libhwcomposer/hwc_uevents.cpp

/*
 * Copyright (C) 2010 The Android Open Source Project
 * Copyright (C) 2012, The Linux Foundation. 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 UEVENT_DEBUG 0
#include <hardware_legacy/uevent.h>
#include <utils/Log.h>
#include <sys/resource.h>
#include <sys/prctl.h>
#include <string.h>
#include <stdlib.h>
#include "hwc_utils.h"
#include "external.h"

namespace qhwc {

#define HWC_UEVENT_THREAD_NAME "hwcUeventThread"

static void handle_uevent(hwc_context_t* ctx, const char* udata, int len)
{
    int vsync = 0;
    int64_t timestamp = 0;
    const char *str = udata;

    if(!strcasestr(str, "change@/devices/virtual/switch/hdmi") &&
       !strcasestr(str, "change@/devices/virtual/switch/wfd")) {
        ALOGD_IF(UEVENT_DEBUG, "%s: Not Ext Disp Event ", __FUNCTION__);
        return;
    }

    int connected = -1; // initial value - will be set to  1/0 based on hotplug
    // parse HDMI/WFD switch state for connect/disconnect
    // for HDMI:
    // The event will be of the form:
    // change@/devices/virtual/switch/hdmi ACTION=change
    // SWITCH_STATE=1 or SWITCH_STATE=0

    while(*str) {
        if (!strncmp(str, "SWITCH_STATE=", strlen("SWITCH_STATE="))) {
            connected = atoi(str + strlen("SWITCH_STATE="));
            //Disabled until SF calls unblank
            ctx->dpyAttr[HWC_DISPLAY_EXTERNAL].isActive = false;
            break;
        }
        str += strlen(str) + 1;
        if (str - udata >= len)
            break;
    }

    if(connected != -1) { //either we got switch_state connected or disconnect
        ctx->dpyAttr[HWC_DISPLAY_EXTERNAL].connected = connected;
        if(connected) {
            ctx->mExtDisplay->processUEventOnline(udata);
        }else {
            ctx->mExtDisplay->processUEventOffline(udata);
        }
        ALOGD("%s sending hotplug: connected = %d", __FUNCTION__, connected);
        Locker::Autolock _l(ctx->mExtSetLock); //hwc comp could be on
        ctx->proc->hotplug(ctx->proc, HWC_DISPLAY_EXTERNAL, connected);
    }
}

static void *uevent_loop(void *param)
{
    int len = 0;
    static char udata[PAGE_SIZE];
    hwc_context_t * ctx = reinterpret_cast<hwc_context_t *>(param);
    char thread_name[64] = HWC_UEVENT_THREAD_NAME;
    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;
}

void init_uevent_thread(hwc_context_t* ctx)
{
    pthread_t uevent_thread;
    int ret;

    ALOGI("Initializing UEVENT Thread");
    ret = pthread_create(&uevent_thread, NULL, uevent_loop, (void*) ctx);
    if (ret) {
        ALOGE("%s: failed to create %s: %s", __FUNCTION__,
            HWC_UEVENT_THREAD_NAME, strerror(ret));
    }
}

}; //namespace