xref: /openbmc/linux/drivers/usb/serial/pl2303.c (revision 8730046c)
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 	unsigned char num_ports = serial->num_ports;
224 	enum pl2303_type type = TYPE_01;
225 	unsigned char *buf;
226 
227 	if (serial->num_bulk_in < num_ports ||
228 			serial->num_bulk_out < num_ports ||
229 			serial->num_interrupt_in < num_ports) {
230 		dev_err(&serial->interface->dev, "missing endpoints\n");
231 		return -ENODEV;
232 	}
233 
234 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
235 	if (!spriv)
236 		return -ENOMEM;
237 
238 	buf = kmalloc(1, GFP_KERNEL);
239 	if (!buf) {
240 		kfree(spriv);
241 		return -ENOMEM;
242 	}
243 
244 	if (serial->dev->descriptor.bDeviceClass == 0x02)
245 		type = TYPE_01;		/* type 0 */
246 	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
247 		type = TYPE_HX;
248 	else if (serial->dev->descriptor.bDeviceClass == 0x00)
249 		type = TYPE_01;		/* type 1 */
250 	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
251 		type = TYPE_01;		/* type 1 */
252 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
253 
254 	spriv->type = &pl2303_type_data[type];
255 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
256 	spriv->quirks |= spriv->type->quirks;
257 
258 	usb_set_serial_data(serial, spriv);
259 
260 	pl2303_vendor_read(serial, 0x8484, buf);
261 	pl2303_vendor_write(serial, 0x0404, 0);
262 	pl2303_vendor_read(serial, 0x8484, buf);
263 	pl2303_vendor_read(serial, 0x8383, buf);
264 	pl2303_vendor_read(serial, 0x8484, buf);
265 	pl2303_vendor_write(serial, 0x0404, 1);
266 	pl2303_vendor_read(serial, 0x8484, buf);
267 	pl2303_vendor_read(serial, 0x8383, buf);
268 	pl2303_vendor_write(serial, 0, 1);
269 	pl2303_vendor_write(serial, 1, 0);
270 	if (spriv->quirks & PL2303_QUIRK_LEGACY)
271 		pl2303_vendor_write(serial, 2, 0x24);
272 	else
273 		pl2303_vendor_write(serial, 2, 0x44);
274 
275 	kfree(buf);
276 
277 	return 0;
278 }
279 
280 static void pl2303_release(struct usb_serial *serial)
281 {
282 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
283 
284 	kfree(spriv);
285 }
286 
287 static int pl2303_port_probe(struct usb_serial_port *port)
288 {
289 	struct pl2303_private *priv;
290 
291 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
292 	if (!priv)
293 		return -ENOMEM;
294 
295 	spin_lock_init(&priv->lock);
296 
297 	usb_set_serial_port_data(port, priv);
298 
299 	port->port.drain_delay = 256;
300 
301 	return 0;
302 }
303 
304 static int pl2303_port_remove(struct usb_serial_port *port)
305 {
306 	struct pl2303_private *priv = usb_get_serial_port_data(port);
307 
308 	kfree(priv);
309 
310 	return 0;
311 }
312 
313 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
314 {
315 	struct usb_device *dev = port->serial->dev;
316 	int retval;
317 
318 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
319 
320 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
321 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
322 				 value, 0, NULL, 0, 100);
323 	if (retval)
324 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
325 
326 	return retval;
327 }
328 
329 /*
330  * Returns the nearest supported baud rate that can be set directly without
331  * using divisors.
332  */
333 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
334 {
335 	static const speed_t baud_sup[] = {
336 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
337 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
338 		614400, 921600, 1228800, 2457600, 3000000, 6000000
339 	};
340 
341 	unsigned i;
342 
343 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
344 		if (baud_sup[i] > baud)
345 			break;
346 	}
347 
348 	if (i == ARRAY_SIZE(baud_sup))
349 		baud = baud_sup[i - 1];
350 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
351 		baud = baud_sup[i - 1];
352 	else
353 		baud = baud_sup[i];
354 
355 	return baud;
356 }
357 
358 /*
359  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
360  *       use 9600 baud.
361  */
362 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
363 								speed_t baud)
364 {
365 	put_unaligned_le32(baud, buf);
366 
367 	return baud;
368 }
369 
370 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
371 								speed_t baud)
372 {
373 	unsigned int baseline, mantissa, exponent;
374 
375 	/*
376 	 * Apparently the formula is:
377 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
378 	 * where
379 	 *   mantissa = buf[8:0]
380 	 *   exponent = buf[11:9]
381 	 */
382 	baseline = 12000000 * 32;
383 	mantissa = baseline / baud;
384 	if (mantissa == 0)
385 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
386 	exponent = 0;
387 	while (mantissa >= 512) {
388 		if (exponent < 7) {
389 			mantissa >>= 2;	/* divide by 4 */
390 			exponent++;
391 		} else {
392 			/* Exponent is maxed. Trim mantissa and leave. */
393 			mantissa = 511;
394 			break;
395 		}
396 	}
397 
398 	buf[3] = 0x80;
399 	buf[2] = 0;
400 	buf[1] = exponent << 1 | mantissa >> 8;
401 	buf[0] = mantissa & 0xff;
402 
403 	/* Calculate and return the exact baud rate. */
404 	baud = (baseline / mantissa) >> (exponent << 1);
405 
406 	return baud;
407 }
408 
409 static void pl2303_encode_baud_rate(struct tty_struct *tty,
410 					struct usb_serial_port *port,
411 					u8 buf[4])
412 {
413 	struct usb_serial *serial = port->serial;
414 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
415 	speed_t	baud_sup;
416 	speed_t baud;
417 
418 	baud = tty_get_baud_rate(tty);
419 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
420 	if (!baud)
421 		return;
422 
423 	if (spriv->type->max_baud_rate)
424 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
425 	/*
426 	 * Use direct method for supported baud rates, otherwise use divisors.
427 	 */
428 	baud_sup = pl2303_get_supported_baud_rate(baud);
429 
430 	if (baud == baud_sup)
431 		baud = pl2303_encode_baud_rate_direct(buf, baud);
432 	else
433 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
434 
435 	/* Save resulting baud rate */
436 	tty_encode_baud_rate(tty, baud, baud);
437 	dev_dbg(&port->dev, "baud set = %u\n", baud);
438 }
439 
440 static int pl2303_get_line_request(struct usb_serial_port *port,
441 							unsigned char buf[7])
442 {
443 	struct usb_device *udev = port->serial->dev;
444 	int ret;
445 
446 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
447 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
448 				0, 0, buf, 7, 100);
449 	if (ret != 7) {
450 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
451 
452 		if (ret > 0)
453 			ret = -EIO;
454 
455 		return ret;
456 	}
457 
458 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
459 
460 	return 0;
461 }
462 
463 static int pl2303_set_line_request(struct usb_serial_port *port,
464 							unsigned char buf[7])
465 {
466 	struct usb_device *udev = port->serial->dev;
467 	int ret;
468 
469 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
470 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
471 				0, 0, buf, 7, 100);
472 	if (ret != 7) {
473 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
474 
475 		if (ret > 0)
476 			ret = -EIO;
477 
478 		return ret;
479 	}
480 
481 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
482 
483 	return 0;
484 }
485 
486 static void pl2303_set_termios(struct tty_struct *tty,
487 		struct usb_serial_port *port, struct ktermios *old_termios)
488 {
489 	struct usb_serial *serial = port->serial;
490 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
491 	struct pl2303_private *priv = usb_get_serial_port_data(port);
492 	unsigned long flags;
493 	unsigned char *buf;
494 	int ret;
495 	u8 control;
496 
497 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
498 		return;
499 
500 	buf = kzalloc(7, GFP_KERNEL);
501 	if (!buf) {
502 		/* Report back no change occurred */
503 		if (old_termios)
504 			tty->termios = *old_termios;
505 		return;
506 	}
507 
508 	pl2303_get_line_request(port, buf);
509 
510 	switch (C_CSIZE(tty)) {
511 	case CS5:
512 		buf[6] = 5;
513 		break;
514 	case CS6:
515 		buf[6] = 6;
516 		break;
517 	case CS7:
518 		buf[6] = 7;
519 		break;
520 	default:
521 	case CS8:
522 		buf[6] = 8;
523 	}
524 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
525 
526 	/* For reference buf[0]:buf[3] baud rate value */
527 	pl2303_encode_baud_rate(tty, port, &buf[0]);
528 
529 	/* For reference buf[4]=0 is 1 stop bits */
530 	/* For reference buf[4]=1 is 1.5 stop bits */
531 	/* For reference buf[4]=2 is 2 stop bits */
532 	if (C_CSTOPB(tty)) {
533 		/*
534 		 * NOTE: Comply with "real" UARTs / RS232:
535 		 *       use 1.5 instead of 2 stop bits with 5 data bits
536 		 */
537 		if (C_CSIZE(tty) == CS5) {
538 			buf[4] = 1;
539 			dev_dbg(&port->dev, "stop bits = 1.5\n");
540 		} else {
541 			buf[4] = 2;
542 			dev_dbg(&port->dev, "stop bits = 2\n");
543 		}
544 	} else {
545 		buf[4] = 0;
546 		dev_dbg(&port->dev, "stop bits = 1\n");
547 	}
548 
549 	if (C_PARENB(tty)) {
550 		/* For reference buf[5]=0 is none parity */
551 		/* For reference buf[5]=1 is odd parity */
552 		/* For reference buf[5]=2 is even parity */
553 		/* For reference buf[5]=3 is mark parity */
554 		/* For reference buf[5]=4 is space parity */
555 		if (C_PARODD(tty)) {
556 			if (C_CMSPAR(tty)) {
557 				buf[5] = 3;
558 				dev_dbg(&port->dev, "parity = mark\n");
559 			} else {
560 				buf[5] = 1;
561 				dev_dbg(&port->dev, "parity = odd\n");
562 			}
563 		} else {
564 			if (C_CMSPAR(tty)) {
565 				buf[5] = 4;
566 				dev_dbg(&port->dev, "parity = space\n");
567 			} else {
568 				buf[5] = 2;
569 				dev_dbg(&port->dev, "parity = even\n");
570 			}
571 		}
572 	} else {
573 		buf[5] = 0;
574 		dev_dbg(&port->dev, "parity = none\n");
575 	}
576 
577 	/*
578 	 * Some PL2303 are known to lose bytes if you change serial settings
579 	 * even to the same values as before. Thus we actually need to filter
580 	 * in this specific case.
581 	 *
582 	 * Note that the tty_termios_hw_change check above is not sufficient
583 	 * as a previously requested baud rate may differ from the one
584 	 * actually used (and stored in old_termios).
585 	 *
586 	 * NOTE: No additional locking needed for line_settings as it is
587 	 *       only used in set_termios, which is serialised against itself.
588 	 */
589 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
590 		ret = pl2303_set_line_request(port, buf);
591 		if (!ret)
592 			memcpy(priv->line_settings, buf, 7);
593 	}
594 
595 	/* change control lines if we are switching to or from B0 */
596 	spin_lock_irqsave(&priv->lock, flags);
597 	control = priv->line_control;
598 	if (C_BAUD(tty) == B0)
599 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
600 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
601 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
602 	if (control != priv->line_control) {
603 		control = priv->line_control;
604 		spin_unlock_irqrestore(&priv->lock, flags);
605 		pl2303_set_control_lines(port, control);
606 	} else {
607 		spin_unlock_irqrestore(&priv->lock, flags);
608 	}
609 
610 	if (C_CRTSCTS(tty)) {
611 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
612 			pl2303_vendor_write(serial, 0x0, 0x41);
613 		else
614 			pl2303_vendor_write(serial, 0x0, 0x61);
615 	} else {
616 		pl2303_vendor_write(serial, 0x0, 0x0);
617 	}
618 
619 	kfree(buf);
620 }
621 
622 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
623 {
624 	struct pl2303_private *priv = usb_get_serial_port_data(port);
625 	unsigned long flags;
626 	u8 control;
627 
628 	spin_lock_irqsave(&priv->lock, flags);
629 	if (on)
630 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
631 	else
632 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
633 	control = priv->line_control;
634 	spin_unlock_irqrestore(&priv->lock, flags);
635 
636 	pl2303_set_control_lines(port, control);
637 }
638 
639 static void pl2303_close(struct usb_serial_port *port)
640 {
641 	usb_serial_generic_close(port);
642 	usb_kill_urb(port->interrupt_in_urb);
643 	pl2303_set_break(port, false);
644 }
645 
646 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
647 {
648 	struct usb_serial *serial = port->serial;
649 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
650 	int result;
651 
652 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
653 		usb_clear_halt(serial->dev, port->write_urb->pipe);
654 		usb_clear_halt(serial->dev, port->read_urb->pipe);
655 	} else {
656 		/* reset upstream data pipes */
657 		pl2303_vendor_write(serial, 8, 0);
658 		pl2303_vendor_write(serial, 9, 0);
659 	}
660 
661 	/* Setup termios */
662 	if (tty)
663 		pl2303_set_termios(tty, port, NULL);
664 
665 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
666 	if (result) {
667 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
668 			result);
669 		return result;
670 	}
671 
672 	result = usb_serial_generic_open(tty, port);
673 	if (result) {
674 		usb_kill_urb(port->interrupt_in_urb);
675 		return result;
676 	}
677 
678 	return 0;
679 }
680 
681 static int pl2303_tiocmset(struct tty_struct *tty,
682 			   unsigned int set, unsigned int clear)
683 {
684 	struct usb_serial_port *port = tty->driver_data;
685 	struct pl2303_private *priv = usb_get_serial_port_data(port);
686 	unsigned long flags;
687 	u8 control;
688 	int ret;
689 
690 	spin_lock_irqsave(&priv->lock, flags);
691 	if (set & TIOCM_RTS)
692 		priv->line_control |= CONTROL_RTS;
693 	if (set & TIOCM_DTR)
694 		priv->line_control |= CONTROL_DTR;
695 	if (clear & TIOCM_RTS)
696 		priv->line_control &= ~CONTROL_RTS;
697 	if (clear & TIOCM_DTR)
698 		priv->line_control &= ~CONTROL_DTR;
699 	control = priv->line_control;
700 	spin_unlock_irqrestore(&priv->lock, flags);
701 
702 	ret = pl2303_set_control_lines(port, control);
703 	if (ret)
704 		return usb_translate_errors(ret);
705 
706 	return 0;
707 }
708 
709 static int pl2303_tiocmget(struct tty_struct *tty)
710 {
711 	struct usb_serial_port *port = tty->driver_data;
712 	struct pl2303_private *priv = usb_get_serial_port_data(port);
713 	unsigned long flags;
714 	unsigned int mcr;
715 	unsigned int status;
716 	unsigned int result;
717 
718 	spin_lock_irqsave(&priv->lock, flags);
719 	mcr = priv->line_control;
720 	status = priv->line_status;
721 	spin_unlock_irqrestore(&priv->lock, flags);
722 
723 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
724 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
725 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
726 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
727 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
728 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
729 
730 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
731 
732 	return result;
733 }
734 
735 static int pl2303_carrier_raised(struct usb_serial_port *port)
736 {
737 	struct pl2303_private *priv = usb_get_serial_port_data(port);
738 
739 	if (priv->line_status & UART_DCD)
740 		return 1;
741 
742 	return 0;
743 }
744 
745 static int pl2303_ioctl(struct tty_struct *tty,
746 			unsigned int cmd, unsigned long arg)
747 {
748 	struct serial_struct ser;
749 	struct usb_serial_port *port = tty->driver_data;
750 
751 	switch (cmd) {
752 	case TIOCGSERIAL:
753 		memset(&ser, 0, sizeof ser);
754 		ser.type = PORT_16654;
755 		ser.line = port->minor;
756 		ser.port = port->port_number;
757 		ser.baud_base = 460800;
758 
759 		if (copy_to_user((void __user *)arg, &ser, sizeof ser))
760 			return -EFAULT;
761 
762 		return 0;
763 	default:
764 		break;
765 	}
766 
767 	return -ENOIOCTLCMD;
768 }
769 
770 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
771 {
772 	struct usb_serial *serial = port->serial;
773 	u16 state;
774 	int result;
775 
776 	if (enable)
777 		state = BREAK_ON;
778 	else
779 		state = BREAK_OFF;
780 
781 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
782 			state == BREAK_OFF ? "off" : "on");
783 
784 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
785 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
786 				 0, NULL, 0, 100);
787 	if (result)
788 		dev_err(&port->dev, "error sending break = %d\n", result);
789 }
790 
791 static void pl2303_break_ctl(struct tty_struct *tty, int state)
792 {
793 	struct usb_serial_port *port = tty->driver_data;
794 
795 	pl2303_set_break(port, state);
796 }
797 
798 static void pl2303_update_line_status(struct usb_serial_port *port,
799 				      unsigned char *data,
800 				      unsigned int actual_length)
801 {
802 	struct usb_serial *serial = port->serial;
803 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
804 	struct pl2303_private *priv = usb_get_serial_port_data(port);
805 	struct tty_struct *tty;
806 	unsigned long flags;
807 	unsigned int status_idx = UART_STATE_INDEX;
808 	u8 status;
809 	u8 delta;
810 
811 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
812 		status_idx = 0;
813 
814 	if (actual_length < status_idx + 1)
815 		return;
816 
817 	status = data[status_idx];
818 
819 	/* Save off the uart status for others to look at */
820 	spin_lock_irqsave(&priv->lock, flags);
821 	delta = priv->line_status ^ status;
822 	priv->line_status = status;
823 	spin_unlock_irqrestore(&priv->lock, flags);
824 
825 	if (status & UART_BREAK_ERROR)
826 		usb_serial_handle_break(port);
827 
828 	if (delta & UART_STATE_MSR_MASK) {
829 		if (delta & UART_CTS)
830 			port->icount.cts++;
831 		if (delta & UART_DSR)
832 			port->icount.dsr++;
833 		if (delta & UART_RING)
834 			port->icount.rng++;
835 		if (delta & UART_DCD) {
836 			port->icount.dcd++;
837 			tty = tty_port_tty_get(&port->port);
838 			if (tty) {
839 				usb_serial_handle_dcd_change(port, tty,
840 							status & UART_DCD);
841 				tty_kref_put(tty);
842 			}
843 		}
844 
845 		wake_up_interruptible(&port->port.delta_msr_wait);
846 	}
847 }
848 
849 static void pl2303_read_int_callback(struct urb *urb)
850 {
851 	struct usb_serial_port *port =  urb->context;
852 	unsigned char *data = urb->transfer_buffer;
853 	unsigned int actual_length = urb->actual_length;
854 	int status = urb->status;
855 	int retval;
856 
857 	switch (status) {
858 	case 0:
859 		/* success */
860 		break;
861 	case -ECONNRESET:
862 	case -ENOENT:
863 	case -ESHUTDOWN:
864 		/* this urb is terminated, clean up */
865 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
866 			__func__, status);
867 		return;
868 	default:
869 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
870 			__func__, status);
871 		goto exit;
872 	}
873 
874 	usb_serial_debug_data(&port->dev, __func__,
875 			      urb->actual_length, urb->transfer_buffer);
876 
877 	pl2303_update_line_status(port, data, actual_length);
878 
879 exit:
880 	retval = usb_submit_urb(urb, GFP_ATOMIC);
881 	if (retval) {
882 		dev_err(&port->dev,
883 			"%s - usb_submit_urb failed with result %d\n",
884 			__func__, retval);
885 	}
886 }
887 
888 static void pl2303_process_read_urb(struct urb *urb)
889 {
890 	struct usb_serial_port *port = urb->context;
891 	struct pl2303_private *priv = usb_get_serial_port_data(port);
892 	unsigned char *data = urb->transfer_buffer;
893 	char tty_flag = TTY_NORMAL;
894 	unsigned long flags;
895 	u8 line_status;
896 	int i;
897 
898 	/* update line status */
899 	spin_lock_irqsave(&priv->lock, flags);
900 	line_status = priv->line_status;
901 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
902 	spin_unlock_irqrestore(&priv->lock, flags);
903 
904 	if (!urb->actual_length)
905 		return;
906 
907 	/*
908 	 * Break takes precedence over parity, which takes precedence over
909 	 * framing errors.
910 	 */
911 	if (line_status & UART_BREAK_ERROR)
912 		tty_flag = TTY_BREAK;
913 	else if (line_status & UART_PARITY_ERROR)
914 		tty_flag = TTY_PARITY;
915 	else if (line_status & UART_FRAME_ERROR)
916 		tty_flag = TTY_FRAME;
917 
918 	if (tty_flag != TTY_NORMAL)
919 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
920 								tty_flag);
921 	/* overrun is special, not associated with a char */
922 	if (line_status & UART_OVERRUN_ERROR)
923 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
924 
925 	if (port->port.console && port->sysrq) {
926 		for (i = 0; i < urb->actual_length; ++i)
927 			if (!usb_serial_handle_sysrq_char(port, data[i]))
928 				tty_insert_flip_char(&port->port, data[i],
929 						tty_flag);
930 	} else {
931 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
932 							urb->actual_length);
933 	}
934 
935 	tty_flip_buffer_push(&port->port);
936 }
937 
938 static struct usb_serial_driver pl2303_device = {
939 	.driver = {
940 		.owner =	THIS_MODULE,
941 		.name =		"pl2303",
942 	},
943 	.id_table =		id_table,
944 	.num_ports =		1,
945 	.bulk_in_size =		256,
946 	.bulk_out_size =	256,
947 	.open =			pl2303_open,
948 	.close =		pl2303_close,
949 	.dtr_rts =		pl2303_dtr_rts,
950 	.carrier_raised =	pl2303_carrier_raised,
951 	.ioctl =		pl2303_ioctl,
952 	.break_ctl =		pl2303_break_ctl,
953 	.set_termios =		pl2303_set_termios,
954 	.tiocmget =		pl2303_tiocmget,
955 	.tiocmset =		pl2303_tiocmset,
956 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
957 	.process_read_urb =	pl2303_process_read_urb,
958 	.read_int_callback =	pl2303_read_int_callback,
959 	.probe =		pl2303_probe,
960 	.attach =		pl2303_startup,
961 	.release =		pl2303_release,
962 	.port_probe =		pl2303_port_probe,
963 	.port_remove =		pl2303_port_remove,
964 };
965 
966 static struct usb_serial_driver * const serial_drivers[] = {
967 	&pl2303_device, NULL
968 };
969 
970 module_usb_serial_driver(serial_drivers, id_table);
971 
972 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
973 MODULE_LICENSE("GPL");
974