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 <linux/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 #define PL2303_QUIRK_NO_BREAK_GETLINE		BIT(3)
35 
36 static const struct usb_device_id id_table[] = {
37 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID),
38 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
39 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ2) },
40 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_DCU11) },
41 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ3) },
42 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_CHILITAG) },
43 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_PHAROS) },
44 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ALDIGA) },
45 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MMX) },
46 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GPRS) },
47 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_HCR331) },
48 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MOTOROLA) },
49 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ZTEK) },
50 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_TB) },
51 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GC) },
52 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GB) },
53 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GT) },
54 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GL) },
55 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GE) },
56 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GS) },
57 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
58 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID_RSAQ5) },
59 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID),
60 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
61 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC485),
62 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
63 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC232B),
64 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
65 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID2) },
66 	{ USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
67 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
68 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
69 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
70 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
71 	{ USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
72 	{ USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
73 	{ USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
74 	{ USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
75 	{ USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
76 	{ USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
77 	{ USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_PRODUCT_ID) },
78 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1),
79 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
80 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65),
81 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
82 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75),
83 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
84 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_EF81),
85 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
86 	{ USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_ID_S81) }, /* Benq/Siemens S81 */
87 	{ USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
88 	{ USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
89 	{ USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
90 	{ USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
91 	{ USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
92 	{ USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
93 	{ USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
94 	{ USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
95 	{ USB_DEVICE(ALCOR_VENDOR_ID, ALCOR_PRODUCT_ID),
96 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
97 	{ USB_DEVICE(WS002IN_VENDOR_ID, WS002IN_PRODUCT_ID) },
98 	{ USB_DEVICE(COREGA_VENDOR_ID, COREGA_PRODUCT_ID) },
99 	{ USB_DEVICE(YCCABLE_VENDOR_ID, YCCABLE_PRODUCT_ID) },
100 	{ USB_DEVICE(SUPERIAL_VENDOR_ID, SUPERIAL_PRODUCT_ID) },
101 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220_PRODUCT_ID) },
102 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220TA_PRODUCT_ID) },
103 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD381_PRODUCT_ID) },
104 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD381GC_PRODUCT_ID) },
105 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
106 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960TA_PRODUCT_ID) },
107 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
108 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
109 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM920_PRODUCT_ID) },
110 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM930_PRODUCT_ID) },
111 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM940_PRODUCT_ID) },
112 	{ USB_DEVICE(HP_VENDOR_ID, HP_TD620_PRODUCT_ID) },
113 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
114 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
115 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
116 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
117 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
118 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530GC_PRODUCT_ID) },
119 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
120 	{ USB_DEVICE(AT_VENDOR_ID, AT_VTKIT3_PRODUCT_ID) },
121 	{ USB_DEVICE(IBM_VENDOR_ID, IBM_PRODUCT_ID) },
122 	{ USB_DEVICE(MACROSILICON_VENDOR_ID, MACROSILICON_MS3020_PRODUCT_ID) },
123 	{ }					/* Terminating entry */
124 };
125 
126 MODULE_DEVICE_TABLE(usb, id_table);
127 
128 #define SET_LINE_REQUEST_TYPE		0x21
129 #define SET_LINE_REQUEST		0x20
130 
131 #define SET_CONTROL_REQUEST_TYPE	0x21
132 #define SET_CONTROL_REQUEST		0x22
133 #define CONTROL_DTR			0x01
134 #define CONTROL_RTS			0x02
135 
136 #define BREAK_REQUEST_TYPE		0x21
137 #define BREAK_REQUEST			0x23
138 #define BREAK_ON			0xffff
139 #define BREAK_OFF			0x0000
140 
141 #define GET_LINE_REQUEST_TYPE		0xa1
142 #define GET_LINE_REQUEST		0x21
143 
144 #define VENDOR_WRITE_REQUEST_TYPE	0x40
145 #define VENDOR_WRITE_REQUEST		0x01
146 #define VENDOR_WRITE_NREQUEST		0x80
147 
148 #define VENDOR_READ_REQUEST_TYPE	0xc0
149 #define VENDOR_READ_REQUEST		0x01
150 #define VENDOR_READ_NREQUEST		0x81
151 
152 #define UART_STATE_INDEX		8
153 #define UART_STATE_MSR_MASK		0x8b
154 #define UART_STATE_TRANSIENT_MASK	0x74
155 #define UART_DCD			0x01
156 #define UART_DSR			0x02
157 #define UART_BREAK_ERROR		0x04
158 #define UART_RING			0x08
159 #define UART_FRAME_ERROR		0x10
160 #define UART_PARITY_ERROR		0x20
161 #define UART_OVERRUN_ERROR		0x40
162 #define UART_CTS			0x80
163 
164 #define PL2303_FLOWCTRL_MASK		0xf0
165 
166 #define PL2303_READ_TYPE_HX_STATUS	0x8080
167 
168 #define PL2303_HXN_RESET_REG		0x07
169 #define PL2303_HXN_RESET_UPSTREAM_PIPE	0x02
170 #define PL2303_HXN_RESET_DOWNSTREAM_PIPE	0x01
171 
172 #define PL2303_HXN_FLOWCTRL_REG		0x0a
173 #define PL2303_HXN_FLOWCTRL_MASK	0x1c
174 #define PL2303_HXN_FLOWCTRL_NONE	0x1c
175 #define PL2303_HXN_FLOWCTRL_RTS_CTS	0x18
176 #define PL2303_HXN_FLOWCTRL_XON_XOFF	0x0c
177 
178 static int pl2303_set_break(struct usb_serial_port *port, bool enable);
179 
180 enum pl2303_type {
181 	TYPE_H,
182 	TYPE_HX,
183 	TYPE_TA,
184 	TYPE_TB,
185 	TYPE_HXD,
186 	TYPE_HXN,
187 	TYPE_COUNT
188 };
189 
190 struct pl2303_type_data {
191 	const char *name;
192 	speed_t max_baud_rate;
193 	unsigned long quirks;
194 	unsigned int no_autoxonxoff:1;
195 	unsigned int no_divisors:1;
196 	unsigned int alt_divisors:1;
197 };
198 
199 struct pl2303_serial_private {
200 	const struct pl2303_type_data *type;
201 	unsigned long quirks;
202 };
203 
204 struct pl2303_private {
205 	spinlock_t lock;
206 	u8 line_control;
207 	u8 line_status;
208 
209 	u8 line_settings[7];
210 };
211 
212 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
213 	[TYPE_H] = {
214 		.name			= "H",
215 		.max_baud_rate		= 1228800,
216 		.quirks			= PL2303_QUIRK_LEGACY,
217 		.no_autoxonxoff		= true,
218 	},
219 	[TYPE_HX] = {
220 		.name			= "HX",
221 		.max_baud_rate		= 6000000,
222 	},
223 	[TYPE_TA] = {
224 		.name			= "TA",
225 		.max_baud_rate		= 6000000,
226 		.alt_divisors		= true,
227 	},
228 	[TYPE_TB] = {
229 		.name			= "TB",
230 		.max_baud_rate		= 12000000,
231 		.alt_divisors		= true,
232 	},
233 	[TYPE_HXD] = {
234 		.name			= "HXD",
235 		.max_baud_rate		= 12000000,
236 	},
237 	[TYPE_HXN] = {
238 		.name			= "G",
239 		.max_baud_rate		= 12000000,
240 		.no_divisors		= true,
241 	},
242 };
243 
244 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
245 							unsigned char buf[1])
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 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
253 		request = VENDOR_READ_NREQUEST;
254 	else
255 		request = VENDOR_READ_REQUEST;
256 
257 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
258 			request, VENDOR_READ_REQUEST_TYPE,
259 			value, 0, buf, 1, 100);
260 	if (res != 1) {
261 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
262 								value, res);
263 		if (res >= 0)
264 			res = -EIO;
265 
266 		return res;
267 	}
268 
269 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
270 
271 	return 0;
272 }
273 
274 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
275 {
276 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
277 	struct device *dev = &serial->interface->dev;
278 	u8 request;
279 	int res;
280 
281 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
282 
283 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
284 		request = VENDOR_WRITE_NREQUEST;
285 	else
286 		request = VENDOR_WRITE_REQUEST;
287 
288 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
289 			request, VENDOR_WRITE_REQUEST_TYPE,
290 			value, index, NULL, 0, 100);
291 	if (res) {
292 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
293 								value, res);
294 		return res;
295 	}
296 
297 	return 0;
298 }
299 
300 static int pl2303_update_reg(struct usb_serial *serial, u8 reg, u8 mask, u8 val)
301 {
302 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
303 	int ret = 0;
304 	u8 *buf;
305 
306 	buf = kmalloc(1, GFP_KERNEL);
307 	if (!buf)
308 		return -ENOMEM;
309 
310 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
311 		ret = pl2303_vendor_read(serial, reg, buf);
312 	else
313 		ret = pl2303_vendor_read(serial, reg | 0x80, buf);
314 
315 	if (ret)
316 		goto out_free;
317 
318 	*buf &= ~mask;
319 	*buf |= val & mask;
320 
321 	ret = pl2303_vendor_write(serial, reg, *buf);
322 out_free:
323 	kfree(buf);
324 
325 	return ret;
326 }
327 
328 static int pl2303_probe(struct usb_serial *serial,
329 					const struct usb_device_id *id)
330 {
331 	usb_set_serial_data(serial, (void *)id->driver_info);
332 
333 	return 0;
334 }
335 
336 /*
337  * Use interrupt endpoint from first interface if available.
338  *
339  * This is needed due to the looney way its endpoints are set up.
340  */
341 static int pl2303_endpoint_hack(struct usb_serial *serial,
342 					struct usb_serial_endpoints *epds)
343 {
344 	struct usb_interface *interface = serial->interface;
345 	struct usb_device *dev = serial->dev;
346 	struct device *ddev = &interface->dev;
347 	struct usb_host_interface *iface_desc;
348 	struct usb_endpoint_descriptor *endpoint;
349 	unsigned int i;
350 
351 	if (interface == dev->actconfig->interface[0])
352 		return 0;
353 
354 	/* check out the endpoints of the other interface */
355 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
356 
357 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
358 		endpoint = &iface_desc->endpoint[i].desc;
359 
360 		if (!usb_endpoint_is_int_in(endpoint))
361 			continue;
362 
363 		dev_dbg(ddev, "found interrupt in on separate interface\n");
364 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
365 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
366 	}
367 
368 	return 0;
369 }
370 
371 static int pl2303_calc_num_ports(struct usb_serial *serial,
372 					struct usb_serial_endpoints *epds)
373 {
374 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
375 	struct device *dev = &serial->interface->dev;
376 	int ret;
377 
378 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
379 		ret = pl2303_endpoint_hack(serial, epds);
380 		if (ret)
381 			return ret;
382 	}
383 
384 	if (epds->num_interrupt_in < 1) {
385 		dev_err(dev, "required interrupt-in endpoint missing\n");
386 		return -ENODEV;
387 	}
388 
389 	return 1;
390 }
391 
392 static bool pl2303_supports_hx_status(struct usb_serial *serial)
393 {
394 	int ret;
395 	u8 buf;
396 
397 	ret = usb_control_msg_recv(serial->dev, 0, VENDOR_READ_REQUEST,
398 			VENDOR_READ_REQUEST_TYPE, PL2303_READ_TYPE_HX_STATUS,
399 			0, &buf, 1, 100, GFP_KERNEL);
400 
401 	return ret == 0;
402 }
403 
404 static int pl2303_detect_type(struct usb_serial *serial)
405 {
406 	struct usb_device_descriptor *desc = &serial->dev->descriptor;
407 	u16 bcdDevice, bcdUSB;
408 
409 	/*
410 	 * Legacy PL2303H, variants 0 and 1 (difference unknown).
411 	 */
412 	if (desc->bDeviceClass == 0x02)
413 		return TYPE_H;		/* variant 0 */
414 
415 	if (desc->bMaxPacketSize0 != 0x40) {
416 		if (desc->bDeviceClass == 0x00 || desc->bDeviceClass == 0xff)
417 			return TYPE_H;	/* variant 1 */
418 
419 		return TYPE_H;		/* variant 0 */
420 	}
421 
422 	bcdDevice = le16_to_cpu(desc->bcdDevice);
423 	bcdUSB = le16_to_cpu(desc->bcdUSB);
424 
425 	switch (bcdUSB) {
426 	case 0x101:
427 		/* USB 1.0.1? Let's assume they meant 1.1... */
428 		fallthrough;
429 	case 0x110:
430 		switch (bcdDevice) {
431 		case 0x300:
432 			return TYPE_HX;
433 		case 0x400:
434 			return TYPE_HXD;
435 		default:
436 			return TYPE_HX;
437 		}
438 		break;
439 	case 0x200:
440 		switch (bcdDevice) {
441 		case 0x100:	/* GC */
442 		case 0x105:
443 			return TYPE_HXN;
444 		case 0x300:	/* GT / TA */
445 			if (pl2303_supports_hx_status(serial))
446 				return TYPE_TA;
447 			fallthrough;
448 		case 0x305:
449 		case 0x400:	/* GL */
450 		case 0x405:
451 			return TYPE_HXN;
452 		case 0x500:	/* GE / TB */
453 			if (pl2303_supports_hx_status(serial))
454 				return TYPE_TB;
455 			fallthrough;
456 		case 0x505:
457 		case 0x600:	/* GS */
458 		case 0x605:
459 		case 0x700:	/* GR */
460 		case 0x705:
461 		case 0x905:	/* GT-2AB */
462 		case 0x1005:	/* GC-Q20 */
463 			return TYPE_HXN;
464 		}
465 		break;
466 	}
467 
468 	dev_err(&serial->interface->dev,
469 			"unknown device type, please report to linux-usb@vger.kernel.org\n");
470 	return -ENODEV;
471 }
472 
473 static bool pl2303_is_hxd_clone(struct usb_serial *serial)
474 {
475 	struct usb_device *udev = serial->dev;
476 	unsigned char *buf;
477 	int ret;
478 
479 	buf = kmalloc(7, GFP_KERNEL);
480 	if (!buf)
481 		return false;
482 
483 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
484 			      GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
485 			      0, 0, buf, 7, 100);
486 
487 	kfree(buf);
488 
489 	return ret == -EPIPE;
490 }
491 
492 static int pl2303_startup(struct usb_serial *serial)
493 {
494 	struct pl2303_serial_private *spriv;
495 	enum pl2303_type type;
496 	unsigned char *buf;
497 	int ret;
498 
499 	ret = pl2303_detect_type(serial);
500 	if (ret < 0)
501 		return ret;
502 
503 	type = ret;
504 	dev_dbg(&serial->interface->dev, "device type: %s\n", pl2303_type_data[type].name);
505 
506 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
507 	if (!spriv)
508 		return -ENOMEM;
509 
510 	spriv->type = &pl2303_type_data[type];
511 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
512 	spriv->quirks |= spriv->type->quirks;
513 
514 	if (type == TYPE_HXD && pl2303_is_hxd_clone(serial))
515 		spriv->quirks |= PL2303_QUIRK_NO_BREAK_GETLINE;
516 
517 	usb_set_serial_data(serial, spriv);
518 
519 	if (type != TYPE_HXN) {
520 		buf = kmalloc(1, GFP_KERNEL);
521 		if (!buf) {
522 			kfree(spriv);
523 			return -ENOMEM;
524 		}
525 
526 		pl2303_vendor_read(serial, 0x8484, buf);
527 		pl2303_vendor_write(serial, 0x0404, 0);
528 		pl2303_vendor_read(serial, 0x8484, buf);
529 		pl2303_vendor_read(serial, 0x8383, buf);
530 		pl2303_vendor_read(serial, 0x8484, buf);
531 		pl2303_vendor_write(serial, 0x0404, 1);
532 		pl2303_vendor_read(serial, 0x8484, buf);
533 		pl2303_vendor_read(serial, 0x8383, buf);
534 		pl2303_vendor_write(serial, 0, 1);
535 		pl2303_vendor_write(serial, 1, 0);
536 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
537 			pl2303_vendor_write(serial, 2, 0x24);
538 		else
539 			pl2303_vendor_write(serial, 2, 0x44);
540 
541 		kfree(buf);
542 	}
543 
544 	return 0;
545 }
546 
547 static void pl2303_release(struct usb_serial *serial)
548 {
549 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
550 
551 	kfree(spriv);
552 }
553 
554 static int pl2303_port_probe(struct usb_serial_port *port)
555 {
556 	struct pl2303_private *priv;
557 
558 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
559 	if (!priv)
560 		return -ENOMEM;
561 
562 	spin_lock_init(&priv->lock);
563 
564 	usb_set_serial_port_data(port, priv);
565 
566 	port->port.drain_delay = 256;
567 
568 	return 0;
569 }
570 
571 static void pl2303_port_remove(struct usb_serial_port *port)
572 {
573 	struct pl2303_private *priv = usb_get_serial_port_data(port);
574 
575 	kfree(priv);
576 }
577 
578 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
579 {
580 	struct usb_device *dev = port->serial->dev;
581 	int retval;
582 
583 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
584 
585 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
586 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
587 				 value, 0, NULL, 0, 100);
588 	if (retval)
589 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
590 
591 	return retval;
592 }
593 
594 /*
595  * Returns the nearest supported baud rate that can be set directly without
596  * using divisors.
597  */
598 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
599 {
600 	static const speed_t baud_sup[] = {
601 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
602 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
603 		614400, 921600, 1228800, 2457600, 3000000, 6000000
604 	};
605 
606 	unsigned i;
607 
608 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
609 		if (baud_sup[i] > baud)
610 			break;
611 	}
612 
613 	if (i == ARRAY_SIZE(baud_sup))
614 		baud = baud_sup[i - 1];
615 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
616 		baud = baud_sup[i - 1];
617 	else
618 		baud = baud_sup[i];
619 
620 	return baud;
621 }
622 
623 /*
624  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
625  *       use 9600 baud.
626  */
627 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
628 								speed_t baud)
629 {
630 	put_unaligned_le32(baud, buf);
631 
632 	return baud;
633 }
634 
635 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
636 								speed_t baud)
637 {
638 	unsigned int baseline, mantissa, exponent;
639 
640 	/*
641 	 * Apparently the formula is:
642 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
643 	 * where
644 	 *   mantissa = buf[8:0]
645 	 *   exponent = buf[11:9]
646 	 */
647 	baseline = 12000000 * 32;
648 	mantissa = baseline / baud;
649 	if (mantissa == 0)
650 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
651 	exponent = 0;
652 	while (mantissa >= 512) {
653 		if (exponent < 7) {
654 			mantissa >>= 2;	/* divide by 4 */
655 			exponent++;
656 		} else {
657 			/* Exponent is maxed. Trim mantissa and leave. */
658 			mantissa = 511;
659 			break;
660 		}
661 	}
662 
663 	buf[3] = 0x80;
664 	buf[2] = 0;
665 	buf[1] = exponent << 1 | mantissa >> 8;
666 	buf[0] = mantissa & 0xff;
667 
668 	/* Calculate and return the exact baud rate. */
669 	baud = (baseline / mantissa) >> (exponent << 1);
670 
671 	return baud;
672 }
673 
674 static speed_t pl2303_encode_baud_rate_divisor_alt(unsigned char buf[4],
675 								speed_t baud)
676 {
677 	unsigned int baseline, mantissa, exponent;
678 
679 	/*
680 	 * Apparently, for the TA version the formula is:
681 	 *   baudrate = 12M * 32 / (mantissa * 2^exponent)
682 	 * where
683 	 *   mantissa = buf[10:0]
684 	 *   exponent = buf[15:13 16]
685 	 */
686 	baseline = 12000000 * 32;
687 	mantissa = baseline / baud;
688 	if (mantissa == 0)
689 		mantissa = 1;   /* Avoid dividing by zero if baud > 32*12M. */
690 	exponent = 0;
691 	while (mantissa >= 2048) {
692 		if (exponent < 15) {
693 			mantissa >>= 1; /* divide by 2 */
694 			exponent++;
695 		} else {
696 			/* Exponent is maxed. Trim mantissa and leave. */
697 			mantissa = 2047;
698 			break;
699 		}
700 	}
701 
702 	buf[3] = 0x80;
703 	buf[2] = exponent & 0x01;
704 	buf[1] = (exponent & ~0x01) << 4 | mantissa >> 8;
705 	buf[0] = mantissa & 0xff;
706 
707 	/* Calculate and return the exact baud rate. */
708 	baud = (baseline / mantissa) >> exponent;
709 
710 	return baud;
711 }
712 
713 static void pl2303_encode_baud_rate(struct tty_struct *tty,
714 					struct usb_serial_port *port,
715 					u8 buf[4])
716 {
717 	struct usb_serial *serial = port->serial;
718 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
719 	speed_t	baud_sup;
720 	speed_t baud;
721 
722 	baud = tty_get_baud_rate(tty);
723 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
724 	if (!baud)
725 		return;
726 
727 	if (spriv->type->max_baud_rate)
728 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
729 	/*
730 	 * Use direct method for supported baud rates, otherwise use divisors.
731 	 * Newer chip types do not support divisor encoding.
732 	 */
733 	if (spriv->type->no_divisors)
734 		baud_sup = baud;
735 	else
736 		baud_sup = pl2303_get_supported_baud_rate(baud);
737 
738 	if (baud == baud_sup)
739 		baud = pl2303_encode_baud_rate_direct(buf, baud);
740 	else if (spriv->type->alt_divisors)
741 		baud = pl2303_encode_baud_rate_divisor_alt(buf, baud);
742 	else
743 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
744 
745 	/* Save resulting baud rate */
746 	tty_encode_baud_rate(tty, baud, baud);
747 	dev_dbg(&port->dev, "baud set = %u\n", baud);
748 }
749 
750 static int pl2303_get_line_request(struct usb_serial_port *port,
751 							unsigned char buf[7])
752 {
753 	struct usb_serial *serial = port->serial;
754 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
755 	struct usb_device *udev = serial->dev;
756 	int ret;
757 
758 	if (spriv->quirks & PL2303_QUIRK_NO_BREAK_GETLINE) {
759 		struct pl2303_private *priv = usb_get_serial_port_data(port);
760 
761 		memcpy(buf, priv->line_settings, 7);
762 		return 0;
763 	}
764 
765 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
766 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
767 				0, 0, buf, 7, 100);
768 	if (ret != 7) {
769 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
770 
771 		if (ret >= 0)
772 			ret = -EIO;
773 
774 		return ret;
775 	}
776 
777 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
778 
779 	return 0;
780 }
781 
782 static int pl2303_set_line_request(struct usb_serial_port *port,
783 							unsigned char buf[7])
784 {
785 	struct usb_device *udev = port->serial->dev;
786 	int ret;
787 
788 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
789 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
790 				0, 0, buf, 7, 100);
791 	if (ret < 0) {
792 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
793 		return ret;
794 	}
795 
796 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
797 
798 	return 0;
799 }
800 
801 static bool pl2303_termios_change(const struct ktermios *a, const struct ktermios *b)
802 {
803 	bool ixon_change;
804 
805 	ixon_change = ((a->c_iflag ^ b->c_iflag) & (IXON | IXANY)) ||
806 			a->c_cc[VSTART] != b->c_cc[VSTART] ||
807 			a->c_cc[VSTOP] != b->c_cc[VSTOP];
808 
809 	return tty_termios_hw_change(a, b) || ixon_change;
810 }
811 
812 static bool pl2303_enable_xonxoff(struct tty_struct *tty, const struct pl2303_type_data *type)
813 {
814 	if (!I_IXON(tty) || I_IXANY(tty))
815 		return false;
816 
817 	if (START_CHAR(tty) != 0x11 || STOP_CHAR(tty) != 0x13)
818 		return false;
819 
820 	if (type->no_autoxonxoff)
821 		return false;
822 
823 	return true;
824 }
825 
826 static void pl2303_set_termios(struct tty_struct *tty,
827 			       struct usb_serial_port *port,
828 			       const struct ktermios *old_termios)
829 {
830 	struct usb_serial *serial = port->serial;
831 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
832 	struct pl2303_private *priv = usb_get_serial_port_data(port);
833 	unsigned long flags;
834 	unsigned char *buf;
835 	int ret;
836 	u8 control;
837 
838 	if (old_termios && !pl2303_termios_change(&tty->termios, old_termios))
839 		return;
840 
841 	buf = kzalloc(7, GFP_KERNEL);
842 	if (!buf) {
843 		/* Report back no change occurred */
844 		if (old_termios)
845 			tty->termios = *old_termios;
846 		return;
847 	}
848 
849 	pl2303_get_line_request(port, buf);
850 
851 	buf[6] = tty_get_char_size(tty->termios.c_cflag);
852 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
853 
854 	/* For reference buf[0]:buf[3] baud rate value */
855 	pl2303_encode_baud_rate(tty, port, &buf[0]);
856 
857 	/* For reference buf[4]=0 is 1 stop bits */
858 	/* For reference buf[4]=1 is 1.5 stop bits */
859 	/* For reference buf[4]=2 is 2 stop bits */
860 	if (C_CSTOPB(tty)) {
861 		/*
862 		 * NOTE: Comply with "real" UARTs / RS232:
863 		 *       use 1.5 instead of 2 stop bits with 5 data bits
864 		 */
865 		if (C_CSIZE(tty) == CS5) {
866 			buf[4] = 1;
867 			dev_dbg(&port->dev, "stop bits = 1.5\n");
868 		} else {
869 			buf[4] = 2;
870 			dev_dbg(&port->dev, "stop bits = 2\n");
871 		}
872 	} else {
873 		buf[4] = 0;
874 		dev_dbg(&port->dev, "stop bits = 1\n");
875 	}
876 
877 	if (C_PARENB(tty)) {
878 		/* For reference buf[5]=0 is none parity */
879 		/* For reference buf[5]=1 is odd parity */
880 		/* For reference buf[5]=2 is even parity */
881 		/* For reference buf[5]=3 is mark parity */
882 		/* For reference buf[5]=4 is space parity */
883 		if (C_PARODD(tty)) {
884 			if (C_CMSPAR(tty)) {
885 				buf[5] = 3;
886 				dev_dbg(&port->dev, "parity = mark\n");
887 			} else {
888 				buf[5] = 1;
889 				dev_dbg(&port->dev, "parity = odd\n");
890 			}
891 		} else {
892 			if (C_CMSPAR(tty)) {
893 				buf[5] = 4;
894 				dev_dbg(&port->dev, "parity = space\n");
895 			} else {
896 				buf[5] = 2;
897 				dev_dbg(&port->dev, "parity = even\n");
898 			}
899 		}
900 	} else {
901 		buf[5] = 0;
902 		dev_dbg(&port->dev, "parity = none\n");
903 	}
904 
905 	/*
906 	 * Some PL2303 are known to lose bytes if you change serial settings
907 	 * even to the same values as before. Thus we actually need to filter
908 	 * in this specific case.
909 	 *
910 	 * Note that the tty_termios_hw_change check above is not sufficient
911 	 * as a previously requested baud rate may differ from the one
912 	 * actually used (and stored in old_termios).
913 	 *
914 	 * NOTE: No additional locking needed for line_settings as it is
915 	 *       only used in set_termios, which is serialised against itself.
916 	 */
917 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
918 		ret = pl2303_set_line_request(port, buf);
919 		if (!ret)
920 			memcpy(priv->line_settings, buf, 7);
921 	}
922 
923 	/* change control lines if we are switching to or from B0 */
924 	spin_lock_irqsave(&priv->lock, flags);
925 	control = priv->line_control;
926 	if (C_BAUD(tty) == B0)
927 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
928 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
929 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
930 	if (control != priv->line_control) {
931 		control = priv->line_control;
932 		spin_unlock_irqrestore(&priv->lock, flags);
933 		pl2303_set_control_lines(port, control);
934 	} else {
935 		spin_unlock_irqrestore(&priv->lock, flags);
936 	}
937 
938 	if (C_CRTSCTS(tty)) {
939 		if (spriv->quirks & PL2303_QUIRK_LEGACY) {
940 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x40);
941 		} else if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
942 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
943 					PL2303_HXN_FLOWCTRL_MASK,
944 					PL2303_HXN_FLOWCTRL_RTS_CTS);
945 		} else {
946 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x60);
947 		}
948 	} else if (pl2303_enable_xonxoff(tty, spriv->type)) {
949 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
950 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
951 					PL2303_HXN_FLOWCTRL_MASK,
952 					PL2303_HXN_FLOWCTRL_XON_XOFF);
953 		} else {
954 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0xc0);
955 		}
956 	} else {
957 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
958 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
959 					PL2303_HXN_FLOWCTRL_MASK,
960 					PL2303_HXN_FLOWCTRL_NONE);
961 		} else {
962 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0);
963 		}
964 	}
965 
966 	kfree(buf);
967 }
968 
969 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
970 {
971 	struct pl2303_private *priv = usb_get_serial_port_data(port);
972 	unsigned long flags;
973 	u8 control;
974 
975 	spin_lock_irqsave(&priv->lock, flags);
976 	if (on)
977 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
978 	else
979 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
980 	control = priv->line_control;
981 	spin_unlock_irqrestore(&priv->lock, flags);
982 
983 	pl2303_set_control_lines(port, control);
984 }
985 
986 static void pl2303_close(struct usb_serial_port *port)
987 {
988 	usb_serial_generic_close(port);
989 	usb_kill_urb(port->interrupt_in_urb);
990 	pl2303_set_break(port, false);
991 }
992 
993 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
994 {
995 	struct usb_serial *serial = port->serial;
996 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
997 	int result;
998 
999 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
1000 		usb_clear_halt(serial->dev, port->write_urb->pipe);
1001 		usb_clear_halt(serial->dev, port->read_urb->pipe);
1002 	} else {
1003 		/* reset upstream data pipes */
1004 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
1005 			pl2303_vendor_write(serial, PL2303_HXN_RESET_REG,
1006 					PL2303_HXN_RESET_UPSTREAM_PIPE |
1007 					PL2303_HXN_RESET_DOWNSTREAM_PIPE);
1008 		} else {
1009 			pl2303_vendor_write(serial, 8, 0);
1010 			pl2303_vendor_write(serial, 9, 0);
1011 		}
1012 	}
1013 
1014 	/* Setup termios */
1015 	if (tty)
1016 		pl2303_set_termios(tty, port, NULL);
1017 
1018 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1019 	if (result) {
1020 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
1021 			result);
1022 		return result;
1023 	}
1024 
1025 	result = usb_serial_generic_open(tty, port);
1026 	if (result) {
1027 		usb_kill_urb(port->interrupt_in_urb);
1028 		return result;
1029 	}
1030 
1031 	return 0;
1032 }
1033 
1034 static int pl2303_tiocmset(struct tty_struct *tty,
1035 			   unsigned int set, unsigned int clear)
1036 {
1037 	struct usb_serial_port *port = tty->driver_data;
1038 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1039 	unsigned long flags;
1040 	u8 control;
1041 	int ret;
1042 
1043 	spin_lock_irqsave(&priv->lock, flags);
1044 	if (set & TIOCM_RTS)
1045 		priv->line_control |= CONTROL_RTS;
1046 	if (set & TIOCM_DTR)
1047 		priv->line_control |= CONTROL_DTR;
1048 	if (clear & TIOCM_RTS)
1049 		priv->line_control &= ~CONTROL_RTS;
1050 	if (clear & TIOCM_DTR)
1051 		priv->line_control &= ~CONTROL_DTR;
1052 	control = priv->line_control;
1053 	spin_unlock_irqrestore(&priv->lock, flags);
1054 
1055 	ret = pl2303_set_control_lines(port, control);
1056 	if (ret)
1057 		return usb_translate_errors(ret);
1058 
1059 	return 0;
1060 }
1061 
1062 static int pl2303_tiocmget(struct tty_struct *tty)
1063 {
1064 	struct usb_serial_port *port = tty->driver_data;
1065 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1066 	unsigned long flags;
1067 	unsigned int mcr;
1068 	unsigned int status;
1069 	unsigned int result;
1070 
1071 	spin_lock_irqsave(&priv->lock, flags);
1072 	mcr = priv->line_control;
1073 	status = priv->line_status;
1074 	spin_unlock_irqrestore(&priv->lock, flags);
1075 
1076 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
1077 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
1078 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
1079 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
1080 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
1081 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
1082 
1083 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
1084 
1085 	return result;
1086 }
1087 
1088 static int pl2303_carrier_raised(struct usb_serial_port *port)
1089 {
1090 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1091 
1092 	if (priv->line_status & UART_DCD)
1093 		return 1;
1094 
1095 	return 0;
1096 }
1097 
1098 static int pl2303_set_break(struct usb_serial_port *port, bool enable)
1099 {
1100 	struct usb_serial *serial = port->serial;
1101 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
1102 	u16 state;
1103 	int result;
1104 
1105 	if (spriv->quirks & PL2303_QUIRK_NO_BREAK_GETLINE)
1106 		return -ENOTTY;
1107 
1108 	if (enable)
1109 		state = BREAK_ON;
1110 	else
1111 		state = BREAK_OFF;
1112 
1113 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
1114 			state == BREAK_OFF ? "off" : "on");
1115 
1116 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
1117 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
1118 				 0, NULL, 0, 100);
1119 	if (result) {
1120 		dev_err(&port->dev, "error sending break = %d\n", result);
1121 		return result;
1122 	}
1123 
1124 	return 0;
1125 }
1126 
1127 static int pl2303_break_ctl(struct tty_struct *tty, int state)
1128 {
1129 	struct usb_serial_port *port = tty->driver_data;
1130 
1131 	return pl2303_set_break(port, state);
1132 }
1133 
1134 static void pl2303_update_line_status(struct usb_serial_port *port,
1135 				      unsigned char *data,
1136 				      unsigned int actual_length)
1137 {
1138 	struct usb_serial *serial = port->serial;
1139 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
1140 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1141 	struct tty_struct *tty;
1142 	unsigned long flags;
1143 	unsigned int status_idx = UART_STATE_INDEX;
1144 	u8 status;
1145 	u8 delta;
1146 
1147 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
1148 		status_idx = 0;
1149 
1150 	if (actual_length < status_idx + 1)
1151 		return;
1152 
1153 	status = data[status_idx];
1154 
1155 	/* Save off the uart status for others to look at */
1156 	spin_lock_irqsave(&priv->lock, flags);
1157 	delta = priv->line_status ^ status;
1158 	priv->line_status = status;
1159 	spin_unlock_irqrestore(&priv->lock, flags);
1160 
1161 	if (status & UART_BREAK_ERROR)
1162 		usb_serial_handle_break(port);
1163 
1164 	if (delta & UART_STATE_MSR_MASK) {
1165 		if (delta & UART_CTS)
1166 			port->icount.cts++;
1167 		if (delta & UART_DSR)
1168 			port->icount.dsr++;
1169 		if (delta & UART_RING)
1170 			port->icount.rng++;
1171 		if (delta & UART_DCD) {
1172 			port->icount.dcd++;
1173 			tty = tty_port_tty_get(&port->port);
1174 			if (tty) {
1175 				usb_serial_handle_dcd_change(port, tty,
1176 							status & UART_DCD);
1177 				tty_kref_put(tty);
1178 			}
1179 		}
1180 
1181 		wake_up_interruptible(&port->port.delta_msr_wait);
1182 	}
1183 }
1184 
1185 static void pl2303_read_int_callback(struct urb *urb)
1186 {
1187 	struct usb_serial_port *port =  urb->context;
1188 	unsigned char *data = urb->transfer_buffer;
1189 	unsigned int actual_length = urb->actual_length;
1190 	int status = urb->status;
1191 	int retval;
1192 
1193 	switch (status) {
1194 	case 0:
1195 		/* success */
1196 		break;
1197 	case -ECONNRESET:
1198 	case -ENOENT:
1199 	case -ESHUTDOWN:
1200 		/* this urb is terminated, clean up */
1201 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
1202 			__func__, status);
1203 		return;
1204 	default:
1205 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
1206 			__func__, status);
1207 		goto exit;
1208 	}
1209 
1210 	usb_serial_debug_data(&port->dev, __func__,
1211 			      urb->actual_length, urb->transfer_buffer);
1212 
1213 	pl2303_update_line_status(port, data, actual_length);
1214 
1215 exit:
1216 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1217 	if (retval) {
1218 		dev_err(&port->dev,
1219 			"%s - usb_submit_urb failed with result %d\n",
1220 			__func__, retval);
1221 	}
1222 }
1223 
1224 static void pl2303_process_read_urb(struct urb *urb)
1225 {
1226 	struct usb_serial_port *port = urb->context;
1227 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1228 	unsigned char *data = urb->transfer_buffer;
1229 	char tty_flag = TTY_NORMAL;
1230 	unsigned long flags;
1231 	u8 line_status;
1232 	int i;
1233 
1234 	/* update line status */
1235 	spin_lock_irqsave(&priv->lock, flags);
1236 	line_status = priv->line_status;
1237 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
1238 	spin_unlock_irqrestore(&priv->lock, flags);
1239 
1240 	if (!urb->actual_length)
1241 		return;
1242 
1243 	/*
1244 	 * Break takes precedence over parity, which takes precedence over
1245 	 * framing errors.
1246 	 */
1247 	if (line_status & UART_BREAK_ERROR)
1248 		tty_flag = TTY_BREAK;
1249 	else if (line_status & UART_PARITY_ERROR)
1250 		tty_flag = TTY_PARITY;
1251 	else if (line_status & UART_FRAME_ERROR)
1252 		tty_flag = TTY_FRAME;
1253 
1254 	if (tty_flag != TTY_NORMAL)
1255 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
1256 								tty_flag);
1257 	/* overrun is special, not associated with a char */
1258 	if (line_status & UART_OVERRUN_ERROR)
1259 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
1260 
1261 	if (port->sysrq) {
1262 		for (i = 0; i < urb->actual_length; ++i)
1263 			if (!usb_serial_handle_sysrq_char(port, data[i]))
1264 				tty_insert_flip_char(&port->port, data[i],
1265 						tty_flag);
1266 	} else {
1267 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
1268 							urb->actual_length);
1269 	}
1270 
1271 	tty_flip_buffer_push(&port->port);
1272 }
1273 
1274 static struct usb_serial_driver pl2303_device = {
1275 	.driver = {
1276 		.name =		"pl2303",
1277 	},
1278 	.id_table =		id_table,
1279 	.num_bulk_in =		1,
1280 	.num_bulk_out =		1,
1281 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
1282 	.bulk_in_size =		256,
1283 	.bulk_out_size =	256,
1284 	.open =			pl2303_open,
1285 	.close =		pl2303_close,
1286 	.dtr_rts =		pl2303_dtr_rts,
1287 	.carrier_raised =	pl2303_carrier_raised,
1288 	.break_ctl =		pl2303_break_ctl,
1289 	.set_termios =		pl2303_set_termios,
1290 	.tiocmget =		pl2303_tiocmget,
1291 	.tiocmset =		pl2303_tiocmset,
1292 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1293 	.process_read_urb =	pl2303_process_read_urb,
1294 	.read_int_callback =	pl2303_read_int_callback,
1295 	.probe =		pl2303_probe,
1296 	.calc_num_ports =	pl2303_calc_num_ports,
1297 	.attach =		pl2303_startup,
1298 	.release =		pl2303_release,
1299 	.port_probe =		pl2303_port_probe,
1300 	.port_remove =		pl2303_port_remove,
1301 };
1302 
1303 static struct usb_serial_driver * const serial_drivers[] = {
1304 	&pl2303_device, NULL
1305 };
1306 
1307 module_usb_serial_driver(serial_drivers, id_table);
1308 
1309 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1310 MODULE_LICENSE("GPL v2");
1311