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Commit | Line | Data |
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02fd473b DM |
1 | /* sunhv.c: Serial driver for SUN4V hypervisor console. |
2 | * | |
3 | * Copyright (C) 2006 David S. Miller ([email protected]) | |
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> | |
93872ba2 DM |
23 | #include <asm/prom.h> |
24 | #include <asm/of_device.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 | ||
7d12e780 | 76 | static struct tty_struct *receive_chars(struct uart_port *port) |
02fd473b DM |
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) { | |
7d12e780 | 109 | uart_handle_sysrq_char(port, c); |
02fd473b DM |
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 | ||
7d12e780 | 122 | if (uart_handle_sysrq_char(port, c)) |
02fd473b DM |
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 | ||
7d12e780 | 164 | static irqreturn_t sunhv_interrupt(int irq, void *dev_id) |
02fd473b DM |
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); | |
7d12e780 | 171 | tty = receive_chars(port); |
02fd473b DM |
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; | |
02fd473b DM |
213 | |
214 | while (!uart_circ_empty(xmit)) { | |
215 | long status = hypervisor_con_putchar(xmit->buf[xmit->tail]); | |
216 | ||
217 | if (status != HV_EOK) | |
218 | break; | |
219 | ||
220 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
221 | port->icount.tx++; | |
222 | } | |
02fd473b DM |
223 | } |
224 | ||
225 | /* port->lock is not held. */ | |
226 | static void sunhv_send_xchar(struct uart_port *port, char ch) | |
227 | { | |
228 | unsigned long flags; | |
229 | int limit = 10000; | |
230 | ||
231 | spin_lock_irqsave(&port->lock, flags); | |
232 | ||
233 | while (limit-- > 0) { | |
234 | long status = hypervisor_con_putchar(ch); | |
235 | if (status == HV_EOK) | |
236 | break; | |
237 | } | |
238 | ||
239 | spin_unlock_irqrestore(&port->lock, flags); | |
240 | } | |
241 | ||
242 | /* port->lock held by caller. */ | |
243 | static void sunhv_stop_rx(struct uart_port *port) | |
244 | { | |
245 | } | |
246 | ||
247 | /* port->lock held by caller. */ | |
248 | static void sunhv_enable_ms(struct uart_port *port) | |
249 | { | |
250 | } | |
251 | ||
252 | /* port->lock is not held. */ | |
253 | static void sunhv_break_ctl(struct uart_port *port, int break_state) | |
254 | { | |
255 | if (break_state) { | |
256 | unsigned long flags; | |
843dfb4d | 257 | int limit = 1000000; |
02fd473b DM |
258 | |
259 | spin_lock_irqsave(&port->lock, flags); | |
260 | ||
261 | while (limit-- > 0) { | |
262 | long status = hypervisor_con_putchar(CON_BREAK); | |
263 | if (status == HV_EOK) | |
264 | break; | |
843dfb4d | 265 | udelay(2); |
02fd473b DM |
266 | } |
267 | ||
268 | spin_unlock_irqrestore(&port->lock, flags); | |
269 | } | |
270 | } | |
271 | ||
272 | /* port->lock is not held. */ | |
273 | static int sunhv_startup(struct uart_port *port) | |
274 | { | |
275 | return 0; | |
276 | } | |
277 | ||
278 | /* port->lock is not held. */ | |
279 | static void sunhv_shutdown(struct uart_port *port) | |
280 | { | |
281 | } | |
282 | ||
283 | /* port->lock is not held. */ | |
284 | static void sunhv_set_termios(struct uart_port *port, struct termios *termios, | |
285 | struct termios *old) | |
286 | { | |
287 | unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000); | |
288 | unsigned int quot = uart_get_divisor(port, baud); | |
289 | unsigned int iflag, cflag; | |
290 | unsigned long flags; | |
291 | ||
292 | spin_lock_irqsave(&port->lock, flags); | |
293 | ||
294 | iflag = termios->c_iflag; | |
295 | cflag = termios->c_cflag; | |
296 | ||
297 | port->ignore_status_mask = 0; | |
298 | if (iflag & IGNBRK) | |
299 | port->ignore_status_mask |= IGNORE_BREAK; | |
300 | if ((cflag & CREAD) == 0) | |
301 | port->ignore_status_mask |= IGNORE_ALL; | |
302 | ||
303 | /* XXX */ | |
304 | uart_update_timeout(port, cflag, | |
305 | (port->uartclk / (16 * quot))); | |
306 | ||
307 | spin_unlock_irqrestore(&port->lock, flags); | |
308 | } | |
309 | ||
310 | static const char *sunhv_type(struct uart_port *port) | |
311 | { | |
312 | return "SUN4V HCONS"; | |
313 | } | |
314 | ||
315 | static void sunhv_release_port(struct uart_port *port) | |
316 | { | |
317 | } | |
318 | ||
319 | static int sunhv_request_port(struct uart_port *port) | |
320 | { | |
321 | return 0; | |
322 | } | |
323 | ||
324 | static void sunhv_config_port(struct uart_port *port, int flags) | |
325 | { | |
326 | } | |
327 | ||
328 | static int sunhv_verify_port(struct uart_port *port, struct serial_struct *ser) | |
329 | { | |
330 | return -EINVAL; | |
331 | } | |
332 | ||
333 | static struct uart_ops sunhv_pops = { | |
334 | .tx_empty = sunhv_tx_empty, | |
335 | .set_mctrl = sunhv_set_mctrl, | |
336 | .get_mctrl = sunhv_get_mctrl, | |
337 | .stop_tx = sunhv_stop_tx, | |
338 | .start_tx = sunhv_start_tx, | |
339 | .send_xchar = sunhv_send_xchar, | |
340 | .stop_rx = sunhv_stop_rx, | |
341 | .enable_ms = sunhv_enable_ms, | |
342 | .break_ctl = sunhv_break_ctl, | |
343 | .startup = sunhv_startup, | |
344 | .shutdown = sunhv_shutdown, | |
345 | .set_termios = sunhv_set_termios, | |
346 | .type = sunhv_type, | |
347 | .release_port = sunhv_release_port, | |
348 | .request_port = sunhv_request_port, | |
349 | .config_port = sunhv_config_port, | |
350 | .verify_port = sunhv_verify_port, | |
351 | }; | |
352 | ||
353 | static struct uart_driver sunhv_reg = { | |
354 | .owner = THIS_MODULE, | |
355 | .driver_name = "serial", | |
02fd473b DM |
356 | .dev_name = "ttyS", |
357 | .major = TTY_MAJOR, | |
358 | }; | |
359 | ||
360 | static struct uart_port *sunhv_port; | |
361 | ||
362 | static inline void sunhv_console_putchar(struct uart_port *port, char c) | |
363 | { | |
364 | unsigned long flags; | |
d5a2aa24 | 365 | int limit = 1000000; |
02fd473b DM |
366 | |
367 | spin_lock_irqsave(&port->lock, flags); | |
368 | ||
369 | while (limit-- > 0) { | |
370 | long status = hypervisor_con_putchar(c); | |
371 | if (status == HV_EOK) | |
372 | break; | |
d5a2aa24 | 373 | udelay(2); |
02fd473b DM |
374 | } |
375 | ||
376 | spin_unlock_irqrestore(&port->lock, flags); | |
377 | } | |
378 | ||
379 | static void sunhv_console_write(struct console *con, const char *s, unsigned n) | |
380 | { | |
381 | struct uart_port *port = sunhv_port; | |
382 | int i; | |
383 | ||
384 | for (i = 0; i < n; i++) { | |
385 | if (*s == '\n') | |
386 | sunhv_console_putchar(port, '\r'); | |
387 | sunhv_console_putchar(port, *s++); | |
388 | } | |
389 | } | |
390 | ||
02fd473b | 391 | static struct console sunhv_console = { |
d5a2aa24 | 392 | .name = "ttyHV", |
02fd473b DM |
393 | .write = sunhv_console_write, |
394 | .device = uart_console_device, | |
02fd473b DM |
395 | .flags = CON_PRINTBUFFER, |
396 | .index = -1, | |
397 | .data = &sunhv_reg, | |
398 | }; | |
399 | ||
d5a2aa24 | 400 | static inline struct console *SUNHV_CONSOLE(void) |
02fd473b DM |
401 | { |
402 | if (con_is_present()) | |
d5a2aa24 | 403 | return NULL; |
02fd473b DM |
404 | |
405 | sunhv_console.index = 0; | |
d5a2aa24 DM |
406 | |
407 | return &sunhv_console; | |
02fd473b DM |
408 | } |
409 | ||
93872ba2 | 410 | static int __devinit hv_probe(struct of_device *op, const struct of_device_id *match) |
02fd473b DM |
411 | { |
412 | struct uart_port *port; | |
93872ba2 | 413 | int err; |
02fd473b | 414 | |
93872ba2 | 415 | if (op->irqs[0] == 0xffffffff) |
02fd473b DM |
416 | return -ENODEV; |
417 | ||
93872ba2 | 418 | port = kzalloc(sizeof(struct uart_port), GFP_KERNEL); |
02fd473b DM |
419 | if (unlikely(!port)) |
420 | return -ENOMEM; | |
421 | ||
93872ba2 | 422 | sunhv_port = port; |
db33f9bc | 423 | |
02fd473b DM |
424 | port->line = 0; |
425 | port->ops = &sunhv_pops; | |
426 | port->type = PORT_SUNHV; | |
427 | port->uartclk = ( 29491200 / 16 ); /* arbitrary */ | |
428 | ||
db33f9bc DM |
429 | port->membase = (unsigned char __iomem *) __pa(port); |
430 | ||
93872ba2 DM |
431 | port->irq = op->irqs[0]; |
432 | ||
433 | port->dev = &op->dev; | |
02fd473b DM |
434 | |
435 | sunhv_reg.minor = sunserial_current_minor; | |
436 | sunhv_reg.nr = 1; | |
02fd473b | 437 | |
93872ba2 DM |
438 | err = uart_register_driver(&sunhv_reg); |
439 | if (err) | |
440 | goto out_free_port; | |
02fd473b | 441 | |
f5deb807 | 442 | sunhv_reg.tty_driver->name_base = sunhv_reg.minor - 64; |
02fd473b DM |
443 | sunserial_current_minor += 1; |
444 | ||
d5a2aa24 DM |
445 | sunhv_reg.cons = SUNHV_CONSOLE(); |
446 | ||
93872ba2 DM |
447 | err = uart_add_one_port(&sunhv_reg, port); |
448 | if (err) | |
449 | goto out_unregister_driver; | |
02fd473b | 450 | |
93872ba2 DM |
451 | err = request_irq(port->irq, sunhv_interrupt, 0, "hvcons", port); |
452 | if (err) | |
453 | goto out_remove_port; | |
db33f9bc | 454 | |
93872ba2 | 455 | dev_set_drvdata(&op->dev, port); |
02fd473b DM |
456 | |
457 | return 0; | |
93872ba2 DM |
458 | |
459 | out_remove_port: | |
460 | uart_remove_one_port(&sunhv_reg, port); | |
461 | ||
462 | out_unregister_driver: | |
463 | sunserial_current_minor -= 1; | |
464 | uart_unregister_driver(&sunhv_reg); | |
465 | ||
466 | out_free_port: | |
467 | kfree(port); | |
468 | sunhv_port = NULL; | |
469 | return err; | |
02fd473b DM |
470 | } |
471 | ||
93872ba2 | 472 | static int __devexit hv_remove(struct of_device *dev) |
02fd473b | 473 | { |
93872ba2 | 474 | struct uart_port *port = dev_get_drvdata(&dev->dev); |
02fd473b | 475 | |
db33f9bc DM |
476 | free_irq(port->irq, port); |
477 | ||
02fd473b | 478 | uart_remove_one_port(&sunhv_reg, port); |
02fd473b | 479 | |
93872ba2 | 480 | sunserial_current_minor -= 1; |
02fd473b DM |
481 | uart_unregister_driver(&sunhv_reg); |
482 | ||
93872ba2 | 483 | kfree(port); |
02fd473b | 484 | sunhv_port = NULL; |
93872ba2 DM |
485 | |
486 | dev_set_drvdata(&dev->dev, NULL); | |
487 | ||
488 | return 0; | |
489 | } | |
490 | ||
491 | static struct of_device_id hv_match[] = { | |
492 | { | |
493 | .name = "console", | |
494 | .compatible = "qcn", | |
495 | }, | |
496 | {}, | |
497 | }; | |
498 | MODULE_DEVICE_TABLE(of, hv_match); | |
499 | ||
500 | static struct of_platform_driver hv_driver = { | |
501 | .name = "hv", | |
502 | .match_table = hv_match, | |
503 | .probe = hv_probe, | |
504 | .remove = __devexit_p(hv_remove), | |
505 | }; | |
506 | ||
507 | static int __init sunhv_init(void) | |
508 | { | |
509 | if (tlb_type != hypervisor) | |
510 | return -ENODEV; | |
511 | ||
512 | return of_register_driver(&hv_driver, &of_bus_type); | |
513 | } | |
514 | ||
515 | static void __exit sunhv_exit(void) | |
516 | { | |
517 | of_unregister_driver(&hv_driver); | |
02fd473b DM |
518 | } |
519 | ||
520 | module_init(sunhv_init); | |
521 | module_exit(sunhv_exit); | |
522 | ||
523 | MODULE_AUTHOR("David S. Miller"); | |
93872ba2 DM |
524 | MODULE_DESCRIPTION("SUN4V Hypervisor console driver"); |
525 | MODULE_VERSION("2.0"); | |
02fd473b | 526 | MODULE_LICENSE("GPL"); |