LXR linux/drivers/gpu/drm/drm

   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>
   7
   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
  12 *
  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.
  15 */
  16static uint32_t drm_crtc_port_mask(struct drm_device *dev,
  17                                   struct device_node *port)
  18{
  19        unsigned int index = 0;
  20        struct drm_crtc *tmp;
  21
  22        list_for_each_entry(tmp, &dev->mode_config.crtc_list, head) {
  23                if (tmp->port == port)
  24                        return 1 << index;
  25
  26                index++;
  27        }
  28
  29        return 0;
  30}
  31
  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
  36 *
  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.
  40 *
  41 * See Documentation/devicetree/bindings/graph.txt for the bindings.
  42 */
  43uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
  44                                    struct device_node *port)
  45{
  46        struct device_node *remote_port, *ep;
  47        uint32_t possible_crtcs = 0;
  48
  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;
  54                }
  55
  56                possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
  57
  58                of_node_put(remote_port);
  59        }
  60
  61        return possible_crtcs;
  62}
  63EXPORT_SYMBOL(drm_of_find_possible_crtcs);
  64