xref: /openbmc/linux/drivers/ipack/devices/ipoctal.c (revision 234489ac)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * driver for the GE IP-OCTAL boards
4  *
5  * Copyright (C) 2009-2012 CERN (www.cern.ch)
6  * Author: Nicolas Serafini, EIC2 SA
7  * Author: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
8  */
9 
10 #include <linux/device.h>
11 #include <linux/module.h>
12 #include <linux/interrupt.h>
13 #include <linux/sched.h>
14 #include <linux/tty.h>
15 #include <linux/serial.h>
16 #include <linux/tty_flip.h>
17 #include <linux/slab.h>
18 #include <linux/io.h>
19 #include <linux/ipack.h>
20 #include "ipoctal.h"
21 #include "scc2698.h"
22 
23 #define IP_OCTAL_ID_SPACE_VECTOR    0x41
24 #define IP_OCTAL_NB_BLOCKS          4
25 
26 static const struct tty_operations ipoctal_fops;
27 
28 struct ipoctal_channel {
29 	struct ipoctal_stats		stats;
30 	unsigned int			nb_bytes;
31 	wait_queue_head_t		queue;
32 	spinlock_t			lock;
33 	unsigned int			pointer_read;
34 	unsigned int			pointer_write;
35 	struct tty_port			tty_port;
36 	bool				tty_registered;
37 	union scc2698_channel __iomem	*regs;
38 	union scc2698_block __iomem	*block_regs;
39 	unsigned int			board_id;
40 	u8				isr_rx_rdy_mask;
41 	u8				isr_tx_rdy_mask;
42 	unsigned int			rx_enable;
43 };
44 
45 struct ipoctal {
46 	struct ipack_device		*dev;
47 	unsigned int			board_id;
48 	struct ipoctal_channel		channel[NR_CHANNELS];
49 	struct tty_driver		*tty_drv;
50 	u8 __iomem			*mem8_space;
51 	u8 __iomem			*int_space;
52 };
53 
54 static inline struct ipoctal *chan_to_ipoctal(struct ipoctal_channel *chan,
55 					      unsigned int index)
56 {
57 	return container_of(chan, struct ipoctal, channel[index]);
58 }
59 
60 static void ipoctal_reset_channel(struct ipoctal_channel *channel)
61 {
62 	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
63 	channel->rx_enable = 0;
64 	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
65 	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
66 	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
67 	iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
68 }
69 
70 static int ipoctal_port_activate(struct tty_port *port, struct tty_struct *tty)
71 {
72 	struct ipoctal_channel *channel;
73 
74 	channel = dev_get_drvdata(tty->dev);
75 
76 	/*
77 	 * Enable RX. TX will be enabled when
78 	 * there is something to send
79 	 */
80 	iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
81 	channel->rx_enable = 1;
82 	return 0;
83 }
84 
85 static int ipoctal_install(struct tty_driver *driver, struct tty_struct *tty)
86 {
87 	struct ipoctal_channel *channel = dev_get_drvdata(tty->dev);
88 	struct ipoctal *ipoctal = chan_to_ipoctal(channel, tty->index);
89 	int res;
90 
91 	if (!ipack_get_carrier(ipoctal->dev))
92 		return -EBUSY;
93 
94 	res = tty_standard_install(driver, tty);
95 	if (res)
96 		goto err_put_carrier;
97 
98 	tty->driver_data = channel;
99 
100 	return 0;
101 
102 err_put_carrier:
103 	ipack_put_carrier(ipoctal->dev);
104 
105 	return res;
106 }
107 
108 static int ipoctal_open(struct tty_struct *tty, struct file *file)
109 {
110 	struct ipoctal_channel *channel = tty->driver_data;
111 
112 	return tty_port_open(&channel->tty_port, tty, file);
113 }
114 
115 static void ipoctal_reset_stats(struct ipoctal_stats *stats)
116 {
117 	stats->tx = 0;
118 	stats->rx = 0;
119 	stats->rcv_break = 0;
120 	stats->framing_err = 0;
121 	stats->overrun_err = 0;
122 	stats->parity_err = 0;
123 }
124 
125 static void ipoctal_free_channel(struct ipoctal_channel *channel)
126 {
127 	ipoctal_reset_stats(&channel->stats);
128 	channel->pointer_read = 0;
129 	channel->pointer_write = 0;
130 	channel->nb_bytes = 0;
131 }
132 
133 static void ipoctal_close(struct tty_struct *tty, struct file *filp)
134 {
135 	struct ipoctal_channel *channel = tty->driver_data;
136 
137 	tty_port_close(&channel->tty_port, tty, filp);
138 	ipoctal_free_channel(channel);
139 }
140 
141 static int ipoctal_get_icount(struct tty_struct *tty,
142 			      struct serial_icounter_struct *icount)
143 {
144 	struct ipoctal_channel *channel = tty->driver_data;
145 
146 	icount->cts = 0;
147 	icount->dsr = 0;
148 	icount->rng = 0;
149 	icount->dcd = 0;
150 	icount->rx = channel->stats.rx;
151 	icount->tx = channel->stats.tx;
152 	icount->frame = channel->stats.framing_err;
153 	icount->parity = channel->stats.parity_err;
154 	icount->brk = channel->stats.rcv_break;
155 	return 0;
156 }
157 
158 static void ipoctal_irq_rx(struct ipoctal_channel *channel, u8 sr)
159 {
160 	struct tty_port *port = &channel->tty_port;
161 	unsigned char value;
162 	unsigned char flag;
163 	u8 isr;
164 
165 	do {
166 		value = ioread8(&channel->regs->r.rhr);
167 		flag = TTY_NORMAL;
168 		/* Error: count statistics */
169 		if (sr & SR_ERROR) {
170 			iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
171 
172 			if (sr & SR_OVERRUN_ERROR) {
173 				channel->stats.overrun_err++;
174 				/* Overrun doesn't affect the current character*/
175 				tty_insert_flip_char(port, 0, TTY_OVERRUN);
176 			}
177 			if (sr & SR_PARITY_ERROR) {
178 				channel->stats.parity_err++;
179 				flag = TTY_PARITY;
180 			}
181 			if (sr & SR_FRAMING_ERROR) {
182 				channel->stats.framing_err++;
183 				flag = TTY_FRAME;
184 			}
185 			if (sr & SR_RECEIVED_BREAK) {
186 				channel->stats.rcv_break++;
187 				flag = TTY_BREAK;
188 			}
189 		}
190 		tty_insert_flip_char(port, value, flag);
191 
192 		/* Check if there are more characters in RX FIFO
193 		 * If there are more, the isr register for this channel
194 		 * has enabled the RxRDY|FFULL bit.
195 		 */
196 		isr = ioread8(&channel->block_regs->r.isr);
197 		sr = ioread8(&channel->regs->r.sr);
198 	} while (isr & channel->isr_rx_rdy_mask);
199 
200 	tty_flip_buffer_push(port);
201 }
202 
203 static void ipoctal_irq_tx(struct ipoctal_channel *channel)
204 {
205 	unsigned char value;
206 	unsigned int *pointer_write = &channel->pointer_write;
207 
208 	if (channel->nb_bytes == 0)
209 		return;
210 
211 	spin_lock(&channel->lock);
212 	value = channel->tty_port.xmit_buf[*pointer_write];
213 	iowrite8(value, &channel->regs->w.thr);
214 	channel->stats.tx++;
215 	(*pointer_write)++;
216 	*pointer_write = *pointer_write % PAGE_SIZE;
217 	channel->nb_bytes--;
218 	spin_unlock(&channel->lock);
219 }
220 
221 static void ipoctal_irq_channel(struct ipoctal_channel *channel)
222 {
223 	u8 isr, sr;
224 
225 	/* The HW is organized in pair of channels.  See which register we need
226 	 * to read from */
227 	isr = ioread8(&channel->block_regs->r.isr);
228 	sr = ioread8(&channel->regs->r.sr);
229 
230 	if (isr & (IMR_DELTA_BREAK_A | IMR_DELTA_BREAK_B))
231 		iowrite8(CR_CMD_RESET_BREAK_CHANGE, &channel->regs->w.cr);
232 
233 	if ((sr & SR_TX_EMPTY) && (channel->nb_bytes == 0)) {
234 		iowrite8(CR_DISABLE_TX, &channel->regs->w.cr);
235 		/* In case of RS-485, change from TX to RX when finishing TX.
236 		 * Half-duplex. */
237 		if (channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) {
238 			iowrite8(CR_CMD_NEGATE_RTSN, &channel->regs->w.cr);
239 			iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
240 			channel->rx_enable = 1;
241 		}
242 	}
243 
244 	/* RX data */
245 	if ((isr & channel->isr_rx_rdy_mask) && (sr & SR_RX_READY))
246 		ipoctal_irq_rx(channel, sr);
247 
248 	/* TX of each character */
249 	if ((isr & channel->isr_tx_rdy_mask) && (sr & SR_TX_READY))
250 		ipoctal_irq_tx(channel);
251 }
252 
253 static irqreturn_t ipoctal_irq_handler(void *arg)
254 {
255 	unsigned int i;
256 	struct ipoctal *ipoctal = arg;
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 	/* Check all channels */
263 	for (i = 0; i < NR_CHANNELS; i++)
264 		ipoctal_irq_channel(&ipoctal->channel[i]);
265 
266 	return IRQ_HANDLED;
267 }
268 
269 static const struct tty_port_operations ipoctal_tty_port_ops = {
270 	.dtr_rts = NULL,
271 	.activate = ipoctal_port_activate,
272 };
273 
274 static int ipoctal_inst_slot(struct ipoctal *ipoctal, unsigned int bus_nr,
275 			     unsigned int slot)
276 {
277 	int res;
278 	int i;
279 	struct tty_driver *drv;
280 	struct ipoctal_channel *channel;
281 	struct ipack_region *region;
282 	void __iomem *addr;
283 	union scc2698_channel __iomem *chan_regs;
284 	union scc2698_block __iomem *block_regs;
285 
286 	ipoctal->board_id = ipoctal->dev->id_device;
287 
288 	region = &ipoctal->dev->region[IPACK_IO_SPACE];
289 	addr = devm_ioremap(&ipoctal->dev->dev,
290 				    region->start, region->size);
291 	if (!addr) {
292 		dev_err(&ipoctal->dev->dev,
293 			"Unable to map slot [%d:%d] IO space!\n",
294 			bus_nr, slot);
295 		return -EADDRNOTAVAIL;
296 	}
297 	/* Save the virtual address to access the registers easily */
298 	chan_regs =
299 		(union scc2698_channel __iomem *) addr;
300 	block_regs =
301 		(union scc2698_block __iomem *) addr;
302 
303 	region = &ipoctal->dev->region[IPACK_INT_SPACE];
304 	ipoctal->int_space =
305 		devm_ioremap(&ipoctal->dev->dev,
306 				     region->start, region->size);
307 	if (!ipoctal->int_space) {
308 		dev_err(&ipoctal->dev->dev,
309 			"Unable to map slot [%d:%d] INT space!\n",
310 			bus_nr, slot);
311 		return -EADDRNOTAVAIL;
312 	}
313 
314 	region = &ipoctal->dev->region[IPACK_MEM8_SPACE];
315 	ipoctal->mem8_space =
316 		devm_ioremap(&ipoctal->dev->dev,
317 				     region->start, 0x8000);
318 	if (!ipoctal->mem8_space) {
319 		dev_err(&ipoctal->dev->dev,
320 			"Unable to map slot [%d:%d] MEM8 space!\n",
321 			bus_nr, slot);
322 		return -EADDRNOTAVAIL;
323 	}
324 
325 
326 	/* Disable RX and TX before touching anything */
327 	for (i = 0; i < NR_CHANNELS ; i++) {
328 		struct ipoctal_channel *channel = &ipoctal->channel[i];
329 		channel->regs = chan_regs + i;
330 		channel->block_regs = block_regs + (i >> 1);
331 		channel->board_id = ipoctal->board_id;
332 		if (i & 1) {
333 			channel->isr_tx_rdy_mask = ISR_TxRDY_B;
334 			channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_B;
335 		} else {
336 			channel->isr_tx_rdy_mask = ISR_TxRDY_A;
337 			channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_A;
338 		}
339 
340 		ipoctal_reset_channel(channel);
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 	/* Dummy write */
357 	iowrite8(1, ipoctal->mem8_space + 1);
358 
359 	/* Register the TTY device */
360 
361 	/* Each IP-OCTAL channel is a TTY port */
362 	drv = tty_alloc_driver(NR_CHANNELS, TTY_DRIVER_REAL_RAW |
363 			TTY_DRIVER_DYNAMIC_DEV);
364 	if (IS_ERR(drv))
365 		return PTR_ERR(drv);
366 
367 	/* Fill struct tty_driver with ipoctal data */
368 	drv->owner = THIS_MODULE;
369 	drv->driver_name = KBUILD_MODNAME;
370 	drv->name = kasprintf(GFP_KERNEL, KBUILD_MODNAME ".%d.%d.", bus_nr, slot);
371 	if (!drv->name) {
372 		res = -ENOMEM;
373 		goto err_put_driver;
374 	}
375 	drv->major = 0;
376 
377 	drv->minor_start = 0;
378 	drv->type = TTY_DRIVER_TYPE_SERIAL;
379 	drv->subtype = SERIAL_TYPE_NORMAL;
380 	drv->init_termios = tty_std_termios;
381 	drv->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
382 	drv->init_termios.c_ispeed = 9600;
383 	drv->init_termios.c_ospeed = 9600;
384 
385 	tty_set_operations(drv, &ipoctal_fops);
386 	res = tty_register_driver(drv);
387 	if (res) {
388 		dev_err(&ipoctal->dev->dev, "Can't register tty driver.\n");
389 		goto err_free_name;
390 	}
391 
392 	/* Save struct tty_driver for use it when uninstalling the device */
393 	ipoctal->tty_drv = drv;
394 
395 	for (i = 0; i < NR_CHANNELS; i++) {
396 		struct device *tty_dev;
397 
398 		channel = &ipoctal->channel[i];
399 		tty_port_init(&channel->tty_port);
400 		res = tty_port_alloc_xmit_buf(&channel->tty_port);
401 		if (res)
402 			continue;
403 		channel->tty_port.ops = &ipoctal_tty_port_ops;
404 
405 		ipoctal_reset_stats(&channel->stats);
406 		channel->nb_bytes = 0;
407 		spin_lock_init(&channel->lock);
408 		channel->pointer_read = 0;
409 		channel->pointer_write = 0;
410 		tty_dev = tty_port_register_device_attr(&channel->tty_port, drv,
411 							i, NULL, channel, NULL);
412 		if (IS_ERR(tty_dev)) {
413 			dev_err(&ipoctal->dev->dev, "Failed to register tty device.\n");
414 			tty_port_free_xmit_buf(&channel->tty_port);
415 			tty_port_destroy(&channel->tty_port);
416 			continue;
417 		}
418 		channel->tty_registered = true;
419 	}
420 
421 	/*
422 	 * IP-OCTAL has different addresses to copy its IRQ vector.
423 	 * Depending of the carrier these addresses are accesible or not.
424 	 * More info in the datasheet.
425 	 */
426 	ipoctal->dev->bus->ops->request_irq(ipoctal->dev,
427 				       ipoctal_irq_handler, ipoctal);
428 
429 	return 0;
430 
431 err_free_name:
432 	kfree(drv->name);
433 err_put_driver:
434 	tty_driver_kref_put(drv);
435 
436 	return res;
437 }
438 
439 static inline int ipoctal_copy_write_buffer(struct ipoctal_channel *channel,
440 					    const unsigned char *buf,
441 					    int count)
442 {
443 	unsigned long flags;
444 	int i;
445 	unsigned int *pointer_read = &channel->pointer_read;
446 
447 	/* Copy the bytes from the user buffer to the internal one */
448 	for (i = 0; i < count; i++) {
449 		if (i <= (PAGE_SIZE - channel->nb_bytes)) {
450 			spin_lock_irqsave(&channel->lock, flags);
451 			channel->tty_port.xmit_buf[*pointer_read] = buf[i];
452 			*pointer_read = (*pointer_read + 1) % PAGE_SIZE;
453 			channel->nb_bytes++;
454 			spin_unlock_irqrestore(&channel->lock, flags);
455 		} else {
456 			break;
457 		}
458 	}
459 	return i;
460 }
461 
462 static int ipoctal_write_tty(struct tty_struct *tty,
463 			     const unsigned char *buf, int count)
464 {
465 	struct ipoctal_channel *channel = tty->driver_data;
466 	unsigned int char_copied;
467 
468 	char_copied = ipoctal_copy_write_buffer(channel, buf, count);
469 
470 	/* As the IP-OCTAL 485 only supports half duplex, do it manually */
471 	if (channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) {
472 		iowrite8(CR_DISABLE_RX, &channel->regs->w.cr);
473 		channel->rx_enable = 0;
474 		iowrite8(CR_CMD_ASSERT_RTSN, &channel->regs->w.cr);
475 	}
476 
477 	/*
478 	 * Send a packet and then disable TX to avoid failure after several send
479 	 * operations
480 	 */
481 	iowrite8(CR_ENABLE_TX, &channel->regs->w.cr);
482 	return char_copied;
483 }
484 
485 static unsigned int ipoctal_write_room(struct tty_struct *tty)
486 {
487 	struct ipoctal_channel *channel = tty->driver_data;
488 
489 	return PAGE_SIZE - channel->nb_bytes;
490 }
491 
492 static unsigned int ipoctal_chars_in_buffer(struct tty_struct *tty)
493 {
494 	struct ipoctal_channel *channel = tty->driver_data;
495 
496 	return channel->nb_bytes;
497 }
498 
499 static void ipoctal_set_termios(struct tty_struct *tty,
500 				const struct ktermios *old_termios)
501 {
502 	unsigned int cflag;
503 	unsigned char mr1 = 0;
504 	unsigned char mr2 = 0;
505 	unsigned char csr = 0;
506 	struct ipoctal_channel *channel = tty->driver_data;
507 	speed_t baud;
508 
509 	cflag = tty->termios.c_cflag;
510 
511 	/* Disable and reset everything before change the setup */
512 	ipoctal_reset_channel(channel);
513 
514 	/* Set Bits per chars */
515 	switch (cflag & CSIZE) {
516 	case CS6:
517 		mr1 |= MR1_CHRL_6_BITS;
518 		break;
519 	case CS7:
520 		mr1 |= MR1_CHRL_7_BITS;
521 		break;
522 	case CS8:
523 	default:
524 		mr1 |= MR1_CHRL_8_BITS;
525 		/* By default, select CS8 */
526 		tty->termios.c_cflag = (cflag & ~CSIZE) | CS8;
527 		break;
528 	}
529 
530 	/* Set Parity */
531 	if (cflag & PARENB)
532 		if (cflag & PARODD)
533 			mr1 |= MR1_PARITY_ON | MR1_PARITY_ODD;
534 		else
535 			mr1 |= MR1_PARITY_ON | MR1_PARITY_EVEN;
536 	else
537 		mr1 |= MR1_PARITY_OFF;
538 
539 	/* Mark or space parity is not supported */
540 	tty->termios.c_cflag &= ~CMSPAR;
541 
542 	/* Set stop bits */
543 	if (cflag & CSTOPB)
544 		mr2 |= MR2_STOP_BITS_LENGTH_2;
545 	else
546 		mr2 |= MR2_STOP_BITS_LENGTH_1;
547 
548 	/* Set the flow control */
549 	switch (channel->board_id) {
550 	case IPACK1_DEVICE_ID_SBS_OCTAL_232:
551 		if (cflag & CRTSCTS) {
552 			mr1 |= MR1_RxRTS_CONTROL_ON;
553 			mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_ON;
554 		} else {
555 			mr1 |= MR1_RxRTS_CONTROL_OFF;
556 			mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_OFF;
557 		}
558 		break;
559 	case IPACK1_DEVICE_ID_SBS_OCTAL_422:
560 		mr1 |= MR1_RxRTS_CONTROL_OFF;
561 		mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_OFF;
562 		break;
563 	case IPACK1_DEVICE_ID_SBS_OCTAL_485:
564 		mr1 |= MR1_RxRTS_CONTROL_OFF;
565 		mr2 |= MR2_TxRTS_CONTROL_ON | MR2_CTS_ENABLE_TX_OFF;
566 		break;
567 	default:
568 		return;
569 	}
570 
571 	baud = tty_get_baud_rate(tty);
572 	tty_termios_encode_baud_rate(&tty->termios, baud, baud);
573 
574 	/* Set baud rate */
575 	switch (baud) {
576 	case 75:
577 		csr |= TX_CLK_75 | RX_CLK_75;
578 		break;
579 	case 110:
580 		csr |= TX_CLK_110 | RX_CLK_110;
581 		break;
582 	case 150:
583 		csr |= TX_CLK_150 | RX_CLK_150;
584 		break;
585 	case 300:
586 		csr |= TX_CLK_300 | RX_CLK_300;
587 		break;
588 	case 600:
589 		csr |= TX_CLK_600 | RX_CLK_600;
590 		break;
591 	case 1200:
592 		csr |= TX_CLK_1200 | RX_CLK_1200;
593 		break;
594 	case 1800:
595 		csr |= TX_CLK_1800 | RX_CLK_1800;
596 		break;
597 	case 2000:
598 		csr |= TX_CLK_2000 | RX_CLK_2000;
599 		break;
600 	case 2400:
601 		csr |= TX_CLK_2400 | RX_CLK_2400;
602 		break;
603 	case 4800:
604 		csr |= TX_CLK_4800  | RX_CLK_4800;
605 		break;
606 	case 9600:
607 		csr |= TX_CLK_9600  | RX_CLK_9600;
608 		break;
609 	case 19200:
610 		csr |= TX_CLK_19200 | RX_CLK_19200;
611 		break;
612 	case 38400:
613 	default:
614 		csr |= TX_CLK_38400 | RX_CLK_38400;
615 		/* In case of default, we establish 38400 bps */
616 		tty_termios_encode_baud_rate(&tty->termios, 38400, 38400);
617 		break;
618 	}
619 
620 	mr1 |= MR1_ERROR_CHAR;
621 	mr1 |= MR1_RxINT_RxRDY;
622 
623 	/* Write the control registers */
624 	iowrite8(mr1, &channel->regs->w.mr);
625 	iowrite8(mr2, &channel->regs->w.mr);
626 	iowrite8(csr, &channel->regs->w.csr);
627 
628 	/* Enable again the RX, if it was before */
629 	if (channel->rx_enable)
630 		iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
631 }
632 
633 static void ipoctal_hangup(struct tty_struct *tty)
634 {
635 	unsigned long flags;
636 	struct ipoctal_channel *channel = tty->driver_data;
637 
638 	if (channel == NULL)
639 		return;
640 
641 	spin_lock_irqsave(&channel->lock, flags);
642 	channel->nb_bytes = 0;
643 	channel->pointer_read = 0;
644 	channel->pointer_write = 0;
645 	spin_unlock_irqrestore(&channel->lock, flags);
646 
647 	tty_port_hangup(&channel->tty_port);
648 
649 	ipoctal_reset_channel(channel);
650 	tty_port_set_initialized(&channel->tty_port, false);
651 	wake_up_interruptible(&channel->tty_port.open_wait);
652 }
653 
654 static void ipoctal_shutdown(struct tty_struct *tty)
655 {
656 	struct ipoctal_channel *channel = tty->driver_data;
657 
658 	if (channel == NULL)
659 		return;
660 
661 	ipoctal_reset_channel(channel);
662 	tty_port_set_initialized(&channel->tty_port, false);
663 }
664 
665 static void ipoctal_cleanup(struct tty_struct *tty)
666 {
667 	struct ipoctal_channel *channel = tty->driver_data;
668 	struct ipoctal *ipoctal = chan_to_ipoctal(channel, tty->index);
669 
670 	/* release the carrier driver */
671 	ipack_put_carrier(ipoctal->dev);
672 }
673 
674 static const struct tty_operations ipoctal_fops = {
675 	.ioctl =		NULL,
676 	.install =		ipoctal_install,
677 	.open =			ipoctal_open,
678 	.close =		ipoctal_close,
679 	.write =		ipoctal_write_tty,
680 	.set_termios =		ipoctal_set_termios,
681 	.write_room =		ipoctal_write_room,
682 	.chars_in_buffer =	ipoctal_chars_in_buffer,
683 	.get_icount =		ipoctal_get_icount,
684 	.hangup =		ipoctal_hangup,
685 	.shutdown =		ipoctal_shutdown,
686 	.cleanup =              ipoctal_cleanup,
687 };
688 
689 static int ipoctal_probe(struct ipack_device *dev)
690 {
691 	int res;
692 	struct ipoctal *ipoctal;
693 
694 	ipoctal = kzalloc(sizeof(struct ipoctal), GFP_KERNEL);
695 	if (ipoctal == NULL)
696 		return -ENOMEM;
697 
698 	ipoctal->dev = dev;
699 	res = ipoctal_inst_slot(ipoctal, dev->bus->bus_nr, dev->slot);
700 	if (res)
701 		goto out_uninst;
702 
703 	dev_set_drvdata(&dev->dev, ipoctal);
704 	return 0;
705 
706 out_uninst:
707 	kfree(ipoctal);
708 	return res;
709 }
710 
711 static void __ipoctal_remove(struct ipoctal *ipoctal)
712 {
713 	int i;
714 
715 	ipoctal->dev->bus->ops->free_irq(ipoctal->dev);
716 
717 	for (i = 0; i < NR_CHANNELS; i++) {
718 		struct ipoctal_channel *channel = &ipoctal->channel[i];
719 
720 		if (!channel->tty_registered)
721 			continue;
722 
723 		tty_unregister_device(ipoctal->tty_drv, i);
724 		tty_port_free_xmit_buf(&channel->tty_port);
725 		tty_port_destroy(&channel->tty_port);
726 	}
727 
728 	tty_unregister_driver(ipoctal->tty_drv);
729 	kfree(ipoctal->tty_drv->name);
730 	tty_driver_kref_put(ipoctal->tty_drv);
731 	kfree(ipoctal);
732 }
733 
734 static void ipoctal_remove(struct ipack_device *idev)
735 {
736 	__ipoctal_remove(dev_get_drvdata(&idev->dev));
737 }
738 
739 static DEFINE_IPACK_DEVICE_TABLE(ipoctal_ids) = {
740 	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
741 			IPACK1_DEVICE_ID_SBS_OCTAL_232) },
742 	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
743 			IPACK1_DEVICE_ID_SBS_OCTAL_422) },
744 	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
745 			IPACK1_DEVICE_ID_SBS_OCTAL_485) },
746 	{ 0, },
747 };
748 
749 MODULE_DEVICE_TABLE(ipack, ipoctal_ids);
750 
751 static const struct ipack_driver_ops ipoctal_drv_ops = {
752 	.probe  = ipoctal_probe,
753 	.remove = ipoctal_remove,
754 };
755 
756 static struct ipack_driver driver = {
757 	.ops      = &ipoctal_drv_ops,
758 	.id_table = ipoctal_ids,
759 };
760 
761 static int __init ipoctal_init(void)
762 {
763 	return ipack_driver_register(&driver, THIS_MODULE, KBUILD_MODNAME);
764 }
765 
766 static void __exit ipoctal_exit(void)
767 {
768 	ipack_driver_unregister(&driver);
769 }
770 
771 MODULE_DESCRIPTION("IP-Octal 232, 422 and 485 device driver");
772 MODULE_LICENSE("GPL");
773 
774 module_init(ipoctal_init);
775 module_exit(ipoctal_exit);
776