xref: /linux/drivers/usb/serial/cp210x.c (revision 110e6f26af80dfd90b6e5c645b1aed7228aa580d)
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 /*
331  * Reads a variable-sized block of CP210X_ registers, identified by req.
332  * Returns data into buf in native USB byte order.
333  */
334 static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req,
335 		void *buf, int bufsize)
336 {
337 	struct usb_serial *serial = port->serial;
338 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
339 	void *dmabuf;
340 	int result;
341 
342 	dmabuf = kmalloc(bufsize, GFP_KERNEL);
343 	if (!dmabuf) {
344 		/*
345 		 * FIXME Some callers don't bother to check for error,
346 		 * at least give them consistent junk until they are fixed
347 		 */
348 		memset(buf, 0, bufsize);
349 		return -ENOMEM;
350 	}
351 
352 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
353 			req, REQTYPE_INTERFACE_TO_HOST, 0,
354 			port_priv->bInterfaceNumber, dmabuf, bufsize,
355 			USB_CTRL_SET_TIMEOUT);
356 	if (result == bufsize) {
357 		memcpy(buf, dmabuf, bufsize);
358 		result = 0;
359 	} else {
360 		dev_err(&port->dev, "failed get req 0x%x size %d status: %d\n",
361 				req, bufsize, result);
362 		if (result >= 0)
363 			result = -EPROTO;
364 
365 		/*
366 		 * FIXME Some callers don't bother to check for error,
367 		 * at least give them consistent junk until they are fixed
368 		 */
369 		memset(buf, 0, bufsize);
370 	}
371 
372 	kfree(dmabuf);
373 
374 	return result;
375 }
376 
377 /*
378  * Reads any 32-bit CP210X_ register identified by req.
379  */
380 static int cp210x_read_u32_reg(struct usb_serial_port *port, u8 req, u32 *val)
381 {
382 	__le32 le32_val;
383 	int err;
384 
385 	err = cp210x_read_reg_block(port, req, &le32_val, sizeof(le32_val));
386 	if (err) {
387 		/*
388 		 * FIXME Some callers don't bother to check for error,
389 		 * at least give them consistent junk until they are fixed
390 		 */
391 		*val = 0;
392 		return err;
393 	}
394 
395 	*val = le32_to_cpu(le32_val);
396 
397 	return 0;
398 }
399 
400 /*
401  * Reads any 16-bit CP210X_ register identified by req.
402  */
403 static int cp210x_read_u16_reg(struct usb_serial_port *port, u8 req, u16 *val)
404 {
405 	__le16 le16_val;
406 	int err;
407 
408 	err = cp210x_read_reg_block(port, req, &le16_val, sizeof(le16_val));
409 	if (err)
410 		return err;
411 
412 	*val = le16_to_cpu(le16_val);
413 
414 	return 0;
415 }
416 
417 /*
418  * Reads any 8-bit CP210X_ register identified by req.
419  */
420 static int cp210x_read_u8_reg(struct usb_serial_port *port, u8 req, u8 *val)
421 {
422 	return cp210x_read_reg_block(port, req, val, sizeof(*val));
423 }
424 
425 /*
426  * Writes any 16-bit CP210X_ register (req) whose value is passed
427  * entirely in the wValue field of the USB request.
428  */
429 static int cp210x_write_u16_reg(struct usb_serial_port *port, u8 req, u16 val)
430 {
431 	struct usb_serial *serial = port->serial;
432 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
433 	int result;
434 
435 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
436 			req, REQTYPE_HOST_TO_INTERFACE, val,
437 			port_priv->bInterfaceNumber, NULL, 0,
438 			USB_CTRL_SET_TIMEOUT);
439 	if (result < 0) {
440 		dev_err(&port->dev, "failed set request 0x%x status: %d\n",
441 				req, result);
442 	}
443 
444 	return result;
445 }
446 
447 /*
448  * Writes a variable-sized block of CP210X_ registers, identified by req.
449  * Data in buf must be in native USB byte order.
450  */
451 static int cp210x_write_reg_block(struct usb_serial_port *port, u8 req,
452 		void *buf, int bufsize)
453 {
454 	struct usb_serial *serial = port->serial;
455 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
456 	void *dmabuf;
457 	int result;
458 
459 	dmabuf = kmalloc(bufsize, GFP_KERNEL);
460 	if (!dmabuf)
461 		return -ENOMEM;
462 
463 	memcpy(dmabuf, buf, bufsize);
464 
465 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
466 			req, REQTYPE_HOST_TO_INTERFACE, 0,
467 			port_priv->bInterfaceNumber, dmabuf, bufsize,
468 			USB_CTRL_SET_TIMEOUT);
469 
470 	kfree(dmabuf);
471 
472 	if (result == bufsize) {
473 		result = 0;
474 	} else {
475 		dev_err(&port->dev, "failed set req 0x%x size %d status: %d\n",
476 				req, bufsize, result);
477 		if (result >= 0)
478 			result = -EPROTO;
479 	}
480 
481 	return result;
482 }
483 
484 /*
485  * Writes any 32-bit CP210X_ register identified by req.
486  */
487 static int cp210x_write_u32_reg(struct usb_serial_port *port, u8 req, u32 val)
488 {
489 	__le32 le32_val;
490 
491 	le32_val = cpu_to_le32(val);
492 
493 	return cp210x_write_reg_block(port, req, &le32_val, sizeof(le32_val));
494 }
495 
496 /*
497  * Detect CP2108 GET_LINE_CTL bug and activate workaround.
498  * Write a known good value 0x800, read it back.
499  * If it comes back swapped the bug is detected.
500  * Preserve the original register value.
501  */
502 static int cp210x_detect_swapped_line_ctl(struct usb_serial_port *port)
503 {
504 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
505 	u16 line_ctl_save;
506 	u16 line_ctl_test;
507 	int err;
508 
509 	err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, &line_ctl_save);
510 	if (err)
511 		return err;
512 
513 	err = cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, 0x800);
514 	if (err)
515 		return err;
516 
517 	err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, &line_ctl_test);
518 	if (err)
519 		return err;
520 
521 	if (line_ctl_test == 8) {
522 		port_priv->has_swapped_line_ctl = true;
523 		line_ctl_save = swab16(line_ctl_save);
524 	}
525 
526 	return cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, line_ctl_save);
527 }
528 
529 /*
530  * Must always be called instead of cp210x_read_u16_reg(CP210X_GET_LINE_CTL)
531  * to workaround cp2108 bug and get correct value.
532  */
533 static int cp210x_get_line_ctl(struct usb_serial_port *port, u16 *ctl)
534 {
535 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
536 	int err;
537 
538 	err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, ctl);
539 	if (err)
540 		return err;
541 
542 	/* Workaround swapped bytes in 16-bit value from CP210X_GET_LINE_CTL */
543 	if (port_priv->has_swapped_line_ctl)
544 		*ctl = swab16(*ctl);
545 
546 	return 0;
547 }
548 
549 /*
550  * cp210x_quantise_baudrate
551  * Quantises the baud rate as per AN205 Table 1
552  */
553 static unsigned int cp210x_quantise_baudrate(unsigned int baud)
554 {
555 	if (baud <= 300)
556 		baud = 300;
557 	else if (baud <= 600)      baud = 600;
558 	else if (baud <= 1200)     baud = 1200;
559 	else if (baud <= 1800)     baud = 1800;
560 	else if (baud <= 2400)     baud = 2400;
561 	else if (baud <= 4000)     baud = 4000;
562 	else if (baud <= 4803)     baud = 4800;
563 	else if (baud <= 7207)     baud = 7200;
564 	else if (baud <= 9612)     baud = 9600;
565 	else if (baud <= 14428)    baud = 14400;
566 	else if (baud <= 16062)    baud = 16000;
567 	else if (baud <= 19250)    baud = 19200;
568 	else if (baud <= 28912)    baud = 28800;
569 	else if (baud <= 38601)    baud = 38400;
570 	else if (baud <= 51558)    baud = 51200;
571 	else if (baud <= 56280)    baud = 56000;
572 	else if (baud <= 58053)    baud = 57600;
573 	else if (baud <= 64111)    baud = 64000;
574 	else if (baud <= 77608)    baud = 76800;
575 	else if (baud <= 117028)   baud = 115200;
576 	else if (baud <= 129347)   baud = 128000;
577 	else if (baud <= 156868)   baud = 153600;
578 	else if (baud <= 237832)   baud = 230400;
579 	else if (baud <= 254234)   baud = 250000;
580 	else if (baud <= 273066)   baud = 256000;
581 	else if (baud <= 491520)   baud = 460800;
582 	else if (baud <= 567138)   baud = 500000;
583 	else if (baud <= 670254)   baud = 576000;
584 	else if (baud < 1000000)
585 		baud = 921600;
586 	else if (baud > 2000000)
587 		baud = 2000000;
588 	return baud;
589 }
590 
591 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
592 {
593 	int result;
594 
595 	result = cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_ENABLE);
596 	if (result) {
597 		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
598 		return result;
599 	}
600 
601 	/* Configure the termios structure */
602 	cp210x_get_termios(tty, port);
603 
604 	/* The baud rate must be initialised on cp2104 */
605 	if (tty)
606 		cp210x_change_speed(tty, port, NULL);
607 
608 	return usb_serial_generic_open(tty, port);
609 }
610 
611 static void cp210x_close(struct usb_serial_port *port)
612 {
613 	usb_serial_generic_close(port);
614 
615 	/* Clear both queues; cp2108 needs this to avoid an occasional hang */
616 	cp210x_write_u16_reg(port, CP210X_PURGE, PURGE_ALL);
617 
618 	cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);
619 }
620 
621 /*
622  * Read how many bytes are waiting in the TX queue.
623  */
624 static int cp210x_get_tx_queue_byte_count(struct usb_serial_port *port,
625 		u32 *count)
626 {
627 	struct usb_serial *serial = port->serial;
628 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
629 	struct cp210x_comm_status *sts;
630 	int result;
631 
632 	sts = kmalloc(sizeof(*sts), GFP_KERNEL);
633 	if (!sts)
634 		return -ENOMEM;
635 
636 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
637 			CP210X_GET_COMM_STATUS, REQTYPE_INTERFACE_TO_HOST,
638 			0, port_priv->bInterfaceNumber, sts, sizeof(*sts),
639 			USB_CTRL_GET_TIMEOUT);
640 	if (result == sizeof(*sts)) {
641 		*count = le32_to_cpu(sts->ulAmountInOutQueue);
642 		result = 0;
643 	} else {
644 		dev_err(&port->dev, "failed to get comm status: %d\n", result);
645 		if (result >= 0)
646 			result = -EPROTO;
647 	}
648 
649 	kfree(sts);
650 
651 	return result;
652 }
653 
654 static bool cp210x_tx_empty(struct usb_serial_port *port)
655 {
656 	int err;
657 	u32 count;
658 
659 	err = cp210x_get_tx_queue_byte_count(port, &count);
660 	if (err)
661 		return true;
662 
663 	return !count;
664 }
665 
666 /*
667  * cp210x_get_termios
668  * Reads the baud rate, data bits, parity, stop bits and flow control mode
669  * from the device, corrects any unsupported values, and configures the
670  * termios structure to reflect the state of the device
671  */
672 static void cp210x_get_termios(struct tty_struct *tty,
673 	struct usb_serial_port *port)
674 {
675 	unsigned int baud;
676 
677 	if (tty) {
678 		cp210x_get_termios_port(tty->driver_data,
679 			&tty->termios.c_cflag, &baud);
680 		tty_encode_baud_rate(tty, baud, baud);
681 	} else {
682 		unsigned int cflag;
683 		cflag = 0;
684 		cp210x_get_termios_port(port, &cflag, &baud);
685 	}
686 }
687 
688 /*
689  * cp210x_get_termios_port
690  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
691  */
692 static void cp210x_get_termios_port(struct usb_serial_port *port,
693 	unsigned int *cflagp, unsigned int *baudp)
694 {
695 	struct device *dev = &port->dev;
696 	unsigned int cflag;
697 	u8 modem_ctl[16];
698 	u32 baud;
699 	u16 bits;
700 
701 	cp210x_read_u32_reg(port, CP210X_GET_BAUDRATE, &baud);
702 
703 	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
704 	*baudp = baud;
705 
706 	cflag = *cflagp;
707 
708 	cp210x_get_line_ctl(port, &bits);
709 	cflag &= ~CSIZE;
710 	switch (bits & BITS_DATA_MASK) {
711 	case BITS_DATA_5:
712 		dev_dbg(dev, "%s - data bits = 5\n", __func__);
713 		cflag |= CS5;
714 		break;
715 	case BITS_DATA_6:
716 		dev_dbg(dev, "%s - data bits = 6\n", __func__);
717 		cflag |= CS6;
718 		break;
719 	case BITS_DATA_7:
720 		dev_dbg(dev, "%s - data bits = 7\n", __func__);
721 		cflag |= CS7;
722 		break;
723 	case BITS_DATA_8:
724 		dev_dbg(dev, "%s - data bits = 8\n", __func__);
725 		cflag |= CS8;
726 		break;
727 	case BITS_DATA_9:
728 		dev_dbg(dev, "%s - data bits = 9 (not supported, using 8 data bits)\n", __func__);
729 		cflag |= CS8;
730 		bits &= ~BITS_DATA_MASK;
731 		bits |= BITS_DATA_8;
732 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
733 		break;
734 	default:
735 		dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
736 		cflag |= CS8;
737 		bits &= ~BITS_DATA_MASK;
738 		bits |= BITS_DATA_8;
739 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
740 		break;
741 	}
742 
743 	switch (bits & BITS_PARITY_MASK) {
744 	case BITS_PARITY_NONE:
745 		dev_dbg(dev, "%s - parity = NONE\n", __func__);
746 		cflag &= ~PARENB;
747 		break;
748 	case BITS_PARITY_ODD:
749 		dev_dbg(dev, "%s - parity = ODD\n", __func__);
750 		cflag |= (PARENB|PARODD);
751 		break;
752 	case BITS_PARITY_EVEN:
753 		dev_dbg(dev, "%s - parity = EVEN\n", __func__);
754 		cflag &= ~PARODD;
755 		cflag |= PARENB;
756 		break;
757 	case BITS_PARITY_MARK:
758 		dev_dbg(dev, "%s - parity = MARK\n", __func__);
759 		cflag |= (PARENB|PARODD|CMSPAR);
760 		break;
761 	case BITS_PARITY_SPACE:
762 		dev_dbg(dev, "%s - parity = SPACE\n", __func__);
763 		cflag &= ~PARODD;
764 		cflag |= (PARENB|CMSPAR);
765 		break;
766 	default:
767 		dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
768 		cflag &= ~PARENB;
769 		bits &= ~BITS_PARITY_MASK;
770 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
771 		break;
772 	}
773 
774 	cflag &= ~CSTOPB;
775 	switch (bits & BITS_STOP_MASK) {
776 	case BITS_STOP_1:
777 		dev_dbg(dev, "%s - stop bits = 1\n", __func__);
778 		break;
779 	case BITS_STOP_1_5:
780 		dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
781 		bits &= ~BITS_STOP_MASK;
782 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
783 		break;
784 	case BITS_STOP_2:
785 		dev_dbg(dev, "%s - stop bits = 2\n", __func__);
786 		cflag |= CSTOPB;
787 		break;
788 	default:
789 		dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __func__);
790 		bits &= ~BITS_STOP_MASK;
791 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
792 		break;
793 	}
794 
795 	cp210x_read_reg_block(port, CP210X_GET_FLOW, modem_ctl,
796 			sizeof(modem_ctl));
797 	if (modem_ctl[0] & 0x08) {
798 		dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
799 		cflag |= CRTSCTS;
800 	} else {
801 		dev_dbg(dev, "%s - flow control = NONE\n", __func__);
802 		cflag &= ~CRTSCTS;
803 	}
804 
805 	*cflagp = cflag;
806 }
807 
808 /*
809  * CP2101 supports the following baud rates:
810  *
811  *	300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
812  *	38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
813  *
814  * CP2102 and CP2103 support the following additional rates:
815  *
816  *	4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
817  *	576000
818  *
819  * The device will map a requested rate to a supported one, but the result
820  * of requests for rates greater than 1053257 is undefined (see AN205).
821  *
822  * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
823  * respectively, with an error less than 1%. The actual rates are determined
824  * by
825  *
826  *	div = round(freq / (2 x prescale x request))
827  *	actual = freq / (2 x prescale x div)
828  *
829  * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
830  * or 1 otherwise.
831  * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
832  * otherwise.
833  */
834 static void cp210x_change_speed(struct tty_struct *tty,
835 		struct usb_serial_port *port, struct ktermios *old_termios)
836 {
837 	u32 baud;
838 
839 	baud = tty->termios.c_ospeed;
840 
841 	/* This maps the requested rate to a rate valid on cp2102 or cp2103,
842 	 * or to an arbitrary rate in [1M,2M].
843 	 *
844 	 * NOTE: B0 is not implemented.
845 	 */
846 	baud = cp210x_quantise_baudrate(baud);
847 
848 	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
849 	if (cp210x_write_u32_reg(port, CP210X_SET_BAUDRATE, baud)) {
850 		dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
851 		if (old_termios)
852 			baud = old_termios->c_ospeed;
853 		else
854 			baud = 9600;
855 	}
856 
857 	tty_encode_baud_rate(tty, baud, baud);
858 }
859 
860 static void cp210x_set_termios(struct tty_struct *tty,
861 		struct usb_serial_port *port, struct ktermios *old_termios)
862 {
863 	struct device *dev = &port->dev;
864 	unsigned int cflag, old_cflag;
865 	u16 bits;
866 	u8 modem_ctl[16];
867 
868 	cflag = tty->termios.c_cflag;
869 	old_cflag = old_termios->c_cflag;
870 
871 	if (tty->termios.c_ospeed != old_termios->c_ospeed)
872 		cp210x_change_speed(tty, port, old_termios);
873 
874 	/* If the number of data bits is to be updated */
875 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
876 		cp210x_get_line_ctl(port, &bits);
877 		bits &= ~BITS_DATA_MASK;
878 		switch (cflag & CSIZE) {
879 		case CS5:
880 			bits |= BITS_DATA_5;
881 			dev_dbg(dev, "%s - data bits = 5\n", __func__);
882 			break;
883 		case CS6:
884 			bits |= BITS_DATA_6;
885 			dev_dbg(dev, "%s - data bits = 6\n", __func__);
886 			break;
887 		case CS7:
888 			bits |= BITS_DATA_7;
889 			dev_dbg(dev, "%s - data bits = 7\n", __func__);
890 			break;
891 		case CS8:
892 			bits |= BITS_DATA_8;
893 			dev_dbg(dev, "%s - data bits = 8\n", __func__);
894 			break;
895 		/*case CS9:
896 			bits |= BITS_DATA_9;
897 			dev_dbg(dev, "%s - data bits = 9\n", __func__);
898 			break;*/
899 		default:
900 			dev_dbg(dev, "cp210x driver does not support the number of bits requested, using 8 bit mode\n");
901 			bits |= BITS_DATA_8;
902 			break;
903 		}
904 		if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
905 			dev_dbg(dev, "Number of data bits requested not supported by device\n");
906 	}
907 
908 	if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
909 	    (old_cflag & (PARENB|PARODD|CMSPAR))) {
910 		cp210x_get_line_ctl(port, &bits);
911 		bits &= ~BITS_PARITY_MASK;
912 		if (cflag & PARENB) {
913 			if (cflag & CMSPAR) {
914 				if (cflag & PARODD) {
915 					bits |= BITS_PARITY_MARK;
916 					dev_dbg(dev, "%s - parity = MARK\n", __func__);
917 				} else {
918 					bits |= BITS_PARITY_SPACE;
919 					dev_dbg(dev, "%s - parity = SPACE\n", __func__);
920 				}
921 			} else {
922 				if (cflag & PARODD) {
923 					bits |= BITS_PARITY_ODD;
924 					dev_dbg(dev, "%s - parity = ODD\n", __func__);
925 				} else {
926 					bits |= BITS_PARITY_EVEN;
927 					dev_dbg(dev, "%s - parity = EVEN\n", __func__);
928 				}
929 			}
930 		}
931 		if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
932 			dev_dbg(dev, "Parity mode not supported by device\n");
933 	}
934 
935 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
936 		cp210x_get_line_ctl(port, &bits);
937 		bits &= ~BITS_STOP_MASK;
938 		if (cflag & CSTOPB) {
939 			bits |= BITS_STOP_2;
940 			dev_dbg(dev, "%s - stop bits = 2\n", __func__);
941 		} else {
942 			bits |= BITS_STOP_1;
943 			dev_dbg(dev, "%s - stop bits = 1\n", __func__);
944 		}
945 		if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
946 			dev_dbg(dev, "Number of stop bits requested not supported by device\n");
947 	}
948 
949 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
950 
951 		/* Only bytes 0, 4 and 7 out of first 8 have functional bits */
952 
953 		cp210x_read_reg_block(port, CP210X_GET_FLOW, modem_ctl,
954 				sizeof(modem_ctl));
955 		dev_dbg(dev, "%s - read modem controls = %02x .. .. .. %02x .. .. %02x\n",
956 			__func__, modem_ctl[0], modem_ctl[4], modem_ctl[7]);
957 
958 		if (cflag & CRTSCTS) {
959 			modem_ctl[0] &= ~0x7B;
960 			modem_ctl[0] |= 0x09;
961 			modem_ctl[4] = 0x80;
962 			/* FIXME - why clear reserved bits just read? */
963 			modem_ctl[5] = 0;
964 			modem_ctl[6] = 0;
965 			modem_ctl[7] = 0;
966 			dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
967 		} else {
968 			modem_ctl[0] &= ~0x7B;
969 			modem_ctl[0] |= 0x01;
970 			/* FIXME - OR here instead of assignment looks wrong */
971 			modem_ctl[4] |= 0x40;
972 			dev_dbg(dev, "%s - flow control = NONE\n", __func__);
973 		}
974 
975 		dev_dbg(dev, "%s - write modem controls = %02x .. .. .. %02x .. .. %02x\n",
976 			__func__, modem_ctl[0], modem_ctl[4], modem_ctl[7]);
977 		cp210x_write_reg_block(port, CP210X_SET_FLOW, modem_ctl,
978 				sizeof(modem_ctl));
979 	}
980 
981 }
982 
983 static int cp210x_tiocmset(struct tty_struct *tty,
984 		unsigned int set, unsigned int clear)
985 {
986 	struct usb_serial_port *port = tty->driver_data;
987 	return cp210x_tiocmset_port(port, set, clear);
988 }
989 
990 static int cp210x_tiocmset_port(struct usb_serial_port *port,
991 		unsigned int set, unsigned int clear)
992 {
993 	u16 control = 0;
994 
995 	if (set & TIOCM_RTS) {
996 		control |= CONTROL_RTS;
997 		control |= CONTROL_WRITE_RTS;
998 	}
999 	if (set & TIOCM_DTR) {
1000 		control |= CONTROL_DTR;
1001 		control |= CONTROL_WRITE_DTR;
1002 	}
1003 	if (clear & TIOCM_RTS) {
1004 		control &= ~CONTROL_RTS;
1005 		control |= CONTROL_WRITE_RTS;
1006 	}
1007 	if (clear & TIOCM_DTR) {
1008 		control &= ~CONTROL_DTR;
1009 		control |= CONTROL_WRITE_DTR;
1010 	}
1011 
1012 	dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
1013 
1014 	return cp210x_write_u16_reg(port, CP210X_SET_MHS, control);
1015 }
1016 
1017 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
1018 {
1019 	if (on)
1020 		cp210x_tiocmset_port(p, TIOCM_DTR|TIOCM_RTS, 0);
1021 	else
1022 		cp210x_tiocmset_port(p, 0, TIOCM_DTR|TIOCM_RTS);
1023 }
1024 
1025 static int cp210x_tiocmget(struct tty_struct *tty)
1026 {
1027 	struct usb_serial_port *port = tty->driver_data;
1028 	u8 control;
1029 	int result;
1030 
1031 	cp210x_read_u8_reg(port, CP210X_GET_MDMSTS, &control);
1032 
1033 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
1034 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
1035 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
1036 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
1037 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
1038 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
1039 
1040 	dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);
1041 
1042 	return result;
1043 }
1044 
1045 static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
1046 {
1047 	struct usb_serial_port *port = tty->driver_data;
1048 	u16 state;
1049 
1050 	if (break_state == 0)
1051 		state = BREAK_OFF;
1052 	else
1053 		state = BREAK_ON;
1054 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
1055 		state == BREAK_OFF ? "off" : "on");
1056 	cp210x_write_u16_reg(port, CP210X_SET_BREAK, state);
1057 }
1058 
1059 static int cp210x_port_probe(struct usb_serial_port *port)
1060 {
1061 	struct usb_serial *serial = port->serial;
1062 	struct usb_host_interface *cur_altsetting;
1063 	struct cp210x_port_private *port_priv;
1064 	int ret;
1065 
1066 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
1067 	if (!port_priv)
1068 		return -ENOMEM;
1069 
1070 	cur_altsetting = serial->interface->cur_altsetting;
1071 	port_priv->bInterfaceNumber = cur_altsetting->desc.bInterfaceNumber;
1072 
1073 	usb_set_serial_port_data(port, port_priv);
1074 
1075 	ret = cp210x_detect_swapped_line_ctl(port);
1076 	if (ret) {
1077 		kfree(port_priv);
1078 		return ret;
1079 	}
1080 
1081 	return 0;
1082 }
1083 
1084 static int cp210x_port_remove(struct usb_serial_port *port)
1085 {
1086 	struct cp210x_port_private *port_priv;
1087 
1088 	port_priv = usb_get_serial_port_data(port);
1089 	kfree(port_priv);
1090 
1091 	return 0;
1092 }
1093 
1094 module_usb_serial_driver(serial_drivers, id_table);
1095 
1096 MODULE_DESCRIPTION(DRIVER_DESC);
1097 MODULE_LICENSE("GPL");
1098