xref: /linux/drivers/usb/serial/pl2303.c (revision 5fd54ace4721fc5ce2bb5aef6318fcf17f421460)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Prolific PL2303 USB to serial adaptor driver
4  *
5  * Copyright (C) 2001-2007 Greg Kroah-Hartman (greg@kroah.com)
6  * Copyright (C) 2003 IBM Corp.
7  *
8  * Original driver for 2.2.x by anonymous
9  *
10  *	This program is free software; you can redistribute it and/or
11  *	modify it under the terms of the GNU General Public License version
12  *	2 as published by the Free Software Foundation.
13  *
14  * See Documentation/usb/usb-serial.txt for more information on using this
15  * driver
16  */
17 
18 #include <linux/kernel.h>
19 #include <linux/errno.h>
20 #include <linux/slab.h>
21 #include <linux/tty.h>
22 #include <linux/tty_driver.h>
23 #include <linux/tty_flip.h>
24 #include <linux/serial.h>
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/spinlock.h>
28 #include <linux/uaccess.h>
29 #include <linux/usb.h>
30 #include <linux/usb/serial.h>
31 #include <asm/unaligned.h>
32 #include "pl2303.h"
33 
34 
35 #define PL2303_QUIRK_UART_STATE_IDX0		BIT(0)
36 #define PL2303_QUIRK_LEGACY			BIT(1)
37 #define PL2303_QUIRK_ENDPOINT_HACK		BIT(2)
38 
39 static const struct usb_device_id id_table[] = {
40 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID),
41 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
42 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ2) },
43 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_DCU11) },
44 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ3) },
45 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_PHAROS) },
46 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ALDIGA) },
47 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MMX) },
48 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GPRS) },
49 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_HCR331) },
50 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MOTOROLA) },
51 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ZTEK) },
52 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
53 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID_RSAQ5) },
54 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID),
55 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
56 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC485),
57 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
58 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID2) },
59 	{ USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
60 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
61 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
62 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
63 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
64 	{ USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
65 	{ USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
66 	{ USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
67 	{ USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
68 	{ USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
69 	{ USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
70 	{ USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_PRODUCT_ID) },
71 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1),
72 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
73 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65),
74 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
75 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75),
76 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
77 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_EF81),
78 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
79 	{ USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_ID_S81) }, /* Benq/Siemens S81 */
80 	{ USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
81 	{ USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
82 	{ USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
83 	{ USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
84 	{ USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
85 	{ USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
86 	{ USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
87 	{ USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
88 	{ USB_DEVICE(ALCOR_VENDOR_ID, ALCOR_PRODUCT_ID),
89 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
90 	{ USB_DEVICE(WS002IN_VENDOR_ID, WS002IN_PRODUCT_ID) },
91 	{ USB_DEVICE(COREGA_VENDOR_ID, COREGA_PRODUCT_ID) },
92 	{ USB_DEVICE(YCCABLE_VENDOR_ID, YCCABLE_PRODUCT_ID) },
93 	{ USB_DEVICE(SUPERIAL_VENDOR_ID, SUPERIAL_PRODUCT_ID) },
94 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220_PRODUCT_ID) },
95 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
96 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
97 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
98 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
99 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
100 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
101 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
102 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
103 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
104 	{ }					/* Terminating entry */
105 };
106 
107 MODULE_DEVICE_TABLE(usb, id_table);
108 
109 #define SET_LINE_REQUEST_TYPE		0x21
110 #define SET_LINE_REQUEST		0x20
111 
112 #define SET_CONTROL_REQUEST_TYPE	0x21
113 #define SET_CONTROL_REQUEST		0x22
114 #define CONTROL_DTR			0x01
115 #define CONTROL_RTS			0x02
116 
117 #define BREAK_REQUEST_TYPE		0x21
118 #define BREAK_REQUEST			0x23
119 #define BREAK_ON			0xffff
120 #define BREAK_OFF			0x0000
121 
122 #define GET_LINE_REQUEST_TYPE		0xa1
123 #define GET_LINE_REQUEST		0x21
124 
125 #define VENDOR_WRITE_REQUEST_TYPE	0x40
126 #define VENDOR_WRITE_REQUEST		0x01
127 
128 #define VENDOR_READ_REQUEST_TYPE	0xc0
129 #define VENDOR_READ_REQUEST		0x01
130 
131 #define UART_STATE_INDEX		8
132 #define UART_STATE_MSR_MASK		0x8b
133 #define UART_STATE_TRANSIENT_MASK	0x74
134 #define UART_DCD			0x01
135 #define UART_DSR			0x02
136 #define UART_BREAK_ERROR		0x04
137 #define UART_RING			0x08
138 #define UART_FRAME_ERROR		0x10
139 #define UART_PARITY_ERROR		0x20
140 #define UART_OVERRUN_ERROR		0x40
141 #define UART_CTS			0x80
142 
143 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
144 
145 enum pl2303_type {
146 	TYPE_01,	/* Type 0 and 1 (difference unknown) */
147 	TYPE_HX,	/* HX version of the pl2303 chip */
148 	TYPE_COUNT
149 };
150 
151 struct pl2303_type_data {
152 	speed_t max_baud_rate;
153 	unsigned long quirks;
154 };
155 
156 struct pl2303_serial_private {
157 	const struct pl2303_type_data *type;
158 	unsigned long quirks;
159 };
160 
161 struct pl2303_private {
162 	spinlock_t lock;
163 	u8 line_control;
164 	u8 line_status;
165 
166 	u8 line_settings[7];
167 };
168 
169 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
170 	[TYPE_01] = {
171 		.max_baud_rate =	1228800,
172 		.quirks =		PL2303_QUIRK_LEGACY,
173 	},
174 	[TYPE_HX] = {
175 		.max_baud_rate =	12000000,
176 	},
177 };
178 
179 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
180 							unsigned char buf[1])
181 {
182 	struct device *dev = &serial->interface->dev;
183 	int res;
184 
185 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
186 			VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
187 			value, 0, buf, 1, 100);
188 	if (res != 1) {
189 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
190 								value, res);
191 		if (res >= 0)
192 			res = -EIO;
193 
194 		return res;
195 	}
196 
197 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
198 
199 	return 0;
200 }
201 
202 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
203 {
204 	struct device *dev = &serial->interface->dev;
205 	int res;
206 
207 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
208 
209 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
210 			VENDOR_WRITE_REQUEST, VENDOR_WRITE_REQUEST_TYPE,
211 			value, index, NULL, 0, 100);
212 	if (res) {
213 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
214 								value, res);
215 		return res;
216 	}
217 
218 	return 0;
219 }
220 
221 static int pl2303_probe(struct usb_serial *serial,
222 					const struct usb_device_id *id)
223 {
224 	usb_set_serial_data(serial, (void *)id->driver_info);
225 
226 	return 0;
227 }
228 
229 /*
230  * Use interrupt endpoint from first interface if available.
231  *
232  * This is needed due to the looney way its endpoints are set up.
233  */
234 static int pl2303_endpoint_hack(struct usb_serial *serial,
235 					struct usb_serial_endpoints *epds)
236 {
237 	struct usb_interface *interface = serial->interface;
238 	struct usb_device *dev = serial->dev;
239 	struct device *ddev = &interface->dev;
240 	struct usb_host_interface *iface_desc;
241 	struct usb_endpoint_descriptor *endpoint;
242 	unsigned int i;
243 
244 	if (interface == dev->actconfig->interface[0])
245 		return 0;
246 
247 	/* check out the endpoints of the other interface */
248 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
249 
250 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
251 		endpoint = &iface_desc->endpoint[i].desc;
252 
253 		if (!usb_endpoint_is_int_in(endpoint))
254 			continue;
255 
256 		dev_dbg(ddev, "found interrupt in on separate interface\n");
257 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
258 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
259 	}
260 
261 	return 0;
262 }
263 
264 static int pl2303_calc_num_ports(struct usb_serial *serial,
265 					struct usb_serial_endpoints *epds)
266 {
267 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
268 	struct device *dev = &serial->interface->dev;
269 	int ret;
270 
271 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
272 		ret = pl2303_endpoint_hack(serial, epds);
273 		if (ret)
274 			return ret;
275 	}
276 
277 	if (epds->num_interrupt_in < 1) {
278 		dev_err(dev, "required interrupt-in endpoint missing\n");
279 		return -ENODEV;
280 	}
281 
282 	return 1;
283 }
284 
285 static int pl2303_startup(struct usb_serial *serial)
286 {
287 	struct pl2303_serial_private *spriv;
288 	enum pl2303_type type = TYPE_01;
289 	unsigned char *buf;
290 
291 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
292 	if (!spriv)
293 		return -ENOMEM;
294 
295 	buf = kmalloc(1, GFP_KERNEL);
296 	if (!buf) {
297 		kfree(spriv);
298 		return -ENOMEM;
299 	}
300 
301 	if (serial->dev->descriptor.bDeviceClass == 0x02)
302 		type = TYPE_01;		/* type 0 */
303 	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
304 		type = TYPE_HX;
305 	else if (serial->dev->descriptor.bDeviceClass == 0x00)
306 		type = TYPE_01;		/* type 1 */
307 	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
308 		type = TYPE_01;		/* type 1 */
309 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
310 
311 	spriv->type = &pl2303_type_data[type];
312 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
313 	spriv->quirks |= spriv->type->quirks;
314 
315 	usb_set_serial_data(serial, spriv);
316 
317 	pl2303_vendor_read(serial, 0x8484, buf);
318 	pl2303_vendor_write(serial, 0x0404, 0);
319 	pl2303_vendor_read(serial, 0x8484, buf);
320 	pl2303_vendor_read(serial, 0x8383, buf);
321 	pl2303_vendor_read(serial, 0x8484, buf);
322 	pl2303_vendor_write(serial, 0x0404, 1);
323 	pl2303_vendor_read(serial, 0x8484, buf);
324 	pl2303_vendor_read(serial, 0x8383, buf);
325 	pl2303_vendor_write(serial, 0, 1);
326 	pl2303_vendor_write(serial, 1, 0);
327 	if (spriv->quirks & PL2303_QUIRK_LEGACY)
328 		pl2303_vendor_write(serial, 2, 0x24);
329 	else
330 		pl2303_vendor_write(serial, 2, 0x44);
331 
332 	kfree(buf);
333 
334 	return 0;
335 }
336 
337 static void pl2303_release(struct usb_serial *serial)
338 {
339 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
340 
341 	kfree(spriv);
342 }
343 
344 static int pl2303_port_probe(struct usb_serial_port *port)
345 {
346 	struct pl2303_private *priv;
347 
348 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
349 	if (!priv)
350 		return -ENOMEM;
351 
352 	spin_lock_init(&priv->lock);
353 
354 	usb_set_serial_port_data(port, priv);
355 
356 	port->port.drain_delay = 256;
357 
358 	return 0;
359 }
360 
361 static int pl2303_port_remove(struct usb_serial_port *port)
362 {
363 	struct pl2303_private *priv = usb_get_serial_port_data(port);
364 
365 	kfree(priv);
366 
367 	return 0;
368 }
369 
370 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
371 {
372 	struct usb_device *dev = port->serial->dev;
373 	int retval;
374 
375 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
376 
377 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
378 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
379 				 value, 0, NULL, 0, 100);
380 	if (retval)
381 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
382 
383 	return retval;
384 }
385 
386 /*
387  * Returns the nearest supported baud rate that can be set directly without
388  * using divisors.
389  */
390 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
391 {
392 	static const speed_t baud_sup[] = {
393 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
394 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
395 		614400, 921600, 1228800, 2457600, 3000000, 6000000
396 	};
397 
398 	unsigned i;
399 
400 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
401 		if (baud_sup[i] > baud)
402 			break;
403 	}
404 
405 	if (i == ARRAY_SIZE(baud_sup))
406 		baud = baud_sup[i - 1];
407 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
408 		baud = baud_sup[i - 1];
409 	else
410 		baud = baud_sup[i];
411 
412 	return baud;
413 }
414 
415 /*
416  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
417  *       use 9600 baud.
418  */
419 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
420 								speed_t baud)
421 {
422 	put_unaligned_le32(baud, buf);
423 
424 	return baud;
425 }
426 
427 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
428 								speed_t baud)
429 {
430 	unsigned int baseline, mantissa, exponent;
431 
432 	/*
433 	 * Apparently the formula is:
434 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
435 	 * where
436 	 *   mantissa = buf[8:0]
437 	 *   exponent = buf[11:9]
438 	 */
439 	baseline = 12000000 * 32;
440 	mantissa = baseline / baud;
441 	if (mantissa == 0)
442 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
443 	exponent = 0;
444 	while (mantissa >= 512) {
445 		if (exponent < 7) {
446 			mantissa >>= 2;	/* divide by 4 */
447 			exponent++;
448 		} else {
449 			/* Exponent is maxed. Trim mantissa and leave. */
450 			mantissa = 511;
451 			break;
452 		}
453 	}
454 
455 	buf[3] = 0x80;
456 	buf[2] = 0;
457 	buf[1] = exponent << 1 | mantissa >> 8;
458 	buf[0] = mantissa & 0xff;
459 
460 	/* Calculate and return the exact baud rate. */
461 	baud = (baseline / mantissa) >> (exponent << 1);
462 
463 	return baud;
464 }
465 
466 static void pl2303_encode_baud_rate(struct tty_struct *tty,
467 					struct usb_serial_port *port,
468 					u8 buf[4])
469 {
470 	struct usb_serial *serial = port->serial;
471 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
472 	speed_t	baud_sup;
473 	speed_t baud;
474 
475 	baud = tty_get_baud_rate(tty);
476 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
477 	if (!baud)
478 		return;
479 
480 	if (spriv->type->max_baud_rate)
481 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
482 	/*
483 	 * Use direct method for supported baud rates, otherwise use divisors.
484 	 */
485 	baud_sup = pl2303_get_supported_baud_rate(baud);
486 
487 	if (baud == baud_sup)
488 		baud = pl2303_encode_baud_rate_direct(buf, baud);
489 	else
490 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
491 
492 	/* Save resulting baud rate */
493 	tty_encode_baud_rate(tty, baud, baud);
494 	dev_dbg(&port->dev, "baud set = %u\n", baud);
495 }
496 
497 static int pl2303_get_line_request(struct usb_serial_port *port,
498 							unsigned char buf[7])
499 {
500 	struct usb_device *udev = port->serial->dev;
501 	int ret;
502 
503 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
504 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
505 				0, 0, buf, 7, 100);
506 	if (ret != 7) {
507 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
508 
509 		if (ret >= 0)
510 			ret = -EIO;
511 
512 		return ret;
513 	}
514 
515 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
516 
517 	return 0;
518 }
519 
520 static int pl2303_set_line_request(struct usb_serial_port *port,
521 							unsigned char buf[7])
522 {
523 	struct usb_device *udev = port->serial->dev;
524 	int ret;
525 
526 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
527 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
528 				0, 0, buf, 7, 100);
529 	if (ret < 0) {
530 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
531 		return ret;
532 	}
533 
534 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
535 
536 	return 0;
537 }
538 
539 static void pl2303_set_termios(struct tty_struct *tty,
540 		struct usb_serial_port *port, struct ktermios *old_termios)
541 {
542 	struct usb_serial *serial = port->serial;
543 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
544 	struct pl2303_private *priv = usb_get_serial_port_data(port);
545 	unsigned long flags;
546 	unsigned char *buf;
547 	int ret;
548 	u8 control;
549 
550 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
551 		return;
552 
553 	buf = kzalloc(7, GFP_KERNEL);
554 	if (!buf) {
555 		/* Report back no change occurred */
556 		if (old_termios)
557 			tty->termios = *old_termios;
558 		return;
559 	}
560 
561 	pl2303_get_line_request(port, buf);
562 
563 	switch (C_CSIZE(tty)) {
564 	case CS5:
565 		buf[6] = 5;
566 		break;
567 	case CS6:
568 		buf[6] = 6;
569 		break;
570 	case CS7:
571 		buf[6] = 7;
572 		break;
573 	default:
574 	case CS8:
575 		buf[6] = 8;
576 	}
577 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
578 
579 	/* For reference buf[0]:buf[3] baud rate value */
580 	pl2303_encode_baud_rate(tty, port, &buf[0]);
581 
582 	/* For reference buf[4]=0 is 1 stop bits */
583 	/* For reference buf[4]=1 is 1.5 stop bits */
584 	/* For reference buf[4]=2 is 2 stop bits */
585 	if (C_CSTOPB(tty)) {
586 		/*
587 		 * NOTE: Comply with "real" UARTs / RS232:
588 		 *       use 1.5 instead of 2 stop bits with 5 data bits
589 		 */
590 		if (C_CSIZE(tty) == CS5) {
591 			buf[4] = 1;
592 			dev_dbg(&port->dev, "stop bits = 1.5\n");
593 		} else {
594 			buf[4] = 2;
595 			dev_dbg(&port->dev, "stop bits = 2\n");
596 		}
597 	} else {
598 		buf[4] = 0;
599 		dev_dbg(&port->dev, "stop bits = 1\n");
600 	}
601 
602 	if (C_PARENB(tty)) {
603 		/* For reference buf[5]=0 is none parity */
604 		/* For reference buf[5]=1 is odd parity */
605 		/* For reference buf[5]=2 is even parity */
606 		/* For reference buf[5]=3 is mark parity */
607 		/* For reference buf[5]=4 is space parity */
608 		if (C_PARODD(tty)) {
609 			if (C_CMSPAR(tty)) {
610 				buf[5] = 3;
611 				dev_dbg(&port->dev, "parity = mark\n");
612 			} else {
613 				buf[5] = 1;
614 				dev_dbg(&port->dev, "parity = odd\n");
615 			}
616 		} else {
617 			if (C_CMSPAR(tty)) {
618 				buf[5] = 4;
619 				dev_dbg(&port->dev, "parity = space\n");
620 			} else {
621 				buf[5] = 2;
622 				dev_dbg(&port->dev, "parity = even\n");
623 			}
624 		}
625 	} else {
626 		buf[5] = 0;
627 		dev_dbg(&port->dev, "parity = none\n");
628 	}
629 
630 	/*
631 	 * Some PL2303 are known to lose bytes if you change serial settings
632 	 * even to the same values as before. Thus we actually need to filter
633 	 * in this specific case.
634 	 *
635 	 * Note that the tty_termios_hw_change check above is not sufficient
636 	 * as a previously requested baud rate may differ from the one
637 	 * actually used (and stored in old_termios).
638 	 *
639 	 * NOTE: No additional locking needed for line_settings as it is
640 	 *       only used in set_termios, which is serialised against itself.
641 	 */
642 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
643 		ret = pl2303_set_line_request(port, buf);
644 		if (!ret)
645 			memcpy(priv->line_settings, buf, 7);
646 	}
647 
648 	/* change control lines if we are switching to or from B0 */
649 	spin_lock_irqsave(&priv->lock, flags);
650 	control = priv->line_control;
651 	if (C_BAUD(tty) == B0)
652 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
653 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
654 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
655 	if (control != priv->line_control) {
656 		control = priv->line_control;
657 		spin_unlock_irqrestore(&priv->lock, flags);
658 		pl2303_set_control_lines(port, control);
659 	} else {
660 		spin_unlock_irqrestore(&priv->lock, flags);
661 	}
662 
663 	if (C_CRTSCTS(tty)) {
664 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
665 			pl2303_vendor_write(serial, 0x0, 0x41);
666 		else
667 			pl2303_vendor_write(serial, 0x0, 0x61);
668 	} else {
669 		pl2303_vendor_write(serial, 0x0, 0x0);
670 	}
671 
672 	kfree(buf);
673 }
674 
675 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
676 {
677 	struct pl2303_private *priv = usb_get_serial_port_data(port);
678 	unsigned long flags;
679 	u8 control;
680 
681 	spin_lock_irqsave(&priv->lock, flags);
682 	if (on)
683 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
684 	else
685 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
686 	control = priv->line_control;
687 	spin_unlock_irqrestore(&priv->lock, flags);
688 
689 	pl2303_set_control_lines(port, control);
690 }
691 
692 static void pl2303_close(struct usb_serial_port *port)
693 {
694 	usb_serial_generic_close(port);
695 	usb_kill_urb(port->interrupt_in_urb);
696 	pl2303_set_break(port, false);
697 }
698 
699 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
700 {
701 	struct usb_serial *serial = port->serial;
702 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
703 	int result;
704 
705 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
706 		usb_clear_halt(serial->dev, port->write_urb->pipe);
707 		usb_clear_halt(serial->dev, port->read_urb->pipe);
708 	} else {
709 		/* reset upstream data pipes */
710 		pl2303_vendor_write(serial, 8, 0);
711 		pl2303_vendor_write(serial, 9, 0);
712 	}
713 
714 	/* Setup termios */
715 	if (tty)
716 		pl2303_set_termios(tty, port, NULL);
717 
718 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
719 	if (result) {
720 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
721 			result);
722 		return result;
723 	}
724 
725 	result = usb_serial_generic_open(tty, port);
726 	if (result) {
727 		usb_kill_urb(port->interrupt_in_urb);
728 		return result;
729 	}
730 
731 	return 0;
732 }
733 
734 static int pl2303_tiocmset(struct tty_struct *tty,
735 			   unsigned int set, unsigned int clear)
736 {
737 	struct usb_serial_port *port = tty->driver_data;
738 	struct pl2303_private *priv = usb_get_serial_port_data(port);
739 	unsigned long flags;
740 	u8 control;
741 	int ret;
742 
743 	spin_lock_irqsave(&priv->lock, flags);
744 	if (set & TIOCM_RTS)
745 		priv->line_control |= CONTROL_RTS;
746 	if (set & TIOCM_DTR)
747 		priv->line_control |= CONTROL_DTR;
748 	if (clear & TIOCM_RTS)
749 		priv->line_control &= ~CONTROL_RTS;
750 	if (clear & TIOCM_DTR)
751 		priv->line_control &= ~CONTROL_DTR;
752 	control = priv->line_control;
753 	spin_unlock_irqrestore(&priv->lock, flags);
754 
755 	ret = pl2303_set_control_lines(port, control);
756 	if (ret)
757 		return usb_translate_errors(ret);
758 
759 	return 0;
760 }
761 
762 static int pl2303_tiocmget(struct tty_struct *tty)
763 {
764 	struct usb_serial_port *port = tty->driver_data;
765 	struct pl2303_private *priv = usb_get_serial_port_data(port);
766 	unsigned long flags;
767 	unsigned int mcr;
768 	unsigned int status;
769 	unsigned int result;
770 
771 	spin_lock_irqsave(&priv->lock, flags);
772 	mcr = priv->line_control;
773 	status = priv->line_status;
774 	spin_unlock_irqrestore(&priv->lock, flags);
775 
776 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
777 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
778 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
779 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
780 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
781 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
782 
783 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
784 
785 	return result;
786 }
787 
788 static int pl2303_carrier_raised(struct usb_serial_port *port)
789 {
790 	struct pl2303_private *priv = usb_get_serial_port_data(port);
791 
792 	if (priv->line_status & UART_DCD)
793 		return 1;
794 
795 	return 0;
796 }
797 
798 static int pl2303_ioctl(struct tty_struct *tty,
799 			unsigned int cmd, unsigned long arg)
800 {
801 	struct serial_struct ser;
802 	struct usb_serial_port *port = tty->driver_data;
803 
804 	switch (cmd) {
805 	case TIOCGSERIAL:
806 		memset(&ser, 0, sizeof ser);
807 		ser.type = PORT_16654;
808 		ser.line = port->minor;
809 		ser.port = port->port_number;
810 		ser.baud_base = 460800;
811 
812 		if (copy_to_user((void __user *)arg, &ser, sizeof ser))
813 			return -EFAULT;
814 
815 		return 0;
816 	default:
817 		break;
818 	}
819 
820 	return -ENOIOCTLCMD;
821 }
822 
823 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
824 {
825 	struct usb_serial *serial = port->serial;
826 	u16 state;
827 	int result;
828 
829 	if (enable)
830 		state = BREAK_ON;
831 	else
832 		state = BREAK_OFF;
833 
834 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
835 			state == BREAK_OFF ? "off" : "on");
836 
837 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
838 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
839 				 0, NULL, 0, 100);
840 	if (result)
841 		dev_err(&port->dev, "error sending break = %d\n", result);
842 }
843 
844 static void pl2303_break_ctl(struct tty_struct *tty, int state)
845 {
846 	struct usb_serial_port *port = tty->driver_data;
847 
848 	pl2303_set_break(port, state);
849 }
850 
851 static void pl2303_update_line_status(struct usb_serial_port *port,
852 				      unsigned char *data,
853 				      unsigned int actual_length)
854 {
855 	struct usb_serial *serial = port->serial;
856 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
857 	struct pl2303_private *priv = usb_get_serial_port_data(port);
858 	struct tty_struct *tty;
859 	unsigned long flags;
860 	unsigned int status_idx = UART_STATE_INDEX;
861 	u8 status;
862 	u8 delta;
863 
864 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
865 		status_idx = 0;
866 
867 	if (actual_length < status_idx + 1)
868 		return;
869 
870 	status = data[status_idx];
871 
872 	/* Save off the uart status for others to look at */
873 	spin_lock_irqsave(&priv->lock, flags);
874 	delta = priv->line_status ^ status;
875 	priv->line_status = status;
876 	spin_unlock_irqrestore(&priv->lock, flags);
877 
878 	if (status & UART_BREAK_ERROR)
879 		usb_serial_handle_break(port);
880 
881 	if (delta & UART_STATE_MSR_MASK) {
882 		if (delta & UART_CTS)
883 			port->icount.cts++;
884 		if (delta & UART_DSR)
885 			port->icount.dsr++;
886 		if (delta & UART_RING)
887 			port->icount.rng++;
888 		if (delta & UART_DCD) {
889 			port->icount.dcd++;
890 			tty = tty_port_tty_get(&port->port);
891 			if (tty) {
892 				usb_serial_handle_dcd_change(port, tty,
893 							status & UART_DCD);
894 				tty_kref_put(tty);
895 			}
896 		}
897 
898 		wake_up_interruptible(&port->port.delta_msr_wait);
899 	}
900 }
901 
902 static void pl2303_read_int_callback(struct urb *urb)
903 {
904 	struct usb_serial_port *port =  urb->context;
905 	unsigned char *data = urb->transfer_buffer;
906 	unsigned int actual_length = urb->actual_length;
907 	int status = urb->status;
908 	int retval;
909 
910 	switch (status) {
911 	case 0:
912 		/* success */
913 		break;
914 	case -ECONNRESET:
915 	case -ENOENT:
916 	case -ESHUTDOWN:
917 		/* this urb is terminated, clean up */
918 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
919 			__func__, status);
920 		return;
921 	default:
922 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
923 			__func__, status);
924 		goto exit;
925 	}
926 
927 	usb_serial_debug_data(&port->dev, __func__,
928 			      urb->actual_length, urb->transfer_buffer);
929 
930 	pl2303_update_line_status(port, data, actual_length);
931 
932 exit:
933 	retval = usb_submit_urb(urb, GFP_ATOMIC);
934 	if (retval) {
935 		dev_err(&port->dev,
936 			"%s - usb_submit_urb failed with result %d\n",
937 			__func__, retval);
938 	}
939 }
940 
941 static void pl2303_process_read_urb(struct urb *urb)
942 {
943 	struct usb_serial_port *port = urb->context;
944 	struct pl2303_private *priv = usb_get_serial_port_data(port);
945 	unsigned char *data = urb->transfer_buffer;
946 	char tty_flag = TTY_NORMAL;
947 	unsigned long flags;
948 	u8 line_status;
949 	int i;
950 
951 	/* update line status */
952 	spin_lock_irqsave(&priv->lock, flags);
953 	line_status = priv->line_status;
954 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
955 	spin_unlock_irqrestore(&priv->lock, flags);
956 
957 	if (!urb->actual_length)
958 		return;
959 
960 	/*
961 	 * Break takes precedence over parity, which takes precedence over
962 	 * framing errors.
963 	 */
964 	if (line_status & UART_BREAK_ERROR)
965 		tty_flag = TTY_BREAK;
966 	else if (line_status & UART_PARITY_ERROR)
967 		tty_flag = TTY_PARITY;
968 	else if (line_status & UART_FRAME_ERROR)
969 		tty_flag = TTY_FRAME;
970 
971 	if (tty_flag != TTY_NORMAL)
972 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
973 								tty_flag);
974 	/* overrun is special, not associated with a char */
975 	if (line_status & UART_OVERRUN_ERROR)
976 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
977 
978 	if (port->port.console && port->sysrq) {
979 		for (i = 0; i < urb->actual_length; ++i)
980 			if (!usb_serial_handle_sysrq_char(port, data[i]))
981 				tty_insert_flip_char(&port->port, data[i],
982 						tty_flag);
983 	} else {
984 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
985 							urb->actual_length);
986 	}
987 
988 	tty_flip_buffer_push(&port->port);
989 }
990 
991 static struct usb_serial_driver pl2303_device = {
992 	.driver = {
993 		.owner =	THIS_MODULE,
994 		.name =		"pl2303",
995 	},
996 	.id_table =		id_table,
997 	.num_bulk_in =		1,
998 	.num_bulk_out =		1,
999 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
1000 	.bulk_in_size =		256,
1001 	.bulk_out_size =	256,
1002 	.open =			pl2303_open,
1003 	.close =		pl2303_close,
1004 	.dtr_rts =		pl2303_dtr_rts,
1005 	.carrier_raised =	pl2303_carrier_raised,
1006 	.ioctl =		pl2303_ioctl,
1007 	.break_ctl =		pl2303_break_ctl,
1008 	.set_termios =		pl2303_set_termios,
1009 	.tiocmget =		pl2303_tiocmget,
1010 	.tiocmset =		pl2303_tiocmset,
1011 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1012 	.process_read_urb =	pl2303_process_read_urb,
1013 	.read_int_callback =	pl2303_read_int_callback,
1014 	.probe =		pl2303_probe,
1015 	.calc_num_ports =	pl2303_calc_num_ports,
1016 	.attach =		pl2303_startup,
1017 	.release =		pl2303_release,
1018 	.port_probe =		pl2303_port_probe,
1019 	.port_remove =		pl2303_port_remove,
1020 };
1021 
1022 static struct usb_serial_driver * const serial_drivers[] = {
1023 	&pl2303_device, NULL
1024 };
1025 
1026 module_usb_serial_driver(serial_drivers, id_table);
1027 
1028 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1029 MODULE_LICENSE("GPL");
1030