Home | History | Annotate | Download | only in hw
      1 /* Copyright (C) 2007-2008 The Android Open Source Project
      2 **
      3 ** This software is licensed under the terms of the GNU General Public
      4 ** License version 2, as published by the Free Software Foundation, and
      5 ** may be copied, distributed, and modified under those terms.
      6 **
      7 ** This program is distributed in the hope that it will be useful,
      8 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
      9 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     10 ** GNU General Public License for more details.
     11 */
     12 #include "qemu-common.h"
     13 #include "qemu-timer.h"
     14 #include "cpu.h"
     15 #include "arm_pic.h"
     16 #include "goldfish_device.h"
     17 #include "hw/hw.h"
     18 
     19 enum {
     20     TIMER_TIME_LOW          = 0x00, // get low bits of current time and update TIMER_TIME_HIGH
     21     TIMER_TIME_HIGH         = 0x04, // get high bits of time at last TIMER_TIME_LOW read
     22     TIMER_ALARM_LOW         = 0x08, // set low bits of alarm and activate it
     23     TIMER_ALARM_HIGH        = 0x0c, // set high bits of next alarm
     24     TIMER_CLEAR_INTERRUPT   = 0x10,
     25     TIMER_CLEAR_ALARM       = 0x14
     26 };
     27 
     28 struct timer_state {
     29     struct goldfish_device dev;
     30     uint32_t alarm_low_ns;
     31     int32_t alarm_high_ns;
     32     int64_t now_ns;
     33     int     armed;
     34     QEMUTimer *timer;
     35 };
     36 
     37 #define  GOLDFISH_TIMER_SAVE_VERSION  1
     38 
     39 static void  goldfish_timer_save(QEMUFile*  f, void*  opaque)
     40 {
     41     struct timer_state*  s   = opaque;
     42 
     43     qemu_put_be64(f, s->now_ns);  /* in case the kernel is in the middle of a timer read */
     44     qemu_put_byte(f, s->armed);
     45     if (s->armed) {
     46         int64_t  now_ns   = qemu_get_clock_ns(vm_clock);
     47         int64_t  alarm_ns = (s->alarm_low_ns | (int64_t)s->alarm_high_ns << 32);
     48         qemu_put_be64(f, alarm_ns - now_ns);
     49     }
     50 }
     51 
     52 static int  goldfish_timer_load(QEMUFile*  f, void*  opaque, int  version_id)
     53 {
     54     struct timer_state*  s   = opaque;
     55 
     56     if (version_id != GOLDFISH_TIMER_SAVE_VERSION)
     57         return -1;
     58 
     59     s->now_ns = qemu_get_be64(f);
     60     s->armed  = qemu_get_byte(f);
     61     if (s->armed) {
     62         int64_t  now_tks   = qemu_get_clock(vm_clock);
     63         int64_t  diff_tks  = qemu_get_be64(f);
     64         int64_t  alarm_tks = now_tks + diff_tks;
     65 
     66         if (alarm_tks <= now_tks) {
     67             goldfish_device_set_irq(&s->dev, 0, 1);
     68             s->armed = 0;
     69         } else {
     70             qemu_mod_timer(s->timer, alarm_tks);
     71         }
     72     }
     73     return 0;
     74 }
     75 
     76 static uint32_t goldfish_timer_read(void *opaque, target_phys_addr_t offset)
     77 {
     78     struct timer_state *s = (struct timer_state *)opaque;
     79     switch(offset) {
     80         case TIMER_TIME_LOW:
     81             s->now_ns = qemu_get_clock_ns(vm_clock);
     82             return s->now_ns;
     83         case TIMER_TIME_HIGH:
     84             return s->now_ns >> 32;
     85         default:
     86             cpu_abort (cpu_single_env, "goldfish_timer_read: Bad offset %x\n", offset);
     87             return 0;
     88     }
     89 }
     90 
     91 static void goldfish_timer_write(void *opaque, target_phys_addr_t offset, uint32_t value_ns)
     92 {
     93     struct timer_state *s = (struct timer_state *)opaque;
     94     int64_t alarm_ns, now_ns;
     95     switch(offset) {
     96         case TIMER_ALARM_LOW:
     97             s->alarm_low_ns = value_ns;
     98             alarm_ns = (s->alarm_low_ns | (int64_t)s->alarm_high_ns << 32);
     99             now_ns   = qemu_get_clock_ns(vm_clock);
    100             if (alarm_ns <= now_ns) {
    101                 goldfish_device_set_irq(&s->dev, 0, 1);
    102             } else {
    103                 qemu_mod_timer(s->timer, alarm_ns);
    104                 s->armed = 1;
    105             }
    106             break;
    107         case TIMER_ALARM_HIGH:
    108             s->alarm_high_ns = value_ns;
    109             break;
    110         case TIMER_CLEAR_ALARM:
    111             qemu_del_timer(s->timer);
    112             s->armed = 0;
    113             /* fall through */
    114         case TIMER_CLEAR_INTERRUPT:
    115             goldfish_device_set_irq(&s->dev, 0, 0);
    116             break;
    117         default:
    118             cpu_abort (cpu_single_env, "goldfish_timer_write: Bad offset %x\n", offset);
    119     }
    120 }
    121 
    122 static void goldfish_timer_tick(void *opaque)
    123 {
    124     struct timer_state *s = (struct timer_state *)opaque;
    125 
    126     s->armed = 0;
    127     goldfish_device_set_irq(&s->dev, 0, 1);
    128 }
    129 
    130 struct rtc_state {
    131     struct goldfish_device dev;
    132     uint32_t alarm_low;
    133     int32_t alarm_high;
    134     int64_t now;
    135 };
    136 
    137 /* we save the RTC for the case where the kernel is in the middle of a rtc_read
    138  * (i.e. it has read the low 32-bit of s->now, but not the high 32-bits yet */
    139 #define  GOLDFISH_RTC_SAVE_VERSION  1
    140 
    141 static void  goldfish_rtc_save(QEMUFile*  f, void*  opaque)
    142 {
    143     struct rtc_state*  s = opaque;
    144 
    145     qemu_put_be64(f, s->now);
    146 }
    147 
    148 static int  goldfish_rtc_load(QEMUFile*  f, void*  opaque, int  version_id)
    149 {
    150     struct  rtc_state*  s = opaque;
    151 
    152     if (version_id != GOLDFISH_RTC_SAVE_VERSION)
    153         return -1;
    154 
    155     /* this is an old value that is not correct. but that's ok anyway */
    156     s->now = qemu_get_be64(f);
    157     return 0;
    158 }
    159 
    160 static uint32_t goldfish_rtc_read(void *opaque, target_phys_addr_t offset)
    161 {
    162     struct rtc_state *s = (struct rtc_state *)opaque;
    163     switch(offset) {
    164         case 0x0:
    165             s->now = (int64_t)time(NULL) * 1000000000;
    166             return s->now;
    167         case 0x4:
    168             return s->now >> 32;
    169         default:
    170             cpu_abort (cpu_single_env, "goldfish_rtc_read: Bad offset %x\n", offset);
    171             return 0;
    172     }
    173 }
    174 
    175 static void goldfish_rtc_write(void *opaque, target_phys_addr_t offset, uint32_t value)
    176 {
    177     struct rtc_state *s = (struct rtc_state *)opaque;
    178     int64_t alarm;
    179     switch(offset) {
    180         case 0x8:
    181             s->alarm_low = value;
    182             alarm = s->alarm_low | (int64_t)s->alarm_high << 32;
    183             //printf("next alarm at %lld, tps %lld\n", alarm, ticks_per_sec);
    184             //qemu_mod_timer(s->timer, alarm);
    185             break;
    186         case 0xc:
    187             s->alarm_high = value;
    188             //printf("alarm_high %d\n", s->alarm_high);
    189             break;
    190         case 0x10:
    191             goldfish_device_set_irq(&s->dev, 0, 0);
    192             break;
    193         default:
    194             cpu_abort (cpu_single_env, "goldfish_rtc_write: Bad offset %x\n", offset);
    195     }
    196 }
    197 
    198 static struct timer_state timer_state = {
    199     .dev = {
    200         .name = "goldfish_timer",
    201         .id = -1,
    202         .size = 0x1000,
    203         .irq_count = 1,
    204     }
    205 };
    206 
    207 static struct timer_state rtc_state = {
    208     .dev = {
    209         .name = "goldfish_rtc",
    210         .id = -1,
    211         .size = 0x1000,
    212         .irq_count = 1,
    213     }
    214 };
    215 
    216 static CPUReadMemoryFunc *goldfish_timer_readfn[] = {
    217     goldfish_timer_read,
    218     goldfish_timer_read,
    219     goldfish_timer_read
    220 };
    221 
    222 static CPUWriteMemoryFunc *goldfish_timer_writefn[] = {
    223     goldfish_timer_write,
    224     goldfish_timer_write,
    225     goldfish_timer_write
    226 };
    227 
    228 static CPUReadMemoryFunc *goldfish_rtc_readfn[] = {
    229     goldfish_rtc_read,
    230     goldfish_rtc_read,
    231     goldfish_rtc_read
    232 };
    233 
    234 static CPUWriteMemoryFunc *goldfish_rtc_writefn[] = {
    235     goldfish_rtc_write,
    236     goldfish_rtc_write,
    237     goldfish_rtc_write
    238 };
    239 
    240 void goldfish_timer_and_rtc_init(uint32_t timerbase, int timerirq)
    241 {
    242     timer_state.dev.base = timerbase;
    243     timer_state.dev.irq = timerirq;
    244     timer_state.timer = qemu_new_timer_ns(vm_clock, goldfish_timer_tick, &timer_state);
    245     goldfish_device_add(&timer_state.dev, goldfish_timer_readfn, goldfish_timer_writefn, &timer_state);
    246     register_savevm( "goldfish_timer", 0, GOLDFISH_TIMER_SAVE_VERSION,
    247                      goldfish_timer_save, goldfish_timer_load, &timer_state);
    248 
    249     goldfish_device_add(&rtc_state.dev, goldfish_rtc_readfn, goldfish_rtc_writefn, &rtc_state);
    250     register_savevm( "goldfish_rtc", 0, GOLDFISH_RTC_SAVE_VERSION,
    251                      goldfish_rtc_save, goldfish_rtc_load, &rtc_state);
    252 }
    253 
    254