qemu

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/*
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 * QEMU SMBus host (master) emulation.
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 *
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 * This code emulates SMBus transactions from the master point of view,
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 * it runs the individual I2C transaction to do the SMBus protocol
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 * over I2C.
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 *
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 * Copyright (c) 2007 CodeSourcery.
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 * Written by Paul Brook
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 *
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 * This code is licensed under the LGPL.
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 */
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#include "qemu/osdep.h"
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#include "hw/i2c/i2c.h"
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#include "hw/i2c/smbus_master.h"
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/* Master device commands.  */
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int smbus_quick_command(I2CBus *bus, uint8_t addr, int read)
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{
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    if (i2c_start_transfer(bus, addr, read)) {
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        return -1;
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    }
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    i2c_end_transfer(bus);
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    return 0;
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}
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int smbus_receive_byte(I2CBus *bus, uint8_t addr)
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{
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    uint8_t data;
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    if (i2c_start_recv(bus, addr)) {
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        return -1;
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    }
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    data = i2c_recv(bus);
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    i2c_nack(bus);
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    i2c_end_transfer(bus);
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    return data;
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}
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int smbus_send_byte(I2CBus *bus, uint8_t addr, uint8_t data)
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{
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    if (i2c_start_send(bus, addr)) {
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        return -1;
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    }
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    i2c_send(bus, data);
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    i2c_end_transfer(bus);
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    return 0;
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}
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int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command)
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{
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    uint8_t data;
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    if (i2c_start_send(bus, addr)) {
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        return -1;
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    }
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    i2c_send(bus, command);
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    if (i2c_start_recv(bus, addr)) {
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        i2c_end_transfer(bus);
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        return -1;
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    }
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    data = i2c_recv(bus);
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    i2c_nack(bus);
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    i2c_end_transfer(bus);
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    return data;
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}
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int smbus_write_byte(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t data)
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{
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    if (i2c_start_send(bus, addr)) {
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        return -1;
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    }
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    i2c_send(bus, command);
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    i2c_send(bus, data);
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    i2c_end_transfer(bus);
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    return 0;
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}
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int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command)
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{
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    uint16_t data;
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    if (i2c_start_send(bus, addr)) {
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        return -1;
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    }
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    i2c_send(bus, command);
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    if (i2c_start_recv(bus, addr)) {
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        i2c_end_transfer(bus);
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        return -1;
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    }
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    data = i2c_recv(bus);
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    data |= i2c_recv(bus) << 8;
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    i2c_nack(bus);
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    i2c_end_transfer(bus);
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    return data;
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}
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int smbus_write_word(I2CBus *bus, uint8_t addr, uint8_t command, uint16_t data)
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{
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    if (i2c_start_send(bus, addr)) {
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        return -1;
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    }
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    i2c_send(bus, command);
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    i2c_send(bus, data & 0xff);
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    i2c_send(bus, data >> 8);
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    i2c_end_transfer(bus);
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    return 0;
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}
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int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
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                     int len, bool recv_len, bool send_cmd)
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{
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    int rlen;
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    int i;
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    if (send_cmd) {
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        if (i2c_start_send(bus, addr)) {
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            return -1;
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        }
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        i2c_send(bus, command);
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    }
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    if (i2c_start_recv(bus, addr)) {
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        if (send_cmd) {
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            i2c_end_transfer(bus);
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        }
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        return -1;
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    }
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    if (recv_len) {
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        rlen = i2c_recv(bus);
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    } else {
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        rlen = len;
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    }
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    if (rlen > len) {
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        rlen = 0;
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    }
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    for (i = 0; i < rlen; i++) {
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        data[i] = i2c_recv(bus);
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    }
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    i2c_nack(bus);
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    i2c_end_transfer(bus);
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    return rlen;
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}
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int smbus_write_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
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                      int len, bool send_len)
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{
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    int i;
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    if (len > 32) {
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        len = 32;
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    }
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    if (i2c_start_send(bus, addr)) {
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        return -1;
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    }
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    i2c_send(bus, command);
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    if (send_len) {
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        i2c_send(bus, len);
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    }
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    for (i = 0; i < len; i++) {
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        i2c_send(bus, data[i]);
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    }
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    i2c_end_transfer(bus);
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    return 0;
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}
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