xref: /linux/drivers/gpu/drm/tilcdc/tilcdc_encoder.c (revision cb18dbb74f46bd0aa612aaae144dd191c548739c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2015 Texas Instruments
4  * Author: Jyri Sarha <jsarha@ti.com>
5  */
6 
7 #include <linux/of_graph.h>
8 
9 #include <drm/drm_atomic_helper.h>
10 #include <drm/drm_bridge.h>
11 #include <drm/drm_of.h>
12 #include <drm/drm_simple_kms_helper.h>
13 
14 #include "tilcdc_drv.h"
15 #include "tilcdc_encoder.h"
16 
17 static
18 struct drm_connector *tilcdc_encoder_find_connector(struct drm_device *ddev,
19 						    struct drm_encoder *encoder)
20 {
21 	struct drm_connector *connector;
22 
23 	list_for_each_entry(connector, &ddev->mode_config.connector_list, head) {
24 		if (drm_connector_has_possible_encoder(connector, encoder))
25 			return connector;
26 	}
27 
28 	dev_err(ddev->dev, "No connector found for %s encoder (id %d)\n",
29 		encoder->name, encoder->base.id);
30 
31 	return NULL;
32 }
33 
34 static
35 int tilcdc_attach_bridge(struct drm_device *ddev, struct drm_bridge *bridge)
36 {
37 	struct tilcdc_drm_private *priv = ddev->dev_private;
38 	int ret;
39 
40 	priv->encoder->possible_crtcs = BIT(0);
41 
42 	ret = drm_bridge_attach(priv->encoder, bridge, NULL, 0);
43 	if (ret)
44 		return ret;
45 
46 	priv->connector = tilcdc_encoder_find_connector(ddev, priv->encoder);
47 	if (!priv->connector)
48 		return -ENODEV;
49 
50 	return 0;
51 }
52 
53 int tilcdc_encoder_create(struct drm_device *ddev)
54 {
55 	struct tilcdc_drm_private *priv = ddev->dev_private;
56 	struct drm_bridge *bridge;
57 	struct drm_panel *panel;
58 	int ret;
59 
60 	ret = drm_of_find_panel_or_bridge(ddev->dev->of_node, 0, 0,
61 					  &panel, &bridge);
62 	if (ret == -ENODEV)
63 		return 0;
64 	else if (ret)
65 		return ret;
66 
67 	priv->encoder = devm_kzalloc(ddev->dev, sizeof(*priv->encoder), GFP_KERNEL);
68 	if (!priv->encoder)
69 		return -ENOMEM;
70 
71 	ret = drm_simple_encoder_init(ddev, priv->encoder,
72 				      DRM_MODE_ENCODER_NONE);
73 	if (ret) {
74 		dev_err(ddev->dev, "drm_encoder_init() failed %d\n", ret);
75 		return ret;
76 	}
77 
78 	if (panel) {
79 		bridge = devm_drm_panel_bridge_add_typed(ddev->dev, panel,
80 							 DRM_MODE_CONNECTOR_DPI);
81 		if (IS_ERR(bridge)) {
82 			ret = PTR_ERR(bridge);
83 			goto err_encoder_cleanup;
84 		}
85 	}
86 
87 	ret = tilcdc_attach_bridge(ddev, bridge);
88 	if (ret)
89 		goto err_encoder_cleanup;
90 
91 	return 0;
92 
93 err_encoder_cleanup:
94 	drm_encoder_cleanup(priv->encoder);
95 	return ret;
96 }
97