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