modules/power/power.c

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * 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.
 */
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#define LOG_TAG "Legacy PowerHAL"
#include <utils/Log.h>

#include <hardware/hardware.h>
#include <hardware/power.h>

/*
 * This module implements the legacy interface for requesting early
 * suspend and late resume
 */

#define LEGACY_SYS_POWER_STATE "/sys/power/state"

static int sPowerStatefd;
static const char *pwr_states[] = { "mem", "on" };

static void power_init(struct power_module *module)
{
    char buf[80];

    sPowerStatefd = open(LEGACY_SYS_POWER_STATE, O_RDWR);

    if (sPowerStatefd < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error opening %s: %s\n", LEGACY_SYS_POWER_STATE, buf);
    }
}

static void power_set_interactive(struct power_module *module, int on)
{
    char buf[80];
    int len;

    len = write(sPowerStatefd, pwr_states[!!on], strlen(pwr_states[!!on]));
    if (len < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error writing to %s: %s\n", LEGACY_SYS_POWER_STATE, buf);
    }
}

static void power_hint(struct power_module *module, power_hint_t hint,
                       void *data) {
    switch (hint) {
    default:
        break;
    }
}

static struct hw_module_methods_t power_module_methods = {
    .open = NULL,
};

struct power_module HAL_MODULE_INFO_SYM = {
    .common = {
        .tag = HARDWARE_MODULE_TAG,
        .module_api_version = POWER_MODULE_API_VERSION_0_2,
        .hal_api_version = HARDWARE_HAL_API_VERSION,
        .id = POWER_HARDWARE_MODULE_ID,
        .name = "Default Power HAL",
        .author = "The Android Open Source Project",
        .methods = &power_module_methods,
    },

    .init = power_init,
    .setInteractive = power_set_interactive,
    .powerHint = power_hint,
};