xref: /openbmc/linux/drivers/usb/serial/cp210x.c (revision 9034389cd81681b4f0123173eb836624199209c7)
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(0x1901, 0x0190) }, /* GE B850 CP2105 Recorder interface */
167 	{ USB_DEVICE(0x1901, 0x0193) }, /* GE B650 CP2104 PMC interface */
168 	{ USB_DEVICE(0x1901, 0x0194) },	/* GE Healthcare Remote Alarm Box */
169 	{ USB_DEVICE(0x19CF, 0x3000) }, /* Parrot NMEA GPS Flight Recorder */
170 	{ USB_DEVICE(0x1ADB, 0x0001) }, /* Schweitzer Engineering C662 Cable */
171 	{ USB_DEVICE(0x1B1C, 0x1C00) }, /* Corsair USB Dongle */
172 	{ USB_DEVICE(0x1BA4, 0x0002) },	/* Silicon Labs 358x factory default */
173 	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
174 	{ USB_DEVICE(0x1D6F, 0x0010) }, /* Seluxit ApS RF Dongle */
175 	{ USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
176 	{ USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
177 	{ USB_DEVICE(0x1FB9, 0x0100) }, /* Lake Shore Model 121 Current Source */
178 	{ USB_DEVICE(0x1FB9, 0x0200) }, /* Lake Shore Model 218A Temperature Monitor */
179 	{ USB_DEVICE(0x1FB9, 0x0201) }, /* Lake Shore Model 219 Temperature Monitor */
180 	{ USB_DEVICE(0x1FB9, 0x0202) }, /* Lake Shore Model 233 Temperature Transmitter */
181 	{ USB_DEVICE(0x1FB9, 0x0203) }, /* Lake Shore Model 235 Temperature Transmitter */
182 	{ USB_DEVICE(0x1FB9, 0x0300) }, /* Lake Shore Model 335 Temperature Controller */
183 	{ USB_DEVICE(0x1FB9, 0x0301) }, /* Lake Shore Model 336 Temperature Controller */
184 	{ USB_DEVICE(0x1FB9, 0x0302) }, /* Lake Shore Model 350 Temperature Controller */
185 	{ USB_DEVICE(0x1FB9, 0x0303) }, /* Lake Shore Model 371 AC Bridge */
186 	{ USB_DEVICE(0x1FB9, 0x0400) }, /* Lake Shore Model 411 Handheld Gaussmeter */
187 	{ USB_DEVICE(0x1FB9, 0x0401) }, /* Lake Shore Model 425 Gaussmeter */
188 	{ USB_DEVICE(0x1FB9, 0x0402) }, /* Lake Shore Model 455A Gaussmeter */
189 	{ USB_DEVICE(0x1FB9, 0x0403) }, /* Lake Shore Model 475A Gaussmeter */
190 	{ USB_DEVICE(0x1FB9, 0x0404) }, /* Lake Shore Model 465 Three Axis Gaussmeter */
191 	{ USB_DEVICE(0x1FB9, 0x0600) }, /* Lake Shore Model 625A Superconducting MPS */
192 	{ USB_DEVICE(0x1FB9, 0x0601) }, /* Lake Shore Model 642A Magnet Power Supply */
193 	{ USB_DEVICE(0x1FB9, 0x0602) }, /* Lake Shore Model 648 Magnet Power Supply */
194 	{ USB_DEVICE(0x1FB9, 0x0700) }, /* Lake Shore Model 737 VSM Controller */
195 	{ USB_DEVICE(0x1FB9, 0x0701) }, /* Lake Shore Model 776 Hall Matrix */
196 	{ USB_DEVICE(0x2626, 0xEA60) }, /* Aruba Networks 7xxx USB Serial Console */
197 	{ USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
198 	{ USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
199 	{ USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
200 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
201 	{ } /* Terminating Entry */
202 };
203 
204 MODULE_DEVICE_TABLE(usb, id_table);
205 
206 struct cp210x_port_private {
207 	__u8			bInterfaceNumber;
208 	bool			has_swapped_line_ctl;
209 };
210 
211 static struct usb_serial_driver cp210x_device = {
212 	.driver = {
213 		.owner =	THIS_MODULE,
214 		.name =		"cp210x",
215 	},
216 	.id_table		= id_table,
217 	.num_ports		= 1,
218 	.bulk_in_size		= 256,
219 	.bulk_out_size		= 256,
220 	.open			= cp210x_open,
221 	.close			= cp210x_close,
222 	.break_ctl		= cp210x_break_ctl,
223 	.set_termios		= cp210x_set_termios,
224 	.tx_empty		= cp210x_tx_empty,
225 	.tiocmget		= cp210x_tiocmget,
226 	.tiocmset		= cp210x_tiocmset,
227 	.port_probe		= cp210x_port_probe,
228 	.port_remove		= cp210x_port_remove,
229 	.dtr_rts		= cp210x_dtr_rts
230 };
231 
232 static struct usb_serial_driver * const serial_drivers[] = {
233 	&cp210x_device, NULL
234 };
235 
236 /* Config request types */
237 #define REQTYPE_HOST_TO_INTERFACE	0x41
238 #define REQTYPE_INTERFACE_TO_HOST	0xc1
239 #define REQTYPE_HOST_TO_DEVICE	0x40
240 #define REQTYPE_DEVICE_TO_HOST	0xc0
241 
242 /* Config request codes */
243 #define CP210X_IFC_ENABLE	0x00
244 #define CP210X_SET_BAUDDIV	0x01
245 #define CP210X_GET_BAUDDIV	0x02
246 #define CP210X_SET_LINE_CTL	0x03
247 #define CP210X_GET_LINE_CTL	0x04
248 #define CP210X_SET_BREAK	0x05
249 #define CP210X_IMM_CHAR		0x06
250 #define CP210X_SET_MHS		0x07
251 #define CP210X_GET_MDMSTS	0x08
252 #define CP210X_SET_XON		0x09
253 #define CP210X_SET_XOFF		0x0A
254 #define CP210X_SET_EVENTMASK	0x0B
255 #define CP210X_GET_EVENTMASK	0x0C
256 #define CP210X_SET_CHAR		0x0D
257 #define CP210X_GET_CHARS	0x0E
258 #define CP210X_GET_PROPS	0x0F
259 #define CP210X_GET_COMM_STATUS	0x10
260 #define CP210X_RESET		0x11
261 #define CP210X_PURGE		0x12
262 #define CP210X_SET_FLOW		0x13
263 #define CP210X_GET_FLOW		0x14
264 #define CP210X_EMBED_EVENTS	0x15
265 #define CP210X_GET_EVENTSTATE	0x16
266 #define CP210X_SET_CHARS	0x19
267 #define CP210X_GET_BAUDRATE	0x1D
268 #define CP210X_SET_BAUDRATE	0x1E
269 
270 /* CP210X_IFC_ENABLE */
271 #define UART_ENABLE		0x0001
272 #define UART_DISABLE		0x0000
273 
274 /* CP210X_(SET|GET)_BAUDDIV */
275 #define BAUD_RATE_GEN_FREQ	0x384000
276 
277 /* CP210X_(SET|GET)_LINE_CTL */
278 #define BITS_DATA_MASK		0X0f00
279 #define BITS_DATA_5		0X0500
280 #define BITS_DATA_6		0X0600
281 #define BITS_DATA_7		0X0700
282 #define BITS_DATA_8		0X0800
283 #define BITS_DATA_9		0X0900
284 
285 #define BITS_PARITY_MASK	0x00f0
286 #define BITS_PARITY_NONE	0x0000
287 #define BITS_PARITY_ODD		0x0010
288 #define BITS_PARITY_EVEN	0x0020
289 #define BITS_PARITY_MARK	0x0030
290 #define BITS_PARITY_SPACE	0x0040
291 
292 #define BITS_STOP_MASK		0x000f
293 #define BITS_STOP_1		0x0000
294 #define BITS_STOP_1_5		0x0001
295 #define BITS_STOP_2		0x0002
296 
297 /* CP210X_SET_BREAK */
298 #define BREAK_ON		0x0001
299 #define BREAK_OFF		0x0000
300 
301 /* CP210X_(SET_MHS|GET_MDMSTS) */
302 #define CONTROL_DTR		0x0001
303 #define CONTROL_RTS		0x0002
304 #define CONTROL_CTS		0x0010
305 #define CONTROL_DSR		0x0020
306 #define CONTROL_RING		0x0040
307 #define CONTROL_DCD		0x0080
308 #define CONTROL_WRITE_DTR	0x0100
309 #define CONTROL_WRITE_RTS	0x0200
310 
311 /* CP210X_GET_COMM_STATUS returns these 0x13 bytes */
312 struct cp210x_comm_status {
313 	__le32   ulErrors;
314 	__le32   ulHoldReasons;
315 	__le32   ulAmountInInQueue;
316 	__le32   ulAmountInOutQueue;
317 	u8       bEofReceived;
318 	u8       bWaitForImmediate;
319 	u8       bReserved;
320 } __packed;
321 
322 /*
323  * CP210X_PURGE - 16 bits passed in wValue of USB request.
324  * SiLabs app note AN571 gives a strange description of the 4 bits:
325  * bit 0 or bit 2 clears the transmit queue and 1 or 3 receive.
326  * writing 1 to all, however, purges cp2108 well enough to avoid the hang.
327  */
328 #define PURGE_ALL		0x000f
329 
330 /* CP210X_GET_FLOW/CP210X_SET_FLOW read/write these 0x10 bytes */
331 struct cp210x_flow_ctl {
332 	__le32	ulControlHandshake;
333 	__le32	ulFlowReplace;
334 	__le32	ulXonLimit;
335 	__le32	ulXoffLimit;
336 } __packed;
337 
338 /* cp210x_flow_ctl::ulControlHandshake */
339 #define CP210X_SERIAL_DTR_MASK		GENMASK(1, 0)
340 #define CP210X_SERIAL_DTR_SHIFT(_mode)	(_mode)
341 #define CP210X_SERIAL_CTS_HANDSHAKE	BIT(3)
342 #define CP210X_SERIAL_DSR_HANDSHAKE	BIT(4)
343 #define CP210X_SERIAL_DCD_HANDSHAKE	BIT(5)
344 #define CP210X_SERIAL_DSR_SENSITIVITY	BIT(6)
345 
346 /* values for cp210x_flow_ctl::ulControlHandshake::CP210X_SERIAL_DTR_MASK */
347 #define CP210X_SERIAL_DTR_INACTIVE	0
348 #define CP210X_SERIAL_DTR_ACTIVE	1
349 #define CP210X_SERIAL_DTR_FLOW_CTL	2
350 
351 /* cp210x_flow_ctl::ulFlowReplace */
352 #define CP210X_SERIAL_AUTO_TRANSMIT	BIT(0)
353 #define CP210X_SERIAL_AUTO_RECEIVE	BIT(1)
354 #define CP210X_SERIAL_ERROR_CHAR	BIT(2)
355 #define CP210X_SERIAL_NULL_STRIPPING	BIT(3)
356 #define CP210X_SERIAL_BREAK_CHAR	BIT(4)
357 #define CP210X_SERIAL_RTS_MASK		GENMASK(7, 6)
358 #define CP210X_SERIAL_RTS_SHIFT(_mode)	(_mode << 6)
359 #define CP210X_SERIAL_XOFF_CONTINUE	BIT(31)
360 
361 /* values for cp210x_flow_ctl::ulFlowReplace::CP210X_SERIAL_RTS_MASK */
362 #define CP210X_SERIAL_RTS_INACTIVE	0
363 #define CP210X_SERIAL_RTS_ACTIVE	1
364 #define CP210X_SERIAL_RTS_FLOW_CTL	2
365 
366 /*
367  * Reads a variable-sized block of CP210X_ registers, identified by req.
368  * Returns data into buf in native USB byte order.
369  */
370 static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req,
371 		void *buf, int bufsize)
372 {
373 	struct usb_serial *serial = port->serial;
374 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
375 	void *dmabuf;
376 	int result;
377 
378 	dmabuf = kmalloc(bufsize, GFP_KERNEL);
379 	if (!dmabuf) {
380 		/*
381 		 * FIXME Some callers don't bother to check for error,
382 		 * at least give them consistent junk until they are fixed
383 		 */
384 		memset(buf, 0, bufsize);
385 		return -ENOMEM;
386 	}
387 
388 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
389 			req, REQTYPE_INTERFACE_TO_HOST, 0,
390 			port_priv->bInterfaceNumber, dmabuf, bufsize,
391 			USB_CTRL_SET_TIMEOUT);
392 	if (result == bufsize) {
393 		memcpy(buf, dmabuf, bufsize);
394 		result = 0;
395 	} else {
396 		dev_err(&port->dev, "failed get req 0x%x size %d status: %d\n",
397 				req, bufsize, result);
398 		if (result >= 0)
399 			result = -EPROTO;
400 
401 		/*
402 		 * FIXME Some callers don't bother to check for error,
403 		 * at least give them consistent junk until they are fixed
404 		 */
405 		memset(buf, 0, bufsize);
406 	}
407 
408 	kfree(dmabuf);
409 
410 	return result;
411 }
412 
413 /*
414  * Reads any 32-bit CP210X_ register identified by req.
415  */
416 static int cp210x_read_u32_reg(struct usb_serial_port *port, u8 req, u32 *val)
417 {
418 	__le32 le32_val;
419 	int err;
420 
421 	err = cp210x_read_reg_block(port, req, &le32_val, sizeof(le32_val));
422 	if (err) {
423 		/*
424 		 * FIXME Some callers don't bother to check for error,
425 		 * at least give them consistent junk until they are fixed
426 		 */
427 		*val = 0;
428 		return err;
429 	}
430 
431 	*val = le32_to_cpu(le32_val);
432 
433 	return 0;
434 }
435 
436 /*
437  * Reads any 16-bit CP210X_ register identified by req.
438  */
439 static int cp210x_read_u16_reg(struct usb_serial_port *port, u8 req, u16 *val)
440 {
441 	__le16 le16_val;
442 	int err;
443 
444 	err = cp210x_read_reg_block(port, req, &le16_val, sizeof(le16_val));
445 	if (err)
446 		return err;
447 
448 	*val = le16_to_cpu(le16_val);
449 
450 	return 0;
451 }
452 
453 /*
454  * Reads any 8-bit CP210X_ register identified by req.
455  */
456 static int cp210x_read_u8_reg(struct usb_serial_port *port, u8 req, u8 *val)
457 {
458 	return cp210x_read_reg_block(port, req, val, sizeof(*val));
459 }
460 
461 /*
462  * Writes any 16-bit CP210X_ register (req) whose value is passed
463  * entirely in the wValue field of the USB request.
464  */
465 static int cp210x_write_u16_reg(struct usb_serial_port *port, u8 req, u16 val)
466 {
467 	struct usb_serial *serial = port->serial;
468 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
469 	int result;
470 
471 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
472 			req, REQTYPE_HOST_TO_INTERFACE, val,
473 			port_priv->bInterfaceNumber, NULL, 0,
474 			USB_CTRL_SET_TIMEOUT);
475 	if (result < 0) {
476 		dev_err(&port->dev, "failed set request 0x%x status: %d\n",
477 				req, result);
478 	}
479 
480 	return result;
481 }
482 
483 /*
484  * Writes a variable-sized block of CP210X_ registers, identified by req.
485  * Data in buf must be in native USB byte order.
486  */
487 static int cp210x_write_reg_block(struct usb_serial_port *port, u8 req,
488 		void *buf, int bufsize)
489 {
490 	struct usb_serial *serial = port->serial;
491 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
492 	void *dmabuf;
493 	int result;
494 
495 	dmabuf = kmalloc(bufsize, GFP_KERNEL);
496 	if (!dmabuf)
497 		return -ENOMEM;
498 
499 	memcpy(dmabuf, buf, bufsize);
500 
501 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
502 			req, REQTYPE_HOST_TO_INTERFACE, 0,
503 			port_priv->bInterfaceNumber, dmabuf, bufsize,
504 			USB_CTRL_SET_TIMEOUT);
505 
506 	kfree(dmabuf);
507 
508 	if (result == bufsize) {
509 		result = 0;
510 	} else {
511 		dev_err(&port->dev, "failed set req 0x%x size %d status: %d\n",
512 				req, bufsize, result);
513 		if (result >= 0)
514 			result = -EPROTO;
515 	}
516 
517 	return result;
518 }
519 
520 /*
521  * Writes any 32-bit CP210X_ register identified by req.
522  */
523 static int cp210x_write_u32_reg(struct usb_serial_port *port, u8 req, u32 val)
524 {
525 	__le32 le32_val;
526 
527 	le32_val = cpu_to_le32(val);
528 
529 	return cp210x_write_reg_block(port, req, &le32_val, sizeof(le32_val));
530 }
531 
532 /*
533  * Detect CP2108 GET_LINE_CTL bug and activate workaround.
534  * Write a known good value 0x800, read it back.
535  * If it comes back swapped the bug is detected.
536  * Preserve the original register value.
537  */
538 static int cp210x_detect_swapped_line_ctl(struct usb_serial_port *port)
539 {
540 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
541 	u16 line_ctl_save;
542 	u16 line_ctl_test;
543 	int err;
544 
545 	err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, &line_ctl_save);
546 	if (err)
547 		return err;
548 
549 	err = cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, 0x800);
550 	if (err)
551 		return err;
552 
553 	err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, &line_ctl_test);
554 	if (err)
555 		return err;
556 
557 	if (line_ctl_test == 8) {
558 		port_priv->has_swapped_line_ctl = true;
559 		line_ctl_save = swab16(line_ctl_save);
560 	}
561 
562 	return cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, line_ctl_save);
563 }
564 
565 /*
566  * Must always be called instead of cp210x_read_u16_reg(CP210X_GET_LINE_CTL)
567  * to workaround cp2108 bug and get correct value.
568  */
569 static int cp210x_get_line_ctl(struct usb_serial_port *port, u16 *ctl)
570 {
571 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
572 	int err;
573 
574 	err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, ctl);
575 	if (err)
576 		return err;
577 
578 	/* Workaround swapped bytes in 16-bit value from CP210X_GET_LINE_CTL */
579 	if (port_priv->has_swapped_line_ctl)
580 		*ctl = swab16(*ctl);
581 
582 	return 0;
583 }
584 
585 /*
586  * cp210x_quantise_baudrate
587  * Quantises the baud rate as per AN205 Table 1
588  */
589 static unsigned int cp210x_quantise_baudrate(unsigned int baud)
590 {
591 	if (baud <= 300)
592 		baud = 300;
593 	else if (baud <= 600)      baud = 600;
594 	else if (baud <= 1200)     baud = 1200;
595 	else if (baud <= 1800)     baud = 1800;
596 	else if (baud <= 2400)     baud = 2400;
597 	else if (baud <= 4000)     baud = 4000;
598 	else if (baud <= 4803)     baud = 4800;
599 	else if (baud <= 7207)     baud = 7200;
600 	else if (baud <= 9612)     baud = 9600;
601 	else if (baud <= 14428)    baud = 14400;
602 	else if (baud <= 16062)    baud = 16000;
603 	else if (baud <= 19250)    baud = 19200;
604 	else if (baud <= 28912)    baud = 28800;
605 	else if (baud <= 38601)    baud = 38400;
606 	else if (baud <= 51558)    baud = 51200;
607 	else if (baud <= 56280)    baud = 56000;
608 	else if (baud <= 58053)    baud = 57600;
609 	else if (baud <= 64111)    baud = 64000;
610 	else if (baud <= 77608)    baud = 76800;
611 	else if (baud <= 117028)   baud = 115200;
612 	else if (baud <= 129347)   baud = 128000;
613 	else if (baud <= 156868)   baud = 153600;
614 	else if (baud <= 237832)   baud = 230400;
615 	else if (baud <= 254234)   baud = 250000;
616 	else if (baud <= 273066)   baud = 256000;
617 	else if (baud <= 491520)   baud = 460800;
618 	else if (baud <= 567138)   baud = 500000;
619 	else if (baud <= 670254)   baud = 576000;
620 	else if (baud < 1000000)
621 		baud = 921600;
622 	else if (baud > 2000000)
623 		baud = 2000000;
624 	return baud;
625 }
626 
627 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
628 {
629 	int result;
630 
631 	result = cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_ENABLE);
632 	if (result) {
633 		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
634 		return result;
635 	}
636 
637 	/* Configure the termios structure */
638 	cp210x_get_termios(tty, port);
639 
640 	/* The baud rate must be initialised on cp2104 */
641 	if (tty)
642 		cp210x_change_speed(tty, port, NULL);
643 
644 	return usb_serial_generic_open(tty, port);
645 }
646 
647 static void cp210x_close(struct usb_serial_port *port)
648 {
649 	usb_serial_generic_close(port);
650 
651 	/* Clear both queues; cp2108 needs this to avoid an occasional hang */
652 	cp210x_write_u16_reg(port, CP210X_PURGE, PURGE_ALL);
653 
654 	cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);
655 }
656 
657 /*
658  * Read how many bytes are waiting in the TX queue.
659  */
660 static int cp210x_get_tx_queue_byte_count(struct usb_serial_port *port,
661 		u32 *count)
662 {
663 	struct usb_serial *serial = port->serial;
664 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
665 	struct cp210x_comm_status *sts;
666 	int result;
667 
668 	sts = kmalloc(sizeof(*sts), GFP_KERNEL);
669 	if (!sts)
670 		return -ENOMEM;
671 
672 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
673 			CP210X_GET_COMM_STATUS, REQTYPE_INTERFACE_TO_HOST,
674 			0, port_priv->bInterfaceNumber, sts, sizeof(*sts),
675 			USB_CTRL_GET_TIMEOUT);
676 	if (result == sizeof(*sts)) {
677 		*count = le32_to_cpu(sts->ulAmountInOutQueue);
678 		result = 0;
679 	} else {
680 		dev_err(&port->dev, "failed to get comm status: %d\n", result);
681 		if (result >= 0)
682 			result = -EPROTO;
683 	}
684 
685 	kfree(sts);
686 
687 	return result;
688 }
689 
690 static bool cp210x_tx_empty(struct usb_serial_port *port)
691 {
692 	int err;
693 	u32 count;
694 
695 	err = cp210x_get_tx_queue_byte_count(port, &count);
696 	if (err)
697 		return true;
698 
699 	return !count;
700 }
701 
702 /*
703  * cp210x_get_termios
704  * Reads the baud rate, data bits, parity, stop bits and flow control mode
705  * from the device, corrects any unsupported values, and configures the
706  * termios structure to reflect the state of the device
707  */
708 static void cp210x_get_termios(struct tty_struct *tty,
709 	struct usb_serial_port *port)
710 {
711 	unsigned int baud;
712 
713 	if (tty) {
714 		cp210x_get_termios_port(tty->driver_data,
715 			&tty->termios.c_cflag, &baud);
716 		tty_encode_baud_rate(tty, baud, baud);
717 	} else {
718 		unsigned int cflag;
719 		cflag = 0;
720 		cp210x_get_termios_port(port, &cflag, &baud);
721 	}
722 }
723 
724 /*
725  * cp210x_get_termios_port
726  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
727  */
728 static void cp210x_get_termios_port(struct usb_serial_port *port,
729 	unsigned int *cflagp, unsigned int *baudp)
730 {
731 	struct device *dev = &port->dev;
732 	unsigned int cflag;
733 	struct cp210x_flow_ctl flow_ctl;
734 	u32 baud;
735 	u16 bits;
736 	u32 ctl_hs;
737 
738 	cp210x_read_u32_reg(port, CP210X_GET_BAUDRATE, &baud);
739 
740 	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
741 	*baudp = baud;
742 
743 	cflag = *cflagp;
744 
745 	cp210x_get_line_ctl(port, &bits);
746 	cflag &= ~CSIZE;
747 	switch (bits & BITS_DATA_MASK) {
748 	case BITS_DATA_5:
749 		dev_dbg(dev, "%s - data bits = 5\n", __func__);
750 		cflag |= CS5;
751 		break;
752 	case BITS_DATA_6:
753 		dev_dbg(dev, "%s - data bits = 6\n", __func__);
754 		cflag |= CS6;
755 		break;
756 	case BITS_DATA_7:
757 		dev_dbg(dev, "%s - data bits = 7\n", __func__);
758 		cflag |= CS7;
759 		break;
760 	case BITS_DATA_8:
761 		dev_dbg(dev, "%s - data bits = 8\n", __func__);
762 		cflag |= CS8;
763 		break;
764 	case BITS_DATA_9:
765 		dev_dbg(dev, "%s - data bits = 9 (not supported, using 8 data bits)\n", __func__);
766 		cflag |= CS8;
767 		bits &= ~BITS_DATA_MASK;
768 		bits |= BITS_DATA_8;
769 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
770 		break;
771 	default:
772 		dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
773 		cflag |= CS8;
774 		bits &= ~BITS_DATA_MASK;
775 		bits |= BITS_DATA_8;
776 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
777 		break;
778 	}
779 
780 	switch (bits & BITS_PARITY_MASK) {
781 	case BITS_PARITY_NONE:
782 		dev_dbg(dev, "%s - parity = NONE\n", __func__);
783 		cflag &= ~PARENB;
784 		break;
785 	case BITS_PARITY_ODD:
786 		dev_dbg(dev, "%s - parity = ODD\n", __func__);
787 		cflag |= (PARENB|PARODD);
788 		break;
789 	case BITS_PARITY_EVEN:
790 		dev_dbg(dev, "%s - parity = EVEN\n", __func__);
791 		cflag &= ~PARODD;
792 		cflag |= PARENB;
793 		break;
794 	case BITS_PARITY_MARK:
795 		dev_dbg(dev, "%s - parity = MARK\n", __func__);
796 		cflag |= (PARENB|PARODD|CMSPAR);
797 		break;
798 	case BITS_PARITY_SPACE:
799 		dev_dbg(dev, "%s - parity = SPACE\n", __func__);
800 		cflag &= ~PARODD;
801 		cflag |= (PARENB|CMSPAR);
802 		break;
803 	default:
804 		dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
805 		cflag &= ~PARENB;
806 		bits &= ~BITS_PARITY_MASK;
807 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
808 		break;
809 	}
810 
811 	cflag &= ~CSTOPB;
812 	switch (bits & BITS_STOP_MASK) {
813 	case BITS_STOP_1:
814 		dev_dbg(dev, "%s - stop bits = 1\n", __func__);
815 		break;
816 	case BITS_STOP_1_5:
817 		dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
818 		bits &= ~BITS_STOP_MASK;
819 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
820 		break;
821 	case BITS_STOP_2:
822 		dev_dbg(dev, "%s - stop bits = 2\n", __func__);
823 		cflag |= CSTOPB;
824 		break;
825 	default:
826 		dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __func__);
827 		bits &= ~BITS_STOP_MASK;
828 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
829 		break;
830 	}
831 
832 	cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl,
833 			sizeof(flow_ctl));
834 	ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake);
835 	if (ctl_hs & CP210X_SERIAL_CTS_HANDSHAKE) {
836 		dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
837 		cflag |= CRTSCTS;
838 	} else {
839 		dev_dbg(dev, "%s - flow control = NONE\n", __func__);
840 		cflag &= ~CRTSCTS;
841 	}
842 
843 	*cflagp = cflag;
844 }
845 
846 /*
847  * CP2101 supports the following baud rates:
848  *
849  *	300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
850  *	38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
851  *
852  * CP2102 and CP2103 support the following additional rates:
853  *
854  *	4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
855  *	576000
856  *
857  * The device will map a requested rate to a supported one, but the result
858  * of requests for rates greater than 1053257 is undefined (see AN205).
859  *
860  * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
861  * respectively, with an error less than 1%. The actual rates are determined
862  * by
863  *
864  *	div = round(freq / (2 x prescale x request))
865  *	actual = freq / (2 x prescale x div)
866  *
867  * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
868  * or 1 otherwise.
869  * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
870  * otherwise.
871  */
872 static void cp210x_change_speed(struct tty_struct *tty,
873 		struct usb_serial_port *port, struct ktermios *old_termios)
874 {
875 	u32 baud;
876 
877 	baud = tty->termios.c_ospeed;
878 
879 	/* This maps the requested rate to a rate valid on cp2102 or cp2103,
880 	 * or to an arbitrary rate in [1M,2M].
881 	 *
882 	 * NOTE: B0 is not implemented.
883 	 */
884 	baud = cp210x_quantise_baudrate(baud);
885 
886 	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
887 	if (cp210x_write_u32_reg(port, CP210X_SET_BAUDRATE, baud)) {
888 		dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
889 		if (old_termios)
890 			baud = old_termios->c_ospeed;
891 		else
892 			baud = 9600;
893 	}
894 
895 	tty_encode_baud_rate(tty, baud, baud);
896 }
897 
898 static void cp210x_set_termios(struct tty_struct *tty,
899 		struct usb_serial_port *port, struct ktermios *old_termios)
900 {
901 	struct device *dev = &port->dev;
902 	unsigned int cflag, old_cflag;
903 	u16 bits;
904 
905 	cflag = tty->termios.c_cflag;
906 	old_cflag = old_termios->c_cflag;
907 
908 	if (tty->termios.c_ospeed != old_termios->c_ospeed)
909 		cp210x_change_speed(tty, port, old_termios);
910 
911 	/* If the number of data bits is to be updated */
912 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
913 		cp210x_get_line_ctl(port, &bits);
914 		bits &= ~BITS_DATA_MASK;
915 		switch (cflag & CSIZE) {
916 		case CS5:
917 			bits |= BITS_DATA_5;
918 			dev_dbg(dev, "%s - data bits = 5\n", __func__);
919 			break;
920 		case CS6:
921 			bits |= BITS_DATA_6;
922 			dev_dbg(dev, "%s - data bits = 6\n", __func__);
923 			break;
924 		case CS7:
925 			bits |= BITS_DATA_7;
926 			dev_dbg(dev, "%s - data bits = 7\n", __func__);
927 			break;
928 		case CS8:
929 			bits |= BITS_DATA_8;
930 			dev_dbg(dev, "%s - data bits = 8\n", __func__);
931 			break;
932 		/*case CS9:
933 			bits |= BITS_DATA_9;
934 			dev_dbg(dev, "%s - data bits = 9\n", __func__);
935 			break;*/
936 		default:
937 			dev_dbg(dev, "cp210x driver does not support the number of bits requested, using 8 bit mode\n");
938 			bits |= BITS_DATA_8;
939 			break;
940 		}
941 		if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
942 			dev_dbg(dev, "Number of data bits requested not supported by device\n");
943 	}
944 
945 	if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
946 	    (old_cflag & (PARENB|PARODD|CMSPAR))) {
947 		cp210x_get_line_ctl(port, &bits);
948 		bits &= ~BITS_PARITY_MASK;
949 		if (cflag & PARENB) {
950 			if (cflag & CMSPAR) {
951 				if (cflag & PARODD) {
952 					bits |= BITS_PARITY_MARK;
953 					dev_dbg(dev, "%s - parity = MARK\n", __func__);
954 				} else {
955 					bits |= BITS_PARITY_SPACE;
956 					dev_dbg(dev, "%s - parity = SPACE\n", __func__);
957 				}
958 			} else {
959 				if (cflag & PARODD) {
960 					bits |= BITS_PARITY_ODD;
961 					dev_dbg(dev, "%s - parity = ODD\n", __func__);
962 				} else {
963 					bits |= BITS_PARITY_EVEN;
964 					dev_dbg(dev, "%s - parity = EVEN\n", __func__);
965 				}
966 			}
967 		}
968 		if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
969 			dev_dbg(dev, "Parity mode not supported by device\n");
970 	}
971 
972 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
973 		cp210x_get_line_ctl(port, &bits);
974 		bits &= ~BITS_STOP_MASK;
975 		if (cflag & CSTOPB) {
976 			bits |= BITS_STOP_2;
977 			dev_dbg(dev, "%s - stop bits = 2\n", __func__);
978 		} else {
979 			bits |= BITS_STOP_1;
980 			dev_dbg(dev, "%s - stop bits = 1\n", __func__);
981 		}
982 		if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
983 			dev_dbg(dev, "Number of stop bits requested not supported by device\n");
984 	}
985 
986 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
987 		struct cp210x_flow_ctl flow_ctl;
988 		u32 ctl_hs;
989 		u32 flow_repl;
990 
991 		cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl,
992 				sizeof(flow_ctl));
993 		ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake);
994 		flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace);
995 		dev_dbg(dev, "%s - read ulControlHandshake=0x%08x, ulFlowReplace=0x%08x\n",
996 				__func__, ctl_hs, flow_repl);
997 
998 		if (cflag & CRTSCTS) {
999 			ctl_hs &= ~(CP210X_SERIAL_DTR_MASK |
1000 					CP210X_SERIAL_CTS_HANDSHAKE |
1001 					CP210X_SERIAL_DSR_HANDSHAKE |
1002 					CP210X_SERIAL_DCD_HANDSHAKE |
1003 					CP210X_SERIAL_DSR_SENSITIVITY);
1004 			ctl_hs |= CP210X_SERIAL_DTR_SHIFT(
1005 					CP210X_SERIAL_DTR_ACTIVE);
1006 			ctl_hs |= CP210X_SERIAL_CTS_HANDSHAKE;
1007 			/*
1008 			 * FIXME: Why clear bits unrelated to flow control.
1009 			 * Why clear CP210X_SERIAL_XOFF_CONTINUE which is
1010 			 * never set
1011 			 */
1012 			flow_repl = 0;
1013 			flow_repl |= CP210X_SERIAL_RTS_SHIFT(
1014 					CP210X_SERIAL_RTS_FLOW_CTL);
1015 			dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
1016 		} else {
1017 			ctl_hs &= ~(CP210X_SERIAL_DTR_MASK |
1018 					CP210X_SERIAL_CTS_HANDSHAKE |
1019 					CP210X_SERIAL_DSR_HANDSHAKE |
1020 					CP210X_SERIAL_DCD_HANDSHAKE |
1021 					CP210X_SERIAL_DSR_SENSITIVITY);
1022 			ctl_hs |= CP210X_SERIAL_DTR_SHIFT(
1023 					CP210X_SERIAL_DTR_ACTIVE);
1024 			/* FIXME: Why clear bits unrelated to flow control */
1025 			flow_repl &= 0xffffff00;
1026 			flow_repl |= CP210X_SERIAL_RTS_SHIFT(
1027 					CP210X_SERIAL_RTS_ACTIVE);
1028 			dev_dbg(dev, "%s - flow control = NONE\n", __func__);
1029 		}
1030 
1031 		dev_dbg(dev, "%s - write ulControlHandshake=0x%08x, ulFlowReplace=0x%08x\n",
1032 				__func__, ctl_hs, flow_repl);
1033 		flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs);
1034 		flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl);
1035 		cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl,
1036 				sizeof(flow_ctl));
1037 	}
1038 
1039 }
1040 
1041 static int cp210x_tiocmset(struct tty_struct *tty,
1042 		unsigned int set, unsigned int clear)
1043 {
1044 	struct usb_serial_port *port = tty->driver_data;
1045 	return cp210x_tiocmset_port(port, set, clear);
1046 }
1047 
1048 static int cp210x_tiocmset_port(struct usb_serial_port *port,
1049 		unsigned int set, unsigned int clear)
1050 {
1051 	u16 control = 0;
1052 
1053 	if (set & TIOCM_RTS) {
1054 		control |= CONTROL_RTS;
1055 		control |= CONTROL_WRITE_RTS;
1056 	}
1057 	if (set & TIOCM_DTR) {
1058 		control |= CONTROL_DTR;
1059 		control |= CONTROL_WRITE_DTR;
1060 	}
1061 	if (clear & TIOCM_RTS) {
1062 		control &= ~CONTROL_RTS;
1063 		control |= CONTROL_WRITE_RTS;
1064 	}
1065 	if (clear & TIOCM_DTR) {
1066 		control &= ~CONTROL_DTR;
1067 		control |= CONTROL_WRITE_DTR;
1068 	}
1069 
1070 	dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
1071 
1072 	return cp210x_write_u16_reg(port, CP210X_SET_MHS, control);
1073 }
1074 
1075 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
1076 {
1077 	if (on)
1078 		cp210x_tiocmset_port(p, TIOCM_DTR|TIOCM_RTS, 0);
1079 	else
1080 		cp210x_tiocmset_port(p, 0, TIOCM_DTR|TIOCM_RTS);
1081 }
1082 
1083 static int cp210x_tiocmget(struct tty_struct *tty)
1084 {
1085 	struct usb_serial_port *port = tty->driver_data;
1086 	u8 control;
1087 	int result;
1088 
1089 	cp210x_read_u8_reg(port, CP210X_GET_MDMSTS, &control);
1090 
1091 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
1092 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
1093 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
1094 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
1095 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
1096 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
1097 
1098 	dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);
1099 
1100 	return result;
1101 }
1102 
1103 static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
1104 {
1105 	struct usb_serial_port *port = tty->driver_data;
1106 	u16 state;
1107 
1108 	if (break_state == 0)
1109 		state = BREAK_OFF;
1110 	else
1111 		state = BREAK_ON;
1112 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
1113 		state == BREAK_OFF ? "off" : "on");
1114 	cp210x_write_u16_reg(port, CP210X_SET_BREAK, state);
1115 }
1116 
1117 static int cp210x_port_probe(struct usb_serial_port *port)
1118 {
1119 	struct usb_serial *serial = port->serial;
1120 	struct usb_host_interface *cur_altsetting;
1121 	struct cp210x_port_private *port_priv;
1122 	int ret;
1123 
1124 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
1125 	if (!port_priv)
1126 		return -ENOMEM;
1127 
1128 	cur_altsetting = serial->interface->cur_altsetting;
1129 	port_priv->bInterfaceNumber = cur_altsetting->desc.bInterfaceNumber;
1130 
1131 	usb_set_serial_port_data(port, port_priv);
1132 
1133 	ret = cp210x_detect_swapped_line_ctl(port);
1134 	if (ret) {
1135 		kfree(port_priv);
1136 		return ret;
1137 	}
1138 
1139 	return 0;
1140 }
1141 
1142 static int cp210x_port_remove(struct usb_serial_port *port)
1143 {
1144 	struct cp210x_port_private *port_priv;
1145 
1146 	port_priv = usb_get_serial_port_data(port);
1147 	kfree(port_priv);
1148 
1149 	return 0;
1150 }
1151 
1152 module_usb_serial_driver(serial_drivers, id_table);
1153 
1154 MODULE_DESCRIPTION(DRIVER_DESC);
1155 MODULE_LICENSE("GPL");
1156