xref: /openbmc/linux/drivers/gpu/drm/drm_of.c (revision ba61bb17)
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_bridge.h>
7 #include <drm/drm_crtc.h>
8 #include <drm/drm_encoder.h>
9 #include <drm/drm_panel.h>
10 #include <drm/drm_of.h>
11 
12 static void drm_release_of(struct device *dev, void *data)
13 {
14 	of_node_put(data);
15 }
16 
17 /**
18  * drm_of_crtc_port_mask - find the mask of a registered CRTC by port OF node
19  * @dev: DRM device
20  * @port: port OF node
21  *
22  * Given a port OF node, return the possible mask of the corresponding
23  * CRTC within a device's list of CRTCs.  Returns zero if not found.
24  */
25 uint32_t drm_of_crtc_port_mask(struct drm_device *dev,
26 			    struct device_node *port)
27 {
28 	unsigned int index = 0;
29 	struct drm_crtc *tmp;
30 
31 	drm_for_each_crtc(tmp, dev) {
32 		if (tmp->port == port)
33 			return 1 << index;
34 
35 		index++;
36 	}
37 
38 	return 0;
39 }
40 EXPORT_SYMBOL(drm_of_crtc_port_mask);
41 
42 /**
43  * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
44  * @dev: DRM device
45  * @port: encoder port to scan for endpoints
46  *
47  * Scan all endpoints attached to a port, locate their attached CRTCs,
48  * and generate the DRM mask of CRTCs which may be attached to this
49  * encoder.
50  *
51  * See Documentation/devicetree/bindings/graph.txt for the bindings.
52  */
53 uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
54 				    struct device_node *port)
55 {
56 	struct device_node *remote_port, *ep;
57 	uint32_t possible_crtcs = 0;
58 
59 	for_each_endpoint_of_node(port, ep) {
60 		remote_port = of_graph_get_remote_port(ep);
61 		if (!remote_port) {
62 			of_node_put(ep);
63 			return 0;
64 		}
65 
66 		possible_crtcs |= drm_of_crtc_port_mask(dev, remote_port);
67 
68 		of_node_put(remote_port);
69 	}
70 
71 	return possible_crtcs;
72 }
73 EXPORT_SYMBOL(drm_of_find_possible_crtcs);
74 
75 /**
76  * drm_of_component_match_add - Add a component helper OF node match rule
77  * @master: master device
78  * @matchptr: component match pointer
79  * @compare: compare function used for matching component
80  * @node: of_node
81  */
82 void drm_of_component_match_add(struct device *master,
83 				struct component_match **matchptr,
84 				int (*compare)(struct device *, void *),
85 				struct device_node *node)
86 {
87 	of_node_get(node);
88 	component_match_add_release(master, matchptr, drm_release_of,
89 				    compare, node);
90 }
91 EXPORT_SYMBOL_GPL(drm_of_component_match_add);
92 
93 /**
94  * drm_of_component_probe - Generic probe function for a component based master
95  * @dev: master device containing the OF node
96  * @compare_of: compare function used for matching components
97  * @master_ops: component master ops to be used
98  *
99  * Parse the platform device OF node and bind all the components associated
100  * with the master. Interface ports are added before the encoders in order to
101  * satisfy their .bind requirements
102  * See Documentation/devicetree/bindings/graph.txt for the bindings.
103  *
104  * Returns zero if successful, or one of the standard error codes if it fails.
105  */
106 int drm_of_component_probe(struct device *dev,
107 			   int (*compare_of)(struct device *, void *),
108 			   const struct component_master_ops *m_ops)
109 {
110 	struct device_node *ep, *port, *remote;
111 	struct component_match *match = NULL;
112 	int i;
113 
114 	if (!dev->of_node)
115 		return -EINVAL;
116 
117 	/*
118 	 * Bind the crtc's ports first, so that drm_of_find_possible_crtcs()
119 	 * called from encoder's .bind callbacks works as expected
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 			drm_of_component_match_add(dev, &match, compare_of,
128 						   port);
129 
130 		of_node_put(port);
131 	}
132 
133 	if (i == 0) {
134 		dev_err(dev, "missing 'ports' property\n");
135 		return -ENODEV;
136 	}
137 
138 	if (!match) {
139 		dev_err(dev, "no available port\n");
140 		return -ENODEV;
141 	}
142 
143 	/*
144 	 * For bound crtcs, bind the encoders attached to their remote endpoint
145 	 */
146 	for (i = 0; ; i++) {
147 		port = of_parse_phandle(dev->of_node, "ports", i);
148 		if (!port)
149 			break;
150 
151 		if (!of_device_is_available(port->parent)) {
152 			of_node_put(port);
153 			continue;
154 		}
155 
156 		for_each_child_of_node(port, ep) {
157 			remote = of_graph_get_remote_port_parent(ep);
158 			if (!remote || !of_device_is_available(remote)) {
159 				of_node_put(remote);
160 				continue;
161 			} else if (!of_device_is_available(remote->parent)) {
162 				dev_warn(dev, "parent device of %pOF is not available\n",
163 					 remote);
164 				of_node_put(remote);
165 				continue;
166 			}
167 
168 			drm_of_component_match_add(dev, &match, compare_of,
169 						   remote);
170 			of_node_put(remote);
171 		}
172 		of_node_put(port);
173 	}
174 
175 	return component_master_add_with_match(dev, m_ops, match);
176 }
177 EXPORT_SYMBOL(drm_of_component_probe);
178 
179 /*
180  * drm_of_encoder_active_endpoint - return the active encoder endpoint
181  * @node: device tree node containing encoder input ports
182  * @encoder: drm_encoder
183  *
184  * Given an encoder device node and a drm_encoder with a connected crtc,
185  * parse the encoder endpoint connecting to the crtc port.
186  */
187 int drm_of_encoder_active_endpoint(struct device_node *node,
188 				   struct drm_encoder *encoder,
189 				   struct of_endpoint *endpoint)
190 {
191 	struct device_node *ep;
192 	struct drm_crtc *crtc = encoder->crtc;
193 	struct device_node *port;
194 	int ret;
195 
196 	if (!node || !crtc)
197 		return -EINVAL;
198 
199 	for_each_endpoint_of_node(node, ep) {
200 		port = of_graph_get_remote_port(ep);
201 		of_node_put(port);
202 		if (port == crtc->port) {
203 			ret = of_graph_parse_endpoint(ep, endpoint);
204 			of_node_put(ep);
205 			return ret;
206 		}
207 	}
208 
209 	return -EINVAL;
210 }
211 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
212 
213 /*
214  * drm_of_find_panel_or_bridge - return connected panel or bridge device
215  * @np: device tree node containing encoder output ports
216  * @panel: pointer to hold returned drm_panel
217  * @bridge: pointer to hold returned drm_bridge
218  *
219  * Given a DT node's port and endpoint number, find the connected node and
220  * return either the associated struct drm_panel or drm_bridge device. Either
221  * @panel or @bridge must not be NULL.
222  *
223  * Returns zero if successful, or one of the standard error codes if it fails.
224  */
225 int drm_of_find_panel_or_bridge(const struct device_node *np,
226 				int port, int endpoint,
227 				struct drm_panel **panel,
228 				struct drm_bridge **bridge)
229 {
230 	int ret = -EPROBE_DEFER;
231 	struct device_node *remote;
232 
233 	if (!panel && !bridge)
234 		return -EINVAL;
235 	if (panel)
236 		*panel = NULL;
237 
238 	remote = of_graph_get_remote_node(np, port, endpoint);
239 	if (!remote)
240 		return -ENODEV;
241 
242 	if (panel) {
243 		*panel = of_drm_find_panel(remote);
244 		if (*panel)
245 			ret = 0;
246 	}
247 
248 	/* No panel found yet, check for a bridge next. */
249 	if (bridge) {
250 		if (ret) {
251 			*bridge = of_drm_find_bridge(remote);
252 			if (*bridge)
253 				ret = 0;
254 		} else {
255 			*bridge = NULL;
256 		}
257 
258 	}
259 
260 	of_node_put(remote);
261 	return ret;
262 }
263 EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);
264