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/firmware.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 <linux/mutex.h>
85 #include <linux/uaccess.h>
86 #include <linux/usb.h>
87 #include <linux/usb/serial.h>
88 
89 #include "ti_usb_3410_5052.h"
90 
91 /* Defines */
92 
93 #define TI_DRIVER_VERSION	"v0.9"
94 #define TI_DRIVER_AUTHOR	"Al Borchers <alborchers@steinerpoint.com>"
95 #define TI_DRIVER_DESC		"TI USB 3410/5052 Serial Driver"
96 
97 #define TI_FIRMWARE_BUF_SIZE	16284
98 
99 #define TI_WRITE_BUF_SIZE	1024
100 
101 #define TI_TRANSFER_TIMEOUT	2
102 
103 #define TI_DEFAULT_LOW_LATENCY	0
104 #define TI_DEFAULT_CLOSING_WAIT	4000		/* in .01 secs */
105 
106 /* supported setserial flags */
107 #define TI_SET_SERIAL_FLAGS	(ASYNC_LOW_LATENCY)
108 
109 /* read urb states */
110 #define TI_READ_URB_RUNNING	0
111 #define TI_READ_URB_STOPPING	1
112 #define TI_READ_URB_STOPPED	2
113 
114 #define TI_EXTRA_VID_PID_COUNT	5
115 
116 
117 /* Structures */
118 
119 struct ti_port {
120 	int			tp_is_open;
121 	__u8			tp_msr;
122 	__u8			tp_lsr;
123 	__u8			tp_shadow_mcr;
124 	__u8			tp_uart_mode;	/* 232 or 485 modes */
125 	unsigned int		tp_uart_base_addr;
126 	int			tp_flags;
127 	int			tp_closing_wait;/* in .01 secs */
128 	struct async_icount	tp_icount;
129 	wait_queue_head_t	tp_msr_wait;	/* wait for msr change */
130 	wait_queue_head_t	tp_write_wait;
131 	struct ti_device	*tp_tdev;
132 	struct usb_serial_port	*tp_port;
133 	spinlock_t		tp_lock;
134 	int			tp_read_urb_state;
135 	int			tp_write_urb_in_use;
136 	struct circ_buf		*tp_write_buf;
137 };
138 
139 struct ti_device {
140 	struct mutex		td_open_close_lock;
141 	int			td_open_port_count;
142 	struct usb_serial	*td_serial;
143 	int			td_is_3410;
144 	int			td_urb_error;
145 };
146 
147 
148 /* Function Declarations */
149 
150 static int ti_startup(struct usb_serial *serial);
151 static void ti_shutdown(struct usb_serial *serial);
152 static int ti_open(struct tty_struct *tty, struct usb_serial_port *port,
153 		struct file *file);
154 static void ti_close(struct tty_struct *tty, struct usb_serial_port *port,
155 		struct file *file);
156 static int ti_write(struct tty_struct *tty, struct usb_serial_port *port,
157 		const unsigned char *data, int count);
158 static int ti_write_room(struct tty_struct *tty);
159 static int ti_chars_in_buffer(struct tty_struct *tty);
160 static void ti_throttle(struct tty_struct *tty);
161 static void ti_unthrottle(struct tty_struct *tty);
162 static int ti_ioctl(struct tty_struct *tty, struct file *file,
163 		unsigned int cmd, unsigned long arg);
164 static void ti_set_termios(struct tty_struct *tty,
165 		struct usb_serial_port *port, struct ktermios *old_termios);
166 static int ti_tiocmget(struct tty_struct *tty, struct file *file);
167 static int ti_tiocmset(struct tty_struct *tty, struct file *file,
168 		unsigned int set, unsigned int clear);
169 static void ti_break(struct tty_struct *tty, 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 tty_struct *tty, 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, int type);
199 
200 /* circular buffer */
201 static struct circ_buf *ti_buf_alloc(void);
202 static void ti_buf_free(struct circ_buf *cb);
203 static void ti_buf_clear(struct circ_buf *cb);
204 static int ti_buf_data_avail(struct circ_buf *cb);
205 static int ti_buf_space_avail(struct circ_buf *cb);
206 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count);
207 static int ti_buf_get(struct circ_buf *cb, char *buf, int count);
208 
209 
210 /* Data */
211 
212 /* module parameters */
213 static int debug;
214 static int low_latency = TI_DEFAULT_LOW_LATENCY;
215 static int closing_wait = TI_DEFAULT_CLOSING_WAIT;
216 static ushort vendor_3410[TI_EXTRA_VID_PID_COUNT];
217 static unsigned int vendor_3410_count;
218 static ushort product_3410[TI_EXTRA_VID_PID_COUNT];
219 static unsigned int product_3410_count;
220 static ushort vendor_5052[TI_EXTRA_VID_PID_COUNT];
221 static unsigned int vendor_5052_count;
222 static ushort product_5052[TI_EXTRA_VID_PID_COUNT];
223 static unsigned int product_5052_count;
224 
225 /* supported devices */
226 /* the array dimension is the number of default entries plus */
227 /* TI_EXTRA_VID_PID_COUNT user defined entries plus 1 terminating */
228 /* null entry */
229 static struct usb_device_id ti_id_table_3410[1+TI_EXTRA_VID_PID_COUNT+1] = {
230 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
231 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_EZ430_ID) },
232 };
233 
234 static struct usb_device_id ti_id_table_5052[4+TI_EXTRA_VID_PID_COUNT+1] = {
235 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
236 	{ USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
237 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
238 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
239 };
240 
241 static struct usb_device_id ti_id_table_combined[] = {
242 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
243 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_EZ430_ID) },
244 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
245 	{ USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
246 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
247 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
248 	{ }
249 };
250 
251 static struct usb_driver ti_usb_driver = {
252 	.name			= "ti_usb_3410_5052",
253 	.probe			= usb_serial_probe,
254 	.disconnect		= usb_serial_disconnect,
255 	.id_table		= ti_id_table_combined,
256 	.no_dynamic_id = 	1,
257 };
258 
259 static struct usb_serial_driver ti_1port_device = {
260 	.driver = {
261 		.owner		= THIS_MODULE,
262 		.name		= "ti_usb_3410_5052_1",
263 	},
264 	.description		= "TI USB 3410 1 port adapter",
265 	.usb_driver		= &ti_usb_driver,
266 	.id_table		= ti_id_table_3410,
267 	.num_ports		= 1,
268 	.attach			= ti_startup,
269 	.shutdown		= ti_shutdown,
270 	.open			= ti_open,
271 	.close			= ti_close,
272 	.write			= ti_write,
273 	.write_room		= ti_write_room,
274 	.chars_in_buffer	= ti_chars_in_buffer,
275 	.throttle		= ti_throttle,
276 	.unthrottle		= ti_unthrottle,
277 	.ioctl			= ti_ioctl,
278 	.set_termios		= ti_set_termios,
279 	.tiocmget		= ti_tiocmget,
280 	.tiocmset		= ti_tiocmset,
281 	.break_ctl		= ti_break,
282 	.read_int_callback	= ti_interrupt_callback,
283 	.read_bulk_callback	= ti_bulk_in_callback,
284 	.write_bulk_callback	= ti_bulk_out_callback,
285 };
286 
287 static struct usb_serial_driver ti_2port_device = {
288 	.driver = {
289 		.owner		= THIS_MODULE,
290 		.name		= "ti_usb_3410_5052_2",
291 	},
292 	.description		= "TI USB 5052 2 port adapter",
293 	.usb_driver		= &ti_usb_driver,
294 	.id_table		= ti_id_table_5052,
295 	.num_ports		= 2,
296 	.attach			= ti_startup,
297 	.shutdown		= ti_shutdown,
298 	.open			= ti_open,
299 	.close			= ti_close,
300 	.write			= ti_write,
301 	.write_room		= ti_write_room,
302 	.chars_in_buffer	= ti_chars_in_buffer,
303 	.throttle		= ti_throttle,
304 	.unthrottle		= ti_unthrottle,
305 	.ioctl			= ti_ioctl,
306 	.set_termios		= ti_set_termios,
307 	.tiocmget		= ti_tiocmget,
308 	.tiocmset		= ti_tiocmset,
309 	.break_ctl		= ti_break,
310 	.read_int_callback	= ti_interrupt_callback,
311 	.read_bulk_callback	= ti_bulk_in_callback,
312 	.write_bulk_callback	= ti_bulk_out_callback,
313 };
314 
315 
316 /* Module */
317 
318 MODULE_AUTHOR(TI_DRIVER_AUTHOR);
319 MODULE_DESCRIPTION(TI_DRIVER_DESC);
320 MODULE_VERSION(TI_DRIVER_VERSION);
321 MODULE_LICENSE("GPL");
322 
323 MODULE_FIRMWARE("ti_3410.fw");
324 MODULE_FIRMWARE("ti_5052.fw");
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,
331 		"TTY low_latency flag, 0=off, 1=on, default is off");
332 
333 module_param(closing_wait, int, S_IRUGO | S_IWUSR);
334 MODULE_PARM_DESC(closing_wait,
335     "Maximum wait for data to drain in close, in .01 secs, default is 4000");
336 
337 module_param_array(vendor_3410, ushort, &vendor_3410_count, S_IRUGO);
338 MODULE_PARM_DESC(vendor_3410,
339 		"Vendor ids for 3410 based devices, 1-5 short integers");
340 module_param_array(product_3410, ushort, &product_3410_count, S_IRUGO);
341 MODULE_PARM_DESC(product_3410,
342 		"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,
345 		"Vendor ids for 5052 based devices, 1-5 short integers");
346 module_param_array(product_5052, ushort, &product_5052_count, S_IRUGO);
347 MODULE_PARM_DESC(product_5052,
348 		"Product ids for 5052 based devices, 1-5 short integers");
349 
350 MODULE_DEVICE_TABLE(usb, ti_id_table_combined);
351 
352 
353 /* Functions */
354 
355 static int __init ti_init(void)
356 {
357 	int i, j;
358 	int ret;
359 
360 	/* insert extra vendor and product ids */
361 	j = ARRAY_SIZE(ti_id_table_3410) - TI_EXTRA_VID_PID_COUNT - 1;
362 	for (i = 0; i < min(vendor_3410_count, product_3410_count); i++, j++) {
363 		ti_id_table_3410[j].idVendor = vendor_3410[i];
364 		ti_id_table_3410[j].idProduct = product_3410[i];
365 		ti_id_table_3410[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
366 	}
367 	j = ARRAY_SIZE(ti_id_table_5052) - TI_EXTRA_VID_PID_COUNT - 1;
368 	for (i = 0; i < min(vendor_5052_count, product_5052_count); i++, j++) {
369 		ti_id_table_5052[j].idVendor = vendor_5052[i];
370 		ti_id_table_5052[j].idProduct = product_5052[i];
371 		ti_id_table_5052[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
372 	}
373 
374 	ret = usb_serial_register(&ti_1port_device);
375 	if (ret)
376 		goto failed_1port;
377 	ret = usb_serial_register(&ti_2port_device);
378 	if (ret)
379 		goto failed_2port;
380 
381 	ret = usb_register(&ti_usb_driver);
382 	if (ret)
383 		goto failed_usb;
384 
385 	printk(KERN_INFO KBUILD_MODNAME ": " TI_DRIVER_VERSION ":"
386 	       TI_DRIVER_DESC "\n");
387 
388 	return 0;
389 
390 failed_usb:
391 	usb_serial_deregister(&ti_2port_device);
392 failed_2port:
393 	usb_serial_deregister(&ti_1port_device);
394 failed_1port:
395 	return ret;
396 }
397 
398 
399 static void __exit ti_exit(void)
400 {
401 	usb_serial_deregister(&ti_1port_device);
402 	usb_serial_deregister(&ti_2port_device);
403 	usb_deregister(&ti_usb_driver);
404 }
405 
406 
407 module_init(ti_init);
408 module_exit(ti_exit);
409 
410 
411 static int ti_startup(struct usb_serial *serial)
412 {
413 	struct ti_device *tdev;
414 	struct ti_port *tport;
415 	struct usb_device *dev = serial->dev;
416 	int status;
417 	int i;
418 
419 
420 	dbg("%s - product 0x%4X, num configurations %d, configuration value %d",
421 	    __func__, le16_to_cpu(dev->descriptor.idProduct),
422 	    dev->descriptor.bNumConfigurations,
423 	    dev->actconfig->desc.bConfigurationValue);
424 
425 	/* create device structure */
426 	tdev = kzalloc(sizeof(struct ti_device), GFP_KERNEL);
427 	if (tdev == NULL) {
428 		dev_err(&dev->dev, "%s - out of memory\n", __func__);
429 		return -ENOMEM;
430 	}
431 	mutex_init(&tdev->td_open_close_lock);
432 	tdev->td_serial = serial;
433 	usb_set_serial_data(serial, tdev);
434 
435 	/* determine device type */
436 	if (usb_match_id(serial->interface, ti_id_table_3410))
437 		tdev->td_is_3410 = 1;
438 	dbg("%s - device type is %s", __func__,
439 				tdev->td_is_3410 ? "3410" : "5052");
440 
441 	/* if we have only 1 configuration, download firmware */
442 	if (dev->descriptor.bNumConfigurations == 1) {
443 		if (tdev->td_is_3410)
444 			status = ti_download_firmware(tdev, 3410);
445 		else
446 			status = ti_download_firmware(tdev, 5052);
447 		if (status)
448 			goto free_tdev;
449 
450 		/* 3410 must be reset, 5052 resets itself */
451 		if (tdev->td_is_3410) {
452 			msleep_interruptible(100);
453 			usb_reset_device(dev);
454 		}
455 
456 		status = -ENODEV;
457 		goto free_tdev;
458 	}
459 
460 	/* the second configuration must be set (in sysfs by hotplug script) */
461 	if (dev->actconfig->desc.bConfigurationValue == TI_BOOT_CONFIG) {
462 		status = -ENODEV;
463 		goto free_tdev;
464 	}
465 
466 	/* set up port structures */
467 	for (i = 0; i < serial->num_ports; ++i) {
468 		tport = kzalloc(sizeof(struct ti_port), GFP_KERNEL);
469 		if (tport == NULL) {
470 			dev_err(&dev->dev, "%s - out of memory\n", __func__);
471 			status = -ENOMEM;
472 			goto free_tports;
473 		}
474 		spin_lock_init(&tport->tp_lock);
475 		tport->tp_uart_base_addr = (i == 0 ?
476 				TI_UART1_BASE_ADDR : TI_UART2_BASE_ADDR);
477 		tport->tp_flags = low_latency ? ASYNC_LOW_LATENCY : 0;
478 		tport->tp_closing_wait = closing_wait;
479 		init_waitqueue_head(&tport->tp_msr_wait);
480 		init_waitqueue_head(&tport->tp_write_wait);
481 		tport->tp_write_buf = ti_buf_alloc();
482 		if (tport->tp_write_buf == NULL) {
483 			dev_err(&dev->dev, "%s - out of memory\n", __func__);
484 			kfree(tport);
485 			status = -ENOMEM;
486 			goto free_tports;
487 		}
488 		tport->tp_port = serial->port[i];
489 		tport->tp_tdev = tdev;
490 		usb_set_serial_port_data(serial->port[i], tport);
491 		tport->tp_uart_mode = 0;	/* default is RS232 */
492 	}
493 
494 	return 0;
495 
496 free_tports:
497 	for (--i; i >= 0; --i) {
498 		tport = usb_get_serial_port_data(serial->port[i]);
499 		ti_buf_free(tport->tp_write_buf);
500 		kfree(tport);
501 		usb_set_serial_port_data(serial->port[i], NULL);
502 	}
503 free_tdev:
504 	kfree(tdev);
505 	usb_set_serial_data(serial, NULL);
506 	return status;
507 }
508 
509 
510 static void ti_shutdown(struct usb_serial *serial)
511 {
512 	int i;
513 	struct ti_device *tdev = usb_get_serial_data(serial);
514 	struct ti_port *tport;
515 
516 	dbg("%s", __func__);
517 
518 	for (i = 0; i < serial->num_ports; ++i) {
519 		tport = usb_get_serial_port_data(serial->port[i]);
520 		if (tport) {
521 			ti_buf_free(tport->tp_write_buf);
522 			kfree(tport);
523 			usb_set_serial_port_data(serial->port[i], NULL);
524 		}
525 	}
526 
527 	kfree(tdev);
528 	usb_set_serial_data(serial, NULL);
529 }
530 
531 
532 static int ti_open(struct tty_struct *tty,
533 			struct usb_serial_port *port, struct file *file)
534 {
535 	struct ti_port *tport = usb_get_serial_port_data(port);
536 	struct ti_device *tdev;
537 	struct usb_device *dev;
538 	struct urb *urb;
539 	int port_number;
540 	int status;
541 	__u16 open_settings = (__u8)(TI_PIPE_MODE_CONTINOUS |
542 			     TI_PIPE_TIMEOUT_ENABLE |
543 			     (TI_TRANSFER_TIMEOUT << 2));
544 
545 	dbg("%s - port %d", __func__, port->number);
546 
547 	if (tport == NULL)
548 		return -ENODEV;
549 
550 	dev = port->serial->dev;
551 	tdev = tport->tp_tdev;
552 
553 	/* only one open on any port on a device at a time */
554 	if (mutex_lock_interruptible(&tdev->td_open_close_lock))
555 		return -ERESTARTSYS;
556 
557 	if (tty)
558 		tty->low_latency =
559 				(tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
560 
561 	port_number = port->number - port->serial->minor;
562 
563 	memset(&(tport->tp_icount), 0x00, sizeof(tport->tp_icount));
564 
565 	tport->tp_msr = 0;
566 	tport->tp_shadow_mcr |= (TI_MCR_RTS | TI_MCR_DTR);
567 
568 	/* start interrupt urb the first time a port is opened on this device */
569 	if (tdev->td_open_port_count == 0) {
570 		dbg("%s - start interrupt in urb", __func__);
571 		urb = tdev->td_serial->port[0]->interrupt_in_urb;
572 		if (!urb) {
573 			dev_err(&port->dev, "%s - no interrupt urb\n",
574 								__func__);
575 			status = -EINVAL;
576 			goto release_lock;
577 		}
578 		urb->complete = ti_interrupt_callback;
579 		urb->context = tdev;
580 		urb->dev = dev;
581 		status = usb_submit_urb(urb, GFP_KERNEL);
582 		if (status) {
583 			dev_err(&port->dev,
584 				"%s - submit interrupt urb failed, %d\n",
585 					__func__, status);
586 			goto release_lock;
587 		}
588 	}
589 
590 	if (tty)
591 		ti_set_termios(tty, port, tty->termios);
592 
593 	dbg("%s - sending TI_OPEN_PORT", __func__);
594 	status = ti_command_out_sync(tdev, TI_OPEN_PORT,
595 		(__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
596 	if (status) {
597 		dev_err(&port->dev, "%s - cannot send open command, %d\n",
598 							__func__, status);
599 		goto unlink_int_urb;
600 	}
601 
602 	dbg("%s - sending TI_START_PORT", __func__);
603 	status = ti_command_out_sync(tdev, TI_START_PORT,
604 		(__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
605 	if (status) {
606 		dev_err(&port->dev, "%s - cannot send start command, %d\n",
607 							__func__, status);
608 		goto unlink_int_urb;
609 	}
610 
611 	dbg("%s - sending TI_PURGE_PORT", __func__);
612 	status = ti_command_out_sync(tdev, TI_PURGE_PORT,
613 		(__u8)(TI_UART1_PORT + port_number), TI_PURGE_INPUT, NULL, 0);
614 	if (status) {
615 		dev_err(&port->dev, "%s - cannot clear input buffers, %d\n",
616 							__func__, status);
617 		goto unlink_int_urb;
618 	}
619 	status = ti_command_out_sync(tdev, TI_PURGE_PORT,
620 		(__u8)(TI_UART1_PORT + port_number), TI_PURGE_OUTPUT, NULL, 0);
621 	if (status) {
622 		dev_err(&port->dev, "%s - cannot clear output buffers, %d\n",
623 							__func__, status);
624 		goto unlink_int_urb;
625 	}
626 
627 	/* reset the data toggle on the bulk endpoints to work around bug in
628 	 * host controllers where things get out of sync some times */
629 	usb_clear_halt(dev, port->write_urb->pipe);
630 	usb_clear_halt(dev, port->read_urb->pipe);
631 
632 	if (tty)
633 		ti_set_termios(tty, port, tty->termios);
634 
635 	dbg("%s - sending TI_OPEN_PORT (2)", __func__);
636 	status = ti_command_out_sync(tdev, TI_OPEN_PORT,
637 		(__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
638 	if (status) {
639 		dev_err(&port->dev, "%s - cannot send open command (2), %d\n",
640 							__func__, status);
641 		goto unlink_int_urb;
642 	}
643 
644 	dbg("%s - sending TI_START_PORT (2)", __func__);
645 	status = ti_command_out_sync(tdev, TI_START_PORT,
646 		(__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
647 	if (status) {
648 		dev_err(&port->dev, "%s - cannot send start command (2), %d\n",
649 							__func__, status);
650 		goto unlink_int_urb;
651 	}
652 
653 	/* start read urb */
654 	dbg("%s - start read urb", __func__);
655 	urb = port->read_urb;
656 	if (!urb) {
657 		dev_err(&port->dev, "%s - no read urb\n", __func__);
658 		status = -EINVAL;
659 		goto unlink_int_urb;
660 	}
661 	tport->tp_read_urb_state = TI_READ_URB_RUNNING;
662 	urb->complete = ti_bulk_in_callback;
663 	urb->context = tport;
664 	urb->dev = dev;
665 	status = usb_submit_urb(urb, GFP_KERNEL);
666 	if (status) {
667 		dev_err(&port->dev, "%s - submit read urb failed, %d\n",
668 							__func__, status);
669 		goto unlink_int_urb;
670 	}
671 
672 	tport->tp_is_open = 1;
673 	++tdev->td_open_port_count;
674 
675 	goto release_lock;
676 
677 unlink_int_urb:
678 	if (tdev->td_open_port_count == 0)
679 		usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
680 release_lock:
681 	mutex_unlock(&tdev->td_open_close_lock);
682 	dbg("%s - exit %d", __func__, status);
683 	return status;
684 }
685 
686 
687 static void ti_close(struct tty_struct *tty, struct usb_serial_port *port,
688 							struct file *file)
689 {
690 	struct ti_device *tdev;
691 	struct ti_port *tport;
692 	int port_number;
693 	int status;
694 	int do_unlock;
695 
696 	dbg("%s - port %d", __func__, port->number);
697 
698 	tdev = usb_get_serial_data(port->serial);
699 	tport = usb_get_serial_port_data(port);
700 	if (tdev == NULL || tport == NULL)
701 		return;
702 
703 	tport->tp_is_open = 0;
704 
705 	ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 1);
706 
707 	usb_kill_urb(port->read_urb);
708 	usb_kill_urb(port->write_urb);
709 	tport->tp_write_urb_in_use = 0;
710 
711 	port_number = port->number - port->serial->minor;
712 
713 	dbg("%s - sending TI_CLOSE_PORT", __func__);
714 	status = ti_command_out_sync(tdev, TI_CLOSE_PORT,
715 		     (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
716 	if (status)
717 		dev_err(&port->dev,
718 			"%s - cannot send close port command, %d\n"
719 							, __func__, status);
720 
721 	/* if mutex_lock is interrupted, continue anyway */
722 	do_unlock = !mutex_lock_interruptible(&tdev->td_open_close_lock);
723 	--tport->tp_tdev->td_open_port_count;
724 	if (tport->tp_tdev->td_open_port_count <= 0) {
725 		/* last port is closed, shut down interrupt urb */
726 		usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
727 		tport->tp_tdev->td_open_port_count = 0;
728 	}
729 	if (do_unlock)
730 		mutex_unlock(&tdev->td_open_close_lock);
731 
732 	dbg("%s - exit", __func__);
733 }
734 
735 
736 static int ti_write(struct tty_struct *tty, struct usb_serial_port *port,
737 			const unsigned char *data, int count)
738 {
739 	struct ti_port *tport = usb_get_serial_port_data(port);
740 	unsigned long flags;
741 
742 	dbg("%s - port %d", __func__, port->number);
743 
744 	if (count == 0) {
745 		dbg("%s - write request of 0 bytes", __func__);
746 		return 0;
747 	}
748 
749 	if (tport == NULL || !tport->tp_is_open)
750 		return -ENODEV;
751 
752 	spin_lock_irqsave(&tport->tp_lock, flags);
753 	count = ti_buf_put(tport->tp_write_buf, data, count);
754 	spin_unlock_irqrestore(&tport->tp_lock, flags);
755 
756 	ti_send(tport);
757 
758 	return count;
759 }
760 
761 
762 static int ti_write_room(struct tty_struct *tty)
763 {
764 	struct usb_serial_port *port = tty->driver_data;
765 	struct ti_port *tport = usb_get_serial_port_data(port);
766 	int room = 0;
767 	unsigned long flags;
768 
769 	dbg("%s - port %d", __func__, port->number);
770 
771 	if (tport == NULL)
772 		return -ENODEV;
773 
774 	spin_lock_irqsave(&tport->tp_lock, flags);
775 	room = ti_buf_space_avail(tport->tp_write_buf);
776 	spin_unlock_irqrestore(&tport->tp_lock, flags);
777 
778 	dbg("%s - returns %d", __func__, room);
779 	return room;
780 }
781 
782 
783 static int ti_chars_in_buffer(struct tty_struct *tty)
784 {
785 	struct usb_serial_port *port = tty->driver_data;
786 	struct ti_port *tport = usb_get_serial_port_data(port);
787 	int chars = 0;
788 	unsigned long flags;
789 
790 	dbg("%s - port %d", __func__, port->number);
791 
792 	if (tport == NULL)
793 		return -ENODEV;
794 
795 	spin_lock_irqsave(&tport->tp_lock, flags);
796 	chars = ti_buf_data_avail(tport->tp_write_buf);
797 	spin_unlock_irqrestore(&tport->tp_lock, flags);
798 
799 	dbg("%s - returns %d", __func__, chars);
800 	return chars;
801 }
802 
803 
804 static void ti_throttle(struct tty_struct *tty)
805 {
806 	struct usb_serial_port *port = tty->driver_data;
807 	struct ti_port *tport = usb_get_serial_port_data(port);
808 
809 	dbg("%s - port %d", __func__, port->number);
810 
811 	if (tport == NULL)
812 		return;
813 
814 	if (I_IXOFF(tty) || C_CRTSCTS(tty))
815 		ti_stop_read(tport, tty);
816 
817 }
818 
819 
820 static void ti_unthrottle(struct tty_struct *tty)
821 {
822 	struct usb_serial_port *port = tty->driver_data;
823 	struct ti_port *tport = usb_get_serial_port_data(port);
824 	int status;
825 
826 	dbg("%s - port %d", __func__, port->number);
827 
828 	if (tport == NULL)
829 		return;
830 
831 	if (I_IXOFF(tty) || C_CRTSCTS(tty)) {
832 		status = ti_restart_read(tport, tty);
833 		if (status)
834 			dev_err(&port->dev, "%s - cannot restart read, %d\n",
835 							__func__, status);
836 	}
837 }
838 
839 
840 static int ti_ioctl(struct tty_struct *tty, struct file *file,
841 	unsigned int cmd, unsigned long arg)
842 {
843 	struct usb_serial_port *port = tty->driver_data;
844 	struct ti_port *tport = usb_get_serial_port_data(port);
845 	struct async_icount cnow;
846 	struct async_icount cprev;
847 
848 	dbg("%s - port %d, cmd = 0x%04X", __func__, port->number, cmd);
849 
850 	if (tport == NULL)
851 		return -ENODEV;
852 
853 	switch (cmd) {
854 	case TIOCGSERIAL:
855 		dbg("%s - (%d) TIOCGSERIAL", __func__, port->number);
856 		return ti_get_serial_info(tport,
857 				(struct serial_struct __user *)arg);
858 	case TIOCSSERIAL:
859 		dbg("%s - (%d) TIOCSSERIAL", __func__, port->number);
860 		return ti_set_serial_info(tty, tport,
861 				(struct serial_struct __user *)arg);
862 	case TIOCMIWAIT:
863 		dbg("%s - (%d) TIOCMIWAIT", __func__, port->number);
864 		cprev = tport->tp_icount;
865 		while (1) {
866 			interruptible_sleep_on(&tport->tp_msr_wait);
867 			if (signal_pending(current))
868 				return -ERESTARTSYS;
869 			cnow = tport->tp_icount;
870 			if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
871 			    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
872 				return -EIO; /* no change => error */
873 			if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
874 			    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
875 			    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
876 			    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)))
877 				return 0;
878 			cprev = cnow;
879 		}
880 		break;
881 	case TIOCGICOUNT:
882 		dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d",
883 				__func__, port->number,
884 				tport->tp_icount.rx, tport->tp_icount.tx);
885 		if (copy_to_user((void __user *)arg, &tport->tp_icount,
886 					sizeof(tport->tp_icount)))
887 			return -EFAULT;
888 		return 0;
889 	}
890 	return -ENOIOCTLCMD;
891 }
892 
893 
894 static void ti_set_termios(struct tty_struct *tty,
895 		struct usb_serial_port *port, struct ktermios *old_termios)
896 {
897 	struct ti_port *tport = usb_get_serial_port_data(port);
898 	struct ti_uart_config *config;
899 	tcflag_t cflag, iflag;
900 	int baud;
901 	int status;
902 	int port_number = port->number - port->serial->minor;
903 	unsigned int mcr;
904 
905 	dbg("%s - port %d", __func__, port->number);
906 
907 	cflag = tty->termios->c_cflag;
908 	iflag = tty->termios->c_iflag;
909 
910 	dbg("%s - cflag %08x, iflag %08x", __func__, cflag, iflag);
911 	dbg("%s - old clfag %08x, old iflag %08x", __func__,
912 				old_termios->c_cflag, old_termios->c_iflag);
913 
914 	if (tport == NULL)
915 		return;
916 
917 	config = kmalloc(sizeof(*config), GFP_KERNEL);
918 	if (!config) {
919 		dev_err(&port->dev, "%s - out of memory\n", __func__);
920 		return;
921 	}
922 
923 	config->wFlags = 0;
924 
925 	/* these flags must be set */
926 	config->wFlags |= TI_UART_ENABLE_MS_INTS;
927 	config->wFlags |= TI_UART_ENABLE_AUTO_START_DMA;
928 	config->bUartMode = (__u8)(tport->tp_uart_mode);
929 
930 	switch (cflag & CSIZE) {
931 	case CS5:
932 		    config->bDataBits = TI_UART_5_DATA_BITS;
933 		    break;
934 	case CS6:
935 		    config->bDataBits = TI_UART_6_DATA_BITS;
936 		    break;
937 	case CS7:
938 		    config->bDataBits = TI_UART_7_DATA_BITS;
939 		    break;
940 	default:
941 	case CS8:
942 		    config->bDataBits = TI_UART_8_DATA_BITS;
943 		    break;
944 	}
945 
946 	/* CMSPAR isn't supported by this driver */
947 	tty->termios->c_cflag &= ~CMSPAR;
948 
949 	if (cflag & PARENB) {
950 		if (cflag & PARODD) {
951 			config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
952 			config->bParity = TI_UART_ODD_PARITY;
953 		} else {
954 			config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
955 			config->bParity = TI_UART_EVEN_PARITY;
956 		}
957 	} else {
958 		config->wFlags &= ~TI_UART_ENABLE_PARITY_CHECKING;
959 		config->bParity = TI_UART_NO_PARITY;
960 	}
961 
962 	if (cflag & CSTOPB)
963 		config->bStopBits = TI_UART_2_STOP_BITS;
964 	else
965 		config->bStopBits = TI_UART_1_STOP_BITS;
966 
967 	if (cflag & CRTSCTS) {
968 		/* RTS flow control must be off to drop RTS for baud rate B0 */
969 		if ((cflag & CBAUD) != B0)
970 			config->wFlags |= TI_UART_ENABLE_RTS_IN;
971 		config->wFlags |= TI_UART_ENABLE_CTS_OUT;
972 	} else {
973 		tty->hw_stopped = 0;
974 		ti_restart_read(tport, tty);
975 	}
976 
977 	if (I_IXOFF(tty) || I_IXON(tty)) {
978 		config->cXon  = START_CHAR(tty);
979 		config->cXoff = STOP_CHAR(tty);
980 
981 		if (I_IXOFF(tty))
982 			config->wFlags |= TI_UART_ENABLE_X_IN;
983 		else
984 			ti_restart_read(tport, tty);
985 
986 		if (I_IXON(tty))
987 			config->wFlags |= TI_UART_ENABLE_X_OUT;
988 	}
989 
990 	baud = tty_get_baud_rate(tty);
991 	if (!baud)
992 		baud = 9600;
993 	if (tport->tp_tdev->td_is_3410)
994 		config->wBaudRate = (__u16)((923077 + baud/2) / baud);
995 	else
996 		config->wBaudRate = (__u16)((461538 + baud/2) / baud);
997 
998 	/* FIXME: Should calculate resulting baud here and report it back */
999 	if ((cflag & CBAUD) != B0)
1000 		tty_encode_baud_rate(tty, baud, baud);
1001 
1002 	dbg("%s - BaudRate=%d, wBaudRate=%d, wFlags=0x%04X, bDataBits=%d, bParity=%d, bStopBits=%d, cXon=%d, cXoff=%d, bUartMode=%d",
1003 	__func__, baud, config->wBaudRate, config->wFlags, config->bDataBits, config->bParity, config->bStopBits, config->cXon, config->cXoff, config->bUartMode);
1004 
1005 	cpu_to_be16s(&config->wBaudRate);
1006 	cpu_to_be16s(&config->wFlags);
1007 
1008 	status = ti_command_out_sync(tport->tp_tdev, TI_SET_CONFIG,
1009 		(__u8)(TI_UART1_PORT + port_number), 0, (__u8 *)config,
1010 		sizeof(*config));
1011 	if (status)
1012 		dev_err(&port->dev, "%s - cannot set config on port %d, %d\n",
1013 					__func__, port_number, status);
1014 
1015 	/* SET_CONFIG asserts RTS and DTR, reset them correctly */
1016 	mcr = tport->tp_shadow_mcr;
1017 	/* if baud rate is B0, clear RTS and DTR */
1018 	if ((cflag & CBAUD) == B0)
1019 		mcr &= ~(TI_MCR_DTR | TI_MCR_RTS);
1020 	status = ti_set_mcr(tport, mcr);
1021 	if (status)
1022 		dev_err(&port->dev,
1023 			"%s - cannot set modem control on port %d, %d\n",
1024 						__func__, port_number, status);
1025 
1026 	kfree(config);
1027 }
1028 
1029 
1030 static int ti_tiocmget(struct tty_struct *tty, struct file *file)
1031 {
1032 	struct usb_serial_port *port = tty->driver_data;
1033 	struct ti_port *tport = usb_get_serial_port_data(port);
1034 	unsigned int result;
1035 	unsigned int msr;
1036 	unsigned int mcr;
1037 	unsigned long flags;
1038 
1039 	dbg("%s - port %d", __func__, port->number);
1040 
1041 	if (tport == NULL)
1042 		return -ENODEV;
1043 
1044 	spin_lock_irqsave(&tport->tp_lock, flags);
1045 	msr = tport->tp_msr;
1046 	mcr = tport->tp_shadow_mcr;
1047 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1048 
1049 	result = ((mcr & TI_MCR_DTR) ? TIOCM_DTR : 0)
1050 		| ((mcr & TI_MCR_RTS) ? TIOCM_RTS : 0)
1051 		| ((mcr & TI_MCR_LOOP) ? TIOCM_LOOP : 0)
1052 		| ((msr & TI_MSR_CTS) ? TIOCM_CTS : 0)
1053 		| ((msr & TI_MSR_CD) ? TIOCM_CAR : 0)
1054 		| ((msr & TI_MSR_RI) ? TIOCM_RI : 0)
1055 		| ((msr & TI_MSR_DSR) ? TIOCM_DSR : 0);
1056 
1057 	dbg("%s - 0x%04X", __func__, result);
1058 
1059 	return result;
1060 }
1061 
1062 
1063 static int ti_tiocmset(struct tty_struct *tty, struct file *file,
1064 	unsigned int set, unsigned int clear)
1065 {
1066 	struct usb_serial_port *port = tty->driver_data;
1067 	struct ti_port *tport = usb_get_serial_port_data(port);
1068 	unsigned int mcr;
1069 	unsigned long flags;
1070 
1071 	dbg("%s - port %d", __func__, port->number);
1072 
1073 	if (tport == NULL)
1074 		return -ENODEV;
1075 
1076 	spin_lock_irqsave(&tport->tp_lock, flags);
1077 	mcr = tport->tp_shadow_mcr;
1078 
1079 	if (set & TIOCM_RTS)
1080 		mcr |= TI_MCR_RTS;
1081 	if (set & TIOCM_DTR)
1082 		mcr |= TI_MCR_DTR;
1083 	if (set & TIOCM_LOOP)
1084 		mcr |= TI_MCR_LOOP;
1085 
1086 	if (clear & TIOCM_RTS)
1087 		mcr &= ~TI_MCR_RTS;
1088 	if (clear & TIOCM_DTR)
1089 		mcr &= ~TI_MCR_DTR;
1090 	if (clear & TIOCM_LOOP)
1091 		mcr &= ~TI_MCR_LOOP;
1092 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1093 
1094 	return ti_set_mcr(tport, mcr);
1095 }
1096 
1097 
1098 static void ti_break(struct tty_struct *tty, int break_state)
1099 {
1100 	struct usb_serial_port *port = tty->driver_data;
1101 	struct ti_port *tport = usb_get_serial_port_data(port);
1102 	int status;
1103 
1104 	dbg("%s - state = %d", __func__, break_state);
1105 
1106 	if (tport == NULL)
1107 		return;
1108 
1109 	ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 0);
1110 
1111 	status = ti_write_byte(tport->tp_tdev,
1112 		tport->tp_uart_base_addr + TI_UART_OFFSET_LCR,
1113 		TI_LCR_BREAK, break_state == -1 ? TI_LCR_BREAK : 0);
1114 
1115 	if (status)
1116 		dbg("%s - error setting break, %d", __func__, status);
1117 }
1118 
1119 
1120 static void ti_interrupt_callback(struct urb *urb)
1121 {
1122 	struct ti_device *tdev = urb->context;
1123 	struct usb_serial_port *port;
1124 	struct usb_serial *serial = tdev->td_serial;
1125 	struct ti_port *tport;
1126 	struct device *dev = &urb->dev->dev;
1127 	unsigned char *data = urb->transfer_buffer;
1128 	int length = urb->actual_length;
1129 	int port_number;
1130 	int function;
1131 	int status = urb->status;
1132 	int retval;
1133 	__u8 msr;
1134 
1135 	dbg("%s", __func__);
1136 
1137 	switch (status) {
1138 	case 0:
1139 		break;
1140 	case -ECONNRESET:
1141 	case -ENOENT:
1142 	case -ESHUTDOWN:
1143 		dbg("%s - urb shutting down, %d", __func__, status);
1144 		tdev->td_urb_error = 1;
1145 		return;
1146 	default:
1147 		dev_err(dev, "%s - nonzero urb status, %d\n",
1148 			__func__, status);
1149 		tdev->td_urb_error = 1;
1150 		goto exit;
1151 	}
1152 
1153 	if (length != 2) {
1154 		dbg("%s - bad packet size, %d", __func__, length);
1155 		goto exit;
1156 	}
1157 
1158 	if (data[0] == TI_CODE_HARDWARE_ERROR) {
1159 		dev_err(dev, "%s - hardware error, %d\n", __func__, data[1]);
1160 		goto exit;
1161 	}
1162 
1163 	port_number = TI_GET_PORT_FROM_CODE(data[0]);
1164 	function = TI_GET_FUNC_FROM_CODE(data[0]);
1165 
1166 	dbg("%s - port_number %d, function %d, data 0x%02X",
1167 				__func__, port_number, function, data[1]);
1168 
1169 	if (port_number >= serial->num_ports) {
1170 		dev_err(dev, "%s - bad port number, %d\n",
1171 						__func__, port_number);
1172 		goto exit;
1173 	}
1174 
1175 	port = serial->port[port_number];
1176 
1177 	tport = usb_get_serial_port_data(port);
1178 	if (!tport)
1179 		goto exit;
1180 
1181 	switch (function) {
1182 	case TI_CODE_DATA_ERROR:
1183 		dev_err(dev, "%s - DATA ERROR, port %d, data 0x%02X\n",
1184 					__func__, port_number, data[1]);
1185 		break;
1186 
1187 	case TI_CODE_MODEM_STATUS:
1188 		msr = data[1];
1189 		dbg("%s - port %d, msr 0x%02X", __func__, port_number, msr);
1190 		ti_handle_new_msr(tport, msr);
1191 		break;
1192 
1193 	default:
1194 		dev_err(dev, "%s - unknown interrupt code, 0x%02X\n",
1195 							__func__, data[1]);
1196 		break;
1197 	}
1198 
1199 exit:
1200 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1201 	if (retval)
1202 		dev_err(dev, "%s - resubmit interrupt urb failed, %d\n",
1203 			__func__, retval);
1204 }
1205 
1206 
1207 static void ti_bulk_in_callback(struct urb *urb)
1208 {
1209 	struct ti_port *tport = urb->context;
1210 	struct usb_serial_port *port = tport->tp_port;
1211 	struct device *dev = &urb->dev->dev;
1212 	int status = urb->status;
1213 	int retval = 0;
1214 	struct tty_struct *tty;
1215 
1216 	dbg("%s", __func__);
1217 
1218 	switch (status) {
1219 	case 0:
1220 		break;
1221 	case -ECONNRESET:
1222 	case -ENOENT:
1223 	case -ESHUTDOWN:
1224 		dbg("%s - urb shutting down, %d", __func__, status);
1225 		tport->tp_tdev->td_urb_error = 1;
1226 		wake_up_interruptible(&tport->tp_write_wait);
1227 		return;
1228 	default:
1229 		dev_err(dev, "%s - nonzero urb status, %d\n",
1230 			__func__, status);
1231 		tport->tp_tdev->td_urb_error = 1;
1232 		wake_up_interruptible(&tport->tp_write_wait);
1233 	}
1234 
1235 	if (status == -EPIPE)
1236 		goto exit;
1237 
1238 	if (status) {
1239 		dev_err(dev, "%s - stopping read!\n", __func__);
1240 		return;
1241 	}
1242 
1243 	tty = tty_port_tty_get(&port->port);
1244 	if (tty && urb->actual_length) {
1245 		usb_serial_debug_data(debug, dev, __func__,
1246 			urb->actual_length, urb->transfer_buffer);
1247 
1248 		if (!tport->tp_is_open)
1249 			dbg("%s - port closed, dropping data", __func__);
1250 		else
1251 			ti_recv(&urb->dev->dev, tty,
1252 						urb->transfer_buffer,
1253 						urb->actual_length);
1254 
1255 		spin_lock(&tport->tp_lock);
1256 		tport->tp_icount.rx += urb->actual_length;
1257 		spin_unlock(&tport->tp_lock);
1258 		tty_kref_put(tty);
1259 	}
1260 
1261 exit:
1262 	/* continue to read unless stopping */
1263 	spin_lock(&tport->tp_lock);
1264 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING) {
1265 		urb->dev = port->serial->dev;
1266 		retval = usb_submit_urb(urb, GFP_ATOMIC);
1267 	} else if (tport->tp_read_urb_state == TI_READ_URB_STOPPING) {
1268 		tport->tp_read_urb_state = TI_READ_URB_STOPPED;
1269 	}
1270 	spin_unlock(&tport->tp_lock);
1271 	if (retval)
1272 		dev_err(dev, "%s - resubmit read urb failed, %d\n",
1273 			__func__, retval);
1274 }
1275 
1276 
1277 static void ti_bulk_out_callback(struct urb *urb)
1278 {
1279 	struct ti_port *tport = urb->context;
1280 	struct usb_serial_port *port = tport->tp_port;
1281 	struct device *dev = &urb->dev->dev;
1282 	int status = urb->status;
1283 
1284 	dbg("%s - port %d", __func__, port->number);
1285 
1286 	tport->tp_write_urb_in_use = 0;
1287 
1288 	switch (status) {
1289 	case 0:
1290 		break;
1291 	case -ECONNRESET:
1292 	case -ENOENT:
1293 	case -ESHUTDOWN:
1294 		dbg("%s - urb shutting down, %d", __func__, status);
1295 		tport->tp_tdev->td_urb_error = 1;
1296 		wake_up_interruptible(&tport->tp_write_wait);
1297 		return;
1298 	default:
1299 		dev_err(dev, "%s - nonzero urb status, %d\n",
1300 			__func__, status);
1301 		tport->tp_tdev->td_urb_error = 1;
1302 		wake_up_interruptible(&tport->tp_write_wait);
1303 	}
1304 
1305 	/* send any buffered data */
1306 	ti_send(tport);
1307 }
1308 
1309 
1310 static void ti_recv(struct device *dev, struct tty_struct *tty,
1311 	unsigned char *data, int length)
1312 {
1313 	int cnt;
1314 
1315 	do {
1316 		cnt = tty_buffer_request_room(tty, length);
1317 		if (cnt < length) {
1318 			dev_err(dev, "%s - dropping data, %d bytes lost\n",
1319 						__func__, length - cnt);
1320 			if (cnt == 0)
1321 				break;
1322 		}
1323 		tty_insert_flip_string(tty, data, cnt);
1324 		tty_flip_buffer_push(tty);
1325 		data += cnt;
1326 		length -= cnt;
1327 	} while (length > 0);
1328 
1329 }
1330 
1331 
1332 static void ti_send(struct ti_port *tport)
1333 {
1334 	int count, result;
1335 	struct usb_serial_port *port = tport->tp_port;
1336 	struct tty_struct *tty = tty_port_tty_get(&port->port);	/* FIXME */
1337 	unsigned long flags;
1338 
1339 
1340 	dbg("%s - port %d", __func__, port->number);
1341 
1342 	spin_lock_irqsave(&tport->tp_lock, flags);
1343 
1344 	if (tport->tp_write_urb_in_use)
1345 		goto unlock;
1346 
1347 	count = ti_buf_get(tport->tp_write_buf,
1348 				port->write_urb->transfer_buffer,
1349 				port->bulk_out_size);
1350 
1351 	if (count == 0)
1352 		goto unlock;
1353 
1354 	tport->tp_write_urb_in_use = 1;
1355 
1356 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1357 
1358 	usb_serial_debug_data(debug, &port->dev, __func__, count,
1359 					port->write_urb->transfer_buffer);
1360 
1361 	usb_fill_bulk_urb(port->write_urb, port->serial->dev,
1362 			   usb_sndbulkpipe(port->serial->dev,
1363 					    port->bulk_out_endpointAddress),
1364 			   port->write_urb->transfer_buffer, count,
1365 			   ti_bulk_out_callback, tport);
1366 
1367 	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1368 	if (result) {
1369 		dev_err(&port->dev, "%s - submit write urb failed, %d\n",
1370 							__func__, result);
1371 		tport->tp_write_urb_in_use = 0;
1372 		/* TODO: reschedule ti_send */
1373 	} else {
1374 		spin_lock_irqsave(&tport->tp_lock, flags);
1375 		tport->tp_icount.tx += count;
1376 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1377 	}
1378 
1379 	/* more room in the buffer for new writes, wakeup */
1380 	if (tty)
1381 		tty_wakeup(tty);
1382 	tty_kref_put(tty);
1383 	wake_up_interruptible(&tport->tp_write_wait);
1384 	return;
1385 unlock:
1386 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1387 	tty_kref_put(tty);
1388 	return;
1389 }
1390 
1391 
1392 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr)
1393 {
1394 	unsigned long flags;
1395 	int status;
1396 
1397 	status = ti_write_byte(tport->tp_tdev,
1398 		tport->tp_uart_base_addr + TI_UART_OFFSET_MCR,
1399 		TI_MCR_RTS | TI_MCR_DTR | TI_MCR_LOOP, mcr);
1400 
1401 	spin_lock_irqsave(&tport->tp_lock, flags);
1402 	if (!status)
1403 		tport->tp_shadow_mcr = mcr;
1404 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1405 
1406 	return status;
1407 }
1408 
1409 
1410 static int ti_get_lsr(struct ti_port *tport)
1411 {
1412 	int size, status;
1413 	struct ti_device *tdev = tport->tp_tdev;
1414 	struct usb_serial_port *port = tport->tp_port;
1415 	int port_number = port->number - port->serial->minor;
1416 	struct ti_port_status *data;
1417 
1418 	dbg("%s - port %d", __func__, port->number);
1419 
1420 	size = sizeof(struct ti_port_status);
1421 	data = kmalloc(size, GFP_KERNEL);
1422 	if (!data) {
1423 		dev_err(&port->dev, "%s - out of memory\n", __func__);
1424 		return -ENOMEM;
1425 	}
1426 
1427 	status = ti_command_in_sync(tdev, TI_GET_PORT_STATUS,
1428 		(__u8)(TI_UART1_PORT+port_number), 0, (__u8 *)data, size);
1429 	if (status) {
1430 		dev_err(&port->dev,
1431 			"%s - get port status command failed, %d\n",
1432 							__func__, status);
1433 		goto free_data;
1434 	}
1435 
1436 	dbg("%s - lsr 0x%02X", __func__, data->bLSR);
1437 
1438 	tport->tp_lsr = data->bLSR;
1439 
1440 free_data:
1441 	kfree(data);
1442 	return status;
1443 }
1444 
1445 
1446 static int ti_get_serial_info(struct ti_port *tport,
1447 	struct serial_struct __user *ret_arg)
1448 {
1449 	struct usb_serial_port *port = tport->tp_port;
1450 	struct serial_struct ret_serial;
1451 
1452 	if (!ret_arg)
1453 		return -EFAULT;
1454 
1455 	memset(&ret_serial, 0, sizeof(ret_serial));
1456 
1457 	ret_serial.type = PORT_16550A;
1458 	ret_serial.line = port->serial->minor;
1459 	ret_serial.port = port->number - port->serial->minor;
1460 	ret_serial.flags = tport->tp_flags;
1461 	ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
1462 	ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
1463 	ret_serial.closing_wait = tport->tp_closing_wait;
1464 
1465 	if (copy_to_user(ret_arg, &ret_serial, sizeof(*ret_arg)))
1466 		return -EFAULT;
1467 
1468 	return 0;
1469 }
1470 
1471 
1472 static int ti_set_serial_info(struct tty_struct *tty, struct ti_port *tport,
1473 	struct serial_struct __user *new_arg)
1474 {
1475 	struct serial_struct new_serial;
1476 
1477 	if (copy_from_user(&new_serial, new_arg, sizeof(new_serial)))
1478 		return -EFAULT;
1479 
1480 	tport->tp_flags = new_serial.flags & TI_SET_SERIAL_FLAGS;
1481 	tty->low_latency = (tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1482 	tport->tp_closing_wait = new_serial.closing_wait;
1483 
1484 	return 0;
1485 }
1486 
1487 
1488 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr)
1489 {
1490 	struct async_icount *icount;
1491 	struct tty_struct *tty;
1492 	unsigned long flags;
1493 
1494 	dbg("%s - msr 0x%02X", __func__, msr);
1495 
1496 	if (msr & TI_MSR_DELTA_MASK) {
1497 		spin_lock_irqsave(&tport->tp_lock, flags);
1498 		icount = &tport->tp_icount;
1499 		if (msr & TI_MSR_DELTA_CTS)
1500 			icount->cts++;
1501 		if (msr & TI_MSR_DELTA_DSR)
1502 			icount->dsr++;
1503 		if (msr & TI_MSR_DELTA_CD)
1504 			icount->dcd++;
1505 		if (msr & TI_MSR_DELTA_RI)
1506 			icount->rng++;
1507 		wake_up_interruptible(&tport->tp_msr_wait);
1508 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1509 	}
1510 
1511 	tport->tp_msr = msr & TI_MSR_MASK;
1512 
1513 	/* handle CTS flow control */
1514 	tty = tty_port_tty_get(&tport->tp_port->port);
1515 	if (tty && C_CRTSCTS(tty)) {
1516 		if (msr & TI_MSR_CTS) {
1517 			tty->hw_stopped = 0;
1518 			tty_wakeup(tty);
1519 		} else {
1520 			tty->hw_stopped = 1;
1521 		}
1522 	}
1523 	tty_kref_put(tty);
1524 }
1525 
1526 
1527 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
1528 {
1529 	struct ti_device *tdev = tport->tp_tdev;
1530 	struct usb_serial_port *port = tport->tp_port;
1531 	wait_queue_t wait;
1532 
1533 	dbg("%s - port %d", __func__, port->number);
1534 
1535 	spin_lock_irq(&tport->tp_lock);
1536 
1537 	/* wait for data to drain from the buffer */
1538 	tdev->td_urb_error = 0;
1539 	init_waitqueue_entry(&wait, current);
1540 	add_wait_queue(&tport->tp_write_wait, &wait);
1541 	for (;;) {
1542 		set_current_state(TASK_INTERRUPTIBLE);
1543 		if (ti_buf_data_avail(tport->tp_write_buf) == 0
1544 		|| timeout == 0 || signal_pending(current)
1545 		|| tdev->td_urb_error
1546 		|| port->serial->disconnected)  /* disconnect */
1547 			break;
1548 		spin_unlock_irq(&tport->tp_lock);
1549 		timeout = schedule_timeout(timeout);
1550 		spin_lock_irq(&tport->tp_lock);
1551 	}
1552 	set_current_state(TASK_RUNNING);
1553 	remove_wait_queue(&tport->tp_write_wait, &wait);
1554 
1555 	/* flush any remaining data in the buffer */
1556 	if (flush)
1557 		ti_buf_clear(tport->tp_write_buf);
1558 
1559 	spin_unlock_irq(&tport->tp_lock);
1560 
1561 	mutex_lock(&port->serial->disc_mutex);
1562 	/* wait for data to drain from the device */
1563 	/* wait for empty tx register, plus 20 ms */
1564 	timeout += jiffies;
1565 	tport->tp_lsr &= ~TI_LSR_TX_EMPTY;
1566 	while ((long)(jiffies - timeout) < 0 && !signal_pending(current)
1567 	&& !(tport->tp_lsr&TI_LSR_TX_EMPTY) && !tdev->td_urb_error
1568 	&& !port->serial->disconnected) {
1569 		if (ti_get_lsr(tport))
1570 			break;
1571 		mutex_unlock(&port->serial->disc_mutex);
1572 		msleep_interruptible(20);
1573 		mutex_lock(&port->serial->disc_mutex);
1574 	}
1575 	mutex_unlock(&port->serial->disc_mutex);
1576 }
1577 
1578 
1579 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty)
1580 {
1581 	unsigned long flags;
1582 
1583 	spin_lock_irqsave(&tport->tp_lock, flags);
1584 
1585 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING)
1586 		tport->tp_read_urb_state = TI_READ_URB_STOPPING;
1587 
1588 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1589 }
1590 
1591 
1592 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty)
1593 {
1594 	struct urb *urb;
1595 	int status = 0;
1596 	unsigned long flags;
1597 
1598 	spin_lock_irqsave(&tport->tp_lock, flags);
1599 
1600 	if (tport->tp_read_urb_state == TI_READ_URB_STOPPED) {
1601 		tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1602 		urb = tport->tp_port->read_urb;
1603 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1604 		urb->complete = ti_bulk_in_callback;
1605 		urb->context = tport;
1606 		urb->dev = tport->tp_port->serial->dev;
1607 		status = usb_submit_urb(urb, GFP_KERNEL);
1608 	} else  {
1609 		tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1610 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1611 	}
1612 
1613 	return status;
1614 }
1615 
1616 
1617 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
1618 	__u16 moduleid, __u16 value, __u8 *data, int size)
1619 {
1620 	int status;
1621 
1622 	status = usb_control_msg(tdev->td_serial->dev,
1623 		usb_sndctrlpipe(tdev->td_serial->dev, 0), command,
1624 		(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT),
1625 		value, moduleid, data, size, 1000);
1626 
1627 	if (status == size)
1628 		status = 0;
1629 
1630 	if (status > 0)
1631 		status = -ECOMM;
1632 
1633 	return status;
1634 }
1635 
1636 
1637 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
1638 	__u16 moduleid, __u16 value, __u8 *data, int size)
1639 {
1640 	int status;
1641 
1642 	status = usb_control_msg(tdev->td_serial->dev,
1643 		usb_rcvctrlpipe(tdev->td_serial->dev, 0), command,
1644 		(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN),
1645 		value, moduleid, data, size, 1000);
1646 
1647 	if (status == size)
1648 		status = 0;
1649 
1650 	if (status > 0)
1651 		status = -ECOMM;
1652 
1653 	return status;
1654 }
1655 
1656 
1657 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
1658 	__u8 mask, __u8 byte)
1659 {
1660 	int status;
1661 	unsigned int size;
1662 	struct ti_write_data_bytes *data;
1663 	struct device *dev = &tdev->td_serial->dev->dev;
1664 
1665 	dbg("%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X",
1666 					__func__, addr, mask, byte);
1667 
1668 	size = sizeof(struct ti_write_data_bytes) + 2;
1669 	data = kmalloc(size, GFP_KERNEL);
1670 	if (!data) {
1671 		dev_err(dev, "%s - out of memory\n", __func__);
1672 		return -ENOMEM;
1673 	}
1674 
1675 	data->bAddrType = TI_RW_DATA_ADDR_XDATA;
1676 	data->bDataType = TI_RW_DATA_BYTE;
1677 	data->bDataCounter = 1;
1678 	data->wBaseAddrHi = cpu_to_be16(addr>>16);
1679 	data->wBaseAddrLo = cpu_to_be16(addr);
1680 	data->bData[0] = mask;
1681 	data->bData[1] = byte;
1682 
1683 	status = ti_command_out_sync(tdev, TI_WRITE_DATA, TI_RAM_PORT, 0,
1684 		(__u8 *)data, size);
1685 
1686 	if (status < 0)
1687 		dev_err(dev, "%s - failed, %d\n", __func__, status);
1688 
1689 	kfree(data);
1690 
1691 	return status;
1692 }
1693 
1694 static int ti_do_download(struct usb_device *dev, int pipe,
1695 						u8 *buffer, int size)
1696 {
1697 	int pos;
1698 	u8 cs = 0;
1699 	int done;
1700 	struct ti_firmware_header *header;
1701 	int status;
1702 	int len;
1703 
1704 	for (pos = sizeof(struct ti_firmware_header); pos < size; pos++)
1705 		cs = (__u8)(cs + buffer[pos]);
1706 
1707 	header = (struct ti_firmware_header *)buffer;
1708 	header->wLength = cpu_to_le16((__u16)(size
1709 					- sizeof(struct ti_firmware_header)));
1710 	header->bCheckSum = cs;
1711 
1712 	dbg("%s - downloading firmware", __func__);
1713 	for (pos = 0; pos < size; pos += done) {
1714 		len = min(size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
1715 		status = usb_bulk_msg(dev, pipe, buffer + pos, len,
1716 								&done, 1000);
1717 		if (status)
1718 			break;
1719 	}
1720 	return status;
1721 }
1722 
1723 static int ti_download_firmware(struct ti_device *tdev, int type)
1724 {
1725 	int status = -ENOMEM;
1726 	int buffer_size;
1727 	__u8 *buffer;
1728 	struct usb_device *dev = tdev->td_serial->dev;
1729 	unsigned int pipe = usb_sndbulkpipe(dev,
1730 		tdev->td_serial->port[0]->bulk_out_endpointAddress);
1731 	const struct firmware *fw_p;
1732 	char buf[32];
1733 	sprintf(buf, "ti_usb-%d.bin", type);
1734 
1735 	if (request_firmware(&fw_p, buf, &dev->dev)) {
1736 		dev_err(&dev->dev, "%s - firmware not found\n", __func__);
1737 		return -ENOENT;
1738 	}
1739 	if (fw_p->size > TI_FIRMWARE_BUF_SIZE) {
1740 		dev_err(&dev->dev, "%s - firmware too large\n", __func__);
1741 		return -ENOENT;
1742 	}
1743 
1744 	buffer_size = TI_FIRMWARE_BUF_SIZE + sizeof(struct ti_firmware_header);
1745 	buffer = kmalloc(buffer_size, GFP_KERNEL);
1746 	if (buffer) {
1747 		memcpy(buffer, fw_p->data, fw_p->size);
1748 		memset(buffer + fw_p->size, 0xff, buffer_size - fw_p->size);
1749 		status = ti_do_download(dev, pipe, buffer, fw_p->size);
1750 		kfree(buffer);
1751 	}
1752 	release_firmware(fw_p);
1753 	if (status) {
1754 		dev_err(&dev->dev, "%s - error downloading firmware, %d\n",
1755 							__func__, status);
1756 		return status;
1757 	}
1758 
1759 	dbg("%s - download successful", __func__);
1760 
1761 	return 0;
1762 }
1763 
1764 
1765 /* Circular Buffer Functions */
1766 
1767 /*
1768  * ti_buf_alloc
1769  *
1770  * Allocate a circular buffer and all associated memory.
1771  */
1772 
1773 static struct circ_buf *ti_buf_alloc(void)
1774 {
1775 	struct circ_buf *cb;
1776 
1777 	cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
1778 	if (cb == NULL)
1779 		return NULL;
1780 
1781 	cb->buf = kmalloc(TI_WRITE_BUF_SIZE, GFP_KERNEL);
1782 	if (cb->buf == NULL) {
1783 		kfree(cb);
1784 		return NULL;
1785 	}
1786 
1787 	ti_buf_clear(cb);
1788 
1789 	return cb;
1790 }
1791 
1792 
1793 /*
1794  * ti_buf_free
1795  *
1796  * Free the buffer and all associated memory.
1797  */
1798 
1799 static void ti_buf_free(struct circ_buf *cb)
1800 {
1801 	kfree(cb->buf);
1802 	kfree(cb);
1803 }
1804 
1805 
1806 /*
1807  * ti_buf_clear
1808  *
1809  * Clear out all data in the circular buffer.
1810  */
1811 
1812 static void ti_buf_clear(struct circ_buf *cb)
1813 {
1814 	cb->head = cb->tail = 0;
1815 }
1816 
1817 
1818 /*
1819  * ti_buf_data_avail
1820  *
1821  * Return the number of bytes of data available in the circular
1822  * buffer.
1823  */
1824 
1825 static int ti_buf_data_avail(struct circ_buf *cb)
1826 {
1827 	return CIRC_CNT(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1828 }
1829 
1830 
1831 /*
1832  * ti_buf_space_avail
1833  *
1834  * Return the number of bytes of space available in the circular
1835  * buffer.
1836  */
1837 
1838 static int ti_buf_space_avail(struct circ_buf *cb)
1839 {
1840 	return CIRC_SPACE(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1841 }
1842 
1843 
1844 /*
1845  * ti_buf_put
1846  *
1847  * Copy data data from a user buffer and put it into the circular buffer.
1848  * Restrict to the amount of space available.
1849  *
1850  * Return the number of bytes copied.
1851  */
1852 
1853 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count)
1854 {
1855 	int c, ret = 0;
1856 
1857 	while (1) {
1858 		c = CIRC_SPACE_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1859 		if (count < c)
1860 			c = count;
1861 		if (c <= 0)
1862 			break;
1863 		memcpy(cb->buf + cb->head, buf, c);
1864 		cb->head = (cb->head + c) & (TI_WRITE_BUF_SIZE-1);
1865 		buf += c;
1866 		count -= c;
1867 		ret += c;
1868 	}
1869 
1870 	return ret;
1871 }
1872 
1873 
1874 /*
1875  * ti_buf_get
1876  *
1877  * Get data from the circular buffer and copy to the given buffer.
1878  * Restrict to the amount of data available.
1879  *
1880  * Return the number of bytes copied.
1881  */
1882 
1883 static int ti_buf_get(struct circ_buf *cb, char *buf, int count)
1884 {
1885 	int c, ret = 0;
1886 
1887 	while (1) {
1888 		c = CIRC_CNT_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1889 		if (count < c)
1890 			c = count;
1891 		if (c <= 0)
1892 			break;
1893 		memcpy(buf, cb->buf + cb->tail, c);
1894 		cb->tail = (cb->tail + c) & (TI_WRITE_BUF_SIZE-1);
1895 		buf += c;
1896 		count -= c;
1897 		ret += c;
1898 	}
1899 
1900 	return ret;
1901 }
1902