diff options
Diffstat (limited to 'drivers/serial/8250.c')
| -rw-r--r-- | drivers/serial/8250.c | 67 |
1 files changed, 64 insertions, 3 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 77f7a7f0646e..ea41f2626458 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1740,6 +1740,60 @@ static inline void wait_for_xmitr(struct uart_8250_port *up, int bits) } } +#ifdef CONFIG_CONSOLE_POLL +/* + * Console polling routines for writing and reading from the uart while + * in an interrupt or debug context. + */ + +static int serial8250_get_poll_char(struct uart_port *port) +{ + struct uart_8250_port *up = (struct uart_8250_port *)port; + unsigned char lsr = serial_inp(up, UART_LSR); + + while (!(lsr & UART_LSR_DR)) + lsr = serial_inp(up, UART_LSR); + + return serial_inp(up, UART_RX); +} + + +static void serial8250_put_poll_char(struct uart_port *port, + unsigned char c) +{ + unsigned int ier; + struct uart_8250_port *up = (struct uart_8250_port *)port; + + /* + * First save the IER then disable the interrupts + */ + ier = serial_in(up, UART_IER); + if (up->capabilities & UART_CAP_UUE) + serial_out(up, UART_IER, UART_IER_UUE); + else + serial_out(up, UART_IER, 0); + + wait_for_xmitr(up, BOTH_EMPTY); + /* + * Send the character out. + * If a LF, also do CR... + */ + serial_out(up, UART_TX, c); + if (c == 10) { + wait_for_xmitr(up, BOTH_EMPTY); + serial_out(up, UART_TX, 13); + } + + /* + * Finally, wait for transmitter to become empty + * and restore the IER + */ + wait_for_xmitr(up, BOTH_EMPTY); + serial_out(up, UART_IER, ier); +} + +#endif /* CONFIG_CONSOLE_POLL */ + static int serial8250_startup(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; @@ -1814,6 +1868,7 @@ static int serial8250_startup(struct uart_port *port) } if (is_real_interrupt(up->port.irq)) { + unsigned char iir1; /* * Test for UARTs that do not reassert THRE when the * transmitter is idle and the interrupt has already @@ -1827,7 +1882,7 @@ static int serial8250_startup(struct uart_port *port) wait_for_xmitr(up, UART_LSR_THRE); serial_out_sync(up, UART_IER, UART_IER_THRI); udelay(1); /* allow THRE to set */ - serial_in(up, UART_IIR); + iir1 = serial_in(up, UART_IIR); serial_out(up, UART_IER, 0); serial_out_sync(up, UART_IER, UART_IER_THRI); udelay(1); /* allow a working UART time to re-assert THRE */ @@ -1840,7 +1895,7 @@ static int serial8250_startup(struct uart_port *port) * If the interrupt is not reasserted, setup a timer to * kick the UART on a regular basis. */ - if (iir & UART_IIR_NO_INT) { + if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) { pr_debug("ttyS%d - using backup timer\n", port->line); up->timer.function = serial8250_backup_timeout; up->timer.data = (unsigned long)up; @@ -2174,7 +2229,9 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios, } serial8250_set_mctrl(&up->port, up->port.mctrl); spin_unlock_irqrestore(&up->port.lock, flags); - tty_termios_encode_baud_rate(termios, baud, baud); + /* Don't rewrite B0 */ + if (tty_termios_baud_rate(termios)) + tty_termios_encode_baud_rate(termios, baud, baud); } static void @@ -2386,6 +2443,10 @@ static struct uart_ops serial8250_pops = { .request_port = serial8250_request_port, .config_port = serial8250_config_port, .verify_port = serial8250_verify_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = serial8250_get_poll_char, + .poll_put_char = serial8250_put_poll_char, +#endif }; static struct uart_8250_port serial8250_ports[UART_NR]; |