xref: /linux/drivers/usb/serial/cp210x.c (revision 3a2f2ac9b96f9a9f5538396a212d3b9fb543bfc5)
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 bool cp210x_tx_empty(struct usb_serial_port *port);
42 static int cp210x_tiocmget(struct tty_struct *);
43 static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
44 static int cp210x_tiocmset_port(struct usb_serial_port *port,
45 		unsigned int, unsigned int);
46 static void cp210x_break_ctl(struct tty_struct *, int);
47 static int cp210x_port_probe(struct usb_serial_port *);
48 static int cp210x_port_remove(struct usb_serial_port *);
49 static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
50 
51 static const struct usb_device_id id_table[] = {
52 	{ USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
53 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
54 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
55 	{ USB_DEVICE(0x0489, 0xE003) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
56 	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
57 	{ USB_DEVICE(0x0846, 0x1100) }, /* NetGear Managed Switch M4100 series, M5300 series, M7100 series */
58 	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
59 	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
60 	{ USB_DEVICE(0x0908, 0x01FF) }, /* Siemens RUGGEDCOM USB Serial Console */
61 	{ USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
62 	{ USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
63 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
64 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
65 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
66 	{ USB_DEVICE(0x0FDE, 0xCA05) }, /* OWL Wireless Electricity Monitor CM-160 */
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, 0x8044) }, /* Cygnal Debug Adapter */
76 	{ USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
77 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
78 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
79 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
80 	{ USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
81 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
82 	{ USB_DEVICE(0x10C4, 0x80C4) }, /* Cygnal Integrated Products, Inc., Optris infrared thermometer */
83 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
84 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
85 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
86 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
87 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
88 	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
89 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
90 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
91 	{ USB_DEVICE(0x2405, 0x0003) }, /* West Mountain Radio RIGblaster Advantage */
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, 0x81D7) }, /* IAI Corp. RCB-CV-USB USB to RS485 Adaptor */
103 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
104 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
105 	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
106 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
107 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
108 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
109 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
110 	{ USB_DEVICE(0x10C4, 0x8281) }, /* Nanotec Plug & Drive */
111 	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
112 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
113 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
114 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
115 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
116 	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
117 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
118 	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
119 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
120 	{ USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
121 	{ USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
122 	{ USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
123 	{ USB_DEVICE(0x10C4, 0x85F8) }, /* Virtenio Preon32 */
124 	{ USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
125 	{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
126 	{ USB_DEVICE(0x10C4, 0x8856) },	/* CEL EM357 ZigBee USB Stick - LR */
127 	{ USB_DEVICE(0x10C4, 0x8857) },	/* CEL EM357 ZigBee USB Stick */
128 	{ USB_DEVICE(0x10C4, 0x88A4) }, /* MMB Networks ZigBee USB Device */
129 	{ USB_DEVICE(0x10C4, 0x88A5) }, /* Planet Innovation Ingeni ZigBee USB Device */
130 	{ USB_DEVICE(0x10C4, 0x8946) }, /* Ketra N1 Wireless Interface */
131 	{ USB_DEVICE(0x10C4, 0x8977) },	/* CEL MeshWorks DevKit Device */
132 	{ USB_DEVICE(0x10C4, 0x8998) }, /* KCF Technologies PRN */
133 	{ USB_DEVICE(0x10C4, 0x8A2A) }, /* HubZ dual ZigBee and Z-Wave dongle */
134 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
135 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
136 	{ USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
137 	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
138 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
139 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
140 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
141 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
142 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
143 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
144 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
145 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
146 	{ USB_DEVICE(0x166A, 0x0201) }, /* Clipsal 5500PACA C-Bus Pascal Automation Controller */
147 	{ USB_DEVICE(0x166A, 0x0301) }, /* Clipsal 5800PC C-Bus Wireless PC Interface */
148 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
149 	{ USB_DEVICE(0x166A, 0x0304) }, /* Clipsal 5000CT2 C-Bus Black and White Touchscreen */
150 	{ USB_DEVICE(0x166A, 0x0305) }, /* Clipsal C-5000CT2 C-Bus Spectrum Colour Touchscreen */
151 	{ USB_DEVICE(0x166A, 0x0401) }, /* Clipsal L51xx C-Bus Architectural Dimmer */
152 	{ USB_DEVICE(0x166A, 0x0101) }, /* Clipsal 5560884 C-Bus Multi-room Audio Matrix Switcher */
153 	{ USB_DEVICE(0x16C0, 0x09B0) }, /* Lunatico Seletek */
154 	{ USB_DEVICE(0x16C0, 0x09B1) }, /* Lunatico Seletek */
155 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
156 	{ USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
157 	{ USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
158 	{ USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
159 	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
160 	{ USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
161 	{ USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
162 	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
163 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
164 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
165 	{ USB_DEVICE(0x18EF, 0xE025) }, /* ELV Marble Sound Board 1 */
166 	{ USB_DEVICE(0x1ADB, 0x0001) }, /* Schweitzer Engineering C662 Cable */
167 	{ USB_DEVICE(0x1B1C, 0x1C00) }, /* Corsair USB Dongle */
168 	{ USB_DEVICE(0x1BA4, 0x0002) },	/* Silicon Labs 358x factory default */
169 	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
170 	{ USB_DEVICE(0x1D6F, 0x0010) }, /* Seluxit ApS RF Dongle */
171 	{ USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
172 	{ USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
173 	{ USB_DEVICE(0x1FB9, 0x0100) }, /* Lake Shore Model 121 Current Source */
174 	{ USB_DEVICE(0x1FB9, 0x0200) }, /* Lake Shore Model 218A Temperature Monitor */
175 	{ USB_DEVICE(0x1FB9, 0x0201) }, /* Lake Shore Model 219 Temperature Monitor */
176 	{ USB_DEVICE(0x1FB9, 0x0202) }, /* Lake Shore Model 233 Temperature Transmitter */
177 	{ USB_DEVICE(0x1FB9, 0x0203) }, /* Lake Shore Model 235 Temperature Transmitter */
178 	{ USB_DEVICE(0x1FB9, 0x0300) }, /* Lake Shore Model 335 Temperature Controller */
179 	{ USB_DEVICE(0x1FB9, 0x0301) }, /* Lake Shore Model 336 Temperature Controller */
180 	{ USB_DEVICE(0x1FB9, 0x0302) }, /* Lake Shore Model 350 Temperature Controller */
181 	{ USB_DEVICE(0x1FB9, 0x0303) }, /* Lake Shore Model 371 AC Bridge */
182 	{ USB_DEVICE(0x1FB9, 0x0400) }, /* Lake Shore Model 411 Handheld Gaussmeter */
183 	{ USB_DEVICE(0x1FB9, 0x0401) }, /* Lake Shore Model 425 Gaussmeter */
184 	{ USB_DEVICE(0x1FB9, 0x0402) }, /* Lake Shore Model 455A Gaussmeter */
185 	{ USB_DEVICE(0x1FB9, 0x0403) }, /* Lake Shore Model 475A Gaussmeter */
186 	{ USB_DEVICE(0x1FB9, 0x0404) }, /* Lake Shore Model 465 Three Axis Gaussmeter */
187 	{ USB_DEVICE(0x1FB9, 0x0600) }, /* Lake Shore Model 625A Superconducting MPS */
188 	{ USB_DEVICE(0x1FB9, 0x0601) }, /* Lake Shore Model 642A Magnet Power Supply */
189 	{ USB_DEVICE(0x1FB9, 0x0602) }, /* Lake Shore Model 648 Magnet Power Supply */
190 	{ USB_DEVICE(0x1FB9, 0x0700) }, /* Lake Shore Model 737 VSM Controller */
191 	{ USB_DEVICE(0x1FB9, 0x0701) }, /* Lake Shore Model 776 Hall Matrix */
192 	{ USB_DEVICE(0x2626, 0xEA60) }, /* Aruba Networks 7xxx USB Serial Console */
193 	{ USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
194 	{ USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
195 	{ USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
196 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
197 	{ } /* Terminating Entry */
198 };
199 
200 MODULE_DEVICE_TABLE(usb, id_table);
201 
202 struct cp210x_port_private {
203 	__u8			bInterfaceNumber;
204 	bool			has_swapped_line_ctl;
205 };
206 
207 static struct usb_serial_driver cp210x_device = {
208 	.driver = {
209 		.owner =	THIS_MODULE,
210 		.name =		"cp210x",
211 	},
212 	.id_table		= id_table,
213 	.num_ports		= 1,
214 	.bulk_in_size		= 256,
215 	.bulk_out_size		= 256,
216 	.open			= cp210x_open,
217 	.close			= cp210x_close,
218 	.break_ctl		= cp210x_break_ctl,
219 	.set_termios		= cp210x_set_termios,
220 	.tx_empty		= cp210x_tx_empty,
221 	.tiocmget		= cp210x_tiocmget,
222 	.tiocmset		= cp210x_tiocmset,
223 	.port_probe		= cp210x_port_probe,
224 	.port_remove		= cp210x_port_remove,
225 	.dtr_rts		= cp210x_dtr_rts
226 };
227 
228 static struct usb_serial_driver * const serial_drivers[] = {
229 	&cp210x_device, NULL
230 };
231 
232 /* Config request types */
233 #define REQTYPE_HOST_TO_INTERFACE	0x41
234 #define REQTYPE_INTERFACE_TO_HOST	0xc1
235 #define REQTYPE_HOST_TO_DEVICE	0x40
236 #define REQTYPE_DEVICE_TO_HOST	0xc0
237 
238 /* Config request codes */
239 #define CP210X_IFC_ENABLE	0x00
240 #define CP210X_SET_BAUDDIV	0x01
241 #define CP210X_GET_BAUDDIV	0x02
242 #define CP210X_SET_LINE_CTL	0x03
243 #define CP210X_GET_LINE_CTL	0x04
244 #define CP210X_SET_BREAK	0x05
245 #define CP210X_IMM_CHAR		0x06
246 #define CP210X_SET_MHS		0x07
247 #define CP210X_GET_MDMSTS	0x08
248 #define CP210X_SET_XON		0x09
249 #define CP210X_SET_XOFF		0x0A
250 #define CP210X_SET_EVENTMASK	0x0B
251 #define CP210X_GET_EVENTMASK	0x0C
252 #define CP210X_SET_CHAR		0x0D
253 #define CP210X_GET_CHARS	0x0E
254 #define CP210X_GET_PROPS	0x0F
255 #define CP210X_GET_COMM_STATUS	0x10
256 #define CP210X_RESET		0x11
257 #define CP210X_PURGE		0x12
258 #define CP210X_SET_FLOW		0x13
259 #define CP210X_GET_FLOW		0x14
260 #define CP210X_EMBED_EVENTS	0x15
261 #define CP210X_GET_EVENTSTATE	0x16
262 #define CP210X_SET_CHARS	0x19
263 #define CP210X_GET_BAUDRATE	0x1D
264 #define CP210X_SET_BAUDRATE	0x1E
265 
266 /* CP210X_IFC_ENABLE */
267 #define UART_ENABLE		0x0001
268 #define UART_DISABLE		0x0000
269 
270 /* CP210X_(SET|GET)_BAUDDIV */
271 #define BAUD_RATE_GEN_FREQ	0x384000
272 
273 /* CP210X_(SET|GET)_LINE_CTL */
274 #define BITS_DATA_MASK		0X0f00
275 #define BITS_DATA_5		0X0500
276 #define BITS_DATA_6		0X0600
277 #define BITS_DATA_7		0X0700
278 #define BITS_DATA_8		0X0800
279 #define BITS_DATA_9		0X0900
280 
281 #define BITS_PARITY_MASK	0x00f0
282 #define BITS_PARITY_NONE	0x0000
283 #define BITS_PARITY_ODD		0x0010
284 #define BITS_PARITY_EVEN	0x0020
285 #define BITS_PARITY_MARK	0x0030
286 #define BITS_PARITY_SPACE	0x0040
287 
288 #define BITS_STOP_MASK		0x000f
289 #define BITS_STOP_1		0x0000
290 #define BITS_STOP_1_5		0x0001
291 #define BITS_STOP_2		0x0002
292 
293 /* CP210X_SET_BREAK */
294 #define BREAK_ON		0x0001
295 #define BREAK_OFF		0x0000
296 
297 /* CP210X_(SET_MHS|GET_MDMSTS) */
298 #define CONTROL_DTR		0x0001
299 #define CONTROL_RTS		0x0002
300 #define CONTROL_CTS		0x0010
301 #define CONTROL_DSR		0x0020
302 #define CONTROL_RING		0x0040
303 #define CONTROL_DCD		0x0080
304 #define CONTROL_WRITE_DTR	0x0100
305 #define CONTROL_WRITE_RTS	0x0200
306 
307 /* CP210X_GET_COMM_STATUS returns these 0x13 bytes */
308 struct cp210x_comm_status {
309 	__le32   ulErrors;
310 	__le32   ulHoldReasons;
311 	__le32   ulAmountInInQueue;
312 	__le32   ulAmountInOutQueue;
313 	u8       bEofReceived;
314 	u8       bWaitForImmediate;
315 	u8       bReserved;
316 } __packed;
317 
318 /*
319  * CP210X_PURGE - 16 bits passed in wValue of USB request.
320  * SiLabs app note AN571 gives a strange description of the 4 bits:
321  * bit 0 or bit 2 clears the transmit queue and 1 or 3 receive.
322  * writing 1 to all, however, purges cp2108 well enough to avoid the hang.
323  */
324 #define PURGE_ALL		0x000f
325 
326 /*
327  * cp210x_get_config
328  * Reads from the CP210x configuration registers
329  * 'size' is specified in bytes.
330  * 'data' is a pointer to a pre-allocated array of integers large
331  * enough to hold 'size' bytes (with 4 bytes to each integer)
332  */
333 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
334 		unsigned int *data, int size)
335 {
336 	struct usb_serial *serial = port->serial;
337 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
338 	__le32 *buf;
339 	int result, i, length;
340 
341 	/* Number of integers required to contain the array */
342 	length = (((size - 1) | 3) + 1) / 4;
343 
344 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
345 	if (!buf)
346 		return -ENOMEM;
347 
348 	/* Issue the request, attempting to read 'size' bytes */
349 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
350 				request, REQTYPE_INTERFACE_TO_HOST, 0x0000,
351 				port_priv->bInterfaceNumber, buf, size,
352 				USB_CTRL_GET_TIMEOUT);
353 
354 	/* Convert data into an array of integers */
355 	for (i = 0; i < length; i++)
356 		data[i] = le32_to_cpu(buf[i]);
357 
358 	kfree(buf);
359 
360 	if (result != size) {
361 		dev_dbg(&port->dev, "%s - Unable to send config 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
374  * Writes to the CP210x configuration registers
375  * Values less than 16 bits wide are sent directly
376  * 'size' is specified in bytes.
377  */
378 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
379 		unsigned int *data, int size)
380 {
381 	struct usb_serial *serial = port->serial;
382 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
383 	__le32 *buf;
384 	int result, i, length;
385 
386 	/* Number of integers required to contain the array */
387 	length = (((size - 1) | 3) + 1) / 4;
388 
389 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
390 	if (!buf)
391 		return -ENOMEM;
392 
393 	/* Array of integers into bytes */
394 	for (i = 0; i < length; i++)
395 		buf[i] = cpu_to_le32(data[i]);
396 
397 	if (size > 2) {
398 		result = usb_control_msg(serial->dev,
399 				usb_sndctrlpipe(serial->dev, 0),
400 				request, REQTYPE_HOST_TO_INTERFACE, 0x0000,
401 				port_priv->bInterfaceNumber, buf, size,
402 				USB_CTRL_SET_TIMEOUT);
403 	} else {
404 		result = usb_control_msg(serial->dev,
405 				usb_sndctrlpipe(serial->dev, 0),
406 				request, REQTYPE_HOST_TO_INTERFACE, data[0],
407 				port_priv->bInterfaceNumber, NULL, 0,
408 				USB_CTRL_SET_TIMEOUT);
409 	}
410 
411 	kfree(buf);
412 
413 	if ((size > 2 && result != size) || result < 0) {
414 		dev_dbg(&port->dev, "%s - Unable to send request, request=0x%x size=%d result=%d\n",
415 			__func__, request, size, result);
416 		if (result > 0)
417 			result = -EPROTO;
418 
419 		return result;
420 	}
421 
422 	return 0;
423 }
424 
425 /*
426  * cp210x_set_config_single
427  * Convenience function for calling cp210x_set_config on single data values
428  * without requiring an integer pointer
429  */
430 static inline int cp210x_set_config_single(struct usb_serial_port *port,
431 		u8 request, unsigned int data)
432 {
433 	return cp210x_set_config(port, request, &data, 2);
434 }
435 
436 /*
437  * Detect CP2108 GET_LINE_CTL bug and activate workaround.
438  * Write a known good value 0x800, read it back.
439  * If it comes back swapped the bug is detected.
440  * Preserve the original register value.
441  */
442 static int cp210x_detect_swapped_line_ctl(struct usb_serial_port *port)
443 {
444 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
445 	unsigned int line_ctl_save;
446 	unsigned int line_ctl_test;
447 	int err;
448 
449 	err = cp210x_get_config(port, CP210X_GET_LINE_CTL, &line_ctl_save, 2);
450 	if (err)
451 		return err;
452 
453 	line_ctl_test = 0x800;
454 	err = cp210x_set_config(port, CP210X_SET_LINE_CTL, &line_ctl_test, 2);
455 	if (err)
456 		return err;
457 
458 	err = cp210x_get_config(port, CP210X_GET_LINE_CTL, &line_ctl_test, 2);
459 	if (err)
460 		return err;
461 
462 	if (line_ctl_test == 8) {
463 		port_priv->has_swapped_line_ctl = true;
464 		line_ctl_save = swab16((u16)line_ctl_save);
465 	}
466 
467 	return cp210x_set_config(port, CP210X_SET_LINE_CTL, &line_ctl_save, 2);
468 }
469 
470 /*
471  * Must always be called instead of cp210x_get_config(CP210X_GET_LINE_CTL)
472  * to workaround cp2108 bug and get correct value.
473  */
474 static int cp210x_get_line_ctl(struct usb_serial_port *port, unsigned int *ctl)
475 {
476 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
477 	int err;
478 
479 	err = cp210x_get_config(port, CP210X_GET_LINE_CTL, ctl, 2);
480 	if (err)
481 		return err;
482 
483 	/* Workaround swapped bytes in 16-bit value from CP210X_GET_LINE_CTL */
484 	if (port_priv->has_swapped_line_ctl)
485 		*ctl = swab16((u16)(*ctl));
486 
487 	return 0;
488 }
489 
490 /*
491  * cp210x_quantise_baudrate
492  * Quantises the baud rate as per AN205 Table 1
493  */
494 static unsigned int cp210x_quantise_baudrate(unsigned int baud)
495 {
496 	if (baud <= 300)
497 		baud = 300;
498 	else if (baud <= 600)      baud = 600;
499 	else if (baud <= 1200)     baud = 1200;
500 	else if (baud <= 1800)     baud = 1800;
501 	else if (baud <= 2400)     baud = 2400;
502 	else if (baud <= 4000)     baud = 4000;
503 	else if (baud <= 4803)     baud = 4800;
504 	else if (baud <= 7207)     baud = 7200;
505 	else if (baud <= 9612)     baud = 9600;
506 	else if (baud <= 14428)    baud = 14400;
507 	else if (baud <= 16062)    baud = 16000;
508 	else if (baud <= 19250)    baud = 19200;
509 	else if (baud <= 28912)    baud = 28800;
510 	else if (baud <= 38601)    baud = 38400;
511 	else if (baud <= 51558)    baud = 51200;
512 	else if (baud <= 56280)    baud = 56000;
513 	else if (baud <= 58053)    baud = 57600;
514 	else if (baud <= 64111)    baud = 64000;
515 	else if (baud <= 77608)    baud = 76800;
516 	else if (baud <= 117028)   baud = 115200;
517 	else if (baud <= 129347)   baud = 128000;
518 	else if (baud <= 156868)   baud = 153600;
519 	else if (baud <= 237832)   baud = 230400;
520 	else if (baud <= 254234)   baud = 250000;
521 	else if (baud <= 273066)   baud = 256000;
522 	else if (baud <= 491520)   baud = 460800;
523 	else if (baud <= 567138)   baud = 500000;
524 	else if (baud <= 670254)   baud = 576000;
525 	else if (baud < 1000000)
526 		baud = 921600;
527 	else if (baud > 2000000)
528 		baud = 2000000;
529 	return baud;
530 }
531 
532 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
533 {
534 	int result;
535 
536 	result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
537 								UART_ENABLE);
538 	if (result) {
539 		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
540 		return result;
541 	}
542 
543 	/* Configure the termios structure */
544 	cp210x_get_termios(tty, port);
545 
546 	/* The baud rate must be initialised on cp2104 */
547 	if (tty)
548 		cp210x_change_speed(tty, port, NULL);
549 
550 	return usb_serial_generic_open(tty, port);
551 }
552 
553 static void cp210x_close(struct usb_serial_port *port)
554 {
555 	unsigned int purge_ctl;
556 
557 	usb_serial_generic_close(port);
558 
559 	/* Clear both queues; cp2108 needs this to avoid an occasional hang */
560 	purge_ctl = PURGE_ALL;
561 	cp210x_set_config(port, CP210X_PURGE, &purge_ctl, 2);
562 
563 	cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
564 }
565 
566 /*
567  * Read how many bytes are waiting in the TX queue.
568  */
569 static int cp210x_get_tx_queue_byte_count(struct usb_serial_port *port,
570 		u32 *count)
571 {
572 	struct usb_serial *serial = port->serial;
573 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
574 	struct cp210x_comm_status *sts;
575 	int result;
576 
577 	sts = kmalloc(sizeof(*sts), GFP_KERNEL);
578 	if (!sts)
579 		return -ENOMEM;
580 
581 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
582 			CP210X_GET_COMM_STATUS, REQTYPE_INTERFACE_TO_HOST,
583 			0, port_priv->bInterfaceNumber, sts, sizeof(*sts),
584 			USB_CTRL_GET_TIMEOUT);
585 	if (result == sizeof(*sts)) {
586 		*count = le32_to_cpu(sts->ulAmountInOutQueue);
587 		result = 0;
588 	} else {
589 		dev_err(&port->dev, "failed to get comm status: %d\n", result);
590 		if (result >= 0)
591 			result = -EPROTO;
592 	}
593 
594 	kfree(sts);
595 
596 	return result;
597 }
598 
599 static bool cp210x_tx_empty(struct usb_serial_port *port)
600 {
601 	int err;
602 	u32 count;
603 
604 	err = cp210x_get_tx_queue_byte_count(port, &count);
605 	if (err)
606 		return true;
607 
608 	return !count;
609 }
610 
611 /*
612  * cp210x_get_termios
613  * Reads the baud rate, data bits, parity, stop bits and flow control mode
614  * from the device, corrects any unsupported values, and configures the
615  * termios structure to reflect the state of the device
616  */
617 static void cp210x_get_termios(struct tty_struct *tty,
618 	struct usb_serial_port *port)
619 {
620 	unsigned int baud;
621 
622 	if (tty) {
623 		cp210x_get_termios_port(tty->driver_data,
624 			&tty->termios.c_cflag, &baud);
625 		tty_encode_baud_rate(tty, baud, baud);
626 	} else {
627 		unsigned int cflag;
628 		cflag = 0;
629 		cp210x_get_termios_port(port, &cflag, &baud);
630 	}
631 }
632 
633 /*
634  * cp210x_get_termios_port
635  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
636  */
637 static void cp210x_get_termios_port(struct usb_serial_port *port,
638 	unsigned int *cflagp, unsigned int *baudp)
639 {
640 	struct device *dev = &port->dev;
641 	unsigned int cflag, modem_ctl[4];
642 	unsigned int baud;
643 	unsigned int bits;
644 
645 	cp210x_get_config(port, CP210X_GET_BAUDRATE, &baud, 4);
646 
647 	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
648 	*baudp = baud;
649 
650 	cflag = *cflagp;
651 
652 	cp210x_get_line_ctl(port, &bits);
653 	cflag &= ~CSIZE;
654 	switch (bits & BITS_DATA_MASK) {
655 	case BITS_DATA_5:
656 		dev_dbg(dev, "%s - data bits = 5\n", __func__);
657 		cflag |= CS5;
658 		break;
659 	case BITS_DATA_6:
660 		dev_dbg(dev, "%s - data bits = 6\n", __func__);
661 		cflag |= CS6;
662 		break;
663 	case BITS_DATA_7:
664 		dev_dbg(dev, "%s - data bits = 7\n", __func__);
665 		cflag |= CS7;
666 		break;
667 	case BITS_DATA_8:
668 		dev_dbg(dev, "%s - data bits = 8\n", __func__);
669 		cflag |= CS8;
670 		break;
671 	case BITS_DATA_9:
672 		dev_dbg(dev, "%s - data bits = 9 (not supported, using 8 data bits)\n", __func__);
673 		cflag |= CS8;
674 		bits &= ~BITS_DATA_MASK;
675 		bits |= BITS_DATA_8;
676 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
677 		break;
678 	default:
679 		dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
680 		cflag |= CS8;
681 		bits &= ~BITS_DATA_MASK;
682 		bits |= BITS_DATA_8;
683 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
684 		break;
685 	}
686 
687 	switch (bits & BITS_PARITY_MASK) {
688 	case BITS_PARITY_NONE:
689 		dev_dbg(dev, "%s - parity = NONE\n", __func__);
690 		cflag &= ~PARENB;
691 		break;
692 	case BITS_PARITY_ODD:
693 		dev_dbg(dev, "%s - parity = ODD\n", __func__);
694 		cflag |= (PARENB|PARODD);
695 		break;
696 	case BITS_PARITY_EVEN:
697 		dev_dbg(dev, "%s - parity = EVEN\n", __func__);
698 		cflag &= ~PARODD;
699 		cflag |= PARENB;
700 		break;
701 	case BITS_PARITY_MARK:
702 		dev_dbg(dev, "%s - parity = MARK\n", __func__);
703 		cflag |= (PARENB|PARODD|CMSPAR);
704 		break;
705 	case BITS_PARITY_SPACE:
706 		dev_dbg(dev, "%s - parity = SPACE\n", __func__);
707 		cflag &= ~PARODD;
708 		cflag |= (PARENB|CMSPAR);
709 		break;
710 	default:
711 		dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
712 		cflag &= ~PARENB;
713 		bits &= ~BITS_PARITY_MASK;
714 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
715 		break;
716 	}
717 
718 	cflag &= ~CSTOPB;
719 	switch (bits & BITS_STOP_MASK) {
720 	case BITS_STOP_1:
721 		dev_dbg(dev, "%s - stop bits = 1\n", __func__);
722 		break;
723 	case BITS_STOP_1_5:
724 		dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
725 		bits &= ~BITS_STOP_MASK;
726 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
727 		break;
728 	case BITS_STOP_2:
729 		dev_dbg(dev, "%s - stop bits = 2\n", __func__);
730 		cflag |= CSTOPB;
731 		break;
732 	default:
733 		dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __func__);
734 		bits &= ~BITS_STOP_MASK;
735 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
736 		break;
737 	}
738 
739 	cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
740 	if (modem_ctl[0] & 0x0008) {
741 		dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
742 		cflag |= CRTSCTS;
743 	} else {
744 		dev_dbg(dev, "%s - flow control = NONE\n", __func__);
745 		cflag &= ~CRTSCTS;
746 	}
747 
748 	*cflagp = cflag;
749 }
750 
751 /*
752  * CP2101 supports the following baud rates:
753  *
754  *	300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
755  *	38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
756  *
757  * CP2102 and CP2103 support the following additional rates:
758  *
759  *	4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
760  *	576000
761  *
762  * The device will map a requested rate to a supported one, but the result
763  * of requests for rates greater than 1053257 is undefined (see AN205).
764  *
765  * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
766  * respectively, with an error less than 1%. The actual rates are determined
767  * by
768  *
769  *	div = round(freq / (2 x prescale x request))
770  *	actual = freq / (2 x prescale x div)
771  *
772  * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
773  * or 1 otherwise.
774  * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
775  * otherwise.
776  */
777 static void cp210x_change_speed(struct tty_struct *tty,
778 		struct usb_serial_port *port, struct ktermios *old_termios)
779 {
780 	u32 baud;
781 
782 	baud = tty->termios.c_ospeed;
783 
784 	/* This maps the requested rate to a rate valid on cp2102 or cp2103,
785 	 * or to an arbitrary rate in [1M,2M].
786 	 *
787 	 * NOTE: B0 is not implemented.
788 	 */
789 	baud = cp210x_quantise_baudrate(baud);
790 
791 	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
792 	if (cp210x_set_config(port, CP210X_SET_BAUDRATE, &baud,
793 							sizeof(baud))) {
794 		dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
795 		if (old_termios)
796 			baud = old_termios->c_ospeed;
797 		else
798 			baud = 9600;
799 	}
800 
801 	tty_encode_baud_rate(tty, baud, baud);
802 }
803 
804 static void cp210x_set_termios(struct tty_struct *tty,
805 		struct usb_serial_port *port, struct ktermios *old_termios)
806 {
807 	struct device *dev = &port->dev;
808 	unsigned int cflag, old_cflag;
809 	unsigned int bits;
810 	unsigned int modem_ctl[4];
811 
812 	cflag = tty->termios.c_cflag;
813 	old_cflag = old_termios->c_cflag;
814 
815 	if (tty->termios.c_ospeed != old_termios->c_ospeed)
816 		cp210x_change_speed(tty, port, old_termios);
817 
818 	/* If the number of data bits is to be updated */
819 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
820 		cp210x_get_line_ctl(port, &bits);
821 		bits &= ~BITS_DATA_MASK;
822 		switch (cflag & CSIZE) {
823 		case CS5:
824 			bits |= BITS_DATA_5;
825 			dev_dbg(dev, "%s - data bits = 5\n", __func__);
826 			break;
827 		case CS6:
828 			bits |= BITS_DATA_6;
829 			dev_dbg(dev, "%s - data bits = 6\n", __func__);
830 			break;
831 		case CS7:
832 			bits |= BITS_DATA_7;
833 			dev_dbg(dev, "%s - data bits = 7\n", __func__);
834 			break;
835 		case CS8:
836 			bits |= BITS_DATA_8;
837 			dev_dbg(dev, "%s - data bits = 8\n", __func__);
838 			break;
839 		/*case CS9:
840 			bits |= BITS_DATA_9;
841 			dev_dbg(dev, "%s - data bits = 9\n", __func__);
842 			break;*/
843 		default:
844 			dev_dbg(dev, "cp210x driver does not support the number of bits requested, using 8 bit mode\n");
845 			bits |= BITS_DATA_8;
846 			break;
847 		}
848 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
849 			dev_dbg(dev, "Number of data bits requested not supported by device\n");
850 	}
851 
852 	if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
853 	    (old_cflag & (PARENB|PARODD|CMSPAR))) {
854 		cp210x_get_line_ctl(port, &bits);
855 		bits &= ~BITS_PARITY_MASK;
856 		if (cflag & PARENB) {
857 			if (cflag & CMSPAR) {
858 				if (cflag & PARODD) {
859 					bits |= BITS_PARITY_MARK;
860 					dev_dbg(dev, "%s - parity = MARK\n", __func__);
861 				} else {
862 					bits |= BITS_PARITY_SPACE;
863 					dev_dbg(dev, "%s - parity = SPACE\n", __func__);
864 				}
865 			} else {
866 				if (cflag & PARODD) {
867 					bits |= BITS_PARITY_ODD;
868 					dev_dbg(dev, "%s - parity = ODD\n", __func__);
869 				} else {
870 					bits |= BITS_PARITY_EVEN;
871 					dev_dbg(dev, "%s - parity = EVEN\n", __func__);
872 				}
873 			}
874 		}
875 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
876 			dev_dbg(dev, "Parity mode not supported by device\n");
877 	}
878 
879 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
880 		cp210x_get_line_ctl(port, &bits);
881 		bits &= ~BITS_STOP_MASK;
882 		if (cflag & CSTOPB) {
883 			bits |= BITS_STOP_2;
884 			dev_dbg(dev, "%s - stop bits = 2\n", __func__);
885 		} else {
886 			bits |= BITS_STOP_1;
887 			dev_dbg(dev, "%s - stop bits = 1\n", __func__);
888 		}
889 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
890 			dev_dbg(dev, "Number of stop bits requested not supported by device\n");
891 	}
892 
893 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
894 		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
895 		dev_dbg(dev, "%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
896 			__func__, modem_ctl[0], modem_ctl[1],
897 			modem_ctl[2], modem_ctl[3]);
898 
899 		if (cflag & CRTSCTS) {
900 			modem_ctl[0] &= ~0x7B;
901 			modem_ctl[0] |= 0x09;
902 			modem_ctl[1] = 0x80;
903 			dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
904 		} else {
905 			modem_ctl[0] &= ~0x7B;
906 			modem_ctl[0] |= 0x01;
907 			modem_ctl[1] |= 0x40;
908 			dev_dbg(dev, "%s - flow control = NONE\n", __func__);
909 		}
910 
911 		dev_dbg(dev, "%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
912 			__func__, modem_ctl[0], modem_ctl[1],
913 			modem_ctl[2], modem_ctl[3]);
914 		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
915 	}
916 
917 }
918 
919 static int cp210x_tiocmset(struct tty_struct *tty,
920 		unsigned int set, unsigned int clear)
921 {
922 	struct usb_serial_port *port = tty->driver_data;
923 	return cp210x_tiocmset_port(port, set, clear);
924 }
925 
926 static int cp210x_tiocmset_port(struct usb_serial_port *port,
927 		unsigned int set, unsigned int clear)
928 {
929 	unsigned int control = 0;
930 
931 	if (set & TIOCM_RTS) {
932 		control |= CONTROL_RTS;
933 		control |= CONTROL_WRITE_RTS;
934 	}
935 	if (set & TIOCM_DTR) {
936 		control |= CONTROL_DTR;
937 		control |= CONTROL_WRITE_DTR;
938 	}
939 	if (clear & TIOCM_RTS) {
940 		control &= ~CONTROL_RTS;
941 		control |= CONTROL_WRITE_RTS;
942 	}
943 	if (clear & TIOCM_DTR) {
944 		control &= ~CONTROL_DTR;
945 		control |= CONTROL_WRITE_DTR;
946 	}
947 
948 	dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
949 
950 	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
951 }
952 
953 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
954 {
955 	if (on)
956 		cp210x_tiocmset_port(p, TIOCM_DTR|TIOCM_RTS, 0);
957 	else
958 		cp210x_tiocmset_port(p, 0, TIOCM_DTR|TIOCM_RTS);
959 }
960 
961 static int cp210x_tiocmget(struct tty_struct *tty)
962 {
963 	struct usb_serial_port *port = tty->driver_data;
964 	unsigned int control;
965 	int result;
966 
967 	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
968 
969 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
970 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
971 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
972 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
973 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
974 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
975 
976 	dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);
977 
978 	return result;
979 }
980 
981 static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
982 {
983 	struct usb_serial_port *port = tty->driver_data;
984 	unsigned int state;
985 
986 	if (break_state == 0)
987 		state = BREAK_OFF;
988 	else
989 		state = BREAK_ON;
990 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
991 		state == BREAK_OFF ? "off" : "on");
992 	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
993 }
994 
995 static int cp210x_port_probe(struct usb_serial_port *port)
996 {
997 	struct usb_serial *serial = port->serial;
998 	struct usb_host_interface *cur_altsetting;
999 	struct cp210x_port_private *port_priv;
1000 	int ret;
1001 
1002 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
1003 	if (!port_priv)
1004 		return -ENOMEM;
1005 
1006 	cur_altsetting = serial->interface->cur_altsetting;
1007 	port_priv->bInterfaceNumber = cur_altsetting->desc.bInterfaceNumber;
1008 
1009 	usb_set_serial_port_data(port, port_priv);
1010 
1011 	ret = cp210x_detect_swapped_line_ctl(port);
1012 	if (ret) {
1013 		kfree(port_priv);
1014 		return ret;
1015 	}
1016 
1017 	return 0;
1018 }
1019 
1020 static int cp210x_port_remove(struct usb_serial_port *port)
1021 {
1022 	struct cp210x_port_private *port_priv;
1023 
1024 	port_priv = usb_get_serial_port_data(port);
1025 	kfree(port_priv);
1026 
1027 	return 0;
1028 }
1029 
1030 module_usb_serial_driver(serial_drivers, id_table);
1031 
1032 MODULE_DESCRIPTION(DRIVER_DESC);
1033 MODULE_LICENSE("GPL");
1034