xref: /openbmc/linux/drivers/usb/serial/pl2303.c (revision b8265621)
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.rst 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(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GC) },
51 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GB) },
52 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GT) },
53 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GL) },
54 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GE) },
55 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GS) },
56 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
57 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID_RSAQ5) },
58 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID),
59 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
60 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC485),
61 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
62 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC232B),
63 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
64 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID2) },
65 	{ USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
66 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
67 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
68 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
69 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
70 	{ USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
71 	{ USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
72 	{ USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
73 	{ USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
74 	{ USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
75 	{ USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
76 	{ USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_PRODUCT_ID) },
77 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1),
78 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
79 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65),
80 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
81 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75),
82 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
83 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_EF81),
84 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
85 	{ USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_ID_S81) }, /* Benq/Siemens S81 */
86 	{ USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
87 	{ USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
88 	{ USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
89 	{ USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
90 	{ USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
91 	{ USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
92 	{ USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
93 	{ USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
94 	{ USB_DEVICE(ALCOR_VENDOR_ID, ALCOR_PRODUCT_ID),
95 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
96 	{ USB_DEVICE(WS002IN_VENDOR_ID, WS002IN_PRODUCT_ID) },
97 	{ USB_DEVICE(COREGA_VENDOR_ID, COREGA_PRODUCT_ID) },
98 	{ USB_DEVICE(YCCABLE_VENDOR_ID, YCCABLE_PRODUCT_ID) },
99 	{ USB_DEVICE(SUPERIAL_VENDOR_ID, SUPERIAL_PRODUCT_ID) },
100 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220_PRODUCT_ID) },
101 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220TA_PRODUCT_ID) },
102 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD381_PRODUCT_ID) },
103 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
104 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960TA_PRODUCT_ID) },
105 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
106 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
107 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM920_PRODUCT_ID) },
108 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM940_PRODUCT_ID) },
109 	{ USB_DEVICE(HP_VENDOR_ID, HP_TD620_PRODUCT_ID) },
110 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
111 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
112 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
113 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
114 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
115 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
116 	{ USB_DEVICE(AT_VENDOR_ID, AT_VTKIT3_PRODUCT_ID) },
117 	{ }					/* Terminating entry */
118 };
119 
120 MODULE_DEVICE_TABLE(usb, id_table);
121 
122 #define SET_LINE_REQUEST_TYPE		0x21
123 #define SET_LINE_REQUEST		0x20
124 
125 #define SET_CONTROL_REQUEST_TYPE	0x21
126 #define SET_CONTROL_REQUEST		0x22
127 #define CONTROL_DTR			0x01
128 #define CONTROL_RTS			0x02
129 
130 #define BREAK_REQUEST_TYPE		0x21
131 #define BREAK_REQUEST			0x23
132 #define BREAK_ON			0xffff
133 #define BREAK_OFF			0x0000
134 
135 #define GET_LINE_REQUEST_TYPE		0xa1
136 #define GET_LINE_REQUEST		0x21
137 
138 #define VENDOR_WRITE_REQUEST_TYPE	0x40
139 #define VENDOR_WRITE_REQUEST		0x01
140 #define VENDOR_WRITE_NREQUEST		0x80
141 
142 #define VENDOR_READ_REQUEST_TYPE	0xc0
143 #define VENDOR_READ_REQUEST		0x01
144 #define VENDOR_READ_NREQUEST		0x81
145 
146 #define UART_STATE_INDEX		8
147 #define UART_STATE_MSR_MASK		0x8b
148 #define UART_STATE_TRANSIENT_MASK	0x74
149 #define UART_DCD			0x01
150 #define UART_DSR			0x02
151 #define UART_BREAK_ERROR		0x04
152 #define UART_RING			0x08
153 #define UART_FRAME_ERROR		0x10
154 #define UART_PARITY_ERROR		0x20
155 #define UART_OVERRUN_ERROR		0x40
156 #define UART_CTS			0x80
157 
158 #define PL2303_FLOWCTRL_MASK		0xf0
159 
160 #define PL2303_READ_TYPE_HX_STATUS	0x8080
161 
162 #define PL2303_HXN_RESET_REG		0x07
163 #define PL2303_HXN_RESET_UPSTREAM_PIPE	0x02
164 #define PL2303_HXN_RESET_DOWNSTREAM_PIPE	0x01
165 
166 #define PL2303_HXN_FLOWCTRL_REG		0x0a
167 #define PL2303_HXN_FLOWCTRL_MASK	0x1c
168 #define PL2303_HXN_FLOWCTRL_NONE	0x1c
169 #define PL2303_HXN_FLOWCTRL_RTS_CTS	0x18
170 #define PL2303_HXN_FLOWCTRL_XON_XOFF	0x0c
171 
172 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
173 
174 enum pl2303_type {
175 	TYPE_01,	/* Type 0 and 1 (difference unknown) */
176 	TYPE_HX,	/* HX version of the pl2303 chip */
177 	TYPE_HXN,	/* HXN version of the pl2303 chip */
178 	TYPE_COUNT
179 };
180 
181 struct pl2303_type_data {
182 	speed_t max_baud_rate;
183 	unsigned long quirks;
184 	unsigned int no_autoxonxoff:1;
185 };
186 
187 struct pl2303_serial_private {
188 	const struct pl2303_type_data *type;
189 	unsigned long quirks;
190 };
191 
192 struct pl2303_private {
193 	spinlock_t lock;
194 	u8 line_control;
195 	u8 line_status;
196 
197 	u8 line_settings[7];
198 };
199 
200 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
201 	[TYPE_01] = {
202 		.max_baud_rate		= 1228800,
203 		.quirks			= PL2303_QUIRK_LEGACY,
204 		.no_autoxonxoff		= true,
205 	},
206 	[TYPE_HX] = {
207 		.max_baud_rate		= 12000000,
208 	},
209 	[TYPE_HXN] = {
210 		.max_baud_rate		= 12000000,
211 	},
212 };
213 
214 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
215 							unsigned char buf[1])
216 {
217 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
218 	struct device *dev = &serial->interface->dev;
219 	u8 request;
220 	int res;
221 
222 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
223 		request = VENDOR_READ_NREQUEST;
224 	else
225 		request = VENDOR_READ_REQUEST;
226 
227 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
228 			request, VENDOR_READ_REQUEST_TYPE,
229 			value, 0, buf, 1, 100);
230 	if (res != 1) {
231 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
232 								value, res);
233 		if (res >= 0)
234 			res = -EIO;
235 
236 		return res;
237 	}
238 
239 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
240 
241 	return 0;
242 }
243 
244 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
245 {
246 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
247 	struct device *dev = &serial->interface->dev;
248 	u8 request;
249 	int res;
250 
251 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
252 
253 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
254 		request = VENDOR_WRITE_NREQUEST;
255 	else
256 		request = VENDOR_WRITE_REQUEST;
257 
258 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
259 			request, VENDOR_WRITE_REQUEST_TYPE,
260 			value, index, NULL, 0, 100);
261 	if (res) {
262 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
263 								value, res);
264 		return res;
265 	}
266 
267 	return 0;
268 }
269 
270 static int pl2303_update_reg(struct usb_serial *serial, u8 reg, u8 mask, u8 val)
271 {
272 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
273 	int ret = 0;
274 	u8 *buf;
275 
276 	buf = kmalloc(1, GFP_KERNEL);
277 	if (!buf)
278 		return -ENOMEM;
279 
280 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
281 		ret = pl2303_vendor_read(serial, reg, buf);
282 	else
283 		ret = pl2303_vendor_read(serial, reg | 0x80, buf);
284 
285 	if (ret)
286 		goto out_free;
287 
288 	*buf &= ~mask;
289 	*buf |= val & mask;
290 
291 	ret = pl2303_vendor_write(serial, reg, *buf);
292 out_free:
293 	kfree(buf);
294 
295 	return ret;
296 }
297 
298 static int pl2303_probe(struct usb_serial *serial,
299 					const struct usb_device_id *id)
300 {
301 	usb_set_serial_data(serial, (void *)id->driver_info);
302 
303 	return 0;
304 }
305 
306 /*
307  * Use interrupt endpoint from first interface if available.
308  *
309  * This is needed due to the looney way its endpoints are set up.
310  */
311 static int pl2303_endpoint_hack(struct usb_serial *serial,
312 					struct usb_serial_endpoints *epds)
313 {
314 	struct usb_interface *interface = serial->interface;
315 	struct usb_device *dev = serial->dev;
316 	struct device *ddev = &interface->dev;
317 	struct usb_host_interface *iface_desc;
318 	struct usb_endpoint_descriptor *endpoint;
319 	unsigned int i;
320 
321 	if (interface == dev->actconfig->interface[0])
322 		return 0;
323 
324 	/* check out the endpoints of the other interface */
325 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
326 
327 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
328 		endpoint = &iface_desc->endpoint[i].desc;
329 
330 		if (!usb_endpoint_is_int_in(endpoint))
331 			continue;
332 
333 		dev_dbg(ddev, "found interrupt in on separate interface\n");
334 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
335 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
336 	}
337 
338 	return 0;
339 }
340 
341 static int pl2303_calc_num_ports(struct usb_serial *serial,
342 					struct usb_serial_endpoints *epds)
343 {
344 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
345 	struct device *dev = &serial->interface->dev;
346 	int ret;
347 
348 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
349 		ret = pl2303_endpoint_hack(serial, epds);
350 		if (ret)
351 			return ret;
352 	}
353 
354 	if (epds->num_interrupt_in < 1) {
355 		dev_err(dev, "required interrupt-in endpoint missing\n");
356 		return -ENODEV;
357 	}
358 
359 	return 1;
360 }
361 
362 static int pl2303_startup(struct usb_serial *serial)
363 {
364 	struct pl2303_serial_private *spriv;
365 	enum pl2303_type type = TYPE_01;
366 	unsigned char *buf;
367 	int res;
368 
369 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
370 	if (!spriv)
371 		return -ENOMEM;
372 
373 	buf = kmalloc(1, GFP_KERNEL);
374 	if (!buf) {
375 		kfree(spriv);
376 		return -ENOMEM;
377 	}
378 
379 	if (serial->dev->descriptor.bDeviceClass == 0x02)
380 		type = TYPE_01;		/* type 0 */
381 	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
382 		type = TYPE_HX;
383 	else if (serial->dev->descriptor.bDeviceClass == 0x00)
384 		type = TYPE_01;		/* type 1 */
385 	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
386 		type = TYPE_01;		/* type 1 */
387 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
388 
389 	if (type == TYPE_HX) {
390 		res = usb_control_msg(serial->dev,
391 				usb_rcvctrlpipe(serial->dev, 0),
392 				VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
393 				PL2303_READ_TYPE_HX_STATUS, 0, buf, 1, 100);
394 		if (res != 1)
395 			type = TYPE_HXN;
396 	}
397 
398 	spriv->type = &pl2303_type_data[type];
399 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
400 	spriv->quirks |= spriv->type->quirks;
401 
402 	usb_set_serial_data(serial, spriv);
403 
404 	if (type != TYPE_HXN) {
405 		pl2303_vendor_read(serial, 0x8484, buf);
406 		pl2303_vendor_write(serial, 0x0404, 0);
407 		pl2303_vendor_read(serial, 0x8484, buf);
408 		pl2303_vendor_read(serial, 0x8383, buf);
409 		pl2303_vendor_read(serial, 0x8484, buf);
410 		pl2303_vendor_write(serial, 0x0404, 1);
411 		pl2303_vendor_read(serial, 0x8484, buf);
412 		pl2303_vendor_read(serial, 0x8383, buf);
413 		pl2303_vendor_write(serial, 0, 1);
414 		pl2303_vendor_write(serial, 1, 0);
415 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
416 			pl2303_vendor_write(serial, 2, 0x24);
417 		else
418 			pl2303_vendor_write(serial, 2, 0x44);
419 	}
420 
421 	kfree(buf);
422 
423 	return 0;
424 }
425 
426 static void pl2303_release(struct usb_serial *serial)
427 {
428 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
429 
430 	kfree(spriv);
431 }
432 
433 static int pl2303_port_probe(struct usb_serial_port *port)
434 {
435 	struct pl2303_private *priv;
436 
437 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
438 	if (!priv)
439 		return -ENOMEM;
440 
441 	spin_lock_init(&priv->lock);
442 
443 	usb_set_serial_port_data(port, priv);
444 
445 	port->port.drain_delay = 256;
446 
447 	return 0;
448 }
449 
450 static int pl2303_port_remove(struct usb_serial_port *port)
451 {
452 	struct pl2303_private *priv = usb_get_serial_port_data(port);
453 
454 	kfree(priv);
455 
456 	return 0;
457 }
458 
459 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
460 {
461 	struct usb_device *dev = port->serial->dev;
462 	int retval;
463 
464 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
465 
466 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
467 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
468 				 value, 0, NULL, 0, 100);
469 	if (retval)
470 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
471 
472 	return retval;
473 }
474 
475 /*
476  * Returns the nearest supported baud rate that can be set directly without
477  * using divisors.
478  */
479 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
480 {
481 	static const speed_t baud_sup[] = {
482 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
483 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
484 		614400, 921600, 1228800, 2457600, 3000000, 6000000
485 	};
486 
487 	unsigned i;
488 
489 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
490 		if (baud_sup[i] > baud)
491 			break;
492 	}
493 
494 	if (i == ARRAY_SIZE(baud_sup))
495 		baud = baud_sup[i - 1];
496 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
497 		baud = baud_sup[i - 1];
498 	else
499 		baud = baud_sup[i];
500 
501 	return baud;
502 }
503 
504 /*
505  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
506  *       use 9600 baud.
507  */
508 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
509 								speed_t baud)
510 {
511 	put_unaligned_le32(baud, buf);
512 
513 	return baud;
514 }
515 
516 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
517 								speed_t baud)
518 {
519 	unsigned int baseline, mantissa, exponent;
520 
521 	/*
522 	 * Apparently the formula is:
523 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
524 	 * where
525 	 *   mantissa = buf[8:0]
526 	 *   exponent = buf[11:9]
527 	 */
528 	baseline = 12000000 * 32;
529 	mantissa = baseline / baud;
530 	if (mantissa == 0)
531 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
532 	exponent = 0;
533 	while (mantissa >= 512) {
534 		if (exponent < 7) {
535 			mantissa >>= 2;	/* divide by 4 */
536 			exponent++;
537 		} else {
538 			/* Exponent is maxed. Trim mantissa and leave. */
539 			mantissa = 511;
540 			break;
541 		}
542 	}
543 
544 	buf[3] = 0x80;
545 	buf[2] = 0;
546 	buf[1] = exponent << 1 | mantissa >> 8;
547 	buf[0] = mantissa & 0xff;
548 
549 	/* Calculate and return the exact baud rate. */
550 	baud = (baseline / mantissa) >> (exponent << 1);
551 
552 	return baud;
553 }
554 
555 static void pl2303_encode_baud_rate(struct tty_struct *tty,
556 					struct usb_serial_port *port,
557 					u8 buf[4])
558 {
559 	struct usb_serial *serial = port->serial;
560 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
561 	speed_t	baud_sup;
562 	speed_t baud;
563 
564 	baud = tty_get_baud_rate(tty);
565 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
566 	if (!baud)
567 		return;
568 
569 	if (spriv->type->max_baud_rate)
570 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
571 	/*
572 	 * Use direct method for supported baud rates, otherwise use divisors.
573 	 */
574 	baud_sup = pl2303_get_supported_baud_rate(baud);
575 
576 	if (baud == baud_sup)
577 		baud = pl2303_encode_baud_rate_direct(buf, baud);
578 	else
579 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
580 
581 	/* Save resulting baud rate */
582 	tty_encode_baud_rate(tty, baud, baud);
583 	dev_dbg(&port->dev, "baud set = %u\n", baud);
584 }
585 
586 static int pl2303_get_line_request(struct usb_serial_port *port,
587 							unsigned char buf[7])
588 {
589 	struct usb_device *udev = port->serial->dev;
590 	int ret;
591 
592 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
593 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
594 				0, 0, buf, 7, 100);
595 	if (ret != 7) {
596 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
597 
598 		if (ret >= 0)
599 			ret = -EIO;
600 
601 		return ret;
602 	}
603 
604 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
605 
606 	return 0;
607 }
608 
609 static int pl2303_set_line_request(struct usb_serial_port *port,
610 							unsigned char buf[7])
611 {
612 	struct usb_device *udev = port->serial->dev;
613 	int ret;
614 
615 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
616 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
617 				0, 0, buf, 7, 100);
618 	if (ret < 0) {
619 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
620 		return ret;
621 	}
622 
623 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
624 
625 	return 0;
626 }
627 
628 static bool pl2303_termios_change(const struct ktermios *a, const struct ktermios *b)
629 {
630 	bool ixon_change;
631 
632 	ixon_change = ((a->c_iflag ^ b->c_iflag) & (IXON | IXANY)) ||
633 			a->c_cc[VSTART] != b->c_cc[VSTART] ||
634 			a->c_cc[VSTOP] != b->c_cc[VSTOP];
635 
636 	return tty_termios_hw_change(a, b) || ixon_change;
637 }
638 
639 static bool pl2303_enable_xonxoff(struct tty_struct *tty, const struct pl2303_type_data *type)
640 {
641 	if (!I_IXON(tty) || I_IXANY(tty))
642 		return false;
643 
644 	if (START_CHAR(tty) != 0x11 || STOP_CHAR(tty) != 0x13)
645 		return false;
646 
647 	if (type->no_autoxonxoff)
648 		return false;
649 
650 	return true;
651 }
652 
653 static void pl2303_set_termios(struct tty_struct *tty,
654 		struct usb_serial_port *port, struct ktermios *old_termios)
655 {
656 	struct usb_serial *serial = port->serial;
657 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
658 	struct pl2303_private *priv = usb_get_serial_port_data(port);
659 	unsigned long flags;
660 	unsigned char *buf;
661 	int ret;
662 	u8 control;
663 
664 	if (old_termios && !pl2303_termios_change(&tty->termios, old_termios))
665 		return;
666 
667 	buf = kzalloc(7, GFP_KERNEL);
668 	if (!buf) {
669 		/* Report back no change occurred */
670 		if (old_termios)
671 			tty->termios = *old_termios;
672 		return;
673 	}
674 
675 	pl2303_get_line_request(port, buf);
676 
677 	switch (C_CSIZE(tty)) {
678 	case CS5:
679 		buf[6] = 5;
680 		break;
681 	case CS6:
682 		buf[6] = 6;
683 		break;
684 	case CS7:
685 		buf[6] = 7;
686 		break;
687 	default:
688 	case CS8:
689 		buf[6] = 8;
690 	}
691 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
692 
693 	/* For reference buf[0]:buf[3] baud rate value */
694 	pl2303_encode_baud_rate(tty, port, &buf[0]);
695 
696 	/* For reference buf[4]=0 is 1 stop bits */
697 	/* For reference buf[4]=1 is 1.5 stop bits */
698 	/* For reference buf[4]=2 is 2 stop bits */
699 	if (C_CSTOPB(tty)) {
700 		/*
701 		 * NOTE: Comply with "real" UARTs / RS232:
702 		 *       use 1.5 instead of 2 stop bits with 5 data bits
703 		 */
704 		if (C_CSIZE(tty) == CS5) {
705 			buf[4] = 1;
706 			dev_dbg(&port->dev, "stop bits = 1.5\n");
707 		} else {
708 			buf[4] = 2;
709 			dev_dbg(&port->dev, "stop bits = 2\n");
710 		}
711 	} else {
712 		buf[4] = 0;
713 		dev_dbg(&port->dev, "stop bits = 1\n");
714 	}
715 
716 	if (C_PARENB(tty)) {
717 		/* For reference buf[5]=0 is none parity */
718 		/* For reference buf[5]=1 is odd parity */
719 		/* For reference buf[5]=2 is even parity */
720 		/* For reference buf[5]=3 is mark parity */
721 		/* For reference buf[5]=4 is space parity */
722 		if (C_PARODD(tty)) {
723 			if (C_CMSPAR(tty)) {
724 				buf[5] = 3;
725 				dev_dbg(&port->dev, "parity = mark\n");
726 			} else {
727 				buf[5] = 1;
728 				dev_dbg(&port->dev, "parity = odd\n");
729 			}
730 		} else {
731 			if (C_CMSPAR(tty)) {
732 				buf[5] = 4;
733 				dev_dbg(&port->dev, "parity = space\n");
734 			} else {
735 				buf[5] = 2;
736 				dev_dbg(&port->dev, "parity = even\n");
737 			}
738 		}
739 	} else {
740 		buf[5] = 0;
741 		dev_dbg(&port->dev, "parity = none\n");
742 	}
743 
744 	/*
745 	 * Some PL2303 are known to lose bytes if you change serial settings
746 	 * even to the same values as before. Thus we actually need to filter
747 	 * in this specific case.
748 	 *
749 	 * Note that the tty_termios_hw_change check above is not sufficient
750 	 * as a previously requested baud rate may differ from the one
751 	 * actually used (and stored in old_termios).
752 	 *
753 	 * NOTE: No additional locking needed for line_settings as it is
754 	 *       only used in set_termios, which is serialised against itself.
755 	 */
756 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
757 		ret = pl2303_set_line_request(port, buf);
758 		if (!ret)
759 			memcpy(priv->line_settings, buf, 7);
760 	}
761 
762 	/* change control lines if we are switching to or from B0 */
763 	spin_lock_irqsave(&priv->lock, flags);
764 	control = priv->line_control;
765 	if (C_BAUD(tty) == B0)
766 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
767 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
768 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
769 	if (control != priv->line_control) {
770 		control = priv->line_control;
771 		spin_unlock_irqrestore(&priv->lock, flags);
772 		pl2303_set_control_lines(port, control);
773 	} else {
774 		spin_unlock_irqrestore(&priv->lock, flags);
775 	}
776 
777 	if (C_CRTSCTS(tty)) {
778 		if (spriv->quirks & PL2303_QUIRK_LEGACY) {
779 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x40);
780 		} else if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
781 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
782 					PL2303_HXN_FLOWCTRL_MASK,
783 					PL2303_HXN_FLOWCTRL_RTS_CTS);
784 		} else {
785 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x60);
786 		}
787 	} else if (pl2303_enable_xonxoff(tty, spriv->type)) {
788 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
789 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
790 					PL2303_HXN_FLOWCTRL_MASK,
791 					PL2303_HXN_FLOWCTRL_XON_XOFF);
792 		} else {
793 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0xc0);
794 		}
795 	} else {
796 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
797 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
798 					PL2303_HXN_FLOWCTRL_MASK,
799 					PL2303_HXN_FLOWCTRL_NONE);
800 		} else {
801 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0);
802 		}
803 	}
804 
805 	kfree(buf);
806 }
807 
808 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
809 {
810 	struct pl2303_private *priv = usb_get_serial_port_data(port);
811 	unsigned long flags;
812 	u8 control;
813 
814 	spin_lock_irqsave(&priv->lock, flags);
815 	if (on)
816 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
817 	else
818 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
819 	control = priv->line_control;
820 	spin_unlock_irqrestore(&priv->lock, flags);
821 
822 	pl2303_set_control_lines(port, control);
823 }
824 
825 static void pl2303_close(struct usb_serial_port *port)
826 {
827 	usb_serial_generic_close(port);
828 	usb_kill_urb(port->interrupt_in_urb);
829 	pl2303_set_break(port, false);
830 }
831 
832 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
833 {
834 	struct usb_serial *serial = port->serial;
835 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
836 	int result;
837 
838 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
839 		usb_clear_halt(serial->dev, port->write_urb->pipe);
840 		usb_clear_halt(serial->dev, port->read_urb->pipe);
841 	} else {
842 		/* reset upstream data pipes */
843 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
844 			pl2303_vendor_write(serial, PL2303_HXN_RESET_REG,
845 					PL2303_HXN_RESET_UPSTREAM_PIPE |
846 					PL2303_HXN_RESET_DOWNSTREAM_PIPE);
847 		} else {
848 			pl2303_vendor_write(serial, 8, 0);
849 			pl2303_vendor_write(serial, 9, 0);
850 		}
851 	}
852 
853 	/* Setup termios */
854 	if (tty)
855 		pl2303_set_termios(tty, port, NULL);
856 
857 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
858 	if (result) {
859 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
860 			result);
861 		return result;
862 	}
863 
864 	result = usb_serial_generic_open(tty, port);
865 	if (result) {
866 		usb_kill_urb(port->interrupt_in_urb);
867 		return result;
868 	}
869 
870 	return 0;
871 }
872 
873 static int pl2303_tiocmset(struct tty_struct *tty,
874 			   unsigned int set, unsigned int clear)
875 {
876 	struct usb_serial_port *port = tty->driver_data;
877 	struct pl2303_private *priv = usb_get_serial_port_data(port);
878 	unsigned long flags;
879 	u8 control;
880 	int ret;
881 
882 	spin_lock_irqsave(&priv->lock, flags);
883 	if (set & TIOCM_RTS)
884 		priv->line_control |= CONTROL_RTS;
885 	if (set & TIOCM_DTR)
886 		priv->line_control |= CONTROL_DTR;
887 	if (clear & TIOCM_RTS)
888 		priv->line_control &= ~CONTROL_RTS;
889 	if (clear & TIOCM_DTR)
890 		priv->line_control &= ~CONTROL_DTR;
891 	control = priv->line_control;
892 	spin_unlock_irqrestore(&priv->lock, flags);
893 
894 	ret = pl2303_set_control_lines(port, control);
895 	if (ret)
896 		return usb_translate_errors(ret);
897 
898 	return 0;
899 }
900 
901 static int pl2303_tiocmget(struct tty_struct *tty)
902 {
903 	struct usb_serial_port *port = tty->driver_data;
904 	struct pl2303_private *priv = usb_get_serial_port_data(port);
905 	unsigned long flags;
906 	unsigned int mcr;
907 	unsigned int status;
908 	unsigned int result;
909 
910 	spin_lock_irqsave(&priv->lock, flags);
911 	mcr = priv->line_control;
912 	status = priv->line_status;
913 	spin_unlock_irqrestore(&priv->lock, flags);
914 
915 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
916 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
917 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
918 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
919 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
920 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
921 
922 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
923 
924 	return result;
925 }
926 
927 static int pl2303_carrier_raised(struct usb_serial_port *port)
928 {
929 	struct pl2303_private *priv = usb_get_serial_port_data(port);
930 
931 	if (priv->line_status & UART_DCD)
932 		return 1;
933 
934 	return 0;
935 }
936 
937 static int pl2303_get_serial(struct tty_struct *tty,
938 			struct serial_struct *ss)
939 {
940 	struct usb_serial_port *port = tty->driver_data;
941 
942 	ss->type = PORT_16654;
943 	ss->line = port->minor;
944 	ss->port = port->port_number;
945 	ss->baud_base = 460800;
946 	return 0;
947 }
948 
949 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
950 {
951 	struct usb_serial *serial = port->serial;
952 	u16 state;
953 	int result;
954 
955 	if (enable)
956 		state = BREAK_ON;
957 	else
958 		state = BREAK_OFF;
959 
960 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
961 			state == BREAK_OFF ? "off" : "on");
962 
963 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
964 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
965 				 0, NULL, 0, 100);
966 	if (result)
967 		dev_err(&port->dev, "error sending break = %d\n", result);
968 }
969 
970 static void pl2303_break_ctl(struct tty_struct *tty, int state)
971 {
972 	struct usb_serial_port *port = tty->driver_data;
973 
974 	pl2303_set_break(port, state);
975 }
976 
977 static void pl2303_update_line_status(struct usb_serial_port *port,
978 				      unsigned char *data,
979 				      unsigned int actual_length)
980 {
981 	struct usb_serial *serial = port->serial;
982 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
983 	struct pl2303_private *priv = usb_get_serial_port_data(port);
984 	struct tty_struct *tty;
985 	unsigned long flags;
986 	unsigned int status_idx = UART_STATE_INDEX;
987 	u8 status;
988 	u8 delta;
989 
990 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
991 		status_idx = 0;
992 
993 	if (actual_length < status_idx + 1)
994 		return;
995 
996 	status = data[status_idx];
997 
998 	/* Save off the uart status for others to look at */
999 	spin_lock_irqsave(&priv->lock, flags);
1000 	delta = priv->line_status ^ status;
1001 	priv->line_status = status;
1002 	spin_unlock_irqrestore(&priv->lock, flags);
1003 
1004 	if (status & UART_BREAK_ERROR)
1005 		usb_serial_handle_break(port);
1006 
1007 	if (delta & UART_STATE_MSR_MASK) {
1008 		if (delta & UART_CTS)
1009 			port->icount.cts++;
1010 		if (delta & UART_DSR)
1011 			port->icount.dsr++;
1012 		if (delta & UART_RING)
1013 			port->icount.rng++;
1014 		if (delta & UART_DCD) {
1015 			port->icount.dcd++;
1016 			tty = tty_port_tty_get(&port->port);
1017 			if (tty) {
1018 				usb_serial_handle_dcd_change(port, tty,
1019 							status & UART_DCD);
1020 				tty_kref_put(tty);
1021 			}
1022 		}
1023 
1024 		wake_up_interruptible(&port->port.delta_msr_wait);
1025 	}
1026 }
1027 
1028 static void pl2303_read_int_callback(struct urb *urb)
1029 {
1030 	struct usb_serial_port *port =  urb->context;
1031 	unsigned char *data = urb->transfer_buffer;
1032 	unsigned int actual_length = urb->actual_length;
1033 	int status = urb->status;
1034 	int retval;
1035 
1036 	switch (status) {
1037 	case 0:
1038 		/* success */
1039 		break;
1040 	case -ECONNRESET:
1041 	case -ENOENT:
1042 	case -ESHUTDOWN:
1043 		/* this urb is terminated, clean up */
1044 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
1045 			__func__, status);
1046 		return;
1047 	default:
1048 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
1049 			__func__, status);
1050 		goto exit;
1051 	}
1052 
1053 	usb_serial_debug_data(&port->dev, __func__,
1054 			      urb->actual_length, urb->transfer_buffer);
1055 
1056 	pl2303_update_line_status(port, data, actual_length);
1057 
1058 exit:
1059 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1060 	if (retval) {
1061 		dev_err(&port->dev,
1062 			"%s - usb_submit_urb failed with result %d\n",
1063 			__func__, retval);
1064 	}
1065 }
1066 
1067 static void pl2303_process_read_urb(struct urb *urb)
1068 {
1069 	struct usb_serial_port *port = urb->context;
1070 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1071 	unsigned char *data = urb->transfer_buffer;
1072 	char tty_flag = TTY_NORMAL;
1073 	unsigned long flags;
1074 	u8 line_status;
1075 	int i;
1076 
1077 	/* update line status */
1078 	spin_lock_irqsave(&priv->lock, flags);
1079 	line_status = priv->line_status;
1080 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
1081 	spin_unlock_irqrestore(&priv->lock, flags);
1082 
1083 	if (!urb->actual_length)
1084 		return;
1085 
1086 	/*
1087 	 * Break takes precedence over parity, which takes precedence over
1088 	 * framing errors.
1089 	 */
1090 	if (line_status & UART_BREAK_ERROR)
1091 		tty_flag = TTY_BREAK;
1092 	else if (line_status & UART_PARITY_ERROR)
1093 		tty_flag = TTY_PARITY;
1094 	else if (line_status & UART_FRAME_ERROR)
1095 		tty_flag = TTY_FRAME;
1096 
1097 	if (tty_flag != TTY_NORMAL)
1098 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
1099 								tty_flag);
1100 	/* overrun is special, not associated with a char */
1101 	if (line_status & UART_OVERRUN_ERROR)
1102 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
1103 
1104 	if (port->port.console && port->sysrq) {
1105 		for (i = 0; i < urb->actual_length; ++i)
1106 			if (!usb_serial_handle_sysrq_char(port, data[i]))
1107 				tty_insert_flip_char(&port->port, data[i],
1108 						tty_flag);
1109 	} else {
1110 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
1111 							urb->actual_length);
1112 	}
1113 
1114 	tty_flip_buffer_push(&port->port);
1115 }
1116 
1117 static struct usb_serial_driver pl2303_device = {
1118 	.driver = {
1119 		.owner =	THIS_MODULE,
1120 		.name =		"pl2303",
1121 	},
1122 	.id_table =		id_table,
1123 	.num_bulk_in =		1,
1124 	.num_bulk_out =		1,
1125 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
1126 	.bulk_in_size =		256,
1127 	.bulk_out_size =	256,
1128 	.open =			pl2303_open,
1129 	.close =		pl2303_close,
1130 	.dtr_rts =		pl2303_dtr_rts,
1131 	.carrier_raised =	pl2303_carrier_raised,
1132 	.get_serial =		pl2303_get_serial,
1133 	.break_ctl =		pl2303_break_ctl,
1134 	.set_termios =		pl2303_set_termios,
1135 	.tiocmget =		pl2303_tiocmget,
1136 	.tiocmset =		pl2303_tiocmset,
1137 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1138 	.process_read_urb =	pl2303_process_read_urb,
1139 	.read_int_callback =	pl2303_read_int_callback,
1140 	.probe =		pl2303_probe,
1141 	.calc_num_ports =	pl2303_calc_num_ports,
1142 	.attach =		pl2303_startup,
1143 	.release =		pl2303_release,
1144 	.port_probe =		pl2303_port_probe,
1145 	.port_remove =		pl2303_port_remove,
1146 };
1147 
1148 static struct usb_serial_driver * const serial_drivers[] = {
1149 	&pl2303_device, NULL
1150 };
1151 
1152 module_usb_serial_driver(serial_drivers, id_table);
1153 
1154 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1155 MODULE_LICENSE("GPL v2");
1156