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-target.h"
  31 #include "usb.h"
  32
  33 /*===========================================================================
  34  * These parameters may be defined per target:
  35  *
  36  *   BATT_FULL_VOLTAGE - Upon connect a charge cycle begins if the reading is
  37  *                       lower than this value (millivolts).
  38  *
  39  * BATT_VAUTO_RECHARGE - While left plugged after cycle completion, the
  40  *                       charger restarts automatically if the reading drops
  41  *                       below this value (millivolts). Must be less than
  42  *                       BATT_FULL_VOLTAGE.
  43  *
  44  *         ADC_BATTERY - ADC channel from which to read the battery voltage
  45  *
  46  *          BATT_CHG_V - Charger voltage regulation setting (as3514 regval)
  47  *
  48  *          BATT_CHG_I - Charger current regulation setting (as3514 regval)
  49  *
  50  * CHARGER_TOTAL_TIMER - Maximum allowed charging time (1/2-second steps)
  51  *===========================================================================
  52  */
  53
  54 /* This code assumes USB power input is not distinguishable from main
  55  * power and charger connect cannot wait for USB configuration before
  56  * considering USB charging available. Where they are distinguishable,
  57  * things get more complicated. */
  58 static bool charger_close = false;  /* Shutting down? */
  59 static int charger_total_timer = 0; /* Timeout in algorithm steps */
  60
  61 /* Current battery threshold for (re)charge:
  62  * First plugged = BATT_FULL_VOLTAGE
  63  * After charge cycle or non-start = BATT_VAUTO_RECHARGE
  64  */
  65 static unsigned int batt_threshold = 0;
  66
  67 /* ADC should read 0x3ff=5.12V */
  68 /* full-scale ADC readout (2^10) in millivolt */
  69
  70 /* Returns battery voltage from ADC [millivolts] */
  71 unsigned int battery_adc_voltage(void)
  72 {
  73     return (adc_read(ADC_BATTERY) * 5125 + 512) >> 10;
  74 }
  75
  76 /* Returns true if the unit is charging the batteries. */
  77 bool charging_state(void)
  78 {
  79     return charge_state == CHARGING;
  80 }
  81
  82 /* Reset the battery filter to a new voltage */
  83 static void battery_voltage_sync(void)
  84 {
  85     int i;
  86     unsigned int mv;
  87
  88     for (i = 0, mv = 0; i < 5; i++)
  89         mv += battery_adc_voltage();
  90
  91     reset_battery_filter(mv / 5);
  92 }
  93
  94 /* Disable charger and minimize all settings. Reset timers, etc. */
  95 static void disable_charger(void)
  96 {
  97     ascodec_write_charger(TMPSUP_OFF | CHG_I_50MA | CHG_V_3_90V | CHG_OFF);
  98
  99     if (charge_state > DISCHARGING)
 100         charge_state = DISCHARGING; /* Not an error state already */
 101
 102     charger_total_timer = 0;
 103     battery_voltage_sync();
 104 }
 105
 106 /* Enable charger with specified settings. Start timers, etc. */
 107 static void enable_charger(void)
 108 {
 109     ascodec_write_charger(BATT_CHG_I | BATT_CHG_V);
 110
 111     sleep(HZ/10); /* Allow charger turn-on time (it could be gradual). */
 112
 113 #if CONFIG_CPU != AS3525v2
 114     /* acknowledge first end of charging interrupt, it seems to happen both
 115      * at charger plug and charger unplug
 116      * It doesn't happen on newer AS3543
 117      */
 118     ascodec_endofch();
 119 #endif
 120
 121     charge_state = CHARGING;
 122     charger_total_timer = CHARGER_TOTAL_TIMER;
 123     battery_voltage_sync();
 124 }
 125
 126 void powermgmt_init_target(void)
 127 {
 128     /* Everything CHARGER, OFF! */
 129 #if CONFIG_CPU == AS3525v2
 130     ascodec_write_pmu(AS3543_CHARGER, 2, 0x01); //EOC current theshold 30%
 131 #endif
 132     ascodec_monitor_endofch();
 133     ascodec_write_charger(TMPSUP_OFF | CHG_I_50MA | CHG_V_3_90V | CHG_OFF);
 134 }
 135
 136 static inline void charger_plugged(void)
 137 {
 138     batt_threshold = BATT_FULL_VOLTAGE; /* Start with topped value. */
 139     battery_voltage_sync();
 140 }
 141
 142 static inline void charger_control(void)
 143 {
 144     switch (charge_state)
 145     {
 146     case DISCHARGING:
 147     {
 148         unsigned int millivolts;
 149         unsigned int thresh = batt_threshold;
 150
 151         if (BATT_FULL_VOLTAGE == thresh)
 152         {
 153             /* Wait for CHG_status to be indicated. */
 154             if (!ascodec_chg_status())
 155                 break;
 156
 157             batt_threshold = BATT_VAUTO_RECHARGE;
 158         }
 159
 160         millivolts = battery_voltage();
 161
 162         if (millivolts <= thresh)
 163             enable_charger();
 164         break;
 165         } /* DISCHARGING: */
 166
 167     case CHARGING:
 168     {
 169         if (!ascodec_endofch())
 170         {
 171             if (--charger_total_timer > 0)
 172                 break;
 173
 174             /* Timer ran out - require replug. */
 175             charge_state = CHARGE_STATE_ERROR;
 176         }
 177         /* else end of charge */
 178
 179         disable_charger();
 180         break;
 181         } /* CHARGING: */
 182
 183     default:
 184         /* DISABLED, ERROR */
 185         break;
 186     }
 187 }
 188
 189 static inline void charger_unplugged(void)
 190 {
 191     disable_charger();
 192     if (charge_state >= CHARGE_STATE_ERROR)
 193         charge_state = DISCHARGING; /* Reset error */
 194 }
 195
 196 /* Main charging algorithm - called from powermgmt.c */
 197 void charging_algorithm_step(void)
 198 {
 199     switch (charger_input_state)
 200     {
 201     case NO_CHARGER:
 202         /* Nothing to do */
 203         break;
 204
 205     case CHARGER_PLUGGED:
 206         charger_plugged();
 207         break;
 208
 209     case CHARGER:
 210         charger_control();
 211         break;
 212
 213     case CHARGER_UNPLUGGED:
 214         charger_unplugged();
 215         break;
 216     }
 217
 218     if (charger_close)
 219     {
 220         /* Disable further charging and ack. */
 221         charge_state = CHARGE_STATE_DISABLED;
 222         disable_charger();
 223         charger_close = false;
 224     }
 225 }
 226
 227 /* Disable the charger and prepare for poweroff - called off-thread so we
 228  * signal the charging thread to prepare to quit. */
 229 void charging_algorithm_close(void)
 230 {
 231     charger_close = true;
 232
 233     /* Power management thread will set it false again. */
 234     while (charger_close)
 235         sleep(HZ/10);
 236 }