drm/amd/display: Add a check for idle power optimization

[why]
Need a helper function to check idle power is allowed
so that dc doesn't access any registers that are power-gated.

[how]
Implement helper function to check idle power optimization.
Enable a hook to check if detection is allowed.

Signed-off-by: Sung Joon Kim <Sungjoon.Kim@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -4803,7 +4803,8 @@ bool dc_set_psr_allow_active(struct dc *dc, bool enable)
 
 void dc_allow_idle_optimizations(struct dc *dc, bool allow)
 {
-	if (dc->debug.disable_idle_power_optimizations)
+	if (dc->debug.disable_idle_power_optimizations ||
+		(dc->caps.ips_support && dc->config.disable_ips))
 		return;
 
 	if (dc->clk_mgr != NULL && dc->clk_mgr->funcs->is_smu_present)
@@ -4817,6 +4818,23 @@ void dc_allow_idle_optimizations(struct dc *dc, bool allow)
 		dc->idle_optimizations_allowed = allow;
 }
 
+bool dc_is_idle_power_optimized(struct dc *dc)
+{
+	uint32_t idle_state = 0;
+
+	if (dc->debug.disable_idle_power_optimizations)
+		return false;
+
+	if (dc->hwss.get_idle_state)
+		idle_state = dc->hwss.get_idle_state(dc);
+
+	if ((idle_state & DMUB_IPS1_ALLOW_MASK) ||
+		(idle_state & DMUB_IPS2_ALLOW_MASK))
+		return true;
+
+	return false;
+}
+
 /* set min and max memory clock to lowest and highest DPM level, respectively */
 void dc_unlock_memory_clock_frequency(struct dc *dc)
 {

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

@@ -2311,6 +2311,7 @@ bool dc_is_plane_eligible_for_idle_optimizations(struct dc *dc, struct dc_plane_
 				struct dc_cursor_attributes *cursor_attr);
 
 void dc_allow_idle_optimizations(struct dc *dc, bool allow);
+bool dc_is_idle_power_optimized(struct dc *dc);
 
 /* set min and max memory clock to lowest and highest DPM level, respectively */
 void dc_unlock_memory_clock_frequency(struct dc *dc);

drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c

@@ -352,6 +352,7 @@ static bool dmub_srv_hw_setup(struct dmub_srv *dmub, enum dmub_asic asic)
 			funcs->init_reg_offsets = dmub_srv_dcn35_regs_init;
 
 			funcs->is_hw_powered_up = dmub_dcn35_is_hw_powered_up;
+			funcs->should_detect = dmub_dcn35_should_detect;
 			break;
 
 	default: