FreeBSD/Linux Kernel Cross Reference
sys/dev/acpica/acpi_battery.c

     /*-
      * Copyright (c) 2005 Nate Lawson
      * Copyright (c) 2000 Mitsuru IWASAKI <iwasaki@jp.freebsd.org>
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include "opt_acpi.h"
    #include <sys/param.h>
    #include <sys/kernel.h>
    #include <sys/malloc.h>
    #include <sys/bus.h>
    #include <sys/ioccom.h>
    #include <sys/sysctl.h>
    
    #include <contrib/dev/acpica/include/acpi.h>
    
    #include <dev/acpica/acpivar.h>
    #include <dev/acpica/acpiio.h>
    
    /* Default seconds before re-sampling the battery state. */
    #define ACPI_BATTERY_INFO_EXPIRE        5
    
    static int      acpi_batteries_initted;
    static int      acpi_battery_info_expire = ACPI_BATTERY_INFO_EXPIRE;
    static struct   acpi_battinfo   acpi_battery_battinfo;
    static struct   sysctl_ctx_list acpi_battery_sysctl_ctx;
    static struct   sysctl_oid      *acpi_battery_sysctl_tree;
    
    ACPI_SERIAL_DECL(battery, "ACPI generic battery");
    
    static void acpi_reset_battinfo(struct acpi_battinfo *info);
    static void acpi_battery_clean_str(char *str, int len);
    static device_t acpi_battery_find_dev(u_int logical_unit);
    static int acpi_battery_ioctl(u_long cmd, caddr_t addr, void *arg);
    static int acpi_battery_sysctl(SYSCTL_HANDLER_ARGS);
    static int acpi_battery_units_sysctl(SYSCTL_HANDLER_ARGS);
    static int acpi_battery_init(void);
    
    int
    acpi_battery_register(device_t dev)
    {
        int error;
    
        error = 0;
        ACPI_SERIAL_BEGIN(battery);
        if (!acpi_batteries_initted)
            error = acpi_battery_init();
        ACPI_SERIAL_END(battery);
        return (error);
    }
    
    int
    acpi_battery_remove(device_t dev)
    {
    
        return (0);
    }
    
    int
    acpi_battery_get_units(void)
    {
        devclass_t batt_dc;
    
        batt_dc = devclass_find("battery");
        if (batt_dc == NULL)
            return (0);
        return (devclass_get_count(batt_dc));
    }
    
    int
    acpi_battery_get_info_expire(void)
    {
    
        return (acpi_battery_info_expire);
    }
   
   /* Check _BST results for validity. */
   int
   acpi_battery_bst_valid(struct acpi_bst *bst)
   {
   
       return (bst->state != ACPI_BATT_STAT_NOT_PRESENT &&
           bst->cap != ACPI_BATT_UNKNOWN && bst->volt != ACPI_BATT_UNKNOWN);
   }
   
   /* Check _BIF results for validity. */
   int
   acpi_battery_bif_valid(struct acpi_bif *bif)
   {
       return (bif->lfcap != 0);
   }
   
   /* Get info about one or all batteries. */
   int
   acpi_battery_get_battinfo(device_t dev, struct acpi_battinfo *battinfo)
   {
       int batt_stat, devcount, dev_idx, error, i;
       int total_cap, total_min, valid_rate, valid_units;
       devclass_t batt_dc;
       device_t batt_dev;
       struct acpi_bst *bst;
       struct acpi_bif *bif;
       struct acpi_battinfo *bi;
   
       /*
        * Get the battery devclass and max unit for battery devices.  If there
        * are none or error, return immediately.
        */
       batt_dc = devclass_find("battery");
       if (batt_dc == NULL)
           return (ENXIO);
       devcount = devclass_get_maxunit(batt_dc);
       if (devcount == 0)
           return (ENXIO);
   
       /*
        * Allocate storage for all _BST data, their derived battinfo data,
        * and the current battery's _BIF data.
        */
       bst = malloc(devcount * sizeof(*bst), M_TEMP, M_WAITOK | M_ZERO);
       bi = malloc(devcount * sizeof(*bi), M_TEMP, M_WAITOK | M_ZERO);
       bif = malloc(sizeof(*bif), M_TEMP, M_WAITOK | M_ZERO);
   
       /*
        * Pass 1:  for each battery that is present and valid, get its status,
        * calculate percent capacity remaining, and sum all the current
        * discharge rates.
        */
       dev_idx = -1;
       batt_stat = valid_rate = valid_units = 0;
       for (i = 0; i < devcount; i++) {
           /* Default info for every battery is "not present". */
           acpi_reset_battinfo(&bi[i]);
   
           /*
            * Find the device.  Since devcount is in terms of max units, this
            * may be a sparse array so skip devices that aren't present.
            */
           batt_dev = devclass_get_device(batt_dc, i);
           if (batt_dev == NULL)
               continue;
   
           /* If examining a specific battery and this is it, record its index. */
           if (dev != NULL && dev == batt_dev)
               dev_idx = i;
   
           /*
            * Be sure we can get various info from the battery.  Note that
            * acpi_BatteryIsPresent() is not enough because smart batteries only
            * return that the device is present.
            */
           if (!acpi_BatteryIsPresent(batt_dev) ||
               ACPI_BATT_GET_STATUS(batt_dev, &bst[i]) != 0 ||
               ACPI_BATT_GET_INFO(batt_dev, bif) != 0)
               continue;
   
           /* If a battery is not installed, we sometimes get strange values. */
           if (!acpi_battery_bst_valid(&bst[i]) ||
               !acpi_battery_bif_valid(bif))
               continue;
   
           /*
            * Record current state.  If both charging and discharging are set,
            * ignore the charging flag.
            */
           valid_units++;
           if ((bst[i].state & ACPI_BATT_STAT_DISCHARG) != 0)
               bst[i].state &= ~ACPI_BATT_STAT_CHARGING;
           batt_stat |= bst[i].state;
           bi[i].state = bst[i].state;
   
           /*
            * If the battery info is in terms of mA, convert to mW by
            * multiplying by the design voltage.  If the design voltage
            * is 0 (due to some error reading the battery), skip this
            * conversion.
            */
           if (bif->units == ACPI_BIF_UNITS_MA && bif->dvol != 0 && dev == NULL) {
               bst[i].rate = (bst[i].rate * bif->dvol) / 1000;
               bst[i].cap = (bst[i].cap * bif->dvol) / 1000;
               bif->lfcap = (bif->lfcap * bif->dvol) / 1000;
           }
   
           /*
            * The calculation above may set bif->lfcap to zero. This was
            * seen on a laptop with a broken battery. The result of the
            * division was rounded to zero.
            */
           if (!acpi_battery_bif_valid(bif))
               continue;
   
           /* Calculate percent capacity remaining. */
           bi[i].cap = (100 * bst[i].cap) / bif->lfcap;
   
           /*
            * Some laptops report the "design-capacity" instead of the
            * "real-capacity" when the battery is fully charged.  That breaks
            * the above arithmetic as it needs to be 100% maximum.
            */
           if (bi[i].cap > 100)
               bi[i].cap = 100;
   
           /*
            * On systems with more than one battery, they may get used
            * sequentially, thus bst.rate may only signify the one currently
            * in use.  For the remaining batteries, bst.rate will be zero,
            * which makes it impossible to calculate the total remaining time.
            * Therefore, we sum the bst.rate for batteries in the discharging
            * state and use the sum to calculate the total remaining time.
            */
           if (bst[i].rate != ACPI_BATT_UNKNOWN &&
               (bst[i].state & ACPI_BATT_STAT_DISCHARG) != 0)
               valid_rate += bst[i].rate;
       }
   
       /* If the caller asked for a device but we didn't find it, error. */
       if (dev != NULL && dev_idx == -1) {
           error = ENXIO;
           goto out;
       }
   
       /* Pass 2:  calculate capacity and remaining time for all batteries. */
       total_cap = total_min = 0;
       for (i = 0; i < devcount; i++) {
           /*
            * If any batteries are discharging, use the sum of the bst.rate
            * values.  Otherwise, we are on AC power, and there is infinite
            * time remaining for this battery until we go offline.
            */
           if (valid_rate > 0)
               bi[i].min = (60 * bst[i].cap) / valid_rate;
           else
               bi[i].min = 0;
           total_min += bi[i].min;
   
           /* If this battery is not present, don't use its capacity. */
           if (bi[i].cap != -1)
               total_cap += bi[i].cap;
       }
   
       /*
        * Return total battery percent and time remaining.  If there are
        * no valid batteries, report values as unknown.
        */
       if (valid_units > 0) {
           if (dev == NULL) {
               battinfo->cap = total_cap / valid_units;
               battinfo->min = total_min;
               battinfo->state = batt_stat;
               battinfo->rate = valid_rate;
           } else {
               battinfo->cap = bi[dev_idx].cap;
               battinfo->min = bi[dev_idx].min;
               battinfo->state = bi[dev_idx].state;
               battinfo->rate = bst[dev_idx].rate;
           }
   
           /*
            * If the queried battery has no discharge rate or is charging,
            * report that we don't know the remaining time.
            */
           if (valid_rate == 0 || (battinfo->state & ACPI_BATT_STAT_CHARGING))
               battinfo->min = -1;
       } else
           acpi_reset_battinfo(battinfo);
   
       error = 0;
   
   out:
       if (bi)
           free(bi, M_TEMP);
       if (bif)
           free(bif, M_TEMP);
       if (bst)
           free(bst, M_TEMP);
       return (error);
   }
   
   static void
   acpi_reset_battinfo(struct acpi_battinfo *info)
   {
       info->cap = -1;
       info->min = -1;
       info->state = ACPI_BATT_STAT_NOT_PRESENT;
       info->rate = -1;
   }
   
   /* Make string printable, removing invalid chars. */
   static void
   acpi_battery_clean_str(char *str, int len)
   {
       int i;
   
       for (i = 0; i < len && *str != '\0'; i++, str++) {
           if (!isprint(*str))
               *str = '?';
       }
   
       /* NUL-terminate the string if we reached the end. */
       if (i == len)
           *str = '\0';
   }
   
   /*
    * The battery interface deals with devices and methods but userland
    * expects a logical unit number.  Convert a logical unit to a device_t.
    */
   static device_t
   acpi_battery_find_dev(u_int logical_unit)
   {
       int found_unit, i, maxunit;
       device_t dev;
       devclass_t batt_dc;
   
       dev = NULL;
       found_unit = 0;
       batt_dc = devclass_find("battery");
       maxunit = devclass_get_maxunit(batt_dc);
       for (i = 0; i < maxunit; i++) {
           dev = devclass_get_device(batt_dc, i);
           if (dev == NULL)
               continue;
           if (logical_unit == found_unit)
               break;
           found_unit++;
           dev = NULL;
       }
   
       return (dev);
   }
   
   static int
   acpi_battery_ioctl(u_long cmd, caddr_t addr, void *arg)
   {
       union acpi_battery_ioctl_arg *ioctl_arg;
       int error, unit;
       device_t dev;
   
   
       /*
        * Giant is acquired to work around a reference counting bug in ACPICA
        * versions prior to 20130328.  If not for that bug this function could
        * be executed concurrently without any problems.
        * The bug is in acpi_BatteryIsPresent -> AcpiGetObjectInfo call tree,
        * where AcpiUtExecute_HID, AcpiUtExecute_UID, etc are executed without
        * protection of any ACPICA lock and may concurrently call
        * AcpiUtRemoveReference on a battery object.
        */
       mtx_lock(&Giant);
   
       /* For commands that use the ioctl_arg struct, validate it first. */
       error = ENXIO;
       unit = 0;
       dev = NULL;
       ioctl_arg = NULL;
       if (IOCPARM_LEN(cmd) == sizeof(*ioctl_arg)) {
           ioctl_arg = (union acpi_battery_ioctl_arg *)addr;
           unit = ioctl_arg->unit;
           if (unit != ACPI_BATTERY_ALL_UNITS)
               dev = acpi_battery_find_dev(unit);
       }
   
       /*
        * No security check required: information retrieval only.  If
        * new functions are added here, a check might be required.
        */
       switch (cmd) {
       case ACPIIO_BATT_GET_UNITS:
           *(int *)addr = acpi_battery_get_units();
           error = 0;
           break;
       case ACPIIO_BATT_GET_BATTINFO:
           if (dev != NULL || unit == ACPI_BATTERY_ALL_UNITS) {
               bzero(&ioctl_arg->battinfo, sizeof(ioctl_arg->battinfo));
               error = acpi_battery_get_battinfo(dev, &ioctl_arg->battinfo);
           }
           break;
       case ACPIIO_BATT_GET_BIF:
           if (dev != NULL) {
               bzero(&ioctl_arg->bif, sizeof(ioctl_arg->bif));
               error = ACPI_BATT_GET_INFO(dev, &ioctl_arg->bif);
   
               /*
                * Remove invalid characters.  Perhaps this should be done
                * within a convenience function so all callers get the
                * benefit.
                */
               acpi_battery_clean_str(ioctl_arg->bif.model,
                   sizeof(ioctl_arg->bif.model));
               acpi_battery_clean_str(ioctl_arg->bif.serial,
                   sizeof(ioctl_arg->bif.serial));
               acpi_battery_clean_str(ioctl_arg->bif.type,
                   sizeof(ioctl_arg->bif.type));
               acpi_battery_clean_str(ioctl_arg->bif.oeminfo,
                   sizeof(ioctl_arg->bif.oeminfo));
           }
           break;
       case ACPIIO_BATT_GET_BST:
           if (dev != NULL) {
               bzero(&ioctl_arg->bst, sizeof(ioctl_arg->bst));
               error = ACPI_BATT_GET_STATUS(dev, &ioctl_arg->bst);
           }
           break;
       default:
           error = EINVAL;
       }
   
       mtx_unlock(&Giant);
       return (error);
   }
   
   static int
   acpi_battery_sysctl(SYSCTL_HANDLER_ARGS)
   {
       int val, error;
   
       acpi_battery_get_battinfo(NULL, &acpi_battery_battinfo);
       val = *(u_int *)oidp->oid_arg1;
       error = sysctl_handle_int(oidp, &val, 0, req);
       return (error);
   }
   
   static int
   acpi_battery_units_sysctl(SYSCTL_HANDLER_ARGS)
   {
       int count, error;
   
       count = acpi_battery_get_units();
       error = sysctl_handle_int(oidp, &count, 0, req);
       return (error);
   }
   
   static int
   acpi_battery_init(void)
   {
       struct acpi_softc   *sc;
       device_t             dev;
       int                  error;
   
       ACPI_SERIAL_ASSERT(battery);
   
       error = ENXIO;
       dev = devclass_get_device(devclass_find("acpi"), 0);
       if (dev == NULL)
           goto out;
       sc = device_get_softc(dev);
   
       error = acpi_register_ioctl(ACPIIO_BATT_GET_UNITS, acpi_battery_ioctl,
           NULL);
       if (error != 0)
           goto out;
       error = acpi_register_ioctl(ACPIIO_BATT_GET_BATTINFO, acpi_battery_ioctl,
           NULL);
       if (error != 0)
           goto out;
       error = acpi_register_ioctl(ACPIIO_BATT_GET_BIF, acpi_battery_ioctl, NULL);
       if (error != 0)
           goto out;
       error = acpi_register_ioctl(ACPIIO_BATT_GET_BST, acpi_battery_ioctl, NULL);
       if (error != 0)
           goto out;
   
       sysctl_ctx_init(&acpi_battery_sysctl_ctx);
       acpi_battery_sysctl_tree = SYSCTL_ADD_NODE(&acpi_battery_sysctl_ctx,
           SYSCTL_CHILDREN(sc->acpi_sysctl_tree), OID_AUTO, "battery", CTLFLAG_RD,
           0, "battery status and info");
       SYSCTL_ADD_PROC(&acpi_battery_sysctl_ctx,
           SYSCTL_CHILDREN(acpi_battery_sysctl_tree),
           OID_AUTO, "life", CTLTYPE_INT | CTLFLAG_RD,
           &acpi_battery_battinfo.cap, 0, acpi_battery_sysctl, "I",
           "percent capacity remaining");
       SYSCTL_ADD_PROC(&acpi_battery_sysctl_ctx,
           SYSCTL_CHILDREN(acpi_battery_sysctl_tree),
           OID_AUTO, "time", CTLTYPE_INT | CTLFLAG_RD,
           &acpi_battery_battinfo.min, 0, acpi_battery_sysctl, "I",
           "remaining time in minutes");
       SYSCTL_ADD_PROC(&acpi_battery_sysctl_ctx,
           SYSCTL_CHILDREN(acpi_battery_sysctl_tree),
           OID_AUTO, "state", CTLTYPE_INT | CTLFLAG_RD,
           &acpi_battery_battinfo.state, 0, acpi_battery_sysctl, "I",
           "current status flags");
       SYSCTL_ADD_PROC(&acpi_battery_sysctl_ctx,
           SYSCTL_CHILDREN(acpi_battery_sysctl_tree),
           OID_AUTO, "units", CTLTYPE_INT | CTLFLAG_RD,
           NULL, 0, acpi_battery_units_sysctl, "I", "number of batteries");
       SYSCTL_ADD_INT(&acpi_battery_sysctl_ctx,
           SYSCTL_CHILDREN(acpi_battery_sysctl_tree),
           OID_AUTO, "info_expire", CTLFLAG_RW,
           &acpi_battery_info_expire, 0,
           "time in seconds until info is refreshed");
   
       acpi_batteries_initted = TRUE;
   
   out:
       if (error != 0) {
           acpi_deregister_ioctl(ACPIIO_BATT_GET_UNITS, acpi_battery_ioctl);
           acpi_deregister_ioctl(ACPIIO_BATT_GET_BATTINFO, acpi_battery_ioctl);
           acpi_deregister_ioctl(ACPIIO_BATT_GET_BIF, acpi_battery_ioctl);
           acpi_deregister_ioctl(ACPIIO_BATT_GET_BST, acpi_battery_ioctl);
       }
       return (error);
   }

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