xref: /openbmc/linux/drivers/ipack/devices/ipoctal.c (revision 293d5b43)
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/io.h>
24 #include <linux/ipack.h>
25 #include "ipoctal.h"
26 #include "scc2698.h"
27 
28 #define IP_OCTAL_ID_SPACE_VECTOR    0x41
29 #define IP_OCTAL_NB_BLOCKS          4
30 
31 static const struct tty_operations ipoctal_fops;
32 
33 struct ipoctal_channel {
34 	struct ipoctal_stats		stats;
35 	unsigned int			nb_bytes;
36 	wait_queue_head_t		queue;
37 	spinlock_t			lock;
38 	unsigned int			pointer_read;
39 	unsigned int			pointer_write;
40 	struct tty_port			tty_port;
41 	union scc2698_channel __iomem	*regs;
42 	union scc2698_block __iomem	*block_regs;
43 	unsigned int			board_id;
44 	u8				isr_rx_rdy_mask;
45 	u8				isr_tx_rdy_mask;
46 	unsigned int			rx_enable;
47 };
48 
49 struct ipoctal {
50 	struct ipack_device		*dev;
51 	unsigned int			board_id;
52 	struct ipoctal_channel		channel[NR_CHANNELS];
53 	struct tty_driver		*tty_drv;
54 	u8 __iomem			*mem8_space;
55 	u8 __iomem			*int_space;
56 };
57 
58 static inline struct ipoctal *chan_to_ipoctal(struct ipoctal_channel *chan,
59 					      unsigned int index)
60 {
61 	return container_of(chan, struct ipoctal, channel[index]);
62 }
63 
64 static void ipoctal_reset_channel(struct ipoctal_channel *channel)
65 {
66 	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
67 	channel->rx_enable = 0;
68 	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
69 	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
70 	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
71 	iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
72 }
73 
74 static int ipoctal_port_activate(struct tty_port *port, struct tty_struct *tty)
75 {
76 	struct ipoctal_channel *channel;
77 
78 	channel = dev_get_drvdata(tty->dev);
79 
80 	/*
81 	 * Enable RX. TX will be enabled when
82 	 * there is something to send
83 	 */
84 	iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
85 	channel->rx_enable = 1;
86 	return 0;
87 }
88 
89 static int ipoctal_open(struct tty_struct *tty, struct file *file)
90 {
91 	struct ipoctal_channel *channel = dev_get_drvdata(tty->dev);
92 	struct ipoctal *ipoctal = chan_to_ipoctal(channel, tty->index);
93 	int err;
94 
95 	tty->driver_data = channel;
96 
97 	if (!ipack_get_carrier(ipoctal->dev))
98 		return -EBUSY;
99 
100 	err = tty_port_open(&channel->tty_port, tty, file);
101 	if (err)
102 		ipack_put_carrier(ipoctal->dev);
103 
104 	return err;
105 }
106 
107 static void ipoctal_reset_stats(struct ipoctal_stats *stats)
108 {
109 	stats->tx = 0;
110 	stats->rx = 0;
111 	stats->rcv_break = 0;
112 	stats->framing_err = 0;
113 	stats->overrun_err = 0;
114 	stats->parity_err = 0;
115 }
116 
117 static void ipoctal_free_channel(struct ipoctal_channel *channel)
118 {
119 	ipoctal_reset_stats(&channel->stats);
120 	channel->pointer_read = 0;
121 	channel->pointer_write = 0;
122 	channel->nb_bytes = 0;
123 }
124 
125 static void ipoctal_close(struct tty_struct *tty, struct file *filp)
126 {
127 	struct ipoctal_channel *channel = tty->driver_data;
128 
129 	tty_port_close(&channel->tty_port, tty, filp);
130 	ipoctal_free_channel(channel);
131 }
132 
133 static int ipoctal_get_icount(struct tty_struct *tty,
134 			      struct serial_icounter_struct *icount)
135 {
136 	struct ipoctal_channel *channel = tty->driver_data;
137 
138 	icount->cts = 0;
139 	icount->dsr = 0;
140 	icount->rng = 0;
141 	icount->dcd = 0;
142 	icount->rx = channel->stats.rx;
143 	icount->tx = channel->stats.tx;
144 	icount->frame = channel->stats.framing_err;
145 	icount->parity = channel->stats.parity_err;
146 	icount->brk = channel->stats.rcv_break;
147 	return 0;
148 }
149 
150 static void ipoctal_irq_rx(struct ipoctal_channel *channel, u8 sr)
151 {
152 	struct tty_port *port = &channel->tty_port;
153 	unsigned char value;
154 	unsigned char flag;
155 	u8 isr;
156 
157 	do {
158 		value = ioread8(&channel->regs->r.rhr);
159 		flag = TTY_NORMAL;
160 		/* Error: count statistics */
161 		if (sr & SR_ERROR) {
162 			iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
163 
164 			if (sr & SR_OVERRUN_ERROR) {
165 				channel->stats.overrun_err++;
166 				/* Overrun doesn't affect the current character*/
167 				tty_insert_flip_char(port, 0, TTY_OVERRUN);
168 			}
169 			if (sr & SR_PARITY_ERROR) {
170 				channel->stats.parity_err++;
171 				flag = TTY_PARITY;
172 			}
173 			if (sr & SR_FRAMING_ERROR) {
174 				channel->stats.framing_err++;
175 				flag = TTY_FRAME;
176 			}
177 			if (sr & SR_RECEIVED_BREAK) {
178 				channel->stats.rcv_break++;
179 				flag = TTY_BREAK;
180 			}
181 		}
182 		tty_insert_flip_char(port, value, flag);
183 
184 		/* Check if there are more characters in RX FIFO
185 		 * If there are more, the isr register for this channel
186 		 * has enabled the RxRDY|FFULL bit.
187 		 */
188 		isr = ioread8(&channel->block_regs->r.isr);
189 		sr = ioread8(&channel->regs->r.sr);
190 	} while (isr & channel->isr_rx_rdy_mask);
191 
192 	tty_flip_buffer_push(port);
193 }
194 
195 static void ipoctal_irq_tx(struct ipoctal_channel *channel)
196 {
197 	unsigned char value;
198 	unsigned int *pointer_write = &channel->pointer_write;
199 
200 	if (channel->nb_bytes == 0)
201 		return;
202 
203 	spin_lock(&channel->lock);
204 	value = channel->tty_port.xmit_buf[*pointer_write];
205 	iowrite8(value, &channel->regs->w.thr);
206 	channel->stats.tx++;
207 	(*pointer_write)++;
208 	*pointer_write = *pointer_write % PAGE_SIZE;
209 	channel->nb_bytes--;
210 	spin_unlock(&channel->lock);
211 }
212 
213 static void ipoctal_irq_channel(struct ipoctal_channel *channel)
214 {
215 	u8 isr, sr;
216 
217 	/* The HW is organized in pair of channels.  See which register we need
218 	 * to read from */
219 	isr = ioread8(&channel->block_regs->r.isr);
220 	sr = ioread8(&channel->regs->r.sr);
221 
222 	if (isr & (IMR_DELTA_BREAK_A | IMR_DELTA_BREAK_B))
223 		iowrite8(CR_CMD_RESET_BREAK_CHANGE, &channel->regs->w.cr);
224 
225 	if ((sr & SR_TX_EMPTY) && (channel->nb_bytes == 0)) {
226 		iowrite8(CR_DISABLE_TX, &channel->regs->w.cr);
227 		/* In case of RS-485, change from TX to RX when finishing TX.
228 		 * Half-duplex. */
229 		if (channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) {
230 			iowrite8(CR_CMD_NEGATE_RTSN, &channel->regs->w.cr);
231 			iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
232 			channel->rx_enable = 1;
233 		}
234 	}
235 
236 	/* RX data */
237 	if ((isr & channel->isr_rx_rdy_mask) && (sr & SR_RX_READY))
238 		ipoctal_irq_rx(channel, sr);
239 
240 	/* TX of each character */
241 	if ((isr & channel->isr_tx_rdy_mask) && (sr & SR_TX_READY))
242 		ipoctal_irq_tx(channel);
243 }
244 
245 static irqreturn_t ipoctal_irq_handler(void *arg)
246 {
247 	unsigned int i;
248 	struct ipoctal *ipoctal = (struct ipoctal *) arg;
249 
250 	/* Clear the IPack device interrupt */
251 	readw(ipoctal->int_space + ACK_INT_REQ0);
252 	readw(ipoctal->int_space + ACK_INT_REQ1);
253 
254 	/* Check all channels */
255 	for (i = 0; i < NR_CHANNELS; i++)
256 		ipoctal_irq_channel(&ipoctal->channel[i]);
257 
258 	return IRQ_HANDLED;
259 }
260 
261 static const struct tty_port_operations ipoctal_tty_port_ops = {
262 	.dtr_rts = NULL,
263 	.activate = ipoctal_port_activate,
264 };
265 
266 static int ipoctal_inst_slot(struct ipoctal *ipoctal, unsigned int bus_nr,
267 			     unsigned int slot)
268 {
269 	int res;
270 	int i;
271 	struct tty_driver *tty;
272 	char name[20];
273 	struct ipoctal_channel *channel;
274 	struct ipack_region *region;
275 	void __iomem *addr;
276 	union scc2698_channel __iomem *chan_regs;
277 	union scc2698_block __iomem *block_regs;
278 
279 	ipoctal->board_id = ipoctal->dev->id_device;
280 
281 	region = &ipoctal->dev->region[IPACK_IO_SPACE];
282 	addr = devm_ioremap_nocache(&ipoctal->dev->dev,
283 				    region->start, region->size);
284 	if (!addr) {
285 		dev_err(&ipoctal->dev->dev,
286 			"Unable to map slot [%d:%d] IO space!\n",
287 			bus_nr, slot);
288 		return -EADDRNOTAVAIL;
289 	}
290 	/* Save the virtual address to access the registers easily */
291 	chan_regs =
292 		(union scc2698_channel __iomem *) addr;
293 	block_regs =
294 		(union scc2698_block __iomem *) addr;
295 
296 	region = &ipoctal->dev->region[IPACK_INT_SPACE];
297 	ipoctal->int_space =
298 		devm_ioremap_nocache(&ipoctal->dev->dev,
299 				     region->start, region->size);
300 	if (!ipoctal->int_space) {
301 		dev_err(&ipoctal->dev->dev,
302 			"Unable to map slot [%d:%d] INT space!\n",
303 			bus_nr, slot);
304 		return -EADDRNOTAVAIL;
305 	}
306 
307 	region = &ipoctal->dev->region[IPACK_MEM8_SPACE];
308 	ipoctal->mem8_space =
309 		devm_ioremap_nocache(&ipoctal->dev->dev,
310 				     region->start, 0x8000);
311 	if (!ipoctal->mem8_space) {
312 		dev_err(&ipoctal->dev->dev,
313 			"Unable to map slot [%d:%d] MEM8 space!\n",
314 			bus_nr, slot);
315 		return -EADDRNOTAVAIL;
316 	}
317 
318 
319 	/* Disable RX and TX before touching anything */
320 	for (i = 0; i < NR_CHANNELS ; i++) {
321 		struct ipoctal_channel *channel = &ipoctal->channel[i];
322 		channel->regs = chan_regs + i;
323 		channel->block_regs = block_regs + (i >> 1);
324 		channel->board_id = ipoctal->board_id;
325 		if (i & 1) {
326 			channel->isr_tx_rdy_mask = ISR_TxRDY_B;
327 			channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_B;
328 		} else {
329 			channel->isr_tx_rdy_mask = ISR_TxRDY_A;
330 			channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_A;
331 		}
332 
333 		ipoctal_reset_channel(channel);
334 		iowrite8(MR1_CHRL_8_BITS | MR1_ERROR_CHAR | MR1_RxINT_RxRDY,
335 			 &channel->regs->w.mr); /* mr1 */
336 		iowrite8(0, &channel->regs->w.mr); /* mr2 */
337 		iowrite8(TX_CLK_9600  | RX_CLK_9600, &channel->regs->w.csr);
338 	}
339 
340 	for (i = 0; i < IP_OCTAL_NB_BLOCKS; i++) {
341 		iowrite8(ACR_BRG_SET2, &block_regs[i].w.acr);
342 		iowrite8(OPCR_MPP_OUTPUT | OPCR_MPOa_RTSN | OPCR_MPOb_RTSN,
343 			 &block_regs[i].w.opcr);
344 		iowrite8(IMR_TxRDY_A | IMR_RxRDY_FFULL_A | IMR_DELTA_BREAK_A |
345 			 IMR_TxRDY_B | IMR_RxRDY_FFULL_B | IMR_DELTA_BREAK_B,
346 			 &block_regs[i].w.imr);
347 	}
348 
349 	/* Dummy write */
350 	iowrite8(1, ipoctal->mem8_space + 1);
351 
352 	/* Register the TTY device */
353 
354 	/* Each IP-OCTAL channel is a TTY port */
355 	tty = alloc_tty_driver(NR_CHANNELS);
356 
357 	if (!tty)
358 		return -ENOMEM;
359 
360 	/* Fill struct tty_driver with ipoctal data */
361 	tty->owner = THIS_MODULE;
362 	tty->driver_name = KBUILD_MODNAME;
363 	sprintf(name, KBUILD_MODNAME ".%d.%d.", bus_nr, slot);
364 	tty->name = name;
365 	tty->major = 0;
366 
367 	tty->minor_start = 0;
368 	tty->type = TTY_DRIVER_TYPE_SERIAL;
369 	tty->subtype = SERIAL_TYPE_NORMAL;
370 	tty->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
371 	tty->init_termios = tty_std_termios;
372 	tty->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
373 	tty->init_termios.c_ispeed = 9600;
374 	tty->init_termios.c_ospeed = 9600;
375 
376 	tty_set_operations(tty, &ipoctal_fops);
377 	res = tty_register_driver(tty);
378 	if (res) {
379 		dev_err(&ipoctal->dev->dev, "Can't register tty driver.\n");
380 		put_tty_driver(tty);
381 		return res;
382 	}
383 
384 	/* Save struct tty_driver for use it when uninstalling the device */
385 	ipoctal->tty_drv = tty;
386 
387 	for (i = 0; i < NR_CHANNELS; i++) {
388 		struct device *tty_dev;
389 
390 		channel = &ipoctal->channel[i];
391 		tty_port_init(&channel->tty_port);
392 		tty_port_alloc_xmit_buf(&channel->tty_port);
393 		channel->tty_port.ops = &ipoctal_tty_port_ops;
394 
395 		ipoctal_reset_stats(&channel->stats);
396 		channel->nb_bytes = 0;
397 		spin_lock_init(&channel->lock);
398 		channel->pointer_read = 0;
399 		channel->pointer_write = 0;
400 		tty_dev = tty_port_register_device(&channel->tty_port, tty, i, NULL);
401 		if (IS_ERR(tty_dev)) {
402 			dev_err(&ipoctal->dev->dev, "Failed to register tty device.\n");
403 			tty_port_destroy(&channel->tty_port);
404 			continue;
405 		}
406 		dev_set_drvdata(tty_dev, channel);
407 	}
408 
409 	/*
410 	 * IP-OCTAL has different addresses to copy its IRQ vector.
411 	 * Depending of the carrier these addresses are accesible or not.
412 	 * More info in the datasheet.
413 	 */
414 	ipoctal->dev->bus->ops->request_irq(ipoctal->dev,
415 				       ipoctal_irq_handler, ipoctal);
416 
417 	return 0;
418 }
419 
420 static inline int ipoctal_copy_write_buffer(struct ipoctal_channel *channel,
421 					    const unsigned char *buf,
422 					    int count)
423 {
424 	unsigned long flags;
425 	int i;
426 	unsigned int *pointer_read = &channel->pointer_read;
427 
428 	/* Copy the bytes from the user buffer to the internal one */
429 	for (i = 0; i < count; i++) {
430 		if (i <= (PAGE_SIZE - channel->nb_bytes)) {
431 			spin_lock_irqsave(&channel->lock, flags);
432 			channel->tty_port.xmit_buf[*pointer_read] = buf[i];
433 			*pointer_read = (*pointer_read + 1) % PAGE_SIZE;
434 			channel->nb_bytes++;
435 			spin_unlock_irqrestore(&channel->lock, flags);
436 		} else {
437 			break;
438 		}
439 	}
440 	return i;
441 }
442 
443 static int ipoctal_write_tty(struct tty_struct *tty,
444 			     const unsigned char *buf, int count)
445 {
446 	struct ipoctal_channel *channel = tty->driver_data;
447 	unsigned int char_copied;
448 
449 	char_copied = ipoctal_copy_write_buffer(channel, buf, count);
450 
451 	/* As the IP-OCTAL 485 only supports half duplex, do it manually */
452 	if (channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) {
453 		iowrite8(CR_DISABLE_RX, &channel->regs->w.cr);
454 		channel->rx_enable = 0;
455 		iowrite8(CR_CMD_ASSERT_RTSN, &channel->regs->w.cr);
456 	}
457 
458 	/*
459 	 * Send a packet and then disable TX to avoid failure after several send
460 	 * operations
461 	 */
462 	iowrite8(CR_ENABLE_TX, &channel->regs->w.cr);
463 	return char_copied;
464 }
465 
466 static int ipoctal_write_room(struct tty_struct *tty)
467 {
468 	struct ipoctal_channel *channel = tty->driver_data;
469 
470 	return PAGE_SIZE - channel->nb_bytes;
471 }
472 
473 static int ipoctal_chars_in_buffer(struct tty_struct *tty)
474 {
475 	struct ipoctal_channel *channel = tty->driver_data;
476 
477 	return channel->nb_bytes;
478 }
479 
480 static void ipoctal_set_termios(struct tty_struct *tty,
481 				struct ktermios *old_termios)
482 {
483 	unsigned int cflag;
484 	unsigned char mr1 = 0;
485 	unsigned char mr2 = 0;
486 	unsigned char csr = 0;
487 	struct ipoctal_channel *channel = tty->driver_data;
488 	speed_t baud;
489 
490 	cflag = tty->termios.c_cflag;
491 
492 	/* Disable and reset everything before change the setup */
493 	ipoctal_reset_channel(channel);
494 
495 	/* Set Bits per chars */
496 	switch (cflag & CSIZE) {
497 	case CS6:
498 		mr1 |= MR1_CHRL_6_BITS;
499 		break;
500 	case CS7:
501 		mr1 |= MR1_CHRL_7_BITS;
502 		break;
503 	case CS8:
504 	default:
505 		mr1 |= MR1_CHRL_8_BITS;
506 		/* By default, select CS8 */
507 		tty->termios.c_cflag = (cflag & ~CSIZE) | CS8;
508 		break;
509 	}
510 
511 	/* Set Parity */
512 	if (cflag & PARENB)
513 		if (cflag & PARODD)
514 			mr1 |= MR1_PARITY_ON | MR1_PARITY_ODD;
515 		else
516 			mr1 |= MR1_PARITY_ON | MR1_PARITY_EVEN;
517 	else
518 		mr1 |= MR1_PARITY_OFF;
519 
520 	/* Mark or space parity is not supported */
521 	tty->termios.c_cflag &= ~CMSPAR;
522 
523 	/* Set stop bits */
524 	if (cflag & CSTOPB)
525 		mr2 |= MR2_STOP_BITS_LENGTH_2;
526 	else
527 		mr2 |= MR2_STOP_BITS_LENGTH_1;
528 
529 	/* Set the flow control */
530 	switch (channel->board_id) {
531 	case IPACK1_DEVICE_ID_SBS_OCTAL_232:
532 		if (cflag & CRTSCTS) {
533 			mr1 |= MR1_RxRTS_CONTROL_ON;
534 			mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_ON;
535 		} else {
536 			mr1 |= MR1_RxRTS_CONTROL_OFF;
537 			mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_OFF;
538 		}
539 		break;
540 	case IPACK1_DEVICE_ID_SBS_OCTAL_422:
541 		mr1 |= MR1_RxRTS_CONTROL_OFF;
542 		mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_OFF;
543 		break;
544 	case IPACK1_DEVICE_ID_SBS_OCTAL_485:
545 		mr1 |= MR1_RxRTS_CONTROL_OFF;
546 		mr2 |= MR2_TxRTS_CONTROL_ON | MR2_CTS_ENABLE_TX_OFF;
547 		break;
548 	default:
549 		return;
550 		break;
551 	}
552 
553 	baud = tty_get_baud_rate(tty);
554 	tty_termios_encode_baud_rate(&tty->termios, baud, baud);
555 
556 	/* Set baud rate */
557 	switch (baud) {
558 	case 75:
559 		csr |= TX_CLK_75 | RX_CLK_75;
560 		break;
561 	case 110:
562 		csr |= TX_CLK_110 | RX_CLK_110;
563 		break;
564 	case 150:
565 		csr |= TX_CLK_150 | RX_CLK_150;
566 		break;
567 	case 300:
568 		csr |= TX_CLK_300 | RX_CLK_300;
569 		break;
570 	case 600:
571 		csr |= TX_CLK_600 | RX_CLK_600;
572 		break;
573 	case 1200:
574 		csr |= TX_CLK_1200 | RX_CLK_1200;
575 		break;
576 	case 1800:
577 		csr |= TX_CLK_1800 | RX_CLK_1800;
578 		break;
579 	case 2000:
580 		csr |= TX_CLK_2000 | RX_CLK_2000;
581 		break;
582 	case 2400:
583 		csr |= TX_CLK_2400 | RX_CLK_2400;
584 		break;
585 	case 4800:
586 		csr |= TX_CLK_4800  | RX_CLK_4800;
587 		break;
588 	case 9600:
589 		csr |= TX_CLK_9600  | RX_CLK_9600;
590 		break;
591 	case 19200:
592 		csr |= TX_CLK_19200 | RX_CLK_19200;
593 		break;
594 	case 38400:
595 	default:
596 		csr |= TX_CLK_38400 | RX_CLK_38400;
597 		/* In case of default, we establish 38400 bps */
598 		tty_termios_encode_baud_rate(&tty->termios, 38400, 38400);
599 		break;
600 	}
601 
602 	mr1 |= MR1_ERROR_CHAR;
603 	mr1 |= MR1_RxINT_RxRDY;
604 
605 	/* Write the control registers */
606 	iowrite8(mr1, &channel->regs->w.mr);
607 	iowrite8(mr2, &channel->regs->w.mr);
608 	iowrite8(csr, &channel->regs->w.csr);
609 
610 	/* Enable again the RX, if it was before */
611 	if (channel->rx_enable)
612 		iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
613 }
614 
615 static void ipoctal_hangup(struct tty_struct *tty)
616 {
617 	unsigned long flags;
618 	struct ipoctal_channel *channel = tty->driver_data;
619 
620 	if (channel == NULL)
621 		return;
622 
623 	spin_lock_irqsave(&channel->lock, flags);
624 	channel->nb_bytes = 0;
625 	channel->pointer_read = 0;
626 	channel->pointer_write = 0;
627 	spin_unlock_irqrestore(&channel->lock, flags);
628 
629 	tty_port_hangup(&channel->tty_port);
630 
631 	ipoctal_reset_channel(channel);
632 	tty_port_set_initialized(&channel->tty_port, 0);
633 	wake_up_interruptible(&channel->tty_port.open_wait);
634 }
635 
636 static void ipoctal_shutdown(struct tty_struct *tty)
637 {
638 	struct ipoctal_channel *channel = tty->driver_data;
639 
640 	if (channel == NULL)
641 		return;
642 
643 	ipoctal_reset_channel(channel);
644 	tty_port_set_initialized(&channel->tty_port, 0);
645 }
646 
647 static void ipoctal_cleanup(struct tty_struct *tty)
648 {
649 	struct ipoctal_channel *channel = tty->driver_data;
650 	struct ipoctal *ipoctal = chan_to_ipoctal(channel, tty->index);
651 
652 	/* release the carrier driver */
653 	ipack_put_carrier(ipoctal->dev);
654 }
655 
656 static const struct tty_operations ipoctal_fops = {
657 	.ioctl =		NULL,
658 	.open =			ipoctal_open,
659 	.close =		ipoctal_close,
660 	.write =		ipoctal_write_tty,
661 	.set_termios =		ipoctal_set_termios,
662 	.write_room =		ipoctal_write_room,
663 	.chars_in_buffer =	ipoctal_chars_in_buffer,
664 	.get_icount =		ipoctal_get_icount,
665 	.hangup =		ipoctal_hangup,
666 	.shutdown =		ipoctal_shutdown,
667 	.cleanup =              ipoctal_cleanup,
668 };
669 
670 static int ipoctal_probe(struct ipack_device *dev)
671 {
672 	int res;
673 	struct ipoctal *ipoctal;
674 
675 	ipoctal = kzalloc(sizeof(struct ipoctal), GFP_KERNEL);
676 	if (ipoctal == NULL)
677 		return -ENOMEM;
678 
679 	ipoctal->dev = dev;
680 	res = ipoctal_inst_slot(ipoctal, dev->bus->bus_nr, dev->slot);
681 	if (res)
682 		goto out_uninst;
683 
684 	dev_set_drvdata(&dev->dev, ipoctal);
685 	return 0;
686 
687 out_uninst:
688 	kfree(ipoctal);
689 	return res;
690 }
691 
692 static void __ipoctal_remove(struct ipoctal *ipoctal)
693 {
694 	int i;
695 
696 	ipoctal->dev->bus->ops->free_irq(ipoctal->dev);
697 
698 	for (i = 0; i < NR_CHANNELS; i++) {
699 		struct ipoctal_channel *channel = &ipoctal->channel[i];
700 		tty_unregister_device(ipoctal->tty_drv, i);
701 		tty_port_free_xmit_buf(&channel->tty_port);
702 		tty_port_destroy(&channel->tty_port);
703 	}
704 
705 	tty_unregister_driver(ipoctal->tty_drv);
706 	put_tty_driver(ipoctal->tty_drv);
707 	kfree(ipoctal);
708 }
709 
710 static void ipoctal_remove(struct ipack_device *idev)
711 {
712 	__ipoctal_remove(dev_get_drvdata(&idev->dev));
713 }
714 
715 static DEFINE_IPACK_DEVICE_TABLE(ipoctal_ids) = {
716 	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
717 			IPACK1_DEVICE_ID_SBS_OCTAL_232) },
718 	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
719 			IPACK1_DEVICE_ID_SBS_OCTAL_422) },
720 	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
721 			IPACK1_DEVICE_ID_SBS_OCTAL_485) },
722 	{ 0, },
723 };
724 
725 MODULE_DEVICE_TABLE(ipack, ipoctal_ids);
726 
727 static const struct ipack_driver_ops ipoctal_drv_ops = {
728 	.probe  = ipoctal_probe,
729 	.remove = ipoctal_remove,
730 };
731 
732 static struct ipack_driver driver = {
733 	.ops      = &ipoctal_drv_ops,
734 	.id_table = ipoctal_ids,
735 };
736 
737 static int __init ipoctal_init(void)
738 {
739 	return ipack_driver_register(&driver, THIS_MODULE, KBUILD_MODNAME);
740 }
741 
742 static void __exit ipoctal_exit(void)
743 {
744 	ipack_driver_unregister(&driver);
745 }
746 
747 MODULE_DESCRIPTION("IP-Octal 232, 422 and 485 device driver");
748 MODULE_LICENSE("GPL");
749 
750 module_init(ipoctal_init);
751 module_exit(ipoctal_exit);
752