drm/amd/display: Call DMUB for eDP power control

[Why]
If DMUB is used, LVTMA VBIOS call can be used to control eDP instead
of tranditional transmitter control. Interface is agreed with VBIOS
for eDP to use this new path to program LVTMA registers.

[How]
Expose DAL interface to send DMUB command for LVTMA control that VBIOS
currently uses.

Signed-off-by: Chris Park <[e-mail]>
Reviewed-by: Nicholas Kazlauskas <[e-mail]>
Acked-by: Eryk Brol <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dc/bios/command_table2.c

···
 
 }
 
+static void enable_lvtma_control_dmcub(
+	struct dc_dmub_srv *dmcub,
+	uint8_t uc_pwr_on)
+{
+
+	union dmub_rb_cmd cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+
+	cmd.cmd_common.header.type = DMUB_CMD__VBIOS;
+	cmd.cmd_common.header.sub_type =
+			DMUB_CMD__VBIOS_LVTMA_CONTROL;
+	cmd.cmd_common.cmd_buffer[0] =
+			uc_pwr_on;
+
+	dc_dmub_srv_cmd_queue(dmcub, &cmd);
+	dc_dmub_srv_cmd_execute(dmcub);
+	dc_dmub_srv_wait_idle(dmcub);
+
+}
+
 static enum bp_result enable_lvtma_control(
 	struct bios_parser *bp,
 	uint8_t uc_pwr_on)
 {
 	enum bp_result result = BP_RESULT_FAILURE;
+
+	if (bp->base.ctx->dc->ctx->dmub_srv &&
+	    bp->base.ctx->dc->debug.dmub_command_table) {
+		enable_lvtma_control_dmcub(bp->base.ctx->dmub_srv,
+				uc_pwr_on);
+		return BP_RESULT_OK;
+	}
 	return result;
 }