android_hardware_qcom_display/libhwcomposer/hwc_uevents.cpp

/*
 * Copyright (C) 2010 The Android Open Source Project
 * Copyright (C) 2012, Code Aurora Forum. All rights reserved.
 *
 * Not a Contribution, Apache license notifications and license are
 * retained for attribution purposes only.

 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#define DEBUG 0
#ifndef HWC_UEVENTS_H
#define HWC_UEVENTS_H
#include <hardware_legacy/uevent.h>
#include <utils/Log.h>
#include <sys/resource.h>
#include <sys/prctl.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include "hwc_utils.h"
#include "hwc_external.h"

namespace qhwc {

const char* MSMFB_DEVICE_FB0 = "change@/devices/virtual/graphics/fb0";
const char* MSMFB_DEVICE_FB1 = "change@/devices/virtual/graphics/fb1";
const char* MSMFB_FB_NODE = "fb";

static void handle_uevent(hwc_context_t* ctx, const char* udata, int len)
{
    int vsync = 0;
    int64_t timestamp = 0;
    const char *str = udata;
    hwc_procs* proc = (hwc_procs*)ctx->device.reserved_proc[0];
    int hdmiconnected = ctx->mExtDisplay->getExternalDisplay();

    if(!strcasestr(str, "@/devices/virtual/graphics/fb")) {
        ALOGD_IF(DEBUG, "%s: Not Ext Disp Event ", __FUNCTION__);
        return;
    }

    if(ctx->mExtDisplay->isHDMIConfigured() &&
            (hdmiconnected == EXTERN_DISPLAY_FB1))
        vsync = !strncmp(str, MSMFB_DEVICE_FB1, strlen(MSMFB_DEVICE_FB1));
    else
        vsync = !strncmp(str, MSMFB_DEVICE_FB0, strlen(MSMFB_DEVICE_FB0));

    if(vsync) {
        str += strlen(str) + 1;
        while(*str) {
            if (!strncmp(str, "VSYNC=", strlen("VSYNC="))) {
                timestamp = strtoull(str + strlen("VSYNC="), NULL, 0);
                proc->vsync(proc, 0, timestamp);
            }
            str += strlen(str) + 1;
            if(str - udata >= len)
                break;
        }
        return;
    }

    // parse HDMI events
    // The event will be of the form:
    // change@/devices/virtual/graphics/fb1 ACTION=change
    // DEVPATH=/devices/virtual/graphics/fb1
    // SUBSYSTEM=graphics HDCP_STATE=FAIL MAJOR=29
    // for now just parsing onlin/offline info is enough
    str = udata;
    if(!(strncmp(str,"online@",strlen("online@")))) {
        ctx->mExtDisplay->processUEventOnline(str);
    } else if(!(strncmp(str,"offline@",strlen("offline@")))) {
        ctx->mExtDisplay->processUEventOffline(str);
    }
}

static void *uevent_loop(void *param)
{
    int len = 0;
    static char udata[4096];
    memset(udata, 0, sizeof(udata));
    hwc_context_t * ctx = reinterpret_cast<hwc_context_t *>(param);

    char thread_name[64] = "hwcUeventThread";
    prctl(PR_SET_NAME, (unsigned long) &thread_name, 0, 0, 0);
    setpriority(PRIO_PROCESS, 0, HAL_PRIORITY_URGENT_DISPLAY);
    uevent_init();

    while(1) {
        len = uevent_next_event(udata, sizeof(udata) - 2);
        handle_uevent(ctx, udata, len);
    }

    return NULL;
}

static void *vsync_loop(void *param)
{
    static char buf[4096];
    int fb0_vsync_fd;
    fd_set exceptfds;
    int res;
    int64_t timestamp = 0;
    hwc_context_t * ctx = reinterpret_cast<hwc_context_t *>(param);
    hwc_procs* proc = (hwc_procs*)ctx->device.reserved_proc[0];

    fb0_vsync_fd = open("/sys/devices/virtual/graphics/fb0/vsync_time", O_RDONLY);
    if (!fb0_vsync_fd)
        return NULL;

    char thread_name[64] = "hwcVsyncThread";
    prctl(PR_SET_NAME, (unsigned long) &thread_name, 0, 0, 0);
    setpriority(PRIO_PROCESS, 0, -20);
    memset(buf, 0, sizeof(buf));

    ALOGI("Using sysfs mechanism for VSYNC notification");

    FD_ZERO(&exceptfds);
    FD_SET(fb0_vsync_fd, &exceptfds);

    do {
        ssize_t len = read(fb0_vsync_fd, buf, sizeof(buf));
        timestamp = strtoull(buf, NULL, 0);
        proc->vsync(proc, 0, timestamp);
        select(fb0_vsync_fd + 1, NULL, NULL, &exceptfds, NULL);
        lseek(fb0_vsync_fd, 0, SEEK_SET);
    } while (1);

    return NULL;
}

void init_uevent_thread(hwc_context_t* ctx)
{
    pthread_t uevent_thread;
    pthread_t vsync_thread;
    ALOGI("Initializing UEvent Listener Thread");
    pthread_create(&uevent_thread, NULL, uevent_loop, (void*) ctx);
    pthread_create(&vsync_thread, NULL, vsync_loop, (void*) ctx);
}

}; //namespace
#endif //HWC_UEVENTS_H