text: /*
   * 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>
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License v2. See the file COPYING in the main directory of this archive for
   * more details.
   */
  
  #include <drm/drmP.h>
  #include <drm/drm_crtc.h>
  #include <drm/drm_edid.h>
  #include <drm/drm_crtc_helper.h>
  #include <drm/drm_probe_helper.h>
  #include "udl_connector.h"
  #include "udl_drv.h"
  
  static bool udl_get_edid_block(struct udl_device *udl, int block_idx,
  							   u8 *buff)
  {
  	int ret, i;
  	u8 *read_buff;
  
  	read_buff = kmalloc(2, GFP_KERNEL);
  	if (!read_buff)
  		return false;
  
  	for (i = 0; i < EDID_LENGTH; i++) {
  		int bval = (i + block_idx * 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 false;
  		}
  		buff[i] = read_buff[1];
  	}
  
  	kfree(read_buff);
  	return true;
  }
  
  static bool udl_get_edid(struct udl_device *udl, u8 **result_buff,
  			 int *result_buff_size)
  {
  	int i, extensions;
  	u8 *block_buff = NULL, *buff_ptr;
  
  	block_buff = kmalloc(EDID_LENGTH, GFP_KERNEL);
  	if (block_buff == NULL)
  		return false;
  
  	if (udl_get_edid_block(udl, 0, block_buff) &&
  	    memchr_inv(block_buff, 0, EDID_LENGTH)) {
  		extensions = ((struct edid *)block_buff)->extensions;
  		if (extensions > 0) {
  			/* we have to read all extensions one by one */
  			*result_buff_size = EDID_LENGTH * (extensions + 1);
  			*result_buff = kmalloc(*result_buff_size, GFP_KERNEL);
  			buff_ptr = *result_buff;
  			if (buff_ptr == NULL) {
  				kfree(block_buff);
  				return false;
  			}
  			memcpy(buff_ptr, block_buff, EDID_LENGTH);
  			kfree(block_buff);
  			buff_ptr += EDID_LENGTH;
  			for (i = 1; i < extensions; ++i) {
  				if (udl_get_edid_block(udl, i, buff_ptr)) {
  					buff_ptr += EDID_LENGTH;
  				} else {
  					kfree(*result_buff);
  					*result_buff = NULL;
  					return false;
  				}
  			}
  			return true;
  		}
  		/* we have only base edid block */
  		*result_buff = block_buff;
  		*result_buff_size = EDID_LENGTH;
  		return true;
  	}
  
  	kfree(block_buff);
  
  	return false;
  }
  
  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 = connector->dev->dev_private;
  	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)
  {
  	u8 *edid_buff = NULL;
  	int edid_buff_size = 0;
  	struct udl_device *udl = connector->dev->dev_private;
  	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;
  	}
  
  
  	if (!udl_get_edid(udl, &edid_buff, &edid_buff_size))
  		return connector_status_disconnected;
  
  	udl_connector->edid = (struct edid *)edid_buff;
  	
  	return connector_status_connected;
  }
  
  static struct drm_encoder*
  udl_best_single_encoder(struct drm_connector *connector)
  {
  	int enc_id = connector->encoder_ids[0];
  	return drm_encoder_find(connector->dev, NULL, enc_id);
  }
  
  static int udl_connector_set_property(struct drm_connector *connector,
  				      struct drm_property *property,
  				      uint64_t val)
  {
  	return 0;
  }
  
  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_unregister(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,
  	.best_encoder = udl_best_single_encoder,
  };
  
  static const struct drm_connector_funcs udl_connector_funcs = {
  	.dpms = drm_helper_connector_dpms,
  	.detect = udl_detect,
  	.fill_modes = drm_helper_probe_single_connector_modes,
  	.destroy = udl_connector_destroy,
  	.set_property = udl_connector_set_property,
  };
  
  int udl_connector_init(struct drm_device *dev, struct drm_encoder *encoder)
  {
  	struct udl_drm_connector *udl_connector;
  	struct drm_connector *connector;
  
  	udl_connector = kzalloc(sizeof(struct udl_drm_connector), GFP_KERNEL);
  	if (!udl_connector)
  		return -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);
  
  	drm_connector_register(connector);
  	drm_connector_attach_encoder(connector, encoder);
  	connector->polled = DRM_CONNECTOR_POLL_HPD |
  		DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT;
  
  	return 0;
  }
  