]>
Commit | Line | Data |
---|---|---|
02fd473b DM |
1 | /* sunhv.c: Serial driver for SUN4V hypervisor console. |
2 | * | |
3 | * Copyright (C) 2006 David S. Miller (davem@davemloft.net) | |
4 | */ | |
5 | ||
6 | #include <linux/module.h> | |
7 | #include <linux/kernel.h> | |
8 | #include <linux/errno.h> | |
9 | #include <linux/tty.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 | ||
21 | #include <asm/hypervisor.h> | |
22 | #include <asm/spitfire.h> | |
f4266ab4 | 23 | #include <asm/vdev.h> |
9d29a3fa | 24 | #include <asm/oplib.h> |
f4266ab4 | 25 | #include <asm/irq.h> |
02fd473b DM |
26 | |
27 | #if defined(CONFIG_MAGIC_SYSRQ) | |
28 | #define SUPPORT_SYSRQ | |
29 | #endif | |
30 | ||
31 | #include <linux/serial_core.h> | |
32 | ||
33 | #include "suncore.h" | |
34 | ||
35 | #define CON_BREAK ((long)-1) | |
36 | #define CON_HUP ((long)-2) | |
37 | ||
38 | static inline long hypervisor_con_getchar(long *status) | |
39 | { | |
40 | register unsigned long func asm("%o5"); | |
41 | register unsigned long arg0 asm("%o0"); | |
42 | register unsigned long arg1 asm("%o1"); | |
43 | ||
44 | func = HV_FAST_CONS_GETCHAR; | |
45 | arg0 = 0; | |
46 | arg1 = 0; | |
47 | __asm__ __volatile__("ta %6" | |
48 | : "=&r" (func), "=&r" (arg0), "=&r" (arg1) | |
49 | : "0" (func), "1" (arg0), "2" (arg1), | |
50 | "i" (HV_FAST_TRAP)); | |
51 | ||
52 | *status = arg0; | |
53 | ||
54 | return (long) arg1; | |
55 | } | |
56 | ||
57 | static inline long hypervisor_con_putchar(long ch) | |
58 | { | |
59 | register unsigned long func asm("%o5"); | |
60 | register unsigned long arg0 asm("%o0"); | |
61 | ||
62 | func = HV_FAST_CONS_PUTCHAR; | |
63 | arg0 = ch; | |
64 | __asm__ __volatile__("ta %4" | |
65 | : "=&r" (func), "=&r" (arg0) | |
66 | : "0" (func), "1" (arg0), "i" (HV_FAST_TRAP)); | |
67 | ||
68 | return (long) arg0; | |
69 | } | |
70 | ||
71 | #define IGNORE_BREAK 0x1 | |
72 | #define IGNORE_ALL 0x2 | |
73 | ||
74 | static int hung_up = 0; | |
75 | ||
76 | static struct tty_struct *receive_chars(struct uart_port *port, struct pt_regs *regs) | |
77 | { | |
78 | struct tty_struct *tty = NULL; | |
79 | int saw_console_brk = 0; | |
80 | int limit = 10000; | |
81 | ||
82 | if (port->info != NULL) /* Unopened serial console */ | |
83 | tty = port->info->tty; | |
84 | ||
85 | while (limit-- > 0) { | |
86 | long status; | |
87 | long c = hypervisor_con_getchar(&status); | |
88 | unsigned char flag; | |
89 | ||
90 | if (status == HV_EWOULDBLOCK) | |
91 | break; | |
92 | ||
93 | if (c == CON_BREAK) { | |
135066a2 DM |
94 | if (uart_handle_break(port)) |
95 | continue; | |
02fd473b DM |
96 | saw_console_brk = 1; |
97 | c = 0; | |
98 | } | |
99 | ||
100 | if (c == CON_HUP) { | |
101 | hung_up = 1; | |
102 | uart_handle_dcd_change(port, 0); | |
103 | } else if (hung_up) { | |
104 | hung_up = 0; | |
105 | uart_handle_dcd_change(port, 1); | |
106 | } | |
107 | ||
108 | if (tty == NULL) { | |
109 | uart_handle_sysrq_char(port, c, regs); | |
110 | continue; | |
111 | } | |
112 | ||
113 | flag = TTY_NORMAL; | |
114 | port->icount.rx++; | |
115 | if (c == CON_BREAK) { | |
116 | port->icount.brk++; | |
117 | if (uart_handle_break(port)) | |
118 | continue; | |
119 | flag = TTY_BREAK; | |
120 | } | |
121 | ||
122 | if (uart_handle_sysrq_char(port, c, regs)) | |
123 | continue; | |
124 | ||
125 | if ((port->ignore_status_mask & IGNORE_ALL) || | |
126 | ((port->ignore_status_mask & IGNORE_BREAK) && | |
127 | (c == CON_BREAK))) | |
128 | continue; | |
129 | ||
130 | tty_insert_flip_char(tty, c, flag); | |
131 | } | |
132 | ||
133 | if (saw_console_brk) | |
134 | sun_do_break(); | |
135 | ||
136 | return tty; | |
137 | } | |
138 | ||
139 | static void transmit_chars(struct uart_port *port) | |
140 | { | |
db33f9bc DM |
141 | struct circ_buf *xmit; |
142 | ||
143 | if (!port->info) | |
144 | return; | |
02fd473b | 145 | |
db33f9bc | 146 | xmit = &port->info->xmit; |
02fd473b DM |
147 | if (uart_circ_empty(xmit) || uart_tx_stopped(port)) |
148 | return; | |
149 | ||
150 | while (!uart_circ_empty(xmit)) { | |
151 | long status = hypervisor_con_putchar(xmit->buf[xmit->tail]); | |
152 | ||
153 | if (status != HV_EOK) | |
154 | break; | |
155 | ||
156 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
157 | port->icount.tx++; | |
158 | } | |
159 | ||
160 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
161 | uart_write_wakeup(port); | |
162 | } | |
163 | ||
164 | static irqreturn_t sunhv_interrupt(int irq, void *dev_id, struct pt_regs *regs) | |
165 | { | |
166 | struct uart_port *port = dev_id; | |
167 | struct tty_struct *tty; | |
168 | unsigned long flags; | |
169 | ||
170 | spin_lock_irqsave(&port->lock, flags); | |
171 | tty = receive_chars(port, regs); | |
172 | transmit_chars(port); | |
173 | spin_unlock_irqrestore(&port->lock, flags); | |
174 | ||
175 | if (tty) | |
176 | tty_flip_buffer_push(tty); | |
177 | ||
178 | return IRQ_HANDLED; | |
179 | } | |
180 | ||
181 | /* port->lock is not held. */ | |
182 | static unsigned int sunhv_tx_empty(struct uart_port *port) | |
183 | { | |
184 | /* Transmitter is always empty for us. If the circ buffer | |
185 | * is non-empty or there is an x_char pending, our caller | |
186 | * will do the right thing and ignore what we return here. | |
187 | */ | |
188 | return TIOCSER_TEMT; | |
189 | } | |
190 | ||
191 | /* port->lock held by caller. */ | |
192 | static void sunhv_set_mctrl(struct uart_port *port, unsigned int mctrl) | |
193 | { | |
194 | return; | |
195 | } | |
196 | ||
197 | /* port->lock is held by caller and interrupts are disabled. */ | |
198 | static unsigned int sunhv_get_mctrl(struct uart_port *port) | |
199 | { | |
200 | return TIOCM_DSR | TIOCM_CAR | TIOCM_CTS; | |
201 | } | |
202 | ||
203 | /* port->lock held by caller. */ | |
204 | static void sunhv_stop_tx(struct uart_port *port) | |
205 | { | |
206 | return; | |
207 | } | |
208 | ||
209 | /* port->lock held by caller. */ | |
210 | static void sunhv_start_tx(struct uart_port *port) | |
211 | { | |
212 | struct circ_buf *xmit = &port->info->xmit; | |
213 | unsigned long flags; | |
214 | ||
215 | spin_lock_irqsave(&port->lock, flags); | |
216 | ||
217 | while (!uart_circ_empty(xmit)) { | |
218 | long status = hypervisor_con_putchar(xmit->buf[xmit->tail]); | |
219 | ||
220 | if (status != HV_EOK) | |
221 | break; | |
222 | ||
223 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
224 | port->icount.tx++; | |
225 | } | |
226 | ||
227 | spin_unlock_irqrestore(&port->lock, flags); | |
228 | } | |
229 | ||
230 | /* port->lock is not held. */ | |
231 | static void sunhv_send_xchar(struct uart_port *port, char ch) | |
232 | { | |
233 | unsigned long flags; | |
234 | int limit = 10000; | |
235 | ||
236 | spin_lock_irqsave(&port->lock, flags); | |
237 | ||
238 | while (limit-- > 0) { | |
239 | long status = hypervisor_con_putchar(ch); | |
240 | if (status == HV_EOK) | |
241 | break; | |
242 | } | |
243 | ||
244 | spin_unlock_irqrestore(&port->lock, flags); | |
245 | } | |
246 | ||
247 | /* port->lock held by caller. */ | |
248 | static void sunhv_stop_rx(struct uart_port *port) | |
249 | { | |
250 | } | |
251 | ||
252 | /* port->lock held by caller. */ | |
253 | static void sunhv_enable_ms(struct uart_port *port) | |
254 | { | |
255 | } | |
256 | ||
257 | /* port->lock is not held. */ | |
258 | static void sunhv_break_ctl(struct uart_port *port, int break_state) | |
259 | { | |
260 | if (break_state) { | |
261 | unsigned long flags; | |
262 | int limit = 10000; | |
263 | ||
264 | spin_lock_irqsave(&port->lock, flags); | |
265 | ||
266 | while (limit-- > 0) { | |
267 | long status = hypervisor_con_putchar(CON_BREAK); | |
268 | if (status == HV_EOK) | |
269 | break; | |
270 | } | |
271 | ||
272 | spin_unlock_irqrestore(&port->lock, flags); | |
273 | } | |
274 | } | |
275 | ||
276 | /* port->lock is not held. */ | |
277 | static int sunhv_startup(struct uart_port *port) | |
278 | { | |
279 | return 0; | |
280 | } | |
281 | ||
282 | /* port->lock is not held. */ | |
283 | static void sunhv_shutdown(struct uart_port *port) | |
284 | { | |
285 | } | |
286 | ||
287 | /* port->lock is not held. */ | |
288 | static void sunhv_set_termios(struct uart_port *port, struct termios *termios, | |
289 | struct termios *old) | |
290 | { | |
291 | unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000); | |
292 | unsigned int quot = uart_get_divisor(port, baud); | |
293 | unsigned int iflag, cflag; | |
294 | unsigned long flags; | |
295 | ||
296 | spin_lock_irqsave(&port->lock, flags); | |
297 | ||
298 | iflag = termios->c_iflag; | |
299 | cflag = termios->c_cflag; | |
300 | ||
301 | port->ignore_status_mask = 0; | |
302 | if (iflag & IGNBRK) | |
303 | port->ignore_status_mask |= IGNORE_BREAK; | |
304 | if ((cflag & CREAD) == 0) | |
305 | port->ignore_status_mask |= IGNORE_ALL; | |
306 | ||
307 | /* XXX */ | |
308 | uart_update_timeout(port, cflag, | |
309 | (port->uartclk / (16 * quot))); | |
310 | ||
311 | spin_unlock_irqrestore(&port->lock, flags); | |
312 | } | |
313 | ||
314 | static const char *sunhv_type(struct uart_port *port) | |
315 | { | |
316 | return "SUN4V HCONS"; | |
317 | } | |
318 | ||
319 | static void sunhv_release_port(struct uart_port *port) | |
320 | { | |
321 | } | |
322 | ||
323 | static int sunhv_request_port(struct uart_port *port) | |
324 | { | |
325 | return 0; | |
326 | } | |
327 | ||
328 | static void sunhv_config_port(struct uart_port *port, int flags) | |
329 | { | |
330 | } | |
331 | ||
332 | static int sunhv_verify_port(struct uart_port *port, struct serial_struct *ser) | |
333 | { | |
334 | return -EINVAL; | |
335 | } | |
336 | ||
337 | static struct uart_ops sunhv_pops = { | |
338 | .tx_empty = sunhv_tx_empty, | |
339 | .set_mctrl = sunhv_set_mctrl, | |
340 | .get_mctrl = sunhv_get_mctrl, | |
341 | .stop_tx = sunhv_stop_tx, | |
342 | .start_tx = sunhv_start_tx, | |
343 | .send_xchar = sunhv_send_xchar, | |
344 | .stop_rx = sunhv_stop_rx, | |
345 | .enable_ms = sunhv_enable_ms, | |
346 | .break_ctl = sunhv_break_ctl, | |
347 | .startup = sunhv_startup, | |
348 | .shutdown = sunhv_shutdown, | |
349 | .set_termios = sunhv_set_termios, | |
350 | .type = sunhv_type, | |
351 | .release_port = sunhv_release_port, | |
352 | .request_port = sunhv_request_port, | |
353 | .config_port = sunhv_config_port, | |
354 | .verify_port = sunhv_verify_port, | |
355 | }; | |
356 | ||
357 | static struct uart_driver sunhv_reg = { | |
358 | .owner = THIS_MODULE, | |
359 | .driver_name = "serial", | |
360 | .devfs_name = "tts/", | |
361 | .dev_name = "ttyS", | |
362 | .major = TTY_MAJOR, | |
363 | }; | |
364 | ||
365 | static struct uart_port *sunhv_port; | |
366 | ||
367 | static inline void sunhv_console_putchar(struct uart_port *port, char c) | |
368 | { | |
369 | unsigned long flags; | |
d5a2aa24 | 370 | int limit = 1000000; |
02fd473b DM |
371 | |
372 | spin_lock_irqsave(&port->lock, flags); | |
373 | ||
374 | while (limit-- > 0) { | |
375 | long status = hypervisor_con_putchar(c); | |
376 | if (status == HV_EOK) | |
377 | break; | |
d5a2aa24 | 378 | udelay(2); |
02fd473b DM |
379 | } |
380 | ||
381 | spin_unlock_irqrestore(&port->lock, flags); | |
382 | } | |
383 | ||
384 | static void sunhv_console_write(struct console *con, const char *s, unsigned n) | |
385 | { | |
386 | struct uart_port *port = sunhv_port; | |
387 | int i; | |
388 | ||
389 | for (i = 0; i < n; i++) { | |
390 | if (*s == '\n') | |
391 | sunhv_console_putchar(port, '\r'); | |
392 | sunhv_console_putchar(port, *s++); | |
393 | } | |
394 | } | |
395 | ||
02fd473b | 396 | static struct console sunhv_console = { |
d5a2aa24 | 397 | .name = "ttyHV", |
02fd473b DM |
398 | .write = sunhv_console_write, |
399 | .device = uart_console_device, | |
02fd473b DM |
400 | .flags = CON_PRINTBUFFER, |
401 | .index = -1, | |
402 | .data = &sunhv_reg, | |
403 | }; | |
404 | ||
d5a2aa24 | 405 | static inline struct console *SUNHV_CONSOLE(void) |
02fd473b DM |
406 | { |
407 | if (con_is_present()) | |
d5a2aa24 | 408 | return NULL; |
02fd473b DM |
409 | |
410 | sunhv_console.index = 0; | |
d5a2aa24 DM |
411 | |
412 | return &sunhv_console; | |
02fd473b DM |
413 | } |
414 | ||
f4266ab4 DM |
415 | static int __init hv_console_compatible(char *buf, int len) |
416 | { | |
417 | while (len) { | |
418 | int this_len; | |
419 | ||
420 | if (!strcmp(buf, "qcn")) | |
421 | return 1; | |
422 | ||
423 | this_len = strlen(buf) + 1; | |
424 | ||
425 | buf += this_len; | |
426 | len -= this_len; | |
427 | } | |
428 | ||
429 | return 0; | |
430 | } | |
431 | ||
432 | static unsigned int __init get_interrupt(void) | |
433 | { | |
434 | const char *cons_str = "console"; | |
435 | const char *compat_str = "compatible"; | |
436 | int node = prom_getchild(sun4v_vdev_root); | |
f4266ab4 DM |
437 | char buf[64]; |
438 | int err, len; | |
439 | ||
440 | node = prom_searchsiblings(node, cons_str); | |
441 | if (!node) | |
442 | return 0; | |
443 | ||
444 | len = prom_getproplen(node, compat_str); | |
445 | if (len == 0 || len == -1) | |
446 | return 0; | |
447 | ||
448 | err = prom_getproperty(node, compat_str, buf, 64); | |
449 | if (err == -1) | |
450 | return 0; | |
451 | ||
452 | if (!hv_console_compatible(buf, len)) | |
453 | return 0; | |
454 | ||
455 | /* Ok, the this is the OBP node for the sun4v hypervisor | |
456 | * console device. Decode the interrupt. | |
457 | */ | |
9d29a3fa | 458 | return sun4v_vdev_device_interrupt(node); |
f4266ab4 DM |
459 | } |
460 | ||
02fd473b DM |
461 | static int __init sunhv_init(void) |
462 | { | |
463 | struct uart_port *port; | |
464 | int ret; | |
465 | ||
466 | if (tlb_type != hypervisor) | |
467 | return -ENODEV; | |
468 | ||
469 | port = kmalloc(sizeof(struct uart_port), GFP_KERNEL); | |
470 | if (unlikely(!port)) | |
471 | return -ENOMEM; | |
472 | ||
db33f9bc DM |
473 | memset(port, 0, sizeof(struct uart_port)); |
474 | ||
02fd473b DM |
475 | port->line = 0; |
476 | port->ops = &sunhv_pops; | |
477 | port->type = PORT_SUNHV; | |
478 | port->uartclk = ( 29491200 / 16 ); /* arbitrary */ | |
479 | ||
db33f9bc DM |
480 | /* Set this just to make uart_configure_port() happy. */ |
481 | port->membase = (unsigned char __iomem *) __pa(port); | |
482 | ||
483 | port->irq = get_interrupt(); | |
484 | if (!port->irq) { | |
02fd473b DM |
485 | kfree(port); |
486 | return -ENODEV; | |
487 | } | |
488 | ||
489 | sunhv_reg.minor = sunserial_current_minor; | |
490 | sunhv_reg.nr = 1; | |
02fd473b DM |
491 | |
492 | ret = uart_register_driver(&sunhv_reg); | |
493 | if (ret < 0) { | |
db33f9bc DM |
494 | printk(KERN_ERR "SUNHV: uart_register_driver() failed %d\n", |
495 | ret); | |
02fd473b DM |
496 | kfree(port); |
497 | ||
498 | return ret; | |
499 | } | |
500 | ||
02fd473b DM |
501 | sunserial_current_minor += 1; |
502 | ||
d5a2aa24 DM |
503 | sunhv_reg.cons = SUNHV_CONSOLE(); |
504 | ||
505 | sunhv_port = port; | |
02fd473b | 506 | |
db33f9bc DM |
507 | ret = uart_add_one_port(&sunhv_reg, port); |
508 | if (ret < 0) { | |
509 | printk(KERN_ERR "SUNHV: uart_add_one_port() failed %d\n", ret); | |
510 | sunserial_current_minor -= 1; | |
511 | uart_unregister_driver(&sunhv_reg); | |
512 | kfree(port); | |
513 | sunhv_port = NULL; | |
514 | return -ENODEV; | |
515 | } | |
516 | ||
517 | if (request_irq(port->irq, sunhv_interrupt, | |
518 | SA_SHIRQ, "serial(sunhv)", port)) { | |
519 | printk(KERN_ERR "sunhv: Cannot register IRQ\n"); | |
520 | uart_remove_one_port(&sunhv_reg, port); | |
521 | sunserial_current_minor -= 1; | |
522 | uart_unregister_driver(&sunhv_reg); | |
523 | kfree(port); | |
524 | sunhv_port = NULL; | |
525 | return -ENODEV; | |
526 | } | |
02fd473b DM |
527 | |
528 | return 0; | |
529 | } | |
530 | ||
531 | static void __exit sunhv_exit(void) | |
532 | { | |
533 | struct uart_port *port = sunhv_port; | |
534 | ||
535 | BUG_ON(!port); | |
536 | ||
db33f9bc DM |
537 | free_irq(port->irq, port); |
538 | ||
02fd473b | 539 | uart_remove_one_port(&sunhv_reg, port); |
02fd473b DM |
540 | sunserial_current_minor -= 1; |
541 | ||
542 | uart_unregister_driver(&sunhv_reg); | |
543 | ||
544 | kfree(sunhv_port); | |
545 | sunhv_port = NULL; | |
546 | } | |
547 | ||
548 | module_init(sunhv_init); | |
549 | module_exit(sunhv_exit); | |
550 | ||
551 | MODULE_AUTHOR("David S. Miller"); | |
552 | MODULE_DESCRIPTION("SUN4V Hypervisor console driver") | |
553 | MODULE_LICENSE("GPL"); |