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1da177e4 LT |
1 | /* |
2 | ** mux.c: | |
3 | ** serial driver for the Mux console found in some PA-RISC servers. | |
4 | ** | |
5 | ** (c) Copyright 2002 Ryan Bradetich | |
6 | ** (c) Copyright 2002 Hewlett-Packard Company | |
7 | ** | |
8 | ** This program is free software; you can redistribute it and/or modify | |
9 | ** it under the terms of the GNU General Public License as published by | |
10 | ** the Free Software Foundation; either version 2 of the License, or | |
11 | ** (at your option) any later version. | |
12 | ** | |
13 | ** This Driver currently only supports the console (port 0) on the MUX. | |
14 | ** Additional work will be needed on this driver to enable the full | |
15 | ** functionality of the MUX. | |
16 | ** | |
17 | */ | |
18 | ||
19 | #include <linux/config.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/tty.h> | |
22 | #include <linux/ioport.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/serial.h> | |
25 | #include <linux/console.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/delay.h> /* for udelay */ | |
28 | #include <linux/device.h> | |
29 | #include <asm/io.h> | |
30 | #include <asm/parisc-device.h> | |
31 | ||
32 | #ifdef CONFIG_MAGIC_SYSRQ | |
33 | #include <linux/sysrq.h> | |
34 | #define SUPPORT_SYSRQ | |
35 | #endif | |
36 | ||
37 | #include <linux/serial_core.h> | |
38 | ||
39 | #define MUX_OFFSET 0x800 | |
40 | #define MUX_LINE_OFFSET 0x80 | |
41 | ||
42 | #define MUX_FIFO_SIZE 255 | |
43 | #define MUX_POLL_DELAY (30 * HZ / 1000) | |
44 | ||
45 | #define IO_DATA_REG_OFFSET 0x3c | |
46 | #define IO_DCOUNT_REG_OFFSET 0x40 | |
47 | ||
48 | #define MUX_EOFIFO(status) ((status & 0xF000) == 0xF000) | |
49 | #define MUX_STATUS(status) ((status & 0xF000) == 0x8000) | |
50 | #define MUX_BREAK(status) ((status & 0xF000) == 0x2000) | |
51 | ||
52 | #define MUX_NR 256 | |
53 | static unsigned int port_cnt = 0; | |
54 | static struct uart_port mux_ports[MUX_NR]; | |
55 | ||
56 | static struct uart_driver mux_driver = { | |
57 | .owner = THIS_MODULE, | |
58 | .driver_name = "ttyB", | |
59 | .dev_name = "ttyB", | |
60 | .major = MUX_MAJOR, | |
61 | .minor = 0, | |
62 | .nr = MUX_NR, | |
63 | }; | |
64 | ||
65 | static struct timer_list mux_timer; | |
66 | ||
67 | #define UART_PUT_CHAR(p, c) __raw_writel((c), (unsigned long)(p)->membase + IO_DATA_REG_OFFSET) | |
68 | #define UART_GET_FIFO_CNT(p) __raw_readl((unsigned long)(p)->membase + IO_DCOUNT_REG_OFFSET) | |
69 | #define GET_MUX_PORTS(iodc_data) ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8 | |
70 | ||
71 | /** | |
72 | * mux_tx_empty - Check if the transmitter fifo is empty. | |
73 | * @port: Ptr to the uart_port. | |
74 | * | |
75 | * This function test if the transmitter fifo for the port | |
76 | * described by 'port' is empty. If it is empty, this function | |
77 | * should return TIOCSER_TEMT, otherwise return 0. | |
78 | */ | |
79 | static unsigned int mux_tx_empty(struct uart_port *port) | |
80 | { | |
81 | unsigned int cnt = __raw_readl((unsigned long)port->membase | |
82 | + IO_DCOUNT_REG_OFFSET); | |
83 | ||
84 | return cnt ? 0 : TIOCSER_TEMT; | |
85 | } | |
86 | ||
87 | /** | |
88 | * mux_set_mctrl - Set the current state of the modem control inputs. | |
89 | * @ports: Ptr to the uart_port. | |
90 | * @mctrl: Modem control bits. | |
91 | * | |
92 | * The Serial MUX does not support CTS, DCD or DSR so this function | |
93 | * is ignored. | |
94 | */ | |
95 | static void mux_set_mctrl(struct uart_port *port, unsigned int mctrl) | |
96 | { | |
97 | } | |
98 | ||
99 | /** | |
100 | * mux_get_mctrl - Returns the current state of modem control inputs. | |
101 | * @port: Ptr to the uart_port. | |
102 | * | |
103 | * The Serial MUX does not support CTS, DCD or DSR so these lines are | |
104 | * treated as permanently active. | |
105 | */ | |
106 | static unsigned int mux_get_mctrl(struct uart_port *port) | |
107 | { | |
108 | return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; | |
109 | } | |
110 | ||
111 | /** | |
112 | * mux_stop_tx - Stop transmitting characters. | |
113 | * @port: Ptr to the uart_port. | |
114 | * @tty_stop: tty layer issue this command? | |
115 | * | |
116 | * The Serial MUX does not support this function. | |
117 | */ | |
118 | static void mux_stop_tx(struct uart_port *port, unsigned int tty_stop) | |
119 | { | |
120 | } | |
121 | ||
122 | /** | |
123 | * mux_start_tx - Start transmitting characters. | |
124 | * @port: Ptr to the uart_port. | |
125 | * @tty_start: tty layer issue this command? | |
126 | * | |
127 | * The Serial Mux does not support this function. | |
128 | */ | |
129 | static void mux_start_tx(struct uart_port *port, unsigned int tty_start) | |
130 | { | |
131 | } | |
132 | ||
133 | /** | |
134 | * mux_stop_rx - Stop receiving characters. | |
135 | * @port: Ptr to the uart_port. | |
136 | * | |
137 | * The Serial Mux does not support this function. | |
138 | */ | |
139 | static void mux_stop_rx(struct uart_port *port) | |
140 | { | |
141 | } | |
142 | ||
143 | /** | |
144 | * mux_enable_ms - Enable modum status interrupts. | |
145 | * @port: Ptr to the uart_port. | |
146 | * | |
147 | * The Serial Mux does not support this function. | |
148 | */ | |
149 | static void mux_enable_ms(struct uart_port *port) | |
150 | { | |
151 | } | |
152 | ||
153 | /** | |
154 | * mux_break_ctl - Control the transmitssion of a break signal. | |
155 | * @port: Ptr to the uart_port. | |
156 | * @break_state: Raise/Lower the break signal. | |
157 | * | |
158 | * The Serial Mux does not support this function. | |
159 | */ | |
160 | static void mux_break_ctl(struct uart_port *port, int break_state) | |
161 | { | |
162 | } | |
163 | ||
164 | /** | |
165 | * mux_write - Write chars to the mux fifo. | |
166 | * @port: Ptr to the uart_port. | |
167 | * | |
168 | * This function writes all the data from the uart buffer to | |
169 | * the mux fifo. | |
170 | */ | |
171 | static void mux_write(struct uart_port *port) | |
172 | { | |
173 | int count; | |
174 | struct circ_buf *xmit = &port->info->xmit; | |
175 | ||
176 | if(port->x_char) { | |
177 | UART_PUT_CHAR(port, port->x_char); | |
178 | port->icount.tx++; | |
179 | port->x_char = 0; | |
180 | return; | |
181 | } | |
182 | ||
183 | if(uart_circ_empty(xmit) || uart_tx_stopped(port)) { | |
184 | mux_stop_tx(port, 0); | |
185 | return; | |
186 | } | |
187 | ||
188 | count = (port->fifosize) - UART_GET_FIFO_CNT(port); | |
189 | do { | |
190 | UART_PUT_CHAR(port, xmit->buf[xmit->tail]); | |
191 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
192 | port->icount.tx++; | |
193 | if(uart_circ_empty(xmit)) | |
194 | break; | |
195 | ||
196 | } while(--count > 0); | |
197 | ||
198 | while(UART_GET_FIFO_CNT(port)) | |
199 | udelay(1); | |
200 | ||
201 | if(uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
202 | uart_write_wakeup(port); | |
203 | ||
204 | if (uart_circ_empty(xmit)) | |
205 | mux_stop_tx(port, 0); | |
206 | } | |
207 | ||
208 | /** | |
209 | * mux_read - Read chars from the mux fifo. | |
210 | * @port: Ptr to the uart_port. | |
211 | * | |
212 | * This reads all available data from the mux's fifo and pushes | |
213 | * the data to the tty layer. | |
214 | */ | |
215 | static void mux_read(struct uart_port *port) | |
216 | { | |
217 | int data; | |
218 | struct tty_struct *tty = port->info->tty; | |
219 | __u32 start_count = port->icount.rx; | |
220 | ||
221 | while(1) { | |
222 | data = __raw_readl((unsigned long)port->membase | |
223 | + IO_DATA_REG_OFFSET); | |
224 | ||
225 | if (MUX_STATUS(data)) | |
226 | continue; | |
227 | ||
228 | if (MUX_EOFIFO(data)) | |
229 | break; | |
230 | ||
231 | if (tty->flip.count >= TTY_FLIPBUF_SIZE) | |
232 | continue; | |
233 | ||
234 | *tty->flip.char_buf_ptr = data & 0xffu; | |
235 | *tty->flip.flag_buf_ptr = TTY_NORMAL; | |
236 | port->icount.rx++; | |
237 | ||
238 | if (MUX_BREAK(data)) { | |
239 | port->icount.brk++; | |
240 | if(uart_handle_break(port)) | |
241 | continue; | |
242 | } | |
243 | ||
244 | if (uart_handle_sysrq_char(port, data & 0xffu, NULL)) | |
245 | continue; | |
246 | ||
247 | tty->flip.flag_buf_ptr++; | |
248 | tty->flip.char_buf_ptr++; | |
249 | tty->flip.count++; | |
250 | } | |
251 | ||
252 | if (start_count != port->icount.rx) { | |
253 | tty_flip_buffer_push(tty); | |
254 | } | |
255 | } | |
256 | ||
257 | /** | |
258 | * mux_startup - Initialize the port. | |
259 | * @port: Ptr to the uart_port. | |
260 | * | |
261 | * Grab any resources needed for this port and start the | |
262 | * mux timer. | |
263 | */ | |
264 | static int mux_startup(struct uart_port *port) | |
265 | { | |
266 | mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY); | |
267 | return 0; | |
268 | } | |
269 | ||
270 | /** | |
271 | * mux_shutdown - Disable the port. | |
272 | * @port: Ptr to the uart_port. | |
273 | * | |
274 | * Release any resources needed for the port. | |
275 | */ | |
276 | static void mux_shutdown(struct uart_port *port) | |
277 | { | |
278 | } | |
279 | ||
280 | /** | |
281 | * mux_set_termios - Chane port parameters. | |
282 | * @port: Ptr to the uart_port. | |
283 | * @termios: new termios settings. | |
284 | * @old: old termios settings. | |
285 | * | |
286 | * The Serial Mux does not support this function. | |
287 | */ | |
288 | static void | |
289 | mux_set_termios(struct uart_port *port, struct termios *termios, | |
290 | struct termios *old) | |
291 | { | |
292 | } | |
293 | ||
294 | /** | |
295 | * mux_type - Describe the port. | |
296 | * @port: Ptr to the uart_port. | |
297 | * | |
298 | * Return a pointer to a string constant describing the | |
299 | * specified port. | |
300 | */ | |
301 | static const char *mux_type(struct uart_port *port) | |
302 | { | |
303 | return "Mux"; | |
304 | } | |
305 | ||
306 | /** | |
307 | * mux_release_port - Release memory and IO regions. | |
308 | * @port: Ptr to the uart_port. | |
309 | * | |
310 | * Release any memory and IO region resources currently in use by | |
311 | * the port. | |
312 | */ | |
313 | static void mux_release_port(struct uart_port *port) | |
314 | { | |
315 | } | |
316 | ||
317 | /** | |
318 | * mux_request_port - Request memory and IO regions. | |
319 | * @port: Ptr to the uart_port. | |
320 | * | |
321 | * Request any memory and IO region resources required by the port. | |
322 | * If any fail, no resources should be registered when this function | |
323 | * returns, and it should return -EBUSY on failure. | |
324 | */ | |
325 | static int mux_request_port(struct uart_port *port) | |
326 | { | |
327 | return 0; | |
328 | } | |
329 | ||
330 | /** | |
331 | * mux_config_port - Perform port autoconfiguration. | |
332 | * @port: Ptr to the uart_port. | |
333 | * @type: Bitmask of required configurations. | |
334 | * | |
335 | * Perform any autoconfiguration steps for the port. This functino is | |
336 | * called if the UPF_BOOT_AUTOCONF flag is specified for the port. | |
337 | * [Note: This is required for now because of a bug in the Serial core. | |
338 | * rmk has already submitted a patch to linus, should be available for | |
339 | * 2.5.47.] | |
340 | */ | |
341 | static void mux_config_port(struct uart_port *port, int type) | |
342 | { | |
343 | port->type = PORT_MUX; | |
344 | } | |
345 | ||
346 | /** | |
347 | * mux_verify_port - Verify the port information. | |
348 | * @port: Ptr to the uart_port. | |
349 | * @ser: Ptr to the serial information. | |
350 | * | |
351 | * Verify the new serial port information contained within serinfo is | |
352 | * suitable for this port type. | |
353 | */ | |
354 | static int mux_verify_port(struct uart_port *port, struct serial_struct *ser) | |
355 | { | |
356 | if(port->membase == NULL) | |
357 | return -EINVAL; | |
358 | ||
359 | return 0; | |
360 | } | |
361 | ||
362 | /** | |
363 | * mux_drv_poll - Mux poll function. | |
364 | * @unused: Unused variable | |
365 | * | |
366 | * This function periodically polls the Serial MUX to check for new data. | |
367 | */ | |
368 | static void mux_poll(unsigned long unused) | |
369 | { | |
370 | int i; | |
371 | ||
372 | for(i = 0; i < port_cnt; ++i) { | |
373 | if(!mux_ports[i].info) | |
374 | continue; | |
375 | ||
376 | mux_read(&mux_ports[i]); | |
377 | mux_write(&mux_ports[i]); | |
378 | } | |
379 | ||
380 | mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY); | |
381 | } | |
382 | ||
383 | ||
384 | #ifdef CONFIG_SERIAL_MUX_CONSOLE | |
385 | static void mux_console_write(struct console *co, const char *s, unsigned count) | |
386 | { | |
387 | while(count--) | |
388 | pdc_iodc_putc(*s++); | |
389 | } | |
390 | ||
391 | static int mux_console_setup(struct console *co, char *options) | |
392 | { | |
393 | return 0; | |
394 | } | |
395 | ||
396 | struct tty_driver *mux_console_device(struct console *co, int *index) | |
397 | { | |
398 | *index = co->index; | |
399 | return mux_driver.tty_driver; | |
400 | } | |
401 | ||
402 | static struct console mux_console = { | |
403 | .name = "ttyB", | |
404 | .write = mux_console_write, | |
405 | .device = mux_console_device, | |
406 | .setup = mux_console_setup, | |
407 | .flags = CON_ENABLED | CON_PRINTBUFFER, | |
408 | .index = 0, | |
409 | }; | |
410 | ||
411 | #define MUX_CONSOLE &mux_console | |
412 | #else | |
413 | #define MUX_CONSOLE NULL | |
414 | #endif | |
415 | ||
416 | static struct uart_ops mux_pops = { | |
417 | .tx_empty = mux_tx_empty, | |
418 | .set_mctrl = mux_set_mctrl, | |
419 | .get_mctrl = mux_get_mctrl, | |
420 | .stop_tx = mux_stop_tx, | |
421 | .start_tx = mux_start_tx, | |
422 | .stop_rx = mux_stop_rx, | |
423 | .enable_ms = mux_enable_ms, | |
424 | .break_ctl = mux_break_ctl, | |
425 | .startup = mux_startup, | |
426 | .shutdown = mux_shutdown, | |
427 | .set_termios = mux_set_termios, | |
428 | .type = mux_type, | |
429 | .release_port = mux_release_port, | |
430 | .request_port = mux_request_port, | |
431 | .config_port = mux_config_port, | |
432 | .verify_port = mux_verify_port, | |
433 | }; | |
434 | ||
435 | /** | |
436 | * mux_probe - Determine if the Serial Mux should claim this device. | |
437 | * @dev: The parisc device. | |
438 | * | |
439 | * Deterimine if the Serial Mux should claim this chip (return 0) | |
440 | * or not (return 1). | |
441 | */ | |
442 | static int __init mux_probe(struct parisc_device *dev) | |
443 | { | |
444 | int i, status, ports; | |
445 | u8 iodc_data[32]; | |
446 | unsigned long bytecnt; | |
447 | struct uart_port *port; | |
448 | ||
449 | status = pdc_iodc_read(&bytecnt, dev->hpa, 0, iodc_data, 32); | |
450 | if(status != PDC_OK) { | |
451 | printk(KERN_ERR "Serial mux: Unable to read IODC.\n"); | |
452 | return 1; | |
453 | } | |
454 | ||
455 | ports = GET_MUX_PORTS(iodc_data); | |
456 | printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.3\n", ports); | |
457 | ||
458 | if(!port_cnt) { | |
459 | mux_driver.cons = MUX_CONSOLE; | |
460 | ||
461 | status = uart_register_driver(&mux_driver); | |
462 | if(status) { | |
463 | printk(KERN_ERR "Serial mux: Unable to register driver.\n"); | |
464 | return 1; | |
465 | } | |
466 | ||
467 | init_timer(&mux_timer); | |
468 | mux_timer.function = mux_poll; | |
469 | } | |
470 | ||
471 | for(i = 0; i < ports; ++i, ++port_cnt) { | |
472 | port = &mux_ports[port_cnt]; | |
473 | port->iobase = 0; | |
474 | port->mapbase = dev->hpa + MUX_OFFSET + (i * MUX_LINE_OFFSET); | |
475 | port->membase = ioremap(port->mapbase, MUX_LINE_OFFSET); | |
476 | port->iotype = SERIAL_IO_MEM; | |
477 | port->type = PORT_MUX; | |
478 | port->irq = SERIAL_IRQ_NONE; | |
479 | port->uartclk = 0; | |
480 | port->fifosize = MUX_FIFO_SIZE; | |
481 | port->ops = &mux_pops; | |
482 | port->flags = UPF_BOOT_AUTOCONF; | |
483 | port->line = port_cnt; | |
484 | status = uart_add_one_port(&mux_driver, port); | |
485 | BUG_ON(status); | |
486 | } | |
487 | ||
488 | #ifdef CONFIG_SERIAL_MUX_CONSOLE | |
489 | register_console(&mux_console); | |
490 | #endif | |
491 | return 0; | |
492 | } | |
493 | ||
494 | static struct parisc_device_id mux_tbl[] = { | |
495 | { HPHW_A_DIRECT, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0000D }, | |
496 | { 0, } | |
497 | }; | |
498 | ||
499 | MODULE_DEVICE_TABLE(parisc, mux_tbl); | |
500 | ||
501 | static struct parisc_driver serial_mux_driver = { | |
502 | .name = "Serial MUX", | |
503 | .id_table = mux_tbl, | |
504 | .probe = mux_probe, | |
505 | }; | |
506 | ||
507 | /** | |
508 | * mux_init - Serial MUX initalization procedure. | |
509 | * | |
510 | * Register the Serial MUX driver. | |
511 | */ | |
512 | static int __init mux_init(void) | |
513 | { | |
514 | return register_parisc_driver(&serial_mux_driver); | |
515 | } | |
516 | ||
517 | /** | |
518 | * mux_exit - Serial MUX cleanup procedure. | |
519 | * | |
520 | * Unregister the Serial MUX driver from the tty layer. | |
521 | */ | |
522 | static void __exit mux_exit(void) | |
523 | { | |
524 | int i; | |
525 | ||
526 | for (i = 0; i < port_cnt; i++) { | |
527 | uart_remove_one_port(&mux_driver, &mux_ports[i]); | |
528 | } | |
529 | ||
530 | uart_unregister_driver(&mux_driver); | |
531 | } | |
532 | ||
533 | module_init(mux_init); | |
534 | module_exit(mux_exit); | |
535 | ||
536 | MODULE_AUTHOR("Ryan Bradetich"); | |
537 | MODULE_DESCRIPTION("Serial MUX driver"); | |
538 | MODULE_LICENSE("GPL"); | |
539 | MODULE_ALIAS_CHARDEV_MAJOR(MUX_MAJOR); |