xref: /openbmc/linux/drivers/usb/serial/pl2303.c (revision 82e6fdd6)
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_ID2) },
56 	{ USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
57 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
58 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
59 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
60 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
61 	{ USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
62 	{ USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
63 	{ USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
64 	{ USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
65 	{ USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
66 	{ USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
67 	{ USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_PRODUCT_ID) },
68 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1),
69 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
70 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65),
71 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
72 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75),
73 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
74 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_EF81),
75 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
76 	{ USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_ID_S81) }, /* Benq/Siemens S81 */
77 	{ USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
78 	{ USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
79 	{ USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
80 	{ USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
81 	{ USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
82 	{ USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
83 	{ USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
84 	{ USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
85 	{ USB_DEVICE(ALCOR_VENDOR_ID, ALCOR_PRODUCT_ID),
86 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
87 	{ USB_DEVICE(WS002IN_VENDOR_ID, WS002IN_PRODUCT_ID) },
88 	{ USB_DEVICE(COREGA_VENDOR_ID, COREGA_PRODUCT_ID) },
89 	{ USB_DEVICE(YCCABLE_VENDOR_ID, YCCABLE_PRODUCT_ID) },
90 	{ USB_DEVICE(SUPERIAL_VENDOR_ID, SUPERIAL_PRODUCT_ID) },
91 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220_PRODUCT_ID) },
92 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
93 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
94 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
95 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
96 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
97 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
98 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
99 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
100 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
101 	{ }					/* Terminating entry */
102 };
103 
104 MODULE_DEVICE_TABLE(usb, id_table);
105 
106 #define SET_LINE_REQUEST_TYPE		0x21
107 #define SET_LINE_REQUEST		0x20
108 
109 #define SET_CONTROL_REQUEST_TYPE	0x21
110 #define SET_CONTROL_REQUEST		0x22
111 #define CONTROL_DTR			0x01
112 #define CONTROL_RTS			0x02
113 
114 #define BREAK_REQUEST_TYPE		0x21
115 #define BREAK_REQUEST			0x23
116 #define BREAK_ON			0xffff
117 #define BREAK_OFF			0x0000
118 
119 #define GET_LINE_REQUEST_TYPE		0xa1
120 #define GET_LINE_REQUEST		0x21
121 
122 #define VENDOR_WRITE_REQUEST_TYPE	0x40
123 #define VENDOR_WRITE_REQUEST		0x01
124 
125 #define VENDOR_READ_REQUEST_TYPE	0xc0
126 #define VENDOR_READ_REQUEST		0x01
127 
128 #define UART_STATE_INDEX		8
129 #define UART_STATE_MSR_MASK		0x8b
130 #define UART_STATE_TRANSIENT_MASK	0x74
131 #define UART_DCD			0x01
132 #define UART_DSR			0x02
133 #define UART_BREAK_ERROR		0x04
134 #define UART_RING			0x08
135 #define UART_FRAME_ERROR		0x10
136 #define UART_PARITY_ERROR		0x20
137 #define UART_OVERRUN_ERROR		0x40
138 #define UART_CTS			0x80
139 
140 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
141 
142 enum pl2303_type {
143 	TYPE_01,	/* Type 0 and 1 (difference unknown) */
144 	TYPE_HX,	/* HX version of the pl2303 chip */
145 	TYPE_COUNT
146 };
147 
148 struct pl2303_type_data {
149 	speed_t max_baud_rate;
150 	unsigned long quirks;
151 };
152 
153 struct pl2303_serial_private {
154 	const struct pl2303_type_data *type;
155 	unsigned long quirks;
156 };
157 
158 struct pl2303_private {
159 	spinlock_t lock;
160 	u8 line_control;
161 	u8 line_status;
162 
163 	u8 line_settings[7];
164 };
165 
166 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
167 	[TYPE_01] = {
168 		.max_baud_rate =	1228800,
169 		.quirks =		PL2303_QUIRK_LEGACY,
170 	},
171 	[TYPE_HX] = {
172 		.max_baud_rate =	12000000,
173 	},
174 };
175 
176 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
177 							unsigned char buf[1])
178 {
179 	struct device *dev = &serial->interface->dev;
180 	int res;
181 
182 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
183 			VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
184 			value, 0, buf, 1, 100);
185 	if (res != 1) {
186 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
187 								value, res);
188 		if (res >= 0)
189 			res = -EIO;
190 
191 		return res;
192 	}
193 
194 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
195 
196 	return 0;
197 }
198 
199 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
200 {
201 	struct device *dev = &serial->interface->dev;
202 	int res;
203 
204 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
205 
206 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
207 			VENDOR_WRITE_REQUEST, VENDOR_WRITE_REQUEST_TYPE,
208 			value, index, NULL, 0, 100);
209 	if (res) {
210 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
211 								value, res);
212 		return res;
213 	}
214 
215 	return 0;
216 }
217 
218 static int pl2303_probe(struct usb_serial *serial,
219 					const struct usb_device_id *id)
220 {
221 	usb_set_serial_data(serial, (void *)id->driver_info);
222 
223 	return 0;
224 }
225 
226 /*
227  * Use interrupt endpoint from first interface if available.
228  *
229  * This is needed due to the looney way its endpoints are set up.
230  */
231 static int pl2303_endpoint_hack(struct usb_serial *serial,
232 					struct usb_serial_endpoints *epds)
233 {
234 	struct usb_interface *interface = serial->interface;
235 	struct usb_device *dev = serial->dev;
236 	struct device *ddev = &interface->dev;
237 	struct usb_host_interface *iface_desc;
238 	struct usb_endpoint_descriptor *endpoint;
239 	unsigned int i;
240 
241 	if (interface == dev->actconfig->interface[0])
242 		return 0;
243 
244 	/* check out the endpoints of the other interface */
245 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
246 
247 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
248 		endpoint = &iface_desc->endpoint[i].desc;
249 
250 		if (!usb_endpoint_is_int_in(endpoint))
251 			continue;
252 
253 		dev_dbg(ddev, "found interrupt in on separate interface\n");
254 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
255 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
256 	}
257 
258 	return 0;
259 }
260 
261 static int pl2303_calc_num_ports(struct usb_serial *serial,
262 					struct usb_serial_endpoints *epds)
263 {
264 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
265 	struct device *dev = &serial->interface->dev;
266 	int ret;
267 
268 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
269 		ret = pl2303_endpoint_hack(serial, epds);
270 		if (ret)
271 			return ret;
272 	}
273 
274 	if (epds->num_interrupt_in < 1) {
275 		dev_err(dev, "required interrupt-in endpoint missing\n");
276 		return -ENODEV;
277 	}
278 
279 	return 1;
280 }
281 
282 static int pl2303_startup(struct usb_serial *serial)
283 {
284 	struct pl2303_serial_private *spriv;
285 	enum pl2303_type type = TYPE_01;
286 	unsigned char *buf;
287 
288 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
289 	if (!spriv)
290 		return -ENOMEM;
291 
292 	buf = kmalloc(1, GFP_KERNEL);
293 	if (!buf) {
294 		kfree(spriv);
295 		return -ENOMEM;
296 	}
297 
298 	if (serial->dev->descriptor.bDeviceClass == 0x02)
299 		type = TYPE_01;		/* type 0 */
300 	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
301 		type = TYPE_HX;
302 	else if (serial->dev->descriptor.bDeviceClass == 0x00)
303 		type = TYPE_01;		/* type 1 */
304 	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
305 		type = TYPE_01;		/* type 1 */
306 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
307 
308 	spriv->type = &pl2303_type_data[type];
309 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
310 	spriv->quirks |= spriv->type->quirks;
311 
312 	usb_set_serial_data(serial, spriv);
313 
314 	pl2303_vendor_read(serial, 0x8484, buf);
315 	pl2303_vendor_write(serial, 0x0404, 0);
316 	pl2303_vendor_read(serial, 0x8484, buf);
317 	pl2303_vendor_read(serial, 0x8383, buf);
318 	pl2303_vendor_read(serial, 0x8484, buf);
319 	pl2303_vendor_write(serial, 0x0404, 1);
320 	pl2303_vendor_read(serial, 0x8484, buf);
321 	pl2303_vendor_read(serial, 0x8383, buf);
322 	pl2303_vendor_write(serial, 0, 1);
323 	pl2303_vendor_write(serial, 1, 0);
324 	if (spriv->quirks & PL2303_QUIRK_LEGACY)
325 		pl2303_vendor_write(serial, 2, 0x24);
326 	else
327 		pl2303_vendor_write(serial, 2, 0x44);
328 
329 	kfree(buf);
330 
331 	return 0;
332 }
333 
334 static void pl2303_release(struct usb_serial *serial)
335 {
336 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
337 
338 	kfree(spriv);
339 }
340 
341 static int pl2303_port_probe(struct usb_serial_port *port)
342 {
343 	struct pl2303_private *priv;
344 
345 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
346 	if (!priv)
347 		return -ENOMEM;
348 
349 	spin_lock_init(&priv->lock);
350 
351 	usb_set_serial_port_data(port, priv);
352 
353 	port->port.drain_delay = 256;
354 
355 	return 0;
356 }
357 
358 static int pl2303_port_remove(struct usb_serial_port *port)
359 {
360 	struct pl2303_private *priv = usb_get_serial_port_data(port);
361 
362 	kfree(priv);
363 
364 	return 0;
365 }
366 
367 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
368 {
369 	struct usb_device *dev = port->serial->dev;
370 	int retval;
371 
372 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
373 
374 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
375 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
376 				 value, 0, NULL, 0, 100);
377 	if (retval)
378 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
379 
380 	return retval;
381 }
382 
383 /*
384  * Returns the nearest supported baud rate that can be set directly without
385  * using divisors.
386  */
387 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
388 {
389 	static const speed_t baud_sup[] = {
390 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
391 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
392 		614400, 921600, 1228800, 2457600, 3000000, 6000000
393 	};
394 
395 	unsigned i;
396 
397 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
398 		if (baud_sup[i] > baud)
399 			break;
400 	}
401 
402 	if (i == ARRAY_SIZE(baud_sup))
403 		baud = baud_sup[i - 1];
404 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
405 		baud = baud_sup[i - 1];
406 	else
407 		baud = baud_sup[i];
408 
409 	return baud;
410 }
411 
412 /*
413  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
414  *       use 9600 baud.
415  */
416 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
417 								speed_t baud)
418 {
419 	put_unaligned_le32(baud, buf);
420 
421 	return baud;
422 }
423 
424 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
425 								speed_t baud)
426 {
427 	unsigned int baseline, mantissa, exponent;
428 
429 	/*
430 	 * Apparently the formula is:
431 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
432 	 * where
433 	 *   mantissa = buf[8:0]
434 	 *   exponent = buf[11:9]
435 	 */
436 	baseline = 12000000 * 32;
437 	mantissa = baseline / baud;
438 	if (mantissa == 0)
439 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
440 	exponent = 0;
441 	while (mantissa >= 512) {
442 		if (exponent < 7) {
443 			mantissa >>= 2;	/* divide by 4 */
444 			exponent++;
445 		} else {
446 			/* Exponent is maxed. Trim mantissa and leave. */
447 			mantissa = 511;
448 			break;
449 		}
450 	}
451 
452 	buf[3] = 0x80;
453 	buf[2] = 0;
454 	buf[1] = exponent << 1 | mantissa >> 8;
455 	buf[0] = mantissa & 0xff;
456 
457 	/* Calculate and return the exact baud rate. */
458 	baud = (baseline / mantissa) >> (exponent << 1);
459 
460 	return baud;
461 }
462 
463 static void pl2303_encode_baud_rate(struct tty_struct *tty,
464 					struct usb_serial_port *port,
465 					u8 buf[4])
466 {
467 	struct usb_serial *serial = port->serial;
468 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
469 	speed_t	baud_sup;
470 	speed_t baud;
471 
472 	baud = tty_get_baud_rate(tty);
473 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
474 	if (!baud)
475 		return;
476 
477 	if (spriv->type->max_baud_rate)
478 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
479 	/*
480 	 * Use direct method for supported baud rates, otherwise use divisors.
481 	 */
482 	baud_sup = pl2303_get_supported_baud_rate(baud);
483 
484 	if (baud == baud_sup)
485 		baud = pl2303_encode_baud_rate_direct(buf, baud);
486 	else
487 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
488 
489 	/* Save resulting baud rate */
490 	tty_encode_baud_rate(tty, baud, baud);
491 	dev_dbg(&port->dev, "baud set = %u\n", baud);
492 }
493 
494 static int pl2303_get_line_request(struct usb_serial_port *port,
495 							unsigned char buf[7])
496 {
497 	struct usb_device *udev = port->serial->dev;
498 	int ret;
499 
500 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
501 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
502 				0, 0, buf, 7, 100);
503 	if (ret != 7) {
504 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
505 
506 		if (ret >= 0)
507 			ret = -EIO;
508 
509 		return ret;
510 	}
511 
512 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
513 
514 	return 0;
515 }
516 
517 static int pl2303_set_line_request(struct usb_serial_port *port,
518 							unsigned char buf[7])
519 {
520 	struct usb_device *udev = port->serial->dev;
521 	int ret;
522 
523 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
524 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
525 				0, 0, buf, 7, 100);
526 	if (ret < 0) {
527 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
528 		return ret;
529 	}
530 
531 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
532 
533 	return 0;
534 }
535 
536 static void pl2303_set_termios(struct tty_struct *tty,
537 		struct usb_serial_port *port, struct ktermios *old_termios)
538 {
539 	struct usb_serial *serial = port->serial;
540 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
541 	struct pl2303_private *priv = usb_get_serial_port_data(port);
542 	unsigned long flags;
543 	unsigned char *buf;
544 	int ret;
545 	u8 control;
546 
547 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
548 		return;
549 
550 	buf = kzalloc(7, GFP_KERNEL);
551 	if (!buf) {
552 		/* Report back no change occurred */
553 		if (old_termios)
554 			tty->termios = *old_termios;
555 		return;
556 	}
557 
558 	pl2303_get_line_request(port, buf);
559 
560 	switch (C_CSIZE(tty)) {
561 	case CS5:
562 		buf[6] = 5;
563 		break;
564 	case CS6:
565 		buf[6] = 6;
566 		break;
567 	case CS7:
568 		buf[6] = 7;
569 		break;
570 	default:
571 	case CS8:
572 		buf[6] = 8;
573 	}
574 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
575 
576 	/* For reference buf[0]:buf[3] baud rate value */
577 	pl2303_encode_baud_rate(tty, port, &buf[0]);
578 
579 	/* For reference buf[4]=0 is 1 stop bits */
580 	/* For reference buf[4]=1 is 1.5 stop bits */
581 	/* For reference buf[4]=2 is 2 stop bits */
582 	if (C_CSTOPB(tty)) {
583 		/*
584 		 * NOTE: Comply with "real" UARTs / RS232:
585 		 *       use 1.5 instead of 2 stop bits with 5 data bits
586 		 */
587 		if (C_CSIZE(tty) == CS5) {
588 			buf[4] = 1;
589 			dev_dbg(&port->dev, "stop bits = 1.5\n");
590 		} else {
591 			buf[4] = 2;
592 			dev_dbg(&port->dev, "stop bits = 2\n");
593 		}
594 	} else {
595 		buf[4] = 0;
596 		dev_dbg(&port->dev, "stop bits = 1\n");
597 	}
598 
599 	if (C_PARENB(tty)) {
600 		/* For reference buf[5]=0 is none parity */
601 		/* For reference buf[5]=1 is odd parity */
602 		/* For reference buf[5]=2 is even parity */
603 		/* For reference buf[5]=3 is mark parity */
604 		/* For reference buf[5]=4 is space parity */
605 		if (C_PARODD(tty)) {
606 			if (C_CMSPAR(tty)) {
607 				buf[5] = 3;
608 				dev_dbg(&port->dev, "parity = mark\n");
609 			} else {
610 				buf[5] = 1;
611 				dev_dbg(&port->dev, "parity = odd\n");
612 			}
613 		} else {
614 			if (C_CMSPAR(tty)) {
615 				buf[5] = 4;
616 				dev_dbg(&port->dev, "parity = space\n");
617 			} else {
618 				buf[5] = 2;
619 				dev_dbg(&port->dev, "parity = even\n");
620 			}
621 		}
622 	} else {
623 		buf[5] = 0;
624 		dev_dbg(&port->dev, "parity = none\n");
625 	}
626 
627 	/*
628 	 * Some PL2303 are known to lose bytes if you change serial settings
629 	 * even to the same values as before. Thus we actually need to filter
630 	 * in this specific case.
631 	 *
632 	 * Note that the tty_termios_hw_change check above is not sufficient
633 	 * as a previously requested baud rate may differ from the one
634 	 * actually used (and stored in old_termios).
635 	 *
636 	 * NOTE: No additional locking needed for line_settings as it is
637 	 *       only used in set_termios, which is serialised against itself.
638 	 */
639 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
640 		ret = pl2303_set_line_request(port, buf);
641 		if (!ret)
642 			memcpy(priv->line_settings, buf, 7);
643 	}
644 
645 	/* change control lines if we are switching to or from B0 */
646 	spin_lock_irqsave(&priv->lock, flags);
647 	control = priv->line_control;
648 	if (C_BAUD(tty) == B0)
649 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
650 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
651 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
652 	if (control != priv->line_control) {
653 		control = priv->line_control;
654 		spin_unlock_irqrestore(&priv->lock, flags);
655 		pl2303_set_control_lines(port, control);
656 	} else {
657 		spin_unlock_irqrestore(&priv->lock, flags);
658 	}
659 
660 	if (C_CRTSCTS(tty)) {
661 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
662 			pl2303_vendor_write(serial, 0x0, 0x41);
663 		else
664 			pl2303_vendor_write(serial, 0x0, 0x61);
665 	} else {
666 		pl2303_vendor_write(serial, 0x0, 0x0);
667 	}
668 
669 	kfree(buf);
670 }
671 
672 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
673 {
674 	struct pl2303_private *priv = usb_get_serial_port_data(port);
675 	unsigned long flags;
676 	u8 control;
677 
678 	spin_lock_irqsave(&priv->lock, flags);
679 	if (on)
680 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
681 	else
682 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
683 	control = priv->line_control;
684 	spin_unlock_irqrestore(&priv->lock, flags);
685 
686 	pl2303_set_control_lines(port, control);
687 }
688 
689 static void pl2303_close(struct usb_serial_port *port)
690 {
691 	usb_serial_generic_close(port);
692 	usb_kill_urb(port->interrupt_in_urb);
693 	pl2303_set_break(port, false);
694 }
695 
696 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
697 {
698 	struct usb_serial *serial = port->serial;
699 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
700 	int result;
701 
702 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
703 		usb_clear_halt(serial->dev, port->write_urb->pipe);
704 		usb_clear_halt(serial->dev, port->read_urb->pipe);
705 	} else {
706 		/* reset upstream data pipes */
707 		pl2303_vendor_write(serial, 8, 0);
708 		pl2303_vendor_write(serial, 9, 0);
709 	}
710 
711 	/* Setup termios */
712 	if (tty)
713 		pl2303_set_termios(tty, port, NULL);
714 
715 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
716 	if (result) {
717 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
718 			result);
719 		return result;
720 	}
721 
722 	result = usb_serial_generic_open(tty, port);
723 	if (result) {
724 		usb_kill_urb(port->interrupt_in_urb);
725 		return result;
726 	}
727 
728 	return 0;
729 }
730 
731 static int pl2303_tiocmset(struct tty_struct *tty,
732 			   unsigned int set, unsigned int clear)
733 {
734 	struct usb_serial_port *port = tty->driver_data;
735 	struct pl2303_private *priv = usb_get_serial_port_data(port);
736 	unsigned long flags;
737 	u8 control;
738 	int ret;
739 
740 	spin_lock_irqsave(&priv->lock, flags);
741 	if (set & TIOCM_RTS)
742 		priv->line_control |= CONTROL_RTS;
743 	if (set & TIOCM_DTR)
744 		priv->line_control |= CONTROL_DTR;
745 	if (clear & TIOCM_RTS)
746 		priv->line_control &= ~CONTROL_RTS;
747 	if (clear & TIOCM_DTR)
748 		priv->line_control &= ~CONTROL_DTR;
749 	control = priv->line_control;
750 	spin_unlock_irqrestore(&priv->lock, flags);
751 
752 	ret = pl2303_set_control_lines(port, control);
753 	if (ret)
754 		return usb_translate_errors(ret);
755 
756 	return 0;
757 }
758 
759 static int pl2303_tiocmget(struct tty_struct *tty)
760 {
761 	struct usb_serial_port *port = tty->driver_data;
762 	struct pl2303_private *priv = usb_get_serial_port_data(port);
763 	unsigned long flags;
764 	unsigned int mcr;
765 	unsigned int status;
766 	unsigned int result;
767 
768 	spin_lock_irqsave(&priv->lock, flags);
769 	mcr = priv->line_control;
770 	status = priv->line_status;
771 	spin_unlock_irqrestore(&priv->lock, flags);
772 
773 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
774 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
775 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
776 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
777 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
778 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
779 
780 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
781 
782 	return result;
783 }
784 
785 static int pl2303_carrier_raised(struct usb_serial_port *port)
786 {
787 	struct pl2303_private *priv = usb_get_serial_port_data(port);
788 
789 	if (priv->line_status & UART_DCD)
790 		return 1;
791 
792 	return 0;
793 }
794 
795 static int pl2303_ioctl(struct tty_struct *tty,
796 			unsigned int cmd, unsigned long arg)
797 {
798 	struct serial_struct ser;
799 	struct usb_serial_port *port = tty->driver_data;
800 
801 	switch (cmd) {
802 	case TIOCGSERIAL:
803 		memset(&ser, 0, sizeof ser);
804 		ser.type = PORT_16654;
805 		ser.line = port->minor;
806 		ser.port = port->port_number;
807 		ser.baud_base = 460800;
808 
809 		if (copy_to_user((void __user *)arg, &ser, sizeof ser))
810 			return -EFAULT;
811 
812 		return 0;
813 	default:
814 		break;
815 	}
816 
817 	return -ENOIOCTLCMD;
818 }
819 
820 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
821 {
822 	struct usb_serial *serial = port->serial;
823 	u16 state;
824 	int result;
825 
826 	if (enable)
827 		state = BREAK_ON;
828 	else
829 		state = BREAK_OFF;
830 
831 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
832 			state == BREAK_OFF ? "off" : "on");
833 
834 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
835 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
836 				 0, NULL, 0, 100);
837 	if (result)
838 		dev_err(&port->dev, "error sending break = %d\n", result);
839 }
840 
841 static void pl2303_break_ctl(struct tty_struct *tty, int state)
842 {
843 	struct usb_serial_port *port = tty->driver_data;
844 
845 	pl2303_set_break(port, state);
846 }
847 
848 static void pl2303_update_line_status(struct usb_serial_port *port,
849 				      unsigned char *data,
850 				      unsigned int actual_length)
851 {
852 	struct usb_serial *serial = port->serial;
853 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
854 	struct pl2303_private *priv = usb_get_serial_port_data(port);
855 	struct tty_struct *tty;
856 	unsigned long flags;
857 	unsigned int status_idx = UART_STATE_INDEX;
858 	u8 status;
859 	u8 delta;
860 
861 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
862 		status_idx = 0;
863 
864 	if (actual_length < status_idx + 1)
865 		return;
866 
867 	status = data[status_idx];
868 
869 	/* Save off the uart status for others to look at */
870 	spin_lock_irqsave(&priv->lock, flags);
871 	delta = priv->line_status ^ status;
872 	priv->line_status = status;
873 	spin_unlock_irqrestore(&priv->lock, flags);
874 
875 	if (status & UART_BREAK_ERROR)
876 		usb_serial_handle_break(port);
877 
878 	if (delta & UART_STATE_MSR_MASK) {
879 		if (delta & UART_CTS)
880 			port->icount.cts++;
881 		if (delta & UART_DSR)
882 			port->icount.dsr++;
883 		if (delta & UART_RING)
884 			port->icount.rng++;
885 		if (delta & UART_DCD) {
886 			port->icount.dcd++;
887 			tty = tty_port_tty_get(&port->port);
888 			if (tty) {
889 				usb_serial_handle_dcd_change(port, tty,
890 							status & UART_DCD);
891 				tty_kref_put(tty);
892 			}
893 		}
894 
895 		wake_up_interruptible(&port->port.delta_msr_wait);
896 	}
897 }
898 
899 static void pl2303_read_int_callback(struct urb *urb)
900 {
901 	struct usb_serial_port *port =  urb->context;
902 	unsigned char *data = urb->transfer_buffer;
903 	unsigned int actual_length = urb->actual_length;
904 	int status = urb->status;
905 	int retval;
906 
907 	switch (status) {
908 	case 0:
909 		/* success */
910 		break;
911 	case -ECONNRESET:
912 	case -ENOENT:
913 	case -ESHUTDOWN:
914 		/* this urb is terminated, clean up */
915 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
916 			__func__, status);
917 		return;
918 	default:
919 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
920 			__func__, status);
921 		goto exit;
922 	}
923 
924 	usb_serial_debug_data(&port->dev, __func__,
925 			      urb->actual_length, urb->transfer_buffer);
926 
927 	pl2303_update_line_status(port, data, actual_length);
928 
929 exit:
930 	retval = usb_submit_urb(urb, GFP_ATOMIC);
931 	if (retval) {
932 		dev_err(&port->dev,
933 			"%s - usb_submit_urb failed with result %d\n",
934 			__func__, retval);
935 	}
936 }
937 
938 static void pl2303_process_read_urb(struct urb *urb)
939 {
940 	struct usb_serial_port *port = urb->context;
941 	struct pl2303_private *priv = usb_get_serial_port_data(port);
942 	unsigned char *data = urb->transfer_buffer;
943 	char tty_flag = TTY_NORMAL;
944 	unsigned long flags;
945 	u8 line_status;
946 	int i;
947 
948 	/* update line status */
949 	spin_lock_irqsave(&priv->lock, flags);
950 	line_status = priv->line_status;
951 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
952 	spin_unlock_irqrestore(&priv->lock, flags);
953 
954 	if (!urb->actual_length)
955 		return;
956 
957 	/*
958 	 * Break takes precedence over parity, which takes precedence over
959 	 * framing errors.
960 	 */
961 	if (line_status & UART_BREAK_ERROR)
962 		tty_flag = TTY_BREAK;
963 	else if (line_status & UART_PARITY_ERROR)
964 		tty_flag = TTY_PARITY;
965 	else if (line_status & UART_FRAME_ERROR)
966 		tty_flag = TTY_FRAME;
967 
968 	if (tty_flag != TTY_NORMAL)
969 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
970 								tty_flag);
971 	/* overrun is special, not associated with a char */
972 	if (line_status & UART_OVERRUN_ERROR)
973 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
974 
975 	if (port->port.console && port->sysrq) {
976 		for (i = 0; i < urb->actual_length; ++i)
977 			if (!usb_serial_handle_sysrq_char(port, data[i]))
978 				tty_insert_flip_char(&port->port, data[i],
979 						tty_flag);
980 	} else {
981 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
982 							urb->actual_length);
983 	}
984 
985 	tty_flip_buffer_push(&port->port);
986 }
987 
988 static struct usb_serial_driver pl2303_device = {
989 	.driver = {
990 		.owner =	THIS_MODULE,
991 		.name =		"pl2303",
992 	},
993 	.id_table =		id_table,
994 	.num_bulk_in =		1,
995 	.num_bulk_out =		1,
996 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
997 	.bulk_in_size =		256,
998 	.bulk_out_size =	256,
999 	.open =			pl2303_open,
1000 	.close =		pl2303_close,
1001 	.dtr_rts =		pl2303_dtr_rts,
1002 	.carrier_raised =	pl2303_carrier_raised,
1003 	.ioctl =		pl2303_ioctl,
1004 	.break_ctl =		pl2303_break_ctl,
1005 	.set_termios =		pl2303_set_termios,
1006 	.tiocmget =		pl2303_tiocmget,
1007 	.tiocmset =		pl2303_tiocmset,
1008 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1009 	.process_read_urb =	pl2303_process_read_urb,
1010 	.read_int_callback =	pl2303_read_int_callback,
1011 	.probe =		pl2303_probe,
1012 	.calc_num_ports =	pl2303_calc_num_ports,
1013 	.attach =		pl2303_startup,
1014 	.release =		pl2303_release,
1015 	.port_probe =		pl2303_port_probe,
1016 	.port_remove =		pl2303_port_remove,
1017 };
1018 
1019 static struct usb_serial_driver * const serial_drivers[] = {
1020 	&pl2303_device, NULL
1021 };
1022 
1023 module_usb_serial_driver(serial_drivers, id_table);
1024 
1025 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1026 MODULE_LICENSE("GPL v2");
1027