drm_of.c
#include <linux/export.h>
#include <linux/list.h>
#include <linux/of_graph.h>
#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_of.h>
/**
* drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
* @dev: DRM device
* @port: port OF node
*
* Given a port OF node, return the possible mask of the corresponding
* CRTC within a device's list of CRTCs. Returns zero if not found.
*/
static uint32_t drm_crtc_port_mask(struct drm_device *dev,
struct device_node *port)
{
unsigned int index = 0;
struct drm_crtc *tmp;
list_for_each_entry(tmp, &dev->mode_config.crtc_list, head) {
if (tmp->port == port)
return 1 << index;
index++;
}
return 0;
}
/**
* drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
* @dev: DRM device
* @port: encoder port to scan for endpoints
*
* Scan all endpoints attached to a port, locate their attached CRTCs,
* and generate the DRM mask of CRTCs which may be attached to this
* encoder.
*
* See Documentation/devicetree/bindings/graph.txt for the bindings.
*/
uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
struct device_node *port)
{
struct device_node *remote_port, *ep = NULL;
uint32_t possible_crtcs = 0;
do {
ep = of_graph_get_next_endpoint(port, ep);
if (!ep)
break;
remote_port = of_graph_get_remote_port(ep);
if (!remote_port) {
of_node_put(ep);
return 0;
}
possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
of_node_put(remote_port);
} while (1);
return possible_crtcs;
}
EXPORT_SYMBOL(drm_of_find_possible_crtcs);