xref: /openbmc/linux/drivers/usb/serial/pl2303.c (revision be709d48)
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(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_TB) },
50 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
51 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID_RSAQ5) },
52 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID),
53 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
54 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC485),
55 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
56 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC232B),
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_LD220TA_PRODUCT_ID) },
96 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
97 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960TA_PRODUCT_ID) },
98 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
99 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
100 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM920_PRODUCT_ID) },
101 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM940_PRODUCT_ID) },
102 	{ USB_DEVICE(HP_VENDOR_ID, HP_TD620_PRODUCT_ID) },
103 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
104 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
105 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
106 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
107 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
108 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
109 	{ }					/* Terminating entry */
110 };
111 
112 MODULE_DEVICE_TABLE(usb, id_table);
113 
114 #define SET_LINE_REQUEST_TYPE		0x21
115 #define SET_LINE_REQUEST		0x20
116 
117 #define SET_CONTROL_REQUEST_TYPE	0x21
118 #define SET_CONTROL_REQUEST		0x22
119 #define CONTROL_DTR			0x01
120 #define CONTROL_RTS			0x02
121 
122 #define BREAK_REQUEST_TYPE		0x21
123 #define BREAK_REQUEST			0x23
124 #define BREAK_ON			0xffff
125 #define BREAK_OFF			0x0000
126 
127 #define GET_LINE_REQUEST_TYPE		0xa1
128 #define GET_LINE_REQUEST		0x21
129 
130 #define VENDOR_WRITE_REQUEST_TYPE	0x40
131 #define VENDOR_WRITE_REQUEST		0x01
132 
133 #define VENDOR_READ_REQUEST_TYPE	0xc0
134 #define VENDOR_READ_REQUEST		0x01
135 
136 #define UART_STATE_INDEX		8
137 #define UART_STATE_MSR_MASK		0x8b
138 #define UART_STATE_TRANSIENT_MASK	0x74
139 #define UART_DCD			0x01
140 #define UART_DSR			0x02
141 #define UART_BREAK_ERROR		0x04
142 #define UART_RING			0x08
143 #define UART_FRAME_ERROR		0x10
144 #define UART_PARITY_ERROR		0x20
145 #define UART_OVERRUN_ERROR		0x40
146 #define UART_CTS			0x80
147 
148 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
149 
150 enum pl2303_type {
151 	TYPE_01,	/* Type 0 and 1 (difference unknown) */
152 	TYPE_HX,	/* HX version of the pl2303 chip */
153 	TYPE_COUNT
154 };
155 
156 struct pl2303_type_data {
157 	speed_t max_baud_rate;
158 	unsigned long quirks;
159 };
160 
161 struct pl2303_serial_private {
162 	const struct pl2303_type_data *type;
163 	unsigned long quirks;
164 };
165 
166 struct pl2303_private {
167 	spinlock_t lock;
168 	u8 line_control;
169 	u8 line_status;
170 
171 	u8 line_settings[7];
172 };
173 
174 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
175 	[TYPE_01] = {
176 		.max_baud_rate =	1228800,
177 		.quirks =		PL2303_QUIRK_LEGACY,
178 	},
179 	[TYPE_HX] = {
180 		.max_baud_rate =	12000000,
181 	},
182 };
183 
184 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
185 							unsigned char buf[1])
186 {
187 	struct device *dev = &serial->interface->dev;
188 	int res;
189 
190 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
191 			VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
192 			value, 0, buf, 1, 100);
193 	if (res != 1) {
194 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
195 								value, res);
196 		if (res >= 0)
197 			res = -EIO;
198 
199 		return res;
200 	}
201 
202 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
203 
204 	return 0;
205 }
206 
207 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
208 {
209 	struct device *dev = &serial->interface->dev;
210 	int res;
211 
212 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
213 
214 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
215 			VENDOR_WRITE_REQUEST, VENDOR_WRITE_REQUEST_TYPE,
216 			value, index, NULL, 0, 100);
217 	if (res) {
218 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
219 								value, res);
220 		return res;
221 	}
222 
223 	return 0;
224 }
225 
226 static int pl2303_probe(struct usb_serial *serial,
227 					const struct usb_device_id *id)
228 {
229 	usb_set_serial_data(serial, (void *)id->driver_info);
230 
231 	return 0;
232 }
233 
234 /*
235  * Use interrupt endpoint from first interface if available.
236  *
237  * This is needed due to the looney way its endpoints are set up.
238  */
239 static int pl2303_endpoint_hack(struct usb_serial *serial,
240 					struct usb_serial_endpoints *epds)
241 {
242 	struct usb_interface *interface = serial->interface;
243 	struct usb_device *dev = serial->dev;
244 	struct device *ddev = &interface->dev;
245 	struct usb_host_interface *iface_desc;
246 	struct usb_endpoint_descriptor *endpoint;
247 	unsigned int i;
248 
249 	if (interface == dev->actconfig->interface[0])
250 		return 0;
251 
252 	/* check out the endpoints of the other interface */
253 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
254 
255 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
256 		endpoint = &iface_desc->endpoint[i].desc;
257 
258 		if (!usb_endpoint_is_int_in(endpoint))
259 			continue;
260 
261 		dev_dbg(ddev, "found interrupt in on separate interface\n");
262 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
263 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
264 	}
265 
266 	return 0;
267 }
268 
269 static int pl2303_calc_num_ports(struct usb_serial *serial,
270 					struct usb_serial_endpoints *epds)
271 {
272 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
273 	struct device *dev = &serial->interface->dev;
274 	int ret;
275 
276 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
277 		ret = pl2303_endpoint_hack(serial, epds);
278 		if (ret)
279 			return ret;
280 	}
281 
282 	if (epds->num_interrupt_in < 1) {
283 		dev_err(dev, "required interrupt-in endpoint missing\n");
284 		return -ENODEV;
285 	}
286 
287 	return 1;
288 }
289 
290 static int pl2303_startup(struct usb_serial *serial)
291 {
292 	struct pl2303_serial_private *spriv;
293 	enum pl2303_type type = TYPE_01;
294 	unsigned char *buf;
295 
296 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
297 	if (!spriv)
298 		return -ENOMEM;
299 
300 	buf = kmalloc(1, GFP_KERNEL);
301 	if (!buf) {
302 		kfree(spriv);
303 		return -ENOMEM;
304 	}
305 
306 	if (serial->dev->descriptor.bDeviceClass == 0x02)
307 		type = TYPE_01;		/* type 0 */
308 	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
309 		type = TYPE_HX;
310 	else if (serial->dev->descriptor.bDeviceClass == 0x00)
311 		type = TYPE_01;		/* type 1 */
312 	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
313 		type = TYPE_01;		/* type 1 */
314 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
315 
316 	spriv->type = &pl2303_type_data[type];
317 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
318 	spriv->quirks |= spriv->type->quirks;
319 
320 	usb_set_serial_data(serial, spriv);
321 
322 	pl2303_vendor_read(serial, 0x8484, buf);
323 	pl2303_vendor_write(serial, 0x0404, 0);
324 	pl2303_vendor_read(serial, 0x8484, buf);
325 	pl2303_vendor_read(serial, 0x8383, buf);
326 	pl2303_vendor_read(serial, 0x8484, buf);
327 	pl2303_vendor_write(serial, 0x0404, 1);
328 	pl2303_vendor_read(serial, 0x8484, buf);
329 	pl2303_vendor_read(serial, 0x8383, buf);
330 	pl2303_vendor_write(serial, 0, 1);
331 	pl2303_vendor_write(serial, 1, 0);
332 	if (spriv->quirks & PL2303_QUIRK_LEGACY)
333 		pl2303_vendor_write(serial, 2, 0x24);
334 	else
335 		pl2303_vendor_write(serial, 2, 0x44);
336 
337 	kfree(buf);
338 
339 	return 0;
340 }
341 
342 static void pl2303_release(struct usb_serial *serial)
343 {
344 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
345 
346 	kfree(spriv);
347 }
348 
349 static int pl2303_port_probe(struct usb_serial_port *port)
350 {
351 	struct pl2303_private *priv;
352 
353 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
354 	if (!priv)
355 		return -ENOMEM;
356 
357 	spin_lock_init(&priv->lock);
358 
359 	usb_set_serial_port_data(port, priv);
360 
361 	port->port.drain_delay = 256;
362 
363 	return 0;
364 }
365 
366 static int pl2303_port_remove(struct usb_serial_port *port)
367 {
368 	struct pl2303_private *priv = usb_get_serial_port_data(port);
369 
370 	kfree(priv);
371 
372 	return 0;
373 }
374 
375 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
376 {
377 	struct usb_device *dev = port->serial->dev;
378 	int retval;
379 
380 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
381 
382 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
383 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
384 				 value, 0, NULL, 0, 100);
385 	if (retval)
386 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
387 
388 	return retval;
389 }
390 
391 /*
392  * Returns the nearest supported baud rate that can be set directly without
393  * using divisors.
394  */
395 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
396 {
397 	static const speed_t baud_sup[] = {
398 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
399 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
400 		614400, 921600, 1228800, 2457600, 3000000, 6000000
401 	};
402 
403 	unsigned i;
404 
405 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
406 		if (baud_sup[i] > baud)
407 			break;
408 	}
409 
410 	if (i == ARRAY_SIZE(baud_sup))
411 		baud = baud_sup[i - 1];
412 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
413 		baud = baud_sup[i - 1];
414 	else
415 		baud = baud_sup[i];
416 
417 	return baud;
418 }
419 
420 /*
421  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
422  *       use 9600 baud.
423  */
424 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
425 								speed_t baud)
426 {
427 	put_unaligned_le32(baud, buf);
428 
429 	return baud;
430 }
431 
432 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
433 								speed_t baud)
434 {
435 	unsigned int baseline, mantissa, exponent;
436 
437 	/*
438 	 * Apparently the formula is:
439 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
440 	 * where
441 	 *   mantissa = buf[8:0]
442 	 *   exponent = buf[11:9]
443 	 */
444 	baseline = 12000000 * 32;
445 	mantissa = baseline / baud;
446 	if (mantissa == 0)
447 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
448 	exponent = 0;
449 	while (mantissa >= 512) {
450 		if (exponent < 7) {
451 			mantissa >>= 2;	/* divide by 4 */
452 			exponent++;
453 		} else {
454 			/* Exponent is maxed. Trim mantissa and leave. */
455 			mantissa = 511;
456 			break;
457 		}
458 	}
459 
460 	buf[3] = 0x80;
461 	buf[2] = 0;
462 	buf[1] = exponent << 1 | mantissa >> 8;
463 	buf[0] = mantissa & 0xff;
464 
465 	/* Calculate and return the exact baud rate. */
466 	baud = (baseline / mantissa) >> (exponent << 1);
467 
468 	return baud;
469 }
470 
471 static void pl2303_encode_baud_rate(struct tty_struct *tty,
472 					struct usb_serial_port *port,
473 					u8 buf[4])
474 {
475 	struct usb_serial *serial = port->serial;
476 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
477 	speed_t	baud_sup;
478 	speed_t baud;
479 
480 	baud = tty_get_baud_rate(tty);
481 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
482 	if (!baud)
483 		return;
484 
485 	if (spriv->type->max_baud_rate)
486 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
487 	/*
488 	 * Use direct method for supported baud rates, otherwise use divisors.
489 	 */
490 	baud_sup = pl2303_get_supported_baud_rate(baud);
491 
492 	if (baud == baud_sup)
493 		baud = pl2303_encode_baud_rate_direct(buf, baud);
494 	else
495 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
496 
497 	/* Save resulting baud rate */
498 	tty_encode_baud_rate(tty, baud, baud);
499 	dev_dbg(&port->dev, "baud set = %u\n", baud);
500 }
501 
502 static int pl2303_get_line_request(struct usb_serial_port *port,
503 							unsigned char buf[7])
504 {
505 	struct usb_device *udev = port->serial->dev;
506 	int ret;
507 
508 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
509 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
510 				0, 0, buf, 7, 100);
511 	if (ret != 7) {
512 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
513 
514 		if (ret >= 0)
515 			ret = -EIO;
516 
517 		return ret;
518 	}
519 
520 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
521 
522 	return 0;
523 }
524 
525 static int pl2303_set_line_request(struct usb_serial_port *port,
526 							unsigned char buf[7])
527 {
528 	struct usb_device *udev = port->serial->dev;
529 	int ret;
530 
531 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
532 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
533 				0, 0, buf, 7, 100);
534 	if (ret < 0) {
535 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
536 		return ret;
537 	}
538 
539 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
540 
541 	return 0;
542 }
543 
544 static bool pl2303_termios_change(const struct ktermios *a, const struct ktermios *b)
545 {
546 	bool ixon_change;
547 
548 	ixon_change = ((a->c_iflag ^ b->c_iflag) & (IXON | IXANY)) ||
549 			a->c_cc[VSTART] != b->c_cc[VSTART] ||
550 			a->c_cc[VSTOP] != b->c_cc[VSTOP];
551 
552 	return tty_termios_hw_change(a, b) || ixon_change;
553 }
554 
555 static void pl2303_set_termios(struct tty_struct *tty,
556 		struct usb_serial_port *port, struct ktermios *old_termios)
557 {
558 	struct usb_serial *serial = port->serial;
559 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
560 	struct pl2303_private *priv = usb_get_serial_port_data(port);
561 	unsigned long flags;
562 	unsigned char *buf;
563 	int ret;
564 	u8 control;
565 
566 	if (old_termios && !pl2303_termios_change(&tty->termios, old_termios))
567 		return;
568 
569 	buf = kzalloc(7, GFP_KERNEL);
570 	if (!buf) {
571 		/* Report back no change occurred */
572 		if (old_termios)
573 			tty->termios = *old_termios;
574 		return;
575 	}
576 
577 	pl2303_get_line_request(port, buf);
578 
579 	switch (C_CSIZE(tty)) {
580 	case CS5:
581 		buf[6] = 5;
582 		break;
583 	case CS6:
584 		buf[6] = 6;
585 		break;
586 	case CS7:
587 		buf[6] = 7;
588 		break;
589 	default:
590 	case CS8:
591 		buf[6] = 8;
592 	}
593 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
594 
595 	/* For reference buf[0]:buf[3] baud rate value */
596 	pl2303_encode_baud_rate(tty, port, &buf[0]);
597 
598 	/* For reference buf[4]=0 is 1 stop bits */
599 	/* For reference buf[4]=1 is 1.5 stop bits */
600 	/* For reference buf[4]=2 is 2 stop bits */
601 	if (C_CSTOPB(tty)) {
602 		/*
603 		 * NOTE: Comply with "real" UARTs / RS232:
604 		 *       use 1.5 instead of 2 stop bits with 5 data bits
605 		 */
606 		if (C_CSIZE(tty) == CS5) {
607 			buf[4] = 1;
608 			dev_dbg(&port->dev, "stop bits = 1.5\n");
609 		} else {
610 			buf[4] = 2;
611 			dev_dbg(&port->dev, "stop bits = 2\n");
612 		}
613 	} else {
614 		buf[4] = 0;
615 		dev_dbg(&port->dev, "stop bits = 1\n");
616 	}
617 
618 	if (C_PARENB(tty)) {
619 		/* For reference buf[5]=0 is none parity */
620 		/* For reference buf[5]=1 is odd parity */
621 		/* For reference buf[5]=2 is even parity */
622 		/* For reference buf[5]=3 is mark parity */
623 		/* For reference buf[5]=4 is space parity */
624 		if (C_PARODD(tty)) {
625 			if (C_CMSPAR(tty)) {
626 				buf[5] = 3;
627 				dev_dbg(&port->dev, "parity = mark\n");
628 			} else {
629 				buf[5] = 1;
630 				dev_dbg(&port->dev, "parity = odd\n");
631 			}
632 		} else {
633 			if (C_CMSPAR(tty)) {
634 				buf[5] = 4;
635 				dev_dbg(&port->dev, "parity = space\n");
636 			} else {
637 				buf[5] = 2;
638 				dev_dbg(&port->dev, "parity = even\n");
639 			}
640 		}
641 	} else {
642 		buf[5] = 0;
643 		dev_dbg(&port->dev, "parity = none\n");
644 	}
645 
646 	/*
647 	 * Some PL2303 are known to lose bytes if you change serial settings
648 	 * even to the same values as before. Thus we actually need to filter
649 	 * in this specific case.
650 	 *
651 	 * Note that the tty_termios_hw_change check above is not sufficient
652 	 * as a previously requested baud rate may differ from the one
653 	 * actually used (and stored in old_termios).
654 	 *
655 	 * NOTE: No additional locking needed for line_settings as it is
656 	 *       only used in set_termios, which is serialised against itself.
657 	 */
658 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
659 		ret = pl2303_set_line_request(port, buf);
660 		if (!ret)
661 			memcpy(priv->line_settings, buf, 7);
662 	}
663 
664 	/* change control lines if we are switching to or from B0 */
665 	spin_lock_irqsave(&priv->lock, flags);
666 	control = priv->line_control;
667 	if (C_BAUD(tty) == B0)
668 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
669 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
670 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
671 	if (control != priv->line_control) {
672 		control = priv->line_control;
673 		spin_unlock_irqrestore(&priv->lock, flags);
674 		pl2303_set_control_lines(port, control);
675 	} else {
676 		spin_unlock_irqrestore(&priv->lock, flags);
677 	}
678 
679 	if (C_CRTSCTS(tty)) {
680 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
681 			pl2303_vendor_write(serial, 0x0, 0x41);
682 		else
683 			pl2303_vendor_write(serial, 0x0, 0x61);
684 	} else if (I_IXON(tty) && !I_IXANY(tty) && START_CHAR(tty) == 0x11 &&
685 			STOP_CHAR(tty) == 0x13) {
686 		pl2303_vendor_write(serial, 0x0, 0xc0);
687 	} else {
688 		pl2303_vendor_write(serial, 0x0, 0x0);
689 	}
690 
691 	kfree(buf);
692 }
693 
694 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
695 {
696 	struct pl2303_private *priv = usb_get_serial_port_data(port);
697 	unsigned long flags;
698 	u8 control;
699 
700 	spin_lock_irqsave(&priv->lock, flags);
701 	if (on)
702 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
703 	else
704 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
705 	control = priv->line_control;
706 	spin_unlock_irqrestore(&priv->lock, flags);
707 
708 	pl2303_set_control_lines(port, control);
709 }
710 
711 static void pl2303_close(struct usb_serial_port *port)
712 {
713 	usb_serial_generic_close(port);
714 	usb_kill_urb(port->interrupt_in_urb);
715 	pl2303_set_break(port, false);
716 }
717 
718 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
719 {
720 	struct usb_serial *serial = port->serial;
721 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
722 	int result;
723 
724 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
725 		usb_clear_halt(serial->dev, port->write_urb->pipe);
726 		usb_clear_halt(serial->dev, port->read_urb->pipe);
727 	} else {
728 		/* reset upstream data pipes */
729 		pl2303_vendor_write(serial, 8, 0);
730 		pl2303_vendor_write(serial, 9, 0);
731 	}
732 
733 	/* Setup termios */
734 	if (tty)
735 		pl2303_set_termios(tty, port, NULL);
736 
737 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
738 	if (result) {
739 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
740 			result);
741 		return result;
742 	}
743 
744 	result = usb_serial_generic_open(tty, port);
745 	if (result) {
746 		usb_kill_urb(port->interrupt_in_urb);
747 		return result;
748 	}
749 
750 	return 0;
751 }
752 
753 static int pl2303_tiocmset(struct tty_struct *tty,
754 			   unsigned int set, unsigned int clear)
755 {
756 	struct usb_serial_port *port = tty->driver_data;
757 	struct pl2303_private *priv = usb_get_serial_port_data(port);
758 	unsigned long flags;
759 	u8 control;
760 	int ret;
761 
762 	spin_lock_irqsave(&priv->lock, flags);
763 	if (set & TIOCM_RTS)
764 		priv->line_control |= CONTROL_RTS;
765 	if (set & TIOCM_DTR)
766 		priv->line_control |= CONTROL_DTR;
767 	if (clear & TIOCM_RTS)
768 		priv->line_control &= ~CONTROL_RTS;
769 	if (clear & TIOCM_DTR)
770 		priv->line_control &= ~CONTROL_DTR;
771 	control = priv->line_control;
772 	spin_unlock_irqrestore(&priv->lock, flags);
773 
774 	ret = pl2303_set_control_lines(port, control);
775 	if (ret)
776 		return usb_translate_errors(ret);
777 
778 	return 0;
779 }
780 
781 static int pl2303_tiocmget(struct tty_struct *tty)
782 {
783 	struct usb_serial_port *port = tty->driver_data;
784 	struct pl2303_private *priv = usb_get_serial_port_data(port);
785 	unsigned long flags;
786 	unsigned int mcr;
787 	unsigned int status;
788 	unsigned int result;
789 
790 	spin_lock_irqsave(&priv->lock, flags);
791 	mcr = priv->line_control;
792 	status = priv->line_status;
793 	spin_unlock_irqrestore(&priv->lock, flags);
794 
795 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
796 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
797 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
798 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
799 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
800 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
801 
802 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
803 
804 	return result;
805 }
806 
807 static int pl2303_carrier_raised(struct usb_serial_port *port)
808 {
809 	struct pl2303_private *priv = usb_get_serial_port_data(port);
810 
811 	if (priv->line_status & UART_DCD)
812 		return 1;
813 
814 	return 0;
815 }
816 
817 static int pl2303_get_serial(struct tty_struct *tty,
818 			struct serial_struct *ss)
819 {
820 	struct usb_serial_port *port = tty->driver_data;
821 
822 	ss->type = PORT_16654;
823 	ss->line = port->minor;
824 	ss->port = port->port_number;
825 	ss->baud_base = 460800;
826 	return 0;
827 }
828 
829 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
830 {
831 	struct usb_serial *serial = port->serial;
832 	u16 state;
833 	int result;
834 
835 	if (enable)
836 		state = BREAK_ON;
837 	else
838 		state = BREAK_OFF;
839 
840 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
841 			state == BREAK_OFF ? "off" : "on");
842 
843 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
844 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
845 				 0, NULL, 0, 100);
846 	if (result)
847 		dev_err(&port->dev, "error sending break = %d\n", result);
848 }
849 
850 static void pl2303_break_ctl(struct tty_struct *tty, int state)
851 {
852 	struct usb_serial_port *port = tty->driver_data;
853 
854 	pl2303_set_break(port, state);
855 }
856 
857 static void pl2303_update_line_status(struct usb_serial_port *port,
858 				      unsigned char *data,
859 				      unsigned int actual_length)
860 {
861 	struct usb_serial *serial = port->serial;
862 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
863 	struct pl2303_private *priv = usb_get_serial_port_data(port);
864 	struct tty_struct *tty;
865 	unsigned long flags;
866 	unsigned int status_idx = UART_STATE_INDEX;
867 	u8 status;
868 	u8 delta;
869 
870 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
871 		status_idx = 0;
872 
873 	if (actual_length < status_idx + 1)
874 		return;
875 
876 	status = data[status_idx];
877 
878 	/* Save off the uart status for others to look at */
879 	spin_lock_irqsave(&priv->lock, flags);
880 	delta = priv->line_status ^ status;
881 	priv->line_status = status;
882 	spin_unlock_irqrestore(&priv->lock, flags);
883 
884 	if (status & UART_BREAK_ERROR)
885 		usb_serial_handle_break(port);
886 
887 	if (delta & UART_STATE_MSR_MASK) {
888 		if (delta & UART_CTS)
889 			port->icount.cts++;
890 		if (delta & UART_DSR)
891 			port->icount.dsr++;
892 		if (delta & UART_RING)
893 			port->icount.rng++;
894 		if (delta & UART_DCD) {
895 			port->icount.dcd++;
896 			tty = tty_port_tty_get(&port->port);
897 			if (tty) {
898 				usb_serial_handle_dcd_change(port, tty,
899 							status & UART_DCD);
900 				tty_kref_put(tty);
901 			}
902 		}
903 
904 		wake_up_interruptible(&port->port.delta_msr_wait);
905 	}
906 }
907 
908 static void pl2303_read_int_callback(struct urb *urb)
909 {
910 	struct usb_serial_port *port =  urb->context;
911 	unsigned char *data = urb->transfer_buffer;
912 	unsigned int actual_length = urb->actual_length;
913 	int status = urb->status;
914 	int retval;
915 
916 	switch (status) {
917 	case 0:
918 		/* success */
919 		break;
920 	case -ECONNRESET:
921 	case -ENOENT:
922 	case -ESHUTDOWN:
923 		/* this urb is terminated, clean up */
924 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
925 			__func__, status);
926 		return;
927 	default:
928 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
929 			__func__, status);
930 		goto exit;
931 	}
932 
933 	usb_serial_debug_data(&port->dev, __func__,
934 			      urb->actual_length, urb->transfer_buffer);
935 
936 	pl2303_update_line_status(port, data, actual_length);
937 
938 exit:
939 	retval = usb_submit_urb(urb, GFP_ATOMIC);
940 	if (retval) {
941 		dev_err(&port->dev,
942 			"%s - usb_submit_urb failed with result %d\n",
943 			__func__, retval);
944 	}
945 }
946 
947 static void pl2303_process_read_urb(struct urb *urb)
948 {
949 	struct usb_serial_port *port = urb->context;
950 	struct pl2303_private *priv = usb_get_serial_port_data(port);
951 	unsigned char *data = urb->transfer_buffer;
952 	char tty_flag = TTY_NORMAL;
953 	unsigned long flags;
954 	u8 line_status;
955 	int i;
956 
957 	/* update line status */
958 	spin_lock_irqsave(&priv->lock, flags);
959 	line_status = priv->line_status;
960 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
961 	spin_unlock_irqrestore(&priv->lock, flags);
962 
963 	if (!urb->actual_length)
964 		return;
965 
966 	/*
967 	 * Break takes precedence over parity, which takes precedence over
968 	 * framing errors.
969 	 */
970 	if (line_status & UART_BREAK_ERROR)
971 		tty_flag = TTY_BREAK;
972 	else if (line_status & UART_PARITY_ERROR)
973 		tty_flag = TTY_PARITY;
974 	else if (line_status & UART_FRAME_ERROR)
975 		tty_flag = TTY_FRAME;
976 
977 	if (tty_flag != TTY_NORMAL)
978 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
979 								tty_flag);
980 	/* overrun is special, not associated with a char */
981 	if (line_status & UART_OVERRUN_ERROR)
982 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
983 
984 	if (port->port.console && port->sysrq) {
985 		for (i = 0; i < urb->actual_length; ++i)
986 			if (!usb_serial_handle_sysrq_char(port, data[i]))
987 				tty_insert_flip_char(&port->port, data[i],
988 						tty_flag);
989 	} else {
990 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
991 							urb->actual_length);
992 	}
993 
994 	tty_flip_buffer_push(&port->port);
995 }
996 
997 static struct usb_serial_driver pl2303_device = {
998 	.driver = {
999 		.owner =	THIS_MODULE,
1000 		.name =		"pl2303",
1001 	},
1002 	.id_table =		id_table,
1003 	.num_bulk_in =		1,
1004 	.num_bulk_out =		1,
1005 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
1006 	.bulk_in_size =		256,
1007 	.bulk_out_size =	256,
1008 	.open =			pl2303_open,
1009 	.close =		pl2303_close,
1010 	.dtr_rts =		pl2303_dtr_rts,
1011 	.carrier_raised =	pl2303_carrier_raised,
1012 	.get_serial =		pl2303_get_serial,
1013 	.break_ctl =		pl2303_break_ctl,
1014 	.set_termios =		pl2303_set_termios,
1015 	.tiocmget =		pl2303_tiocmget,
1016 	.tiocmset =		pl2303_tiocmset,
1017 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1018 	.process_read_urb =	pl2303_process_read_urb,
1019 	.read_int_callback =	pl2303_read_int_callback,
1020 	.probe =		pl2303_probe,
1021 	.calc_num_ports =	pl2303_calc_num_ports,
1022 	.attach =		pl2303_startup,
1023 	.release =		pl2303_release,
1024 	.port_probe =		pl2303_port_probe,
1025 	.port_remove =		pl2303_port_remove,
1026 };
1027 
1028 static struct usb_serial_driver * const serial_drivers[] = {
1029 	&pl2303_device, NULL
1030 };
1031 
1032 module_usb_serial_driver(serial_drivers, id_table);
1033 
1034 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1035 MODULE_LICENSE("GPL v2");
1036