Linux 4.2.1
[linux/fpc-iii.git] / drivers / gpu / drm / drm_of.c
blobaaa130736bf8d303bd949d0e5588b413e137b23d
1 #include <linux/export.h>
2 #include <linux/list.h>
3 #include <linux/of_graph.h>
4 #include <drm/drmP.h>
5 #include <drm/drm_crtc.h>
6 #include <drm/drm_of.h>
8 /**
9 * drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
10 * @dev: DRM device
11 * @port: port OF node
13 * Given a port OF node, return the possible mask of the corresponding
14 * CRTC within a device's list of CRTCs. Returns zero if not found.
16 static uint32_t drm_crtc_port_mask(struct drm_device *dev,
17 struct device_node *port)
19 unsigned int index = 0;
20 struct drm_crtc *tmp;
22 list_for_each_entry(tmp, &dev->mode_config.crtc_list, head) {
23 if (tmp->port == port)
24 return 1 << index;
26 index++;
29 return 0;
32 /**
33 * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
34 * @dev: DRM device
35 * @port: encoder port to scan for endpoints
37 * Scan all endpoints attached to a port, locate their attached CRTCs,
38 * and generate the DRM mask of CRTCs which may be attached to this
39 * encoder.
41 * See Documentation/devicetree/bindings/graph.txt for the bindings.
43 uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
44 struct device_node *port)
46 struct device_node *remote_port, *ep;
47 uint32_t possible_crtcs = 0;
49 for_each_endpoint_of_node(port, ep) {
50 remote_port = of_graph_get_remote_port(ep);
51 if (!remote_port) {
52 of_node_put(ep);
53 return 0;
56 possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
58 of_node_put(remote_port);
61 return possible_crtcs;
63 EXPORT_SYMBOL(drm_of_find_possible_crtcs);