LXR qemu/hw/timer/m41t80.c

   1/*
   2 * M41T80 serial rtc emulation
   3 *
   4 * Copyright (c) 2018 BALATON Zoltan
   5 *
   6 * This work is licensed under the GNU GPL license version 2 or later.
   7 *
   8 */
   9
  10#include "qemu/osdep.h"
  11#include "qemu/log.h"
  12#include "qemu/timer.h"
  13#include "qemu/bcd.h"
  14#include "hw/i2c/i2c.h"
  15
  16#define TYPE_M41T80 "m41t80"
  17#define M41T80(obj) OBJECT_CHECK(M41t80State, (obj), TYPE_M41T80)
  18
  19typedef struct M41t80State {
  20    I2CSlave parent_obj;
  21    int8_t addr;
  22} M41t80State;
  23
  24static void m41t80_realize(DeviceState *dev, Error **errp)
  25{
  26    M41t80State *s = M41T80(dev);
  27
  28    s->addr = -1;
  29}
  30
  31static int m41t80_send(I2CSlave *i2c, uint8_t data)
  32{
  33    M41t80State *s = M41T80(i2c);
  34
  35    if (s->addr < 0) {
  36        s->addr = data;
  37    } else {
  38        s->addr++;
  39    }
  40    return 0;
  41}
  42
  43static int m41t80_recv(I2CSlave *i2c)
  44{
  45    M41t80State *s = M41T80(i2c);
  46    struct tm now;
  47    qemu_timeval tv;
  48
  49    if (s->addr < 0) {
  50        s->addr = 0;
  51    }
  52    if (s->addr >= 1 && s->addr <= 7) {
  53        qemu_get_timedate(&now, -1);
  54    }
  55    switch (s->addr++) {
  56    case 0:
  57        qemu_gettimeofday(&tv);
  58        return to_bcd(tv.tv_usec / 10000);
  59    case 1:
  60        return to_bcd(now.tm_sec);
  61    case 2:
  62        return to_bcd(now.tm_min);
  63    case 3:
  64        return to_bcd(now.tm_hour);
  65    case 4:
  66        return to_bcd(now.tm_wday);
  67    case 5:
  68        return to_bcd(now.tm_mday);
  69    case 6:
  70        return to_bcd(now.tm_mon + 1);
  71    case 7:
  72        return to_bcd(now.tm_year % 100);
  73    case 8 ... 19:
  74        qemu_log_mask(LOG_UNIMP, "%s: unimplemented register: %d\n",
  75                      __func__, s->addr - 1);
  76        return 0;
  77    default:
  78        qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid register: %d\n",
  79                      __func__, s->addr - 1);
  80        return 0;
  81    }
  82}
  83
  84static int m41t80_event(I2CSlave *i2c, enum i2c_event event)
  85{
  86    M41t80State *s = M41T80(i2c);
  87
  88    if (event == I2C_START_SEND) {
  89        s->addr = -1;
  90    }
  91    return 0;
  92}
  93
  94static void m41t80_class_init(ObjectClass *klass, void *data)
  95{
  96    DeviceClass *dc = DEVICE_CLASS(klass);
  97    I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass);
  98
  99    dc->realize = m41t80_realize;
 100    sc->send = m41t80_send;
 101    sc->recv = m41t80_recv;
 102    sc->event = m41t80_event;
 103}
 104
 105static const TypeInfo m41t80_info = {
 106    .name          = TYPE_M41T80,
 107    .parent        = TYPE_I2C_SLAVE,
 108    .instance_size = sizeof(M41t80State),
 109    .class_init    = m41t80_class_init,
 110};
 111
 112static void m41t80_register_types(void)
 113{
 114    type_register_static(&m41t80_info);
 115}
 116
 117type_init(m41t80_register_types)
 118