xref: /linux/drivers/usb/serial/pl2303.c (revision bd628c1bed7902ec1f24ba0fe70758949146abbe)
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  * See Documentation/usb/usb-serial.txt for more information on using this
11  * driver
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/tty.h>
18 #include <linux/tty_driver.h>
19 #include <linux/tty_flip.h>
20 #include <linux/serial.h>
21 #include <linux/module.h>
22 #include <linux/moduleparam.h>
23 #include <linux/spinlock.h>
24 #include <linux/uaccess.h>
25 #include <linux/usb.h>
26 #include <linux/usb/serial.h>
27 #include <asm/unaligned.h>
28 #include "pl2303.h"
29 
30 
31 #define PL2303_QUIRK_UART_STATE_IDX0		BIT(0)
32 #define PL2303_QUIRK_LEGACY			BIT(1)
33 #define PL2303_QUIRK_ENDPOINT_HACK		BIT(2)
34 
35 static const struct usb_device_id id_table[] = {
36 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID),
37 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
38 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ2) },
39 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_DCU11) },
40 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ3) },
41 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_CHILITAG) },
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 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
53 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC485),
54 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
55 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC232B),
56 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
57 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID2) },
58 	{ USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
59 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
60 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
61 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
62 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
63 	{ USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
64 	{ USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
65 	{ USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
66 	{ USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
67 	{ USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
68 	{ USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
69 	{ USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_PRODUCT_ID) },
70 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1),
71 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
72 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65),
73 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
74 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75),
75 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
76 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_EF81),
77 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
78 	{ USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_ID_S81) }, /* Benq/Siemens S81 */
79 	{ USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
80 	{ USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
81 	{ USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
82 	{ USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
83 	{ USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
84 	{ USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
85 	{ USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
86 	{ USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
87 	{ USB_DEVICE(ALCOR_VENDOR_ID, ALCOR_PRODUCT_ID),
88 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
89 	{ USB_DEVICE(WS002IN_VENDOR_ID, WS002IN_PRODUCT_ID) },
90 	{ USB_DEVICE(COREGA_VENDOR_ID, COREGA_PRODUCT_ID) },
91 	{ USB_DEVICE(YCCABLE_VENDOR_ID, YCCABLE_PRODUCT_ID) },
92 	{ USB_DEVICE(SUPERIAL_VENDOR_ID, SUPERIAL_PRODUCT_ID) },
93 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220_PRODUCT_ID) },
94 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220TA_PRODUCT_ID) },
95 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
96 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960TA_PRODUCT_ID) },
97 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
98 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
99 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM920_PRODUCT_ID) },
100 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM940_PRODUCT_ID) },
101 	{ USB_DEVICE(HP_VENDOR_ID, HP_TD620_PRODUCT_ID) },
102 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
103 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
104 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
105 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
106 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
107 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
108 	{ }					/* Terminating entry */
109 };
110 
111 MODULE_DEVICE_TABLE(usb, id_table);
112 
113 #define SET_LINE_REQUEST_TYPE		0x21
114 #define SET_LINE_REQUEST		0x20
115 
116 #define SET_CONTROL_REQUEST_TYPE	0x21
117 #define SET_CONTROL_REQUEST		0x22
118 #define CONTROL_DTR			0x01
119 #define CONTROL_RTS			0x02
120 
121 #define BREAK_REQUEST_TYPE		0x21
122 #define BREAK_REQUEST			0x23
123 #define BREAK_ON			0xffff
124 #define BREAK_OFF			0x0000
125 
126 #define GET_LINE_REQUEST_TYPE		0xa1
127 #define GET_LINE_REQUEST		0x21
128 
129 #define VENDOR_WRITE_REQUEST_TYPE	0x40
130 #define VENDOR_WRITE_REQUEST		0x01
131 
132 #define VENDOR_READ_REQUEST_TYPE	0xc0
133 #define VENDOR_READ_REQUEST		0x01
134 
135 #define UART_STATE_INDEX		8
136 #define UART_STATE_MSR_MASK		0x8b
137 #define UART_STATE_TRANSIENT_MASK	0x74
138 #define UART_DCD			0x01
139 #define UART_DSR			0x02
140 #define UART_BREAK_ERROR		0x04
141 #define UART_RING			0x08
142 #define UART_FRAME_ERROR		0x10
143 #define UART_PARITY_ERROR		0x20
144 #define UART_OVERRUN_ERROR		0x40
145 #define UART_CTS			0x80
146 
147 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
148 
149 enum pl2303_type {
150 	TYPE_01,	/* Type 0 and 1 (difference unknown) */
151 	TYPE_HX,	/* HX version of the pl2303 chip */
152 	TYPE_COUNT
153 };
154 
155 struct pl2303_type_data {
156 	speed_t max_baud_rate;
157 	unsigned long quirks;
158 };
159 
160 struct pl2303_serial_private {
161 	const struct pl2303_type_data *type;
162 	unsigned long quirks;
163 };
164 
165 struct pl2303_private {
166 	spinlock_t lock;
167 	u8 line_control;
168 	u8 line_status;
169 
170 	u8 line_settings[7];
171 };
172 
173 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
174 	[TYPE_01] = {
175 		.max_baud_rate =	1228800,
176 		.quirks =		PL2303_QUIRK_LEGACY,
177 	},
178 	[TYPE_HX] = {
179 		.max_baud_rate =	12000000,
180 	},
181 };
182 
183 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
184 							unsigned char buf[1])
185 {
186 	struct device *dev = &serial->interface->dev;
187 	int res;
188 
189 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
190 			VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
191 			value, 0, buf, 1, 100);
192 	if (res != 1) {
193 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
194 								value, res);
195 		if (res >= 0)
196 			res = -EIO;
197 
198 		return res;
199 	}
200 
201 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
202 
203 	return 0;
204 }
205 
206 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
207 {
208 	struct device *dev = &serial->interface->dev;
209 	int res;
210 
211 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
212 
213 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
214 			VENDOR_WRITE_REQUEST, VENDOR_WRITE_REQUEST_TYPE,
215 			value, index, NULL, 0, 100);
216 	if (res) {
217 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
218 								value, res);
219 		return res;
220 	}
221 
222 	return 0;
223 }
224 
225 static int pl2303_probe(struct usb_serial *serial,
226 					const struct usb_device_id *id)
227 {
228 	usb_set_serial_data(serial, (void *)id->driver_info);
229 
230 	return 0;
231 }
232 
233 /*
234  * Use interrupt endpoint from first interface if available.
235  *
236  * This is needed due to the looney way its endpoints are set up.
237  */
238 static int pl2303_endpoint_hack(struct usb_serial *serial,
239 					struct usb_serial_endpoints *epds)
240 {
241 	struct usb_interface *interface = serial->interface;
242 	struct usb_device *dev = serial->dev;
243 	struct device *ddev = &interface->dev;
244 	struct usb_host_interface *iface_desc;
245 	struct usb_endpoint_descriptor *endpoint;
246 	unsigned int i;
247 
248 	if (interface == dev->actconfig->interface[0])
249 		return 0;
250 
251 	/* check out the endpoints of the other interface */
252 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
253 
254 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
255 		endpoint = &iface_desc->endpoint[i].desc;
256 
257 		if (!usb_endpoint_is_int_in(endpoint))
258 			continue;
259 
260 		dev_dbg(ddev, "found interrupt in on separate interface\n");
261 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
262 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
263 	}
264 
265 	return 0;
266 }
267 
268 static int pl2303_calc_num_ports(struct usb_serial *serial,
269 					struct usb_serial_endpoints *epds)
270 {
271 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
272 	struct device *dev = &serial->interface->dev;
273 	int ret;
274 
275 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
276 		ret = pl2303_endpoint_hack(serial, epds);
277 		if (ret)
278 			return ret;
279 	}
280 
281 	if (epds->num_interrupt_in < 1) {
282 		dev_err(dev, "required interrupt-in endpoint missing\n");
283 		return -ENODEV;
284 	}
285 
286 	return 1;
287 }
288 
289 static int pl2303_startup(struct usb_serial *serial)
290 {
291 	struct pl2303_serial_private *spriv;
292 	enum pl2303_type type = TYPE_01;
293 	unsigned char *buf;
294 
295 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
296 	if (!spriv)
297 		return -ENOMEM;
298 
299 	buf = kmalloc(1, GFP_KERNEL);
300 	if (!buf) {
301 		kfree(spriv);
302 		return -ENOMEM;
303 	}
304 
305 	if (serial->dev->descriptor.bDeviceClass == 0x02)
306 		type = TYPE_01;		/* type 0 */
307 	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
308 		type = TYPE_HX;
309 	else if (serial->dev->descriptor.bDeviceClass == 0x00)
310 		type = TYPE_01;		/* type 1 */
311 	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
312 		type = TYPE_01;		/* type 1 */
313 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
314 
315 	spriv->type = &pl2303_type_data[type];
316 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
317 	spriv->quirks |= spriv->type->quirks;
318 
319 	usb_set_serial_data(serial, spriv);
320 
321 	pl2303_vendor_read(serial, 0x8484, buf);
322 	pl2303_vendor_write(serial, 0x0404, 0);
323 	pl2303_vendor_read(serial, 0x8484, buf);
324 	pl2303_vendor_read(serial, 0x8383, buf);
325 	pl2303_vendor_read(serial, 0x8484, buf);
326 	pl2303_vendor_write(serial, 0x0404, 1);
327 	pl2303_vendor_read(serial, 0x8484, buf);
328 	pl2303_vendor_read(serial, 0x8383, buf);
329 	pl2303_vendor_write(serial, 0, 1);
330 	pl2303_vendor_write(serial, 1, 0);
331 	if (spriv->quirks & PL2303_QUIRK_LEGACY)
332 		pl2303_vendor_write(serial, 2, 0x24);
333 	else
334 		pl2303_vendor_write(serial, 2, 0x44);
335 
336 	kfree(buf);
337 
338 	return 0;
339 }
340 
341 static void pl2303_release(struct usb_serial *serial)
342 {
343 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
344 
345 	kfree(spriv);
346 }
347 
348 static int pl2303_port_probe(struct usb_serial_port *port)
349 {
350 	struct pl2303_private *priv;
351 
352 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
353 	if (!priv)
354 		return -ENOMEM;
355 
356 	spin_lock_init(&priv->lock);
357 
358 	usb_set_serial_port_data(port, priv);
359 
360 	port->port.drain_delay = 256;
361 
362 	return 0;
363 }
364 
365 static int pl2303_port_remove(struct usb_serial_port *port)
366 {
367 	struct pl2303_private *priv = usb_get_serial_port_data(port);
368 
369 	kfree(priv);
370 
371 	return 0;
372 }
373 
374 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
375 {
376 	struct usb_device *dev = port->serial->dev;
377 	int retval;
378 
379 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
380 
381 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
382 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
383 				 value, 0, NULL, 0, 100);
384 	if (retval)
385 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
386 
387 	return retval;
388 }
389 
390 /*
391  * Returns the nearest supported baud rate that can be set directly without
392  * using divisors.
393  */
394 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
395 {
396 	static const speed_t baud_sup[] = {
397 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
398 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
399 		614400, 921600, 1228800, 2457600, 3000000, 6000000
400 	};
401 
402 	unsigned i;
403 
404 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
405 		if (baud_sup[i] > baud)
406 			break;
407 	}
408 
409 	if (i == ARRAY_SIZE(baud_sup))
410 		baud = baud_sup[i - 1];
411 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
412 		baud = baud_sup[i - 1];
413 	else
414 		baud = baud_sup[i];
415 
416 	return baud;
417 }
418 
419 /*
420  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
421  *       use 9600 baud.
422  */
423 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
424 								speed_t baud)
425 {
426 	put_unaligned_le32(baud, buf);
427 
428 	return baud;
429 }
430 
431 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
432 								speed_t baud)
433 {
434 	unsigned int baseline, mantissa, exponent;
435 
436 	/*
437 	 * Apparently the formula is:
438 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
439 	 * where
440 	 *   mantissa = buf[8:0]
441 	 *   exponent = buf[11:9]
442 	 */
443 	baseline = 12000000 * 32;
444 	mantissa = baseline / baud;
445 	if (mantissa == 0)
446 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
447 	exponent = 0;
448 	while (mantissa >= 512) {
449 		if (exponent < 7) {
450 			mantissa >>= 2;	/* divide by 4 */
451 			exponent++;
452 		} else {
453 			/* Exponent is maxed. Trim mantissa and leave. */
454 			mantissa = 511;
455 			break;
456 		}
457 	}
458 
459 	buf[3] = 0x80;
460 	buf[2] = 0;
461 	buf[1] = exponent << 1 | mantissa >> 8;
462 	buf[0] = mantissa & 0xff;
463 
464 	/* Calculate and return the exact baud rate. */
465 	baud = (baseline / mantissa) >> (exponent << 1);
466 
467 	return baud;
468 }
469 
470 static void pl2303_encode_baud_rate(struct tty_struct *tty,
471 					struct usb_serial_port *port,
472 					u8 buf[4])
473 {
474 	struct usb_serial *serial = port->serial;
475 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
476 	speed_t	baud_sup;
477 	speed_t baud;
478 
479 	baud = tty_get_baud_rate(tty);
480 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
481 	if (!baud)
482 		return;
483 
484 	if (spriv->type->max_baud_rate)
485 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
486 	/*
487 	 * Use direct method for supported baud rates, otherwise use divisors.
488 	 */
489 	baud_sup = pl2303_get_supported_baud_rate(baud);
490 
491 	if (baud == baud_sup)
492 		baud = pl2303_encode_baud_rate_direct(buf, baud);
493 	else
494 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
495 
496 	/* Save resulting baud rate */
497 	tty_encode_baud_rate(tty, baud, baud);
498 	dev_dbg(&port->dev, "baud set = %u\n", baud);
499 }
500 
501 static int pl2303_get_line_request(struct usb_serial_port *port,
502 							unsigned char buf[7])
503 {
504 	struct usb_device *udev = port->serial->dev;
505 	int ret;
506 
507 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
508 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
509 				0, 0, buf, 7, 100);
510 	if (ret != 7) {
511 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
512 
513 		if (ret >= 0)
514 			ret = -EIO;
515 
516 		return ret;
517 	}
518 
519 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
520 
521 	return 0;
522 }
523 
524 static int pl2303_set_line_request(struct usb_serial_port *port,
525 							unsigned char buf[7])
526 {
527 	struct usb_device *udev = port->serial->dev;
528 	int ret;
529 
530 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
531 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
532 				0, 0, buf, 7, 100);
533 	if (ret < 0) {
534 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
535 		return ret;
536 	}
537 
538 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
539 
540 	return 0;
541 }
542 
543 static bool pl2303_termios_change(const struct ktermios *a, const struct ktermios *b)
544 {
545 	bool ixon_change;
546 
547 	ixon_change = ((a->c_iflag ^ b->c_iflag) & (IXON | IXANY)) ||
548 			a->c_cc[VSTART] != b->c_cc[VSTART] ||
549 			a->c_cc[VSTOP] != b->c_cc[VSTOP];
550 
551 	return tty_termios_hw_change(a, b) || ixon_change;
552 }
553 
554 static void pl2303_set_termios(struct tty_struct *tty,
555 		struct usb_serial_port *port, struct ktermios *old_termios)
556 {
557 	struct usb_serial *serial = port->serial;
558 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
559 	struct pl2303_private *priv = usb_get_serial_port_data(port);
560 	unsigned long flags;
561 	unsigned char *buf;
562 	int ret;
563 	u8 control;
564 
565 	if (old_termios && !pl2303_termios_change(&tty->termios, old_termios))
566 		return;
567 
568 	buf = kzalloc(7, GFP_KERNEL);
569 	if (!buf) {
570 		/* Report back no change occurred */
571 		if (old_termios)
572 			tty->termios = *old_termios;
573 		return;
574 	}
575 
576 	pl2303_get_line_request(port, buf);
577 
578 	switch (C_CSIZE(tty)) {
579 	case CS5:
580 		buf[6] = 5;
581 		break;
582 	case CS6:
583 		buf[6] = 6;
584 		break;
585 	case CS7:
586 		buf[6] = 7;
587 		break;
588 	default:
589 	case CS8:
590 		buf[6] = 8;
591 	}
592 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
593 
594 	/* For reference buf[0]:buf[3] baud rate value */
595 	pl2303_encode_baud_rate(tty, port, &buf[0]);
596 
597 	/* For reference buf[4]=0 is 1 stop bits */
598 	/* For reference buf[4]=1 is 1.5 stop bits */
599 	/* For reference buf[4]=2 is 2 stop bits */
600 	if (C_CSTOPB(tty)) {
601 		/*
602 		 * NOTE: Comply with "real" UARTs / RS232:
603 		 *       use 1.5 instead of 2 stop bits with 5 data bits
604 		 */
605 		if (C_CSIZE(tty) == CS5) {
606 			buf[4] = 1;
607 			dev_dbg(&port->dev, "stop bits = 1.5\n");
608 		} else {
609 			buf[4] = 2;
610 			dev_dbg(&port->dev, "stop bits = 2\n");
611 		}
612 	} else {
613 		buf[4] = 0;
614 		dev_dbg(&port->dev, "stop bits = 1\n");
615 	}
616 
617 	if (C_PARENB(tty)) {
618 		/* For reference buf[5]=0 is none parity */
619 		/* For reference buf[5]=1 is odd parity */
620 		/* For reference buf[5]=2 is even parity */
621 		/* For reference buf[5]=3 is mark parity */
622 		/* For reference buf[5]=4 is space parity */
623 		if (C_PARODD(tty)) {
624 			if (C_CMSPAR(tty)) {
625 				buf[5] = 3;
626 				dev_dbg(&port->dev, "parity = mark\n");
627 			} else {
628 				buf[5] = 1;
629 				dev_dbg(&port->dev, "parity = odd\n");
630 			}
631 		} else {
632 			if (C_CMSPAR(tty)) {
633 				buf[5] = 4;
634 				dev_dbg(&port->dev, "parity = space\n");
635 			} else {
636 				buf[5] = 2;
637 				dev_dbg(&port->dev, "parity = even\n");
638 			}
639 		}
640 	} else {
641 		buf[5] = 0;
642 		dev_dbg(&port->dev, "parity = none\n");
643 	}
644 
645 	/*
646 	 * Some PL2303 are known to lose bytes if you change serial settings
647 	 * even to the same values as before. Thus we actually need to filter
648 	 * in this specific case.
649 	 *
650 	 * Note that the tty_termios_hw_change check above is not sufficient
651 	 * as a previously requested baud rate may differ from the one
652 	 * actually used (and stored in old_termios).
653 	 *
654 	 * NOTE: No additional locking needed for line_settings as it is
655 	 *       only used in set_termios, which is serialised against itself.
656 	 */
657 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
658 		ret = pl2303_set_line_request(port, buf);
659 		if (!ret)
660 			memcpy(priv->line_settings, buf, 7);
661 	}
662 
663 	/* change control lines if we are switching to or from B0 */
664 	spin_lock_irqsave(&priv->lock, flags);
665 	control = priv->line_control;
666 	if (C_BAUD(tty) == B0)
667 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
668 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
669 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
670 	if (control != priv->line_control) {
671 		control = priv->line_control;
672 		spin_unlock_irqrestore(&priv->lock, flags);
673 		pl2303_set_control_lines(port, control);
674 	} else {
675 		spin_unlock_irqrestore(&priv->lock, flags);
676 	}
677 
678 	if (C_CRTSCTS(tty)) {
679 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
680 			pl2303_vendor_write(serial, 0x0, 0x41);
681 		else
682 			pl2303_vendor_write(serial, 0x0, 0x61);
683 	} else if (I_IXON(tty) && !I_IXANY(tty) && START_CHAR(tty) == 0x11 &&
684 			STOP_CHAR(tty) == 0x13) {
685 		pl2303_vendor_write(serial, 0x0, 0xc0);
686 	} else {
687 		pl2303_vendor_write(serial, 0x0, 0x0);
688 	}
689 
690 	kfree(buf);
691 }
692 
693 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
694 {
695 	struct pl2303_private *priv = usb_get_serial_port_data(port);
696 	unsigned long flags;
697 	u8 control;
698 
699 	spin_lock_irqsave(&priv->lock, flags);
700 	if (on)
701 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
702 	else
703 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
704 	control = priv->line_control;
705 	spin_unlock_irqrestore(&priv->lock, flags);
706 
707 	pl2303_set_control_lines(port, control);
708 }
709 
710 static void pl2303_close(struct usb_serial_port *port)
711 {
712 	usb_serial_generic_close(port);
713 	usb_kill_urb(port->interrupt_in_urb);
714 	pl2303_set_break(port, false);
715 }
716 
717 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
718 {
719 	struct usb_serial *serial = port->serial;
720 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
721 	int result;
722 
723 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
724 		usb_clear_halt(serial->dev, port->write_urb->pipe);
725 		usb_clear_halt(serial->dev, port->read_urb->pipe);
726 	} else {
727 		/* reset upstream data pipes */
728 		pl2303_vendor_write(serial, 8, 0);
729 		pl2303_vendor_write(serial, 9, 0);
730 	}
731 
732 	/* Setup termios */
733 	if (tty)
734 		pl2303_set_termios(tty, port, NULL);
735 
736 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
737 	if (result) {
738 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
739 			result);
740 		return result;
741 	}
742 
743 	result = usb_serial_generic_open(tty, port);
744 	if (result) {
745 		usb_kill_urb(port->interrupt_in_urb);
746 		return result;
747 	}
748 
749 	return 0;
750 }
751 
752 static int pl2303_tiocmset(struct tty_struct *tty,
753 			   unsigned int set, unsigned int clear)
754 {
755 	struct usb_serial_port *port = tty->driver_data;
756 	struct pl2303_private *priv = usb_get_serial_port_data(port);
757 	unsigned long flags;
758 	u8 control;
759 	int ret;
760 
761 	spin_lock_irqsave(&priv->lock, flags);
762 	if (set & TIOCM_RTS)
763 		priv->line_control |= CONTROL_RTS;
764 	if (set & TIOCM_DTR)
765 		priv->line_control |= CONTROL_DTR;
766 	if (clear & TIOCM_RTS)
767 		priv->line_control &= ~CONTROL_RTS;
768 	if (clear & TIOCM_DTR)
769 		priv->line_control &= ~CONTROL_DTR;
770 	control = priv->line_control;
771 	spin_unlock_irqrestore(&priv->lock, flags);
772 
773 	ret = pl2303_set_control_lines(port, control);
774 	if (ret)
775 		return usb_translate_errors(ret);
776 
777 	return 0;
778 }
779 
780 static int pl2303_tiocmget(struct tty_struct *tty)
781 {
782 	struct usb_serial_port *port = tty->driver_data;
783 	struct pl2303_private *priv = usb_get_serial_port_data(port);
784 	unsigned long flags;
785 	unsigned int mcr;
786 	unsigned int status;
787 	unsigned int result;
788 
789 	spin_lock_irqsave(&priv->lock, flags);
790 	mcr = priv->line_control;
791 	status = priv->line_status;
792 	spin_unlock_irqrestore(&priv->lock, flags);
793 
794 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
795 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
796 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
797 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
798 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
799 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
800 
801 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
802 
803 	return result;
804 }
805 
806 static int pl2303_carrier_raised(struct usb_serial_port *port)
807 {
808 	struct pl2303_private *priv = usb_get_serial_port_data(port);
809 
810 	if (priv->line_status & UART_DCD)
811 		return 1;
812 
813 	return 0;
814 }
815 
816 static int pl2303_get_serial(struct tty_struct *tty,
817 			struct serial_struct *ss)
818 {
819 	struct usb_serial_port *port = tty->driver_data;
820 
821 	ss->type = PORT_16654;
822 	ss->line = port->minor;
823 	ss->port = port->port_number;
824 	ss->baud_base = 460800;
825 	return 0;
826 }
827 
828 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
829 {
830 	struct usb_serial *serial = port->serial;
831 	u16 state;
832 	int result;
833 
834 	if (enable)
835 		state = BREAK_ON;
836 	else
837 		state = BREAK_OFF;
838 
839 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
840 			state == BREAK_OFF ? "off" : "on");
841 
842 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
843 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
844 				 0, NULL, 0, 100);
845 	if (result)
846 		dev_err(&port->dev, "error sending break = %d\n", result);
847 }
848 
849 static void pl2303_break_ctl(struct tty_struct *tty, int state)
850 {
851 	struct usb_serial_port *port = tty->driver_data;
852 
853 	pl2303_set_break(port, state);
854 }
855 
856 static void pl2303_update_line_status(struct usb_serial_port *port,
857 				      unsigned char *data,
858 				      unsigned int actual_length)
859 {
860 	struct usb_serial *serial = port->serial;
861 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
862 	struct pl2303_private *priv = usb_get_serial_port_data(port);
863 	struct tty_struct *tty;
864 	unsigned long flags;
865 	unsigned int status_idx = UART_STATE_INDEX;
866 	u8 status;
867 	u8 delta;
868 
869 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
870 		status_idx = 0;
871 
872 	if (actual_length < status_idx + 1)
873 		return;
874 
875 	status = data[status_idx];
876 
877 	/* Save off the uart status for others to look at */
878 	spin_lock_irqsave(&priv->lock, flags);
879 	delta = priv->line_status ^ status;
880 	priv->line_status = status;
881 	spin_unlock_irqrestore(&priv->lock, flags);
882 
883 	if (status & UART_BREAK_ERROR)
884 		usb_serial_handle_break(port);
885 
886 	if (delta & UART_STATE_MSR_MASK) {
887 		if (delta & UART_CTS)
888 			port->icount.cts++;
889 		if (delta & UART_DSR)
890 			port->icount.dsr++;
891 		if (delta & UART_RING)
892 			port->icount.rng++;
893 		if (delta & UART_DCD) {
894 			port->icount.dcd++;
895 			tty = tty_port_tty_get(&port->port);
896 			if (tty) {
897 				usb_serial_handle_dcd_change(port, tty,
898 							status & UART_DCD);
899 				tty_kref_put(tty);
900 			}
901 		}
902 
903 		wake_up_interruptible(&port->port.delta_msr_wait);
904 	}
905 }
906 
907 static void pl2303_read_int_callback(struct urb *urb)
908 {
909 	struct usb_serial_port *port =  urb->context;
910 	unsigned char *data = urb->transfer_buffer;
911 	unsigned int actual_length = urb->actual_length;
912 	int status = urb->status;
913 	int retval;
914 
915 	switch (status) {
916 	case 0:
917 		/* success */
918 		break;
919 	case -ECONNRESET:
920 	case -ENOENT:
921 	case -ESHUTDOWN:
922 		/* this urb is terminated, clean up */
923 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
924 			__func__, status);
925 		return;
926 	default:
927 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
928 			__func__, status);
929 		goto exit;
930 	}
931 
932 	usb_serial_debug_data(&port->dev, __func__,
933 			      urb->actual_length, urb->transfer_buffer);
934 
935 	pl2303_update_line_status(port, data, actual_length);
936 
937 exit:
938 	retval = usb_submit_urb(urb, GFP_ATOMIC);
939 	if (retval) {
940 		dev_err(&port->dev,
941 			"%s - usb_submit_urb failed with result %d\n",
942 			__func__, retval);
943 	}
944 }
945 
946 static void pl2303_process_read_urb(struct urb *urb)
947 {
948 	struct usb_serial_port *port = urb->context;
949 	struct pl2303_private *priv = usb_get_serial_port_data(port);
950 	unsigned char *data = urb->transfer_buffer;
951 	char tty_flag = TTY_NORMAL;
952 	unsigned long flags;
953 	u8 line_status;
954 	int i;
955 
956 	/* update line status */
957 	spin_lock_irqsave(&priv->lock, flags);
958 	line_status = priv->line_status;
959 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
960 	spin_unlock_irqrestore(&priv->lock, flags);
961 
962 	if (!urb->actual_length)
963 		return;
964 
965 	/*
966 	 * Break takes precedence over parity, which takes precedence over
967 	 * framing errors.
968 	 */
969 	if (line_status & UART_BREAK_ERROR)
970 		tty_flag = TTY_BREAK;
971 	else if (line_status & UART_PARITY_ERROR)
972 		tty_flag = TTY_PARITY;
973 	else if (line_status & UART_FRAME_ERROR)
974 		tty_flag = TTY_FRAME;
975 
976 	if (tty_flag != TTY_NORMAL)
977 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
978 								tty_flag);
979 	/* overrun is special, not associated with a char */
980 	if (line_status & UART_OVERRUN_ERROR)
981 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
982 
983 	if (port->port.console && port->sysrq) {
984 		for (i = 0; i < urb->actual_length; ++i)
985 			if (!usb_serial_handle_sysrq_char(port, data[i]))
986 				tty_insert_flip_char(&port->port, data[i],
987 						tty_flag);
988 	} else {
989 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
990 							urb->actual_length);
991 	}
992 
993 	tty_flip_buffer_push(&port->port);
994 }
995 
996 static struct usb_serial_driver pl2303_device = {
997 	.driver = {
998 		.owner =	THIS_MODULE,
999 		.name =		"pl2303",
1000 	},
1001 	.id_table =		id_table,
1002 	.num_bulk_in =		1,
1003 	.num_bulk_out =		1,
1004 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
1005 	.bulk_in_size =		256,
1006 	.bulk_out_size =	256,
1007 	.open =			pl2303_open,
1008 	.close =		pl2303_close,
1009 	.dtr_rts =		pl2303_dtr_rts,
1010 	.carrier_raised =	pl2303_carrier_raised,
1011 	.get_serial =		pl2303_get_serial,
1012 	.break_ctl =		pl2303_break_ctl,
1013 	.set_termios =		pl2303_set_termios,
1014 	.tiocmget =		pl2303_tiocmget,
1015 	.tiocmset =		pl2303_tiocmset,
1016 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1017 	.process_read_urb =	pl2303_process_read_urb,
1018 	.read_int_callback =	pl2303_read_int_callback,
1019 	.probe =		pl2303_probe,
1020 	.calc_num_ports =	pl2303_calc_num_ports,
1021 	.attach =		pl2303_startup,
1022 	.release =		pl2303_release,
1023 	.port_probe =		pl2303_port_probe,
1024 	.port_remove =		pl2303_port_remove,
1025 };
1026 
1027 static struct usb_serial_driver * const serial_drivers[] = {
1028 	&pl2303_device, NULL
1029 };
1030 
1031 module_usb_serial_driver(serial_drivers, id_table);
1032 
1033 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1034 MODULE_LICENSE("GPL v2");
1035