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serial: jz_uart: Add UART polling support #47

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Merged
ZubairLK merged 1 commit into from
Jul 13, 2015
Merged

serial: jz_uart: Add UART polling support #47

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52 changes: 52 additions & 0 deletions drivers/tty/serial/jz_uart.c
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Original file line number Diff line number Diff line change
Expand Up @@ -82,6 +82,8 @@ struct uart_jz47xx_port {
static inline void check_modem_status(struct uart_jz47xx_port *up);
static unsigned short *serial47xx_get_divisor(struct uart_port *port, unsigned int baud);
static inline void serial_dl_write(struct uart_port *up, int value);
static int uart_jz47xx_get_poll_char(struct uart_port *port);
static void uart_jz47xx_put_poll_char(struct uart_port *port, unsigned char c);

static inline unsigned int serial_in(struct uart_jz47xx_port *up, int offset)
{
Expand Down Expand Up @@ -994,6 +996,52 @@ static void serial_jz47xx_console_write(struct console *co, const char *s, unsig
spin_unlock(&up->port.lock);
}

#ifdef CONFIG_CONSOLE_POLL
static int uart_jz47xx_get_poll_char(struct uart_port *port)
{
struct uart_jz47xx_port *up =
container_of(port, struct uart_jz47xx_port, port);
unsigned char lsr = serial_in(up, UART_LSR);

if (!(lsr & UART_LSR_DR))
return NO_POLL_CHAR;

return serial_in(up, UART_RX);
}

static void uart_jz47xx_put_poll_char(struct uart_port *port,
unsigned char c)
{
unsigned int ier;
struct uart_jz47xx_port *up =
container_of(port, struct uart_jz47xx_port, port);

/*
* First save the IER then disable the interrupts
*/
ier = serial_in(up, UART_IER);
serial_out(up, UART_IER, 0);

wait_for_xmitr(up);
/*
* Send the character out.
* If a LF, also do CR...
*/
serial_out(up, UART_TX, c);
if (c == 10) {
wait_for_xmitr(up);
serial_out(up, UART_TX, 13);
}

/*
* Finally, wait for transmitter to become empty
* and restore the IER
*/
wait_for_xmitr(up);
serial_out(up, UART_IER, ier);
}
#endif

static int __init serial_jz47xx_console_setup(struct console *co, char *options)
{
struct uart_jz47xx_port *up;
Expand Down Expand Up @@ -1046,6 +1094,10 @@ struct uart_ops serial_jz47xx_pops = {
.request_port = serial_jz47xx_request_port,
.config_port = serial_jz47xx_config_port,
.verify_port = serial_jz47xx_verify_port,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = uart_jz47xx_get_poll_char,
.poll_put_char = uart_jz47xx_put_poll_char,
#endif
};

static struct uart_driver serial_jz47xx_reg = {
Expand Down