xref: /openbmc/linux/drivers/ipack/devices/ipoctal.c (revision 92a19f9cec9a80ad93c06e115822deb729e2c6ad)
1 /**
2  * ipoctal.c
3  *
4  * driver for the GE IP-OCTAL boards
5  *
6  * Copyright (C) 2009-2012 CERN (www.cern.ch)
7  * Author: Nicolas Serafini, EIC2 SA
8  * Author: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
9  *
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms of the GNU General Public License as published by the Free
12  * Software Foundation; version 2 of the License.
13  */
14 
15 #include <linux/device.h>
16 #include <linux/module.h>
17 #include <linux/interrupt.h>
18 #include <linux/sched.h>
19 #include <linux/tty.h>
20 #include <linux/serial.h>
21 #include <linux/tty_flip.h>
22 #include <linux/slab.h>
23 #include <linux/atomic.h>
24 #include <linux/io.h>
25 #include <linux/ipack.h>
26 #include "ipoctal.h"
27 #include "scc2698.h"
28 
29 #define IP_OCTAL_ID_SPACE_VECTOR    0x41
30 #define IP_OCTAL_NB_BLOCKS          4
31 
32 static const struct tty_operations ipoctal_fops;
33 
34 struct ipoctal_channel {
35 	struct ipoctal_stats		stats;
36 	unsigned int			nb_bytes;
37 	wait_queue_head_t		queue;
38 	spinlock_t			lock;
39 	unsigned int			pointer_read;
40 	unsigned int			pointer_write;
41 	atomic_t			open;
42 	struct tty_port			tty_port;
43 	union scc2698_channel __iomem	*regs;
44 	union scc2698_block __iomem	*block_regs;
45 	unsigned int			board_id;
46 	unsigned char			*board_write;
47 	u8				isr_rx_rdy_mask;
48 	u8				isr_tx_rdy_mask;
49 };
50 
51 struct ipoctal {
52 	struct ipack_device		*dev;
53 	unsigned int			board_id;
54 	struct ipoctal_channel		channel[NR_CHANNELS];
55 	unsigned char			write;
56 	struct tty_driver		*tty_drv;
57 	u8 __iomem			*mem8_space;
58 	u8 __iomem			*int_space;
59 };
60 
61 static int ipoctal_port_activate(struct tty_port *port, struct tty_struct *tty)
62 {
63 	struct ipoctal_channel *channel;
64 
65 	channel = dev_get_drvdata(tty->dev);
66 
67 	iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
68 	return 0;
69 }
70 
71 static int ipoctal_open(struct tty_struct *tty, struct file *file)
72 {
73 	int res;
74 	struct ipoctal_channel *channel;
75 
76 	channel = dev_get_drvdata(tty->dev);
77 
78 	if (atomic_read(&channel->open))
79 		return -EBUSY;
80 
81 	tty->driver_data = channel;
82 
83 	res = tty_port_open(&channel->tty_port, tty, file);
84 	if (res)
85 		return res;
86 
87 	atomic_inc(&channel->open);
88 	return 0;
89 }
90 
91 static void ipoctal_reset_stats(struct ipoctal_stats *stats)
92 {
93 	stats->tx = 0;
94 	stats->rx = 0;
95 	stats->rcv_break = 0;
96 	stats->framing_err = 0;
97 	stats->overrun_err = 0;
98 	stats->parity_err = 0;
99 }
100 
101 static void ipoctal_free_channel(struct ipoctal_channel *channel)
102 {
103 	ipoctal_reset_stats(&channel->stats);
104 	channel->pointer_read = 0;
105 	channel->pointer_write = 0;
106 	channel->nb_bytes = 0;
107 }
108 
109 static void ipoctal_close(struct tty_struct *tty, struct file *filp)
110 {
111 	struct ipoctal_channel *channel = tty->driver_data;
112 
113 	tty_port_close(&channel->tty_port, tty, filp);
114 
115 	if (atomic_dec_and_test(&channel->open))
116 		ipoctal_free_channel(channel);
117 }
118 
119 static int ipoctal_get_icount(struct tty_struct *tty,
120 			      struct serial_icounter_struct *icount)
121 {
122 	struct ipoctal_channel *channel = tty->driver_data;
123 
124 	icount->cts = 0;
125 	icount->dsr = 0;
126 	icount->rng = 0;
127 	icount->dcd = 0;
128 	icount->rx = channel->stats.rx;
129 	icount->tx = channel->stats.tx;
130 	icount->frame = channel->stats.framing_err;
131 	icount->parity = channel->stats.parity_err;
132 	icount->brk = channel->stats.rcv_break;
133 	return 0;
134 }
135 
136 static void ipoctal_irq_rx(struct ipoctal_channel *channel,
137 			   struct tty_struct *tty, u8 sr)
138 {
139 	struct tty_port *port = &channel->tty_port;
140 	unsigned char value;
141 	unsigned char flag = TTY_NORMAL;
142 	u8 isr;
143 
144 	do {
145 		value = ioread8(&channel->regs->r.rhr);
146 		/* Error: count statistics */
147 		if (sr & SR_ERROR) {
148 			iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
149 
150 			if (sr & SR_OVERRUN_ERROR) {
151 				channel->stats.overrun_err++;
152 				/* Overrun doesn't affect the current character*/
153 				tty_insert_flip_char(port, 0, TTY_OVERRUN);
154 			}
155 			if (sr & SR_PARITY_ERROR) {
156 				channel->stats.parity_err++;
157 				flag = TTY_PARITY;
158 			}
159 			if (sr & SR_FRAMING_ERROR) {
160 				channel->stats.framing_err++;
161 				flag = TTY_FRAME;
162 			}
163 			if (sr & SR_RECEIVED_BREAK) {
164 				iowrite8(CR_CMD_RESET_BREAK_CHANGE, &channel->regs->w.cr);
165 				channel->stats.rcv_break++;
166 				flag = TTY_BREAK;
167 			}
168 		}
169 		tty_insert_flip_char(port, value, flag);
170 
171 		/* Check if there are more characters in RX FIFO
172 		 * If there are more, the isr register for this channel
173 		 * has enabled the RxRDY|FFULL bit.
174 		 */
175 		isr = ioread8(&channel->block_regs->r.isr);
176 		sr = ioread8(&channel->regs->r.sr);
177 	} while (isr & channel->isr_rx_rdy_mask);
178 
179 	tty_flip_buffer_push(tty);
180 }
181 
182 static void ipoctal_irq_tx(struct ipoctal_channel *channel)
183 {
184 	unsigned char value;
185 	unsigned int *pointer_write = &channel->pointer_write;
186 
187 	if (channel->nb_bytes <= 0) {
188 		channel->nb_bytes = 0;
189 		return;
190 	}
191 
192 	value = channel->tty_port.xmit_buf[*pointer_write];
193 	iowrite8(value, &channel->regs->w.thr);
194 	channel->stats.tx++;
195 	(*pointer_write)++;
196 	*pointer_write = *pointer_write % PAGE_SIZE;
197 	channel->nb_bytes--;
198 
199 	if ((channel->nb_bytes == 0) &&
200 	    (waitqueue_active(&channel->queue))) {
201 
202 		if (channel->board_id != IPACK1_DEVICE_ID_SBS_OCTAL_485) {
203 			*channel->board_write = 1;
204 			wake_up_interruptible(&channel->queue);
205 		}
206 	}
207 }
208 
209 static void ipoctal_irq_channel(struct ipoctal_channel *channel)
210 {
211 	u8 isr, sr;
212 	struct tty_struct *tty;
213 
214 	/* If there is no client, skip the check */
215 	if (!atomic_read(&channel->open))
216 		return;
217 
218 	tty = tty_port_tty_get(&channel->tty_port);
219 	if (!tty)
220 		return;
221 	/* The HW is organized in pair of channels.  See which register we need
222 	 * to read from */
223 	isr = ioread8(&channel->block_regs->r.isr);
224 	sr = ioread8(&channel->regs->r.sr);
225 
226 	/* In case of RS-485, change from TX to RX when finishing TX.
227 	 * Half-duplex. */
228 	if ((channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) &&
229 	    (sr & SR_TX_EMPTY) && (channel->nb_bytes == 0)) {
230 		iowrite8(CR_DISABLE_TX, &channel->regs->w.cr);
231 		iowrite8(CR_CMD_NEGATE_RTSN, &channel->regs->w.cr);
232 		iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
233 		*channel->board_write = 1;
234 		wake_up_interruptible(&channel->queue);
235 	}
236 
237 	/* RX data */
238 	if ((isr & channel->isr_rx_rdy_mask) && (sr & SR_RX_READY))
239 		ipoctal_irq_rx(channel, tty, sr);
240 
241 	/* TX of each character */
242 	if ((isr & channel->isr_tx_rdy_mask) && (sr & SR_TX_READY))
243 		ipoctal_irq_tx(channel);
244 
245 	tty_flip_buffer_push(tty);
246 	tty_kref_put(tty);
247 }
248 
249 static irqreturn_t ipoctal_irq_handler(void *arg)
250 {
251 	unsigned int i;
252 	struct ipoctal *ipoctal = (struct ipoctal *) arg;
253 
254 	/* Check all channels */
255 	for (i = 0; i < NR_CHANNELS; i++)
256 		ipoctal_irq_channel(&ipoctal->channel[i]);
257 
258 	/* Clear the IPack device interrupt */
259 	readw(ipoctal->int_space + ACK_INT_REQ0);
260 	readw(ipoctal->int_space + ACK_INT_REQ1);
261 
262 	return IRQ_HANDLED;
263 }
264 
265 static const struct tty_port_operations ipoctal_tty_port_ops = {
266 	.dtr_rts = NULL,
267 	.activate = ipoctal_port_activate,
268 };
269 
270 static int ipoctal_inst_slot(struct ipoctal *ipoctal, unsigned int bus_nr,
271 			     unsigned int slot)
272 {
273 	int res;
274 	int i;
275 	struct tty_driver *tty;
276 	char name[20];
277 	struct ipoctal_channel *channel;
278 	struct ipack_region *region;
279 	void __iomem *addr;
280 	union scc2698_channel __iomem *chan_regs;
281 	union scc2698_block __iomem *block_regs;
282 
283 	ipoctal->board_id = ipoctal->dev->id_device;
284 
285 	region = &ipoctal->dev->region[IPACK_IO_SPACE];
286 	addr = devm_ioremap_nocache(&ipoctal->dev->dev,
287 				    region->start, region->size);
288 	if (!addr) {
289 		dev_err(&ipoctal->dev->dev,
290 			"Unable to map slot [%d:%d] IO space!\n",
291 			bus_nr, slot);
292 		return -EADDRNOTAVAIL;
293 	}
294 	/* Save the virtual address to access the registers easily */
295 	chan_regs =
296 		(union scc2698_channel __iomem *) addr;
297 	block_regs =
298 		(union scc2698_block __iomem *) addr;
299 
300 	region = &ipoctal->dev->region[IPACK_INT_SPACE];
301 	ipoctal->int_space =
302 		devm_ioremap_nocache(&ipoctal->dev->dev,
303 				     region->start, region->size);
304 	if (!ipoctal->int_space) {
305 		dev_err(&ipoctal->dev->dev,
306 			"Unable to map slot [%d:%d] INT space!\n",
307 			bus_nr, slot);
308 		return -EADDRNOTAVAIL;
309 	}
310 
311 	region = &ipoctal->dev->region[IPACK_MEM8_SPACE];
312 	ipoctal->mem8_space =
313 		devm_ioremap_nocache(&ipoctal->dev->dev,
314 				     region->start, 0x8000);
315 	if (!addr) {
316 		dev_err(&ipoctal->dev->dev,
317 			"Unable to map slot [%d:%d] MEM8 space!\n",
318 			bus_nr, slot);
319 		return -EADDRNOTAVAIL;
320 	}
321 
322 
323 	/* Disable RX and TX before touching anything */
324 	for (i = 0; i < NR_CHANNELS ; i++) {
325 		struct ipoctal_channel *channel = &ipoctal->channel[i];
326 		channel->regs = chan_regs + i;
327 		channel->block_regs = block_regs + (i >> 1);
328 		channel->board_write = &ipoctal->write;
329 		channel->board_id = ipoctal->board_id;
330 		if (i & 1) {
331 			channel->isr_tx_rdy_mask = ISR_TxRDY_B;
332 			channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_B;
333 		} else {
334 			channel->isr_tx_rdy_mask = ISR_TxRDY_A;
335 			channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_A;
336 		}
337 
338 		iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
339 		iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
340 		iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
341 		iowrite8(MR1_CHRL_8_BITS | MR1_ERROR_CHAR | MR1_RxINT_RxRDY,
342 			 &channel->regs->w.mr); /* mr1 */
343 		iowrite8(0, &channel->regs->w.mr); /* mr2 */
344 		iowrite8(TX_CLK_9600  | RX_CLK_9600, &channel->regs->w.csr);
345 	}
346 
347 	for (i = 0; i < IP_OCTAL_NB_BLOCKS; i++) {
348 		iowrite8(ACR_BRG_SET2, &block_regs[i].w.acr);
349 		iowrite8(OPCR_MPP_OUTPUT | OPCR_MPOa_RTSN | OPCR_MPOb_RTSN,
350 			 &block_regs[i].w.opcr);
351 		iowrite8(IMR_TxRDY_A | IMR_RxRDY_FFULL_A | IMR_DELTA_BREAK_A |
352 			 IMR_TxRDY_B | IMR_RxRDY_FFULL_B | IMR_DELTA_BREAK_B,
353 			 &block_regs[i].w.imr);
354 	}
355 
356 	/*
357 	 * IP-OCTAL has different addresses to copy its IRQ vector.
358 	 * Depending of the carrier these addresses are accesible or not.
359 	 * More info in the datasheet.
360 	 */
361 	ipoctal->dev->bus->ops->request_irq(ipoctal->dev,
362 				       ipoctal_irq_handler, ipoctal);
363 	/* Dummy write */
364 	iowrite8(1, ipoctal->mem8_space + 1);
365 
366 	/* Register the TTY device */
367 
368 	/* Each IP-OCTAL channel is a TTY port */
369 	tty = alloc_tty_driver(NR_CHANNELS);
370 
371 	if (!tty)
372 		return -ENOMEM;
373 
374 	/* Fill struct tty_driver with ipoctal data */
375 	tty->owner = THIS_MODULE;
376 	tty->driver_name = KBUILD_MODNAME;
377 	sprintf(name, KBUILD_MODNAME ".%d.%d.", bus_nr, slot);
378 	tty->name = name;
379 	tty->major = 0;
380 
381 	tty->minor_start = 0;
382 	tty->type = TTY_DRIVER_TYPE_SERIAL;
383 	tty->subtype = SERIAL_TYPE_NORMAL;
384 	tty->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
385 	tty->init_termios = tty_std_termios;
386 	tty->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
387 	tty->init_termios.c_ispeed = 9600;
388 	tty->init_termios.c_ospeed = 9600;
389 
390 	tty_set_operations(tty, &ipoctal_fops);
391 	res = tty_register_driver(tty);
392 	if (res) {
393 		dev_err(&ipoctal->dev->dev, "Can't register tty driver.\n");
394 		put_tty_driver(tty);
395 		return res;
396 	}
397 
398 	/* Save struct tty_driver for use it when uninstalling the device */
399 	ipoctal->tty_drv = tty;
400 
401 	for (i = 0; i < NR_CHANNELS; i++) {
402 		struct device *tty_dev;
403 
404 		channel = &ipoctal->channel[i];
405 		tty_port_init(&channel->tty_port);
406 		tty_port_alloc_xmit_buf(&channel->tty_port);
407 		channel->tty_port.ops = &ipoctal_tty_port_ops;
408 
409 		ipoctal_reset_stats(&channel->stats);
410 		channel->nb_bytes = 0;
411 		init_waitqueue_head(&channel->queue);
412 
413 		spin_lock_init(&channel->lock);
414 		channel->pointer_read = 0;
415 		channel->pointer_write = 0;
416 		tty_dev = tty_port_register_device(&channel->tty_port, tty, i, NULL);
417 		if (IS_ERR(tty_dev)) {
418 			dev_err(&ipoctal->dev->dev, "Failed to register tty device.\n");
419 			tty_port_destroy(&channel->tty_port);
420 			continue;
421 		}
422 		dev_set_drvdata(tty_dev, channel);
423 
424 		/*
425 		 * Enable again the RX. TX will be enabled when
426 		 * there is something to send
427 		 */
428 		iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
429 	}
430 
431 	return 0;
432 }
433 
434 static inline int ipoctal_copy_write_buffer(struct ipoctal_channel *channel,
435 					    const unsigned char *buf,
436 					    int count)
437 {
438 	unsigned long flags;
439 	int i;
440 	unsigned int *pointer_read = &channel->pointer_read;
441 
442 	/* Copy the bytes from the user buffer to the internal one */
443 	for (i = 0; i < count; i++) {
444 		if (i <= (PAGE_SIZE - channel->nb_bytes)) {
445 			spin_lock_irqsave(&channel->lock, flags);
446 			channel->tty_port.xmit_buf[*pointer_read] = buf[i];
447 			*pointer_read = (*pointer_read + 1) % PAGE_SIZE;
448 			channel->nb_bytes++;
449 			spin_unlock_irqrestore(&channel->lock, flags);
450 		} else {
451 			break;
452 		}
453 	}
454 	return i;
455 }
456 
457 static int ipoctal_write_tty(struct tty_struct *tty,
458 			     const unsigned char *buf, int count)
459 {
460 	struct ipoctal_channel *channel = tty->driver_data;
461 	unsigned int char_copied;
462 
463 	char_copied = ipoctal_copy_write_buffer(channel, buf, count);
464 
465 	/* As the IP-OCTAL 485 only supports half duplex, do it manually */
466 	if (channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) {
467 		iowrite8(CR_DISABLE_RX, &channel->regs->w.cr);
468 		iowrite8(CR_CMD_ASSERT_RTSN, &channel->regs->w.cr);
469 	}
470 
471 	/*
472 	 * Send a packet and then disable TX to avoid failure after several send
473 	 * operations
474 	 */
475 	iowrite8(CR_ENABLE_TX, &channel->regs->w.cr);
476 	wait_event_interruptible(channel->queue, *channel->board_write);
477 	iowrite8(CR_DISABLE_TX, &channel->regs->w.cr);
478 
479 	*channel->board_write = 0;
480 	return char_copied;
481 }
482 
483 static int ipoctal_write_room(struct tty_struct *tty)
484 {
485 	struct ipoctal_channel *channel = tty->driver_data;
486 
487 	return PAGE_SIZE - channel->nb_bytes;
488 }
489 
490 static int ipoctal_chars_in_buffer(struct tty_struct *tty)
491 {
492 	struct ipoctal_channel *channel = tty->driver_data;
493 
494 	return channel->nb_bytes;
495 }
496 
497 static void ipoctal_set_termios(struct tty_struct *tty,
498 				struct ktermios *old_termios)
499 {
500 	unsigned int cflag;
501 	unsigned char mr1 = 0;
502 	unsigned char mr2 = 0;
503 	unsigned char csr = 0;
504 	struct ipoctal_channel *channel = tty->driver_data;
505 	speed_t baud;
506 
507 	cflag = tty->termios.c_cflag;
508 
509 	/* Disable and reset everything before change the setup */
510 	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
511 	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
512 	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
513 	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
514 	iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
515 
516 	/* Set Bits per chars */
517 	switch (cflag & CSIZE) {
518 	case CS6:
519 		mr1 |= MR1_CHRL_6_BITS;
520 		break;
521 	case CS7:
522 		mr1 |= MR1_CHRL_7_BITS;
523 		break;
524 	case CS8:
525 	default:
526 		mr1 |= MR1_CHRL_8_BITS;
527 		/* By default, select CS8 */
528 		tty->termios.c_cflag = (cflag & ~CSIZE) | CS8;
529 		break;
530 	}
531 
532 	/* Set Parity */
533 	if (cflag & PARENB)
534 		if (cflag & PARODD)
535 			mr1 |= MR1_PARITY_ON | MR1_PARITY_ODD;
536 		else
537 			mr1 |= MR1_PARITY_ON | MR1_PARITY_EVEN;
538 	else
539 		mr1 |= MR1_PARITY_OFF;
540 
541 	/* Mark or space parity is not supported */
542 	tty->termios.c_cflag &= ~CMSPAR;
543 
544 	/* Set stop bits */
545 	if (cflag & CSTOPB)
546 		mr2 |= MR2_STOP_BITS_LENGTH_2;
547 	else
548 		mr2 |= MR2_STOP_BITS_LENGTH_1;
549 
550 	/* Set the flow control */
551 	switch (channel->board_id) {
552 	case IPACK1_DEVICE_ID_SBS_OCTAL_232:
553 		if (cflag & CRTSCTS) {
554 			mr1 |= MR1_RxRTS_CONTROL_ON;
555 			mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_ON;
556 		} else {
557 			mr1 |= MR1_RxRTS_CONTROL_OFF;
558 			mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_OFF;
559 		}
560 		break;
561 	case IPACK1_DEVICE_ID_SBS_OCTAL_422:
562 		mr1 |= MR1_RxRTS_CONTROL_OFF;
563 		mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_OFF;
564 		break;
565 	case IPACK1_DEVICE_ID_SBS_OCTAL_485:
566 		mr1 |= MR1_RxRTS_CONTROL_OFF;
567 		mr2 |= MR2_TxRTS_CONTROL_ON | MR2_CTS_ENABLE_TX_OFF;
568 		break;
569 	default:
570 		return;
571 		break;
572 	}
573 
574 	baud = tty_get_baud_rate(tty);
575 	tty_termios_encode_baud_rate(&tty->termios, baud, baud);
576 
577 	/* Set baud rate */
578 	switch (baud) {
579 	case 75:
580 		csr |= TX_CLK_75 | RX_CLK_75;
581 		break;
582 	case 110:
583 		csr |= TX_CLK_110 | RX_CLK_110;
584 		break;
585 	case 150:
586 		csr |= TX_CLK_150 | RX_CLK_150;
587 		break;
588 	case 300:
589 		csr |= TX_CLK_300 | RX_CLK_300;
590 		break;
591 	case 600:
592 		csr |= TX_CLK_600 | RX_CLK_600;
593 		break;
594 	case 1200:
595 		csr |= TX_CLK_1200 | RX_CLK_1200;
596 		break;
597 	case 1800:
598 		csr |= TX_CLK_1800 | RX_CLK_1800;
599 		break;
600 	case 2000:
601 		csr |= TX_CLK_2000 | RX_CLK_2000;
602 		break;
603 	case 2400:
604 		csr |= TX_CLK_2400 | RX_CLK_2400;
605 		break;
606 	case 4800:
607 		csr |= TX_CLK_4800  | RX_CLK_4800;
608 		break;
609 	case 9600:
610 		csr |= TX_CLK_9600  | RX_CLK_9600;
611 		break;
612 	case 19200:
613 		csr |= TX_CLK_19200 | RX_CLK_19200;
614 		break;
615 	case 38400:
616 	default:
617 		csr |= TX_CLK_38400 | RX_CLK_38400;
618 		/* In case of default, we establish 38400 bps */
619 		tty_termios_encode_baud_rate(&tty->termios, 38400, 38400);
620 		break;
621 	}
622 
623 	mr1 |= MR1_ERROR_CHAR;
624 	mr1 |= MR1_RxINT_RxRDY;
625 
626 	/* Write the control registers */
627 	iowrite8(mr1, &channel->regs->w.mr);
628 	iowrite8(mr2, &channel->regs->w.mr);
629 	iowrite8(csr, &channel->regs->w.csr);
630 
631 	/* Enable again the RX */
632 	iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
633 }
634 
635 static void ipoctal_hangup(struct tty_struct *tty)
636 {
637 	unsigned long flags;
638 	struct ipoctal_channel *channel = tty->driver_data;
639 
640 	if (channel == NULL)
641 		return;
642 
643 	spin_lock_irqsave(&channel->lock, flags);
644 	channel->nb_bytes = 0;
645 	channel->pointer_read = 0;
646 	channel->pointer_write = 0;
647 	spin_unlock_irqrestore(&channel->lock, flags);
648 
649 	tty_port_hangup(&channel->tty_port);
650 
651 	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
652 	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
653 	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
654 	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
655 	iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
656 
657 	clear_bit(ASYNCB_INITIALIZED, &channel->tty_port.flags);
658 	wake_up_interruptible(&channel->tty_port.open_wait);
659 }
660 
661 static const struct tty_operations ipoctal_fops = {
662 	.ioctl =		NULL,
663 	.open =			ipoctal_open,
664 	.close =		ipoctal_close,
665 	.write =		ipoctal_write_tty,
666 	.set_termios =		ipoctal_set_termios,
667 	.write_room =		ipoctal_write_room,
668 	.chars_in_buffer =	ipoctal_chars_in_buffer,
669 	.get_icount =		ipoctal_get_icount,
670 	.hangup =		ipoctal_hangup,
671 };
672 
673 static int ipoctal_probe(struct ipack_device *dev)
674 {
675 	int res;
676 	struct ipoctal *ipoctal;
677 
678 	ipoctal = kzalloc(sizeof(struct ipoctal), GFP_KERNEL);
679 	if (ipoctal == NULL)
680 		return -ENOMEM;
681 
682 	ipoctal->dev = dev;
683 	res = ipoctal_inst_slot(ipoctal, dev->bus->bus_nr, dev->slot);
684 	if (res)
685 		goto out_uninst;
686 
687 	dev_set_drvdata(&dev->dev, ipoctal);
688 	return 0;
689 
690 out_uninst:
691 	kfree(ipoctal);
692 	return res;
693 }
694 
695 static void __ipoctal_remove(struct ipoctal *ipoctal)
696 {
697 	int i;
698 
699 	ipoctal->dev->bus->ops->free_irq(ipoctal->dev);
700 
701 	for (i = 0; i < NR_CHANNELS; i++) {
702 		struct ipoctal_channel *channel = &ipoctal->channel[i];
703 		tty_unregister_device(ipoctal->tty_drv, i);
704 		tty_port_free_xmit_buf(&channel->tty_port);
705 		tty_port_destroy(&channel->tty_port);
706 	}
707 
708 	tty_unregister_driver(ipoctal->tty_drv);
709 	put_tty_driver(ipoctal->tty_drv);
710 	kfree(ipoctal);
711 }
712 
713 static void ipoctal_remove(struct ipack_device *idev)
714 {
715 	__ipoctal_remove(dev_get_drvdata(&idev->dev));
716 }
717 
718 static DEFINE_IPACK_DEVICE_TABLE(ipoctal_ids) = {
719 	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
720 			IPACK1_DEVICE_ID_SBS_OCTAL_232) },
721 	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
722 			IPACK1_DEVICE_ID_SBS_OCTAL_422) },
723 	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
724 			IPACK1_DEVICE_ID_SBS_OCTAL_485) },
725 	{ 0, },
726 };
727 
728 MODULE_DEVICE_TABLE(ipack, ipoctal_ids);
729 
730 static const struct ipack_driver_ops ipoctal_drv_ops = {
731 	.probe  = ipoctal_probe,
732 	.remove = ipoctal_remove,
733 };
734 
735 static struct ipack_driver driver = {
736 	.ops      = &ipoctal_drv_ops,
737 	.id_table = ipoctal_ids,
738 };
739 
740 static int __init ipoctal_init(void)
741 {
742 	return ipack_driver_register(&driver, THIS_MODULE, KBUILD_MODNAME);
743 }
744 
745 static void __exit ipoctal_exit(void)
746 {
747 	ipack_driver_unregister(&driver);
748 }
749 
750 MODULE_DESCRIPTION("IP-Octal 232, 422 and 485 device driver");
751 MODULE_LICENSE("GPL");
752 
753 module_init(ipoctal_init);
754 module_exit(ipoctal_exit);
755