2 * Driver for AMBA serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000 Deep Blue Solutions Ltd.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 * This is a generic driver for ARM AMBA-type serial ports. They
24 * have a lot of 16550-like features, but are not register compatible.
25 * Note that although they do have CTS, DCD and DSR inputs, they do
26 * not have an RI input, nor do they have DTR or RTS outputs. If
27 * required, these have to be supplied via some other means (eg, GPIO)
28 * and hooked into this driver.
31 #if defined(CONFIG_SERIAL_AMBA_PL010_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
35 #include <linux/module.h>
36 #include <linux/ioport.h>
37 #include <linux/init.h>
38 #include <linux/console.h>
39 #include <linux/sysrq.h>
40 #include <linux/device.h>
41 #include <linux/tty.h>
42 #include <linux/tty_flip.h>
43 #include <linux/serial_core.h>
44 #include <linux/serial.h>
45 #include <linux/amba/bus.h>
46 #include <linux/amba/serial.h>
47 #include <linux/clk.h>
48 #include <linux/slab.h>
54 #define SERIAL_AMBA_MAJOR 204
55 #define SERIAL_AMBA_MINOR 16
56 #define SERIAL_AMBA_NR UART_NR
58 #define AMBA_ISR_PASS_LIMIT 256
60 #define UART_RX_DATA(s) (((s) & UART01x_FR_RXFE) == 0)
61 #define UART_TX_READY(s) (((s) & UART01x_FR_TXFF) == 0)
63 #define UART_DUMMY_RSR_RX 256
64 #define UART_PORT_SIZE 64
67 * We wrap our port structure around the generic uart_port.
69 struct uart_amba_port
{
70 struct uart_port port
;
72 struct amba_device
*dev
;
73 struct amba_pl010_data
*data
;
74 unsigned int old_status
;
77 static void pl010_stop_tx(struct uart_port
*port
)
79 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
82 cr
= readb(uap
->port
.membase
+ UART010_CR
);
83 cr
&= ~UART010_CR_TIE
;
84 writel(cr
, uap
->port
.membase
+ UART010_CR
);
87 static void pl010_start_tx(struct uart_port
*port
)
89 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
92 cr
= readb(uap
->port
.membase
+ UART010_CR
);
94 writel(cr
, uap
->port
.membase
+ UART010_CR
);
97 static void pl010_stop_rx(struct uart_port
*port
)
99 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
102 cr
= readb(uap
->port
.membase
+ UART010_CR
);
103 cr
&= ~(UART010_CR_RIE
| UART010_CR_RTIE
);
104 writel(cr
, uap
->port
.membase
+ UART010_CR
);
107 static void pl010_enable_ms(struct uart_port
*port
)
109 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
112 cr
= readb(uap
->port
.membase
+ UART010_CR
);
113 cr
|= UART010_CR_MSIE
;
114 writel(cr
, uap
->port
.membase
+ UART010_CR
);
117 static void pl010_rx_chars(struct uart_amba_port
*uap
)
119 unsigned int status
, ch
, flag
, rsr
, max_count
= 256;
121 status
= readb(uap
->port
.membase
+ UART01x_FR
);
122 while (UART_RX_DATA(status
) && max_count
--) {
123 ch
= readb(uap
->port
.membase
+ UART01x_DR
);
126 uap
->port
.icount
.rx
++;
129 * Note that the error handling code is
130 * out of the main execution path
132 rsr
= readb(uap
->port
.membase
+ UART01x_RSR
) | UART_DUMMY_RSR_RX
;
133 if (unlikely(rsr
& UART01x_RSR_ANY
)) {
134 writel(0, uap
->port
.membase
+ UART01x_ECR
);
136 if (rsr
& UART01x_RSR_BE
) {
137 rsr
&= ~(UART01x_RSR_FE
| UART01x_RSR_PE
);
138 uap
->port
.icount
.brk
++;
139 if (uart_handle_break(&uap
->port
))
141 } else if (rsr
& UART01x_RSR_PE
)
142 uap
->port
.icount
.parity
++;
143 else if (rsr
& UART01x_RSR_FE
)
144 uap
->port
.icount
.frame
++;
145 if (rsr
& UART01x_RSR_OE
)
146 uap
->port
.icount
.overrun
++;
148 rsr
&= uap
->port
.read_status_mask
;
150 if (rsr
& UART01x_RSR_BE
)
152 else if (rsr
& UART01x_RSR_PE
)
154 else if (rsr
& UART01x_RSR_FE
)
158 if (uart_handle_sysrq_char(&uap
->port
, ch
))
161 uart_insert_char(&uap
->port
, rsr
, UART01x_RSR_OE
, ch
, flag
);
164 status
= readb(uap
->port
.membase
+ UART01x_FR
);
166 spin_unlock(&uap
->port
.lock
);
167 tty_flip_buffer_push(&uap
->port
.state
->port
);
168 spin_lock(&uap
->port
.lock
);
171 static void pl010_tx_chars(struct uart_amba_port
*uap
)
173 struct circ_buf
*xmit
= &uap
->port
.state
->xmit
;
176 if (uap
->port
.x_char
) {
177 writel(uap
->port
.x_char
, uap
->port
.membase
+ UART01x_DR
);
178 uap
->port
.icount
.tx
++;
179 uap
->port
.x_char
= 0;
182 if (uart_circ_empty(xmit
) || uart_tx_stopped(&uap
->port
)) {
183 pl010_stop_tx(&uap
->port
);
187 count
= uap
->port
.fifosize
>> 1;
189 writel(xmit
->buf
[xmit
->tail
], uap
->port
.membase
+ UART01x_DR
);
190 xmit
->tail
= (xmit
->tail
+ 1) & (UART_XMIT_SIZE
- 1);
191 uap
->port
.icount
.tx
++;
192 if (uart_circ_empty(xmit
))
194 } while (--count
> 0);
196 if (uart_circ_chars_pending(xmit
) < WAKEUP_CHARS
)
197 uart_write_wakeup(&uap
->port
);
199 if (uart_circ_empty(xmit
))
200 pl010_stop_tx(&uap
->port
);
203 static void pl010_modem_status(struct uart_amba_port
*uap
)
205 unsigned int status
, delta
;
207 writel(0, uap
->port
.membase
+ UART010_ICR
);
209 status
= readb(uap
->port
.membase
+ UART01x_FR
) & UART01x_FR_MODEM_ANY
;
211 delta
= status
^ uap
->old_status
;
212 uap
->old_status
= status
;
217 if (delta
& UART01x_FR_DCD
)
218 uart_handle_dcd_change(&uap
->port
, status
& UART01x_FR_DCD
);
220 if (delta
& UART01x_FR_DSR
)
221 uap
->port
.icount
.dsr
++;
223 if (delta
& UART01x_FR_CTS
)
224 uart_handle_cts_change(&uap
->port
, status
& UART01x_FR_CTS
);
226 wake_up_interruptible(&uap
->port
.state
->port
.delta_msr_wait
);
229 static irqreturn_t
pl010_int(int irq
, void *dev_id
)
231 struct uart_amba_port
*uap
= dev_id
;
232 unsigned int status
, pass_counter
= AMBA_ISR_PASS_LIMIT
;
235 spin_lock(&uap
->port
.lock
);
237 status
= readb(uap
->port
.membase
+ UART010_IIR
);
240 if (status
& (UART010_IIR_RTIS
| UART010_IIR_RIS
))
242 if (status
& UART010_IIR_MIS
)
243 pl010_modem_status(uap
);
244 if (status
& UART010_IIR_TIS
)
247 if (pass_counter
-- == 0)
250 status
= readb(uap
->port
.membase
+ UART010_IIR
);
251 } while (status
& (UART010_IIR_RTIS
| UART010_IIR_RIS
|
256 spin_unlock(&uap
->port
.lock
);
258 return IRQ_RETVAL(handled
);
261 static unsigned int pl010_tx_empty(struct uart_port
*port
)
263 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
264 unsigned int status
= readb(uap
->port
.membase
+ UART01x_FR
);
265 return status
& UART01x_FR_BUSY
? 0 : TIOCSER_TEMT
;
268 static unsigned int pl010_get_mctrl(struct uart_port
*port
)
270 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
271 unsigned int result
= 0;
274 status
= readb(uap
->port
.membase
+ UART01x_FR
);
275 if (status
& UART01x_FR_DCD
)
277 if (status
& UART01x_FR_DSR
)
279 if (status
& UART01x_FR_CTS
)
285 static void pl010_set_mctrl(struct uart_port
*port
, unsigned int mctrl
)
287 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
290 uap
->data
->set_mctrl(uap
->dev
, uap
->port
.membase
, mctrl
);
293 static void pl010_break_ctl(struct uart_port
*port
, int break_state
)
295 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
299 spin_lock_irqsave(&uap
->port
.lock
, flags
);
300 lcr_h
= readb(uap
->port
.membase
+ UART010_LCRH
);
301 if (break_state
== -1)
302 lcr_h
|= UART01x_LCRH_BRK
;
304 lcr_h
&= ~UART01x_LCRH_BRK
;
305 writel(lcr_h
, uap
->port
.membase
+ UART010_LCRH
);
306 spin_unlock_irqrestore(&uap
->port
.lock
, flags
);
309 static int pl010_startup(struct uart_port
*port
)
311 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
315 * Try to enable the clock producer.
317 retval
= clk_prepare_enable(uap
->clk
);
321 uap
->port
.uartclk
= clk_get_rate(uap
->clk
);
326 retval
= request_irq(uap
->port
.irq
, pl010_int
, 0, "uart-pl010", uap
);
331 * initialise the old status of the modem signals
333 uap
->old_status
= readb(uap
->port
.membase
+ UART01x_FR
) & UART01x_FR_MODEM_ANY
;
336 * Finally, enable interrupts
338 writel(UART01x_CR_UARTEN
| UART010_CR_RIE
| UART010_CR_RTIE
,
339 uap
->port
.membase
+ UART010_CR
);
344 clk_disable_unprepare(uap
->clk
);
349 static void pl010_shutdown(struct uart_port
*port
)
351 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
356 free_irq(uap
->port
.irq
, uap
);
359 * disable all interrupts, disable the port
361 writel(0, uap
->port
.membase
+ UART010_CR
);
363 /* disable break condition and fifos */
364 writel(readb(uap
->port
.membase
+ UART010_LCRH
) &
365 ~(UART01x_LCRH_BRK
| UART01x_LCRH_FEN
),
366 uap
->port
.membase
+ UART010_LCRH
);
369 * Shut down the clock producer
371 clk_disable_unprepare(uap
->clk
);
375 pl010_set_termios(struct uart_port
*port
, struct ktermios
*termios
,
376 struct ktermios
*old
)
378 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
379 unsigned int lcr_h
, old_cr
;
381 unsigned int baud
, quot
;
384 * Ask the core to calculate the divisor for us.
386 baud
= uart_get_baud_rate(port
, termios
, old
, 0, uap
->port
.uartclk
/16);
387 quot
= uart_get_divisor(port
, baud
);
389 switch (termios
->c_cflag
& CSIZE
) {
391 lcr_h
= UART01x_LCRH_WLEN_5
;
394 lcr_h
= UART01x_LCRH_WLEN_6
;
397 lcr_h
= UART01x_LCRH_WLEN_7
;
400 lcr_h
= UART01x_LCRH_WLEN_8
;
403 if (termios
->c_cflag
& CSTOPB
)
404 lcr_h
|= UART01x_LCRH_STP2
;
405 if (termios
->c_cflag
& PARENB
) {
406 lcr_h
|= UART01x_LCRH_PEN
;
407 if (!(termios
->c_cflag
& PARODD
))
408 lcr_h
|= UART01x_LCRH_EPS
;
410 if (uap
->port
.fifosize
> 1)
411 lcr_h
|= UART01x_LCRH_FEN
;
413 spin_lock_irqsave(&uap
->port
.lock
, flags
);
416 * Update the per-port timeout.
418 uart_update_timeout(port
, termios
->c_cflag
, baud
);
420 uap
->port
.read_status_mask
= UART01x_RSR_OE
;
421 if (termios
->c_iflag
& INPCK
)
422 uap
->port
.read_status_mask
|= UART01x_RSR_FE
| UART01x_RSR_PE
;
423 if (termios
->c_iflag
& (IGNBRK
| BRKINT
| PARMRK
))
424 uap
->port
.read_status_mask
|= UART01x_RSR_BE
;
427 * Characters to ignore
429 uap
->port
.ignore_status_mask
= 0;
430 if (termios
->c_iflag
& IGNPAR
)
431 uap
->port
.ignore_status_mask
|= UART01x_RSR_FE
| UART01x_RSR_PE
;
432 if (termios
->c_iflag
& IGNBRK
) {
433 uap
->port
.ignore_status_mask
|= UART01x_RSR_BE
;
435 * If we're ignoring parity and break indicators,
436 * ignore overruns too (for real raw support).
438 if (termios
->c_iflag
& IGNPAR
)
439 uap
->port
.ignore_status_mask
|= UART01x_RSR_OE
;
443 * Ignore all characters if CREAD is not set.
445 if ((termios
->c_cflag
& CREAD
) == 0)
446 uap
->port
.ignore_status_mask
|= UART_DUMMY_RSR_RX
;
448 /* first, disable everything */
449 old_cr
= readb(uap
->port
.membase
+ UART010_CR
) & ~UART010_CR_MSIE
;
451 if (UART_ENABLE_MS(port
, termios
->c_cflag
))
452 old_cr
|= UART010_CR_MSIE
;
454 writel(0, uap
->port
.membase
+ UART010_CR
);
458 writel((quot
& 0xf00) >> 8, uap
->port
.membase
+ UART010_LCRM
);
459 writel(quot
& 0xff, uap
->port
.membase
+ UART010_LCRL
);
462 * ----------v----------v----------v----------v-----
463 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
464 * ----------^----------^----------^----------^-----
466 writel(lcr_h
, uap
->port
.membase
+ UART010_LCRH
);
467 writel(old_cr
, uap
->port
.membase
+ UART010_CR
);
469 spin_unlock_irqrestore(&uap
->port
.lock
, flags
);
472 static void pl010_set_ldisc(struct uart_port
*port
, int new)
475 port
->flags
|= UPF_HARDPPS_CD
;
476 pl010_enable_ms(port
);
478 port
->flags
&= ~UPF_HARDPPS_CD
;
481 static const char *pl010_type(struct uart_port
*port
)
483 return port
->type
== PORT_AMBA
? "AMBA" : NULL
;
487 * Release the memory region(s) being used by 'port'
489 static void pl010_release_port(struct uart_port
*port
)
491 release_mem_region(port
->mapbase
, UART_PORT_SIZE
);
495 * Request the memory region(s) being used by 'port'
497 static int pl010_request_port(struct uart_port
*port
)
499 return request_mem_region(port
->mapbase
, UART_PORT_SIZE
, "uart-pl010")
500 != NULL
? 0 : -EBUSY
;
504 * Configure/autoconfigure the port.
506 static void pl010_config_port(struct uart_port
*port
, int flags
)
508 if (flags
& UART_CONFIG_TYPE
) {
509 port
->type
= PORT_AMBA
;
510 pl010_request_port(port
);
515 * verify the new serial_struct (for TIOCSSERIAL).
517 static int pl010_verify_port(struct uart_port
*port
, struct serial_struct
*ser
)
520 if (ser
->type
!= PORT_UNKNOWN
&& ser
->type
!= PORT_AMBA
)
522 if (ser
->irq
< 0 || ser
->irq
>= nr_irqs
)
524 if (ser
->baud_base
< 9600)
529 static struct uart_ops amba_pl010_pops
= {
530 .tx_empty
= pl010_tx_empty
,
531 .set_mctrl
= pl010_set_mctrl
,
532 .get_mctrl
= pl010_get_mctrl
,
533 .stop_tx
= pl010_stop_tx
,
534 .start_tx
= pl010_start_tx
,
535 .stop_rx
= pl010_stop_rx
,
536 .enable_ms
= pl010_enable_ms
,
537 .break_ctl
= pl010_break_ctl
,
538 .startup
= pl010_startup
,
539 .shutdown
= pl010_shutdown
,
540 .set_termios
= pl010_set_termios
,
541 .set_ldisc
= pl010_set_ldisc
,
543 .release_port
= pl010_release_port
,
544 .request_port
= pl010_request_port
,
545 .config_port
= pl010_config_port
,
546 .verify_port
= pl010_verify_port
,
549 static struct uart_amba_port
*amba_ports
[UART_NR
];
551 #ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
553 static void pl010_console_putchar(struct uart_port
*port
, int ch
)
555 struct uart_amba_port
*uap
= (struct uart_amba_port
*)port
;
559 status
= readb(uap
->port
.membase
+ UART01x_FR
);
561 } while (!UART_TX_READY(status
));
562 writel(ch
, uap
->port
.membase
+ UART01x_DR
);
566 pl010_console_write(struct console
*co
, const char *s
, unsigned int count
)
568 struct uart_amba_port
*uap
= amba_ports
[co
->index
];
569 unsigned int status
, old_cr
;
571 clk_enable(uap
->clk
);
574 * First save the CR then disable the interrupts
576 old_cr
= readb(uap
->port
.membase
+ UART010_CR
);
577 writel(UART01x_CR_UARTEN
, uap
->port
.membase
+ UART010_CR
);
579 uart_console_write(&uap
->port
, s
, count
, pl010_console_putchar
);
582 * Finally, wait for transmitter to become empty
583 * and restore the TCR
586 status
= readb(uap
->port
.membase
+ UART01x_FR
);
588 } while (status
& UART01x_FR_BUSY
);
589 writel(old_cr
, uap
->port
.membase
+ UART010_CR
);
591 clk_disable(uap
->clk
);
595 pl010_console_get_options(struct uart_amba_port
*uap
, int *baud
,
596 int *parity
, int *bits
)
598 if (readb(uap
->port
.membase
+ UART010_CR
) & UART01x_CR_UARTEN
) {
599 unsigned int lcr_h
, quot
;
600 lcr_h
= readb(uap
->port
.membase
+ UART010_LCRH
);
603 if (lcr_h
& UART01x_LCRH_PEN
) {
604 if (lcr_h
& UART01x_LCRH_EPS
)
610 if ((lcr_h
& 0x60) == UART01x_LCRH_WLEN_7
)
615 quot
= readb(uap
->port
.membase
+ UART010_LCRL
) |
616 readb(uap
->port
.membase
+ UART010_LCRM
) << 8;
617 *baud
= uap
->port
.uartclk
/ (16 * (quot
+ 1));
621 static int __init
pl010_console_setup(struct console
*co
, char *options
)
623 struct uart_amba_port
*uap
;
631 * Check whether an invalid uart number has been specified, and
632 * if so, search for the first available port that does have
635 if (co
->index
>= UART_NR
)
637 uap
= amba_ports
[co
->index
];
641 ret
= clk_prepare(uap
->clk
);
645 uap
->port
.uartclk
= clk_get_rate(uap
->clk
);
648 uart_parse_options(options
, &baud
, &parity
, &bits
, &flow
);
650 pl010_console_get_options(uap
, &baud
, &parity
, &bits
);
652 return uart_set_options(&uap
->port
, co
, baud
, parity
, bits
, flow
);
655 static struct uart_driver amba_reg
;
656 static struct console amba_console
= {
658 .write
= pl010_console_write
,
659 .device
= uart_console_device
,
660 .setup
= pl010_console_setup
,
661 .flags
= CON_PRINTBUFFER
,
666 #define AMBA_CONSOLE &amba_console
668 #define AMBA_CONSOLE NULL
671 static struct uart_driver amba_reg
= {
672 .owner
= THIS_MODULE
,
673 .driver_name
= "ttyAM",
675 .major
= SERIAL_AMBA_MAJOR
,
676 .minor
= SERIAL_AMBA_MINOR
,
678 .cons
= AMBA_CONSOLE
,
681 static int pl010_probe(struct amba_device
*dev
, const struct amba_id
*id
)
683 struct uart_amba_port
*uap
;
687 for (i
= 0; i
< ARRAY_SIZE(amba_ports
); i
++)
688 if (amba_ports
[i
] == NULL
)
691 if (i
== ARRAY_SIZE(amba_ports
)) {
696 uap
= kzalloc(sizeof(struct uart_amba_port
), GFP_KERNEL
);
702 base
= ioremap(dev
->res
.start
, resource_size(&dev
->res
));
708 uap
->clk
= clk_get(&dev
->dev
, NULL
);
709 if (IS_ERR(uap
->clk
)) {
710 ret
= PTR_ERR(uap
->clk
);
714 uap
->port
.dev
= &dev
->dev
;
715 uap
->port
.mapbase
= dev
->res
.start
;
716 uap
->port
.membase
= base
;
717 uap
->port
.iotype
= UPIO_MEM
;
718 uap
->port
.irq
= dev
->irq
[0];
719 uap
->port
.fifosize
= 16;
720 uap
->port
.ops
= &amba_pl010_pops
;
721 uap
->port
.flags
= UPF_BOOT_AUTOCONF
;
724 uap
->data
= dev_get_platdata(&dev
->dev
);
728 amba_set_drvdata(dev
, uap
);
729 ret
= uart_add_one_port(&amba_reg
, &uap
->port
);
731 amba_set_drvdata(dev
, NULL
);
732 amba_ports
[i
] = NULL
;
743 static int pl010_remove(struct amba_device
*dev
)
745 struct uart_amba_port
*uap
= amba_get_drvdata(dev
);
748 amba_set_drvdata(dev
, NULL
);
750 uart_remove_one_port(&amba_reg
, &uap
->port
);
752 for (i
= 0; i
< ARRAY_SIZE(amba_ports
); i
++)
753 if (amba_ports
[i
] == uap
)
754 amba_ports
[i
] = NULL
;
756 iounmap(uap
->port
.membase
);
762 static int pl010_suspend(struct amba_device
*dev
, pm_message_t state
)
764 struct uart_amba_port
*uap
= amba_get_drvdata(dev
);
767 uart_suspend_port(&amba_reg
, &uap
->port
);
772 static int pl010_resume(struct amba_device
*dev
)
774 struct uart_amba_port
*uap
= amba_get_drvdata(dev
);
777 uart_resume_port(&amba_reg
, &uap
->port
);
782 static struct amba_id pl010_ids
[] = {
790 MODULE_DEVICE_TABLE(amba
, pl010_ids
);
792 static struct amba_driver pl010_driver
= {
794 .name
= "uart-pl010",
796 .id_table
= pl010_ids
,
797 .probe
= pl010_probe
,
798 .remove
= pl010_remove
,
799 .suspend
= pl010_suspend
,
800 .resume
= pl010_resume
,
803 static int __init
pl010_init(void)
807 printk(KERN_INFO
"Serial: AMBA driver\n");
809 ret
= uart_register_driver(&amba_reg
);
811 ret
= amba_driver_register(&pl010_driver
);
813 uart_unregister_driver(&amba_reg
);
818 static void __exit
pl010_exit(void)
820 amba_driver_unregister(&pl010_driver
);
821 uart_unregister_driver(&amba_reg
);
824 module_init(pl010_init
);
825 module_exit(pl010_exit
);
827 MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
828 MODULE_DESCRIPTION("ARM AMBA serial port driver");
829 MODULE_LICENSE("GPL");