xref: /linux/drivers/usb/serial/ti_usb_3410_5052.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
1 /* vi: ts=8 sw=8
2  *
3  * TI 3410/5052 USB Serial Driver
4  *
5  * Copyright (C) 2004 Texas Instruments
6  *
7  * This driver is based on the Linux io_ti driver, which is
8  *   Copyright (C) 2000-2002 Inside Out Networks
9  *   Copyright (C) 2001-2002 Greg Kroah-Hartman
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * For questions or problems with this driver, contact Texas Instruments
17  * technical support, or Al Borchers <alborchers@steinerpoint.com>, or
18  * Peter Berger <pberger@brimson.com>.
19  *
20  * This driver needs this hotplug script in /etc/hotplug/usb/ti_usb_3410_5052
21  * or in /etc/hotplug.d/usb/ti_usb_3410_5052.hotplug to set the device
22  * configuration.
23  *
24  * #!/bin/bash
25  *
26  * BOOT_CONFIG=1
27  * ACTIVE_CONFIG=2
28  *
29  * if [[ "$ACTION" != "add" ]]
30  * then
31  * 	exit
32  * fi
33  *
34  * CONFIG_PATH=/sys${DEVPATH%/?*}/bConfigurationValue
35  *
36  * if [[ 0`cat $CONFIG_PATH` -ne $BOOT_CONFIG ]]
37  * then
38  * 	exit
39  * fi
40  *
41  * PRODUCT=${PRODUCT%/?*}		# delete version
42  * VENDOR_ID=`printf "%d" 0x${PRODUCT%/?*}`
43  * PRODUCT_ID=`printf "%d" 0x${PRODUCT#*?/}`
44  *
45  * PARAM_PATH=/sys/module/ti_usb_3410_5052/parameters
46  *
47  * function scan() {
48  * 	s=$1
49  * 	shift
50  * 	for i
51  * 	do
52  * 		if [[ $s -eq $i ]]
53  * 		then
54  * 			return 0
55  * 		fi
56  * 	done
57  * 	return 1
58  * }
59  *
60  * IFS=$IFS,
61  *
62  * if (scan $VENDOR_ID 1105 `cat $PARAM_PATH/vendor_3410` &&
63  * scan $PRODUCT_ID 13328 `cat $PARAM_PATH/product_3410`) ||
64  * (scan $VENDOR_ID 1105 `cat $PARAM_PATH/vendor_5052` &&
65  * scan $PRODUCT_ID 20562 20818 20570 20575 `cat $PARAM_PATH/product_5052`)
66  * then
67  * 	echo $ACTIVE_CONFIG > $CONFIG_PATH
68  * fi
69  */
70 
71 #include <linux/config.h>
72 #include <linux/kernel.h>
73 #include <linux/errno.h>
74 #include <linux/init.h>
75 #include <linux/slab.h>
76 #include <linux/tty.h>
77 #include <linux/tty_driver.h>
78 #include <linux/tty_flip.h>
79 #include <linux/module.h>
80 #include <linux/spinlock.h>
81 #include <linux/ioctl.h>
82 #include <linux/serial.h>
83 #include <linux/circ_buf.h>
84 #include <asm/uaccess.h>
85 #include <asm/semaphore.h>
86 #include <linux/usb.h>
87 
88 #include "usb-serial.h"
89 #include "ti_usb_3410_5052.h"
90 #include "ti_fw_3410.h"		/* firmware image for 3410 */
91 #include "ti_fw_5052.h"		/* firmware image for 5052 */
92 
93 
94 /* Defines */
95 
96 #define TI_DRIVER_VERSION	"v0.9"
97 #define TI_DRIVER_AUTHOR	"Al Borchers <alborchers@steinerpoint.com>"
98 #define TI_DRIVER_DESC		"TI USB 3410/5052 Serial Driver"
99 
100 #define TI_FIRMWARE_BUF_SIZE	16284
101 
102 #define TI_WRITE_BUF_SIZE	1024
103 
104 #define TI_TRANSFER_TIMEOUT	2
105 
106 #define TI_DEFAULT_LOW_LATENCY	0
107 #define TI_DEFAULT_CLOSING_WAIT	4000		/* in .01 secs */
108 
109 /* supported setserial flags */
110 #define TI_SET_SERIAL_FLAGS	(ASYNC_LOW_LATENCY)
111 
112 /* read urb states */
113 #define TI_READ_URB_RUNNING	0
114 #define TI_READ_URB_STOPPING	1
115 #define TI_READ_URB_STOPPED	2
116 
117 #define TI_EXTRA_VID_PID_COUNT	5
118 
119 
120 /* Structures */
121 
122 struct ti_port {
123 	int			tp_is_open;
124 	__u8			tp_msr;
125 	__u8			tp_lsr;
126 	__u8			tp_shadow_mcr;
127 	__u8			tp_uart_mode;	/* 232 or 485 modes */
128 	unsigned int		tp_uart_base_addr;
129 	int			tp_flags;
130 	int			tp_closing_wait;/* in .01 secs */
131 	struct async_icount	tp_icount;
132 	wait_queue_head_t	tp_msr_wait;	/* wait for msr change */
133 	wait_queue_head_t	tp_write_wait;
134 	struct ti_device	*tp_tdev;
135 	struct usb_serial_port	*tp_port;
136 	spinlock_t		tp_lock;
137 	int			tp_read_urb_state;
138 	int			tp_write_urb_in_use;
139 	struct circ_buf		*tp_write_buf;
140 };
141 
142 struct ti_device {
143 	struct semaphore	td_open_close_sem;
144 	int			td_open_port_count;
145 	struct usb_serial	*td_serial;
146 	int			td_is_3410;
147 	int			td_urb_error;
148 };
149 
150 
151 /* Function Declarations */
152 
153 static int ti_startup(struct usb_serial *serial);
154 static void ti_shutdown(struct usb_serial *serial);
155 static int ti_open(struct usb_serial_port *port, struct file *file);
156 static void ti_close(struct usb_serial_port *port, struct file *file);
157 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
158 	int count);
159 static int ti_write_room(struct usb_serial_port *port);
160 static int ti_chars_in_buffer(struct usb_serial_port *port);
161 static void ti_throttle(struct usb_serial_port *port);
162 static void ti_unthrottle(struct usb_serial_port *port);
163 static int ti_ioctl(struct usb_serial_port *port, struct file *file, unsigned int cmd, unsigned long arg);
164 static void ti_set_termios(struct usb_serial_port *port,
165 	struct termios *old_termios);
166 static int ti_tiocmget(struct usb_serial_port *port, struct file *file);
167 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
168 	unsigned int set, unsigned int clear);
169 static void ti_break(struct usb_serial_port *port, int break_state);
170 static void ti_interrupt_callback(struct urb *urb, struct pt_regs *regs);
171 static void ti_bulk_in_callback(struct urb *urb, struct pt_regs *regs);
172 static void ti_bulk_out_callback(struct urb *urb, struct pt_regs *regs);
173 
174 static void ti_recv(struct device *dev, struct tty_struct *tty,
175 	unsigned char *data, int length);
176 static void ti_send(struct ti_port *tport);
177 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr);
178 static int ti_get_lsr(struct ti_port *tport);
179 static int ti_get_serial_info(struct ti_port *tport,
180 	struct serial_struct __user *ret_arg);
181 static int ti_set_serial_info(struct ti_port *tport,
182 	struct serial_struct __user *new_arg);
183 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr);
184 
185 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush);
186 
187 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty);
188 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty);
189 
190 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
191 	__u16 moduleid, __u16 value, __u8 *data, int size);
192 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
193 	__u16 moduleid, __u16 value, __u8 *data, int size);
194 
195 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
196 	__u8 mask, __u8 byte);
197 
198 static int ti_download_firmware(struct ti_device *tdev,
199 	unsigned char *firmware, unsigned int firmware_size);
200 
201 /* circular buffer */
202 static struct circ_buf *ti_buf_alloc(void);
203 static void ti_buf_free(struct circ_buf *cb);
204 static void ti_buf_clear(struct circ_buf *cb);
205 static int ti_buf_data_avail(struct circ_buf *cb);
206 static int ti_buf_space_avail(struct circ_buf *cb);
207 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count);
208 static int ti_buf_get(struct circ_buf *cb, char *buf, int count);
209 
210 
211 /* Data */
212 
213 /* module parameters */
214 static int debug;
215 static int low_latency = TI_DEFAULT_LOW_LATENCY;
216 static int closing_wait = TI_DEFAULT_CLOSING_WAIT;
217 static ushort vendor_3410[TI_EXTRA_VID_PID_COUNT];
218 static int vendor_3410_count;
219 static ushort product_3410[TI_EXTRA_VID_PID_COUNT];
220 static int product_3410_count;
221 static ushort vendor_5052[TI_EXTRA_VID_PID_COUNT];
222 static int vendor_5052_count;
223 static ushort product_5052[TI_EXTRA_VID_PID_COUNT];
224 static int product_5052_count;
225 
226 /* supported devices */
227 /* the array dimension is the number of default entries plus */
228 /* TI_EXTRA_VID_PID_COUNT user defined entries plus 1 terminating */
229 /* null entry */
230 static struct usb_device_id ti_id_table_3410[1+TI_EXTRA_VID_PID_COUNT+1] = {
231 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
232 };
233 
234 static struct usb_device_id ti_id_table_5052[4+TI_EXTRA_VID_PID_COUNT+1] = {
235 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
236 	{ USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
237 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
238 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
239 };
240 
241 static struct usb_device_id ti_id_table_combined[] = {
242 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
243 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
244 	{ USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
245 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
246 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
247 	{ }
248 };
249 
250 static struct usb_driver ti_usb_driver = {
251 	.owner			= THIS_MODULE,
252 	.name			= "ti_usb_3410_5052",
253 	.probe			= usb_serial_probe,
254 	.disconnect		= usb_serial_disconnect,
255 	.id_table		= ti_id_table_combined,
256 };
257 
258 static struct usb_serial_driver ti_1port_device = {
259 	.driver = {
260 		.owner		= THIS_MODULE,
261 		.name		= "ti_usb_3410_5052_1",
262 	},
263 	.description		= "TI USB 3410 1 port adapter",
264 	.id_table		= ti_id_table_3410,
265 	.num_interrupt_in	= 1,
266 	.num_bulk_in		= 1,
267 	.num_bulk_out		= 1,
268 	.num_ports		= 1,
269 	.attach			= ti_startup,
270 	.shutdown		= ti_shutdown,
271 	.open			= ti_open,
272 	.close			= ti_close,
273 	.write			= ti_write,
274 	.write_room		= ti_write_room,
275 	.chars_in_buffer	= ti_chars_in_buffer,
276 	.throttle		= ti_throttle,
277 	.unthrottle		= ti_unthrottle,
278 	.ioctl			= ti_ioctl,
279 	.set_termios		= ti_set_termios,
280 	.tiocmget		= ti_tiocmget,
281 	.tiocmset		= ti_tiocmset,
282 	.break_ctl		= ti_break,
283 	.read_int_callback	= ti_interrupt_callback,
284 	.read_bulk_callback	= ti_bulk_in_callback,
285 	.write_bulk_callback	= ti_bulk_out_callback,
286 };
287 
288 static struct usb_serial_driver ti_2port_device = {
289 	.driver = {
290 		.owner		= THIS_MODULE,
291 		.name		= "ti_usb_3410_5052_2",
292 	},
293 	.description		= "TI USB 5052 2 port adapter",
294 	.id_table		= ti_id_table_5052,
295 	.num_interrupt_in	= 1,
296 	.num_bulk_in		= 2,
297 	.num_bulk_out		= 2,
298 	.num_ports		= 2,
299 	.attach			= ti_startup,
300 	.shutdown		= ti_shutdown,
301 	.open			= ti_open,
302 	.close			= ti_close,
303 	.write			= ti_write,
304 	.write_room		= ti_write_room,
305 	.chars_in_buffer	= ti_chars_in_buffer,
306 	.throttle		= ti_throttle,
307 	.unthrottle		= ti_unthrottle,
308 	.ioctl			= ti_ioctl,
309 	.set_termios		= ti_set_termios,
310 	.tiocmget		= ti_tiocmget,
311 	.tiocmset		= ti_tiocmset,
312 	.break_ctl		= ti_break,
313 	.read_int_callback	= ti_interrupt_callback,
314 	.read_bulk_callback	= ti_bulk_in_callback,
315 	.write_bulk_callback	= ti_bulk_out_callback,
316 };
317 
318 
319 /* Module */
320 
321 MODULE_AUTHOR(TI_DRIVER_AUTHOR);
322 MODULE_DESCRIPTION(TI_DRIVER_DESC);
323 MODULE_VERSION(TI_DRIVER_VERSION);
324 MODULE_LICENSE("GPL");
325 
326 module_param(debug, bool, S_IRUGO | S_IWUSR);
327 MODULE_PARM_DESC(debug, "Enable debugging, 0=no, 1=yes");
328 
329 module_param(low_latency, bool, S_IRUGO | S_IWUSR);
330 MODULE_PARM_DESC(low_latency, "TTY low_latency flag, 0=off, 1=on, default is off");
331 
332 module_param(closing_wait, int, S_IRUGO | S_IWUSR);
333 MODULE_PARM_DESC(closing_wait, "Maximum wait for data to drain in close, in .01 secs, default is 4000");
334 
335 module_param_array(vendor_3410, ushort, &vendor_3410_count, S_IRUGO);
336 MODULE_PARM_DESC(vendor_3410, "Vendor ids for 3410 based devices, 1-5 short integers");
337 module_param_array(product_3410, ushort, &product_3410_count, S_IRUGO);
338 MODULE_PARM_DESC(product_3410, "Product ids for 3410 based devices, 1-5 short integers");
339 module_param_array(vendor_5052, ushort, &vendor_5052_count, S_IRUGO);
340 MODULE_PARM_DESC(vendor_5052, "Vendor ids for 5052 based devices, 1-5 short integers");
341 module_param_array(product_5052, ushort, &product_5052_count, S_IRUGO);
342 MODULE_PARM_DESC(product_5052, "Product ids for 5052 based devices, 1-5 short integers");
343 
344 MODULE_DEVICE_TABLE(usb, ti_id_table_combined);
345 
346 
347 /* Functions */
348 
349 static int __init ti_init(void)
350 {
351 	int i,j;
352 	int ret;
353 
354 
355 	/* insert extra vendor and product ids */
356 	j = sizeof(ti_id_table_3410)/sizeof(struct usb_device_id)
357 		- TI_EXTRA_VID_PID_COUNT - 1;
358 	for (i=0; i<min(vendor_3410_count,product_3410_count); i++,j++) {
359 		ti_id_table_3410[j].idVendor = vendor_3410[i];
360 		ti_id_table_3410[j].idProduct = product_3410[i];
361 		ti_id_table_3410[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
362 	}
363 	j = sizeof(ti_id_table_5052)/sizeof(struct usb_device_id)
364 		- 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 = kmalloc(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 	memset(tdev, 0, sizeof(struct ti_device));
428 	sema_init(&tdev->td_open_close_sem, 1);
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 = kmalloc(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 		memset(tport, 0, sizeof(struct ti_port));
474 		spin_lock_init(&tport->tp_lock);
475 		tport->tp_uart_base_addr = (i == 0 ? TI_UART1_BASE_ADDR : TI_UART2_BASE_ADDR);
476 		tport->tp_flags = low_latency ? ASYNC_LOW_LATENCY : 0;
477 		tport->tp_closing_wait = closing_wait;
478 		init_waitqueue_head(&tport->tp_msr_wait);
479 		init_waitqueue_head(&tport->tp_write_wait);
480 		tport->tp_write_buf = ti_buf_alloc();
481 		if (tport->tp_write_buf == NULL) {
482 			dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
483 			kfree(tport);
484 			status = -ENOMEM;
485 			goto free_tports;
486 		}
487 		tport->tp_port = serial->port[i];
488 		tport->tp_tdev = tdev;
489 		usb_set_serial_port_data(serial->port[i], tport);
490 		tport->tp_uart_mode = 0;	/* default is RS232 */
491 	}
492 
493 	return 0;
494 
495 free_tports:
496 	for (--i; i>=0; --i) {
497 		tport = usb_get_serial_port_data(serial->port[i]);
498 		ti_buf_free(tport->tp_write_buf);
499 		kfree(tport);
500 		usb_set_serial_port_data(serial->port[i], NULL);
501 	}
502 free_tdev:
503 	kfree(tdev);
504 	usb_set_serial_data(serial, NULL);
505 	return status;
506 }
507 
508 
509 static void ti_shutdown(struct usb_serial *serial)
510 {
511 	int i;
512 	struct ti_device *tdev = usb_get_serial_data(serial);
513 	struct ti_port *tport;
514 
515 	dbg("%s", __FUNCTION__);
516 
517 	for (i=0; i < serial->num_ports; ++i) {
518 		tport = usb_get_serial_port_data(serial->port[i]);
519 		if (tport) {
520 			ti_buf_free(tport->tp_write_buf);
521 			kfree(tport);
522 			usb_set_serial_port_data(serial->port[i], NULL);
523 		}
524 	}
525 
526 	kfree(tdev);
527 	usb_set_serial_data(serial, NULL);
528 }
529 
530 
531 static int ti_open(struct usb_serial_port *port, struct file *file)
532 {
533 	struct ti_port *tport = usb_get_serial_port_data(port);
534 	struct ti_device *tdev;
535 	struct usb_device *dev;
536 	struct urb *urb;
537 	int port_number;
538 	int status;
539 	__u16 open_settings = (__u8)(TI_PIPE_MODE_CONTINOUS |
540 			     TI_PIPE_TIMEOUT_ENABLE |
541 			     (TI_TRANSFER_TIMEOUT << 2));
542 
543 	dbg("%s - port %d", __FUNCTION__, port->number);
544 
545 	if (tport == NULL)
546 		return -ENODEV;
547 
548 	dev = port->serial->dev;
549 	tdev = tport->tp_tdev;
550 
551 	/* only one open on any port on a device at a time */
552 	if (down_interruptible(&tdev->td_open_close_sem))
553 		return -ERESTARTSYS;
554 
555 	if (port->tty)
556 		port->tty->low_latency =
557 			(tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
558 
559 	port_number = port->number - port->serial->minor;
560 
561 	memset(&(tport->tp_icount), 0x00, sizeof(tport->tp_icount));
562 
563 	tport->tp_msr = 0;
564 	tport->tp_shadow_mcr |= (TI_MCR_RTS | TI_MCR_DTR);
565 
566 	/* start interrupt urb the first time a port is opened on this device */
567 	if (tdev->td_open_port_count == 0) {
568 		dbg("%s - start interrupt in urb", __FUNCTION__);
569 		urb = tdev->td_serial->port[0]->interrupt_in_urb;
570 		if (!urb) {
571 			dev_err(&port->dev, "%s - no interrupt urb\n", __FUNCTION__);
572 			status = -EINVAL;
573 			goto up_sem;
574 		}
575 		urb->complete = ti_interrupt_callback;
576 		urb->context = tdev;
577 		urb->dev = dev;
578 		status = usb_submit_urb(urb, GFP_KERNEL);
579 		if (status) {
580 			dev_err(&port->dev, "%s - submit interrupt urb failed, %d\n", __FUNCTION__, status);
581 			goto up_sem;
582 		}
583 	}
584 
585 	ti_set_termios(port, NULL);
586 
587 	dbg("%s - sending TI_OPEN_PORT", __FUNCTION__);
588 	status = ti_command_out_sync(tdev, TI_OPEN_PORT,
589 		(__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
590 	if (status) {
591 		dev_err(&port->dev, "%s - cannot send open command, %d\n", __FUNCTION__, status);
592 		goto unlink_int_urb;
593 	}
594 
595 	dbg("%s - sending TI_START_PORT", __FUNCTION__);
596 	status = ti_command_out_sync(tdev, TI_START_PORT,
597 		(__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
598 	if (status) {
599 		dev_err(&port->dev, "%s - cannot send start command, %d\n", __FUNCTION__, status);
600 		goto unlink_int_urb;
601 	}
602 
603 	dbg("%s - sending TI_PURGE_PORT", __FUNCTION__);
604 	status = ti_command_out_sync(tdev, TI_PURGE_PORT,
605 		(__u8)(TI_UART1_PORT + port_number), TI_PURGE_INPUT, NULL, 0);
606 	if (status) {
607 		dev_err(&port->dev, "%s - cannot clear input buffers, %d\n", __FUNCTION__, status);
608 		goto unlink_int_urb;
609 	}
610 	status = ti_command_out_sync(tdev, TI_PURGE_PORT,
611 		(__u8)(TI_UART1_PORT + port_number), TI_PURGE_OUTPUT, NULL, 0);
612 	if (status) {
613 		dev_err(&port->dev, "%s - cannot clear output buffers, %d\n", __FUNCTION__, status);
614 		goto unlink_int_urb;
615 	}
616 
617 	/* reset the data toggle on the bulk endpoints to work around bug in
618 	 * host controllers where things get out of sync some times */
619 	usb_clear_halt(dev, port->write_urb->pipe);
620 	usb_clear_halt(dev, port->read_urb->pipe);
621 
622 	ti_set_termios(port, NULL);
623 
624 	dbg("%s - sending TI_OPEN_PORT (2)", __FUNCTION__);
625 	status = ti_command_out_sync(tdev, TI_OPEN_PORT,
626 		(__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
627 	if (status) {
628 		dev_err(&port->dev, "%s - cannot send open command (2), %d\n", __FUNCTION__, status);
629 		goto unlink_int_urb;
630 	}
631 
632 	dbg("%s - sending TI_START_PORT (2)", __FUNCTION__);
633 	status = ti_command_out_sync(tdev, TI_START_PORT,
634 		(__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
635 	if (status) {
636 		dev_err(&port->dev, "%s - cannot send start command (2), %d\n", __FUNCTION__, status);
637 		goto unlink_int_urb;
638 	}
639 
640 	/* start read urb */
641 	dbg("%s - start read urb", __FUNCTION__);
642 	urb = port->read_urb;
643 	if (!urb) {
644 		dev_err(&port->dev, "%s - no read urb\n", __FUNCTION__);
645 		status = -EINVAL;
646 		goto unlink_int_urb;
647 	}
648 	tport->tp_read_urb_state = TI_READ_URB_RUNNING;
649 	urb->complete = ti_bulk_in_callback;
650 	urb->context = tport;
651 	urb->dev = dev;
652 	status = usb_submit_urb(urb, GFP_KERNEL);
653 	if (status) {
654 		dev_err(&port->dev, "%s - submit read urb failed, %d\n", __FUNCTION__, status);
655 		goto unlink_int_urb;
656 	}
657 
658 	tport->tp_is_open = 1;
659 	++tdev->td_open_port_count;
660 
661 	goto up_sem;
662 
663 unlink_int_urb:
664 	if (tdev->td_open_port_count == 0)
665 		usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
666 up_sem:
667 	up(&tdev->td_open_close_sem);
668 	dbg("%s - exit %d", __FUNCTION__, status);
669 	return status;
670 }
671 
672 
673 static void ti_close(struct usb_serial_port *port, struct file *file)
674 {
675 	struct ti_device *tdev;
676 	struct ti_port *tport;
677 	int port_number;
678 	int status;
679 	int do_up;
680 
681 	dbg("%s - port %d", __FUNCTION__, port->number);
682 
683 	tdev = usb_get_serial_data(port->serial);
684 	tport = usb_get_serial_port_data(port);
685 	if (tdev == NULL || tport == NULL)
686 		return;
687 
688 	tport->tp_is_open = 0;
689 
690 	ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 1);
691 
692 	usb_kill_urb(port->read_urb);
693 	usb_kill_urb(port->write_urb);
694 	tport->tp_write_urb_in_use = 0;
695 
696 	port_number = port->number - port->serial->minor;
697 
698 	dbg("%s - sending TI_CLOSE_PORT", __FUNCTION__);
699 	status = ti_command_out_sync(tdev, TI_CLOSE_PORT,
700 		     (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
701 	if (status)
702 		dev_err(&port->dev, "%s - cannot send close port command, %d\n" , __FUNCTION__, status);
703 
704 	/* if down is interrupted, continue anyway */
705 	do_up = !down_interruptible(&tdev->td_open_close_sem);
706 	--tport->tp_tdev->td_open_port_count;
707 	if (tport->tp_tdev->td_open_port_count <= 0) {
708 		/* last port is closed, shut down interrupt urb */
709 		usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
710 		tport->tp_tdev->td_open_port_count = 0;
711 	}
712 	if (do_up)
713 		up(&tdev->td_open_close_sem);
714 
715 	dbg("%s - exit", __FUNCTION__);
716 }
717 
718 
719 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
720 	int count)
721 {
722 	struct ti_port *tport = usb_get_serial_port_data(port);
723 	unsigned long flags;
724 
725 	dbg("%s - port %d", __FUNCTION__, port->number);
726 
727 	if (count == 0) {
728 		dbg("%s - write request of 0 bytes", __FUNCTION__);
729 		return 0;
730 	}
731 
732 	if (tport == NULL || !tport->tp_is_open)
733 		return -ENODEV;
734 
735 	spin_lock_irqsave(&tport->tp_lock, flags);
736 	count = ti_buf_put(tport->tp_write_buf, data, count);
737 	spin_unlock_irqrestore(&tport->tp_lock, flags);
738 
739 	ti_send(tport);
740 
741 	return count;
742 }
743 
744 
745 static int ti_write_room(struct usb_serial_port *port)
746 {
747 	struct ti_port *tport = usb_get_serial_port_data(port);
748 	int room = 0;
749 	unsigned long flags;
750 
751 	dbg("%s - port %d", __FUNCTION__, port->number);
752 
753 	if (tport == NULL)
754 		return -ENODEV;
755 
756 	spin_lock_irqsave(&tport->tp_lock, flags);
757 	room = ti_buf_space_avail(tport->tp_write_buf);
758 	spin_unlock_irqrestore(&tport->tp_lock, flags);
759 
760 	dbg("%s - returns %d", __FUNCTION__, room);
761 	return room;
762 }
763 
764 
765 static int ti_chars_in_buffer(struct usb_serial_port *port)
766 {
767 	struct ti_port *tport = usb_get_serial_port_data(port);
768 	int chars = 0;
769 	unsigned long flags;
770 
771 	dbg("%s - port %d", __FUNCTION__, port->number);
772 
773 	if (tport == NULL)
774 		return -ENODEV;
775 
776 	spin_lock_irqsave(&tport->tp_lock, flags);
777 	chars = ti_buf_data_avail(tport->tp_write_buf);
778 	spin_unlock_irqrestore(&tport->tp_lock, flags);
779 
780 	dbg("%s - returns %d", __FUNCTION__, chars);
781 	return chars;
782 }
783 
784 
785 static void ti_throttle(struct usb_serial_port *port)
786 {
787 	struct ti_port *tport = usb_get_serial_port_data(port);
788 	struct tty_struct *tty;
789 
790 	dbg("%s - port %d", __FUNCTION__, port->number);
791 
792 	if (tport == NULL)
793 		return;
794 
795 	tty = port->tty;
796 	if (!tty) {
797 		dbg("%s - no tty", __FUNCTION__);
798 		return;
799 	}
800 
801 	if (I_IXOFF(tty) || C_CRTSCTS(tty))
802 		ti_stop_read(tport, tty);
803 
804 }
805 
806 
807 static void ti_unthrottle(struct usb_serial_port *port)
808 {
809 	struct ti_port *tport = usb_get_serial_port_data(port);
810 	struct tty_struct *tty;
811 	int status;
812 
813 	dbg("%s - port %d", __FUNCTION__, port->number);
814 
815 	if (tport == NULL)
816 		return;
817 
818 	tty = port->tty;
819 	if (!tty) {
820 		dbg("%s - no tty", __FUNCTION__);
821 		return;
822 	}
823 
824 	if (I_IXOFF(tty) || C_CRTSCTS(tty)) {
825 		status = ti_restart_read(tport, tty);
826 		if (status)
827 			dev_err(&port->dev, "%s - cannot restart read, %d\n", __FUNCTION__, status);
828 	}
829 }
830 
831 
832 static int ti_ioctl(struct usb_serial_port *port, struct file *file,
833 	unsigned int cmd, unsigned long arg)
834 {
835 	struct ti_port *tport = usb_get_serial_port_data(port);
836 	struct async_icount cnow;
837 	struct async_icount cprev;
838 
839 	dbg("%s - port %d, cmd = 0x%04X", __FUNCTION__, port->number, cmd);
840 
841 	if (tport == NULL)
842 		return -ENODEV;
843 
844 	switch (cmd) {
845 		case TIOCGSERIAL:
846 			dbg("%s - (%d) TIOCGSERIAL", __FUNCTION__, port->number);
847 			return ti_get_serial_info(tport, (struct serial_struct __user *)arg);
848 			break;
849 
850 		case TIOCSSERIAL:
851 			dbg("%s - (%d) TIOCSSERIAL", __FUNCTION__, port->number);
852 			return ti_set_serial_info(tport, (struct serial_struct __user *)arg);
853 			break;
854 
855 		case TIOCMIWAIT:
856 			dbg("%s - (%d) TIOCMIWAIT", __FUNCTION__, port->number);
857 			cprev = tport->tp_icount;
858 			while (1) {
859 				interruptible_sleep_on(&tport->tp_msr_wait);
860 				if (signal_pending(current))
861 					return -ERESTARTSYS;
862 				cnow = tport->tp_icount;
863 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
864 				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
865 					return -EIO; /* no change => error */
866 				if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
867 				    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
868 				    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
869 				    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
870 					return 0;
871 				}
872 				cprev = cnow;
873 			}
874 			break;
875 
876 		case TIOCGICOUNT:
877 			dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d", __FUNCTION__, port->number, tport->tp_icount.rx, tport->tp_icount.tx);
878 			if (copy_to_user((void __user *)arg, &tport->tp_icount, sizeof(tport->tp_icount)))
879 				return -EFAULT;
880 			return 0;
881 	}
882 
883 	return -ENOIOCTLCMD;
884 }
885 
886 
887 static void ti_set_termios(struct usb_serial_port *port,
888 	struct termios *old_termios)
889 {
890 	struct ti_port *tport = usb_get_serial_port_data(port);
891 	struct tty_struct *tty = port->tty;
892 	struct ti_uart_config *config;
893 	tcflag_t cflag,iflag;
894 	int baud;
895 	int status;
896 	int port_number = port->number - port->serial->minor;
897 	unsigned int mcr;
898 
899 	dbg("%s - port %d", __FUNCTION__, port->number);
900 
901 	if (!tty || !tty->termios) {
902 		dbg("%s - no tty or termios", __FUNCTION__);
903 		return;
904 	}
905 
906 	cflag = tty->termios->c_cflag;
907 	iflag = tty->termios->c_iflag;
908 
909 	if (old_termios && cflag == old_termios->c_cflag
910 	&& iflag == old_termios->c_iflag) {
911 		dbg("%s - nothing to change", __FUNCTION__);
912 		return;
913 	}
914 
915 	dbg("%s - clfag %08x, iflag %08x", __FUNCTION__, cflag, iflag);
916 
917 	if (old_termios)
918 		dbg("%s - old clfag %08x, old iflag %08x", __FUNCTION__, old_termios->c_cflag, old_termios->c_iflag);
919 
920 	if (tport == NULL)
921 		return;
922 
923 	config = kmalloc(sizeof(*config), GFP_KERNEL);
924 	if (!config) {
925 		dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
926 		return;
927 	}
928 
929 	config->wFlags = 0;
930 
931 	/* these flags must be set */
932 	config->wFlags |= TI_UART_ENABLE_MS_INTS;
933 	config->wFlags |= TI_UART_ENABLE_AUTO_START_DMA;
934 	config->bUartMode = (__u8)(tport->tp_uart_mode);
935 
936 	switch (cflag & CSIZE) {
937 		case CS5:
938 			    config->bDataBits = TI_UART_5_DATA_BITS;
939 			    break;
940 		case CS6:
941 			    config->bDataBits = TI_UART_6_DATA_BITS;
942 			    break;
943 		case CS7:
944 			    config->bDataBits = TI_UART_7_DATA_BITS;
945 			    break;
946 		default:
947 		case CS8:
948 			    config->bDataBits = TI_UART_8_DATA_BITS;
949 			    break;
950 	}
951 
952 	if (cflag & PARENB) {
953 		if (cflag & PARODD) {
954 			config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
955 			config->bParity = TI_UART_ODD_PARITY;
956 		} else {
957 			config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
958 			config->bParity = TI_UART_EVEN_PARITY;
959 		}
960 	} else {
961 		config->wFlags &= ~TI_UART_ENABLE_PARITY_CHECKING;
962 		config->bParity = TI_UART_NO_PARITY;
963 	}
964 
965 	if (cflag & CSTOPB)
966 		config->bStopBits = TI_UART_2_STOP_BITS;
967 	else
968 		config->bStopBits = TI_UART_1_STOP_BITS;
969 
970 	if (cflag & CRTSCTS) {
971 		/* RTS flow control must be off to drop RTS for baud rate B0 */
972 		if ((cflag & CBAUD) != B0)
973 			config->wFlags |= TI_UART_ENABLE_RTS_IN;
974 		config->wFlags |= TI_UART_ENABLE_CTS_OUT;
975 	} else {
976 		tty->hw_stopped = 0;
977 		ti_restart_read(tport, tty);
978 	}
979 
980 	if (I_IXOFF(tty) || I_IXON(tty)) {
981 		config->cXon  = START_CHAR(tty);
982 		config->cXoff = STOP_CHAR(tty);
983 
984 		if (I_IXOFF(tty))
985 			config->wFlags |= TI_UART_ENABLE_X_IN;
986 		else
987 			ti_restart_read(tport, tty);
988 
989 		if (I_IXON(tty))
990 			config->wFlags |= TI_UART_ENABLE_X_OUT;
991 	}
992 
993 	baud = tty_get_baud_rate(tty);
994 	if (!baud) baud = 9600;
995 	if (tport->tp_tdev->td_is_3410)
996 		config->wBaudRate = (__u16)((923077 + baud/2) / baud);
997 	else
998 		config->wBaudRate = (__u16)((461538 + baud/2) / baud);
999 
1000 	dbg("%s - BaudRate=%d, wBaudRate=%d, wFlags=0x%04X, bDataBits=%d, bParity=%d, bStopBits=%d, cXon=%d, cXoff=%d, bUartMode=%d",
1001 	__FUNCTION__, baud, config->wBaudRate, config->wFlags, config->bDataBits, config->bParity, config->bStopBits, config->cXon, config->cXoff, config->bUartMode);
1002 
1003 	cpu_to_be16s(&config->wBaudRate);
1004 	cpu_to_be16s(&config->wFlags);
1005 
1006 	status = ti_command_out_sync(tport->tp_tdev, TI_SET_CONFIG,
1007 		(__u8)(TI_UART1_PORT + port_number), 0, (__u8 *)config,
1008 		sizeof(*config));
1009 	if (status)
1010 		dev_err(&port->dev, "%s - cannot set config on port %d, %d\n", __FUNCTION__, port_number, status);
1011 
1012 	/* SET_CONFIG asserts RTS and DTR, reset them correctly */
1013 	mcr = tport->tp_shadow_mcr;
1014 	/* if baud rate is B0, clear RTS and DTR */
1015 	if ((cflag & CBAUD) == B0)
1016 		mcr &= ~(TI_MCR_DTR | TI_MCR_RTS);
1017 	status = ti_set_mcr(tport, mcr);
1018 	if (status)
1019 		dev_err(&port->dev, "%s - cannot set modem control on port %d, %d\n", __FUNCTION__, port_number, status);
1020 
1021 	kfree(config);
1022 }
1023 
1024 
1025 static int ti_tiocmget(struct usb_serial_port *port, struct file *file)
1026 {
1027 	struct ti_port *tport = usb_get_serial_port_data(port);
1028 	unsigned int result;
1029 	unsigned int msr;
1030 	unsigned int mcr;
1031 
1032 	dbg("%s - port %d", __FUNCTION__, port->number);
1033 
1034 	if (tport == NULL)
1035 		return -ENODEV;
1036 
1037 	msr = tport->tp_msr;
1038 	mcr = tport->tp_shadow_mcr;
1039 
1040 	result = ((mcr & TI_MCR_DTR) ? TIOCM_DTR : 0)
1041 		| ((mcr & TI_MCR_RTS) ? TIOCM_RTS : 0)
1042 		| ((mcr & TI_MCR_LOOP) ? TIOCM_LOOP : 0)
1043 		| ((msr & TI_MSR_CTS) ? TIOCM_CTS : 0)
1044 		| ((msr & TI_MSR_CD) ? TIOCM_CAR : 0)
1045 		| ((msr & TI_MSR_RI) ? TIOCM_RI : 0)
1046 		| ((msr & TI_MSR_DSR) ? TIOCM_DSR : 0);
1047 
1048 	dbg("%s - 0x%04X", __FUNCTION__, result);
1049 
1050 	return result;
1051 }
1052 
1053 
1054 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
1055 	unsigned int set, unsigned int clear)
1056 {
1057 	struct ti_port *tport = usb_get_serial_port_data(port);
1058 	unsigned int mcr;
1059 
1060 	dbg("%s - port %d", __FUNCTION__, port->number);
1061 
1062 	if (tport == NULL)
1063 		return -ENODEV;
1064 
1065 	mcr = tport->tp_shadow_mcr;
1066 
1067 	if (set & TIOCM_RTS)
1068 		mcr |= TI_MCR_RTS;
1069 	if (set & TIOCM_DTR)
1070 		mcr |= TI_MCR_DTR;
1071 	if (set & TIOCM_LOOP)
1072 		mcr |= TI_MCR_LOOP;
1073 
1074 	if (clear & TIOCM_RTS)
1075 		mcr &= ~TI_MCR_RTS;
1076 	if (clear & TIOCM_DTR)
1077 		mcr &= ~TI_MCR_DTR;
1078 	if (clear & TIOCM_LOOP)
1079 		mcr &= ~TI_MCR_LOOP;
1080 
1081 	return ti_set_mcr(tport, mcr);
1082 }
1083 
1084 
1085 static void ti_break(struct usb_serial_port *port, int break_state)
1086 {
1087 	struct ti_port *tport = usb_get_serial_port_data(port);
1088 	int status;
1089 
1090 	dbg("%s - state = %d", __FUNCTION__, break_state);
1091 
1092 	if (tport == NULL)
1093 		return;
1094 
1095 	ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 0);
1096 
1097 	status = ti_write_byte(tport->tp_tdev,
1098 		tport->tp_uart_base_addr + TI_UART_OFFSET_LCR,
1099 		TI_LCR_BREAK, break_state == -1 ? TI_LCR_BREAK : 0);
1100 
1101 	if (status)
1102 		dbg("%s - error setting break, %d", __FUNCTION__, status);
1103 }
1104 
1105 
1106 static void ti_interrupt_callback(struct urb *urb, struct pt_regs *regs)
1107 {
1108 	struct ti_device *tdev = (struct ti_device *)urb->context;
1109 	struct usb_serial_port *port;
1110 	struct usb_serial *serial = tdev->td_serial;
1111 	struct ti_port *tport;
1112 	struct device *dev = &urb->dev->dev;
1113 	unsigned char *data = urb->transfer_buffer;
1114 	int length = urb->actual_length;
1115 	int port_number;
1116 	int function;
1117 	int status;
1118 	__u8 msr;
1119 
1120 	dbg("%s", __FUNCTION__);
1121 
1122 	switch (urb->status) {
1123 	case 0:
1124 		break;
1125 	case -ECONNRESET:
1126 	case -ENOENT:
1127 	case -ESHUTDOWN:
1128 		dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1129 		tdev->td_urb_error = 1;
1130 		return;
1131 	default:
1132 		dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status);
1133 		tdev->td_urb_error = 1;
1134 		goto exit;
1135 	}
1136 
1137 	if (length != 2) {
1138 		dbg("%s - bad packet size, %d", __FUNCTION__, length);
1139 		goto exit;
1140 	}
1141 
1142 	if (data[0] == TI_CODE_HARDWARE_ERROR) {
1143 		dev_err(dev, "%s - hardware error, %d\n", __FUNCTION__, data[1]);
1144 		goto exit;
1145 	}
1146 
1147 	port_number = TI_GET_PORT_FROM_CODE(data[0]);
1148 	function = TI_GET_FUNC_FROM_CODE(data[0]);
1149 
1150 	dbg("%s - port_number %d, function %d, data 0x%02X", __FUNCTION__, port_number, function, data[1]);
1151 
1152 	if (port_number >= serial->num_ports) {
1153 		dev_err(dev, "%s - bad port number, %d\n", __FUNCTION__, port_number);
1154 		goto exit;
1155 	}
1156 
1157 	port = serial->port[port_number];
1158 
1159 	tport = usb_get_serial_port_data(port);
1160 	if (!tport)
1161 		goto exit;
1162 
1163 	switch (function) {
1164 	case TI_CODE_DATA_ERROR:
1165 		dev_err(dev, "%s - DATA ERROR, port %d, data 0x%02X\n", __FUNCTION__, port_number, data[1]);
1166 		break;
1167 
1168 	case TI_CODE_MODEM_STATUS:
1169 		msr = data[1];
1170 		dbg("%s - port %d, msr 0x%02X", __FUNCTION__, port_number, msr);
1171 		ti_handle_new_msr(tport, msr);
1172 		break;
1173 
1174 	default:
1175 		dev_err(dev, "%s - unknown interrupt code, 0x%02X\n", __FUNCTION__, data[1]);
1176 		break;
1177 	}
1178 
1179 exit:
1180 	status = usb_submit_urb(urb, GFP_ATOMIC);
1181 	if (status)
1182 		dev_err(dev, "%s - resubmit interrupt urb failed, %d\n", __FUNCTION__, status);
1183 }
1184 
1185 
1186 static void ti_bulk_in_callback(struct urb *urb, struct pt_regs *regs)
1187 {
1188 	struct ti_port *tport = (struct ti_port *)urb->context;
1189 	struct usb_serial_port *port = tport->tp_port;
1190 	struct device *dev = &urb->dev->dev;
1191 	int status = 0;
1192 
1193 	dbg("%s", __FUNCTION__);
1194 
1195 	switch (urb->status) {
1196 	case 0:
1197 		break;
1198 	case -ECONNRESET:
1199 	case -ENOENT:
1200 	case -ESHUTDOWN:
1201 		dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1202 		tport->tp_tdev->td_urb_error = 1;
1203 		wake_up_interruptible(&tport->tp_write_wait);
1204 		return;
1205 	default:
1206 		dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status );
1207 		tport->tp_tdev->td_urb_error = 1;
1208 		wake_up_interruptible(&tport->tp_write_wait);
1209 	}
1210 
1211 	if (urb->status == -EPIPE)
1212 		goto exit;
1213 
1214 	if (urb->status) {
1215 		dev_err(dev, "%s - stopping read!\n", __FUNCTION__);
1216 		return;
1217 	}
1218 
1219 	if (port->tty && urb->actual_length) {
1220 		usb_serial_debug_data(debug, dev, __FUNCTION__,
1221 			urb->actual_length, urb->transfer_buffer);
1222 
1223 		if (!tport->tp_is_open)
1224 			dbg("%s - port closed, dropping data", __FUNCTION__);
1225 		else
1226 			ti_recv(&urb->dev->dev, port->tty, urb->transfer_buffer,
1227 				urb->actual_length);
1228 
1229 		spin_lock(&tport->tp_lock);
1230 		tport->tp_icount.rx += urb->actual_length;
1231 		spin_unlock(&tport->tp_lock);
1232 	}
1233 
1234 exit:
1235 	/* continue to read unless stopping */
1236 	spin_lock(&tport->tp_lock);
1237 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING) {
1238 		urb->dev = port->serial->dev;
1239 		status = usb_submit_urb(urb, GFP_ATOMIC);
1240 	} else if (tport->tp_read_urb_state == TI_READ_URB_STOPPING) {
1241 		tport->tp_read_urb_state = TI_READ_URB_STOPPED;
1242 	}
1243 	spin_unlock(&tport->tp_lock);
1244 	if (status)
1245 		dev_err(dev, "%s - resubmit read urb failed, %d\n", __FUNCTION__, status);
1246 }
1247 
1248 
1249 static void ti_bulk_out_callback(struct urb *urb, struct pt_regs *regs)
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 
1255 	dbg("%s - port %d", __FUNCTION__, port->number);
1256 
1257 	tport->tp_write_urb_in_use = 0;
1258 
1259 	switch (urb->status) {
1260 	case 0:
1261 		break;
1262 	case -ECONNRESET:
1263 	case -ENOENT:
1264 	case -ESHUTDOWN:
1265 		dbg("%s - urb shutting down, %d", __FUNCTION__, urb->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", __FUNCTION__, urb->status);
1271 		tport->tp_tdev->td_urb_error = 1;
1272 		wake_up_interruptible(&tport->tp_write_wait);
1273 	}
1274 
1275 	/* send any buffered data */
1276 	ti_send(tport);
1277 }
1278 
1279 
1280 static void ti_recv(struct device *dev, struct tty_struct *tty,
1281 	unsigned char *data, int length)
1282 {
1283 	int cnt;
1284 
1285 	do {
1286 		if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
1287 			tty_flip_buffer_push(tty);
1288 			if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
1289 				dev_err(dev, "%s - dropping data, %d bytes lost\n", __FUNCTION__, length);
1290 				return;
1291 			}
1292 		}
1293 		cnt = min(length, TTY_FLIPBUF_SIZE - tty->flip.count);
1294 		memcpy(tty->flip.char_buf_ptr, data, cnt);
1295 		memset(tty->flip.flag_buf_ptr, 0, cnt);
1296 		tty->flip.char_buf_ptr += cnt;
1297 		tty->flip.flag_buf_ptr += cnt;
1298 		tty->flip.count += cnt;
1299 		data += cnt;
1300 		length -= cnt;
1301 	} while (length > 0);
1302 
1303 	tty_flip_buffer_push(tty);
1304 }
1305 
1306 
1307 static void ti_send(struct ti_port *tport)
1308 {
1309 	int count, result;
1310 	struct usb_serial_port *port = tport->tp_port;
1311 	struct tty_struct *tty = port->tty;
1312 	unsigned long flags;
1313 
1314 
1315 	dbg("%s - port %d", __FUNCTION__, port->number);
1316 
1317 	spin_lock_irqsave(&tport->tp_lock, flags);
1318 
1319 	if (tport->tp_write_urb_in_use) {
1320 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1321 		return;
1322 	}
1323 
1324 	count = ti_buf_get(tport->tp_write_buf,
1325 				port->write_urb->transfer_buffer,
1326 				port->bulk_out_size);
1327 
1328 	if (count == 0) {
1329 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1330 		return;
1331 	}
1332 
1333 	tport->tp_write_urb_in_use = 1;
1334 
1335 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1336 
1337 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, port->write_urb->transfer_buffer);
1338 
1339 	usb_fill_bulk_urb(port->write_urb, port->serial->dev,
1340 			   usb_sndbulkpipe(port->serial->dev,
1341 					    port->bulk_out_endpointAddress),
1342 			   port->write_urb->transfer_buffer, count,
1343 			   ti_bulk_out_callback, tport);
1344 
1345 	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1346 	if (result) {
1347 		dev_err(&port->dev, "%s - submit write urb failed, %d\n", __FUNCTION__, result);
1348 		tport->tp_write_urb_in_use = 0;
1349 		/* TODO: reschedule ti_send */
1350 	} else {
1351 		spin_lock_irqsave(&tport->tp_lock, flags);
1352 		tport->tp_icount.tx += count;
1353 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1354 	}
1355 
1356 	/* more room in the buffer for new writes, wakeup */
1357 	if (tty)
1358 		tty_wakeup(tty);
1359 	wake_up_interruptible(&tport->tp_write_wait);
1360 }
1361 
1362 
1363 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr)
1364 {
1365 	int status;
1366 
1367 	status = ti_write_byte(tport->tp_tdev,
1368 		tport->tp_uart_base_addr + TI_UART_OFFSET_MCR,
1369 		TI_MCR_RTS | TI_MCR_DTR | TI_MCR_LOOP, mcr);
1370 
1371 	if (!status)
1372 		tport->tp_shadow_mcr = mcr;
1373 
1374 	return status;
1375 }
1376 
1377 
1378 static int ti_get_lsr(struct ti_port *tport)
1379 {
1380 	int size,status;
1381 	struct ti_device *tdev = tport->tp_tdev;
1382 	struct usb_serial_port *port = tport->tp_port;
1383 	int port_number = port->number - port->serial->minor;
1384 	struct ti_port_status *data;
1385 
1386 	dbg("%s - port %d", __FUNCTION__, port->number);
1387 
1388 	size = sizeof(struct ti_port_status);
1389 	data = kmalloc(size, GFP_KERNEL);
1390 	if (!data) {
1391 		dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
1392 		return -ENOMEM;
1393 	}
1394 
1395 	status = ti_command_in_sync(tdev, TI_GET_PORT_STATUS,
1396 		(__u8)(TI_UART1_PORT+port_number), 0, (__u8 *)data, size);
1397 	if (status) {
1398 		dev_err(&port->dev, "%s - get port status command failed, %d\n", __FUNCTION__, status);
1399 		goto free_data;
1400 	}
1401 
1402 	dbg("%s - lsr 0x%02X", __FUNCTION__, data->bLSR);
1403 
1404 	tport->tp_lsr = data->bLSR;
1405 
1406 free_data:
1407 	kfree(data);
1408 	return status;
1409 }
1410 
1411 
1412 static int ti_get_serial_info(struct ti_port *tport,
1413 	struct serial_struct __user *ret_arg)
1414 {
1415 	struct usb_serial_port *port = tport->tp_port;
1416 	struct serial_struct ret_serial;
1417 
1418 	if (!ret_arg)
1419 		return -EFAULT;
1420 
1421 	memset(&ret_serial, 0, sizeof(ret_serial));
1422 
1423 	ret_serial.type = PORT_16550A;
1424 	ret_serial.line = port->serial->minor;
1425 	ret_serial.port = port->number - port->serial->minor;
1426 	ret_serial.flags = tport->tp_flags;
1427 	ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
1428 	ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
1429 	ret_serial.closing_wait = tport->tp_closing_wait;
1430 
1431 	if (copy_to_user(ret_arg, &ret_serial, sizeof(*ret_arg)))
1432 		return -EFAULT;
1433 
1434 	return 0;
1435 }
1436 
1437 
1438 static int ti_set_serial_info(struct ti_port *tport,
1439 	struct serial_struct __user *new_arg)
1440 {
1441 	struct usb_serial_port *port = tport->tp_port;
1442 	struct serial_struct new_serial;
1443 
1444 	if (copy_from_user(&new_serial, new_arg, sizeof(new_serial)))
1445 		return -EFAULT;
1446 
1447 	tport->tp_flags = new_serial.flags & TI_SET_SERIAL_FLAGS;
1448 	if (port->tty)
1449 		port->tty->low_latency =
1450 			(tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1451 	tport->tp_closing_wait = new_serial.closing_wait;
1452 
1453 	return 0;
1454 }
1455 
1456 
1457 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr)
1458 {
1459 	struct async_icount *icount;
1460 	struct tty_struct *tty;
1461 	unsigned long flags;
1462 
1463 	dbg("%s - msr 0x%02X", __FUNCTION__, msr);
1464 
1465 	if (msr & TI_MSR_DELTA_MASK) {
1466 		spin_lock_irqsave(&tport->tp_lock, flags);
1467 		icount = &tport->tp_icount;
1468 		if (msr & TI_MSR_DELTA_CTS)
1469 			icount->cts++;
1470 		if (msr & TI_MSR_DELTA_DSR)
1471 			icount->dsr++;
1472 		if (msr & TI_MSR_DELTA_CD)
1473 			icount->dcd++;
1474 		if (msr & TI_MSR_DELTA_RI)
1475 			icount->rng++;
1476 		wake_up_interruptible(&tport->tp_msr_wait);
1477 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1478 	}
1479 
1480 	tport->tp_msr = msr & TI_MSR_MASK;
1481 
1482 	/* handle CTS flow control */
1483 	tty = tport->tp_port->tty;
1484 	if (tty && C_CRTSCTS(tty)) {
1485 		if (msr & TI_MSR_CTS) {
1486 			tty->hw_stopped = 0;
1487 			tty_wakeup(tty);
1488 		} else {
1489 			tty->hw_stopped = 1;
1490 		}
1491 	}
1492 }
1493 
1494 
1495 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
1496 {
1497 	struct ti_device *tdev = tport->tp_tdev;
1498 	struct usb_serial_port *port = tport->tp_port;
1499 	wait_queue_t wait;
1500 	unsigned long flags;
1501 
1502 	dbg("%s - port %d", __FUNCTION__, port->number);
1503 
1504 	spin_lock_irqsave(&tport->tp_lock, flags);
1505 
1506 	/* wait for data to drain from the buffer */
1507 	tdev->td_urb_error = 0;
1508 	init_waitqueue_entry(&wait, current);
1509 	add_wait_queue(&tport->tp_write_wait, &wait);
1510 	for (;;) {
1511 		set_current_state(TASK_INTERRUPTIBLE);
1512 		if (ti_buf_data_avail(tport->tp_write_buf) == 0
1513 		|| timeout == 0 || signal_pending(current)
1514 		|| tdev->td_urb_error
1515 		|| !usb_get_intfdata(port->serial->interface))  /* disconnect */
1516 			break;
1517 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1518 		timeout = schedule_timeout(timeout);
1519 		spin_lock_irqsave(&tport->tp_lock, flags);
1520 	}
1521 	set_current_state(TASK_RUNNING);
1522 	remove_wait_queue(&tport->tp_write_wait, &wait);
1523 
1524 	/* flush any remaining data in the buffer */
1525 	if (flush)
1526 		ti_buf_clear(tport->tp_write_buf);
1527 
1528 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1529 
1530 	/* wait for data to drain from the device */
1531 	/* wait for empty tx register, plus 20 ms */
1532 	timeout += jiffies;
1533 	tport->tp_lsr &= ~TI_LSR_TX_EMPTY;
1534 	while ((long)(jiffies - timeout) < 0 && !signal_pending(current)
1535 	&& !(tport->tp_lsr&TI_LSR_TX_EMPTY) && !tdev->td_urb_error
1536 	&& usb_get_intfdata(port->serial->interface)) {  /* not disconnected */
1537 		if (ti_get_lsr(tport))
1538 			break;
1539 		msleep_interruptible(20);
1540 	}
1541 }
1542 
1543 
1544 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty)
1545 {
1546 	unsigned long flags;
1547 
1548 	spin_lock_irqsave(&tport->tp_lock, flags);
1549 
1550 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING)
1551 		tport->tp_read_urb_state = TI_READ_URB_STOPPING;
1552 
1553 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1554 }
1555 
1556 
1557 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty)
1558 {
1559 	struct urb *urb;
1560 	int status = 0;
1561 	unsigned long flags;
1562 
1563 	spin_lock_irqsave(&tport->tp_lock, flags);
1564 
1565 	if (tport->tp_read_urb_state == TI_READ_URB_STOPPED) {
1566 		urb = tport->tp_port->read_urb;
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 	}
1572 	tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1573 
1574 	spin_unlock_irqrestore(&tport->tp_lock, flags);
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 = (struct circ_buf *)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