drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c

   1 /*
   2  * Copyright (C) 2014 Traphandler
   3  * Copyright (C) 2014 Free Electrons
   4  * Copyright (C) 2014 Atmel
   5  *
   6  * Author: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
   7  * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License version 2 as published by
  11  * the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  16  * more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along with
  19  * this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <linux/of_graph.h>
  23
  24 #include <drm/drmP.h>
  25 #include <drm/drm_of.h>
  26 #include <drm/drm_bridge.h>
  27
  28 #include "atmel_hlcdc_dc.h"
  29
  30 static const struct drm_encoder_funcs atmel_hlcdc_panel_encoder_funcs = {
  31         .destroy = drm_encoder_cleanup,
  32 };
  33
  34 static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint)
  35 {
  36         struct drm_encoder *encoder;
  37         struct drm_panel *panel;
  38         struct drm_bridge *bridge;
  39         int ret;
  40
  41         ret = drm_of_find_panel_or_bridge(dev->dev->of_node, 0, endpoint,
  42                                           &panel, &bridge);
  43         if (ret)
  44                 return ret;
  45
  46         encoder = devm_kzalloc(dev->dev, sizeof(*encoder), GFP_KERNEL);
  47         if (!encoder)
  48                 return -EINVAL;
  49
  50         ret = drm_encoder_init(dev, encoder,
  51                                &atmel_hlcdc_panel_encoder_funcs,
  52                                DRM_MODE_ENCODER_NONE, NULL);
  53         if (ret)
  54                 return ret;
  55
  56         encoder->possible_crtcs = 0x1;
  57
  58         if (panel) {
  59                 bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_Unknown);
  60                 if (IS_ERR(bridge))
  61                         return PTR_ERR(bridge);
  62         }
  63
  64         if (bridge) {
  65                 ret = drm_bridge_attach(encoder, bridge, NULL);
  66                 if (!ret)
  67                         return 0;
  68
  69                 if (panel)
  70                         drm_panel_bridge_remove(bridge);
  71         }
  72
  73         drm_encoder_cleanup(encoder);
  74
  75         return ret;
  76 }
  77
  78 int atmel_hlcdc_create_outputs(struct drm_device *dev)
  79 {
  80         int endpoint, ret = 0;
  81
  82         for (endpoint = 0; !ret; endpoint++)
  83                 ret = atmel_hlcdc_attach_endpoint(dev, endpoint);
  84
  85         /* At least one device was successfully attached.*/
  86         if (ret == -ENODEV && endpoint)
  87                 return 0;
  88
  89         return ret;
  90 }