xref: /openbmc/linux/drivers/usb/serial/pl2303.c (revision 3c39f253)
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_LM930_PRODUCT_ID) },
110 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM940_PRODUCT_ID) },
111 	{ USB_DEVICE(HP_VENDOR_ID, HP_TD620_PRODUCT_ID) },
112 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
113 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
114 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
115 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
116 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
117 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530GC_PRODUCT_ID) },
118 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
119 	{ USB_DEVICE(AT_VENDOR_ID, AT_VTKIT3_PRODUCT_ID) },
120 	{ USB_DEVICE(IBM_VENDOR_ID, IBM_PRODUCT_ID) },
121 	{ USB_DEVICE(MACROSILICON_VENDOR_ID, MACROSILICON_MS3020_PRODUCT_ID) },
122 	{ }					/* Terminating entry */
123 };
124 
125 MODULE_DEVICE_TABLE(usb, id_table);
126 
127 #define SET_LINE_REQUEST_TYPE		0x21
128 #define SET_LINE_REQUEST		0x20
129 
130 #define SET_CONTROL_REQUEST_TYPE	0x21
131 #define SET_CONTROL_REQUEST		0x22
132 #define CONTROL_DTR			0x01
133 #define CONTROL_RTS			0x02
134 
135 #define BREAK_REQUEST_TYPE		0x21
136 #define BREAK_REQUEST			0x23
137 #define BREAK_ON			0xffff
138 #define BREAK_OFF			0x0000
139 
140 #define GET_LINE_REQUEST_TYPE		0xa1
141 #define GET_LINE_REQUEST		0x21
142 
143 #define VENDOR_WRITE_REQUEST_TYPE	0x40
144 #define VENDOR_WRITE_REQUEST		0x01
145 #define VENDOR_WRITE_NREQUEST		0x80
146 
147 #define VENDOR_READ_REQUEST_TYPE	0xc0
148 #define VENDOR_READ_REQUEST		0x01
149 #define VENDOR_READ_NREQUEST		0x81
150 
151 #define UART_STATE_INDEX		8
152 #define UART_STATE_MSR_MASK		0x8b
153 #define UART_STATE_TRANSIENT_MASK	0x74
154 #define UART_DCD			0x01
155 #define UART_DSR			0x02
156 #define UART_BREAK_ERROR		0x04
157 #define UART_RING			0x08
158 #define UART_FRAME_ERROR		0x10
159 #define UART_PARITY_ERROR		0x20
160 #define UART_OVERRUN_ERROR		0x40
161 #define UART_CTS			0x80
162 
163 #define PL2303_FLOWCTRL_MASK		0xf0
164 
165 #define PL2303_READ_TYPE_HX_STATUS	0x8080
166 
167 #define PL2303_HXN_RESET_REG		0x07
168 #define PL2303_HXN_RESET_UPSTREAM_PIPE	0x02
169 #define PL2303_HXN_RESET_DOWNSTREAM_PIPE	0x01
170 
171 #define PL2303_HXN_FLOWCTRL_REG		0x0a
172 #define PL2303_HXN_FLOWCTRL_MASK	0x1c
173 #define PL2303_HXN_FLOWCTRL_NONE	0x1c
174 #define PL2303_HXN_FLOWCTRL_RTS_CTS	0x18
175 #define PL2303_HXN_FLOWCTRL_XON_XOFF	0x0c
176 
177 static int pl2303_set_break(struct usb_serial_port *port, bool enable);
178 
179 enum pl2303_type {
180 	TYPE_H,
181 	TYPE_HX,
182 	TYPE_TA,
183 	TYPE_TB,
184 	TYPE_HXD,
185 	TYPE_HXN,
186 	TYPE_COUNT
187 };
188 
189 struct pl2303_type_data {
190 	const char *name;
191 	speed_t max_baud_rate;
192 	unsigned long quirks;
193 	unsigned int no_autoxonxoff:1;
194 	unsigned int no_divisors:1;
195 	unsigned int alt_divisors:1;
196 };
197 
198 struct pl2303_serial_private {
199 	const struct pl2303_type_data *type;
200 	unsigned long quirks;
201 };
202 
203 struct pl2303_private {
204 	spinlock_t lock;
205 	u8 line_control;
206 	u8 line_status;
207 
208 	u8 line_settings[7];
209 };
210 
211 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
212 	[TYPE_H] = {
213 		.name			= "H",
214 		.max_baud_rate		= 1228800,
215 		.quirks			= PL2303_QUIRK_LEGACY,
216 		.no_autoxonxoff		= true,
217 	},
218 	[TYPE_HX] = {
219 		.name			= "HX",
220 		.max_baud_rate		= 6000000,
221 	},
222 	[TYPE_TA] = {
223 		.name			= "TA",
224 		.max_baud_rate		= 6000000,
225 		.alt_divisors		= true,
226 	},
227 	[TYPE_TB] = {
228 		.name			= "TB",
229 		.max_baud_rate		= 12000000,
230 		.alt_divisors		= true,
231 	},
232 	[TYPE_HXD] = {
233 		.name			= "HXD",
234 		.max_baud_rate		= 12000000,
235 	},
236 	[TYPE_HXN] = {
237 		.name			= "G",
238 		.max_baud_rate		= 12000000,
239 		.no_divisors		= true,
240 	},
241 };
242 
243 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
244 							unsigned char buf[1])
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 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
252 		request = VENDOR_READ_NREQUEST;
253 	else
254 		request = VENDOR_READ_REQUEST;
255 
256 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
257 			request, VENDOR_READ_REQUEST_TYPE,
258 			value, 0, buf, 1, 100);
259 	if (res != 1) {
260 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
261 								value, res);
262 		if (res >= 0)
263 			res = -EIO;
264 
265 		return res;
266 	}
267 
268 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
269 
270 	return 0;
271 }
272 
273 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
274 {
275 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
276 	struct device *dev = &serial->interface->dev;
277 	u8 request;
278 	int res;
279 
280 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
281 
282 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
283 		request = VENDOR_WRITE_NREQUEST;
284 	else
285 		request = VENDOR_WRITE_REQUEST;
286 
287 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
288 			request, VENDOR_WRITE_REQUEST_TYPE,
289 			value, index, NULL, 0, 100);
290 	if (res) {
291 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
292 								value, res);
293 		return res;
294 	}
295 
296 	return 0;
297 }
298 
299 static int pl2303_update_reg(struct usb_serial *serial, u8 reg, u8 mask, u8 val)
300 {
301 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
302 	int ret = 0;
303 	u8 *buf;
304 
305 	buf = kmalloc(1, GFP_KERNEL);
306 	if (!buf)
307 		return -ENOMEM;
308 
309 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
310 		ret = pl2303_vendor_read(serial, reg, buf);
311 	else
312 		ret = pl2303_vendor_read(serial, reg | 0x80, buf);
313 
314 	if (ret)
315 		goto out_free;
316 
317 	*buf &= ~mask;
318 	*buf |= val & mask;
319 
320 	ret = pl2303_vendor_write(serial, reg, *buf);
321 out_free:
322 	kfree(buf);
323 
324 	return ret;
325 }
326 
327 static int pl2303_probe(struct usb_serial *serial,
328 					const struct usb_device_id *id)
329 {
330 	usb_set_serial_data(serial, (void *)id->driver_info);
331 
332 	return 0;
333 }
334 
335 /*
336  * Use interrupt endpoint from first interface if available.
337  *
338  * This is needed due to the looney way its endpoints are set up.
339  */
340 static int pl2303_endpoint_hack(struct usb_serial *serial,
341 					struct usb_serial_endpoints *epds)
342 {
343 	struct usb_interface *interface = serial->interface;
344 	struct usb_device *dev = serial->dev;
345 	struct device *ddev = &interface->dev;
346 	struct usb_host_interface *iface_desc;
347 	struct usb_endpoint_descriptor *endpoint;
348 	unsigned int i;
349 
350 	if (interface == dev->actconfig->interface[0])
351 		return 0;
352 
353 	/* check out the endpoints of the other interface */
354 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
355 
356 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
357 		endpoint = &iface_desc->endpoint[i].desc;
358 
359 		if (!usb_endpoint_is_int_in(endpoint))
360 			continue;
361 
362 		dev_dbg(ddev, "found interrupt in on separate interface\n");
363 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
364 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
365 	}
366 
367 	return 0;
368 }
369 
370 static int pl2303_calc_num_ports(struct usb_serial *serial,
371 					struct usb_serial_endpoints *epds)
372 {
373 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
374 	struct device *dev = &serial->interface->dev;
375 	int ret;
376 
377 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
378 		ret = pl2303_endpoint_hack(serial, epds);
379 		if (ret)
380 			return ret;
381 	}
382 
383 	if (epds->num_interrupt_in < 1) {
384 		dev_err(dev, "required interrupt-in endpoint missing\n");
385 		return -ENODEV;
386 	}
387 
388 	return 1;
389 }
390 
391 static bool pl2303_supports_hx_status(struct usb_serial *serial)
392 {
393 	int ret;
394 	u8 buf;
395 
396 	ret = usb_control_msg_recv(serial->dev, 0, VENDOR_READ_REQUEST,
397 			VENDOR_READ_REQUEST_TYPE, PL2303_READ_TYPE_HX_STATUS,
398 			0, &buf, 1, 100, GFP_KERNEL);
399 
400 	return ret == 0;
401 }
402 
403 static int pl2303_detect_type(struct usb_serial *serial)
404 {
405 	struct usb_device_descriptor *desc = &serial->dev->descriptor;
406 	u16 bcdDevice, bcdUSB;
407 
408 	/*
409 	 * Legacy PL2303H, variants 0 and 1 (difference unknown).
410 	 */
411 	if (desc->bDeviceClass == 0x02)
412 		return TYPE_H;		/* variant 0 */
413 
414 	if (desc->bMaxPacketSize0 != 0x40) {
415 		if (desc->bDeviceClass == 0x00 || desc->bDeviceClass == 0xff)
416 			return TYPE_H;	/* variant 1 */
417 
418 		return TYPE_H;		/* variant 0 */
419 	}
420 
421 	bcdDevice = le16_to_cpu(desc->bcdDevice);
422 	bcdUSB = le16_to_cpu(desc->bcdUSB);
423 
424 	switch (bcdUSB) {
425 	case 0x101:
426 		/* USB 1.0.1? Let's assume they meant 1.1... */
427 		fallthrough;
428 	case 0x110:
429 		switch (bcdDevice) {
430 		case 0x300:
431 			return TYPE_HX;
432 		case 0x400:
433 			return TYPE_HXD;
434 		default:
435 			return TYPE_HX;
436 		}
437 		break;
438 	case 0x200:
439 		switch (bcdDevice) {
440 		case 0x100:	/* GC */
441 		case 0x105:
442 			return TYPE_HXN;
443 		case 0x300:	/* GT / TA */
444 			if (pl2303_supports_hx_status(serial))
445 				return TYPE_TA;
446 			fallthrough;
447 		case 0x305:
448 		case 0x400:	/* GL */
449 		case 0x405:
450 			return TYPE_HXN;
451 		case 0x500:	/* GE / TB */
452 			if (pl2303_supports_hx_status(serial))
453 				return TYPE_TB;
454 			fallthrough;
455 		case 0x505:
456 		case 0x600:	/* GS */
457 		case 0x605:
458 		case 0x700:	/* GR */
459 		case 0x705:
460 			return TYPE_HXN;
461 		}
462 		break;
463 	}
464 
465 	dev_err(&serial->interface->dev,
466 			"unknown device type, please report to linux-usb@vger.kernel.org\n");
467 	return -ENODEV;
468 }
469 
470 static int pl2303_startup(struct usb_serial *serial)
471 {
472 	struct pl2303_serial_private *spriv;
473 	enum pl2303_type type;
474 	unsigned char *buf;
475 	int ret;
476 
477 	ret = pl2303_detect_type(serial);
478 	if (ret < 0)
479 		return ret;
480 
481 	type = ret;
482 	dev_dbg(&serial->interface->dev, "device type: %s\n", pl2303_type_data[type].name);
483 
484 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
485 	if (!spriv)
486 		return -ENOMEM;
487 
488 	spriv->type = &pl2303_type_data[type];
489 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
490 	spriv->quirks |= spriv->type->quirks;
491 
492 	usb_set_serial_data(serial, spriv);
493 
494 	if (type != TYPE_HXN) {
495 		buf = kmalloc(1, GFP_KERNEL);
496 		if (!buf) {
497 			kfree(spriv);
498 			return -ENOMEM;
499 		}
500 
501 		pl2303_vendor_read(serial, 0x8484, buf);
502 		pl2303_vendor_write(serial, 0x0404, 0);
503 		pl2303_vendor_read(serial, 0x8484, buf);
504 		pl2303_vendor_read(serial, 0x8383, buf);
505 		pl2303_vendor_read(serial, 0x8484, buf);
506 		pl2303_vendor_write(serial, 0x0404, 1);
507 		pl2303_vendor_read(serial, 0x8484, buf);
508 		pl2303_vendor_read(serial, 0x8383, buf);
509 		pl2303_vendor_write(serial, 0, 1);
510 		pl2303_vendor_write(serial, 1, 0);
511 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
512 			pl2303_vendor_write(serial, 2, 0x24);
513 		else
514 			pl2303_vendor_write(serial, 2, 0x44);
515 
516 		kfree(buf);
517 	}
518 
519 	return 0;
520 }
521 
522 static void pl2303_release(struct usb_serial *serial)
523 {
524 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
525 
526 	kfree(spriv);
527 }
528 
529 static int pl2303_port_probe(struct usb_serial_port *port)
530 {
531 	struct pl2303_private *priv;
532 
533 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
534 	if (!priv)
535 		return -ENOMEM;
536 
537 	spin_lock_init(&priv->lock);
538 
539 	usb_set_serial_port_data(port, priv);
540 
541 	port->port.drain_delay = 256;
542 
543 	return 0;
544 }
545 
546 static void pl2303_port_remove(struct usb_serial_port *port)
547 {
548 	struct pl2303_private *priv = usb_get_serial_port_data(port);
549 
550 	kfree(priv);
551 }
552 
553 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
554 {
555 	struct usb_device *dev = port->serial->dev;
556 	int retval;
557 
558 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
559 
560 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
561 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
562 				 value, 0, NULL, 0, 100);
563 	if (retval)
564 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
565 
566 	return retval;
567 }
568 
569 /*
570  * Returns the nearest supported baud rate that can be set directly without
571  * using divisors.
572  */
573 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
574 {
575 	static const speed_t baud_sup[] = {
576 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
577 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
578 		614400, 921600, 1228800, 2457600, 3000000, 6000000
579 	};
580 
581 	unsigned i;
582 
583 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
584 		if (baud_sup[i] > baud)
585 			break;
586 	}
587 
588 	if (i == ARRAY_SIZE(baud_sup))
589 		baud = baud_sup[i - 1];
590 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
591 		baud = baud_sup[i - 1];
592 	else
593 		baud = baud_sup[i];
594 
595 	return baud;
596 }
597 
598 /*
599  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
600  *       use 9600 baud.
601  */
602 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
603 								speed_t baud)
604 {
605 	put_unaligned_le32(baud, buf);
606 
607 	return baud;
608 }
609 
610 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
611 								speed_t baud)
612 {
613 	unsigned int baseline, mantissa, exponent;
614 
615 	/*
616 	 * Apparently the formula is:
617 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
618 	 * where
619 	 *   mantissa = buf[8:0]
620 	 *   exponent = buf[11:9]
621 	 */
622 	baseline = 12000000 * 32;
623 	mantissa = baseline / baud;
624 	if (mantissa == 0)
625 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
626 	exponent = 0;
627 	while (mantissa >= 512) {
628 		if (exponent < 7) {
629 			mantissa >>= 2;	/* divide by 4 */
630 			exponent++;
631 		} else {
632 			/* Exponent is maxed. Trim mantissa and leave. */
633 			mantissa = 511;
634 			break;
635 		}
636 	}
637 
638 	buf[3] = 0x80;
639 	buf[2] = 0;
640 	buf[1] = exponent << 1 | mantissa >> 8;
641 	buf[0] = mantissa & 0xff;
642 
643 	/* Calculate and return the exact baud rate. */
644 	baud = (baseline / mantissa) >> (exponent << 1);
645 
646 	return baud;
647 }
648 
649 static speed_t pl2303_encode_baud_rate_divisor_alt(unsigned char buf[4],
650 								speed_t baud)
651 {
652 	unsigned int baseline, mantissa, exponent;
653 
654 	/*
655 	 * Apparently, for the TA version the formula is:
656 	 *   baudrate = 12M * 32 / (mantissa * 2^exponent)
657 	 * where
658 	 *   mantissa = buf[10:0]
659 	 *   exponent = buf[15:13 16]
660 	 */
661 	baseline = 12000000 * 32;
662 	mantissa = baseline / baud;
663 	if (mantissa == 0)
664 		mantissa = 1;   /* Avoid dividing by zero if baud > 32*12M. */
665 	exponent = 0;
666 	while (mantissa >= 2048) {
667 		if (exponent < 15) {
668 			mantissa >>= 1; /* divide by 2 */
669 			exponent++;
670 		} else {
671 			/* Exponent is maxed. Trim mantissa and leave. */
672 			mantissa = 2047;
673 			break;
674 		}
675 	}
676 
677 	buf[3] = 0x80;
678 	buf[2] = exponent & 0x01;
679 	buf[1] = (exponent & ~0x01) << 4 | mantissa >> 8;
680 	buf[0] = mantissa & 0xff;
681 
682 	/* Calculate and return the exact baud rate. */
683 	baud = (baseline / mantissa) >> exponent;
684 
685 	return baud;
686 }
687 
688 static void pl2303_encode_baud_rate(struct tty_struct *tty,
689 					struct usb_serial_port *port,
690 					u8 buf[4])
691 {
692 	struct usb_serial *serial = port->serial;
693 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
694 	speed_t	baud_sup;
695 	speed_t baud;
696 
697 	baud = tty_get_baud_rate(tty);
698 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
699 	if (!baud)
700 		return;
701 
702 	if (spriv->type->max_baud_rate)
703 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
704 	/*
705 	 * Use direct method for supported baud rates, otherwise use divisors.
706 	 * Newer chip types do not support divisor encoding.
707 	 */
708 	if (spriv->type->no_divisors)
709 		baud_sup = baud;
710 	else
711 		baud_sup = pl2303_get_supported_baud_rate(baud);
712 
713 	if (baud == baud_sup)
714 		baud = pl2303_encode_baud_rate_direct(buf, baud);
715 	else if (spriv->type->alt_divisors)
716 		baud = pl2303_encode_baud_rate_divisor_alt(buf, baud);
717 	else
718 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
719 
720 	/* Save resulting baud rate */
721 	tty_encode_baud_rate(tty, baud, baud);
722 	dev_dbg(&port->dev, "baud set = %u\n", baud);
723 }
724 
725 static int pl2303_get_line_request(struct usb_serial_port *port,
726 							unsigned char buf[7])
727 {
728 	struct usb_device *udev = port->serial->dev;
729 	int ret;
730 
731 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
732 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
733 				0, 0, buf, 7, 100);
734 	if (ret != 7) {
735 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
736 
737 		if (ret >= 0)
738 			ret = -EIO;
739 
740 		return ret;
741 	}
742 
743 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
744 
745 	return 0;
746 }
747 
748 static int pl2303_set_line_request(struct usb_serial_port *port,
749 							unsigned char buf[7])
750 {
751 	struct usb_device *udev = port->serial->dev;
752 	int ret;
753 
754 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
755 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
756 				0, 0, buf, 7, 100);
757 	if (ret < 0) {
758 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
759 		return ret;
760 	}
761 
762 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
763 
764 	return 0;
765 }
766 
767 static bool pl2303_termios_change(const struct ktermios *a, const struct ktermios *b)
768 {
769 	bool ixon_change;
770 
771 	ixon_change = ((a->c_iflag ^ b->c_iflag) & (IXON | IXANY)) ||
772 			a->c_cc[VSTART] != b->c_cc[VSTART] ||
773 			a->c_cc[VSTOP] != b->c_cc[VSTOP];
774 
775 	return tty_termios_hw_change(a, b) || ixon_change;
776 }
777 
778 static bool pl2303_enable_xonxoff(struct tty_struct *tty, const struct pl2303_type_data *type)
779 {
780 	if (!I_IXON(tty) || I_IXANY(tty))
781 		return false;
782 
783 	if (START_CHAR(tty) != 0x11 || STOP_CHAR(tty) != 0x13)
784 		return false;
785 
786 	if (type->no_autoxonxoff)
787 		return false;
788 
789 	return true;
790 }
791 
792 static void pl2303_set_termios(struct tty_struct *tty,
793 			       struct usb_serial_port *port,
794 			       const struct ktermios *old_termios)
795 {
796 	struct usb_serial *serial = port->serial;
797 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
798 	struct pl2303_private *priv = usb_get_serial_port_data(port);
799 	unsigned long flags;
800 	unsigned char *buf;
801 	int ret;
802 	u8 control;
803 
804 	if (old_termios && !pl2303_termios_change(&tty->termios, old_termios))
805 		return;
806 
807 	buf = kzalloc(7, GFP_KERNEL);
808 	if (!buf) {
809 		/* Report back no change occurred */
810 		if (old_termios)
811 			tty->termios = *old_termios;
812 		return;
813 	}
814 
815 	pl2303_get_line_request(port, buf);
816 
817 	buf[6] = tty_get_char_size(tty->termios.c_cflag);
818 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
819 
820 	/* For reference buf[0]:buf[3] baud rate value */
821 	pl2303_encode_baud_rate(tty, port, &buf[0]);
822 
823 	/* For reference buf[4]=0 is 1 stop bits */
824 	/* For reference buf[4]=1 is 1.5 stop bits */
825 	/* For reference buf[4]=2 is 2 stop bits */
826 	if (C_CSTOPB(tty)) {
827 		/*
828 		 * NOTE: Comply with "real" UARTs / RS232:
829 		 *       use 1.5 instead of 2 stop bits with 5 data bits
830 		 */
831 		if (C_CSIZE(tty) == CS5) {
832 			buf[4] = 1;
833 			dev_dbg(&port->dev, "stop bits = 1.5\n");
834 		} else {
835 			buf[4] = 2;
836 			dev_dbg(&port->dev, "stop bits = 2\n");
837 		}
838 	} else {
839 		buf[4] = 0;
840 		dev_dbg(&port->dev, "stop bits = 1\n");
841 	}
842 
843 	if (C_PARENB(tty)) {
844 		/* For reference buf[5]=0 is none parity */
845 		/* For reference buf[5]=1 is odd parity */
846 		/* For reference buf[5]=2 is even parity */
847 		/* For reference buf[5]=3 is mark parity */
848 		/* For reference buf[5]=4 is space parity */
849 		if (C_PARODD(tty)) {
850 			if (C_CMSPAR(tty)) {
851 				buf[5] = 3;
852 				dev_dbg(&port->dev, "parity = mark\n");
853 			} else {
854 				buf[5] = 1;
855 				dev_dbg(&port->dev, "parity = odd\n");
856 			}
857 		} else {
858 			if (C_CMSPAR(tty)) {
859 				buf[5] = 4;
860 				dev_dbg(&port->dev, "parity = space\n");
861 			} else {
862 				buf[5] = 2;
863 				dev_dbg(&port->dev, "parity = even\n");
864 			}
865 		}
866 	} else {
867 		buf[5] = 0;
868 		dev_dbg(&port->dev, "parity = none\n");
869 	}
870 
871 	/*
872 	 * Some PL2303 are known to lose bytes if you change serial settings
873 	 * even to the same values as before. Thus we actually need to filter
874 	 * in this specific case.
875 	 *
876 	 * Note that the tty_termios_hw_change check above is not sufficient
877 	 * as a previously requested baud rate may differ from the one
878 	 * actually used (and stored in old_termios).
879 	 *
880 	 * NOTE: No additional locking needed for line_settings as it is
881 	 *       only used in set_termios, which is serialised against itself.
882 	 */
883 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
884 		ret = pl2303_set_line_request(port, buf);
885 		if (!ret)
886 			memcpy(priv->line_settings, buf, 7);
887 	}
888 
889 	/* change control lines if we are switching to or from B0 */
890 	spin_lock_irqsave(&priv->lock, flags);
891 	control = priv->line_control;
892 	if (C_BAUD(tty) == B0)
893 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
894 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
895 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
896 	if (control != priv->line_control) {
897 		control = priv->line_control;
898 		spin_unlock_irqrestore(&priv->lock, flags);
899 		pl2303_set_control_lines(port, control);
900 	} else {
901 		spin_unlock_irqrestore(&priv->lock, flags);
902 	}
903 
904 	if (C_CRTSCTS(tty)) {
905 		if (spriv->quirks & PL2303_QUIRK_LEGACY) {
906 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x40);
907 		} else if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
908 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
909 					PL2303_HXN_FLOWCTRL_MASK,
910 					PL2303_HXN_FLOWCTRL_RTS_CTS);
911 		} else {
912 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x60);
913 		}
914 	} else if (pl2303_enable_xonxoff(tty, spriv->type)) {
915 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
916 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
917 					PL2303_HXN_FLOWCTRL_MASK,
918 					PL2303_HXN_FLOWCTRL_XON_XOFF);
919 		} else {
920 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0xc0);
921 		}
922 	} else {
923 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
924 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
925 					PL2303_HXN_FLOWCTRL_MASK,
926 					PL2303_HXN_FLOWCTRL_NONE);
927 		} else {
928 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0);
929 		}
930 	}
931 
932 	kfree(buf);
933 }
934 
935 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
936 {
937 	struct pl2303_private *priv = usb_get_serial_port_data(port);
938 	unsigned long flags;
939 	u8 control;
940 
941 	spin_lock_irqsave(&priv->lock, flags);
942 	if (on)
943 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
944 	else
945 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
946 	control = priv->line_control;
947 	spin_unlock_irqrestore(&priv->lock, flags);
948 
949 	pl2303_set_control_lines(port, control);
950 }
951 
952 static void pl2303_close(struct usb_serial_port *port)
953 {
954 	usb_serial_generic_close(port);
955 	usb_kill_urb(port->interrupt_in_urb);
956 	pl2303_set_break(port, false);
957 }
958 
959 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
960 {
961 	struct usb_serial *serial = port->serial;
962 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
963 	int result;
964 
965 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
966 		usb_clear_halt(serial->dev, port->write_urb->pipe);
967 		usb_clear_halt(serial->dev, port->read_urb->pipe);
968 	} else {
969 		/* reset upstream data pipes */
970 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
971 			pl2303_vendor_write(serial, PL2303_HXN_RESET_REG,
972 					PL2303_HXN_RESET_UPSTREAM_PIPE |
973 					PL2303_HXN_RESET_DOWNSTREAM_PIPE);
974 		} else {
975 			pl2303_vendor_write(serial, 8, 0);
976 			pl2303_vendor_write(serial, 9, 0);
977 		}
978 	}
979 
980 	/* Setup termios */
981 	if (tty)
982 		pl2303_set_termios(tty, port, NULL);
983 
984 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
985 	if (result) {
986 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
987 			result);
988 		return result;
989 	}
990 
991 	result = usb_serial_generic_open(tty, port);
992 	if (result) {
993 		usb_kill_urb(port->interrupt_in_urb);
994 		return result;
995 	}
996 
997 	return 0;
998 }
999 
1000 static int pl2303_tiocmset(struct tty_struct *tty,
1001 			   unsigned int set, unsigned int clear)
1002 {
1003 	struct usb_serial_port *port = tty->driver_data;
1004 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1005 	unsigned long flags;
1006 	u8 control;
1007 	int ret;
1008 
1009 	spin_lock_irqsave(&priv->lock, flags);
1010 	if (set & TIOCM_RTS)
1011 		priv->line_control |= CONTROL_RTS;
1012 	if (set & TIOCM_DTR)
1013 		priv->line_control |= CONTROL_DTR;
1014 	if (clear & TIOCM_RTS)
1015 		priv->line_control &= ~CONTROL_RTS;
1016 	if (clear & TIOCM_DTR)
1017 		priv->line_control &= ~CONTROL_DTR;
1018 	control = priv->line_control;
1019 	spin_unlock_irqrestore(&priv->lock, flags);
1020 
1021 	ret = pl2303_set_control_lines(port, control);
1022 	if (ret)
1023 		return usb_translate_errors(ret);
1024 
1025 	return 0;
1026 }
1027 
1028 static int pl2303_tiocmget(struct tty_struct *tty)
1029 {
1030 	struct usb_serial_port *port = tty->driver_data;
1031 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1032 	unsigned long flags;
1033 	unsigned int mcr;
1034 	unsigned int status;
1035 	unsigned int result;
1036 
1037 	spin_lock_irqsave(&priv->lock, flags);
1038 	mcr = priv->line_control;
1039 	status = priv->line_status;
1040 	spin_unlock_irqrestore(&priv->lock, flags);
1041 
1042 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
1043 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
1044 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
1045 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
1046 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
1047 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
1048 
1049 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
1050 
1051 	return result;
1052 }
1053 
1054 static int pl2303_carrier_raised(struct usb_serial_port *port)
1055 {
1056 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1057 
1058 	if (priv->line_status & UART_DCD)
1059 		return 1;
1060 
1061 	return 0;
1062 }
1063 
1064 static int pl2303_set_break(struct usb_serial_port *port, bool enable)
1065 {
1066 	struct usb_serial *serial = port->serial;
1067 	u16 state;
1068 	int result;
1069 
1070 	if (enable)
1071 		state = BREAK_ON;
1072 	else
1073 		state = BREAK_OFF;
1074 
1075 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
1076 			state == BREAK_OFF ? "off" : "on");
1077 
1078 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
1079 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
1080 				 0, NULL, 0, 100);
1081 	if (result) {
1082 		dev_err(&port->dev, "error sending break = %d\n", result);
1083 		return result;
1084 	}
1085 
1086 	return 0;
1087 }
1088 
1089 static int pl2303_break_ctl(struct tty_struct *tty, int state)
1090 {
1091 	struct usb_serial_port *port = tty->driver_data;
1092 
1093 	return pl2303_set_break(port, state);
1094 }
1095 
1096 static void pl2303_update_line_status(struct usb_serial_port *port,
1097 				      unsigned char *data,
1098 				      unsigned int actual_length)
1099 {
1100 	struct usb_serial *serial = port->serial;
1101 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
1102 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1103 	struct tty_struct *tty;
1104 	unsigned long flags;
1105 	unsigned int status_idx = UART_STATE_INDEX;
1106 	u8 status;
1107 	u8 delta;
1108 
1109 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
1110 		status_idx = 0;
1111 
1112 	if (actual_length < status_idx + 1)
1113 		return;
1114 
1115 	status = data[status_idx];
1116 
1117 	/* Save off the uart status for others to look at */
1118 	spin_lock_irqsave(&priv->lock, flags);
1119 	delta = priv->line_status ^ status;
1120 	priv->line_status = status;
1121 	spin_unlock_irqrestore(&priv->lock, flags);
1122 
1123 	if (status & UART_BREAK_ERROR)
1124 		usb_serial_handle_break(port);
1125 
1126 	if (delta & UART_STATE_MSR_MASK) {
1127 		if (delta & UART_CTS)
1128 			port->icount.cts++;
1129 		if (delta & UART_DSR)
1130 			port->icount.dsr++;
1131 		if (delta & UART_RING)
1132 			port->icount.rng++;
1133 		if (delta & UART_DCD) {
1134 			port->icount.dcd++;
1135 			tty = tty_port_tty_get(&port->port);
1136 			if (tty) {
1137 				usb_serial_handle_dcd_change(port, tty,
1138 							status & UART_DCD);
1139 				tty_kref_put(tty);
1140 			}
1141 		}
1142 
1143 		wake_up_interruptible(&port->port.delta_msr_wait);
1144 	}
1145 }
1146 
1147 static void pl2303_read_int_callback(struct urb *urb)
1148 {
1149 	struct usb_serial_port *port =  urb->context;
1150 	unsigned char *data = urb->transfer_buffer;
1151 	unsigned int actual_length = urb->actual_length;
1152 	int status = urb->status;
1153 	int retval;
1154 
1155 	switch (status) {
1156 	case 0:
1157 		/* success */
1158 		break;
1159 	case -ECONNRESET:
1160 	case -ENOENT:
1161 	case -ESHUTDOWN:
1162 		/* this urb is terminated, clean up */
1163 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
1164 			__func__, status);
1165 		return;
1166 	default:
1167 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
1168 			__func__, status);
1169 		goto exit;
1170 	}
1171 
1172 	usb_serial_debug_data(&port->dev, __func__,
1173 			      urb->actual_length, urb->transfer_buffer);
1174 
1175 	pl2303_update_line_status(port, data, actual_length);
1176 
1177 exit:
1178 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1179 	if (retval) {
1180 		dev_err(&port->dev,
1181 			"%s - usb_submit_urb failed with result %d\n",
1182 			__func__, retval);
1183 	}
1184 }
1185 
1186 static void pl2303_process_read_urb(struct urb *urb)
1187 {
1188 	struct usb_serial_port *port = urb->context;
1189 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1190 	unsigned char *data = urb->transfer_buffer;
1191 	char tty_flag = TTY_NORMAL;
1192 	unsigned long flags;
1193 	u8 line_status;
1194 	int i;
1195 
1196 	/* update line status */
1197 	spin_lock_irqsave(&priv->lock, flags);
1198 	line_status = priv->line_status;
1199 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
1200 	spin_unlock_irqrestore(&priv->lock, flags);
1201 
1202 	if (!urb->actual_length)
1203 		return;
1204 
1205 	/*
1206 	 * Break takes precedence over parity, which takes precedence over
1207 	 * framing errors.
1208 	 */
1209 	if (line_status & UART_BREAK_ERROR)
1210 		tty_flag = TTY_BREAK;
1211 	else if (line_status & UART_PARITY_ERROR)
1212 		tty_flag = TTY_PARITY;
1213 	else if (line_status & UART_FRAME_ERROR)
1214 		tty_flag = TTY_FRAME;
1215 
1216 	if (tty_flag != TTY_NORMAL)
1217 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
1218 								tty_flag);
1219 	/* overrun is special, not associated with a char */
1220 	if (line_status & UART_OVERRUN_ERROR)
1221 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
1222 
1223 	if (port->sysrq) {
1224 		for (i = 0; i < urb->actual_length; ++i)
1225 			if (!usb_serial_handle_sysrq_char(port, data[i]))
1226 				tty_insert_flip_char(&port->port, data[i],
1227 						tty_flag);
1228 	} else {
1229 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
1230 							urb->actual_length);
1231 	}
1232 
1233 	tty_flip_buffer_push(&port->port);
1234 }
1235 
1236 static struct usb_serial_driver pl2303_device = {
1237 	.driver = {
1238 		.owner =	THIS_MODULE,
1239 		.name =		"pl2303",
1240 	},
1241 	.id_table =		id_table,
1242 	.num_bulk_in =		1,
1243 	.num_bulk_out =		1,
1244 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
1245 	.bulk_in_size =		256,
1246 	.bulk_out_size =	256,
1247 	.open =			pl2303_open,
1248 	.close =		pl2303_close,
1249 	.dtr_rts =		pl2303_dtr_rts,
1250 	.carrier_raised =	pl2303_carrier_raised,
1251 	.break_ctl =		pl2303_break_ctl,
1252 	.set_termios =		pl2303_set_termios,
1253 	.tiocmget =		pl2303_tiocmget,
1254 	.tiocmset =		pl2303_tiocmset,
1255 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1256 	.process_read_urb =	pl2303_process_read_urb,
1257 	.read_int_callback =	pl2303_read_int_callback,
1258 	.probe =		pl2303_probe,
1259 	.calc_num_ports =	pl2303_calc_num_ports,
1260 	.attach =		pl2303_startup,
1261 	.release =		pl2303_release,
1262 	.port_probe =		pl2303_port_probe,
1263 	.port_remove =		pl2303_port_remove,
1264 };
1265 
1266 static struct usb_serial_driver * const serial_drivers[] = {
1267 	&pl2303_device, NULL
1268 };
1269 
1270 module_usb_serial_driver(serial_drivers, id_table);
1271 
1272 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1273 MODULE_LICENSE("GPL v2");
1274