Files
86Box/src/smbus_piix4.c
2020-05-17 00:49:03 -03:00

254 lines
6.3 KiB
C

/*
* 86Box A hypervisor and IBM PC system emulator that specializes in
* running old operating systems and software designed for IBM
* PC systems and compatibles from 1981 through fairly recent
* system designs based on the PCI bus.
*
* This file is part of the 86Box distribution.
*
* Implementation of a generic PIIX4-compatible SMBus host controller.
*
*
*
* Authors: RichardG, <richardg867@gmail.com>
*
* Copyright 2020 RichardG.
*/
#include <stdarg.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#define HAVE_STDARG_H
#include <86box/86box.h>
#include <86box/io.h>
#include <86box/device.h>
#include <86box/timer.h>
#include <86box/smbus.h>
#include <86box/smbus_piix4.h>
#ifdef ENABLE_SMBUS_PIIX4_LOG
int smbus_piix4_do_log = ENABLE_SMBUS_PIIX4_LOG;
static void
smbus_piix4_log(const char *fmt, ...)
{
va_list ap;
if (smbus_piix4_do_log) {
va_start(ap, fmt);
pclog_ex(fmt, ap);
va_end(ap);
}
}
#else
#define smbus_piix4_log(fmt, ...)
#endif
static uint8_t
smbus_piix4_read(uint16_t addr, void *priv)
{
smbus_piix4_t *dev = (smbus_piix4_t *) priv;
uint8_t ret = 0x00;
switch (addr - dev->io_base) {
case 0x00:
ret = dev->stat;
break;
case 0x02:
dev->index = 0; /* reading from this resets the block data index */
ret = dev->ctl;
break;
case 0x03:
ret = dev->cmd;
break;
case 0x04:
ret = dev->addr;
break;
case 0x05:
ret = dev->data0;
break;
case 0x06:
ret = dev->data1;
break;
case 0x07:
ret = dev->data[dev->index++];
if (dev->index >= SMBUS_PIIX4_BLOCK_DATA_SIZE)
dev->index = 0;
break;
}
smbus_piix4_log("SMBus PIIX4: read(%02x) = %02x\n", addr, ret);
return ret;
}
static void
smbus_piix4_write(uint16_t addr, uint8_t val, void *priv)
{
smbus_piix4_t *dev = (smbus_piix4_t *) priv;
uint8_t smbus_addr, smbus_read, prev_stat;
uint16_t temp;
smbus_piix4_log("SMBus PIIX4: write(%02x, %02x)\n", addr, val);
prev_stat = dev->next_stat;
dev->next_stat = 0;
switch (addr - dev->io_base) {
case 0x00:
/* some status bits are reset by writing 1 to them */
for (smbus_addr = 0x02; smbus_addr <= 0x10; smbus_addr = smbus_addr << 1) {
if (val & smbus_addr)
dev->stat = dev->stat & ~smbus_addr;
}
break;
case 0x02:
dev->ctl = val & ~(0x40); /* START always reads 0 */
if (val & 0x02) { /* cancel an in-progress command if KILL is set */
/* cancel only if a command is in progress */
if (prev_stat) {
dev->stat = 0x10; /* raise FAILED */
timer_disable(&dev->response_timer);
}
}
if (val & 0x40) { /* dispatch command if START is set */
smbus_addr = (dev->addr >> 1);
if (!smbus_has_device(smbus_addr)) {
/* raise DEV_ERR if no device is at this address */
dev->next_stat = 0x4;
break;
}
smbus_read = (dev->addr & 0x01);
/* decode the 3-bit command protocol */
switch ((val >> 2) & 0x7) {
case 0x0: /* quick R/W */
dev->next_stat = 0x2;
break;
case 0x1: /* byte R/W */
if (smbus_read)
dev->data0 = smbus_read_byte(smbus_addr);
else
smbus_write_byte(smbus_addr, dev->data0);
dev->next_stat = 0x2;
break;
case 0x2: /* byte data R/W */
if (smbus_read)
dev->data0 = smbus_read_byte_cmd(smbus_addr, dev->cmd);
else
smbus_write_byte_cmd(smbus_addr, dev->cmd, dev->data0);
dev->next_stat = 0x2;
break;
case 0x3: /* word data R/W */
if (smbus_read) {
temp = smbus_read_word_cmd(smbus_addr, dev->cmd);
dev->data0 = (temp & 0xFF);
dev->data1 = (temp >> 8);
} else {
temp = (dev->data1 << 8) | dev->data0;
smbus_write_word_cmd(smbus_addr, dev->cmd, temp);
}
dev->next_stat = 0x2;
break;
case 0x5: /* block R/W */
if (smbus_read)
dev->data0 = smbus_read_block_cmd(smbus_addr, dev->cmd, dev->data, SMBUS_PIIX4_BLOCK_DATA_SIZE);
else
smbus_write_block_cmd(smbus_addr, dev->cmd, dev->data, dev->data0);
dev->next_stat = 0x2;
break;
default:
/* other command protocols have undefined behavior, but raise DEV_ERR to be safe */
dev->next_stat = 0x4;
break;
}
}
break;
case 0x03:
dev->cmd = val;
break;
case 0x04:
dev->addr = val;
break;
case 0x05:
dev->data0 = val;
break;
case 0x06:
dev->data1 = val;
break;
case 0x07:
dev->data[dev->index++] = val;
if (dev->index >= SMBUS_PIIX4_BLOCK_DATA_SIZE)
dev->index = 0;
break;
}
/* if a status register update was given, dispatch it after 10ms to ensure nothing breaks */
if (dev->next_stat) {
dev->stat = 0x1; /* raise HOST_BUSY while waiting */
timer_disable(&dev->response_timer);
timer_set_delay_u64(&dev->response_timer, 10 * TIMER_USEC);
}
}
static void
smbus_piix4_response(void *priv)
{
smbus_piix4_t *dev = (smbus_piix4_t *) priv;
/* dispatch the status register update */
dev->stat = dev->next_stat;
}
void
smbus_piix4_remap(smbus_piix4_t *dev, uint16_t new_io_base, uint8_t enable)
{
if (dev->io_base != 0x0000)
io_removehandler(dev->io_base, 0x10, smbus_piix4_read, NULL, NULL, smbus_piix4_write, NULL, NULL, dev);
dev->io_base = new_io_base;
smbus_piix4_log("SMBus PIIX4: remap to %04Xh\n", dev->io_base);
if (enable && (dev->io_base != 0x0000))
io_sethandler(dev->io_base, 0x10, smbus_piix4_read, NULL, NULL, smbus_piix4_write, NULL, NULL, dev);
}
static void *
smbus_piix4_init(const device_t *info)
{
smbus_piix4_t *dev = (smbus_piix4_t *) malloc(sizeof(smbus_piix4_t));
memset(dev, 0, sizeof(smbus_piix4_t));
smbus_init();
timer_add(&dev->response_timer, smbus_piix4_response, dev, 0);
return dev;
}
static void
smbus_piix4_close(void *priv)
{
smbus_piix4_t *dev = (smbus_piix4_t *) priv;
free(dev);
}
const device_t piix4_smbus_device = {
"PIIX4-compatible SMBus Host Controller",
DEVICE_AT,
0,
smbus_piix4_init, smbus_piix4_close, NULL,
NULL, NULL, NULL,
NULL
};