xref: /openbmc/linux/drivers/usb/serial/ti_usb_3410_5052.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /* vi: ts=8 sw=8
2  *
3  * TI 3410/5052 USB Serial Driver
4  *
5  * Copyright (C) 2004 Texas Instruments
6  *
7  * This driver is based on the Linux io_ti driver, which is
8  *   Copyright (C) 2000-2002 Inside Out Networks
9  *   Copyright (C) 2001-2002 Greg Kroah-Hartman
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * For questions or problems with this driver, contact Texas Instruments
17  * technical support, or Al Borchers <alborchers@steinerpoint.com>, or
18  * Peter Berger <pberger@brimson.com>.
19  *
20  * This driver needs this hotplug script in /etc/hotplug/usb/ti_usb_3410_5052
21  * or in /etc/hotplug.d/usb/ti_usb_3410_5052.hotplug to set the device
22  * configuration.
23  *
24  * #!/bin/bash
25  *
26  * BOOT_CONFIG=1
27  * ACTIVE_CONFIG=2
28  *
29  * if [[ "$ACTION" != "add" ]]
30  * then
31  * 	exit
32  * fi
33  *
34  * CONFIG_PATH=/sys${DEVPATH%/?*}/bConfigurationValue
35  *
36  * if [[ 0`cat $CONFIG_PATH` -ne $BOOT_CONFIG ]]
37  * then
38  * 	exit
39  * fi
40  *
41  * PRODUCT=${PRODUCT%/?*}		# delete version
42  * VENDOR_ID=`printf "%d" 0x${PRODUCT%/?*}`
43  * PRODUCT_ID=`printf "%d" 0x${PRODUCT#*?/}`
44  *
45  * PARAM_PATH=/sys/module/ti_usb_3410_5052/parameters
46  *
47  * function scan() {
48  * 	s=$1
49  * 	shift
50  * 	for i
51  * 	do
52  * 		if [[ $s -eq $i ]]
53  * 		then
54  * 			return 0
55  * 		fi
56  * 	done
57  * 	return 1
58  * }
59  *
60  * IFS=$IFS,
61  *
62  * if (scan $VENDOR_ID 1105 `cat $PARAM_PATH/vendor_3410` &&
63  * scan $PRODUCT_ID 13328 `cat $PARAM_PATH/product_3410`) ||
64  * (scan $VENDOR_ID 1105 `cat $PARAM_PATH/vendor_5052` &&
65  * scan $PRODUCT_ID 20562 20818 20570 20575 `cat $PARAM_PATH/product_5052`)
66  * then
67  * 	echo $ACTIVE_CONFIG > $CONFIG_PATH
68  * fi
69  */
70 
71 #include <linux/kernel.h>
72 #include <linux/errno.h>
73 #include <linux/init.h>
74 #include <linux/slab.h>
75 #include <linux/tty.h>
76 #include <linux/tty_driver.h>
77 #include <linux/tty_flip.h>
78 #include <linux/module.h>
79 #include <linux/spinlock.h>
80 #include <linux/ioctl.h>
81 #include <linux/serial.h>
82 #include <linux/circ_buf.h>
83 #include <asm/uaccess.h>
84 #include <asm/semaphore.h>
85 #include <linux/usb.h>
86 #include <linux/usb/serial.h>
87 
88 #include "ti_usb_3410_5052.h"
89 #include "ti_fw_3410.h"		/* firmware image for 3410 */
90 #include "ti_fw_5052.h"		/* firmware image for 5052 */
91 
92 
93 /* Defines */
94 
95 #define TI_DRIVER_VERSION	"v0.9"
96 #define TI_DRIVER_AUTHOR	"Al Borchers <alborchers@steinerpoint.com>"
97 #define TI_DRIVER_DESC		"TI USB 3410/5052 Serial Driver"
98 
99 #define TI_FIRMWARE_BUF_SIZE	16284
100 
101 #define TI_WRITE_BUF_SIZE	1024
102 
103 #define TI_TRANSFER_TIMEOUT	2
104 
105 #define TI_DEFAULT_LOW_LATENCY	0
106 #define TI_DEFAULT_CLOSING_WAIT	4000		/* in .01 secs */
107 
108 /* supported setserial flags */
109 #define TI_SET_SERIAL_FLAGS	(ASYNC_LOW_LATENCY)
110 
111 /* read urb states */
112 #define TI_READ_URB_RUNNING	0
113 #define TI_READ_URB_STOPPING	1
114 #define TI_READ_URB_STOPPED	2
115 
116 #define TI_EXTRA_VID_PID_COUNT	5
117 
118 
119 /* Structures */
120 
121 struct ti_port {
122 	int			tp_is_open;
123 	__u8			tp_msr;
124 	__u8			tp_lsr;
125 	__u8			tp_shadow_mcr;
126 	__u8			tp_uart_mode;	/* 232 or 485 modes */
127 	unsigned int		tp_uart_base_addr;
128 	int			tp_flags;
129 	int			tp_closing_wait;/* in .01 secs */
130 	struct async_icount	tp_icount;
131 	wait_queue_head_t	tp_msr_wait;	/* wait for msr change */
132 	wait_queue_head_t	tp_write_wait;
133 	struct ti_device	*tp_tdev;
134 	struct usb_serial_port	*tp_port;
135 	spinlock_t		tp_lock;
136 	int			tp_read_urb_state;
137 	int			tp_write_urb_in_use;
138 	struct circ_buf		*tp_write_buf;
139 };
140 
141 struct ti_device {
142 	struct semaphore	td_open_close_sem;
143 	int			td_open_port_count;
144 	struct usb_serial	*td_serial;
145 	int			td_is_3410;
146 	int			td_urb_error;
147 };
148 
149 
150 /* Function Declarations */
151 
152 static int ti_startup(struct usb_serial *serial);
153 static void ti_shutdown(struct usb_serial *serial);
154 static int ti_open(struct usb_serial_port *port, struct file *file);
155 static void ti_close(struct usb_serial_port *port, struct file *file);
156 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
157 	int count);
158 static int ti_write_room(struct usb_serial_port *port);
159 static int ti_chars_in_buffer(struct usb_serial_port *port);
160 static void ti_throttle(struct usb_serial_port *port);
161 static void ti_unthrottle(struct usb_serial_port *port);
162 static int ti_ioctl(struct usb_serial_port *port, struct file *file, unsigned int cmd, unsigned long arg);
163 static void ti_set_termios(struct usb_serial_port *port,
164 	struct ktermios *old_termios);
165 static int ti_tiocmget(struct usb_serial_port *port, struct file *file);
166 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
167 	unsigned int set, unsigned int clear);
168 static void ti_break(struct usb_serial_port *port, int break_state);
169 static void ti_interrupt_callback(struct urb *urb);
170 static void ti_bulk_in_callback(struct urb *urb);
171 static void ti_bulk_out_callback(struct urb *urb);
172 
173 static void ti_recv(struct device *dev, struct tty_struct *tty,
174 	unsigned char *data, int length);
175 static void ti_send(struct ti_port *tport);
176 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr);
177 static int ti_get_lsr(struct ti_port *tport);
178 static int ti_get_serial_info(struct ti_port *tport,
179 	struct serial_struct __user *ret_arg);
180 static int ti_set_serial_info(struct ti_port *tport,
181 	struct serial_struct __user *new_arg);
182 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr);
183 
184 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush);
185 
186 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty);
187 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty);
188 
189 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
190 	__u16 moduleid, __u16 value, __u8 *data, int size);
191 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
192 	__u16 moduleid, __u16 value, __u8 *data, int size);
193 
194 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
195 	__u8 mask, __u8 byte);
196 
197 static int ti_download_firmware(struct ti_device *tdev,
198 	unsigned char *firmware, unsigned int firmware_size);
199 
200 /* circular buffer */
201 static struct circ_buf *ti_buf_alloc(void);
202 static void ti_buf_free(struct circ_buf *cb);
203 static void ti_buf_clear(struct circ_buf *cb);
204 static int ti_buf_data_avail(struct circ_buf *cb);
205 static int ti_buf_space_avail(struct circ_buf *cb);
206 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count);
207 static int ti_buf_get(struct circ_buf *cb, char *buf, int count);
208 
209 
210 /* Data */
211 
212 /* module parameters */
213 static int debug;
214 static int low_latency = TI_DEFAULT_LOW_LATENCY;
215 static int closing_wait = TI_DEFAULT_CLOSING_WAIT;
216 static ushort vendor_3410[TI_EXTRA_VID_PID_COUNT];
217 static unsigned int vendor_3410_count;
218 static ushort product_3410[TI_EXTRA_VID_PID_COUNT];
219 static unsigned int product_3410_count;
220 static ushort vendor_5052[TI_EXTRA_VID_PID_COUNT];
221 static unsigned int vendor_5052_count;
222 static ushort product_5052[TI_EXTRA_VID_PID_COUNT];
223 static unsigned int product_5052_count;
224 
225 /* supported devices */
226 /* the array dimension is the number of default entries plus */
227 /* TI_EXTRA_VID_PID_COUNT user defined entries plus 1 terminating */
228 /* null entry */
229 static struct usb_device_id ti_id_table_3410[1+TI_EXTRA_VID_PID_COUNT+1] = {
230 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
231 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_EZ430_ID) },
232 };
233 
234 static struct usb_device_id ti_id_table_5052[4+TI_EXTRA_VID_PID_COUNT+1] = {
235 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
236 	{ USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
237 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
238 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
239 };
240 
241 static struct usb_device_id ti_id_table_combined[] = {
242 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
243 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_EZ430_ID) },
244 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
245 	{ USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
246 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
247 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
248 	{ }
249 };
250 
251 static struct usb_driver ti_usb_driver = {
252 	.name			= "ti_usb_3410_5052",
253 	.probe			= usb_serial_probe,
254 	.disconnect		= usb_serial_disconnect,
255 	.id_table		= ti_id_table_combined,
256 	.no_dynamic_id = 	1,
257 };
258 
259 static struct usb_serial_driver ti_1port_device = {
260 	.driver = {
261 		.owner		= THIS_MODULE,
262 		.name		= "ti_usb_3410_5052_1",
263 	},
264 	.description		= "TI USB 3410 1 port adapter",
265 	.usb_driver		= &ti_usb_driver,
266 	.id_table		= ti_id_table_3410,
267 	.num_interrupt_in	= 1,
268 	.num_bulk_in		= 1,
269 	.num_bulk_out		= 1,
270 	.num_ports		= 1,
271 	.attach			= ti_startup,
272 	.shutdown		= ti_shutdown,
273 	.open			= ti_open,
274 	.close			= ti_close,
275 	.write			= ti_write,
276 	.write_room		= ti_write_room,
277 	.chars_in_buffer	= ti_chars_in_buffer,
278 	.throttle		= ti_throttle,
279 	.unthrottle		= ti_unthrottle,
280 	.ioctl			= ti_ioctl,
281 	.set_termios		= ti_set_termios,
282 	.tiocmget		= ti_tiocmget,
283 	.tiocmset		= ti_tiocmset,
284 	.break_ctl		= ti_break,
285 	.read_int_callback	= ti_interrupt_callback,
286 	.read_bulk_callback	= ti_bulk_in_callback,
287 	.write_bulk_callback	= ti_bulk_out_callback,
288 };
289 
290 static struct usb_serial_driver ti_2port_device = {
291 	.driver = {
292 		.owner		= THIS_MODULE,
293 		.name		= "ti_usb_3410_5052_2",
294 	},
295 	.description		= "TI USB 5052 2 port adapter",
296 	.usb_driver		= &ti_usb_driver,
297 	.id_table		= ti_id_table_5052,
298 	.num_interrupt_in	= 1,
299 	.num_bulk_in		= 2,
300 	.num_bulk_out		= 2,
301 	.num_ports		= 2,
302 	.attach			= ti_startup,
303 	.shutdown		= ti_shutdown,
304 	.open			= ti_open,
305 	.close			= ti_close,
306 	.write			= ti_write,
307 	.write_room		= ti_write_room,
308 	.chars_in_buffer	= ti_chars_in_buffer,
309 	.throttle		= ti_throttle,
310 	.unthrottle		= ti_unthrottle,
311 	.ioctl			= ti_ioctl,
312 	.set_termios		= ti_set_termios,
313 	.tiocmget		= ti_tiocmget,
314 	.tiocmset		= ti_tiocmset,
315 	.break_ctl		= ti_break,
316 	.read_int_callback	= ti_interrupt_callback,
317 	.read_bulk_callback	= ti_bulk_in_callback,
318 	.write_bulk_callback	= ti_bulk_out_callback,
319 };
320 
321 
322 /* Module */
323 
324 MODULE_AUTHOR(TI_DRIVER_AUTHOR);
325 MODULE_DESCRIPTION(TI_DRIVER_DESC);
326 MODULE_VERSION(TI_DRIVER_VERSION);
327 MODULE_LICENSE("GPL");
328 
329 module_param(debug, bool, S_IRUGO | S_IWUSR);
330 MODULE_PARM_DESC(debug, "Enable debugging, 0=no, 1=yes");
331 
332 module_param(low_latency, bool, S_IRUGO | S_IWUSR);
333 MODULE_PARM_DESC(low_latency, "TTY low_latency flag, 0=off, 1=on, default is off");
334 
335 module_param(closing_wait, int, S_IRUGO | S_IWUSR);
336 MODULE_PARM_DESC(closing_wait, "Maximum wait for data to drain in close, in .01 secs, default is 4000");
337 
338 module_param_array(vendor_3410, ushort, &vendor_3410_count, S_IRUGO);
339 MODULE_PARM_DESC(vendor_3410, "Vendor ids for 3410 based devices, 1-5 short integers");
340 module_param_array(product_3410, ushort, &product_3410_count, S_IRUGO);
341 MODULE_PARM_DESC(product_3410, "Product ids for 3410 based devices, 1-5 short integers");
342 module_param_array(vendor_5052, ushort, &vendor_5052_count, S_IRUGO);
343 MODULE_PARM_DESC(vendor_5052, "Vendor ids for 5052 based devices, 1-5 short integers");
344 module_param_array(product_5052, ushort, &product_5052_count, S_IRUGO);
345 MODULE_PARM_DESC(product_5052, "Product ids for 5052 based devices, 1-5 short integers");
346 
347 MODULE_DEVICE_TABLE(usb, ti_id_table_combined);
348 
349 
350 /* Functions */
351 
352 static int __init ti_init(void)
353 {
354 	int i,j;
355 	int ret;
356 
357 	/* insert extra vendor and product ids */
358 	j = ARRAY_SIZE(ti_id_table_3410) - TI_EXTRA_VID_PID_COUNT - 1;
359 	for (i=0; i<min(vendor_3410_count,product_3410_count); i++,j++) {
360 		ti_id_table_3410[j].idVendor = vendor_3410[i];
361 		ti_id_table_3410[j].idProduct = product_3410[i];
362 		ti_id_table_3410[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
363 	}
364 	j = ARRAY_SIZE(ti_id_table_5052) - TI_EXTRA_VID_PID_COUNT - 1;
365 	for (i=0; i<min(vendor_5052_count,product_5052_count); i++,j++) {
366 		ti_id_table_5052[j].idVendor = vendor_5052[i];
367 		ti_id_table_5052[j].idProduct = product_5052[i];
368 		ti_id_table_5052[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
369 	}
370 
371 	ret = usb_serial_register(&ti_1port_device);
372 	if (ret)
373 		goto failed_1port;
374 	ret = usb_serial_register(&ti_2port_device);
375 	if (ret)
376 		goto failed_2port;
377 
378 	ret = usb_register(&ti_usb_driver);
379 	if (ret)
380 		goto failed_usb;
381 
382 	info(TI_DRIVER_DESC " " TI_DRIVER_VERSION);
383 
384 	return 0;
385 
386 failed_usb:
387 	usb_serial_deregister(&ti_2port_device);
388 failed_2port:
389 	usb_serial_deregister(&ti_1port_device);
390 failed_1port:
391 	return ret;
392 }
393 
394 
395 static void __exit ti_exit(void)
396 {
397 	usb_serial_deregister(&ti_1port_device);
398 	usb_serial_deregister(&ti_2port_device);
399 	usb_deregister(&ti_usb_driver);
400 }
401 
402 
403 module_init(ti_init);
404 module_exit(ti_exit);
405 
406 
407 static int ti_startup(struct usb_serial *serial)
408 {
409 	struct ti_device *tdev;
410 	struct ti_port *tport;
411 	struct usb_device *dev = serial->dev;
412 	int status;
413 	int i;
414 
415 
416 	dbg("%s - product 0x%4X, num configurations %d, configuration value %d",
417 	    __FUNCTION__, le16_to_cpu(dev->descriptor.idProduct),
418 	    dev->descriptor.bNumConfigurations,
419 	    dev->actconfig->desc.bConfigurationValue);
420 
421 	/* create device structure */
422 	tdev = kzalloc(sizeof(struct ti_device), GFP_KERNEL);
423 	if (tdev == NULL) {
424 		dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
425 		return -ENOMEM;
426 	}
427 	sema_init(&tdev->td_open_close_sem, 1);
428 	tdev->td_serial = serial;
429 	usb_set_serial_data(serial, tdev);
430 
431 	/* determine device type */
432 	if (usb_match_id(serial->interface, ti_id_table_3410))
433 		tdev->td_is_3410 = 1;
434 	dbg("%s - device type is %s", __FUNCTION__, tdev->td_is_3410 ? "3410" : "5052");
435 
436 	/* if we have only 1 configuration, download firmware */
437 	if (dev->descriptor.bNumConfigurations == 1) {
438 
439 		if (tdev->td_is_3410)
440 			status = ti_download_firmware(tdev, ti_fw_3410,
441 				sizeof(ti_fw_3410));
442 		else
443 			status = ti_download_firmware(tdev, ti_fw_5052,
444 				sizeof(ti_fw_5052));
445 		if (status)
446 			goto free_tdev;
447 
448 		/* 3410 must be reset, 5052 resets itself */
449 		if (tdev->td_is_3410) {
450 			msleep_interruptible(100);
451 			usb_reset_device(dev);
452 		}
453 
454 		status = -ENODEV;
455 		goto free_tdev;
456 	}
457 
458 	/* the second configuration must be set (in sysfs by hotplug script) */
459 	if (dev->actconfig->desc.bConfigurationValue == TI_BOOT_CONFIG) {
460 		status = -ENODEV;
461 		goto free_tdev;
462 	}
463 
464 	/* set up port structures */
465 	for (i = 0; i < serial->num_ports; ++i) {
466 		tport = kzalloc(sizeof(struct ti_port), GFP_KERNEL);
467 		if (tport == NULL) {
468 			dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
469 			status = -ENOMEM;
470 			goto free_tports;
471 		}
472 		spin_lock_init(&tport->tp_lock);
473 		tport->tp_uart_base_addr = (i == 0 ? TI_UART1_BASE_ADDR : TI_UART2_BASE_ADDR);
474 		tport->tp_flags = low_latency ? ASYNC_LOW_LATENCY : 0;
475 		tport->tp_closing_wait = closing_wait;
476 		init_waitqueue_head(&tport->tp_msr_wait);
477 		init_waitqueue_head(&tport->tp_write_wait);
478 		tport->tp_write_buf = ti_buf_alloc();
479 		if (tport->tp_write_buf == NULL) {
480 			dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
481 			kfree(tport);
482 			status = -ENOMEM;
483 			goto free_tports;
484 		}
485 		tport->tp_port = serial->port[i];
486 		tport->tp_tdev = tdev;
487 		usb_set_serial_port_data(serial->port[i], tport);
488 		tport->tp_uart_mode = 0;	/* default is RS232 */
489 	}
490 
491 	return 0;
492 
493 free_tports:
494 	for (--i; i>=0; --i) {
495 		tport = usb_get_serial_port_data(serial->port[i]);
496 		ti_buf_free(tport->tp_write_buf);
497 		kfree(tport);
498 		usb_set_serial_port_data(serial->port[i], NULL);
499 	}
500 free_tdev:
501 	kfree(tdev);
502 	usb_set_serial_data(serial, NULL);
503 	return status;
504 }
505 
506 
507 static void ti_shutdown(struct usb_serial *serial)
508 {
509 	int i;
510 	struct ti_device *tdev = usb_get_serial_data(serial);
511 	struct ti_port *tport;
512 
513 	dbg("%s", __FUNCTION__);
514 
515 	for (i=0; i < serial->num_ports; ++i) {
516 		tport = usb_get_serial_port_data(serial->port[i]);
517 		if (tport) {
518 			ti_buf_free(tport->tp_write_buf);
519 			kfree(tport);
520 			usb_set_serial_port_data(serial->port[i], NULL);
521 		}
522 	}
523 
524 	kfree(tdev);
525 	usb_set_serial_data(serial, NULL);
526 }
527 
528 
529 static int ti_open(struct usb_serial_port *port, struct file *file)
530 {
531 	struct ti_port *tport = usb_get_serial_port_data(port);
532 	struct ti_device *tdev;
533 	struct usb_device *dev;
534 	struct urb *urb;
535 	int port_number;
536 	int status;
537 	__u16 open_settings = (__u8)(TI_PIPE_MODE_CONTINOUS |
538 			     TI_PIPE_TIMEOUT_ENABLE |
539 			     (TI_TRANSFER_TIMEOUT << 2));
540 
541 	dbg("%s - port %d", __FUNCTION__, port->number);
542 
543 	if (tport == NULL)
544 		return -ENODEV;
545 
546 	dev = port->serial->dev;
547 	tdev = tport->tp_tdev;
548 
549 	/* only one open on any port on a device at a time */
550 	if (down_interruptible(&tdev->td_open_close_sem))
551 		return -ERESTARTSYS;
552 
553 	if (port->tty)
554 		port->tty->low_latency =
555 			(tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
556 
557 	port_number = port->number - port->serial->minor;
558 
559 	memset(&(tport->tp_icount), 0x00, sizeof(tport->tp_icount));
560 
561 	tport->tp_msr = 0;
562 	tport->tp_shadow_mcr |= (TI_MCR_RTS | TI_MCR_DTR);
563 
564 	/* start interrupt urb the first time a port is opened on this device */
565 	if (tdev->td_open_port_count == 0) {
566 		dbg("%s - start interrupt in urb", __FUNCTION__);
567 		urb = tdev->td_serial->port[0]->interrupt_in_urb;
568 		if (!urb) {
569 			dev_err(&port->dev, "%s - no interrupt urb\n", __FUNCTION__);
570 			status = -EINVAL;
571 			goto up_sem;
572 		}
573 		urb->complete = ti_interrupt_callback;
574 		urb->context = tdev;
575 		urb->dev = dev;
576 		status = usb_submit_urb(urb, GFP_KERNEL);
577 		if (status) {
578 			dev_err(&port->dev, "%s - submit interrupt urb failed, %d\n", __FUNCTION__, status);
579 			goto up_sem;
580 		}
581 	}
582 
583 	ti_set_termios(port, NULL);
584 
585 	dbg("%s - sending TI_OPEN_PORT", __FUNCTION__);
586 	status = ti_command_out_sync(tdev, TI_OPEN_PORT,
587 		(__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
588 	if (status) {
589 		dev_err(&port->dev, "%s - cannot send open command, %d\n", __FUNCTION__, status);
590 		goto unlink_int_urb;
591 	}
592 
593 	dbg("%s - sending TI_START_PORT", __FUNCTION__);
594 	status = ti_command_out_sync(tdev, TI_START_PORT,
595 		(__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
596 	if (status) {
597 		dev_err(&port->dev, "%s - cannot send start command, %d\n", __FUNCTION__, status);
598 		goto unlink_int_urb;
599 	}
600 
601 	dbg("%s - sending TI_PURGE_PORT", __FUNCTION__);
602 	status = ti_command_out_sync(tdev, TI_PURGE_PORT,
603 		(__u8)(TI_UART1_PORT + port_number), TI_PURGE_INPUT, NULL, 0);
604 	if (status) {
605 		dev_err(&port->dev, "%s - cannot clear input buffers, %d\n", __FUNCTION__, status);
606 		goto unlink_int_urb;
607 	}
608 	status = ti_command_out_sync(tdev, TI_PURGE_PORT,
609 		(__u8)(TI_UART1_PORT + port_number), TI_PURGE_OUTPUT, NULL, 0);
610 	if (status) {
611 		dev_err(&port->dev, "%s - cannot clear output buffers, %d\n", __FUNCTION__, status);
612 		goto unlink_int_urb;
613 	}
614 
615 	/* reset the data toggle on the bulk endpoints to work around bug in
616 	 * host controllers where things get out of sync some times */
617 	usb_clear_halt(dev, port->write_urb->pipe);
618 	usb_clear_halt(dev, port->read_urb->pipe);
619 
620 	ti_set_termios(port, NULL);
621 
622 	dbg("%s - sending TI_OPEN_PORT (2)", __FUNCTION__);
623 	status = ti_command_out_sync(tdev, TI_OPEN_PORT,
624 		(__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
625 	if (status) {
626 		dev_err(&port->dev, "%s - cannot send open command (2), %d\n", __FUNCTION__, status);
627 		goto unlink_int_urb;
628 	}
629 
630 	dbg("%s - sending TI_START_PORT (2)", __FUNCTION__);
631 	status = ti_command_out_sync(tdev, TI_START_PORT,
632 		(__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
633 	if (status) {
634 		dev_err(&port->dev, "%s - cannot send start command (2), %d\n", __FUNCTION__, status);
635 		goto unlink_int_urb;
636 	}
637 
638 	/* start read urb */
639 	dbg("%s - start read urb", __FUNCTION__);
640 	urb = port->read_urb;
641 	if (!urb) {
642 		dev_err(&port->dev, "%s - no read urb\n", __FUNCTION__);
643 		status = -EINVAL;
644 		goto unlink_int_urb;
645 	}
646 	tport->tp_read_urb_state = TI_READ_URB_RUNNING;
647 	urb->complete = ti_bulk_in_callback;
648 	urb->context = tport;
649 	urb->dev = dev;
650 	status = usb_submit_urb(urb, GFP_KERNEL);
651 	if (status) {
652 		dev_err(&port->dev, "%s - submit read urb failed, %d\n", __FUNCTION__, status);
653 		goto unlink_int_urb;
654 	}
655 
656 	tport->tp_is_open = 1;
657 	++tdev->td_open_port_count;
658 
659 	goto up_sem;
660 
661 unlink_int_urb:
662 	if (tdev->td_open_port_count == 0)
663 		usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
664 up_sem:
665 	up(&tdev->td_open_close_sem);
666 	dbg("%s - exit %d", __FUNCTION__, status);
667 	return status;
668 }
669 
670 
671 static void ti_close(struct usb_serial_port *port, struct file *file)
672 {
673 	struct ti_device *tdev;
674 	struct ti_port *tport;
675 	int port_number;
676 	int status;
677 	int do_up;
678 
679 	dbg("%s - port %d", __FUNCTION__, port->number);
680 
681 	tdev = usb_get_serial_data(port->serial);
682 	tport = usb_get_serial_port_data(port);
683 	if (tdev == NULL || tport == NULL)
684 		return;
685 
686 	tport->tp_is_open = 0;
687 
688 	ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 1);
689 
690 	usb_kill_urb(port->read_urb);
691 	usb_kill_urb(port->write_urb);
692 	tport->tp_write_urb_in_use = 0;
693 
694 	port_number = port->number - port->serial->minor;
695 
696 	dbg("%s - sending TI_CLOSE_PORT", __FUNCTION__);
697 	status = ti_command_out_sync(tdev, TI_CLOSE_PORT,
698 		     (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
699 	if (status)
700 		dev_err(&port->dev, "%s - cannot send close port command, %d\n" , __FUNCTION__, status);
701 
702 	/* if down is interrupted, continue anyway */
703 	do_up = !down_interruptible(&tdev->td_open_close_sem);
704 	--tport->tp_tdev->td_open_port_count;
705 	if (tport->tp_tdev->td_open_port_count <= 0) {
706 		/* last port is closed, shut down interrupt urb */
707 		usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
708 		tport->tp_tdev->td_open_port_count = 0;
709 	}
710 	if (do_up)
711 		up(&tdev->td_open_close_sem);
712 
713 	dbg("%s - exit", __FUNCTION__);
714 }
715 
716 
717 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
718 	int count)
719 {
720 	struct ti_port *tport = usb_get_serial_port_data(port);
721 	unsigned long flags;
722 
723 	dbg("%s - port %d", __FUNCTION__, port->number);
724 
725 	if (count == 0) {
726 		dbg("%s - write request of 0 bytes", __FUNCTION__);
727 		return 0;
728 	}
729 
730 	if (tport == NULL || !tport->tp_is_open)
731 		return -ENODEV;
732 
733 	spin_lock_irqsave(&tport->tp_lock, flags);
734 	count = ti_buf_put(tport->tp_write_buf, data, count);
735 	spin_unlock_irqrestore(&tport->tp_lock, flags);
736 
737 	ti_send(tport);
738 
739 	return count;
740 }
741 
742 
743 static int ti_write_room(struct usb_serial_port *port)
744 {
745 	struct ti_port *tport = usb_get_serial_port_data(port);
746 	int room = 0;
747 	unsigned long flags;
748 
749 	dbg("%s - port %d", __FUNCTION__, port->number);
750 
751 	if (tport == NULL)
752 		return -ENODEV;
753 
754 	spin_lock_irqsave(&tport->tp_lock, flags);
755 	room = ti_buf_space_avail(tport->tp_write_buf);
756 	spin_unlock_irqrestore(&tport->tp_lock, flags);
757 
758 	dbg("%s - returns %d", __FUNCTION__, room);
759 	return room;
760 }
761 
762 
763 static int ti_chars_in_buffer(struct usb_serial_port *port)
764 {
765 	struct ti_port *tport = usb_get_serial_port_data(port);
766 	int chars = 0;
767 	unsigned long flags;
768 
769 	dbg("%s - port %d", __FUNCTION__, port->number);
770 
771 	if (tport == NULL)
772 		return -ENODEV;
773 
774 	spin_lock_irqsave(&tport->tp_lock, flags);
775 	chars = ti_buf_data_avail(tport->tp_write_buf);
776 	spin_unlock_irqrestore(&tport->tp_lock, flags);
777 
778 	dbg("%s - returns %d", __FUNCTION__, chars);
779 	return chars;
780 }
781 
782 
783 static void ti_throttle(struct usb_serial_port *port)
784 {
785 	struct ti_port *tport = usb_get_serial_port_data(port);
786 	struct tty_struct *tty;
787 
788 	dbg("%s - port %d", __FUNCTION__, port->number);
789 
790 	if (tport == NULL)
791 		return;
792 
793 	tty = port->tty;
794 	if (!tty) {
795 		dbg("%s - no tty", __FUNCTION__);
796 		return;
797 	}
798 
799 	if (I_IXOFF(tty) || C_CRTSCTS(tty))
800 		ti_stop_read(tport, tty);
801 
802 }
803 
804 
805 static void ti_unthrottle(struct usb_serial_port *port)
806 {
807 	struct ti_port *tport = usb_get_serial_port_data(port);
808 	struct tty_struct *tty;
809 	int status;
810 
811 	dbg("%s - port %d", __FUNCTION__, port->number);
812 
813 	if (tport == NULL)
814 		return;
815 
816 	tty = port->tty;
817 	if (!tty) {
818 		dbg("%s - no tty", __FUNCTION__);
819 		return;
820 	}
821 
822 	if (I_IXOFF(tty) || C_CRTSCTS(tty)) {
823 		status = ti_restart_read(tport, tty);
824 		if (status)
825 			dev_err(&port->dev, "%s - cannot restart read, %d\n", __FUNCTION__, status);
826 	}
827 }
828 
829 
830 static int ti_ioctl(struct usb_serial_port *port, struct file *file,
831 	unsigned int cmd, unsigned long arg)
832 {
833 	struct ti_port *tport = usb_get_serial_port_data(port);
834 	struct async_icount cnow;
835 	struct async_icount cprev;
836 
837 	dbg("%s - port %d, cmd = 0x%04X", __FUNCTION__, port->number, cmd);
838 
839 	if (tport == NULL)
840 		return -ENODEV;
841 
842 	switch (cmd) {
843 		case TIOCGSERIAL:
844 			dbg("%s - (%d) TIOCGSERIAL", __FUNCTION__, port->number);
845 			return ti_get_serial_info(tport, (struct serial_struct __user *)arg);
846 			break;
847 
848 		case TIOCSSERIAL:
849 			dbg("%s - (%d) TIOCSSERIAL", __FUNCTION__, port->number);
850 			return ti_set_serial_info(tport, (struct serial_struct __user *)arg);
851 			break;
852 
853 		case TIOCMIWAIT:
854 			dbg("%s - (%d) TIOCMIWAIT", __FUNCTION__, port->number);
855 			cprev = tport->tp_icount;
856 			while (1) {
857 				interruptible_sleep_on(&tport->tp_msr_wait);
858 				if (signal_pending(current))
859 					return -ERESTARTSYS;
860 				cnow = tport->tp_icount;
861 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
862 				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
863 					return -EIO; /* no change => error */
864 				if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
865 				    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
866 				    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
867 				    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
868 					return 0;
869 				}
870 				cprev = cnow;
871 			}
872 			break;
873 
874 		case TIOCGICOUNT:
875 			dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d", __FUNCTION__, port->number, tport->tp_icount.rx, tport->tp_icount.tx);
876 			if (copy_to_user((void __user *)arg, &tport->tp_icount, sizeof(tport->tp_icount)))
877 				return -EFAULT;
878 			return 0;
879 	}
880 
881 	return -ENOIOCTLCMD;
882 }
883 
884 
885 static void ti_set_termios(struct usb_serial_port *port,
886 	struct ktermios *old_termios)
887 {
888 	struct ti_port *tport = usb_get_serial_port_data(port);
889 	struct tty_struct *tty = port->tty;
890 	struct ti_uart_config *config;
891 	tcflag_t cflag,iflag;
892 	int baud;
893 	int status;
894 	int port_number = port->number - port->serial->minor;
895 	unsigned int mcr;
896 
897 	dbg("%s - port %d", __FUNCTION__, port->number);
898 
899 	if (!tty || !tty->termios) {
900 		dbg("%s - no tty or termios", __FUNCTION__);
901 		return;
902 	}
903 
904 	cflag = tty->termios->c_cflag;
905 	iflag = tty->termios->c_iflag;
906 
907 	if (old_termios && cflag == old_termios->c_cflag
908 	&& iflag == old_termios->c_iflag) {
909 		dbg("%s - nothing to change", __FUNCTION__);
910 		return;
911 	}
912 
913 	dbg("%s - clfag %08x, iflag %08x", __FUNCTION__, cflag, iflag);
914 
915 	if (old_termios)
916 		dbg("%s - old clfag %08x, old iflag %08x", __FUNCTION__, old_termios->c_cflag, old_termios->c_iflag);
917 
918 	if (tport == NULL)
919 		return;
920 
921 	config = kmalloc(sizeof(*config), GFP_KERNEL);
922 	if (!config) {
923 		dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
924 		return;
925 	}
926 
927 	config->wFlags = 0;
928 
929 	/* these flags must be set */
930 	config->wFlags |= TI_UART_ENABLE_MS_INTS;
931 	config->wFlags |= TI_UART_ENABLE_AUTO_START_DMA;
932 	config->bUartMode = (__u8)(tport->tp_uart_mode);
933 
934 	switch (cflag & CSIZE) {
935 		case CS5:
936 			    config->bDataBits = TI_UART_5_DATA_BITS;
937 			    break;
938 		case CS6:
939 			    config->bDataBits = TI_UART_6_DATA_BITS;
940 			    break;
941 		case CS7:
942 			    config->bDataBits = TI_UART_7_DATA_BITS;
943 			    break;
944 		default:
945 		case CS8:
946 			    config->bDataBits = TI_UART_8_DATA_BITS;
947 			    break;
948 	}
949 
950 	if (cflag & PARENB) {
951 		if (cflag & PARODD) {
952 			config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
953 			config->bParity = TI_UART_ODD_PARITY;
954 		} else {
955 			config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
956 			config->bParity = TI_UART_EVEN_PARITY;
957 		}
958 	} else {
959 		config->wFlags &= ~TI_UART_ENABLE_PARITY_CHECKING;
960 		config->bParity = TI_UART_NO_PARITY;
961 	}
962 
963 	if (cflag & CSTOPB)
964 		config->bStopBits = TI_UART_2_STOP_BITS;
965 	else
966 		config->bStopBits = TI_UART_1_STOP_BITS;
967 
968 	if (cflag & CRTSCTS) {
969 		/* RTS flow control must be off to drop RTS for baud rate B0 */
970 		if ((cflag & CBAUD) != B0)
971 			config->wFlags |= TI_UART_ENABLE_RTS_IN;
972 		config->wFlags |= TI_UART_ENABLE_CTS_OUT;
973 	} else {
974 		tty->hw_stopped = 0;
975 		ti_restart_read(tport, tty);
976 	}
977 
978 	if (I_IXOFF(tty) || I_IXON(tty)) {
979 		config->cXon  = START_CHAR(tty);
980 		config->cXoff = STOP_CHAR(tty);
981 
982 		if (I_IXOFF(tty))
983 			config->wFlags |= TI_UART_ENABLE_X_IN;
984 		else
985 			ti_restart_read(tport, tty);
986 
987 		if (I_IXON(tty))
988 			config->wFlags |= TI_UART_ENABLE_X_OUT;
989 	}
990 
991 	baud = tty_get_baud_rate(tty);
992 	if (!baud) baud = 9600;
993 	if (tport->tp_tdev->td_is_3410)
994 		config->wBaudRate = (__u16)((923077 + baud/2) / baud);
995 	else
996 		config->wBaudRate = (__u16)((461538 + baud/2) / baud);
997 
998 	dbg("%s - BaudRate=%d, wBaudRate=%d, wFlags=0x%04X, bDataBits=%d, bParity=%d, bStopBits=%d, cXon=%d, cXoff=%d, bUartMode=%d",
999 	__FUNCTION__, baud, config->wBaudRate, config->wFlags, config->bDataBits, config->bParity, config->bStopBits, config->cXon, config->cXoff, config->bUartMode);
1000 
1001 	cpu_to_be16s(&config->wBaudRate);
1002 	cpu_to_be16s(&config->wFlags);
1003 
1004 	status = ti_command_out_sync(tport->tp_tdev, TI_SET_CONFIG,
1005 		(__u8)(TI_UART1_PORT + port_number), 0, (__u8 *)config,
1006 		sizeof(*config));
1007 	if (status)
1008 		dev_err(&port->dev, "%s - cannot set config on port %d, %d\n", __FUNCTION__, port_number, status);
1009 
1010 	/* SET_CONFIG asserts RTS and DTR, reset them correctly */
1011 	mcr = tport->tp_shadow_mcr;
1012 	/* if baud rate is B0, clear RTS and DTR */
1013 	if ((cflag & CBAUD) == B0)
1014 		mcr &= ~(TI_MCR_DTR | TI_MCR_RTS);
1015 	status = ti_set_mcr(tport, mcr);
1016 	if (status)
1017 		dev_err(&port->dev, "%s - cannot set modem control on port %d, %d\n", __FUNCTION__, port_number, status);
1018 
1019 	kfree(config);
1020 }
1021 
1022 
1023 static int ti_tiocmget(struct usb_serial_port *port, struct file *file)
1024 {
1025 	struct ti_port *tport = usb_get_serial_port_data(port);
1026 	unsigned int result;
1027 	unsigned int msr;
1028 	unsigned int mcr;
1029 
1030 	dbg("%s - port %d", __FUNCTION__, port->number);
1031 
1032 	if (tport == NULL)
1033 		return -ENODEV;
1034 
1035 	msr = tport->tp_msr;
1036 	mcr = tport->tp_shadow_mcr;
1037 
1038 	result = ((mcr & TI_MCR_DTR) ? TIOCM_DTR : 0)
1039 		| ((mcr & TI_MCR_RTS) ? TIOCM_RTS : 0)
1040 		| ((mcr & TI_MCR_LOOP) ? TIOCM_LOOP : 0)
1041 		| ((msr & TI_MSR_CTS) ? TIOCM_CTS : 0)
1042 		| ((msr & TI_MSR_CD) ? TIOCM_CAR : 0)
1043 		| ((msr & TI_MSR_RI) ? TIOCM_RI : 0)
1044 		| ((msr & TI_MSR_DSR) ? TIOCM_DSR : 0);
1045 
1046 	dbg("%s - 0x%04X", __FUNCTION__, result);
1047 
1048 	return result;
1049 }
1050 
1051 
1052 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
1053 	unsigned int set, unsigned int clear)
1054 {
1055 	struct ti_port *tport = usb_get_serial_port_data(port);
1056 	unsigned int mcr;
1057 
1058 	dbg("%s - port %d", __FUNCTION__, port->number);
1059 
1060 	if (tport == NULL)
1061 		return -ENODEV;
1062 
1063 	mcr = tport->tp_shadow_mcr;
1064 
1065 	if (set & TIOCM_RTS)
1066 		mcr |= TI_MCR_RTS;
1067 	if (set & TIOCM_DTR)
1068 		mcr |= TI_MCR_DTR;
1069 	if (set & TIOCM_LOOP)
1070 		mcr |= TI_MCR_LOOP;
1071 
1072 	if (clear & TIOCM_RTS)
1073 		mcr &= ~TI_MCR_RTS;
1074 	if (clear & TIOCM_DTR)
1075 		mcr &= ~TI_MCR_DTR;
1076 	if (clear & TIOCM_LOOP)
1077 		mcr &= ~TI_MCR_LOOP;
1078 
1079 	return ti_set_mcr(tport, mcr);
1080 }
1081 
1082 
1083 static void ti_break(struct usb_serial_port *port, int break_state)
1084 {
1085 	struct ti_port *tport = usb_get_serial_port_data(port);
1086 	int status;
1087 
1088 	dbg("%s - state = %d", __FUNCTION__, break_state);
1089 
1090 	if (tport == NULL)
1091 		return;
1092 
1093 	ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 0);
1094 
1095 	status = ti_write_byte(tport->tp_tdev,
1096 		tport->tp_uart_base_addr + TI_UART_OFFSET_LCR,
1097 		TI_LCR_BREAK, break_state == -1 ? TI_LCR_BREAK : 0);
1098 
1099 	if (status)
1100 		dbg("%s - error setting break, %d", __FUNCTION__, status);
1101 }
1102 
1103 
1104 static void ti_interrupt_callback(struct urb *urb)
1105 {
1106 	struct ti_device *tdev = (struct ti_device *)urb->context;
1107 	struct usb_serial_port *port;
1108 	struct usb_serial *serial = tdev->td_serial;
1109 	struct ti_port *tport;
1110 	struct device *dev = &urb->dev->dev;
1111 	unsigned char *data = urb->transfer_buffer;
1112 	int length = urb->actual_length;
1113 	int port_number;
1114 	int function;
1115 	int status = urb->status;
1116 	int retval;
1117 	__u8 msr;
1118 
1119 	dbg("%s", __FUNCTION__);
1120 
1121 	switch (status) {
1122 	case 0:
1123 		break;
1124 	case -ECONNRESET:
1125 	case -ENOENT:
1126 	case -ESHUTDOWN:
1127 		dbg("%s - urb shutting down, %d", __FUNCTION__, status);
1128 		tdev->td_urb_error = 1;
1129 		return;
1130 	default:
1131 		dev_err(dev, "%s - nonzero urb status, %d\n",
1132 			__FUNCTION__, status);
1133 		tdev->td_urb_error = 1;
1134 		goto exit;
1135 	}
1136 
1137 	if (length != 2) {
1138 		dbg("%s - bad packet size, %d", __FUNCTION__, length);
1139 		goto exit;
1140 	}
1141 
1142 	if (data[0] == TI_CODE_HARDWARE_ERROR) {
1143 		dev_err(dev, "%s - hardware error, %d\n", __FUNCTION__, data[1]);
1144 		goto exit;
1145 	}
1146 
1147 	port_number = TI_GET_PORT_FROM_CODE(data[0]);
1148 	function = TI_GET_FUNC_FROM_CODE(data[0]);
1149 
1150 	dbg("%s - port_number %d, function %d, data 0x%02X", __FUNCTION__, port_number, function, data[1]);
1151 
1152 	if (port_number >= serial->num_ports) {
1153 		dev_err(dev, "%s - bad port number, %d\n", __FUNCTION__, port_number);
1154 		goto exit;
1155 	}
1156 
1157 	port = serial->port[port_number];
1158 
1159 	tport = usb_get_serial_port_data(port);
1160 	if (!tport)
1161 		goto exit;
1162 
1163 	switch (function) {
1164 	case TI_CODE_DATA_ERROR:
1165 		dev_err(dev, "%s - DATA ERROR, port %d, data 0x%02X\n", __FUNCTION__, port_number, data[1]);
1166 		break;
1167 
1168 	case TI_CODE_MODEM_STATUS:
1169 		msr = data[1];
1170 		dbg("%s - port %d, msr 0x%02X", __FUNCTION__, port_number, msr);
1171 		ti_handle_new_msr(tport, msr);
1172 		break;
1173 
1174 	default:
1175 		dev_err(dev, "%s - unknown interrupt code, 0x%02X\n", __FUNCTION__, data[1]);
1176 		break;
1177 	}
1178 
1179 exit:
1180 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1181 	if (retval)
1182 		dev_err(dev, "%s - resubmit interrupt urb failed, %d\n",
1183 			__FUNCTION__, retval);
1184 }
1185 
1186 
1187 static void ti_bulk_in_callback(struct urb *urb)
1188 {
1189 	struct ti_port *tport = (struct ti_port *)urb->context;
1190 	struct usb_serial_port *port = tport->tp_port;
1191 	struct device *dev = &urb->dev->dev;
1192 	int status = urb->status;
1193 	int retval = 0;
1194 
1195 	dbg("%s", __FUNCTION__);
1196 
1197 	switch (status) {
1198 	case 0:
1199 		break;
1200 	case -ECONNRESET:
1201 	case -ENOENT:
1202 	case -ESHUTDOWN:
1203 		dbg("%s - urb shutting down, %d", __FUNCTION__, status);
1204 		tport->tp_tdev->td_urb_error = 1;
1205 		wake_up_interruptible(&tport->tp_write_wait);
1206 		return;
1207 	default:
1208 		dev_err(dev, "%s - nonzero urb status, %d\n",
1209 			__FUNCTION__, status );
1210 		tport->tp_tdev->td_urb_error = 1;
1211 		wake_up_interruptible(&tport->tp_write_wait);
1212 	}
1213 
1214 	if (status == -EPIPE)
1215 		goto exit;
1216 
1217 	if (status) {
1218 		dev_err(dev, "%s - stopping read!\n", __FUNCTION__);
1219 		return;
1220 	}
1221 
1222 	if (port->tty && urb->actual_length) {
1223 		usb_serial_debug_data(debug, dev, __FUNCTION__,
1224 			urb->actual_length, urb->transfer_buffer);
1225 
1226 		if (!tport->tp_is_open)
1227 			dbg("%s - port closed, dropping data", __FUNCTION__);
1228 		else
1229 			ti_recv(&urb->dev->dev, port->tty, urb->transfer_buffer,
1230 				urb->actual_length);
1231 
1232 		spin_lock(&tport->tp_lock);
1233 		tport->tp_icount.rx += urb->actual_length;
1234 		spin_unlock(&tport->tp_lock);
1235 	}
1236 
1237 exit:
1238 	/* continue to read unless stopping */
1239 	spin_lock(&tport->tp_lock);
1240 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING) {
1241 		urb->dev = port->serial->dev;
1242 		retval = usb_submit_urb(urb, GFP_ATOMIC);
1243 	} else if (tport->tp_read_urb_state == TI_READ_URB_STOPPING) {
1244 		tport->tp_read_urb_state = TI_READ_URB_STOPPED;
1245 	}
1246 	spin_unlock(&tport->tp_lock);
1247 	if (retval)
1248 		dev_err(dev, "%s - resubmit read urb failed, %d\n",
1249 			__FUNCTION__, retval);
1250 }
1251 
1252 
1253 static void ti_bulk_out_callback(struct urb *urb)
1254 {
1255 	struct ti_port *tport = (struct ti_port *)urb->context;
1256 	struct usb_serial_port *port = tport->tp_port;
1257 	struct device *dev = &urb->dev->dev;
1258 	int status = urb->status;
1259 
1260 	dbg("%s - port %d", __FUNCTION__, port->number);
1261 
1262 	tport->tp_write_urb_in_use = 0;
1263 
1264 	switch (status) {
1265 	case 0:
1266 		break;
1267 	case -ECONNRESET:
1268 	case -ENOENT:
1269 	case -ESHUTDOWN:
1270 		dbg("%s - urb shutting down, %d", __FUNCTION__, status);
1271 		tport->tp_tdev->td_urb_error = 1;
1272 		wake_up_interruptible(&tport->tp_write_wait);
1273 		return;
1274 	default:
1275 		dev_err(dev, "%s - nonzero urb status, %d\n",
1276 			__FUNCTION__, status);
1277 		tport->tp_tdev->td_urb_error = 1;
1278 		wake_up_interruptible(&tport->tp_write_wait);
1279 	}
1280 
1281 	/* send any buffered data */
1282 	ti_send(tport);
1283 }
1284 
1285 
1286 static void ti_recv(struct device *dev, struct tty_struct *tty,
1287 	unsigned char *data, int length)
1288 {
1289 	int cnt;
1290 
1291 	do {
1292 		cnt = tty_buffer_request_room(tty, length);
1293 		if (cnt < length) {
1294 			dev_err(dev, "%s - dropping data, %d bytes lost\n", __FUNCTION__, length - cnt);
1295 			if(cnt == 0)
1296 				break;
1297 		}
1298 		tty_insert_flip_string(tty, data, cnt);
1299 		tty_flip_buffer_push(tty);
1300 		data += cnt;
1301 		length -= cnt;
1302 	} while (length > 0);
1303 
1304 }
1305 
1306 
1307 static void ti_send(struct ti_port *tport)
1308 {
1309 	int count, result;
1310 	struct usb_serial_port *port = tport->tp_port;
1311 	struct tty_struct *tty = port->tty;
1312 	unsigned long flags;
1313 
1314 
1315 	dbg("%s - port %d", __FUNCTION__, port->number);
1316 
1317 	spin_lock_irqsave(&tport->tp_lock, flags);
1318 
1319 	if (tport->tp_write_urb_in_use) {
1320 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1321 		return;
1322 	}
1323 
1324 	count = ti_buf_get(tport->tp_write_buf,
1325 				port->write_urb->transfer_buffer,
1326 				port->bulk_out_size);
1327 
1328 	if (count == 0) {
1329 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1330 		return;
1331 	}
1332 
1333 	tport->tp_write_urb_in_use = 1;
1334 
1335 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1336 
1337 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, port->write_urb->transfer_buffer);
1338 
1339 	usb_fill_bulk_urb(port->write_urb, port->serial->dev,
1340 			   usb_sndbulkpipe(port->serial->dev,
1341 					    port->bulk_out_endpointAddress),
1342 			   port->write_urb->transfer_buffer, count,
1343 			   ti_bulk_out_callback, tport);
1344 
1345 	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1346 	if (result) {
1347 		dev_err(&port->dev, "%s - submit write urb failed, %d\n", __FUNCTION__, result);
1348 		tport->tp_write_urb_in_use = 0;
1349 		/* TODO: reschedule ti_send */
1350 	} else {
1351 		spin_lock_irqsave(&tport->tp_lock, flags);
1352 		tport->tp_icount.tx += count;
1353 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1354 	}
1355 
1356 	/* more room in the buffer for new writes, wakeup */
1357 	if (tty)
1358 		tty_wakeup(tty);
1359 	wake_up_interruptible(&tport->tp_write_wait);
1360 }
1361 
1362 
1363 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr)
1364 {
1365 	int status;
1366 
1367 	status = ti_write_byte(tport->tp_tdev,
1368 		tport->tp_uart_base_addr + TI_UART_OFFSET_MCR,
1369 		TI_MCR_RTS | TI_MCR_DTR | TI_MCR_LOOP, mcr);
1370 
1371 	if (!status)
1372 		tport->tp_shadow_mcr = mcr;
1373 
1374 	return status;
1375 }
1376 
1377 
1378 static int ti_get_lsr(struct ti_port *tport)
1379 {
1380 	int size,status;
1381 	struct ti_device *tdev = tport->tp_tdev;
1382 	struct usb_serial_port *port = tport->tp_port;
1383 	int port_number = port->number - port->serial->minor;
1384 	struct ti_port_status *data;
1385 
1386 	dbg("%s - port %d", __FUNCTION__, port->number);
1387 
1388 	size = sizeof(struct ti_port_status);
1389 	data = kmalloc(size, GFP_KERNEL);
1390 	if (!data) {
1391 		dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
1392 		return -ENOMEM;
1393 	}
1394 
1395 	status = ti_command_in_sync(tdev, TI_GET_PORT_STATUS,
1396 		(__u8)(TI_UART1_PORT+port_number), 0, (__u8 *)data, size);
1397 	if (status) {
1398 		dev_err(&port->dev, "%s - get port status command failed, %d\n", __FUNCTION__, status);
1399 		goto free_data;
1400 	}
1401 
1402 	dbg("%s - lsr 0x%02X", __FUNCTION__, data->bLSR);
1403 
1404 	tport->tp_lsr = data->bLSR;
1405 
1406 free_data:
1407 	kfree(data);
1408 	return status;
1409 }
1410 
1411 
1412 static int ti_get_serial_info(struct ti_port *tport,
1413 	struct serial_struct __user *ret_arg)
1414 {
1415 	struct usb_serial_port *port = tport->tp_port;
1416 	struct serial_struct ret_serial;
1417 
1418 	if (!ret_arg)
1419 		return -EFAULT;
1420 
1421 	memset(&ret_serial, 0, sizeof(ret_serial));
1422 
1423 	ret_serial.type = PORT_16550A;
1424 	ret_serial.line = port->serial->minor;
1425 	ret_serial.port = port->number - port->serial->minor;
1426 	ret_serial.flags = tport->tp_flags;
1427 	ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
1428 	ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
1429 	ret_serial.closing_wait = tport->tp_closing_wait;
1430 
1431 	if (copy_to_user(ret_arg, &ret_serial, sizeof(*ret_arg)))
1432 		return -EFAULT;
1433 
1434 	return 0;
1435 }
1436 
1437 
1438 static int ti_set_serial_info(struct ti_port *tport,
1439 	struct serial_struct __user *new_arg)
1440 {
1441 	struct usb_serial_port *port = tport->tp_port;
1442 	struct serial_struct new_serial;
1443 
1444 	if (copy_from_user(&new_serial, new_arg, sizeof(new_serial)))
1445 		return -EFAULT;
1446 
1447 	tport->tp_flags = new_serial.flags & TI_SET_SERIAL_FLAGS;
1448 	if (port->tty)
1449 		port->tty->low_latency =
1450 			(tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1451 	tport->tp_closing_wait = new_serial.closing_wait;
1452 
1453 	return 0;
1454 }
1455 
1456 
1457 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr)
1458 {
1459 	struct async_icount *icount;
1460 	struct tty_struct *tty;
1461 	unsigned long flags;
1462 
1463 	dbg("%s - msr 0x%02X", __FUNCTION__, msr);
1464 
1465 	if (msr & TI_MSR_DELTA_MASK) {
1466 		spin_lock_irqsave(&tport->tp_lock, flags);
1467 		icount = &tport->tp_icount;
1468 		if (msr & TI_MSR_DELTA_CTS)
1469 			icount->cts++;
1470 		if (msr & TI_MSR_DELTA_DSR)
1471 			icount->dsr++;
1472 		if (msr & TI_MSR_DELTA_CD)
1473 			icount->dcd++;
1474 		if (msr & TI_MSR_DELTA_RI)
1475 			icount->rng++;
1476 		wake_up_interruptible(&tport->tp_msr_wait);
1477 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1478 	}
1479 
1480 	tport->tp_msr = msr & TI_MSR_MASK;
1481 
1482 	/* handle CTS flow control */
1483 	tty = tport->tp_port->tty;
1484 	if (tty && C_CRTSCTS(tty)) {
1485 		if (msr & TI_MSR_CTS) {
1486 			tty->hw_stopped = 0;
1487 			tty_wakeup(tty);
1488 		} else {
1489 			tty->hw_stopped = 1;
1490 		}
1491 	}
1492 }
1493 
1494 
1495 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
1496 {
1497 	struct ti_device *tdev = tport->tp_tdev;
1498 	struct usb_serial_port *port = tport->tp_port;
1499 	wait_queue_t wait;
1500 	unsigned long flags;
1501 
1502 	dbg("%s - port %d", __FUNCTION__, port->number);
1503 
1504 	spin_lock_irqsave(&tport->tp_lock, flags);
1505 
1506 	/* wait for data to drain from the buffer */
1507 	tdev->td_urb_error = 0;
1508 	init_waitqueue_entry(&wait, current);
1509 	add_wait_queue(&tport->tp_write_wait, &wait);
1510 	for (;;) {
1511 		set_current_state(TASK_INTERRUPTIBLE);
1512 		if (ti_buf_data_avail(tport->tp_write_buf) == 0
1513 		|| timeout == 0 || signal_pending(current)
1514 		|| tdev->td_urb_error
1515 		|| !usb_get_intfdata(port->serial->interface))  /* disconnect */
1516 			break;
1517 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1518 		timeout = schedule_timeout(timeout);
1519 		spin_lock_irqsave(&tport->tp_lock, flags);
1520 	}
1521 	set_current_state(TASK_RUNNING);
1522 	remove_wait_queue(&tport->tp_write_wait, &wait);
1523 
1524 	/* flush any remaining data in the buffer */
1525 	if (flush)
1526 		ti_buf_clear(tport->tp_write_buf);
1527 
1528 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1529 
1530 	/* wait for data to drain from the device */
1531 	/* wait for empty tx register, plus 20 ms */
1532 	timeout += jiffies;
1533 	tport->tp_lsr &= ~TI_LSR_TX_EMPTY;
1534 	while ((long)(jiffies - timeout) < 0 && !signal_pending(current)
1535 	&& !(tport->tp_lsr&TI_LSR_TX_EMPTY) && !tdev->td_urb_error
1536 	&& usb_get_intfdata(port->serial->interface)) {  /* not disconnected */
1537 		if (ti_get_lsr(tport))
1538 			break;
1539 		msleep_interruptible(20);
1540 	}
1541 }
1542 
1543 
1544 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty)
1545 {
1546 	unsigned long flags;
1547 
1548 	spin_lock_irqsave(&tport->tp_lock, flags);
1549 
1550 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING)
1551 		tport->tp_read_urb_state = TI_READ_URB_STOPPING;
1552 
1553 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1554 }
1555 
1556 
1557 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty)
1558 {
1559 	struct urb *urb;
1560 	int status = 0;
1561 	unsigned long flags;
1562 
1563 	spin_lock_irqsave(&tport->tp_lock, flags);
1564 
1565 	if (tport->tp_read_urb_state == TI_READ_URB_STOPPED) {
1566 		tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1567 		urb = tport->tp_port->read_urb;
1568 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1569 		urb->complete = ti_bulk_in_callback;
1570 		urb->context = tport;
1571 		urb->dev = tport->tp_port->serial->dev;
1572 		status = usb_submit_urb(urb, GFP_KERNEL);
1573 	} else  {
1574 		tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1575 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1576 	}
1577 
1578 	return status;
1579 }
1580 
1581 
1582 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
1583 	__u16 moduleid, __u16 value, __u8 *data, int size)
1584 {
1585 	int status;
1586 
1587 	status = usb_control_msg(tdev->td_serial->dev,
1588 		usb_sndctrlpipe(tdev->td_serial->dev, 0), command,
1589 		(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT),
1590 		value, moduleid, data, size, 1000);
1591 
1592 	if (status == size)
1593 		status = 0;
1594 
1595 	if (status > 0)
1596 		status = -ECOMM;
1597 
1598 	return status;
1599 }
1600 
1601 
1602 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
1603 	__u16 moduleid, __u16 value, __u8 *data, int size)
1604 {
1605 	int status;
1606 
1607 	status = usb_control_msg(tdev->td_serial->dev,
1608 		usb_rcvctrlpipe(tdev->td_serial->dev, 0), command,
1609 		(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN),
1610 		value, moduleid, data, size, 1000);
1611 
1612 	if (status == size)
1613 		status = 0;
1614 
1615 	if (status > 0)
1616 		status = -ECOMM;
1617 
1618 	return status;
1619 }
1620 
1621 
1622 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
1623 	__u8 mask, __u8 byte)
1624 {
1625 	int status;
1626 	unsigned int size;
1627 	struct ti_write_data_bytes *data;
1628 	struct device *dev = &tdev->td_serial->dev->dev;
1629 
1630 	dbg("%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X", __FUNCTION__, addr, mask, byte);
1631 
1632 	size = sizeof(struct ti_write_data_bytes) + 2;
1633 	data = kmalloc(size, GFP_KERNEL);
1634 	if (!data) {
1635 		dev_err(dev, "%s - out of memory\n", __FUNCTION__);
1636 		return -ENOMEM;
1637 	}
1638 
1639 	data->bAddrType = TI_RW_DATA_ADDR_XDATA;
1640 	data->bDataType = TI_RW_DATA_BYTE;
1641 	data->bDataCounter = 1;
1642 	data->wBaseAddrHi = cpu_to_be16(addr>>16);
1643 	data->wBaseAddrLo = cpu_to_be16(addr);
1644 	data->bData[0] = mask;
1645 	data->bData[1] = byte;
1646 
1647 	status = ti_command_out_sync(tdev, TI_WRITE_DATA, TI_RAM_PORT, 0,
1648 		(__u8 *)data, size);
1649 
1650 	if (status < 0)
1651 		dev_err(dev, "%s - failed, %d\n", __FUNCTION__, status);
1652 
1653 	kfree(data);
1654 
1655 	return status;
1656 }
1657 
1658 
1659 static int ti_download_firmware(struct ti_device *tdev,
1660 	unsigned char *firmware, unsigned int firmware_size)
1661 {
1662 	int status = 0;
1663 	int buffer_size;
1664 	int pos;
1665 	int len;
1666 	int done;
1667 	__u8 cs = 0;
1668 	__u8 *buffer;
1669 	struct usb_device *dev = tdev->td_serial->dev;
1670 	struct ti_firmware_header *header;
1671 	unsigned int pipe = usb_sndbulkpipe(dev,
1672 		tdev->td_serial->port[0]->bulk_out_endpointAddress);
1673 
1674 
1675 	buffer_size = TI_FIRMWARE_BUF_SIZE + sizeof(struct ti_firmware_header);
1676 	buffer = kmalloc(buffer_size, GFP_KERNEL);
1677 	if (!buffer) {
1678 		dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
1679 		return -ENOMEM;
1680 	}
1681 
1682 	memcpy(buffer, firmware, firmware_size);
1683 	memset(buffer+firmware_size, 0xff, buffer_size-firmware_size);
1684 
1685 	for(pos = sizeof(struct ti_firmware_header); pos < buffer_size; pos++)
1686 		cs = (__u8)(cs + buffer[pos]);
1687 
1688 	header = (struct ti_firmware_header *)buffer;
1689 	header->wLength = cpu_to_le16((__u16)(buffer_size - sizeof(struct ti_firmware_header)));
1690 	header->bCheckSum = cs;
1691 
1692 	dbg("%s - downloading firmware", __FUNCTION__);
1693 	for (pos = 0; pos < buffer_size; pos += done) {
1694 		len = min(buffer_size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
1695 		status = usb_bulk_msg(dev, pipe, buffer+pos, len, &done, 1000);
1696 		if (status)
1697 			break;
1698 	}
1699 
1700 	kfree(buffer);
1701 
1702 	if (status) {
1703 		dev_err(&dev->dev, "%s - error downloading firmware, %d\n", __FUNCTION__, status);
1704 		return status;
1705 	}
1706 
1707 	dbg("%s - download successful", __FUNCTION__);
1708 
1709 	return 0;
1710 }
1711 
1712 
1713 /* Circular Buffer Functions */
1714 
1715 /*
1716  * ti_buf_alloc
1717  *
1718  * Allocate a circular buffer and all associated memory.
1719  */
1720 
1721 static struct circ_buf *ti_buf_alloc(void)
1722 {
1723 	struct circ_buf *cb;
1724 
1725 	cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
1726 	if (cb == NULL)
1727 		return NULL;
1728 
1729 	cb->buf = kmalloc(TI_WRITE_BUF_SIZE, GFP_KERNEL);
1730 	if (cb->buf == NULL) {
1731 		kfree(cb);
1732 		return NULL;
1733 	}
1734 
1735 	ti_buf_clear(cb);
1736 
1737 	return cb;
1738 }
1739 
1740 
1741 /*
1742  * ti_buf_free
1743  *
1744  * Free the buffer and all associated memory.
1745  */
1746 
1747 static void ti_buf_free(struct circ_buf *cb)
1748 {
1749 	kfree(cb->buf);
1750 	kfree(cb);
1751 }
1752 
1753 
1754 /*
1755  * ti_buf_clear
1756  *
1757  * Clear out all data in the circular buffer.
1758  */
1759 
1760 static void ti_buf_clear(struct circ_buf *cb)
1761 {
1762 	cb->head = cb->tail = 0;
1763 }
1764 
1765 
1766 /*
1767  * ti_buf_data_avail
1768  *
1769  * Return the number of bytes of data available in the circular
1770  * buffer.
1771  */
1772 
1773 static int ti_buf_data_avail(struct circ_buf *cb)
1774 {
1775 	return CIRC_CNT(cb->head,cb->tail,TI_WRITE_BUF_SIZE);
1776 }
1777 
1778 
1779 /*
1780  * ti_buf_space_avail
1781  *
1782  * Return the number of bytes of space available in the circular
1783  * buffer.
1784  */
1785 
1786 static int ti_buf_space_avail(struct circ_buf *cb)
1787 {
1788 	return CIRC_SPACE(cb->head,cb->tail,TI_WRITE_BUF_SIZE);
1789 }
1790 
1791 
1792 /*
1793  * ti_buf_put
1794  *
1795  * Copy data data from a user buffer and put it into the circular buffer.
1796  * Restrict to the amount of space available.
1797  *
1798  * Return the number of bytes copied.
1799  */
1800 
1801 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count)
1802 {
1803 	int c, ret = 0;
1804 
1805 	while (1) {
1806 		c = CIRC_SPACE_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1807 		if (count < c)
1808 			c = count;
1809 		if (c <= 0)
1810 			break;
1811 		memcpy(cb->buf + cb->head, buf, c);
1812 		cb->head = (cb->head + c) & (TI_WRITE_BUF_SIZE-1);
1813 		buf += c;
1814 		count -= c;
1815 		ret += c;
1816 	}
1817 
1818 	return ret;
1819 }
1820 
1821 
1822 /*
1823  * ti_buf_get
1824  *
1825  * Get data from the circular buffer and copy to the given buffer.
1826  * Restrict to the amount of data available.
1827  *
1828  * Return the number of bytes copied.
1829  */
1830 
1831 static int ti_buf_get(struct circ_buf *cb, char *buf, int count)
1832 {
1833 	int c, ret = 0;
1834 
1835 	while (1) {
1836 		c = CIRC_CNT_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1837 		if (count < c)
1838 			c = count;
1839 		if (c <= 0)
1840 			break;
1841 		memcpy(buf, cb->buf + cb->tail, c);
1842 		cb->tail = (cb->tail + c) & (TI_WRITE_BUF_SIZE-1);
1843 		buf += c;
1844 		count -= c;
1845 		ret += c;
1846 	}
1847 
1848 	return ret;
1849 }
1850