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/config.h>
72 #include <linux/kernel.h>
73 #include <linux/errno.h>
74 #include <linux/init.h>
75 #include <linux/slab.h>
76 #include <linux/tty.h>
77 #include <linux/tty_driver.h>
78 #include <linux/tty_flip.h>
79 #include <linux/module.h>
80 #include <linux/spinlock.h>
81 #include <linux/ioctl.h>
82 #include <linux/serial.h>
83 #include <linux/circ_buf.h>
84 #include <asm/uaccess.h>
85 #include <asm/semaphore.h>
86 #include <linux/usb.h>
87 
88 #include "usb-serial.h"
89 #include "ti_usb_3410_5052.h"
90 #include "ti_fw_3410.h"		/* firmware image for 3410 */
91 #include "ti_fw_5052.h"		/* firmware image for 5052 */
92 
93 
94 /* Defines */
95 
96 #define TI_DRIVER_VERSION	"v0.9"
97 #define TI_DRIVER_AUTHOR	"Al Borchers <alborchers@steinerpoint.com>"
98 #define TI_DRIVER_DESC		"TI USB 3410/5052 Serial Driver"
99 
100 #define TI_FIRMWARE_BUF_SIZE	16284
101 
102 #define TI_WRITE_BUF_SIZE	1024
103 
104 #define TI_TRANSFER_TIMEOUT	2
105 
106 #define TI_DEFAULT_LOW_LATENCY	0
107 #define TI_DEFAULT_CLOSING_WAIT	4000		/* in .01 secs */
108 
109 /* supported setserial flags */
110 #define TI_SET_SERIAL_FLAGS	(ASYNC_LOW_LATENCY)
111 
112 /* read urb states */
113 #define TI_READ_URB_RUNNING	0
114 #define TI_READ_URB_STOPPING	1
115 #define TI_READ_URB_STOPPED	2
116 
117 #define TI_EXTRA_VID_PID_COUNT	5
118 
119 
120 /* Structures */
121 
122 struct ti_port {
123 	int			tp_is_open;
124 	__u8			tp_msr;
125 	__u8			tp_lsr;
126 	__u8			tp_shadow_mcr;
127 	__u8			tp_uart_mode;	/* 232 or 485 modes */
128 	unsigned int		tp_uart_base_addr;
129 	int			tp_flags;
130 	int			tp_closing_wait;/* in .01 secs */
131 	struct async_icount	tp_icount;
132 	wait_queue_head_t	tp_msr_wait;	/* wait for msr change */
133 	wait_queue_head_t	tp_write_wait;
134 	struct ti_device	*tp_tdev;
135 	struct usb_serial_port	*tp_port;
136 	spinlock_t		tp_lock;
137 	int			tp_read_urb_state;
138 	int			tp_write_urb_in_use;
139 	struct circ_buf		*tp_write_buf;
140 };
141 
142 struct ti_device {
143 	struct semaphore	td_open_close_sem;
144 	int			td_open_port_count;
145 	struct usb_serial	*td_serial;
146 	int			td_is_3410;
147 	int			td_urb_error;
148 };
149 
150 
151 /* Function Declarations */
152 
153 static int ti_startup(struct usb_serial *serial);
154 static void ti_shutdown(struct usb_serial *serial);
155 static int ti_open(struct usb_serial_port *port, struct file *file);
156 static void ti_close(struct usb_serial_port *port, struct file *file);
157 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
158 	int count);
159 static int ti_write_room(struct usb_serial_port *port);
160 static int ti_chars_in_buffer(struct usb_serial_port *port);
161 static void ti_throttle(struct usb_serial_port *port);
162 static void ti_unthrottle(struct usb_serial_port *port);
163 static int ti_ioctl(struct usb_serial_port *port, struct file *file, unsigned int cmd, unsigned long arg);
164 static void ti_set_termios(struct usb_serial_port *port,
165 	struct termios *old_termios);
166 static int ti_tiocmget(struct usb_serial_port *port, struct file *file);
167 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
168 	unsigned int set, unsigned int clear);
169 static void ti_break(struct usb_serial_port *port, int break_state);
170 static void ti_interrupt_callback(struct urb *urb, struct pt_regs *regs);
171 static void ti_bulk_in_callback(struct urb *urb, struct pt_regs *regs);
172 static void ti_bulk_out_callback(struct urb *urb, struct pt_regs *regs);
173 
174 static void ti_recv(struct device *dev, struct tty_struct *tty,
175 	unsigned char *data, int length);
176 static void ti_send(struct ti_port *tport);
177 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr);
178 static int ti_get_lsr(struct ti_port *tport);
179 static int ti_get_serial_info(struct ti_port *tport,
180 	struct serial_struct __user *ret_arg);
181 static int ti_set_serial_info(struct ti_port *tport,
182 	struct serial_struct __user *new_arg);
183 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr);
184 
185 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush);
186 
187 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty);
188 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty);
189 
190 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
191 	__u16 moduleid, __u16 value, __u8 *data, int size);
192 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
193 	__u16 moduleid, __u16 value, __u8 *data, int size);
194 
195 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
196 	__u8 mask, __u8 byte);
197 
198 static int ti_download_firmware(struct ti_device *tdev,
199 	unsigned char *firmware, unsigned int firmware_size);
200 
201 /* circular buffer */
202 static struct circ_buf *ti_buf_alloc(void);
203 static void ti_buf_free(struct circ_buf *cb);
204 static void ti_buf_clear(struct circ_buf *cb);
205 static int ti_buf_data_avail(struct circ_buf *cb);
206 static int ti_buf_space_avail(struct circ_buf *cb);
207 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count);
208 static int ti_buf_get(struct circ_buf *cb, char *buf, int count);
209 
210 
211 /* Data */
212 
213 /* module parameters */
214 static int debug;
215 static int low_latency = TI_DEFAULT_LOW_LATENCY;
216 static int closing_wait = TI_DEFAULT_CLOSING_WAIT;
217 static ushort vendor_3410[TI_EXTRA_VID_PID_COUNT];
218 static int vendor_3410_count;
219 static ushort product_3410[TI_EXTRA_VID_PID_COUNT];
220 static int product_3410_count;
221 static ushort vendor_5052[TI_EXTRA_VID_PID_COUNT];
222 static int vendor_5052_count;
223 static ushort product_5052[TI_EXTRA_VID_PID_COUNT];
224 static int product_5052_count;
225 
226 /* supported devices */
227 /* the array dimension is the number of default entries plus */
228 /* TI_EXTRA_VID_PID_COUNT user defined entries plus 1 terminating */
229 /* null entry */
230 static struct usb_device_id ti_id_table_3410[1+TI_EXTRA_VID_PID_COUNT+1] = {
231 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_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_5052_BOOT_PRODUCT_ID) },
244 	{ USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
245 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
246 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
247 	{ }
248 };
249 
250 static struct usb_driver ti_usb_driver = {
251 	.name			= "ti_usb_3410_5052",
252 	.probe			= usb_serial_probe,
253 	.disconnect		= usb_serial_disconnect,
254 	.id_table		= ti_id_table_combined,
255 	.no_dynamic_id = 	1,
256 };
257 
258 static struct usb_serial_driver ti_1port_device = {
259 	.driver = {
260 		.owner		= THIS_MODULE,
261 		.name		= "ti_usb_3410_5052_1",
262 	},
263 	.description		= "TI USB 3410 1 port adapter",
264 	.id_table		= ti_id_table_3410,
265 	.num_interrupt_in	= 1,
266 	.num_bulk_in		= 1,
267 	.num_bulk_out		= 1,
268 	.num_ports		= 1,
269 	.attach			= ti_startup,
270 	.shutdown		= ti_shutdown,
271 	.open			= ti_open,
272 	.close			= ti_close,
273 	.write			= ti_write,
274 	.write_room		= ti_write_room,
275 	.chars_in_buffer	= ti_chars_in_buffer,
276 	.throttle		= ti_throttle,
277 	.unthrottle		= ti_unthrottle,
278 	.ioctl			= ti_ioctl,
279 	.set_termios		= ti_set_termios,
280 	.tiocmget		= ti_tiocmget,
281 	.tiocmset		= ti_tiocmset,
282 	.break_ctl		= ti_break,
283 	.read_int_callback	= ti_interrupt_callback,
284 	.read_bulk_callback	= ti_bulk_in_callback,
285 	.write_bulk_callback	= ti_bulk_out_callback,
286 };
287 
288 static struct usb_serial_driver ti_2port_device = {
289 	.driver = {
290 		.owner		= THIS_MODULE,
291 		.name		= "ti_usb_3410_5052_2",
292 	},
293 	.description		= "TI USB 5052 2 port adapter",
294 	.id_table		= ti_id_table_5052,
295 	.num_interrupt_in	= 1,
296 	.num_bulk_in		= 2,
297 	.num_bulk_out		= 2,
298 	.num_ports		= 2,
299 	.attach			= ti_startup,
300 	.shutdown		= ti_shutdown,
301 	.open			= ti_open,
302 	.close			= ti_close,
303 	.write			= ti_write,
304 	.write_room		= ti_write_room,
305 	.chars_in_buffer	= ti_chars_in_buffer,
306 	.throttle		= ti_throttle,
307 	.unthrottle		= ti_unthrottle,
308 	.ioctl			= ti_ioctl,
309 	.set_termios		= ti_set_termios,
310 	.tiocmget		= ti_tiocmget,
311 	.tiocmset		= ti_tiocmset,
312 	.break_ctl		= ti_break,
313 	.read_int_callback	= ti_interrupt_callback,
314 	.read_bulk_callback	= ti_bulk_in_callback,
315 	.write_bulk_callback	= ti_bulk_out_callback,
316 };
317 
318 
319 /* Module */
320 
321 MODULE_AUTHOR(TI_DRIVER_AUTHOR);
322 MODULE_DESCRIPTION(TI_DRIVER_DESC);
323 MODULE_VERSION(TI_DRIVER_VERSION);
324 MODULE_LICENSE("GPL");
325 
326 module_param(debug, bool, S_IRUGO | S_IWUSR);
327 MODULE_PARM_DESC(debug, "Enable debugging, 0=no, 1=yes");
328 
329 module_param(low_latency, bool, S_IRUGO | S_IWUSR);
330 MODULE_PARM_DESC(low_latency, "TTY low_latency flag, 0=off, 1=on, default is off");
331 
332 module_param(closing_wait, int, S_IRUGO | S_IWUSR);
333 MODULE_PARM_DESC(closing_wait, "Maximum wait for data to drain in close, in .01 secs, default is 4000");
334 
335 module_param_array(vendor_3410, ushort, &vendor_3410_count, S_IRUGO);
336 MODULE_PARM_DESC(vendor_3410, "Vendor ids for 3410 based devices, 1-5 short integers");
337 module_param_array(product_3410, ushort, &product_3410_count, S_IRUGO);
338 MODULE_PARM_DESC(product_3410, "Product ids for 3410 based devices, 1-5 short integers");
339 module_param_array(vendor_5052, ushort, &vendor_5052_count, S_IRUGO);
340 MODULE_PARM_DESC(vendor_5052, "Vendor ids for 5052 based devices, 1-5 short integers");
341 module_param_array(product_5052, ushort, &product_5052_count, S_IRUGO);
342 MODULE_PARM_DESC(product_5052, "Product ids for 5052 based devices, 1-5 short integers");
343 
344 MODULE_DEVICE_TABLE(usb, ti_id_table_combined);
345 
346 
347 /* Functions */
348 
349 static int __init ti_init(void)
350 {
351 	int i,j;
352 	int ret;
353 
354 	/* insert extra vendor and product ids */
355 	j = ARRAY_SIZE(ti_id_table_3410) - TI_EXTRA_VID_PID_COUNT - 1;
356 	for (i=0; i<min(vendor_3410_count,product_3410_count); i++,j++) {
357 		ti_id_table_3410[j].idVendor = vendor_3410[i];
358 		ti_id_table_3410[j].idProduct = product_3410[i];
359 		ti_id_table_3410[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
360 	}
361 	j = ARRAY_SIZE(ti_id_table_5052) - TI_EXTRA_VID_PID_COUNT - 1;
362 	for (i=0; i<min(vendor_5052_count,product_5052_count); i++,j++) {
363 		ti_id_table_5052[j].idVendor = vendor_5052[i];
364 		ti_id_table_5052[j].idProduct = product_5052[i];
365 		ti_id_table_5052[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
366 	}
367 
368 	ret = usb_serial_register(&ti_1port_device);
369 	if (ret)
370 		goto failed_1port;
371 	ret = usb_serial_register(&ti_2port_device);
372 	if (ret)
373 		goto failed_2port;
374 
375 	ret = usb_register(&ti_usb_driver);
376 	if (ret)
377 		goto failed_usb;
378 
379 	info(TI_DRIVER_DESC " " TI_DRIVER_VERSION);
380 
381 	return 0;
382 
383 failed_usb:
384 	usb_serial_deregister(&ti_2port_device);
385 failed_2port:
386 	usb_serial_deregister(&ti_1port_device);
387 failed_1port:
388 	return ret;
389 }
390 
391 
392 static void __exit ti_exit(void)
393 {
394 	usb_serial_deregister(&ti_1port_device);
395 	usb_serial_deregister(&ti_2port_device);
396 	usb_deregister(&ti_usb_driver);
397 }
398 
399 
400 module_init(ti_init);
401 module_exit(ti_exit);
402 
403 
404 static int ti_startup(struct usb_serial *serial)
405 {
406 	struct ti_device *tdev;
407 	struct ti_port *tport;
408 	struct usb_device *dev = serial->dev;
409 	int status;
410 	int i;
411 
412 
413 	dbg("%s - product 0x%4X, num configurations %d, configuration value %d",
414 	    __FUNCTION__, le16_to_cpu(dev->descriptor.idProduct),
415 	    dev->descriptor.bNumConfigurations,
416 	    dev->actconfig->desc.bConfigurationValue);
417 
418 	/* create device structure */
419 	tdev = kmalloc(sizeof(struct ti_device), GFP_KERNEL);
420 	if (tdev == NULL) {
421 		dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
422 		return -ENOMEM;
423 	}
424 	memset(tdev, 0, sizeof(struct ti_device));
425 	sema_init(&tdev->td_open_close_sem, 1);
426 	tdev->td_serial = serial;
427 	usb_set_serial_data(serial, tdev);
428 
429 	/* determine device type */
430 	if (usb_match_id(serial->interface, ti_id_table_3410))
431 		tdev->td_is_3410 = 1;
432 	dbg("%s - device type is %s", __FUNCTION__, tdev->td_is_3410 ? "3410" : "5052");
433 
434 	/* if we have only 1 configuration, download firmware */
435 	if (dev->descriptor.bNumConfigurations == 1) {
436 
437 		if (tdev->td_is_3410)
438 			status = ti_download_firmware(tdev, ti_fw_3410,
439 				sizeof(ti_fw_3410));
440 		else
441 			status = ti_download_firmware(tdev, ti_fw_5052,
442 				sizeof(ti_fw_5052));
443 		if (status)
444 			goto free_tdev;
445 
446 		/* 3410 must be reset, 5052 resets itself */
447 		if (tdev->td_is_3410) {
448 			msleep_interruptible(100);
449 			usb_reset_device(dev);
450 		}
451 
452 		status = -ENODEV;
453 		goto free_tdev;
454 	}
455 
456 	/* the second configuration must be set (in sysfs by hotplug script) */
457 	if (dev->actconfig->desc.bConfigurationValue == TI_BOOT_CONFIG) {
458 		status = -ENODEV;
459 		goto free_tdev;
460 	}
461 
462 	/* set up port structures */
463 	for (i = 0; i < serial->num_ports; ++i) {
464 		tport = kmalloc(sizeof(struct ti_port), GFP_KERNEL);
465 		if (tport == NULL) {
466 			dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
467 			status = -ENOMEM;
468 			goto free_tports;
469 		}
470 		memset(tport, 0, sizeof(struct ti_port));
471 		spin_lock_init(&tport->tp_lock);
472 		tport->tp_uart_base_addr = (i == 0 ? TI_UART1_BASE_ADDR : TI_UART2_BASE_ADDR);
473 		tport->tp_flags = low_latency ? ASYNC_LOW_LATENCY : 0;
474 		tport->tp_closing_wait = closing_wait;
475 		init_waitqueue_head(&tport->tp_msr_wait);
476 		init_waitqueue_head(&tport->tp_write_wait);
477 		tport->tp_write_buf = ti_buf_alloc();
478 		if (tport->tp_write_buf == NULL) {
479 			dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
480 			kfree(tport);
481 			status = -ENOMEM;
482 			goto free_tports;
483 		}
484 		tport->tp_port = serial->port[i];
485 		tport->tp_tdev = tdev;
486 		usb_set_serial_port_data(serial->port[i], tport);
487 		tport->tp_uart_mode = 0;	/* default is RS232 */
488 	}
489 
490 	return 0;
491 
492 free_tports:
493 	for (--i; i>=0; --i) {
494 		tport = usb_get_serial_port_data(serial->port[i]);
495 		ti_buf_free(tport->tp_write_buf);
496 		kfree(tport);
497 		usb_set_serial_port_data(serial->port[i], NULL);
498 	}
499 free_tdev:
500 	kfree(tdev);
501 	usb_set_serial_data(serial, NULL);
502 	return status;
503 }
504 
505 
506 static void ti_shutdown(struct usb_serial *serial)
507 {
508 	int i;
509 	struct ti_device *tdev = usb_get_serial_data(serial);
510 	struct ti_port *tport;
511 
512 	dbg("%s", __FUNCTION__);
513 
514 	for (i=0; i < serial->num_ports; ++i) {
515 		tport = usb_get_serial_port_data(serial->port[i]);
516 		if (tport) {
517 			ti_buf_free(tport->tp_write_buf);
518 			kfree(tport);
519 			usb_set_serial_port_data(serial->port[i], NULL);
520 		}
521 	}
522 
523 	kfree(tdev);
524 	usb_set_serial_data(serial, NULL);
525 }
526 
527 
528 static int ti_open(struct usb_serial_port *port, struct file *file)
529 {
530 	struct ti_port *tport = usb_get_serial_port_data(port);
531 	struct ti_device *tdev;
532 	struct usb_device *dev;
533 	struct urb *urb;
534 	int port_number;
535 	int status;
536 	__u16 open_settings = (__u8)(TI_PIPE_MODE_CONTINOUS |
537 			     TI_PIPE_TIMEOUT_ENABLE |
538 			     (TI_TRANSFER_TIMEOUT << 2));
539 
540 	dbg("%s - port %d", __FUNCTION__, port->number);
541 
542 	if (tport == NULL)
543 		return -ENODEV;
544 
545 	dev = port->serial->dev;
546 	tdev = tport->tp_tdev;
547 
548 	/* only one open on any port on a device at a time */
549 	if (down_interruptible(&tdev->td_open_close_sem))
550 		return -ERESTARTSYS;
551 
552 	if (port->tty)
553 		port->tty->low_latency =
554 			(tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
555 
556 	port_number = port->number - port->serial->minor;
557 
558 	memset(&(tport->tp_icount), 0x00, sizeof(tport->tp_icount));
559 
560 	tport->tp_msr = 0;
561 	tport->tp_shadow_mcr |= (TI_MCR_RTS | TI_MCR_DTR);
562 
563 	/* start interrupt urb the first time a port is opened on this device */
564 	if (tdev->td_open_port_count == 0) {
565 		dbg("%s - start interrupt in urb", __FUNCTION__);
566 		urb = tdev->td_serial->port[0]->interrupt_in_urb;
567 		if (!urb) {
568 			dev_err(&port->dev, "%s - no interrupt urb\n", __FUNCTION__);
569 			status = -EINVAL;
570 			goto up_sem;
571 		}
572 		urb->complete = ti_interrupt_callback;
573 		urb->context = tdev;
574 		urb->dev = dev;
575 		status = usb_submit_urb(urb, GFP_KERNEL);
576 		if (status) {
577 			dev_err(&port->dev, "%s - submit interrupt urb failed, %d\n", __FUNCTION__, status);
578 			goto up_sem;
579 		}
580 	}
581 
582 	ti_set_termios(port, NULL);
583 
584 	dbg("%s - sending TI_OPEN_PORT", __FUNCTION__);
585 	status = ti_command_out_sync(tdev, TI_OPEN_PORT,
586 		(__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
587 	if (status) {
588 		dev_err(&port->dev, "%s - cannot send open command, %d\n", __FUNCTION__, status);
589 		goto unlink_int_urb;
590 	}
591 
592 	dbg("%s - sending TI_START_PORT", __FUNCTION__);
593 	status = ti_command_out_sync(tdev, TI_START_PORT,
594 		(__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
595 	if (status) {
596 		dev_err(&port->dev, "%s - cannot send start command, %d\n", __FUNCTION__, status);
597 		goto unlink_int_urb;
598 	}
599 
600 	dbg("%s - sending TI_PURGE_PORT", __FUNCTION__);
601 	status = ti_command_out_sync(tdev, TI_PURGE_PORT,
602 		(__u8)(TI_UART1_PORT + port_number), TI_PURGE_INPUT, NULL, 0);
603 	if (status) {
604 		dev_err(&port->dev, "%s - cannot clear input buffers, %d\n", __FUNCTION__, status);
605 		goto unlink_int_urb;
606 	}
607 	status = ti_command_out_sync(tdev, TI_PURGE_PORT,
608 		(__u8)(TI_UART1_PORT + port_number), TI_PURGE_OUTPUT, NULL, 0);
609 	if (status) {
610 		dev_err(&port->dev, "%s - cannot clear output buffers, %d\n", __FUNCTION__, status);
611 		goto unlink_int_urb;
612 	}
613 
614 	/* reset the data toggle on the bulk endpoints to work around bug in
615 	 * host controllers where things get out of sync some times */
616 	usb_clear_halt(dev, port->write_urb->pipe);
617 	usb_clear_halt(dev, port->read_urb->pipe);
618 
619 	ti_set_termios(port, NULL);
620 
621 	dbg("%s - sending TI_OPEN_PORT (2)", __FUNCTION__);
622 	status = ti_command_out_sync(tdev, TI_OPEN_PORT,
623 		(__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
624 	if (status) {
625 		dev_err(&port->dev, "%s - cannot send open command (2), %d\n", __FUNCTION__, status);
626 		goto unlink_int_urb;
627 	}
628 
629 	dbg("%s - sending TI_START_PORT (2)", __FUNCTION__);
630 	status = ti_command_out_sync(tdev, TI_START_PORT,
631 		(__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
632 	if (status) {
633 		dev_err(&port->dev, "%s - cannot send start command (2), %d\n", __FUNCTION__, status);
634 		goto unlink_int_urb;
635 	}
636 
637 	/* start read urb */
638 	dbg("%s - start read urb", __FUNCTION__);
639 	urb = port->read_urb;
640 	if (!urb) {
641 		dev_err(&port->dev, "%s - no read urb\n", __FUNCTION__);
642 		status = -EINVAL;
643 		goto unlink_int_urb;
644 	}
645 	tport->tp_read_urb_state = TI_READ_URB_RUNNING;
646 	urb->complete = ti_bulk_in_callback;
647 	urb->context = tport;
648 	urb->dev = dev;
649 	status = usb_submit_urb(urb, GFP_KERNEL);
650 	if (status) {
651 		dev_err(&port->dev, "%s - submit read urb failed, %d\n", __FUNCTION__, status);
652 		goto unlink_int_urb;
653 	}
654 
655 	tport->tp_is_open = 1;
656 	++tdev->td_open_port_count;
657 
658 	goto up_sem;
659 
660 unlink_int_urb:
661 	if (tdev->td_open_port_count == 0)
662 		usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
663 up_sem:
664 	up(&tdev->td_open_close_sem);
665 	dbg("%s - exit %d", __FUNCTION__, status);
666 	return status;
667 }
668 
669 
670 static void ti_close(struct usb_serial_port *port, struct file *file)
671 {
672 	struct ti_device *tdev;
673 	struct ti_port *tport;
674 	int port_number;
675 	int status;
676 	int do_up;
677 
678 	dbg("%s - port %d", __FUNCTION__, port->number);
679 
680 	tdev = usb_get_serial_data(port->serial);
681 	tport = usb_get_serial_port_data(port);
682 	if (tdev == NULL || tport == NULL)
683 		return;
684 
685 	tport->tp_is_open = 0;
686 
687 	ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 1);
688 
689 	usb_kill_urb(port->read_urb);
690 	usb_kill_urb(port->write_urb);
691 	tport->tp_write_urb_in_use = 0;
692 
693 	port_number = port->number - port->serial->minor;
694 
695 	dbg("%s - sending TI_CLOSE_PORT", __FUNCTION__);
696 	status = ti_command_out_sync(tdev, TI_CLOSE_PORT,
697 		     (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
698 	if (status)
699 		dev_err(&port->dev, "%s - cannot send close port command, %d\n" , __FUNCTION__, status);
700 
701 	/* if down is interrupted, continue anyway */
702 	do_up = !down_interruptible(&tdev->td_open_close_sem);
703 	--tport->tp_tdev->td_open_port_count;
704 	if (tport->tp_tdev->td_open_port_count <= 0) {
705 		/* last port is closed, shut down interrupt urb */
706 		usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
707 		tport->tp_tdev->td_open_port_count = 0;
708 	}
709 	if (do_up)
710 		up(&tdev->td_open_close_sem);
711 
712 	dbg("%s - exit", __FUNCTION__);
713 }
714 
715 
716 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
717 	int count)
718 {
719 	struct ti_port *tport = usb_get_serial_port_data(port);
720 	unsigned long flags;
721 
722 	dbg("%s - port %d", __FUNCTION__, port->number);
723 
724 	if (count == 0) {
725 		dbg("%s - write request of 0 bytes", __FUNCTION__);
726 		return 0;
727 	}
728 
729 	if (tport == NULL || !tport->tp_is_open)
730 		return -ENODEV;
731 
732 	spin_lock_irqsave(&tport->tp_lock, flags);
733 	count = ti_buf_put(tport->tp_write_buf, data, count);
734 	spin_unlock_irqrestore(&tport->tp_lock, flags);
735 
736 	ti_send(tport);
737 
738 	return count;
739 }
740 
741 
742 static int ti_write_room(struct usb_serial_port *port)
743 {
744 	struct ti_port *tport = usb_get_serial_port_data(port);
745 	int room = 0;
746 	unsigned long flags;
747 
748 	dbg("%s - port %d", __FUNCTION__, port->number);
749 
750 	if (tport == NULL)
751 		return -ENODEV;
752 
753 	spin_lock_irqsave(&tport->tp_lock, flags);
754 	room = ti_buf_space_avail(tport->tp_write_buf);
755 	spin_unlock_irqrestore(&tport->tp_lock, flags);
756 
757 	dbg("%s - returns %d", __FUNCTION__, room);
758 	return room;
759 }
760 
761 
762 static int ti_chars_in_buffer(struct usb_serial_port *port)
763 {
764 	struct ti_port *tport = usb_get_serial_port_data(port);
765 	int chars = 0;
766 	unsigned long flags;
767 
768 	dbg("%s - port %d", __FUNCTION__, port->number);
769 
770 	if (tport == NULL)
771 		return -ENODEV;
772 
773 	spin_lock_irqsave(&tport->tp_lock, flags);
774 	chars = ti_buf_data_avail(tport->tp_write_buf);
775 	spin_unlock_irqrestore(&tport->tp_lock, flags);
776 
777 	dbg("%s - returns %d", __FUNCTION__, chars);
778 	return chars;
779 }
780 
781 
782 static void ti_throttle(struct usb_serial_port *port)
783 {
784 	struct ti_port *tport = usb_get_serial_port_data(port);
785 	struct tty_struct *tty;
786 
787 	dbg("%s - port %d", __FUNCTION__, port->number);
788 
789 	if (tport == NULL)
790 		return;
791 
792 	tty = port->tty;
793 	if (!tty) {
794 		dbg("%s - no tty", __FUNCTION__);
795 		return;
796 	}
797 
798 	if (I_IXOFF(tty) || C_CRTSCTS(tty))
799 		ti_stop_read(tport, tty);
800 
801 }
802 
803 
804 static void ti_unthrottle(struct usb_serial_port *port)
805 {
806 	struct ti_port *tport = usb_get_serial_port_data(port);
807 	struct tty_struct *tty;
808 	int status;
809 
810 	dbg("%s - port %d", __FUNCTION__, port->number);
811 
812 	if (tport == NULL)
813 		return;
814 
815 	tty = port->tty;
816 	if (!tty) {
817 		dbg("%s - no tty", __FUNCTION__);
818 		return;
819 	}
820 
821 	if (I_IXOFF(tty) || C_CRTSCTS(tty)) {
822 		status = ti_restart_read(tport, tty);
823 		if (status)
824 			dev_err(&port->dev, "%s - cannot restart read, %d\n", __FUNCTION__, status);
825 	}
826 }
827 
828 
829 static int ti_ioctl(struct usb_serial_port *port, struct file *file,
830 	unsigned int cmd, unsigned long arg)
831 {
832 	struct ti_port *tport = usb_get_serial_port_data(port);
833 	struct async_icount cnow;
834 	struct async_icount cprev;
835 
836 	dbg("%s - port %d, cmd = 0x%04X", __FUNCTION__, port->number, cmd);
837 
838 	if (tport == NULL)
839 		return -ENODEV;
840 
841 	switch (cmd) {
842 		case TIOCGSERIAL:
843 			dbg("%s - (%d) TIOCGSERIAL", __FUNCTION__, port->number);
844 			return ti_get_serial_info(tport, (struct serial_struct __user *)arg);
845 			break;
846 
847 		case TIOCSSERIAL:
848 			dbg("%s - (%d) TIOCSSERIAL", __FUNCTION__, port->number);
849 			return ti_set_serial_info(tport, (struct serial_struct __user *)arg);
850 			break;
851 
852 		case TIOCMIWAIT:
853 			dbg("%s - (%d) TIOCMIWAIT", __FUNCTION__, port->number);
854 			cprev = tport->tp_icount;
855 			while (1) {
856 				interruptible_sleep_on(&tport->tp_msr_wait);
857 				if (signal_pending(current))
858 					return -ERESTARTSYS;
859 				cnow = tport->tp_icount;
860 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
861 				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
862 					return -EIO; /* no change => error */
863 				if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
864 				    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
865 				    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
866 				    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
867 					return 0;
868 				}
869 				cprev = cnow;
870 			}
871 			break;
872 
873 		case TIOCGICOUNT:
874 			dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d", __FUNCTION__, port->number, tport->tp_icount.rx, tport->tp_icount.tx);
875 			if (copy_to_user((void __user *)arg, &tport->tp_icount, sizeof(tport->tp_icount)))
876 				return -EFAULT;
877 			return 0;
878 	}
879 
880 	return -ENOIOCTLCMD;
881 }
882 
883 
884 static void ti_set_termios(struct usb_serial_port *port,
885 	struct termios *old_termios)
886 {
887 	struct ti_port *tport = usb_get_serial_port_data(port);
888 	struct tty_struct *tty = port->tty;
889 	struct ti_uart_config *config;
890 	tcflag_t cflag,iflag;
891 	int baud;
892 	int status;
893 	int port_number = port->number - port->serial->minor;
894 	unsigned int mcr;
895 
896 	dbg("%s - port %d", __FUNCTION__, port->number);
897 
898 	if (!tty || !tty->termios) {
899 		dbg("%s - no tty or termios", __FUNCTION__);
900 		return;
901 	}
902 
903 	cflag = tty->termios->c_cflag;
904 	iflag = tty->termios->c_iflag;
905 
906 	if (old_termios && cflag == old_termios->c_cflag
907 	&& iflag == old_termios->c_iflag) {
908 		dbg("%s - nothing to change", __FUNCTION__);
909 		return;
910 	}
911 
912 	dbg("%s - clfag %08x, iflag %08x", __FUNCTION__, cflag, iflag);
913 
914 	if (old_termios)
915 		dbg("%s - old clfag %08x, old iflag %08x", __FUNCTION__, old_termios->c_cflag, old_termios->c_iflag);
916 
917 	if (tport == NULL)
918 		return;
919 
920 	config = kmalloc(sizeof(*config), GFP_KERNEL);
921 	if (!config) {
922 		dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
923 		return;
924 	}
925 
926 	config->wFlags = 0;
927 
928 	/* these flags must be set */
929 	config->wFlags |= TI_UART_ENABLE_MS_INTS;
930 	config->wFlags |= TI_UART_ENABLE_AUTO_START_DMA;
931 	config->bUartMode = (__u8)(tport->tp_uart_mode);
932 
933 	switch (cflag & CSIZE) {
934 		case CS5:
935 			    config->bDataBits = TI_UART_5_DATA_BITS;
936 			    break;
937 		case CS6:
938 			    config->bDataBits = TI_UART_6_DATA_BITS;
939 			    break;
940 		case CS7:
941 			    config->bDataBits = TI_UART_7_DATA_BITS;
942 			    break;
943 		default:
944 		case CS8:
945 			    config->bDataBits = TI_UART_8_DATA_BITS;
946 			    break;
947 	}
948 
949 	if (cflag & PARENB) {
950 		if (cflag & PARODD) {
951 			config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
952 			config->bParity = TI_UART_ODD_PARITY;
953 		} else {
954 			config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
955 			config->bParity = TI_UART_EVEN_PARITY;
956 		}
957 	} else {
958 		config->wFlags &= ~TI_UART_ENABLE_PARITY_CHECKING;
959 		config->bParity = TI_UART_NO_PARITY;
960 	}
961 
962 	if (cflag & CSTOPB)
963 		config->bStopBits = TI_UART_2_STOP_BITS;
964 	else
965 		config->bStopBits = TI_UART_1_STOP_BITS;
966 
967 	if (cflag & CRTSCTS) {
968 		/* RTS flow control must be off to drop RTS for baud rate B0 */
969 		if ((cflag & CBAUD) != B0)
970 			config->wFlags |= TI_UART_ENABLE_RTS_IN;
971 		config->wFlags |= TI_UART_ENABLE_CTS_OUT;
972 	} else {
973 		tty->hw_stopped = 0;
974 		ti_restart_read(tport, tty);
975 	}
976 
977 	if (I_IXOFF(tty) || I_IXON(tty)) {
978 		config->cXon  = START_CHAR(tty);
979 		config->cXoff = STOP_CHAR(tty);
980 
981 		if (I_IXOFF(tty))
982 			config->wFlags |= TI_UART_ENABLE_X_IN;
983 		else
984 			ti_restart_read(tport, tty);
985 
986 		if (I_IXON(tty))
987 			config->wFlags |= TI_UART_ENABLE_X_OUT;
988 	}
989 
990 	baud = tty_get_baud_rate(tty);
991 	if (!baud) baud = 9600;
992 	if (tport->tp_tdev->td_is_3410)
993 		config->wBaudRate = (__u16)((923077 + baud/2) / baud);
994 	else
995 		config->wBaudRate = (__u16)((461538 + baud/2) / baud);
996 
997 	dbg("%s - BaudRate=%d, wBaudRate=%d, wFlags=0x%04X, bDataBits=%d, bParity=%d, bStopBits=%d, cXon=%d, cXoff=%d, bUartMode=%d",
998 	__FUNCTION__, baud, config->wBaudRate, config->wFlags, config->bDataBits, config->bParity, config->bStopBits, config->cXon, config->cXoff, config->bUartMode);
999 
1000 	cpu_to_be16s(&config->wBaudRate);
1001 	cpu_to_be16s(&config->wFlags);
1002 
1003 	status = ti_command_out_sync(tport->tp_tdev, TI_SET_CONFIG,
1004 		(__u8)(TI_UART1_PORT + port_number), 0, (__u8 *)config,
1005 		sizeof(*config));
1006 	if (status)
1007 		dev_err(&port->dev, "%s - cannot set config on port %d, %d\n", __FUNCTION__, port_number, status);
1008 
1009 	/* SET_CONFIG asserts RTS and DTR, reset them correctly */
1010 	mcr = tport->tp_shadow_mcr;
1011 	/* if baud rate is B0, clear RTS and DTR */
1012 	if ((cflag & CBAUD) == B0)
1013 		mcr &= ~(TI_MCR_DTR | TI_MCR_RTS);
1014 	status = ti_set_mcr(tport, mcr);
1015 	if (status)
1016 		dev_err(&port->dev, "%s - cannot set modem control on port %d, %d\n", __FUNCTION__, port_number, status);
1017 
1018 	kfree(config);
1019 }
1020 
1021 
1022 static int ti_tiocmget(struct usb_serial_port *port, struct file *file)
1023 {
1024 	struct ti_port *tport = usb_get_serial_port_data(port);
1025 	unsigned int result;
1026 	unsigned int msr;
1027 	unsigned int mcr;
1028 
1029 	dbg("%s - port %d", __FUNCTION__, port->number);
1030 
1031 	if (tport == NULL)
1032 		return -ENODEV;
1033 
1034 	msr = tport->tp_msr;
1035 	mcr = tport->tp_shadow_mcr;
1036 
1037 	result = ((mcr & TI_MCR_DTR) ? TIOCM_DTR : 0)
1038 		| ((mcr & TI_MCR_RTS) ? TIOCM_RTS : 0)
1039 		| ((mcr & TI_MCR_LOOP) ? TIOCM_LOOP : 0)
1040 		| ((msr & TI_MSR_CTS) ? TIOCM_CTS : 0)
1041 		| ((msr & TI_MSR_CD) ? TIOCM_CAR : 0)
1042 		| ((msr & TI_MSR_RI) ? TIOCM_RI : 0)
1043 		| ((msr & TI_MSR_DSR) ? TIOCM_DSR : 0);
1044 
1045 	dbg("%s - 0x%04X", __FUNCTION__, result);
1046 
1047 	return result;
1048 }
1049 
1050 
1051 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
1052 	unsigned int set, unsigned int clear)
1053 {
1054 	struct ti_port *tport = usb_get_serial_port_data(port);
1055 	unsigned int mcr;
1056 
1057 	dbg("%s - port %d", __FUNCTION__, port->number);
1058 
1059 	if (tport == NULL)
1060 		return -ENODEV;
1061 
1062 	mcr = tport->tp_shadow_mcr;
1063 
1064 	if (set & TIOCM_RTS)
1065 		mcr |= TI_MCR_RTS;
1066 	if (set & TIOCM_DTR)
1067 		mcr |= TI_MCR_DTR;
1068 	if (set & TIOCM_LOOP)
1069 		mcr |= TI_MCR_LOOP;
1070 
1071 	if (clear & TIOCM_RTS)
1072 		mcr &= ~TI_MCR_RTS;
1073 	if (clear & TIOCM_DTR)
1074 		mcr &= ~TI_MCR_DTR;
1075 	if (clear & TIOCM_LOOP)
1076 		mcr &= ~TI_MCR_LOOP;
1077 
1078 	return ti_set_mcr(tport, mcr);
1079 }
1080 
1081 
1082 static void ti_break(struct usb_serial_port *port, int break_state)
1083 {
1084 	struct ti_port *tport = usb_get_serial_port_data(port);
1085 	int status;
1086 
1087 	dbg("%s - state = %d", __FUNCTION__, break_state);
1088 
1089 	if (tport == NULL)
1090 		return;
1091 
1092 	ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 0);
1093 
1094 	status = ti_write_byte(tport->tp_tdev,
1095 		tport->tp_uart_base_addr + TI_UART_OFFSET_LCR,
1096 		TI_LCR_BREAK, break_state == -1 ? TI_LCR_BREAK : 0);
1097 
1098 	if (status)
1099 		dbg("%s - error setting break, %d", __FUNCTION__, status);
1100 }
1101 
1102 
1103 static void ti_interrupt_callback(struct urb *urb, struct pt_regs *regs)
1104 {
1105 	struct ti_device *tdev = (struct ti_device *)urb->context;
1106 	struct usb_serial_port *port;
1107 	struct usb_serial *serial = tdev->td_serial;
1108 	struct ti_port *tport;
1109 	struct device *dev = &urb->dev->dev;
1110 	unsigned char *data = urb->transfer_buffer;
1111 	int length = urb->actual_length;
1112 	int port_number;
1113 	int function;
1114 	int status;
1115 	__u8 msr;
1116 
1117 	dbg("%s", __FUNCTION__);
1118 
1119 	switch (urb->status) {
1120 	case 0:
1121 		break;
1122 	case -ECONNRESET:
1123 	case -ENOENT:
1124 	case -ESHUTDOWN:
1125 		dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1126 		tdev->td_urb_error = 1;
1127 		return;
1128 	default:
1129 		dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status);
1130 		tdev->td_urb_error = 1;
1131 		goto exit;
1132 	}
1133 
1134 	if (length != 2) {
1135 		dbg("%s - bad packet size, %d", __FUNCTION__, length);
1136 		goto exit;
1137 	}
1138 
1139 	if (data[0] == TI_CODE_HARDWARE_ERROR) {
1140 		dev_err(dev, "%s - hardware error, %d\n", __FUNCTION__, data[1]);
1141 		goto exit;
1142 	}
1143 
1144 	port_number = TI_GET_PORT_FROM_CODE(data[0]);
1145 	function = TI_GET_FUNC_FROM_CODE(data[0]);
1146 
1147 	dbg("%s - port_number %d, function %d, data 0x%02X", __FUNCTION__, port_number, function, data[1]);
1148 
1149 	if (port_number >= serial->num_ports) {
1150 		dev_err(dev, "%s - bad port number, %d\n", __FUNCTION__, port_number);
1151 		goto exit;
1152 	}
1153 
1154 	port = serial->port[port_number];
1155 
1156 	tport = usb_get_serial_port_data(port);
1157 	if (!tport)
1158 		goto exit;
1159 
1160 	switch (function) {
1161 	case TI_CODE_DATA_ERROR:
1162 		dev_err(dev, "%s - DATA ERROR, port %d, data 0x%02X\n", __FUNCTION__, port_number, data[1]);
1163 		break;
1164 
1165 	case TI_CODE_MODEM_STATUS:
1166 		msr = data[1];
1167 		dbg("%s - port %d, msr 0x%02X", __FUNCTION__, port_number, msr);
1168 		ti_handle_new_msr(tport, msr);
1169 		break;
1170 
1171 	default:
1172 		dev_err(dev, "%s - unknown interrupt code, 0x%02X\n", __FUNCTION__, data[1]);
1173 		break;
1174 	}
1175 
1176 exit:
1177 	status = usb_submit_urb(urb, GFP_ATOMIC);
1178 	if (status)
1179 		dev_err(dev, "%s - resubmit interrupt urb failed, %d\n", __FUNCTION__, status);
1180 }
1181 
1182 
1183 static void ti_bulk_in_callback(struct urb *urb, struct pt_regs *regs)
1184 {
1185 	struct ti_port *tport = (struct ti_port *)urb->context;
1186 	struct usb_serial_port *port = tport->tp_port;
1187 	struct device *dev = &urb->dev->dev;
1188 	int status = 0;
1189 
1190 	dbg("%s", __FUNCTION__);
1191 
1192 	switch (urb->status) {
1193 	case 0:
1194 		break;
1195 	case -ECONNRESET:
1196 	case -ENOENT:
1197 	case -ESHUTDOWN:
1198 		dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1199 		tport->tp_tdev->td_urb_error = 1;
1200 		wake_up_interruptible(&tport->tp_write_wait);
1201 		return;
1202 	default:
1203 		dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status );
1204 		tport->tp_tdev->td_urb_error = 1;
1205 		wake_up_interruptible(&tport->tp_write_wait);
1206 	}
1207 
1208 	if (urb->status == -EPIPE)
1209 		goto exit;
1210 
1211 	if (urb->status) {
1212 		dev_err(dev, "%s - stopping read!\n", __FUNCTION__);
1213 		return;
1214 	}
1215 
1216 	if (port->tty && urb->actual_length) {
1217 		usb_serial_debug_data(debug, dev, __FUNCTION__,
1218 			urb->actual_length, urb->transfer_buffer);
1219 
1220 		if (!tport->tp_is_open)
1221 			dbg("%s - port closed, dropping data", __FUNCTION__);
1222 		else
1223 			ti_recv(&urb->dev->dev, port->tty, urb->transfer_buffer,
1224 				urb->actual_length);
1225 
1226 		spin_lock(&tport->tp_lock);
1227 		tport->tp_icount.rx += urb->actual_length;
1228 		spin_unlock(&tport->tp_lock);
1229 	}
1230 
1231 exit:
1232 	/* continue to read unless stopping */
1233 	spin_lock(&tport->tp_lock);
1234 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING) {
1235 		urb->dev = port->serial->dev;
1236 		status = usb_submit_urb(urb, GFP_ATOMIC);
1237 	} else if (tport->tp_read_urb_state == TI_READ_URB_STOPPING) {
1238 		tport->tp_read_urb_state = TI_READ_URB_STOPPED;
1239 	}
1240 	spin_unlock(&tport->tp_lock);
1241 	if (status)
1242 		dev_err(dev, "%s - resubmit read urb failed, %d\n", __FUNCTION__, status);
1243 }
1244 
1245 
1246 static void ti_bulk_out_callback(struct urb *urb, struct pt_regs *regs)
1247 {
1248 	struct ti_port *tport = (struct ti_port *)urb->context;
1249 	struct usb_serial_port *port = tport->tp_port;
1250 	struct device *dev = &urb->dev->dev;
1251 
1252 	dbg("%s - port %d", __FUNCTION__, port->number);
1253 
1254 	tport->tp_write_urb_in_use = 0;
1255 
1256 	switch (urb->status) {
1257 	case 0:
1258 		break;
1259 	case -ECONNRESET:
1260 	case -ENOENT:
1261 	case -ESHUTDOWN:
1262 		dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1263 		tport->tp_tdev->td_urb_error = 1;
1264 		wake_up_interruptible(&tport->tp_write_wait);
1265 		return;
1266 	default:
1267 		dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status);
1268 		tport->tp_tdev->td_urb_error = 1;
1269 		wake_up_interruptible(&tport->tp_write_wait);
1270 	}
1271 
1272 	/* send any buffered data */
1273 	ti_send(tport);
1274 }
1275 
1276 
1277 static void ti_recv(struct device *dev, struct tty_struct *tty,
1278 	unsigned char *data, int length)
1279 {
1280 	int cnt;
1281 
1282 	do {
1283 		if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
1284 			tty_flip_buffer_push(tty);
1285 			if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
1286 				dev_err(dev, "%s - dropping data, %d bytes lost\n", __FUNCTION__, length);
1287 				return;
1288 			}
1289 		}
1290 		cnt = min(length, TTY_FLIPBUF_SIZE - tty->flip.count);
1291 		memcpy(tty->flip.char_buf_ptr, data, cnt);
1292 		memset(tty->flip.flag_buf_ptr, 0, cnt);
1293 		tty->flip.char_buf_ptr += cnt;
1294 		tty->flip.flag_buf_ptr += cnt;
1295 		tty->flip.count += cnt;
1296 		data += cnt;
1297 		length -= cnt;
1298 	} while (length > 0);
1299 
1300 	tty_flip_buffer_push(tty);
1301 }
1302 
1303 
1304 static void ti_send(struct ti_port *tport)
1305 {
1306 	int count, result;
1307 	struct usb_serial_port *port = tport->tp_port;
1308 	struct tty_struct *tty = port->tty;
1309 	unsigned long flags;
1310 
1311 
1312 	dbg("%s - port %d", __FUNCTION__, port->number);
1313 
1314 	spin_lock_irqsave(&tport->tp_lock, flags);
1315 
1316 	if (tport->tp_write_urb_in_use) {
1317 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1318 		return;
1319 	}
1320 
1321 	count = ti_buf_get(tport->tp_write_buf,
1322 				port->write_urb->transfer_buffer,
1323 				port->bulk_out_size);
1324 
1325 	if (count == 0) {
1326 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1327 		return;
1328 	}
1329 
1330 	tport->tp_write_urb_in_use = 1;
1331 
1332 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1333 
1334 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, port->write_urb->transfer_buffer);
1335 
1336 	usb_fill_bulk_urb(port->write_urb, port->serial->dev,
1337 			   usb_sndbulkpipe(port->serial->dev,
1338 					    port->bulk_out_endpointAddress),
1339 			   port->write_urb->transfer_buffer, count,
1340 			   ti_bulk_out_callback, tport);
1341 
1342 	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1343 	if (result) {
1344 		dev_err(&port->dev, "%s - submit write urb failed, %d\n", __FUNCTION__, result);
1345 		tport->tp_write_urb_in_use = 0;
1346 		/* TODO: reschedule ti_send */
1347 	} else {
1348 		spin_lock_irqsave(&tport->tp_lock, flags);
1349 		tport->tp_icount.tx += count;
1350 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1351 	}
1352 
1353 	/* more room in the buffer for new writes, wakeup */
1354 	if (tty)
1355 		tty_wakeup(tty);
1356 	wake_up_interruptible(&tport->tp_write_wait);
1357 }
1358 
1359 
1360 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr)
1361 {
1362 	int status;
1363 
1364 	status = ti_write_byte(tport->tp_tdev,
1365 		tport->tp_uart_base_addr + TI_UART_OFFSET_MCR,
1366 		TI_MCR_RTS | TI_MCR_DTR | TI_MCR_LOOP, mcr);
1367 
1368 	if (!status)
1369 		tport->tp_shadow_mcr = mcr;
1370 
1371 	return status;
1372 }
1373 
1374 
1375 static int ti_get_lsr(struct ti_port *tport)
1376 {
1377 	int size,status;
1378 	struct ti_device *tdev = tport->tp_tdev;
1379 	struct usb_serial_port *port = tport->tp_port;
1380 	int port_number = port->number - port->serial->minor;
1381 	struct ti_port_status *data;
1382 
1383 	dbg("%s - port %d", __FUNCTION__, port->number);
1384 
1385 	size = sizeof(struct ti_port_status);
1386 	data = kmalloc(size, GFP_KERNEL);
1387 	if (!data) {
1388 		dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
1389 		return -ENOMEM;
1390 	}
1391 
1392 	status = ti_command_in_sync(tdev, TI_GET_PORT_STATUS,
1393 		(__u8)(TI_UART1_PORT+port_number), 0, (__u8 *)data, size);
1394 	if (status) {
1395 		dev_err(&port->dev, "%s - get port status command failed, %d\n", __FUNCTION__, status);
1396 		goto free_data;
1397 	}
1398 
1399 	dbg("%s - lsr 0x%02X", __FUNCTION__, data->bLSR);
1400 
1401 	tport->tp_lsr = data->bLSR;
1402 
1403 free_data:
1404 	kfree(data);
1405 	return status;
1406 }
1407 
1408 
1409 static int ti_get_serial_info(struct ti_port *tport,
1410 	struct serial_struct __user *ret_arg)
1411 {
1412 	struct usb_serial_port *port = tport->tp_port;
1413 	struct serial_struct ret_serial;
1414 
1415 	if (!ret_arg)
1416 		return -EFAULT;
1417 
1418 	memset(&ret_serial, 0, sizeof(ret_serial));
1419 
1420 	ret_serial.type = PORT_16550A;
1421 	ret_serial.line = port->serial->minor;
1422 	ret_serial.port = port->number - port->serial->minor;
1423 	ret_serial.flags = tport->tp_flags;
1424 	ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
1425 	ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
1426 	ret_serial.closing_wait = tport->tp_closing_wait;
1427 
1428 	if (copy_to_user(ret_arg, &ret_serial, sizeof(*ret_arg)))
1429 		return -EFAULT;
1430 
1431 	return 0;
1432 }
1433 
1434 
1435 static int ti_set_serial_info(struct ti_port *tport,
1436 	struct serial_struct __user *new_arg)
1437 {
1438 	struct usb_serial_port *port = tport->tp_port;
1439 	struct serial_struct new_serial;
1440 
1441 	if (copy_from_user(&new_serial, new_arg, sizeof(new_serial)))
1442 		return -EFAULT;
1443 
1444 	tport->tp_flags = new_serial.flags & TI_SET_SERIAL_FLAGS;
1445 	if (port->tty)
1446 		port->tty->low_latency =
1447 			(tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1448 	tport->tp_closing_wait = new_serial.closing_wait;
1449 
1450 	return 0;
1451 }
1452 
1453 
1454 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr)
1455 {
1456 	struct async_icount *icount;
1457 	struct tty_struct *tty;
1458 	unsigned long flags;
1459 
1460 	dbg("%s - msr 0x%02X", __FUNCTION__, msr);
1461 
1462 	if (msr & TI_MSR_DELTA_MASK) {
1463 		spin_lock_irqsave(&tport->tp_lock, flags);
1464 		icount = &tport->tp_icount;
1465 		if (msr & TI_MSR_DELTA_CTS)
1466 			icount->cts++;
1467 		if (msr & TI_MSR_DELTA_DSR)
1468 			icount->dsr++;
1469 		if (msr & TI_MSR_DELTA_CD)
1470 			icount->dcd++;
1471 		if (msr & TI_MSR_DELTA_RI)
1472 			icount->rng++;
1473 		wake_up_interruptible(&tport->tp_msr_wait);
1474 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1475 	}
1476 
1477 	tport->tp_msr = msr & TI_MSR_MASK;
1478 
1479 	/* handle CTS flow control */
1480 	tty = tport->tp_port->tty;
1481 	if (tty && C_CRTSCTS(tty)) {
1482 		if (msr & TI_MSR_CTS) {
1483 			tty->hw_stopped = 0;
1484 			tty_wakeup(tty);
1485 		} else {
1486 			tty->hw_stopped = 1;
1487 		}
1488 	}
1489 }
1490 
1491 
1492 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
1493 {
1494 	struct ti_device *tdev = tport->tp_tdev;
1495 	struct usb_serial_port *port = tport->tp_port;
1496 	wait_queue_t wait;
1497 	unsigned long flags;
1498 
1499 	dbg("%s - port %d", __FUNCTION__, port->number);
1500 
1501 	spin_lock_irqsave(&tport->tp_lock, flags);
1502 
1503 	/* wait for data to drain from the buffer */
1504 	tdev->td_urb_error = 0;
1505 	init_waitqueue_entry(&wait, current);
1506 	add_wait_queue(&tport->tp_write_wait, &wait);
1507 	for (;;) {
1508 		set_current_state(TASK_INTERRUPTIBLE);
1509 		if (ti_buf_data_avail(tport->tp_write_buf) == 0
1510 		|| timeout == 0 || signal_pending(current)
1511 		|| tdev->td_urb_error
1512 		|| !usb_get_intfdata(port->serial->interface))  /* disconnect */
1513 			break;
1514 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1515 		timeout = schedule_timeout(timeout);
1516 		spin_lock_irqsave(&tport->tp_lock, flags);
1517 	}
1518 	set_current_state(TASK_RUNNING);
1519 	remove_wait_queue(&tport->tp_write_wait, &wait);
1520 
1521 	/* flush any remaining data in the buffer */
1522 	if (flush)
1523 		ti_buf_clear(tport->tp_write_buf);
1524 
1525 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1526 
1527 	/* wait for data to drain from the device */
1528 	/* wait for empty tx register, plus 20 ms */
1529 	timeout += jiffies;
1530 	tport->tp_lsr &= ~TI_LSR_TX_EMPTY;
1531 	while ((long)(jiffies - timeout) < 0 && !signal_pending(current)
1532 	&& !(tport->tp_lsr&TI_LSR_TX_EMPTY) && !tdev->td_urb_error
1533 	&& usb_get_intfdata(port->serial->interface)) {  /* not disconnected */
1534 		if (ti_get_lsr(tport))
1535 			break;
1536 		msleep_interruptible(20);
1537 	}
1538 }
1539 
1540 
1541 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty)
1542 {
1543 	unsigned long flags;
1544 
1545 	spin_lock_irqsave(&tport->tp_lock, flags);
1546 
1547 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING)
1548 		tport->tp_read_urb_state = TI_READ_URB_STOPPING;
1549 
1550 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1551 }
1552 
1553 
1554 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty)
1555 {
1556 	struct urb *urb;
1557 	int status = 0;
1558 	unsigned long flags;
1559 
1560 	spin_lock_irqsave(&tport->tp_lock, flags);
1561 
1562 	if (tport->tp_read_urb_state == TI_READ_URB_STOPPED) {
1563 		urb = tport->tp_port->read_urb;
1564 		urb->complete = ti_bulk_in_callback;
1565 		urb->context = tport;
1566 		urb->dev = tport->tp_port->serial->dev;
1567 		status = usb_submit_urb(urb, GFP_KERNEL);
1568 	}
1569 	tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1570 
1571 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1572 
1573 	return status;
1574 }
1575 
1576 
1577 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
1578 	__u16 moduleid, __u16 value, __u8 *data, int size)
1579 {
1580 	int status;
1581 
1582 	status = usb_control_msg(tdev->td_serial->dev,
1583 		usb_sndctrlpipe(tdev->td_serial->dev, 0), command,
1584 		(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT),
1585 		value, moduleid, data, size, 1000);
1586 
1587 	if (status == size)
1588 		status = 0;
1589 
1590 	if (status > 0)
1591 		status = -ECOMM;
1592 
1593 	return status;
1594 }
1595 
1596 
1597 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
1598 	__u16 moduleid, __u16 value, __u8 *data, int size)
1599 {
1600 	int status;
1601 
1602 	status = usb_control_msg(tdev->td_serial->dev,
1603 		usb_rcvctrlpipe(tdev->td_serial->dev, 0), command,
1604 		(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN),
1605 		value, moduleid, data, size, 1000);
1606 
1607 	if (status == size)
1608 		status = 0;
1609 
1610 	if (status > 0)
1611 		status = -ECOMM;
1612 
1613 	return status;
1614 }
1615 
1616 
1617 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
1618 	__u8 mask, __u8 byte)
1619 {
1620 	int status;
1621 	unsigned int size;
1622 	struct ti_write_data_bytes *data;
1623 	struct device *dev = &tdev->td_serial->dev->dev;
1624 
1625 	dbg("%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X", __FUNCTION__, addr, mask, byte);
1626 
1627 	size = sizeof(struct ti_write_data_bytes) + 2;
1628 	data = kmalloc(size, GFP_KERNEL);
1629 	if (!data) {
1630 		dev_err(dev, "%s - out of memory\n", __FUNCTION__);
1631 		return -ENOMEM;
1632 	}
1633 
1634 	data->bAddrType = TI_RW_DATA_ADDR_XDATA;
1635 	data->bDataType = TI_RW_DATA_BYTE;
1636 	data->bDataCounter = 1;
1637 	data->wBaseAddrHi = cpu_to_be16(addr>>16);
1638 	data->wBaseAddrLo = cpu_to_be16(addr);
1639 	data->bData[0] = mask;
1640 	data->bData[1] = byte;
1641 
1642 	status = ti_command_out_sync(tdev, TI_WRITE_DATA, TI_RAM_PORT, 0,
1643 		(__u8 *)data, size);
1644 
1645 	if (status < 0)
1646 		dev_err(dev, "%s - failed, %d\n", __FUNCTION__, status);
1647 
1648 	kfree(data);
1649 
1650 	return status;
1651 }
1652 
1653 
1654 static int ti_download_firmware(struct ti_device *tdev,
1655 	unsigned char *firmware, unsigned int firmware_size)
1656 {
1657 	int status = 0;
1658 	int buffer_size;
1659 	int pos;
1660 	int len;
1661 	int done;
1662 	__u8 cs = 0;
1663 	__u8 *buffer;
1664 	struct usb_device *dev = tdev->td_serial->dev;
1665 	struct ti_firmware_header *header;
1666 	unsigned int pipe = usb_sndbulkpipe(dev,
1667 		tdev->td_serial->port[0]->bulk_out_endpointAddress);
1668 
1669 
1670 	buffer_size = TI_FIRMWARE_BUF_SIZE + sizeof(struct ti_firmware_header);
1671 	buffer = kmalloc(buffer_size, GFP_KERNEL);
1672 	if (!buffer) {
1673 		dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
1674 		return -ENOMEM;
1675 	}
1676 
1677 	memcpy(buffer, firmware, firmware_size);
1678 	memset(buffer+firmware_size, 0xff, buffer_size-firmware_size);
1679 
1680 	for(pos = sizeof(struct ti_firmware_header); pos < buffer_size; pos++)
1681 		cs = (__u8)(cs + buffer[pos]);
1682 
1683 	header = (struct ti_firmware_header *)buffer;
1684 	header->wLength = cpu_to_le16((__u16)(buffer_size - sizeof(struct ti_firmware_header)));
1685 	header->bCheckSum = cs;
1686 
1687 	dbg("%s - downloading firmware", __FUNCTION__);
1688 	for (pos = 0; pos < buffer_size; pos += done) {
1689 		len = min(buffer_size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
1690 		status = usb_bulk_msg(dev, pipe, buffer+pos, len, &done, 1000);
1691 		if (status)
1692 			break;
1693 	}
1694 
1695 	kfree(buffer);
1696 
1697 	if (status) {
1698 		dev_err(&dev->dev, "%s - error downloading firmware, %d\n", __FUNCTION__, status);
1699 		return status;
1700 	}
1701 
1702 	dbg("%s - download successful", __FUNCTION__);
1703 
1704 	return 0;
1705 }
1706 
1707 
1708 /* Circular Buffer Functions */
1709 
1710 /*
1711  * ti_buf_alloc
1712  *
1713  * Allocate a circular buffer and all associated memory.
1714  */
1715 
1716 static struct circ_buf *ti_buf_alloc(void)
1717 {
1718 	struct circ_buf *cb;
1719 
1720 	cb = (struct circ_buf *)kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
1721 	if (cb == NULL)
1722 		return NULL;
1723 
1724 	cb->buf = kmalloc(TI_WRITE_BUF_SIZE, GFP_KERNEL);
1725 	if (cb->buf == NULL) {
1726 		kfree(cb);
1727 		return NULL;
1728 	}
1729 
1730 	ti_buf_clear(cb);
1731 
1732 	return cb;
1733 }
1734 
1735 
1736 /*
1737  * ti_buf_free
1738  *
1739  * Free the buffer and all associated memory.
1740  */
1741 
1742 static void ti_buf_free(struct circ_buf *cb)
1743 {
1744 	kfree(cb->buf);
1745 	kfree(cb);
1746 }
1747 
1748 
1749 /*
1750  * ti_buf_clear
1751  *
1752  * Clear out all data in the circular buffer.
1753  */
1754 
1755 static void ti_buf_clear(struct circ_buf *cb)
1756 {
1757 	cb->head = cb->tail = 0;
1758 }
1759 
1760 
1761 /*
1762  * ti_buf_data_avail
1763  *
1764  * Return the number of bytes of data available in the circular
1765  * buffer.
1766  */
1767 
1768 static int ti_buf_data_avail(struct circ_buf *cb)
1769 {
1770 	return CIRC_CNT(cb->head,cb->tail,TI_WRITE_BUF_SIZE);
1771 }
1772 
1773 
1774 /*
1775  * ti_buf_space_avail
1776  *
1777  * Return the number of bytes of space available in the circular
1778  * buffer.
1779  */
1780 
1781 static int ti_buf_space_avail(struct circ_buf *cb)
1782 {
1783 	return CIRC_SPACE(cb->head,cb->tail,TI_WRITE_BUF_SIZE);
1784 }
1785 
1786 
1787 /*
1788  * ti_buf_put
1789  *
1790  * Copy data data from a user buffer and put it into the circular buffer.
1791  * Restrict to the amount of space available.
1792  *
1793  * Return the number of bytes copied.
1794  */
1795 
1796 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count)
1797 {
1798 	int c, ret = 0;
1799 
1800 	while (1) {
1801 		c = CIRC_SPACE_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1802 		if (count < c)
1803 			c = count;
1804 		if (c <= 0)
1805 			break;
1806 		memcpy(cb->buf + cb->head, buf, c);
1807 		cb->head = (cb->head + c) & (TI_WRITE_BUF_SIZE-1);
1808 		buf += c;
1809 		count -= c;
1810 		ret += c;
1811 	}
1812 
1813 	return ret;
1814 }
1815 
1816 
1817 /*
1818  * ti_buf_get
1819  *
1820  * Get data from the circular buffer and copy to the given buffer.
1821  * Restrict to the amount of data available.
1822  *
1823  * Return the number of bytes copied.
1824  */
1825 
1826 static int ti_buf_get(struct circ_buf *cb, char *buf, int count)
1827 {
1828 	int c, ret = 0;
1829 
1830 	while (1) {
1831 		c = CIRC_CNT_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1832 		if (count < c)
1833 			c = count;
1834 		if (c <= 0)
1835 			break;
1836 		memcpy(buf, cb->buf + cb->tail, c);
1837 		cb->tail = (cb->tail + c) & (TI_WRITE_BUF_SIZE-1);
1838 		buf += c;
1839 		count -= c;
1840 		ret += c;
1841 	}
1842 
1843 	return ret;
1844 }
1845