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