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c6f2594c4b
Basic emulation of the M41T80 serial (I2C) RTC chip. Only getting time of day is implemented. Setting time and RTC alarm are not supported. Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
118 lines
2.5 KiB
C
118 lines
2.5 KiB
C
/*
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* M41T80 serial rtc emulation
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*
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* Copyright (c) 2018 BALATON Zoltan
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*
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* This work is licensed under the GNU GPL license version 2 or later.
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*
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*/
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#include "qemu/osdep.h"
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#include "qemu/log.h"
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#include "qemu/timer.h"
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#include "qemu/bcd.h"
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#include "hw/i2c/i2c.h"
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#define TYPE_M41T80 "m41t80"
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#define M41T80(obj) OBJECT_CHECK(M41t80State, (obj), TYPE_M41T80)
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typedef struct M41t80State {
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I2CSlave parent_obj;
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int8_t addr;
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} M41t80State;
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static void m41t80_realize(DeviceState *dev, Error **errp)
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{
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M41t80State *s = M41T80(dev);
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s->addr = -1;
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}
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static int m41t80_send(I2CSlave *i2c, uint8_t data)
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{
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M41t80State *s = M41T80(i2c);
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if (s->addr < 0) {
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s->addr = data;
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} else {
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s->addr++;
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}
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return 0;
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}
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static int m41t80_recv(I2CSlave *i2c)
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{
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M41t80State *s = M41T80(i2c);
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struct tm now;
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qemu_timeval tv;
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if (s->addr < 0) {
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s->addr = 0;
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}
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if (s->addr >= 1 && s->addr <= 7) {
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qemu_get_timedate(&now, -1);
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}
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switch (s->addr++) {
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case 0:
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qemu_gettimeofday(&tv);
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return to_bcd(tv.tv_usec / 10000);
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case 1:
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return to_bcd(now.tm_sec);
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case 2:
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return to_bcd(now.tm_min);
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case 3:
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return to_bcd(now.tm_hour);
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case 4:
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return to_bcd(now.tm_wday);
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case 5:
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return to_bcd(now.tm_mday);
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case 6:
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return to_bcd(now.tm_mon + 1);
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case 7:
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return to_bcd(now.tm_year % 100);
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case 8 ... 19:
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qemu_log_mask(LOG_UNIMP, "%s: unimplemented register: %d\n",
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__func__, s->addr - 1);
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return 0;
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default:
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qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid register: %d\n",
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__func__, s->addr - 1);
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return 0;
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}
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}
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static int m41t80_event(I2CSlave *i2c, enum i2c_event event)
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{
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M41t80State *s = M41T80(i2c);
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if (event == I2C_START_SEND) {
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s->addr = -1;
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}
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return 0;
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}
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static void m41t80_class_init(ObjectClass *klass, void *data)
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{
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DeviceClass *dc = DEVICE_CLASS(klass);
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I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass);
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dc->realize = m41t80_realize;
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sc->send = m41t80_send;
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sc->recv = m41t80_recv;
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sc->event = m41t80_event;
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}
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static const TypeInfo m41t80_info = {
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.name = TYPE_M41T80,
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.parent = TYPE_I2C_SLAVE,
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.instance_size = sizeof(M41t80State),
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.class_init = m41t80_class_init,
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};
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static void m41t80_register_types(void)
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{
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type_register_static(&m41t80_info);
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}
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type_init(m41t80_register_types)
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