1 /* sunhv.c: Serial driver for SUN4V hypervisor console.
3 * Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net)
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/errno.h>
10 #include <linux/tty_flip.h>
11 #include <linux/major.h>
12 #include <linux/circ_buf.h>
13 #include <linux/serial.h>
14 #include <linux/sysrq.h>
15 #include <linux/console.h>
16 #include <linux/spinlock.h>
17 #include <linux/slab.h>
18 #include <linux/delay.h>
19 #include <linux/init.h>
20 #include <linux/of_device.h>
22 #include <asm/hypervisor.h>
23 #include <asm/spitfire.h>
27 #if defined(CONFIG_MAGIC_SYSRQ)
31 #include <linux/serial_core.h>
32 #include <linux/sunserialcore.h>
34 #define CON_BREAK ((long)-1)
35 #define CON_HUP ((long)-2)
37 #define IGNORE_BREAK 0x1
38 #define IGNORE_ALL 0x2
40 static char *con_write_page
;
41 static char *con_read_page
;
43 static int hung_up
= 0;
45 static void transmit_chars_putchar(struct uart_port
*port
, struct circ_buf
*xmit
)
47 while (!uart_circ_empty(xmit
)) {
48 long status
= sun4v_con_putchar(xmit
->buf
[xmit
->tail
]);
53 xmit
->tail
= (xmit
->tail
+ 1) & (UART_XMIT_SIZE
- 1);
58 static void transmit_chars_write(struct uart_port
*port
, struct circ_buf
*xmit
)
60 while (!uart_circ_empty(xmit
)) {
61 unsigned long ra
= __pa(xmit
->buf
+ xmit
->tail
);
62 unsigned long len
, status
, sent
;
64 len
= CIRC_CNT_TO_END(xmit
->head
, xmit
->tail
,
66 status
= sun4v_con_write(ra
, len
, &sent
);
69 xmit
->tail
= (xmit
->tail
+ sent
) & (UART_XMIT_SIZE
- 1);
70 port
->icount
.tx
+= sent
;
74 static int receive_chars_getchar(struct uart_port
*port
, struct tty_struct
*tty
)
76 int saw_console_brk
= 0;
81 long c
= sun4v_con_getchar(&status
);
83 if (status
== HV_EWOULDBLOCK
)
87 if (uart_handle_break(port
))
95 uart_handle_dcd_change(port
, 0);
98 uart_handle_dcd_change(port
, 1);
102 uart_handle_sysrq_char(port
, c
);
108 if (uart_handle_sysrq_char(port
, c
))
111 tty_insert_flip_char(tty
, c
, TTY_NORMAL
);
114 return saw_console_brk
;
117 static int receive_chars_read(struct uart_port
*port
, struct tty_struct
*tty
)
119 int saw_console_brk
= 0;
122 while (limit
-- > 0) {
123 unsigned long ra
= __pa(con_read_page
);
124 unsigned long bytes_read
, i
;
125 long stat
= sun4v_con_read(ra
, PAGE_SIZE
, &bytes_read
);
127 if (stat
!= HV_EOK
) {
130 if (stat
== CON_BREAK
) {
131 if (uart_handle_break(port
))
136 } else if (stat
== CON_HUP
) {
138 uart_handle_dcd_change(port
, 0);
141 /* HV_EWOULDBLOCK, etc. */
148 uart_handle_dcd_change(port
, 1);
151 for (i
= 0; i
< bytes_read
; i
++)
152 uart_handle_sysrq_char(port
, con_read_page
[i
]);
157 port
->icount
.rx
+= bytes_read
;
159 tty_insert_flip_string(tty
, con_read_page
, bytes_read
);
162 return saw_console_brk
;
166 void (*transmit_chars
)(struct uart_port
*port
, struct circ_buf
*xmit
);
167 int (*receive_chars
)(struct uart_port
*port
, struct tty_struct
*tty
);
170 static struct sunhv_ops bychar_ops
= {
171 .transmit_chars
= transmit_chars_putchar
,
172 .receive_chars
= receive_chars_getchar
,
175 static struct sunhv_ops bywrite_ops
= {
176 .transmit_chars
= transmit_chars_write
,
177 .receive_chars
= receive_chars_read
,
180 static struct sunhv_ops
*sunhv_ops
= &bychar_ops
;
182 static struct tty_struct
*receive_chars(struct uart_port
*port
)
184 struct tty_struct
*tty
= NULL
;
186 if (port
->state
!= NULL
) /* Unopened serial console */
187 tty
= port
->state
->port
.tty
;
189 if (sunhv_ops
->receive_chars(port
, tty
))
195 static void transmit_chars(struct uart_port
*port
)
197 struct circ_buf
*xmit
;
202 xmit
= &port
->state
->xmit
;
203 if (uart_circ_empty(xmit
) || uart_tx_stopped(port
))
206 sunhv_ops
->transmit_chars(port
, xmit
);
208 if (uart_circ_chars_pending(xmit
) < WAKEUP_CHARS
)
209 uart_write_wakeup(port
);
212 static irqreturn_t
sunhv_interrupt(int irq
, void *dev_id
)
214 struct uart_port
*port
= dev_id
;
215 struct tty_struct
*tty
;
218 spin_lock_irqsave(&port
->lock
, flags
);
219 tty
= receive_chars(port
);
220 transmit_chars(port
);
221 spin_unlock_irqrestore(&port
->lock
, flags
);
224 tty_flip_buffer_push(tty
);
229 /* port->lock is not held. */
230 static unsigned int sunhv_tx_empty(struct uart_port
*port
)
232 /* Transmitter is always empty for us. If the circ buffer
233 * is non-empty or there is an x_char pending, our caller
234 * will do the right thing and ignore what we return here.
239 /* port->lock held by caller. */
240 static void sunhv_set_mctrl(struct uart_port
*port
, unsigned int mctrl
)
245 /* port->lock is held by caller and interrupts are disabled. */
246 static unsigned int sunhv_get_mctrl(struct uart_port
*port
)
248 return TIOCM_DSR
| TIOCM_CAR
| TIOCM_CTS
;
251 /* port->lock held by caller. */
252 static void sunhv_stop_tx(struct uart_port
*port
)
257 /* port->lock held by caller. */
258 static void sunhv_start_tx(struct uart_port
*port
)
260 transmit_chars(port
);
263 /* port->lock is not held. */
264 static void sunhv_send_xchar(struct uart_port
*port
, char ch
)
269 spin_lock_irqsave(&port
->lock
, flags
);
271 while (limit
-- > 0) {
272 long status
= sun4v_con_putchar(ch
);
273 if (status
== HV_EOK
)
278 spin_unlock_irqrestore(&port
->lock
, flags
);
281 /* port->lock held by caller. */
282 static void sunhv_stop_rx(struct uart_port
*port
)
286 /* port->lock held by caller. */
287 static void sunhv_enable_ms(struct uart_port
*port
)
291 /* port->lock is not held. */
292 static void sunhv_break_ctl(struct uart_port
*port
, int break_state
)
298 spin_lock_irqsave(&port
->lock
, flags
);
300 while (limit
-- > 0) {
301 long status
= sun4v_con_putchar(CON_BREAK
);
302 if (status
== HV_EOK
)
307 spin_unlock_irqrestore(&port
->lock
, flags
);
311 /* port->lock is not held. */
312 static int sunhv_startup(struct uart_port
*port
)
317 /* port->lock is not held. */
318 static void sunhv_shutdown(struct uart_port
*port
)
322 /* port->lock is not held. */
323 static void sunhv_set_termios(struct uart_port
*port
, struct ktermios
*termios
,
324 struct ktermios
*old
)
326 unsigned int baud
= uart_get_baud_rate(port
, termios
, old
, 0, 4000000);
327 unsigned int quot
= uart_get_divisor(port
, baud
);
328 unsigned int iflag
, cflag
;
331 spin_lock_irqsave(&port
->lock
, flags
);
333 iflag
= termios
->c_iflag
;
334 cflag
= termios
->c_cflag
;
336 port
->ignore_status_mask
= 0;
338 port
->ignore_status_mask
|= IGNORE_BREAK
;
339 if ((cflag
& CREAD
) == 0)
340 port
->ignore_status_mask
|= IGNORE_ALL
;
343 uart_update_timeout(port
, cflag
,
344 (port
->uartclk
/ (16 * quot
)));
346 spin_unlock_irqrestore(&port
->lock
, flags
);
349 static const char *sunhv_type(struct uart_port
*port
)
351 return "SUN4V HCONS";
354 static void sunhv_release_port(struct uart_port
*port
)
358 static int sunhv_request_port(struct uart_port
*port
)
363 static void sunhv_config_port(struct uart_port
*port
, int flags
)
367 static int sunhv_verify_port(struct uart_port
*port
, struct serial_struct
*ser
)
372 static struct uart_ops sunhv_pops
= {
373 .tx_empty
= sunhv_tx_empty
,
374 .set_mctrl
= sunhv_set_mctrl
,
375 .get_mctrl
= sunhv_get_mctrl
,
376 .stop_tx
= sunhv_stop_tx
,
377 .start_tx
= sunhv_start_tx
,
378 .send_xchar
= sunhv_send_xchar
,
379 .stop_rx
= sunhv_stop_rx
,
380 .enable_ms
= sunhv_enable_ms
,
381 .break_ctl
= sunhv_break_ctl
,
382 .startup
= sunhv_startup
,
383 .shutdown
= sunhv_shutdown
,
384 .set_termios
= sunhv_set_termios
,
386 .release_port
= sunhv_release_port
,
387 .request_port
= sunhv_request_port
,
388 .config_port
= sunhv_config_port
,
389 .verify_port
= sunhv_verify_port
,
392 static struct uart_driver sunhv_reg
= {
393 .owner
= THIS_MODULE
,
394 .driver_name
= "sunhv",
399 static struct uart_port
*sunhv_port
;
401 /* Copy 's' into the con_write_page, decoding "\n" into
402 * "\r\n" along the way. We have to return two lengths
403 * because the caller needs to know how much to advance
404 * 's' and also how many bytes to output via con_write_page.
406 static int fill_con_write_page(const char *s
, unsigned int n
,
407 unsigned long *page_bytes
)
409 const char *orig_s
= s
;
410 char *p
= con_write_page
;
411 int left
= PAGE_SIZE
;
424 *page_bytes
= p
- con_write_page
;
428 static void sunhv_console_write_paged(struct console
*con
, const char *s
, unsigned n
)
430 struct uart_port
*port
= sunhv_port
;
434 local_irq_save(flags
);
437 } else if (oops_in_progress
) {
438 locked
= spin_trylock(&port
->lock
);
440 spin_lock(&port
->lock
);
443 unsigned long ra
= __pa(con_write_page
);
444 unsigned long page_bytes
;
445 unsigned int cpy
= fill_con_write_page(s
, n
,
450 while (page_bytes
> 0) {
451 unsigned long written
;
457 stat
= sun4v_con_write(ra
, page_bytes
,
465 page_bytes
-= written
;
471 spin_unlock(&port
->lock
);
472 local_irq_restore(flags
);
475 static inline void sunhv_console_putchar(struct uart_port
*port
, char c
)
479 while (limit
-- > 0) {
480 long status
= sun4v_con_putchar(c
);
481 if (status
== HV_EOK
)
487 static void sunhv_console_write_bychar(struct console
*con
, const char *s
, unsigned n
)
489 struct uart_port
*port
= sunhv_port
;
493 local_irq_save(flags
);
496 } else if (oops_in_progress
) {
497 locked
= spin_trylock(&port
->lock
);
499 spin_lock(&port
->lock
);
501 for (i
= 0; i
< n
; i
++) {
503 sunhv_console_putchar(port
, '\r');
504 sunhv_console_putchar(port
, *s
++);
508 spin_unlock(&port
->lock
);
509 local_irq_restore(flags
);
512 static struct console sunhv_console
= {
514 .write
= sunhv_console_write_bychar
,
515 .device
= uart_console_device
,
516 .flags
= CON_PRINTBUFFER
,
521 static int __devinit
hv_probe(struct platform_device
*op
)
523 struct uart_port
*port
;
527 if (op
->archdata
.irqs
[0] == 0xffffffff)
530 port
= kzalloc(sizeof(struct uart_port
), GFP_KERNEL
);
535 if (sun4v_hvapi_register(HV_GRP_CORE
, 1, &minor
) == 0 &&
538 con_write_page
= kzalloc(PAGE_SIZE
, GFP_KERNEL
);
542 con_read_page
= kzalloc(PAGE_SIZE
, GFP_KERNEL
);
544 goto out_free_con_write_page
;
546 sunhv_console
.write
= sunhv_console_write_paged
;
547 sunhv_ops
= &bywrite_ops
;
553 port
->ops
= &sunhv_pops
;
554 port
->type
= PORT_SUNHV
;
555 port
->uartclk
= ( 29491200 / 16 ); /* arbitrary */
557 port
->membase
= (unsigned char __iomem
*) __pa(port
);
559 port
->irq
= op
->archdata
.irqs
[0];
561 port
->dev
= &op
->dev
;
563 err
= sunserial_register_minors(&sunhv_reg
, 1);
565 goto out_free_con_read_page
;
567 sunserial_console_match(&sunhv_console
, op
->dev
.of_node
,
568 &sunhv_reg
, port
->line
, false);
570 err
= uart_add_one_port(&sunhv_reg
, port
);
572 goto out_unregister_driver
;
574 err
= request_irq(port
->irq
, sunhv_interrupt
, 0, "hvcons", port
);
576 goto out_remove_port
;
578 dev_set_drvdata(&op
->dev
, port
);
583 uart_remove_one_port(&sunhv_reg
, port
);
585 out_unregister_driver
:
586 sunserial_unregister_minors(&sunhv_reg
, 1);
588 out_free_con_read_page
:
589 kfree(con_read_page
);
591 out_free_con_write_page
:
592 kfree(con_write_page
);
600 static int __devexit
hv_remove(struct platform_device
*dev
)
602 struct uart_port
*port
= dev_get_drvdata(&dev
->dev
);
604 free_irq(port
->irq
, port
);
606 uart_remove_one_port(&sunhv_reg
, port
);
608 sunserial_unregister_minors(&sunhv_reg
, 1);
613 dev_set_drvdata(&dev
->dev
, NULL
);
618 static const struct of_device_id hv_match
[] = {
625 .compatible
= "SUNW,sun4v-console",
629 MODULE_DEVICE_TABLE(of
, hv_match
);
631 static struct platform_driver hv_driver
= {
634 .owner
= THIS_MODULE
,
635 .of_match_table
= hv_match
,
638 .remove
= __devexit_p(hv_remove
),
641 static int __init
sunhv_init(void)
643 if (tlb_type
!= hypervisor
)
646 return platform_driver_register(&hv_driver
);
649 static void __exit
sunhv_exit(void)
651 platform_driver_unregister(&hv_driver
);
654 module_init(sunhv_init
);
655 module_exit(sunhv_exit
);
657 MODULE_AUTHOR("David S. Miller");
658 MODULE_DESCRIPTION("SUN4V Hypervisor console driver");
659 MODULE_VERSION("2.0");
660 MODULE_LICENSE("GPL");