hw/i2c/smbus_master.c

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