xref: /openbmc/linux/drivers/usb/serial/pl2303.c (revision 828ff2ad)
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_LD960_PRODUCT_ID) },
95 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
96 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
97 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
98 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
99 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
100 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
101 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
102 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
103 	{ }					/* Terminating entry */
104 };
105 
106 MODULE_DEVICE_TABLE(usb, id_table);
107 
108 #define SET_LINE_REQUEST_TYPE		0x21
109 #define SET_LINE_REQUEST		0x20
110 
111 #define SET_CONTROL_REQUEST_TYPE	0x21
112 #define SET_CONTROL_REQUEST		0x22
113 #define CONTROL_DTR			0x01
114 #define CONTROL_RTS			0x02
115 
116 #define BREAK_REQUEST_TYPE		0x21
117 #define BREAK_REQUEST			0x23
118 #define BREAK_ON			0xffff
119 #define BREAK_OFF			0x0000
120 
121 #define GET_LINE_REQUEST_TYPE		0xa1
122 #define GET_LINE_REQUEST		0x21
123 
124 #define VENDOR_WRITE_REQUEST_TYPE	0x40
125 #define VENDOR_WRITE_REQUEST		0x01
126 
127 #define VENDOR_READ_REQUEST_TYPE	0xc0
128 #define VENDOR_READ_REQUEST		0x01
129 
130 #define UART_STATE_INDEX		8
131 #define UART_STATE_MSR_MASK		0x8b
132 #define UART_STATE_TRANSIENT_MASK	0x74
133 #define UART_DCD			0x01
134 #define UART_DSR			0x02
135 #define UART_BREAK_ERROR		0x04
136 #define UART_RING			0x08
137 #define UART_FRAME_ERROR		0x10
138 #define UART_PARITY_ERROR		0x20
139 #define UART_OVERRUN_ERROR		0x40
140 #define UART_CTS			0x80
141 
142 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
143 
144 enum pl2303_type {
145 	TYPE_01,	/* Type 0 and 1 (difference unknown) */
146 	TYPE_HX,	/* HX version of the pl2303 chip */
147 	TYPE_COUNT
148 };
149 
150 struct pl2303_type_data {
151 	speed_t max_baud_rate;
152 	unsigned long quirks;
153 };
154 
155 struct pl2303_serial_private {
156 	const struct pl2303_type_data *type;
157 	unsigned long quirks;
158 };
159 
160 struct pl2303_private {
161 	spinlock_t lock;
162 	u8 line_control;
163 	u8 line_status;
164 
165 	u8 line_settings[7];
166 };
167 
168 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
169 	[TYPE_01] = {
170 		.max_baud_rate =	1228800,
171 		.quirks =		PL2303_QUIRK_LEGACY,
172 	},
173 	[TYPE_HX] = {
174 		.max_baud_rate =	12000000,
175 	},
176 };
177 
178 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
179 							unsigned char buf[1])
180 {
181 	struct device *dev = &serial->interface->dev;
182 	int res;
183 
184 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
185 			VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
186 			value, 0, buf, 1, 100);
187 	if (res != 1) {
188 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
189 								value, res);
190 		if (res >= 0)
191 			res = -EIO;
192 
193 		return res;
194 	}
195 
196 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
197 
198 	return 0;
199 }
200 
201 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
202 {
203 	struct device *dev = &serial->interface->dev;
204 	int res;
205 
206 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
207 
208 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
209 			VENDOR_WRITE_REQUEST, VENDOR_WRITE_REQUEST_TYPE,
210 			value, index, NULL, 0, 100);
211 	if (res) {
212 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
213 								value, res);
214 		return res;
215 	}
216 
217 	return 0;
218 }
219 
220 static int pl2303_probe(struct usb_serial *serial,
221 					const struct usb_device_id *id)
222 {
223 	usb_set_serial_data(serial, (void *)id->driver_info);
224 
225 	return 0;
226 }
227 
228 /*
229  * Use interrupt endpoint from first interface if available.
230  *
231  * This is needed due to the looney way its endpoints are set up.
232  */
233 static int pl2303_endpoint_hack(struct usb_serial *serial,
234 					struct usb_serial_endpoints *epds)
235 {
236 	struct usb_interface *interface = serial->interface;
237 	struct usb_device *dev = serial->dev;
238 	struct device *ddev = &interface->dev;
239 	struct usb_host_interface *iface_desc;
240 	struct usb_endpoint_descriptor *endpoint;
241 	unsigned int i;
242 
243 	if (interface == dev->actconfig->interface[0])
244 		return 0;
245 
246 	/* check out the endpoints of the other interface */
247 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
248 
249 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
250 		endpoint = &iface_desc->endpoint[i].desc;
251 
252 		if (!usb_endpoint_is_int_in(endpoint))
253 			continue;
254 
255 		dev_dbg(ddev, "found interrupt in on separate interface\n");
256 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
257 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
258 	}
259 
260 	return 0;
261 }
262 
263 static int pl2303_calc_num_ports(struct usb_serial *serial,
264 					struct usb_serial_endpoints *epds)
265 {
266 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
267 	struct device *dev = &serial->interface->dev;
268 	int ret;
269 
270 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
271 		ret = pl2303_endpoint_hack(serial, epds);
272 		if (ret)
273 			return ret;
274 	}
275 
276 	if (epds->num_interrupt_in < 1) {
277 		dev_err(dev, "required interrupt-in endpoint missing\n");
278 		return -ENODEV;
279 	}
280 
281 	return 1;
282 }
283 
284 static int pl2303_startup(struct usb_serial *serial)
285 {
286 	struct pl2303_serial_private *spriv;
287 	enum pl2303_type type = TYPE_01;
288 	unsigned char *buf;
289 
290 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
291 	if (!spriv)
292 		return -ENOMEM;
293 
294 	buf = kmalloc(1, GFP_KERNEL);
295 	if (!buf) {
296 		kfree(spriv);
297 		return -ENOMEM;
298 	}
299 
300 	if (serial->dev->descriptor.bDeviceClass == 0x02)
301 		type = TYPE_01;		/* type 0 */
302 	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
303 		type = TYPE_HX;
304 	else if (serial->dev->descriptor.bDeviceClass == 0x00)
305 		type = TYPE_01;		/* type 1 */
306 	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
307 		type = TYPE_01;		/* type 1 */
308 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
309 
310 	spriv->type = &pl2303_type_data[type];
311 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
312 	spriv->quirks |= spriv->type->quirks;
313 
314 	usb_set_serial_data(serial, spriv);
315 
316 	pl2303_vendor_read(serial, 0x8484, buf);
317 	pl2303_vendor_write(serial, 0x0404, 0);
318 	pl2303_vendor_read(serial, 0x8484, buf);
319 	pl2303_vendor_read(serial, 0x8383, buf);
320 	pl2303_vendor_read(serial, 0x8484, buf);
321 	pl2303_vendor_write(serial, 0x0404, 1);
322 	pl2303_vendor_read(serial, 0x8484, buf);
323 	pl2303_vendor_read(serial, 0x8383, buf);
324 	pl2303_vendor_write(serial, 0, 1);
325 	pl2303_vendor_write(serial, 1, 0);
326 	if (spriv->quirks & PL2303_QUIRK_LEGACY)
327 		pl2303_vendor_write(serial, 2, 0x24);
328 	else
329 		pl2303_vendor_write(serial, 2, 0x44);
330 
331 	kfree(buf);
332 
333 	return 0;
334 }
335 
336 static void pl2303_release(struct usb_serial *serial)
337 {
338 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
339 
340 	kfree(spriv);
341 }
342 
343 static int pl2303_port_probe(struct usb_serial_port *port)
344 {
345 	struct pl2303_private *priv;
346 
347 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
348 	if (!priv)
349 		return -ENOMEM;
350 
351 	spin_lock_init(&priv->lock);
352 
353 	usb_set_serial_port_data(port, priv);
354 
355 	port->port.drain_delay = 256;
356 
357 	return 0;
358 }
359 
360 static int pl2303_port_remove(struct usb_serial_port *port)
361 {
362 	struct pl2303_private *priv = usb_get_serial_port_data(port);
363 
364 	kfree(priv);
365 
366 	return 0;
367 }
368 
369 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
370 {
371 	struct usb_device *dev = port->serial->dev;
372 	int retval;
373 
374 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
375 
376 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
377 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
378 				 value, 0, NULL, 0, 100);
379 	if (retval)
380 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
381 
382 	return retval;
383 }
384 
385 /*
386  * Returns the nearest supported baud rate that can be set directly without
387  * using divisors.
388  */
389 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
390 {
391 	static const speed_t baud_sup[] = {
392 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
393 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
394 		614400, 921600, 1228800, 2457600, 3000000, 6000000
395 	};
396 
397 	unsigned i;
398 
399 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
400 		if (baud_sup[i] > baud)
401 			break;
402 	}
403 
404 	if (i == ARRAY_SIZE(baud_sup))
405 		baud = baud_sup[i - 1];
406 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
407 		baud = baud_sup[i - 1];
408 	else
409 		baud = baud_sup[i];
410 
411 	return baud;
412 }
413 
414 /*
415  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
416  *       use 9600 baud.
417  */
418 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
419 								speed_t baud)
420 {
421 	put_unaligned_le32(baud, buf);
422 
423 	return baud;
424 }
425 
426 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
427 								speed_t baud)
428 {
429 	unsigned int baseline, mantissa, exponent;
430 
431 	/*
432 	 * Apparently the formula is:
433 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
434 	 * where
435 	 *   mantissa = buf[8:0]
436 	 *   exponent = buf[11:9]
437 	 */
438 	baseline = 12000000 * 32;
439 	mantissa = baseline / baud;
440 	if (mantissa == 0)
441 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
442 	exponent = 0;
443 	while (mantissa >= 512) {
444 		if (exponent < 7) {
445 			mantissa >>= 2;	/* divide by 4 */
446 			exponent++;
447 		} else {
448 			/* Exponent is maxed. Trim mantissa and leave. */
449 			mantissa = 511;
450 			break;
451 		}
452 	}
453 
454 	buf[3] = 0x80;
455 	buf[2] = 0;
456 	buf[1] = exponent << 1 | mantissa >> 8;
457 	buf[0] = mantissa & 0xff;
458 
459 	/* Calculate and return the exact baud rate. */
460 	baud = (baseline / mantissa) >> (exponent << 1);
461 
462 	return baud;
463 }
464 
465 static void pl2303_encode_baud_rate(struct tty_struct *tty,
466 					struct usb_serial_port *port,
467 					u8 buf[4])
468 {
469 	struct usb_serial *serial = port->serial;
470 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
471 	speed_t	baud_sup;
472 	speed_t baud;
473 
474 	baud = tty_get_baud_rate(tty);
475 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
476 	if (!baud)
477 		return;
478 
479 	if (spriv->type->max_baud_rate)
480 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
481 	/*
482 	 * Use direct method for supported baud rates, otherwise use divisors.
483 	 */
484 	baud_sup = pl2303_get_supported_baud_rate(baud);
485 
486 	if (baud == baud_sup)
487 		baud = pl2303_encode_baud_rate_direct(buf, baud);
488 	else
489 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
490 
491 	/* Save resulting baud rate */
492 	tty_encode_baud_rate(tty, baud, baud);
493 	dev_dbg(&port->dev, "baud set = %u\n", baud);
494 }
495 
496 static int pl2303_get_line_request(struct usb_serial_port *port,
497 							unsigned char buf[7])
498 {
499 	struct usb_device *udev = port->serial->dev;
500 	int ret;
501 
502 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
503 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
504 				0, 0, buf, 7, 100);
505 	if (ret != 7) {
506 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
507 
508 		if (ret >= 0)
509 			ret = -EIO;
510 
511 		return ret;
512 	}
513 
514 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
515 
516 	return 0;
517 }
518 
519 static int pl2303_set_line_request(struct usb_serial_port *port,
520 							unsigned char buf[7])
521 {
522 	struct usb_device *udev = port->serial->dev;
523 	int ret;
524 
525 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
526 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
527 				0, 0, buf, 7, 100);
528 	if (ret < 0) {
529 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
530 		return ret;
531 	}
532 
533 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
534 
535 	return 0;
536 }
537 
538 static bool pl2303_termios_change(const struct ktermios *a, const struct ktermios *b)
539 {
540 	bool ixon_change;
541 
542 	ixon_change = ((a->c_iflag ^ b->c_iflag) & (IXON | IXANY)) ||
543 			a->c_cc[VSTART] != b->c_cc[VSTART] ||
544 			a->c_cc[VSTOP] != b->c_cc[VSTOP];
545 
546 	return tty_termios_hw_change(a, b) || ixon_change;
547 }
548 
549 static void pl2303_set_termios(struct tty_struct *tty,
550 		struct usb_serial_port *port, struct ktermios *old_termios)
551 {
552 	struct usb_serial *serial = port->serial;
553 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
554 	struct pl2303_private *priv = usb_get_serial_port_data(port);
555 	unsigned long flags;
556 	unsigned char *buf;
557 	int ret;
558 	u8 control;
559 
560 	if (old_termios && !pl2303_termios_change(&tty->termios, old_termios))
561 		return;
562 
563 	buf = kzalloc(7, GFP_KERNEL);
564 	if (!buf) {
565 		/* Report back no change occurred */
566 		if (old_termios)
567 			tty->termios = *old_termios;
568 		return;
569 	}
570 
571 	pl2303_get_line_request(port, buf);
572 
573 	switch (C_CSIZE(tty)) {
574 	case CS5:
575 		buf[6] = 5;
576 		break;
577 	case CS6:
578 		buf[6] = 6;
579 		break;
580 	case CS7:
581 		buf[6] = 7;
582 		break;
583 	default:
584 	case CS8:
585 		buf[6] = 8;
586 	}
587 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
588 
589 	/* For reference buf[0]:buf[3] baud rate value */
590 	pl2303_encode_baud_rate(tty, port, &buf[0]);
591 
592 	/* For reference buf[4]=0 is 1 stop bits */
593 	/* For reference buf[4]=1 is 1.5 stop bits */
594 	/* For reference buf[4]=2 is 2 stop bits */
595 	if (C_CSTOPB(tty)) {
596 		/*
597 		 * NOTE: Comply with "real" UARTs / RS232:
598 		 *       use 1.5 instead of 2 stop bits with 5 data bits
599 		 */
600 		if (C_CSIZE(tty) == CS5) {
601 			buf[4] = 1;
602 			dev_dbg(&port->dev, "stop bits = 1.5\n");
603 		} else {
604 			buf[4] = 2;
605 			dev_dbg(&port->dev, "stop bits = 2\n");
606 		}
607 	} else {
608 		buf[4] = 0;
609 		dev_dbg(&port->dev, "stop bits = 1\n");
610 	}
611 
612 	if (C_PARENB(tty)) {
613 		/* For reference buf[5]=0 is none parity */
614 		/* For reference buf[5]=1 is odd parity */
615 		/* For reference buf[5]=2 is even parity */
616 		/* For reference buf[5]=3 is mark parity */
617 		/* For reference buf[5]=4 is space parity */
618 		if (C_PARODD(tty)) {
619 			if (C_CMSPAR(tty)) {
620 				buf[5] = 3;
621 				dev_dbg(&port->dev, "parity = mark\n");
622 			} else {
623 				buf[5] = 1;
624 				dev_dbg(&port->dev, "parity = odd\n");
625 			}
626 		} else {
627 			if (C_CMSPAR(tty)) {
628 				buf[5] = 4;
629 				dev_dbg(&port->dev, "parity = space\n");
630 			} else {
631 				buf[5] = 2;
632 				dev_dbg(&port->dev, "parity = even\n");
633 			}
634 		}
635 	} else {
636 		buf[5] = 0;
637 		dev_dbg(&port->dev, "parity = none\n");
638 	}
639 
640 	/*
641 	 * Some PL2303 are known to lose bytes if you change serial settings
642 	 * even to the same values as before. Thus we actually need to filter
643 	 * in this specific case.
644 	 *
645 	 * Note that the tty_termios_hw_change check above is not sufficient
646 	 * as a previously requested baud rate may differ from the one
647 	 * actually used (and stored in old_termios).
648 	 *
649 	 * NOTE: No additional locking needed for line_settings as it is
650 	 *       only used in set_termios, which is serialised against itself.
651 	 */
652 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
653 		ret = pl2303_set_line_request(port, buf);
654 		if (!ret)
655 			memcpy(priv->line_settings, buf, 7);
656 	}
657 
658 	/* change control lines if we are switching to or from B0 */
659 	spin_lock_irqsave(&priv->lock, flags);
660 	control = priv->line_control;
661 	if (C_BAUD(tty) == B0)
662 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
663 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
664 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
665 	if (control != priv->line_control) {
666 		control = priv->line_control;
667 		spin_unlock_irqrestore(&priv->lock, flags);
668 		pl2303_set_control_lines(port, control);
669 	} else {
670 		spin_unlock_irqrestore(&priv->lock, flags);
671 	}
672 
673 	if (C_CRTSCTS(tty)) {
674 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
675 			pl2303_vendor_write(serial, 0x0, 0x41);
676 		else
677 			pl2303_vendor_write(serial, 0x0, 0x61);
678 	} else if (I_IXON(tty) && !I_IXANY(tty) && START_CHAR(tty) == 0x11 &&
679 			STOP_CHAR(tty) == 0x13) {
680 		pl2303_vendor_write(serial, 0x0, 0xc0);
681 	} else {
682 		pl2303_vendor_write(serial, 0x0, 0x0);
683 	}
684 
685 	kfree(buf);
686 }
687 
688 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
689 {
690 	struct pl2303_private *priv = usb_get_serial_port_data(port);
691 	unsigned long flags;
692 	u8 control;
693 
694 	spin_lock_irqsave(&priv->lock, flags);
695 	if (on)
696 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
697 	else
698 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
699 	control = priv->line_control;
700 	spin_unlock_irqrestore(&priv->lock, flags);
701 
702 	pl2303_set_control_lines(port, control);
703 }
704 
705 static void pl2303_close(struct usb_serial_port *port)
706 {
707 	usb_serial_generic_close(port);
708 	usb_kill_urb(port->interrupt_in_urb);
709 	pl2303_set_break(port, false);
710 }
711 
712 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
713 {
714 	struct usb_serial *serial = port->serial;
715 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
716 	int result;
717 
718 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
719 		usb_clear_halt(serial->dev, port->write_urb->pipe);
720 		usb_clear_halt(serial->dev, port->read_urb->pipe);
721 	} else {
722 		/* reset upstream data pipes */
723 		pl2303_vendor_write(serial, 8, 0);
724 		pl2303_vendor_write(serial, 9, 0);
725 	}
726 
727 	/* Setup termios */
728 	if (tty)
729 		pl2303_set_termios(tty, port, NULL);
730 
731 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
732 	if (result) {
733 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
734 			result);
735 		return result;
736 	}
737 
738 	result = usb_serial_generic_open(tty, port);
739 	if (result) {
740 		usb_kill_urb(port->interrupt_in_urb);
741 		return result;
742 	}
743 
744 	return 0;
745 }
746 
747 static int pl2303_tiocmset(struct tty_struct *tty,
748 			   unsigned int set, unsigned int clear)
749 {
750 	struct usb_serial_port *port = tty->driver_data;
751 	struct pl2303_private *priv = usb_get_serial_port_data(port);
752 	unsigned long flags;
753 	u8 control;
754 	int ret;
755 
756 	spin_lock_irqsave(&priv->lock, flags);
757 	if (set & TIOCM_RTS)
758 		priv->line_control |= CONTROL_RTS;
759 	if (set & TIOCM_DTR)
760 		priv->line_control |= CONTROL_DTR;
761 	if (clear & TIOCM_RTS)
762 		priv->line_control &= ~CONTROL_RTS;
763 	if (clear & TIOCM_DTR)
764 		priv->line_control &= ~CONTROL_DTR;
765 	control = priv->line_control;
766 	spin_unlock_irqrestore(&priv->lock, flags);
767 
768 	ret = pl2303_set_control_lines(port, control);
769 	if (ret)
770 		return usb_translate_errors(ret);
771 
772 	return 0;
773 }
774 
775 static int pl2303_tiocmget(struct tty_struct *tty)
776 {
777 	struct usb_serial_port *port = tty->driver_data;
778 	struct pl2303_private *priv = usb_get_serial_port_data(port);
779 	unsigned long flags;
780 	unsigned int mcr;
781 	unsigned int status;
782 	unsigned int result;
783 
784 	spin_lock_irqsave(&priv->lock, flags);
785 	mcr = priv->line_control;
786 	status = priv->line_status;
787 	spin_unlock_irqrestore(&priv->lock, flags);
788 
789 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
790 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
791 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
792 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
793 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
794 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
795 
796 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
797 
798 	return result;
799 }
800 
801 static int pl2303_carrier_raised(struct usb_serial_port *port)
802 {
803 	struct pl2303_private *priv = usb_get_serial_port_data(port);
804 
805 	if (priv->line_status & UART_DCD)
806 		return 1;
807 
808 	return 0;
809 }
810 
811 static int pl2303_get_serial(struct tty_struct *tty,
812 			struct serial_struct *ss)
813 {
814 	struct usb_serial_port *port = tty->driver_data;
815 
816 	ss->type = PORT_16654;
817 	ss->line = port->minor;
818 	ss->port = port->port_number;
819 	ss->baud_base = 460800;
820 	return 0;
821 }
822 
823 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
824 {
825 	struct usb_serial *serial = port->serial;
826 	u16 state;
827 	int result;
828 
829 	if (enable)
830 		state = BREAK_ON;
831 	else
832 		state = BREAK_OFF;
833 
834 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
835 			state == BREAK_OFF ? "off" : "on");
836 
837 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
838 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
839 				 0, NULL, 0, 100);
840 	if (result)
841 		dev_err(&port->dev, "error sending break = %d\n", result);
842 }
843 
844 static void pl2303_break_ctl(struct tty_struct *tty, int state)
845 {
846 	struct usb_serial_port *port = tty->driver_data;
847 
848 	pl2303_set_break(port, state);
849 }
850 
851 static void pl2303_update_line_status(struct usb_serial_port *port,
852 				      unsigned char *data,
853 				      unsigned int actual_length)
854 {
855 	struct usb_serial *serial = port->serial;
856 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
857 	struct pl2303_private *priv = usb_get_serial_port_data(port);
858 	struct tty_struct *tty;
859 	unsigned long flags;
860 	unsigned int status_idx = UART_STATE_INDEX;
861 	u8 status;
862 	u8 delta;
863 
864 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
865 		status_idx = 0;
866 
867 	if (actual_length < status_idx + 1)
868 		return;
869 
870 	status = data[status_idx];
871 
872 	/* Save off the uart status for others to look at */
873 	spin_lock_irqsave(&priv->lock, flags);
874 	delta = priv->line_status ^ status;
875 	priv->line_status = status;
876 	spin_unlock_irqrestore(&priv->lock, flags);
877 
878 	if (status & UART_BREAK_ERROR)
879 		usb_serial_handle_break(port);
880 
881 	if (delta & UART_STATE_MSR_MASK) {
882 		if (delta & UART_CTS)
883 			port->icount.cts++;
884 		if (delta & UART_DSR)
885 			port->icount.dsr++;
886 		if (delta & UART_RING)
887 			port->icount.rng++;
888 		if (delta & UART_DCD) {
889 			port->icount.dcd++;
890 			tty = tty_port_tty_get(&port->port);
891 			if (tty) {
892 				usb_serial_handle_dcd_change(port, tty,
893 							status & UART_DCD);
894 				tty_kref_put(tty);
895 			}
896 		}
897 
898 		wake_up_interruptible(&port->port.delta_msr_wait);
899 	}
900 }
901 
902 static void pl2303_read_int_callback(struct urb *urb)
903 {
904 	struct usb_serial_port *port =  urb->context;
905 	unsigned char *data = urb->transfer_buffer;
906 	unsigned int actual_length = urb->actual_length;
907 	int status = urb->status;
908 	int retval;
909 
910 	switch (status) {
911 	case 0:
912 		/* success */
913 		break;
914 	case -ECONNRESET:
915 	case -ENOENT:
916 	case -ESHUTDOWN:
917 		/* this urb is terminated, clean up */
918 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
919 			__func__, status);
920 		return;
921 	default:
922 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
923 			__func__, status);
924 		goto exit;
925 	}
926 
927 	usb_serial_debug_data(&port->dev, __func__,
928 			      urb->actual_length, urb->transfer_buffer);
929 
930 	pl2303_update_line_status(port, data, actual_length);
931 
932 exit:
933 	retval = usb_submit_urb(urb, GFP_ATOMIC);
934 	if (retval) {
935 		dev_err(&port->dev,
936 			"%s - usb_submit_urb failed with result %d\n",
937 			__func__, retval);
938 	}
939 }
940 
941 static void pl2303_process_read_urb(struct urb *urb)
942 {
943 	struct usb_serial_port *port = urb->context;
944 	struct pl2303_private *priv = usb_get_serial_port_data(port);
945 	unsigned char *data = urb->transfer_buffer;
946 	char tty_flag = TTY_NORMAL;
947 	unsigned long flags;
948 	u8 line_status;
949 	int i;
950 
951 	/* update line status */
952 	spin_lock_irqsave(&priv->lock, flags);
953 	line_status = priv->line_status;
954 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
955 	spin_unlock_irqrestore(&priv->lock, flags);
956 
957 	if (!urb->actual_length)
958 		return;
959 
960 	/*
961 	 * Break takes precedence over parity, which takes precedence over
962 	 * framing errors.
963 	 */
964 	if (line_status & UART_BREAK_ERROR)
965 		tty_flag = TTY_BREAK;
966 	else if (line_status & UART_PARITY_ERROR)
967 		tty_flag = TTY_PARITY;
968 	else if (line_status & UART_FRAME_ERROR)
969 		tty_flag = TTY_FRAME;
970 
971 	if (tty_flag != TTY_NORMAL)
972 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
973 								tty_flag);
974 	/* overrun is special, not associated with a char */
975 	if (line_status & UART_OVERRUN_ERROR)
976 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
977 
978 	if (port->port.console && port->sysrq) {
979 		for (i = 0; i < urb->actual_length; ++i)
980 			if (!usb_serial_handle_sysrq_char(port, data[i]))
981 				tty_insert_flip_char(&port->port, data[i],
982 						tty_flag);
983 	} else {
984 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
985 							urb->actual_length);
986 	}
987 
988 	tty_flip_buffer_push(&port->port);
989 }
990 
991 static struct usb_serial_driver pl2303_device = {
992 	.driver = {
993 		.owner =	THIS_MODULE,
994 		.name =		"pl2303",
995 	},
996 	.id_table =		id_table,
997 	.num_bulk_in =		1,
998 	.num_bulk_out =		1,
999 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
1000 	.bulk_in_size =		256,
1001 	.bulk_out_size =	256,
1002 	.open =			pl2303_open,
1003 	.close =		pl2303_close,
1004 	.dtr_rts =		pl2303_dtr_rts,
1005 	.carrier_raised =	pl2303_carrier_raised,
1006 	.get_serial =		pl2303_get_serial,
1007 	.break_ctl =		pl2303_break_ctl,
1008 	.set_termios =		pl2303_set_termios,
1009 	.tiocmget =		pl2303_tiocmget,
1010 	.tiocmset =		pl2303_tiocmset,
1011 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1012 	.process_read_urb =	pl2303_process_read_urb,
1013 	.read_int_callback =	pl2303_read_int_callback,
1014 	.probe =		pl2303_probe,
1015 	.calc_num_ports =	pl2303_calc_num_ports,
1016 	.attach =		pl2303_startup,
1017 	.release =		pl2303_release,
1018 	.port_probe =		pl2303_port_probe,
1019 	.port_remove =		pl2303_port_remove,
1020 };
1021 
1022 static struct usb_serial_driver * const serial_drivers[] = {
1023 	&pl2303_device, NULL
1024 };
1025 
1026 module_usb_serial_driver(serial_drivers, id_table);
1027 
1028 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1029 MODULE_LICENSE("GPL v2");
1030