int i2c_xfer(const imx_i2c_request_t *rq, int dir)
{
uint32_t reg;
uint32_t ret = 0;
uint16_t i2cr;
uint8_t i;
uint8_t data;
uint32_t instance = i2c_get_request_instance(rq);
uint8_t address = (rq->device ? rq->device->address : rq->dev_addr) << 1;
if (rq->buffer_sz == 0 || rq->buffer == NULL) {
debug_printf("Invalid register address size=%x, buffer size=%x, buffer=%x\n",
rq->reg_addr_sz, rq->buffer_sz, (unsigned int)rq->buffer);
return ERR_INVALID_REQUEST;
}
// clear the status register
HW_I2C_I2SR_WR(instance, 0);
// enable the I2C controller
HW_I2C_I2CR_WR(instance, BM_I2C_I2CR_IEN);
// Check if bus is free, if not return error
if (is_bus_free(instance) != 0) {
return -1;
}
// If the request has device info attached and it has a non-zero bit rate, then
// change the clock to the specified rate.
if (rq->device && rq->device->freq)
{
set_i2c_clock(instance, rq->device->freq);
}
// Step 1: Select master mode, assert START signal and also indicate TX mode
HW_I2C_I2CR_WR(instance, BM_I2C_I2CR_IEN | BM_I2C_I2CR_MSTA | BM_I2C_I2CR_MTX);
// make sure bus is busy after the START signal
if (wait_till_busy(instance) != 0) {
debug_printf("1\n");
return -1;
}
// Step 2: send slave address + read/write at the LSB
data = address | I2C_WRITE;
if ((ret = tx_byte(&data, instance)) != 0) {
debug_printf("START TX ERR %d\n", ret);
if (ret == ERR_NO_ACK) {
return ERR_NO_ACK_ON_START;
} else {
return ret;
}
}
// Step 3: send I2C device register address
if (rq->reg_addr_sz > 4) {
debug_printf("Warning register address size %d should less than 4\n", rq->reg_addr_sz);
return ERR_INVALID_REQUEST;
}
reg = rq->reg_addr;
for (i = 0; i < rq->reg_addr_sz; i++, reg >>= 8) {
data = reg & 0xFF;
#if TRACE_I2C
debug_printf("sending I2C=%d device register: data=0x%x, byte %d\n", instance, data, i);
#endif // TRACE_I2C
if (tx_byte(&data, instance) != 0) {
return -1;
}
}
// Step 4: read/write data
if (dir == I2C_READ) {
// do repeat-start
HW_I2C_I2CR(instance).B.RSTA = 1;
// make sure bus is busy after the REPEATED START signal
if (wait_till_busy(instance) != 0) {
return ERR_TX;
}
// send slave address again, but indicate read operation
data = address | I2C_READ;
if (tx_byte(&data, instance) != 0) {
return -1;
}
// change to receive mode
i2cr = HW_I2C_I2CR_RD(instance) & ~BM_I2C_I2CR_MTX;
// if only one byte to read, make sure don't send ack
if (rq->buffer_sz == 1) {
i2cr |= BM_I2C_I2CR_TXAK;
}
HW_I2C_I2CR_WR(instance, i2cr);
// dummy read
data = HW_I2C_I2DR_RD(instance);
// now reading ...
if (rx_bytes(rq->buffer, instance, rq->buffer_sz) != 0) {
return -1;
}
} else {
// I2C_WRITE
for (i = 0; i < rq->buffer_sz; i++) {
// send device register value
data = rq->buffer[i];
if ((ret = tx_byte(&data, instance)) != 0) {
break;
}
}
}
// generate STOP by clearing MSTA bit
imx_send_stop(instance);
// Check if bus is free, if not return error
if (is_bus_free(instance) != 0) {
debug_printf("WARNING: bus is not free\n");
}
// disable the controller
HW_I2C_I2CR_WR(instance, 0);
return ret;
}
int main(int argc, char *argv[])
{
int sockfd;
struct addrinfo hints, *servinfo, *p;
int rv;
int numbytes;
struct sockaddr_storage their_addr;
char buf[MAXBUFLEN];
socklen_t addr_len;
char s[INET6_ADDRSTRLEN];
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC; // set to AF_INET to force IPv4
hints.ai_socktype = SOCK_DGRAM;
hints.ai_flags = AI_PASSIVE; // use my IP
if ((rv = getaddrinfo(NULL, MYPORT, &hints, &servinfo)) != 0) {
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
return 1;
}
// loop through all the results and bind to the first we can
for(p = servinfo; p != NULL; p = p->ai_next) {
if ((sockfd = socket(p->ai_family, p->ai_socktype,
p->ai_protocol)) == -1) {
perror("listener: socket");
continue;
}
if (bind(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
close(sockfd);
perror("listener: bind");
continue;
}
break;
}
if (p == NULL) {
fprintf(stderr, "listener: failed to bind socket\n");
return 2;
}
freeaddrinfo(servinfo);
printf("listener: waiting to recvfrom...\n");
int run = 1;
while(run){
addr_len = sizeof their_addr;
if ((numbytes = recvfrom(sockfd, buf, MAXBUFLEN-1 , 0,
(struct sockaddr *)&their_addr, &addr_len)) == -1) {
perror("recvfrom");
exit(1);
}
printf("listener: got packet from %s\n",
inet_ntop(their_addr.ss_family,
get_in_addr((struct sockaddr *)&their_addr),
s, sizeof s));
printf("listener: packet is %d bytes long\n", numbytes);
buf[numbytes] = '\0';
printf("listener: packet contains \"%s\"\n", buf);
if(!strcmp(buf, "terminator")){
printf("> Shutting down client interface...\n");
run = 0;
} else if(strcmp(buf, "name") == 0){
printf("> requesting hostname\n");
char name[256] = {'\0'};
get_hostname(name);
printf("listener: hostname = %s\n", name);
} else if(!strcmp(buf, "uptime")){
char name[128] = {'\0'};
get_uptime(name);
printf("listener: uptime = %s\n", name);
} else if(!strcmp(buf, "users")){
char buf[128] = {'\0'};
get_logged_in(buf);
} else if(!strcmp(buf, "rxb")){
char buf[128] = {'\0'};
uint64_t bytes = rx_bytes("eth0");
printf("listener: rx bytes = %uld\n", bytes);
} else{
printf("listener: unknown command: %s", buf);
}
}
close(sockfd);
printf("Good bye.\n");
return 0;
}
