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/*
* MAX7310 8-port GPIO expansion chip.
*
* Copyright (c) 2006 Openedhand Ltd.
* Written by Andrzej Zaborowski <balrog@zabor.org>
*
* This file is licensed under GNU GPL.
*/
#include "i2c.h"
typedef struct {
I2CSlave i2c;
int i2c_command_byte;
int len;
uint8_t level;
uint8_t direction;
uint8_t polarity;
uint8_t status;
uint8_t command;
qemu_irq handler[8];
qemu_irq *gpio_in;
} MAX7310State;
static void max7310_reset(DeviceState *dev)
{
MAX7310State *s = FROM_I2C_SLAVE(MAX7310State, I2C_SLAVE_FROM_QDEV(dev));
s->level &= s->direction;
s->direction = 0xff;
s->polarity = 0xf0;
s->status = 0x01;
s->command = 0x00;
}
static int max7310_rx(I2CSlave *i2c)
{
MAX7310State *s = (MAX7310State *) i2c;
switch (s->command) {
case 0x00: /* Input port */
return s->level ^ s->polarity;
break;
case 0x01: /* Output port */
return s->level & ~s->direction;
break;
case 0x02: /* Polarity inversion */
return s->polarity;
case 0x03: /* Configuration */
return s->direction;
case 0x04: /* Timeout */
return s->status;
break;
case 0xff: /* Reserved */
return 0xff;
default:
#ifdef VERBOSE
printf("%s: unknown register %02x\n", __FUNCTION__, s->command);
#endif
break;
}
return 0xff;
}
static int max7310_tx(I2CSlave *i2c, uint8_t data)
{
MAX7310State *s = (MAX7310State *) i2c;
uint8_t diff;
int line;
if (s->len ++ > 1) {
#ifdef VERBOSE
printf("%s: message too long (%i bytes)\n", __FUNCTION__, s->len);
#endif
return 1;
}
if (s->i2c_command_byte) {
s->command = data;
s->i2c_command_byte = 0;
return 0;
}
switch (s->command) {
case 0x01: /* Output port */
for (diff = (data ^ s->level) & ~s->direction; diff;
diff &= ~(1 << line)) {
line = ffs(diff) - 1;
if (s->handler[line])
qemu_set_irq(s->handler[line], (data >> line) & 1);
}
s->level = (s->level & s->direction) | (data & ~s->direction);
break;
case 0x02: /* Polarity inversion */
s->polarity = data;
break;
case 0x03: /* Configuration */
s->level &= ~(s->direction ^ data);
s->direction = data;
break;
case 0x04: /* Timeout */
s->status = data;
break;
case 0x00: /* Input port - ignore writes */
break;
default:
#ifdef VERBOSE
printf("%s: unknown register %02x\n", __FUNCTION__, s->command);
#endif
return 1;
}
return 0;
}
static void max7310_event(I2CSlave *i2c, enum i2c_event event)
{
MAX7310State *s = (MAX7310State *) i2c;
s->len = 0;
switch (event) {
case I2C_START_SEND:
s->i2c_command_byte = 1;
break;
case I2C_FINISH:
#ifdef VERBOSE
if (s->len == 1)
printf("%s: message too short (%i bytes)\n", __FUNCTION__, s->len);
#endif
break;
default:
break;
}
}
static const VMStateDescription vmstate_max7310 = {
.name = "max7310",
.version_id = 0,
.minimum_version_id = 0,
.minimum_version_id_old = 0,
.fields = (VMStateField []) {
VMSTATE_INT32(i2c_command_byte, MAX7310State),
VMSTATE_INT32(len, MAX7310State),
VMSTATE_UINT8(level, MAX7310State),
VMSTATE_UINT8(direction, MAX7310State),
VMSTATE_UINT8(polarity, MAX7310State),
VMSTATE_UINT8(status, MAX7310State),
VMSTATE_UINT8(command, MAX7310State),
VMSTATE_I2C_SLAVE(i2c, MAX7310State),
VMSTATE_END_OF_LIST()
}
};
static void max7310_gpio_set(void *opaque, int line, int level)
{
MAX7310State *s = (MAX7310State *) opaque;
if (line >= ARRAY_SIZE(s->handler) || line < 0)
hw_error("bad GPIO line");
if (level)
s->level |= s->direction & (1 << line);
else
s->level &= ~(s->direction & (1 << line));
}
/* MAX7310 is SMBus-compatible (can be used with only SMBus protocols),
* but also accepts sequences that are not SMBus so return an I2C device. */
static int max7310_init(I2CSlave *i2c)
{
MAX7310State *s = FROM_I2C_SLAVE(MAX7310State, i2c);
qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8);
qdev_init_gpio_out(&i2c->qdev, s->handler, 8);
return 0;
}
static void max7310_class_init(ObjectClass *klass, void *data)
{
I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
k->init = max7310_init;
k->event = max7310_event;
k->recv = max7310_rx;
k->send = max7310_tx;
}
static DeviceInfo max7310_info = {
.name = "max7310",
.size = sizeof(MAX7310State),
.vmsd = &vmstate_max7310,
.reset = max7310_reset,
.class_init = max7310_class_init,
};
static void max7310_register_devices(void)
{
i2c_register_slave(&max7310_info);
}
device_init(max7310_register_devices)
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