int uart_read(char *c, int rsize)
{
struct uart_token token;
token.cur_bytes = 0;
token.req_bytes = rsize;
token.buf = c;
if(ps_cdev_read(&serial_device, token.buf, token.req_bytes, &read_callback, &token) < 0){
printf("Error reading from UART\n");
return -1;
}
read_sem_wait();
return token.cur_bytes;
}
static void
read_callback(ps_chardevice_t* device, enum chardev_status stat,
size_t bytes_transfered, void* token){
struct uart_token* t;
t = (struct uart_token*)token;
/* We might get a short read due to a timeout. */
t->cur_bytes += bytes_transfered;
t->buf += bytes_transfered;
if(t->cur_bytes < t->req_bytes){
int ret;
ret = ps_cdev_read(device, t->buf, t->req_bytes - t->cur_bytes,
&read_callback, token);
if(ret < 0){
printf("Error reading from UART\n");
read_sem_post();
}
}else{
read_sem_post();
}
}