1 #include <linux/component.h>
2 #include <linux/export.h>
3 #include <linux/list.h>
4 #include <linux/of_graph.h>
5 #include <drm/drmP.h>
6 #include <drm/drm_crtc.h>
7 #include <drm/drm_of.h>
8
9 /**
10 * drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
11 * @dev: DRM device
12 * @port: port OF node
13 *
14 * Given a port OF node, return the possible mask of the corresponding
15 * CRTC within a device's list of CRTCs. Returns zero if not found.
16 */
drm_crtc_port_mask(struct drm_device * dev,struct device_node * port)17 static uint32_t drm_crtc_port_mask(struct drm_device *dev,
18 struct device_node *port)
19 {
20 unsigned int index = 0;
21 struct drm_crtc *tmp;
22
23 drm_for_each_crtc(tmp, dev) {
24 if (tmp->port == port)
25 return 1 << index;
26
27 index++;
28 }
29
30 return 0;
31 }
32
33 /**
34 * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
35 * @dev: DRM device
36 * @port: encoder port to scan for endpoints
37 *
38 * Scan all endpoints attached to a port, locate their attached CRTCs,
39 * and generate the DRM mask of CRTCs which may be attached to this
40 * encoder.
41 *
42 * See Documentation/devicetree/bindings/graph.txt for the bindings.
43 */
drm_of_find_possible_crtcs(struct drm_device * dev,struct device_node * port)44 uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
45 struct device_node *port)
46 {
47 struct device_node *remote_port, *ep;
48 uint32_t possible_crtcs = 0;
49
50 for_each_endpoint_of_node(port, ep) {
51 remote_port = of_graph_get_remote_port(ep);
52 if (!remote_port) {
53 of_node_put(ep);
54 return 0;
55 }
56
57 possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
58
59 of_node_put(remote_port);
60 }
61
62 return possible_crtcs;
63 }
64 EXPORT_SYMBOL(drm_of_find_possible_crtcs);
65
66 /**
67 * drm_of_component_probe - Generic probe function for a component based master
68 * @dev: master device containing the OF node
69 * @compare_of: compare function used for matching components
70 * @master_ops: component master ops to be used
71 *
72 * Parse the platform device OF node and bind all the components associated
73 * with the master. Interface ports are added before the encoders in order to
74 * satisfy their .bind requirements
75 * See Documentation/devicetree/bindings/graph.txt for the bindings.
76 *
77 * Returns zero if successful, or one of the standard error codes if it fails.
78 */
drm_of_component_probe(struct device * dev,int (* compare_of)(struct device *,void *),const struct component_master_ops * m_ops)79 int drm_of_component_probe(struct device *dev,
80 int (*compare_of)(struct device *, void *),
81 const struct component_master_ops *m_ops)
82 {
83 struct device_node *ep, *port, *remote;
84 struct component_match *match = NULL;
85 int i;
86
87 if (!dev->of_node)
88 return -EINVAL;
89
90 /*
91 * Bind the crtc's ports first, so that drm_of_find_possible_crtcs()
92 * called from encoder's .bind callbacks works as expected
93 */
94 for (i = 0; ; i++) {
95 port = of_parse_phandle(dev->of_node, "ports", i);
96 if (!port)
97 break;
98
99 if (!of_device_is_available(port->parent)) {
100 of_node_put(port);
101 continue;
102 }
103
104 component_match_add(dev, &match, compare_of, port);
105 of_node_put(port);
106 }
107
108 if (i == 0) {
109 dev_err(dev, "missing 'ports' property\n");
110 return -ENODEV;
111 }
112
113 if (!match) {
114 dev_err(dev, "no available port\n");
115 return -ENODEV;
116 }
117
118 /*
119 * For bound crtcs, bind the encoders attached to their remote endpoint
120 */
121 for (i = 0; ; i++) {
122 port = of_parse_phandle(dev->of_node, "ports", i);
123 if (!port)
124 break;
125
126 if (!of_device_is_available(port->parent)) {
127 of_node_put(port);
128 continue;
129 }
130
131 for_each_child_of_node(port, ep) {
132 remote = of_graph_get_remote_port_parent(ep);
133 if (!remote || !of_device_is_available(remote)) {
134 of_node_put(remote);
135 continue;
136 } else if (!of_device_is_available(remote->parent)) {
137 dev_warn(dev, "parent device of %s is not available\n",
138 remote->full_name);
139 of_node_put(remote);
140 continue;
141 }
142
143 component_match_add(dev, &match, compare_of, remote);
144 of_node_put(remote);
145 }
146 of_node_put(port);
147 }
148
149 return component_master_add_with_match(dev, m_ops, match);
150 }
151 EXPORT_SYMBOL(drm_of_component_probe);
152
153 /*
154 * drm_of_encoder_active_endpoint - return the active encoder endpoint
155 * @node: device tree node containing encoder input ports
156 * @encoder: drm_encoder
157 *
158 * Given an encoder device node and a drm_encoder with a connected crtc,
159 * parse the encoder endpoint connecting to the crtc port.
160 */
drm_of_encoder_active_endpoint(struct device_node * node,struct drm_encoder * encoder,struct of_endpoint * endpoint)161 int drm_of_encoder_active_endpoint(struct device_node *node,
162 struct drm_encoder *encoder,
163 struct of_endpoint *endpoint)
164 {
165 struct device_node *ep;
166 struct drm_crtc *crtc = encoder->crtc;
167 struct device_node *port;
168 int ret;
169
170 if (!node || !crtc)
171 return -EINVAL;
172
173 for_each_endpoint_of_node(node, ep) {
174 port = of_graph_get_remote_port(ep);
175 of_node_put(port);
176 if (port == crtc->port) {
177 ret = of_graph_parse_endpoint(ep, endpoint);
178 of_node_put(ep);
179 return ret;
180 }
181 }
182
183 return -EINVAL;
184 }
185 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
186