LXR qemu/hw/i2c/smbus

   1/*
   2 * QEMU SMBus host (master) emulation.
   3 *
   4 * This code emulates SMBus transactions from the master point of view,
   5 * it runs the individual I2C transaction to do the SMBus protocol
   6 * over I2C.
   7 *
   8 * Copyright (c) 2007 CodeSourcery.
   9 * Written by Paul Brook
  10 *
  11 * This code is licensed under the LGPL.
  12 */
  13
  14#include "qemu/osdep.h"
  15#include "hw/i2c/i2c.h"
  16#include "hw/i2c/smbus_master.h"
  17
  18/* Master device commands.  */
  19int smbus_quick_command(I2CBus *bus, uint8_t addr, int read)
  20{
  21    if (i2c_start_transfer(bus, addr, read)) {
  22        return -1;
  23    }
  24    i2c_end_transfer(bus);
  25    return 0;
  26}
  27
  28int smbus_receive_byte(I2CBus *bus, uint8_t addr)
  29{
  30    uint8_t data;
  31
  32    if (i2c_start_transfer(bus, addr, 1)) {
  33        return -1;
  34    }
  35    data = i2c_recv(bus);
  36    i2c_nack(bus);
  37    i2c_end_transfer(bus);
  38    return data;
  39}
  40
  41int smbus_send_byte(I2CBus *bus, uint8_t addr, uint8_t data)
  42{
  43    if (i2c_start_transfer(bus, addr, 0)) {
  44        return -1;
  45    }
  46    i2c_send(bus, data);
  47    i2c_end_transfer(bus);
  48    return 0;
  49}
  50
  51int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command)
  52{
  53    uint8_t data;
  54    if (i2c_start_transfer(bus, addr, 0)) {
  55        return -1;
  56    }
  57    i2c_send(bus, command);
  58    if (i2c_start_transfer(bus, addr, 1)) {
  59        i2c_end_transfer(bus);
  60        return -1;
  61    }
  62    data = i2c_recv(bus);
  63    i2c_nack(bus);
  64    i2c_end_transfer(bus);
  65    return data;
  66}
  67
  68int smbus_write_byte(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t data)
  69{
  70    if (i2c_start_transfer(bus, addr, 0)) {
  71        return -1;
  72    }
  73    i2c_send(bus, command);
  74    i2c_send(bus, data);
  75    i2c_end_transfer(bus);
  76    return 0;
  77}
  78
  79int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command)
  80{
  81    uint16_t data;
  82    if (i2c_start_transfer(bus, addr, 0)) {
  83        return -1;
  84    }
  85    i2c_send(bus, command);
  86    if (i2c_start_transfer(bus, addr, 1)) {
  87        i2c_end_transfer(bus);
  88        return -1;
  89    }
  90    data = i2c_recv(bus);
  91    data |= i2c_recv(bus) << 8;
  92    i2c_nack(bus);
  93    i2c_end_transfer(bus);
  94    return data;
  95}
  96
  97int smbus_write_word(I2CBus *bus, uint8_t addr, uint8_t command, uint16_t data)
  98{
  99    if (i2c_start_transfer(bus, addr, 0)) {
 100        return -1;
 101    }
 102    i2c_send(bus, command);
 103    i2c_send(bus, data & 0xff);
 104    i2c_send(bus, data >> 8);
 105    i2c_end_transfer(bus);
 106    return 0;
 107}
 108
 109int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
 110                     int len, bool recv_len, bool send_cmd)
 111{
 112    int rlen;
 113    int i;
 114
 115    if (send_cmd) {
 116        if (i2c_start_transfer(bus, addr, 0)) {
 117            return -1;
 118        }
 119        i2c_send(bus, command);
 120    }
 121    if (i2c_start_transfer(bus, addr, 1)) {
 122        if (send_cmd) {
 123            i2c_end_transfer(bus);
 124        }
 125        return -1;
 126    }
 127    if (recv_len) {
 128        rlen = i2c_recv(bus);
 129    } else {
 130        rlen = len;
 131    }
 132    if (rlen > len) {
 133        rlen = 0;
 134    }
 135    for (i = 0; i < rlen; i++) {
 136        data[i] = i2c_recv(bus);
 137    }
 138    i2c_nack(bus);
 139    i2c_end_transfer(bus);
 140    return rlen;
 141}
 142
 143int smbus_write_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
 144                      int len, bool send_len)
 145{
 146    int i;
 147
 148    if (len > 32) {
 149        len = 32;
 150    }
 151
 152    if (i2c_start_transfer(bus, addr, 0)) {
 153        return -1;
 154    }
 155    i2c_send(bus, command);
 156    if (send_len) {
 157        i2c_send(bus, len);
 158    }
 159    for (i = 0; i < len; i++) {
 160        i2c_send(bus, data[i]);
 161    }
 162    i2c_end_transfer(bus);
 163    return 0;
 164}
 165