qemu/hw/i2c/pm_smbus.c

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/*
* PC SMBus implementation
* splitted from acpi.c
*
* Copyright (c) 2006 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2 as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see
* <http://www.gnu.org/licenses/>.
*/
#include "hw/hw.h"
#include "hw/i386/pc.h"
#include "hw/i2c/pm_smbus.h"
#include "hw/i2c/smbus.h"
/* no save/load? */
#define SMBHSTSTS 0x00
#define SMBHSTCNT 0x02
#define SMBHSTCMD 0x03
#define SMBHSTADD 0x04
#define SMBHSTDAT0 0x05
#define SMBHSTDAT1 0x06
#define SMBBLKDAT 0x07
//#define DEBUG
#ifdef DEBUG
# define SMBUS_DPRINTF(format, ...) printf(format, ## __VA_ARGS__)
#else
# define SMBUS_DPRINTF(format, ...) do { } while (0)
#endif
static void smb_transaction(PMSMBus *s)
{
uint8_t prot = (s->smb_ctl >> 2) & 0x07;
uint8_t read = s->smb_addr & 0x01;
uint8_t cmd = s->smb_cmd;
uint8_t addr = s->smb_addr >> 1;
i2c_bus *bus = s->smbus;
SMBUS_DPRINTF("SMBus trans addr=0x%02x prot=0x%02x\n", addr, prot);
switch(prot) {
case 0x0:
smbus_quick_command(bus, addr, read);
break;
case 0x1:
if (read) {
s->smb_data0 = smbus_receive_byte(bus, addr);
} else {
smbus_send_byte(bus, addr, cmd);
}
break;
case 0x2:
if (read) {
s->smb_data0 = smbus_read_byte(bus, addr, cmd);
} else {
smbus_write_byte(bus, addr, cmd, s->smb_data0);
}
break;
case 0x3:
if (read) {
uint16_t val;
val = smbus_read_word(bus, addr, cmd);
s->smb_data0 = val;
s->smb_data1 = val >> 8;
} else {
smbus_write_word(bus, addr, cmd, (s->smb_data1 << 8) | s->smb_data0);
}
break;
case 0x5:
if (read) {
s->smb_data0 = smbus_read_block(bus, addr, cmd, s->smb_data);
} else {
smbus_write_block(bus, addr, cmd, s->smb_data, s->smb_data0);
}
break;
default:
goto error;
}
return;
error:
s->smb_stat |= 0x04;
}
static void smb_ioport_writeb(void *opaque, hwaddr addr, uint64_t val,
unsigned width)
{
PMSMBus *s = opaque;
SMBUS_DPRINTF("SMB writeb port=0x%04x val=0x%02x\n", addr, val);
switch(addr) {
case SMBHSTSTS:
s->smb_stat = 0;
s->smb_index = 0;
break;
case SMBHSTCNT:
s->smb_ctl = val;
if (val & 0x40)
smb_transaction(s);
break;
case SMBHSTCMD:
s->smb_cmd = val;
break;
case SMBHSTADD:
s->smb_addr = val;
break;
case SMBHSTDAT0:
s->smb_data0 = val;
break;
case SMBHSTDAT1:
s->smb_data1 = val;
break;
case SMBBLKDAT:
s->smb_data[s->smb_index++] = val;
if (s->smb_index > 31)
s->smb_index = 0;
break;
default:
break;
}
}
static uint64_t smb_ioport_readb(void *opaque, hwaddr addr, unsigned width)
{
PMSMBus *s = opaque;
uint32_t val;
switch(addr) {
case SMBHSTSTS:
val = s->smb_stat;
break;
case SMBHSTCNT:
s->smb_index = 0;
val = s->smb_ctl & 0x1f;
break;
case SMBHSTCMD:
val = s->smb_cmd;
break;
case SMBHSTADD:
val = s->smb_addr;
break;
case SMBHSTDAT0:
val = s->smb_data0;
break;
case SMBHSTDAT1:
val = s->smb_data1;
break;
case SMBBLKDAT:
val = s->smb_data[s->smb_index++];
if (s->smb_index > 31)
s->smb_index = 0;
break;
default:
val = 0;
break;
}
SMBUS_DPRINTF("SMB readb port=0x%04x val=0x%02x\n", addr, val);
return val;
}
static const MemoryRegionOps pm_smbus_ops = {
.read = smb_ioport_readb,
.write = smb_ioport_writeb,
.valid.min_access_size = 1,
.valid.max_access_size = 1,
.endianness = DEVICE_LITTLE_ENDIAN,
};
void pm_smbus_init(DeviceState *parent, PMSMBus *smb)
{
smb->smbus = i2c_init_bus(parent, "i2c");
memory_region_init_io(&smb->io, &pm_smbus_ops, smb, "pm-smbus", 64);
}