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>
26 #include <asm/setup.h>
28 #if defined(CONFIG_MAGIC_SYSRQ)
32 #include <linux/serial_core.h>
33 #include <linux/sunserialcore.h>
35 #define CON_BREAK ((long)-1)
36 #define CON_HUP ((long)-2)
38 #define IGNORE_BREAK 0x1
39 #define IGNORE_ALL 0x2
41 static char *con_write_page
;
42 static char *con_read_page
;
44 static int hung_up
= 0;
46 static void transmit_chars_putchar(struct uart_port
*port
, struct circ_buf
*xmit
)
48 while (!uart_circ_empty(xmit
)) {
49 long status
= sun4v_con_putchar(xmit
->buf
[xmit
->tail
]);
54 xmit
->tail
= (xmit
->tail
+ 1) & (UART_XMIT_SIZE
- 1);
59 static void transmit_chars_write(struct uart_port
*port
, struct circ_buf
*xmit
)
61 while (!uart_circ_empty(xmit
)) {
62 unsigned long ra
= __pa(xmit
->buf
+ xmit
->tail
);
63 unsigned long len
, status
, sent
;
65 len
= CIRC_CNT_TO_END(xmit
->head
, xmit
->tail
,
67 status
= sun4v_con_write(ra
, len
, &sent
);
70 xmit
->tail
= (xmit
->tail
+ sent
) & (UART_XMIT_SIZE
- 1);
71 port
->icount
.tx
+= sent
;
75 static int receive_chars_getchar(struct uart_port
*port
)
77 int saw_console_brk
= 0;
82 long c
= sun4v_con_getchar(&status
);
84 if (status
== HV_EWOULDBLOCK
)
88 if (uart_handle_break(port
))
96 uart_handle_dcd_change(port
, 0);
99 uart_handle_dcd_change(port
, 1);
102 if (port
->state
== NULL
) {
103 uart_handle_sysrq_char(port
, c
);
109 if (uart_handle_sysrq_char(port
, c
))
112 tty_insert_flip_char(&port
->state
->port
, c
, TTY_NORMAL
);
115 return saw_console_brk
;
118 static int receive_chars_read(struct uart_port
*port
)
120 int saw_console_brk
= 0;
123 while (limit
-- > 0) {
124 unsigned long ra
= __pa(con_read_page
);
125 unsigned long bytes_read
, i
;
126 long stat
= sun4v_con_read(ra
, PAGE_SIZE
, &bytes_read
);
128 if (stat
!= HV_EOK
) {
131 if (stat
== CON_BREAK
) {
132 if (uart_handle_break(port
))
137 } else if (stat
== CON_HUP
) {
139 uart_handle_dcd_change(port
, 0);
142 /* HV_EWOULDBLOCK, etc. */
149 uart_handle_dcd_change(port
, 1);
152 for (i
= 0; i
< bytes_read
; i
++)
153 uart_handle_sysrq_char(port
, con_read_page
[i
]);
155 if (port
->state
== NULL
)
158 port
->icount
.rx
+= bytes_read
;
160 tty_insert_flip_string(&port
->state
->port
, con_read_page
,
164 return saw_console_brk
;
168 void (*transmit_chars
)(struct uart_port
*port
, struct circ_buf
*xmit
);
169 int (*receive_chars
)(struct uart_port
*port
);
172 static struct sunhv_ops bychar_ops
= {
173 .transmit_chars
= transmit_chars_putchar
,
174 .receive_chars
= receive_chars_getchar
,
177 static struct sunhv_ops bywrite_ops
= {
178 .transmit_chars
= transmit_chars_write
,
179 .receive_chars
= receive_chars_read
,
182 static struct sunhv_ops
*sunhv_ops
= &bychar_ops
;
184 static struct tty_port
*receive_chars(struct uart_port
*port
)
186 struct tty_port
*tport
= NULL
;
188 if (port
->state
!= NULL
) /* Unopened serial console */
189 tport
= &port
->state
->port
;
191 if (sunhv_ops
->receive_chars(port
))
197 static void transmit_chars(struct uart_port
*port
)
199 struct circ_buf
*xmit
;
204 xmit
= &port
->state
->xmit
;
205 if (uart_circ_empty(xmit
) || uart_tx_stopped(port
))
208 sunhv_ops
->transmit_chars(port
, xmit
);
210 if (uart_circ_chars_pending(xmit
) < WAKEUP_CHARS
)
211 uart_write_wakeup(port
);
214 static irqreturn_t
sunhv_interrupt(int irq
, void *dev_id
)
216 struct uart_port
*port
= dev_id
;
217 struct tty_port
*tport
;
220 spin_lock_irqsave(&port
->lock
, flags
);
221 tport
= receive_chars(port
);
222 transmit_chars(port
);
223 spin_unlock_irqrestore(&port
->lock
, flags
);
226 tty_flip_buffer_push(tport
);
231 /* port->lock is not held. */
232 static unsigned int sunhv_tx_empty(struct uart_port
*port
)
234 /* Transmitter is always empty for us. If the circ buffer
235 * is non-empty or there is an x_char pending, our caller
236 * will do the right thing and ignore what we return here.
241 /* port->lock held by caller. */
242 static void sunhv_set_mctrl(struct uart_port
*port
, unsigned int mctrl
)
247 /* port->lock is held by caller and interrupts are disabled. */
248 static unsigned int sunhv_get_mctrl(struct uart_port
*port
)
250 return TIOCM_DSR
| TIOCM_CAR
| TIOCM_CTS
;
253 /* port->lock held by caller. */
254 static void sunhv_stop_tx(struct uart_port
*port
)
259 /* port->lock held by caller. */
260 static void sunhv_start_tx(struct uart_port
*port
)
262 transmit_chars(port
);
265 /* port->lock is not held. */
266 static void sunhv_send_xchar(struct uart_port
*port
, char ch
)
271 if (ch
== __DISABLED_CHAR
)
274 spin_lock_irqsave(&port
->lock
, flags
);
276 while (limit
-- > 0) {
277 long status
= sun4v_con_putchar(ch
);
278 if (status
== HV_EOK
)
283 spin_unlock_irqrestore(&port
->lock
, flags
);
286 /* port->lock held by caller. */
287 static void sunhv_stop_rx(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 .break_ctl
= sunhv_break_ctl
,
381 .startup
= sunhv_startup
,
382 .shutdown
= sunhv_shutdown
,
383 .set_termios
= sunhv_set_termios
,
385 .release_port
= sunhv_release_port
,
386 .request_port
= sunhv_request_port
,
387 .config_port
= sunhv_config_port
,
388 .verify_port
= sunhv_verify_port
,
391 static struct uart_driver sunhv_reg
= {
392 .owner
= THIS_MODULE
,
393 .driver_name
= "sunhv",
398 static struct uart_port
*sunhv_port
;
400 /* Copy 's' into the con_write_page, decoding "\n" into
401 * "\r\n" along the way. We have to return two lengths
402 * because the caller needs to know how much to advance
403 * 's' and also how many bytes to output via con_write_page.
405 static int fill_con_write_page(const char *s
, unsigned int n
,
406 unsigned long *page_bytes
)
408 const char *orig_s
= s
;
409 char *p
= con_write_page
;
410 int left
= PAGE_SIZE
;
423 *page_bytes
= p
- con_write_page
;
427 static void sunhv_console_write_paged(struct console
*con
, const char *s
, unsigned n
)
429 struct uart_port
*port
= sunhv_port
;
433 if (port
->sysrq
|| oops_in_progress
)
434 locked
= spin_trylock_irqsave(&port
->lock
, flags
);
436 spin_lock_irqsave(&port
->lock
, flags
);
439 unsigned long ra
= __pa(con_write_page
);
440 unsigned long page_bytes
;
441 unsigned int cpy
= fill_con_write_page(s
, n
,
446 while (page_bytes
> 0) {
447 unsigned long written
;
453 stat
= sun4v_con_write(ra
, page_bytes
,
461 page_bytes
-= written
;
467 spin_unlock_irqrestore(&port
->lock
, flags
);
470 static inline void sunhv_console_putchar(struct uart_port
*port
, char c
)
474 while (limit
-- > 0) {
475 long status
= sun4v_con_putchar(c
);
476 if (status
== HV_EOK
)
482 static void sunhv_console_write_bychar(struct console
*con
, const char *s
, unsigned n
)
484 struct uart_port
*port
= sunhv_port
;
488 if (port
->sysrq
|| oops_in_progress
)
489 locked
= spin_trylock_irqsave(&port
->lock
, flags
);
491 spin_lock_irqsave(&port
->lock
, flags
);
494 } else if (oops_in_progress
) {
495 locked
= spin_trylock(&port
->lock
);
497 spin_lock(&port
->lock
);
499 for (i
= 0; i
< n
; i
++) {
501 sunhv_console_putchar(port
, '\r');
502 sunhv_console_putchar(port
, *s
++);
506 spin_unlock_irqrestore(&port
->lock
, flags
);
509 static struct console sunhv_console
= {
511 .write
= sunhv_console_write_bychar
,
512 .device
= uart_console_device
,
513 .flags
= CON_PRINTBUFFER
,
518 static int hv_probe(struct platform_device
*op
)
520 struct uart_port
*port
;
524 if (op
->archdata
.irqs
[0] == 0xffffffff)
527 port
= kzalloc(sizeof(struct uart_port
), GFP_KERNEL
);
532 if (sun4v_hvapi_register(HV_GRP_CORE
, 1, &minor
) == 0 &&
535 con_write_page
= kzalloc(PAGE_SIZE
, GFP_KERNEL
);
539 con_read_page
= kzalloc(PAGE_SIZE
, GFP_KERNEL
);
541 goto out_free_con_write_page
;
543 sunhv_console
.write
= sunhv_console_write_paged
;
544 sunhv_ops
= &bywrite_ops
;
550 port
->ops
= &sunhv_pops
;
551 port
->type
= PORT_SUNHV
;
552 port
->uartclk
= ( 29491200 / 16 ); /* arbitrary */
554 port
->membase
= (unsigned char __iomem
*) __pa(port
);
556 port
->irq
= op
->archdata
.irqs
[0];
558 port
->dev
= &op
->dev
;
560 err
= sunserial_register_minors(&sunhv_reg
, 1);
562 goto out_free_con_read_page
;
564 sunserial_console_match(&sunhv_console
, op
->dev
.of_node
,
565 &sunhv_reg
, port
->line
, false);
567 err
= uart_add_one_port(&sunhv_reg
, port
);
569 goto out_unregister_driver
;
571 err
= request_irq(port
->irq
, sunhv_interrupt
, 0, "hvcons", port
);
573 goto out_remove_port
;
575 platform_set_drvdata(op
, port
);
580 uart_remove_one_port(&sunhv_reg
, port
);
582 out_unregister_driver
:
583 sunserial_unregister_minors(&sunhv_reg
, 1);
585 out_free_con_read_page
:
586 kfree(con_read_page
);
588 out_free_con_write_page
:
589 kfree(con_write_page
);
597 static int hv_remove(struct platform_device
*dev
)
599 struct uart_port
*port
= platform_get_drvdata(dev
);
601 free_irq(port
->irq
, port
);
603 uart_remove_one_port(&sunhv_reg
, port
);
605 sunserial_unregister_minors(&sunhv_reg
, 1);
613 static const struct of_device_id hv_match
[] = {
620 .compatible
= "SUNW,sun4v-console",
624 MODULE_DEVICE_TABLE(of
, hv_match
);
626 static struct platform_driver hv_driver
= {
629 .of_match_table
= hv_match
,
635 static int __init
sunhv_init(void)
637 if (tlb_type
!= hypervisor
)
640 return platform_driver_register(&hv_driver
);
643 static void __exit
sunhv_exit(void)
645 platform_driver_unregister(&hv_driver
);
648 module_init(sunhv_init
);
649 module_exit(sunhv_exit
);
651 MODULE_AUTHOR("David S. Miller");
652 MODULE_DESCRIPTION("SUN4V Hypervisor console driver");
653 MODULE_VERSION("2.0");
654 MODULE_LICENSE("GPL");