/*
 * sysfs.c sysfs ABI access functions for TMON program
 *
 * Copyright (C) 2013 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 or later as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Author: Jacob Pan <jacob.jun.pan@linux.intel.com>
 *
 */
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <dirent.h>
#include <libintl.h>
#include <ctype.h>
#include <time.h>
#include <syslog.h>
#include <sys/time.h>
#include <errno.h>

#include "tmon.h"

struct tmon_platform_data ptdata;
const char *trip_type_name[] = {
        "critical",
        "hot",
        "passive",
        "active",
};

int sysfs_set_ulong(char *path, char *filename, unsigned long val)
{
        FILE *fd;
        int ret = -1;
        char filepath[256];

        snprintf(filepath, 256, "%s/%s", path, filename);

        fd = fopen(filepath, "w");
        if (!fd) {
                syslog(LOG_ERR, "Err: open %s: %s\n", __func__, filepath);
                return ret;
        }
        ret = fprintf(fd, "%lu", val);
        fclose(fd);

        return 0;
}

/* history of thermal data, used for control algo */
#define NR_THERMAL_RECORDS 3
struct thermal_data_record trec[NR_THERMAL_RECORDS];
int cur_thermal_record; /* index to the trec array */

static int sysfs_get_ulong(char *path, char *filename, unsigned long *p_ulong)
{
        FILE *fd;
        int ret = -1;
        char filepath[256];

        snprintf(filepath, 256, "%s/%s", path, filename);

        fd = fopen(filepath, "r");
        if (!fd) {
                syslog(LOG_ERR, "Err: open %s: %s\n", __func__, filepath);
                return ret;
        }
        ret = fscanf(fd, "%lu", p_ulong);
        fclose(fd);

        return 0;
}

static int sysfs_get_string(char *path, char *filename, char *str)
{
        FILE *fd;
        int ret = -1;
        char filepath[256];

        snprintf(filepath, 256, "%s/%s", path, filename);

        fd = fopen(filepath, "r");
        if (!fd) {
                syslog(LOG_ERR, "Err: open %s: %s\n", __func__, filepath);
                return ret;
        }
        ret = fscanf(fd, "%256s", str);
        fclose(fd);

        return ret;
}

/* get states of the cooling device instance */
static int probe_cdev(struct cdev_info *cdi, char *path)
{
        sysfs_get_string(path, "type", cdi->type);
        sysfs_get_ulong(path, "max_state",  &cdi->max_state);
        sysfs_get_ulong(path, "cur_state", &cdi->cur_state);

        syslog(LOG_INFO, "%s: %s: type %s, max %lu, curr %lu inst %d\n",
                __func__, path,
                cdi->type, cdi->max_state, cdi->cur_state, cdi->instance);

        return 0;
}

static int str_to_trip_type(char *name)
{
        int i;

        for (i = 0; i < NR_THERMAL_TRIP_TYPE; i++) {
                if (!strcmp(name, trip_type_name[i]))
                        return i;
        }

        return -ENOENT;
}

/* scan and fill in trip point info for a thermal zone and trip point id */
static int get_trip_point_data(char *tz_path, int tzid, int tpid)
{
        char filename[256];
        char temp_str[256];
        int trip_type;

        if (tpid >= MAX_NR_TRIP)
                return -EINVAL;
        /* check trip point type */
        snprintf(filename, sizeof(filename), "trip_point_%d_type", tpid);
        sysfs_get_string(tz_path, filename, temp_str);
        trip_type = str_to_trip_type(temp_str);
        if (trip_type < 0) {
                syslog(LOG_ERR, "%s:%s no matching type\n", __func__, temp_str);
                return -ENOENT;
        }
        ptdata.tzi[tzid].tp[tpid].type = trip_type;
        syslog(LOG_INFO, "%s:tz:%d tp:%d:type:%s type id %d\n", __func__, tzid,
                tpid, temp_str, trip_type);

        /* TODO: check attribute */

        return 0;
}

/* return instance id for file format such as trip_point_4_temp */
static int get_instance_id(char *name, int pos, int skip)
{
        char *ch;
        int i = 0;

        ch = strtok(name, "_");
        while (ch != NULL) {
                ++i;
                syslog(LOG_INFO, "%s:%s:%s:%d", __func__, name, ch, i);
                ch = strtok(NULL, "_");
                if (pos == i)
                        return atol(ch + skip);
        }

        return -1;
}

/* Find trip point info of a thermal zone */
static int find_tzone_tp(char *tz_name, char *d_name, struct tz_info *tzi,
                        int tz_id)
{
        int tp_id;
        unsigned long temp_ulong;

        if (strstr(d_name, "trip_point") &&
                strstr(d_name, "temp")) {
                /* check if trip point temp is non-zero
                 * ignore 0/invalid trip points
                 */
                sysfs_get_ulong(tz_name, d_name, &temp_ulong);
                if (temp_ulong < MAX_TEMP_KC) {
                        tzi->nr_trip_pts++;
                        /* found a valid trip point */
                        tp_id = get_instance_id(d_name, 2, 0);
                        syslog(LOG_DEBUG, "tzone %s trip %d temp %lu tpnode %s",
                                tz_name, tp_id, temp_ulong, d_name);
                        if (tp_id < 0 || tp_id >= MAX_NR_TRIP) {
                                syslog(LOG_ERR, "Failed to find TP inst %s\n",
                                        d_name);
                                return -1;
                        }
                        get_trip_point_data(tz_name, tz_id, tp_id);
                        tzi->tp[tp_id].temp = temp_ulong;
                }
        }

        return 0;
}

/* check cooling devices for binding info. */
static int find_tzone_cdev(struct dirent *nl, char *tz_name,
                        struct tz_info *tzi, int tz_id, int cid)
{
        unsigned long trip_instance = 0;
        char cdev_name_linked[256];
        char cdev_name[256];
        char cdev_trip_name[256];
        int cdev_id;

        if (nl->d_type == DT_LNK) {
                syslog(LOG_DEBUG, "TZ%d: cdev: %s cid %d\n", tz_id, nl->d_name,
                        cid);
                tzi->nr_cdev++;
                if (tzi->nr_cdev > ptdata.nr_cooling_dev) {
                        syslog(LOG_ERR, "Err: Too many cdev? %d\n",
                                tzi->nr_cdev);
                        return -EINVAL;
                }
                /* find the link to real cooling device record binding */
                snprintf(cdev_name, 256, "%s/%s", tz_name, nl->d_name);
                memset(cdev_name_linked, 0, sizeof(cdev_name_linked));
                if (readlink(cdev_name, cdev_name_linked,
                                sizeof(cdev_name_linked) - 1) != -1) {
                        cdev_id = get_instance_id(cdev_name_linked, 1,
                                                sizeof("device") - 1);
                        syslog(LOG_DEBUG, "cdev %s linked to %s : %d\n",
                                cdev_name, cdev_name_linked, cdev_id);
                        tzi->cdev_binding |= (1 << cdev_id);

                        /* find the trip point in which the cdev is binded to
                         * in this tzone
                         */
                        snprintf(cdev_trip_name, 256, "%s%s", nl->d_name,
                                "_trip_point");
                        sysfs_get_ulong(tz_name, cdev_trip_name,
                                        &trip_instance);
                        /* validate trip point range, e.g. trip could return -1
                         * when passive is enabled
                         */
                        if (trip_instance > MAX_NR_TRIP)
                                trip_instance = 0;
                        tzi->trip_binding[cdev_id] |= 1 << trip_instance;
                        syslog(LOG_DEBUG, "cdev %s -> trip:%lu: 0x%lx %d\n",
                                cdev_name, trip_instance,
                                tzi->trip_binding[cdev_id],
                                cdev_id);


                }
                return 0;
        }

        return -ENODEV;
}



/*****************************************************************************
 * Before calling scan_tzones, thermal sysfs must be probed to determine
 * the number of thermal zones and cooling devices.
 * We loop through each thermal zone and fill in tz_info struct, i.e.
 * ptdata.tzi[]
root@jacob-chiefriver:~# tree -d /sys/class/thermal/thermal_zone0
/sys/class/thermal/thermal_zone0
|-- cdev0 -> ../cooling_device4
|-- cdev1 -> ../cooling_device3
|-- cdev10 -> ../cooling_device7
|-- cdev11 -> ../cooling_device6
|-- cdev12 -> ../cooling_device5
|-- cdev2 -> ../cooling_device2
|-- cdev3 -> ../cooling_device1
|-- cdev4 -> ../cooling_device0
|-- cdev5 -> ../cooling_device12
|-- cdev6 -> ../cooling_device11
|-- cdev7 -> ../cooling_device10
|-- cdev8 -> ../cooling_device9
|-- cdev9 -> ../cooling_device8
|-- device -> ../../../LNXSYSTM:00/device:62/LNXTHERM:00
|-- power
`-- subsystem -> ../../../../class/thermal
*****************************************************************************/
static int scan_tzones(void)
{
        DIR *dir;
        struct dirent **namelist;
        char tz_name[256];
        int i, j, n, k = 0;

        if (!ptdata.nr_tz_sensor)
                return -1;

        for (i = 0; i <= ptdata.max_tz_instance; i++) {
                memset(tz_name, 0, sizeof(tz_name));
                snprintf(tz_name, 256, "%s/%s%d", THERMAL_SYSFS, TZONE, i);

                dir = opendir(tz_name);
                if (!dir) {
                        syslog(LOG_INFO, "Thermal zone %s skipped\n", tz_name);
                        continue;
                }
                /* keep track of valid tzones */
                n = scandir(tz_name, &namelist, 0, alphasort);
                if (n < 0)
                        syslog(LOG_ERR, "scandir failed in %s",  tz_name);
                else {
                        sysfs_get_string(tz_name, "type", ptdata.tzi[k].type);
                        ptdata.tzi[k].instance = i;
                        /* detect trip points and cdev attached to this tzone */
                        j = 0; /* index for cdev */
                        ptdata.tzi[k].nr_cdev = 0;
                        ptdata.tzi[k].nr_trip_pts = 0;
                        while (n--) {
                                char *temp_str;

                                if (find_tzone_tp(tz_name, namelist[n]->d_name,
                                                        &ptdata.tzi[k], k))
                                        break;
                                temp_str = strstr(namelist[n]->d_name, "cdev");
                                if (!temp_str) {
                                        free(namelist[n]);
                                        continue;
                                }
                                if (!find_tzone_cdev(namelist[n], tz_name,
                                                        &ptdata.tzi[k], i, j))
                                        j++; /* increment cdev index */
                                free(namelist[n]);
                        }
                        free(namelist);
                }
                /*TODO: reverse trip points */
                closedir(dir);
                syslog(LOG_INFO, "TZ %d has %d cdev\n", i,
                        ptdata.tzi[k].nr_cdev);
                k++;
        }

        return 0;
}

static int scan_cdevs(void)
{
        DIR *dir;
        struct dirent **namelist;
        char cdev_name[256];
        int i, n, k = 0;

        if (!ptdata.nr_cooling_dev) {
                fprintf(stderr, "No cooling devices found\n");
                return 0;
        }
        for (i = 0; i <= ptdata.max_cdev_instance; i++) {
                memset(cdev_name, 0, sizeof(cdev_name));
                snprintf(cdev_name, 256, "%s/%s%d", THERMAL_SYSFS, CDEV, i);

                dir = opendir(cdev_name);
                if (!dir) {
                        syslog(LOG_INFO, "Cooling dev %s skipped\n", cdev_name);
                        /* there is a gap in cooling device id, check again
                         * for the same index.
                         */
                        continue;
                }

                n = scandir(cdev_name, &namelist, 0, alphasort);
                if (n < 0)
                        syslog(LOG_ERR, "scandir failed in %s",  cdev_name);
                else {
                        sysfs_get_string(cdev_name, "type", ptdata.cdi[k].type);
                        ptdata.cdi[k].instance = i;
                        if (strstr(ptdata.cdi[k].type, ctrl_cdev)) {
                                ptdata.cdi[k].flag |= CDEV_FLAG_IN_CONTROL;
                                syslog(LOG_DEBUG, "control cdev id %d\n", i);
                        }
                        while (n--)
                                free(namelist[n]);
                        free(namelist);
                }
                closedir(dir);
                k++;
        }
        return 0;
}


int probe_thermal_sysfs(void)
{
        DIR *dir;
        struct dirent **namelist;
        int n;

        dir = opendir(THERMAL_SYSFS);
        if (!dir) {
                fprintf(stderr, "\nNo thermal sysfs, exit\n");
                return -1;
        }
        n = scandir(THERMAL_SYSFS, &namelist, 0, alphasort);
        if (n < 0)
                syslog(LOG_ERR, "scandir failed in thermal sysfs");
        else {
                /* detect number of thermal zones and cooling devices */
                while (n--) {
                        int inst;

                        if (strstr(namelist[n]->d_name, CDEV)) {
                                inst = get_instance_id(namelist[n]->d_name, 1,
                                                sizeof("device") - 1);
                                /* keep track of the max cooling device since
                                 * there may be gaps.
                                 */
                                if (inst > ptdata.max_cdev_instance)
                                        ptdata.max_cdev_instance = inst;

                                syslog(LOG_DEBUG, "found cdev: %s %d %d\n",
                                        namelist[n]->d_name,
                                        ptdata.nr_cooling_dev,
                                        ptdata.max_cdev_instance);
                                ptdata.nr_cooling_dev++;
                        } else if (strstr(namelist[n]->d_name, TZONE)) {
                                inst = get_instance_id(namelist[n]->d_name, 1,
                                                sizeof("zone") - 1);
                                if (inst > ptdata.max_tz_instance)
                                        ptdata.max_tz_instance = inst;

                                syslog(LOG_DEBUG, "found tzone: %s %d %d\n",
                                        namelist[n]->d_name,
                                        ptdata.nr_tz_sensor,
                                        ptdata.max_tz_instance);
                                ptdata.nr_tz_sensor++;
                        }
                        free(namelist[n]);
                }
                free(namelist);
        }
        syslog(LOG_INFO, "found %d tzone(s), %d cdev(s), target zone %d\n",
                ptdata.nr_tz_sensor, ptdata.nr_cooling_dev,
                target_thermal_zone);
        closedir(dir);

        if (!ptdata.nr_tz_sensor) {
                fprintf(stderr, "\nNo thermal zones found, exit\n\n");
                return -1;
        }

        ptdata.tzi = calloc(ptdata.max_tz_instance+1, sizeof(struct tz_info));
        if (!ptdata.tzi) {
                fprintf(stderr, "Err: allocate tz_info\n");
                return -1;
        }

        /* we still show thermal zone information if there is no cdev */
        if (ptdata.nr_cooling_dev) {
                ptdata.cdi = calloc(ptdata.max_cdev_instance + 1,
                                sizeof(struct cdev_info));
                if (!ptdata.cdi) {
                        free(ptdata.tzi);
                        fprintf(stderr, "Err: allocate cdev_info\n");
                        return -1;
                }
        }

        /* now probe tzones */
        if (scan_tzones())
                return -1;
        if (scan_cdevs())
                return -1;
        return 0;
}

/* convert sysfs zone instance to zone array index */
int zone_instance_to_index(int zone_inst)
{
        int i;

        for (i = 0; i < ptdata.nr_tz_sensor; i++)
                if (ptdata.tzi[i].instance == zone_inst)
                        return i;
        return -ENOENT;
}

/* read temperature of all thermal zones */
int update_thermal_data()
{
        int i;
        char tz_name[256];
        static unsigned long samples;

        if (!ptdata.nr_tz_sensor) {
                syslog(LOG_ERR, "No thermal zones found!\n");
                return -1;
        }

        /* circular buffer for keeping historic data */
        if (cur_thermal_record >= NR_THERMAL_RECORDS)
                cur_thermal_record = 0;
        gettimeofday(&trec[cur_thermal_record].tv, NULL);
        if (tmon_log) {
                fprintf(tmon_log, "%lu ", ++samples);
                fprintf(tmon_log, "%3.1f ", p_param.t_target);
        }
        for (i = 0; i < ptdata.nr_tz_sensor; i++) {
                memset(tz_name, 0, sizeof(tz_name));
                snprintf(tz_name, 256, "%s/%s%d", THERMAL_SYSFS, TZONE,
                        ptdata.tzi[i].instance);
                sysfs_get_ulong(tz_name, "temp",
                                &trec[cur_thermal_record].temp[i]);
                if (tmon_log)
                        fprintf(tmon_log, "%lu ",
                                trec[cur_thermal_record].temp[i]/1000);
        }
        for (i = 0; i < ptdata.nr_cooling_dev; i++) {
                char cdev_name[256];
                unsigned long val;

                snprintf(cdev_name, 256, "%s/%s%d", THERMAL_SYSFS, CDEV,
                        ptdata.cdi[i].instance);
                probe_cdev(&ptdata.cdi[i], cdev_name);
                val = ptdata.cdi[i].cur_state;
                if (val > 1000000)
                        val = 0;
                if (tmon_log)
                        fprintf(tmon_log, "%lu ", val);
        }

        if (tmon_log) {
                fprintf(tmon_log, "\n");
                fflush(tmon_log);
        }

        return 0;
}

void set_ctrl_state(unsigned long state)
{
        char ctrl_cdev_path[256];
        int i;
        unsigned long cdev_state;

        if (no_control)
                return;
        /* set all ctrl cdev to the same state */
        for (i = 0; i < ptdata.nr_cooling_dev; i++) {
                if (ptdata.cdi[i].flag & CDEV_FLAG_IN_CONTROL) {
                        if (ptdata.cdi[i].max_state < 10) {
                                strcpy(ctrl_cdev, "None.");
                                return;
                        }
                        /* scale to percentage of max_state */
                        cdev_state = state * ptdata.cdi[i].max_state/100;
                        syslog(LOG_DEBUG,
                                "ctrl cdev %d set state %lu scaled to %lu\n",
                                ptdata.cdi[i].instance, state, cdev_state);
                        snprintf(ctrl_cdev_path, 256, "%s/%s%d", THERMAL_SYSFS,
                                CDEV, ptdata.cdi[i].instance);
                        syslog(LOG_DEBUG, "ctrl cdev path %s", ctrl_cdev_path);
                        sysfs_set_ulong(ctrl_cdev_path, "cur_state",
                                        cdev_state);
                }
        }
}

void get_ctrl_state(unsigned long *state)
{
        char ctrl_cdev_path[256];
        int ctrl_cdev_id = -1;
        int i;

        /* TODO: take average of all ctrl types. also consider change based on
         * uevent. Take the first reading for now.
         */
        for (i = 0; i < ptdata.nr_cooling_dev; i++) {
                if (ptdata.cdi[i].flag & CDEV_FLAG_IN_CONTROL) {
                        ctrl_cdev_id = ptdata.cdi[i].instance;
                        syslog(LOG_INFO, "ctrl cdev %d get state\n",
                                ptdata.cdi[i].instance);
                        break;
                }
        }
        if (ctrl_cdev_id == -1) {
                *state = 0;
                return;
        }
        snprintf(ctrl_cdev_path, 256, "%s/%s%d", THERMAL_SYSFS,
                CDEV, ctrl_cdev_id);
        sysfs_get_ulong(ctrl_cdev_path, "cur_state", state);
}

void free_thermal_data(void)
{
        free(ptdata.tzi);
        free(ptdata.cdi);
}