xref: /openbmc/linux/drivers/usb/serial/pl2303.c (revision f3539c12)
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(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1),
65 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
66 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65),
67 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
68 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75),
69 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
70 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_EF81) },
71 	{ USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_ID_S81) }, /* Benq/Siemens S81 */
72 	{ USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
73 	{ USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
74 	{ USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
75 	{ USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
76 	{ USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
77 	{ USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
78 	{ USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
79 	{ USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
80 	{ USB_DEVICE(ALCOR_VENDOR_ID, ALCOR_PRODUCT_ID) },
81 	{ USB_DEVICE(WS002IN_VENDOR_ID, WS002IN_PRODUCT_ID) },
82 	{ USB_DEVICE(COREGA_VENDOR_ID, COREGA_PRODUCT_ID) },
83 	{ USB_DEVICE(YCCABLE_VENDOR_ID, YCCABLE_PRODUCT_ID) },
84 	{ USB_DEVICE(SUPERIAL_VENDOR_ID, SUPERIAL_PRODUCT_ID) },
85 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220_PRODUCT_ID) },
86 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
87 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
88 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
89 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
90 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
91 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
92 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
93 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
94 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
95 	{ }					/* Terminating entry */
96 };
97 
98 MODULE_DEVICE_TABLE(usb, id_table);
99 
100 #define SET_LINE_REQUEST_TYPE		0x21
101 #define SET_LINE_REQUEST		0x20
102 
103 #define SET_CONTROL_REQUEST_TYPE	0x21
104 #define SET_CONTROL_REQUEST		0x22
105 #define CONTROL_DTR			0x01
106 #define CONTROL_RTS			0x02
107 
108 #define BREAK_REQUEST_TYPE		0x21
109 #define BREAK_REQUEST			0x23
110 #define BREAK_ON			0xffff
111 #define BREAK_OFF			0x0000
112 
113 #define GET_LINE_REQUEST_TYPE		0xa1
114 #define GET_LINE_REQUEST		0x21
115 
116 #define VENDOR_WRITE_REQUEST_TYPE	0x40
117 #define VENDOR_WRITE_REQUEST		0x01
118 
119 #define VENDOR_READ_REQUEST_TYPE	0xc0
120 #define VENDOR_READ_REQUEST		0x01
121 
122 #define UART_STATE_INDEX		8
123 #define UART_STATE_MSR_MASK		0x8b
124 #define UART_STATE_TRANSIENT_MASK	0x74
125 #define UART_DCD			0x01
126 #define UART_DSR			0x02
127 #define UART_BREAK_ERROR		0x04
128 #define UART_RING			0x08
129 #define UART_FRAME_ERROR		0x10
130 #define UART_PARITY_ERROR		0x20
131 #define UART_OVERRUN_ERROR		0x40
132 #define UART_CTS			0x80
133 
134 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
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 baseline, mantissa, exponent;
366 
367 	/*
368 	 * Apparently the formula is:
369 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
370 	 * where
371 	 *   mantissa = buf[8:0]
372 	 *   exponent = buf[11:9]
373 	 */
374 	baseline = 12000000 * 32;
375 	mantissa = baseline / baud;
376 	if (mantissa == 0)
377 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
378 	exponent = 0;
379 	while (mantissa >= 512) {
380 		if (exponent < 7) {
381 			mantissa >>= 2;	/* divide by 4 */
382 			exponent++;
383 		} else {
384 			/* Exponent is maxed. Trim mantissa and leave. */
385 			mantissa = 511;
386 			break;
387 		}
388 	}
389 
390 	buf[3] = 0x80;
391 	buf[2] = 0;
392 	buf[1] = exponent << 1 | mantissa >> 8;
393 	buf[0] = mantissa & 0xff;
394 
395 	/* Calculate and return the exact baud rate. */
396 	baud = (baseline / mantissa) >> (exponent << 1);
397 
398 	return baud;
399 }
400 
401 static void pl2303_encode_baud_rate(struct tty_struct *tty,
402 					struct usb_serial_port *port,
403 					u8 buf[4])
404 {
405 	struct usb_serial *serial = port->serial;
406 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
407 	speed_t	baud_sup;
408 	speed_t baud;
409 
410 	baud = tty_get_baud_rate(tty);
411 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
412 	if (!baud)
413 		return;
414 
415 	if (spriv->type->max_baud_rate)
416 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
417 	/*
418 	 * Use direct method for supported baud rates, otherwise use divisors.
419 	 */
420 	baud_sup = pl2303_get_supported_baud_rate(baud);
421 
422 	if (baud == baud_sup)
423 		baud = pl2303_encode_baud_rate_direct(buf, baud);
424 	else
425 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
426 
427 	/* Save resulting baud rate */
428 	tty_encode_baud_rate(tty, baud, baud);
429 	dev_dbg(&port->dev, "baud set = %u\n", baud);
430 }
431 
432 static int pl2303_get_line_request(struct usb_serial_port *port,
433 							unsigned char buf[7])
434 {
435 	struct usb_device *udev = port->serial->dev;
436 	int ret;
437 
438 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
439 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
440 				0, 0, buf, 7, 100);
441 	if (ret != 7) {
442 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
443 
444 		if (ret > 0)
445 			ret = -EIO;
446 
447 		return ret;
448 	}
449 
450 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
451 
452 	return 0;
453 }
454 
455 static int pl2303_set_line_request(struct usb_serial_port *port,
456 							unsigned char buf[7])
457 {
458 	struct usb_device *udev = port->serial->dev;
459 	int ret;
460 
461 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
462 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
463 				0, 0, buf, 7, 100);
464 	if (ret != 7) {
465 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
466 
467 		if (ret > 0)
468 			ret = -EIO;
469 
470 		return ret;
471 	}
472 
473 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
474 
475 	return 0;
476 }
477 
478 static void pl2303_set_termios(struct tty_struct *tty,
479 		struct usb_serial_port *port, struct ktermios *old_termios)
480 {
481 	struct usb_serial *serial = port->serial;
482 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
483 	struct pl2303_private *priv = usb_get_serial_port_data(port);
484 	unsigned long flags;
485 	unsigned char *buf;
486 	int ret;
487 	u8 control;
488 
489 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
490 		return;
491 
492 	buf = kzalloc(7, GFP_KERNEL);
493 	if (!buf) {
494 		/* Report back no change occurred */
495 		if (old_termios)
496 			tty->termios = *old_termios;
497 		return;
498 	}
499 
500 	pl2303_get_line_request(port, buf);
501 
502 	switch (C_CSIZE(tty)) {
503 	case CS5:
504 		buf[6] = 5;
505 		break;
506 	case CS6:
507 		buf[6] = 6;
508 		break;
509 	case CS7:
510 		buf[6] = 7;
511 		break;
512 	default:
513 	case CS8:
514 		buf[6] = 8;
515 	}
516 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
517 
518 	/* For reference buf[0]:buf[3] baud rate value */
519 	pl2303_encode_baud_rate(tty, port, &buf[0]);
520 
521 	/* For reference buf[4]=0 is 1 stop bits */
522 	/* For reference buf[4]=1 is 1.5 stop bits */
523 	/* For reference buf[4]=2 is 2 stop bits */
524 	if (C_CSTOPB(tty)) {
525 		/*
526 		 * NOTE: Comply with "real" UARTs / RS232:
527 		 *       use 1.5 instead of 2 stop bits with 5 data bits
528 		 */
529 		if (C_CSIZE(tty) == CS5) {
530 			buf[4] = 1;
531 			dev_dbg(&port->dev, "stop bits = 1.5\n");
532 		} else {
533 			buf[4] = 2;
534 			dev_dbg(&port->dev, "stop bits = 2\n");
535 		}
536 	} else {
537 		buf[4] = 0;
538 		dev_dbg(&port->dev, "stop bits = 1\n");
539 	}
540 
541 	if (C_PARENB(tty)) {
542 		/* For reference buf[5]=0 is none parity */
543 		/* For reference buf[5]=1 is odd parity */
544 		/* For reference buf[5]=2 is even parity */
545 		/* For reference buf[5]=3 is mark parity */
546 		/* For reference buf[5]=4 is space parity */
547 		if (C_PARODD(tty)) {
548 			if (C_CMSPAR(tty)) {
549 				buf[5] = 3;
550 				dev_dbg(&port->dev, "parity = mark\n");
551 			} else {
552 				buf[5] = 1;
553 				dev_dbg(&port->dev, "parity = odd\n");
554 			}
555 		} else {
556 			if (C_CMSPAR(tty)) {
557 				buf[5] = 4;
558 				dev_dbg(&port->dev, "parity = space\n");
559 			} else {
560 				buf[5] = 2;
561 				dev_dbg(&port->dev, "parity = even\n");
562 			}
563 		}
564 	} else {
565 		buf[5] = 0;
566 		dev_dbg(&port->dev, "parity = none\n");
567 	}
568 
569 	/*
570 	 * Some PL2303 are known to lose bytes if you change serial settings
571 	 * even to the same values as before. Thus we actually need to filter
572 	 * in this specific case.
573 	 *
574 	 * Note that the tty_termios_hw_change check above is not sufficient
575 	 * as a previously requested baud rate may differ from the one
576 	 * actually used (and stored in old_termios).
577 	 *
578 	 * NOTE: No additional locking needed for line_settings as it is
579 	 *       only used in set_termios, which is serialised against itself.
580 	 */
581 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
582 		ret = pl2303_set_line_request(port, buf);
583 		if (!ret)
584 			memcpy(priv->line_settings, buf, 7);
585 	}
586 
587 	/* change control lines if we are switching to or from B0 */
588 	spin_lock_irqsave(&priv->lock, flags);
589 	control = priv->line_control;
590 	if (C_BAUD(tty) == B0)
591 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
592 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
593 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
594 	if (control != priv->line_control) {
595 		control = priv->line_control;
596 		spin_unlock_irqrestore(&priv->lock, flags);
597 		pl2303_set_control_lines(port, control);
598 	} else {
599 		spin_unlock_irqrestore(&priv->lock, flags);
600 	}
601 
602 	if (C_CRTSCTS(tty)) {
603 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
604 			pl2303_vendor_write(serial, 0x0, 0x41);
605 		else
606 			pl2303_vendor_write(serial, 0x0, 0x61);
607 	} else {
608 		pl2303_vendor_write(serial, 0x0, 0x0);
609 	}
610 
611 	kfree(buf);
612 }
613 
614 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
615 {
616 	struct pl2303_private *priv = usb_get_serial_port_data(port);
617 	unsigned long flags;
618 	u8 control;
619 
620 	spin_lock_irqsave(&priv->lock, flags);
621 	if (on)
622 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
623 	else
624 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
625 	control = priv->line_control;
626 	spin_unlock_irqrestore(&priv->lock, flags);
627 
628 	pl2303_set_control_lines(port, control);
629 }
630 
631 static void pl2303_close(struct usb_serial_port *port)
632 {
633 	usb_serial_generic_close(port);
634 	usb_kill_urb(port->interrupt_in_urb);
635 	pl2303_set_break(port, false);
636 }
637 
638 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
639 {
640 	struct usb_serial *serial = port->serial;
641 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
642 	int result;
643 
644 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
645 		usb_clear_halt(serial->dev, port->write_urb->pipe);
646 		usb_clear_halt(serial->dev, port->read_urb->pipe);
647 	} else {
648 		/* reset upstream data pipes */
649 		pl2303_vendor_write(serial, 8, 0);
650 		pl2303_vendor_write(serial, 9, 0);
651 	}
652 
653 	/* Setup termios */
654 	if (tty)
655 		pl2303_set_termios(tty, port, NULL);
656 
657 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
658 	if (result) {
659 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
660 			result);
661 		return result;
662 	}
663 
664 	result = usb_serial_generic_open(tty, port);
665 	if (result) {
666 		usb_kill_urb(port->interrupt_in_urb);
667 		return result;
668 	}
669 
670 	return 0;
671 }
672 
673 static int pl2303_tiocmset(struct tty_struct *tty,
674 			   unsigned int set, unsigned int clear)
675 {
676 	struct usb_serial_port *port = tty->driver_data;
677 	struct pl2303_private *priv = usb_get_serial_port_data(port);
678 	unsigned long flags;
679 	u8 control;
680 	int ret;
681 
682 	spin_lock_irqsave(&priv->lock, flags);
683 	if (set & TIOCM_RTS)
684 		priv->line_control |= CONTROL_RTS;
685 	if (set & TIOCM_DTR)
686 		priv->line_control |= CONTROL_DTR;
687 	if (clear & TIOCM_RTS)
688 		priv->line_control &= ~CONTROL_RTS;
689 	if (clear & TIOCM_DTR)
690 		priv->line_control &= ~CONTROL_DTR;
691 	control = priv->line_control;
692 	spin_unlock_irqrestore(&priv->lock, flags);
693 
694 	ret = pl2303_set_control_lines(port, control);
695 	if (ret)
696 		return usb_translate_errors(ret);
697 
698 	return 0;
699 }
700 
701 static int pl2303_tiocmget(struct tty_struct *tty)
702 {
703 	struct usb_serial_port *port = tty->driver_data;
704 	struct pl2303_private *priv = usb_get_serial_port_data(port);
705 	unsigned long flags;
706 	unsigned int mcr;
707 	unsigned int status;
708 	unsigned int result;
709 
710 	spin_lock_irqsave(&priv->lock, flags);
711 	mcr = priv->line_control;
712 	status = priv->line_status;
713 	spin_unlock_irqrestore(&priv->lock, flags);
714 
715 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
716 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
717 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
718 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
719 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
720 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
721 
722 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
723 
724 	return result;
725 }
726 
727 static int pl2303_carrier_raised(struct usb_serial_port *port)
728 {
729 	struct pl2303_private *priv = usb_get_serial_port_data(port);
730 
731 	if (priv->line_status & UART_DCD)
732 		return 1;
733 
734 	return 0;
735 }
736 
737 static int pl2303_ioctl(struct tty_struct *tty,
738 			unsigned int cmd, unsigned long arg)
739 {
740 	struct serial_struct ser;
741 	struct usb_serial_port *port = tty->driver_data;
742 
743 	switch (cmd) {
744 	case TIOCGSERIAL:
745 		memset(&ser, 0, sizeof ser);
746 		ser.type = PORT_16654;
747 		ser.line = port->minor;
748 		ser.port = port->port_number;
749 		ser.baud_base = 460800;
750 
751 		if (copy_to_user((void __user *)arg, &ser, sizeof ser))
752 			return -EFAULT;
753 
754 		return 0;
755 	default:
756 		break;
757 	}
758 
759 	return -ENOIOCTLCMD;
760 }
761 
762 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
763 {
764 	struct usb_serial *serial = port->serial;
765 	u16 state;
766 	int result;
767 
768 	if (enable)
769 		state = BREAK_ON;
770 	else
771 		state = BREAK_OFF;
772 
773 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
774 			state == BREAK_OFF ? "off" : "on");
775 
776 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
777 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
778 				 0, NULL, 0, 100);
779 	if (result)
780 		dev_err(&port->dev, "error sending break = %d\n", result);
781 }
782 
783 static void pl2303_break_ctl(struct tty_struct *tty, int state)
784 {
785 	struct usb_serial_port *port = tty->driver_data;
786 
787 	pl2303_set_break(port, state);
788 }
789 
790 static void pl2303_update_line_status(struct usb_serial_port *port,
791 				      unsigned char *data,
792 				      unsigned int actual_length)
793 {
794 	struct usb_serial *serial = port->serial;
795 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
796 	struct pl2303_private *priv = usb_get_serial_port_data(port);
797 	struct tty_struct *tty;
798 	unsigned long flags;
799 	unsigned int status_idx = UART_STATE_INDEX;
800 	u8 status;
801 	u8 delta;
802 
803 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
804 		status_idx = 0;
805 
806 	if (actual_length < status_idx + 1)
807 		return;
808 
809 	status = data[status_idx];
810 
811 	/* Save off the uart status for others to look at */
812 	spin_lock_irqsave(&priv->lock, flags);
813 	delta = priv->line_status ^ status;
814 	priv->line_status = status;
815 	spin_unlock_irqrestore(&priv->lock, flags);
816 
817 	if (status & UART_BREAK_ERROR)
818 		usb_serial_handle_break(port);
819 
820 	if (delta & UART_STATE_MSR_MASK) {
821 		if (delta & UART_CTS)
822 			port->icount.cts++;
823 		if (delta & UART_DSR)
824 			port->icount.dsr++;
825 		if (delta & UART_RING)
826 			port->icount.rng++;
827 		if (delta & UART_DCD) {
828 			port->icount.dcd++;
829 			tty = tty_port_tty_get(&port->port);
830 			if (tty) {
831 				usb_serial_handle_dcd_change(port, tty,
832 							status & UART_DCD);
833 				tty_kref_put(tty);
834 			}
835 		}
836 
837 		wake_up_interruptible(&port->port.delta_msr_wait);
838 	}
839 }
840 
841 static void pl2303_read_int_callback(struct urb *urb)
842 {
843 	struct usb_serial_port *port =  urb->context;
844 	unsigned char *data = urb->transfer_buffer;
845 	unsigned int actual_length = urb->actual_length;
846 	int status = urb->status;
847 	int retval;
848 
849 	switch (status) {
850 	case 0:
851 		/* success */
852 		break;
853 	case -ECONNRESET:
854 	case -ENOENT:
855 	case -ESHUTDOWN:
856 		/* this urb is terminated, clean up */
857 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
858 			__func__, status);
859 		return;
860 	default:
861 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
862 			__func__, status);
863 		goto exit;
864 	}
865 
866 	usb_serial_debug_data(&port->dev, __func__,
867 			      urb->actual_length, urb->transfer_buffer);
868 
869 	pl2303_update_line_status(port, data, actual_length);
870 
871 exit:
872 	retval = usb_submit_urb(urb, GFP_ATOMIC);
873 	if (retval) {
874 		dev_err(&port->dev,
875 			"%s - usb_submit_urb failed with result %d\n",
876 			__func__, retval);
877 	}
878 }
879 
880 static void pl2303_process_read_urb(struct urb *urb)
881 {
882 	struct usb_serial_port *port = urb->context;
883 	struct pl2303_private *priv = usb_get_serial_port_data(port);
884 	unsigned char *data = urb->transfer_buffer;
885 	char tty_flag = TTY_NORMAL;
886 	unsigned long flags;
887 	u8 line_status;
888 	int i;
889 
890 	/* update line status */
891 	spin_lock_irqsave(&priv->lock, flags);
892 	line_status = priv->line_status;
893 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
894 	spin_unlock_irqrestore(&priv->lock, flags);
895 
896 	if (!urb->actual_length)
897 		return;
898 
899 	/*
900 	 * Break takes precedence over parity, which takes precedence over
901 	 * framing errors.
902 	 */
903 	if (line_status & UART_BREAK_ERROR)
904 		tty_flag = TTY_BREAK;
905 	else if (line_status & UART_PARITY_ERROR)
906 		tty_flag = TTY_PARITY;
907 	else if (line_status & UART_FRAME_ERROR)
908 		tty_flag = TTY_FRAME;
909 
910 	if (tty_flag != TTY_NORMAL)
911 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
912 								tty_flag);
913 	/* overrun is special, not associated with a char */
914 	if (line_status & UART_OVERRUN_ERROR)
915 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
916 
917 	if (port->port.console && port->sysrq) {
918 		for (i = 0; i < urb->actual_length; ++i)
919 			if (!usb_serial_handle_sysrq_char(port, data[i]))
920 				tty_insert_flip_char(&port->port, data[i],
921 						tty_flag);
922 	} else {
923 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
924 							urb->actual_length);
925 	}
926 
927 	tty_flip_buffer_push(&port->port);
928 }
929 
930 static struct usb_serial_driver pl2303_device = {
931 	.driver = {
932 		.owner =	THIS_MODULE,
933 		.name =		"pl2303",
934 	},
935 	.id_table =		id_table,
936 	.num_ports =		1,
937 	.bulk_in_size =		256,
938 	.bulk_out_size =	256,
939 	.open =			pl2303_open,
940 	.close =		pl2303_close,
941 	.dtr_rts =		pl2303_dtr_rts,
942 	.carrier_raised =	pl2303_carrier_raised,
943 	.ioctl =		pl2303_ioctl,
944 	.break_ctl =		pl2303_break_ctl,
945 	.set_termios =		pl2303_set_termios,
946 	.tiocmget =		pl2303_tiocmget,
947 	.tiocmset =		pl2303_tiocmset,
948 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
949 	.process_read_urb =	pl2303_process_read_urb,
950 	.read_int_callback =	pl2303_read_int_callback,
951 	.probe =		pl2303_probe,
952 	.attach =		pl2303_startup,
953 	.release =		pl2303_release,
954 	.port_probe =		pl2303_port_probe,
955 	.port_remove =		pl2303_port_remove,
956 };
957 
958 static struct usb_serial_driver * const serial_drivers[] = {
959 	&pl2303_device, NULL
960 };
961 
962 module_usb_serial_driver(serial_drivers, id_table);
963 
964 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
965 MODULE_LICENSE("GPL");
966