xref: /linux/drivers/usb/serial/cp210x.c (revision 2c4cdf5950b1a7a9d731c03c56e2cea3bd8ca7b7)
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 #define DRIVER_DESC "Silicon Labs CP210x RS232 serial adaptor driver"
28 
29 /*
30  * Function Prototypes
31  */
32 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
33 static void cp210x_close(struct usb_serial_port *);
34 static void cp210x_get_termios(struct tty_struct *, struct usb_serial_port *);
35 static void cp210x_get_termios_port(struct usb_serial_port *port,
36 	unsigned int *cflagp, unsigned int *baudp);
37 static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
38 							struct ktermios *);
39 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
40 							struct ktermios*);
41 static int cp210x_tiocmget(struct tty_struct *);
42 static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
43 static int cp210x_tiocmset_port(struct usb_serial_port *port,
44 		unsigned int, unsigned int);
45 static void cp210x_break_ctl(struct tty_struct *, int);
46 static int cp210x_startup(struct usb_serial *);
47 static void cp210x_release(struct usb_serial *);
48 static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
49 
50 static const struct usb_device_id id_table[] = {
51 	{ USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
52 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
53 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
54 	{ USB_DEVICE(0x0489, 0xE003) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
55 	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
56 	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
57 	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
58 	{ USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
59 	{ USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
60 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
61 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
62 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
63 	{ USB_DEVICE(0x0FDE, 0xCA05) }, /* OWL Wireless Electricity Monitor CM-160 */
64 	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
65 	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
66 	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
67 	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
68 	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
69 	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
70 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
71 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
72 	{ USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
73 	{ USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
74 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
75 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
76 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
77 	{ USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
78 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
79 	{ USB_DEVICE(0x10C4, 0x80C4) }, /* Cygnal Integrated Products, Inc., Optris infrared thermometer */
80 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
81 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
82 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
83 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
84 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
85 	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
86 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
87 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
88 	{ USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
89 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
90 	{ USB_DEVICE(0x10C4, 0x815F) }, /* Timewave HamLinkUSB */
91 	{ USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
92 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
93 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
94 	{ USB_DEVICE(0x10C4, 0x81A9) }, /* Multiplex RC Interface */
95 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
96 	{ USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
97 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
98 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
99 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
100 	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
101 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
102 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
103 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
104 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
105 	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
106 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
107 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
108 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
109 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
110 	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
111 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
112 	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
113 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
114 	{ USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
115 	{ USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
116 	{ USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
117 	{ USB_DEVICE(0x10C4, 0x85F8) }, /* Virtenio Preon32 */
118 	{ USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
119 	{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
120 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
121 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
122 	{ USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
123 	{ USB_DEVICE(0x10C4, 0xEA80) }, /* Silicon Labs factory default */
124 	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
125 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
126 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
127 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
128 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
129 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
130 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
131 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
132 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
133 	{ USB_DEVICE(0x166A, 0x0201) }, /* Clipsal 5500PACA C-Bus Pascal Automation Controller */
134 	{ USB_DEVICE(0x166A, 0x0301) }, /* Clipsal 5800PC C-Bus Wireless PC Interface */
135 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
136 	{ USB_DEVICE(0x166A, 0x0304) }, /* Clipsal 5000CT2 C-Bus Black and White Touchscreen */
137 	{ USB_DEVICE(0x166A, 0x0305) }, /* Clipsal C-5000CT2 C-Bus Spectrum Colour Touchscreen */
138 	{ USB_DEVICE(0x166A, 0x0401) }, /* Clipsal L51xx C-Bus Architectural Dimmer */
139 	{ USB_DEVICE(0x166A, 0x0101) }, /* Clipsal 5560884 C-Bus Multi-room Audio Matrix Switcher */
140 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
141 	{ USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
142 	{ USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
143 	{ USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
144 	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
145 	{ USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
146 	{ USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
147 	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
148 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
149 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
150 	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
151 	{ USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
152 	{ USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
153 	{ USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
154 	{ USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
155 	{ USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
156 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
157 	{ } /* Terminating Entry */
158 };
159 
160 MODULE_DEVICE_TABLE(usb, id_table);
161 
162 struct cp210x_serial_private {
163 	__u8			bInterfaceNumber;
164 };
165 
166 static struct usb_serial_driver cp210x_device = {
167 	.driver = {
168 		.owner =	THIS_MODULE,
169 		.name =		"cp210x",
170 	},
171 	.id_table		= id_table,
172 	.num_ports		= 1,
173 	.bulk_in_size		= 256,
174 	.bulk_out_size		= 256,
175 	.open			= cp210x_open,
176 	.close			= cp210x_close,
177 	.break_ctl		= cp210x_break_ctl,
178 	.set_termios		= cp210x_set_termios,
179 	.tiocmget		= cp210x_tiocmget,
180 	.tiocmset		= cp210x_tiocmset,
181 	.attach			= cp210x_startup,
182 	.release		= cp210x_release,
183 	.dtr_rts		= cp210x_dtr_rts
184 };
185 
186 static struct usb_serial_driver * const serial_drivers[] = {
187 	&cp210x_device, NULL
188 };
189 
190 /* Config request types */
191 #define REQTYPE_HOST_TO_INTERFACE	0x41
192 #define REQTYPE_INTERFACE_TO_HOST	0xc1
193 #define REQTYPE_HOST_TO_DEVICE	0x40
194 #define REQTYPE_DEVICE_TO_HOST	0xc0
195 
196 /* Config request codes */
197 #define CP210X_IFC_ENABLE	0x00
198 #define CP210X_SET_BAUDDIV	0x01
199 #define CP210X_GET_BAUDDIV	0x02
200 #define CP210X_SET_LINE_CTL	0x03
201 #define CP210X_GET_LINE_CTL	0x04
202 #define CP210X_SET_BREAK	0x05
203 #define CP210X_IMM_CHAR		0x06
204 #define CP210X_SET_MHS		0x07
205 #define CP210X_GET_MDMSTS	0x08
206 #define CP210X_SET_XON		0x09
207 #define CP210X_SET_XOFF		0x0A
208 #define CP210X_SET_EVENTMASK	0x0B
209 #define CP210X_GET_EVENTMASK	0x0C
210 #define CP210X_SET_CHAR		0x0D
211 #define CP210X_GET_CHARS	0x0E
212 #define CP210X_GET_PROPS	0x0F
213 #define CP210X_GET_COMM_STATUS	0x10
214 #define CP210X_RESET		0x11
215 #define CP210X_PURGE		0x12
216 #define CP210X_SET_FLOW		0x13
217 #define CP210X_GET_FLOW		0x14
218 #define CP210X_EMBED_EVENTS	0x15
219 #define CP210X_GET_EVENTSTATE	0x16
220 #define CP210X_SET_CHARS	0x19
221 #define CP210X_GET_BAUDRATE	0x1D
222 #define CP210X_SET_BAUDRATE	0x1E
223 
224 /* CP210X_IFC_ENABLE */
225 #define UART_ENABLE		0x0001
226 #define UART_DISABLE		0x0000
227 
228 /* CP210X_(SET|GET)_BAUDDIV */
229 #define BAUD_RATE_GEN_FREQ	0x384000
230 
231 /* CP210X_(SET|GET)_LINE_CTL */
232 #define BITS_DATA_MASK		0X0f00
233 #define BITS_DATA_5		0X0500
234 #define BITS_DATA_6		0X0600
235 #define BITS_DATA_7		0X0700
236 #define BITS_DATA_8		0X0800
237 #define BITS_DATA_9		0X0900
238 
239 #define BITS_PARITY_MASK	0x00f0
240 #define BITS_PARITY_NONE	0x0000
241 #define BITS_PARITY_ODD		0x0010
242 #define BITS_PARITY_EVEN	0x0020
243 #define BITS_PARITY_MARK	0x0030
244 #define BITS_PARITY_SPACE	0x0040
245 
246 #define BITS_STOP_MASK		0x000f
247 #define BITS_STOP_1		0x0000
248 #define BITS_STOP_1_5		0x0001
249 #define BITS_STOP_2		0x0002
250 
251 /* CP210X_SET_BREAK */
252 #define BREAK_ON		0x0001
253 #define BREAK_OFF		0x0000
254 
255 /* CP210X_(SET_MHS|GET_MDMSTS) */
256 #define CONTROL_DTR		0x0001
257 #define CONTROL_RTS		0x0002
258 #define CONTROL_CTS		0x0010
259 #define CONTROL_DSR		0x0020
260 #define CONTROL_RING		0x0040
261 #define CONTROL_DCD		0x0080
262 #define CONTROL_WRITE_DTR	0x0100
263 #define CONTROL_WRITE_RTS	0x0200
264 
265 /*
266  * cp210x_get_config
267  * Reads from the CP210x configuration registers
268  * 'size' is specified in bytes.
269  * 'data' is a pointer to a pre-allocated array of integers large
270  * enough to hold 'size' bytes (with 4 bytes to each integer)
271  */
272 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
273 		unsigned int *data, int size)
274 {
275 	struct usb_serial *serial = port->serial;
276 	struct cp210x_serial_private *spriv = usb_get_serial_data(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 = kcalloc(length, sizeof(__le32), GFP_KERNEL);
284 	if (!buf) {
285 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
286 		return -ENOMEM;
287 	}
288 
289 	/* Issue the request, attempting to read 'size' bytes */
290 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
291 				request, REQTYPE_INTERFACE_TO_HOST, 0x0000,
292 				spriv->bInterfaceNumber, buf, size,
293 				USB_CTRL_GET_TIMEOUT);
294 
295 	/* Convert data into an array of integers */
296 	for (i = 0; i < length; i++)
297 		data[i] = le32_to_cpu(buf[i]);
298 
299 	kfree(buf);
300 
301 	if (result != size) {
302 		dev_dbg(&port->dev, "%s - Unable to send config request, request=0x%x size=%d result=%d\n",
303 			__func__, request, size, result);
304 		if (result > 0)
305 			result = -EPROTO;
306 
307 		return result;
308 	}
309 
310 	return 0;
311 }
312 
313 /*
314  * cp210x_set_config
315  * Writes to the CP210x configuration registers
316  * Values less than 16 bits wide are sent directly
317  * 'size' is specified in bytes.
318  */
319 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
320 		unsigned int *data, int size)
321 {
322 	struct usb_serial *serial = port->serial;
323 	struct cp210x_serial_private *spriv = usb_get_serial_data(serial);
324 	__le32 *buf;
325 	int result, i, length;
326 
327 	/* Number of integers required to contain the array */
328 	length = (((size - 1) | 3) + 1) / 4;
329 
330 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
331 	if (!buf) {
332 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
333 		return -ENOMEM;
334 	}
335 
336 	/* Array of integers into bytes */
337 	for (i = 0; i < length; i++)
338 		buf[i] = cpu_to_le32(data[i]);
339 
340 	if (size > 2) {
341 		result = usb_control_msg(serial->dev,
342 				usb_sndctrlpipe(serial->dev, 0),
343 				request, REQTYPE_HOST_TO_INTERFACE, 0x0000,
344 				spriv->bInterfaceNumber, buf, size,
345 				USB_CTRL_SET_TIMEOUT);
346 	} else {
347 		result = usb_control_msg(serial->dev,
348 				usb_sndctrlpipe(serial->dev, 0),
349 				request, REQTYPE_HOST_TO_INTERFACE, data[0],
350 				spriv->bInterfaceNumber, NULL, 0,
351 				USB_CTRL_SET_TIMEOUT);
352 	}
353 
354 	kfree(buf);
355 
356 	if ((size > 2 && result != size) || result < 0) {
357 		dev_dbg(&port->dev, "%s - Unable to send request, request=0x%x size=%d result=%d\n",
358 			__func__, request, size, result);
359 		if (result > 0)
360 			result = -EPROTO;
361 
362 		return result;
363 	}
364 
365 	return 0;
366 }
367 
368 /*
369  * cp210x_set_config_single
370  * Convenience function for calling cp210x_set_config on single data values
371  * without requiring an integer pointer
372  */
373 static inline int cp210x_set_config_single(struct usb_serial_port *port,
374 		u8 request, unsigned int data)
375 {
376 	return cp210x_set_config(port, request, &data, 2);
377 }
378 
379 /*
380  * cp210x_quantise_baudrate
381  * Quantises the baud rate as per AN205 Table 1
382  */
383 static unsigned int cp210x_quantise_baudrate(unsigned int baud)
384 {
385 	if (baud <= 300)
386 		baud = 300;
387 	else if (baud <= 600)      baud = 600;
388 	else if (baud <= 1200)     baud = 1200;
389 	else if (baud <= 1800)     baud = 1800;
390 	else if (baud <= 2400)     baud = 2400;
391 	else if (baud <= 4000)     baud = 4000;
392 	else if (baud <= 4803)     baud = 4800;
393 	else if (baud <= 7207)     baud = 7200;
394 	else if (baud <= 9612)     baud = 9600;
395 	else if (baud <= 14428)    baud = 14400;
396 	else if (baud <= 16062)    baud = 16000;
397 	else if (baud <= 19250)    baud = 19200;
398 	else if (baud <= 28912)    baud = 28800;
399 	else if (baud <= 38601)    baud = 38400;
400 	else if (baud <= 51558)    baud = 51200;
401 	else if (baud <= 56280)    baud = 56000;
402 	else if (baud <= 58053)    baud = 57600;
403 	else if (baud <= 64111)    baud = 64000;
404 	else if (baud <= 77608)    baud = 76800;
405 	else if (baud <= 117028)   baud = 115200;
406 	else if (baud <= 129347)   baud = 128000;
407 	else if (baud <= 156868)   baud = 153600;
408 	else if (baud <= 237832)   baud = 230400;
409 	else if (baud <= 254234)   baud = 250000;
410 	else if (baud <= 273066)   baud = 256000;
411 	else if (baud <= 491520)   baud = 460800;
412 	else if (baud <= 567138)   baud = 500000;
413 	else if (baud <= 670254)   baud = 576000;
414 	else if (baud < 1000000)
415 		baud = 921600;
416 	else if (baud > 2000000)
417 		baud = 2000000;
418 	return baud;
419 }
420 
421 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
422 {
423 	int result;
424 
425 	result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
426 								UART_ENABLE);
427 	if (result) {
428 		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
429 		return result;
430 	}
431 
432 	/* Configure the termios structure */
433 	cp210x_get_termios(tty, port);
434 
435 	/* The baud rate must be initialised on cp2104 */
436 	if (tty)
437 		cp210x_change_speed(tty, port, NULL);
438 
439 	return usb_serial_generic_open(tty, port);
440 }
441 
442 static void cp210x_close(struct usb_serial_port *port)
443 {
444 	usb_serial_generic_close(port);
445 
446 	mutex_lock(&port->serial->disc_mutex);
447 	if (!port->serial->disconnected)
448 		cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
449 	mutex_unlock(&port->serial->disc_mutex);
450 }
451 
452 /*
453  * cp210x_get_termios
454  * Reads the baud rate, data bits, parity, stop bits and flow control mode
455  * from the device, corrects any unsupported values, and configures the
456  * termios structure to reflect the state of the device
457  */
458 static void cp210x_get_termios(struct tty_struct *tty,
459 	struct usb_serial_port *port)
460 {
461 	unsigned int baud;
462 
463 	if (tty) {
464 		cp210x_get_termios_port(tty->driver_data,
465 			&tty->termios.c_cflag, &baud);
466 		tty_encode_baud_rate(tty, baud, baud);
467 	} else {
468 		unsigned int cflag;
469 		cflag = 0;
470 		cp210x_get_termios_port(port, &cflag, &baud);
471 	}
472 }
473 
474 /*
475  * cp210x_get_termios_port
476  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
477  */
478 static void cp210x_get_termios_port(struct usb_serial_port *port,
479 	unsigned int *cflagp, unsigned int *baudp)
480 {
481 	struct device *dev = &port->dev;
482 	unsigned int cflag, modem_ctl[4];
483 	unsigned int baud;
484 	unsigned int bits;
485 
486 	cp210x_get_config(port, CP210X_GET_BAUDRATE, &baud, 4);
487 
488 	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
489 	*baudp = baud;
490 
491 	cflag = *cflagp;
492 
493 	cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
494 	cflag &= ~CSIZE;
495 	switch (bits & BITS_DATA_MASK) {
496 	case BITS_DATA_5:
497 		dev_dbg(dev, "%s - data bits = 5\n", __func__);
498 		cflag |= CS5;
499 		break;
500 	case BITS_DATA_6:
501 		dev_dbg(dev, "%s - data bits = 6\n", __func__);
502 		cflag |= CS6;
503 		break;
504 	case BITS_DATA_7:
505 		dev_dbg(dev, "%s - data bits = 7\n", __func__);
506 		cflag |= CS7;
507 		break;
508 	case BITS_DATA_8:
509 		dev_dbg(dev, "%s - data bits = 8\n", __func__);
510 		cflag |= CS8;
511 		break;
512 	case BITS_DATA_9:
513 		dev_dbg(dev, "%s - data bits = 9 (not supported, using 8 data bits)\n", __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 	default:
520 		dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
521 		cflag |= CS8;
522 		bits &= ~BITS_DATA_MASK;
523 		bits |= BITS_DATA_8;
524 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
525 		break;
526 	}
527 
528 	switch (bits & BITS_PARITY_MASK) {
529 	case BITS_PARITY_NONE:
530 		dev_dbg(dev, "%s - parity = NONE\n", __func__);
531 		cflag &= ~PARENB;
532 		break;
533 	case BITS_PARITY_ODD:
534 		dev_dbg(dev, "%s - parity = ODD\n", __func__);
535 		cflag |= (PARENB|PARODD);
536 		break;
537 	case BITS_PARITY_EVEN:
538 		dev_dbg(dev, "%s - parity = EVEN\n", __func__);
539 		cflag &= ~PARODD;
540 		cflag |= PARENB;
541 		break;
542 	case BITS_PARITY_MARK:
543 		dev_dbg(dev, "%s - parity = MARK\n", __func__);
544 		cflag |= (PARENB|PARODD|CMSPAR);
545 		break;
546 	case BITS_PARITY_SPACE:
547 		dev_dbg(dev, "%s - parity = SPACE\n", __func__);
548 		cflag &= ~PARODD;
549 		cflag |= (PARENB|CMSPAR);
550 		break;
551 	default:
552 		dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
553 		cflag &= ~PARENB;
554 		bits &= ~BITS_PARITY_MASK;
555 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
556 		break;
557 	}
558 
559 	cflag &= ~CSTOPB;
560 	switch (bits & BITS_STOP_MASK) {
561 	case BITS_STOP_1:
562 		dev_dbg(dev, "%s - stop bits = 1\n", __func__);
563 		break;
564 	case BITS_STOP_1_5:
565 		dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
566 		bits &= ~BITS_STOP_MASK;
567 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
568 		break;
569 	case BITS_STOP_2:
570 		dev_dbg(dev, "%s - stop bits = 2\n", __func__);
571 		cflag |= CSTOPB;
572 		break;
573 	default:
574 		dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __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 		dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
583 		cflag |= CRTSCTS;
584 	} else {
585 		dev_dbg(dev, "%s - flow control = NONE\n", __func__);
586 		cflag &= ~CRTSCTS;
587 	}
588 
589 	*cflagp = cflag;
590 }
591 
592 /*
593  * CP2101 supports the following baud rates:
594  *
595  *	300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
596  *	38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
597  *
598  * CP2102 and CP2103 support the following additional rates:
599  *
600  *	4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
601  *	576000
602  *
603  * The device will map a requested rate to a supported one, but the result
604  * of requests for rates greater than 1053257 is undefined (see AN205).
605  *
606  * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
607  * respectively, with an error less than 1%. The actual rates are determined
608  * by
609  *
610  *	div = round(freq / (2 x prescale x request))
611  *	actual = freq / (2 x prescale x div)
612  *
613  * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
614  * or 1 otherwise.
615  * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
616  * otherwise.
617  */
618 static void cp210x_change_speed(struct tty_struct *tty,
619 		struct usb_serial_port *port, struct ktermios *old_termios)
620 {
621 	u32 baud;
622 
623 	baud = tty->termios.c_ospeed;
624 
625 	/* This maps the requested rate to a rate valid on cp2102 or cp2103,
626 	 * or to an arbitrary rate in [1M,2M].
627 	 *
628 	 * NOTE: B0 is not implemented.
629 	 */
630 	baud = cp210x_quantise_baudrate(baud);
631 
632 	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
633 	if (cp210x_set_config(port, CP210X_SET_BAUDRATE, &baud,
634 							sizeof(baud))) {
635 		dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
636 		if (old_termios)
637 			baud = old_termios->c_ospeed;
638 		else
639 			baud = 9600;
640 	}
641 
642 	tty_encode_baud_rate(tty, baud, baud);
643 }
644 
645 static void cp210x_set_termios(struct tty_struct *tty,
646 		struct usb_serial_port *port, struct ktermios *old_termios)
647 {
648 	struct device *dev = &port->dev;
649 	unsigned int cflag, old_cflag;
650 	unsigned int bits;
651 	unsigned int modem_ctl[4];
652 
653 	dev_dbg(dev, "%s - port %d\n", __func__, port->number);
654 
655 	if (!tty)
656 		return;
657 
658 	cflag = tty->termios.c_cflag;
659 	old_cflag = old_termios->c_cflag;
660 
661 	if (tty->termios.c_ospeed != old_termios->c_ospeed)
662 		cp210x_change_speed(tty, port, old_termios);
663 
664 	/* If the number of data bits is to be updated */
665 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
666 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
667 		bits &= ~BITS_DATA_MASK;
668 		switch (cflag & CSIZE) {
669 		case CS5:
670 			bits |= BITS_DATA_5;
671 			dev_dbg(dev, "%s - data bits = 5\n", __func__);
672 			break;
673 		case CS6:
674 			bits |= BITS_DATA_6;
675 			dev_dbg(dev, "%s - data bits = 6\n", __func__);
676 			break;
677 		case CS7:
678 			bits |= BITS_DATA_7;
679 			dev_dbg(dev, "%s - data bits = 7\n", __func__);
680 			break;
681 		case CS8:
682 			bits |= BITS_DATA_8;
683 			dev_dbg(dev, "%s - data bits = 8\n", __func__);
684 			break;
685 		/*case CS9:
686 			bits |= BITS_DATA_9;
687 			dev_dbg(dev, "%s - data bits = 9\n", __func__);
688 			break;*/
689 		default:
690 			dev_dbg(dev, "cp210x driver does not support the number of bits requested, using 8 bit mode\n");
691 			bits |= BITS_DATA_8;
692 			break;
693 		}
694 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
695 			dev_dbg(dev, "Number of data bits requested not supported by device\n");
696 	}
697 
698 	if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
699 	    (old_cflag & (PARENB|PARODD|CMSPAR))) {
700 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
701 		bits &= ~BITS_PARITY_MASK;
702 		if (cflag & PARENB) {
703 			if (cflag & CMSPAR) {
704 				if (cflag & PARODD) {
705 					bits |= BITS_PARITY_MARK;
706 					dev_dbg(dev, "%s - parity = MARK\n", __func__);
707 				} else {
708 					bits |= BITS_PARITY_SPACE;
709 					dev_dbg(dev, "%s - parity = SPACE\n", __func__);
710 				}
711 			} else {
712 				if (cflag & PARODD) {
713 					bits |= BITS_PARITY_ODD;
714 					dev_dbg(dev, "%s - parity = ODD\n", __func__);
715 				} else {
716 					bits |= BITS_PARITY_EVEN;
717 					dev_dbg(dev, "%s - parity = EVEN\n", __func__);
718 				}
719 			}
720 		}
721 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
722 			dev_dbg(dev, "Parity mode not supported by device\n");
723 	}
724 
725 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
726 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
727 		bits &= ~BITS_STOP_MASK;
728 		if (cflag & CSTOPB) {
729 			bits |= BITS_STOP_2;
730 			dev_dbg(dev, "%s - stop bits = 2\n", __func__);
731 		} else {
732 			bits |= BITS_STOP_1;
733 			dev_dbg(dev, "%s - stop bits = 1\n", __func__);
734 		}
735 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
736 			dev_dbg(dev, "Number of stop bits requested not supported by device\n");
737 	}
738 
739 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
740 		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
741 		dev_dbg(dev, "%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
742 			__func__, modem_ctl[0], modem_ctl[1],
743 			modem_ctl[2], modem_ctl[3]);
744 
745 		if (cflag & CRTSCTS) {
746 			modem_ctl[0] &= ~0x7B;
747 			modem_ctl[0] |= 0x09;
748 			modem_ctl[1] = 0x80;
749 			dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
750 		} else {
751 			modem_ctl[0] &= ~0x7B;
752 			modem_ctl[0] |= 0x01;
753 			modem_ctl[1] |= 0x40;
754 			dev_dbg(dev, "%s - flow control = NONE\n", __func__);
755 		}
756 
757 		dev_dbg(dev, "%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
758 			__func__, modem_ctl[0], modem_ctl[1],
759 			modem_ctl[2], modem_ctl[3]);
760 		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
761 	}
762 
763 }
764 
765 static int cp210x_tiocmset(struct tty_struct *tty,
766 		unsigned int set, unsigned int clear)
767 {
768 	struct usb_serial_port *port = tty->driver_data;
769 	return cp210x_tiocmset_port(port, set, clear);
770 }
771 
772 static int cp210x_tiocmset_port(struct usb_serial_port *port,
773 		unsigned int set, unsigned int clear)
774 {
775 	unsigned int control = 0;
776 
777 	if (set & TIOCM_RTS) {
778 		control |= CONTROL_RTS;
779 		control |= CONTROL_WRITE_RTS;
780 	}
781 	if (set & TIOCM_DTR) {
782 		control |= CONTROL_DTR;
783 		control |= CONTROL_WRITE_DTR;
784 	}
785 	if (clear & TIOCM_RTS) {
786 		control &= ~CONTROL_RTS;
787 		control |= CONTROL_WRITE_RTS;
788 	}
789 	if (clear & TIOCM_DTR) {
790 		control &= ~CONTROL_DTR;
791 		control |= CONTROL_WRITE_DTR;
792 	}
793 
794 	dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
795 
796 	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
797 }
798 
799 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
800 {
801 	if (on)
802 		cp210x_tiocmset_port(p, TIOCM_DTR|TIOCM_RTS, 0);
803 	else
804 		cp210x_tiocmset_port(p, 0, TIOCM_DTR|TIOCM_RTS);
805 }
806 
807 static int cp210x_tiocmget(struct tty_struct *tty)
808 {
809 	struct usb_serial_port *port = tty->driver_data;
810 	unsigned int control;
811 	int result;
812 
813 	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
814 
815 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
816 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
817 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
818 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
819 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
820 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
821 
822 	dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);
823 
824 	return result;
825 }
826 
827 static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
828 {
829 	struct usb_serial_port *port = tty->driver_data;
830 	unsigned int state;
831 
832 	if (break_state == 0)
833 		state = BREAK_OFF;
834 	else
835 		state = BREAK_ON;
836 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
837 		state == BREAK_OFF ? "off" : "on");
838 	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
839 }
840 
841 static int cp210x_startup(struct usb_serial *serial)
842 {
843 	struct usb_host_interface *cur_altsetting;
844 	struct cp210x_serial_private *spriv;
845 
846 	/* cp210x buffers behave strangely unless device is reset */
847 	usb_reset_device(serial->dev);
848 
849 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
850 	if (!spriv)
851 		return -ENOMEM;
852 
853 	cur_altsetting = serial->interface->cur_altsetting;
854 	spriv->bInterfaceNumber = cur_altsetting->desc.bInterfaceNumber;
855 
856 	usb_set_serial_data(serial, spriv);
857 
858 	return 0;
859 }
860 
861 static void cp210x_release(struct usb_serial *serial)
862 {
863 	struct cp210x_serial_private *spriv;
864 
865 	spriv = usb_get_serial_data(serial);
866 	kfree(spriv);
867 }
868 
869 module_usb_serial_driver(serial_drivers, id_table);
870 
871 MODULE_DESCRIPTION(DRIVER_DESC);
872 MODULE_LICENSE("GPL");
873