drm/i915/display: add intel_dig_port_alloc()

Add a common allocator function for struct intel_digital_port, with some
member default initialization to deduplicate them from everywhere
else. This is similar to intel_connector_alloc().

At least for now, place this in intel_encoder.[ch]. We don't have a
dedicated file for dig port stuff, and there wouldn't be much to add
there anyway. A digital port is a sort of subclass of encoder, so the
location isn't far off the mark.

Reviewed-by: Dibin Moolakadan Subrahmanian <[e-mail]>
Link: https://lore.kernel.org/r/4d2[e-mail]
Signed-off-by: Jani Nikula <[e-mail]>

drivers/gpu/drm/i915/display/g4x_dp.c

···
 		drm_dbg_kms(display->drm, "No VBT child device for DP-%c\n",
 			    port_name(port));
 
-	dig_port = kzalloc(sizeof(*dig_port), GFP_KERNEL);
+	dig_port = intel_dig_port_alloc();
 	if (!dig_port)
 		return false;
-
-	dig_port->aux_ch = AUX_CH_NONE;
 
 	intel_connector = intel_connector_alloc();
 	if (!intel_connector)
···
 	encoder = &intel_encoder->base;
 
 	intel_encoder->devdata = devdata;
-
-	mutex_init(&dig_port->hdcp.mutex);
 
 	if (drm_encoder_init(display->drm, &intel_encoder->base,
 			     &intel_dp_enc_funcs, DRM_MODE_ENCODER_TMDS,
···
 	}
 
 	dig_port->dp.output_reg = output_reg;
-	dig_port->max_lanes = 4;
 
 	intel_encoder->type = INTEL_OUTPUT_DP;
 	intel_encoder->power_domain = intel_display_power_ddi_lanes_domain(display, port);

drivers/gpu/drm/i915/display/g4x_hdmi.c

···
 #include "intel_display_types.h"
 #include "intel_dp_aux.h"
 #include "intel_dpio_phy.h"
+#include "intel_encoder.h"
 #include "intel_fdi.h"
 #include "intel_fifo_underrun.h"
 #include "intel_hdmi.h"
···
 		drm_dbg_kms(display->drm, "No VBT child device for HDMI-%c\n",
 			    port_name(port));
 
-	dig_port = kzalloc(sizeof(*dig_port), GFP_KERNEL);
+	dig_port = intel_dig_port_alloc();
 	if (!dig_port)
 		return false;
-
-	dig_port->aux_ch = AUX_CH_NONE;
 
 	intel_connector = intel_connector_alloc();
 	if (!intel_connector)
···
 	intel_encoder = &dig_port->base;
 
 	intel_encoder->devdata = devdata;
-
-	mutex_init(&dig_port->hdcp.mutex);
 
 	if (drm_encoder_init(display->drm, &intel_encoder->base,
 			     &intel_hdmi_enc_funcs, DRM_MODE_ENCODER_TMDS,
···
 		intel_encoder->cloneable |= BIT(INTEL_OUTPUT_HDMI);
 
 	dig_port->hdmi.hdmi_reg = hdmi_reg;
-	dig_port->dp.output_reg = INVALID_MMIO_REG;
-	dig_port->max_lanes = 4;
 
 	intel_infoframe_init(dig_port);
 

drivers/gpu/drm/i915/display/intel_ddi.c

···
 			    phy_name(phy));
 	}
 
-	dig_port = kzalloc(sizeof(*dig_port), GFP_KERNEL);
+	dig_port = intel_dig_port_alloc();
 	if (!dig_port)
 		return;
-
-	dig_port->aux_ch = AUX_CH_NONE;
 
 	encoder = &dig_port->base;
 	encoder->devdata = devdata;
···
 	}
 
 	intel_encoder_link_check_init(encoder, intel_ddi_link_check);
-
-	mutex_init(&dig_port->hdcp.mutex);
-	dig_port->hdcp.num_streams = 0;
 
 	encoder->hotplug = intel_ddi_hotplug;
 	encoder->compute_output_type = intel_ddi_compute_output_type;
···
 
 	dig_port->ddi_a_4_lanes = DISPLAY_VER(display) < 11 && ddi_buf_ctl & DDI_A_4_LANES;
 
-	dig_port->dp.output_reg = INVALID_MMIO_REG;
 	dig_port->max_lanes = intel_ddi_max_lanes(dig_port);
 
 	if (need_aux_ch(encoder, init_dp)) {

drivers/gpu/drm/i915/display/intel_encoder.c

···
 		if (encoder->shutdown_complete)
 			encoder->shutdown_complete(encoder);
 }
+
+struct intel_digital_port *intel_dig_port_alloc(void)
+{
+	struct intel_digital_port *dig_port;
+
+	dig_port = kzalloc(sizeof(*dig_port), GFP_KERNEL);
+	if (!dig_port)
+		return NULL;
+
+	dig_port->hdmi.hdmi_reg = INVALID_MMIO_REG;
+	dig_port->dp.output_reg = INVALID_MMIO_REG;
+	dig_port->aux_ch = AUX_CH_NONE;
+	dig_port->max_lanes = 4;
+
+	mutex_init(&dig_port->hdcp.mutex);
+
+	return dig_port;
+}

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

···
 #ifndef __INTEL_ENCODER_H__
 #define __INTEL_ENCODER_H__
 
+struct intel_digital_port;
 struct intel_display;
 struct intel_encoder;
 
···
 
 void intel_encoder_block_all_hpds(struct intel_display *display);
 void intel_encoder_unblock_all_hpds(struct intel_display *display);
+
+struct intel_digital_port *intel_dig_port_alloc(void);
 
 #endif /* __INTEL_ENCODER_H__ */