.(RK)
v3:
 - Increase wait timeout for ddi buf active (Mika)
v4:
 - Increase idle timeout for ddi buf idle (Mika)
v5: use rmw in mtl_disable_ddi_buf. Donot clear
    link training mask(Imre)

BSpec: 65448 65505
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Satyeshwar Singh <satyeshwar.singh@intel.com>
Cc: Clint Taylor <clinton.a.taylor@intel.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230413212443.1504245-7-radhakrishna.sripada@intel.com

drivers/gpu/drm/i915/display/intel_cx0_phy_regs.h

@@ -59,8 +59,16 @@
 										 _XELPDP_PORT_BUF_CTL1_LN0_B, \
 										 _XELPDP_PORT_BUF_CTL1_LN0_USBC1, \
 										 _XELPDP_PORT_BUF_CTL1_LN0_USBC2))
+#define   XELPDP_PORT_BUF_D2D_LINK_ENABLE		REG_BIT(29)
+#define   XELPDP_PORT_BUF_D2D_LINK_STATE		REG_BIT(28)
 #define   XELPDP_PORT_BUF_SOC_PHY_READY			REG_BIT(24)
+#define   XELPDP_PORT_BUF_PORT_DATA_WIDTH_MASK		REG_GENMASK(19, 18)
+#define   XELPDP_PORT_BUF_PORT_DATA_10BIT		REG_FIELD_PREP(XELPDP_PORT_BUF_PORT_DATA_WIDTH_MASK, 0)
+#define   XELPDP_PORT_BUF_PORT_DATA_20BIT		REG_FIELD_PREP(XELPDP_PORT_BUF_PORT_DATA_WIDTH_MASK, 1)
+#define   XELPDP_PORT_BUF_PORT_DATA_40BIT		REG_FIELD_PREP(XELPDP_PORT_BUF_PORT_DATA_WIDTH_MASK, 2)
 #define   XELPDP_PORT_REVERSAL				REG_BIT(16)
+#define   XELPDP_PORT_BUF_IO_SELECT_TBT			REG_BIT(11)
+#define   XELPDP_PORT_BUF_PHY_IDLE			REG_BIT(7)
 #define   XELPDP_TC_PHY_OWNERSHIP			REG_BIT(6)
 #define   XELPDP_TCSS_POWER_REQUEST			REG_BIT(5)
 #define   XELPDP_TCSS_POWER_STATE			REG_BIT(4)

drivers/gpu/drm/i915/i915_reg.h

@@ -5645,11 +5645,16 @@ enum skl_power_gate {
 /* DDI Buffer Control */
 #define _DDI_BUF_CTL_A				0x64000
 #define _DDI_BUF_CTL_B				0x64100
+/* Known as DDI_CTL_DE in MTL+ */
 #define DDI_BUF_CTL(port) _MMIO_PORT(port, _DDI_BUF_CTL_A, _DDI_BUF_CTL_B)
 #define  DDI_BUF_CTL_ENABLE			(1 << 31)
 #define  DDI_BUF_TRANS_SELECT(n)	((n) << 24)
 #define  DDI_BUF_EMP_MASK			(0xf << 24)
 #define  DDI_BUF_PHY_LINK_RATE(r)		((r) << 20)
+#define  DDI_BUF_PORT_DATA_MASK			REG_GENMASK(19, 18)
+#define  DDI_BUF_PORT_DATA_10BIT		REG_FIELD_PREP(DDI_BUF_PORT_DATA_MASK, 0)
+#define  DDI_BUF_PORT_DATA_20BIT		REG_FIELD_PREP(DDI_BUF_PORT_DATA_MASK, 1)
+#define  DDI_BUF_PORT_DATA_40BIT		REG_FIELD_PREP(DDI_BUF_PORT_DATA_MASK, 2)
 #define  DDI_BUF_PORT_REVERSAL			(1 << 16)
 #define  DDI_BUF_IS_IDLE			(1 << 7)
 #define  DDI_BUF_CTL_TC_PHY_OWNERSHIP		REG_BIT(6)