xref: /openbmc/linux/drivers/usb/serial/pl2303.c (revision 808643ea)
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(ADLINK_VENDOR_ID, ADLINK_ND6530GC_PRODUCT_ID) },
117 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
118 	{ USB_DEVICE(AT_VENDOR_ID, AT_VTKIT3_PRODUCT_ID) },
119 	{ }					/* Terminating entry */
120 };
121 
122 MODULE_DEVICE_TABLE(usb, id_table);
123 
124 #define SET_LINE_REQUEST_TYPE		0x21
125 #define SET_LINE_REQUEST		0x20
126 
127 #define SET_CONTROL_REQUEST_TYPE	0x21
128 #define SET_CONTROL_REQUEST		0x22
129 #define CONTROL_DTR			0x01
130 #define CONTROL_RTS			0x02
131 
132 #define BREAK_REQUEST_TYPE		0x21
133 #define BREAK_REQUEST			0x23
134 #define BREAK_ON			0xffff
135 #define BREAK_OFF			0x0000
136 
137 #define GET_LINE_REQUEST_TYPE		0xa1
138 #define GET_LINE_REQUEST		0x21
139 
140 #define VENDOR_WRITE_REQUEST_TYPE	0x40
141 #define VENDOR_WRITE_REQUEST		0x01
142 #define VENDOR_WRITE_NREQUEST		0x80
143 
144 #define VENDOR_READ_REQUEST_TYPE	0xc0
145 #define VENDOR_READ_REQUEST		0x01
146 #define VENDOR_READ_NREQUEST		0x81
147 
148 #define UART_STATE_INDEX		8
149 #define UART_STATE_MSR_MASK		0x8b
150 #define UART_STATE_TRANSIENT_MASK	0x74
151 #define UART_DCD			0x01
152 #define UART_DSR			0x02
153 #define UART_BREAK_ERROR		0x04
154 #define UART_RING			0x08
155 #define UART_FRAME_ERROR		0x10
156 #define UART_PARITY_ERROR		0x20
157 #define UART_OVERRUN_ERROR		0x40
158 #define UART_CTS			0x80
159 
160 #define PL2303_FLOWCTRL_MASK		0xf0
161 
162 #define PL2303_READ_TYPE_HX_STATUS	0x8080
163 
164 #define PL2303_HXN_RESET_REG		0x07
165 #define PL2303_HXN_RESET_UPSTREAM_PIPE	0x02
166 #define PL2303_HXN_RESET_DOWNSTREAM_PIPE	0x01
167 
168 #define PL2303_HXN_FLOWCTRL_REG		0x0a
169 #define PL2303_HXN_FLOWCTRL_MASK	0x1c
170 #define PL2303_HXN_FLOWCTRL_NONE	0x1c
171 #define PL2303_HXN_FLOWCTRL_RTS_CTS	0x18
172 #define PL2303_HXN_FLOWCTRL_XON_XOFF	0x0c
173 
174 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
175 
176 enum pl2303_type {
177 	TYPE_H,
178 	TYPE_HX,
179 	TYPE_TA,
180 	TYPE_TB,
181 	TYPE_HXD,
182 	TYPE_HXN,
183 	TYPE_COUNT
184 };
185 
186 struct pl2303_type_data {
187 	const char *name;
188 	speed_t max_baud_rate;
189 	unsigned long quirks;
190 	unsigned int no_autoxonxoff:1;
191 	unsigned int no_divisors:1;
192 	unsigned int alt_divisors:1;
193 };
194 
195 struct pl2303_serial_private {
196 	const struct pl2303_type_data *type;
197 	unsigned long quirks;
198 };
199 
200 struct pl2303_private {
201 	spinlock_t lock;
202 	u8 line_control;
203 	u8 line_status;
204 
205 	u8 line_settings[7];
206 };
207 
208 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
209 	[TYPE_H] = {
210 		.name			= "H",
211 		.max_baud_rate		= 1228800,
212 		.quirks			= PL2303_QUIRK_LEGACY,
213 		.no_autoxonxoff		= true,
214 	},
215 	[TYPE_HX] = {
216 		.name			= "HX",
217 		.max_baud_rate		= 6000000,
218 	},
219 	[TYPE_TA] = {
220 		.name			= "TA",
221 		.max_baud_rate		= 6000000,
222 		.alt_divisors		= true,
223 	},
224 	[TYPE_TB] = {
225 		.name			= "TB",
226 		.max_baud_rate		= 12000000,
227 		.alt_divisors		= true,
228 	},
229 	[TYPE_HXD] = {
230 		.name			= "HXD",
231 		.max_baud_rate		= 12000000,
232 	},
233 	[TYPE_HXN] = {
234 		.name			= "G",
235 		.max_baud_rate		= 12000000,
236 		.no_divisors		= true,
237 	},
238 };
239 
240 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
241 							unsigned char buf[1])
242 {
243 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
244 	struct device *dev = &serial->interface->dev;
245 	u8 request;
246 	int res;
247 
248 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
249 		request = VENDOR_READ_NREQUEST;
250 	else
251 		request = VENDOR_READ_REQUEST;
252 
253 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
254 			request, VENDOR_READ_REQUEST_TYPE,
255 			value, 0, buf, 1, 100);
256 	if (res != 1) {
257 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
258 								value, res);
259 		if (res >= 0)
260 			res = -EIO;
261 
262 		return res;
263 	}
264 
265 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
266 
267 	return 0;
268 }
269 
270 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
271 {
272 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
273 	struct device *dev = &serial->interface->dev;
274 	u8 request;
275 	int res;
276 
277 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
278 
279 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
280 		request = VENDOR_WRITE_NREQUEST;
281 	else
282 		request = VENDOR_WRITE_REQUEST;
283 
284 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
285 			request, VENDOR_WRITE_REQUEST_TYPE,
286 			value, index, NULL, 0, 100);
287 	if (res) {
288 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
289 								value, res);
290 		return res;
291 	}
292 
293 	return 0;
294 }
295 
296 static int pl2303_update_reg(struct usb_serial *serial, u8 reg, u8 mask, u8 val)
297 {
298 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
299 	int ret = 0;
300 	u8 *buf;
301 
302 	buf = kmalloc(1, GFP_KERNEL);
303 	if (!buf)
304 		return -ENOMEM;
305 
306 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
307 		ret = pl2303_vendor_read(serial, reg, buf);
308 	else
309 		ret = pl2303_vendor_read(serial, reg | 0x80, buf);
310 
311 	if (ret)
312 		goto out_free;
313 
314 	*buf &= ~mask;
315 	*buf |= val & mask;
316 
317 	ret = pl2303_vendor_write(serial, reg, *buf);
318 out_free:
319 	kfree(buf);
320 
321 	return ret;
322 }
323 
324 static int pl2303_probe(struct usb_serial *serial,
325 					const struct usb_device_id *id)
326 {
327 	usb_set_serial_data(serial, (void *)id->driver_info);
328 
329 	return 0;
330 }
331 
332 /*
333  * Use interrupt endpoint from first interface if available.
334  *
335  * This is needed due to the looney way its endpoints are set up.
336  */
337 static int pl2303_endpoint_hack(struct usb_serial *serial,
338 					struct usb_serial_endpoints *epds)
339 {
340 	struct usb_interface *interface = serial->interface;
341 	struct usb_device *dev = serial->dev;
342 	struct device *ddev = &interface->dev;
343 	struct usb_host_interface *iface_desc;
344 	struct usb_endpoint_descriptor *endpoint;
345 	unsigned int i;
346 
347 	if (interface == dev->actconfig->interface[0])
348 		return 0;
349 
350 	/* check out the endpoints of the other interface */
351 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
352 
353 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
354 		endpoint = &iface_desc->endpoint[i].desc;
355 
356 		if (!usb_endpoint_is_int_in(endpoint))
357 			continue;
358 
359 		dev_dbg(ddev, "found interrupt in on separate interface\n");
360 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
361 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
362 	}
363 
364 	return 0;
365 }
366 
367 static int pl2303_calc_num_ports(struct usb_serial *serial,
368 					struct usb_serial_endpoints *epds)
369 {
370 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
371 	struct device *dev = &serial->interface->dev;
372 	int ret;
373 
374 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
375 		ret = pl2303_endpoint_hack(serial, epds);
376 		if (ret)
377 			return ret;
378 	}
379 
380 	if (epds->num_interrupt_in < 1) {
381 		dev_err(dev, "required interrupt-in endpoint missing\n");
382 		return -ENODEV;
383 	}
384 
385 	return 1;
386 }
387 
388 static bool pl2303_supports_hx_status(struct usb_serial *serial)
389 {
390 	int ret;
391 	u8 buf;
392 
393 	ret = usb_control_msg_recv(serial->dev, 0, VENDOR_READ_REQUEST,
394 			VENDOR_READ_REQUEST_TYPE, PL2303_READ_TYPE_HX_STATUS,
395 			0, &buf, 1, 100, GFP_KERNEL);
396 
397 	return ret == 0;
398 }
399 
400 static int pl2303_detect_type(struct usb_serial *serial)
401 {
402 	struct usb_device_descriptor *desc = &serial->dev->descriptor;
403 	u16 bcdDevice, bcdUSB;
404 
405 	/*
406 	 * Legacy PL2303H, variants 0 and 1 (difference unknown).
407 	 */
408 	if (desc->bDeviceClass == 0x02)
409 		return TYPE_H;		/* variant 0 */
410 
411 	if (desc->bMaxPacketSize0 != 0x40) {
412 		if (desc->bDeviceClass == 0x00 || desc->bDeviceClass == 0xff)
413 			return TYPE_H;	/* variant 1 */
414 
415 		return TYPE_H;		/* variant 0 */
416 	}
417 
418 	bcdDevice = le16_to_cpu(desc->bcdDevice);
419 	bcdUSB = le16_to_cpu(desc->bcdUSB);
420 
421 	switch (bcdDevice) {
422 	case 0x100:
423 		/*
424 		 * Assume it's an HXN-type if the device doesn't support the old read
425 		 * request value.
426 		 */
427 		if (bcdUSB == 0x200 && !pl2303_supports_hx_status(serial))
428 			return TYPE_HXN;
429 		break;
430 	case 0x300:
431 		if (bcdUSB == 0x200)
432 			return TYPE_TA;
433 
434 		return TYPE_HX;
435 	case 0x400:
436 		return TYPE_HXD;
437 	case 0x500:
438 		return TYPE_TB;
439 	}
440 
441 	dev_err(&serial->interface->dev,
442 			"unknown device type, please report to linux-usb@vger.kernel.org\n");
443 	return -ENODEV;
444 }
445 
446 static int pl2303_startup(struct usb_serial *serial)
447 {
448 	struct pl2303_serial_private *spriv;
449 	enum pl2303_type type;
450 	unsigned char *buf;
451 	int ret;
452 
453 	ret = pl2303_detect_type(serial);
454 	if (ret < 0)
455 		return ret;
456 
457 	type = ret;
458 	dev_dbg(&serial->interface->dev, "device type: %s\n", pl2303_type_data[type].name);
459 
460 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
461 	if (!spriv)
462 		return -ENOMEM;
463 
464 	spriv->type = &pl2303_type_data[type];
465 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
466 	spriv->quirks |= spriv->type->quirks;
467 
468 	usb_set_serial_data(serial, spriv);
469 
470 	if (type != TYPE_HXN) {
471 		buf = kmalloc(1, GFP_KERNEL);
472 		if (!buf) {
473 			kfree(spriv);
474 			return -ENOMEM;
475 		}
476 
477 		pl2303_vendor_read(serial, 0x8484, buf);
478 		pl2303_vendor_write(serial, 0x0404, 0);
479 		pl2303_vendor_read(serial, 0x8484, buf);
480 		pl2303_vendor_read(serial, 0x8383, buf);
481 		pl2303_vendor_read(serial, 0x8484, buf);
482 		pl2303_vendor_write(serial, 0x0404, 1);
483 		pl2303_vendor_read(serial, 0x8484, buf);
484 		pl2303_vendor_read(serial, 0x8383, buf);
485 		pl2303_vendor_write(serial, 0, 1);
486 		pl2303_vendor_write(serial, 1, 0);
487 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
488 			pl2303_vendor_write(serial, 2, 0x24);
489 		else
490 			pl2303_vendor_write(serial, 2, 0x44);
491 
492 		kfree(buf);
493 	}
494 
495 	return 0;
496 }
497 
498 static void pl2303_release(struct usb_serial *serial)
499 {
500 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
501 
502 	kfree(spriv);
503 }
504 
505 static int pl2303_port_probe(struct usb_serial_port *port)
506 {
507 	struct pl2303_private *priv;
508 
509 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
510 	if (!priv)
511 		return -ENOMEM;
512 
513 	spin_lock_init(&priv->lock);
514 
515 	usb_set_serial_port_data(port, priv);
516 
517 	port->port.drain_delay = 256;
518 
519 	return 0;
520 }
521 
522 static void pl2303_port_remove(struct usb_serial_port *port)
523 {
524 	struct pl2303_private *priv = usb_get_serial_port_data(port);
525 
526 	kfree(priv);
527 }
528 
529 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
530 {
531 	struct usb_device *dev = port->serial->dev;
532 	int retval;
533 
534 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
535 
536 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
537 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
538 				 value, 0, NULL, 0, 100);
539 	if (retval)
540 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
541 
542 	return retval;
543 }
544 
545 /*
546  * Returns the nearest supported baud rate that can be set directly without
547  * using divisors.
548  */
549 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
550 {
551 	static const speed_t baud_sup[] = {
552 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
553 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
554 		614400, 921600, 1228800, 2457600, 3000000, 6000000
555 	};
556 
557 	unsigned i;
558 
559 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
560 		if (baud_sup[i] > baud)
561 			break;
562 	}
563 
564 	if (i == ARRAY_SIZE(baud_sup))
565 		baud = baud_sup[i - 1];
566 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
567 		baud = baud_sup[i - 1];
568 	else
569 		baud = baud_sup[i];
570 
571 	return baud;
572 }
573 
574 /*
575  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
576  *       use 9600 baud.
577  */
578 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
579 								speed_t baud)
580 {
581 	put_unaligned_le32(baud, buf);
582 
583 	return baud;
584 }
585 
586 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
587 								speed_t baud)
588 {
589 	unsigned int baseline, mantissa, exponent;
590 
591 	/*
592 	 * Apparently the formula is:
593 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
594 	 * where
595 	 *   mantissa = buf[8:0]
596 	 *   exponent = buf[11:9]
597 	 */
598 	baseline = 12000000 * 32;
599 	mantissa = baseline / baud;
600 	if (mantissa == 0)
601 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
602 	exponent = 0;
603 	while (mantissa >= 512) {
604 		if (exponent < 7) {
605 			mantissa >>= 2;	/* divide by 4 */
606 			exponent++;
607 		} else {
608 			/* Exponent is maxed. Trim mantissa and leave. */
609 			mantissa = 511;
610 			break;
611 		}
612 	}
613 
614 	buf[3] = 0x80;
615 	buf[2] = 0;
616 	buf[1] = exponent << 1 | mantissa >> 8;
617 	buf[0] = mantissa & 0xff;
618 
619 	/* Calculate and return the exact baud rate. */
620 	baud = (baseline / mantissa) >> (exponent << 1);
621 
622 	return baud;
623 }
624 
625 static speed_t pl2303_encode_baud_rate_divisor_alt(unsigned char buf[4],
626 								speed_t baud)
627 {
628 	unsigned int baseline, mantissa, exponent;
629 
630 	/*
631 	 * Apparently, for the TA version the formula is:
632 	 *   baudrate = 12M * 32 / (mantissa * 2^exponent)
633 	 * where
634 	 *   mantissa = buf[10:0]
635 	 *   exponent = buf[15:13 16]
636 	 */
637 	baseline = 12000000 * 32;
638 	mantissa = baseline / baud;
639 	if (mantissa == 0)
640 		mantissa = 1;   /* Avoid dividing by zero if baud > 32*12M. */
641 	exponent = 0;
642 	while (mantissa >= 2048) {
643 		if (exponent < 15) {
644 			mantissa >>= 1; /* divide by 2 */
645 			exponent++;
646 		} else {
647 			/* Exponent is maxed. Trim mantissa and leave. */
648 			mantissa = 2047;
649 			break;
650 		}
651 	}
652 
653 	buf[3] = 0x80;
654 	buf[2] = exponent & 0x01;
655 	buf[1] = (exponent & ~0x01) << 4 | mantissa >> 8;
656 	buf[0] = mantissa & 0xff;
657 
658 	/* Calculate and return the exact baud rate. */
659 	baud = (baseline / mantissa) >> exponent;
660 
661 	return baud;
662 }
663 
664 static void pl2303_encode_baud_rate(struct tty_struct *tty,
665 					struct usb_serial_port *port,
666 					u8 buf[4])
667 {
668 	struct usb_serial *serial = port->serial;
669 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
670 	speed_t	baud_sup;
671 	speed_t baud;
672 
673 	baud = tty_get_baud_rate(tty);
674 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
675 	if (!baud)
676 		return;
677 
678 	if (spriv->type->max_baud_rate)
679 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
680 	/*
681 	 * Use direct method for supported baud rates, otherwise use divisors.
682 	 * Newer chip types do not support divisor encoding.
683 	 */
684 	if (spriv->type->no_divisors)
685 		baud_sup = baud;
686 	else
687 		baud_sup = pl2303_get_supported_baud_rate(baud);
688 
689 	if (baud == baud_sup)
690 		baud = pl2303_encode_baud_rate_direct(buf, baud);
691 	else if (spriv->type->alt_divisors)
692 		baud = pl2303_encode_baud_rate_divisor_alt(buf, baud);
693 	else
694 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
695 
696 	/* Save resulting baud rate */
697 	tty_encode_baud_rate(tty, baud, baud);
698 	dev_dbg(&port->dev, "baud set = %u\n", baud);
699 }
700 
701 static int pl2303_get_line_request(struct usb_serial_port *port,
702 							unsigned char buf[7])
703 {
704 	struct usb_device *udev = port->serial->dev;
705 	int ret;
706 
707 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
708 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
709 				0, 0, buf, 7, 100);
710 	if (ret != 7) {
711 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
712 
713 		if (ret >= 0)
714 			ret = -EIO;
715 
716 		return ret;
717 	}
718 
719 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
720 
721 	return 0;
722 }
723 
724 static int pl2303_set_line_request(struct usb_serial_port *port,
725 							unsigned char buf[7])
726 {
727 	struct usb_device *udev = port->serial->dev;
728 	int ret;
729 
730 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
731 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
732 				0, 0, buf, 7, 100);
733 	if (ret < 0) {
734 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
735 		return ret;
736 	}
737 
738 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
739 
740 	return 0;
741 }
742 
743 static bool pl2303_termios_change(const struct ktermios *a, const struct ktermios *b)
744 {
745 	bool ixon_change;
746 
747 	ixon_change = ((a->c_iflag ^ b->c_iflag) & (IXON | IXANY)) ||
748 			a->c_cc[VSTART] != b->c_cc[VSTART] ||
749 			a->c_cc[VSTOP] != b->c_cc[VSTOP];
750 
751 	return tty_termios_hw_change(a, b) || ixon_change;
752 }
753 
754 static bool pl2303_enable_xonxoff(struct tty_struct *tty, const struct pl2303_type_data *type)
755 {
756 	if (!I_IXON(tty) || I_IXANY(tty))
757 		return false;
758 
759 	if (START_CHAR(tty) != 0x11 || STOP_CHAR(tty) != 0x13)
760 		return false;
761 
762 	if (type->no_autoxonxoff)
763 		return false;
764 
765 	return true;
766 }
767 
768 static void pl2303_set_termios(struct tty_struct *tty,
769 		struct usb_serial_port *port, struct ktermios *old_termios)
770 {
771 	struct usb_serial *serial = port->serial;
772 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
773 	struct pl2303_private *priv = usb_get_serial_port_data(port);
774 	unsigned long flags;
775 	unsigned char *buf;
776 	int ret;
777 	u8 control;
778 
779 	if (old_termios && !pl2303_termios_change(&tty->termios, old_termios))
780 		return;
781 
782 	buf = kzalloc(7, GFP_KERNEL);
783 	if (!buf) {
784 		/* Report back no change occurred */
785 		if (old_termios)
786 			tty->termios = *old_termios;
787 		return;
788 	}
789 
790 	pl2303_get_line_request(port, buf);
791 
792 	buf[6] = tty_get_char_size(tty->termios.c_cflag);
793 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
794 
795 	/* For reference buf[0]:buf[3] baud rate value */
796 	pl2303_encode_baud_rate(tty, port, &buf[0]);
797 
798 	/* For reference buf[4]=0 is 1 stop bits */
799 	/* For reference buf[4]=1 is 1.5 stop bits */
800 	/* For reference buf[4]=2 is 2 stop bits */
801 	if (C_CSTOPB(tty)) {
802 		/*
803 		 * NOTE: Comply with "real" UARTs / RS232:
804 		 *       use 1.5 instead of 2 stop bits with 5 data bits
805 		 */
806 		if (C_CSIZE(tty) == CS5) {
807 			buf[4] = 1;
808 			dev_dbg(&port->dev, "stop bits = 1.5\n");
809 		} else {
810 			buf[4] = 2;
811 			dev_dbg(&port->dev, "stop bits = 2\n");
812 		}
813 	} else {
814 		buf[4] = 0;
815 		dev_dbg(&port->dev, "stop bits = 1\n");
816 	}
817 
818 	if (C_PARENB(tty)) {
819 		/* For reference buf[5]=0 is none parity */
820 		/* For reference buf[5]=1 is odd parity */
821 		/* For reference buf[5]=2 is even parity */
822 		/* For reference buf[5]=3 is mark parity */
823 		/* For reference buf[5]=4 is space parity */
824 		if (C_PARODD(tty)) {
825 			if (C_CMSPAR(tty)) {
826 				buf[5] = 3;
827 				dev_dbg(&port->dev, "parity = mark\n");
828 			} else {
829 				buf[5] = 1;
830 				dev_dbg(&port->dev, "parity = odd\n");
831 			}
832 		} else {
833 			if (C_CMSPAR(tty)) {
834 				buf[5] = 4;
835 				dev_dbg(&port->dev, "parity = space\n");
836 			} else {
837 				buf[5] = 2;
838 				dev_dbg(&port->dev, "parity = even\n");
839 			}
840 		}
841 	} else {
842 		buf[5] = 0;
843 		dev_dbg(&port->dev, "parity = none\n");
844 	}
845 
846 	/*
847 	 * Some PL2303 are known to lose bytes if you change serial settings
848 	 * even to the same values as before. Thus we actually need to filter
849 	 * in this specific case.
850 	 *
851 	 * Note that the tty_termios_hw_change check above is not sufficient
852 	 * as a previously requested baud rate may differ from the one
853 	 * actually used (and stored in old_termios).
854 	 *
855 	 * NOTE: No additional locking needed for line_settings as it is
856 	 *       only used in set_termios, which is serialised against itself.
857 	 */
858 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
859 		ret = pl2303_set_line_request(port, buf);
860 		if (!ret)
861 			memcpy(priv->line_settings, buf, 7);
862 	}
863 
864 	/* change control lines if we are switching to or from B0 */
865 	spin_lock_irqsave(&priv->lock, flags);
866 	control = priv->line_control;
867 	if (C_BAUD(tty) == B0)
868 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
869 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
870 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
871 	if (control != priv->line_control) {
872 		control = priv->line_control;
873 		spin_unlock_irqrestore(&priv->lock, flags);
874 		pl2303_set_control_lines(port, control);
875 	} else {
876 		spin_unlock_irqrestore(&priv->lock, flags);
877 	}
878 
879 	if (C_CRTSCTS(tty)) {
880 		if (spriv->quirks & PL2303_QUIRK_LEGACY) {
881 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x40);
882 		} else if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
883 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
884 					PL2303_HXN_FLOWCTRL_MASK,
885 					PL2303_HXN_FLOWCTRL_RTS_CTS);
886 		} else {
887 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x60);
888 		}
889 	} else if (pl2303_enable_xonxoff(tty, spriv->type)) {
890 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
891 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
892 					PL2303_HXN_FLOWCTRL_MASK,
893 					PL2303_HXN_FLOWCTRL_XON_XOFF);
894 		} else {
895 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0xc0);
896 		}
897 	} else {
898 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
899 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
900 					PL2303_HXN_FLOWCTRL_MASK,
901 					PL2303_HXN_FLOWCTRL_NONE);
902 		} else {
903 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0);
904 		}
905 	}
906 
907 	kfree(buf);
908 }
909 
910 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
911 {
912 	struct pl2303_private *priv = usb_get_serial_port_data(port);
913 	unsigned long flags;
914 	u8 control;
915 
916 	spin_lock_irqsave(&priv->lock, flags);
917 	if (on)
918 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
919 	else
920 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
921 	control = priv->line_control;
922 	spin_unlock_irqrestore(&priv->lock, flags);
923 
924 	pl2303_set_control_lines(port, control);
925 }
926 
927 static void pl2303_close(struct usb_serial_port *port)
928 {
929 	usb_serial_generic_close(port);
930 	usb_kill_urb(port->interrupt_in_urb);
931 	pl2303_set_break(port, false);
932 }
933 
934 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
935 {
936 	struct usb_serial *serial = port->serial;
937 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
938 	int result;
939 
940 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
941 		usb_clear_halt(serial->dev, port->write_urb->pipe);
942 		usb_clear_halt(serial->dev, port->read_urb->pipe);
943 	} else {
944 		/* reset upstream data pipes */
945 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
946 			pl2303_vendor_write(serial, PL2303_HXN_RESET_REG,
947 					PL2303_HXN_RESET_UPSTREAM_PIPE |
948 					PL2303_HXN_RESET_DOWNSTREAM_PIPE);
949 		} else {
950 			pl2303_vendor_write(serial, 8, 0);
951 			pl2303_vendor_write(serial, 9, 0);
952 		}
953 	}
954 
955 	/* Setup termios */
956 	if (tty)
957 		pl2303_set_termios(tty, port, NULL);
958 
959 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
960 	if (result) {
961 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
962 			result);
963 		return result;
964 	}
965 
966 	result = usb_serial_generic_open(tty, port);
967 	if (result) {
968 		usb_kill_urb(port->interrupt_in_urb);
969 		return result;
970 	}
971 
972 	return 0;
973 }
974 
975 static int pl2303_tiocmset(struct tty_struct *tty,
976 			   unsigned int set, unsigned int clear)
977 {
978 	struct usb_serial_port *port = tty->driver_data;
979 	struct pl2303_private *priv = usb_get_serial_port_data(port);
980 	unsigned long flags;
981 	u8 control;
982 	int ret;
983 
984 	spin_lock_irqsave(&priv->lock, flags);
985 	if (set & TIOCM_RTS)
986 		priv->line_control |= CONTROL_RTS;
987 	if (set & TIOCM_DTR)
988 		priv->line_control |= CONTROL_DTR;
989 	if (clear & TIOCM_RTS)
990 		priv->line_control &= ~CONTROL_RTS;
991 	if (clear & TIOCM_DTR)
992 		priv->line_control &= ~CONTROL_DTR;
993 	control = priv->line_control;
994 	spin_unlock_irqrestore(&priv->lock, flags);
995 
996 	ret = pl2303_set_control_lines(port, control);
997 	if (ret)
998 		return usb_translate_errors(ret);
999 
1000 	return 0;
1001 }
1002 
1003 static int pl2303_tiocmget(struct tty_struct *tty)
1004 {
1005 	struct usb_serial_port *port = tty->driver_data;
1006 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1007 	unsigned long flags;
1008 	unsigned int mcr;
1009 	unsigned int status;
1010 	unsigned int result;
1011 
1012 	spin_lock_irqsave(&priv->lock, flags);
1013 	mcr = priv->line_control;
1014 	status = priv->line_status;
1015 	spin_unlock_irqrestore(&priv->lock, flags);
1016 
1017 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
1018 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
1019 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
1020 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
1021 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
1022 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
1023 
1024 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
1025 
1026 	return result;
1027 }
1028 
1029 static int pl2303_carrier_raised(struct usb_serial_port *port)
1030 {
1031 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1032 
1033 	if (priv->line_status & UART_DCD)
1034 		return 1;
1035 
1036 	return 0;
1037 }
1038 
1039 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
1040 {
1041 	struct usb_serial *serial = port->serial;
1042 	u16 state;
1043 	int result;
1044 
1045 	if (enable)
1046 		state = BREAK_ON;
1047 	else
1048 		state = BREAK_OFF;
1049 
1050 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
1051 			state == BREAK_OFF ? "off" : "on");
1052 
1053 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
1054 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
1055 				 0, NULL, 0, 100);
1056 	if (result)
1057 		dev_err(&port->dev, "error sending break = %d\n", result);
1058 }
1059 
1060 static void pl2303_break_ctl(struct tty_struct *tty, int state)
1061 {
1062 	struct usb_serial_port *port = tty->driver_data;
1063 
1064 	pl2303_set_break(port, state);
1065 }
1066 
1067 static void pl2303_update_line_status(struct usb_serial_port *port,
1068 				      unsigned char *data,
1069 				      unsigned int actual_length)
1070 {
1071 	struct usb_serial *serial = port->serial;
1072 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
1073 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1074 	struct tty_struct *tty;
1075 	unsigned long flags;
1076 	unsigned int status_idx = UART_STATE_INDEX;
1077 	u8 status;
1078 	u8 delta;
1079 
1080 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
1081 		status_idx = 0;
1082 
1083 	if (actual_length < status_idx + 1)
1084 		return;
1085 
1086 	status = data[status_idx];
1087 
1088 	/* Save off the uart status for others to look at */
1089 	spin_lock_irqsave(&priv->lock, flags);
1090 	delta = priv->line_status ^ status;
1091 	priv->line_status = status;
1092 	spin_unlock_irqrestore(&priv->lock, flags);
1093 
1094 	if (status & UART_BREAK_ERROR)
1095 		usb_serial_handle_break(port);
1096 
1097 	if (delta & UART_STATE_MSR_MASK) {
1098 		if (delta & UART_CTS)
1099 			port->icount.cts++;
1100 		if (delta & UART_DSR)
1101 			port->icount.dsr++;
1102 		if (delta & UART_RING)
1103 			port->icount.rng++;
1104 		if (delta & UART_DCD) {
1105 			port->icount.dcd++;
1106 			tty = tty_port_tty_get(&port->port);
1107 			if (tty) {
1108 				usb_serial_handle_dcd_change(port, tty,
1109 							status & UART_DCD);
1110 				tty_kref_put(tty);
1111 			}
1112 		}
1113 
1114 		wake_up_interruptible(&port->port.delta_msr_wait);
1115 	}
1116 }
1117 
1118 static void pl2303_read_int_callback(struct urb *urb)
1119 {
1120 	struct usb_serial_port *port =  urb->context;
1121 	unsigned char *data = urb->transfer_buffer;
1122 	unsigned int actual_length = urb->actual_length;
1123 	int status = urb->status;
1124 	int retval;
1125 
1126 	switch (status) {
1127 	case 0:
1128 		/* success */
1129 		break;
1130 	case -ECONNRESET:
1131 	case -ENOENT:
1132 	case -ESHUTDOWN:
1133 		/* this urb is terminated, clean up */
1134 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
1135 			__func__, status);
1136 		return;
1137 	default:
1138 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
1139 			__func__, status);
1140 		goto exit;
1141 	}
1142 
1143 	usb_serial_debug_data(&port->dev, __func__,
1144 			      urb->actual_length, urb->transfer_buffer);
1145 
1146 	pl2303_update_line_status(port, data, actual_length);
1147 
1148 exit:
1149 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1150 	if (retval) {
1151 		dev_err(&port->dev,
1152 			"%s - usb_submit_urb failed with result %d\n",
1153 			__func__, retval);
1154 	}
1155 }
1156 
1157 static void pl2303_process_read_urb(struct urb *urb)
1158 {
1159 	struct usb_serial_port *port = urb->context;
1160 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1161 	unsigned char *data = urb->transfer_buffer;
1162 	char tty_flag = TTY_NORMAL;
1163 	unsigned long flags;
1164 	u8 line_status;
1165 	int i;
1166 
1167 	/* update line status */
1168 	spin_lock_irqsave(&priv->lock, flags);
1169 	line_status = priv->line_status;
1170 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
1171 	spin_unlock_irqrestore(&priv->lock, flags);
1172 
1173 	if (!urb->actual_length)
1174 		return;
1175 
1176 	/*
1177 	 * Break takes precedence over parity, which takes precedence over
1178 	 * framing errors.
1179 	 */
1180 	if (line_status & UART_BREAK_ERROR)
1181 		tty_flag = TTY_BREAK;
1182 	else if (line_status & UART_PARITY_ERROR)
1183 		tty_flag = TTY_PARITY;
1184 	else if (line_status & UART_FRAME_ERROR)
1185 		tty_flag = TTY_FRAME;
1186 
1187 	if (tty_flag != TTY_NORMAL)
1188 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
1189 								tty_flag);
1190 	/* overrun is special, not associated with a char */
1191 	if (line_status & UART_OVERRUN_ERROR)
1192 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
1193 
1194 	if (port->sysrq) {
1195 		for (i = 0; i < urb->actual_length; ++i)
1196 			if (!usb_serial_handle_sysrq_char(port, data[i]))
1197 				tty_insert_flip_char(&port->port, data[i],
1198 						tty_flag);
1199 	} else {
1200 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
1201 							urb->actual_length);
1202 	}
1203 
1204 	tty_flip_buffer_push(&port->port);
1205 }
1206 
1207 static struct usb_serial_driver pl2303_device = {
1208 	.driver = {
1209 		.owner =	THIS_MODULE,
1210 		.name =		"pl2303",
1211 	},
1212 	.id_table =		id_table,
1213 	.num_bulk_in =		1,
1214 	.num_bulk_out =		1,
1215 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
1216 	.bulk_in_size =		256,
1217 	.bulk_out_size =	256,
1218 	.open =			pl2303_open,
1219 	.close =		pl2303_close,
1220 	.dtr_rts =		pl2303_dtr_rts,
1221 	.carrier_raised =	pl2303_carrier_raised,
1222 	.break_ctl =		pl2303_break_ctl,
1223 	.set_termios =		pl2303_set_termios,
1224 	.tiocmget =		pl2303_tiocmget,
1225 	.tiocmset =		pl2303_tiocmset,
1226 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1227 	.process_read_urb =	pl2303_process_read_urb,
1228 	.read_int_callback =	pl2303_read_int_callback,
1229 	.probe =		pl2303_probe,
1230 	.calc_num_ports =	pl2303_calc_num_ports,
1231 	.attach =		pl2303_startup,
1232 	.release =		pl2303_release,
1233 	.port_probe =		pl2303_port_probe,
1234 	.port_remove =		pl2303_port_remove,
1235 };
1236 
1237 static struct usb_serial_driver * const serial_drivers[] = {
1238 	&pl2303_device, NULL
1239 };
1240 
1241 module_usb_serial_driver(serial_drivers, id_table);
1242 
1243 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1244 MODULE_LICENSE("GPL v2");
1245