xref: /linux/drivers/usb/serial/cp210x.c (revision b7c7cbc898e8a97829f33ad3bcd1b5e91690d8f4)
1 /*
2  * Silicon Laboratories CP2101/CP2102 USB to RS232 serial adaptor driver
3  *
4  * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License version
8  *	2 as published by the Free Software Foundation.
9  *
10  * Support to set flow control line levels using TIOCMGET and TIOCMSET
11  * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
12  * control thanks to Munir Nassar nassarmu@real-time.com
13  *
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <linux/tty.h>
20 #include <linux/tty_flip.h>
21 #include <linux/module.h>
22 #include <linux/moduleparam.h>
23 #include <linux/usb.h>
24 #include <linux/uaccess.h>
25 #include <linux/usb/serial.h>
26 
27 /*
28  * Version Information
29  */
30 #define DRIVER_VERSION "v0.08"
31 #define DRIVER_DESC "Silicon Labs CP2101/CP2102 RS232 serial adaptor driver"
32 
33 /*
34  * Function Prototypes
35  */
36 static int cp2101_open(struct tty_struct *, struct usb_serial_port *,
37 							struct file *);
38 static void cp2101_cleanup(struct usb_serial_port *);
39 static void cp2101_close(struct usb_serial_port *);
40 static void cp2101_get_termios(struct tty_struct *,
41 	struct usb_serial_port *port);
42 static void cp2101_get_termios_port(struct usb_serial_port *port,
43 	unsigned int *cflagp, unsigned int *baudp);
44 static void cp2101_set_termios(struct tty_struct *, struct usb_serial_port *,
45 							struct ktermios*);
46 static int cp2101_tiocmget(struct tty_struct *, struct file *);
47 static int cp2101_tiocmset(struct tty_struct *, struct file *,
48 		unsigned int, unsigned int);
49 static int cp2101_tiocmset_port(struct usb_serial_port *port, struct file *,
50 		unsigned int, unsigned int);
51 static void cp2101_break_ctl(struct tty_struct *, int);
52 static int cp2101_startup(struct usb_serial *);
53 static void cp2101_shutdown(struct usb_serial *);
54 
55 static int debug;
56 
57 static struct usb_device_id id_table [] = {
58 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
59 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
60 	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
61 	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
62 	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
63 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
64 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
65 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
66 	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
67 	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
68 	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
69 	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
70 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
71 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
72 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
73 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
74 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
75 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
76 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
77 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
78 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
79 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
80 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
81 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
82 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
83 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
84 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
85 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
86 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
87 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
88 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
89 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
90 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
91 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
92 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
93 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demostration module */
94 	{ USB_DEVICE(0x10c4, 0x8293) }, /* Telegesys ETRX2USB */
95 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
96 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
97 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
98 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
99 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
100 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
101 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
102 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
103 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
104 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
105 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
106 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
107 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
108 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
109 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
110 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
111 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
112 	{ } /* Terminating Entry */
113 };
114 
115 MODULE_DEVICE_TABLE(usb, id_table);
116 
117 static struct usb_driver cp2101_driver = {
118 	.name		= "cp2101",
119 	.probe		= usb_serial_probe,
120 	.disconnect	= usb_serial_disconnect,
121 	.id_table	= id_table,
122 	.no_dynamic_id	= 	1,
123 };
124 
125 static struct usb_serial_driver cp2101_device = {
126 	.driver = {
127 		.owner =	THIS_MODULE,
128 		.name = 	"cp2101",
129 	},
130 	.usb_driver		= &cp2101_driver,
131 	.id_table		= id_table,
132 	.num_ports		= 1,
133 	.open			= cp2101_open,
134 	.close			= cp2101_close,
135 	.break_ctl		= cp2101_break_ctl,
136 	.set_termios		= cp2101_set_termios,
137 	.tiocmget 		= cp2101_tiocmget,
138 	.tiocmset		= cp2101_tiocmset,
139 	.attach			= cp2101_startup,
140 	.shutdown		= cp2101_shutdown,
141 };
142 
143 /* Config request types */
144 #define REQTYPE_HOST_TO_DEVICE	0x41
145 #define REQTYPE_DEVICE_TO_HOST	0xc1
146 
147 /* Config SET requests. To GET, add 1 to the request number */
148 #define CP2101_UART 		0x00	/* Enable / Disable */
149 #define CP2101_BAUDRATE		0x01	/* (BAUD_RATE_GEN_FREQ / baudrate) */
150 #define CP2101_BITS		0x03	/* 0x(0)(databits)(parity)(stopbits) */
151 #define CP2101_BREAK		0x05	/* On / Off */
152 #define CP2101_CONTROL		0x07	/* Flow control line states */
153 #define CP2101_MODEMCTL		0x13	/* Modem controls */
154 #define CP2101_CONFIG_6		0x19	/* 6 bytes of config data ??? */
155 
156 /* CP2101_UART */
157 #define UART_ENABLE		0x0001
158 #define UART_DISABLE		0x0000
159 
160 /* CP2101_BAUDRATE */
161 #define BAUD_RATE_GEN_FREQ	0x384000
162 
163 /* CP2101_BITS */
164 #define BITS_DATA_MASK		0X0f00
165 #define BITS_DATA_5		0X0500
166 #define BITS_DATA_6		0X0600
167 #define BITS_DATA_7		0X0700
168 #define BITS_DATA_8		0X0800
169 #define BITS_DATA_9		0X0900
170 
171 #define BITS_PARITY_MASK	0x00f0
172 #define BITS_PARITY_NONE	0x0000
173 #define BITS_PARITY_ODD		0x0010
174 #define BITS_PARITY_EVEN	0x0020
175 #define BITS_PARITY_MARK	0x0030
176 #define BITS_PARITY_SPACE	0x0040
177 
178 #define BITS_STOP_MASK		0x000f
179 #define BITS_STOP_1		0x0000
180 #define BITS_STOP_1_5		0x0001
181 #define BITS_STOP_2		0x0002
182 
183 /* CP2101_BREAK */
184 #define BREAK_ON		0x0000
185 #define BREAK_OFF		0x0001
186 
187 /* CP2101_CONTROL */
188 #define CONTROL_DTR		0x0001
189 #define CONTROL_RTS		0x0002
190 #define CONTROL_CTS		0x0010
191 #define CONTROL_DSR		0x0020
192 #define CONTROL_RING		0x0040
193 #define CONTROL_DCD		0x0080
194 #define CONTROL_WRITE_DTR	0x0100
195 #define CONTROL_WRITE_RTS	0x0200
196 
197 /*
198  * cp2101_get_config
199  * Reads from the CP2101 configuration registers
200  * 'size' is specified in bytes.
201  * 'data' is a pointer to a pre-allocated array of integers large
202  * enough to hold 'size' bytes (with 4 bytes to each integer)
203  */
204 static int cp2101_get_config(struct usb_serial_port *port, u8 request,
205 		unsigned int *data, int size)
206 {
207 	struct usb_serial *serial = port->serial;
208 	__le32 *buf;
209 	int result, i, length;
210 
211 	/* Number of integers required to contain the array */
212 	length = (((size - 1) | 3) + 1)/4;
213 
214 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
215 	if (!buf) {
216 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
217 		return -ENOMEM;
218 	}
219 
220 	/* For get requests, the request number must be incremented */
221 	request++;
222 
223 	/* Issue the request, attempting to read 'size' bytes */
224 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
225 				request, REQTYPE_DEVICE_TO_HOST, 0x0000,
226 				0, buf, size, 300);
227 
228 	/* Convert data into an array of integers */
229 	for (i = 0; i < length; i++)
230 		data[i] = le32_to_cpu(buf[i]);
231 
232 	kfree(buf);
233 
234 	if (result != size) {
235 		dbg("%s - Unable to send config request, "
236 				"request=0x%x size=%d result=%d\n",
237 				__func__, request, size, result);
238 		return -EPROTO;
239 	}
240 
241 	return 0;
242 }
243 
244 /*
245  * cp2101_set_config
246  * Writes to the CP2101 configuration registers
247  * Values less than 16 bits wide are sent directly
248  * 'size' is specified in bytes.
249  */
250 static int cp2101_set_config(struct usb_serial_port *port, u8 request,
251 		unsigned int *data, int size)
252 {
253 	struct usb_serial *serial = port->serial;
254 	__le32 *buf;
255 	int result, i, length;
256 
257 	/* Number of integers required to contain the array */
258 	length = (((size - 1) | 3) + 1)/4;
259 
260 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
261 	if (!buf) {
262 		dev_err(&port->dev, "%s - out of memory.\n",
263 				__func__);
264 		return -ENOMEM;
265 	}
266 
267 	/* Array of integers into bytes */
268 	for (i = 0; i < length; i++)
269 		buf[i] = cpu_to_le32(data[i]);
270 
271 	if (size > 2) {
272 		result = usb_control_msg(serial->dev,
273 				usb_sndctrlpipe(serial->dev, 0),
274 				request, REQTYPE_HOST_TO_DEVICE, 0x0000,
275 				0, buf, size, 300);
276 	} else {
277 		result = usb_control_msg(serial->dev,
278 				usb_sndctrlpipe(serial->dev, 0),
279 				request, REQTYPE_HOST_TO_DEVICE, data[0],
280 				0, NULL, 0, 300);
281 	}
282 
283 	kfree(buf);
284 
285 	if ((size > 2 && result != size) || result < 0) {
286 		dbg("%s - Unable to send request, "
287 				"request=0x%x size=%d result=%d\n",
288 				__func__, request, size, result);
289 		return -EPROTO;
290 	}
291 
292 	/* Single data value */
293 	result = usb_control_msg(serial->dev,
294 			usb_sndctrlpipe(serial->dev, 0),
295 			request, REQTYPE_HOST_TO_DEVICE, data[0],
296 			0, NULL, 0, 300);
297 	return 0;
298 }
299 
300 /*
301  * cp2101_set_config_single
302  * Convenience function for calling cp2101_set_config on single data values
303  * without requiring an integer pointer
304  */
305 static inline int cp2101_set_config_single(struct usb_serial_port *port,
306 		u8 request, unsigned int data)
307 {
308 	return cp2101_set_config(port, request, &data, 2);
309 }
310 
311 /*
312  * cp2101_quantise_baudrate
313  * Quantises the baud rate as per AN205 Table 1
314  */
315 static unsigned int cp2101_quantise_baudrate(unsigned int baud) {
316 	if      (baud <= 56)       baud = 0;
317 	else if (baud <= 300)      baud = 300;
318 	else if (baud <= 600)      baud = 600;
319 	else if (baud <= 1200)     baud = 1200;
320 	else if (baud <= 1800)     baud = 1800;
321 	else if (baud <= 2400)     baud = 2400;
322 	else if (baud <= 4000)     baud = 4000;
323 	else if (baud <= 4803)     baud = 4800;
324 	else if (baud <= 7207)     baud = 7200;
325 	else if (baud <= 9612)     baud = 9600;
326 	else if (baud <= 14428)    baud = 14400;
327 	else if (baud <= 16062)    baud = 16000;
328 	else if (baud <= 19250)    baud = 19200;
329 	else if (baud <= 28912)    baud = 28800;
330 	else if (baud <= 38601)    baud = 38400;
331 	else if (baud <= 51558)    baud = 51200;
332 	else if (baud <= 56280)    baud = 56000;
333 	else if (baud <= 58053)    baud = 57600;
334 	else if (baud <= 64111)    baud = 64000;
335 	else if (baud <= 77608)    baud = 76800;
336 	else if (baud <= 117028)   baud = 115200;
337 	else if (baud <= 129347)   baud = 128000;
338 	else if (baud <= 156868)   baud = 153600;
339 	else if (baud <= 237832)   baud = 230400;
340 	else if (baud <= 254234)   baud = 250000;
341 	else if (baud <= 273066)   baud = 256000;
342 	else if (baud <= 491520)   baud = 460800;
343 	else if (baud <= 567138)   baud = 500000;
344 	else if (baud <= 670254)   baud = 576000;
345 	else if (baud <= 1053257)  baud = 921600;
346 	else if (baud <= 1474560)  baud = 1228800;
347 	else if (baud <= 2457600)  baud = 1843200;
348 	else                       baud = 3686400;
349 	return baud;
350 }
351 
352 static int cp2101_open(struct tty_struct *tty, struct usb_serial_port *port,
353 				struct file *filp)
354 {
355 	struct usb_serial *serial = port->serial;
356 	int result;
357 
358 	dbg("%s - port %d", __func__, port->number);
359 
360 	if (cp2101_set_config_single(port, CP2101_UART, UART_ENABLE)) {
361 		dev_err(&port->dev, "%s - Unable to enable UART\n",
362 				__func__);
363 		return -EPROTO;
364 	}
365 
366 	/* Start reading from the device */
367 	usb_fill_bulk_urb(port->read_urb, serial->dev,
368 			usb_rcvbulkpipe(serial->dev,
369 			port->bulk_in_endpointAddress),
370 			port->read_urb->transfer_buffer,
371 			port->read_urb->transfer_buffer_length,
372 			serial->type->read_bulk_callback,
373 			port);
374 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
375 	if (result) {
376 		dev_err(&port->dev, "%s - failed resubmitting read urb, "
377 				"error %d\n", __func__, result);
378 		return result;
379 	}
380 
381 	/* Configure the termios structure */
382 	cp2101_get_termios(tty, port);
383 
384 	/* Set the DTR and RTS pins low */
385 	cp2101_tiocmset_port(tty ? (struct usb_serial_port *) tty->driver_data
386 			: port,
387 		NULL, TIOCM_DTR | TIOCM_RTS, 0);
388 
389 	return 0;
390 }
391 
392 static void cp2101_cleanup(struct usb_serial_port *port)
393 {
394 	struct usb_serial *serial = port->serial;
395 
396 	dbg("%s - port %d", __func__, port->number);
397 
398 	if (serial->dev) {
399 		/* shutdown any bulk reads that might be going on */
400 		if (serial->num_bulk_out)
401 			usb_kill_urb(port->write_urb);
402 		if (serial->num_bulk_in)
403 			usb_kill_urb(port->read_urb);
404 	}
405 }
406 
407 static void cp2101_close(struct usb_serial_port *port)
408 {
409 	dbg("%s - port %d", __func__, port->number);
410 
411 	/* shutdown our urbs */
412 	dbg("%s - shutting down urbs", __func__);
413 	usb_kill_urb(port->write_urb);
414 	usb_kill_urb(port->read_urb);
415 
416 	mutex_lock(&port->serial->disc_mutex);
417 	if (!port->serial->disconnected)
418 		cp2101_set_config_single(port, CP2101_UART, UART_DISABLE);
419 	mutex_unlock(&port->serial->disc_mutex);
420 }
421 
422 /*
423  * cp2101_get_termios
424  * Reads the baud rate, data bits, parity, stop bits and flow control mode
425  * from the device, corrects any unsupported values, and configures the
426  * termios structure to reflect the state of the device
427  */
428 static void cp2101_get_termios(struct tty_struct *tty,
429 	struct usb_serial_port *port)
430 {
431 	unsigned int baud;
432 
433 	if (tty) {
434 		cp2101_get_termios_port(tty->driver_data,
435 			&tty->termios->c_cflag, &baud);
436 		tty_encode_baud_rate(tty, baud, baud);
437 	}
438 
439 	else {
440 		unsigned int cflag;
441 		cflag = 0;
442 		cp2101_get_termios_port(port, &cflag, &baud);
443 	}
444 }
445 
446 /*
447  * cp2101_get_termios_port
448  * This is the heart of cp2101_get_termios which always uses a &usb_serial_port.
449  */
450 static void cp2101_get_termios_port(struct usb_serial_port *port,
451 	unsigned int *cflagp, unsigned int *baudp)
452 {
453 	unsigned int cflag, modem_ctl[4];
454 	unsigned int baud;
455 	unsigned int bits;
456 
457 	dbg("%s - port %d", __func__, port->number);
458 
459 	cp2101_get_config(port, CP2101_BAUDRATE, &baud, 2);
460 	/* Convert to baudrate */
461 	if (baud)
462 		baud = cp2101_quantise_baudrate((BAUD_RATE_GEN_FREQ + baud/2)/ baud);
463 
464 	dbg("%s - baud rate = %d", __func__, baud);
465 	*baudp = baud;
466 
467 	cflag = *cflagp;
468 
469 	cp2101_get_config(port, CP2101_BITS, &bits, 2);
470 	cflag &= ~CSIZE;
471 	switch (bits & BITS_DATA_MASK) {
472 	case BITS_DATA_5:
473 		dbg("%s - data bits = 5", __func__);
474 		cflag |= CS5;
475 		break;
476 	case BITS_DATA_6:
477 		dbg("%s - data bits = 6", __func__);
478 		cflag |= CS6;
479 		break;
480 	case BITS_DATA_7:
481 		dbg("%s - data bits = 7", __func__);
482 		cflag |= CS7;
483 		break;
484 	case BITS_DATA_8:
485 		dbg("%s - data bits = 8", __func__);
486 		cflag |= CS8;
487 		break;
488 	case BITS_DATA_9:
489 		dbg("%s - data bits = 9 (not supported, using 8 data bits)",
490 								__func__);
491 		cflag |= CS8;
492 		bits &= ~BITS_DATA_MASK;
493 		bits |= BITS_DATA_8;
494 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
495 		break;
496 	default:
497 		dbg("%s - Unknown number of data bits, using 8", __func__);
498 		cflag |= CS8;
499 		bits &= ~BITS_DATA_MASK;
500 		bits |= BITS_DATA_8;
501 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
502 		break;
503 	}
504 
505 	switch (bits & BITS_PARITY_MASK) {
506 	case BITS_PARITY_NONE:
507 		dbg("%s - parity = NONE", __func__);
508 		cflag &= ~PARENB;
509 		break;
510 	case BITS_PARITY_ODD:
511 		dbg("%s - parity = ODD", __func__);
512 		cflag |= (PARENB|PARODD);
513 		break;
514 	case BITS_PARITY_EVEN:
515 		dbg("%s - parity = EVEN", __func__);
516 		cflag &= ~PARODD;
517 		cflag |= PARENB;
518 		break;
519 	case BITS_PARITY_MARK:
520 		dbg("%s - parity = MARK (not supported, disabling parity)",
521 				__func__);
522 		cflag &= ~PARENB;
523 		bits &= ~BITS_PARITY_MASK;
524 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
525 		break;
526 	case BITS_PARITY_SPACE:
527 		dbg("%s - parity = SPACE (not supported, disabling parity)",
528 				__func__);
529 		cflag &= ~PARENB;
530 		bits &= ~BITS_PARITY_MASK;
531 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
532 		break;
533 	default:
534 		dbg("%s - Unknown parity mode, disabling parity", __func__);
535 		cflag &= ~PARENB;
536 		bits &= ~BITS_PARITY_MASK;
537 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
538 		break;
539 	}
540 
541 	cflag &= ~CSTOPB;
542 	switch (bits & BITS_STOP_MASK) {
543 	case BITS_STOP_1:
544 		dbg("%s - stop bits = 1", __func__);
545 		break;
546 	case BITS_STOP_1_5:
547 		dbg("%s - stop bits = 1.5 (not supported, using 1 stop bit)",
548 								__func__);
549 		bits &= ~BITS_STOP_MASK;
550 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
551 		break;
552 	case BITS_STOP_2:
553 		dbg("%s - stop bits = 2", __func__);
554 		cflag |= CSTOPB;
555 		break;
556 	default:
557 		dbg("%s - Unknown number of stop bits, using 1 stop bit",
558 								__func__);
559 		bits &= ~BITS_STOP_MASK;
560 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
561 		break;
562 	}
563 
564 	cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16);
565 	if (modem_ctl[0] & 0x0008) {
566 		dbg("%s - flow control = CRTSCTS", __func__);
567 		cflag |= CRTSCTS;
568 	} else {
569 		dbg("%s - flow control = NONE", __func__);
570 		cflag &= ~CRTSCTS;
571 	}
572 
573 	*cflagp = cflag;
574 }
575 
576 static void cp2101_set_termios(struct tty_struct *tty,
577 		struct usb_serial_port *port, struct ktermios *old_termios)
578 {
579 	unsigned int cflag, old_cflag;
580 	unsigned int baud = 0, bits;
581 	unsigned int modem_ctl[4];
582 
583 	dbg("%s - port %d", __func__, port->number);
584 
585 	if (!tty)
586 		return;
587 
588 	tty->termios->c_cflag &= ~CMSPAR;
589 	cflag = tty->termios->c_cflag;
590 	old_cflag = old_termios->c_cflag;
591 	baud = cp2101_quantise_baudrate(tty_get_baud_rate(tty));
592 
593 	/* If the baud rate is to be updated*/
594 	if (baud != tty_termios_baud_rate(old_termios) && baud != 0) {
595 		dbg("%s - Setting baud rate to %d baud", __func__,
596 				baud);
597 		if (cp2101_set_config_single(port, CP2101_BAUDRATE,
598 					((BAUD_RATE_GEN_FREQ + baud/2) / baud))) {
599 			dbg("Baud rate requested not supported by device\n");
600 			baud = tty_termios_baud_rate(old_termios);
601 		}
602 	}
603 	/* Report back the resulting baud rate */
604 	tty_encode_baud_rate(tty, baud, baud);
605 
606 	/* If the number of data bits is to be updated */
607 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
608 		cp2101_get_config(port, CP2101_BITS, &bits, 2);
609 		bits &= ~BITS_DATA_MASK;
610 		switch (cflag & CSIZE) {
611 		case CS5:
612 			bits |= BITS_DATA_5;
613 			dbg("%s - data bits = 5", __func__);
614 			break;
615 		case CS6:
616 			bits |= BITS_DATA_6;
617 			dbg("%s - data bits = 6", __func__);
618 			break;
619 		case CS7:
620 			bits |= BITS_DATA_7;
621 			dbg("%s - data bits = 7", __func__);
622 			break;
623 		case CS8:
624 			bits |= BITS_DATA_8;
625 			dbg("%s - data bits = 8", __func__);
626 			break;
627 		/*case CS9:
628 			bits |= BITS_DATA_9;
629 			dbg("%s - data bits = 9", __func__);
630 			break;*/
631 		default:
632 			dbg("cp2101 driver does not "
633 					"support the number of bits requested,"
634 					" using 8 bit mode\n");
635 				bits |= BITS_DATA_8;
636 				break;
637 		}
638 		if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
639 			dbg("Number of data bits requested "
640 					"not supported by device\n");
641 	}
642 
643 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {
644 		cp2101_get_config(port, CP2101_BITS, &bits, 2);
645 		bits &= ~BITS_PARITY_MASK;
646 		if (cflag & PARENB) {
647 			if (cflag & PARODD) {
648 				bits |= BITS_PARITY_ODD;
649 				dbg("%s - parity = ODD", __func__);
650 			} else {
651 				bits |= BITS_PARITY_EVEN;
652 				dbg("%s - parity = EVEN", __func__);
653 			}
654 		}
655 		if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
656 			dbg("Parity mode not supported "
657 					"by device\n");
658 	}
659 
660 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
661 		cp2101_get_config(port, CP2101_BITS, &bits, 2);
662 		bits &= ~BITS_STOP_MASK;
663 		if (cflag & CSTOPB) {
664 			bits |= BITS_STOP_2;
665 			dbg("%s - stop bits = 2", __func__);
666 		} else {
667 			bits |= BITS_STOP_1;
668 			dbg("%s - stop bits = 1", __func__);
669 		}
670 		if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
671 			dbg("Number of stop bits requested "
672 					"not supported by device\n");
673 	}
674 
675 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
676 		cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16);
677 		dbg("%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
678 				__func__, modem_ctl[0], modem_ctl[1],
679 				modem_ctl[2], modem_ctl[3]);
680 
681 		if (cflag & CRTSCTS) {
682 			modem_ctl[0] &= ~0x7B;
683 			modem_ctl[0] |= 0x09;
684 			modem_ctl[1] = 0x80;
685 			dbg("%s - flow control = CRTSCTS", __func__);
686 		} else {
687 			modem_ctl[0] &= ~0x7B;
688 			modem_ctl[0] |= 0x01;
689 			modem_ctl[1] |= 0x40;
690 			dbg("%s - flow control = NONE", __func__);
691 		}
692 
693 		dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
694 				__func__, modem_ctl[0], modem_ctl[1],
695 				modem_ctl[2], modem_ctl[3]);
696 		cp2101_set_config(port, CP2101_MODEMCTL, modem_ctl, 16);
697 	}
698 
699 }
700 
701 static int cp2101_tiocmset (struct tty_struct *tty, struct file *file,
702 		unsigned int set, unsigned int clear)
703 {
704 	struct usb_serial_port *port = tty->driver_data;
705 	return cp2101_tiocmset_port(port, file, set, clear);
706 }
707 
708 static int cp2101_tiocmset_port(struct usb_serial_port *port, struct file *file,
709 		unsigned int set, unsigned int clear)
710 {
711 	unsigned int control = 0;
712 
713 	dbg("%s - port %d", __func__, port->number);
714 
715 	if (set & TIOCM_RTS) {
716 		control |= CONTROL_RTS;
717 		control |= CONTROL_WRITE_RTS;
718 	}
719 	if (set & TIOCM_DTR) {
720 		control |= CONTROL_DTR;
721 		control |= CONTROL_WRITE_DTR;
722 	}
723 	if (clear & TIOCM_RTS) {
724 		control &= ~CONTROL_RTS;
725 		control |= CONTROL_WRITE_RTS;
726 	}
727 	if (clear & TIOCM_DTR) {
728 		control &= ~CONTROL_DTR;
729 		control |= CONTROL_WRITE_DTR;
730 	}
731 
732 	dbg("%s - control = 0x%.4x", __func__, control);
733 
734 	return cp2101_set_config(port, CP2101_CONTROL, &control, 2);
735 }
736 
737 static int cp2101_tiocmget (struct tty_struct *tty, struct file *file)
738 {
739 	struct usb_serial_port *port = tty->driver_data;
740 	unsigned int control;
741 	int result;
742 
743 	dbg("%s - port %d", __func__, port->number);
744 
745 	cp2101_get_config(port, CP2101_CONTROL, &control, 1);
746 
747 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
748 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
749 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
750 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
751 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
752 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
753 
754 	dbg("%s - control = 0x%.2x", __func__, control);
755 
756 	return result;
757 }
758 
759 static void cp2101_break_ctl (struct tty_struct *tty, int break_state)
760 {
761 	struct usb_serial_port *port = tty->driver_data;
762 	unsigned int state;
763 
764 	dbg("%s - port %d", __func__, port->number);
765 	if (break_state == 0)
766 		state = BREAK_OFF;
767 	else
768 		state = BREAK_ON;
769 	dbg("%s - turning break %s", __func__,
770 			state == BREAK_OFF ? "off" : "on");
771 	cp2101_set_config(port, CP2101_BREAK, &state, 2);
772 }
773 
774 static int cp2101_startup(struct usb_serial *serial)
775 {
776 	/* CP2101 buffers behave strangely unless device is reset */
777 	usb_reset_device(serial->dev);
778 	return 0;
779 }
780 
781 static void cp2101_shutdown(struct usb_serial *serial)
782 {
783 	int i;
784 
785 	dbg("%s", __func__);
786 
787 	/* Stop reads and writes on all ports */
788 	for (i = 0; i < serial->num_ports; ++i)
789 		cp2101_cleanup(serial->port[i]);
790 }
791 
792 static int __init cp2101_init(void)
793 {
794 	int retval;
795 
796 	retval = usb_serial_register(&cp2101_device);
797 	if (retval)
798 		return retval; /* Failed to register */
799 
800 	retval = usb_register(&cp2101_driver);
801 	if (retval) {
802 		/* Failed to register */
803 		usb_serial_deregister(&cp2101_device);
804 		return retval;
805 	}
806 
807 	/* Success */
808 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
809 	       DRIVER_DESC "\n");
810 	return 0;
811 }
812 
813 static void __exit cp2101_exit(void)
814 {
815 	usb_deregister(&cp2101_driver);
816 	usb_serial_deregister(&cp2101_device);
817 }
818 
819 module_init(cp2101_init);
820 module_exit(cp2101_exit);
821 
822 MODULE_DESCRIPTION(DRIVER_DESC);
823 MODULE_VERSION(DRIVER_VERSION);
824 MODULE_LICENSE("GPL");
825 
826 module_param(debug, bool, S_IRUGO | S_IWUSR);
827 MODULE_PARM_DESC(debug, "Enable verbose debugging messages");
828