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