1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #define LOG_TAG "hwc-drm-event-listener"
18 
19 #include "drmeventlistener.h"
20 #include "drmresources.h"
21 
22 #include <linux/netlink.h>
23 #include <sys/socket.h>
24 
25 #include <cutils/log.h>
26 #include <xf86drm.h>
27 
28 namespace android {
29 
DrmEventListener(DrmResources * drm)30 DrmEventListener::DrmEventListener(DrmResources *drm)
31     : Worker("drm-event-listener", HAL_PRIORITY_URGENT_DISPLAY),
32       drm_(drm) {
33 }
34 
Init()35 int DrmEventListener::Init() {
36   uevent_fd_.Set(socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT));
37   if (uevent_fd_.get() < 0) {
38     ALOGE("Failed to open uevent socket %d", uevent_fd_.get());
39     return uevent_fd_.get();
40   }
41 
42   struct sockaddr_nl addr;
43   memset(&addr, 0, sizeof(addr));
44   addr.nl_family = AF_NETLINK;
45   addr.nl_pid = getpid();
46   addr.nl_groups = 0xFFFFFFFF;
47 
48   int ret = bind(uevent_fd_.get(), (struct sockaddr *)&addr, sizeof(addr));
49   if (ret) {
50     ALOGE("Failed to bind uevent socket %d", -errno);
51     return -errno;
52   }
53 
54   FD_ZERO(&fds_);
55   FD_SET(drm_->fd(), &fds_);
56   FD_SET(uevent_fd_.get(), &fds_);
57   max_fd_ = std::max(drm_->fd(), uevent_fd_.get());
58 
59   return InitWorker();
60 }
61 
RegisterHotplugHandler(DrmEventHandler * handler)62 void DrmEventListener::RegisterHotplugHandler(DrmEventHandler *handler) {
63   assert(!hotplug_handler_);
64   hotplug_handler_ = handler;
65 }
66 
FlipHandler(int,unsigned int,unsigned int tv_sec,unsigned int tv_usec,void * user_data)67 void DrmEventListener::FlipHandler(int /* fd */, unsigned int /* sequence */,
68                                    unsigned int tv_sec, unsigned int tv_usec,
69                                    void *user_data) {
70   DrmEventHandler *handler = (DrmEventHandler *)user_data;
71   if (!handler)
72     return;
73 
74   handler->HandleEvent((uint64_t)tv_sec * 1000 * 1000 + tv_usec);
75   delete handler;
76 }
77 
UEventHandler()78 void DrmEventListener::UEventHandler() {
79   char buffer[1024];
80   int ret;
81 
82   struct timespec ts;
83   uint64_t timestamp = 0;
84   ret = clock_gettime(CLOCK_MONOTONIC, &ts);
85   if (!ret)
86     timestamp = ts.tv_sec * 1000 * 1000 * 1000 + ts.tv_nsec;
87   else
88     ALOGE("Failed to get monotonic clock on hotplug %d", ret);
89 
90   while (true) {
91     ret = read(uevent_fd_.get(), &buffer, sizeof(buffer));
92     if (ret == 0) {
93       return;
94     } else if (ret < 0) {
95       ALOGE("Got error reading uevent %d", ret);
96       return;
97     }
98 
99     if (!hotplug_handler_)
100       continue;
101 
102     bool drm_event = false, hotplug_event = false;
103     for (int i = 0; i < ret;) {
104       char *event = buffer + i;
105       if (strcmp(event, "DEVTYPE=drm_minor"))
106         drm_event = true;
107       else if (strcmp(event, "HOTPLUG=1"))
108         hotplug_event = true;
109 
110       i += strlen(event) + 1;
111     }
112 
113     if (drm_event && hotplug_event)
114       hotplug_handler_->HandleEvent(timestamp);
115   }
116 }
117 
Routine()118 void DrmEventListener::Routine() {
119   int ret;
120   do {
121     ret = select(max_fd_ + 1, &fds_, NULL, NULL, NULL);
122   } while (ret == -1 && errno == EINTR);
123 
124   if (FD_ISSET(drm_->fd(), &fds_)) {
125     drmEventContext event_context = {
126         .version = DRM_EVENT_CONTEXT_VERSION,
127         .vblank_handler = NULL,
128         .page_flip_handler = DrmEventListener::FlipHandler};
129     drmHandleEvent(drm_->fd(), &event_context);
130   }
131 
132   if (FD_ISSET(uevent_fd_.get(), &fds_))
133     UEventHandler();
134 }
135 }
136