xref: /openbmc/linux/drivers/usb/serial/ti_usb_3410_5052.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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 	.owner			= THIS_MODULE,
252 	.name			= "ti_usb_3410_5052",
253 	.probe			= usb_serial_probe,
254 	.disconnect		= usb_serial_disconnect,
255 	.id_table		= ti_id_table_combined,
256 };
257 
258 static struct usb_serial_device_type ti_1port_device = {
259 	.owner			= THIS_MODULE,
260 	.name			= "TI USB 3410 1 port adapter",
261 	.id_table		= ti_id_table_3410,
262 	.num_interrupt_in	= 1,
263 	.num_bulk_in		= 1,
264 	.num_bulk_out		= 1,
265 	.num_ports		= 1,
266 	.attach			= ti_startup,
267 	.shutdown		= ti_shutdown,
268 	.open			= ti_open,
269 	.close			= ti_close,
270 	.write			= ti_write,
271 	.write_room		= ti_write_room,
272 	.chars_in_buffer	= ti_chars_in_buffer,
273 	.throttle		= ti_throttle,
274 	.unthrottle		= ti_unthrottle,
275 	.ioctl			= ti_ioctl,
276 	.set_termios		= ti_set_termios,
277 	.tiocmget		= ti_tiocmget,
278 	.tiocmset		= ti_tiocmset,
279 	.break_ctl		= ti_break,
280 	.read_int_callback	= ti_interrupt_callback,
281 	.read_bulk_callback	= ti_bulk_in_callback,
282 	.write_bulk_callback	= ti_bulk_out_callback,
283 };
284 
285 static struct usb_serial_device_type ti_2port_device = {
286 	.owner			= THIS_MODULE,
287 	.name			= "TI USB 5052 2 port adapter",
288 	.id_table		= ti_id_table_5052,
289 	.num_interrupt_in	= 1,
290 	.num_bulk_in		= 2,
291 	.num_bulk_out		= 2,
292 	.num_ports		= 2,
293 	.attach			= ti_startup,
294 	.shutdown		= ti_shutdown,
295 	.open			= ti_open,
296 	.close			= ti_close,
297 	.write			= ti_write,
298 	.write_room		= ti_write_room,
299 	.chars_in_buffer	= ti_chars_in_buffer,
300 	.throttle		= ti_throttle,
301 	.unthrottle		= ti_unthrottle,
302 	.ioctl			= ti_ioctl,
303 	.set_termios		= ti_set_termios,
304 	.tiocmget		= ti_tiocmget,
305 	.tiocmset		= ti_tiocmset,
306 	.break_ctl		= ti_break,
307 	.read_int_callback	= ti_interrupt_callback,
308 	.read_bulk_callback	= ti_bulk_in_callback,
309 	.write_bulk_callback	= ti_bulk_out_callback,
310 };
311 
312 
313 /* Module */
314 
315 MODULE_AUTHOR(TI_DRIVER_AUTHOR);
316 MODULE_DESCRIPTION(TI_DRIVER_DESC);
317 MODULE_VERSION(TI_DRIVER_VERSION);
318 MODULE_LICENSE("GPL");
319 
320 module_param(debug, bool, S_IRUGO | S_IWUSR);
321 MODULE_PARM_DESC(debug, "Enable debugging, 0=no, 1=yes");
322 
323 module_param(low_latency, bool, S_IRUGO | S_IWUSR);
324 MODULE_PARM_DESC(low_latency, "TTY low_latency flag, 0=off, 1=on, default is off");
325 
326 module_param(closing_wait, int, S_IRUGO | S_IWUSR);
327 MODULE_PARM_DESC(closing_wait, "Maximum wait for data to drain in close, in .01 secs, default is 4000");
328 
329 module_param_array(vendor_3410, ushort, &vendor_3410_count, S_IRUGO);
330 MODULE_PARM_DESC(vendor_3410, "Vendor ids for 3410 based devices, 1-5 short integers");
331 module_param_array(product_3410, ushort, &product_3410_count, S_IRUGO);
332 MODULE_PARM_DESC(product_3410, "Product ids for 3410 based devices, 1-5 short integers");
333 module_param_array(vendor_5052, ushort, &vendor_5052_count, S_IRUGO);
334 MODULE_PARM_DESC(vendor_5052, "Vendor ids for 5052 based devices, 1-5 short integers");
335 module_param_array(product_5052, ushort, &product_5052_count, S_IRUGO);
336 MODULE_PARM_DESC(product_5052, "Product ids for 5052 based devices, 1-5 short integers");
337 
338 MODULE_DEVICE_TABLE(usb, ti_id_table_combined);
339 
340 
341 /* Functions */
342 
343 static int __init ti_init(void)
344 {
345 	int i,j;
346 	int ret;
347 
348 
349 	/* insert extra vendor and product ids */
350 	j = sizeof(ti_id_table_3410)/sizeof(struct usb_device_id)
351 		- TI_EXTRA_VID_PID_COUNT - 1;
352 	for (i=0; i<min(vendor_3410_count,product_3410_count); i++,j++) {
353 		ti_id_table_3410[j].idVendor = vendor_3410[i];
354 		ti_id_table_3410[j].idProduct = product_3410[i];
355 		ti_id_table_3410[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
356 	}
357 	j = sizeof(ti_id_table_5052)/sizeof(struct usb_device_id)
358 		- TI_EXTRA_VID_PID_COUNT - 1;
359 	for (i=0; i<min(vendor_5052_count,product_5052_count); i++,j++) {
360 		ti_id_table_5052[j].idVendor = vendor_5052[i];
361 		ti_id_table_5052[j].idProduct = product_5052[i];
362 		ti_id_table_5052[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
363 	}
364 
365 	ret = usb_serial_register(&ti_1port_device);
366 	if (ret)
367 		goto failed_1port;
368 	ret = usb_serial_register(&ti_2port_device);
369 	if (ret)
370 		goto failed_2port;
371 
372 	ret = usb_register(&ti_usb_driver);
373 	if (ret)
374 		goto failed_usb;
375 
376 	info(TI_DRIVER_DESC " " TI_DRIVER_VERSION);
377 
378 	return 0;
379 
380 failed_usb:
381 	usb_serial_deregister(&ti_2port_device);
382 failed_2port:
383 	usb_serial_deregister(&ti_1port_device);
384 failed_1port:
385 	return ret;
386 }
387 
388 
389 static void __exit ti_exit(void)
390 {
391 	usb_serial_deregister(&ti_1port_device);
392 	usb_serial_deregister(&ti_2port_device);
393 	usb_deregister(&ti_usb_driver);
394 }
395 
396 
397 module_init(ti_init);
398 module_exit(ti_exit);
399 
400 
401 static int ti_startup(struct usb_serial *serial)
402 {
403 	struct ti_device *tdev;
404 	struct ti_port *tport;
405 	struct usb_device *dev = serial->dev;
406 	int status;
407 	int i;
408 
409 
410 	dbg("%s - product 0x%4X, num configurations %d, configuration value %d",
411 	    __FUNCTION__, le16_to_cpu(dev->descriptor.idProduct),
412 	    dev->descriptor.bNumConfigurations,
413 	    dev->actconfig->desc.bConfigurationValue);
414 
415 	/* create device structure */
416 	tdev = kmalloc(sizeof(struct ti_device), GFP_KERNEL);
417 	if (tdev == NULL) {
418 		dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
419 		return -ENOMEM;
420 	}
421 	memset(tdev, 0, sizeof(struct ti_device));
422 	sema_init(&tdev->td_open_close_sem, 1);
423 	tdev->td_serial = serial;
424 	usb_set_serial_data(serial, tdev);
425 
426 	/* determine device type */
427 	if (usb_match_id(serial->interface, ti_id_table_3410))
428 		tdev->td_is_3410 = 1;
429 	dbg("%s - device type is %s", __FUNCTION__, tdev->td_is_3410 ? "3410" : "5052");
430 
431 	/* if we have only 1 configuration, download firmware */
432 	if (dev->descriptor.bNumConfigurations == 1) {
433 
434 		if (tdev->td_is_3410)
435 			status = ti_download_firmware(tdev, ti_fw_3410,
436 				sizeof(ti_fw_3410));
437 		else
438 			status = ti_download_firmware(tdev, ti_fw_5052,
439 				sizeof(ti_fw_5052));
440 		if (status)
441 			goto free_tdev;
442 
443 		/* 3410 must be reset, 5052 resets itself */
444 		if (tdev->td_is_3410) {
445 			msleep_interruptible(100);
446 			usb_reset_device(dev);
447 		}
448 
449 		status = -ENODEV;
450 		goto free_tdev;
451 	}
452 
453 	/* the second configuration must be set (in sysfs by hotplug script) */
454 	if (dev->actconfig->desc.bConfigurationValue == TI_BOOT_CONFIG) {
455 		status = -ENODEV;
456 		goto free_tdev;
457 	}
458 
459 	/* set up port structures */
460 	for (i = 0; i < serial->num_ports; ++i) {
461 		tport = kmalloc(sizeof(struct ti_port), GFP_KERNEL);
462 		if (tport == NULL) {
463 			dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
464 			status = -ENOMEM;
465 			goto free_tports;
466 		}
467 		memset(tport, 0, sizeof(struct ti_port));
468 		spin_lock_init(&tport->tp_lock);
469 		tport->tp_uart_base_addr = (i == 0 ? TI_UART1_BASE_ADDR : TI_UART2_BASE_ADDR);
470 		tport->tp_flags = low_latency ? ASYNC_LOW_LATENCY : 0;
471 		tport->tp_closing_wait = closing_wait;
472 		init_waitqueue_head(&tport->tp_msr_wait);
473 		init_waitqueue_head(&tport->tp_write_wait);
474 		tport->tp_write_buf = ti_buf_alloc();
475 		if (tport->tp_write_buf == NULL) {
476 			dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
477 			kfree(tport);
478 			status = -ENOMEM;
479 			goto free_tports;
480 		}
481 		tport->tp_port = serial->port[i];
482 		tport->tp_tdev = tdev;
483 		usb_set_serial_port_data(serial->port[i], tport);
484 		tport->tp_uart_mode = 0;	/* default is RS232 */
485 	}
486 
487 	return 0;
488 
489 free_tports:
490 	for (--i; i>=0; --i) {
491 		tport = usb_get_serial_port_data(serial->port[i]);
492 		ti_buf_free(tport->tp_write_buf);
493 		kfree(tport);
494 		usb_set_serial_port_data(serial->port[i], NULL);
495 	}
496 free_tdev:
497 	kfree(tdev);
498 	usb_set_serial_data(serial, NULL);
499 	return status;
500 }
501 
502 
503 static void ti_shutdown(struct usb_serial *serial)
504 {
505 	int i;
506 	struct ti_device *tdev = usb_get_serial_data(serial);
507 	struct ti_port *tport;
508 
509 	dbg("%s", __FUNCTION__);
510 
511 	for (i=0; i < serial->num_ports; ++i) {
512 		tport = usb_get_serial_port_data(serial->port[i]);
513 		if (tport) {
514 			ti_buf_free(tport->tp_write_buf);
515 			kfree(tport);
516 			usb_set_serial_port_data(serial->port[i], NULL);
517 		}
518 	}
519 
520 	if (tdev)
521 		kfree(tdev);
522 	usb_set_serial_data(serial, NULL);
523 }
524 
525 
526 static int ti_open(struct usb_serial_port *port, struct file *file)
527 {
528 	struct ti_port *tport = usb_get_serial_port_data(port);
529 	struct ti_device *tdev;
530 	struct usb_device *dev;
531 	struct urb *urb;
532 	int port_number;
533 	int status;
534 	__u16 open_settings = (__u8)(TI_PIPE_MODE_CONTINOUS |
535 			     TI_PIPE_TIMEOUT_ENABLE |
536 			     (TI_TRANSFER_TIMEOUT << 2));
537 
538 	dbg("%s - port %d", __FUNCTION__, port->number);
539 
540 	if (tport == NULL)
541 		return -ENODEV;
542 
543 	dev = port->serial->dev;
544 	tdev = tport->tp_tdev;
545 
546 	/* only one open on any port on a device at a time */
547 	if (down_interruptible(&tdev->td_open_close_sem))
548 		return -ERESTARTSYS;
549 
550 	if (port->tty)
551 		port->tty->low_latency =
552 			(tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
553 
554 	port_number = port->number - port->serial->minor;
555 
556 	memset(&(tport->tp_icount), 0x00, sizeof(tport->tp_icount));
557 
558 	tport->tp_msr = 0;
559 	tport->tp_shadow_mcr |= (TI_MCR_RTS | TI_MCR_DTR);
560 
561 	/* start interrupt urb the first time a port is opened on this device */
562 	if (tdev->td_open_port_count == 0) {
563 		dbg("%s - start interrupt in urb", __FUNCTION__);
564 		urb = tdev->td_serial->port[0]->interrupt_in_urb;
565 		if (!urb) {
566 			dev_err(&port->dev, "%s - no interrupt urb\n", __FUNCTION__);
567 			status = -EINVAL;
568 			goto up_sem;
569 		}
570 		urb->complete = ti_interrupt_callback;
571 		urb->context = tdev;
572 		urb->dev = dev;
573 		status = usb_submit_urb(urb, GFP_KERNEL);
574 		if (status) {
575 			dev_err(&port->dev, "%s - submit interrupt urb failed, %d\n", __FUNCTION__, status);
576 			goto up_sem;
577 		}
578 	}
579 
580 	ti_set_termios(port, NULL);
581 
582 	dbg("%s - sending TI_OPEN_PORT", __FUNCTION__);
583 	status = ti_command_out_sync(tdev, TI_OPEN_PORT,
584 		(__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
585 	if (status) {
586 		dev_err(&port->dev, "%s - cannot send open command, %d\n", __FUNCTION__, status);
587 		goto unlink_int_urb;
588 	}
589 
590 	dbg("%s - sending TI_START_PORT", __FUNCTION__);
591 	status = ti_command_out_sync(tdev, TI_START_PORT,
592 		(__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
593 	if (status) {
594 		dev_err(&port->dev, "%s - cannot send start command, %d\n", __FUNCTION__, status);
595 		goto unlink_int_urb;
596 	}
597 
598 	dbg("%s - sending TI_PURGE_PORT", __FUNCTION__);
599 	status = ti_command_out_sync(tdev, TI_PURGE_PORT,
600 		(__u8)(TI_UART1_PORT + port_number), TI_PURGE_INPUT, NULL, 0);
601 	if (status) {
602 		dev_err(&port->dev, "%s - cannot clear input buffers, %d\n", __FUNCTION__, status);
603 		goto unlink_int_urb;
604 	}
605 	status = ti_command_out_sync(tdev, TI_PURGE_PORT,
606 		(__u8)(TI_UART1_PORT + port_number), TI_PURGE_OUTPUT, NULL, 0);
607 	if (status) {
608 		dev_err(&port->dev, "%s - cannot clear output buffers, %d\n", __FUNCTION__, status);
609 		goto unlink_int_urb;
610 	}
611 
612 	/* reset the data toggle on the bulk endpoints to work around bug in
613 	 * host controllers where things get out of sync some times */
614 	usb_clear_halt(dev, port->write_urb->pipe);
615 	usb_clear_halt(dev, port->read_urb->pipe);
616 
617 	ti_set_termios(port, NULL);
618 
619 	dbg("%s - sending TI_OPEN_PORT (2)", __FUNCTION__);
620 	status = ti_command_out_sync(tdev, TI_OPEN_PORT,
621 		(__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
622 	if (status) {
623 		dev_err(&port->dev, "%s - cannot send open command (2), %d\n", __FUNCTION__, status);
624 		goto unlink_int_urb;
625 	}
626 
627 	dbg("%s - sending TI_START_PORT (2)", __FUNCTION__);
628 	status = ti_command_out_sync(tdev, TI_START_PORT,
629 		(__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
630 	if (status) {
631 		dev_err(&port->dev, "%s - cannot send start command (2), %d\n", __FUNCTION__, status);
632 		goto unlink_int_urb;
633 	}
634 
635 	/* start read urb */
636 	dbg("%s - start read urb", __FUNCTION__);
637 	urb = port->read_urb;
638 	if (!urb) {
639 		dev_err(&port->dev, "%s - no read urb\n", __FUNCTION__);
640 		status = -EINVAL;
641 		goto unlink_int_urb;
642 	}
643 	tport->tp_read_urb_state = TI_READ_URB_RUNNING;
644 	urb->complete = ti_bulk_in_callback;
645 	urb->context = tport;
646 	urb->dev = dev;
647 	status = usb_submit_urb(urb, GFP_KERNEL);
648 	if (status) {
649 		dev_err(&port->dev, "%s - submit read urb failed, %d\n", __FUNCTION__, status);
650 		goto unlink_int_urb;
651 	}
652 
653 	tport->tp_is_open = 1;
654 	++tdev->td_open_port_count;
655 
656 	goto up_sem;
657 
658 unlink_int_urb:
659 	if (tdev->td_open_port_count == 0)
660 		usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
661 up_sem:
662 	up(&tdev->td_open_close_sem);
663 	dbg("%s - exit %d", __FUNCTION__, status);
664 	return status;
665 }
666 
667 
668 static void ti_close(struct usb_serial_port *port, struct file *file)
669 {
670 	struct ti_device *tdev;
671 	struct ti_port *tport;
672 	int port_number;
673 	int status;
674 	int do_up;
675 
676 	dbg("%s - port %d", __FUNCTION__, port->number);
677 
678 	tdev = usb_get_serial_data(port->serial);
679 	tport = usb_get_serial_port_data(port);
680 	if (tdev == NULL || tport == NULL)
681 		return;
682 
683 	tport->tp_is_open = 0;
684 
685 	ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 1);
686 
687 	usb_kill_urb(port->read_urb);
688 	usb_kill_urb(port->write_urb);
689 	tport->tp_write_urb_in_use = 0;
690 
691 	port_number = port->number - port->serial->minor;
692 
693 	dbg("%s - sending TI_CLOSE_PORT", __FUNCTION__);
694 	status = ti_command_out_sync(tdev, TI_CLOSE_PORT,
695 		     (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
696 	if (status)
697 		dev_err(&port->dev, "%s - cannot send close port command, %d\n" , __FUNCTION__, status);
698 
699 	/* if down is interrupted, continue anyway */
700 	do_up = !down_interruptible(&tdev->td_open_close_sem);
701 	--tport->tp_tdev->td_open_port_count;
702 	if (tport->tp_tdev->td_open_port_count <= 0) {
703 		/* last port is closed, shut down interrupt urb */
704 		usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
705 		tport->tp_tdev->td_open_port_count = 0;
706 	}
707 	if (do_up)
708 		up(&tdev->td_open_close_sem);
709 
710 	dbg("%s - exit", __FUNCTION__);
711 }
712 
713 
714 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
715 	int count)
716 {
717 	struct ti_port *tport = usb_get_serial_port_data(port);
718 	unsigned long flags;
719 
720 	dbg("%s - port %d", __FUNCTION__, port->number);
721 
722 	if (count == 0) {
723 		dbg("%s - write request of 0 bytes", __FUNCTION__);
724 		return 0;
725 	}
726 
727 	if (tport == NULL || !tport->tp_is_open)
728 		return -ENODEV;
729 
730 	spin_lock_irqsave(&tport->tp_lock, flags);
731 	count = ti_buf_put(tport->tp_write_buf, data, count);
732 	spin_unlock_irqrestore(&tport->tp_lock, flags);
733 
734 	ti_send(tport);
735 
736 	return count;
737 }
738 
739 
740 static int ti_write_room(struct usb_serial_port *port)
741 {
742 	struct ti_port *tport = usb_get_serial_port_data(port);
743 	int room = 0;
744 	unsigned long flags;
745 
746 	dbg("%s - port %d", __FUNCTION__, port->number);
747 
748 	if (tport == NULL)
749 		return -ENODEV;
750 
751 	spin_lock_irqsave(&tport->tp_lock, flags);
752 	room = ti_buf_space_avail(tport->tp_write_buf);
753 	spin_unlock_irqrestore(&tport->tp_lock, flags);
754 
755 	dbg("%s - returns %d", __FUNCTION__, room);
756 	return room;
757 }
758 
759 
760 static int ti_chars_in_buffer(struct usb_serial_port *port)
761 {
762 	struct ti_port *tport = usb_get_serial_port_data(port);
763 	int chars = 0;
764 	unsigned long flags;
765 
766 	dbg("%s - port %d", __FUNCTION__, port->number);
767 
768 	if (tport == NULL)
769 		return -ENODEV;
770 
771 	spin_lock_irqsave(&tport->tp_lock, flags);
772 	chars = ti_buf_data_avail(tport->tp_write_buf);
773 	spin_unlock_irqrestore(&tport->tp_lock, flags);
774 
775 	dbg("%s - returns %d", __FUNCTION__, chars);
776 	return chars;
777 }
778 
779 
780 static void ti_throttle(struct usb_serial_port *port)
781 {
782 	struct ti_port *tport = usb_get_serial_port_data(port);
783 	struct tty_struct *tty;
784 
785 	dbg("%s - port %d", __FUNCTION__, port->number);
786 
787 	if (tport == NULL)
788 		return;
789 
790 	tty = port->tty;
791 	if (!tty) {
792 		dbg("%s - no tty", __FUNCTION__);
793 		return;
794 	}
795 
796 	if (I_IXOFF(tty) || C_CRTSCTS(tty))
797 		ti_stop_read(tport, tty);
798 
799 }
800 
801 
802 static void ti_unthrottle(struct usb_serial_port *port)
803 {
804 	struct ti_port *tport = usb_get_serial_port_data(port);
805 	struct tty_struct *tty;
806 	int status;
807 
808 	dbg("%s - port %d", __FUNCTION__, port->number);
809 
810 	if (tport == NULL)
811 		return;
812 
813 	tty = port->tty;
814 	if (!tty) {
815 		dbg("%s - no tty", __FUNCTION__);
816 		return;
817 	}
818 
819 	if (I_IXOFF(tty) || C_CRTSCTS(tty)) {
820 		status = ti_restart_read(tport, tty);
821 		if (status)
822 			dev_err(&port->dev, "%s - cannot restart read, %d\n", __FUNCTION__, status);
823 	}
824 }
825 
826 
827 static int ti_ioctl(struct usb_serial_port *port, struct file *file,
828 	unsigned int cmd, unsigned long arg)
829 {
830 	struct ti_port *tport = usb_get_serial_port_data(port);
831 	struct async_icount cnow;
832 	struct async_icount cprev;
833 
834 	dbg("%s - port %d, cmd = 0x%04X", __FUNCTION__, port->number, cmd);
835 
836 	if (tport == NULL)
837 		return -ENODEV;
838 
839 	switch (cmd) {
840 		case TIOCGSERIAL:
841 			dbg("%s - (%d) TIOCGSERIAL", __FUNCTION__, port->number);
842 			return ti_get_serial_info(tport, (struct serial_struct __user *)arg);
843 			break;
844 
845 		case TIOCSSERIAL:
846 			dbg("%s - (%d) TIOCSSERIAL", __FUNCTION__, port->number);
847 			return ti_set_serial_info(tport, (struct serial_struct __user *)arg);
848 			break;
849 
850 		case TIOCMIWAIT:
851 			dbg("%s - (%d) TIOCMIWAIT", __FUNCTION__, port->number);
852 			cprev = tport->tp_icount;
853 			while (1) {
854 				interruptible_sleep_on(&tport->tp_msr_wait);
855 				if (signal_pending(current))
856 					return -ERESTARTSYS;
857 				cnow = tport->tp_icount;
858 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
859 				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
860 					return -EIO; /* no change => error */
861 				if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
862 				    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
863 				    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
864 				    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
865 					return 0;
866 				}
867 				cprev = cnow;
868 			}
869 			break;
870 
871 		case TIOCGICOUNT:
872 			dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d", __FUNCTION__, port->number, tport->tp_icount.rx, tport->tp_icount.tx);
873 			if (copy_to_user((void __user *)arg, &tport->tp_icount, sizeof(tport->tp_icount)))
874 				return -EFAULT;
875 			return 0;
876 	}
877 
878 	return -ENOIOCTLCMD;
879 }
880 
881 
882 static void ti_set_termios(struct usb_serial_port *port,
883 	struct termios *old_termios)
884 {
885 	struct ti_port *tport = usb_get_serial_port_data(port);
886 	struct tty_struct *tty = port->tty;
887 	struct ti_uart_config *config;
888 	tcflag_t cflag,iflag;
889 	int baud;
890 	int status;
891 	int port_number = port->number - port->serial->minor;
892 	unsigned int mcr;
893 
894 	dbg("%s - port %d", __FUNCTION__, port->number);
895 
896 	if (!tty || !tty->termios) {
897 		dbg("%s - no tty or termios", __FUNCTION__);
898 		return;
899 	}
900 
901 	cflag = tty->termios->c_cflag;
902 	iflag = tty->termios->c_iflag;
903 
904 	if (old_termios && cflag == old_termios->c_cflag
905 	&& iflag == old_termios->c_iflag) {
906 		dbg("%s - nothing to change", __FUNCTION__);
907 		return;
908 	}
909 
910 	dbg("%s - clfag %08x, iflag %08x", __FUNCTION__, cflag, iflag);
911 
912 	if (old_termios)
913 		dbg("%s - old clfag %08x, old iflag %08x", __FUNCTION__, old_termios->c_cflag, old_termios->c_iflag);
914 
915 	if (tport == NULL)
916 		return;
917 
918 	config = kmalloc(sizeof(*config), GFP_KERNEL);
919 	if (!config) {
920 		dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
921 		return;
922 	}
923 
924 	config->wFlags = 0;
925 
926 	/* these flags must be set */
927 	config->wFlags |= TI_UART_ENABLE_MS_INTS;
928 	config->wFlags |= TI_UART_ENABLE_AUTO_START_DMA;
929 	config->bUartMode = (__u8)(tport->tp_uart_mode);
930 
931 	switch (cflag & CSIZE) {
932 		case CS5:
933 			    config->bDataBits = TI_UART_5_DATA_BITS;
934 			    break;
935 		case CS6:
936 			    config->bDataBits = TI_UART_6_DATA_BITS;
937 			    break;
938 		case CS7:
939 			    config->bDataBits = TI_UART_7_DATA_BITS;
940 			    break;
941 		default:
942 		case CS8:
943 			    config->bDataBits = TI_UART_8_DATA_BITS;
944 			    break;
945 	}
946 
947 	if (cflag & PARENB) {
948 		if (cflag & PARODD) {
949 			config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
950 			config->bParity = TI_UART_ODD_PARITY;
951 		} else {
952 			config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
953 			config->bParity = TI_UART_EVEN_PARITY;
954 		}
955 	} else {
956 		config->wFlags &= ~TI_UART_ENABLE_PARITY_CHECKING;
957 		config->bParity = TI_UART_NO_PARITY;
958 	}
959 
960 	if (cflag & CSTOPB)
961 		config->bStopBits = TI_UART_2_STOP_BITS;
962 	else
963 		config->bStopBits = TI_UART_1_STOP_BITS;
964 
965 	if (cflag & CRTSCTS) {
966 		/* RTS flow control must be off to drop RTS for baud rate B0 */
967 		if ((cflag & CBAUD) != B0)
968 			config->wFlags |= TI_UART_ENABLE_RTS_IN;
969 		config->wFlags |= TI_UART_ENABLE_CTS_OUT;
970 	} else {
971 		tty->hw_stopped = 0;
972 		ti_restart_read(tport, tty);
973 	}
974 
975 	if (I_IXOFF(tty) || I_IXON(tty)) {
976 		config->cXon  = START_CHAR(tty);
977 		config->cXoff = STOP_CHAR(tty);
978 
979 		if (I_IXOFF(tty))
980 			config->wFlags |= TI_UART_ENABLE_X_IN;
981 		else
982 			ti_restart_read(tport, tty);
983 
984 		if (I_IXON(tty))
985 			config->wFlags |= TI_UART_ENABLE_X_OUT;
986 	}
987 
988 	baud = tty_get_baud_rate(tty);
989 	if (!baud) baud = 9600;
990 	if (tport->tp_tdev->td_is_3410)
991 		config->wBaudRate = (__u16)((923077 + baud/2) / baud);
992 	else
993 		config->wBaudRate = (__u16)((461538 + baud/2) / baud);
994 
995 	dbg("%s - BaudRate=%d, wBaudRate=%d, wFlags=0x%04X, bDataBits=%d, bParity=%d, bStopBits=%d, cXon=%d, cXoff=%d, bUartMode=%d",
996 	__FUNCTION__, baud, config->wBaudRate, config->wFlags, config->bDataBits, config->bParity, config->bStopBits, config->cXon, config->cXoff, config->bUartMode);
997 
998 	cpu_to_be16s(&config->wBaudRate);
999 	cpu_to_be16s(&config->wFlags);
1000 
1001 	status = ti_command_out_sync(tport->tp_tdev, TI_SET_CONFIG,
1002 		(__u8)(TI_UART1_PORT + port_number), 0, (__u8 *)config,
1003 		sizeof(*config));
1004 	if (status)
1005 		dev_err(&port->dev, "%s - cannot set config on port %d, %d\n", __FUNCTION__, port_number, status);
1006 
1007 	/* SET_CONFIG asserts RTS and DTR, reset them correctly */
1008 	mcr = tport->tp_shadow_mcr;
1009 	/* if baud rate is B0, clear RTS and DTR */
1010 	if ((cflag & CBAUD) == B0)
1011 		mcr &= ~(TI_MCR_DTR | TI_MCR_RTS);
1012 	status = ti_set_mcr(tport, mcr);
1013 	if (status)
1014 		dev_err(&port->dev, "%s - cannot set modem control on port %d, %d\n", __FUNCTION__, port_number, status);
1015 
1016 	kfree(config);
1017 }
1018 
1019 
1020 static int ti_tiocmget(struct usb_serial_port *port, struct file *file)
1021 {
1022 	struct ti_port *tport = usb_get_serial_port_data(port);
1023 	unsigned int result;
1024 	unsigned int msr;
1025 	unsigned int mcr;
1026 
1027 	dbg("%s - port %d", __FUNCTION__, port->number);
1028 
1029 	if (tport == NULL)
1030 		return -ENODEV;
1031 
1032 	msr = tport->tp_msr;
1033 	mcr = tport->tp_shadow_mcr;
1034 
1035 	result = ((mcr & TI_MCR_DTR) ? TIOCM_DTR : 0)
1036 		| ((mcr & TI_MCR_RTS) ? TIOCM_RTS : 0)
1037 		| ((mcr & TI_MCR_LOOP) ? TIOCM_LOOP : 0)
1038 		| ((msr & TI_MSR_CTS) ? TIOCM_CTS : 0)
1039 		| ((msr & TI_MSR_CD) ? TIOCM_CAR : 0)
1040 		| ((msr & TI_MSR_RI) ? TIOCM_RI : 0)
1041 		| ((msr & TI_MSR_DSR) ? TIOCM_DSR : 0);
1042 
1043 	dbg("%s - 0x%04X", __FUNCTION__, result);
1044 
1045 	return result;
1046 }
1047 
1048 
1049 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
1050 	unsigned int set, unsigned int clear)
1051 {
1052 	struct ti_port *tport = usb_get_serial_port_data(port);
1053 	unsigned int mcr;
1054 
1055 	dbg("%s - port %d", __FUNCTION__, port->number);
1056 
1057 	if (tport == NULL)
1058 		return -ENODEV;
1059 
1060 	mcr = tport->tp_shadow_mcr;
1061 
1062 	if (set & TIOCM_RTS)
1063 		mcr |= TI_MCR_RTS;
1064 	if (set & TIOCM_DTR)
1065 		mcr |= TI_MCR_DTR;
1066 	if (set & TIOCM_LOOP)
1067 		mcr |= TI_MCR_LOOP;
1068 
1069 	if (clear & TIOCM_RTS)
1070 		mcr &= ~TI_MCR_RTS;
1071 	if (clear & TIOCM_DTR)
1072 		mcr &= ~TI_MCR_DTR;
1073 	if (clear & TIOCM_LOOP)
1074 		mcr &= ~TI_MCR_LOOP;
1075 
1076 	return ti_set_mcr(tport, mcr);
1077 }
1078 
1079 
1080 static void ti_break(struct usb_serial_port *port, int break_state)
1081 {
1082 	struct ti_port *tport = usb_get_serial_port_data(port);
1083 	int status;
1084 
1085 	dbg("%s - state = %d", __FUNCTION__, break_state);
1086 
1087 	if (tport == NULL)
1088 		return;
1089 
1090 	ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 0);
1091 
1092 	status = ti_write_byte(tport->tp_tdev,
1093 		tport->tp_uart_base_addr + TI_UART_OFFSET_LCR,
1094 		TI_LCR_BREAK, break_state == -1 ? TI_LCR_BREAK : 0);
1095 
1096 	if (status)
1097 		dbg("%s - error setting break, %d", __FUNCTION__, status);
1098 }
1099 
1100 
1101 static void ti_interrupt_callback(struct urb *urb, struct pt_regs *regs)
1102 {
1103 	struct ti_device *tdev = (struct ti_device *)urb->context;
1104 	struct usb_serial_port *port;
1105 	struct usb_serial *serial = tdev->td_serial;
1106 	struct ti_port *tport;
1107 	struct device *dev = &urb->dev->dev;
1108 	unsigned char *data = urb->transfer_buffer;
1109 	int length = urb->actual_length;
1110 	int port_number;
1111 	int function;
1112 	int status;
1113 	__u8 msr;
1114 
1115 	dbg("%s", __FUNCTION__);
1116 
1117 	switch (urb->status) {
1118 	case 0:
1119 		break;
1120 	case -ECONNRESET:
1121 	case -ENOENT:
1122 	case -ESHUTDOWN:
1123 		dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1124 		tdev->td_urb_error = 1;
1125 		return;
1126 	default:
1127 		dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status);
1128 		tdev->td_urb_error = 1;
1129 		goto exit;
1130 	}
1131 
1132 	if (length != 2) {
1133 		dbg("%s - bad packet size, %d", __FUNCTION__, length);
1134 		goto exit;
1135 	}
1136 
1137 	if (data[0] == TI_CODE_HARDWARE_ERROR) {
1138 		dev_err(dev, "%s - hardware error, %d\n", __FUNCTION__, data[1]);
1139 		goto exit;
1140 	}
1141 
1142 	port_number = TI_GET_PORT_FROM_CODE(data[0]);
1143 	function = TI_GET_FUNC_FROM_CODE(data[0]);
1144 
1145 	dbg("%s - port_number %d, function %d, data 0x%02X", __FUNCTION__, port_number, function, data[1]);
1146 
1147 	if (port_number >= serial->num_ports) {
1148 		dev_err(dev, "%s - bad port number, %d\n", __FUNCTION__, port_number);
1149 		goto exit;
1150 	}
1151 
1152 	port = serial->port[port_number];
1153 
1154 	tport = usb_get_serial_port_data(port);
1155 	if (!tport)
1156 		goto exit;
1157 
1158 	switch (function) {
1159 	case TI_CODE_DATA_ERROR:
1160 		dev_err(dev, "%s - DATA ERROR, port %d, data 0x%02X\n", __FUNCTION__, port_number, data[1]);
1161 		break;
1162 
1163 	case TI_CODE_MODEM_STATUS:
1164 		msr = data[1];
1165 		dbg("%s - port %d, msr 0x%02X", __FUNCTION__, port_number, msr);
1166 		ti_handle_new_msr(tport, msr);
1167 		break;
1168 
1169 	default:
1170 		dev_err(dev, "%s - unknown interrupt code, 0x%02X\n", __FUNCTION__, data[1]);
1171 		break;
1172 	}
1173 
1174 exit:
1175 	status = usb_submit_urb(urb, GFP_ATOMIC);
1176 	if (status)
1177 		dev_err(dev, "%s - resubmit interrupt urb failed, %d\n", __FUNCTION__, status);
1178 }
1179 
1180 
1181 static void ti_bulk_in_callback(struct urb *urb, struct pt_regs *regs)
1182 {
1183 	struct ti_port *tport = (struct ti_port *)urb->context;
1184 	struct usb_serial_port *port = tport->tp_port;
1185 	struct device *dev = &urb->dev->dev;
1186 	int status = 0;
1187 
1188 	dbg("%s", __FUNCTION__);
1189 
1190 	switch (urb->status) {
1191 	case 0:
1192 		break;
1193 	case -ECONNRESET:
1194 	case -ENOENT:
1195 	case -ESHUTDOWN:
1196 		dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1197 		tport->tp_tdev->td_urb_error = 1;
1198 		wake_up_interruptible(&tport->tp_write_wait);
1199 		return;
1200 	default:
1201 		dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status );
1202 		tport->tp_tdev->td_urb_error = 1;
1203 		wake_up_interruptible(&tport->tp_write_wait);
1204 	}
1205 
1206 	if (urb->status == -EPIPE)
1207 		goto exit;
1208 
1209 	if (urb->status) {
1210 		dev_err(dev, "%s - stopping read!\n", __FUNCTION__);
1211 		return;
1212 	}
1213 
1214 	if (port->tty && urb->actual_length) {
1215 		usb_serial_debug_data(debug, dev, __FUNCTION__,
1216 			urb->actual_length, urb->transfer_buffer);
1217 
1218 		if (!tport->tp_is_open)
1219 			dbg("%s - port closed, dropping data", __FUNCTION__);
1220 		else
1221 			ti_recv(&urb->dev->dev, port->tty, urb->transfer_buffer,
1222 				urb->actual_length);
1223 
1224 		spin_lock(&tport->tp_lock);
1225 		tport->tp_icount.rx += urb->actual_length;
1226 		spin_unlock(&tport->tp_lock);
1227 	}
1228 
1229 exit:
1230 	/* continue to read unless stopping */
1231 	spin_lock(&tport->tp_lock);
1232 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING) {
1233 		urb->dev = port->serial->dev;
1234 		status = usb_submit_urb(urb, GFP_ATOMIC);
1235 	} else if (tport->tp_read_urb_state == TI_READ_URB_STOPPING) {
1236 		tport->tp_read_urb_state = TI_READ_URB_STOPPED;
1237 	}
1238 	spin_unlock(&tport->tp_lock);
1239 	if (status)
1240 		dev_err(dev, "%s - resubmit read urb failed, %d\n", __FUNCTION__, status);
1241 }
1242 
1243 
1244 static void ti_bulk_out_callback(struct urb *urb, struct pt_regs *regs)
1245 {
1246 	struct ti_port *tport = (struct ti_port *)urb->context;
1247 	struct usb_serial_port *port = tport->tp_port;
1248 	struct device *dev = &urb->dev->dev;
1249 
1250 	dbg("%s - port %d", __FUNCTION__, port->number);
1251 
1252 	tport->tp_write_urb_in_use = 0;
1253 
1254 	switch (urb->status) {
1255 	case 0:
1256 		break;
1257 	case -ECONNRESET:
1258 	case -ENOENT:
1259 	case -ESHUTDOWN:
1260 		dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1261 		tport->tp_tdev->td_urb_error = 1;
1262 		wake_up_interruptible(&tport->tp_write_wait);
1263 		return;
1264 	default:
1265 		dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status);
1266 		tport->tp_tdev->td_urb_error = 1;
1267 		wake_up_interruptible(&tport->tp_write_wait);
1268 	}
1269 
1270 	/* send any buffered data */
1271 	ti_send(tport);
1272 }
1273 
1274 
1275 static void ti_recv(struct device *dev, struct tty_struct *tty,
1276 	unsigned char *data, int length)
1277 {
1278 	int cnt;
1279 
1280 	do {
1281 		if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
1282 			tty_flip_buffer_push(tty);
1283 			if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
1284 				dev_err(dev, "%s - dropping data, %d bytes lost\n", __FUNCTION__, length);
1285 				return;
1286 			}
1287 		}
1288 		cnt = min(length, TTY_FLIPBUF_SIZE - tty->flip.count);
1289 		memcpy(tty->flip.char_buf_ptr, data, cnt);
1290 		memset(tty->flip.flag_buf_ptr, 0, cnt);
1291 		tty->flip.char_buf_ptr += cnt;
1292 		tty->flip.flag_buf_ptr += cnt;
1293 		tty->flip.count += cnt;
1294 		data += cnt;
1295 		length -= cnt;
1296 	} while (length > 0);
1297 
1298 	tty_flip_buffer_push(tty);
1299 }
1300 
1301 
1302 static void ti_send(struct ti_port *tport)
1303 {
1304 	int count, result;
1305 	struct usb_serial_port *port = tport->tp_port;
1306 	struct tty_struct *tty = port->tty;
1307 	unsigned long flags;
1308 
1309 
1310 	dbg("%s - port %d", __FUNCTION__, port->number);
1311 
1312 	spin_lock_irqsave(&tport->tp_lock, flags);
1313 
1314 	if (tport->tp_write_urb_in_use) {
1315 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1316 		return;
1317 	}
1318 
1319 	count = ti_buf_get(tport->tp_write_buf,
1320 				port->write_urb->transfer_buffer,
1321 				port->bulk_out_size);
1322 
1323 	if (count == 0) {
1324 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1325 		return;
1326 	}
1327 
1328 	tport->tp_write_urb_in_use = 1;
1329 
1330 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1331 
1332 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, port->write_urb->transfer_buffer);
1333 
1334 	usb_fill_bulk_urb(port->write_urb, port->serial->dev,
1335 			   usb_sndbulkpipe(port->serial->dev,
1336 					    port->bulk_out_endpointAddress),
1337 			   port->write_urb->transfer_buffer, count,
1338 			   ti_bulk_out_callback, tport);
1339 
1340 	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1341 	if (result) {
1342 		dev_err(&port->dev, "%s - submit write urb failed, %d\n", __FUNCTION__, result);
1343 		tport->tp_write_urb_in_use = 0;
1344 		/* TODO: reschedule ti_send */
1345 	} else {
1346 		spin_lock_irqsave(&tport->tp_lock, flags);
1347 		tport->tp_icount.tx += count;
1348 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1349 	}
1350 
1351 	/* more room in the buffer for new writes, wakeup */
1352 	if (tty)
1353 		tty_wakeup(tty);
1354 	wake_up_interruptible(&tport->tp_write_wait);
1355 }
1356 
1357 
1358 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr)
1359 {
1360 	int status;
1361 
1362 	status = ti_write_byte(tport->tp_tdev,
1363 		tport->tp_uart_base_addr + TI_UART_OFFSET_MCR,
1364 		TI_MCR_RTS | TI_MCR_DTR | TI_MCR_LOOP, mcr);
1365 
1366 	if (!status)
1367 		tport->tp_shadow_mcr = mcr;
1368 
1369 	return status;
1370 }
1371 
1372 
1373 static int ti_get_lsr(struct ti_port *tport)
1374 {
1375 	int size,status;
1376 	struct ti_device *tdev = tport->tp_tdev;
1377 	struct usb_serial_port *port = tport->tp_port;
1378 	int port_number = port->number - port->serial->minor;
1379 	struct ti_port_status *data;
1380 
1381 	dbg("%s - port %d", __FUNCTION__, port->number);
1382 
1383 	size = sizeof(struct ti_port_status);
1384 	data = kmalloc(size, GFP_KERNEL);
1385 	if (!data) {
1386 		dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
1387 		return -ENOMEM;
1388 	}
1389 
1390 	status = ti_command_in_sync(tdev, TI_GET_PORT_STATUS,
1391 		(__u8)(TI_UART1_PORT+port_number), 0, (__u8 *)data, size);
1392 	if (status) {
1393 		dev_err(&port->dev, "%s - get port status command failed, %d\n", __FUNCTION__, status);
1394 		goto free_data;
1395 	}
1396 
1397 	dbg("%s - lsr 0x%02X", __FUNCTION__, data->bLSR);
1398 
1399 	tport->tp_lsr = data->bLSR;
1400 
1401 free_data:
1402 	kfree(data);
1403 	return status;
1404 }
1405 
1406 
1407 static int ti_get_serial_info(struct ti_port *tport,
1408 	struct serial_struct __user *ret_arg)
1409 {
1410 	struct usb_serial_port *port = tport->tp_port;
1411 	struct serial_struct ret_serial;
1412 
1413 	if (!ret_arg)
1414 		return -EFAULT;
1415 
1416 	memset(&ret_serial, 0, sizeof(ret_serial));
1417 
1418 	ret_serial.type = PORT_16550A;
1419 	ret_serial.line = port->serial->minor;
1420 	ret_serial.port = port->number - port->serial->minor;
1421 	ret_serial.flags = tport->tp_flags;
1422 	ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
1423 	ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
1424 	ret_serial.closing_wait = tport->tp_closing_wait;
1425 
1426 	if (copy_to_user(ret_arg, &ret_serial, sizeof(*ret_arg)))
1427 		return -EFAULT;
1428 
1429 	return 0;
1430 }
1431 
1432 
1433 static int ti_set_serial_info(struct ti_port *tport,
1434 	struct serial_struct __user *new_arg)
1435 {
1436 	struct usb_serial_port *port = tport->tp_port;
1437 	struct serial_struct new_serial;
1438 
1439 	if (copy_from_user(&new_serial, new_arg, sizeof(new_serial)))
1440 		return -EFAULT;
1441 
1442 	tport->tp_flags = new_serial.flags & TI_SET_SERIAL_FLAGS;
1443 	if (port->tty)
1444 		port->tty->low_latency =
1445 			(tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1446 	tport->tp_closing_wait = new_serial.closing_wait;
1447 
1448 	return 0;
1449 }
1450 
1451 
1452 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr)
1453 {
1454 	struct async_icount *icount;
1455 	struct tty_struct *tty;
1456 	unsigned long flags;
1457 
1458 	dbg("%s - msr 0x%02X", __FUNCTION__, msr);
1459 
1460 	if (msr & TI_MSR_DELTA_MASK) {
1461 		spin_lock_irqsave(&tport->tp_lock, flags);
1462 		icount = &tport->tp_icount;
1463 		if (msr & TI_MSR_DELTA_CTS)
1464 			icount->cts++;
1465 		if (msr & TI_MSR_DELTA_DSR)
1466 			icount->dsr++;
1467 		if (msr & TI_MSR_DELTA_CD)
1468 			icount->dcd++;
1469 		if (msr & TI_MSR_DELTA_RI)
1470 			icount->rng++;
1471 		wake_up_interruptible(&tport->tp_msr_wait);
1472 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1473 	}
1474 
1475 	tport->tp_msr = msr & TI_MSR_MASK;
1476 
1477 	/* handle CTS flow control */
1478 	tty = tport->tp_port->tty;
1479 	if (tty && C_CRTSCTS(tty)) {
1480 		if (msr & TI_MSR_CTS) {
1481 			tty->hw_stopped = 0;
1482 			tty_wakeup(tty);
1483 		} else {
1484 			tty->hw_stopped = 1;
1485 		}
1486 	}
1487 }
1488 
1489 
1490 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
1491 {
1492 	struct ti_device *tdev = tport->tp_tdev;
1493 	struct usb_serial_port *port = tport->tp_port;
1494 	wait_queue_t wait;
1495 	unsigned long flags;
1496 
1497 	dbg("%s - port %d", __FUNCTION__, port->number);
1498 
1499 	spin_lock_irqsave(&tport->tp_lock, flags);
1500 
1501 	/* wait for data to drain from the buffer */
1502 	tdev->td_urb_error = 0;
1503 	init_waitqueue_entry(&wait, current);
1504 	add_wait_queue(&tport->tp_write_wait, &wait);
1505 	for (;;) {
1506 		set_current_state(TASK_INTERRUPTIBLE);
1507 		if (ti_buf_data_avail(tport->tp_write_buf) == 0
1508 		|| timeout == 0 || signal_pending(current)
1509 		|| tdev->td_urb_error
1510 		|| !usb_get_intfdata(port->serial->interface))  /* disconnect */
1511 			break;
1512 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1513 		timeout = schedule_timeout(timeout);
1514 		spin_lock_irqsave(&tport->tp_lock, flags);
1515 	}
1516 	set_current_state(TASK_RUNNING);
1517 	remove_wait_queue(&tport->tp_write_wait, &wait);
1518 
1519 	/* flush any remaining data in the buffer */
1520 	if (flush)
1521 		ti_buf_clear(tport->tp_write_buf);
1522 
1523 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1524 
1525 	/* wait for data to drain from the device */
1526 	/* wait for empty tx register, plus 20 ms */
1527 	timeout += jiffies;
1528 	tport->tp_lsr &= ~TI_LSR_TX_EMPTY;
1529 	while ((long)(jiffies - timeout) < 0 && !signal_pending(current)
1530 	&& !(tport->tp_lsr&TI_LSR_TX_EMPTY) && !tdev->td_urb_error
1531 	&& usb_get_intfdata(port->serial->interface)) {  /* not disconnected */
1532 		if (ti_get_lsr(tport))
1533 			break;
1534 		msleep_interruptible(20);
1535 	}
1536 }
1537 
1538 
1539 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty)
1540 {
1541 	unsigned long flags;
1542 
1543 	spin_lock_irqsave(&tport->tp_lock, flags);
1544 
1545 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING)
1546 		tport->tp_read_urb_state = TI_READ_URB_STOPPING;
1547 
1548 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1549 }
1550 
1551 
1552 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty)
1553 {
1554 	struct urb *urb;
1555 	int status = 0;
1556 	unsigned long flags;
1557 
1558 	spin_lock_irqsave(&tport->tp_lock, flags);
1559 
1560 	if (tport->tp_read_urb_state == TI_READ_URB_STOPPED) {
1561 		urb = tport->tp_port->read_urb;
1562 		urb->complete = ti_bulk_in_callback;
1563 		urb->context = tport;
1564 		urb->dev = tport->tp_port->serial->dev;
1565 		status = usb_submit_urb(urb, GFP_KERNEL);
1566 	}
1567 	tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1568 
1569 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1570 
1571 	return status;
1572 }
1573 
1574 
1575 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
1576 	__u16 moduleid, __u16 value, __u8 *data, int size)
1577 {
1578 	int status;
1579 
1580 	status = usb_control_msg(tdev->td_serial->dev,
1581 		usb_sndctrlpipe(tdev->td_serial->dev, 0), command,
1582 		(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT),
1583 		value, moduleid, data, size, 1000);
1584 
1585 	if (status == size)
1586 		status = 0;
1587 
1588 	if (status > 0)
1589 		status = -ECOMM;
1590 
1591 	return status;
1592 }
1593 
1594 
1595 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
1596 	__u16 moduleid, __u16 value, __u8 *data, int size)
1597 {
1598 	int status;
1599 
1600 	status = usb_control_msg(tdev->td_serial->dev,
1601 		usb_rcvctrlpipe(tdev->td_serial->dev, 0), command,
1602 		(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN),
1603 		value, moduleid, data, size, 1000);
1604 
1605 	if (status == size)
1606 		status = 0;
1607 
1608 	if (status > 0)
1609 		status = -ECOMM;
1610 
1611 	return status;
1612 }
1613 
1614 
1615 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
1616 	__u8 mask, __u8 byte)
1617 {
1618 	int status;
1619 	unsigned int size;
1620 	struct ti_write_data_bytes *data;
1621 	struct device *dev = &tdev->td_serial->dev->dev;
1622 
1623 	dbg("%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X", __FUNCTION__, addr, mask, byte);
1624 
1625 	size = sizeof(struct ti_write_data_bytes) + 2;
1626 	data = kmalloc(size, GFP_KERNEL);
1627 	if (!data) {
1628 		dev_err(dev, "%s - out of memory\n", __FUNCTION__);
1629 		return -ENOMEM;
1630 	}
1631 
1632 	data->bAddrType = TI_RW_DATA_ADDR_XDATA;
1633 	data->bDataType = TI_RW_DATA_BYTE;
1634 	data->bDataCounter = 1;
1635 	data->wBaseAddrHi = cpu_to_be16(addr>>16);
1636 	data->wBaseAddrLo = cpu_to_be16(addr);
1637 	data->bData[0] = mask;
1638 	data->bData[1] = byte;
1639 
1640 	status = ti_command_out_sync(tdev, TI_WRITE_DATA, TI_RAM_PORT, 0,
1641 		(__u8 *)data, size);
1642 
1643 	if (status < 0)
1644 		dev_err(dev, "%s - failed, %d\n", __FUNCTION__, status);
1645 
1646 	kfree(data);
1647 
1648 	return status;
1649 }
1650 
1651 
1652 static int ti_download_firmware(struct ti_device *tdev,
1653 	unsigned char *firmware, unsigned int firmware_size)
1654 {
1655 	int status = 0;
1656 	int buffer_size;
1657 	int pos;
1658 	int len;
1659 	int done;
1660 	__u8 cs = 0;
1661 	__u8 *buffer;
1662 	struct usb_device *dev = tdev->td_serial->dev;
1663 	struct ti_firmware_header *header;
1664 	unsigned int pipe = usb_sndbulkpipe(dev,
1665 		tdev->td_serial->port[0]->bulk_out_endpointAddress);
1666 
1667 
1668 	buffer_size = TI_FIRMWARE_BUF_SIZE + sizeof(struct ti_firmware_header);
1669 	buffer = kmalloc(buffer_size, GFP_KERNEL);
1670 	if (!buffer) {
1671 		dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
1672 		return -ENOMEM;
1673 	}
1674 
1675 	memcpy(buffer, firmware, firmware_size);
1676 	memset(buffer+firmware_size, 0xff, buffer_size-firmware_size);
1677 
1678 	for(pos = sizeof(struct ti_firmware_header); pos < buffer_size; pos++)
1679 		cs = (__u8)(cs + buffer[pos]);
1680 
1681 	header = (struct ti_firmware_header *)buffer;
1682 	header->wLength = cpu_to_le16((__u16)(buffer_size - sizeof(struct ti_firmware_header)));
1683 	header->bCheckSum = cs;
1684 
1685 	dbg("%s - downloading firmware", __FUNCTION__);
1686 	for (pos = 0; pos < buffer_size; pos += done) {
1687 		len = min(buffer_size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
1688 		status = usb_bulk_msg(dev, pipe, buffer+pos, len, &done, 1000);
1689 		if (status)
1690 			break;
1691 	}
1692 
1693 	kfree(buffer);
1694 
1695 	if (status) {
1696 		dev_err(&dev->dev, "%s - error downloading firmware, %d\n", __FUNCTION__, status);
1697 		return status;
1698 	}
1699 
1700 	dbg("%s - download successful", __FUNCTION__);
1701 
1702 	return 0;
1703 }
1704 
1705 
1706 /* Circular Buffer Functions */
1707 
1708 /*
1709  * ti_buf_alloc
1710  *
1711  * Allocate a circular buffer and all associated memory.
1712  */
1713 
1714 static struct circ_buf *ti_buf_alloc(void)
1715 {
1716 	struct circ_buf *cb;
1717 
1718 	cb = (struct circ_buf *)kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
1719 	if (cb == NULL)
1720 		return NULL;
1721 
1722 	cb->buf = kmalloc(TI_WRITE_BUF_SIZE, GFP_KERNEL);
1723 	if (cb->buf == NULL) {
1724 		kfree(cb);
1725 		return NULL;
1726 	}
1727 
1728 	ti_buf_clear(cb);
1729 
1730 	return cb;
1731 }
1732 
1733 
1734 /*
1735  * ti_buf_free
1736  *
1737  * Free the buffer and all associated memory.
1738  */
1739 
1740 static void ti_buf_free(struct circ_buf *cb)
1741 {
1742 	kfree(cb->buf);
1743 	kfree(cb);
1744 }
1745 
1746 
1747 /*
1748  * ti_buf_clear
1749  *
1750  * Clear out all data in the circular buffer.
1751  */
1752 
1753 static void ti_buf_clear(struct circ_buf *cb)
1754 {
1755 	cb->head = cb->tail = 0;
1756 }
1757 
1758 
1759 /*
1760  * ti_buf_data_avail
1761  *
1762  * Return the number of bytes of data available in the circular
1763  * buffer.
1764  */
1765 
1766 static int ti_buf_data_avail(struct circ_buf *cb)
1767 {
1768 	return CIRC_CNT(cb->head,cb->tail,TI_WRITE_BUF_SIZE);
1769 }
1770 
1771 
1772 /*
1773  * ti_buf_space_avail
1774  *
1775  * Return the number of bytes of space available in the circular
1776  * buffer.
1777  */
1778 
1779 static int ti_buf_space_avail(struct circ_buf *cb)
1780 {
1781 	return CIRC_SPACE(cb->head,cb->tail,TI_WRITE_BUF_SIZE);
1782 }
1783 
1784 
1785 /*
1786  * ti_buf_put
1787  *
1788  * Copy data data from a user buffer and put it into the circular buffer.
1789  * Restrict to the amount of space available.
1790  *
1791  * Return the number of bytes copied.
1792  */
1793 
1794 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count)
1795 {
1796 	int c, ret = 0;
1797 
1798 	while (1) {
1799 		c = CIRC_SPACE_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1800 		if (count < c)
1801 			c = count;
1802 		if (c <= 0)
1803 			break;
1804 		memcpy(cb->buf + cb->head, buf, c);
1805 		cb->head = (cb->head + c) & (TI_WRITE_BUF_SIZE-1);
1806 		buf += c;
1807 		count -= c;
1808 		ret += c;
1809 	}
1810 
1811 	return ret;
1812 }
1813 
1814 
1815 /*
1816  * ti_buf_get
1817  *
1818  * Get data from the circular buffer and copy to the given buffer.
1819  * Restrict to the amount of data available.
1820  *
1821  * Return the number of bytes copied.
1822  */
1823 
1824 static int ti_buf_get(struct circ_buf *cb, char *buf, int count)
1825 {
1826 	int c, ret = 0;
1827 
1828 	while (1) {
1829 		c = CIRC_CNT_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1830 		if (count < c)
1831 			c = count;
1832 		if (c <= 0)
1833 			break;
1834 		memcpy(buf, cb->buf + cb->tail, c);
1835 		cb->tail = (cb->tail + c) & (TI_WRITE_BUF_SIZE-1);
1836 		buf += c;
1837 		count -= c;
1838 		ret += c;
1839 	}
1840 
1841 	return ret;
1842 }
1843