drm/amd/display: Added HPO HW control shutdown support

[Why]
HPO is only used for DP2.0. HPO HW control should be
disable when not being used to save power.

[How]
Shutdown HPO HW control during init hw.
Shutdown HPO HW control during stream disable.
Enable HPO HW control during stream enable if DP2.0.

Acked-by: Aurabindo Pillai <[e-mail]>
Signed-off-by: Jake Wang <[e-mail]>
Reviewed-by: Nicholas Kazlauskas <[e-mail]>
Tested-by: Daniel Wheeler <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dc/dc.h

···
 #endif
 	union mem_low_power_enable_options enable_mem_low_power;
 	union root_clock_optimization_options root_clock_optimization;
+	bool hpo_optimization;
 	bool force_vblank_alignment;
 
 	/* Enable dmub aux for legacy ddc */

drivers/gpu/drm/amd/display/dc/dce/dce_hwseq.h

···
 	uint32_t MC_VM_FB_LOCATION_BASE;
 	uint32_t MC_VM_FB_LOCATION_TOP;
 	uint32_t MC_VM_FB_OFFSET;
+	uint32_t HPO_TOP_HW_CONTROL;
 };
  /* set field name */
 #define HWS_SF(blk_name, reg_name, field_name, post_fix)\
···
 	type DOMAIN_PGFSM_PWR_STATUS;\
 	type HPO_HDMISTREAMCLK_G_GATE_DIS;\
 	type DISABLE_HOSTVM_FORCE_ALLOW_PSTATE;\
-	type I2C_LIGHT_SLEEP_FORCE;
+	type I2C_LIGHT_SLEEP_FORCE;\
+	type HPO_IO_EN;
 
 struct dce_hwseq_shift {
 	HWSEQ_REG_FIELD_LIST(uint8_t)

drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c

···
 #endif
 	if (dc_is_dp_signal(pipe_ctx->stream->signal))
 		dp_source_sequence_trace(link, DPCD_SOURCE_SEQ_AFTER_DISCONNECT_DIG_FE_BE);
+
+#if defined(CONFIG_DRM_AMD_DC_DCN)
+	if (dc->hwseq->funcs.setup_hpo_hw_control && is_dp_128b_132b_signal(pipe_ctx))
+		dc->hwseq->funcs.setup_hpo_hw_control(dc->hwseq, false);
+#endif
+
 }
 
 void dce110_unblank_stream(struct pipe_ctx *pipe_ctx,

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c

···
 	 * BY this, it is logic clean to separate stream and link
 	 */
 	if (is_dp_128b_132b_signal(pipe_ctx)) {
+		if (pipe_ctx->stream->ctx->dc->hwseq->funcs.setup_hpo_hw_control)
+			pipe_ctx->stream->ctx->dc->hwseq->funcs.setup_hpo_hw_control(
+				pipe_ctx->stream->ctx->dc->hwseq, true);
 		setup_dp_hpo_stream(pipe_ctx, true);
 		pipe_ctx->stream_res.hpo_dp_stream_enc->funcs->enable_stream(
 				pipe_ctx->stream_res.hpo_dp_stream_enc);

drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c

···
 	if (dc->debug.enable_mem_low_power.bits.i2c)
 		REG_UPDATE(DIO_MEM_PWR_CTRL, I2C_LIGHT_SLEEP_FORCE, 1);
 
+	if (hws->funcs.setup_hpo_hw_control)
+		hws->funcs.setup_hpo_hw_control(hws, false);
+
 	if (!dc->debug.disable_clock_gate) {
 		/* enable all DCN clock gating */
 		REG_WRITE(DCCG_GATE_DISABLE_CNTL, 0);
···
 
 	/* New dc_state in the process of being applied to hardware. */
 	dc->current_state->res_ctx.link_enc_cfg_ctx.mode = LINK_ENC_CFG_TRANSIENT;
+}
+
+void dcn31_setup_hpo_hw_control(const struct dce_hwseq *hws, bool enable)
+{
+	if (hws->ctx->dc->debug.hpo_optimization)
+		REG_UPDATE(HPO_TOP_HW_CONTROL, HPO_IO_EN, !!enable);
 }

drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.h

···
 bool dcn31_is_abm_supported(struct dc *dc,
 		struct dc_state *context, struct dc_stream_state *stream);
 void dcn31_init_pipes(struct dc *dc, struct dc_state *context);
+void dcn31_setup_hpo_hw_control(const struct dce_hwseq *hws, bool enable);
 
 #endif /* __DC_HWSS_DCN31_H__ */

drivers/gpu/drm/amd/display/dc/dcn31/dcn31_init.c

···
 	.dccg_init = dcn20_dccg_init,
 	.set_blend_lut = dcn30_set_blend_lut,
 	.set_shaper_3dlut = dcn20_set_shaper_3dlut,
+	.setup_hpo_hw_control = dcn31_setup_hpo_hw_control,
 };
 
 void dcn31_hw_sequencer_construct(struct dc *dc)

drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c

···
 	SR(D6VGA_CONTROL), \
 	SR(DC_IP_REQUEST_CNTL), \
 	SR(AZALIA_AUDIO_DTO), \
-	SR(AZALIA_CONTROLLER_CLOCK_GATING)
+	SR(AZALIA_CONTROLLER_CLOCK_GATING), \
+	SR(HPO_TOP_HW_CONTROL)
 
 static const struct dce_hwseq_registers hwseq_reg = {
 		HWSEQ_DCN31_REG_LIST()
···
 	HWS_SF(, ODM_MEM_PWR_CTRL3, ODM_MEM_UNASSIGNED_PWR_MODE, mask_sh), \
 	HWS_SF(, ODM_MEM_PWR_CTRL3, ODM_MEM_VBLANK_PWR_MODE, mask_sh), \
 	HWS_SF(, MMHUBBUB_MEM_PWR_CNTL, VGA_MEM_PWR_FORCE, mask_sh), \
-	HWS_SF(, DIO_MEM_PWR_CTRL, I2C_LIGHT_SLEEP_FORCE, mask_sh)
+	HWS_SF(, DIO_MEM_PWR_CTRL, I2C_LIGHT_SLEEP_FORCE, mask_sh), \
+	HWS_SF(, HPO_TOP_HW_CONTROL, HPO_IO_EN, mask_sh)
 
 static const struct dce_hwseq_shift hwseq_shift = {
 		HWSEQ_DCN31_MASK_SH_LIST(__SHIFT)

drivers/gpu/drm/amd/display/dc/inc/hw_sequencer_private.h

···
 			const struct dc_plane_state *plane_state);
 	void (*PLAT_58856_wa)(struct dc_state *context,
 			struct pipe_ctx *pipe_ctx);
+	void (*setup_hpo_hw_control)(const struct dce_hwseq *hws, bool enable);
 };
 
 struct dce_hwseq {