[qemu.git] / hw / smbus.c

/*
 * QEMU SMBus device emulation.
 *
 * Copyright (c) 2007 CodeSourcery.
 * Written by Paul Brook
 *
 * This code is licenced under the LGPL.
 */

/* TODO: Implement PEC.  */

#include "hw.h"
#include "i2c.h"
#include "smbus.h"

//#define DEBUG_SMBUS 1

#ifdef DEBUG_SMBUS
#define DPRINTF(fmt, ...) \
do { printf("smbus(%02x): " fmt , dev->i2c.address, ## __VA_ARGS__); } while (0)
#define BADF(fmt, ...) \
do { fprintf(stderr, "smbus: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
#else
#define DPRINTF(fmt, ...) do {} while(0)
#define BADF(fmt, ...) \
do { fprintf(stderr, "smbus: error: " fmt , ## __VA_ARGS__);} while (0)
#endif

enum {
    SMBUS_IDLE,
    SMBUS_WRITE_DATA,
    SMBUS_RECV_BYTE,
    SMBUS_READ_DATA,
    SMBUS_DONE,
    SMBUS_CONFUSED = -1
};

static void smbus_do_quick_cmd(SMBusDevice *dev, int recv)
{
    SMBusDeviceInfo *t = container_of(dev->i2c.info, SMBusDeviceInfo, i2c);

    DPRINTF("Quick Command %d\n", recv);
    if (t->quick_cmd)
        t->quick_cmd(dev, recv);
}

static void smbus_do_write(SMBusDevice *dev)
{
    SMBusDeviceInfo *t = container_of(dev->i2c.info, SMBusDeviceInfo, i2c);

    if (dev->data_len == 0) {
        smbus_do_quick_cmd(dev, 0);
    } else if (dev->data_len == 1) {
        DPRINTF("Send Byte\n");
        if (t->send_byte) {
            t->send_byte(dev, dev->data_buf[0]);
        }
    } else {
        dev->command = dev->data_buf[0];
        DPRINTF("Command %d len %d\n", dev->command, dev->data_len - 1);
        if (t->write_data) {
            t->write_data(dev, dev->command, dev->data_buf + 1,
                          dev->data_len - 1);
        }
    }
}

static void smbus_i2c_event(i2c_slave *s, enum i2c_event event)
{
    SMBusDevice *dev = FROM_I2C_SLAVE(SMBusDevice, s);

    switch (event) {
    case I2C_START_SEND:
        switch (dev->mode) {
        case SMBUS_IDLE:
            DPRINTF("Incoming data\n");
            dev->mode = SMBUS_WRITE_DATA;
            break;
        default:
            BADF("Unexpected send start condition in state %d\n", dev->mode);
            dev->mode = SMBUS_CONFUSED;
            break;
        }
        break;

    case I2C_START_RECV:
        switch (dev->mode) {
        case SMBUS_IDLE:
            DPRINTF("Read mode\n");
            dev->mode = SMBUS_RECV_BYTE;
            break;
        case SMBUS_WRITE_DATA:
            if (dev->data_len == 0) {
                BADF("Read after write with no data\n");
                dev->mode = SMBUS_CONFUSED;
            } else {
                if (dev->data_len > 1) {
                    smbus_do_write(dev);
                } else {
                    dev->command = dev->data_buf[0];
                    DPRINTF("%02x: Command %d\n", dev->i2c.address,
                            dev->command);
                }
                DPRINTF("Read mode\n");
                dev->data_len = 0;
                dev->mode = SMBUS_READ_DATA;
            }
            break;
        default:
            BADF("Unexpected recv start condition in state %d\n", dev->mode);
            dev->mode = SMBUS_CONFUSED;
            break;
        }
        break;

    case I2C_FINISH:
        switch (dev->mode) {
        case SMBUS_WRITE_DATA:
            smbus_do_write(dev);
            break;
        case SMBUS_RECV_BYTE:
            smbus_do_quick_cmd(dev, 1);
            break;
        case SMBUS_READ_DATA:
            BADF("Unexpected stop during receive\n");
            break;
        default:
            /* Nothing to do.  */
            break;
        }
        dev->mode = SMBUS_IDLE;
        dev->data_len = 0;
        break;

    case I2C_NACK:
        switch (dev->mode) {
        case SMBUS_DONE:
            /* Nothing to do.  */
            break;
        case SMBUS_READ_DATA:
            dev->mode = SMBUS_DONE;
            break;
        default:
            BADF("Unexpected NACK in state %d\n", dev->mode);
            dev->mode = SMBUS_CONFUSED;
            break;
        }
    }
}

static int smbus_i2c_recv(i2c_slave *s)
{
    SMBusDeviceInfo *t = container_of(s->info, SMBusDeviceInfo, i2c);
    SMBusDevice *dev = FROM_I2C_SLAVE(SMBusDevice, s);
    int ret;

    switch (dev->mode) {
    case SMBUS_RECV_BYTE:
        if (t->receive_byte) {
            ret = t->receive_byte(dev);
        } else {
            ret = 0;
        }
        DPRINTF("Receive Byte %02x\n", ret);
        dev->mode = SMBUS_DONE;
        break;
    case SMBUS_READ_DATA:
        if (t->read_data) {
            ret = t->read_data(dev, dev->command, dev->data_len);
            dev->data_len++;
        } else {
            ret = 0;
        }
        DPRINTF("Read data %02x\n", ret);
        break;
    default:
        BADF("Unexpected read in state %d\n", dev->mode);
        dev->mode = SMBUS_CONFUSED;
        ret = 0;
        break;
    }
    return ret;
}

static int smbus_i2c_send(i2c_slave *s, uint8_t data)
{
    SMBusDevice *dev = FROM_I2C_SLAVE(SMBusDevice, s);

    switch (dev->mode) {
    case SMBUS_WRITE_DATA:
        DPRINTF("Write data %02x\n", data);
        dev->data_buf[dev->data_len++] = data;
        break;
    default:
        BADF("Unexpected write in state %d\n", dev->mode);
        break;
    }
    return 0;
}

static int smbus_device_init(i2c_slave *i2c)
{
    SMBusDeviceInfo *t = container_of(i2c->info, SMBusDeviceInfo, i2c);
    SMBusDevice *dev = FROM_I2C_SLAVE(SMBusDevice, i2c);

    return t->init(dev);
}

void smbus_register_device(SMBusDeviceInfo *info)
{
    assert(info->i2c.qdev.size >= sizeof(SMBusDevice));
    info->i2c.init = smbus_device_init;
    info->i2c.event = smbus_i2c_event;
    info->i2c.recv = smbus_i2c_recv;
    info->i2c.send = smbus_i2c_send;
    i2c_register_slave(&info->i2c);
}

/* Master device commands.  */
void smbus_quick_command(i2c_bus *bus, uint8_t addr, int read)
{
    i2c_start_transfer(bus, addr, read);
    i2c_end_transfer(bus);
}

uint8_t smbus_receive_byte(i2c_bus *bus, uint8_t addr)
{
    uint8_t data;

    i2c_start_transfer(bus, addr, 1);
    data = i2c_recv(bus);
    i2c_nack(bus);
    i2c_end_transfer(bus);
    return data;
}

void smbus_send_byte(i2c_bus *bus, uint8_t addr, uint8_t data)
{
    i2c_start_transfer(bus, addr, 0);
    i2c_send(bus, data);
    i2c_end_transfer(bus);
}

uint8_t smbus_read_byte(i2c_bus *bus, uint8_t addr, uint8_t command)
{
    uint8_t data;
    i2c_start_transfer(bus, addr, 0);
    i2c_send(bus, command);
    i2c_start_transfer(bus, addr, 1);
    data = i2c_recv(bus);
    i2c_nack(bus);
    i2c_end_transfer(bus);
    return data;
}

void smbus_write_byte(i2c_bus *bus, uint8_t addr, uint8_t command, uint8_t data)
{
    i2c_start_transfer(bus, addr, 0);
    i2c_send(bus, command);
    i2c_send(bus, data);
    i2c_end_transfer(bus);
}

uint16_t smbus_read_word(i2c_bus *bus, uint8_t addr, uint8_t command)
{
    uint16_t data;
    i2c_start_transfer(bus, addr, 0);
    i2c_send(bus, command);
    i2c_start_transfer(bus, addr, 1);
    data = i2c_recv(bus);
    data |= i2c_recv(bus) << 8;
    i2c_nack(bus);
    i2c_end_transfer(bus);
    return data;
}

void smbus_write_word(i2c_bus *bus, uint8_t addr, uint8_t command, uint16_t data)
{
    i2c_start_transfer(bus, addr, 0);
    i2c_send(bus, command);
    i2c_send(bus, data & 0xff);
    i2c_send(bus, data >> 8);
    i2c_end_transfer(bus);
}

int smbus_read_block(i2c_bus *bus, uint8_t addr, uint8_t command, uint8_t *data)
{
    int len;
    int i;

    i2c_start_transfer(bus, addr, 0);
    i2c_send(bus, command);
    i2c_start_transfer(bus, addr, 1);
    len = i2c_recv(bus);
    if (len > 32)
        len = 0;
    for (i = 0; i < len; i++)
        data[i] = i2c_recv(bus);
    i2c_nack(bus);
    i2c_end_transfer(bus);
    return len;
}

void smbus_write_block(i2c_bus *bus, uint8_t addr, uint8_t command, uint8_t *data,
                       int len)
{
    int i;

    if (len > 32)
        len = 32;

    i2c_start_transfer(bus, addr, 0);
    i2c_send(bus, command);
    i2c_send(bus, len);
    for (i = 0; i < len; i++)
        i2c_send(bus, data[i]);
    i2c_end_transfer(bus);
}
Commit	Line	Data
5fafdf24	1	/*
0ff596d0 PB	2	* QEMU SMBus device emulation.
	3	*
	4	* Copyright (c) 2007 CodeSourcery.
	5	* Written by Paul Brook
	6	*
	7	* This code is licenced under the LGPL.
	8	*/
	9
	10	/* TODO: Implement PEC. */
	11
87ecb68b PB	12	#include "hw.h"
	13	#include "i2c.h"
	14	#include "smbus.h"
0ff596d0 PB	15
	16	//#define DEBUG_SMBUS 1
	17
	18	#ifdef DEBUG_SMBUS
001faf32 BS	19	#define DPRINTF(fmt, ...) \
	20	do { printf("smbus(%02x): " fmt , dev->i2c.address, ## __VA_ARGS__); } while (0)
	21	#define BADF(fmt, ...) \
	22	do { fprintf(stderr, "smbus: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
0ff596d0	23	#else
001faf32 BS	24	#define DPRINTF(fmt, ...) do {} while(0)
	25	#define BADF(fmt, ...) \
	26	do { fprintf(stderr, "smbus: error: " fmt , ## __VA_ARGS__);} while (0)
0ff596d0 PB	27	#endif
	28
	29	enum {
	30	SMBUS_IDLE,
	31	SMBUS_WRITE_DATA,
	32	SMBUS_RECV_BYTE,
	33	SMBUS_READ_DATA,
	34	SMBUS_DONE,
	35	SMBUS_CONFUSED = -1
	36	};
	37
	38	static void smbus_do_quick_cmd(SMBusDevice *dev, int recv)
	39	{
1ea96673 PB	40	SMBusDeviceInfo *t = container_of(dev->i2c.info, SMBusDeviceInfo, i2c);
1ea96673 PB	41
0ff596d0	42	DPRINTF("Quick Command %d\n", recv);
1ea96673 PB	43	if (t->quick_cmd)
1ea96673 PB	44	t->quick_cmd(dev, recv);
0ff596d0 PB	45	}
	46
	47	static void smbus_do_write(SMBusDevice *dev)
	48	{
1ea96673 PB	49	SMBusDeviceInfo *t = container_of(dev->i2c.info, SMBusDeviceInfo, i2c);
1ea96673 PB	50
0ff596d0 PB	51	if (dev->data_len == 0) {
	52	smbus_do_quick_cmd(dev, 0);
	53	} else if (dev->data_len == 1) {
	54	DPRINTF("Send Byte\n");
1ea96673 PB	55	if (t->send_byte) {
1ea96673 PB	56	t->send_byte(dev, dev->data_buf[0]);
0ff596d0 PB	57	}
	58	} else {
	59	dev->command = dev->data_buf[0];
	60	DPRINTF("Command %d len %d\n", dev->command, dev->data_len - 1);
1ea96673 PB	61	if (t->write_data) {
	62	t->write_data(dev, dev->command, dev->data_buf + 1,
	63	dev->data_len - 1);
0ff596d0 PB	64	}
	65	}
	66	}
	67
9596ebb7	68	static void smbus_i2c_event(i2c_slave *s, enum i2c_event event)
0ff596d0	69	{
1ea96673 PB	70	SMBusDevice *dev = FROM_I2C_SLAVE(SMBusDevice, s);
1ea96673 PB	71
0ff596d0 PB	72	switch (event) {
	73	case I2C_START_SEND:
	74	switch (dev->mode) {
	75	case SMBUS_IDLE:
	76	DPRINTF("Incoming data\n");
	77	dev->mode = SMBUS_WRITE_DATA;
	78	break;
	79	default:
	80	BADF("Unexpected send start condition in state %d\n", dev->mode);
	81	dev->mode = SMBUS_CONFUSED;
	82	break;
	83	}
	84	break;
	85
	86	case I2C_START_RECV:
	87	switch (dev->mode) {
	88	case SMBUS_IDLE:
	89	DPRINTF("Read mode\n");
	90	dev->mode = SMBUS_RECV_BYTE;
	91	break;
	92	case SMBUS_WRITE_DATA:
	93	if (dev->data_len == 0) {
	94	BADF("Read after write with no data\n");
	95	dev->mode = SMBUS_CONFUSED;
	96	} else {
	97	if (dev->data_len > 1) {
	98	smbus_do_write(dev);
	99	} else {
	100	dev->command = dev->data_buf[0];
	101	DPRINTF("%02x: Command %d\n", dev->i2c.address,
	102	dev->command);
	103	}
	104	DPRINTF("Read mode\n");
	105	dev->data_len = 0;
	106	dev->mode = SMBUS_READ_DATA;
	107	}
	108	break;
	109	default:
	110	BADF("Unexpected recv start condition in state %d\n", dev->mode);
	111	dev->mode = SMBUS_CONFUSED;
	112	break;
	113	}
	114	break;
	115
	116	case I2C_FINISH:
	117	switch (dev->mode) {
	118	case SMBUS_WRITE_DATA:
	119	smbus_do_write(dev);
	120	break;
	121	case SMBUS_RECV_BYTE:
	122	smbus_do_quick_cmd(dev, 1);
	123	break;
	124	case SMBUS_READ_DATA:
	125	BADF("Unexpected stop during receive\n");
	126	break;
	127	default:
	128	/* Nothing to do. */
	129	break;
	130	}
	131	dev->mode = SMBUS_IDLE;
	132	dev->data_len = 0;
	133	break;
	134
	135	case I2C_NACK:
136	switch (dev->mode) {
137	case SMBUS_DONE:
138	/* Nothing to do. */
139	break;
140	case SMBUS_READ_DATA:
141	dev->mode = SMBUS_DONE;
142	break;
143	default:
144	BADF("Unexpected NACK in state %d\n", dev->mode);
145	dev->mode = SMBUS_CONFUSED;
146	break;
147	}
148	}
149	}
150
151	static int smbus_i2c_recv(i2c_slave *s)
152	{
1ea96673 PB	153	SMBusDeviceInfo *t = container_of(s->info, SMBusDeviceInfo, i2c);
1ea96673 PB	154	SMBusDevice *dev = FROM_I2C_SLAVE(SMBusDevice, s);
0ff596d0 PB	155	int ret;
	156
	157	switch (dev->mode) {
	158	case SMBUS_RECV_BYTE:
1ea96673 PB	159	if (t->receive_byte) {
1ea96673 PB	160	ret = t->receive_byte(dev);
0ff596d0 PB	161	} else {
	162	ret = 0;
	163	}
	164	DPRINTF("Receive Byte %02x\n", ret);
	165	dev->mode = SMBUS_DONE;
	166	break;
	167	case SMBUS_READ_DATA:
1ea96673 PB	168	if (t->read_data) {
1ea96673 PB	169	ret = t->read_data(dev, dev->command, dev->data_len);
0ff596d0 PB	170	dev->data_len++;
	171	} else {
	172	ret = 0;
	173	}
	174	DPRINTF("Read data %02x\n", ret);
	175	break;
	176	default:
	177	BADF("Unexpected read in state %d\n", dev->mode);
	178	dev->mode = SMBUS_CONFUSED;
	179	ret = 0;
	180	break;
	181	}
	182	return ret;
	183	}
	184
	185	static int smbus_i2c_send(i2c_slave *s, uint8_t data)
	186	{
1ea96673 PB	187	SMBusDevice *dev = FROM_I2C_SLAVE(SMBusDevice, s);
1ea96673 PB	188
0ff596d0 PB	189	switch (dev->mode) {
	190	case SMBUS_WRITE_DATA:
	191	DPRINTF("Write data %02x\n", data);
	192	dev->data_buf[dev->data_len++] = data;
	193	break;
	194	default:
	195	BADF("Unexpected write in state %d\n", dev->mode);
	196	break;
	197	}
	198	return 0;
	199	}
	200
81a322d4	201	static int smbus_device_init(i2c_slave *i2c)
0ff596d0	202	{
1ea96673 PB	203	SMBusDeviceInfo *t = container_of(i2c->info, SMBusDeviceInfo, i2c);
1ea96673 PB	204	SMBusDevice *dev = FROM_I2C_SLAVE(SMBusDevice, i2c);
0ff596d0	205
81a322d4	206	return t->init(dev);
1ea96673	207	}
0ff596d0	208
074f2fff	209	void smbus_register_device(SMBusDeviceInfo *info)
1ea96673	210	{
074f2fff	211	assert(info->i2c.qdev.size >= sizeof(SMBusDevice));
1ea96673 PB	212	info->i2c.init = smbus_device_init;
	213	info->i2c.event = smbus_i2c_event;
	214	info->i2c.recv = smbus_i2c_recv;
	215	info->i2c.send = smbus_i2c_send;
074f2fff	216	i2c_register_slave(&info->i2c);
0ff596d0 PB	217	}
	218
	219	/* Master device commands. */
5b7f5327	220	void smbus_quick_command(i2c_bus *bus, uint8_t addr, int read)
0ff596d0 PB	221	{
	222	i2c_start_transfer(bus, addr, read);
	223	i2c_end_transfer(bus);
	224	}
	225
5b7f5327	226	uint8_t smbus_receive_byte(i2c_bus *bus, uint8_t addr)
0ff596d0 PB	227	{
	228	uint8_t data;
	229
	230	i2c_start_transfer(bus, addr, 1);
	231	data = i2c_recv(bus);
	232	i2c_nack(bus);
	233	i2c_end_transfer(bus);
	234	return data;
	235	}
	236
5b7f5327	237	void smbus_send_byte(i2c_bus *bus, uint8_t addr, uint8_t data)
0ff596d0 PB	238	{
	239	i2c_start_transfer(bus, addr, 0);
	240	i2c_send(bus, data);
	241	i2c_end_transfer(bus);
	242	}
	243
5b7f5327	244	uint8_t smbus_read_byte(i2c_bus *bus, uint8_t addr, uint8_t command)
0ff596d0 PB	245	{
	246	uint8_t data;
	247	i2c_start_transfer(bus, addr, 0);
	248	i2c_send(bus, command);
	249	i2c_start_transfer(bus, addr, 1);
	250	data = i2c_recv(bus);
	251	i2c_nack(bus);
	252	i2c_end_transfer(bus);
	253	return data;
	254	}
	255
5b7f5327	256	void smbus_write_byte(i2c_bus *bus, uint8_t addr, uint8_t command, uint8_t data)
0ff596d0 PB	257	{
	258	i2c_start_transfer(bus, addr, 0);
	259	i2c_send(bus, command);
	260	i2c_send(bus, data);
	261	i2c_end_transfer(bus);
	262	}
	263
5b7f5327	264	uint16_t smbus_read_word(i2c_bus *bus, uint8_t addr, uint8_t command)
0ff596d0 PB	265	{
	266	uint16_t data;
	267	i2c_start_transfer(bus, addr, 0);
	268	i2c_send(bus, command);
	269	i2c_start_transfer(bus, addr, 1);
	270	data = i2c_recv(bus);
	271	data \|= i2c_recv(bus) << 8;
	272	i2c_nack(bus);
	273	i2c_end_transfer(bus);
	274	return data;
	275	}
	276
5b7f5327	277	void smbus_write_word(i2c_bus *bus, uint8_t addr, uint8_t command, uint16_t data)
0ff596d0 PB	278	{
	279	i2c_start_transfer(bus, addr, 0);
	280	i2c_send(bus, command);
	281	i2c_send(bus, data & 0xff);
	282	i2c_send(bus, data >> 8);
	283	i2c_end_transfer(bus);
	284	}
	285
5b7f5327	286	int smbus_read_block(i2c_bus bus, uint8_t addr, uint8_t command, uint8_t data)
0ff596d0 PB	287	{
	288	int len;
	289	int i;
	290
	291	i2c_start_transfer(bus, addr, 0);
	292	i2c_send(bus, command);
	293	i2c_start_transfer(bus, addr, 1);
	294	len = i2c_recv(bus);
	295	if (len > 32)
	296	len = 0;
	297	for (i = 0; i < len; i++)
	298	data[i] = i2c_recv(bus);
	299	i2c_nack(bus);
	300	i2c_end_transfer(bus);
	301	return len;
	302	}
	303
5b7f5327	304	void smbus_write_block(i2c_bus bus, uint8_t addr, uint8_t command, uint8_t data,
0ff596d0 PB	305	int len)
	306	{
	307	int i;
	308
	309	if (len > 32)
	310	len = 32;
	311
	312	i2c_start_transfer(bus, addr, 0);
	313	i2c_send(bus, command);
	314	i2c_send(bus, len);
	315	for (i = 0; i < len; i++)
	316	i2c_send(bus, data[i]);
	317	i2c_end_transfer(bus);
	318	}