xref: /openbmc/linux/drivers/usb/serial/pl2303.c (revision 3a35093a)
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_LD381GC_PRODUCT_ID) },
104 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
105 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960TA_PRODUCT_ID) },
106 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
107 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
108 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM920_PRODUCT_ID) },
109 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM940_PRODUCT_ID) },
110 	{ USB_DEVICE(HP_VENDOR_ID, HP_TD620_PRODUCT_ID) },
111 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
112 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
113 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
114 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
115 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
116 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
117 	{ USB_DEVICE(AT_VENDOR_ID, AT_VTKIT3_PRODUCT_ID) },
118 	{ }					/* Terminating entry */
119 };
120 
121 MODULE_DEVICE_TABLE(usb, id_table);
122 
123 #define SET_LINE_REQUEST_TYPE		0x21
124 #define SET_LINE_REQUEST		0x20
125 
126 #define SET_CONTROL_REQUEST_TYPE	0x21
127 #define SET_CONTROL_REQUEST		0x22
128 #define CONTROL_DTR			0x01
129 #define CONTROL_RTS			0x02
130 
131 #define BREAK_REQUEST_TYPE		0x21
132 #define BREAK_REQUEST			0x23
133 #define BREAK_ON			0xffff
134 #define BREAK_OFF			0x0000
135 
136 #define GET_LINE_REQUEST_TYPE		0xa1
137 #define GET_LINE_REQUEST		0x21
138 
139 #define VENDOR_WRITE_REQUEST_TYPE	0x40
140 #define VENDOR_WRITE_REQUEST		0x01
141 #define VENDOR_WRITE_NREQUEST		0x80
142 
143 #define VENDOR_READ_REQUEST_TYPE	0xc0
144 #define VENDOR_READ_REQUEST		0x01
145 #define VENDOR_READ_NREQUEST		0x81
146 
147 #define UART_STATE_INDEX		8
148 #define UART_STATE_MSR_MASK		0x8b
149 #define UART_STATE_TRANSIENT_MASK	0x74
150 #define UART_DCD			0x01
151 #define UART_DSR			0x02
152 #define UART_BREAK_ERROR		0x04
153 #define UART_RING			0x08
154 #define UART_FRAME_ERROR		0x10
155 #define UART_PARITY_ERROR		0x20
156 #define UART_OVERRUN_ERROR		0x40
157 #define UART_CTS			0x80
158 
159 #define PL2303_FLOWCTRL_MASK		0xf0
160 
161 #define PL2303_READ_TYPE_HX_STATUS	0x8080
162 
163 #define PL2303_HXN_RESET_REG		0x07
164 #define PL2303_HXN_RESET_UPSTREAM_PIPE	0x02
165 #define PL2303_HXN_RESET_DOWNSTREAM_PIPE	0x01
166 
167 #define PL2303_HXN_FLOWCTRL_REG		0x0a
168 #define PL2303_HXN_FLOWCTRL_MASK	0x1c
169 #define PL2303_HXN_FLOWCTRL_NONE	0x1c
170 #define PL2303_HXN_FLOWCTRL_RTS_CTS	0x18
171 #define PL2303_HXN_FLOWCTRL_XON_XOFF	0x0c
172 
173 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
174 
175 enum pl2303_type {
176 	TYPE_01,	/* Type 0 and 1 (difference unknown) */
177 	TYPE_HX,	/* HX version of the pl2303 chip */
178 	TYPE_HXN,	/* HXN version of the pl2303 chip */
179 	TYPE_COUNT
180 };
181 
182 struct pl2303_type_data {
183 	speed_t max_baud_rate;
184 	unsigned long quirks;
185 	unsigned int no_autoxonxoff:1;
186 };
187 
188 struct pl2303_serial_private {
189 	const struct pl2303_type_data *type;
190 	unsigned long quirks;
191 };
192 
193 struct pl2303_private {
194 	spinlock_t lock;
195 	u8 line_control;
196 	u8 line_status;
197 
198 	u8 line_settings[7];
199 };
200 
201 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
202 	[TYPE_01] = {
203 		.max_baud_rate		= 1228800,
204 		.quirks			= PL2303_QUIRK_LEGACY,
205 		.no_autoxonxoff		= true,
206 	},
207 	[TYPE_HX] = {
208 		.max_baud_rate		= 12000000,
209 	},
210 	[TYPE_HXN] = {
211 		.max_baud_rate		= 12000000,
212 	},
213 };
214 
215 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
216 							unsigned char buf[1])
217 {
218 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
219 	struct device *dev = &serial->interface->dev;
220 	u8 request;
221 	int res;
222 
223 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
224 		request = VENDOR_READ_NREQUEST;
225 	else
226 		request = VENDOR_READ_REQUEST;
227 
228 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
229 			request, VENDOR_READ_REQUEST_TYPE,
230 			value, 0, buf, 1, 100);
231 	if (res != 1) {
232 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
233 								value, res);
234 		if (res >= 0)
235 			res = -EIO;
236 
237 		return res;
238 	}
239 
240 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
241 
242 	return 0;
243 }
244 
245 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
246 {
247 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
248 	struct device *dev = &serial->interface->dev;
249 	u8 request;
250 	int res;
251 
252 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
253 
254 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
255 		request = VENDOR_WRITE_NREQUEST;
256 	else
257 		request = VENDOR_WRITE_REQUEST;
258 
259 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
260 			request, VENDOR_WRITE_REQUEST_TYPE,
261 			value, index, NULL, 0, 100);
262 	if (res) {
263 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
264 								value, res);
265 		return res;
266 	}
267 
268 	return 0;
269 }
270 
271 static int pl2303_update_reg(struct usb_serial *serial, u8 reg, u8 mask, u8 val)
272 {
273 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
274 	int ret = 0;
275 	u8 *buf;
276 
277 	buf = kmalloc(1, GFP_KERNEL);
278 	if (!buf)
279 		return -ENOMEM;
280 
281 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
282 		ret = pl2303_vendor_read(serial, reg, buf);
283 	else
284 		ret = pl2303_vendor_read(serial, reg | 0x80, buf);
285 
286 	if (ret)
287 		goto out_free;
288 
289 	*buf &= ~mask;
290 	*buf |= val & mask;
291 
292 	ret = pl2303_vendor_write(serial, reg, *buf);
293 out_free:
294 	kfree(buf);
295 
296 	return ret;
297 }
298 
299 static int pl2303_probe(struct usb_serial *serial,
300 					const struct usb_device_id *id)
301 {
302 	usb_set_serial_data(serial, (void *)id->driver_info);
303 
304 	return 0;
305 }
306 
307 /*
308  * Use interrupt endpoint from first interface if available.
309  *
310  * This is needed due to the looney way its endpoints are set up.
311  */
312 static int pl2303_endpoint_hack(struct usb_serial *serial,
313 					struct usb_serial_endpoints *epds)
314 {
315 	struct usb_interface *interface = serial->interface;
316 	struct usb_device *dev = serial->dev;
317 	struct device *ddev = &interface->dev;
318 	struct usb_host_interface *iface_desc;
319 	struct usb_endpoint_descriptor *endpoint;
320 	unsigned int i;
321 
322 	if (interface == dev->actconfig->interface[0])
323 		return 0;
324 
325 	/* check out the endpoints of the other interface */
326 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
327 
328 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
329 		endpoint = &iface_desc->endpoint[i].desc;
330 
331 		if (!usb_endpoint_is_int_in(endpoint))
332 			continue;
333 
334 		dev_dbg(ddev, "found interrupt in on separate interface\n");
335 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
336 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
337 	}
338 
339 	return 0;
340 }
341 
342 static int pl2303_calc_num_ports(struct usb_serial *serial,
343 					struct usb_serial_endpoints *epds)
344 {
345 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
346 	struct device *dev = &serial->interface->dev;
347 	int ret;
348 
349 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
350 		ret = pl2303_endpoint_hack(serial, epds);
351 		if (ret)
352 			return ret;
353 	}
354 
355 	if (epds->num_interrupt_in < 1) {
356 		dev_err(dev, "required interrupt-in endpoint missing\n");
357 		return -ENODEV;
358 	}
359 
360 	return 1;
361 }
362 
363 static int pl2303_startup(struct usb_serial *serial)
364 {
365 	struct pl2303_serial_private *spriv;
366 	enum pl2303_type type = TYPE_01;
367 	unsigned char *buf;
368 	int res;
369 
370 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
371 	if (!spriv)
372 		return -ENOMEM;
373 
374 	buf = kmalloc(1, GFP_KERNEL);
375 	if (!buf) {
376 		kfree(spriv);
377 		return -ENOMEM;
378 	}
379 
380 	if (serial->dev->descriptor.bDeviceClass == 0x02)
381 		type = TYPE_01;		/* type 0 */
382 	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
383 		type = TYPE_HX;
384 	else if (serial->dev->descriptor.bDeviceClass == 0x00)
385 		type = TYPE_01;		/* type 1 */
386 	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
387 		type = TYPE_01;		/* type 1 */
388 	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
389 
390 	if (type == TYPE_HX) {
391 		res = usb_control_msg(serial->dev,
392 				usb_rcvctrlpipe(serial->dev, 0),
393 				VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
394 				PL2303_READ_TYPE_HX_STATUS, 0, buf, 1, 100);
395 		if (res != 1)
396 			type = TYPE_HXN;
397 	}
398 
399 	spriv->type = &pl2303_type_data[type];
400 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
401 	spriv->quirks |= spriv->type->quirks;
402 
403 	usb_set_serial_data(serial, spriv);
404 
405 	if (type != TYPE_HXN) {
406 		pl2303_vendor_read(serial, 0x8484, buf);
407 		pl2303_vendor_write(serial, 0x0404, 0);
408 		pl2303_vendor_read(serial, 0x8484, buf);
409 		pl2303_vendor_read(serial, 0x8383, buf);
410 		pl2303_vendor_read(serial, 0x8484, buf);
411 		pl2303_vendor_write(serial, 0x0404, 1);
412 		pl2303_vendor_read(serial, 0x8484, buf);
413 		pl2303_vendor_read(serial, 0x8383, buf);
414 		pl2303_vendor_write(serial, 0, 1);
415 		pl2303_vendor_write(serial, 1, 0);
416 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
417 			pl2303_vendor_write(serial, 2, 0x24);
418 		else
419 			pl2303_vendor_write(serial, 2, 0x44);
420 	}
421 
422 	kfree(buf);
423 
424 	return 0;
425 }
426 
427 static void pl2303_release(struct usb_serial *serial)
428 {
429 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
430 
431 	kfree(spriv);
432 }
433 
434 static int pl2303_port_probe(struct usb_serial_port *port)
435 {
436 	struct pl2303_private *priv;
437 
438 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
439 	if (!priv)
440 		return -ENOMEM;
441 
442 	spin_lock_init(&priv->lock);
443 
444 	usb_set_serial_port_data(port, priv);
445 
446 	port->port.drain_delay = 256;
447 
448 	return 0;
449 }
450 
451 static int pl2303_port_remove(struct usb_serial_port *port)
452 {
453 	struct pl2303_private *priv = usb_get_serial_port_data(port);
454 
455 	kfree(priv);
456 
457 	return 0;
458 }
459 
460 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
461 {
462 	struct usb_device *dev = port->serial->dev;
463 	int retval;
464 
465 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
466 
467 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
468 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
469 				 value, 0, NULL, 0, 100);
470 	if (retval)
471 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
472 
473 	return retval;
474 }
475 
476 /*
477  * Returns the nearest supported baud rate that can be set directly without
478  * using divisors.
479  */
480 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
481 {
482 	static const speed_t baud_sup[] = {
483 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
484 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
485 		614400, 921600, 1228800, 2457600, 3000000, 6000000
486 	};
487 
488 	unsigned i;
489 
490 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
491 		if (baud_sup[i] > baud)
492 			break;
493 	}
494 
495 	if (i == ARRAY_SIZE(baud_sup))
496 		baud = baud_sup[i - 1];
497 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
498 		baud = baud_sup[i - 1];
499 	else
500 		baud = baud_sup[i];
501 
502 	return baud;
503 }
504 
505 /*
506  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
507  *       use 9600 baud.
508  */
509 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
510 								speed_t baud)
511 {
512 	put_unaligned_le32(baud, buf);
513 
514 	return baud;
515 }
516 
517 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
518 								speed_t baud)
519 {
520 	unsigned int baseline, mantissa, exponent;
521 
522 	/*
523 	 * Apparently the formula is:
524 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
525 	 * where
526 	 *   mantissa = buf[8:0]
527 	 *   exponent = buf[11:9]
528 	 */
529 	baseline = 12000000 * 32;
530 	mantissa = baseline / baud;
531 	if (mantissa == 0)
532 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
533 	exponent = 0;
534 	while (mantissa >= 512) {
535 		if (exponent < 7) {
536 			mantissa >>= 2;	/* divide by 4 */
537 			exponent++;
538 		} else {
539 			/* Exponent is maxed. Trim mantissa and leave. */
540 			mantissa = 511;
541 			break;
542 		}
543 	}
544 
545 	buf[3] = 0x80;
546 	buf[2] = 0;
547 	buf[1] = exponent << 1 | mantissa >> 8;
548 	buf[0] = mantissa & 0xff;
549 
550 	/* Calculate and return the exact baud rate. */
551 	baud = (baseline / mantissa) >> (exponent << 1);
552 
553 	return baud;
554 }
555 
556 static void pl2303_encode_baud_rate(struct tty_struct *tty,
557 					struct usb_serial_port *port,
558 					u8 buf[4])
559 {
560 	struct usb_serial *serial = port->serial;
561 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
562 	speed_t	baud_sup;
563 	speed_t baud;
564 
565 	baud = tty_get_baud_rate(tty);
566 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
567 	if (!baud)
568 		return;
569 
570 	if (spriv->type->max_baud_rate)
571 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
572 	/*
573 	 * Use direct method for supported baud rates, otherwise use divisors.
574 	 */
575 	baud_sup = pl2303_get_supported_baud_rate(baud);
576 
577 	if (baud == baud_sup)
578 		baud = pl2303_encode_baud_rate_direct(buf, baud);
579 	else
580 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
581 
582 	/* Save resulting baud rate */
583 	tty_encode_baud_rate(tty, baud, baud);
584 	dev_dbg(&port->dev, "baud set = %u\n", baud);
585 }
586 
587 static int pl2303_get_line_request(struct usb_serial_port *port,
588 							unsigned char buf[7])
589 {
590 	struct usb_device *udev = port->serial->dev;
591 	int ret;
592 
593 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
594 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
595 				0, 0, buf, 7, 100);
596 	if (ret != 7) {
597 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
598 
599 		if (ret >= 0)
600 			ret = -EIO;
601 
602 		return ret;
603 	}
604 
605 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
606 
607 	return 0;
608 }
609 
610 static int pl2303_set_line_request(struct usb_serial_port *port,
611 							unsigned char buf[7])
612 {
613 	struct usb_device *udev = port->serial->dev;
614 	int ret;
615 
616 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
617 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
618 				0, 0, buf, 7, 100);
619 	if (ret < 0) {
620 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
621 		return ret;
622 	}
623 
624 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
625 
626 	return 0;
627 }
628 
629 static bool pl2303_termios_change(const struct ktermios *a, const struct ktermios *b)
630 {
631 	bool ixon_change;
632 
633 	ixon_change = ((a->c_iflag ^ b->c_iflag) & (IXON | IXANY)) ||
634 			a->c_cc[VSTART] != b->c_cc[VSTART] ||
635 			a->c_cc[VSTOP] != b->c_cc[VSTOP];
636 
637 	return tty_termios_hw_change(a, b) || ixon_change;
638 }
639 
640 static bool pl2303_enable_xonxoff(struct tty_struct *tty, const struct pl2303_type_data *type)
641 {
642 	if (!I_IXON(tty) || I_IXANY(tty))
643 		return false;
644 
645 	if (START_CHAR(tty) != 0x11 || STOP_CHAR(tty) != 0x13)
646 		return false;
647 
648 	if (type->no_autoxonxoff)
649 		return false;
650 
651 	return true;
652 }
653 
654 static void pl2303_set_termios(struct tty_struct *tty,
655 		struct usb_serial_port *port, struct ktermios *old_termios)
656 {
657 	struct usb_serial *serial = port->serial;
658 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
659 	struct pl2303_private *priv = usb_get_serial_port_data(port);
660 	unsigned long flags;
661 	unsigned char *buf;
662 	int ret;
663 	u8 control;
664 
665 	if (old_termios && !pl2303_termios_change(&tty->termios, old_termios))
666 		return;
667 
668 	buf = kzalloc(7, GFP_KERNEL);
669 	if (!buf) {
670 		/* Report back no change occurred */
671 		if (old_termios)
672 			tty->termios = *old_termios;
673 		return;
674 	}
675 
676 	pl2303_get_line_request(port, buf);
677 
678 	switch (C_CSIZE(tty)) {
679 	case CS5:
680 		buf[6] = 5;
681 		break;
682 	case CS6:
683 		buf[6] = 6;
684 		break;
685 	case CS7:
686 		buf[6] = 7;
687 		break;
688 	default:
689 	case CS8:
690 		buf[6] = 8;
691 	}
692 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
693 
694 	/* For reference buf[0]:buf[3] baud rate value */
695 	pl2303_encode_baud_rate(tty, port, &buf[0]);
696 
697 	/* For reference buf[4]=0 is 1 stop bits */
698 	/* For reference buf[4]=1 is 1.5 stop bits */
699 	/* For reference buf[4]=2 is 2 stop bits */
700 	if (C_CSTOPB(tty)) {
701 		/*
702 		 * NOTE: Comply with "real" UARTs / RS232:
703 		 *       use 1.5 instead of 2 stop bits with 5 data bits
704 		 */
705 		if (C_CSIZE(tty) == CS5) {
706 			buf[4] = 1;
707 			dev_dbg(&port->dev, "stop bits = 1.5\n");
708 		} else {
709 			buf[4] = 2;
710 			dev_dbg(&port->dev, "stop bits = 2\n");
711 		}
712 	} else {
713 		buf[4] = 0;
714 		dev_dbg(&port->dev, "stop bits = 1\n");
715 	}
716 
717 	if (C_PARENB(tty)) {
718 		/* For reference buf[5]=0 is none parity */
719 		/* For reference buf[5]=1 is odd parity */
720 		/* For reference buf[5]=2 is even parity */
721 		/* For reference buf[5]=3 is mark parity */
722 		/* For reference buf[5]=4 is space parity */
723 		if (C_PARODD(tty)) {
724 			if (C_CMSPAR(tty)) {
725 				buf[5] = 3;
726 				dev_dbg(&port->dev, "parity = mark\n");
727 			} else {
728 				buf[5] = 1;
729 				dev_dbg(&port->dev, "parity = odd\n");
730 			}
731 		} else {
732 			if (C_CMSPAR(tty)) {
733 				buf[5] = 4;
734 				dev_dbg(&port->dev, "parity = space\n");
735 			} else {
736 				buf[5] = 2;
737 				dev_dbg(&port->dev, "parity = even\n");
738 			}
739 		}
740 	} else {
741 		buf[5] = 0;
742 		dev_dbg(&port->dev, "parity = none\n");
743 	}
744 
745 	/*
746 	 * Some PL2303 are known to lose bytes if you change serial settings
747 	 * even to the same values as before. Thus we actually need to filter
748 	 * in this specific case.
749 	 *
750 	 * Note that the tty_termios_hw_change check above is not sufficient
751 	 * as a previously requested baud rate may differ from the one
752 	 * actually used (and stored in old_termios).
753 	 *
754 	 * NOTE: No additional locking needed for line_settings as it is
755 	 *       only used in set_termios, which is serialised against itself.
756 	 */
757 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
758 		ret = pl2303_set_line_request(port, buf);
759 		if (!ret)
760 			memcpy(priv->line_settings, buf, 7);
761 	}
762 
763 	/* change control lines if we are switching to or from B0 */
764 	spin_lock_irqsave(&priv->lock, flags);
765 	control = priv->line_control;
766 	if (C_BAUD(tty) == B0)
767 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
768 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
769 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
770 	if (control != priv->line_control) {
771 		control = priv->line_control;
772 		spin_unlock_irqrestore(&priv->lock, flags);
773 		pl2303_set_control_lines(port, control);
774 	} else {
775 		spin_unlock_irqrestore(&priv->lock, flags);
776 	}
777 
778 	if (C_CRTSCTS(tty)) {
779 		if (spriv->quirks & PL2303_QUIRK_LEGACY) {
780 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x40);
781 		} else if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
782 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
783 					PL2303_HXN_FLOWCTRL_MASK,
784 					PL2303_HXN_FLOWCTRL_RTS_CTS);
785 		} else {
786 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x60);
787 		}
788 	} else if (pl2303_enable_xonxoff(tty, spriv->type)) {
789 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
790 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
791 					PL2303_HXN_FLOWCTRL_MASK,
792 					PL2303_HXN_FLOWCTRL_XON_XOFF);
793 		} else {
794 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0xc0);
795 		}
796 	} else {
797 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
798 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
799 					PL2303_HXN_FLOWCTRL_MASK,
800 					PL2303_HXN_FLOWCTRL_NONE);
801 		} else {
802 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0);
803 		}
804 	}
805 
806 	kfree(buf);
807 }
808 
809 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
810 {
811 	struct pl2303_private *priv = usb_get_serial_port_data(port);
812 	unsigned long flags;
813 	u8 control;
814 
815 	spin_lock_irqsave(&priv->lock, flags);
816 	if (on)
817 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
818 	else
819 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
820 	control = priv->line_control;
821 	spin_unlock_irqrestore(&priv->lock, flags);
822 
823 	pl2303_set_control_lines(port, control);
824 }
825 
826 static void pl2303_close(struct usb_serial_port *port)
827 {
828 	usb_serial_generic_close(port);
829 	usb_kill_urb(port->interrupt_in_urb);
830 	pl2303_set_break(port, false);
831 }
832 
833 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
834 {
835 	struct usb_serial *serial = port->serial;
836 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
837 	int result;
838 
839 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
840 		usb_clear_halt(serial->dev, port->write_urb->pipe);
841 		usb_clear_halt(serial->dev, port->read_urb->pipe);
842 	} else {
843 		/* reset upstream data pipes */
844 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
845 			pl2303_vendor_write(serial, PL2303_HXN_RESET_REG,
846 					PL2303_HXN_RESET_UPSTREAM_PIPE |
847 					PL2303_HXN_RESET_DOWNSTREAM_PIPE);
848 		} else {
849 			pl2303_vendor_write(serial, 8, 0);
850 			pl2303_vendor_write(serial, 9, 0);
851 		}
852 	}
853 
854 	/* Setup termios */
855 	if (tty)
856 		pl2303_set_termios(tty, port, NULL);
857 
858 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
859 	if (result) {
860 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
861 			result);
862 		return result;
863 	}
864 
865 	result = usb_serial_generic_open(tty, port);
866 	if (result) {
867 		usb_kill_urb(port->interrupt_in_urb);
868 		return result;
869 	}
870 
871 	return 0;
872 }
873 
874 static int pl2303_tiocmset(struct tty_struct *tty,
875 			   unsigned int set, unsigned int clear)
876 {
877 	struct usb_serial_port *port = tty->driver_data;
878 	struct pl2303_private *priv = usb_get_serial_port_data(port);
879 	unsigned long flags;
880 	u8 control;
881 	int ret;
882 
883 	spin_lock_irqsave(&priv->lock, flags);
884 	if (set & TIOCM_RTS)
885 		priv->line_control |= CONTROL_RTS;
886 	if (set & TIOCM_DTR)
887 		priv->line_control |= CONTROL_DTR;
888 	if (clear & TIOCM_RTS)
889 		priv->line_control &= ~CONTROL_RTS;
890 	if (clear & TIOCM_DTR)
891 		priv->line_control &= ~CONTROL_DTR;
892 	control = priv->line_control;
893 	spin_unlock_irqrestore(&priv->lock, flags);
894 
895 	ret = pl2303_set_control_lines(port, control);
896 	if (ret)
897 		return usb_translate_errors(ret);
898 
899 	return 0;
900 }
901 
902 static int pl2303_tiocmget(struct tty_struct *tty)
903 {
904 	struct usb_serial_port *port = tty->driver_data;
905 	struct pl2303_private *priv = usb_get_serial_port_data(port);
906 	unsigned long flags;
907 	unsigned int mcr;
908 	unsigned int status;
909 	unsigned int result;
910 
911 	spin_lock_irqsave(&priv->lock, flags);
912 	mcr = priv->line_control;
913 	status = priv->line_status;
914 	spin_unlock_irqrestore(&priv->lock, flags);
915 
916 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
917 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
918 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
919 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
920 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
921 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
922 
923 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
924 
925 	return result;
926 }
927 
928 static int pl2303_carrier_raised(struct usb_serial_port *port)
929 {
930 	struct pl2303_private *priv = usb_get_serial_port_data(port);
931 
932 	if (priv->line_status & UART_DCD)
933 		return 1;
934 
935 	return 0;
936 }
937 
938 static int pl2303_get_serial(struct tty_struct *tty,
939 			struct serial_struct *ss)
940 {
941 	struct usb_serial_port *port = tty->driver_data;
942 
943 	ss->type = PORT_16654;
944 	ss->line = port->minor;
945 	ss->port = port->port_number;
946 	ss->baud_base = 460800;
947 	return 0;
948 }
949 
950 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
951 {
952 	struct usb_serial *serial = port->serial;
953 	u16 state;
954 	int result;
955 
956 	if (enable)
957 		state = BREAK_ON;
958 	else
959 		state = BREAK_OFF;
960 
961 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
962 			state == BREAK_OFF ? "off" : "on");
963 
964 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
965 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
966 				 0, NULL, 0, 100);
967 	if (result)
968 		dev_err(&port->dev, "error sending break = %d\n", result);
969 }
970 
971 static void pl2303_break_ctl(struct tty_struct *tty, int state)
972 {
973 	struct usb_serial_port *port = tty->driver_data;
974 
975 	pl2303_set_break(port, state);
976 }
977 
978 static void pl2303_update_line_status(struct usb_serial_port *port,
979 				      unsigned char *data,
980 				      unsigned int actual_length)
981 {
982 	struct usb_serial *serial = port->serial;
983 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
984 	struct pl2303_private *priv = usb_get_serial_port_data(port);
985 	struct tty_struct *tty;
986 	unsigned long flags;
987 	unsigned int status_idx = UART_STATE_INDEX;
988 	u8 status;
989 	u8 delta;
990 
991 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
992 		status_idx = 0;
993 
994 	if (actual_length < status_idx + 1)
995 		return;
996 
997 	status = data[status_idx];
998 
999 	/* Save off the uart status for others to look at */
1000 	spin_lock_irqsave(&priv->lock, flags);
1001 	delta = priv->line_status ^ status;
1002 	priv->line_status = status;
1003 	spin_unlock_irqrestore(&priv->lock, flags);
1004 
1005 	if (status & UART_BREAK_ERROR)
1006 		usb_serial_handle_break(port);
1007 
1008 	if (delta & UART_STATE_MSR_MASK) {
1009 		if (delta & UART_CTS)
1010 			port->icount.cts++;
1011 		if (delta & UART_DSR)
1012 			port->icount.dsr++;
1013 		if (delta & UART_RING)
1014 			port->icount.rng++;
1015 		if (delta & UART_DCD) {
1016 			port->icount.dcd++;
1017 			tty = tty_port_tty_get(&port->port);
1018 			if (tty) {
1019 				usb_serial_handle_dcd_change(port, tty,
1020 							status & UART_DCD);
1021 				tty_kref_put(tty);
1022 			}
1023 		}
1024 
1025 		wake_up_interruptible(&port->port.delta_msr_wait);
1026 	}
1027 }
1028 
1029 static void pl2303_read_int_callback(struct urb *urb)
1030 {
1031 	struct usb_serial_port *port =  urb->context;
1032 	unsigned char *data = urb->transfer_buffer;
1033 	unsigned int actual_length = urb->actual_length;
1034 	int status = urb->status;
1035 	int retval;
1036 
1037 	switch (status) {
1038 	case 0:
1039 		/* success */
1040 		break;
1041 	case -ECONNRESET:
1042 	case -ENOENT:
1043 	case -ESHUTDOWN:
1044 		/* this urb is terminated, clean up */
1045 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
1046 			__func__, status);
1047 		return;
1048 	default:
1049 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
1050 			__func__, status);
1051 		goto exit;
1052 	}
1053 
1054 	usb_serial_debug_data(&port->dev, __func__,
1055 			      urb->actual_length, urb->transfer_buffer);
1056 
1057 	pl2303_update_line_status(port, data, actual_length);
1058 
1059 exit:
1060 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1061 	if (retval) {
1062 		dev_err(&port->dev,
1063 			"%s - usb_submit_urb failed with result %d\n",
1064 			__func__, retval);
1065 	}
1066 }
1067 
1068 static void pl2303_process_read_urb(struct urb *urb)
1069 {
1070 	struct usb_serial_port *port = urb->context;
1071 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1072 	unsigned char *data = urb->transfer_buffer;
1073 	char tty_flag = TTY_NORMAL;
1074 	unsigned long flags;
1075 	u8 line_status;
1076 	int i;
1077 
1078 	/* update line status */
1079 	spin_lock_irqsave(&priv->lock, flags);
1080 	line_status = priv->line_status;
1081 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
1082 	spin_unlock_irqrestore(&priv->lock, flags);
1083 
1084 	if (!urb->actual_length)
1085 		return;
1086 
1087 	/*
1088 	 * Break takes precedence over parity, which takes precedence over
1089 	 * framing errors.
1090 	 */
1091 	if (line_status & UART_BREAK_ERROR)
1092 		tty_flag = TTY_BREAK;
1093 	else if (line_status & UART_PARITY_ERROR)
1094 		tty_flag = TTY_PARITY;
1095 	else if (line_status & UART_FRAME_ERROR)
1096 		tty_flag = TTY_FRAME;
1097 
1098 	if (tty_flag != TTY_NORMAL)
1099 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
1100 								tty_flag);
1101 	/* overrun is special, not associated with a char */
1102 	if (line_status & UART_OVERRUN_ERROR)
1103 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
1104 
1105 	if (port->sysrq) {
1106 		for (i = 0; i < urb->actual_length; ++i)
1107 			if (!usb_serial_handle_sysrq_char(port, data[i]))
1108 				tty_insert_flip_char(&port->port, data[i],
1109 						tty_flag);
1110 	} else {
1111 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
1112 							urb->actual_length);
1113 	}
1114 
1115 	tty_flip_buffer_push(&port->port);
1116 }
1117 
1118 static struct usb_serial_driver pl2303_device = {
1119 	.driver = {
1120 		.owner =	THIS_MODULE,
1121 		.name =		"pl2303",
1122 	},
1123 	.id_table =		id_table,
1124 	.num_bulk_in =		1,
1125 	.num_bulk_out =		1,
1126 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
1127 	.bulk_in_size =		256,
1128 	.bulk_out_size =	256,
1129 	.open =			pl2303_open,
1130 	.close =		pl2303_close,
1131 	.dtr_rts =		pl2303_dtr_rts,
1132 	.carrier_raised =	pl2303_carrier_raised,
1133 	.get_serial =		pl2303_get_serial,
1134 	.break_ctl =		pl2303_break_ctl,
1135 	.set_termios =		pl2303_set_termios,
1136 	.tiocmget =		pl2303_tiocmget,
1137 	.tiocmset =		pl2303_tiocmset,
1138 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1139 	.process_read_urb =	pl2303_process_read_urb,
1140 	.read_int_callback =	pl2303_read_int_callback,
1141 	.probe =		pl2303_probe,
1142 	.calc_num_ports =	pl2303_calc_num_ports,
1143 	.attach =		pl2303_startup,
1144 	.release =		pl2303_release,
1145 	.port_probe =		pl2303_port_probe,
1146 	.port_remove =		pl2303_port_remove,
1147 };
1148 
1149 static struct usb_serial_driver * const serial_drivers[] = {
1150 	&pl2303_device, NULL
1151 };
1152 
1153 module_usb_serial_driver(serial_drivers, id_table);
1154 
1155 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1156 MODULE_LICENSE("GPL v2");
1157