xref: /linux/drivers/usb/serial/cp210x.c (revision 6fa79bcaecdbb0eb417afbc7fb0a8fa204308b62)
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_close(struct usb_serial_port *);
38 static void cp210x_get_termios(struct tty_struct *,
39 	struct usb_serial_port *port);
40 static void cp210x_get_termios_port(struct usb_serial_port *port,
41 	unsigned int *cflagp, unsigned int *baudp);
42 static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
43 							struct ktermios *);
44 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
45 							struct ktermios*);
46 static int cp210x_tiocmget(struct tty_struct *);
47 static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
48 static int cp210x_tiocmset_port(struct usb_serial_port *port,
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_release(struct usb_serial *);
53 static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
54 
55 static const struct usb_device_id id_table[] = {
56 	{ USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
57 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
58 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
59 	{ USB_DEVICE(0x0489, 0xE003) }, /* 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(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
64 	{ USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
65 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
66 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
67 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
68 	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
69 	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
70 	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
71 	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
72 	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
73 	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
74 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
75 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
76 	{ USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
77 	{ USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
78 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
79 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
80 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
81 	{ USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
82 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
83 	{ USB_DEVICE(0x10C4, 0x80C4) }, /* Cygnal Integrated Products, Inc., Optris infrared thermometer */
84 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
85 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
86 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
87 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
88 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
89 	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
90 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
91 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
92 	{ USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
93 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
94 	{ USB_DEVICE(0x10C4, 0x815F) }, /* Timewave HamLinkUSB */
95 	{ USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
96 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
97 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
98 	{ USB_DEVICE(0x10C4, 0x81A9) }, /* Multiplex RC Interface */
99 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
100 	{ USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
101 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
102 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
103 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
104 	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
105 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
106 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
107 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
108 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
109 	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
110 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
111 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
112 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
113 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
114 	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
115 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
116 	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
117 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
118 	{ USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
119 	{ USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
120 	{ USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
121 	{ USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
122 	{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
123 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
124 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
125 	{ USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
126 	{ USB_DEVICE(0x10C4, 0xEA80) }, /* Silicon Labs factory default */
127 	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
128 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
129 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
130 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
131 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
132 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
133 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
134 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
135 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
136 	{ USB_DEVICE(0x166A, 0x0201) }, /* Clipsal 5500PACA C-Bus Pascal Automation Controller */
137 	{ USB_DEVICE(0x166A, 0x0301) }, /* Clipsal 5800PC C-Bus Wireless PC Interface */
138 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
139 	{ USB_DEVICE(0x166A, 0x0304) }, /* Clipsal 5000CT2 C-Bus Black and White Touchscreen */
140 	{ USB_DEVICE(0x166A, 0x0305) }, /* Clipsal C-5000CT2 C-Bus Spectrum Colour Touchscreen */
141 	{ USB_DEVICE(0x166A, 0x0401) }, /* Clipsal L51xx C-Bus Architectural Dimmer */
142 	{ USB_DEVICE(0x166A, 0x0101) }, /* Clipsal 5560884 C-Bus Multi-room Audio Matrix Switcher */
143 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
144 	{ USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
145 	{ USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
146 	{ USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
147 	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
148 	{ USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
149 	{ USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
150 	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
151 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
152 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
153 	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
154 	{ USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
155 	{ USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
156 	{ USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
157 	{ USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
158 	{ USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
159 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
160 	{ } /* Terminating Entry */
161 };
162 
163 MODULE_DEVICE_TABLE(usb, id_table);
164 
165 struct cp210x_serial_private {
166 	__u8			bInterfaceNumber;
167 };
168 
169 static struct usb_serial_driver cp210x_device = {
170 	.driver = {
171 		.owner =	THIS_MODULE,
172 		.name = 	"cp210x",
173 	},
174 	.id_table		= id_table,
175 	.num_ports		= 1,
176 	.bulk_in_size		= 256,
177 	.bulk_out_size		= 256,
178 	.open			= cp210x_open,
179 	.close			= cp210x_close,
180 	.break_ctl		= cp210x_break_ctl,
181 	.set_termios		= cp210x_set_termios,
182 	.tiocmget 		= cp210x_tiocmget,
183 	.tiocmset		= cp210x_tiocmset,
184 	.attach			= cp210x_startup,
185 	.release		= cp210x_release,
186 	.dtr_rts		= cp210x_dtr_rts
187 };
188 
189 static struct usb_serial_driver * const serial_drivers[] = {
190 	&cp210x_device, NULL
191 };
192 
193 /* Config request types */
194 #define REQTYPE_HOST_TO_INTERFACE	0x41
195 #define REQTYPE_INTERFACE_TO_HOST	0xc1
196 #define REQTYPE_HOST_TO_DEVICE	0x40
197 #define REQTYPE_DEVICE_TO_HOST	0xc0
198 
199 /* Config request codes */
200 #define CP210X_IFC_ENABLE	0x00
201 #define CP210X_SET_BAUDDIV	0x01
202 #define CP210X_GET_BAUDDIV	0x02
203 #define CP210X_SET_LINE_CTL	0x03
204 #define CP210X_GET_LINE_CTL	0x04
205 #define CP210X_SET_BREAK	0x05
206 #define CP210X_IMM_CHAR		0x06
207 #define CP210X_SET_MHS		0x07
208 #define CP210X_GET_MDMSTS	0x08
209 #define CP210X_SET_XON		0x09
210 #define CP210X_SET_XOFF		0x0A
211 #define CP210X_SET_EVENTMASK	0x0B
212 #define CP210X_GET_EVENTMASK	0x0C
213 #define CP210X_SET_CHAR		0x0D
214 #define CP210X_GET_CHARS	0x0E
215 #define CP210X_GET_PROPS	0x0F
216 #define CP210X_GET_COMM_STATUS	0x10
217 #define CP210X_RESET		0x11
218 #define CP210X_PURGE		0x12
219 #define CP210X_SET_FLOW		0x13
220 #define CP210X_GET_FLOW		0x14
221 #define CP210X_EMBED_EVENTS	0x15
222 #define CP210X_GET_EVENTSTATE	0x16
223 #define CP210X_SET_CHARS	0x19
224 #define CP210X_GET_BAUDRATE	0x1D
225 #define CP210X_SET_BAUDRATE	0x1E
226 
227 /* CP210X_IFC_ENABLE */
228 #define UART_ENABLE		0x0001
229 #define UART_DISABLE		0x0000
230 
231 /* CP210X_(SET|GET)_BAUDDIV */
232 #define BAUD_RATE_GEN_FREQ	0x384000
233 
234 /* CP210X_(SET|GET)_LINE_CTL */
235 #define BITS_DATA_MASK		0X0f00
236 #define BITS_DATA_5		0X0500
237 #define BITS_DATA_6		0X0600
238 #define BITS_DATA_7		0X0700
239 #define BITS_DATA_8		0X0800
240 #define BITS_DATA_9		0X0900
241 
242 #define BITS_PARITY_MASK	0x00f0
243 #define BITS_PARITY_NONE	0x0000
244 #define BITS_PARITY_ODD		0x0010
245 #define BITS_PARITY_EVEN	0x0020
246 #define BITS_PARITY_MARK	0x0030
247 #define BITS_PARITY_SPACE	0x0040
248 
249 #define BITS_STOP_MASK		0x000f
250 #define BITS_STOP_1		0x0000
251 #define BITS_STOP_1_5		0x0001
252 #define BITS_STOP_2		0x0002
253 
254 /* CP210X_SET_BREAK */
255 #define BREAK_ON		0x0001
256 #define BREAK_OFF		0x0000
257 
258 /* CP210X_(SET_MHS|GET_MDMSTS) */
259 #define CONTROL_DTR		0x0001
260 #define CONTROL_RTS		0x0002
261 #define CONTROL_CTS		0x0010
262 #define CONTROL_DSR		0x0020
263 #define CONTROL_RING		0x0040
264 #define CONTROL_DCD		0x0080
265 #define CONTROL_WRITE_DTR	0x0100
266 #define CONTROL_WRITE_RTS	0x0200
267 
268 /*
269  * cp210x_get_config
270  * Reads from the CP210x configuration registers
271  * 'size' is specified in bytes.
272  * 'data' is a pointer to a pre-allocated array of integers large
273  * enough to hold 'size' bytes (with 4 bytes to each integer)
274  */
275 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
276 		unsigned int *data, int size)
277 {
278 	struct usb_serial *serial = port->serial;
279 	struct cp210x_serial_private *spriv = usb_get_serial_data(serial);
280 	__le32 *buf;
281 	int result, i, length;
282 
283 	/* Number of integers required to contain the array */
284 	length = (((size - 1) | 3) + 1)/4;
285 
286 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
287 	if (!buf) {
288 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
289 		return -ENOMEM;
290 	}
291 
292 	/* Issue the request, attempting to read 'size' bytes */
293 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
294 				request, REQTYPE_INTERFACE_TO_HOST, 0x0000,
295 				spriv->bInterfaceNumber, buf, size,
296 				USB_CTRL_GET_TIMEOUT);
297 
298 	/* Convert data into an array of integers */
299 	for (i = 0; i < length; i++)
300 		data[i] = le32_to_cpu(buf[i]);
301 
302 	kfree(buf);
303 
304 	if (result != size) {
305 		dev_dbg(&port->dev, "%s - Unable to send config request, request=0x%x size=%d result=%d\n",
306 			__func__, request, size, result);
307 		if (result > 0)
308 			result = -EPROTO;
309 
310 		return result;
311 	}
312 
313 	return 0;
314 }
315 
316 /*
317  * cp210x_set_config
318  * Writes to the CP210x configuration registers
319  * Values less than 16 bits wide are sent directly
320  * 'size' is specified in bytes.
321  */
322 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
323 		unsigned int *data, int size)
324 {
325 	struct usb_serial *serial = port->serial;
326 	struct cp210x_serial_private *spriv = usb_get_serial_data(serial);
327 	__le32 *buf;
328 	int result, i, length;
329 
330 	/* Number of integers required to contain the array */
331 	length = (((size - 1) | 3) + 1)/4;
332 
333 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
334 	if (!buf) {
335 		dev_err(&port->dev, "%s - out of memory.\n",
336 				__func__);
337 		return -ENOMEM;
338 	}
339 
340 	/* Array of integers into bytes */
341 	for (i = 0; i < length; i++)
342 		buf[i] = cpu_to_le32(data[i]);
343 
344 	if (size > 2) {
345 		result = usb_control_msg(serial->dev,
346 				usb_sndctrlpipe(serial->dev, 0),
347 				request, REQTYPE_HOST_TO_INTERFACE, 0x0000,
348 				spriv->bInterfaceNumber, buf, size,
349 				USB_CTRL_SET_TIMEOUT);
350 	} else {
351 		result = usb_control_msg(serial->dev,
352 				usb_sndctrlpipe(serial->dev, 0),
353 				request, REQTYPE_HOST_TO_INTERFACE, data[0],
354 				spriv->bInterfaceNumber, NULL, 0,
355 				USB_CTRL_SET_TIMEOUT);
356 	}
357 
358 	kfree(buf);
359 
360 	if ((size > 2 && result != size) || result < 0) {
361 		dev_dbg(&port->dev, "%s - Unable to send request, request=0x%x size=%d result=%d\n",
362 			__func__, request, size, result);
363 		if (result > 0)
364 			result = -EPROTO;
365 
366 		return result;
367 	}
368 
369 	return 0;
370 }
371 
372 /*
373  * cp210x_set_config_single
374  * Convenience function for calling cp210x_set_config on single data values
375  * without requiring an integer pointer
376  */
377 static inline int cp210x_set_config_single(struct usb_serial_port *port,
378 		u8 request, unsigned int data)
379 {
380 	return cp210x_set_config(port, request, &data, 2);
381 }
382 
383 /*
384  * cp210x_quantise_baudrate
385  * Quantises the baud rate as per AN205 Table 1
386  */
387 static unsigned int cp210x_quantise_baudrate(unsigned int baud) {
388 	if (baud <= 300)
389 		baud = 300;
390 	else if (baud <= 600)      baud = 600;
391 	else if (baud <= 1200)     baud = 1200;
392 	else if (baud <= 1800)     baud = 1800;
393 	else if (baud <= 2400)     baud = 2400;
394 	else if (baud <= 4000)     baud = 4000;
395 	else if (baud <= 4803)     baud = 4800;
396 	else if (baud <= 7207)     baud = 7200;
397 	else if (baud <= 9612)     baud = 9600;
398 	else if (baud <= 14428)    baud = 14400;
399 	else if (baud <= 16062)    baud = 16000;
400 	else if (baud <= 19250)    baud = 19200;
401 	else if (baud <= 28912)    baud = 28800;
402 	else if (baud <= 38601)    baud = 38400;
403 	else if (baud <= 51558)    baud = 51200;
404 	else if (baud <= 56280)    baud = 56000;
405 	else if (baud <= 58053)    baud = 57600;
406 	else if (baud <= 64111)    baud = 64000;
407 	else if (baud <= 77608)    baud = 76800;
408 	else if (baud <= 117028)   baud = 115200;
409 	else if (baud <= 129347)   baud = 128000;
410 	else if (baud <= 156868)   baud = 153600;
411 	else if (baud <= 237832)   baud = 230400;
412 	else if (baud <= 254234)   baud = 250000;
413 	else if (baud <= 273066)   baud = 256000;
414 	else if (baud <= 491520)   baud = 460800;
415 	else if (baud <= 567138)   baud = 500000;
416 	else if (baud <= 670254)   baud = 576000;
417 	else if (baud < 1000000)
418 		baud = 921600;
419 	else if (baud > 2000000)
420 		baud = 2000000;
421 	return baud;
422 }
423 
424 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
425 {
426 	int result;
427 
428 	result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
429 								UART_ENABLE);
430 	if (result) {
431 		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
432 		return result;
433 	}
434 
435 	/* Configure the termios structure */
436 	cp210x_get_termios(tty, port);
437 
438 	/* The baud rate must be initialised on cp2104 */
439 	if (tty)
440 		cp210x_change_speed(tty, port, NULL);
441 
442 	return usb_serial_generic_open(tty, port);
443 }
444 
445 static void cp210x_close(struct usb_serial_port *port)
446 {
447 	usb_serial_generic_close(port);
448 
449 	mutex_lock(&port->serial->disc_mutex);
450 	if (!port->serial->disconnected)
451 		cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
452 	mutex_unlock(&port->serial->disc_mutex);
453 }
454 
455 /*
456  * cp210x_get_termios
457  * Reads the baud rate, data bits, parity, stop bits and flow control mode
458  * from the device, corrects any unsupported values, and configures the
459  * termios structure to reflect the state of the device
460  */
461 static void cp210x_get_termios(struct tty_struct *tty,
462 	struct usb_serial_port *port)
463 {
464 	unsigned int baud;
465 
466 	if (tty) {
467 		cp210x_get_termios_port(tty->driver_data,
468 			&tty->termios.c_cflag, &baud);
469 		tty_encode_baud_rate(tty, baud, baud);
470 	}
471 
472 	else {
473 		unsigned int cflag;
474 		cflag = 0;
475 		cp210x_get_termios_port(port, &cflag, &baud);
476 	}
477 }
478 
479 /*
480  * cp210x_get_termios_port
481  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
482  */
483 static void cp210x_get_termios_port(struct usb_serial_port *port,
484 	unsigned int *cflagp, unsigned int *baudp)
485 {
486 	struct device *dev = &port->dev;
487 	unsigned int cflag, modem_ctl[4];
488 	unsigned int baud;
489 	unsigned int bits;
490 
491 	cp210x_get_config(port, CP210X_GET_BAUDRATE, &baud, 4);
492 
493 	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
494 	*baudp = baud;
495 
496 	cflag = *cflagp;
497 
498 	cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
499 	cflag &= ~CSIZE;
500 	switch (bits & BITS_DATA_MASK) {
501 	case BITS_DATA_5:
502 		dev_dbg(dev, "%s - data bits = 5\n", __func__);
503 		cflag |= CS5;
504 		break;
505 	case BITS_DATA_6:
506 		dev_dbg(dev, "%s - data bits = 6\n", __func__);
507 		cflag |= CS6;
508 		break;
509 	case BITS_DATA_7:
510 		dev_dbg(dev, "%s - data bits = 7\n", __func__);
511 		cflag |= CS7;
512 		break;
513 	case BITS_DATA_8:
514 		dev_dbg(dev, "%s - data bits = 8\n", __func__);
515 		cflag |= CS8;
516 		break;
517 	case BITS_DATA_9:
518 		dev_dbg(dev, "%s - data bits = 9 (not supported, using 8 data bits)\n", __func__);
519 		cflag |= CS8;
520 		bits &= ~BITS_DATA_MASK;
521 		bits |= BITS_DATA_8;
522 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
523 		break;
524 	default:
525 		dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
526 		cflag |= CS8;
527 		bits &= ~BITS_DATA_MASK;
528 		bits |= BITS_DATA_8;
529 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
530 		break;
531 	}
532 
533 	switch (bits & BITS_PARITY_MASK) {
534 	case BITS_PARITY_NONE:
535 		dev_dbg(dev, "%s - parity = NONE\n", __func__);
536 		cflag &= ~PARENB;
537 		break;
538 	case BITS_PARITY_ODD:
539 		dev_dbg(dev, "%s - parity = ODD\n", __func__);
540 		cflag |= (PARENB|PARODD);
541 		break;
542 	case BITS_PARITY_EVEN:
543 		dev_dbg(dev, "%s - parity = EVEN\n", __func__);
544 		cflag &= ~PARODD;
545 		cflag |= PARENB;
546 		break;
547 	case BITS_PARITY_MARK:
548 		dev_dbg(dev, "%s - parity = MARK\n", __func__);
549 		cflag |= (PARENB|PARODD|CMSPAR);
550 		break;
551 	case BITS_PARITY_SPACE:
552 		dev_dbg(dev, "%s - parity = SPACE\n", __func__);
553 		cflag &= ~PARODD;
554 		cflag |= (PARENB|CMSPAR);
555 		break;
556 	default:
557 		dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
558 		cflag &= ~PARENB;
559 		bits &= ~BITS_PARITY_MASK;
560 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
561 		break;
562 	}
563 
564 	cflag &= ~CSTOPB;
565 	switch (bits & BITS_STOP_MASK) {
566 	case BITS_STOP_1:
567 		dev_dbg(dev, "%s - stop bits = 1\n", __func__);
568 		break;
569 	case BITS_STOP_1_5:
570 		dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
571 		bits &= ~BITS_STOP_MASK;
572 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
573 		break;
574 	case BITS_STOP_2:
575 		dev_dbg(dev, "%s - stop bits = 2\n", __func__);
576 		cflag |= CSTOPB;
577 		break;
578 	default:
579 		dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __func__);
580 		bits &= ~BITS_STOP_MASK;
581 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
582 		break;
583 	}
584 
585 	cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
586 	if (modem_ctl[0] & 0x0008) {
587 		dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
588 		cflag |= CRTSCTS;
589 	} else {
590 		dev_dbg(dev, "%s - flow control = NONE\n", __func__);
591 		cflag &= ~CRTSCTS;
592 	}
593 
594 	*cflagp = cflag;
595 }
596 
597 /*
598  * CP2101 supports the following baud rates:
599  *
600  *	300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
601  *	38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
602  *
603  * CP2102 and CP2103 support the following additional rates:
604  *
605  *	4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
606  *	576000
607  *
608  * The device will map a requested rate to a supported one, but the result
609  * of requests for rates greater than 1053257 is undefined (see AN205).
610  *
611  * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
612  * respectively, with an error less than 1%. The actual rates are determined
613  * by
614  *
615  *	div = round(freq / (2 x prescale x request))
616  *	actual = freq / (2 x prescale x div)
617  *
618  * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
619  * or 1 otherwise.
620  * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
621  * otherwise.
622  */
623 static void cp210x_change_speed(struct tty_struct *tty,
624 		struct usb_serial_port *port, struct ktermios *old_termios)
625 {
626 	u32 baud;
627 
628 	baud = tty->termios.c_ospeed;
629 
630 	/* This maps the requested rate to a rate valid on cp2102 or cp2103,
631 	 * or to an arbitrary rate in [1M,2M].
632 	 *
633 	 * NOTE: B0 is not implemented.
634 	 */
635 	baud = cp210x_quantise_baudrate(baud);
636 
637 	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
638 	if (cp210x_set_config(port, CP210X_SET_BAUDRATE, &baud,
639 							sizeof(baud))) {
640 		dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
641 		if (old_termios)
642 			baud = old_termios->c_ospeed;
643 		else
644 			baud = 9600;
645 	}
646 
647 	tty_encode_baud_rate(tty, baud, baud);
648 }
649 
650 static void cp210x_set_termios(struct tty_struct *tty,
651 		struct usb_serial_port *port, struct ktermios *old_termios)
652 {
653 	struct device *dev = &port->dev;
654 	unsigned int cflag, old_cflag;
655 	unsigned int bits;
656 	unsigned int modem_ctl[4];
657 
658 	dev_dbg(dev, "%s - port %d\n", __func__, port->number);
659 
660 	if (!tty)
661 		return;
662 
663 	cflag = tty->termios.c_cflag;
664 	old_cflag = old_termios->c_cflag;
665 
666 	if (tty->termios.c_ospeed != old_termios->c_ospeed)
667 		cp210x_change_speed(tty, port, old_termios);
668 
669 	/* If the number of data bits is to be updated */
670 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
671 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
672 		bits &= ~BITS_DATA_MASK;
673 		switch (cflag & CSIZE) {
674 		case CS5:
675 			bits |= BITS_DATA_5;
676 			dev_dbg(dev, "%s - data bits = 5\n", __func__);
677 			break;
678 		case CS6:
679 			bits |= BITS_DATA_6;
680 			dev_dbg(dev, "%s - data bits = 6\n", __func__);
681 			break;
682 		case CS7:
683 			bits |= BITS_DATA_7;
684 			dev_dbg(dev, "%s - data bits = 7\n", __func__);
685 			break;
686 		case CS8:
687 			bits |= BITS_DATA_8;
688 			dev_dbg(dev, "%s - data bits = 8\n", __func__);
689 			break;
690 		/*case CS9:
691 			bits |= BITS_DATA_9;
692 			dev_dbg(dev, "%s - data bits = 9\n", __func__);
693 			break;*/
694 		default:
695 			dev_dbg(dev, "cp210x driver does not support the number of bits requested, using 8 bit mode\n");
696 				bits |= BITS_DATA_8;
697 				break;
698 		}
699 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
700 			dev_dbg(dev, "Number of data bits requested not supported by device\n");
701 	}
702 
703 	if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
704 	    (old_cflag & (PARENB|PARODD|CMSPAR))) {
705 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
706 		bits &= ~BITS_PARITY_MASK;
707 		if (cflag & PARENB) {
708 			if (cflag & CMSPAR) {
709 				if (cflag & PARODD) {
710 					bits |= BITS_PARITY_MARK;
711 					dev_dbg(dev, "%s - parity = MARK\n", __func__);
712 				} else {
713 					bits |= BITS_PARITY_SPACE;
714 					dev_dbg(dev, "%s - parity = SPACE\n", __func__);
715 				}
716 			} else {
717 				if (cflag & PARODD) {
718 					bits |= BITS_PARITY_ODD;
719 					dev_dbg(dev, "%s - parity = ODD\n", __func__);
720 				} else {
721 					bits |= BITS_PARITY_EVEN;
722 					dev_dbg(dev, "%s - parity = EVEN\n", __func__);
723 				}
724 			}
725 		}
726 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
727 			dev_dbg(dev, "Parity mode not supported by device\n");
728 	}
729 
730 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
731 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
732 		bits &= ~BITS_STOP_MASK;
733 		if (cflag & CSTOPB) {
734 			bits |= BITS_STOP_2;
735 			dev_dbg(dev, "%s - stop bits = 2\n", __func__);
736 		} else {
737 			bits |= BITS_STOP_1;
738 			dev_dbg(dev, "%s - stop bits = 1\n", __func__);
739 		}
740 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
741 			dev_dbg(dev, "Number of stop bits requested not supported by device\n");
742 	}
743 
744 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
745 		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
746 		dev_dbg(dev, "%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
747 			__func__, modem_ctl[0], modem_ctl[1],
748 			modem_ctl[2], modem_ctl[3]);
749 
750 		if (cflag & CRTSCTS) {
751 			modem_ctl[0] &= ~0x7B;
752 			modem_ctl[0] |= 0x09;
753 			modem_ctl[1] = 0x80;
754 			dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
755 		} else {
756 			modem_ctl[0] &= ~0x7B;
757 			modem_ctl[0] |= 0x01;
758 			modem_ctl[1] |= 0x40;
759 			dev_dbg(dev, "%s - flow control = NONE\n", __func__);
760 		}
761 
762 		dev_dbg(dev, "%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
763 			__func__, modem_ctl[0], modem_ctl[1],
764 			modem_ctl[2], modem_ctl[3]);
765 		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
766 	}
767 
768 }
769 
770 static int cp210x_tiocmset (struct tty_struct *tty,
771 		unsigned int set, unsigned int clear)
772 {
773 	struct usb_serial_port *port = tty->driver_data;
774 	return cp210x_tiocmset_port(port, set, clear);
775 }
776 
777 static int cp210x_tiocmset_port(struct usb_serial_port *port,
778 		unsigned int set, unsigned int clear)
779 {
780 	unsigned int control = 0;
781 
782 	if (set & TIOCM_RTS) {
783 		control |= CONTROL_RTS;
784 		control |= CONTROL_WRITE_RTS;
785 	}
786 	if (set & TIOCM_DTR) {
787 		control |= CONTROL_DTR;
788 		control |= CONTROL_WRITE_DTR;
789 	}
790 	if (clear & TIOCM_RTS) {
791 		control &= ~CONTROL_RTS;
792 		control |= CONTROL_WRITE_RTS;
793 	}
794 	if (clear & TIOCM_DTR) {
795 		control &= ~CONTROL_DTR;
796 		control |= CONTROL_WRITE_DTR;
797 	}
798 
799 	dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
800 
801 	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
802 }
803 
804 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
805 {
806 	if (on)
807 		cp210x_tiocmset_port(p, TIOCM_DTR|TIOCM_RTS, 0);
808 	else
809 		cp210x_tiocmset_port(p, 0, TIOCM_DTR|TIOCM_RTS);
810 }
811 
812 static int cp210x_tiocmget (struct tty_struct *tty)
813 {
814 	struct usb_serial_port *port = tty->driver_data;
815 	unsigned int control;
816 	int result;
817 
818 	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
819 
820 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
821 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
822 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
823 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
824 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
825 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
826 
827 	dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);
828 
829 	return result;
830 }
831 
832 static void cp210x_break_ctl (struct tty_struct *tty, int break_state)
833 {
834 	struct usb_serial_port *port = tty->driver_data;
835 	unsigned int state;
836 
837 	if (break_state == 0)
838 		state = BREAK_OFF;
839 	else
840 		state = BREAK_ON;
841 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
842 		state == BREAK_OFF ? "off" : "on");
843 	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
844 }
845 
846 static int cp210x_startup(struct usb_serial *serial)
847 {
848 	struct usb_host_interface *cur_altsetting;
849 	struct cp210x_serial_private *spriv;
850 
851 	/* cp210x buffers behave strangely unless device is reset */
852 	usb_reset_device(serial->dev);
853 
854 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
855 	if (!spriv)
856 		return -ENOMEM;
857 
858 	cur_altsetting = serial->interface->cur_altsetting;
859 	spriv->bInterfaceNumber = cur_altsetting->desc.bInterfaceNumber;
860 
861 	usb_set_serial_data(serial, spriv);
862 
863 	return 0;
864 }
865 
866 static void cp210x_release(struct usb_serial *serial)
867 {
868 	struct cp210x_serial_private *spriv;
869 
870 	spriv = usb_get_serial_data(serial);
871 	kfree(spriv);
872 }
873 
874 module_usb_serial_driver(serial_drivers, id_table);
875 
876 MODULE_DESCRIPTION(DRIVER_DESC);
877 MODULE_VERSION(DRIVER_VERSION);
878 MODULE_LICENSE("GPL");
879