xref: /openbmc/linux/drivers/usb/serial/pl2303.c (revision e5bd61e8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Prolific PL2303 USB to serial adaptor driver
4  *
5  * Copyright (C) 2001-2007 Greg Kroah-Hartman (greg@kroah.com)
6  * Copyright (C) 2003 IBM Corp.
7  *
8  * Original driver for 2.2.x by anonymous
9  *
10  * See Documentation/usb/usb-serial.rst for more information on using this
11  * driver
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/tty.h>
18 #include <linux/tty_driver.h>
19 #include <linux/tty_flip.h>
20 #include <linux/serial.h>
21 #include <linux/module.h>
22 #include <linux/moduleparam.h>
23 #include <linux/spinlock.h>
24 #include <linux/uaccess.h>
25 #include <linux/usb.h>
26 #include <linux/usb/serial.h>
27 #include <asm/unaligned.h>
28 #include "pl2303.h"
29 
30 
31 #define PL2303_QUIRK_UART_STATE_IDX0		BIT(0)
32 #define PL2303_QUIRK_LEGACY			BIT(1)
33 #define PL2303_QUIRK_ENDPOINT_HACK		BIT(2)
34 
35 static const struct usb_device_id id_table[] = {
36 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID),
37 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
38 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ2) },
39 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_DCU11) },
40 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ3) },
41 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_CHILITAG) },
42 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_PHAROS) },
43 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ALDIGA) },
44 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MMX) },
45 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GPRS) },
46 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_HCR331) },
47 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MOTOROLA) },
48 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ZTEK) },
49 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_TB) },
50 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GC) },
51 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GB) },
52 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GT) },
53 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GL) },
54 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GE) },
55 	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GS) },
56 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
57 	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID_RSAQ5) },
58 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID),
59 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
60 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC485),
61 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
62 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_UC232B),
63 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
64 	{ USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID2) },
65 	{ USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
66 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
67 	{ USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
68 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
69 	{ USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
70 	{ USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
71 	{ USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
72 	{ USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
73 	{ USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
74 	{ USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
75 	{ USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
76 	{ USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_PRODUCT_ID) },
77 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1),
78 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
79 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65),
80 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
81 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75),
82 		.driver_info = PL2303_QUIRK_UART_STATE_IDX0 },
83 	{ USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_EF81),
84 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
85 	{ USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_ID_S81) }, /* Benq/Siemens S81 */
86 	{ USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
87 	{ USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
88 	{ USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
89 	{ USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
90 	{ USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
91 	{ USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
92 	{ USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
93 	{ USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
94 	{ USB_DEVICE(ALCOR_VENDOR_ID, ALCOR_PRODUCT_ID),
95 		.driver_info = PL2303_QUIRK_ENDPOINT_HACK },
96 	{ USB_DEVICE(WS002IN_VENDOR_ID, WS002IN_PRODUCT_ID) },
97 	{ USB_DEVICE(COREGA_VENDOR_ID, COREGA_PRODUCT_ID) },
98 	{ USB_DEVICE(YCCABLE_VENDOR_ID, YCCABLE_PRODUCT_ID) },
99 	{ USB_DEVICE(SUPERIAL_VENDOR_ID, SUPERIAL_PRODUCT_ID) },
100 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220_PRODUCT_ID) },
101 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD220TA_PRODUCT_ID) },
102 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD381_PRODUCT_ID) },
103 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD381GC_PRODUCT_ID) },
104 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960_PRODUCT_ID) },
105 	{ USB_DEVICE(HP_VENDOR_ID, HP_LD960TA_PRODUCT_ID) },
106 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM220_PRODUCT_ID) },
107 	{ USB_DEVICE(HP_VENDOR_ID, HP_LCM960_PRODUCT_ID) },
108 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM920_PRODUCT_ID) },
109 	{ USB_DEVICE(HP_VENDOR_ID, HP_LM940_PRODUCT_ID) },
110 	{ USB_DEVICE(HP_VENDOR_ID, HP_TD620_PRODUCT_ID) },
111 	{ USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
112 	{ USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
113 	{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
114 	{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
115 	{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
116 	{ USB_DEVICE(SMART_VENDOR_ID, SMART_PRODUCT_ID) },
117 	{ USB_DEVICE(AT_VENDOR_ID, AT_VTKIT3_PRODUCT_ID) },
118 	{ }					/* Terminating entry */
119 };
120 
121 MODULE_DEVICE_TABLE(usb, id_table);
122 
123 #define SET_LINE_REQUEST_TYPE		0x21
124 #define SET_LINE_REQUEST		0x20
125 
126 #define SET_CONTROL_REQUEST_TYPE	0x21
127 #define SET_CONTROL_REQUEST		0x22
128 #define CONTROL_DTR			0x01
129 #define CONTROL_RTS			0x02
130 
131 #define BREAK_REQUEST_TYPE		0x21
132 #define BREAK_REQUEST			0x23
133 #define BREAK_ON			0xffff
134 #define BREAK_OFF			0x0000
135 
136 #define GET_LINE_REQUEST_TYPE		0xa1
137 #define GET_LINE_REQUEST		0x21
138 
139 #define VENDOR_WRITE_REQUEST_TYPE	0x40
140 #define VENDOR_WRITE_REQUEST		0x01
141 #define VENDOR_WRITE_NREQUEST		0x80
142 
143 #define VENDOR_READ_REQUEST_TYPE	0xc0
144 #define VENDOR_READ_REQUEST		0x01
145 #define VENDOR_READ_NREQUEST		0x81
146 
147 #define UART_STATE_INDEX		8
148 #define UART_STATE_MSR_MASK		0x8b
149 #define UART_STATE_TRANSIENT_MASK	0x74
150 #define UART_DCD			0x01
151 #define UART_DSR			0x02
152 #define UART_BREAK_ERROR		0x04
153 #define UART_RING			0x08
154 #define UART_FRAME_ERROR		0x10
155 #define UART_PARITY_ERROR		0x20
156 #define UART_OVERRUN_ERROR		0x40
157 #define UART_CTS			0x80
158 
159 #define PL2303_FLOWCTRL_MASK		0xf0
160 
161 #define PL2303_READ_TYPE_HX_STATUS	0x8080
162 
163 #define PL2303_HXN_RESET_REG		0x07
164 #define PL2303_HXN_RESET_UPSTREAM_PIPE	0x02
165 #define PL2303_HXN_RESET_DOWNSTREAM_PIPE	0x01
166 
167 #define PL2303_HXN_FLOWCTRL_REG		0x0a
168 #define PL2303_HXN_FLOWCTRL_MASK	0x1c
169 #define PL2303_HXN_FLOWCTRL_NONE	0x1c
170 #define PL2303_HXN_FLOWCTRL_RTS_CTS	0x18
171 #define PL2303_HXN_FLOWCTRL_XON_XOFF	0x0c
172 
173 static void pl2303_set_break(struct usb_serial_port *port, bool enable);
174 
175 enum pl2303_type {
176 	TYPE_H,
177 	TYPE_HX,
178 	TYPE_TA,
179 	TYPE_TB,
180 	TYPE_HXD,
181 	TYPE_HXN,
182 	TYPE_COUNT
183 };
184 
185 struct pl2303_type_data {
186 	const char *name;
187 	speed_t max_baud_rate;
188 	unsigned long quirks;
189 	unsigned int no_autoxonxoff:1;
190 	unsigned int no_divisors:1;
191 	unsigned int alt_divisors:1;
192 };
193 
194 struct pl2303_serial_private {
195 	const struct pl2303_type_data *type;
196 	unsigned long quirks;
197 };
198 
199 struct pl2303_private {
200 	spinlock_t lock;
201 	u8 line_control;
202 	u8 line_status;
203 
204 	u8 line_settings[7];
205 };
206 
207 static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
208 	[TYPE_H] = {
209 		.name			= "H",
210 		.max_baud_rate		= 1228800,
211 		.quirks			= PL2303_QUIRK_LEGACY,
212 		.no_autoxonxoff		= true,
213 	},
214 	[TYPE_HX] = {
215 		.name			= "HX",
216 		.max_baud_rate		= 6000000,
217 	},
218 	[TYPE_TA] = {
219 		.name			= "TA",
220 		.max_baud_rate		= 6000000,
221 		.alt_divisors		= true,
222 	},
223 	[TYPE_TB] = {
224 		.name			= "TB",
225 		.max_baud_rate		= 12000000,
226 		.alt_divisors		= true,
227 	},
228 	[TYPE_HXD] = {
229 		.name			= "HXD",
230 		.max_baud_rate		= 12000000,
231 	},
232 	[TYPE_HXN] = {
233 		.name			= "G",
234 		.max_baud_rate		= 12000000,
235 		.no_divisors		= true,
236 	},
237 };
238 
239 static int pl2303_vendor_read(struct usb_serial *serial, u16 value,
240 							unsigned char buf[1])
241 {
242 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
243 	struct device *dev = &serial->interface->dev;
244 	u8 request;
245 	int res;
246 
247 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
248 		request = VENDOR_READ_NREQUEST;
249 	else
250 		request = VENDOR_READ_REQUEST;
251 
252 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
253 			request, VENDOR_READ_REQUEST_TYPE,
254 			value, 0, buf, 1, 100);
255 	if (res != 1) {
256 		dev_err(dev, "%s - failed to read [%04x]: %d\n", __func__,
257 								value, res);
258 		if (res >= 0)
259 			res = -EIO;
260 
261 		return res;
262 	}
263 
264 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, buf[0]);
265 
266 	return 0;
267 }
268 
269 static int pl2303_vendor_write(struct usb_serial *serial, u16 value, u16 index)
270 {
271 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
272 	struct device *dev = &serial->interface->dev;
273 	u8 request;
274 	int res;
275 
276 	dev_dbg(dev, "%s - [%04x] = %02x\n", __func__, value, index);
277 
278 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
279 		request = VENDOR_WRITE_NREQUEST;
280 	else
281 		request = VENDOR_WRITE_REQUEST;
282 
283 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
284 			request, VENDOR_WRITE_REQUEST_TYPE,
285 			value, index, NULL, 0, 100);
286 	if (res) {
287 		dev_err(dev, "%s - failed to write [%04x]: %d\n", __func__,
288 								value, res);
289 		return res;
290 	}
291 
292 	return 0;
293 }
294 
295 static int pl2303_update_reg(struct usb_serial *serial, u8 reg, u8 mask, u8 val)
296 {
297 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
298 	int ret = 0;
299 	u8 *buf;
300 
301 	buf = kmalloc(1, GFP_KERNEL);
302 	if (!buf)
303 		return -ENOMEM;
304 
305 	if (spriv->type == &pl2303_type_data[TYPE_HXN])
306 		ret = pl2303_vendor_read(serial, reg, buf);
307 	else
308 		ret = pl2303_vendor_read(serial, reg | 0x80, buf);
309 
310 	if (ret)
311 		goto out_free;
312 
313 	*buf &= ~mask;
314 	*buf |= val & mask;
315 
316 	ret = pl2303_vendor_write(serial, reg, *buf);
317 out_free:
318 	kfree(buf);
319 
320 	return ret;
321 }
322 
323 static int pl2303_probe(struct usb_serial *serial,
324 					const struct usb_device_id *id)
325 {
326 	usb_set_serial_data(serial, (void *)id->driver_info);
327 
328 	return 0;
329 }
330 
331 /*
332  * Use interrupt endpoint from first interface if available.
333  *
334  * This is needed due to the looney way its endpoints are set up.
335  */
336 static int pl2303_endpoint_hack(struct usb_serial *serial,
337 					struct usb_serial_endpoints *epds)
338 {
339 	struct usb_interface *interface = serial->interface;
340 	struct usb_device *dev = serial->dev;
341 	struct device *ddev = &interface->dev;
342 	struct usb_host_interface *iface_desc;
343 	struct usb_endpoint_descriptor *endpoint;
344 	unsigned int i;
345 
346 	if (interface == dev->actconfig->interface[0])
347 		return 0;
348 
349 	/* check out the endpoints of the other interface */
350 	iface_desc = dev->actconfig->interface[0]->cur_altsetting;
351 
352 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
353 		endpoint = &iface_desc->endpoint[i].desc;
354 
355 		if (!usb_endpoint_is_int_in(endpoint))
356 			continue;
357 
358 		dev_dbg(ddev, "found interrupt in on separate interface\n");
359 		if (epds->num_interrupt_in < ARRAY_SIZE(epds->interrupt_in))
360 			epds->interrupt_in[epds->num_interrupt_in++] = endpoint;
361 	}
362 
363 	return 0;
364 }
365 
366 static int pl2303_calc_num_ports(struct usb_serial *serial,
367 					struct usb_serial_endpoints *epds)
368 {
369 	unsigned long quirks = (unsigned long)usb_get_serial_data(serial);
370 	struct device *dev = &serial->interface->dev;
371 	int ret;
372 
373 	if (quirks & PL2303_QUIRK_ENDPOINT_HACK) {
374 		ret = pl2303_endpoint_hack(serial, epds);
375 		if (ret)
376 			return ret;
377 	}
378 
379 	if (epds->num_interrupt_in < 1) {
380 		dev_err(dev, "required interrupt-in endpoint missing\n");
381 		return -ENODEV;
382 	}
383 
384 	return 1;
385 }
386 
387 static bool pl2303_supports_hx_status(struct usb_serial *serial)
388 {
389 	int ret;
390 	u8 buf;
391 
392 	ret = usb_control_msg_recv(serial->dev, 0, VENDOR_READ_REQUEST,
393 			VENDOR_READ_REQUEST_TYPE, PL2303_READ_TYPE_HX_STATUS,
394 			0, &buf, 1, 100, GFP_KERNEL);
395 
396 	return ret == 0;
397 }
398 
399 static int pl2303_detect_type(struct usb_serial *serial)
400 {
401 	struct usb_device_descriptor *desc = &serial->dev->descriptor;
402 	u16 bcdDevice, bcdUSB;
403 
404 	/*
405 	 * Legacy PL2303H, variants 0 and 1 (difference unknown).
406 	 */
407 	if (desc->bDeviceClass == 0x02)
408 		return TYPE_H;		/* variant 0 */
409 
410 	if (desc->bMaxPacketSize0 != 0x40) {
411 		if (desc->bDeviceClass == 0x00 || desc->bDeviceClass == 0xff)
412 			return TYPE_H;	/* variant 1 */
413 
414 		return TYPE_H;		/* variant 0 */
415 	}
416 
417 	bcdDevice = le16_to_cpu(desc->bcdDevice);
418 	bcdUSB = le16_to_cpu(desc->bcdUSB);
419 
420 	switch (bcdDevice) {
421 	case 0x100:
422 		/*
423 		 * Assume it's an HXN-type if the device doesn't support the old read
424 		 * request value.
425 		 */
426 		if (bcdUSB == 0x200 && !pl2303_supports_hx_status(serial))
427 			return TYPE_HXN;
428 		break;
429 	case 0x300:
430 		if (bcdUSB == 0x200)
431 			return TYPE_TA;
432 
433 		return TYPE_HX;
434 	case 0x400:
435 		return TYPE_HXD;
436 	case 0x500:
437 		return TYPE_TB;
438 	}
439 
440 	dev_err(&serial->interface->dev,
441 			"unknown device type, please report to linux-usb@vger.kernel.org\n");
442 	return -ENODEV;
443 }
444 
445 static int pl2303_startup(struct usb_serial *serial)
446 {
447 	struct pl2303_serial_private *spriv;
448 	enum pl2303_type type;
449 	unsigned char *buf;
450 	int ret;
451 
452 	ret = pl2303_detect_type(serial);
453 	if (ret < 0)
454 		return ret;
455 
456 	type = ret;
457 	dev_dbg(&serial->interface->dev, "device type: %s\n", pl2303_type_data[type].name);
458 
459 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
460 	if (!spriv)
461 		return -ENOMEM;
462 
463 	spriv->type = &pl2303_type_data[type];
464 	spriv->quirks = (unsigned long)usb_get_serial_data(serial);
465 	spriv->quirks |= spriv->type->quirks;
466 
467 	usb_set_serial_data(serial, spriv);
468 
469 	if (type != TYPE_HXN) {
470 		buf = kmalloc(1, GFP_KERNEL);
471 		if (!buf) {
472 			kfree(spriv);
473 			return -ENOMEM;
474 		}
475 
476 		pl2303_vendor_read(serial, 0x8484, buf);
477 		pl2303_vendor_write(serial, 0x0404, 0);
478 		pl2303_vendor_read(serial, 0x8484, buf);
479 		pl2303_vendor_read(serial, 0x8383, buf);
480 		pl2303_vendor_read(serial, 0x8484, buf);
481 		pl2303_vendor_write(serial, 0x0404, 1);
482 		pl2303_vendor_read(serial, 0x8484, buf);
483 		pl2303_vendor_read(serial, 0x8383, buf);
484 		pl2303_vendor_write(serial, 0, 1);
485 		pl2303_vendor_write(serial, 1, 0);
486 		if (spriv->quirks & PL2303_QUIRK_LEGACY)
487 			pl2303_vendor_write(serial, 2, 0x24);
488 		else
489 			pl2303_vendor_write(serial, 2, 0x44);
490 
491 		kfree(buf);
492 	}
493 
494 	return 0;
495 }
496 
497 static void pl2303_release(struct usb_serial *serial)
498 {
499 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
500 
501 	kfree(spriv);
502 }
503 
504 static int pl2303_port_probe(struct usb_serial_port *port)
505 {
506 	struct pl2303_private *priv;
507 
508 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
509 	if (!priv)
510 		return -ENOMEM;
511 
512 	spin_lock_init(&priv->lock);
513 
514 	usb_set_serial_port_data(port, priv);
515 
516 	port->port.drain_delay = 256;
517 
518 	return 0;
519 }
520 
521 static void pl2303_port_remove(struct usb_serial_port *port)
522 {
523 	struct pl2303_private *priv = usb_get_serial_port_data(port);
524 
525 	kfree(priv);
526 }
527 
528 static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
529 {
530 	struct usb_device *dev = port->serial->dev;
531 	int retval;
532 
533 	dev_dbg(&port->dev, "%s - %02x\n", __func__, value);
534 
535 	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
536 				 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
537 				 value, 0, NULL, 0, 100);
538 	if (retval)
539 		dev_err(&port->dev, "%s - failed: %d\n", __func__, retval);
540 
541 	return retval;
542 }
543 
544 /*
545  * Returns the nearest supported baud rate that can be set directly without
546  * using divisors.
547  */
548 static speed_t pl2303_get_supported_baud_rate(speed_t baud)
549 {
550 	static const speed_t baud_sup[] = {
551 		75, 150, 300, 600, 1200, 1800, 2400, 3600, 4800, 7200, 9600,
552 		14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800,
553 		614400, 921600, 1228800, 2457600, 3000000, 6000000
554 	};
555 
556 	unsigned i;
557 
558 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
559 		if (baud_sup[i] > baud)
560 			break;
561 	}
562 
563 	if (i == ARRAY_SIZE(baud_sup))
564 		baud = baud_sup[i - 1];
565 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
566 		baud = baud_sup[i - 1];
567 	else
568 		baud = baud_sup[i];
569 
570 	return baud;
571 }
572 
573 /*
574  * NOTE: If unsupported baud rates are set directly, the PL2303 seems to
575  *       use 9600 baud.
576  */
577 static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
578 								speed_t baud)
579 {
580 	put_unaligned_le32(baud, buf);
581 
582 	return baud;
583 }
584 
585 static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
586 								speed_t baud)
587 {
588 	unsigned int baseline, mantissa, exponent;
589 
590 	/*
591 	 * Apparently the formula is:
592 	 *   baudrate = 12M * 32 / (mantissa * 4^exponent)
593 	 * where
594 	 *   mantissa = buf[8:0]
595 	 *   exponent = buf[11:9]
596 	 */
597 	baseline = 12000000 * 32;
598 	mantissa = baseline / baud;
599 	if (mantissa == 0)
600 		mantissa = 1;	/* Avoid dividing by zero if baud > 32*12M. */
601 	exponent = 0;
602 	while (mantissa >= 512) {
603 		if (exponent < 7) {
604 			mantissa >>= 2;	/* divide by 4 */
605 			exponent++;
606 		} else {
607 			/* Exponent is maxed. Trim mantissa and leave. */
608 			mantissa = 511;
609 			break;
610 		}
611 	}
612 
613 	buf[3] = 0x80;
614 	buf[2] = 0;
615 	buf[1] = exponent << 1 | mantissa >> 8;
616 	buf[0] = mantissa & 0xff;
617 
618 	/* Calculate and return the exact baud rate. */
619 	baud = (baseline / mantissa) >> (exponent << 1);
620 
621 	return baud;
622 }
623 
624 static speed_t pl2303_encode_baud_rate_divisor_alt(unsigned char buf[4],
625 								speed_t baud)
626 {
627 	unsigned int baseline, mantissa, exponent;
628 
629 	/*
630 	 * Apparently, for the TA version the formula is:
631 	 *   baudrate = 12M * 32 / (mantissa * 2^exponent)
632 	 * where
633 	 *   mantissa = buf[10:0]
634 	 *   exponent = buf[15:13 16]
635 	 */
636 	baseline = 12000000 * 32;
637 	mantissa = baseline / baud;
638 	if (mantissa == 0)
639 		mantissa = 1;   /* Avoid dividing by zero if baud > 32*12M. */
640 	exponent = 0;
641 	while (mantissa >= 2048) {
642 		if (exponent < 15) {
643 			mantissa >>= 1; /* divide by 2 */
644 			exponent++;
645 		} else {
646 			/* Exponent is maxed. Trim mantissa and leave. */
647 			mantissa = 2047;
648 			break;
649 		}
650 	}
651 
652 	buf[3] = 0x80;
653 	buf[2] = exponent & 0x01;
654 	buf[1] = (exponent & ~0x01) << 4 | mantissa >> 8;
655 	buf[0] = mantissa & 0xff;
656 
657 	/* Calculate and return the exact baud rate. */
658 	baud = (baseline / mantissa) >> exponent;
659 
660 	return baud;
661 }
662 
663 static void pl2303_encode_baud_rate(struct tty_struct *tty,
664 					struct usb_serial_port *port,
665 					u8 buf[4])
666 {
667 	struct usb_serial *serial = port->serial;
668 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
669 	speed_t	baud_sup;
670 	speed_t baud;
671 
672 	baud = tty_get_baud_rate(tty);
673 	dev_dbg(&port->dev, "baud requested = %u\n", baud);
674 	if (!baud)
675 		return;
676 
677 	if (spriv->type->max_baud_rate)
678 		baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
679 	/*
680 	 * Use direct method for supported baud rates, otherwise use divisors.
681 	 * Newer chip types do not support divisor encoding.
682 	 */
683 	if (spriv->type->no_divisors)
684 		baud_sup = baud;
685 	else
686 		baud_sup = pl2303_get_supported_baud_rate(baud);
687 
688 	if (baud == baud_sup)
689 		baud = pl2303_encode_baud_rate_direct(buf, baud);
690 	else if (spriv->type->alt_divisors)
691 		baud = pl2303_encode_baud_rate_divisor_alt(buf, baud);
692 	else
693 		baud = pl2303_encode_baud_rate_divisor(buf, baud);
694 
695 	/* Save resulting baud rate */
696 	tty_encode_baud_rate(tty, baud, baud);
697 	dev_dbg(&port->dev, "baud set = %u\n", baud);
698 }
699 
700 static int pl2303_get_line_request(struct usb_serial_port *port,
701 							unsigned char buf[7])
702 {
703 	struct usb_device *udev = port->serial->dev;
704 	int ret;
705 
706 	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
707 				GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
708 				0, 0, buf, 7, 100);
709 	if (ret != 7) {
710 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
711 
712 		if (ret >= 0)
713 			ret = -EIO;
714 
715 		return ret;
716 	}
717 
718 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
719 
720 	return 0;
721 }
722 
723 static int pl2303_set_line_request(struct usb_serial_port *port,
724 							unsigned char buf[7])
725 {
726 	struct usb_device *udev = port->serial->dev;
727 	int ret;
728 
729 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
730 				SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
731 				0, 0, buf, 7, 100);
732 	if (ret < 0) {
733 		dev_err(&port->dev, "%s - failed: %d\n", __func__, ret);
734 		return ret;
735 	}
736 
737 	dev_dbg(&port->dev, "%s - %7ph\n", __func__, buf);
738 
739 	return 0;
740 }
741 
742 static bool pl2303_termios_change(const struct ktermios *a, const struct ktermios *b)
743 {
744 	bool ixon_change;
745 
746 	ixon_change = ((a->c_iflag ^ b->c_iflag) & (IXON | IXANY)) ||
747 			a->c_cc[VSTART] != b->c_cc[VSTART] ||
748 			a->c_cc[VSTOP] != b->c_cc[VSTOP];
749 
750 	return tty_termios_hw_change(a, b) || ixon_change;
751 }
752 
753 static bool pl2303_enable_xonxoff(struct tty_struct *tty, const struct pl2303_type_data *type)
754 {
755 	if (!I_IXON(tty) || I_IXANY(tty))
756 		return false;
757 
758 	if (START_CHAR(tty) != 0x11 || STOP_CHAR(tty) != 0x13)
759 		return false;
760 
761 	if (type->no_autoxonxoff)
762 		return false;
763 
764 	return true;
765 }
766 
767 static void pl2303_set_termios(struct tty_struct *tty,
768 		struct usb_serial_port *port, struct ktermios *old_termios)
769 {
770 	struct usb_serial *serial = port->serial;
771 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
772 	struct pl2303_private *priv = usb_get_serial_port_data(port);
773 	unsigned long flags;
774 	unsigned char *buf;
775 	int ret;
776 	u8 control;
777 
778 	if (old_termios && !pl2303_termios_change(&tty->termios, old_termios))
779 		return;
780 
781 	buf = kzalloc(7, GFP_KERNEL);
782 	if (!buf) {
783 		/* Report back no change occurred */
784 		if (old_termios)
785 			tty->termios = *old_termios;
786 		return;
787 	}
788 
789 	pl2303_get_line_request(port, buf);
790 
791 	switch (C_CSIZE(tty)) {
792 	case CS5:
793 		buf[6] = 5;
794 		break;
795 	case CS6:
796 		buf[6] = 6;
797 		break;
798 	case CS7:
799 		buf[6] = 7;
800 		break;
801 	default:
802 	case CS8:
803 		buf[6] = 8;
804 	}
805 	dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
806 
807 	/* For reference buf[0]:buf[3] baud rate value */
808 	pl2303_encode_baud_rate(tty, port, &buf[0]);
809 
810 	/* For reference buf[4]=0 is 1 stop bits */
811 	/* For reference buf[4]=1 is 1.5 stop bits */
812 	/* For reference buf[4]=2 is 2 stop bits */
813 	if (C_CSTOPB(tty)) {
814 		/*
815 		 * NOTE: Comply with "real" UARTs / RS232:
816 		 *       use 1.5 instead of 2 stop bits with 5 data bits
817 		 */
818 		if (C_CSIZE(tty) == CS5) {
819 			buf[4] = 1;
820 			dev_dbg(&port->dev, "stop bits = 1.5\n");
821 		} else {
822 			buf[4] = 2;
823 			dev_dbg(&port->dev, "stop bits = 2\n");
824 		}
825 	} else {
826 		buf[4] = 0;
827 		dev_dbg(&port->dev, "stop bits = 1\n");
828 	}
829 
830 	if (C_PARENB(tty)) {
831 		/* For reference buf[5]=0 is none parity */
832 		/* For reference buf[5]=1 is odd parity */
833 		/* For reference buf[5]=2 is even parity */
834 		/* For reference buf[5]=3 is mark parity */
835 		/* For reference buf[5]=4 is space parity */
836 		if (C_PARODD(tty)) {
837 			if (C_CMSPAR(tty)) {
838 				buf[5] = 3;
839 				dev_dbg(&port->dev, "parity = mark\n");
840 			} else {
841 				buf[5] = 1;
842 				dev_dbg(&port->dev, "parity = odd\n");
843 			}
844 		} else {
845 			if (C_CMSPAR(tty)) {
846 				buf[5] = 4;
847 				dev_dbg(&port->dev, "parity = space\n");
848 			} else {
849 				buf[5] = 2;
850 				dev_dbg(&port->dev, "parity = even\n");
851 			}
852 		}
853 	} else {
854 		buf[5] = 0;
855 		dev_dbg(&port->dev, "parity = none\n");
856 	}
857 
858 	/*
859 	 * Some PL2303 are known to lose bytes if you change serial settings
860 	 * even to the same values as before. Thus we actually need to filter
861 	 * in this specific case.
862 	 *
863 	 * Note that the tty_termios_hw_change check above is not sufficient
864 	 * as a previously requested baud rate may differ from the one
865 	 * actually used (and stored in old_termios).
866 	 *
867 	 * NOTE: No additional locking needed for line_settings as it is
868 	 *       only used in set_termios, which is serialised against itself.
869 	 */
870 	if (!old_termios || memcmp(buf, priv->line_settings, 7)) {
871 		ret = pl2303_set_line_request(port, buf);
872 		if (!ret)
873 			memcpy(priv->line_settings, buf, 7);
874 	}
875 
876 	/* change control lines if we are switching to or from B0 */
877 	spin_lock_irqsave(&priv->lock, flags);
878 	control = priv->line_control;
879 	if (C_BAUD(tty) == B0)
880 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
881 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
882 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
883 	if (control != priv->line_control) {
884 		control = priv->line_control;
885 		spin_unlock_irqrestore(&priv->lock, flags);
886 		pl2303_set_control_lines(port, control);
887 	} else {
888 		spin_unlock_irqrestore(&priv->lock, flags);
889 	}
890 
891 	if (C_CRTSCTS(tty)) {
892 		if (spriv->quirks & PL2303_QUIRK_LEGACY) {
893 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x40);
894 		} else if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
895 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
896 					PL2303_HXN_FLOWCTRL_MASK,
897 					PL2303_HXN_FLOWCTRL_RTS_CTS);
898 		} else {
899 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0x60);
900 		}
901 	} else if (pl2303_enable_xonxoff(tty, spriv->type)) {
902 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
903 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
904 					PL2303_HXN_FLOWCTRL_MASK,
905 					PL2303_HXN_FLOWCTRL_XON_XOFF);
906 		} else {
907 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0xc0);
908 		}
909 	} else {
910 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
911 			pl2303_update_reg(serial, PL2303_HXN_FLOWCTRL_REG,
912 					PL2303_HXN_FLOWCTRL_MASK,
913 					PL2303_HXN_FLOWCTRL_NONE);
914 		} else {
915 			pl2303_update_reg(serial, 0, PL2303_FLOWCTRL_MASK, 0);
916 		}
917 	}
918 
919 	kfree(buf);
920 }
921 
922 static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
923 {
924 	struct pl2303_private *priv = usb_get_serial_port_data(port);
925 	unsigned long flags;
926 	u8 control;
927 
928 	spin_lock_irqsave(&priv->lock, flags);
929 	if (on)
930 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
931 	else
932 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
933 	control = priv->line_control;
934 	spin_unlock_irqrestore(&priv->lock, flags);
935 
936 	pl2303_set_control_lines(port, control);
937 }
938 
939 static void pl2303_close(struct usb_serial_port *port)
940 {
941 	usb_serial_generic_close(port);
942 	usb_kill_urb(port->interrupt_in_urb);
943 	pl2303_set_break(port, false);
944 }
945 
946 static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
947 {
948 	struct usb_serial *serial = port->serial;
949 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
950 	int result;
951 
952 	if (spriv->quirks & PL2303_QUIRK_LEGACY) {
953 		usb_clear_halt(serial->dev, port->write_urb->pipe);
954 		usb_clear_halt(serial->dev, port->read_urb->pipe);
955 	} else {
956 		/* reset upstream data pipes */
957 		if (spriv->type == &pl2303_type_data[TYPE_HXN]) {
958 			pl2303_vendor_write(serial, PL2303_HXN_RESET_REG,
959 					PL2303_HXN_RESET_UPSTREAM_PIPE |
960 					PL2303_HXN_RESET_DOWNSTREAM_PIPE);
961 		} else {
962 			pl2303_vendor_write(serial, 8, 0);
963 			pl2303_vendor_write(serial, 9, 0);
964 		}
965 	}
966 
967 	/* Setup termios */
968 	if (tty)
969 		pl2303_set_termios(tty, port, NULL);
970 
971 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
972 	if (result) {
973 		dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
974 			result);
975 		return result;
976 	}
977 
978 	result = usb_serial_generic_open(tty, port);
979 	if (result) {
980 		usb_kill_urb(port->interrupt_in_urb);
981 		return result;
982 	}
983 
984 	return 0;
985 }
986 
987 static int pl2303_tiocmset(struct tty_struct *tty,
988 			   unsigned int set, unsigned int clear)
989 {
990 	struct usb_serial_port *port = tty->driver_data;
991 	struct pl2303_private *priv = usb_get_serial_port_data(port);
992 	unsigned long flags;
993 	u8 control;
994 	int ret;
995 
996 	spin_lock_irqsave(&priv->lock, flags);
997 	if (set & TIOCM_RTS)
998 		priv->line_control |= CONTROL_RTS;
999 	if (set & TIOCM_DTR)
1000 		priv->line_control |= CONTROL_DTR;
1001 	if (clear & TIOCM_RTS)
1002 		priv->line_control &= ~CONTROL_RTS;
1003 	if (clear & TIOCM_DTR)
1004 		priv->line_control &= ~CONTROL_DTR;
1005 	control = priv->line_control;
1006 	spin_unlock_irqrestore(&priv->lock, flags);
1007 
1008 	ret = pl2303_set_control_lines(port, control);
1009 	if (ret)
1010 		return usb_translate_errors(ret);
1011 
1012 	return 0;
1013 }
1014 
1015 static int pl2303_tiocmget(struct tty_struct *tty)
1016 {
1017 	struct usb_serial_port *port = tty->driver_data;
1018 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1019 	unsigned long flags;
1020 	unsigned int mcr;
1021 	unsigned int status;
1022 	unsigned int result;
1023 
1024 	spin_lock_irqsave(&priv->lock, flags);
1025 	mcr = priv->line_control;
1026 	status = priv->line_status;
1027 	spin_unlock_irqrestore(&priv->lock, flags);
1028 
1029 	result = ((mcr & CONTROL_DTR)		? TIOCM_DTR : 0)
1030 		  | ((mcr & CONTROL_RTS)	? TIOCM_RTS : 0)
1031 		  | ((status & UART_CTS)	? TIOCM_CTS : 0)
1032 		  | ((status & UART_DSR)	? TIOCM_DSR : 0)
1033 		  | ((status & UART_RING)	? TIOCM_RI  : 0)
1034 		  | ((status & UART_DCD)	? TIOCM_CD  : 0);
1035 
1036 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
1037 
1038 	return result;
1039 }
1040 
1041 static int pl2303_carrier_raised(struct usb_serial_port *port)
1042 {
1043 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1044 
1045 	if (priv->line_status & UART_DCD)
1046 		return 1;
1047 
1048 	return 0;
1049 }
1050 
1051 static void pl2303_set_break(struct usb_serial_port *port, bool enable)
1052 {
1053 	struct usb_serial *serial = port->serial;
1054 	u16 state;
1055 	int result;
1056 
1057 	if (enable)
1058 		state = BREAK_ON;
1059 	else
1060 		state = BREAK_OFF;
1061 
1062 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
1063 			state == BREAK_OFF ? "off" : "on");
1064 
1065 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
1066 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
1067 				 0, NULL, 0, 100);
1068 	if (result)
1069 		dev_err(&port->dev, "error sending break = %d\n", result);
1070 }
1071 
1072 static void pl2303_break_ctl(struct tty_struct *tty, int state)
1073 {
1074 	struct usb_serial_port *port = tty->driver_data;
1075 
1076 	pl2303_set_break(port, state);
1077 }
1078 
1079 static void pl2303_update_line_status(struct usb_serial_port *port,
1080 				      unsigned char *data,
1081 				      unsigned int actual_length)
1082 {
1083 	struct usb_serial *serial = port->serial;
1084 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
1085 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1086 	struct tty_struct *tty;
1087 	unsigned long flags;
1088 	unsigned int status_idx = UART_STATE_INDEX;
1089 	u8 status;
1090 	u8 delta;
1091 
1092 	if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
1093 		status_idx = 0;
1094 
1095 	if (actual_length < status_idx + 1)
1096 		return;
1097 
1098 	status = data[status_idx];
1099 
1100 	/* Save off the uart status for others to look at */
1101 	spin_lock_irqsave(&priv->lock, flags);
1102 	delta = priv->line_status ^ status;
1103 	priv->line_status = status;
1104 	spin_unlock_irqrestore(&priv->lock, flags);
1105 
1106 	if (status & UART_BREAK_ERROR)
1107 		usb_serial_handle_break(port);
1108 
1109 	if (delta & UART_STATE_MSR_MASK) {
1110 		if (delta & UART_CTS)
1111 			port->icount.cts++;
1112 		if (delta & UART_DSR)
1113 			port->icount.dsr++;
1114 		if (delta & UART_RING)
1115 			port->icount.rng++;
1116 		if (delta & UART_DCD) {
1117 			port->icount.dcd++;
1118 			tty = tty_port_tty_get(&port->port);
1119 			if (tty) {
1120 				usb_serial_handle_dcd_change(port, tty,
1121 							status & UART_DCD);
1122 				tty_kref_put(tty);
1123 			}
1124 		}
1125 
1126 		wake_up_interruptible(&port->port.delta_msr_wait);
1127 	}
1128 }
1129 
1130 static void pl2303_read_int_callback(struct urb *urb)
1131 {
1132 	struct usb_serial_port *port =  urb->context;
1133 	unsigned char *data = urb->transfer_buffer;
1134 	unsigned int actual_length = urb->actual_length;
1135 	int status = urb->status;
1136 	int retval;
1137 
1138 	switch (status) {
1139 	case 0:
1140 		/* success */
1141 		break;
1142 	case -ECONNRESET:
1143 	case -ENOENT:
1144 	case -ESHUTDOWN:
1145 		/* this urb is terminated, clean up */
1146 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
1147 			__func__, status);
1148 		return;
1149 	default:
1150 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
1151 			__func__, status);
1152 		goto exit;
1153 	}
1154 
1155 	usb_serial_debug_data(&port->dev, __func__,
1156 			      urb->actual_length, urb->transfer_buffer);
1157 
1158 	pl2303_update_line_status(port, data, actual_length);
1159 
1160 exit:
1161 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1162 	if (retval) {
1163 		dev_err(&port->dev,
1164 			"%s - usb_submit_urb failed with result %d\n",
1165 			__func__, retval);
1166 	}
1167 }
1168 
1169 static void pl2303_process_read_urb(struct urb *urb)
1170 {
1171 	struct usb_serial_port *port = urb->context;
1172 	struct pl2303_private *priv = usb_get_serial_port_data(port);
1173 	unsigned char *data = urb->transfer_buffer;
1174 	char tty_flag = TTY_NORMAL;
1175 	unsigned long flags;
1176 	u8 line_status;
1177 	int i;
1178 
1179 	/* update line status */
1180 	spin_lock_irqsave(&priv->lock, flags);
1181 	line_status = priv->line_status;
1182 	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
1183 	spin_unlock_irqrestore(&priv->lock, flags);
1184 
1185 	if (!urb->actual_length)
1186 		return;
1187 
1188 	/*
1189 	 * Break takes precedence over parity, which takes precedence over
1190 	 * framing errors.
1191 	 */
1192 	if (line_status & UART_BREAK_ERROR)
1193 		tty_flag = TTY_BREAK;
1194 	else if (line_status & UART_PARITY_ERROR)
1195 		tty_flag = TTY_PARITY;
1196 	else if (line_status & UART_FRAME_ERROR)
1197 		tty_flag = TTY_FRAME;
1198 
1199 	if (tty_flag != TTY_NORMAL)
1200 		dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__,
1201 								tty_flag);
1202 	/* overrun is special, not associated with a char */
1203 	if (line_status & UART_OVERRUN_ERROR)
1204 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
1205 
1206 	if (port->sysrq) {
1207 		for (i = 0; i < urb->actual_length; ++i)
1208 			if (!usb_serial_handle_sysrq_char(port, data[i]))
1209 				tty_insert_flip_char(&port->port, data[i],
1210 						tty_flag);
1211 	} else {
1212 		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
1213 							urb->actual_length);
1214 	}
1215 
1216 	tty_flip_buffer_push(&port->port);
1217 }
1218 
1219 static struct usb_serial_driver pl2303_device = {
1220 	.driver = {
1221 		.owner =	THIS_MODULE,
1222 		.name =		"pl2303",
1223 	},
1224 	.id_table =		id_table,
1225 	.num_bulk_in =		1,
1226 	.num_bulk_out =		1,
1227 	.num_interrupt_in =	0,	/* see pl2303_calc_num_ports */
1228 	.bulk_in_size =		256,
1229 	.bulk_out_size =	256,
1230 	.open =			pl2303_open,
1231 	.close =		pl2303_close,
1232 	.dtr_rts =		pl2303_dtr_rts,
1233 	.carrier_raised =	pl2303_carrier_raised,
1234 	.break_ctl =		pl2303_break_ctl,
1235 	.set_termios =		pl2303_set_termios,
1236 	.tiocmget =		pl2303_tiocmget,
1237 	.tiocmset =		pl2303_tiocmset,
1238 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
1239 	.process_read_urb =	pl2303_process_read_urb,
1240 	.read_int_callback =	pl2303_read_int_callback,
1241 	.probe =		pl2303_probe,
1242 	.calc_num_ports =	pl2303_calc_num_ports,
1243 	.attach =		pl2303_startup,
1244 	.release =		pl2303_release,
1245 	.port_probe =		pl2303_port_probe,
1246 	.port_remove =		pl2303_port_remove,
1247 };
1248 
1249 static struct usb_serial_driver * const serial_drivers[] = {
1250 	&pl2303_device, NULL
1251 };
1252 
1253 module_usb_serial_driver(serial_drivers, id_table);
1254 
1255 MODULE_DESCRIPTION("Prolific PL2303 USB to serial adaptor driver");
1256 MODULE_LICENSE("GPL v2");
1257