1 // SPDX-License-Identifier: GPL-2.0+
3 * Actions Semi Owl family serial console
5 * Copyright 2013 Actions Semi Inc.
6 * Author: Actions Semi, Inc.
8 * Copyright (c) 2016-2017 Andreas Färber
11 #include <linux/clk.h>
12 #include <linux/console.h>
13 #include <linux/delay.h>
15 #include <linux/iopoll.h>
16 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 #include <linux/serial.h>
20 #include <linux/serial_core.h>
21 #include <linux/tty.h>
22 #include <linux/tty_flip.h>
24 #define OWL_UART_PORT_NUM 7
25 #define OWL_UART_DEV_NAME "ttyOWL"
27 #define OWL_UART_CTL 0x000
28 #define OWL_UART_RXDAT 0x004
29 #define OWL_UART_TXDAT 0x008
30 #define OWL_UART_STAT 0x00c
32 #define OWL_UART_CTL_DWLS_MASK GENMASK(1, 0)
33 #define OWL_UART_CTL_DWLS_5BITS (0x0 << 0)
34 #define OWL_UART_CTL_DWLS_6BITS (0x1 << 0)
35 #define OWL_UART_CTL_DWLS_7BITS (0x2 << 0)
36 #define OWL_UART_CTL_DWLS_8BITS (0x3 << 0)
37 #define OWL_UART_CTL_STPS_2BITS BIT(2)
38 #define OWL_UART_CTL_PRS_MASK GENMASK(6, 4)
39 #define OWL_UART_CTL_PRS_NONE (0x0 << 4)
40 #define OWL_UART_CTL_PRS_ODD (0x4 << 4)
41 #define OWL_UART_CTL_PRS_MARK (0x5 << 4)
42 #define OWL_UART_CTL_PRS_EVEN (0x6 << 4)
43 #define OWL_UART_CTL_PRS_SPACE (0x7 << 4)
44 #define OWL_UART_CTL_AFE BIT(12)
45 #define OWL_UART_CTL_TRFS_TX BIT(14)
46 #define OWL_UART_CTL_EN BIT(15)
47 #define OWL_UART_CTL_RXDE BIT(16)
48 #define OWL_UART_CTL_TXDE BIT(17)
49 #define OWL_UART_CTL_RXIE BIT(18)
50 #define OWL_UART_CTL_TXIE BIT(19)
51 #define OWL_UART_CTL_LBEN BIT(20)
53 #define OWL_UART_STAT_RIP BIT(0)
54 #define OWL_UART_STAT_TIP BIT(1)
55 #define OWL_UART_STAT_RXER BIT(2)
56 #define OWL_UART_STAT_TFER BIT(3)
57 #define OWL_UART_STAT_RXST BIT(4)
58 #define OWL_UART_STAT_RFEM BIT(5)
59 #define OWL_UART_STAT_TFFU BIT(6)
60 #define OWL_UART_STAT_CTSS BIT(7)
61 #define OWL_UART_STAT_RTSS BIT(8)
62 #define OWL_UART_STAT_TFES BIT(10)
63 #define OWL_UART_STAT_TRFL_MASK GENMASK(16, 11)
64 #define OWL_UART_STAT_UTBB BIT(17)
66 #define OWL_UART_POLL_USEC 5
67 #define OWL_UART_TIMEOUT_USEC 10000
69 static struct uart_driver owl_uart_driver
;
71 struct owl_uart_info
{
72 unsigned int tx_fifosize
;
75 struct owl_uart_port
{
76 struct uart_port port
;
80 #define to_owl_uart_port(prt) container_of(prt, struct owl_uart_port, prt)
82 static struct owl_uart_port
*owl_uart_ports
[OWL_UART_PORT_NUM
];
84 static inline void owl_uart_write(struct uart_port
*port
, u32 val
, unsigned int off
)
86 writel(val
, port
->membase
+ off
);
89 static inline u32
owl_uart_read(struct uart_port
*port
, unsigned int off
)
91 return readl(port
->membase
+ off
);
94 static void owl_uart_set_mctrl(struct uart_port
*port
, unsigned int mctrl
)
98 ctl
= owl_uart_read(port
, OWL_UART_CTL
);
100 if (mctrl
& TIOCM_LOOP
)
101 ctl
|= OWL_UART_CTL_LBEN
;
103 ctl
&= ~OWL_UART_CTL_LBEN
;
105 owl_uart_write(port
, ctl
, OWL_UART_CTL
);
108 static unsigned int owl_uart_get_mctrl(struct uart_port
*port
)
110 unsigned int mctrl
= TIOCM_CAR
| TIOCM_DSR
;
113 ctl
= owl_uart_read(port
, OWL_UART_CTL
);
114 stat
= owl_uart_read(port
, OWL_UART_STAT
);
115 if (stat
& OWL_UART_STAT_RTSS
)
117 if ((stat
& OWL_UART_STAT_CTSS
) || !(ctl
& OWL_UART_CTL_AFE
))
122 static unsigned int owl_uart_tx_empty(struct uart_port
*port
)
128 uart_port_lock_irqsave(port
, &flags
);
130 val
= owl_uart_read(port
, OWL_UART_STAT
);
131 ret
= (val
& OWL_UART_STAT_TFES
) ? TIOCSER_TEMT
: 0;
133 uart_port_unlock_irqrestore(port
, flags
);
138 static void owl_uart_stop_rx(struct uart_port
*port
)
142 val
= owl_uart_read(port
, OWL_UART_CTL
);
143 val
&= ~(OWL_UART_CTL_RXIE
| OWL_UART_CTL_RXDE
);
144 owl_uart_write(port
, val
, OWL_UART_CTL
);
146 val
= owl_uart_read(port
, OWL_UART_STAT
);
147 val
|= OWL_UART_STAT_RIP
;
148 owl_uart_write(port
, val
, OWL_UART_STAT
);
151 static void owl_uart_stop_tx(struct uart_port
*port
)
155 val
= owl_uart_read(port
, OWL_UART_CTL
);
156 val
&= ~(OWL_UART_CTL_TXIE
| OWL_UART_CTL_TXDE
);
157 owl_uart_write(port
, val
, OWL_UART_CTL
);
159 val
= owl_uart_read(port
, OWL_UART_STAT
);
160 val
|= OWL_UART_STAT_TIP
;
161 owl_uart_write(port
, val
, OWL_UART_STAT
);
164 static void owl_uart_start_tx(struct uart_port
*port
)
168 if (uart_tx_stopped(port
)) {
169 owl_uart_stop_tx(port
);
173 val
= owl_uart_read(port
, OWL_UART_STAT
);
174 val
|= OWL_UART_STAT_TIP
;
175 owl_uart_write(port
, val
, OWL_UART_STAT
);
177 val
= owl_uart_read(port
, OWL_UART_CTL
);
178 val
|= OWL_UART_CTL_TXIE
;
179 owl_uart_write(port
, val
, OWL_UART_CTL
);
182 static void owl_uart_send_chars(struct uart_port
*port
)
186 uart_port_tx(port
, ch
,
187 !(owl_uart_read(port
, OWL_UART_STAT
) & OWL_UART_STAT_TFFU
),
188 owl_uart_write(port
, ch
, OWL_UART_TXDAT
));
191 static void owl_uart_receive_chars(struct uart_port
*port
)
195 val
= owl_uart_read(port
, OWL_UART_CTL
);
196 val
&= ~OWL_UART_CTL_TRFS_TX
;
197 owl_uart_write(port
, val
, OWL_UART_CTL
);
199 stat
= owl_uart_read(port
, OWL_UART_STAT
);
200 while (!(stat
& OWL_UART_STAT_RFEM
)) {
201 char flag
= TTY_NORMAL
;
204 if (stat
& OWL_UART_STAT_RXER
)
205 port
->icount
.overrun
++;
207 if (stat
& OWL_UART_STAT_RXST
) {
208 /* We are not able to distinguish the error type. */
210 port
->icount
.frame
++;
212 stat
&= port
->read_status_mask
;
213 if (stat
& OWL_UART_STAT_RXST
)
218 val
= owl_uart_read(port
, OWL_UART_RXDAT
);
221 sysrq
= uart_prepare_sysrq_char(port
, val
);
223 if (!sysrq
&& (stat
& port
->ignore_status_mask
) == 0)
224 tty_insert_flip_char(&port
->state
->port
, val
, flag
);
226 stat
= owl_uart_read(port
, OWL_UART_STAT
);
229 tty_flip_buffer_push(&port
->state
->port
);
232 static irqreturn_t
owl_uart_irq(int irq
, void *dev_id
)
234 struct uart_port
*port
= dev_id
;
237 uart_port_lock(port
);
239 stat
= owl_uart_read(port
, OWL_UART_STAT
);
241 if (stat
& OWL_UART_STAT_RIP
)
242 owl_uart_receive_chars(port
);
244 if (stat
& OWL_UART_STAT_TIP
)
245 owl_uart_send_chars(port
);
247 stat
= owl_uart_read(port
, OWL_UART_STAT
);
248 stat
|= OWL_UART_STAT_RIP
| OWL_UART_STAT_TIP
;
249 owl_uart_write(port
, stat
, OWL_UART_STAT
);
251 uart_unlock_and_check_sysrq(port
);
256 static void owl_uart_shutdown(struct uart_port
*port
)
261 uart_port_lock_irqsave(port
, &flags
);
263 val
= owl_uart_read(port
, OWL_UART_CTL
);
264 val
&= ~(OWL_UART_CTL_TXIE
| OWL_UART_CTL_RXIE
265 | OWL_UART_CTL_TXDE
| OWL_UART_CTL_RXDE
| OWL_UART_CTL_EN
);
266 owl_uart_write(port
, val
, OWL_UART_CTL
);
268 uart_port_unlock_irqrestore(port
, flags
);
270 free_irq(port
->irq
, port
);
273 static int owl_uart_startup(struct uart_port
*port
)
279 ret
= request_irq(port
->irq
, owl_uart_irq
, IRQF_TRIGGER_HIGH
,
284 uart_port_lock_irqsave(port
, &flags
);
286 val
= owl_uart_read(port
, OWL_UART_STAT
);
287 val
|= OWL_UART_STAT_RIP
| OWL_UART_STAT_TIP
288 | OWL_UART_STAT_RXER
| OWL_UART_STAT_TFER
| OWL_UART_STAT_RXST
;
289 owl_uart_write(port
, val
, OWL_UART_STAT
);
291 val
= owl_uart_read(port
, OWL_UART_CTL
);
292 val
|= OWL_UART_CTL_RXIE
| OWL_UART_CTL_TXIE
;
293 val
|= OWL_UART_CTL_EN
;
294 owl_uart_write(port
, val
, OWL_UART_CTL
);
296 uart_port_unlock_irqrestore(port
, flags
);
301 static void owl_uart_change_baudrate(struct owl_uart_port
*owl_port
,
304 clk_set_rate(owl_port
->clk
, baud
* 8);
307 static void owl_uart_set_termios(struct uart_port
*port
,
308 struct ktermios
*termios
,
309 const struct ktermios
*old
)
311 struct owl_uart_port
*owl_port
= to_owl_uart_port(port
);
316 uart_port_lock_irqsave(port
, &flags
);
318 ctl
= owl_uart_read(port
, OWL_UART_CTL
);
320 ctl
&= ~OWL_UART_CTL_DWLS_MASK
;
321 switch (termios
->c_cflag
& CSIZE
) {
323 ctl
|= OWL_UART_CTL_DWLS_5BITS
;
326 ctl
|= OWL_UART_CTL_DWLS_6BITS
;
329 ctl
|= OWL_UART_CTL_DWLS_7BITS
;
333 ctl
|= OWL_UART_CTL_DWLS_8BITS
;
337 if (termios
->c_cflag
& CSTOPB
)
338 ctl
|= OWL_UART_CTL_STPS_2BITS
;
340 ctl
&= ~OWL_UART_CTL_STPS_2BITS
;
342 ctl
&= ~OWL_UART_CTL_PRS_MASK
;
343 if (termios
->c_cflag
& PARENB
) {
344 if (termios
->c_cflag
& CMSPAR
) {
345 if (termios
->c_cflag
& PARODD
)
346 ctl
|= OWL_UART_CTL_PRS_MARK
;
348 ctl
|= OWL_UART_CTL_PRS_SPACE
;
349 } else if (termios
->c_cflag
& PARODD
)
350 ctl
|= OWL_UART_CTL_PRS_ODD
;
352 ctl
|= OWL_UART_CTL_PRS_EVEN
;
354 ctl
|= OWL_UART_CTL_PRS_NONE
;
356 if (termios
->c_cflag
& CRTSCTS
)
357 ctl
|= OWL_UART_CTL_AFE
;
359 ctl
&= ~OWL_UART_CTL_AFE
;
361 owl_uart_write(port
, ctl
, OWL_UART_CTL
);
363 baud
= uart_get_baud_rate(port
, termios
, old
, 9600, 3200000);
364 owl_uart_change_baudrate(owl_port
, baud
);
366 /* Don't rewrite B0 */
367 if (tty_termios_baud_rate(termios
))
368 tty_termios_encode_baud_rate(termios
, baud
, baud
);
370 port
->read_status_mask
|= OWL_UART_STAT_RXER
;
371 if (termios
->c_iflag
& INPCK
)
372 port
->read_status_mask
|= OWL_UART_STAT_RXST
;
374 uart_update_timeout(port
, termios
->c_cflag
, baud
);
376 uart_port_unlock_irqrestore(port
, flags
);
379 static void owl_uart_release_port(struct uart_port
*port
)
381 struct platform_device
*pdev
= to_platform_device(port
->dev
);
382 struct resource
*res
;
384 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
388 if (port
->flags
& UPF_IOREMAP
) {
389 devm_release_mem_region(port
->dev
, port
->mapbase
,
391 devm_iounmap(port
->dev
, port
->membase
);
392 port
->membase
= NULL
;
396 static int owl_uart_request_port(struct uart_port
*port
)
398 struct platform_device
*pdev
= to_platform_device(port
->dev
);
399 struct resource
*res
;
401 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
405 if (!devm_request_mem_region(port
->dev
, port
->mapbase
,
406 resource_size(res
), dev_name(port
->dev
)))
409 if (port
->flags
& UPF_IOREMAP
) {
410 port
->membase
= devm_ioremap(port
->dev
, port
->mapbase
,
419 static const char *owl_uart_type(struct uart_port
*port
)
421 return (port
->type
== PORT_OWL
) ? "owl-uart" : NULL
;
424 static int owl_uart_verify_port(struct uart_port
*port
,
425 struct serial_struct
*ser
)
427 if (port
->type
!= PORT_OWL
)
430 if (port
->irq
!= ser
->irq
)
436 static void owl_uart_config_port(struct uart_port
*port
, int flags
)
438 if (flags
& UART_CONFIG_TYPE
) {
439 port
->type
= PORT_OWL
;
440 owl_uart_request_port(port
);
444 #ifdef CONFIG_CONSOLE_POLL
446 static int owl_uart_poll_get_char(struct uart_port
*port
)
448 if (owl_uart_read(port
, OWL_UART_STAT
) & OWL_UART_STAT_RFEM
)
451 return owl_uart_read(port
, OWL_UART_RXDAT
);
454 static void owl_uart_poll_put_char(struct uart_port
*port
, unsigned char ch
)
459 /* Wait while FIFO is full or timeout */
460 ret
= readl_poll_timeout_atomic(port
->membase
+ OWL_UART_STAT
, reg
,
461 !(reg
& OWL_UART_STAT_TFFU
),
463 OWL_UART_TIMEOUT_USEC
);
464 if (ret
== -ETIMEDOUT
) {
465 dev_err(port
->dev
, "Timeout waiting while UART TX FULL\n");
469 owl_uart_write(port
, ch
, OWL_UART_TXDAT
);
472 #endif /* CONFIG_CONSOLE_POLL */
474 static const struct uart_ops owl_uart_ops
= {
475 .set_mctrl
= owl_uart_set_mctrl
,
476 .get_mctrl
= owl_uart_get_mctrl
,
477 .tx_empty
= owl_uart_tx_empty
,
478 .start_tx
= owl_uart_start_tx
,
479 .stop_rx
= owl_uart_stop_rx
,
480 .stop_tx
= owl_uart_stop_tx
,
481 .startup
= owl_uart_startup
,
482 .shutdown
= owl_uart_shutdown
,
483 .set_termios
= owl_uart_set_termios
,
484 .type
= owl_uart_type
,
485 .config_port
= owl_uart_config_port
,
486 .request_port
= owl_uart_request_port
,
487 .release_port
= owl_uart_release_port
,
488 .verify_port
= owl_uart_verify_port
,
489 #ifdef CONFIG_CONSOLE_POLL
490 .poll_get_char
= owl_uart_poll_get_char
,
491 .poll_put_char
= owl_uart_poll_put_char
,
495 #ifdef CONFIG_SERIAL_OWL_CONSOLE
497 static void owl_console_putchar(struct uart_port
*port
, unsigned char ch
)
502 while (owl_uart_read(port
, OWL_UART_STAT
) & OWL_UART_STAT_TFFU
)
505 owl_uart_write(port
, ch
, OWL_UART_TXDAT
);
508 static void owl_uart_port_write(struct uart_port
*port
, const char *s
,
515 if (oops_in_progress
)
516 locked
= uart_port_trylock_irqsave(port
, &flags
);
518 uart_port_lock_irqsave(port
, &flags
);
520 old_ctl
= owl_uart_read(port
, OWL_UART_CTL
);
521 val
= old_ctl
| OWL_UART_CTL_TRFS_TX
;
523 val
&= ~(OWL_UART_CTL_RXIE
| OWL_UART_CTL_TXIE
);
524 owl_uart_write(port
, val
, OWL_UART_CTL
);
526 uart_console_write(port
, s
, count
, owl_console_putchar
);
528 /* wait until all contents have been sent out */
529 while (owl_uart_read(port
, OWL_UART_STAT
) & OWL_UART_STAT_TRFL_MASK
)
532 /* clear IRQ pending */
533 val
= owl_uart_read(port
, OWL_UART_STAT
);
534 val
|= OWL_UART_STAT_TIP
| OWL_UART_STAT_RIP
;
535 owl_uart_write(port
, val
, OWL_UART_STAT
);
537 owl_uart_write(port
, old_ctl
, OWL_UART_CTL
);
540 uart_port_unlock_irqrestore(port
, flags
);
543 static void owl_uart_console_write(struct console
*co
, const char *s
,
546 struct owl_uart_port
*owl_port
;
548 owl_port
= owl_uart_ports
[co
->index
];
552 owl_uart_port_write(&owl_port
->port
, s
, count
);
555 static int owl_uart_console_setup(struct console
*co
, char *options
)
557 struct owl_uart_port
*owl_port
;
563 if (co
->index
< 0 || co
->index
>= OWL_UART_PORT_NUM
)
566 owl_port
= owl_uart_ports
[co
->index
];
567 if (!owl_port
|| !owl_port
->port
.membase
)
571 uart_parse_options(options
, &baud
, &parity
, &bits
, &flow
);
573 return uart_set_options(&owl_port
->port
, co
, baud
, parity
, bits
, flow
);
576 static struct console owl_uart_console
= {
577 .name
= OWL_UART_DEV_NAME
,
578 .write
= owl_uart_console_write
,
579 .device
= uart_console_device
,
580 .setup
= owl_uart_console_setup
,
581 .flags
= CON_PRINTBUFFER
,
583 .data
= &owl_uart_driver
,
586 static int __init
owl_uart_console_init(void)
588 register_console(&owl_uart_console
);
592 console_initcall(owl_uart_console_init
);
594 static void owl_uart_early_console_write(struct console
*co
,
598 struct earlycon_device
*dev
= co
->data
;
600 owl_uart_port_write(&dev
->port
, s
, count
);
604 owl_uart_early_console_setup(struct earlycon_device
*device
, const char *opt
)
606 if (!device
->port
.membase
)
609 device
->con
->write
= owl_uart_early_console_write
;
613 OF_EARLYCON_DECLARE(owl
, "actions,owl-uart",
614 owl_uart_early_console_setup
);
616 #define OWL_UART_CONSOLE (&owl_uart_console)
618 #define OWL_UART_CONSOLE NULL
621 static struct uart_driver owl_uart_driver
= {
622 .owner
= THIS_MODULE
,
623 .driver_name
= "owl-uart",
624 .dev_name
= OWL_UART_DEV_NAME
,
625 .nr
= OWL_UART_PORT_NUM
,
626 .cons
= OWL_UART_CONSOLE
,
629 static const struct owl_uart_info owl_s500_info
= {
633 static const struct owl_uart_info owl_s900_info
= {
637 static const struct of_device_id owl_uart_dt_matches
[] = {
638 { .compatible
= "actions,s500-uart", .data
= &owl_s500_info
},
639 { .compatible
= "actions,s900-uart", .data
= &owl_s900_info
},
642 MODULE_DEVICE_TABLE(of
, owl_uart_dt_matches
);
644 static int owl_uart_probe(struct platform_device
*pdev
)
646 const struct of_device_id
*match
;
647 const struct owl_uart_info
*info
= NULL
;
648 struct resource
*res_mem
;
649 struct owl_uart_port
*owl_port
;
652 if (pdev
->dev
.of_node
) {
653 pdev
->id
= of_alias_get_id(pdev
->dev
.of_node
, "serial");
654 match
= of_match_node(owl_uart_dt_matches
, pdev
->dev
.of_node
);
659 if (pdev
->id
< 0 || pdev
->id
>= OWL_UART_PORT_NUM
) {
660 dev_err(&pdev
->dev
, "id %d out of range\n", pdev
->id
);
664 res_mem
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
666 dev_err(&pdev
->dev
, "could not get mem\n");
670 irq
= platform_get_irq(pdev
, 0);
674 if (owl_uart_ports
[pdev
->id
]) {
675 dev_err(&pdev
->dev
, "port %d already allocated\n", pdev
->id
);
679 owl_port
= devm_kzalloc(&pdev
->dev
, sizeof(*owl_port
), GFP_KERNEL
);
683 owl_port
->clk
= devm_clk_get(&pdev
->dev
, NULL
);
684 if (IS_ERR(owl_port
->clk
)) {
685 dev_err(&pdev
->dev
, "could not get clk\n");
686 return PTR_ERR(owl_port
->clk
);
689 ret
= clk_prepare_enable(owl_port
->clk
);
691 dev_err(&pdev
->dev
, "could not enable clk\n");
695 owl_port
->port
.dev
= &pdev
->dev
;
696 owl_port
->port
.line
= pdev
->id
;
697 owl_port
->port
.type
= PORT_OWL
;
698 owl_port
->port
.iotype
= UPIO_MEM
;
699 owl_port
->port
.mapbase
= res_mem
->start
;
700 owl_port
->port
.irq
= irq
;
701 owl_port
->port
.uartclk
= clk_get_rate(owl_port
->clk
);
702 if (owl_port
->port
.uartclk
== 0) {
703 dev_err(&pdev
->dev
, "clock rate is zero\n");
704 clk_disable_unprepare(owl_port
->clk
);
707 owl_port
->port
.flags
= UPF_BOOT_AUTOCONF
| UPF_IOREMAP
| UPF_LOW_LATENCY
;
708 owl_port
->port
.x_char
= 0;
709 owl_port
->port
.fifosize
= (info
) ? info
->tx_fifosize
: 16;
710 owl_port
->port
.ops
= &owl_uart_ops
;
712 owl_uart_ports
[pdev
->id
] = owl_port
;
713 platform_set_drvdata(pdev
, owl_port
);
715 ret
= uart_add_one_port(&owl_uart_driver
, &owl_port
->port
);
717 owl_uart_ports
[pdev
->id
] = NULL
;
722 static void owl_uart_remove(struct platform_device
*pdev
)
724 struct owl_uart_port
*owl_port
= platform_get_drvdata(pdev
);
726 uart_remove_one_port(&owl_uart_driver
, &owl_port
->port
);
727 owl_uart_ports
[pdev
->id
] = NULL
;
728 clk_disable_unprepare(owl_port
->clk
);
731 static struct platform_driver owl_uart_platform_driver
= {
732 .probe
= owl_uart_probe
,
733 .remove_new
= owl_uart_remove
,
736 .of_match_table
= owl_uart_dt_matches
,
740 static int __init
owl_uart_init(void)
744 ret
= uart_register_driver(&owl_uart_driver
);
748 ret
= platform_driver_register(&owl_uart_platform_driver
);
750 uart_unregister_driver(&owl_uart_driver
);
755 static void __exit
owl_uart_exit(void)
757 platform_driver_unregister(&owl_uart_platform_driver
);
758 uart_unregister_driver(&owl_uart_driver
);
761 module_init(owl_uart_init
);
762 module_exit(owl_uart_exit
);
764 MODULE_DESCRIPTION("Actions Semi Owl family serial console");
765 MODULE_LICENSE("GPL");