From 0ff596d02fd9d876a31d038255a6d4f89da9dfed Mon Sep 17 00:00:00 2001 From: pbrook Date: Wed, 23 May 2007 00:03:59 +0000 Subject: I2C/SMBus framework. git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2845 c046a42c-6fe2-441c-8c8c-71466251a162 --- hw/smbus.c | 303 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 303 insertions(+) create mode 100644 hw/smbus.c (limited to 'hw/smbus.c') diff --git a/hw/smbus.c b/hw/smbus.c new file mode 100644 index 0000000000..651a7a0b97 --- /dev/null +++ b/hw/smbus.c @@ -0,0 +1,303 @@ +/* + * QEMU SMBus device emulation. + * + * Copyright (c) 2007 CodeSourcery. + * Written by Paul Brook + * + * This code is licenced under the LGPL. + */ + +/* TODO: Implement PEC. */ + +#include "vl.h" + +//#define DEBUG_SMBUS 1 + +#ifdef DEBUG_SMBUS +#define DPRINTF(fmt, args...) \ +do { printf("smbus(%02x): " fmt , dev->i2c.address, ##args); } while (0) +#define BADF(fmt, args...) \ +do { fprintf(stderr, "smbus: error: " fmt , ##args); exit(1);} while (0) +#else +#define DPRINTF(fmt, args...) do {} while(0) +#define BADF(fmt, args...) \ +do { fprintf(stderr, "smbus: error: " fmt , ##args);} while (0) +#endif + +enum { + SMBUS_IDLE, + SMBUS_WRITE_DATA, + SMBUS_RECV_BYTE, + SMBUS_READ_DATA, + SMBUS_DONE, + SMBUS_CONFUSED = -1 +}; + +static void smbus_do_quick_cmd(SMBusDevice *dev, int recv) +{ + DPRINTF("Quick Command %d\n", recv); + if (dev->quick_cmd) + dev->quick_cmd(dev, recv); +} + +static void smbus_do_write(SMBusDevice *dev) +{ + if (dev->data_len == 0) { + smbus_do_quick_cmd(dev, 0); + } else if (dev->data_len == 1) { + DPRINTF("Send Byte\n"); + if (dev->send_byte) { + dev->send_byte(dev, dev->data_buf[0]); + } + } else { + dev->command = dev->data_buf[0]; + DPRINTF("Command %d len %d\n", dev->command, dev->data_len - 1); + if (dev->write_data) { + dev->write_data(dev, dev->command, dev->data_buf + 1, + dev->data_len - 1); + } + } +} + +void smbus_i2c_event(i2c_slave *s, enum i2c_event event) +{ + SMBusDevice *dev = (SMBusDevice *)s; + switch (event) { + case I2C_START_SEND: + switch (dev->mode) { + case SMBUS_IDLE: + DPRINTF("Incoming data\n"); + dev->mode = SMBUS_WRITE_DATA; + break; + default: + BADF("Unexpected send start condition in state %d\n", dev->mode); + dev->mode = SMBUS_CONFUSED; + break; + } + break; + + case I2C_START_RECV: + switch (dev->mode) { + case SMBUS_IDLE: + DPRINTF("Read mode\n"); + dev->mode = SMBUS_RECV_BYTE; + break; + case SMBUS_WRITE_DATA: + if (dev->data_len == 0) { + BADF("Read after write with no data\n"); + dev->mode = SMBUS_CONFUSED; + } else { + if (dev->data_len > 1) { + smbus_do_write(dev); + } else { + dev->command = dev->data_buf[0]; + DPRINTF("%02x: Command %d\n", dev->i2c.address, + dev->command); + } + DPRINTF("Read mode\n"); + dev->data_len = 0; + dev->mode = SMBUS_READ_DATA; + } + break; + default: + BADF("Unexpected recv start condition in state %d\n", dev->mode); + dev->mode = SMBUS_CONFUSED; + break; + } + break; + + case I2C_FINISH: + switch (dev->mode) { + case SMBUS_WRITE_DATA: + smbus_do_write(dev); + break; + case SMBUS_RECV_BYTE: + smbus_do_quick_cmd(dev, 1); + break; + case SMBUS_READ_DATA: + BADF("Unexpected stop during receive\n"); + break; + default: + /* Nothing to do. */ + break; + } + dev->mode = SMBUS_IDLE; + dev->data_len = 0; + break; + + case I2C_NACK: + switch (dev->mode) { + case SMBUS_DONE: + /* Nothing to do. */ + break; + case SMBUS_READ_DATA: + dev->mode = SMBUS_DONE; + break; + default: + BADF("Unexpected NACK in state %d\n", dev->mode); + dev->mode = SMBUS_CONFUSED; + break; + } + } +} + +static int smbus_i2c_recv(i2c_slave *s) +{ + SMBusDevice *dev = (SMBusDevice *)s; + int ret; + + switch (dev->mode) { + case SMBUS_RECV_BYTE: + if (dev->receive_byte) { + ret = dev->receive_byte(dev); + } else { + ret = 0; + } + DPRINTF("Receive Byte %02x\n", ret); + dev->mode = SMBUS_DONE; + break; + case SMBUS_READ_DATA: + if (dev->read_data) { + ret = dev->read_data(dev, dev->command, dev->data_len); + dev->data_len++; + } else { + ret = 0; + } + DPRINTF("Read data %02x\n", ret); + break; + default: + BADF("Unexpected read in state %d\n", dev->mode); + dev->mode = SMBUS_CONFUSED; + ret = 0; + break; + } + return ret; +} + +static int smbus_i2c_send(i2c_slave *s, uint8_t data) +{ + SMBusDevice *dev = (SMBusDevice *)s; + switch (dev->mode) { + case SMBUS_WRITE_DATA: + DPRINTF("Write data %02x\n", data); + dev->data_buf[dev->data_len++] = data; + break; + default: + BADF("Unexpected write in state %d\n", dev->mode); + break; + } + return 0; +} + +SMBusDevice *smbus_device_init(i2c_bus *bus, int address, int size) +{ + SMBusDevice *dev; + + dev = (SMBusDevice *)i2c_slave_init(bus, address, size); + dev->i2c.event = smbus_i2c_event; + dev->i2c.recv = smbus_i2c_recv; + dev->i2c.send = smbus_i2c_send; + + return dev; +} + +/* Master device commands. */ +void smbus_quick_command(i2c_bus *bus, int addr, int read) +{ + i2c_start_transfer(bus, addr, read); + i2c_end_transfer(bus); +} + +uint8_t smbus_receive_byte(i2c_bus *bus, int addr) +{ + uint8_t data; + + i2c_start_transfer(bus, addr, 1); + data = i2c_recv(bus); + i2c_nack(bus); + i2c_end_transfer(bus); + return data; +} + +void smbus_send_byte(i2c_bus *bus, int addr, uint8_t data) +{ + i2c_start_transfer(bus, addr, 0); + i2c_send(bus, data); + i2c_end_transfer(bus); +} + +uint8_t smbus_read_byte(i2c_bus *bus, int addr, uint8_t command) +{ + uint8_t data; + i2c_start_transfer(bus, addr, 0); + i2c_send(bus, command); + i2c_start_transfer(bus, addr, 1); + data = i2c_recv(bus); + i2c_nack(bus); + i2c_end_transfer(bus); + return data; +} + +void smbus_write_byte(i2c_bus *bus, int addr, uint8_t command, uint8_t data) +{ + i2c_start_transfer(bus, addr, 0); + i2c_send(bus, command); + i2c_send(bus, data); + i2c_end_transfer(bus); +} + +uint16_t smbus_read_word(i2c_bus *bus, int addr, uint8_t command) +{ + uint16_t data; + i2c_start_transfer(bus, addr, 0); + i2c_send(bus, command); + i2c_start_transfer(bus, addr, 1); + data = i2c_recv(bus); + data |= i2c_recv(bus) << 8; + i2c_nack(bus); + i2c_end_transfer(bus); + return data; +} + +void smbus_write_word(i2c_bus *bus, int addr, uint8_t command, uint16_t data) +{ + i2c_start_transfer(bus, addr, 0); + i2c_send(bus, command); + i2c_send(bus, data & 0xff); + i2c_send(bus, data >> 8); + i2c_end_transfer(bus); +} + +int smbus_read_block(i2c_bus *bus, int addr, uint8_t command, uint8_t *data) +{ + int len; + int i; + + i2c_start_transfer(bus, addr, 0); + i2c_send(bus, command); + i2c_start_transfer(bus, addr, 1); + len = i2c_recv(bus); + if (len > 32) + len = 0; + for (i = 0; i < len; i++) + data[i] = i2c_recv(bus); + i2c_nack(bus); + i2c_end_transfer(bus); + return len; +} + +void smbus_write_block(i2c_bus *bus, int addr, uint8_t command, uint8_t *data, + int len) +{ + int i; + + if (len > 32) + len = 32; + + i2c_start_transfer(bus, addr, 0); + i2c_send(bus, command); + i2c_send(bus, len); + for (i = 0; i < len; i++) + i2c_send(bus, data[i]); + i2c_end_transfer(bus); +} -- cgit v1.2.3