xref: /linux/drivers/usb/serial/pl2303.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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_ID, ATEN_PRODUCT_ID2) },
53 	{ USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
54 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
55 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
56 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
57 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
58 	{ USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
59 	{ USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
60 	{ USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
61 	{ USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
62 	{ USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
63 	{ USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
64 	{ USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_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 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
136 
137 enum pl2303_type {
138 	TYPE_01,	/* Type 0 and 1 (difference unknown) */
139 	TYPE_HX,	/* HX version of the pl2303 chip */
140 	TYPE_COUNT
141 };
142 
143 struct pl2303_type_data {
144 	speed_t max_baud_rate;
145 	unsigned long quirks;
146 };
147 
148 struct pl2303_serial_private {
149 	const struct pl2303_type_data *type;
150 	unsigned long quirks;
151 };
152 
153 struct pl2303_private {
154 	spinlock_t lock;
155 	u8 line_control;
156 	u8 line_status;
157 
158 	u8 line_settings[7];
159 };
160 
161 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
162 	[TYPE_01] = {
163 		.max_baud_rate =	1228800,
164 		.quirks =		PL2303_QUIRK_LEGACY,
165 	},
166 	[TYPE_HX] = {
167 		.max_baud_rate =	12000000,
168 	},
169 };
170 
171 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
172 							unsigned char buf[1])
173 {
174 	struct device *dev = &serial->interface->dev;
175 	int res;
176 
177 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
178 			VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
179 			value, 0, buf, 1, 100);
180 	if (res != 1) {
181 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
182 								value, res);
183 		if (res >= 0)
184 			res = -EIO;
185 
186 		return res;
187 	}
188 
189 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
190 
191 	return 0;
192 }
193 
194 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
195 {
196 	struct device *dev = &serial->interface->dev;
197 	int res;
198 
199 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
200 
201 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
202 			VENDOR_WRITE_REQUEST, VENDOR_WRITE_REQUEST_TYPE,
203 			value, index, NULL, 0, 100);
204 	if (res) {
205 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
206 								value, res);
207 		return res;
208 	}
209 
210 	return 0;
211 }
212 
213 static int pl2303_probe(struct usb_serial *serial,
214 					const struct usb_device_id *id)
215 {
216 	usb_set_serial_data(serial, (void *)id->driver_info);
217 
218 	return 0;
219 }
220 
221 static int pl2303_startup(struct usb_serial *serial)
222 {
223 	struct pl2303_serial_private *spriv;
224 	unsigned char num_ports = serial->num_ports;
225 	enum pl2303_type type = TYPE_01;
226 	unsigned char *buf;
227 
228 	if (serial->num_bulk_in < num_ports ||
229 			serial->num_bulk_out < num_ports ||
230 			serial->num_interrupt_in < num_ports) {
231 		dev_err(&serial->interface->dev, "missing endpoints\n");
232 		return -ENODEV;
233 	}
234 
235 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
236 	if (!spriv)
237 		return -ENOMEM;
238 
239 	buf = kmalloc(1, GFP_KERNEL);
240 	if (!buf) {
241 		kfree(spriv);
242 		return -ENOMEM;
243 	}
244 
245 	if (serial->dev->descriptor.bDeviceClass == 0x02)
246 		type = TYPE_01;		/* type 0 */
247 	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
248 		type = TYPE_HX;
249 	else if (serial->dev->descriptor.bDeviceClass == 0x00)
250 		type = TYPE_01;		/* type 1 */
251 	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
252 		type = TYPE_01;		/* type 1 */
253 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
254 
255 	spriv->type = &pl2303_type_data[type];
256 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
257 	spriv->quirks |= spriv->type->quirks;
258 
259 	usb_set_serial_data(serial, spriv);
260 
261 	pl2303_vendor_read(serial, 0x8484, buf);
262 	pl2303_vendor_write(serial, 0x0404, 0);
263 	pl2303_vendor_read(serial, 0x8484, buf);
264 	pl2303_vendor_read(serial, 0x8383, buf);
265 	pl2303_vendor_read(serial, 0x8484, buf);
266 	pl2303_vendor_write(serial, 0x0404, 1);
267 	pl2303_vendor_read(serial, 0x8484, buf);
268 	pl2303_vendor_read(serial, 0x8383, buf);
269 	pl2303_vendor_write(serial, 0, 1);
270 	pl2303_vendor_write(serial, 1, 0);
271 	if (spriv->quirks & PL2303_QUIRK_LEGACY)
272 		pl2303_vendor_write(serial, 2, 0x24);
273 	else
274 		pl2303_vendor_write(serial, 2, 0x44);
275 
276 	kfree(buf);
277 
278 	return 0;
279 }
280 
281 static void pl2303_release(struct usb_serial *serial)
282 {
283 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
284 
285 	kfree(spriv);
286 }
287 
288 static int pl2303_port_probe(struct usb_serial_port *port)
289 {
290 	struct pl2303_private *priv;
291 
292 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
293 	if (!priv)
294 		return -ENOMEM;
295 
296 	spin_lock_init(&priv->lock);
297 
298 	usb_set_serial_port_data(port, priv);
299 
300 	port->port.drain_delay = 256;
301 
302 	return 0;
303 }
304 
305 static int pl2303_port_remove(struct usb_serial_port *port)
306 {
307 	struct pl2303_private *priv = usb_get_serial_port_data(port);
308 
309 	kfree(priv);
310 
311 	return 0;
312 }
313 
314 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
315 {
316 	struct usb_device *dev = port->serial->dev;
317 	int retval;
318 
319 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
320 
321 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
322 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
323 				 value, 0, NULL, 0, 100);
324 	if (retval)
325 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
326 
327 	return retval;
328 }
329 
330 /*
331  * Returns the nearest supported baud rate that can be set directly without
332  * using divisors.
333  */
334 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
335 {
336 	static const speed_t baud_sup[] = {
337 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
338 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
339 		614400, 921600, 1228800, 2457600, 3000000, 6000000
340 	};
341 
342 	unsigned i;
343 
344 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
345 		if (baud_sup[i] > baud)
346 			break;
347 	}
348 
349 	if (i == ARRAY_SIZE(baud_sup))
350 		baud = baud_sup[i - 1];
351 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
352 		baud = baud_sup[i - 1];
353 	else
354 		baud = baud_sup[i];
355 
356 	return baud;
357 }
358 
359 /*
360  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
361  *       use 9600 baud.
362  */
363 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
364 								speed_t baud)
365 {
366 	put_unaligned_le32(baud, buf);
367 
368 	return baud;
369 }
370 
371 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
372 								speed_t baud)
373 {
374 	unsigned int baseline, mantissa, exponent;
375 
376 	/*
377 	 * Apparently the formula is:
378 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
379 	 * where
380 	 *   mantissa = buf[8:0]
381 	 *   exponent = buf[11:9]
382 	 */
383 	baseline = 12000000 * 32;
384 	mantissa = baseline / baud;
385 	if (mantissa == 0)
386 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
387 	exponent = 0;
388 	while (mantissa >= 512) {
389 		if (exponent < 7) {
390 			mantissa >>= 2;	/* divide by 4 */
391 			exponent++;
392 		} else {
393 			/* Exponent is maxed. Trim mantissa and leave. */
394 			mantissa = 511;
395 			break;
396 		}
397 	}
398 
399 	buf[3] = 0x80;
400 	buf[2] = 0;
401 	buf[1] = exponent << 1 | mantissa >> 8;
402 	buf[0] = mantissa & 0xff;
403 
404 	/* Calculate and return the exact baud rate. */
405 	baud = (baseline / mantissa) >> (exponent << 1);
406 
407 	return baud;
408 }
409 
410 static void pl2303_encode_baud_rate(struct tty_struct *tty,
411 					struct usb_serial_port *port,
412 					u8 buf[4])
413 {
414 	struct usb_serial *serial = port->serial;
415 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
416 	speed_t	baud_sup;
417 	speed_t baud;
418 
419 	baud = tty_get_baud_rate(tty);
420 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
421 	if (!baud)
422 		return;
423 
424 	if (spriv->type->max_baud_rate)
425 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
426 	/*
427 	 * Use direct method for supported baud rates, otherwise use divisors.
428 	 */
429 	baud_sup = pl2303_get_supported_baud_rate(baud);
430 
431 	if (baud == baud_sup)
432 		baud = pl2303_encode_baud_rate_direct(buf, baud);
433 	else
434 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
435 
436 	/* Save resulting baud rate */
437 	tty_encode_baud_rate(tty, baud, baud);
438 	dev_dbg(&port->dev, "baud set = %u\n", baud);
439 }
440 
441 static int pl2303_get_line_request(struct usb_serial_port *port,
442 							unsigned char buf[7])
443 {
444 	struct usb_device *udev = port->serial->dev;
445 	int ret;
446 
447 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
448 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
449 				0, 0, buf, 7, 100);
450 	if (ret != 7) {
451 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
452 
453 		if (ret >= 0)
454 			ret = -EIO;
455 
456 		return ret;
457 	}
458 
459 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
460 
461 	return 0;
462 }
463 
464 static int pl2303_set_line_request(struct usb_serial_port *port,
465 							unsigned char buf[7])
466 {
467 	struct usb_device *udev = port->serial->dev;
468 	int ret;
469 
470 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
471 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
472 				0, 0, buf, 7, 100);
473 	if (ret < 0) {
474 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
475 		return ret;
476 	}
477 
478 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
479 
480 	return 0;
481 }
482 
483 static void pl2303_set_termios(struct tty_struct *tty,
484 		struct usb_serial_port *port, struct ktermios *old_termios)
485 {
486 	struct usb_serial *serial = port->serial;
487 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
488 	struct pl2303_private *priv = usb_get_serial_port_data(port);
489 	unsigned long flags;
490 	unsigned char *buf;
491 	int ret;
492 	u8 control;
493 
494 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
495 		return;
496 
497 	buf = kzalloc(7, GFP_KERNEL);
498 	if (!buf) {
499 		/* Report back no change occurred */
500 		if (old_termios)
501 			tty->termios = *old_termios;
502 		return;
503 	}
504 
505 	pl2303_get_line_request(port, buf);
506 
507 	switch (C_CSIZE(tty)) {
508 	case CS5:
509 		buf[6] = 5;
510 		break;
511 	case CS6:
512 		buf[6] = 6;
513 		break;
514 	case CS7:
515 		buf[6] = 7;
516 		break;
517 	default:
518 	case CS8:
519 		buf[6] = 8;
520 	}
521 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
522 
523 	/* For reference buf[0]:buf[3] baud rate value */
524 	pl2303_encode_baud_rate(tty, port, &buf[0]);
525 
526 	/* For reference buf[4]=0 is 1 stop bits */
527 	/* For reference buf[4]=1 is 1.5 stop bits */
528 	/* For reference buf[4]=2 is 2 stop bits */
529 	if (C_CSTOPB(tty)) {
530 		/*
531 		 * NOTE: Comply with "real" UARTs / RS232:
532 		 *       use 1.5 instead of 2 stop bits with 5 data bits
533 		 */
534 		if (C_CSIZE(tty) == CS5) {
535 			buf[4] = 1;
536 			dev_dbg(&port->dev, "stop bits = 1.5\n");
537 		} else {
538 			buf[4] = 2;
539 			dev_dbg(&port->dev, "stop bits = 2\n");
540 		}
541 	} else {
542 		buf[4] = 0;
543 		dev_dbg(&port->dev, "stop bits = 1\n");
544 	}
545 
546 	if (C_PARENB(tty)) {
547 		/* For reference buf[5]=0 is none parity */
548 		/* For reference buf[5]=1 is odd parity */
549 		/* For reference buf[5]=2 is even parity */
550 		/* For reference buf[5]=3 is mark parity */
551 		/* For reference buf[5]=4 is space parity */
552 		if (C_PARODD(tty)) {
553 			if (C_CMSPAR(tty)) {
554 				buf[5] = 3;
555 				dev_dbg(&port->dev, "parity = mark\n");
556 			} else {
557 				buf[5] = 1;
558 				dev_dbg(&port->dev, "parity = odd\n");
559 			}
560 		} else {
561 			if (C_CMSPAR(tty)) {
562 				buf[5] = 4;
563 				dev_dbg(&port->dev, "parity = space\n");
564 			} else {
565 				buf[5] = 2;
566 				dev_dbg(&port->dev, "parity = even\n");
567 			}
568 		}
569 	} else {
570 		buf[5] = 0;
571 		dev_dbg(&port->dev, "parity = none\n");
572 	}
573 
574 	/*
575 	 * Some PL2303 are known to lose bytes if you change serial settings
576 	 * even to the same values as before. Thus we actually need to filter
577 	 * in this specific case.
578 	 *
579 	 * Note that the tty_termios_hw_change check above is not sufficient
580 	 * as a previously requested baud rate may differ from the one
581 	 * actually used (and stored in old_termios).
582 	 *
583 	 * NOTE: No additional locking needed for line_settings as it is
584 	 *       only used in set_termios, which is serialised against itself.
585 	 */
586 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
587 		ret = pl2303_set_line_request(port, buf);
588 		if (!ret)
589 			memcpy(priv->line_settings, buf, 7);
590 	}
591 
592 	/* change control lines if we are switching to or from B0 */
593 	spin_lock_irqsave(&priv->lock, flags);
594 	control = priv->line_control;
595 	if (C_BAUD(tty) == B0)
596 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
597 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
598 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
599 	if (control != priv->line_control) {
600 		control = priv->line_control;
601 		spin_unlock_irqrestore(&priv->lock, flags);
602 		pl2303_set_control_lines(port, control);
603 	} else {
604 		spin_unlock_irqrestore(&priv->lock, flags);
605 	}
606 
607 	if (C_CRTSCTS(tty)) {
608 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
609 			pl2303_vendor_write(serial, 0x0, 0x41);
610 		else
611 			pl2303_vendor_write(serial, 0x0, 0x61);
612 	} else {
613 		pl2303_vendor_write(serial, 0x0, 0x0);
614 	}
615 
616 	kfree(buf);
617 }
618 
619 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
620 {
621 	struct pl2303_private *priv = usb_get_serial_port_data(port);
622 	unsigned long flags;
623 	u8 control;
624 
625 	spin_lock_irqsave(&priv->lock, flags);
626 	if (on)
627 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
628 	else
629 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
630 	control = priv->line_control;
631 	spin_unlock_irqrestore(&priv->lock, flags);
632 
633 	pl2303_set_control_lines(port, control);
634 }
635 
636 static void pl2303_close(struct usb_serial_port *port)
637 {
638 	usb_serial_generic_close(port);
639 	usb_kill_urb(port->interrupt_in_urb);
640 	pl2303_set_break(port, false);
641 }
642 
643 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
644 {
645 	struct usb_serial *serial = port->serial;
646 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
647 	int result;
648 
649 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
650 		usb_clear_halt(serial->dev, port->write_urb->pipe);
651 		usb_clear_halt(serial->dev, port->read_urb->pipe);
652 	} else {
653 		/* reset upstream data pipes */
654 		pl2303_vendor_write(serial, 8, 0);
655 		pl2303_vendor_write(serial, 9, 0);
656 	}
657 
658 	/* Setup termios */
659 	if (tty)
660 		pl2303_set_termios(tty, port, NULL);
661 
662 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
663 	if (result) {
664 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
665 			result);
666 		return result;
667 	}
668 
669 	result = usb_serial_generic_open(tty, port);
670 	if (result) {
671 		usb_kill_urb(port->interrupt_in_urb);
672 		return result;
673 	}
674 
675 	return 0;
676 }
677 
678 static int pl2303_tiocmset(struct tty_struct *tty,
679 			   unsigned int set, unsigned int clear)
680 {
681 	struct usb_serial_port *port = tty->driver_data;
682 	struct pl2303_private *priv = usb_get_serial_port_data(port);
683 	unsigned long flags;
684 	u8 control;
685 	int ret;
686 
687 	spin_lock_irqsave(&priv->lock, flags);
688 	if (set & TIOCM_RTS)
689 		priv->line_control |= CONTROL_RTS;
690 	if (set & TIOCM_DTR)
691 		priv->line_control |= CONTROL_DTR;
692 	if (clear & TIOCM_RTS)
693 		priv->line_control &= ~CONTROL_RTS;
694 	if (clear & TIOCM_DTR)
695 		priv->line_control &= ~CONTROL_DTR;
696 	control = priv->line_control;
697 	spin_unlock_irqrestore(&priv->lock, flags);
698 
699 	ret = pl2303_set_control_lines(port, control);
700 	if (ret)
701 		return usb_translate_errors(ret);
702 
703 	return 0;
704 }
705 
706 static int pl2303_tiocmget(struct tty_struct *tty)
707 {
708 	struct usb_serial_port *port = tty->driver_data;
709 	struct pl2303_private *priv = usb_get_serial_port_data(port);
710 	unsigned long flags;
711 	unsigned int mcr;
712 	unsigned int status;
713 	unsigned int result;
714 
715 	spin_lock_irqsave(&priv->lock, flags);
716 	mcr = priv->line_control;
717 	status = priv->line_status;
718 	spin_unlock_irqrestore(&priv->lock, flags);
719 
720 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
721 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
722 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
723 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
724 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
725 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
726 
727 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
728 
729 	return result;
730 }
731 
732 static int pl2303_carrier_raised(struct usb_serial_port *port)
733 {
734 	struct pl2303_private *priv = usb_get_serial_port_data(port);
735 
736 	if (priv->line_status & UART_DCD)
737 		return 1;
738 
739 	return 0;
740 }
741 
742 static int pl2303_ioctl(struct tty_struct *tty,
743 			unsigned int cmd, unsigned long arg)
744 {
745 	struct serial_struct ser;
746 	struct usb_serial_port *port = tty->driver_data;
747 
748 	switch (cmd) {
749 	case TIOCGSERIAL:
750 		memset(&ser, 0, sizeof ser);
751 		ser.type = PORT_16654;
752 		ser.line = port->minor;
753 		ser.port = port->port_number;
754 		ser.baud_base = 460800;
755 
756 		if (copy_to_user((void __user *)arg, &ser, sizeof ser))
757 			return -EFAULT;
758 
759 		return 0;
760 	default:
761 		break;
762 	}
763 
764 	return -ENOIOCTLCMD;
765 }
766 
767 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
768 {
769 	struct usb_serial *serial = port->serial;
770 	u16 state;
771 	int result;
772 
773 	if (enable)
774 		state = BREAK_ON;
775 	else
776 		state = BREAK_OFF;
777 
778 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
779 			state == BREAK_OFF ? "off" : "on");
780 
781 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
782 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
783 				 0, NULL, 0, 100);
784 	if (result)
785 		dev_err(&port->dev, "error sending break = %d\n", result);
786 }
787 
788 static void pl2303_break_ctl(struct tty_struct *tty, int state)
789 {
790 	struct usb_serial_port *port = tty->driver_data;
791 
792 	pl2303_set_break(port, state);
793 }
794 
795 static void pl2303_update_line_status(struct usb_serial_port *port,
796 				      unsigned char *data,
797 				      unsigned int actual_length)
798 {
799 	struct usb_serial *serial = port->serial;
800 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
801 	struct pl2303_private *priv = usb_get_serial_port_data(port);
802 	struct tty_struct *tty;
803 	unsigned long flags;
804 	unsigned int status_idx = UART_STATE_INDEX;
805 	u8 status;
806 	u8 delta;
807 
808 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
809 		status_idx = 0;
810 
811 	if (actual_length < status_idx + 1)
812 		return;
813 
814 	status = data[status_idx];
815 
816 	/* Save off the uart status for others to look at */
817 	spin_lock_irqsave(&priv->lock, flags);
818 	delta = priv->line_status ^ status;
819 	priv->line_status = status;
820 	spin_unlock_irqrestore(&priv->lock, flags);
821 
822 	if (status & UART_BREAK_ERROR)
823 		usb_serial_handle_break(port);
824 
825 	if (delta & UART_STATE_MSR_MASK) {
826 		if (delta & UART_CTS)
827 			port->icount.cts++;
828 		if (delta & UART_DSR)
829 			port->icount.dsr++;
830 		if (delta & UART_RING)
831 			port->icount.rng++;
832 		if (delta & UART_DCD) {
833 			port->icount.dcd++;
834 			tty = tty_port_tty_get(&port->port);
835 			if (tty) {
836 				usb_serial_handle_dcd_change(port, tty,
837 							status & UART_DCD);
838 				tty_kref_put(tty);
839 			}
840 		}
841 
842 		wake_up_interruptible(&port->port.delta_msr_wait);
843 	}
844 }
845 
846 static void pl2303_read_int_callback(struct urb *urb)
847 {
848 	struct usb_serial_port *port =  urb->context;
849 	unsigned char *data = urb->transfer_buffer;
850 	unsigned int actual_length = urb->actual_length;
851 	int status = urb->status;
852 	int retval;
853 
854 	switch (status) {
855 	case 0:
856 		/* success */
857 		break;
858 	case -ECONNRESET:
859 	case -ENOENT:
860 	case -ESHUTDOWN:
861 		/* this urb is terminated, clean up */
862 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
863 			__func__, status);
864 		return;
865 	default:
866 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
867 			__func__, status);
868 		goto exit;
869 	}
870 
871 	usb_serial_debug_data(&port->dev, __func__,
872 			      urb->actual_length, urb->transfer_buffer);
873 
874 	pl2303_update_line_status(port, data, actual_length);
875 
876 exit:
877 	retval = usb_submit_urb(urb, GFP_ATOMIC);
878 	if (retval) {
879 		dev_err(&port->dev,
880 			"%s - usb_submit_urb failed with result %d\n",
881 			__func__, retval);
882 	}
883 }
884 
885 static void pl2303_process_read_urb(struct urb *urb)
886 {
887 	struct usb_serial_port *port = urb->context;
888 	struct pl2303_private *priv = usb_get_serial_port_data(port);
889 	unsigned char *data = urb->transfer_buffer;
890 	char tty_flag = TTY_NORMAL;
891 	unsigned long flags;
892 	u8 line_status;
893 	int i;
894 
895 	/* update line status */
896 	spin_lock_irqsave(&priv->lock, flags);
897 	line_status = priv->line_status;
898 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
899 	spin_unlock_irqrestore(&priv->lock, flags);
900 
901 	if (!urb->actual_length)
902 		return;
903 
904 	/*
905 	 * Break takes precedence over parity, which takes precedence over
906 	 * framing errors.
907 	 */
908 	if (line_status & UART_BREAK_ERROR)
909 		tty_flag = TTY_BREAK;
910 	else if (line_status & UART_PARITY_ERROR)
911 		tty_flag = TTY_PARITY;
912 	else if (line_status & UART_FRAME_ERROR)
913 		tty_flag = TTY_FRAME;
914 
915 	if (tty_flag != TTY_NORMAL)
916 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
917 								tty_flag);
918 	/* overrun is special, not associated with a char */
919 	if (line_status & UART_OVERRUN_ERROR)
920 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
921 
922 	if (port->port.console && port->sysrq) {
923 		for (i = 0; i < urb->actual_length; ++i)
924 			if (!usb_serial_handle_sysrq_char(port, data[i]))
925 				tty_insert_flip_char(&port->port, data[i],
926 						tty_flag);
927 	} else {
928 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
929 							urb->actual_length);
930 	}
931 
932 	tty_flip_buffer_push(&port->port);
933 }
934 
935 static struct usb_serial_driver pl2303_device = {
936 	.driver = {
937 		.owner =	THIS_MODULE,
938 		.name =		"pl2303",
939 	},
940 	.id_table =		id_table,
941 	.num_ports =		1,
942 	.bulk_in_size =		256,
943 	.bulk_out_size =	256,
944 	.open =			pl2303_open,
945 	.close =		pl2303_close,
946 	.dtr_rts =		pl2303_dtr_rts,
947 	.carrier_raised =	pl2303_carrier_raised,
948 	.ioctl =		pl2303_ioctl,
949 	.break_ctl =		pl2303_break_ctl,
950 	.set_termios =		pl2303_set_termios,
951 	.tiocmget =		pl2303_tiocmget,
952 	.tiocmset =		pl2303_tiocmset,
953 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
954 	.process_read_urb =	pl2303_process_read_urb,
955 	.read_int_callback =	pl2303_read_int_callback,
956 	.probe =		pl2303_probe,
957 	.attach =		pl2303_startup,
958 	.release =		pl2303_release,
959 	.port_probe =		pl2303_port_probe,
960 	.port_remove =		pl2303_port_remove,
961 };
962 
963 static struct usb_serial_driver * const serial_drivers[] = {
964 	&pl2303_device, NULL
965 };
966 
967 module_usb_serial_driver(serial_drivers, id_table);
968 
969 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
970 MODULE_LICENSE("GPL");
971