drivers/usb/serial/cp210x.c

   1 /*
   2  * Silicon Laboratories CP210x USB to RS232 serial adaptor driver
   3  *
   4  * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License version
   8  *      2 as published by the Free Software Foundation.
   9  *
  10  * Support to set flow control line levels using TIOCMGET and TIOCMSET
  11  * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
  12  * control thanks to Munir Nassar nassarmu@real-time.com
  13  *
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <linux/tty.h>
  20 #include <linux/tty_flip.h>
  21 #include <linux/module.h>
  22 #include <linux/moduleparam.h>
  23 #include <linux/usb.h>
  24 #include <linux/uaccess.h>
  25 #include <linux/usb/serial.h>
  26
  27 #define DRIVER_DESC "Silicon Labs CP210x RS232 serial adaptor driver"
  28
  29 /*
  30  * Function Prototypes
  31  */
  32 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
  33 static void cp210x_close(struct usb_serial_port *);
  34 static void cp210x_get_termios(struct tty_struct *, struct usb_serial_port *);
  35 static void cp210x_get_termios_port(struct usb_serial_port *port,
  36         unsigned int *cflagp, unsigned int *baudp);
  37 static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
  38                                                         struct ktermios *);
  39 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
  40                                                         struct ktermios*);
  41 static int cp210x_tiocmget(struct tty_struct *);
  42 static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
  43 static int cp210x_tiocmset_port(struct usb_serial_port *port,
  44                 unsigned int, unsigned int);
  45 static void cp210x_break_ctl(struct tty_struct *, int);
  46 static int cp210x_startup(struct usb_serial *);
  47 static void cp210x_release(struct usb_serial *);
  48 static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
  49
  50 static const struct usb_device_id id_table[] = {
  51         { USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
  52         { USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
  53         { USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
  54         { USB_DEVICE(0x0489, 0xE003) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
  55         { USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
  56         { USB_DEVICE(0x0846, 0x1100) }, /* NetGear Managed Switch M4100 series, M5300 series, M7100 series */
  57         { USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
  58         { USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
  59         { USB_DEVICE(0x0908, 0x01FF) }, /* Siemens RUGGEDCOM USB Serial Console */
  60         { USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
  61         { USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
  62         { USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
  63         { USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
  64         { USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
  65         { USB_DEVICE(0x0FDE, 0xCA05) }, /* OWL Wireless Electricity Monitor CM-160 */
  66         { USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
  67         { USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
  68         { USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
  69         { USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
  70         { USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
  71         { USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
  72         { USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
  73         { USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
  74         { USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
  75         { USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
  76         { USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
  77         { USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
  78         { USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
  79         { USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
  80         { USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
  81         { USB_DEVICE(0x10C4, 0x80C4) }, /* Cygnal Integrated Products, Inc., Optris infrared thermometer */
  82         { USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
  83         { USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
  84         { USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
  85         { USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
  86         { USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
  87         { USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
  88         { USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
  89         { USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
  90         { USB_DEVICE(0x2405, 0x0003) }, /* West Mountain Radio RIGblaster Advantage */
  91         { USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
  92         { USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
  93         { USB_DEVICE(0x10C4, 0x815F) }, /* Timewave HamLinkUSB */
  94         { USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
  95         { USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
  96         { USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
  97         { USB_DEVICE(0x10C4, 0x81A9) }, /* Multiplex RC Interface */
  98         { USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
  99         { USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
 100         { USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
 101         { USB_DEVICE(0x10C4, 0x81D7) }, /* IAI Corp. RCB-CV-USB USB to RS485 Adaptor */
 102         { USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
 103         { USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
 104         { USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
 105         { USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
 106         { USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
 107         { USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
 108         { USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
 109         { USB_DEVICE(0x10C4, 0x8281) }, /* Nanotec Plug & Drive */
 110         { USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
 111         { USB_DEVICE(0x10C4, 0x82F4) }, /* Starizona MicroTouch */
 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, 0x84B6) }, /* Starizona Hyperion */
 122         { USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
 123         { USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
 124         { USB_DEVICE(0x10C4, 0x85F8) }, /* Virtenio Preon32 */
 125         { USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
 126         { USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
 127         { USB_DEVICE(0x10C4, 0x8856) }, /* CEL EM357 ZigBee USB Stick - LR */
 128         { USB_DEVICE(0x10C4, 0x8857) }, /* CEL EM357 ZigBee USB Stick */
 129         { USB_DEVICE(0x10C4, 0x88A4) }, /* MMB Networks ZigBee USB Device */
 130         { USB_DEVICE(0x10C4, 0x88A5) }, /* Planet Innovation Ingeni ZigBee USB Device */
 131         { USB_DEVICE(0x10C4, 0x8946) }, /* Ketra N1 Wireless Interface */
 132         { USB_DEVICE(0x10C4, 0x8977) }, /* CEL MeshWorks DevKit Device */
 133         { USB_DEVICE(0x10C4, 0x8998) }, /* KCF Technologies PRN */
 134         { USB_DEVICE(0x10C4, 0x8A2A) }, /* HubZ dual ZigBee and Z-Wave dongle */
 135         { USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
 136         { USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
 137         { USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
 138         { USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
 139         { USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
 140         { USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
 141         { USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
 142         { USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
 143         { USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
 144         { USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
 145         { USB_DEVICE(0x12B8, 0xEC60) }, /* Link G4 ECU */
 146         { USB_DEVICE(0x12B8, 0xEC62) }, /* Link G4+ ECU */
 147         { USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
 148         { USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
 149         { USB_DEVICE(0x166A, 0x0201) }, /* Clipsal 5500PACA C-Bus Pascal Automation Controller */
 150         { USB_DEVICE(0x166A, 0x0301) }, /* Clipsal 5800PC C-Bus Wireless PC Interface */
 151         { USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
 152         { USB_DEVICE(0x166A, 0x0304) }, /* Clipsal 5000CT2 C-Bus Black and White Touchscreen */
 153         { USB_DEVICE(0x166A, 0x0305) }, /* Clipsal C-5000CT2 C-Bus Spectrum Colour Touchscreen */
 154         { USB_DEVICE(0x166A, 0x0401) }, /* Clipsal L51xx C-Bus Architectural Dimmer */
 155         { USB_DEVICE(0x166A, 0x0101) }, /* Clipsal 5560884 C-Bus Multi-room Audio Matrix Switcher */
 156         { USB_DEVICE(0x16C0, 0x09B0) }, /* Lunatico Seletek */
 157         { USB_DEVICE(0x16C0, 0x09B1) }, /* Lunatico Seletek */
 158         { USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
 159         { USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
 160         { USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
 161         { USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
 162         { USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
 163         { USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
 164         { USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
 165         { USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
 166         { USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
 167         { USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
 168         { USB_DEVICE(0x18EF, 0xE025) }, /* ELV Marble Sound Board 1 */
 169         { USB_DEVICE(0x1901, 0x0190) }, /* GE B850 CP2105 Recorder interface */
 170         { USB_DEVICE(0x1901, 0x0193) }, /* GE B650 CP2104 PMC interface */
 171         { USB_DEVICE(0x1901, 0x0194) }, /* GE Healthcare Remote Alarm Box */
 172         { USB_DEVICE(0x19CF, 0x3000) }, /* Parrot NMEA GPS Flight Recorder */
 173         { USB_DEVICE(0x1ADB, 0x0001) }, /* Schweitzer Engineering C662 Cable */
 174         { USB_DEVICE(0x1B1C, 0x1C00) }, /* Corsair USB Dongle */
 175         { USB_DEVICE(0x1BA4, 0x0002) }, /* Silicon Labs 358x factory default */
 176         { USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
 177         { USB_DEVICE(0x1D6F, 0x0010) }, /* Seluxit ApS RF Dongle */
 178         { USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
 179         { USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
 180         { USB_DEVICE(0x1FB9, 0x0100) }, /* Lake Shore Model 121 Current Source */
 181         { USB_DEVICE(0x1FB9, 0x0200) }, /* Lake Shore Model 218A Temperature Monitor */
 182         { USB_DEVICE(0x1FB9, 0x0201) }, /* Lake Shore Model 219 Temperature Monitor */
 183         { USB_DEVICE(0x1FB9, 0x0202) }, /* Lake Shore Model 233 Temperature Transmitter */
 184         { USB_DEVICE(0x1FB9, 0x0203) }, /* Lake Shore Model 235 Temperature Transmitter */
 185         { USB_DEVICE(0x1FB9, 0x0300) }, /* Lake Shore Model 335 Temperature Controller */
 186         { USB_DEVICE(0x1FB9, 0x0301) }, /* Lake Shore Model 336 Temperature Controller */
 187         { USB_DEVICE(0x1FB9, 0x0302) }, /* Lake Shore Model 350 Temperature Controller */
 188         { USB_DEVICE(0x1FB9, 0x0303) }, /* Lake Shore Model 371 AC Bridge */
 189         { USB_DEVICE(0x1FB9, 0x0400) }, /* Lake Shore Model 411 Handheld Gaussmeter */
 190         { USB_DEVICE(0x1FB9, 0x0401) }, /* Lake Shore Model 425 Gaussmeter */
 191         { USB_DEVICE(0x1FB9, 0x0402) }, /* Lake Shore Model 455A Gaussmeter */
 192         { USB_DEVICE(0x1FB9, 0x0403) }, /* Lake Shore Model 475A Gaussmeter */
 193         { USB_DEVICE(0x1FB9, 0x0404) }, /* Lake Shore Model 465 Three Axis Gaussmeter */
 194         { USB_DEVICE(0x1FB9, 0x0600) }, /* Lake Shore Model 625A Superconducting MPS */
 195         { USB_DEVICE(0x1FB9, 0x0601) }, /* Lake Shore Model 642A Magnet Power Supply */
 196         { USB_DEVICE(0x1FB9, 0x0602) }, /* Lake Shore Model 648 Magnet Power Supply */
 197         { USB_DEVICE(0x1FB9, 0x0700) }, /* Lake Shore Model 737 VSM Controller */
 198         { USB_DEVICE(0x1FB9, 0x0701) }, /* Lake Shore Model 776 Hall Matrix */
 199         { USB_DEVICE(0x2626, 0xEA60) }, /* Aruba Networks 7xxx USB Serial Console */
 200         { USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
 201         { USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
 202         { USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
 203         { USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
 204         { } /* Terminating Entry */
 205 };
 206
 207 MODULE_DEVICE_TABLE(usb, id_table);
 208
 209 struct cp210x_serial_private {
 210         __u8                    bInterfaceNumber;
 211 };
 212
 213 static struct usb_serial_driver cp210x_device = {
 214         .driver = {
 215                 .owner =        THIS_MODULE,
 216                 .name =         "cp210x",
 217         },
 218         .id_table               = id_table,
 219         .num_ports              = 1,
 220         .bulk_in_size           = 256,
 221         .bulk_out_size          = 256,
 222         .open                   = cp210x_open,
 223         .close                  = cp210x_close,
 224         .break_ctl              = cp210x_break_ctl,
 225         .set_termios            = cp210x_set_termios,
 226         .tiocmget               = cp210x_tiocmget,
 227         .tiocmset               = cp210x_tiocmset,
 228         .attach                 = cp210x_startup,
 229         .release                = cp210x_release,
 230         .dtr_rts                = cp210x_dtr_rts
 231 };
 232
 233 static struct usb_serial_driver * const serial_drivers[] = {
 234         &cp210x_device, NULL
 235 };
 236
 237 /* Config request types */
 238 #define REQTYPE_HOST_TO_INTERFACE       0x41
 239 #define REQTYPE_INTERFACE_TO_HOST       0xc1
 240 #define REQTYPE_HOST_TO_DEVICE  0x40
 241 #define REQTYPE_DEVICE_TO_HOST  0xc0
 242
 243 /* Config request codes */
 244 #define CP210X_IFC_ENABLE       0x00
 245 #define CP210X_SET_BAUDDIV      0x01
 246 #define CP210X_GET_BAUDDIV      0x02
 247 #define CP210X_SET_LINE_CTL     0x03
 248 #define CP210X_GET_LINE_CTL     0x04
 249 #define CP210X_SET_BREAK        0x05
 250 #define CP210X_IMM_CHAR         0x06
 251 #define CP210X_SET_MHS          0x07
 252 #define CP210X_GET_MDMSTS       0x08
 253 #define CP210X_SET_XON          0x09
 254 #define CP210X_SET_XOFF         0x0A
 255 #define CP210X_SET_EVENTMASK    0x0B
 256 #define CP210X_GET_EVENTMASK    0x0C
 257 #define CP210X_SET_CHAR         0x0D
 258 #define CP210X_GET_CHARS        0x0E
 259 #define CP210X_GET_PROPS        0x0F
 260 #define CP210X_GET_COMM_STATUS  0x10
 261 #define CP210X_RESET            0x11
 262 #define CP210X_PURGE            0x12
 263 #define CP210X_SET_FLOW         0x13
 264 #define CP210X_GET_FLOW         0x14
 265 #define CP210X_EMBED_EVENTS     0x15
 266 #define CP210X_GET_EVENTSTATE   0x16
 267 #define CP210X_SET_CHARS        0x19
 268 #define CP210X_GET_BAUDRATE     0x1D
 269 #define CP210X_SET_BAUDRATE     0x1E
 270
 271 /* CP210X_IFC_ENABLE */
 272 #define UART_ENABLE             0x0001
 273 #define UART_DISABLE            0x0000
 274
 275 /* CP210X_(SET|GET)_BAUDDIV */
 276 #define BAUD_RATE_GEN_FREQ      0x384000
 277
 278 /* CP210X_(SET|GET)_LINE_CTL */
 279 #define BITS_DATA_MASK          0X0f00
 280 #define BITS_DATA_5             0X0500
 281 #define BITS_DATA_6             0X0600
 282 #define BITS_DATA_7             0X0700
 283 #define BITS_DATA_8             0X0800
 284 #define BITS_DATA_9             0X0900
 285
 286 #define BITS_PARITY_MASK        0x00f0
 287 #define BITS_PARITY_NONE        0x0000
 288 #define BITS_PARITY_ODD         0x0010
 289 #define BITS_PARITY_EVEN        0x0020
 290 #define BITS_PARITY_MARK        0x0030
 291 #define BITS_PARITY_SPACE       0x0040
 292
 293 #define BITS_STOP_MASK          0x000f
 294 #define BITS_STOP_1             0x0000
 295 #define BITS_STOP_1_5           0x0001
 296 #define BITS_STOP_2             0x0002
 297
 298 /* CP210X_SET_BREAK */
 299 #define BREAK_ON                0x0001
 300 #define BREAK_OFF               0x0000
 301
 302 /* CP210X_(SET_MHS|GET_MDMSTS) */
 303 #define CONTROL_DTR             0x0001
 304 #define CONTROL_RTS             0x0002
 305 #define CONTROL_CTS             0x0010
 306 #define CONTROL_DSR             0x0020
 307 #define CONTROL_RING            0x0040
 308 #define CONTROL_DCD             0x0080
 309 #define CONTROL_WRITE_DTR       0x0100
 310 #define CONTROL_WRITE_RTS       0x0200
 311
 312 /*
 313  * cp210x_get_config
 314  * Reads from the CP210x configuration registers
 315  * 'size' is specified in bytes.
 316  * 'data' is a pointer to a pre-allocated array of integers large
 317  * enough to hold 'size' bytes (with 4 bytes to each integer)
 318  */
 319 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
 320                 unsigned int *data, int size)
 321 {
 322         struct usb_serial *serial = port->serial;
 323         struct cp210x_serial_private *spriv = usb_get_serial_data(serial);
 324         __le32 *buf;
 325         int result, i, length;
 326
 327         /* Number of integers required to contain the array */
 328         length = (((size - 1) | 3) + 1) / 4;
 329
 330         buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
 331         if (!buf) {
 332                 dev_err(&port->dev, "%s - out of memory.\n", __func__);
 333                 return -ENOMEM;
 334         }
 335
 336         /* Issue the request, attempting to read 'size' bytes */
 337         result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
 338                                 request, REQTYPE_INTERFACE_TO_HOST, 0x0000,
 339                                 spriv->bInterfaceNumber, buf, size,
 340                                 USB_CTRL_GET_TIMEOUT);
 341
 342         /* Convert data into an array of integers */
 343         for (i = 0; i < length; i++)
 344                 data[i] = le32_to_cpu(buf[i]);
 345
 346         kfree(buf);
 347
 348         if (result != size) {
 349                 dev_dbg(&port->dev, "%s - Unable to send config request, request=0x%x size=%d result=%d\n",
 350                         __func__, request, size, result);
 351                 if (result > 0)
 352                         result = -EPROTO;
 353
 354                 return result;
 355         }
 356
 357         return 0;
 358 }
 359
 360 /*
 361  * cp210x_set_config
 362  * Writes to the CP210x configuration registers
 363  * Values less than 16 bits wide are sent directly
 364  * 'size' is specified in bytes.
 365  */
 366 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
 367                 unsigned int *data, int size)
 368 {
 369         struct usb_serial *serial = port->serial;
 370         struct cp210x_serial_private *spriv = usb_get_serial_data(serial);
 371         __le32 *buf;
 372         int result, i, length;
 373
 374         /* Number of integers required to contain the array */
 375         length = (((size - 1) | 3) + 1) / 4;
 376
 377         buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
 378         if (!buf) {
 379                 dev_err(&port->dev, "%s - out of memory.\n", __func__);
 380                 return -ENOMEM;
 381         }
 382
 383         /* Array of integers into bytes */
 384         for (i = 0; i < length; i++)
 385                 buf[i] = cpu_to_le32(data[i]);
 386
 387         if (size > 2) {
 388                 result = usb_control_msg(serial->dev,
 389                                 usb_sndctrlpipe(serial->dev, 0),
 390                                 request, REQTYPE_HOST_TO_INTERFACE, 0x0000,
 391                                 spriv->bInterfaceNumber, buf, size,
 392                                 USB_CTRL_SET_TIMEOUT);
 393         } else {
 394                 result = usb_control_msg(serial->dev,
 395                                 usb_sndctrlpipe(serial->dev, 0),
 396                                 request, REQTYPE_HOST_TO_INTERFACE, data[0],
 397                                 spriv->bInterfaceNumber, NULL, 0,
 398                                 USB_CTRL_SET_TIMEOUT);
 399         }
 400
 401         kfree(buf);
 402
 403         if ((size > 2 && result != size) || result < 0) {
 404                 dev_dbg(&port->dev, "%s - Unable to send request, request=0x%x size=%d result=%d\n",
 405                         __func__, request, size, result);
 406                 if (result > 0)
 407                         result = -EPROTO;
 408
 409                 return result;
 410         }
 411
 412         return 0;
 413 }
 414
 415 /*
 416  * cp210x_set_config_single
 417  * Convenience function for calling cp210x_set_config on single data values
 418  * without requiring an integer pointer
 419  */
 420 static inline int cp210x_set_config_single(struct usb_serial_port *port,
 421                 u8 request, unsigned int data)
 422 {
 423         return cp210x_set_config(port, request, &data, 2);
 424 }
 425
 426 /*
 427  * cp210x_quantise_baudrate
 428  * Quantises the baud rate as per AN205 Table 1
 429  */
 430 static unsigned int cp210x_quantise_baudrate(unsigned int baud)
 431 {
 432         if (baud <= 300)
 433                 baud = 300;
 434         else if (baud <= 600)      baud = 600;
 435         else if (baud <= 1200)     baud = 1200;
 436         else if (baud <= 1800)     baud = 1800;
 437         else if (baud <= 2400)     baud = 2400;
 438         else if (baud <= 4000)     baud = 4000;
 439         else if (baud <= 4803)     baud = 4800;
 440         else if (baud <= 7207)     baud = 7200;
 441         else if (baud <= 9612)     baud = 9600;
 442         else if (baud <= 14428)    baud = 14400;
 443         else if (baud <= 16062)    baud = 16000;
 444         else if (baud <= 19250)    baud = 19200;
 445         else if (baud <= 28912)    baud = 28800;
 446         else if (baud <= 38601)    baud = 38400;
 447         else if (baud <= 51558)    baud = 51200;
 448         else if (baud <= 56280)    baud = 56000;
 449         else if (baud <= 58053)    baud = 57600;
 450         else if (baud <= 64111)    baud = 64000;
 451         else if (baud <= 77608)    baud = 76800;
 452         else if (baud <= 117028)   baud = 115200;
 453         else if (baud <= 129347)   baud = 128000;
 454         else if (baud <= 156868)   baud = 153600;
 455         else if (baud <= 237832)   baud = 230400;
 456         else if (baud <= 254234)   baud = 250000;
 457         else if (baud <= 273066)   baud = 256000;
 458         else if (baud <= 491520)   baud = 460800;
 459         else if (baud <= 567138)   baud = 500000;
 460         else if (baud <= 670254)   baud = 576000;
 461         else if (baud < 1000000)
 462                 baud = 921600;
 463         else if (baud > 2000000)
 464                 baud = 2000000;
 465         return baud;
 466 }
 467
 468 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
 469 {
 470         int result;
 471
 472         result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
 473                                                                 UART_ENABLE);
 474         if (result) {
 475                 dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
 476                 return result;
 477         }
 478
 479         /* Configure the termios structure */
 480         cp210x_get_termios(tty, port);
 481
 482         /* The baud rate must be initialised on cp2104 */
 483         if (tty)
 484                 cp210x_change_speed(tty, port, NULL);
 485
 486         return usb_serial_generic_open(tty, port);
 487 }
 488
 489 static void cp210x_close(struct usb_serial_port *port)
 490 {
 491         usb_serial_generic_close(port);
 492         cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
 493 }
 494
 495 /*
 496  * cp210x_get_termios
 497  * Reads the baud rate, data bits, parity, stop bits and flow control mode
 498  * from the device, corrects any unsupported values, and configures the
 499  * termios structure to reflect the state of the device
 500  */
 501 static void cp210x_get_termios(struct tty_struct *tty,
 502         struct usb_serial_port *port)
 503 {
 504         unsigned int baud;
 505
 506         if (tty) {
 507                 cp210x_get_termios_port(tty->driver_data,
 508                         &tty->termios.c_cflag, &baud);
 509                 tty_encode_baud_rate(tty, baud, baud);
 510         } else {
 511                 unsigned int cflag;
 512                 cflag = 0;
 513                 cp210x_get_termios_port(port, &cflag, &baud);
 514         }
 515 }
 516
 517 /*
 518  * cp210x_get_termios_port
 519  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
 520  */
 521 static void cp210x_get_termios_port(struct usb_serial_port *port,
 522         unsigned int *cflagp, unsigned int *baudp)
 523 {
 524         struct device *dev = &port->dev;
 525         unsigned int cflag, modem_ctl[4];
 526         unsigned int baud;
 527         unsigned int bits;
 528
 529         cp210x_get_config(port, CP210X_GET_BAUDRATE, &baud, 4);
 530
 531         dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
 532         *baudp = baud;
 533
 534         cflag = *cflagp;
 535
 536         cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
 537         cflag &= ~CSIZE;
 538         switch (bits & BITS_DATA_MASK) {
 539         case BITS_DATA_5:
 540                 dev_dbg(dev, "%s - data bits = 5\n", __func__);
 541                 cflag |= CS5;
 542                 break;
 543         case BITS_DATA_6:
 544                 dev_dbg(dev, "%s - data bits = 6\n", __func__);
 545                 cflag |= CS6;
 546                 break;
 547         case BITS_DATA_7:
 548                 dev_dbg(dev, "%s - data bits = 7\n", __func__);
 549                 cflag |= CS7;
 550                 break;
 551         case BITS_DATA_8:
 552                 dev_dbg(dev, "%s - data bits = 8\n", __func__);
 553                 cflag |= CS8;
 554                 break;
 555         case BITS_DATA_9:
 556                 dev_dbg(dev, "%s - data bits = 9 (not supported, using 8 data bits)\n", __func__);
 557                 cflag |= CS8;
 558                 bits &= ~BITS_DATA_MASK;
 559                 bits |= BITS_DATA_8;
 560                 cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
 561                 break;
 562         default:
 563                 dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
 564                 cflag |= CS8;
 565                 bits &= ~BITS_DATA_MASK;
 566                 bits |= BITS_DATA_8;
 567                 cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
 568                 break;
 569         }
 570
 571         switch (bits & BITS_PARITY_MASK) {
 572         case BITS_PARITY_NONE:
 573                 dev_dbg(dev, "%s - parity = NONE\n", __func__);
 574                 cflag &= ~PARENB;
 575                 break;
 576         case BITS_PARITY_ODD:
 577                 dev_dbg(dev, "%s - parity = ODD\n", __func__);
 578                 cflag |= (PARENB|PARODD);
 579                 break;
 580         case BITS_PARITY_EVEN:
 581                 dev_dbg(dev, "%s - parity = EVEN\n", __func__);
 582                 cflag &= ~PARODD;
 583                 cflag |= PARENB;
 584                 break;
 585         case BITS_PARITY_MARK:
 586                 dev_dbg(dev, "%s - parity = MARK\n", __func__);
 587                 cflag |= (PARENB|PARODD|CMSPAR);
 588                 break;
 589         case BITS_PARITY_SPACE:
 590                 dev_dbg(dev, "%s - parity = SPACE\n", __func__);
 591                 cflag &= ~PARODD;
 592                 cflag |= (PARENB|CMSPAR);
 593                 break;
 594         default:
 595                 dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
 596                 cflag &= ~PARENB;
 597                 bits &= ~BITS_PARITY_MASK;
 598                 cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
 599                 break;
 600         }
 601
 602         cflag &= ~CSTOPB;
 603         switch (bits & BITS_STOP_MASK) {
 604         case BITS_STOP_1:
 605                 dev_dbg(dev, "%s - stop bits = 1\n", __func__);
 606                 break;
 607         case BITS_STOP_1_5:
 608                 dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
 609                 bits &= ~BITS_STOP_MASK;
 610                 cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
 611                 break;
 612         case BITS_STOP_2:
 613                 dev_dbg(dev, "%s - stop bits = 2\n", __func__);
 614                 cflag |= CSTOPB;
 615                 break;
 616         default:
 617                 dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __func__);
 618                 bits &= ~BITS_STOP_MASK;
 619                 cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
 620                 break;
 621         }
 622
 623         cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
 624         if (modem_ctl[0] & 0x0008) {
 625                 dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
 626                 cflag |= CRTSCTS;
 627         } else {
 628                 dev_dbg(dev, "%s - flow control = NONE\n", __func__);
 629                 cflag &= ~CRTSCTS;
 630         }
 631
 632         *cflagp = cflag;
 633 }
 634
 635 /*
 636  * CP2101 supports the following baud rates:
 637  *
 638  *      300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
 639  *      38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
 640  *
 641  * CP2102 and CP2103 support the following additional rates:
 642  *
 643  *      4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
 644  *      576000
 645  *
 646  * The device will map a requested rate to a supported one, but the result
 647  * of requests for rates greater than 1053257 is undefined (see AN205).
 648  *
 649  * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
 650  * respectively, with an error less than 1%. The actual rates are determined
 651  * by
 652  *
 653  *      div = round(freq / (2 x prescale x request))
 654  *      actual = freq / (2 x prescale x div)
 655  *
 656  * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
 657  * or 1 otherwise.
 658  * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
 659  * otherwise.
 660  */
 661 static void cp210x_change_speed(struct tty_struct *tty,
 662                 struct usb_serial_port *port, struct ktermios *old_termios)
 663 {
 664         u32 baud;
 665
 666         baud = tty->termios.c_ospeed;
 667
 668         /* This maps the requested rate to a rate valid on cp2102 or cp2103,
 669          * or to an arbitrary rate in [1M,2M].
 670          *
 671          * NOTE: B0 is not implemented.
 672          */
 673         baud = cp210x_quantise_baudrate(baud);
 674
 675         dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
 676         if (cp210x_set_config(port, CP210X_SET_BAUDRATE, &baud,
 677                                                         sizeof(baud))) {
 678                 dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
 679                 if (old_termios)
 680                         baud = old_termios->c_ospeed;
 681                 else
 682                         baud = 9600;
 683         }
 684
 685         tty_encode_baud_rate(tty, baud, baud);
 686 }
 687
 688 static void cp210x_set_termios(struct tty_struct *tty,
 689                 struct usb_serial_port *port, struct ktermios *old_termios)
 690 {
 691         struct device *dev = &port->dev;
 692         unsigned int cflag, old_cflag;
 693         unsigned int bits;
 694         unsigned int modem_ctl[4];
 695
 696         dev_dbg(dev, "%s - port %d\n", __func__, port->number);
 697
 698         if (!tty)
 699                 return;
 700
 701         cflag = tty->termios.c_cflag;
 702         old_cflag = old_termios->c_cflag;
 703
 704         if (tty->termios.c_ospeed != old_termios->c_ospeed)
 705                 cp210x_change_speed(tty, port, old_termios);
 706
 707         /* If the number of data bits is to be updated */
 708         if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
 709                 cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
 710                 bits &= ~BITS_DATA_MASK;
 711                 switch (cflag & CSIZE) {
 712                 case CS5:
 713                         bits |= BITS_DATA_5;
 714                         dev_dbg(dev, "%s - data bits = 5\n", __func__);
 715                         break;
 716                 case CS6:
 717                         bits |= BITS_DATA_6;
 718                         dev_dbg(dev, "%s - data bits = 6\n", __func__);
 719                         break;
 720                 case CS7:
 721                         bits |= BITS_DATA_7;
 722                         dev_dbg(dev, "%s - data bits = 7\n", __func__);
 723                         break;
 724                 case CS8:
 725                         bits |= BITS_DATA_8;
 726                         dev_dbg(dev, "%s - data bits = 8\n", __func__);
 727                         break;
 728                 /*case CS9:
 729                         bits |= BITS_DATA_9;
 730                         dev_dbg(dev, "%s - data bits = 9\n", __func__);
 731                         break;*/
 732                 default:
 733                         dev_dbg(dev, "cp210x driver does not support the number of bits requested, using 8 bit mode\n");
 734                         bits |= BITS_DATA_8;
 735                         break;
 736                 }
 737                 if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
 738                         dev_dbg(dev, "Number of data bits requested not supported by device\n");
 739         }
 740
 741         if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
 742             (old_cflag & (PARENB|PARODD|CMSPAR))) {
 743                 cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
 744                 bits &= ~BITS_PARITY_MASK;
 745                 if (cflag & PARENB) {
 746                         if (cflag & CMSPAR) {
 747                                 if (cflag & PARODD) {
 748                                         bits |= BITS_PARITY_MARK;
 749                                         dev_dbg(dev, "%s - parity = MARK\n", __func__);
 750                                 } else {
 751                                         bits |= BITS_PARITY_SPACE;
 752                                         dev_dbg(dev, "%s - parity = SPACE\n", __func__);
 753                                 }
 754                         } else {
 755                                 if (cflag & PARODD) {
 756                                         bits |= BITS_PARITY_ODD;
 757                                         dev_dbg(dev, "%s - parity = ODD\n", __func__);
 758                                 } else {
 759                                         bits |= BITS_PARITY_EVEN;
 760                                         dev_dbg(dev, "%s - parity = EVEN\n", __func__);
 761                                 }
 762                         }
 763                 }
 764                 if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
 765                         dev_dbg(dev, "Parity mode not supported by device\n");
 766         }
 767
 768         if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
 769                 cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
 770                 bits &= ~BITS_STOP_MASK;
 771                 if (cflag & CSTOPB) {
 772                         bits |= BITS_STOP_2;
 773                         dev_dbg(dev, "%s - stop bits = 2\n", __func__);
 774                 } else {
 775                         bits |= BITS_STOP_1;
 776                         dev_dbg(dev, "%s - stop bits = 1\n", __func__);
 777                 }
 778                 if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
 779                         dev_dbg(dev, "Number of stop bits requested not supported by device\n");
 780         }
 781
 782         if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
 783                 cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
 784                 dev_dbg(dev, "%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
 785                         __func__, modem_ctl[0], modem_ctl[1],
 786                         modem_ctl[2], modem_ctl[3]);
 787
 788                 if (cflag & CRTSCTS) {
 789                         modem_ctl[0] &= ~0x7B;
 790                         modem_ctl[0] |= 0x09;
 791                         modem_ctl[1] = 0x80;
 792                         dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
 793                 } else {
 794                         modem_ctl[0] &= ~0x7B;
 795                         modem_ctl[0] |= 0x01;
 796                         modem_ctl[1] = 0x40;
 797                         dev_dbg(dev, "%s - flow control = NONE\n", __func__);
 798                 }
 799
 800                 dev_dbg(dev, "%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
 801                         __func__, modem_ctl[0], modem_ctl[1],
 802                         modem_ctl[2], modem_ctl[3]);
 803                 cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
 804         }
 805
 806 }
 807
 808 static int cp210x_tiocmset(struct tty_struct *tty,
 809                 unsigned int set, unsigned int clear)
 810 {
 811         struct usb_serial_port *port = tty->driver_data;
 812         return cp210x_tiocmset_port(port, set, clear);
 813 }
 814
 815 static int cp210x_tiocmset_port(struct usb_serial_port *port,
 816                 unsigned int set, unsigned int clear)
 817 {
 818         unsigned int control = 0;
 819
 820         if (set & TIOCM_RTS) {
 821                 control |= CONTROL_RTS;
 822                 control |= CONTROL_WRITE_RTS;
 823         }
 824         if (set & TIOCM_DTR) {
 825                 control |= CONTROL_DTR;
 826                 control |= CONTROL_WRITE_DTR;
 827         }
 828         if (clear & TIOCM_RTS) {
 829                 control &= ~CONTROL_RTS;
 830                 control |= CONTROL_WRITE_RTS;
 831         }
 832         if (clear & TIOCM_DTR) {
 833                 control &= ~CONTROL_DTR;
 834                 control |= CONTROL_WRITE_DTR;
 835         }
 836
 837         dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
 838
 839         return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
 840 }
 841
 842 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
 843 {
 844         if (on)
 845                 cp210x_tiocmset_port(p, TIOCM_DTR|TIOCM_RTS, 0);
 846         else
 847                 cp210x_tiocmset_port(p, 0, TIOCM_DTR|TIOCM_RTS);
 848 }
 849
 850 static int cp210x_tiocmget(struct tty_struct *tty)
 851 {
 852         struct usb_serial_port *port = tty->driver_data;
 853         unsigned int control;
 854         int result;
 855
 856         result = cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
 857         if (result)
 858                 return result;
 859
 860         result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
 861                 |((control & CONTROL_RTS) ? TIOCM_RTS : 0)
 862                 |((control & CONTROL_CTS) ? TIOCM_CTS : 0)
 863                 |((control & CONTROL_DSR) ? TIOCM_DSR : 0)
 864                 |((control & CONTROL_RING)? TIOCM_RI  : 0)
 865                 |((control & CONTROL_DCD) ? TIOCM_CD  : 0);
 866
 867         dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);
 868
 869         return result;
 870 }
 871
 872 static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
 873 {
 874         struct usb_serial_port *port = tty->driver_data;
 875         unsigned int state;
 876
 877         if (break_state == 0)
 878                 state = BREAK_OFF;
 879         else
 880                 state = BREAK_ON;
 881         dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
 882                 state == BREAK_OFF ? "off" : "on");
 883         cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
 884 }
 885
 886 static int cp210x_startup(struct usb_serial *serial)
 887 {
 888         struct usb_host_interface *cur_altsetting;
 889         struct cp210x_serial_private *spriv;
 890
 891         /* cp210x buffers behave strangely unless device is reset */
 892         usb_reset_device(serial->dev);
 893
 894         spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
 895         if (!spriv)
 896                 return -ENOMEM;
 897
 898         cur_altsetting = serial->interface->cur_altsetting;
 899         spriv->bInterfaceNumber = cur_altsetting->desc.bInterfaceNumber;
 900
 901         usb_set_serial_data(serial, spriv);
 902
 903         return 0;
 904 }
 905
 906 static void cp210x_release(struct usb_serial *serial)
 907 {
 908         struct cp210x_serial_private *spriv;
 909
 910         spriv = usb_get_serial_data(serial);
 911         kfree(spriv);
 912 }
 913
 914 module_usb_serial_driver(serial_drivers, id_table);
 915
 916 MODULE_DESCRIPTION(DRIVER_DESC);
 917 MODULE_LICENSE("GPL");