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 #include <linux/firmware.h>
89 
90 #include "ti_usb_3410_5052.h"
91 
92 /* Defines */
93 
94 #define TI_DRIVER_VERSION	"v0.9"
95 #define TI_DRIVER_AUTHOR	"Al Borchers <alborchers@steinerpoint.com>"
96 #define TI_DRIVER_DESC		"TI USB 3410/5052 Serial Driver"
97 
98 #define TI_FIRMWARE_BUF_SIZE	16284
99 
100 #define TI_WRITE_BUF_SIZE	1024
101 
102 #define TI_TRANSFER_TIMEOUT	2
103 
104 #define TI_DEFAULT_LOW_LATENCY	0
105 #define TI_DEFAULT_CLOSING_WAIT	4000		/* in .01 secs */
106 
107 /* supported setserial flags */
108 #define TI_SET_SERIAL_FLAGS	(ASYNC_LOW_LATENCY)
109 
110 /* read urb states */
111 #define TI_READ_URB_RUNNING	0
112 #define TI_READ_URB_STOPPING	1
113 #define TI_READ_URB_STOPPED	2
114 
115 #define TI_EXTRA_VID_PID_COUNT	5
116 
117 
118 /* Structures */
119 
120 struct ti_port {
121 	int			tp_is_open;
122 	__u8			tp_msr;
123 	__u8			tp_lsr;
124 	__u8			tp_shadow_mcr;
125 	__u8			tp_uart_mode;	/* 232 or 485 modes */
126 	unsigned int		tp_uart_base_addr;
127 	int			tp_flags;
128 	int			tp_closing_wait;/* in .01 secs */
129 	struct async_icount	tp_icount;
130 	wait_queue_head_t	tp_msr_wait;	/* wait for msr change */
131 	wait_queue_head_t	tp_write_wait;
132 	struct ti_device	*tp_tdev;
133 	struct usb_serial_port	*tp_port;
134 	spinlock_t		tp_lock;
135 	int			tp_read_urb_state;
136 	int			tp_write_urb_in_use;
137 	struct circ_buf		*tp_write_buf;
138 };
139 
140 struct ti_device {
141 	struct mutex		td_open_close_lock;
142 	int			td_open_port_count;
143 	struct usb_serial	*td_serial;
144 	int			td_is_3410;
145 	int			td_urb_error;
146 };
147 
148 
149 /* Function Declarations */
150 
151 static int ti_startup(struct usb_serial *serial);
152 static void ti_shutdown(struct usb_serial *serial);
153 static int ti_open(struct tty_struct *tty, struct usb_serial_port *port,
154 		struct file *file);
155 static void ti_close(struct tty_struct *tty, struct usb_serial_port *port,
156 		struct file *file);
157 static int ti_write(struct tty_struct *tty, struct usb_serial_port *port,
158 		const unsigned char *data, int count);
159 static int ti_write_room(struct tty_struct *tty);
160 static int ti_chars_in_buffer(struct tty_struct *tty);
161 static void ti_throttle(struct tty_struct *tty);
162 static void ti_unthrottle(struct tty_struct *tty);
163 static int ti_ioctl(struct tty_struct *tty, struct file *file,
164 		unsigned int cmd, unsigned long arg);
165 static void ti_set_termios(struct tty_struct *tty,
166 		struct usb_serial_port *port, struct ktermios *old_termios);
167 static int ti_tiocmget(struct tty_struct *tty, struct file *file);
168 static int ti_tiocmset(struct tty_struct *tty, struct file *file,
169 		unsigned int set, unsigned int clear);
170 static void ti_break(struct tty_struct *tty, int break_state);
171 static void ti_interrupt_callback(struct urb *urb);
172 static void ti_bulk_in_callback(struct urb *urb);
173 static void ti_bulk_out_callback(struct urb *urb);
174 
175 static void ti_recv(struct device *dev, struct tty_struct *tty,
176 	unsigned char *data, int length);
177 static void ti_send(struct ti_port *tport);
178 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr);
179 static int ti_get_lsr(struct ti_port *tport);
180 static int ti_get_serial_info(struct ti_port *tport,
181 	struct serial_struct __user *ret_arg);
182 static int ti_set_serial_info(struct ti_port *tport,
183 	struct serial_struct __user *new_arg);
184 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr);
185 
186 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush);
187 
188 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty);
189 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty);
190 
191 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
192 	__u16 moduleid, __u16 value, __u8 *data, int size);
193 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
194 	__u16 moduleid, __u16 value, __u8 *data, int size);
195 
196 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
197 	__u8 mask, __u8 byte);
198 
199 static int ti_download_firmware(struct ti_device *tdev, int type);
200 
201 /* circular buffer */
202 static struct circ_buf *ti_buf_alloc(void);
203 static void ti_buf_free(struct circ_buf *cb);
204 static void ti_buf_clear(struct circ_buf *cb);
205 static int ti_buf_data_avail(struct circ_buf *cb);
206 static int ti_buf_space_avail(struct circ_buf *cb);
207 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count);
208 static int ti_buf_get(struct circ_buf *cb, char *buf, int count);
209 
210 
211 /* Data */
212 
213 /* module parameters */
214 static int debug;
215 static int low_latency = TI_DEFAULT_LOW_LATENCY;
216 static int closing_wait = TI_DEFAULT_CLOSING_WAIT;
217 static ushort vendor_3410[TI_EXTRA_VID_PID_COUNT];
218 static unsigned int vendor_3410_count;
219 static ushort product_3410[TI_EXTRA_VID_PID_COUNT];
220 static unsigned int product_3410_count;
221 static ushort vendor_5052[TI_EXTRA_VID_PID_COUNT];
222 static unsigned int vendor_5052_count;
223 static ushort product_5052[TI_EXTRA_VID_PID_COUNT];
224 static unsigned int product_5052_count;
225 
226 /* supported devices */
227 /* the array dimension is the number of default entries plus */
228 /* TI_EXTRA_VID_PID_COUNT user defined entries plus 1 terminating */
229 /* null entry */
230 static struct usb_device_id ti_id_table_3410[1+TI_EXTRA_VID_PID_COUNT+1] = {
231 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
232 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_EZ430_ID) },
233 };
234 
235 static struct usb_device_id ti_id_table_5052[4+TI_EXTRA_VID_PID_COUNT+1] = {
236 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
237 	{ USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
238 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
239 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
240 };
241 
242 static struct usb_device_id ti_id_table_combined[] = {
243 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
244 	{ USB_DEVICE(TI_VENDOR_ID, TI_3410_EZ430_ID) },
245 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
246 	{ USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
247 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
248 	{ USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
249 	{ }
250 };
251 
252 static struct usb_driver ti_usb_driver = {
253 	.name			= "ti_usb_3410_5052",
254 	.probe			= usb_serial_probe,
255 	.disconnect		= usb_serial_disconnect,
256 	.id_table		= ti_id_table_combined,
257 	.no_dynamic_id = 	1,
258 };
259 
260 static struct usb_serial_driver ti_1port_device = {
261 	.driver = {
262 		.owner		= THIS_MODULE,
263 		.name		= "ti_usb_3410_5052_1",
264 	},
265 	.description		= "TI USB 3410 1 port adapter",
266 	.usb_driver		= &ti_usb_driver,
267 	.id_table		= ti_id_table_3410,
268 	.num_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 	.usb_driver		= &ti_usb_driver,
295 	.id_table		= ti_id_table_5052,
296 	.num_ports		= 2,
297 	.attach			= ti_startup,
298 	.shutdown		= ti_shutdown,
299 	.open			= ti_open,
300 	.close			= ti_close,
301 	.write			= ti_write,
302 	.write_room		= ti_write_room,
303 	.chars_in_buffer	= ti_chars_in_buffer,
304 	.throttle		= ti_throttle,
305 	.unthrottle		= ti_unthrottle,
306 	.ioctl			= ti_ioctl,
307 	.set_termios		= ti_set_termios,
308 	.tiocmget		= ti_tiocmget,
309 	.tiocmset		= ti_tiocmset,
310 	.break_ctl		= ti_break,
311 	.read_int_callback	= ti_interrupt_callback,
312 	.read_bulk_callback	= ti_bulk_in_callback,
313 	.write_bulk_callback	= ti_bulk_out_callback,
314 };
315 
316 
317 /* Module */
318 
319 MODULE_AUTHOR(TI_DRIVER_AUTHOR);
320 MODULE_DESCRIPTION(TI_DRIVER_DESC);
321 MODULE_VERSION(TI_DRIVER_VERSION);
322 MODULE_LICENSE("GPL");
323 
324 MODULE_FIRMWARE("ti_3410.fw");
325 MODULE_FIRMWARE("ti_5052.fw");
326 
327 module_param(debug, bool, S_IRUGO | S_IWUSR);
328 MODULE_PARM_DESC(debug, "Enable debugging, 0=no, 1=yes");
329 
330 module_param(low_latency, bool, S_IRUGO | S_IWUSR);
331 MODULE_PARM_DESC(low_latency,
332 		"TTY low_latency flag, 0=off, 1=on, default is off");
333 
334 module_param(closing_wait, int, S_IRUGO | S_IWUSR);
335 MODULE_PARM_DESC(closing_wait,
336     "Maximum wait for data to drain in close, in .01 secs, default is 4000");
337 
338 module_param_array(vendor_3410, ushort, &vendor_3410_count, S_IRUGO);
339 MODULE_PARM_DESC(vendor_3410,
340 		"Vendor ids for 3410 based devices, 1-5 short integers");
341 module_param_array(product_3410, ushort, &product_3410_count, S_IRUGO);
342 MODULE_PARM_DESC(product_3410,
343 		"Product ids for 3410 based devices, 1-5 short integers");
344 module_param_array(vendor_5052, ushort, &vendor_5052_count, S_IRUGO);
345 MODULE_PARM_DESC(vendor_5052,
346 		"Vendor ids for 5052 based devices, 1-5 short integers");
347 module_param_array(product_5052, ushort, &product_5052_count, S_IRUGO);
348 MODULE_PARM_DESC(product_5052,
349 		"Product ids for 5052 based devices, 1-5 short integers");
350 
351 MODULE_DEVICE_TABLE(usb, ti_id_table_combined);
352 
353 
354 /* Functions */
355 
356 static int __init ti_init(void)
357 {
358 	int i, j;
359 	int ret;
360 
361 	/* insert extra vendor and product ids */
362 	j = ARRAY_SIZE(ti_id_table_3410) - TI_EXTRA_VID_PID_COUNT - 1;
363 	for (i = 0; i < min(vendor_3410_count, product_3410_count); i++, j++) {
364 		ti_id_table_3410[j].idVendor = vendor_3410[i];
365 		ti_id_table_3410[j].idProduct = product_3410[i];
366 		ti_id_table_3410[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
367 	}
368 	j = ARRAY_SIZE(ti_id_table_5052) - TI_EXTRA_VID_PID_COUNT - 1;
369 	for (i = 0; i < min(vendor_5052_count, product_5052_count); i++, j++) {
370 		ti_id_table_5052[j].idVendor = vendor_5052[i];
371 		ti_id_table_5052[j].idProduct = product_5052[i];
372 		ti_id_table_5052[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
373 	}
374 
375 	ret = usb_serial_register(&ti_1port_device);
376 	if (ret)
377 		goto failed_1port;
378 	ret = usb_serial_register(&ti_2port_device);
379 	if (ret)
380 		goto failed_2port;
381 
382 	ret = usb_register(&ti_usb_driver);
383 	if (ret)
384 		goto failed_usb;
385 
386 	info(TI_DRIVER_DESC " " TI_DRIVER_VERSION);
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(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 
1215 	dbg("%s", __func__);
1216 
1217 	switch (status) {
1218 	case 0:
1219 		break;
1220 	case -ECONNRESET:
1221 	case -ENOENT:
1222 	case -ESHUTDOWN:
1223 		dbg("%s - urb shutting down, %d", __func__, status);
1224 		tport->tp_tdev->td_urb_error = 1;
1225 		wake_up_interruptible(&tport->tp_write_wait);
1226 		return;
1227 	default:
1228 		dev_err(dev, "%s - nonzero urb status, %d\n",
1229 			__func__, status);
1230 		tport->tp_tdev->td_urb_error = 1;
1231 		wake_up_interruptible(&tport->tp_write_wait);
1232 	}
1233 
1234 	if (status == -EPIPE)
1235 		goto exit;
1236 
1237 	if (status) {
1238 		dev_err(dev, "%s - stopping read!\n", __func__);
1239 		return;
1240 	}
1241 
1242 	if (port->port.tty && urb->actual_length) {
1243 		usb_serial_debug_data(debug, dev, __func__,
1244 			urb->actual_length, urb->transfer_buffer);
1245 
1246 		if (!tport->tp_is_open)
1247 			dbg("%s - port closed, dropping data", __func__);
1248 		else
1249 			ti_recv(&urb->dev->dev, port->port.tty,
1250 						urb->transfer_buffer,
1251 						urb->actual_length);
1252 
1253 		spin_lock(&tport->tp_lock);
1254 		tport->tp_icount.rx += urb->actual_length;
1255 		spin_unlock(&tport->tp_lock);
1256 	}
1257 
1258 exit:
1259 	/* continue to read unless stopping */
1260 	spin_lock(&tport->tp_lock);
1261 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING) {
1262 		urb->dev = port->serial->dev;
1263 		retval = usb_submit_urb(urb, GFP_ATOMIC);
1264 	} else if (tport->tp_read_urb_state == TI_READ_URB_STOPPING) {
1265 		tport->tp_read_urb_state = TI_READ_URB_STOPPED;
1266 	}
1267 	spin_unlock(&tport->tp_lock);
1268 	if (retval)
1269 		dev_err(dev, "%s - resubmit read urb failed, %d\n",
1270 			__func__, retval);
1271 }
1272 
1273 
1274 static void ti_bulk_out_callback(struct urb *urb)
1275 {
1276 	struct ti_port *tport = urb->context;
1277 	struct usb_serial_port *port = tport->tp_port;
1278 	struct device *dev = &urb->dev->dev;
1279 	int status = urb->status;
1280 
1281 	dbg("%s - port %d", __func__, port->number);
1282 
1283 	tport->tp_write_urb_in_use = 0;
1284 
1285 	switch (status) {
1286 	case 0:
1287 		break;
1288 	case -ECONNRESET:
1289 	case -ENOENT:
1290 	case -ESHUTDOWN:
1291 		dbg("%s - urb shutting down, %d", __func__, status);
1292 		tport->tp_tdev->td_urb_error = 1;
1293 		wake_up_interruptible(&tport->tp_write_wait);
1294 		return;
1295 	default:
1296 		dev_err(dev, "%s - nonzero urb status, %d\n",
1297 			__func__, status);
1298 		tport->tp_tdev->td_urb_error = 1;
1299 		wake_up_interruptible(&tport->tp_write_wait);
1300 	}
1301 
1302 	/* send any buffered data */
1303 	ti_send(tport);
1304 }
1305 
1306 
1307 static void ti_recv(struct device *dev, struct tty_struct *tty,
1308 	unsigned char *data, int length)
1309 {
1310 	int cnt;
1311 
1312 	do {
1313 		cnt = tty_buffer_request_room(tty, length);
1314 		if (cnt < length) {
1315 			dev_err(dev, "%s - dropping data, %d bytes lost\n",
1316 						__func__, length - cnt);
1317 			if (cnt == 0)
1318 				break;
1319 		}
1320 		tty_insert_flip_string(tty, data, cnt);
1321 		tty_flip_buffer_push(tty);
1322 		data += cnt;
1323 		length -= cnt;
1324 	} while (length > 0);
1325 
1326 }
1327 
1328 
1329 static void ti_send(struct ti_port *tport)
1330 {
1331 	int count, result;
1332 	struct usb_serial_port *port = tport->tp_port;
1333 	struct tty_struct *tty = port->port.tty;	/* FIXME */
1334 	unsigned long flags;
1335 
1336 
1337 	dbg("%s - port %d", __func__, port->number);
1338 
1339 	spin_lock_irqsave(&tport->tp_lock, flags);
1340 
1341 	if (tport->tp_write_urb_in_use) {
1342 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1343 		return;
1344 	}
1345 
1346 	count = ti_buf_get(tport->tp_write_buf,
1347 				port->write_urb->transfer_buffer,
1348 				port->bulk_out_size);
1349 
1350 	if (count == 0) {
1351 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1352 		return;
1353 	}
1354 
1355 	tport->tp_write_urb_in_use = 1;
1356 
1357 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1358 
1359 	usb_serial_debug_data(debug, &port->dev, __func__, count,
1360 					port->write_urb->transfer_buffer);
1361 
1362 	usb_fill_bulk_urb(port->write_urb, port->serial->dev,
1363 			   usb_sndbulkpipe(port->serial->dev,
1364 					    port->bulk_out_endpointAddress),
1365 			   port->write_urb->transfer_buffer, count,
1366 			   ti_bulk_out_callback, tport);
1367 
1368 	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1369 	if (result) {
1370 		dev_err(&port->dev, "%s - submit write urb failed, %d\n",
1371 							__func__, result);
1372 		tport->tp_write_urb_in_use = 0;
1373 		/* TODO: reschedule ti_send */
1374 	} else {
1375 		spin_lock_irqsave(&tport->tp_lock, flags);
1376 		tport->tp_icount.tx += count;
1377 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1378 	}
1379 
1380 	/* more room in the buffer for new writes, wakeup */
1381 	if (tty)
1382 		tty_wakeup(tty);
1383 	wake_up_interruptible(&tport->tp_write_wait);
1384 }
1385 
1386 
1387 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr)
1388 {
1389 	unsigned long flags;
1390 	int status;
1391 
1392 	status = ti_write_byte(tport->tp_tdev,
1393 		tport->tp_uart_base_addr + TI_UART_OFFSET_MCR,
1394 		TI_MCR_RTS | TI_MCR_DTR | TI_MCR_LOOP, mcr);
1395 
1396 	spin_lock_irqsave(&tport->tp_lock, flags);
1397 	if (!status)
1398 		tport->tp_shadow_mcr = mcr;
1399 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1400 
1401 	return status;
1402 }
1403 
1404 
1405 static int ti_get_lsr(struct ti_port *tport)
1406 {
1407 	int size, status;
1408 	struct ti_device *tdev = tport->tp_tdev;
1409 	struct usb_serial_port *port = tport->tp_port;
1410 	int port_number = port->number - port->serial->minor;
1411 	struct ti_port_status *data;
1412 
1413 	dbg("%s - port %d", __func__, port->number);
1414 
1415 	size = sizeof(struct ti_port_status);
1416 	data = kmalloc(size, GFP_KERNEL);
1417 	if (!data) {
1418 		dev_err(&port->dev, "%s - out of memory\n", __func__);
1419 		return -ENOMEM;
1420 	}
1421 
1422 	status = ti_command_in_sync(tdev, TI_GET_PORT_STATUS,
1423 		(__u8)(TI_UART1_PORT+port_number), 0, (__u8 *)data, size);
1424 	if (status) {
1425 		dev_err(&port->dev,
1426 			"%s - get port status command failed, %d\n",
1427 							__func__, status);
1428 		goto free_data;
1429 	}
1430 
1431 	dbg("%s - lsr 0x%02X", __func__, data->bLSR);
1432 
1433 	tport->tp_lsr = data->bLSR;
1434 
1435 free_data:
1436 	kfree(data);
1437 	return status;
1438 }
1439 
1440 
1441 static int ti_get_serial_info(struct ti_port *tport,
1442 	struct serial_struct __user *ret_arg)
1443 {
1444 	struct usb_serial_port *port = tport->tp_port;
1445 	struct serial_struct ret_serial;
1446 
1447 	if (!ret_arg)
1448 		return -EFAULT;
1449 
1450 	memset(&ret_serial, 0, sizeof(ret_serial));
1451 
1452 	ret_serial.type = PORT_16550A;
1453 	ret_serial.line = port->serial->minor;
1454 	ret_serial.port = port->number - port->serial->minor;
1455 	ret_serial.flags = tport->tp_flags;
1456 	ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
1457 	ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
1458 	ret_serial.closing_wait = tport->tp_closing_wait;
1459 
1460 	if (copy_to_user(ret_arg, &ret_serial, sizeof(*ret_arg)))
1461 		return -EFAULT;
1462 
1463 	return 0;
1464 }
1465 
1466 
1467 static int ti_set_serial_info(struct ti_port *tport,
1468 	struct serial_struct __user *new_arg)
1469 {
1470 	struct usb_serial_port *port = tport->tp_port;
1471 	struct serial_struct new_serial;
1472 
1473 	if (copy_from_user(&new_serial, new_arg, sizeof(new_serial)))
1474 		return -EFAULT;
1475 
1476 	tport->tp_flags = new_serial.flags & TI_SET_SERIAL_FLAGS;
1477 	/* FIXME */
1478 	if (port->port.tty)
1479 		port->port.tty->low_latency =
1480 			(tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1481 	tport->tp_closing_wait = new_serial.closing_wait;
1482 
1483 	return 0;
1484 }
1485 
1486 
1487 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr)
1488 {
1489 	struct async_icount *icount;
1490 	struct tty_struct *tty;
1491 	unsigned long flags;
1492 
1493 	dbg("%s - msr 0x%02X", __func__, msr);
1494 
1495 	if (msr & TI_MSR_DELTA_MASK) {
1496 		spin_lock_irqsave(&tport->tp_lock, flags);
1497 		icount = &tport->tp_icount;
1498 		if (msr & TI_MSR_DELTA_CTS)
1499 			icount->cts++;
1500 		if (msr & TI_MSR_DELTA_DSR)
1501 			icount->dsr++;
1502 		if (msr & TI_MSR_DELTA_CD)
1503 			icount->dcd++;
1504 		if (msr & TI_MSR_DELTA_RI)
1505 			icount->rng++;
1506 		wake_up_interruptible(&tport->tp_msr_wait);
1507 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1508 	}
1509 
1510 	tport->tp_msr = msr & TI_MSR_MASK;
1511 
1512 	/* handle CTS flow control */
1513 	tty = tport->tp_port->port.tty;
1514 	if (tty && C_CRTSCTS(tty)) {
1515 		if (msr & TI_MSR_CTS) {
1516 			tty->hw_stopped = 0;
1517 			tty_wakeup(tty);
1518 		} else {
1519 			tty->hw_stopped = 1;
1520 		}
1521 	}
1522 }
1523 
1524 
1525 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
1526 {
1527 	struct ti_device *tdev = tport->tp_tdev;
1528 	struct usb_serial_port *port = tport->tp_port;
1529 	wait_queue_t wait;
1530 
1531 	dbg("%s - port %d", __func__, port->number);
1532 
1533 	spin_lock_irq(&tport->tp_lock);
1534 
1535 	/* wait for data to drain from the buffer */
1536 	tdev->td_urb_error = 0;
1537 	init_waitqueue_entry(&wait, current);
1538 	add_wait_queue(&tport->tp_write_wait, &wait);
1539 	for (;;) {
1540 		set_current_state(TASK_INTERRUPTIBLE);
1541 		if (ti_buf_data_avail(tport->tp_write_buf) == 0
1542 		|| timeout == 0 || signal_pending(current)
1543 		|| tdev->td_urb_error
1544 		|| port->serial->disconnected)  /* disconnect */
1545 			break;
1546 		spin_unlock_irq(&tport->tp_lock);
1547 		timeout = schedule_timeout(timeout);
1548 		spin_lock_irq(&tport->tp_lock);
1549 	}
1550 	set_current_state(TASK_RUNNING);
1551 	remove_wait_queue(&tport->tp_write_wait, &wait);
1552 
1553 	/* flush any remaining data in the buffer */
1554 	if (flush)
1555 		ti_buf_clear(tport->tp_write_buf);
1556 
1557 	spin_unlock_irq(&tport->tp_lock);
1558 
1559 	mutex_lock(&port->serial->disc_mutex);
1560 	/* wait for data to drain from the device */
1561 	/* wait for empty tx register, plus 20 ms */
1562 	timeout += jiffies;
1563 	tport->tp_lsr &= ~TI_LSR_TX_EMPTY;
1564 	while ((long)(jiffies - timeout) < 0 && !signal_pending(current)
1565 	&& !(tport->tp_lsr&TI_LSR_TX_EMPTY) && !tdev->td_urb_error
1566 	&& !port->serial->disconnected) {
1567 		if (ti_get_lsr(tport))
1568 			break;
1569 		mutex_unlock(&port->serial->disc_mutex);
1570 		msleep_interruptible(20);
1571 		mutex_lock(&port->serial->disc_mutex);
1572 	}
1573 	mutex_unlock(&port->serial->disc_mutex);
1574 }
1575 
1576 
1577 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty)
1578 {
1579 	unsigned long flags;
1580 
1581 	spin_lock_irqsave(&tport->tp_lock, flags);
1582 
1583 	if (tport->tp_read_urb_state == TI_READ_URB_RUNNING)
1584 		tport->tp_read_urb_state = TI_READ_URB_STOPPING;
1585 
1586 	spin_unlock_irqrestore(&tport->tp_lock, flags);
1587 }
1588 
1589 
1590 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty)
1591 {
1592 	struct urb *urb;
1593 	int status = 0;
1594 	unsigned long flags;
1595 
1596 	spin_lock_irqsave(&tport->tp_lock, flags);
1597 
1598 	if (tport->tp_read_urb_state == TI_READ_URB_STOPPED) {
1599 		tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1600 		urb = tport->tp_port->read_urb;
1601 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1602 		urb->complete = ti_bulk_in_callback;
1603 		urb->context = tport;
1604 		urb->dev = tport->tp_port->serial->dev;
1605 		status = usb_submit_urb(urb, GFP_KERNEL);
1606 	} else  {
1607 		tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1608 		spin_unlock_irqrestore(&tport->tp_lock, flags);
1609 	}
1610 
1611 	return status;
1612 }
1613 
1614 
1615 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
1616 	__u16 moduleid, __u16 value, __u8 *data, int size)
1617 {
1618 	int status;
1619 
1620 	status = usb_control_msg(tdev->td_serial->dev,
1621 		usb_sndctrlpipe(tdev->td_serial->dev, 0), command,
1622 		(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT),
1623 		value, moduleid, data, size, 1000);
1624 
1625 	if (status == size)
1626 		status = 0;
1627 
1628 	if (status > 0)
1629 		status = -ECOMM;
1630 
1631 	return status;
1632 }
1633 
1634 
1635 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
1636 	__u16 moduleid, __u16 value, __u8 *data, int size)
1637 {
1638 	int status;
1639 
1640 	status = usb_control_msg(tdev->td_serial->dev,
1641 		usb_rcvctrlpipe(tdev->td_serial->dev, 0), command,
1642 		(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN),
1643 		value, moduleid, data, size, 1000);
1644 
1645 	if (status == size)
1646 		status = 0;
1647 
1648 	if (status > 0)
1649 		status = -ECOMM;
1650 
1651 	return status;
1652 }
1653 
1654 
1655 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
1656 	__u8 mask, __u8 byte)
1657 {
1658 	int status;
1659 	unsigned int size;
1660 	struct ti_write_data_bytes *data;
1661 	struct device *dev = &tdev->td_serial->dev->dev;
1662 
1663 	dbg("%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X",
1664 					__func__, addr, mask, byte);
1665 
1666 	size = sizeof(struct ti_write_data_bytes) + 2;
1667 	data = kmalloc(size, GFP_KERNEL);
1668 	if (!data) {
1669 		dev_err(dev, "%s - out of memory\n", __func__);
1670 		return -ENOMEM;
1671 	}
1672 
1673 	data->bAddrType = TI_RW_DATA_ADDR_XDATA;
1674 	data->bDataType = TI_RW_DATA_BYTE;
1675 	data->bDataCounter = 1;
1676 	data->wBaseAddrHi = cpu_to_be16(addr>>16);
1677 	data->wBaseAddrLo = cpu_to_be16(addr);
1678 	data->bData[0] = mask;
1679 	data->bData[1] = byte;
1680 
1681 	status = ti_command_out_sync(tdev, TI_WRITE_DATA, TI_RAM_PORT, 0,
1682 		(__u8 *)data, size);
1683 
1684 	if (status < 0)
1685 		dev_err(dev, "%s - failed, %d\n", __func__, status);
1686 
1687 	kfree(data);
1688 
1689 	return status;
1690 }
1691 
1692 static int ti_do_download(struct usb_device *dev, int pipe,
1693 						u8 *buffer, int size)
1694 {
1695 	int pos;
1696 	u8 cs = 0;
1697 	int done;
1698 	struct ti_firmware_header *header;
1699 	int status;
1700 	int len;
1701 
1702 	for (pos = sizeof(struct ti_firmware_header); pos < size; pos++)
1703 		cs = (__u8)(cs + buffer[pos]);
1704 
1705 	header = (struct ti_firmware_header *)buffer;
1706 	header->wLength = cpu_to_le16((__u16)(size
1707 					- sizeof(struct ti_firmware_header)));
1708 	header->bCheckSum = cs;
1709 
1710 	dbg("%s - downloading firmware", __func__);
1711 	for (pos = 0; pos < size; pos += done) {
1712 		len = min(size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
1713 		status = usb_bulk_msg(dev, pipe, buffer + pos, len,
1714 								&done, 1000);
1715 		if (status)
1716 			break;
1717 	}
1718 	return status;
1719 }
1720 
1721 static int ti_download_firmware(struct ti_device *tdev, int type)
1722 {
1723 	int status = -ENOMEM;
1724 	int buffer_size;
1725 	__u8 *buffer;
1726 	struct usb_device *dev = tdev->td_serial->dev;
1727 	unsigned int pipe = usb_sndbulkpipe(dev,
1728 		tdev->td_serial->port[0]->bulk_out_endpointAddress);
1729 	const struct firmware *fw_p;
1730 	char buf[32];
1731 	sprintf(buf, "ti_usb-%d.bin", type);
1732 
1733 	if (request_firmware(&fw_p, buf, &dev->dev)) {
1734 		dev_err(&dev->dev, "%s - firmware not found\n", __func__);
1735 		return -ENOENT;
1736 	}
1737 	if (fw_p->size > TI_FIRMWARE_BUF_SIZE) {
1738 		dev_err(&dev->dev, "%s - firmware too large\n", __func__);
1739 		return -ENOENT;
1740 	}
1741 
1742 	buffer_size = TI_FIRMWARE_BUF_SIZE + sizeof(struct ti_firmware_header);
1743 	buffer = kmalloc(buffer_size, GFP_KERNEL);
1744 	if (buffer) {
1745 		memcpy(buffer, fw_p->data, fw_p->size);
1746 		memset(buffer + fw_p->size, 0xff, buffer_size - fw_p->size);
1747 		ti_do_download(dev, pipe, buffer, fw_p->size);
1748 		kfree(buffer);
1749 	}
1750 	release_firmware(fw_p);
1751 	if (status) {
1752 		dev_err(&dev->dev, "%s - error downloading firmware, %d\n",
1753 							__func__, status);
1754 		return status;
1755 	}
1756 
1757 	dbg("%s - download successful", __func__);
1758 
1759 	return 0;
1760 }
1761 
1762 
1763 /* Circular Buffer Functions */
1764 
1765 /*
1766  * ti_buf_alloc
1767  *
1768  * Allocate a circular buffer and all associated memory.
1769  */
1770 
1771 static struct circ_buf *ti_buf_alloc(void)
1772 {
1773 	struct circ_buf *cb;
1774 
1775 	cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
1776 	if (cb == NULL)
1777 		return NULL;
1778 
1779 	cb->buf = kmalloc(TI_WRITE_BUF_SIZE, GFP_KERNEL);
1780 	if (cb->buf == NULL) {
1781 		kfree(cb);
1782 		return NULL;
1783 	}
1784 
1785 	ti_buf_clear(cb);
1786 
1787 	return cb;
1788 }
1789 
1790 
1791 /*
1792  * ti_buf_free
1793  *
1794  * Free the buffer and all associated memory.
1795  */
1796 
1797 static void ti_buf_free(struct circ_buf *cb)
1798 {
1799 	kfree(cb->buf);
1800 	kfree(cb);
1801 }
1802 
1803 
1804 /*
1805  * ti_buf_clear
1806  *
1807  * Clear out all data in the circular buffer.
1808  */
1809 
1810 static void ti_buf_clear(struct circ_buf *cb)
1811 {
1812 	cb->head = cb->tail = 0;
1813 }
1814 
1815 
1816 /*
1817  * ti_buf_data_avail
1818  *
1819  * Return the number of bytes of data available in the circular
1820  * buffer.
1821  */
1822 
1823 static int ti_buf_data_avail(struct circ_buf *cb)
1824 {
1825 	return CIRC_CNT(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1826 }
1827 
1828 
1829 /*
1830  * ti_buf_space_avail
1831  *
1832  * Return the number of bytes of space available in the circular
1833  * buffer.
1834  */
1835 
1836 static int ti_buf_space_avail(struct circ_buf *cb)
1837 {
1838 	return CIRC_SPACE(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1839 }
1840 
1841 
1842 /*
1843  * ti_buf_put
1844  *
1845  * Copy data data from a user buffer and put it into the circular buffer.
1846  * Restrict to the amount of space available.
1847  *
1848  * Return the number of bytes copied.
1849  */
1850 
1851 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count)
1852 {
1853 	int c, ret = 0;
1854 
1855 	while (1) {
1856 		c = CIRC_SPACE_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1857 		if (count < c)
1858 			c = count;
1859 		if (c <= 0)
1860 			break;
1861 		memcpy(cb->buf + cb->head, buf, c);
1862 		cb->head = (cb->head + c) & (TI_WRITE_BUF_SIZE-1);
1863 		buf += c;
1864 		count -= c;
1865 		ret += c;
1866 	}
1867 
1868 	return ret;
1869 }
1870 
1871 
1872 /*
1873  * ti_buf_get
1874  *
1875  * Get data from the circular buffer and copy to the given buffer.
1876  * Restrict to the amount of data available.
1877  *
1878  * Return the number of bytes copied.
1879  */
1880 
1881 static int ti_buf_get(struct circ_buf *cb, char *buf, int count)
1882 {
1883 	int c, ret = 0;
1884 
1885 	while (1) {
1886 		c = CIRC_CNT_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1887 		if (count < c)
1888 			c = count;
1889 		if (c <= 0)
1890 			break;
1891 		memcpy(buf, cb->buf + cb->tail, c);
1892 		cb->tail = (cb->tail + c) & (TI_WRITE_BUF_SIZE-1);
1893 		buf += c;
1894 		count -= c;
1895 		ret += c;
1896 	}
1897 
1898 	return ret;
1899 }
1900