xref: /openbmc/linux/drivers/usb/serial/cp210x.c (revision 78c99ba1)
1 /*
2  * Silicon Laboratories CP210x 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 "v0.09"
31 #define DRIVER_DESC "Silicon Labs CP210x RS232 serial adaptor driver"
32 
33 /*
34  * Function Prototypes
35  */
36 static int cp210x_open(struct tty_struct *, struct usb_serial_port *,
37 							struct file *);
38 static void cp210x_cleanup(struct usb_serial_port *);
39 static void cp210x_close(struct usb_serial_port *);
40 static void cp210x_get_termios(struct tty_struct *,
41 	struct usb_serial_port *port);
42 static void cp210x_get_termios_port(struct usb_serial_port *port,
43 	unsigned int *cflagp, unsigned int *baudp);
44 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
45 							struct ktermios*);
46 static int cp210x_tiocmget(struct tty_struct *, struct file *);
47 static int cp210x_tiocmset(struct tty_struct *, struct file *,
48 		unsigned int, unsigned int);
49 static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *,
50 		unsigned int, unsigned int);
51 static void cp210x_break_ctl(struct tty_struct *, int);
52 static int cp210x_startup(struct usb_serial *);
53 static void cp210x_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 cp210x_driver = {
118 	.name		= "cp210x",
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 cp210x_device = {
126 	.driver = {
127 		.owner =	THIS_MODULE,
128 		.name = 	"cp210x",
129 	},
130 	.usb_driver		= &cp210x_driver,
131 	.id_table		= id_table,
132 	.num_ports		= 1,
133 	.open			= cp210x_open,
134 	.close			= cp210x_close,
135 	.break_ctl		= cp210x_break_ctl,
136 	.set_termios		= cp210x_set_termios,
137 	.tiocmget 		= cp210x_tiocmget,
138 	.tiocmset		= cp210x_tiocmset,
139 	.attach			= cp210x_startup,
140 	.shutdown		= cp210x_shutdown,
141 };
142 
143 /* Config request types */
144 #define REQTYPE_HOST_TO_DEVICE	0x41
145 #define REQTYPE_DEVICE_TO_HOST	0xc1
146 
147 /* Config request codes */
148 #define CP210X_IFC_ENABLE	0x00
149 #define CP210X_SET_BAUDDIV	0x01
150 #define CP210X_GET_BAUDDIV	0x02
151 #define CP210X_SET_LINE_CTL	0x03
152 #define CP210X_GET_LINE_CTL	0x04
153 #define CP210X_SET_BREAK	0x05
154 #define CP210X_IMM_CHAR		0x06
155 #define CP210X_SET_MHS		0x07
156 #define CP210X_GET_MDMSTS	0x08
157 #define CP210X_SET_XON		0x09
158 #define CP210X_SET_XOFF		0x0A
159 #define CP210X_SET_EVENTMASK	0x0B
160 #define CP210X_GET_EVENTMASK	0x0C
161 #define CP210X_SET_CHAR		0x0D
162 #define CP210X_GET_CHARS	0x0E
163 #define CP210X_GET_PROPS	0x0F
164 #define CP210X_GET_COMM_STATUS	0x10
165 #define CP210X_RESET		0x11
166 #define CP210X_PURGE		0x12
167 #define CP210X_SET_FLOW		0x13
168 #define CP210X_GET_FLOW		0x14
169 #define CP210X_EMBED_EVENTS	0x15
170 #define CP210X_GET_EVENTSTATE	0x16
171 #define CP210X_SET_CHARS	0x19
172 
173 /* CP210X_IFC_ENABLE */
174 #define UART_ENABLE		0x0001
175 #define UART_DISABLE		0x0000
176 
177 /* CP210X_(SET|GET)_BAUDDIV */
178 #define BAUD_RATE_GEN_FREQ	0x384000
179 
180 /* CP210X_(SET|GET)_LINE_CTL */
181 #define BITS_DATA_MASK		0X0f00
182 #define BITS_DATA_5		0X0500
183 #define BITS_DATA_6		0X0600
184 #define BITS_DATA_7		0X0700
185 #define BITS_DATA_8		0X0800
186 #define BITS_DATA_9		0X0900
187 
188 #define BITS_PARITY_MASK	0x00f0
189 #define BITS_PARITY_NONE	0x0000
190 #define BITS_PARITY_ODD		0x0010
191 #define BITS_PARITY_EVEN	0x0020
192 #define BITS_PARITY_MARK	0x0030
193 #define BITS_PARITY_SPACE	0x0040
194 
195 #define BITS_STOP_MASK		0x000f
196 #define BITS_STOP_1		0x0000
197 #define BITS_STOP_1_5		0x0001
198 #define BITS_STOP_2		0x0002
199 
200 /* CP210X_SET_BREAK */
201 #define BREAK_ON		0x0000
202 #define BREAK_OFF		0x0001
203 
204 /* CP210X_(SET_MHS|GET_MDMSTS) */
205 #define CONTROL_DTR		0x0001
206 #define CONTROL_RTS		0x0002
207 #define CONTROL_CTS		0x0010
208 #define CONTROL_DSR		0x0020
209 #define CONTROL_RING		0x0040
210 #define CONTROL_DCD		0x0080
211 #define CONTROL_WRITE_DTR	0x0100
212 #define CONTROL_WRITE_RTS	0x0200
213 
214 /*
215  * cp210x_get_config
216  * Reads from the CP210x configuration registers
217  * 'size' is specified in bytes.
218  * 'data' is a pointer to a pre-allocated array of integers large
219  * enough to hold 'size' bytes (with 4 bytes to each integer)
220  */
221 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
222 		unsigned int *data, int size)
223 {
224 	struct usb_serial *serial = port->serial;
225 	__le32 *buf;
226 	int result, i, length;
227 
228 	/* Number of integers required to contain the array */
229 	length = (((size - 1) | 3) + 1)/4;
230 
231 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
232 	if (!buf) {
233 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
234 		return -ENOMEM;
235 	}
236 
237 	/* Issue the request, attempting to read 'size' bytes */
238 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
239 				request, REQTYPE_DEVICE_TO_HOST, 0x0000,
240 				0, buf, size, 300);
241 
242 	/* Convert data into an array of integers */
243 	for (i = 0; i < length; i++)
244 		data[i] = le32_to_cpu(buf[i]);
245 
246 	kfree(buf);
247 
248 	if (result != size) {
249 		dbg("%s - Unable to send config request, "
250 				"request=0x%x size=%d result=%d\n",
251 				__func__, request, size, result);
252 		return -EPROTO;
253 	}
254 
255 	return 0;
256 }
257 
258 /*
259  * cp210x_set_config
260  * Writes to the CP210x configuration registers
261  * Values less than 16 bits wide are sent directly
262  * 'size' is specified in bytes.
263  */
264 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
265 		unsigned int *data, int size)
266 {
267 	struct usb_serial *serial = port->serial;
268 	__le32 *buf;
269 	int result, i, length;
270 
271 	/* Number of integers required to contain the array */
272 	length = (((size - 1) | 3) + 1)/4;
273 
274 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
275 	if (!buf) {
276 		dev_err(&port->dev, "%s - out of memory.\n",
277 				__func__);
278 		return -ENOMEM;
279 	}
280 
281 	/* Array of integers into bytes */
282 	for (i = 0; i < length; i++)
283 		buf[i] = cpu_to_le32(data[i]);
284 
285 	if (size > 2) {
286 		result = usb_control_msg(serial->dev,
287 				usb_sndctrlpipe(serial->dev, 0),
288 				request, REQTYPE_HOST_TO_DEVICE, 0x0000,
289 				0, buf, size, 300);
290 	} else {
291 		result = usb_control_msg(serial->dev,
292 				usb_sndctrlpipe(serial->dev, 0),
293 				request, REQTYPE_HOST_TO_DEVICE, data[0],
294 				0, NULL, 0, 300);
295 	}
296 
297 	kfree(buf);
298 
299 	if ((size > 2 && result != size) || result < 0) {
300 		dbg("%s - Unable to send request, "
301 				"request=0x%x size=%d result=%d\n",
302 				__func__, request, size, result);
303 		return -EPROTO;
304 	}
305 
306 	/* Single data value */
307 	result = usb_control_msg(serial->dev,
308 			usb_sndctrlpipe(serial->dev, 0),
309 			request, REQTYPE_HOST_TO_DEVICE, data[0],
310 			0, NULL, 0, 300);
311 	return 0;
312 }
313 
314 /*
315  * cp210x_set_config_single
316  * Convenience function for calling cp210x_set_config on single data values
317  * without requiring an integer pointer
318  */
319 static inline int cp210x_set_config_single(struct usb_serial_port *port,
320 		u8 request, unsigned int data)
321 {
322 	return cp210x_set_config(port, request, &data, 2);
323 }
324 
325 /*
326  * cp210x_quantise_baudrate
327  * Quantises the baud rate as per AN205 Table 1
328  */
329 static unsigned int cp210x_quantise_baudrate(unsigned int baud) {
330 	if      (baud <= 56)       baud = 0;
331 	else if (baud <= 300)      baud = 300;
332 	else if (baud <= 600)      baud = 600;
333 	else if (baud <= 1200)     baud = 1200;
334 	else if (baud <= 1800)     baud = 1800;
335 	else if (baud <= 2400)     baud = 2400;
336 	else if (baud <= 4000)     baud = 4000;
337 	else if (baud <= 4803)     baud = 4800;
338 	else if (baud <= 7207)     baud = 7200;
339 	else if (baud <= 9612)     baud = 9600;
340 	else if (baud <= 14428)    baud = 14400;
341 	else if (baud <= 16062)    baud = 16000;
342 	else if (baud <= 19250)    baud = 19200;
343 	else if (baud <= 28912)    baud = 28800;
344 	else if (baud <= 38601)    baud = 38400;
345 	else if (baud <= 51558)    baud = 51200;
346 	else if (baud <= 56280)    baud = 56000;
347 	else if (baud <= 58053)    baud = 57600;
348 	else if (baud <= 64111)    baud = 64000;
349 	else if (baud <= 77608)    baud = 76800;
350 	else if (baud <= 117028)   baud = 115200;
351 	else if (baud <= 129347)   baud = 128000;
352 	else if (baud <= 156868)   baud = 153600;
353 	else if (baud <= 237832)   baud = 230400;
354 	else if (baud <= 254234)   baud = 250000;
355 	else if (baud <= 273066)   baud = 256000;
356 	else if (baud <= 491520)   baud = 460800;
357 	else if (baud <= 567138)   baud = 500000;
358 	else if (baud <= 670254)   baud = 576000;
359 	else if (baud <= 1053257)  baud = 921600;
360 	else if (baud <= 1474560)  baud = 1228800;
361 	else if (baud <= 2457600)  baud = 1843200;
362 	else                       baud = 3686400;
363 	return baud;
364 }
365 
366 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port,
367 				struct file *filp)
368 {
369 	struct usb_serial *serial = port->serial;
370 	int result;
371 
372 	dbg("%s - port %d", __func__, port->number);
373 
374 	if (cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_ENABLE)) {
375 		dev_err(&port->dev, "%s - Unable to enable UART\n",
376 				__func__);
377 		return -EPROTO;
378 	}
379 
380 	/* Start reading from the device */
381 	usb_fill_bulk_urb(port->read_urb, serial->dev,
382 			usb_rcvbulkpipe(serial->dev,
383 			port->bulk_in_endpointAddress),
384 			port->read_urb->transfer_buffer,
385 			port->read_urb->transfer_buffer_length,
386 			serial->type->read_bulk_callback,
387 			port);
388 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
389 	if (result) {
390 		dev_err(&port->dev, "%s - failed resubmitting read urb, "
391 				"error %d\n", __func__, result);
392 		return result;
393 	}
394 
395 	/* Configure the termios structure */
396 	cp210x_get_termios(tty, port);
397 
398 	/* Set the DTR and RTS pins low */
399 	cp210x_tiocmset_port(tty ? (struct usb_serial_port *) tty->driver_data
400 			: port,
401 		NULL, TIOCM_DTR | TIOCM_RTS, 0);
402 
403 	return 0;
404 }
405 
406 static void cp210x_cleanup(struct usb_serial_port *port)
407 {
408 	struct usb_serial *serial = port->serial;
409 
410 	dbg("%s - port %d", __func__, port->number);
411 
412 	if (serial->dev) {
413 		/* shutdown any bulk reads that might be going on */
414 		if (serial->num_bulk_out)
415 			usb_kill_urb(port->write_urb);
416 		if (serial->num_bulk_in)
417 			usb_kill_urb(port->read_urb);
418 	}
419 }
420 
421 static void cp210x_close(struct usb_serial_port *port)
422 {
423 	dbg("%s - port %d", __func__, port->number);
424 
425 	/* shutdown our urbs */
426 	dbg("%s - shutting down urbs", __func__);
427 	usb_kill_urb(port->write_urb);
428 	usb_kill_urb(port->read_urb);
429 
430 	mutex_lock(&port->serial->disc_mutex);
431 	if (!port->serial->disconnected)
432 		cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
433 	mutex_unlock(&port->serial->disc_mutex);
434 }
435 
436 /*
437  * cp210x_get_termios
438  * Reads the baud rate, data bits, parity, stop bits and flow control mode
439  * from the device, corrects any unsupported values, and configures the
440  * termios structure to reflect the state of the device
441  */
442 static void cp210x_get_termios(struct tty_struct *tty,
443 	struct usb_serial_port *port)
444 {
445 	unsigned int baud;
446 
447 	if (tty) {
448 		cp210x_get_termios_port(tty->driver_data,
449 			&tty->termios->c_cflag, &baud);
450 		tty_encode_baud_rate(tty, baud, baud);
451 	}
452 
453 	else {
454 		unsigned int cflag;
455 		cflag = 0;
456 		cp210x_get_termios_port(port, &cflag, &baud);
457 	}
458 }
459 
460 /*
461  * cp210x_get_termios_port
462  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
463  */
464 static void cp210x_get_termios_port(struct usb_serial_port *port,
465 	unsigned int *cflagp, unsigned int *baudp)
466 {
467 	unsigned int cflag, modem_ctl[4];
468 	unsigned int baud;
469 	unsigned int bits;
470 
471 	dbg("%s - port %d", __func__, port->number);
472 
473 	cp210x_get_config(port, CP210X_GET_BAUDDIV, &baud, 2);
474 	/* Convert to baudrate */
475 	if (baud)
476 		baud = cp210x_quantise_baudrate((BAUD_RATE_GEN_FREQ + baud/2)/ baud);
477 
478 	dbg("%s - baud rate = %d", __func__, baud);
479 	*baudp = baud;
480 
481 	cflag = *cflagp;
482 
483 	cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
484 	cflag &= ~CSIZE;
485 	switch (bits & BITS_DATA_MASK) {
486 	case BITS_DATA_5:
487 		dbg("%s - data bits = 5", __func__);
488 		cflag |= CS5;
489 		break;
490 	case BITS_DATA_6:
491 		dbg("%s - data bits = 6", __func__);
492 		cflag |= CS6;
493 		break;
494 	case BITS_DATA_7:
495 		dbg("%s - data bits = 7", __func__);
496 		cflag |= CS7;
497 		break;
498 	case BITS_DATA_8:
499 		dbg("%s - data bits = 8", __func__);
500 		cflag |= CS8;
501 		break;
502 	case BITS_DATA_9:
503 		dbg("%s - data bits = 9 (not supported, using 8 data bits)",
504 								__func__);
505 		cflag |= CS8;
506 		bits &= ~BITS_DATA_MASK;
507 		bits |= BITS_DATA_8;
508 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
509 		break;
510 	default:
511 		dbg("%s - Unknown number of data bits, using 8", __func__);
512 		cflag |= CS8;
513 		bits &= ~BITS_DATA_MASK;
514 		bits |= BITS_DATA_8;
515 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
516 		break;
517 	}
518 
519 	switch (bits & BITS_PARITY_MASK) {
520 	case BITS_PARITY_NONE:
521 		dbg("%s - parity = NONE", __func__);
522 		cflag &= ~PARENB;
523 		break;
524 	case BITS_PARITY_ODD:
525 		dbg("%s - parity = ODD", __func__);
526 		cflag |= (PARENB|PARODD);
527 		break;
528 	case BITS_PARITY_EVEN:
529 		dbg("%s - parity = EVEN", __func__);
530 		cflag &= ~PARODD;
531 		cflag |= PARENB;
532 		break;
533 	case BITS_PARITY_MARK:
534 		dbg("%s - parity = MARK (not supported, disabling parity)",
535 				__func__);
536 		cflag &= ~PARENB;
537 		bits &= ~BITS_PARITY_MASK;
538 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
539 		break;
540 	case BITS_PARITY_SPACE:
541 		dbg("%s - parity = SPACE (not supported, disabling parity)",
542 				__func__);
543 		cflag &= ~PARENB;
544 		bits &= ~BITS_PARITY_MASK;
545 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
546 		break;
547 	default:
548 		dbg("%s - Unknown parity mode, disabling parity", __func__);
549 		cflag &= ~PARENB;
550 		bits &= ~BITS_PARITY_MASK;
551 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
552 		break;
553 	}
554 
555 	cflag &= ~CSTOPB;
556 	switch (bits & BITS_STOP_MASK) {
557 	case BITS_STOP_1:
558 		dbg("%s - stop bits = 1", __func__);
559 		break;
560 	case BITS_STOP_1_5:
561 		dbg("%s - stop bits = 1.5 (not supported, using 1 stop bit)",
562 								__func__);
563 		bits &= ~BITS_STOP_MASK;
564 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
565 		break;
566 	case BITS_STOP_2:
567 		dbg("%s - stop bits = 2", __func__);
568 		cflag |= CSTOPB;
569 		break;
570 	default:
571 		dbg("%s - Unknown number of stop bits, using 1 stop bit",
572 								__func__);
573 		bits &= ~BITS_STOP_MASK;
574 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
575 		break;
576 	}
577 
578 	cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
579 	if (modem_ctl[0] & 0x0008) {
580 		dbg("%s - flow control = CRTSCTS", __func__);
581 		cflag |= CRTSCTS;
582 	} else {
583 		dbg("%s - flow control = NONE", __func__);
584 		cflag &= ~CRTSCTS;
585 	}
586 
587 	*cflagp = cflag;
588 }
589 
590 static void cp210x_set_termios(struct tty_struct *tty,
591 		struct usb_serial_port *port, struct ktermios *old_termios)
592 {
593 	unsigned int cflag, old_cflag;
594 	unsigned int baud = 0, bits;
595 	unsigned int modem_ctl[4];
596 
597 	dbg("%s - port %d", __func__, port->number);
598 
599 	if (!tty)
600 		return;
601 
602 	tty->termios->c_cflag &= ~CMSPAR;
603 	cflag = tty->termios->c_cflag;
604 	old_cflag = old_termios->c_cflag;
605 	baud = cp210x_quantise_baudrate(tty_get_baud_rate(tty));
606 
607 	/* If the baud rate is to be updated*/
608 	if (baud != tty_termios_baud_rate(old_termios) && baud != 0) {
609 		dbg("%s - Setting baud rate to %d baud", __func__,
610 				baud);
611 		if (cp210x_set_config_single(port, CP210X_SET_BAUDDIV,
612 					((BAUD_RATE_GEN_FREQ + baud/2) / baud))) {
613 			dbg("Baud rate requested not supported by device\n");
614 			baud = tty_termios_baud_rate(old_termios);
615 		}
616 	}
617 	/* Report back the resulting baud rate */
618 	tty_encode_baud_rate(tty, baud, baud);
619 
620 	/* If the number of data bits is to be updated */
621 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
622 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
623 		bits &= ~BITS_DATA_MASK;
624 		switch (cflag & CSIZE) {
625 		case CS5:
626 			bits |= BITS_DATA_5;
627 			dbg("%s - data bits = 5", __func__);
628 			break;
629 		case CS6:
630 			bits |= BITS_DATA_6;
631 			dbg("%s - data bits = 6", __func__);
632 			break;
633 		case CS7:
634 			bits |= BITS_DATA_7;
635 			dbg("%s - data bits = 7", __func__);
636 			break;
637 		case CS8:
638 			bits |= BITS_DATA_8;
639 			dbg("%s - data bits = 8", __func__);
640 			break;
641 		/*case CS9:
642 			bits |= BITS_DATA_9;
643 			dbg("%s - data bits = 9", __func__);
644 			break;*/
645 		default:
646 			dbg("cp210x driver does not "
647 					"support the number of bits requested,"
648 					" using 8 bit mode\n");
649 				bits |= BITS_DATA_8;
650 				break;
651 		}
652 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
653 			dbg("Number of data bits requested "
654 					"not supported by device\n");
655 	}
656 
657 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {
658 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
659 		bits &= ~BITS_PARITY_MASK;
660 		if (cflag & PARENB) {
661 			if (cflag & PARODD) {
662 				bits |= BITS_PARITY_ODD;
663 				dbg("%s - parity = ODD", __func__);
664 			} else {
665 				bits |= BITS_PARITY_EVEN;
666 				dbg("%s - parity = EVEN", __func__);
667 			}
668 		}
669 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
670 			dbg("Parity mode not supported "
671 					"by device\n");
672 	}
673 
674 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
675 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
676 		bits &= ~BITS_STOP_MASK;
677 		if (cflag & CSTOPB) {
678 			bits |= BITS_STOP_2;
679 			dbg("%s - stop bits = 2", __func__);
680 		} else {
681 			bits |= BITS_STOP_1;
682 			dbg("%s - stop bits = 1", __func__);
683 		}
684 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
685 			dbg("Number of stop bits requested "
686 					"not supported by device\n");
687 	}
688 
689 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
690 		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
691 		dbg("%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
692 				__func__, modem_ctl[0], modem_ctl[1],
693 				modem_ctl[2], modem_ctl[3]);
694 
695 		if (cflag & CRTSCTS) {
696 			modem_ctl[0] &= ~0x7B;
697 			modem_ctl[0] |= 0x09;
698 			modem_ctl[1] = 0x80;
699 			dbg("%s - flow control = CRTSCTS", __func__);
700 		} else {
701 			modem_ctl[0] &= ~0x7B;
702 			modem_ctl[0] |= 0x01;
703 			modem_ctl[1] |= 0x40;
704 			dbg("%s - flow control = NONE", __func__);
705 		}
706 
707 		dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
708 				__func__, modem_ctl[0], modem_ctl[1],
709 				modem_ctl[2], modem_ctl[3]);
710 		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
711 	}
712 
713 }
714 
715 static int cp210x_tiocmset (struct tty_struct *tty, struct file *file,
716 		unsigned int set, unsigned int clear)
717 {
718 	struct usb_serial_port *port = tty->driver_data;
719 	return cp210x_tiocmset_port(port, file, set, clear);
720 }
721 
722 static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *file,
723 		unsigned int set, unsigned int clear)
724 {
725 	unsigned int control = 0;
726 
727 	dbg("%s - port %d", __func__, port->number);
728 
729 	if (set & TIOCM_RTS) {
730 		control |= CONTROL_RTS;
731 		control |= CONTROL_WRITE_RTS;
732 	}
733 	if (set & TIOCM_DTR) {
734 		control |= CONTROL_DTR;
735 		control |= CONTROL_WRITE_DTR;
736 	}
737 	if (clear & TIOCM_RTS) {
738 		control &= ~CONTROL_RTS;
739 		control |= CONTROL_WRITE_RTS;
740 	}
741 	if (clear & TIOCM_DTR) {
742 		control &= ~CONTROL_DTR;
743 		control |= CONTROL_WRITE_DTR;
744 	}
745 
746 	dbg("%s - control = 0x%.4x", __func__, control);
747 
748 	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
749 }
750 
751 static int cp210x_tiocmget (struct tty_struct *tty, struct file *file)
752 {
753 	struct usb_serial_port *port = tty->driver_data;
754 	unsigned int control;
755 	int result;
756 
757 	dbg("%s - port %d", __func__, port->number);
758 
759 	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
760 
761 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
762 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
763 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
764 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
765 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
766 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
767 
768 	dbg("%s - control = 0x%.2x", __func__, control);
769 
770 	return result;
771 }
772 
773 static void cp210x_break_ctl (struct tty_struct *tty, int break_state)
774 {
775 	struct usb_serial_port *port = tty->driver_data;
776 	unsigned int state;
777 
778 	dbg("%s - port %d", __func__, port->number);
779 	if (break_state == 0)
780 		state = BREAK_OFF;
781 	else
782 		state = BREAK_ON;
783 	dbg("%s - turning break %s", __func__,
784 			state == BREAK_OFF ? "off" : "on");
785 	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
786 }
787 
788 static int cp210x_startup(struct usb_serial *serial)
789 {
790 	/* cp210x buffers behave strangely unless device is reset */
791 	usb_reset_device(serial->dev);
792 	return 0;
793 }
794 
795 static void cp210x_shutdown(struct usb_serial *serial)
796 {
797 	int i;
798 
799 	dbg("%s", __func__);
800 
801 	/* Stop reads and writes on all ports */
802 	for (i = 0; i < serial->num_ports; ++i)
803 		cp210x_cleanup(serial->port[i]);
804 }
805 
806 static int __init cp210x_init(void)
807 {
808 	int retval;
809 
810 	retval = usb_serial_register(&cp210x_device);
811 	if (retval)
812 		return retval; /* Failed to register */
813 
814 	retval = usb_register(&cp210x_driver);
815 	if (retval) {
816 		/* Failed to register */
817 		usb_serial_deregister(&cp210x_device);
818 		return retval;
819 	}
820 
821 	/* Success */
822 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
823 	       DRIVER_DESC "\n");
824 	return 0;
825 }
826 
827 static void __exit cp210x_exit(void)
828 {
829 	usb_deregister(&cp210x_driver);
830 	usb_serial_deregister(&cp210x_device);
831 }
832 
833 module_init(cp210x_init);
834 module_exit(cp210x_exit);
835 
836 MODULE_DESCRIPTION(DRIVER_DESC);
837 MODULE_VERSION(DRIVER_VERSION);
838 MODULE_LICENSE("GPL");
839 
840 module_param(debug, bool, S_IRUGO | S_IWUSR);
841 MODULE_PARM_DESC(debug, "Enable verbose debugging messages");
842