Files
86Box/src/device/smbus_piix4.c
2022-02-02 16:31:22 -05:00

407 lines
9.9 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/i2c.h>
#include <86box/smbus.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, cmd, read, block_len, prev_stat;
uint16_t timer_bytes = 0, i;
smbus_piix4_log("SMBus PIIX4: write(%02X, %02X)\n", addr, val);
prev_stat = dev->next_stat;
dev->next_stat = 0x00;
switch (addr - dev->io_base) {
case 0x00:
for (smbus_addr = 0x02; smbus_addr <= 0x10; smbus_addr <<= 1) { /* handle clearable bits */
if (val & smbus_addr)
dev->stat &= ~smbus_addr;
}
break;
case 0x02:
dev->ctl = val & ((dev->local == SMBUS_VIA) ? 0x3f : 0x1f);
if (val & 0x02) { /* cancel an in-progress command if KILL is set */
if (prev_stat) { /* cancel only if a command is in progress */
timer_disable(&dev->response_timer);
dev->stat = 0x10; /* raise FAILED */
}
}
if (val & 0x40) { /* dispatch command if START is set */
timer_bytes++; /* address */
smbus_addr = dev->addr >> 1;
read = dev->addr & 0x01;
cmd = (dev->ctl >> 2) & 0xf;
smbus_piix4_log("SMBus PIIX4: addr=%02X read=%d protocol=%X cmd=%02X data0=%02X data1=%02X\n", smbus_addr, read, cmd, dev->cmd, dev->data0, dev->data1);
/* Raise DEV_ERR if no device is at this address, or if the device returned NAK. */
if (!i2c_start(i2c_smbus, smbus_addr, read)) {
dev->next_stat = 0x04;
break;
}
dev->next_stat = 0x02; /* raise INTER (command completed) by default */
/* Decode the command protocol.
VIA-specific modes (0x4 and [0x6:0xf]) are undocumented and required real hardware research. */
switch (cmd) {
case 0x0: /* quick R/W */
break;
case 0x1: /* byte R/W */
if (read) /* byte read */
dev->data0 = i2c_read(i2c_smbus, smbus_addr);
else /* byte write */
i2c_write(i2c_smbus, smbus_addr, dev->data0);
timer_bytes++;
break;
case 0x2: /* byte data R/W */
/* command write */
i2c_write(i2c_smbus, smbus_addr, dev->cmd);
timer_bytes++;
if (read) /* byte read */
dev->data0 = i2c_read(i2c_smbus, smbus_addr);
else /* byte write */
i2c_write(i2c_smbus, smbus_addr, dev->data0);
timer_bytes++;
break;
case 0x3: /* word data R/W */
/* command write */
i2c_write(i2c_smbus, smbus_addr, dev->cmd);
timer_bytes++;
if (read) { /* word read */
dev->data0 = i2c_read(i2c_smbus, smbus_addr);
dev->data1 = i2c_read(i2c_smbus, smbus_addr);
} else { /* word write */
i2c_write(i2c_smbus, smbus_addr, dev->data0);
i2c_write(i2c_smbus, smbus_addr, dev->data1);
}
timer_bytes += 2;
break;
case 0x4: /* process call */
if (dev->local != SMBUS_VIA) /* VIA only */
goto unknown_protocol;
if (!read) { /* command write (only when writing) */
i2c_write(i2c_smbus, smbus_addr, dev->cmd);
timer_bytes++;
}
/* fall-through */
case 0xc: /* I2C process call */
if (!read) { /* word write (only when writing) */
i2c_write(i2c_smbus, smbus_addr, dev->data0);
i2c_write(i2c_smbus, smbus_addr, dev->data1);
timer_bytes += 2;
}
/* word read */
dev->data0 = i2c_read(i2c_smbus, smbus_addr);
dev->data1 = i2c_read(i2c_smbus, smbus_addr);
timer_bytes += 2;
break;
case 0x5: /* block R/W */
timer_bytes++; /* count the SMBus length byte now */
/* fall-through */
case 0xd: /* I2C block R/W */
i2c_write(i2c_smbus, smbus_addr, dev->cmd);
timer_bytes++;
if (read) {
/* block read [data0] (I2C) or [first byte] (SMBus) bytes */
if (cmd == 0x5)
dev->data0 = i2c_read(i2c_smbus, smbus_addr);
for (i = 0; i < dev->data0; i++)
dev->data[i & SMBUS_PIIX4_BLOCK_DATA_MASK] = i2c_read(i2c_smbus, smbus_addr);
} else {
if (cmd == 0x5) /* send length [data0] as first byte on SMBus */
i2c_write(i2c_smbus, smbus_addr, dev->data0);
/* block write [data0] bytes */
for (i = 0; i < dev->data0; i++) {
if (!i2c_write(i2c_smbus, smbus_addr, dev->data[i & SMBUS_PIIX4_BLOCK_DATA_MASK]))
break;
}
}
timer_bytes += i;
break;
case 0x6: /* I2C with 10-bit address */
if (dev->local != SMBUS_VIA) /* VIA only */
goto unknown_protocol;
/* command write */
i2c_write(i2c_smbus, smbus_addr, dev->cmd);
timer_bytes++;
/* fall-through */
case 0xe: /* I2C with 7-bit address */
if (!read) { /* word write (only when writing) */
i2c_write(i2c_smbus, smbus_addr, dev->data0);
i2c_write(i2c_smbus, smbus_addr, dev->data1);
timer_bytes += 2;
}
/* block read [first byte] bytes */
block_len = dev->data[0];
for (i = 0; i < block_len; i++)
dev->data[i & SMBUS_PIIX4_BLOCK_DATA_MASK] = i2c_read(i2c_smbus, smbus_addr);
timer_bytes += i;
break;
case 0xf: /* universal */
/* block write [data0] bytes */
for (i = 0; i < dev->data0; i++) {
if (!i2c_write(i2c_smbus, smbus_addr, dev->data[i & SMBUS_PIIX4_BLOCK_DATA_MASK]))
break; /* write NAK behavior is unknown */
}
timer_bytes += i;
/* block read [data1] bytes */
for (i = 0; i < dev->data1; i++)
dev->data[i & SMBUS_PIIX4_BLOCK_DATA_MASK] = i2c_read(i2c_smbus, smbus_addr);
timer_bytes += i;
break;
default: /* unknown */
unknown_protocol:
dev->next_stat = 0x04; /* raise DEV_ERR */
timer_bytes = 0;
break;
}
/* Finish transfer. */
i2c_stop(i2c_smbus, smbus_addr);
}
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 (dev->next_stat) { /* schedule dispatch of any pending status register update */
dev->stat = 0x01; /* raise HOST_BUSY while waiting */
timer_disable(&dev->response_timer);
/* delay = ((half clock for start + half clock for stop) + (bytes * (8 bits + ack))) * bit period in usecs */
timer_set_delay_u64(&dev->response_timer, (1 + (timer_bytes * 9)) * dev->bit_period * 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)
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 (%sabled)\n", dev->io_base, enable ? "en" : "dis");
if (enable && dev->io_base)
io_sethandler(dev->io_base, 0x10, smbus_piix4_read, NULL, NULL, smbus_piix4_write, NULL, NULL, dev);
}
void
smbus_piix4_setclock(smbus_piix4_t *dev, int clock)
{
dev->clock = clock;
/* Set the bit period in usecs. */
dev->bit_period = 1000000.0 / dev->clock;
}
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));
dev->local = info->local;
/* We save the I2C bus handle on dev but use i2c_smbus for all operations because
dev and therefore dev->i2c will be invalidated if a device triggers a hard reset. */
i2c_smbus = dev->i2c = i2c_addbus((dev->local == SMBUS_VIA) ? "smbus_vt82c686b" : "smbus_piix4");
timer_add(&dev->response_timer, smbus_piix4_response, dev, 0);
smbus_piix4_setclock(dev, 16384); /* default to 16.384 KHz */
return dev;
}
static void
smbus_piix4_close(void *priv)
{
smbus_piix4_t *dev = (smbus_piix4_t *) priv;
if (i2c_smbus == dev->i2c)
i2c_smbus = NULL;
i2c_removebus(dev->i2c);
free(dev);
}
const device_t piix4_smbus_device = {
"PIIX4-compatible SMBus Host Controller",
"piix4_smbus",
DEVICE_AT,
SMBUS_PIIX4,
smbus_piix4_init, smbus_piix4_close, NULL,
{ NULL }, NULL, NULL,
NULL
};
const device_t via_smbus_device = {
"VIA VT82C686B SMBus Host Controller",
"via_smbus",
DEVICE_AT,
SMBUS_VIA,
smbus_piix4_init, smbus_piix4_close, NULL,
{ NULL }, NULL, NULL,
NULL
};