/*
* write data to serial port
*/
void uart_tx()
{
fd_set tx_fds;
struct timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 500;
FD_ZERO(&tx_fds);
FD_SET(g_fd, &tx_fds);
if (select(g_fd+1, NULL, &tx_fds, NULL, &tv) <= 0)
return;
if (FD_ISSET(g_fd, &tx_fds) && tx_qHead != NULL)
{
void * tx_ptr = uart_tx_dequeue();
if (tx_ptr)
{
int n = write(g_fd, UART_TX_DATA(tx_ptr), UART_TX_DATALEN(tx_ptr));
uart_tx_deallocate((uart_tx_t *)tx_ptr);
#ifdef PRINT_UART_LOG
printf("tx %d\n", n);
#endif
}
}
}
static void omahauart_int_tx(int irq, void *dev_id, struct pt_regs *regs)
{
struct uart_info *info = dev_id;
volatile unsigned int status, pass_counter = OMAHA_ISR_PASS_LIMIT;
status = UART_FIFO_STATUS(info->port);
do {
// TX if FIFO not full
if (UART_TX_DATA(status))
omahauart_tx_chars(info);
if (pass_counter-- == 0)
break;
status = UART_FIFO_STATUS(info->port);
} while (UART_TX_DATA(status));
}
static void omahauart_tx_chars(struct uart_info *info)
{
struct uart_port *port = info->port;
volatile unsigned int status;
if (port->x_char) {
UART_PUT_CHAR(port, port->x_char);
port->icount.tx++;
port->x_char = 0;
return;
}
if (info->xmit.head == info->xmit.tail
|| info->tty->stopped
|| info->tty->hw_stopped) {
omahauart_stop_tx(port, 0);
return;
}
status = UART_FIFO_STATUS(info->port);
// FIll FIFO as far as possible
while(UART_TX_DATA(UART_FIFO_STATUS(info->port)))
{
UART_PUT_CHAR(port, info->xmit.buf[info->xmit.tail]);
info->xmit.tail = (info->xmit.tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
if (info->xmit.head == info->xmit.tail)
break;
}
if (CIRC_CNT(info->xmit.head, info->xmit.tail, UART_XMIT_SIZE) <
WAKEUP_CHARS)
uart_event(info, EVT_WRITE_WAKEUP);
if (info->xmit.head == info->xmit.tail)
omahauart_stop_tx(info->port, 0);
}
