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 } 166