xref: /linux/drivers/usb/serial/pl2303.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
1 /*
2  * Prolific PL2303 USB to serial adaptor driver
3  *
4  * Copyright (C) 2001-2007 Greg Kroah-Hartman (greg@kroah.com)
5  * Copyright (C) 2003 IBM Corp.
6  *
7  * Original driver for 2.2.x by anonymous
8  *
9  *	This program is free software; you can redistribute it and/or
10  *	modify it under the terms of the GNU General Public License version
11  *	2 as published by the Free Software Foundation.
12  *
13  * See Documentation/usb/usb-serial.txt for more information on using this
14  * driver
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/slab.h>
20 #include <linux/tty.h>
21 #include <linux/tty_driver.h>
22 #include <linux/tty_flip.h>
23 #include <linux/serial.h>
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/spinlock.h>
27 #include <linux/uaccess.h>
28 #include <linux/usb.h>
29 #include <linux/usb/serial.h>
30 #include <asm/unaligned.h>
31 #include "pl2303.h"
32 
33 
34 #define PL2303_QUIRK_UART_STATE_IDX0		BIT(0)
35 #define PL2303_QUIRK_LEGACY			BIT(1)
36 
37 static const struct usb_device_id id_table[] = {
38 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID) },
39 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ2) },
40 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_DCU11) },
41 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ3) },
42 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_PHAROS) },
43 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ALDIGA) },
44 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MMX) },
45 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GPRS) },
46 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_HCR331) },
47 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MOTOROLA) },
48 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ZTEK) },
49 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
50 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID_RSAQ5) },
51 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID) },
52 	{ USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
53 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
54 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
55 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
56 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
57 	{ USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
58 	{ USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
59 	{ USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
60 	{ USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
61 	{ USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
62 	{ USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
63 	{ USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_PRODUCT_ID) },
64 	{ USB_DEVICE(SAMSUNG_VENDOR_ID, SAMSUNG_PRODUCT_ID) },
65 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1),
66 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
67 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65),
68 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
69 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75),
70 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
71 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_EF81) },
72 	{ USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_ID_S81) }, /* Benq/Siemens S81 */
73 	{ USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
74 	{ USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
75 	{ USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
76 	{ USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
77 	{ USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
78 	{ USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
79 	{ USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
80 	{ USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
81 	{ USB_DEVICE(ALCOR_VENDOR_ID, ALCOR_PRODUCT_ID) },
82 	{ USB_DEVICE(WS002IN_VENDOR_ID, WS002IN_PRODUCT_ID) },
83 	{ USB_DEVICE(COREGA_VENDOR_ID, COREGA_PRODUCT_ID) },
84 	{ USB_DEVICE(YCCABLE_VENDOR_ID, YCCABLE_PRODUCT_ID) },
85 	{ USB_DEVICE(SUPERIAL_VENDOR_ID, SUPERIAL_PRODUCT_ID) },
86 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220_PRODUCT_ID) },
87 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
88 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
89 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
90 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
91 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
92 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
93 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
94 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
95 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
96 	{ }					/* Terminating entry */
97 };
98 
99 MODULE_DEVICE_TABLE(usb, id_table);
100 
101 #define SET_LINE_REQUEST_TYPE		0x21
102 #define SET_LINE_REQUEST		0x20
103 
104 #define SET_CONTROL_REQUEST_TYPE	0x21
105 #define SET_CONTROL_REQUEST		0x22
106 #define CONTROL_DTR			0x01
107 #define CONTROL_RTS			0x02
108 
109 #define BREAK_REQUEST_TYPE		0x21
110 #define BREAK_REQUEST			0x23
111 #define BREAK_ON			0xffff
112 #define BREAK_OFF			0x0000
113 
114 #define GET_LINE_REQUEST_TYPE		0xa1
115 #define GET_LINE_REQUEST		0x21
116 
117 #define VENDOR_WRITE_REQUEST_TYPE	0x40
118 #define VENDOR_WRITE_REQUEST		0x01
119 
120 #define VENDOR_READ_REQUEST_TYPE	0xc0
121 #define VENDOR_READ_REQUEST		0x01
122 
123 #define UART_STATE_INDEX		8
124 #define UART_STATE_MSR_MASK		0x8b
125 #define UART_STATE_TRANSIENT_MASK	0x74
126 #define UART_DCD			0x01
127 #define UART_DSR			0x02
128 #define UART_BREAK_ERROR		0x04
129 #define UART_RING			0x08
130 #define UART_FRAME_ERROR		0x10
131 #define UART_PARITY_ERROR		0x20
132 #define UART_OVERRUN_ERROR		0x40
133 #define UART_CTS			0x80
134 
135 
136 enum pl2303_type {
137 	TYPE_01,	/* Type 0 and 1 (difference unknown) */
138 	TYPE_HX,	/* HX version of the pl2303 chip */
139 	TYPE_COUNT
140 };
141 
142 struct pl2303_type_data {
143 	speed_t max_baud_rate;
144 	unsigned long quirks;
145 };
146 
147 struct pl2303_serial_private {
148 	const struct pl2303_type_data *type;
149 	unsigned long quirks;
150 };
151 
152 struct pl2303_private {
153 	spinlock_t lock;
154 	u8 line_control;
155 	u8 line_status;
156 
157 	u8 line_settings[7];
158 };
159 
160 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
161 	[TYPE_01] = {
162 		.max_baud_rate =	1228800,
163 		.quirks =		PL2303_QUIRK_LEGACY,
164 	},
165 	[TYPE_HX] = {
166 		.max_baud_rate =	12000000,
167 	},
168 };
169 
170 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
171 							unsigned char buf[1])
172 {
173 	struct device *dev = &serial->interface->dev;
174 	int res;
175 
176 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
177 			VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
178 			value, 0, buf, 1, 100);
179 	if (res != 1) {
180 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
181 								value, res);
182 		if (res >= 0)
183 			res = -EIO;
184 
185 		return res;
186 	}
187 
188 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
189 
190 	return 0;
191 }
192 
193 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
194 {
195 	struct device *dev = &serial->interface->dev;
196 	int res;
197 
198 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
199 
200 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
201 			VENDOR_WRITE_REQUEST, VENDOR_WRITE_REQUEST_TYPE,
202 			value, index, NULL, 0, 100);
203 	if (res) {
204 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
205 								value, res);
206 		return res;
207 	}
208 
209 	return 0;
210 }
211 
212 static int pl2303_probe(struct usb_serial *serial,
213 					const struct usb_device_id *id)
214 {
215 	usb_set_serial_data(serial, (void *)id->driver_info);
216 
217 	return 0;
218 }
219 
220 static int pl2303_startup(struct usb_serial *serial)
221 {
222 	struct pl2303_serial_private *spriv;
223 	enum pl2303_type type = TYPE_01;
224 	unsigned char *buf;
225 
226 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
227 	if (!spriv)
228 		return -ENOMEM;
229 
230 	buf = kmalloc(1, GFP_KERNEL);
231 	if (!buf) {
232 		kfree(spriv);
233 		return -ENOMEM;
234 	}
235 
236 	if (serial->dev->descriptor.bDeviceClass == 0x02)
237 		type = TYPE_01;		/* type 0 */
238 	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
239 		type = TYPE_HX;
240 	else if (serial->dev->descriptor.bDeviceClass == 0x00)
241 		type = TYPE_01;		/* type 1 */
242 	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
243 		type = TYPE_01;		/* type 1 */
244 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
245 
246 	spriv->type = &pl2303_type_data[type];
247 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
248 	spriv->quirks |= spriv->type->quirks;
249 
250 	usb_set_serial_data(serial, spriv);
251 
252 	pl2303_vendor_read(serial, 0x8484, buf);
253 	pl2303_vendor_write(serial, 0x0404, 0);
254 	pl2303_vendor_read(serial, 0x8484, buf);
255 	pl2303_vendor_read(serial, 0x8383, buf);
256 	pl2303_vendor_read(serial, 0x8484, buf);
257 	pl2303_vendor_write(serial, 0x0404, 1);
258 	pl2303_vendor_read(serial, 0x8484, buf);
259 	pl2303_vendor_read(serial, 0x8383, buf);
260 	pl2303_vendor_write(serial, 0, 1);
261 	pl2303_vendor_write(serial, 1, 0);
262 	if (spriv->quirks & PL2303_QUIRK_LEGACY)
263 		pl2303_vendor_write(serial, 2, 0x24);
264 	else
265 		pl2303_vendor_write(serial, 2, 0x44);
266 
267 	kfree(buf);
268 
269 	return 0;
270 }
271 
272 static void pl2303_release(struct usb_serial *serial)
273 {
274 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
275 
276 	kfree(spriv);
277 }
278 
279 static int pl2303_port_probe(struct usb_serial_port *port)
280 {
281 	struct pl2303_private *priv;
282 
283 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
284 	if (!priv)
285 		return -ENOMEM;
286 
287 	spin_lock_init(&priv->lock);
288 
289 	usb_set_serial_port_data(port, priv);
290 
291 	port->port.drain_delay = 256;
292 
293 	return 0;
294 }
295 
296 static int pl2303_port_remove(struct usb_serial_port *port)
297 {
298 	struct pl2303_private *priv = usb_get_serial_port_data(port);
299 
300 	kfree(priv);
301 
302 	return 0;
303 }
304 
305 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
306 {
307 	struct usb_device *dev = port->serial->dev;
308 	int retval;
309 
310 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
311 
312 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
313 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
314 				 value, 0, NULL, 0, 100);
315 	if (retval)
316 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
317 
318 	return retval;
319 }
320 
321 /*
322  * Returns the nearest supported baud rate that can be set directly without
323  * using divisors.
324  */
325 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
326 {
327 	static const speed_t baud_sup[] = {
328 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
329 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
330 		614400, 921600, 1228800, 2457600, 3000000, 6000000
331 	};
332 
333 	unsigned i;
334 
335 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
336 		if (baud_sup[i] > baud)
337 			break;
338 	}
339 
340 	if (i == ARRAY_SIZE(baud_sup))
341 		baud = baud_sup[i - 1];
342 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
343 		baud = baud_sup[i - 1];
344 	else
345 		baud = baud_sup[i];
346 
347 	return baud;
348 }
349 
350 /*
351  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
352  *       use 9600 baud.
353  */
354 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
355 								speed_t baud)
356 {
357 	put_unaligned_le32(baud, buf);
358 
359 	return baud;
360 }
361 
362 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
363 								speed_t baud)
364 {
365 	unsigned int tmp;
366 
367 	/*
368 	 * Apparently the formula is:
369 	 * baudrate = 12M * 32 / (2^buf[1]) / buf[0]
370 	 */
371 	tmp = 12000000 * 32 / baud;
372 	buf[3] = 0x80;
373 	buf[2] = 0;
374 	buf[1] = (tmp >= 256);
375 	while (tmp >= 256) {
376 		tmp >>= 2;
377 		buf[1] <<= 1;
378 	}
379 	buf[0] = tmp;
380 
381 	return baud;
382 }
383 
384 static void pl2303_encode_baud_rate(struct tty_struct *tty,
385 					struct usb_serial_port *port,
386 					u8 buf[4])
387 {
388 	struct usb_serial *serial = port->serial;
389 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
390 	speed_t	baud_sup;
391 	speed_t baud;
392 
393 	baud = tty_get_baud_rate(tty);
394 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
395 	if (!baud)
396 		return;
397 
398 	if (spriv->type->max_baud_rate)
399 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
400 	/*
401 	 * Use direct method for supported baud rates, otherwise use divisors.
402 	 */
403 	baud_sup = pl2303_get_supported_baud_rate(baud);
404 
405 	if (baud == baud_sup)
406 		baud = pl2303_encode_baud_rate_direct(buf, baud);
407 	else
408 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
409 
410 	/* Save resulting baud rate */
411 	tty_encode_baud_rate(tty, baud, baud);
412 	dev_dbg(&port->dev, "baud set = %u\n", baud);
413 }
414 
415 static int pl2303_get_line_request(struct usb_serial_port *port,
416 							unsigned char buf[7])
417 {
418 	struct usb_device *udev = port->serial->dev;
419 	int ret;
420 
421 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
422 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
423 				0, 0, buf, 7, 100);
424 	if (ret != 7) {
425 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
426 
427 		if (ret > 0)
428 			ret = -EIO;
429 
430 		return ret;
431 	}
432 
433 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
434 
435 	return 0;
436 }
437 
438 static int pl2303_set_line_request(struct usb_serial_port *port,
439 							unsigned char buf[7])
440 {
441 	struct usb_device *udev = port->serial->dev;
442 	int ret;
443 
444 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
445 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
446 				0, 0, buf, 7, 100);
447 	if (ret != 7) {
448 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
449 
450 		if (ret > 0)
451 			ret = -EIO;
452 
453 		return ret;
454 	}
455 
456 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
457 
458 	return 0;
459 }
460 
461 static void pl2303_set_termios(struct tty_struct *tty,
462 		struct usb_serial_port *port, struct ktermios *old_termios)
463 {
464 	struct usb_serial *serial = port->serial;
465 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
466 	struct pl2303_private *priv = usb_get_serial_port_data(port);
467 	unsigned long flags;
468 	unsigned char *buf;
469 	int ret;
470 	u8 control;
471 
472 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
473 		return;
474 
475 	buf = kzalloc(7, GFP_KERNEL);
476 	if (!buf) {
477 		/* Report back no change occurred */
478 		if (old_termios)
479 			tty->termios = *old_termios;
480 		return;
481 	}
482 
483 	pl2303_get_line_request(port, buf);
484 
485 	switch (C_CSIZE(tty)) {
486 	case CS5:
487 		buf[6] = 5;
488 		break;
489 	case CS6:
490 		buf[6] = 6;
491 		break;
492 	case CS7:
493 		buf[6] = 7;
494 		break;
495 	default:
496 	case CS8:
497 		buf[6] = 8;
498 	}
499 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
500 
501 	/* For reference buf[0]:buf[3] baud rate value */
502 	pl2303_encode_baud_rate(tty, port, &buf[0]);
503 
504 	/* For reference buf[4]=0 is 1 stop bits */
505 	/* For reference buf[4]=1 is 1.5 stop bits */
506 	/* For reference buf[4]=2 is 2 stop bits */
507 	if (C_CSTOPB(tty)) {
508 		/*
509 		 * NOTE: Comply with "real" UARTs / RS232:
510 		 *       use 1.5 instead of 2 stop bits with 5 data bits
511 		 */
512 		if (C_CSIZE(tty) == CS5) {
513 			buf[4] = 1;
514 			dev_dbg(&port->dev, "stop bits = 1.5\n");
515 		} else {
516 			buf[4] = 2;
517 			dev_dbg(&port->dev, "stop bits = 2\n");
518 		}
519 	} else {
520 		buf[4] = 0;
521 		dev_dbg(&port->dev, "stop bits = 1\n");
522 	}
523 
524 	if (C_PARENB(tty)) {
525 		/* For reference buf[5]=0 is none parity */
526 		/* For reference buf[5]=1 is odd parity */
527 		/* For reference buf[5]=2 is even parity */
528 		/* For reference buf[5]=3 is mark parity */
529 		/* For reference buf[5]=4 is space parity */
530 		if (C_PARODD(tty)) {
531 			if (C_CMSPAR(tty)) {
532 				buf[5] = 3;
533 				dev_dbg(&port->dev, "parity = mark\n");
534 			} else {
535 				buf[5] = 1;
536 				dev_dbg(&port->dev, "parity = odd\n");
537 			}
538 		} else {
539 			if (C_CMSPAR(tty)) {
540 				buf[5] = 4;
541 				dev_dbg(&port->dev, "parity = space\n");
542 			} else {
543 				buf[5] = 2;
544 				dev_dbg(&port->dev, "parity = even\n");
545 			}
546 		}
547 	} else {
548 		buf[5] = 0;
549 		dev_dbg(&port->dev, "parity = none\n");
550 	}
551 
552 	/*
553 	 * Some PL2303 are known to lose bytes if you change serial settings
554 	 * even to the same values as before. Thus we actually need to filter
555 	 * in this specific case.
556 	 *
557 	 * Note that the tty_termios_hw_change check above is not sufficient
558 	 * as a previously requested baud rate may differ from the one
559 	 * actually used (and stored in old_termios).
560 	 *
561 	 * NOTE: No additional locking needed for line_settings as it is
562 	 *       only used in set_termios, which is serialised against itself.
563 	 */
564 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
565 		ret = pl2303_set_line_request(port, buf);
566 		if (!ret)
567 			memcpy(priv->line_settings, buf, 7);
568 	}
569 
570 	/* change control lines if we are switching to or from B0 */
571 	spin_lock_irqsave(&priv->lock, flags);
572 	control = priv->line_control;
573 	if (C_BAUD(tty) == B0)
574 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
575 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
576 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
577 	if (control != priv->line_control) {
578 		control = priv->line_control;
579 		spin_unlock_irqrestore(&priv->lock, flags);
580 		pl2303_set_control_lines(port, control);
581 	} else {
582 		spin_unlock_irqrestore(&priv->lock, flags);
583 	}
584 
585 	if (C_CRTSCTS(tty)) {
586 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
587 			pl2303_vendor_write(serial, 0x0, 0x41);
588 		else
589 			pl2303_vendor_write(serial, 0x0, 0x61);
590 	} else {
591 		pl2303_vendor_write(serial, 0x0, 0x0);
592 	}
593 
594 	kfree(buf);
595 }
596 
597 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
598 {
599 	struct pl2303_private *priv = usb_get_serial_port_data(port);
600 	unsigned long flags;
601 	u8 control;
602 
603 	spin_lock_irqsave(&priv->lock, flags);
604 	if (on)
605 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
606 	else
607 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
608 	control = priv->line_control;
609 	spin_unlock_irqrestore(&priv->lock, flags);
610 
611 	pl2303_set_control_lines(port, control);
612 }
613 
614 static void pl2303_close(struct usb_serial_port *port)
615 {
616 	usb_serial_generic_close(port);
617 	usb_kill_urb(port->interrupt_in_urb);
618 }
619 
620 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
621 {
622 	struct usb_serial *serial = port->serial;
623 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
624 	int result;
625 
626 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
627 		usb_clear_halt(serial->dev, port->write_urb->pipe);
628 		usb_clear_halt(serial->dev, port->read_urb->pipe);
629 	} else {
630 		/* reset upstream data pipes */
631 		pl2303_vendor_write(serial, 8, 0);
632 		pl2303_vendor_write(serial, 9, 0);
633 	}
634 
635 	/* Setup termios */
636 	if (tty)
637 		pl2303_set_termios(tty, port, NULL);
638 
639 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
640 	if (result) {
641 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
642 			result);
643 		return result;
644 	}
645 
646 	result = usb_serial_generic_open(tty, port);
647 	if (result) {
648 		usb_kill_urb(port->interrupt_in_urb);
649 		return result;
650 	}
651 
652 	return 0;
653 }
654 
655 static int pl2303_tiocmset(struct tty_struct *tty,
656 			   unsigned int set, unsigned int clear)
657 {
658 	struct usb_serial_port *port = tty->driver_data;
659 	struct pl2303_private *priv = usb_get_serial_port_data(port);
660 	unsigned long flags;
661 	u8 control;
662 	int ret;
663 
664 	spin_lock_irqsave(&priv->lock, flags);
665 	if (set & TIOCM_RTS)
666 		priv->line_control |= CONTROL_RTS;
667 	if (set & TIOCM_DTR)
668 		priv->line_control |= CONTROL_DTR;
669 	if (clear & TIOCM_RTS)
670 		priv->line_control &= ~CONTROL_RTS;
671 	if (clear & TIOCM_DTR)
672 		priv->line_control &= ~CONTROL_DTR;
673 	control = priv->line_control;
674 	spin_unlock_irqrestore(&priv->lock, flags);
675 
676 	ret = pl2303_set_control_lines(port, control);
677 	if (ret)
678 		return usb_translate_errors(ret);
679 
680 	return 0;
681 }
682 
683 static int pl2303_tiocmget(struct tty_struct *tty)
684 {
685 	struct usb_serial_port *port = tty->driver_data;
686 	struct pl2303_private *priv = usb_get_serial_port_data(port);
687 	unsigned long flags;
688 	unsigned int mcr;
689 	unsigned int status;
690 	unsigned int result;
691 
692 	spin_lock_irqsave(&priv->lock, flags);
693 	mcr = priv->line_control;
694 	status = priv->line_status;
695 	spin_unlock_irqrestore(&priv->lock, flags);
696 
697 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
698 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
699 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
700 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
701 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
702 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
703 
704 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
705 
706 	return result;
707 }
708 
709 static int pl2303_carrier_raised(struct usb_serial_port *port)
710 {
711 	struct pl2303_private *priv = usb_get_serial_port_data(port);
712 
713 	if (priv->line_status & UART_DCD)
714 		return 1;
715 
716 	return 0;
717 }
718 
719 static int pl2303_ioctl(struct tty_struct *tty,
720 			unsigned int cmd, unsigned long arg)
721 {
722 	struct serial_struct ser;
723 	struct usb_serial_port *port = tty->driver_data;
724 
725 	switch (cmd) {
726 	case TIOCGSERIAL:
727 		memset(&ser, 0, sizeof ser);
728 		ser.type = PORT_16654;
729 		ser.line = port->minor;
730 		ser.port = port->port_number;
731 		ser.baud_base = 460800;
732 
733 		if (copy_to_user((void __user *)arg, &ser, sizeof ser))
734 			return -EFAULT;
735 
736 		return 0;
737 	default:
738 		break;
739 	}
740 
741 	return -ENOIOCTLCMD;
742 }
743 
744 static void pl2303_break_ctl(struct tty_struct *tty, int break_state)
745 {
746 	struct usb_serial_port *port = tty->driver_data;
747 	struct usb_serial *serial = port->serial;
748 	u16 state;
749 	int result;
750 
751 	if (break_state == 0)
752 		state = BREAK_OFF;
753 	else
754 		state = BREAK_ON;
755 
756 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
757 			state == BREAK_OFF ? "off" : "on");
758 
759 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
760 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
761 				 0, NULL, 0, 100);
762 	if (result)
763 		dev_err(&port->dev, "error sending break = %d\n", result);
764 }
765 
766 static void pl2303_update_line_status(struct usb_serial_port *port,
767 				      unsigned char *data,
768 				      unsigned int actual_length)
769 {
770 	struct usb_serial *serial = port->serial;
771 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
772 	struct pl2303_private *priv = usb_get_serial_port_data(port);
773 	struct tty_struct *tty;
774 	unsigned long flags;
775 	unsigned int status_idx = UART_STATE_INDEX;
776 	u8 status;
777 	u8 delta;
778 
779 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
780 		status_idx = 0;
781 
782 	if (actual_length < status_idx + 1)
783 		return;
784 
785 	status = data[status_idx];
786 
787 	/* Save off the uart status for others to look at */
788 	spin_lock_irqsave(&priv->lock, flags);
789 	delta = priv->line_status ^ status;
790 	priv->line_status = status;
791 	spin_unlock_irqrestore(&priv->lock, flags);
792 
793 	if (status & UART_BREAK_ERROR)
794 		usb_serial_handle_break(port);
795 
796 	if (delta & UART_STATE_MSR_MASK) {
797 		if (delta & UART_CTS)
798 			port->icount.cts++;
799 		if (delta & UART_DSR)
800 			port->icount.dsr++;
801 		if (delta & UART_RING)
802 			port->icount.rng++;
803 		if (delta & UART_DCD) {
804 			port->icount.dcd++;
805 			tty = tty_port_tty_get(&port->port);
806 			if (tty) {
807 				usb_serial_handle_dcd_change(port, tty,
808 							status & UART_DCD);
809 				tty_kref_put(tty);
810 			}
811 		}
812 
813 		wake_up_interruptible(&port->port.delta_msr_wait);
814 	}
815 }
816 
817 static void pl2303_read_int_callback(struct urb *urb)
818 {
819 	struct usb_serial_port *port =  urb->context;
820 	unsigned char *data = urb->transfer_buffer;
821 	unsigned int actual_length = urb->actual_length;
822 	int status = urb->status;
823 	int retval;
824 
825 	switch (status) {
826 	case 0:
827 		/* success */
828 		break;
829 	case -ECONNRESET:
830 	case -ENOENT:
831 	case -ESHUTDOWN:
832 		/* this urb is terminated, clean up */
833 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
834 			__func__, status);
835 		return;
836 	default:
837 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
838 			__func__, status);
839 		goto exit;
840 	}
841 
842 	usb_serial_debug_data(&port->dev, __func__,
843 			      urb->actual_length, urb->transfer_buffer);
844 
845 	pl2303_update_line_status(port, data, actual_length);
846 
847 exit:
848 	retval = usb_submit_urb(urb, GFP_ATOMIC);
849 	if (retval) {
850 		dev_err(&port->dev,
851 			"%s - usb_submit_urb failed with result %d\n",
852 			__func__, retval);
853 	}
854 }
855 
856 static void pl2303_process_read_urb(struct urb *urb)
857 {
858 	struct usb_serial_port *port = urb->context;
859 	struct pl2303_private *priv = usb_get_serial_port_data(port);
860 	unsigned char *data = urb->transfer_buffer;
861 	char tty_flag = TTY_NORMAL;
862 	unsigned long flags;
863 	u8 line_status;
864 	int i;
865 
866 	/* update line status */
867 	spin_lock_irqsave(&priv->lock, flags);
868 	line_status = priv->line_status;
869 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
870 	spin_unlock_irqrestore(&priv->lock, flags);
871 
872 	if (!urb->actual_length)
873 		return;
874 
875 	/*
876 	 * Break takes precedence over parity, which takes precedence over
877 	 * framing errors.
878 	 */
879 	if (line_status & UART_BREAK_ERROR)
880 		tty_flag = TTY_BREAK;
881 	else if (line_status & UART_PARITY_ERROR)
882 		tty_flag = TTY_PARITY;
883 	else if (line_status & UART_FRAME_ERROR)
884 		tty_flag = TTY_FRAME;
885 
886 	if (tty_flag != TTY_NORMAL)
887 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
888 								tty_flag);
889 	/* overrun is special, not associated with a char */
890 	if (line_status & UART_OVERRUN_ERROR)
891 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
892 
893 	if (port->port.console && port->sysrq) {
894 		for (i = 0; i < urb->actual_length; ++i)
895 			if (!usb_serial_handle_sysrq_char(port, data[i]))
896 				tty_insert_flip_char(&port->port, data[i],
897 						tty_flag);
898 	} else {
899 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
900 							urb->actual_length);
901 	}
902 
903 	tty_flip_buffer_push(&port->port);
904 }
905 
906 static struct usb_serial_driver pl2303_device = {
907 	.driver = {
908 		.owner =	THIS_MODULE,
909 		.name =		"pl2303",
910 	},
911 	.id_table =		id_table,
912 	.num_ports =		1,
913 	.bulk_in_size =		256,
914 	.bulk_out_size =	256,
915 	.open =			pl2303_open,
916 	.close =		pl2303_close,
917 	.dtr_rts =		pl2303_dtr_rts,
918 	.carrier_raised =	pl2303_carrier_raised,
919 	.ioctl =		pl2303_ioctl,
920 	.break_ctl =		pl2303_break_ctl,
921 	.set_termios =		pl2303_set_termios,
922 	.tiocmget =		pl2303_tiocmget,
923 	.tiocmset =		pl2303_tiocmset,
924 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
925 	.process_read_urb =	pl2303_process_read_urb,
926 	.read_int_callback =	pl2303_read_int_callback,
927 	.probe =		pl2303_probe,
928 	.attach =		pl2303_startup,
929 	.release =		pl2303_release,
930 	.port_probe =		pl2303_port_probe,
931 	.port_remove =		pl2303_port_remove,
932 };
933 
934 static struct usb_serial_driver * const serial_drivers[] = {
935 	&pl2303_device, NULL
936 };
937 
938 module_usb_serial_driver(serial_drivers, id_table);
939 
940 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
941 MODULE_LICENSE("GPL");
942