/*
 * Copyright (C) 2013 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.
 *
 * Based on the FlounderPowerHAL
 */

#include <dirent.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdbool.h>
#include <pthread.h>
#include <semaphore.h>
#include <cutils/properties.h>
//#define LOG_NDEBUG 0

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

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

#define SCHEDTUNE_BOOST_PATH "/dev/stune/foreground/schedtune.boost"
#define SCHEDTUNE_BOOST_NORM "10"
#define SCHEDTUNE_BOOST_INTERACTIVE "40"
#define SCHEDTUNE_BOOST_TIME_NS 1000000000LL
#define INTERACTIVE_BOOSTPULSE_PATH "/sys/devices/system/cpu/cpufreq/interactive/boostpulse"
#define INTERACTIVE_IO_IS_BUSY_PATH "/sys/devices/system/cpu/cpufreq/interactive/io_is_busy"
#define CPU_MAX_FREQ_PATH "/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq"
#define LOW_POWER_MAX_FREQ "729000"
#define NORMAL_MAX_FREQ "1200000"
#define SVELTE_PROP "ro.boot.svelte"
#define SVELTE_MAX_FREQ_PROP "ro.config.svelte.max_cpu_freq"
#define SVELTE_LOW_POWER_MAX_FREQ_PROP "ro.config.svelte.low_power_max_cpu_freq"

struct hikey_power_module {
    struct power_module base;
    pthread_mutex_t lock;
    /* interactive gov boost values */
    int boostpulse_fd;
    int boostpulse_warned;
    /* EAS schedtune values */
    int schedtune_boost_fd;
    long long deboost_time;
    sem_t signal_lock;
};

static bool low_power_mode = false;

static char *max_cpu_freq = NORMAL_MAX_FREQ;
static char *low_power_max_cpu_freq = LOW_POWER_MAX_FREQ;


#define container_of(addr, struct_name, field_name) \
    ((struct_name *)((char *)(addr) - offsetof(struct_name, field_name)))


static int sysfs_write(const char *path, char *s)
{
    char buf[80];
    int len;
    int fd = open(path, O_WRONLY);

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

    len = write(fd, s, strlen(s));
    if (len < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error writing to %s: %s\n", path, buf);
    }

    close(fd);
    return len;
}

#define NSEC_PER_SEC 1000000000LL
static long long gettime_ns(void)
{
    struct timespec ts;

    clock_gettime(CLOCK_MONOTONIC, &ts);
    return ts.tv_sec * NSEC_PER_SEC + ts.tv_nsec;
}

static void nanosleep_ns(long long ns)
{
    struct timespec ts;
    ts.tv_sec = ns/NSEC_PER_SEC;
    ts.tv_nsec = ns%NSEC_PER_SEC;
    nanosleep(&ts, NULL);
}

/*[interactive cpufreq gov funcs]*********************************************/
static void interactive_power_init(struct hikey_power_module __unused *hikey)
{
    int32_t is_svelte = property_get_int32(SVELTE_PROP, 0);

    if (sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/timer_rate",
                "20000") < 0)
        return;
    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/timer_slack",
                "20000");
    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/min_sample_time",
                "80000");
    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/hispeed_freq",
                "1200000");
    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load",
                "99");
    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/target_loads",
                "65 729000:75 960000:85");
    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/above_hispeed_delay",
                "20000");
    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/boostpulse_duration",
                "1000000");
    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/io_is_busy", "0");

    if (is_svelte) {
        char prop_buffer[PROPERTY_VALUE_MAX];
        int len = property_get(SVELTE_MAX_FREQ_PROP, prop_buffer,
                               LOW_POWER_MAX_FREQ);

        max_cpu_freq = strndup(prop_buffer, len);
        len = property_get(SVELTE_LOW_POWER_MAX_FREQ_PROP, prop_buffer,
                           LOW_POWER_MAX_FREQ);
        low_power_max_cpu_freq = strndup(prop_buffer, len);
    }
}

static void power_set_interactive(struct power_module __unused *module, int on)
{
    ALOGV("power_set_interactive: %d\n", on);

    /*
     * Lower maximum frequency when screen is off.
     */
    sysfs_write(CPU_MAX_FREQ_PATH,
                (!on || low_power_mode) ? low_power_max_cpu_freq : max_cpu_freq);
    sysfs_write(INTERACTIVE_IO_IS_BUSY_PATH, on ? "1" : "0");
    ALOGV("power_set_interactive: %d done\n", on);
}

static int interactive_boostpulse(struct hikey_power_module *hikey)
{
    char buf[80];
    int len;

   if (hikey->boostpulse_fd < 0)
        hikey->boostpulse_fd = open(INTERACTIVE_BOOSTPULSE_PATH, O_WRONLY);

    if (hikey->boostpulse_fd < 0) {
        if (!hikey->boostpulse_warned) {
            strerror_r(errno, buf, sizeof(buf));
            ALOGE("Error opening %s: %s\n", INTERACTIVE_BOOSTPULSE_PATH,
                      buf);
            hikey->boostpulse_warned = 1;
        }
        return hikey->boostpulse_fd;
    }

    len = write(hikey->boostpulse_fd, "1", 1);
    if (len < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error writing to %s: %s\n",
                                 INTERACTIVE_BOOSTPULSE_PATH, buf);
        return -1;
    }
    return 0;
}

/*[schedtune functions]*******************************************************/

int schedtune_sysfs_boost(struct hikey_power_module *hikey, char* booststr)
{
    char buf[80];
    int len;

    if (hikey->schedtune_boost_fd < 0)
        return hikey->schedtune_boost_fd;

    len = write(hikey->schedtune_boost_fd, booststr, 2);
    if (len < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error writing to %s: %s\n", SCHEDTUNE_BOOST_PATH, buf);
    }
    return len;
}

static void* schedtune_deboost_thread(void* arg)
{
    struct hikey_power_module *hikey = (struct hikey_power_module *)arg;

    while(1) {
        sem_wait(&hikey->signal_lock);
        while(1) {
            long long now, sleeptime = 0;

            pthread_mutex_lock(&hikey->lock);
            now = gettime_ns();
            if (hikey->deboost_time > now) {
                sleeptime = hikey->deboost_time - now;
                pthread_mutex_unlock(&hikey->lock);
                nanosleep_ns(sleeptime);
                continue;
            }

            schedtune_sysfs_boost(hikey, SCHEDTUNE_BOOST_NORM);
            hikey->deboost_time = 0;
            pthread_mutex_unlock(&hikey->lock);
            break;
        }
    }
    return NULL;
}

static int schedtune_boost(struct hikey_power_module *hikey)
{
    long long now;

    if (hikey->schedtune_boost_fd < 0)
        return hikey->schedtune_boost_fd;

    now = gettime_ns();
    if (!hikey->deboost_time) {
        schedtune_sysfs_boost(hikey, SCHEDTUNE_BOOST_INTERACTIVE);
        sem_post(&hikey->signal_lock);
    }
    hikey->deboost_time = now + SCHEDTUNE_BOOST_TIME_NS;

    return 0;
}

static void schedtune_power_init(struct hikey_power_module *hikey)
{
    char buf[50];
    pthread_t tid;


    hikey->deboost_time = 0;
    sem_init(&hikey->signal_lock, 0, 1);

    hikey->schedtune_boost_fd = open(SCHEDTUNE_BOOST_PATH, O_WRONLY);
    if (hikey->schedtune_boost_fd < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error opening %s: %s\n", SCHEDTUNE_BOOST_PATH, buf);
    }

    pthread_create(&tid, NULL, schedtune_deboost_thread, hikey);
}

/*[generic functions]*********************************************************/
static void hikey_power_init(struct power_module __unused *module)
{
    struct hikey_power_module *hikey = container_of(module,
                                              struct hikey_power_module, base);
    interactive_power_init(hikey);
    schedtune_power_init(hikey);
}

static void hikey_hint_interaction(struct hikey_power_module *mod)
{
    /* Try interactive cpufreq boosting first */
    if(!interactive_boostpulse(mod))
        return;
    /* Then try EAS schedtune boosting */
    if(!schedtune_boost(mod))
        return;
}

static void hikey_power_hint(struct power_module *module, power_hint_t hint,
                                void *data)
{
    struct hikey_power_module *hikey = container_of(module,
                                              struct hikey_power_module, base);

    pthread_mutex_lock(&hikey->lock);
    switch (hint) {
     case POWER_HINT_INTERACTION:
        hikey_hint_interaction(hikey);
        break;

   case POWER_HINT_VSYNC:
        break;

    case POWER_HINT_LOW_POWER:
        if (data) {
            sysfs_write(CPU_MAX_FREQ_PATH, low_power_max_cpu_freq);
        } else {
            sysfs_write(CPU_MAX_FREQ_PATH, max_cpu_freq);
        }
        low_power_mode = data;
        break;

    default:
            break;
    }
    pthread_mutex_unlock(&hikey->lock);
}

static void set_feature(struct power_module *module, feature_t feature, int state)
{
    struct hikey_power_module *hikey = container_of(module,
                                              struct hikey_power_module, base);
    switch (feature) {
    default:
        ALOGW("Error setting the feature %d and state %d, it doesn't exist\n",
              feature, state);
        break;
    }
}

static int power_open(const hw_module_t* __unused module, const char* name,
                    hw_device_t** device)
{
    int retval = 0; /* 0 is ok; -1 is error */
    ALOGD("%s: enter; name=%s", __FUNCTION__, name);

    if (strcmp(name, POWER_HARDWARE_MODULE_ID) == 0) {
        power_module_t *dev = (power_module_t *)calloc(1,
                sizeof(power_module_t));

        if (dev) {
            /* Common hw_device_t fields */
            dev->common.tag = HARDWARE_DEVICE_TAG;
            dev->common.module_api_version = POWER_MODULE_API_VERSION_0_5;
            dev->common.hal_api_version = HARDWARE_HAL_API_VERSION;

            dev->init = hikey_power_init;
            dev->powerHint = hikey_power_hint;
            dev->setInteractive = power_set_interactive;
            dev->setFeature = set_feature;

            *device = (hw_device_t*)dev;
        } else
            retval = -ENOMEM;
    } else {
        retval = -EINVAL;
    }

    ALOGD("%s: exit %d", __FUNCTION__, retval);
    return retval;
}

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

struct hikey_power_module HAL_MODULE_INFO_SYM = {
    .base = {
        .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 = "HiKey Power HAL",
            .author = "The Android Open Source Project",
            .methods = &power_module_methods,
        },

        .init = hikey_power_init,
        .setInteractive = power_set_interactive,
        .powerHint = hikey_power_hint,
        .setFeature = set_feature,
    },

    .lock = PTHREAD_MUTEX_INITIALIZER,
    .boostpulse_fd = -1,
    .boostpulse_warned = 0,
};