xref: /linux/drivers/usb/serial/mos7720.c (revision c145211d1f9e2ef19e7b4c2b943f68366daa97af)
1 /*
2  * mos7720.c
3  *   Controls the Moschip 7720 usb to dual port serial convertor
4  *
5  * Copyright 2006 Moschip Semiconductor Tech. Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation, version 2 of the License.
10  *
11  * Developed by:
12  * 	Vijaya Kumar <vijaykumar.gn@gmail.com>
13  *	Ajay Kumar <naanuajay@yahoo.com>
14  *	Gurudeva <ngurudeva@yahoo.com>
15  *
16  * Cleaned up from the original by:
17  *	Greg Kroah-Hartman <gregkh@suse.de>
18  *
19  * Originally based on drivers/usb/serial/io_edgeport.c which is:
20  *	Copyright (C) 2000 Inside Out Networks, All rights reserved.
21  *	Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com>
22  */
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/tty.h>
28 #include <linux/tty_driver.h>
29 #include <linux/tty_flip.h>
30 #include <linux/module.h>
31 #include <linux/spinlock.h>
32 #include <linux/serial.h>
33 #include <linux/serial_reg.h>
34 #include <linux/usb.h>
35 #include <linux/usb/serial.h>
36 #include <linux/uaccess.h>
37 
38 
39 /*
40  * Version Information
41  */
42 #define DRIVER_VERSION "1.0.0.4F"
43 #define DRIVER_AUTHOR "Aspire Communications pvt Ltd."
44 #define DRIVER_DESC "Moschip USB Serial Driver"
45 
46 /* default urb timeout */
47 #define MOS_WDR_TIMEOUT	(HZ * 5)
48 
49 #define MOS_PORT1	0x0200
50 #define MOS_PORT2	0x0300
51 #define MOS_VENREG	0x0000
52 #define MOS_MAX_PORT	0x02
53 #define MOS_WRITE	0x0E
54 #define MOS_READ	0x0D
55 
56 /* Interrupt Rotinue Defines	*/
57 #define SERIAL_IIR_RLS	0x06
58 #define SERIAL_IIR_RDA	0x04
59 #define SERIAL_IIR_CTI	0x0c
60 #define SERIAL_IIR_THR	0x02
61 #define SERIAL_IIR_MS	0x00
62 
63 #define NUM_URBS			16	/* URB Count */
64 #define URB_TRANSFER_BUFFER_SIZE	32	/* URB Size */
65 
66 /* This structure holds all of the local port information */
67 struct moschip_port {
68 	__u8	shadowLCR;		/* last LCR value received */
69 	__u8	shadowMCR;		/* last MCR value received */
70 	__u8	shadowMSR;		/* last MSR value received */
71 	char			open;
72 	struct async_icount	icount;
73 	struct usb_serial_port	*port;	/* loop back to the owner */
74 	struct urb		*write_urb_pool[NUM_URBS];
75 };
76 
77 /* This structure holds all of the individual serial device information */
78 struct moschip_serial {
79 	int interrupt_started;
80 };
81 
82 static int debug;
83 
84 static struct usb_serial_driver moschip7720_2port_driver;
85 
86 #define USB_VENDOR_ID_MOSCHIP		0x9710
87 #define MOSCHIP_DEVICE_ID_7720		0x7720
88 #define MOSCHIP_DEVICE_ID_7715		0x7715
89 
90 static const struct usb_device_id moschip_port_id_table[] = {
91 	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7720) },
92 	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7715) },
93 	{ } /* terminating entry */
94 };
95 MODULE_DEVICE_TABLE(usb, moschip_port_id_table);
96 
97 
98 /*
99  * mos7720_interrupt_callback
100  *	this is the callback function for when we have received data on the
101  *	interrupt endpoint.
102  */
103 static void mos7720_interrupt_callback(struct urb *urb)
104 {
105 	int result;
106 	int length;
107 	int status = urb->status;
108 	__u8 *data;
109 	__u8 sp1;
110 	__u8 sp2;
111 
112 	dbg(" : Entering");
113 
114 	switch (status) {
115 	case 0:
116 		/* success */
117 		break;
118 	case -ECONNRESET:
119 	case -ENOENT:
120 	case -ESHUTDOWN:
121 		/* this urb is terminated, clean up */
122 		dbg("%s - urb shutting down with status: %d", __func__,
123 		    status);
124 		return;
125 	default:
126 		dbg("%s - nonzero urb status received: %d", __func__,
127 		    status);
128 		goto exit;
129 	}
130 
131 	length = urb->actual_length;
132 	data = urb->transfer_buffer;
133 
134 	/* Moschip get 4 bytes
135 	 * Byte 1 IIR Port 1 (port.number is 0)
136 	 * Byte 2 IIR Port 2 (port.number is 1)
137 	 * Byte 3 --------------
138 	 * Byte 4 FIFO status for both */
139 
140 	/* the above description is inverted
141 	 * 	oneukum 2007-03-14 */
142 
143 	if (unlikely(length != 4)) {
144 		dbg("Wrong data !!!");
145 		return;
146 	}
147 
148 	sp1 = data[3];
149 	sp2 = data[2];
150 
151 	if ((sp1 | sp2) & 0x01) {
152 		/* No Interrupt Pending in both the ports */
153 		dbg("No Interrupt !!!");
154 	} else {
155 		switch (sp1 & 0x0f) {
156 		case SERIAL_IIR_RLS:
157 			dbg("Serial Port 1: Receiver status error or address "
158 			    "bit detected in 9-bit mode\n");
159 			break;
160 		case SERIAL_IIR_CTI:
161 			dbg("Serial Port 1: Receiver time out");
162 			break;
163 		case SERIAL_IIR_MS:
164 			dbg("Serial Port 1: Modem status change");
165 			break;
166 		}
167 
168 		switch (sp2 & 0x0f) {
169 		case SERIAL_IIR_RLS:
170 			dbg("Serial Port 2: Receiver status error or address "
171 			    "bit detected in 9-bit mode");
172 			break;
173 		case SERIAL_IIR_CTI:
174 			dbg("Serial Port 2: Receiver time out");
175 			break;
176 		case SERIAL_IIR_MS:
177 			dbg("Serial Port 2: Modem status change");
178 			break;
179 		}
180 	}
181 
182 exit:
183 	result = usb_submit_urb(urb, GFP_ATOMIC);
184 	if (result)
185 		dev_err(&urb->dev->dev,
186 			"%s - Error %d submitting control urb\n",
187 			__func__, result);
188 	return;
189 }
190 
191 /*
192  * mos7715_interrupt_callback
193  *	this is the 7715's callback function for when we have received data on
194  *	the interrupt endpoint.
195  */
196 static void mos7715_interrupt_callback(struct urb *urb)
197 {
198 	int result;
199 	int length;
200 	int status = urb->status;
201 	__u8 *data;
202 	__u8 iir;
203 
204 	switch (status) {
205 	case 0:
206 		/* success */
207 		break;
208 	case -ECONNRESET:
209 	case -ENOENT:
210 	case -ESHUTDOWN:
211 		/* this urb is terminated, clean up */
212 		dbg("%s - urb shutting down with status: %d", __func__,
213 		    status);
214 		return;
215 	default:
216 		dbg("%s - nonzero urb status received: %d", __func__,
217 		    status);
218 		goto exit;
219 	}
220 
221 	length = urb->actual_length;
222 	data = urb->transfer_buffer;
223 
224 	/* Structure of data from 7715 device:
225 	 * Byte 1: IIR serial Port
226 	 * Byte 2: unused
227 	 * Byte 2: DSR parallel port
228 	 * Byte 4: FIFO status for both */
229 
230 	if (unlikely(length != 4)) {
231 		dbg("Wrong data !!!");
232 		return;
233 	}
234 
235 	iir = data[0];
236 	if (!(iir & 0x01)) {	/* serial port interrupt pending */
237 		switch (iir & 0x0f) {
238 		case SERIAL_IIR_RLS:
239 			dbg("Serial Port: Receiver status error or address "
240 			    "bit detected in 9-bit mode\n");
241 			break;
242 		case SERIAL_IIR_CTI:
243 			dbg("Serial Port: Receiver time out");
244 			break;
245 		case SERIAL_IIR_MS:
246 			dbg("Serial Port: Modem status change");
247 			break;
248 		}
249 	}
250 
251 exit:
252 	result = usb_submit_urb(urb, GFP_ATOMIC);
253 	if (result)
254 		dev_err(&urb->dev->dev,
255 			"%s - Error %d submitting control urb\n",
256 			__func__, result);
257 	return;
258 }
259 
260 /*
261  * mos7720_bulk_in_callback
262  *	this is the callback function for when we have received data on the
263  *	bulk in endpoint.
264  */
265 static void mos7720_bulk_in_callback(struct urb *urb)
266 {
267 	int retval;
268 	unsigned char *data ;
269 	struct usb_serial_port *port;
270 	struct moschip_port *mos7720_port;
271 	struct tty_struct *tty;
272 	int status = urb->status;
273 
274 	if (status) {
275 		dbg("nonzero read bulk status received: %d", status);
276 		return;
277 	}
278 
279 	mos7720_port = urb->context;
280 	if (!mos7720_port) {
281 		dbg("NULL mos7720_port pointer");
282 		return ;
283 	}
284 
285 	port = mos7720_port->port;
286 
287 	dbg("Entering...%s", __func__);
288 
289 	data = urb->transfer_buffer;
290 
291 	tty = tty_port_tty_get(&port->port);
292 	if (tty && urb->actual_length) {
293 		tty_insert_flip_string(tty, data, urb->actual_length);
294 		tty_flip_buffer_push(tty);
295 	}
296 	tty_kref_put(tty);
297 
298 	if (!port->read_urb) {
299 		dbg("URB KILLED !!!");
300 		return;
301 	}
302 
303 	if (port->read_urb->status != -EINPROGRESS) {
304 		port->read_urb->dev = port->serial->dev;
305 
306 		retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
307 		if (retval)
308 			dbg("usb_submit_urb(read bulk) failed, retval = %d",
309 			    retval);
310 	}
311 }
312 
313 /*
314  * mos7720_bulk_out_data_callback
315  *	this is the callback function for when we have finished sending serial
316  *	data on the bulk out endpoint.
317  */
318 static void mos7720_bulk_out_data_callback(struct urb *urb)
319 {
320 	struct moschip_port *mos7720_port;
321 	struct tty_struct *tty;
322 	int status = urb->status;
323 
324 	if (status) {
325 		dbg("nonzero write bulk status received:%d", status);
326 		return;
327 	}
328 
329 	mos7720_port = urb->context;
330 	if (!mos7720_port) {
331 		dbg("NULL mos7720_port pointer");
332 		return ;
333 	}
334 
335 	dbg("Entering .........");
336 
337 	tty = tty_port_tty_get(&mos7720_port->port->port);
338 
339 	if (tty && mos7720_port->open)
340 		tty_wakeup(tty);
341 	tty_kref_put(tty);
342 }
343 
344 /*
345  * send_mos_cmd
346  *	this function will be used for sending command to device
347  */
348 static int send_mos_cmd(struct usb_serial *serial, __u8 request, __u16 value,
349 			__u16 index, u8 *data)
350 {
351 	int status;
352 	u8 *buf;
353 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
354 
355 	if (value < MOS_MAX_PORT) {
356 		if (product == MOSCHIP_DEVICE_ID_7715)
357 			value = 0x0200; /* identifies the 7715's serial port */
358 		else
359 			value = value*0x100+0x200;
360 	} else {
361 		value = 0x0000;
362 		if ((product == MOSCHIP_DEVICE_ID_7715) &&
363 		    (index != 0x08)) {
364 			dbg("serial->product== MOSCHIP_DEVICE_ID_7715");
365 			/* index = 0x01 ; */
366 		}
367 	}
368 
369 	if (request == MOS_WRITE) {
370 		value = value + *data;
371 		status = usb_control_msg(serial->dev,
372 				usb_sndctrlpipe(serial->dev, 0), MOS_WRITE,
373 				0x40, value, index, NULL, 0, MOS_WDR_TIMEOUT);
374 	} else {
375 		buf = kmalloc(1, GFP_KERNEL);
376 		if (!buf) {
377 			status = -ENOMEM;
378 			goto out;
379 		}
380 		status = usb_control_msg(serial->dev,
381 				usb_rcvctrlpipe(serial->dev, 0), MOS_READ,
382 				0xc0, value, index, buf, 1, MOS_WDR_TIMEOUT);
383 		*data = *buf;
384 		kfree(buf);
385 	}
386 out:
387 	if (status < 0)
388 		dbg("Command Write failed Value %x index %x", value, index);
389 
390 	return status;
391 }
392 
393 
394 /*
395  * mos77xx_probe
396  *	this function installs the appropriate read interrupt endpoint callback
397  *	depending on whether the device is a 7720 or 7715, thus avoiding costly
398  *	run-time checks in the high-frequency callback routine itself.
399  */
400 static int mos77xx_probe(struct usb_serial *serial,
401 			 const struct usb_device_id *id)
402 {
403 	if (id->idProduct == MOSCHIP_DEVICE_ID_7715)
404 		moschip7720_2port_driver.read_int_callback =
405 			mos7715_interrupt_callback;
406 	else
407 		moschip7720_2port_driver.read_int_callback =
408 			mos7720_interrupt_callback;
409 
410 	return 0;
411 }
412 
413 static int mos77xx_calc_num_ports(struct usb_serial *serial)
414 {
415 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
416 	if (product == MOSCHIP_DEVICE_ID_7715)
417 		return 1;
418 
419 	return 2;
420 }
421 
422 static int mos7720_open(struct tty_struct *tty, struct usb_serial_port *port)
423 {
424 	struct usb_serial *serial;
425 	struct usb_serial_port *port0;
426 	struct urb *urb;
427 	struct moschip_serial *mos7720_serial;
428 	struct moschip_port *mos7720_port;
429 	int response;
430 	int port_number;
431 	char data;
432 	int allocated_urbs = 0;
433 	int j;
434 
435 	serial = port->serial;
436 
437 	mos7720_port = usb_get_serial_port_data(port);
438 	if (mos7720_port == NULL)
439 		return -ENODEV;
440 
441 	port0 = serial->port[0];
442 
443 	mos7720_serial = usb_get_serial_data(serial);
444 
445 	if (mos7720_serial == NULL || port0 == NULL)
446 		return -ENODEV;
447 
448 	usb_clear_halt(serial->dev, port->write_urb->pipe);
449 	usb_clear_halt(serial->dev, port->read_urb->pipe);
450 
451 	/* Initialising the write urb pool */
452 	for (j = 0; j < NUM_URBS; ++j) {
453 		urb = usb_alloc_urb(0, GFP_KERNEL);
454 		mos7720_port->write_urb_pool[j] = urb;
455 
456 		if (urb == NULL) {
457 			dev_err(&port->dev, "No more urbs???\n");
458 			continue;
459 		}
460 
461 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
462 					       GFP_KERNEL);
463 		if (!urb->transfer_buffer) {
464 			dev_err(&port->dev,
465 				"%s-out of memory for urb buffers.\n",
466 				__func__);
467 			usb_free_urb(mos7720_port->write_urb_pool[j]);
468 			mos7720_port->write_urb_pool[j] = NULL;
469 			continue;
470 		}
471 		allocated_urbs++;
472 	}
473 
474 	if (!allocated_urbs)
475 		return -ENOMEM;
476 
477 	 /* Initialize MCS7720 -- Write Init values to corresponding Registers
478 	  *
479 	  * Register Index
480 	  * 0 : THR/RHR
481 	  * 1 : IER
482 	  * 2 : FCR
483 	  * 3 : LCR
484 	  * 4 : MCR
485 	  * 5 : LSR
486 	  * 6 : MSR
487 	  * 7 : SPR
488 	  *
489 	  * 0x08 : SP1/2 Control Reg
490 	  */
491 	port_number = port->number - port->serial->minor;
492 	send_mos_cmd(port->serial, MOS_READ, port_number, UART_LSR, &data);
493 	dbg("SS::%p LSR:%x", mos7720_port, data);
494 
495 	dbg("Check:Sending Command ..........");
496 
497 	data = 0x02;
498 	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x01, &data);
499 	data = 0x02;
500 	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x02, &data);
501 
502 	data = 0x00;
503 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
504 	data = 0x00;
505 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x02, &data);
506 
507 	data = 0xCF;
508 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x02, &data);
509 	data = 0x03;
510 	mos7720_port->shadowLCR  = data;
511 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);
512 	data = 0x0b;
513 	mos7720_port->shadowMCR  = data;
514 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
515 	data = 0x0b;
516 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
517 
518 	data = 0x00;
519 	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, 0x08, &data);
520 	data = 0x00;
521 	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x08, &data);
522 
523 /*	data = 0x00;
524 	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, port_number + 1, &data);
525 	data = 0x03;
526 	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, port_number + 1, &data);
527 	data = 0x00;
528 	send_mos_cmd(port->serial, MOS_WRITE, MOS_MAX_PORT,
529 						port_number + 1, &data);
530 */
531 	data = 0x00;
532 	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, 0x08, &data);
533 
534 	data = data | (port->number - port->serial->minor + 1);
535 	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x08, &data);
536 
537 	data = 0x83;
538 	mos7720_port->shadowLCR  = data;
539 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);
540 	data = 0x0c;
541 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x00, &data);
542 	data = 0x00;
543 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
544 	data = 0x03;
545 	mos7720_port->shadowLCR  = data;
546 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);
547 	data = 0x0c;
548 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
549 	data = 0x0c;
550 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
551 
552 	/* see if we've set up our endpoint info yet   *
553 	 * (can't set it up in mos7720_startup as the  *
554 	 * structures were not set up at that time.)   */
555 	if (!mos7720_serial->interrupt_started) {
556 		dbg("Interrupt buffer NULL !!!");
557 
558 		/* not set up yet, so do it now */
559 		mos7720_serial->interrupt_started = 1;
560 
561 		dbg("To Submit URB !!!");
562 
563 		/* set up our interrupt urb */
564 		usb_fill_int_urb(port0->interrupt_in_urb, serial->dev,
565 			 usb_rcvintpipe(serial->dev,
566 				port->interrupt_in_endpointAddress),
567 			 port0->interrupt_in_buffer,
568 			 port0->interrupt_in_urb->transfer_buffer_length,
569 			 mos7720_interrupt_callback, mos7720_port,
570 			 port0->interrupt_in_urb->interval);
571 
572 		/* start interrupt read for this mos7720 this interrupt *
573 		 * will continue as long as the mos7720 is connected    */
574 		dbg("Submit URB over !!!");
575 		response = usb_submit_urb(port0->interrupt_in_urb, GFP_KERNEL);
576 		if (response)
577 			dev_err(&port->dev,
578 				"%s - Error %d submitting control urb\n",
579 				__func__, response);
580 	}
581 
582 	/* set up our bulk in urb */
583 	usb_fill_bulk_urb(port->read_urb, serial->dev,
584 			  usb_rcvbulkpipe(serial->dev,
585 				port->bulk_in_endpointAddress),
586 			  port->bulk_in_buffer,
587 			  port->read_urb->transfer_buffer_length,
588 			  mos7720_bulk_in_callback, mos7720_port);
589 	response = usb_submit_urb(port->read_urb, GFP_KERNEL);
590 	if (response)
591 		dev_err(&port->dev, "%s - Error %d submitting read urb\n",
592 							__func__, response);
593 
594 	/* initialize our icount structure */
595 	memset(&(mos7720_port->icount), 0x00, sizeof(mos7720_port->icount));
596 
597 	/* initialize our port settings */
598 	mos7720_port->shadowMCR = UART_MCR_OUT2; /* Must set to enable ints! */
599 
600 	/* send a open port command */
601 	mos7720_port->open = 1;
602 
603 	return 0;
604 }
605 
606 /*
607  * mos7720_chars_in_buffer
608  *	this function is called by the tty driver when it wants to know how many
609  *	bytes of data we currently have outstanding in the port (data that has
610  *	been written, but hasn't made it out the port yet)
611  *	If successful, we return the number of bytes left to be written in the
612  *	system,
613  *	Otherwise we return a negative error number.
614  */
615 static int mos7720_chars_in_buffer(struct tty_struct *tty)
616 {
617 	struct usb_serial_port *port = tty->driver_data;
618 	int i;
619 	int chars = 0;
620 	struct moschip_port *mos7720_port;
621 
622 	dbg("%s:entering ...........", __func__);
623 
624 	mos7720_port = usb_get_serial_port_data(port);
625 	if (mos7720_port == NULL) {
626 		dbg("%s:leaving ...........", __func__);
627 		return 0;
628 	}
629 
630 	for (i = 0; i < NUM_URBS; ++i) {
631 		if (mos7720_port->write_urb_pool[i] &&
632 		    mos7720_port->write_urb_pool[i]->status == -EINPROGRESS)
633 			chars += URB_TRANSFER_BUFFER_SIZE;
634 	}
635 	dbg("%s - returns %d", __func__, chars);
636 	return chars;
637 }
638 
639 static void mos7720_close(struct usb_serial_port *port)
640 {
641 	struct usb_serial *serial;
642 	struct moschip_port *mos7720_port;
643 	char data;
644 	int j;
645 
646 	dbg("mos7720_close:entering...");
647 
648 	serial = port->serial;
649 
650 	mos7720_port = usb_get_serial_port_data(port);
651 	if (mos7720_port == NULL)
652 		return;
653 
654 	for (j = 0; j < NUM_URBS; ++j)
655 		usb_kill_urb(mos7720_port->write_urb_pool[j]);
656 
657 	/* Freeing Write URBs */
658 	for (j = 0; j < NUM_URBS; ++j) {
659 		if (mos7720_port->write_urb_pool[j]) {
660 			kfree(mos7720_port->write_urb_pool[j]->transfer_buffer);
661 			usb_free_urb(mos7720_port->write_urb_pool[j]);
662 		}
663 	}
664 
665 	/* While closing port, shutdown all bulk read, write  *
666 	 * and interrupt read if they exists, otherwise nop   */
667 	dbg("Shutdown bulk write");
668 	usb_kill_urb(port->write_urb);
669 	dbg("Shutdown bulk read");
670 	usb_kill_urb(port->read_urb);
671 
672 	mutex_lock(&serial->disc_mutex);
673 	/* these commands must not be issued if the device has
674 	 * been disconnected */
675 	if (!serial->disconnected) {
676 		data = 0x00;
677 		send_mos_cmd(serial, MOS_WRITE,
678 			port->number - port->serial->minor, 0x04, &data);
679 
680 		data = 0x00;
681 		send_mos_cmd(serial, MOS_WRITE,
682 			port->number - port->serial->minor, 0x01, &data);
683 	}
684 	mutex_unlock(&serial->disc_mutex);
685 	mos7720_port->open = 0;
686 
687 	dbg("Leaving %s", __func__);
688 }
689 
690 static void mos7720_break(struct tty_struct *tty, int break_state)
691 {
692 	struct usb_serial_port *port = tty->driver_data;
693 	unsigned char data;
694 	struct usb_serial *serial;
695 	struct moschip_port *mos7720_port;
696 
697 	dbg("Entering %s", __func__);
698 
699 	serial = port->serial;
700 
701 	mos7720_port = usb_get_serial_port_data(port);
702 	if (mos7720_port == NULL)
703 		return;
704 
705 	if (break_state == -1)
706 		data = mos7720_port->shadowLCR | UART_LCR_SBC;
707 	else
708 		data = mos7720_port->shadowLCR & ~UART_LCR_SBC;
709 
710 	mos7720_port->shadowLCR  = data;
711 	send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
712 		     0x03, &data);
713 
714 	return;
715 }
716 
717 /*
718  * mos7720_write_room
719  *	this function is called by the tty driver when it wants to know how many
720  *	bytes of data we can accept for a specific port.
721  *	If successful, we return the amount of room that we have for this port
722  *	Otherwise we return a negative error number.
723  */
724 static int mos7720_write_room(struct tty_struct *tty)
725 {
726 	struct usb_serial_port *port = tty->driver_data;
727 	struct moschip_port *mos7720_port;
728 	int room = 0;
729 	int i;
730 
731 	dbg("%s:entering ...........", __func__);
732 
733 	mos7720_port = usb_get_serial_port_data(port);
734 	if (mos7720_port == NULL) {
735 		dbg("%s:leaving ...........", __func__);
736 		return -ENODEV;
737 	}
738 
739 	/* FIXME: Locking */
740 	for (i = 0; i < NUM_URBS; ++i) {
741 		if (mos7720_port->write_urb_pool[i] &&
742 		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
743 			room += URB_TRANSFER_BUFFER_SIZE;
744 	}
745 
746 	dbg("%s - returns %d", __func__, room);
747 	return room;
748 }
749 
750 static int mos7720_write(struct tty_struct *tty, struct usb_serial_port *port,
751 				 const unsigned char *data, int count)
752 {
753 	int status;
754 	int i;
755 	int bytes_sent = 0;
756 	int transfer_size;
757 
758 	struct moschip_port *mos7720_port;
759 	struct usb_serial *serial;
760 	struct urb    *urb;
761 	const unsigned char *current_position = data;
762 
763 	dbg("%s:entering ...........", __func__);
764 
765 	serial = port->serial;
766 
767 	mos7720_port = usb_get_serial_port_data(port);
768 	if (mos7720_port == NULL) {
769 		dbg("mos7720_port is NULL");
770 		return -ENODEV;
771 	}
772 
773 	/* try to find a free urb in the list */
774 	urb = NULL;
775 
776 	for (i = 0; i < NUM_URBS; ++i) {
777 		if (mos7720_port->write_urb_pool[i] &&
778 		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
779 			urb = mos7720_port->write_urb_pool[i];
780 			dbg("URB:%d", i);
781 			break;
782 		}
783 	}
784 
785 	if (urb == NULL) {
786 		dbg("%s - no more free urbs", __func__);
787 		goto exit;
788 	}
789 
790 	if (urb->transfer_buffer == NULL) {
791 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
792 					       GFP_KERNEL);
793 		if (urb->transfer_buffer == NULL) {
794 			dev_err(&port->dev, "%s no more kernel memory...\n",
795 				__func__);
796 			goto exit;
797 		}
798 	}
799 	transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
800 
801 	memcpy(urb->transfer_buffer, current_position, transfer_size);
802 	usb_serial_debug_data(debug, &port->dev, __func__, transfer_size,
803 			      urb->transfer_buffer);
804 
805 	/* fill urb with data and submit  */
806 	usb_fill_bulk_urb(urb, serial->dev,
807 			  usb_sndbulkpipe(serial->dev,
808 					port->bulk_out_endpointAddress),
809 			  urb->transfer_buffer, transfer_size,
810 			  mos7720_bulk_out_data_callback, mos7720_port);
811 
812 	/* send it down the pipe */
813 	status = usb_submit_urb(urb, GFP_ATOMIC);
814 	if (status) {
815 		dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed "
816 			"with status = %d\n", __func__, status);
817 		bytes_sent = status;
818 		goto exit;
819 	}
820 	bytes_sent = transfer_size;
821 
822 exit:
823 	return bytes_sent;
824 }
825 
826 static void mos7720_throttle(struct tty_struct *tty)
827 {
828 	struct usb_serial_port *port = tty->driver_data;
829 	struct moschip_port *mos7720_port;
830 	int status;
831 
832 	dbg("%s- port %d", __func__, port->number);
833 
834 	mos7720_port = usb_get_serial_port_data(port);
835 
836 	if (mos7720_port == NULL)
837 		return;
838 
839 	if (!mos7720_port->open) {
840 		dbg("port not opened");
841 		return;
842 	}
843 
844 	dbg("%s: Entering ..........", __func__);
845 
846 	/* if we are implementing XON/XOFF, send the stop character */
847 	if (I_IXOFF(tty)) {
848 		unsigned char stop_char = STOP_CHAR(tty);
849 		status = mos7720_write(tty, port, &stop_char, 1);
850 		if (status <= 0)
851 			return;
852 	}
853 
854 	/* if we are implementing RTS/CTS, toggle that line */
855 	if (tty->termios->c_cflag & CRTSCTS) {
856 		mos7720_port->shadowMCR &= ~UART_MCR_RTS;
857 		status = send_mos_cmd(port->serial, MOS_WRITE,
858 				      port->number - port->serial->minor,
859 				      UART_MCR, &mos7720_port->shadowMCR);
860 		if (status != 0)
861 			return;
862 	}
863 }
864 
865 static void mos7720_unthrottle(struct tty_struct *tty)
866 {
867 	struct usb_serial_port *port = tty->driver_data;
868 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
869 	int status;
870 
871 	if (mos7720_port == NULL)
872 		return;
873 
874 	if (!mos7720_port->open) {
875 		dbg("%s - port not opened", __func__);
876 		return;
877 	}
878 
879 	dbg("%s: Entering ..........", __func__);
880 
881 	/* if we are implementing XON/XOFF, send the start character */
882 	if (I_IXOFF(tty)) {
883 		unsigned char start_char = START_CHAR(tty);
884 		status = mos7720_write(tty, port, &start_char, 1);
885 		if (status <= 0)
886 			return;
887 	}
888 
889 	/* if we are implementing RTS/CTS, toggle that line */
890 	if (tty->termios->c_cflag & CRTSCTS) {
891 		mos7720_port->shadowMCR |= UART_MCR_RTS;
892 		status = send_mos_cmd(port->serial, MOS_WRITE,
893 				      port->number - port->serial->minor,
894 				      UART_MCR, &mos7720_port->shadowMCR);
895 		if (status != 0)
896 			return;
897 	}
898 }
899 
900 static int set_higher_rates(struct moschip_port *mos7720_port,
901 			    unsigned int baud)
902 {
903 	unsigned char data;
904 	struct usb_serial_port *port;
905 	struct usb_serial *serial;
906 	int port_number;
907 
908 	if (mos7720_port == NULL)
909 		return -EINVAL;
910 
911 	port = mos7720_port->port;
912 	serial = port->serial;
913 
914 	 /***********************************************
915 	 *      Init Sequence for higher rates
916 	 ***********************************************/
917 	dbg("Sending Setting Commands ..........");
918 	port_number = port->number - port->serial->minor;
919 
920 	data = 0x000;
921 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
922 	data = 0x000;
923 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x02, &data);
924 	data = 0x0CF;
925 	send_mos_cmd(serial, MOS_WRITE, port->number, 0x02, &data);
926 	data = 0x00b;
927 	mos7720_port->shadowMCR  = data;
928 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
929 	data = 0x00b;
930 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
931 
932 	data = 0x000;
933 	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, 0x08, &data);
934 	data = 0x000;
935 	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x08, &data);
936 
937 
938 	/***********************************************
939 	 *              Set for higher rates           *
940 	 ***********************************************/
941 
942 	data = baud * 0x10;
943 	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, port_number + 1, &data);
944 
945 	data = 0x003;
946 	send_mos_cmd(serial, MOS_READ, MOS_MAX_PORT, 0x08, &data);
947 	data = 0x003;
948 	send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT, 0x08, &data);
949 
950 	data = 0x02b;
951 	mos7720_port->shadowMCR  = data;
952 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
953 	data = 0x02b;
954 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
955 
956 	/***********************************************
957 	 *              Set DLL/DLM
958 	 ***********************************************/
959 
960 	data = mos7720_port->shadowLCR | UART_LCR_DLAB;
961 	mos7720_port->shadowLCR  = data;
962 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);
963 
964 	data =  0x001; /* DLL */
965 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x00, &data);
966 	data =  0x000; /* DLM */
967 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x01, &data);
968 
969 	data = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
970 	mos7720_port->shadowLCR  = data;
971 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x03, &data);
972 
973 	return 0;
974 }
975 
976 /* baud rate information */
977 struct divisor_table_entry {
978 	__u32  baudrate;
979 	__u16  divisor;
980 };
981 
982 /* Define table of divisors for moschip 7720 hardware	   *
983  * These assume a 3.6864MHz crystal, the standard /16, and *
984  * MCR.7 = 0.						   */
985 static struct divisor_table_entry divisor_table[] = {
986 	{   50,		2304},
987 	{   110,	1047},	/* 2094.545455 => 230450   => .0217 % over */
988 	{   134,	857},	/* 1713.011152 => 230398.5 => .00065% under */
989 	{   150,	768},
990 	{   300,	384},
991 	{   600,	192},
992 	{   1200,	96},
993 	{   1800,	64},
994 	{   2400,	48},
995 	{   4800,	24},
996 	{   7200,	16},
997 	{   9600,	12},
998 	{   19200,	6},
999 	{   38400,	3},
1000 	{   57600,	2},
1001 	{   115200,	1},
1002 };
1003 
1004 /*****************************************************************************
1005  * calc_baud_rate_divisor
1006  *	this function calculates the proper baud rate divisor for the specified
1007  *	baud rate.
1008  *****************************************************************************/
1009 static int calc_baud_rate_divisor(int baudrate, int *divisor)
1010 {
1011 	int i;
1012 	__u16 custom;
1013 	__u16 round1;
1014 	__u16 round;
1015 
1016 
1017 	dbg("%s - %d", __func__, baudrate);
1018 
1019 	for (i = 0; i < ARRAY_SIZE(divisor_table); i++) {
1020 		if (divisor_table[i].baudrate == baudrate) {
1021 			*divisor = divisor_table[i].divisor;
1022 			return 0;
1023 		}
1024 	}
1025 
1026 	/* After trying for all the standard baud rates    *
1027 	 * Try calculating the divisor for this baud rate  */
1028 	if (baudrate > 75 &&  baudrate < 230400) {
1029 		/* get the divisor */
1030 		custom = (__u16)(230400L  / baudrate);
1031 
1032 		/* Check for round off */
1033 		round1 = (__u16)(2304000L / baudrate);
1034 		round = (__u16)(round1 - (custom * 10));
1035 		if (round > 4)
1036 			custom++;
1037 		*divisor = custom;
1038 
1039 		dbg("Baud %d = %d", baudrate, custom);
1040 		return 0;
1041 	}
1042 
1043 	dbg("Baud calculation Failed...");
1044 	return -EINVAL;
1045 }
1046 
1047 /*
1048  * send_cmd_write_baud_rate
1049  *	this function sends the proper command to change the baud rate of the
1050  *	specified port.
1051  */
1052 static int send_cmd_write_baud_rate(struct moschip_port *mos7720_port,
1053 				    int baudrate)
1054 {
1055 	struct usb_serial_port *port;
1056 	struct usb_serial *serial;
1057 	int divisor;
1058 	int status;
1059 	unsigned char data;
1060 	unsigned char number;
1061 
1062 	if (mos7720_port == NULL)
1063 		return -1;
1064 
1065 	port = mos7720_port->port;
1066 	serial = port->serial;
1067 
1068 	dbg("%s: Entering ..........", __func__);
1069 
1070 	number = port->number - port->serial->minor;
1071 	dbg("%s - port = %d, baud = %d", __func__, port->number, baudrate);
1072 
1073 	/* Calculate the Divisor */
1074 	status = calc_baud_rate_divisor(baudrate, &divisor);
1075 	if (status) {
1076 		dev_err(&port->dev, "%s - bad baud rate\n", __func__);
1077 		return status;
1078 	}
1079 
1080 	/* Enable access to divisor latch */
1081 	data = mos7720_port->shadowLCR | UART_LCR_DLAB;
1082 	mos7720_port->shadowLCR  = data;
1083 	send_mos_cmd(serial, MOS_WRITE, number, UART_LCR, &data);
1084 
1085 	/* Write the divisor */
1086 	data = ((unsigned char)(divisor & 0xff));
1087 	send_mos_cmd(serial, MOS_WRITE, number, 0x00, &data);
1088 
1089 	data = ((unsigned char)((divisor & 0xff00) >> 8));
1090 	send_mos_cmd(serial, MOS_WRITE, number, 0x01, &data);
1091 
1092 	/* Disable access to divisor latch */
1093 	data = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
1094 	mos7720_port->shadowLCR = data;
1095 	send_mos_cmd(serial, MOS_WRITE, number, 0x03, &data);
1096 
1097 	return status;
1098 }
1099 
1100 /*
1101  * change_port_settings
1102  *	This routine is called to set the UART on the device to match
1103  *      the specified new settings.
1104  */
1105 static void change_port_settings(struct tty_struct *tty,
1106 				 struct moschip_port *mos7720_port,
1107 				 struct ktermios *old_termios)
1108 {
1109 	struct usb_serial_port *port;
1110 	struct usb_serial *serial;
1111 	int baud;
1112 	unsigned cflag;
1113 	unsigned iflag;
1114 	__u8 mask = 0xff;
1115 	__u8 lData;
1116 	__u8 lParity;
1117 	__u8 lStop;
1118 	int status;
1119 	int port_number;
1120 	char data;
1121 
1122 	if (mos7720_port == NULL)
1123 		return ;
1124 
1125 	port = mos7720_port->port;
1126 	serial = port->serial;
1127 	port_number = port->number - port->serial->minor;
1128 
1129 	dbg("%s - port %d", __func__, port->number);
1130 
1131 	if (!mos7720_port->open) {
1132 		dbg("%s - port not opened", __func__);
1133 		return;
1134 	}
1135 
1136 	dbg("%s: Entering ..........", __func__);
1137 
1138 	lData = UART_LCR_WLEN8;
1139 	lStop = 0x00;	/* 1 stop bit */
1140 	lParity = 0x00;	/* No parity */
1141 
1142 	cflag = tty->termios->c_cflag;
1143 	iflag = tty->termios->c_iflag;
1144 
1145 	/* Change the number of bits */
1146 	switch (cflag & CSIZE) {
1147 	case CS5:
1148 		lData = UART_LCR_WLEN5;
1149 		mask = 0x1f;
1150 		break;
1151 
1152 	case CS6:
1153 		lData = UART_LCR_WLEN6;
1154 		mask = 0x3f;
1155 		break;
1156 
1157 	case CS7:
1158 		lData = UART_LCR_WLEN7;
1159 		mask = 0x7f;
1160 		break;
1161 	default:
1162 	case CS8:
1163 		lData = UART_LCR_WLEN8;
1164 		break;
1165 	}
1166 
1167 	/* Change the Parity bit */
1168 	if (cflag & PARENB) {
1169 		if (cflag & PARODD) {
1170 			lParity = UART_LCR_PARITY;
1171 			dbg("%s - parity = odd", __func__);
1172 		} else {
1173 			lParity = (UART_LCR_EPAR | UART_LCR_PARITY);
1174 			dbg("%s - parity = even", __func__);
1175 		}
1176 
1177 	} else {
1178 		dbg("%s - parity = none", __func__);
1179 	}
1180 
1181 	if (cflag & CMSPAR)
1182 		lParity = lParity | 0x20;
1183 
1184 	/* Change the Stop bit */
1185 	if (cflag & CSTOPB) {
1186 		lStop = UART_LCR_STOP;
1187 		dbg("%s - stop bits = 2", __func__);
1188 	} else {
1189 		lStop = 0x00;
1190 		dbg("%s - stop bits = 1", __func__);
1191 	}
1192 
1193 #define LCR_BITS_MASK		0x03	/* Mask for bits/char field */
1194 #define LCR_STOP_MASK		0x04	/* Mask for stop bits field */
1195 #define LCR_PAR_MASK		0x38	/* Mask for parity field */
1196 
1197 	/* Update the LCR with the correct value */
1198 	mos7720_port->shadowLCR &=
1199 			~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
1200 	mos7720_port->shadowLCR |= (lData | lParity | lStop);
1201 
1202 
1203 	/* Disable Interrupts */
1204 	data = 0x00;
1205 	send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
1206 							UART_IER, &data);
1207 
1208 	data = 0x00;
1209 	send_mos_cmd(serial, MOS_WRITE, port_number, UART_FCR, &data);
1210 
1211 	data = 0xcf;
1212 	send_mos_cmd(serial, MOS_WRITE, port_number, UART_FCR, &data);
1213 
1214 	/* Send the updated LCR value to the mos7720 */
1215 	data = mos7720_port->shadowLCR;
1216 	send_mos_cmd(serial, MOS_WRITE, port_number, UART_LCR, &data);
1217 
1218 	data = 0x00b;
1219 	mos7720_port->shadowMCR = data;
1220 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
1221 	data = 0x00b;
1222 	send_mos_cmd(serial, MOS_WRITE, port_number, 0x04, &data);
1223 
1224 	/* set up the MCR register and send it to the mos7720 */
1225 	mos7720_port->shadowMCR = UART_MCR_OUT2;
1226 	if (cflag & CBAUD)
1227 		mos7720_port->shadowMCR |= (UART_MCR_DTR | UART_MCR_RTS);
1228 
1229 	if (cflag & CRTSCTS) {
1230 		mos7720_port->shadowMCR |= (UART_MCR_XONANY);
1231 		/* To set hardware flow control to the specified *
1232 		 * serial port, in SP1/2_CONTROL_REG             */
1233 		if (port->number) {
1234 			data = 0x001;
1235 			send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT,
1236 				     0x08, &data);
1237 		} else {
1238 			data = 0x002;
1239 			send_mos_cmd(serial, MOS_WRITE, MOS_MAX_PORT,
1240 				     0x08, &data);
1241 		}
1242 	} else {
1243 		mos7720_port->shadowMCR &= ~(UART_MCR_XONANY);
1244 	}
1245 
1246 	data = mos7720_port->shadowMCR;
1247 	send_mos_cmd(serial, MOS_WRITE, port_number, UART_MCR, &data);
1248 
1249 	/* Determine divisor based on baud rate */
1250 	baud = tty_get_baud_rate(tty);
1251 	if (!baud) {
1252 		/* pick a default, any default... */
1253 		dbg("Picked default baud...");
1254 		baud = 9600;
1255 	}
1256 
1257 	if (baud >= 230400) {
1258 		set_higher_rates(mos7720_port, baud);
1259 		/* Enable Interrupts */
1260 		data = 0x0c;
1261 		send_mos_cmd(serial, MOS_WRITE, port_number, UART_IER, &data);
1262 		return;
1263 	}
1264 
1265 	dbg("%s - baud rate = %d", __func__, baud);
1266 	status = send_cmd_write_baud_rate(mos7720_port, baud);
1267 	/* FIXME: needs to write actual resulting baud back not just
1268 	   blindly do so */
1269 	if (cflag & CBAUD)
1270 		tty_encode_baud_rate(tty, baud, baud);
1271 	/* Enable Interrupts */
1272 	data = 0x0c;
1273 	send_mos_cmd(serial, MOS_WRITE, port_number, UART_IER, &data);
1274 
1275 	if (port->read_urb->status != -EINPROGRESS) {
1276 		port->read_urb->dev = serial->dev;
1277 
1278 		status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1279 		if (status)
1280 			dbg("usb_submit_urb(read bulk) failed, status = %d",
1281 			    status);
1282 	}
1283 	return;
1284 }
1285 
1286 /*
1287  * mos7720_set_termios
1288  *	this function is called by the tty driver when it wants to change the
1289  *	termios structure.
1290  */
1291 static void mos7720_set_termios(struct tty_struct *tty,
1292 		struct usb_serial_port *port, struct ktermios *old_termios)
1293 {
1294 	int status;
1295 	unsigned int cflag;
1296 	struct usb_serial *serial;
1297 	struct moschip_port *mos7720_port;
1298 
1299 	serial = port->serial;
1300 
1301 	mos7720_port = usb_get_serial_port_data(port);
1302 
1303 	if (mos7720_port == NULL)
1304 		return;
1305 
1306 	if (!mos7720_port->open) {
1307 		dbg("%s - port not opened", __func__);
1308 		return;
1309 	}
1310 
1311 	dbg("setting termios - ASPIRE");
1312 
1313 	cflag = tty->termios->c_cflag;
1314 
1315 	dbg("%s - cflag %08x iflag %08x", __func__,
1316 	    tty->termios->c_cflag,
1317 	    RELEVANT_IFLAG(tty->termios->c_iflag));
1318 
1319 	dbg("%s - old cflag %08x old iflag %08x", __func__,
1320 	    old_termios->c_cflag,
1321 	    RELEVANT_IFLAG(old_termios->c_iflag));
1322 
1323 	dbg("%s - port %d", __func__, port->number);
1324 
1325 	/* change the port settings to the new ones specified */
1326 	change_port_settings(tty, mos7720_port, old_termios);
1327 
1328 	if (!port->read_urb) {
1329 		dbg("URB KILLED !!!!!");
1330 		return;
1331 	}
1332 
1333 	if (port->read_urb->status != -EINPROGRESS) {
1334 		port->read_urb->dev = serial->dev;
1335 		status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1336 		if (status)
1337 			dbg("usb_submit_urb(read bulk) failed, status = %d",
1338 			    status);
1339 	}
1340 	return;
1341 }
1342 
1343 /*
1344  * get_lsr_info - get line status register info
1345  *
1346  * Purpose: Let user call ioctl() to get info when the UART physically
1347  * 	    is emptied.  On bus types like RS485, the transmitter must
1348  * 	    release the bus after transmitting. This must be done when
1349  * 	    the transmit shift register is empty, not be done when the
1350  * 	    transmit holding register is empty.  This functionality
1351  * 	    allows an RS485 driver to be written in user space.
1352  */
1353 static int get_lsr_info(struct tty_struct *tty,
1354 		struct moschip_port *mos7720_port, unsigned int __user *value)
1355 {
1356 	struct usb_serial_port *port = tty->driver_data;
1357 	unsigned int result = 0;
1358 	unsigned char data = 0;
1359 	int port_number = port->number - port->serial->minor;
1360 	int count;
1361 
1362 	count = mos7720_chars_in_buffer(tty);
1363 	if (count == 0) {
1364 		send_mos_cmd(port->serial, MOS_READ, port_number,
1365 							UART_LSR, &data);
1366 		if ((data & (UART_LSR_TEMT | UART_LSR_THRE))
1367 					== (UART_LSR_TEMT | UART_LSR_THRE)) {
1368 			dbg("%s -- Empty", __func__);
1369 			result = TIOCSER_TEMT;
1370 		}
1371 	}
1372 	if (copy_to_user(value, &result, sizeof(int)))
1373 		return -EFAULT;
1374 	return 0;
1375 }
1376 
1377 static int mos7720_tiocmget(struct tty_struct *tty, struct file *file)
1378 {
1379 	struct usb_serial_port *port = tty->driver_data;
1380 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1381 	unsigned int result = 0;
1382 	unsigned int mcr ;
1383 	unsigned int msr ;
1384 
1385 	dbg("%s - port %d", __func__, port->number);
1386 
1387 	mcr = mos7720_port->shadowMCR;
1388 	msr = mos7720_port->shadowMSR;
1389 
1390 	result = ((mcr & UART_MCR_DTR)  ? TIOCM_DTR : 0)   /* 0x002 */
1391 	  | ((mcr & UART_MCR_RTS)   ? TIOCM_RTS : 0)   /* 0x004 */
1392 	  | ((msr & UART_MSR_CTS)   ? TIOCM_CTS : 0)   /* 0x020 */
1393 	  | ((msr & UART_MSR_DCD)   ? TIOCM_CAR : 0)   /* 0x040 */
1394 	  | ((msr & UART_MSR_RI)    ? TIOCM_RI :  0)   /* 0x080 */
1395 	  | ((msr & UART_MSR_DSR)   ? TIOCM_DSR : 0);  /* 0x100 */
1396 
1397 	dbg("%s -- %x", __func__, result);
1398 
1399 	return result;
1400 }
1401 
1402 static int mos7720_tiocmset(struct tty_struct *tty, struct file *file,
1403 					unsigned int set, unsigned int clear)
1404 {
1405 	struct usb_serial_port *port = tty->driver_data;
1406 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1407 	unsigned int mcr ;
1408 	unsigned char lmcr;
1409 
1410 	dbg("%s - port %d", __func__, port->number);
1411 	dbg("he was at tiocmget");
1412 
1413 	mcr = mos7720_port->shadowMCR;
1414 
1415 	if (set & TIOCM_RTS)
1416 		mcr |= UART_MCR_RTS;
1417 	if (set & TIOCM_DTR)
1418 		mcr |= UART_MCR_DTR;
1419 	if (set & TIOCM_LOOP)
1420 		mcr |= UART_MCR_LOOP;
1421 
1422 	if (clear & TIOCM_RTS)
1423 		mcr &= ~UART_MCR_RTS;
1424 	if (clear & TIOCM_DTR)
1425 		mcr &= ~UART_MCR_DTR;
1426 	if (clear & TIOCM_LOOP)
1427 		mcr &= ~UART_MCR_LOOP;
1428 
1429 	mos7720_port->shadowMCR = mcr;
1430 	lmcr = mos7720_port->shadowMCR;
1431 
1432 	send_mos_cmd(port->serial, MOS_WRITE,
1433 		port->number - port->serial->minor, UART_MCR, &lmcr);
1434 
1435 	return 0;
1436 }
1437 
1438 static int set_modem_info(struct moschip_port *mos7720_port, unsigned int cmd,
1439 			  unsigned int __user *value)
1440 {
1441 	unsigned int mcr ;
1442 	unsigned int arg;
1443 	unsigned char data;
1444 
1445 	struct usb_serial_port *port;
1446 
1447 	if (mos7720_port == NULL)
1448 		return -1;
1449 
1450 	port = (struct usb_serial_port *)mos7720_port->port;
1451 	mcr = mos7720_port->shadowMCR;
1452 
1453 	if (copy_from_user(&arg, value, sizeof(int)))
1454 		return -EFAULT;
1455 
1456 	switch (cmd) {
1457 	case TIOCMBIS:
1458 		if (arg & TIOCM_RTS)
1459 			mcr |= UART_MCR_RTS;
1460 		if (arg & TIOCM_DTR)
1461 			mcr |= UART_MCR_RTS;
1462 		if (arg & TIOCM_LOOP)
1463 			mcr |= UART_MCR_LOOP;
1464 		break;
1465 
1466 	case TIOCMBIC:
1467 		if (arg & TIOCM_RTS)
1468 			mcr &= ~UART_MCR_RTS;
1469 		if (arg & TIOCM_DTR)
1470 			mcr &= ~UART_MCR_RTS;
1471 		if (arg & TIOCM_LOOP)
1472 			mcr &= ~UART_MCR_LOOP;
1473 		break;
1474 
1475 	}
1476 
1477 	mos7720_port->shadowMCR = mcr;
1478 
1479 	data = mos7720_port->shadowMCR;
1480 	send_mos_cmd(port->serial, MOS_WRITE,
1481 		     port->number - port->serial->minor, UART_MCR, &data);
1482 
1483 	return 0;
1484 }
1485 
1486 static int get_serial_info(struct moschip_port *mos7720_port,
1487 			   struct serial_struct __user *retinfo)
1488 {
1489 	struct serial_struct tmp;
1490 
1491 	if (!retinfo)
1492 		return -EFAULT;
1493 
1494 	memset(&tmp, 0, sizeof(tmp));
1495 
1496 	tmp.type		= PORT_16550A;
1497 	tmp.line		= mos7720_port->port->serial->minor;
1498 	tmp.port		= mos7720_port->port->number;
1499 	tmp.irq			= 0;
1500 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
1501 	tmp.xmit_fifo_size	= NUM_URBS * URB_TRANSFER_BUFFER_SIZE;
1502 	tmp.baud_base		= 9600;
1503 	tmp.close_delay		= 5*HZ;
1504 	tmp.closing_wait	= 30*HZ;
1505 
1506 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
1507 		return -EFAULT;
1508 	return 0;
1509 }
1510 
1511 static int mos7720_ioctl(struct tty_struct *tty, struct file *file,
1512 			 unsigned int cmd, unsigned long arg)
1513 {
1514 	struct usb_serial_port *port = tty->driver_data;
1515 	struct moschip_port *mos7720_port;
1516 	struct async_icount cnow;
1517 	struct async_icount cprev;
1518 	struct serial_icounter_struct icount;
1519 
1520 	mos7720_port = usb_get_serial_port_data(port);
1521 	if (mos7720_port == NULL)
1522 		return -ENODEV;
1523 
1524 	dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
1525 
1526 	switch (cmd) {
1527 	case TIOCSERGETLSR:
1528 		dbg("%s (%d) TIOCSERGETLSR", __func__,  port->number);
1529 		return get_lsr_info(tty, mos7720_port,
1530 					(unsigned int __user *)arg);
1531 		return 0;
1532 
1533 	/* FIXME: These should be using the mode methods */
1534 	case TIOCMBIS:
1535 	case TIOCMBIC:
1536 		dbg("%s (%d) TIOCMSET/TIOCMBIC/TIOCMSET",
1537 					__func__, port->number);
1538 		return set_modem_info(mos7720_port, cmd,
1539 				      (unsigned int __user *)arg);
1540 
1541 	case TIOCGSERIAL:
1542 		dbg("%s (%d) TIOCGSERIAL", __func__,  port->number);
1543 		return get_serial_info(mos7720_port,
1544 				       (struct serial_struct __user *)arg);
1545 
1546 	case TIOCMIWAIT:
1547 		dbg("%s (%d) TIOCMIWAIT", __func__,  port->number);
1548 		cprev = mos7720_port->icount;
1549 		while (1) {
1550 			if (signal_pending(current))
1551 				return -ERESTARTSYS;
1552 			cnow = mos7720_port->icount;
1553 			if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
1554 			    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
1555 				return -EIO; /* no change => error */
1556 			if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1557 			    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1558 			    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1559 			    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1560 				return 0;
1561 			}
1562 			cprev = cnow;
1563 		}
1564 		/* NOTREACHED */
1565 		break;
1566 
1567 	case TIOCGICOUNT:
1568 		cnow = mos7720_port->icount;
1569 		icount.cts = cnow.cts;
1570 		icount.dsr = cnow.dsr;
1571 		icount.rng = cnow.rng;
1572 		icount.dcd = cnow.dcd;
1573 		icount.rx = cnow.rx;
1574 		icount.tx = cnow.tx;
1575 		icount.frame = cnow.frame;
1576 		icount.overrun = cnow.overrun;
1577 		icount.parity = cnow.parity;
1578 		icount.brk = cnow.brk;
1579 		icount.buf_overrun = cnow.buf_overrun;
1580 
1581 		dbg("%s (%d) TIOCGICOUNT RX=%d, TX=%d", __func__,
1582 		    port->number, icount.rx, icount.tx);
1583 		if (copy_to_user((void __user *)arg, &icount, sizeof(icount)))
1584 			return -EFAULT;
1585 		return 0;
1586 	}
1587 
1588 	return -ENOIOCTLCMD;
1589 }
1590 
1591 static int mos7720_startup(struct usb_serial *serial)
1592 {
1593 	struct moschip_serial *mos7720_serial;
1594 	struct moschip_port *mos7720_port;
1595 	struct usb_device *dev;
1596 	int i;
1597 	char data;
1598 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
1599 
1600 	dbg("%s: Entering ..........", __func__);
1601 
1602 	if (!serial) {
1603 		dbg("Invalid Handler");
1604 		return -ENODEV;
1605 	}
1606 
1607 	dev = serial->dev;
1608 
1609 	/* create our private serial structure */
1610 	mos7720_serial = kzalloc(sizeof(struct moschip_serial), GFP_KERNEL);
1611 	if (mos7720_serial == NULL) {
1612 		dev_err(&dev->dev, "%s - Out of memory\n", __func__);
1613 		return -ENOMEM;
1614 	}
1615 
1616 	usb_set_serial_data(serial, mos7720_serial);
1617 
1618 	/*
1619 	 * The 7715 uses the first bulk in/out endpoint pair for the parallel
1620 	 * port, and the second for the serial port.  Because the usbserial core
1621 	 * assumes both pairs are serial ports, we must engage in a bit of
1622 	 * subterfuge and swap the pointers for ports 0 and 1 in order to make
1623 	 * port 0 point to the serial port.  However, both moschip devices use a
1624 	 * single interrupt-in endpoint for both ports (as mentioned a little
1625 	 * further down), and this endpoint was assigned to port 0.  So after
1626 	 * the swap, we must copy the interrupt endpoint elements from port 1
1627 	 * (as newly assigned) to port 0, and null out port 1 pointers.
1628 	 */
1629 	if (product == MOSCHIP_DEVICE_ID_7715) {
1630 		struct usb_serial_port *tmp = serial->port[0];
1631 		serial->port[0] = serial->port[1];
1632 		serial->port[1] = tmp;
1633 		serial->port[0]->interrupt_in_urb = tmp->interrupt_in_urb;
1634 		serial->port[0]->interrupt_in_buffer = tmp->interrupt_in_buffer;
1635 		serial->port[0]->interrupt_in_endpointAddress =
1636 			tmp->interrupt_in_endpointAddress;
1637 		serial->port[1]->interrupt_in_urb = NULL;
1638 		serial->port[1]->interrupt_in_buffer = NULL;
1639 	}
1640 
1641 	/* we set up the pointers to the endpoints in the mos7720_open *
1642 	 * function, as the structures aren't created yet.             */
1643 
1644 	/* set up port private structures */
1645 	for (i = 0; i < serial->num_ports; ++i) {
1646 		mos7720_port = kzalloc(sizeof(struct moschip_port), GFP_KERNEL);
1647 		if (mos7720_port == NULL) {
1648 			dev_err(&dev->dev, "%s - Out of memory\n", __func__);
1649 			usb_set_serial_data(serial, NULL);
1650 			kfree(mos7720_serial);
1651 			return -ENOMEM;
1652 		}
1653 
1654 		/* Initialize all port interrupt end point to port 0 int
1655 		 * endpoint.  Our device has only one interrupt endpoint
1656 		 * common to all ports */
1657 		serial->port[i]->interrupt_in_endpointAddress =
1658 				serial->port[0]->interrupt_in_endpointAddress;
1659 
1660 		mos7720_port->port = serial->port[i];
1661 		usb_set_serial_port_data(serial->port[i], mos7720_port);
1662 
1663 		dbg("port number is %d", serial->port[i]->number);
1664 		dbg("serial number is %d", serial->minor);
1665 	}
1666 
1667 
1668 	/* setting configuration feature to one */
1669 	usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
1670 			(__u8)0x03, 0x00, 0x01, 0x00, NULL, 0x00, 5*HZ);
1671 
1672 	/* LSR For Port 1 */
1673 	send_mos_cmd(serial, MOS_READ, 0x00, UART_LSR, &data);
1674 	dbg("LSR:%x", data);
1675 
1676 	/* LSR For Port 2 */
1677 	send_mos_cmd(serial, MOS_READ, 0x01, UART_LSR, &data);
1678 	dbg("LSR:%x", data);
1679 
1680 	return 0;
1681 }
1682 
1683 static void mos7720_release(struct usb_serial *serial)
1684 {
1685 	int i;
1686 
1687 	/* free private structure allocated for serial port */
1688 	for (i = 0; i < serial->num_ports; ++i)
1689 		kfree(usb_get_serial_port_data(serial->port[i]));
1690 
1691 	/* free private structure allocated for serial device */
1692 	kfree(usb_get_serial_data(serial));
1693 }
1694 
1695 static struct usb_driver usb_driver = {
1696 	.name =		"moschip7720",
1697 	.probe =	usb_serial_probe,
1698 	.disconnect =	usb_serial_disconnect,
1699 	.id_table =	moschip_port_id_table,
1700 	.no_dynamic_id =	1,
1701 };
1702 
1703 static struct usb_serial_driver moschip7720_2port_driver = {
1704 	.driver = {
1705 		.owner =	THIS_MODULE,
1706 		.name =		"moschip7720",
1707 	},
1708 	.description		= "Moschip 2 port adapter",
1709 	.usb_driver		= &usb_driver,
1710 	.id_table		= moschip_port_id_table,
1711 	.calc_num_ports		= mos77xx_calc_num_ports,
1712 	.open			= mos7720_open,
1713 	.close			= mos7720_close,
1714 	.throttle		= mos7720_throttle,
1715 	.unthrottle		= mos7720_unthrottle,
1716 	.probe			= mos77xx_probe,
1717 	.attach			= mos7720_startup,
1718 	.release		= mos7720_release,
1719 	.ioctl			= mos7720_ioctl,
1720 	.tiocmget		= mos7720_tiocmget,
1721 	.tiocmset		= mos7720_tiocmset,
1722 	.set_termios		= mos7720_set_termios,
1723 	.write			= mos7720_write,
1724 	.write_room		= mos7720_write_room,
1725 	.chars_in_buffer	= mos7720_chars_in_buffer,
1726 	.break_ctl		= mos7720_break,
1727 	.read_bulk_callback	= mos7720_bulk_in_callback,
1728 	.read_int_callback	= NULL  /* dynamically assigned in probe() */
1729 };
1730 
1731 static int __init moschip7720_init(void)
1732 {
1733 	int retval;
1734 
1735 	dbg("%s: Entering ..........", __func__);
1736 
1737 	/* Register with the usb serial */
1738 	retval = usb_serial_register(&moschip7720_2port_driver);
1739 	if (retval)
1740 		goto failed_port_device_register;
1741 
1742 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
1743 	       DRIVER_DESC "\n");
1744 
1745 	/* Register with the usb */
1746 	retval = usb_register(&usb_driver);
1747 	if (retval)
1748 		goto failed_usb_register;
1749 
1750 	return 0;
1751 
1752 failed_usb_register:
1753 	usb_serial_deregister(&moschip7720_2port_driver);
1754 
1755 failed_port_device_register:
1756 	return retval;
1757 }
1758 
1759 static void __exit moschip7720_exit(void)
1760 {
1761 	usb_deregister(&usb_driver);
1762 	usb_serial_deregister(&moschip7720_2port_driver);
1763 }
1764 
1765 module_init(moschip7720_init);
1766 module_exit(moschip7720_exit);
1767 
1768 /* Module information */
1769 MODULE_AUTHOR(DRIVER_AUTHOR);
1770 MODULE_DESCRIPTION(DRIVER_DESC);
1771 MODULE_LICENSE("GPL");
1772 
1773 module_param(debug, bool, S_IRUGO | S_IWUSR);
1774 MODULE_PARM_DESC(debug, "Debug enabled or not");
1775