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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> | |
ae8c75c1 | 30 | #include <asm/irq.h> |
1da177e4 LT |
31 | #include <asm/parisc-device.h> |
32 | ||
33 | #ifdef CONFIG_MAGIC_SYSRQ | |
34 | #include <linux/sysrq.h> | |
35 | #define SUPPORT_SYSRQ | |
36 | #endif | |
37 | ||
38 | #include <linux/serial_core.h> | |
39 | ||
40 | #define MUX_OFFSET 0x800 | |
41 | #define MUX_LINE_OFFSET 0x80 | |
42 | ||
43 | #define MUX_FIFO_SIZE 255 | |
44 | #define MUX_POLL_DELAY (30 * HZ / 1000) | |
45 | ||
46 | #define IO_DATA_REG_OFFSET 0x3c | |
47 | #define IO_DCOUNT_REG_OFFSET 0x40 | |
48 | ||
49 | #define MUX_EOFIFO(status) ((status & 0xF000) == 0xF000) | |
50 | #define MUX_STATUS(status) ((status & 0xF000) == 0x8000) | |
51 | #define MUX_BREAK(status) ((status & 0xF000) == 0x2000) | |
52 | ||
53 | #define MUX_NR 256 | |
5076c158 | 54 | static unsigned int port_cnt __read_mostly; |
1da177e4 LT |
55 | static struct uart_port mux_ports[MUX_NR]; |
56 | ||
57 | static struct uart_driver mux_driver = { | |
58 | .owner = THIS_MODULE, | |
59 | .driver_name = "ttyB", | |
60 | .dev_name = "ttyB", | |
61 | .major = MUX_MAJOR, | |
62 | .minor = 0, | |
63 | .nr = MUX_NR, | |
64 | }; | |
65 | ||
66 | static struct timer_list mux_timer; | |
67 | ||
92495c0e RB |
68 | #define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + IO_DATA_REG_OFFSET) |
69 | #define UART_GET_FIFO_CNT(p) __raw_readl((p)->membase + IO_DCOUNT_REG_OFFSET) | |
1da177e4 LT |
70 | #define GET_MUX_PORTS(iodc_data) ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8 |
71 | ||
72 | /** | |
73 | * mux_tx_empty - Check if the transmitter fifo is empty. | |
74 | * @port: Ptr to the uart_port. | |
75 | * | |
76 | * This function test if the transmitter fifo for the port | |
77 | * described by 'port' is empty. If it is empty, this function | |
78 | * should return TIOCSER_TEMT, otherwise return 0. | |
79 | */ | |
80 | static unsigned int mux_tx_empty(struct uart_port *port) | |
81 | { | |
92495c0e | 82 | return UART_GET_FIFO_CNT(port) ? 0 : TIOCSER_TEMT; |
1da177e4 LT |
83 | } |
84 | ||
85 | /** | |
86 | * mux_set_mctrl - Set the current state of the modem control inputs. | |
87 | * @ports: Ptr to the uart_port. | |
88 | * @mctrl: Modem control bits. | |
89 | * | |
90 | * The Serial MUX does not support CTS, DCD or DSR so this function | |
91 | * is ignored. | |
92 | */ | |
93 | static void mux_set_mctrl(struct uart_port *port, unsigned int mctrl) | |
94 | { | |
95 | } | |
96 | ||
97 | /** | |
98 | * mux_get_mctrl - Returns the current state of modem control inputs. | |
99 | * @port: Ptr to the uart_port. | |
100 | * | |
101 | * The Serial MUX does not support CTS, DCD or DSR so these lines are | |
102 | * treated as permanently active. | |
103 | */ | |
104 | static unsigned int mux_get_mctrl(struct uart_port *port) | |
105 | { | |
106 | return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; | |
107 | } | |
108 | ||
109 | /** | |
110 | * mux_stop_tx - Stop transmitting characters. | |
111 | * @port: Ptr to the uart_port. | |
1da177e4 LT |
112 | * |
113 | * The Serial MUX does not support this function. | |
114 | */ | |
b129a8cc | 115 | static void mux_stop_tx(struct uart_port *port) |
1da177e4 LT |
116 | { |
117 | } | |
118 | ||
119 | /** | |
120 | * mux_start_tx - Start transmitting characters. | |
121 | * @port: Ptr to the uart_port. | |
1da177e4 LT |
122 | * |
123 | * The Serial Mux does not support this function. | |
124 | */ | |
b129a8cc | 125 | static void mux_start_tx(struct uart_port *port) |
1da177e4 LT |
126 | { |
127 | } | |
128 | ||
129 | /** | |
130 | * mux_stop_rx - Stop receiving characters. | |
131 | * @port: Ptr to the uart_port. | |
132 | * | |
133 | * The Serial Mux does not support this function. | |
134 | */ | |
135 | static void mux_stop_rx(struct uart_port *port) | |
136 | { | |
137 | } | |
138 | ||
139 | /** | |
140 | * mux_enable_ms - Enable modum status interrupts. | |
141 | * @port: Ptr to the uart_port. | |
142 | * | |
143 | * The Serial Mux does not support this function. | |
144 | */ | |
145 | static void mux_enable_ms(struct uart_port *port) | |
146 | { | |
147 | } | |
148 | ||
149 | /** | |
150 | * mux_break_ctl - Control the transmitssion of a break signal. | |
151 | * @port: Ptr to the uart_port. | |
152 | * @break_state: Raise/Lower the break signal. | |
153 | * | |
154 | * The Serial Mux does not support this function. | |
155 | */ | |
156 | static void mux_break_ctl(struct uart_port *port, int break_state) | |
157 | { | |
158 | } | |
159 | ||
160 | /** | |
161 | * mux_write - Write chars to the mux fifo. | |
162 | * @port: Ptr to the uart_port. | |
163 | * | |
164 | * This function writes all the data from the uart buffer to | |
165 | * the mux fifo. | |
166 | */ | |
167 | static void mux_write(struct uart_port *port) | |
168 | { | |
169 | int count; | |
170 | struct circ_buf *xmit = &port->info->xmit; | |
171 | ||
172 | if(port->x_char) { | |
173 | UART_PUT_CHAR(port, port->x_char); | |
174 | port->icount.tx++; | |
175 | port->x_char = 0; | |
176 | return; | |
177 | } | |
178 | ||
179 | if(uart_circ_empty(xmit) || uart_tx_stopped(port)) { | |
b129a8cc | 180 | mux_stop_tx(port); |
1da177e4 LT |
181 | return; |
182 | } | |
183 | ||
184 | count = (port->fifosize) - UART_GET_FIFO_CNT(port); | |
185 | do { | |
186 | UART_PUT_CHAR(port, xmit->buf[xmit->tail]); | |
187 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
188 | port->icount.tx++; | |
189 | if(uart_circ_empty(xmit)) | |
190 | break; | |
191 | ||
192 | } while(--count > 0); | |
193 | ||
194 | while(UART_GET_FIFO_CNT(port)) | |
195 | udelay(1); | |
196 | ||
197 | if(uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
198 | uart_write_wakeup(port); | |
199 | ||
200 | if (uart_circ_empty(xmit)) | |
b129a8cc | 201 | mux_stop_tx(port); |
1da177e4 LT |
202 | } |
203 | ||
204 | /** | |
205 | * mux_read - Read chars from the mux fifo. | |
206 | * @port: Ptr to the uart_port. | |
207 | * | |
208 | * This reads all available data from the mux's fifo and pushes | |
209 | * the data to the tty layer. | |
210 | */ | |
211 | static void mux_read(struct uart_port *port) | |
212 | { | |
213 | int data; | |
214 | struct tty_struct *tty = port->info->tty; | |
215 | __u32 start_count = port->icount.rx; | |
216 | ||
217 | while(1) { | |
92495c0e | 218 | data = __raw_readl(port->membase + IO_DATA_REG_OFFSET); |
1da177e4 LT |
219 | |
220 | if (MUX_STATUS(data)) | |
221 | continue; | |
222 | ||
223 | if (MUX_EOFIFO(data)) | |
224 | break; | |
225 | ||
1da177e4 LT |
226 | port->icount.rx++; |
227 | ||
228 | if (MUX_BREAK(data)) { | |
229 | port->icount.brk++; | |
230 | if(uart_handle_break(port)) | |
231 | continue; | |
232 | } | |
233 | ||
234 | if (uart_handle_sysrq_char(port, data & 0xffu, NULL)) | |
235 | continue; | |
236 | ||
33f0f88f | 237 | tty_insert_flip_char(tty, data & 0xFF, TTY_NORMAL); |
1da177e4 LT |
238 | } |
239 | ||
240 | if (start_count != port->icount.rx) { | |
241 | tty_flip_buffer_push(tty); | |
242 | } | |
243 | } | |
244 | ||
245 | /** | |
246 | * mux_startup - Initialize the port. | |
247 | * @port: Ptr to the uart_port. | |
248 | * | |
249 | * Grab any resources needed for this port and start the | |
250 | * mux timer. | |
251 | */ | |
252 | static int mux_startup(struct uart_port *port) | |
253 | { | |
254 | mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY); | |
255 | return 0; | |
256 | } | |
257 | ||
258 | /** | |
259 | * mux_shutdown - Disable the port. | |
260 | * @port: Ptr to the uart_port. | |
261 | * | |
262 | * Release any resources needed for the port. | |
263 | */ | |
264 | static void mux_shutdown(struct uart_port *port) | |
265 | { | |
266 | } | |
267 | ||
268 | /** | |
269 | * mux_set_termios - Chane port parameters. | |
270 | * @port: Ptr to the uart_port. | |
271 | * @termios: new termios settings. | |
272 | * @old: old termios settings. | |
273 | * | |
274 | * The Serial Mux does not support this function. | |
275 | */ | |
276 | static void | |
277 | mux_set_termios(struct uart_port *port, struct termios *termios, | |
278 | struct termios *old) | |
279 | { | |
280 | } | |
281 | ||
282 | /** | |
283 | * mux_type - Describe the port. | |
284 | * @port: Ptr to the uart_port. | |
285 | * | |
286 | * Return a pointer to a string constant describing the | |
287 | * specified port. | |
288 | */ | |
289 | static const char *mux_type(struct uart_port *port) | |
290 | { | |
291 | return "Mux"; | |
292 | } | |
293 | ||
294 | /** | |
295 | * mux_release_port - Release memory and IO regions. | |
296 | * @port: Ptr to the uart_port. | |
297 | * | |
298 | * Release any memory and IO region resources currently in use by | |
299 | * the port. | |
300 | */ | |
301 | static void mux_release_port(struct uart_port *port) | |
302 | { | |
303 | } | |
304 | ||
305 | /** | |
306 | * mux_request_port - Request memory and IO regions. | |
307 | * @port: Ptr to the uart_port. | |
308 | * | |
309 | * Request any memory and IO region resources required by the port. | |
310 | * If any fail, no resources should be registered when this function | |
311 | * returns, and it should return -EBUSY on failure. | |
312 | */ | |
313 | static int mux_request_port(struct uart_port *port) | |
314 | { | |
315 | return 0; | |
316 | } | |
317 | ||
318 | /** | |
319 | * mux_config_port - Perform port autoconfiguration. | |
320 | * @port: Ptr to the uart_port. | |
321 | * @type: Bitmask of required configurations. | |
322 | * | |
323 | * Perform any autoconfiguration steps for the port. This functino is | |
324 | * called if the UPF_BOOT_AUTOCONF flag is specified for the port. | |
325 | * [Note: This is required for now because of a bug in the Serial core. | |
326 | * rmk has already submitted a patch to linus, should be available for | |
327 | * 2.5.47.] | |
328 | */ | |
329 | static void mux_config_port(struct uart_port *port, int type) | |
330 | { | |
331 | port->type = PORT_MUX; | |
332 | } | |
333 | ||
334 | /** | |
335 | * mux_verify_port - Verify the port information. | |
336 | * @port: Ptr to the uart_port. | |
337 | * @ser: Ptr to the serial information. | |
338 | * | |
339 | * Verify the new serial port information contained within serinfo is | |
340 | * suitable for this port type. | |
341 | */ | |
342 | static int mux_verify_port(struct uart_port *port, struct serial_struct *ser) | |
343 | { | |
344 | if(port->membase == NULL) | |
345 | return -EINVAL; | |
346 | ||
347 | return 0; | |
348 | } | |
349 | ||
350 | /** | |
351 | * mux_drv_poll - Mux poll function. | |
352 | * @unused: Unused variable | |
353 | * | |
354 | * This function periodically polls the Serial MUX to check for new data. | |
355 | */ | |
356 | static void mux_poll(unsigned long unused) | |
357 | { | |
358 | int i; | |
359 | ||
360 | for(i = 0; i < port_cnt; ++i) { | |
361 | if(!mux_ports[i].info) | |
362 | continue; | |
363 | ||
364 | mux_read(&mux_ports[i]); | |
365 | mux_write(&mux_ports[i]); | |
366 | } | |
367 | ||
368 | mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY); | |
369 | } | |
370 | ||
371 | ||
372 | #ifdef CONFIG_SERIAL_MUX_CONSOLE | |
373 | static void mux_console_write(struct console *co, const char *s, unsigned count) | |
374 | { | |
375 | while(count--) | |
376 | pdc_iodc_putc(*s++); | |
377 | } | |
378 | ||
379 | static int mux_console_setup(struct console *co, char *options) | |
380 | { | |
381 | return 0; | |
382 | } | |
383 | ||
384 | struct tty_driver *mux_console_device(struct console *co, int *index) | |
385 | { | |
386 | *index = co->index; | |
387 | return mux_driver.tty_driver; | |
388 | } | |
389 | ||
390 | static struct console mux_console = { | |
391 | .name = "ttyB", | |
392 | .write = mux_console_write, | |
393 | .device = mux_console_device, | |
394 | .setup = mux_console_setup, | |
395 | .flags = CON_ENABLED | CON_PRINTBUFFER, | |
396 | .index = 0, | |
397 | }; | |
398 | ||
399 | #define MUX_CONSOLE &mux_console | |
400 | #else | |
401 | #define MUX_CONSOLE NULL | |
402 | #endif | |
403 | ||
404 | static struct uart_ops mux_pops = { | |
405 | .tx_empty = mux_tx_empty, | |
406 | .set_mctrl = mux_set_mctrl, | |
407 | .get_mctrl = mux_get_mctrl, | |
408 | .stop_tx = mux_stop_tx, | |
409 | .start_tx = mux_start_tx, | |
410 | .stop_rx = mux_stop_rx, | |
411 | .enable_ms = mux_enable_ms, | |
412 | .break_ctl = mux_break_ctl, | |
413 | .startup = mux_startup, | |
414 | .shutdown = mux_shutdown, | |
415 | .set_termios = mux_set_termios, | |
416 | .type = mux_type, | |
417 | .release_port = mux_release_port, | |
418 | .request_port = mux_request_port, | |
419 | .config_port = mux_config_port, | |
420 | .verify_port = mux_verify_port, | |
421 | }; | |
422 | ||
423 | /** | |
424 | * mux_probe - Determine if the Serial Mux should claim this device. | |
425 | * @dev: The parisc device. | |
426 | * | |
427 | * Deterimine if the Serial Mux should claim this chip (return 0) | |
428 | * or not (return 1). | |
429 | */ | |
430 | static int __init mux_probe(struct parisc_device *dev) | |
431 | { | |
432 | int i, status, ports; | |
433 | u8 iodc_data[32]; | |
434 | unsigned long bytecnt; | |
435 | struct uart_port *port; | |
436 | ||
53f01bba | 437 | status = pdc_iodc_read(&bytecnt, dev->hpa.start, 0, iodc_data, 32); |
1da177e4 LT |
438 | if(status != PDC_OK) { |
439 | printk(KERN_ERR "Serial mux: Unable to read IODC.\n"); | |
440 | return 1; | |
441 | } | |
442 | ||
443 | ports = GET_MUX_PORTS(iodc_data); | |
444 | printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.3\n", ports); | |
445 | ||
446 | if(!port_cnt) { | |
447 | mux_driver.cons = MUX_CONSOLE; | |
448 | ||
449 | status = uart_register_driver(&mux_driver); | |
450 | if(status) { | |
451 | printk(KERN_ERR "Serial mux: Unable to register driver.\n"); | |
452 | return 1; | |
453 | } | |
454 | ||
455 | init_timer(&mux_timer); | |
456 | mux_timer.function = mux_poll; | |
457 | } | |
458 | ||
459 | for(i = 0; i < ports; ++i, ++port_cnt) { | |
460 | port = &mux_ports[port_cnt]; | |
461 | port->iobase = 0; | |
ae8c75c1 MW |
462 | port->mapbase = dev->hpa.start + MUX_OFFSET + |
463 | (i * MUX_LINE_OFFSET); | |
5076c158 | 464 | port->membase = ioremap_nocache(port->mapbase, MUX_LINE_OFFSET); |
9b4a1617 | 465 | port->iotype = UPIO_MEM; |
1da177e4 | 466 | port->type = PORT_MUX; |
ae8c75c1 | 467 | port->irq = NO_IRQ; |
1da177e4 LT |
468 | port->uartclk = 0; |
469 | port->fifosize = MUX_FIFO_SIZE; | |
470 | port->ops = &mux_pops; | |
471 | port->flags = UPF_BOOT_AUTOCONF; | |
472 | port->line = port_cnt; | |
a137ce85 RB |
473 | |
474 | /* The port->timeout needs to match what is present in | |
475 | * uart_wait_until_sent in serial_core.c. Otherwise | |
476 | * the time spent in msleep_interruptable will be very | |
477 | * long, causing the appearance of a console hang. | |
478 | */ | |
479 | port->timeout = HZ / 50; | |
ae8c75c1 | 480 | spin_lock_init(&port->lock); |
1da177e4 LT |
481 | status = uart_add_one_port(&mux_driver, port); |
482 | BUG_ON(status); | |
483 | } | |
484 | ||
485 | #ifdef CONFIG_SERIAL_MUX_CONSOLE | |
486 | register_console(&mux_console); | |
487 | #endif | |
488 | return 0; | |
489 | } | |
490 | ||
491 | static struct parisc_device_id mux_tbl[] = { | |
492 | { HPHW_A_DIRECT, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0000D }, | |
493 | { 0, } | |
494 | }; | |
495 | ||
496 | MODULE_DEVICE_TABLE(parisc, mux_tbl); | |
497 | ||
498 | static struct parisc_driver serial_mux_driver = { | |
bdad1f83 | 499 | .name = "serial_mux", |
1da177e4 LT |
500 | .id_table = mux_tbl, |
501 | .probe = mux_probe, | |
502 | }; | |
503 | ||
504 | /** | |
505 | * mux_init - Serial MUX initalization procedure. | |
506 | * | |
507 | * Register the Serial MUX driver. | |
508 | */ | |
509 | static int __init mux_init(void) | |
510 | { | |
511 | return register_parisc_driver(&serial_mux_driver); | |
512 | } | |
513 | ||
514 | /** | |
515 | * mux_exit - Serial MUX cleanup procedure. | |
516 | * | |
517 | * Unregister the Serial MUX driver from the tty layer. | |
518 | */ | |
519 | static void __exit mux_exit(void) | |
520 | { | |
521 | int i; | |
522 | ||
523 | for (i = 0; i < port_cnt; i++) { | |
524 | uart_remove_one_port(&mux_driver, &mux_ports[i]); | |
525 | } | |
526 | ||
527 | uart_unregister_driver(&mux_driver); | |
528 | } | |
529 | ||
530 | module_init(mux_init); | |
531 | module_exit(mux_exit); | |
532 | ||
533 | MODULE_AUTHOR("Ryan Bradetich"); | |
534 | MODULE_DESCRIPTION("Serial MUX driver"); | |
535 | MODULE_LICENSE("GPL"); | |
536 | MODULE_ALIAS_CHARDEV_MAJOR(MUX_MAJOR); |