diff options
Diffstat (limited to 'hw/i2c/smbus_master.c')
-rw-r--r-- | hw/i2c/smbus_master.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/hw/i2c/smbus_master.c b/hw/i2c/smbus_master.c new file mode 100644 index 0000000000..0a6223744c --- /dev/null +++ b/hw/i2c/smbus_master.c @@ -0,0 +1,165 @@ +/* + * QEMU SMBus host (master) emulation. + * + * This code emulates SMBus transactions from the master point of view, + * it runs the individual I2C transaction to do the SMBus protocol + * over I2C. + * + * Copyright (c) 2007 CodeSourcery. + * Written by Paul Brook + * + * This code is licensed under the LGPL. + */ + +#include "qemu/osdep.h" +#include "hw/hw.h" +#include "hw/i2c/i2c.h" +#include "hw/i2c/smbus_master.h" + +/* Master device commands. */ +int smbus_quick_command(I2CBus *bus, uint8_t addr, int read) +{ + if (i2c_start_transfer(bus, addr, read)) { + return -1; + } + i2c_end_transfer(bus); + return 0; +} + +int smbus_receive_byte(I2CBus *bus, uint8_t addr) +{ + uint8_t data; + + if (i2c_start_transfer(bus, addr, 1)) { + return -1; + } + data = i2c_recv(bus); + i2c_nack(bus); + i2c_end_transfer(bus); + return data; +} + +int smbus_send_byte(I2CBus *bus, uint8_t addr, uint8_t data) +{ + if (i2c_start_transfer(bus, addr, 0)) { + return -1; + } + i2c_send(bus, data); + i2c_end_transfer(bus); + return 0; +} + +int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command) +{ + uint8_t data; + if (i2c_start_transfer(bus, addr, 0)) { + return -1; + } + i2c_send(bus, command); + if (i2c_start_transfer(bus, addr, 1)) { + i2c_end_transfer(bus); + return -1; + } + data = i2c_recv(bus); + i2c_nack(bus); + i2c_end_transfer(bus); + return data; +} + +int smbus_write_byte(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t data) +{ + if (i2c_start_transfer(bus, addr, 0)) { + return -1; + } + i2c_send(bus, command); + i2c_send(bus, data); + i2c_end_transfer(bus); + return 0; +} + +int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command) +{ + uint16_t data; + if (i2c_start_transfer(bus, addr, 0)) { + return -1; + } + i2c_send(bus, command); + if (i2c_start_transfer(bus, addr, 1)) { + i2c_end_transfer(bus); + return -1; + } + data = i2c_recv(bus); + data |= i2c_recv(bus) << 8; + i2c_nack(bus); + i2c_end_transfer(bus); + return data; +} + +int smbus_write_word(I2CBus *bus, uint8_t addr, uint8_t command, uint16_t data) +{ + if (i2c_start_transfer(bus, addr, 0)) { + return -1; + } + i2c_send(bus, command); + i2c_send(bus, data & 0xff); + i2c_send(bus, data >> 8); + i2c_end_transfer(bus); + return 0; +} + +int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data, + int len, bool recv_len, bool send_cmd) +{ + int rlen; + int i; + + if (send_cmd) { + if (i2c_start_transfer(bus, addr, 0)) { + return -1; + } + i2c_send(bus, command); + } + if (i2c_start_transfer(bus, addr, 1)) { + if (send_cmd) { + i2c_end_transfer(bus); + } + return -1; + } + if (recv_len) { + rlen = i2c_recv(bus); + } else { + rlen = len; + } + if (rlen > len) { + rlen = 0; + } + for (i = 0; i < rlen; i++) { + data[i] = i2c_recv(bus); + } + i2c_nack(bus); + i2c_end_transfer(bus); + return rlen; +} + +int smbus_write_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data, + int len, bool send_len) +{ + int i; + + if (len > 32) { + len = 32; + } + + if (i2c_start_transfer(bus, addr, 0)) { + return -1; + } + i2c_send(bus, command); + if (send_len) { + i2c_send(bus, len); + } + for (i = 0; i < len; i++) { + i2c_send(bus, data[i]); + } + i2c_end_transfer(bus); + return 0; +} |