text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   * Copyright (C) 2012 Red Hat
   * based in parts on udlfb.c:
   * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
   * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
   * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
   */
  
  #include <drm/drm_atomic_state_helper.h>
  #include <drm/drm_crtc_helper.h>
  #include <drm/drm_probe_helper.h>
  
  #include "udl_connector.h"
  #include "udl_drv.h"
  
  static int udl_get_edid_block(void *data, u8 *buf, unsigned int block,
  			       size_t len)
  {
  	int ret, i;
  	u8 *read_buff;
  	struct udl_device *udl = data;
  
  	read_buff = kmalloc(2, GFP_KERNEL);
  	if (!read_buff)
  		return -1;
  
  	for (i = 0; i < len; i++) {
  		int bval = (i + block * EDID_LENGTH) << 8;
  		ret = usb_control_msg(udl->udev,
  				      usb_rcvctrlpipe(udl->udev, 0),
  					  (0x02), (0x80 | (0x02 << 5)), bval,
  					  0xA1, read_buff, 2, HZ);
  		if (ret < 1) {
  			DRM_ERROR("Read EDID byte %d failed err %x\n", i, ret);
  			kfree(read_buff);
  			return -1;
  		}
  		buf[i] = read_buff[1];
  	}
  
  	kfree(read_buff);
  	return 0;
  }
  
  static int udl_get_modes(struct drm_connector *connector)
  {
  	struct udl_drm_connector *udl_connector =
  					container_of(connector,
  					struct udl_drm_connector,
  					connector);
  
  	drm_connector_update_edid_property(connector, udl_connector->edid);
  	if (udl_connector->edid)
  		return drm_add_edid_modes(connector, udl_connector->edid);
  	return 0;
  }
  
  static enum drm_mode_status udl_mode_valid(struct drm_connector *connector,
  			  struct drm_display_mode *mode)
  {
  	struct udl_device *udl = to_udl(connector->dev);
  	if (!udl->sku_pixel_limit)
  		return 0;
  
  	if (mode->vdisplay * mode->hdisplay > udl->sku_pixel_limit)
  		return MODE_VIRTUAL_Y;
  
  	return 0;
  }
  
  static enum drm_connector_status
  udl_detect(struct drm_connector *connector, bool force)
  {
  	struct udl_device *udl = to_udl(connector->dev);
  	struct udl_drm_connector *udl_connector =
  					container_of(connector,
  					struct udl_drm_connector,
  					connector);
  
  	/* cleanup previous edid */
  	if (udl_connector->edid != NULL) {
  		kfree(udl_connector->edid);
  		udl_connector->edid = NULL;
  	}
  
  	udl_connector->edid = drm_do_get_edid(connector, udl_get_edid_block, udl);
  	if (!udl_connector->edid)
  		return connector_status_disconnected;
  
  	return connector_status_connected;
  }
  
  static void udl_connector_destroy(struct drm_connector *connector)
  {
  	struct udl_drm_connector *udl_connector =
  					container_of(connector,
  					struct udl_drm_connector,
  					connector);
  
  	drm_connector_cleanup(connector);
  	kfree(udl_connector->edid);
  	kfree(connector);
  }
  
  static const struct drm_connector_helper_funcs udl_connector_helper_funcs = {
  	.get_modes = udl_get_modes,
  	.mode_valid = udl_mode_valid,
  };
  
  static const struct drm_connector_funcs udl_connector_funcs = {
  	.reset = drm_atomic_helper_connector_reset,
  	.detect = udl_detect,
  	.fill_modes = drm_helper_probe_single_connector_modes,
  	.destroy = udl_connector_destroy,
  	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
  	.atomic_destroy_state   = drm_atomic_helper_connector_destroy_state,
  };
  
  struct drm_connector *udl_connector_init(struct drm_device *dev)
  {
  	struct udl_drm_connector *udl_connector;
  	struct drm_connector *connector;
  
  	udl_connector = kzalloc(sizeof(struct udl_drm_connector), GFP_KERNEL);
  	if (!udl_connector)
  		return ERR_PTR(-ENOMEM);
  
  	connector = &udl_connector->connector;
  	drm_connector_init(dev, connector, &udl_connector_funcs,
  			   DRM_MODE_CONNECTOR_DVII);
  	drm_connector_helper_add(connector, &udl_connector_helper_funcs);
  
  	connector->polled = DRM_CONNECTOR_POLL_HPD |
  		DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT;
  
  	return connector;
  }
  