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-common.h"
  12#include "qemu/log.h"
  13#include "qemu/module.h"
  14#include "qemu/timer.h"
  15#include "qemu/bcd.h"
  16#include "hw/i2c/i2c.h"
  17
  18#define TYPE_M41T80 "m41t80"
  19#define M41T80(obj) OBJECT_CHECK(M41t80State, (obj), TYPE_M41T80)
  20
  21typedef struct M41t80State {
  22    I2CSlave parent_obj;
  23    int8_t addr;
  24} M41t80State;
  25
  26static void m41t80_realize(DeviceState *dev, Error **errp)
  27{
  28    M41t80State *s = M41T80(dev);
  29
  30    s->addr = -1;
  31}
  32
  33static int m41t80_send(I2CSlave *i2c, uint8_t data)
  34{
  35    M41t80State *s = M41T80(i2c);
  36
  37    if (s->addr < 0) {
  38        s->addr = data;
  39    } else {
  40        s->addr++;
  41    }
  42    return 0;
  43}
  44
  45static uint8_t m41t80_recv(I2CSlave *i2c)
  46{
  47    M41t80State *s = M41T80(i2c);
  48    struct tm now;
  49    qemu_timeval tv;
  50
  51    if (s->addr < 0) {
  52        s->addr = 0;
  53    }
  54    if (s->addr >= 1 && s->addr <= 7) {
  55        qemu_get_timedate(&now, -1);
  56    }
  57    switch (s->addr++) {
  58    case 0:
  59        qemu_gettimeofday(&tv);
  60        return to_bcd(tv.tv_usec / 10000);
  61    case 1:
  62        return to_bcd(now.tm_sec);
  63    case 2:
  64        return to_bcd(now.tm_min);
  65    case 3:
  66        return to_bcd(now.tm_hour);
  67    case 4:
  68        return to_bcd(now.tm_wday);
  69    case 5:
  70        return to_bcd(now.tm_mday);
  71    case 6:
  72        return to_bcd(now.tm_mon + 1);
  73    case 7:
  74        return to_bcd(now.tm_year % 100);
  75    case 8 ... 19:
  76        qemu_log_mask(LOG_UNIMP, "%s: unimplemented register: %d\n",
  77                      __func__, s->addr - 1);
  78        return 0;
  79    default:
  80        qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid register: %d\n",
  81                      __func__, s->addr - 1);
  82        return 0;
  83    }
  84}
  85
  86static int m41t80_event(I2CSlave *i2c, enum i2c_event event)
  87{
  88    M41t80State *s = M41T80(i2c);
  89
  90    if (event == I2C_START_SEND) {
  91        s->addr = -1;
  92    }
  93    return 0;
  94}
  95
  96static void m41t80_class_init(ObjectClass *klass, void *data)
  97{
  98    DeviceClass *dc = DEVICE_CLASS(klass);
  99    I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass);
 100
 101    dc->realize = m41t80_realize;
 102    sc->send = m41t80_send;
 103    sc->recv = m41t80_recv;
 104    sc->event = m41t80_event;
 105}
 106
 107static const TypeInfo m41t80_info = {
 108    .name          = TYPE_M41T80,
 109    .parent        = TYPE_I2C_SLAVE,
 110    .instance_size = sizeof(M41t80State),
 111    .class_init    = m41t80_class_init,
 112};
 113
 114static void m41t80_register_types(void)
 115{
 116    type_register_static(&m41t80_info);
 117}
 118
 119type_init(m41t80_register_types)
 120