xref: /openbmc/linux/drivers/usb/serial/cp210x.c (revision b6dcefde)
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 *tty, struct usb_serial_port *);
37 static void cp210x_cleanup(struct usb_serial_port *);
38 static void cp210x_close(struct usb_serial_port *);
39 static void cp210x_get_termios(struct tty_struct *,
40 	struct usb_serial_port *port);
41 static void cp210x_get_termios_port(struct usb_serial_port *port,
42 	unsigned int *cflagp, unsigned int *baudp);
43 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
44 							struct ktermios*);
45 static int cp210x_tiocmget(struct tty_struct *, struct file *);
46 static int cp210x_tiocmset(struct tty_struct *, struct file *,
47 		unsigned int, unsigned int);
48 static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *,
49 		unsigned int, unsigned int);
50 static void cp210x_break_ctl(struct tty_struct *, int);
51 static int cp210x_startup(struct usb_serial *);
52 static void cp210x_disconnect(struct usb_serial *);
53 static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
54 static int cp210x_carrier_raised(struct usb_serial_port *p);
55 
56 static int debug;
57 
58 static struct usb_device_id id_table [] = {
59 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
60 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
61 	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
62 	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
63 	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
64 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
65 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
66 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
67 	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
68 	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
69 	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
70 	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
71 	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
72 	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
73 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
74 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
75 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
76 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
77 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
78 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
79 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
80 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
81 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
82 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
83 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
84 	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
85 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
86 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
87 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
88 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
89 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
90 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
91 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
92 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
93 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
94 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
95 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
96 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
97 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demostration module */
98 	{ USB_DEVICE(0x10c4, 0x8293) }, /* Telegesys ETRX2USB */
99 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
100 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
101 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
102 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
103 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
104 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
105 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
106 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
107 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
108 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
109 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
110 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
111 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
112 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
113 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
114 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
115 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
116 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
117 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
118 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
119 	{ } /* Terminating Entry */
120 };
121 
122 MODULE_DEVICE_TABLE(usb, id_table);
123 
124 static struct usb_driver cp210x_driver = {
125 	.name		= "cp210x",
126 	.probe		= usb_serial_probe,
127 	.disconnect	= usb_serial_disconnect,
128 	.id_table	= id_table,
129 	.no_dynamic_id	= 	1,
130 };
131 
132 static struct usb_serial_driver cp210x_device = {
133 	.driver = {
134 		.owner =	THIS_MODULE,
135 		.name = 	"cp210x",
136 	},
137 	.usb_driver		= &cp210x_driver,
138 	.id_table		= id_table,
139 	.num_ports		= 1,
140 	.open			= cp210x_open,
141 	.close			= cp210x_close,
142 	.break_ctl		= cp210x_break_ctl,
143 	.set_termios		= cp210x_set_termios,
144 	.tiocmget 		= cp210x_tiocmget,
145 	.tiocmset		= cp210x_tiocmset,
146 	.attach			= cp210x_startup,
147 	.disconnect		= cp210x_disconnect,
148 	.dtr_rts		= cp210x_dtr_rts,
149 	.carrier_raised		= cp210x_carrier_raised
150 };
151 
152 /* Config request types */
153 #define REQTYPE_HOST_TO_DEVICE	0x41
154 #define REQTYPE_DEVICE_TO_HOST	0xc1
155 
156 /* Config request codes */
157 #define CP210X_IFC_ENABLE	0x00
158 #define CP210X_SET_BAUDDIV	0x01
159 #define CP210X_GET_BAUDDIV	0x02
160 #define CP210X_SET_LINE_CTL	0x03
161 #define CP210X_GET_LINE_CTL	0x04
162 #define CP210X_SET_BREAK	0x05
163 #define CP210X_IMM_CHAR		0x06
164 #define CP210X_SET_MHS		0x07
165 #define CP210X_GET_MDMSTS	0x08
166 #define CP210X_SET_XON		0x09
167 #define CP210X_SET_XOFF		0x0A
168 #define CP210X_SET_EVENTMASK	0x0B
169 #define CP210X_GET_EVENTMASK	0x0C
170 #define CP210X_SET_CHAR		0x0D
171 #define CP210X_GET_CHARS	0x0E
172 #define CP210X_GET_PROPS	0x0F
173 #define CP210X_GET_COMM_STATUS	0x10
174 #define CP210X_RESET		0x11
175 #define CP210X_PURGE		0x12
176 #define CP210X_SET_FLOW		0x13
177 #define CP210X_GET_FLOW		0x14
178 #define CP210X_EMBED_EVENTS	0x15
179 #define CP210X_GET_EVENTSTATE	0x16
180 #define CP210X_SET_CHARS	0x19
181 
182 /* CP210X_IFC_ENABLE */
183 #define UART_ENABLE		0x0001
184 #define UART_DISABLE		0x0000
185 
186 /* CP210X_(SET|GET)_BAUDDIV */
187 #define BAUD_RATE_GEN_FREQ	0x384000
188 
189 /* CP210X_(SET|GET)_LINE_CTL */
190 #define BITS_DATA_MASK		0X0f00
191 #define BITS_DATA_5		0X0500
192 #define BITS_DATA_6		0X0600
193 #define BITS_DATA_7		0X0700
194 #define BITS_DATA_8		0X0800
195 #define BITS_DATA_9		0X0900
196 
197 #define BITS_PARITY_MASK	0x00f0
198 #define BITS_PARITY_NONE	0x0000
199 #define BITS_PARITY_ODD		0x0010
200 #define BITS_PARITY_EVEN	0x0020
201 #define BITS_PARITY_MARK	0x0030
202 #define BITS_PARITY_SPACE	0x0040
203 
204 #define BITS_STOP_MASK		0x000f
205 #define BITS_STOP_1		0x0000
206 #define BITS_STOP_1_5		0x0001
207 #define BITS_STOP_2		0x0002
208 
209 /* CP210X_SET_BREAK */
210 #define BREAK_ON		0x0000
211 #define BREAK_OFF		0x0001
212 
213 /* CP210X_(SET_MHS|GET_MDMSTS) */
214 #define CONTROL_DTR		0x0001
215 #define CONTROL_RTS		0x0002
216 #define CONTROL_CTS		0x0010
217 #define CONTROL_DSR		0x0020
218 #define CONTROL_RING		0x0040
219 #define CONTROL_DCD		0x0080
220 #define CONTROL_WRITE_DTR	0x0100
221 #define CONTROL_WRITE_RTS	0x0200
222 
223 /*
224  * cp210x_get_config
225  * Reads from the CP210x configuration registers
226  * 'size' is specified in bytes.
227  * 'data' is a pointer to a pre-allocated array of integers large
228  * enough to hold 'size' bytes (with 4 bytes to each integer)
229  */
230 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
231 		unsigned int *data, int size)
232 {
233 	struct usb_serial *serial = port->serial;
234 	__le32 *buf;
235 	int result, i, length;
236 
237 	/* Number of integers required to contain the array */
238 	length = (((size - 1) | 3) + 1)/4;
239 
240 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
241 	if (!buf) {
242 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
243 		return -ENOMEM;
244 	}
245 
246 	/* Issue the request, attempting to read 'size' bytes */
247 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
248 				request, REQTYPE_DEVICE_TO_HOST, 0x0000,
249 				0, buf, size, 300);
250 
251 	/* Convert data into an array of integers */
252 	for (i = 0; i < length; i++)
253 		data[i] = le32_to_cpu(buf[i]);
254 
255 	kfree(buf);
256 
257 	if (result != size) {
258 		dbg("%s - Unable to send config request, "
259 				"request=0x%x size=%d result=%d\n",
260 				__func__, request, size, result);
261 		return -EPROTO;
262 	}
263 
264 	return 0;
265 }
266 
267 /*
268  * cp210x_set_config
269  * Writes to the CP210x configuration registers
270  * Values less than 16 bits wide are sent directly
271  * 'size' is specified in bytes.
272  */
273 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
274 		unsigned int *data, int size)
275 {
276 	struct usb_serial *serial = port->serial;
277 	__le32 *buf;
278 	int result, i, length;
279 
280 	/* Number of integers required to contain the array */
281 	length = (((size - 1) | 3) + 1)/4;
282 
283 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
284 	if (!buf) {
285 		dev_err(&port->dev, "%s - out of memory.\n",
286 				__func__);
287 		return -ENOMEM;
288 	}
289 
290 	/* Array of integers into bytes */
291 	for (i = 0; i < length; i++)
292 		buf[i] = cpu_to_le32(data[i]);
293 
294 	if (size > 2) {
295 		result = usb_control_msg(serial->dev,
296 				usb_sndctrlpipe(serial->dev, 0),
297 				request, REQTYPE_HOST_TO_DEVICE, 0x0000,
298 				0, buf, size, 300);
299 	} else {
300 		result = usb_control_msg(serial->dev,
301 				usb_sndctrlpipe(serial->dev, 0),
302 				request, REQTYPE_HOST_TO_DEVICE, data[0],
303 				0, NULL, 0, 300);
304 	}
305 
306 	kfree(buf);
307 
308 	if ((size > 2 && result != size) || result < 0) {
309 		dbg("%s - Unable to send request, "
310 				"request=0x%x size=%d result=%d\n",
311 				__func__, request, size, result);
312 		return -EPROTO;
313 	}
314 
315 	/* Single data value */
316 	result = usb_control_msg(serial->dev,
317 			usb_sndctrlpipe(serial->dev, 0),
318 			request, REQTYPE_HOST_TO_DEVICE, data[0],
319 			0, NULL, 0, 300);
320 	return 0;
321 }
322 
323 /*
324  * cp210x_set_config_single
325  * Convenience function for calling cp210x_set_config on single data values
326  * without requiring an integer pointer
327  */
328 static inline int cp210x_set_config_single(struct usb_serial_port *port,
329 		u8 request, unsigned int data)
330 {
331 	return cp210x_set_config(port, request, &data, 2);
332 }
333 
334 /*
335  * cp210x_quantise_baudrate
336  * Quantises the baud rate as per AN205 Table 1
337  */
338 static unsigned int cp210x_quantise_baudrate(unsigned int baud) {
339 	if      (baud <= 56)       baud = 0;
340 	else if (baud <= 300)      baud = 300;
341 	else if (baud <= 600)      baud = 600;
342 	else if (baud <= 1200)     baud = 1200;
343 	else if (baud <= 1800)     baud = 1800;
344 	else if (baud <= 2400)     baud = 2400;
345 	else if (baud <= 4000)     baud = 4000;
346 	else if (baud <= 4803)     baud = 4800;
347 	else if (baud <= 7207)     baud = 7200;
348 	else if (baud <= 9612)     baud = 9600;
349 	else if (baud <= 14428)    baud = 14400;
350 	else if (baud <= 16062)    baud = 16000;
351 	else if (baud <= 19250)    baud = 19200;
352 	else if (baud <= 28912)    baud = 28800;
353 	else if (baud <= 38601)    baud = 38400;
354 	else if (baud <= 51558)    baud = 51200;
355 	else if (baud <= 56280)    baud = 56000;
356 	else if (baud <= 58053)    baud = 57600;
357 	else if (baud <= 64111)    baud = 64000;
358 	else if (baud <= 77608)    baud = 76800;
359 	else if (baud <= 117028)   baud = 115200;
360 	else if (baud <= 129347)   baud = 128000;
361 	else if (baud <= 156868)   baud = 153600;
362 	else if (baud <= 237832)   baud = 230400;
363 	else if (baud <= 254234)   baud = 250000;
364 	else if (baud <= 273066)   baud = 256000;
365 	else if (baud <= 491520)   baud = 460800;
366 	else if (baud <= 567138)   baud = 500000;
367 	else if (baud <= 670254)   baud = 576000;
368 	else if (baud <= 1053257)  baud = 921600;
369 	else if (baud <= 1474560)  baud = 1228800;
370 	else if (baud <= 2457600)  baud = 1843200;
371 	else                       baud = 3686400;
372 	return baud;
373 }
374 
375 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
376 {
377 	struct usb_serial *serial = port->serial;
378 	int result;
379 
380 	dbg("%s - port %d", __func__, port->number);
381 
382 	if (cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_ENABLE)) {
383 		dev_err(&port->dev, "%s - Unable to enable UART\n",
384 				__func__);
385 		return -EPROTO;
386 	}
387 
388 	/* Start reading from the device */
389 	usb_fill_bulk_urb(port->read_urb, serial->dev,
390 			usb_rcvbulkpipe(serial->dev,
391 			port->bulk_in_endpointAddress),
392 			port->read_urb->transfer_buffer,
393 			port->read_urb->transfer_buffer_length,
394 			serial->type->read_bulk_callback,
395 			port);
396 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
397 	if (result) {
398 		dev_err(&port->dev, "%s - failed resubmitting read urb, "
399 				"error %d\n", __func__, result);
400 		return result;
401 	}
402 
403 	/* Configure the termios structure */
404 	cp210x_get_termios(tty, port);
405 	return 0;
406 }
407 
408 static void cp210x_cleanup(struct usb_serial_port *port)
409 {
410 	struct usb_serial *serial = port->serial;
411 
412 	dbg("%s - port %d", __func__, port->number);
413 
414 	if (serial->dev) {
415 		/* shutdown any bulk reads that might be going on */
416 		if (serial->num_bulk_out)
417 			usb_kill_urb(port->write_urb);
418 		if (serial->num_bulk_in)
419 			usb_kill_urb(port->read_urb);
420 	}
421 }
422 
423 static void cp210x_close(struct usb_serial_port *port)
424 {
425 	dbg("%s - port %d", __func__, port->number);
426 
427 	/* shutdown our urbs */
428 	dbg("%s - shutting down urbs", __func__);
429 	usb_kill_urb(port->write_urb);
430 	usb_kill_urb(port->read_urb);
431 
432 	mutex_lock(&port->serial->disc_mutex);
433 	if (!port->serial->disconnected)
434 		cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
435 	mutex_unlock(&port->serial->disc_mutex);
436 }
437 
438 /*
439  * cp210x_get_termios
440  * Reads the baud rate, data bits, parity, stop bits and flow control mode
441  * from the device, corrects any unsupported values, and configures the
442  * termios structure to reflect the state of the device
443  */
444 static void cp210x_get_termios(struct tty_struct *tty,
445 	struct usb_serial_port *port)
446 {
447 	unsigned int baud;
448 
449 	if (tty) {
450 		cp210x_get_termios_port(tty->driver_data,
451 			&tty->termios->c_cflag, &baud);
452 		tty_encode_baud_rate(tty, baud, baud);
453 	}
454 
455 	else {
456 		unsigned int cflag;
457 		cflag = 0;
458 		cp210x_get_termios_port(port, &cflag, &baud);
459 	}
460 }
461 
462 /*
463  * cp210x_get_termios_port
464  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
465  */
466 static void cp210x_get_termios_port(struct usb_serial_port *port,
467 	unsigned int *cflagp, unsigned int *baudp)
468 {
469 	unsigned int cflag, modem_ctl[4];
470 	unsigned int baud;
471 	unsigned int bits;
472 
473 	dbg("%s - port %d", __func__, port->number);
474 
475 	cp210x_get_config(port, CP210X_GET_BAUDDIV, &baud, 2);
476 	/* Convert to baudrate */
477 	if (baud)
478 		baud = cp210x_quantise_baudrate((BAUD_RATE_GEN_FREQ + baud/2)/ baud);
479 
480 	dbg("%s - baud rate = %d", __func__, baud);
481 	*baudp = baud;
482 
483 	cflag = *cflagp;
484 
485 	cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
486 	cflag &= ~CSIZE;
487 	switch (bits & BITS_DATA_MASK) {
488 	case BITS_DATA_5:
489 		dbg("%s - data bits = 5", __func__);
490 		cflag |= CS5;
491 		break;
492 	case BITS_DATA_6:
493 		dbg("%s - data bits = 6", __func__);
494 		cflag |= CS6;
495 		break;
496 	case BITS_DATA_7:
497 		dbg("%s - data bits = 7", __func__);
498 		cflag |= CS7;
499 		break;
500 	case BITS_DATA_8:
501 		dbg("%s - data bits = 8", __func__);
502 		cflag |= CS8;
503 		break;
504 	case BITS_DATA_9:
505 		dbg("%s - data bits = 9 (not supported, using 8 data bits)",
506 								__func__);
507 		cflag |= CS8;
508 		bits &= ~BITS_DATA_MASK;
509 		bits |= BITS_DATA_8;
510 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
511 		break;
512 	default:
513 		dbg("%s - Unknown number of data bits, using 8", __func__);
514 		cflag |= CS8;
515 		bits &= ~BITS_DATA_MASK;
516 		bits |= BITS_DATA_8;
517 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
518 		break;
519 	}
520 
521 	switch (bits & BITS_PARITY_MASK) {
522 	case BITS_PARITY_NONE:
523 		dbg("%s - parity = NONE", __func__);
524 		cflag &= ~PARENB;
525 		break;
526 	case BITS_PARITY_ODD:
527 		dbg("%s - parity = ODD", __func__);
528 		cflag |= (PARENB|PARODD);
529 		break;
530 	case BITS_PARITY_EVEN:
531 		dbg("%s - parity = EVEN", __func__);
532 		cflag &= ~PARODD;
533 		cflag |= PARENB;
534 		break;
535 	case BITS_PARITY_MARK:
536 		dbg("%s - parity = MARK (not supported, disabling parity)",
537 				__func__);
538 		cflag &= ~PARENB;
539 		bits &= ~BITS_PARITY_MASK;
540 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
541 		break;
542 	case BITS_PARITY_SPACE:
543 		dbg("%s - parity = SPACE (not supported, disabling parity)",
544 				__func__);
545 		cflag &= ~PARENB;
546 		bits &= ~BITS_PARITY_MASK;
547 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
548 		break;
549 	default:
550 		dbg("%s - Unknown parity mode, disabling parity", __func__);
551 		cflag &= ~PARENB;
552 		bits &= ~BITS_PARITY_MASK;
553 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
554 		break;
555 	}
556 
557 	cflag &= ~CSTOPB;
558 	switch (bits & BITS_STOP_MASK) {
559 	case BITS_STOP_1:
560 		dbg("%s - stop bits = 1", __func__);
561 		break;
562 	case BITS_STOP_1_5:
563 		dbg("%s - stop bits = 1.5 (not supported, using 1 stop bit)",
564 								__func__);
565 		bits &= ~BITS_STOP_MASK;
566 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
567 		break;
568 	case BITS_STOP_2:
569 		dbg("%s - stop bits = 2", __func__);
570 		cflag |= CSTOPB;
571 		break;
572 	default:
573 		dbg("%s - Unknown number of stop bits, using 1 stop bit",
574 								__func__);
575 		bits &= ~BITS_STOP_MASK;
576 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
577 		break;
578 	}
579 
580 	cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
581 	if (modem_ctl[0] & 0x0008) {
582 		dbg("%s - flow control = CRTSCTS", __func__);
583 		cflag |= CRTSCTS;
584 	} else {
585 		dbg("%s - flow control = NONE", __func__);
586 		cflag &= ~CRTSCTS;
587 	}
588 
589 	*cflagp = cflag;
590 }
591 
592 static void cp210x_set_termios(struct tty_struct *tty,
593 		struct usb_serial_port *port, struct ktermios *old_termios)
594 {
595 	unsigned int cflag, old_cflag;
596 	unsigned int baud = 0, bits;
597 	unsigned int modem_ctl[4];
598 
599 	dbg("%s - port %d", __func__, port->number);
600 
601 	if (!tty)
602 		return;
603 
604 	tty->termios->c_cflag &= ~CMSPAR;
605 	cflag = tty->termios->c_cflag;
606 	old_cflag = old_termios->c_cflag;
607 	baud = cp210x_quantise_baudrate(tty_get_baud_rate(tty));
608 
609 	/* If the baud rate is to be updated*/
610 	if (baud != tty_termios_baud_rate(old_termios) && baud != 0) {
611 		dbg("%s - Setting baud rate to %d baud", __func__,
612 				baud);
613 		if (cp210x_set_config_single(port, CP210X_SET_BAUDDIV,
614 					((BAUD_RATE_GEN_FREQ + baud/2) / baud))) {
615 			dbg("Baud rate requested not supported by device\n");
616 			baud = tty_termios_baud_rate(old_termios);
617 		}
618 	}
619 	/* Report back the resulting baud rate */
620 	tty_encode_baud_rate(tty, baud, baud);
621 
622 	/* If the number of data bits is to be updated */
623 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
624 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
625 		bits &= ~BITS_DATA_MASK;
626 		switch (cflag & CSIZE) {
627 		case CS5:
628 			bits |= BITS_DATA_5;
629 			dbg("%s - data bits = 5", __func__);
630 			break;
631 		case CS6:
632 			bits |= BITS_DATA_6;
633 			dbg("%s - data bits = 6", __func__);
634 			break;
635 		case CS7:
636 			bits |= BITS_DATA_7;
637 			dbg("%s - data bits = 7", __func__);
638 			break;
639 		case CS8:
640 			bits |= BITS_DATA_8;
641 			dbg("%s - data bits = 8", __func__);
642 			break;
643 		/*case CS9:
644 			bits |= BITS_DATA_9;
645 			dbg("%s - data bits = 9", __func__);
646 			break;*/
647 		default:
648 			dbg("cp210x driver does not "
649 					"support the number of bits requested,"
650 					" using 8 bit mode\n");
651 				bits |= BITS_DATA_8;
652 				break;
653 		}
654 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
655 			dbg("Number of data bits requested "
656 					"not supported by device\n");
657 	}
658 
659 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {
660 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
661 		bits &= ~BITS_PARITY_MASK;
662 		if (cflag & PARENB) {
663 			if (cflag & PARODD) {
664 				bits |= BITS_PARITY_ODD;
665 				dbg("%s - parity = ODD", __func__);
666 			} else {
667 				bits |= BITS_PARITY_EVEN;
668 				dbg("%s - parity = EVEN", __func__);
669 			}
670 		}
671 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
672 			dbg("Parity mode not supported "
673 					"by device\n");
674 	}
675 
676 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
677 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
678 		bits &= ~BITS_STOP_MASK;
679 		if (cflag & CSTOPB) {
680 			bits |= BITS_STOP_2;
681 			dbg("%s - stop bits = 2", __func__);
682 		} else {
683 			bits |= BITS_STOP_1;
684 			dbg("%s - stop bits = 1", __func__);
685 		}
686 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
687 			dbg("Number of stop bits requested "
688 					"not supported by device\n");
689 	}
690 
691 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
692 		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
693 		dbg("%s - read 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 
697 		if (cflag & CRTSCTS) {
698 			modem_ctl[0] &= ~0x7B;
699 			modem_ctl[0] |= 0x09;
700 			modem_ctl[1] = 0x80;
701 			dbg("%s - flow control = CRTSCTS", __func__);
702 		} else {
703 			modem_ctl[0] &= ~0x7B;
704 			modem_ctl[0] |= 0x01;
705 			modem_ctl[1] |= 0x40;
706 			dbg("%s - flow control = NONE", __func__);
707 		}
708 
709 		dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
710 				__func__, modem_ctl[0], modem_ctl[1],
711 				modem_ctl[2], modem_ctl[3]);
712 		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
713 	}
714 
715 }
716 
717 static int cp210x_tiocmset (struct tty_struct *tty, struct file *file,
718 		unsigned int set, unsigned int clear)
719 {
720 	struct usb_serial_port *port = tty->driver_data;
721 	return cp210x_tiocmset_port(port, file, set, clear);
722 }
723 
724 static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *file,
725 		unsigned int set, unsigned int clear)
726 {
727 	unsigned int control = 0;
728 
729 	dbg("%s - port %d", __func__, port->number);
730 
731 	if (set & TIOCM_RTS) {
732 		control |= CONTROL_RTS;
733 		control |= CONTROL_WRITE_RTS;
734 	}
735 	if (set & TIOCM_DTR) {
736 		control |= CONTROL_DTR;
737 		control |= CONTROL_WRITE_DTR;
738 	}
739 	if (clear & TIOCM_RTS) {
740 		control &= ~CONTROL_RTS;
741 		control |= CONTROL_WRITE_RTS;
742 	}
743 	if (clear & TIOCM_DTR) {
744 		control &= ~CONTROL_DTR;
745 		control |= CONTROL_WRITE_DTR;
746 	}
747 
748 	dbg("%s - control = 0x%.4x", __func__, control);
749 
750 	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
751 }
752 
753 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
754 {
755 	if (on)
756 		cp210x_tiocmset_port(p, NULL,  TIOCM_DTR|TIOCM_RTS, 0);
757 	else
758 		cp210x_tiocmset_port(p, NULL,  0, TIOCM_DTR|TIOCM_RTS);
759 }
760 
761 static int cp210x_tiocmget (struct tty_struct *tty, struct file *file)
762 {
763 	struct usb_serial_port *port = tty->driver_data;
764 	unsigned int control;
765 	int result;
766 
767 	dbg("%s - port %d", __func__, port->number);
768 
769 	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
770 
771 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
772 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
773 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
774 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
775 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
776 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
777 
778 	dbg("%s - control = 0x%.2x", __func__, control);
779 
780 	return result;
781 }
782 
783 static int cp210x_carrier_raised(struct usb_serial_port *p)
784 {
785 	unsigned int control;
786 	cp210x_get_config(p, CP210X_GET_MDMSTS, &control, 1);
787 	if (control & CONTROL_DCD)
788 		return 1;
789 	return 0;
790 }
791 
792 static void cp210x_break_ctl (struct tty_struct *tty, int break_state)
793 {
794 	struct usb_serial_port *port = tty->driver_data;
795 	unsigned int state;
796 
797 	dbg("%s - port %d", __func__, port->number);
798 	if (break_state == 0)
799 		state = BREAK_OFF;
800 	else
801 		state = BREAK_ON;
802 	dbg("%s - turning break %s", __func__,
803 			state == BREAK_OFF ? "off" : "on");
804 	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
805 }
806 
807 static int cp210x_startup(struct usb_serial *serial)
808 {
809 	/* cp210x buffers behave strangely unless device is reset */
810 	usb_reset_device(serial->dev);
811 	return 0;
812 }
813 
814 static void cp210x_disconnect(struct usb_serial *serial)
815 {
816 	int i;
817 
818 	dbg("%s", __func__);
819 
820 	/* Stop reads and writes on all ports */
821 	for (i = 0; i < serial->num_ports; ++i)
822 		cp210x_cleanup(serial->port[i]);
823 }
824 
825 static int __init cp210x_init(void)
826 {
827 	int retval;
828 
829 	retval = usb_serial_register(&cp210x_device);
830 	if (retval)
831 		return retval; /* Failed to register */
832 
833 	retval = usb_register(&cp210x_driver);
834 	if (retval) {
835 		/* Failed to register */
836 		usb_serial_deregister(&cp210x_device);
837 		return retval;
838 	}
839 
840 	/* Success */
841 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
842 	       DRIVER_DESC "\n");
843 	return 0;
844 }
845 
846 static void __exit cp210x_exit(void)
847 {
848 	usb_deregister(&cp210x_driver);
849 	usb_serial_deregister(&cp210x_device);
850 }
851 
852 module_init(cp210x_init);
853 module_exit(cp210x_exit);
854 
855 MODULE_DESCRIPTION(DRIVER_DESC);
856 MODULE_VERSION(DRIVER_VERSION);
857 MODULE_LICENSE("GPL");
858 
859 module_param(debug, bool, S_IRUGO | S_IWUSR);
860 MODULE_PARM_DESC(debug, "Enable verbose debugging messages");
861