firmware/target/arm/powermgmt-ascodec.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2009 by Michael Sevakis
  11  * Copyright (C) 2008 by Bertrik Sikken
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License
  15  * as published by the Free Software Foundation; either version 2
  16  * of the License, or (at your option) any later version.
  17  *
  18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  19  * KIND, either express or implied.
  20  *
  21  ****************************************************************************/
  22 #include "config.h"
  23 #include "system.h"
  24 #include "thread.h"
  25 #include "as3514.h"
  26 #include "ascodec.h"
  27 #include "adc.h"
  28 #include "powermgmt.h"
  29 #include "power.h"
  30 #include "usb.h"
  31
  32 /*===========================================================================
  33  * These parameters may be defined per target:
  34  *
  35  *   BATT_FULL_VOLTAGE - Upon connect a charge cycle begins if the reading is
  36  *                       lower than this value (millivolts).
  37  *
  38  * BATT_VAUTO_RECHARGE - While left plugged after cycle completion, the
  39  *                       charger restarts automatically if the reading drops
  40  *                       below this value (millivolts). Must be less than
  41  *                       BATT_FULL_VOLTAGE.
  42  *
  43  *         ADC_BATTERY - ADC channel from which to read the battery voltage
  44  *
  45  *          BATT_CHG_V - Charger voltage regulation setting (as3514 regval)
  46  *
  47  *          BATT_CHG_I - Charger current regulation setting (as3514 regval)
  48  *
  49  * CHARGER_TOTAL_TIMER - Maximum allowed charging time (1/2-second steps)
  50  *===========================================================================
  51  */
  52
  53 /* This code assumes USB power input is not distinguishable from main
  54  * power and charger connect cannot wait for USB configuration before
  55  * considering USB charging available. Where they are distinguishable,
  56  * things get more complicated. */
  57 static bool charger_close = false;  /* Shutting down? */
  58 static int charger_total_timer = 0; /* Timeout in algorithm steps */
  59
  60 /* Current battery threshold for (re)charge:
  61  * First plugged = BATT_FULL_VOLTAGE
  62  * After charge cycle or non-start = BATT_VAUTO_RECHARGE
  63  */
  64 static unsigned int batt_threshold = 0;
  65
  66 /* ADC should read 0x3ff=5.12V */
  67 /* full-scale ADC readout (2^10) in millivolt */
  68
  69 /* Returns battery voltage from ADC [millivolts] */
  70 int _battery_voltage(void)
  71 {
  72     return (adc_read(ADC_BATTERY) * 5125 + 512) >> 10;
  73 }
  74
  75 /* Returns true if the unit is charging the batteries. */
  76 bool charging_state(void)
  77 {
  78     return charge_state == CHARGING;
  79 }
  80
  81 /* Reset the battery filter to a new voltage */
  82 static void battery_voltage_sync(void)
  83 {
  84     int i;
  85     unsigned int mv;
  86
  87     for (i = 0, mv = 0; i < 5; i++)
  88         mv += _battery_voltage();
  89
  90     reset_battery_filter(mv / 5);
  91 }
  92
  93 /* Disable charger and minimize all settings. Reset timers, etc. */
  94 static void disable_charger(void)
  95 {
  96     ascodec_write_charger(TMPSUP_OFF | CHG_OFF);
  97
  98     if (charge_state > DISCHARGING)
  99         charge_state = DISCHARGING; /* Not an error state already */
 100
 101     charger_total_timer = 0;
 102     battery_voltage_sync();
 103 }
 104
 105 /* Enable charger with specified settings. Start timers, etc. */
 106 static void enable_charger(void)
 107 {
 108     ascodec_write_charger(BATT_CHG_I | BATT_CHG_V);
 109
 110     sleep(HZ/10); /* Allow charger turn-on time (it could be gradual). */
 111
 112 #if CONFIG_CPU != AS3525v2
 113     /* acknowledge first end of charging interrupt, it seems to happen both
 114      * at charger plug and charger unplug
 115      * It doesn't happen on newer AS3543
 116      */
 117     ascodec_endofch();
 118 #endif
 119
 120     charge_state = CHARGING;
 121     charger_total_timer = CHARGER_TOTAL_TIMER;
 122     battery_voltage_sync();
 123 }
 124
 125 void powermgmt_init_target(void)
 126 {
 127     /* Everything CHARGER, OFF! */
 128     ascodec_monitor_endofch();
 129     ascodec_write_charger(TMPSUP_OFF | CHG_OFF);
 130 }
 131
 132 static inline void charger_plugged(void)
 133 {
 134     batt_threshold = BATT_FULL_VOLTAGE; /* Start with topped value. */
 135     battery_voltage_sync();
 136 }
 137
 138 static inline void charger_control(void)
 139 {
 140     switch (charge_state)
 141     {
 142     case DISCHARGING:
 143     {
 144         unsigned int millivolts;
 145         unsigned int thresh = batt_threshold;
 146
 147         if (BATT_FULL_VOLTAGE == thresh)
 148         {
 149             /* Wait for CHG_status to be indicated. */
 150             if (!ascodec_chg_status())
 151                 break;
 152
 153             batt_threshold = BATT_VAUTO_RECHARGE;
 154         }
 155
 156         millivolts = battery_voltage();
 157
 158         if (millivolts <= thresh)
 159             enable_charger();
 160         break;
 161         } /* DISCHARGING: */
 162
 163     case CHARGING:
 164     {
 165         if (!ascodec_endofch())
 166         {
 167             if (--charger_total_timer > 0)
 168                 break;
 169
 170             /* Timer ran out - require replug. */
 171             charge_state = CHARGE_STATE_ERROR;
 172         }
 173         /* else end of charge */
 174
 175         disable_charger();
 176         break;
 177         } /* CHARGING: */
 178
 179     default:
 180         /* DISABLED, ERROR */
 181         break;
 182     }
 183 }
 184
 185 static inline void charger_unplugged(void)
 186 {
 187     disable_charger();
 188     if (charge_state >= CHARGE_STATE_ERROR)
 189         charge_state = DISCHARGING; /* Reset error */
 190 }
 191
 192 /* Main charging algorithm - called from powermgmt.c */
 193 void charging_algorithm_step(void)
 194 {
 195     switch (charger_input_state)
 196     {
 197     case NO_CHARGER:
 198         /* Nothing to do */
 199         break;
 200
 201     case CHARGER_PLUGGED:
 202         charger_plugged();
 203         break;
 204
 205     case CHARGER:
 206         charger_control();
 207         break;
 208
 209     case CHARGER_UNPLUGGED:
 210         charger_unplugged();
 211         break;
 212     }
 213
 214     if (charger_close)
 215     {
 216         /* Disable further charging and ack. */
 217         charge_state = CHARGE_STATE_DISABLED;
 218         disable_charger();
 219         charger_close = false;
 220     }
 221 }
 222
 223 /* Disable the charger and prepare for poweroff - called off-thread so we
 224  * signal the charging thread to prepare to quit. */
 225 void charging_algorithm_close(void)
 226 {
 227     charger_close = true;
 228
 229     /* Power management thread will set it false again. */
 230     while (charger_close)
 231         sleep(HZ/10);
 232 }