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 }
91