Alan Cox | e1eaea4 | 2010-03-26 11:32:54 +0000 | [diff] [blame] | 1 | /* |
| 2 | * n_gsm.c GSM 0710 tty multiplexor |
| 3 | * Copyright (c) 2009/10 Intel Corporation |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 17 | * |
| 18 | * * THIS IS A DEVELOPMENT SNAPSHOT IT IS NOT A FINAL RELEASE * |
| 19 | * |
| 20 | * TO DO: |
| 21 | * Mostly done: ioctls for setting modes/timing |
| 22 | * Partly done: hooks so you can pull off frames to non tty devs |
| 23 | * Restart DLCI 0 when it closes ? |
| 24 | * Test basic encoding |
| 25 | * Improve the tx engine |
| 26 | * Resolve tx side locking by adding a queue_head and routing |
| 27 | * all control traffic via it |
| 28 | * General tidy/document |
| 29 | * Review the locking/move to refcounts more (mux now moved to an |
| 30 | * alloc/free model ready) |
| 31 | * Use newest tty open/close port helpers and install hooks |
| 32 | * What to do about power functions ? |
| 33 | * Termios setting and negotiation |
| 34 | * Do we need a 'which mux are you' ioctl to correlate mux and tty sets |
| 35 | * |
| 36 | */ |
| 37 | |
| 38 | #include <linux/types.h> |
| 39 | #include <linux/major.h> |
| 40 | #include <linux/errno.h> |
| 41 | #include <linux/signal.h> |
| 42 | #include <linux/fcntl.h> |
| 43 | #include <linux/sched.h> |
| 44 | #include <linux/interrupt.h> |
| 45 | #include <linux/tty.h> |
| 46 | #include <linux/timer.h> |
| 47 | #include <linux/ctype.h> |
| 48 | #include <linux/mm.h> |
| 49 | #include <linux/string.h> |
| 50 | #include <linux/slab.h> |
| 51 | #include <linux/poll.h> |
| 52 | #include <linux/bitops.h> |
| 53 | #include <linux/file.h> |
| 54 | #include <linux/uaccess.h> |
| 55 | #include <linux/module.h> |
| 56 | #include <linux/timer.h> |
| 57 | #include <linux/tty_flip.h> |
| 58 | #include <linux/tty_driver.h> |
| 59 | #include <linux/serial.h> |
| 60 | #include <linux/kfifo.h> |
| 61 | #include <linux/skbuff.h> |
| 62 | #include <linux/gsmmux.h> |
| 63 | |
| 64 | static int debug; |
| 65 | module_param(debug, int, 0600); |
| 66 | |
| 67 | #define T1 (HZ/10) |
| 68 | #define T2 (HZ/3) |
| 69 | #define N2 3 |
| 70 | |
| 71 | /* Use long timers for testing at low speed with debug on */ |
| 72 | #ifdef DEBUG_TIMING |
| 73 | #define T1 HZ |
| 74 | #define T2 (2 * HZ) |
| 75 | #endif |
| 76 | |
| 77 | /* Semi-arbitary buffer size limits. 0710 is normally run with 32-64 byte |
| 78 | limits so this is plenty */ |
| 79 | #define MAX_MRU 512 |
| 80 | #define MAX_MTU 512 |
| 81 | |
| 82 | /* |
| 83 | * Each block of data we have queued to go out is in the form of |
| 84 | * a gsm_msg which holds everything we need in a link layer independant |
| 85 | * format |
| 86 | */ |
| 87 | |
| 88 | struct gsm_msg { |
| 89 | struct gsm_msg *next; |
| 90 | u8 addr; /* DLCI address + flags */ |
| 91 | u8 ctrl; /* Control byte + flags */ |
| 92 | unsigned int len; /* Length of data block (can be zero) */ |
| 93 | unsigned char *data; /* Points into buffer but not at the start */ |
| 94 | unsigned char buffer[0]; |
| 95 | }; |
| 96 | |
| 97 | /* |
| 98 | * Each active data link has a gsm_dlci structure associated which ties |
| 99 | * the link layer to an optional tty (if the tty side is open). To avoid |
| 100 | * complexity right now these are only ever freed up when the mux is |
| 101 | * shut down. |
| 102 | * |
| 103 | * At the moment we don't free DLCI objects until the mux is torn down |
| 104 | * this avoid object life time issues but might be worth review later. |
| 105 | */ |
| 106 | |
| 107 | struct gsm_dlci { |
| 108 | struct gsm_mux *gsm; |
| 109 | int addr; |
| 110 | int state; |
| 111 | #define DLCI_CLOSED 0 |
| 112 | #define DLCI_OPENING 1 /* Sending SABM not seen UA */ |
| 113 | #define DLCI_OPEN 2 /* SABM/UA complete */ |
| 114 | #define DLCI_CLOSING 3 /* Sending DISC not seen UA/DM */ |
| 115 | |
| 116 | /* Link layer */ |
| 117 | spinlock_t lock; /* Protects the internal state */ |
| 118 | struct timer_list t1; /* Retransmit timer for SABM and UA */ |
| 119 | int retries; |
| 120 | /* Uplink tty if active */ |
| 121 | struct tty_port port; /* The tty bound to this DLCI if there is one */ |
| 122 | struct kfifo *fifo; /* Queue fifo for the DLCI */ |
| 123 | struct kfifo _fifo; /* For new fifo API porting only */ |
| 124 | int adaption; /* Adaption layer in use */ |
| 125 | u32 modem_rx; /* Our incoming virtual modem lines */ |
| 126 | u32 modem_tx; /* Our outgoing modem lines */ |
| 127 | int dead; /* Refuse re-open */ |
| 128 | /* Flow control */ |
| 129 | int throttled; /* Private copy of throttle state */ |
| 130 | int constipated; /* Throttle status for outgoing */ |
| 131 | /* Packetised I/O */ |
| 132 | struct sk_buff *skb; /* Frame being sent */ |
| 133 | struct sk_buff_head skb_list; /* Queued frames */ |
| 134 | /* Data handling callback */ |
| 135 | void (*data)(struct gsm_dlci *dlci, u8 *data, int len); |
| 136 | }; |
| 137 | |
| 138 | /* DLCI 0, 62/63 are special or reseved see gsmtty_open */ |
| 139 | |
| 140 | #define NUM_DLCI 64 |
| 141 | |
| 142 | /* |
| 143 | * DLCI 0 is used to pass control blocks out of band of the data |
| 144 | * flow (and with a higher link priority). One command can be outstanding |
| 145 | * at a time and we use this structure to manage them. They are created |
| 146 | * and destroyed by the user context, and updated by the receive paths |
| 147 | * and timers |
| 148 | */ |
| 149 | |
| 150 | struct gsm_control { |
| 151 | u8 cmd; /* Command we are issuing */ |
| 152 | u8 *data; /* Data for the command in case we retransmit */ |
| 153 | int len; /* Length of block for retransmission */ |
| 154 | int done; /* Done flag */ |
| 155 | int error; /* Error if any */ |
| 156 | }; |
| 157 | |
| 158 | /* |
| 159 | * Each GSM mux we have is represented by this structure. If we are |
| 160 | * operating as an ldisc then we use this structure as our ldisc |
| 161 | * state. We need to sort out lifetimes and locking with respect |
| 162 | * to the gsm mux array. For now we don't free DLCI objects that |
| 163 | * have been instantiated until the mux itself is terminated. |
| 164 | * |
| 165 | * To consider further: tty open versus mux shutdown. |
| 166 | */ |
| 167 | |
| 168 | struct gsm_mux { |
| 169 | struct tty_struct *tty; /* The tty our ldisc is bound to */ |
| 170 | spinlock_t lock; |
| 171 | |
| 172 | /* Events on the GSM channel */ |
| 173 | wait_queue_head_t event; |
| 174 | |
| 175 | /* Bits for GSM mode decoding */ |
| 176 | |
| 177 | /* Framing Layer */ |
| 178 | unsigned char *buf; |
| 179 | int state; |
| 180 | #define GSM_SEARCH 0 |
| 181 | #define GSM_START 1 |
| 182 | #define GSM_ADDRESS 2 |
| 183 | #define GSM_CONTROL 3 |
| 184 | #define GSM_LEN 4 |
| 185 | #define GSM_DATA 5 |
| 186 | #define GSM_FCS 6 |
| 187 | #define GSM_OVERRUN 7 |
| 188 | unsigned int len; |
| 189 | unsigned int address; |
| 190 | unsigned int count; |
| 191 | int escape; |
| 192 | int encoding; |
| 193 | u8 control; |
| 194 | u8 fcs; |
| 195 | u8 *txframe; /* TX framing buffer */ |
| 196 | |
| 197 | /* Methods for the receiver side */ |
| 198 | void (*receive)(struct gsm_mux *gsm, u8 ch); |
| 199 | void (*error)(struct gsm_mux *gsm, u8 ch, u8 flag); |
| 200 | /* And transmit side */ |
| 201 | int (*output)(struct gsm_mux *mux, u8 *data, int len); |
| 202 | |
| 203 | /* Link Layer */ |
| 204 | unsigned int mru; |
| 205 | unsigned int mtu; |
| 206 | int initiator; /* Did we initiate connection */ |
| 207 | int dead; /* Has the mux been shut down */ |
| 208 | struct gsm_dlci *dlci[NUM_DLCI]; |
| 209 | int constipated; /* Asked by remote to shut up */ |
| 210 | |
| 211 | spinlock_t tx_lock; |
| 212 | unsigned int tx_bytes; /* TX data outstanding */ |
| 213 | #define TX_THRESH_HI 8192 |
| 214 | #define TX_THRESH_LO 2048 |
| 215 | struct gsm_msg *tx_head; /* Pending data packets */ |
| 216 | struct gsm_msg *tx_tail; |
| 217 | |
| 218 | /* Control messages */ |
| 219 | struct timer_list t2_timer; /* Retransmit timer for commands */ |
| 220 | int cretries; /* Command retry counter */ |
| 221 | struct gsm_control *pending_cmd;/* Our current pending command */ |
| 222 | spinlock_t control_lock; /* Protects the pending command */ |
| 223 | |
| 224 | /* Configuration */ |
| 225 | int adaption; /* 1 or 2 supported */ |
| 226 | u8 ftype; /* UI or UIH */ |
| 227 | int t1, t2; /* Timers in 1/100th of a sec */ |
| 228 | int n2; /* Retry count */ |
| 229 | |
| 230 | /* Statistics (not currently exposed) */ |
| 231 | unsigned long bad_fcs; |
| 232 | unsigned long malformed; |
| 233 | unsigned long io_error; |
| 234 | unsigned long bad_size; |
| 235 | unsigned long unsupported; |
| 236 | }; |
| 237 | |
| 238 | |
| 239 | /* |
| 240 | * Mux objects - needed so that we can translate a tty index into the |
| 241 | * relevant mux and DLCI. |
| 242 | */ |
| 243 | |
| 244 | #define MAX_MUX 4 /* 256 minors */ |
| 245 | static struct gsm_mux *gsm_mux[MAX_MUX]; /* GSM muxes */ |
| 246 | static spinlock_t gsm_mux_lock; |
| 247 | |
| 248 | /* |
| 249 | * This section of the driver logic implements the GSM encodings |
| 250 | * both the basic and the 'advanced'. Reliable transport is not |
| 251 | * supported. |
| 252 | */ |
| 253 | |
| 254 | #define CR 0x02 |
| 255 | #define EA 0x01 |
| 256 | #define PF 0x10 |
| 257 | |
| 258 | /* I is special: the rest are ..*/ |
| 259 | #define RR 0x01 |
| 260 | #define UI 0x03 |
| 261 | #define RNR 0x05 |
| 262 | #define REJ 0x09 |
| 263 | #define DM 0x0F |
| 264 | #define SABM 0x2F |
| 265 | #define DISC 0x43 |
| 266 | #define UA 0x63 |
| 267 | #define UIH 0xEF |
| 268 | |
| 269 | /* Channel commands */ |
| 270 | #define CMD_NSC 0x09 |
| 271 | #define CMD_TEST 0x11 |
| 272 | #define CMD_PSC 0x21 |
| 273 | #define CMD_RLS 0x29 |
| 274 | #define CMD_FCOFF 0x31 |
| 275 | #define CMD_PN 0x41 |
| 276 | #define CMD_RPN 0x49 |
| 277 | #define CMD_FCON 0x51 |
| 278 | #define CMD_CLD 0x61 |
| 279 | #define CMD_SNC 0x69 |
| 280 | #define CMD_MSC 0x71 |
| 281 | |
| 282 | /* Virtual modem bits */ |
| 283 | #define MDM_FC 0x01 |
| 284 | #define MDM_RTC 0x02 |
| 285 | #define MDM_RTR 0x04 |
| 286 | #define MDM_IC 0x20 |
| 287 | #define MDM_DV 0x40 |
| 288 | |
| 289 | #define GSM0_SOF 0xF9 |
| 290 | #define GSM1_SOF 0x7E |
| 291 | #define GSM1_ESCAPE 0x7D |
| 292 | #define GSM1_ESCAPE_BITS 0x20 |
| 293 | #define XON 0x11 |
| 294 | #define XOFF 0x13 |
| 295 | |
| 296 | static const struct tty_port_operations gsm_port_ops; |
| 297 | |
| 298 | /* |
| 299 | * CRC table for GSM 0710 |
| 300 | */ |
| 301 | |
| 302 | static const u8 gsm_fcs8[256] = { |
| 303 | 0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75, |
| 304 | 0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B, |
| 305 | 0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69, |
| 306 | 0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67, |
| 307 | 0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D, |
| 308 | 0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43, |
| 309 | 0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51, |
| 310 | 0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F, |
| 311 | 0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05, |
| 312 | 0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B, |
| 313 | 0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19, |
| 314 | 0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17, |
| 315 | 0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D, |
| 316 | 0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33, |
| 317 | 0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21, |
| 318 | 0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F, |
| 319 | 0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95, |
| 320 | 0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B, |
| 321 | 0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89, |
| 322 | 0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87, |
| 323 | 0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD, |
| 324 | 0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3, |
| 325 | 0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1, |
| 326 | 0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF, |
| 327 | 0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5, |
| 328 | 0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB, |
| 329 | 0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9, |
| 330 | 0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7, |
| 331 | 0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD, |
| 332 | 0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3, |
| 333 | 0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1, |
| 334 | 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF |
| 335 | }; |
| 336 | |
| 337 | #define INIT_FCS 0xFF |
| 338 | #define GOOD_FCS 0xCF |
| 339 | |
| 340 | /** |
| 341 | * gsm_fcs_add - update FCS |
| 342 | * @fcs: Current FCS |
| 343 | * @c: Next data |
| 344 | * |
| 345 | * Update the FCS to include c. Uses the algorithm in the specification |
| 346 | * notes. |
| 347 | */ |
| 348 | |
| 349 | static inline u8 gsm_fcs_add(u8 fcs, u8 c) |
| 350 | { |
| 351 | return gsm_fcs8[fcs ^ c]; |
| 352 | } |
| 353 | |
| 354 | /** |
| 355 | * gsm_fcs_add_block - update FCS for a block |
| 356 | * @fcs: Current FCS |
| 357 | * @c: buffer of data |
| 358 | * @len: length of buffer |
| 359 | * |
| 360 | * Update the FCS to include c. Uses the algorithm in the specification |
| 361 | * notes. |
| 362 | */ |
| 363 | |
| 364 | static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len) |
| 365 | { |
| 366 | while (len--) |
| 367 | fcs = gsm_fcs8[fcs ^ *c++]; |
| 368 | return fcs; |
| 369 | } |
| 370 | |
| 371 | /** |
| 372 | * gsm_read_ea - read a byte into an EA |
| 373 | * @val: variable holding value |
| 374 | * c: byte going into the EA |
| 375 | * |
| 376 | * Processes one byte of an EA. Updates the passed variable |
| 377 | * and returns 1 if the EA is now completely read |
| 378 | */ |
| 379 | |
| 380 | static int gsm_read_ea(unsigned int *val, u8 c) |
| 381 | { |
| 382 | /* Add the next 7 bits into the value */ |
| 383 | *val <<= 7; |
| 384 | *val |= c >> 1; |
| 385 | /* Was this the last byte of the EA 1 = yes*/ |
| 386 | return c & EA; |
| 387 | } |
| 388 | |
| 389 | /** |
| 390 | * gsm_encode_modem - encode modem data bits |
| 391 | * @dlci: DLCI to encode from |
| 392 | * |
| 393 | * Returns the correct GSM encoded modem status bits (6 bit field) for |
| 394 | * the current status of the DLCI and attached tty object |
| 395 | */ |
| 396 | |
| 397 | static u8 gsm_encode_modem(const struct gsm_dlci *dlci) |
| 398 | { |
| 399 | u8 modembits = 0; |
| 400 | /* FC is true flow control not modem bits */ |
| 401 | if (dlci->throttled) |
| 402 | modembits |= MDM_FC; |
| 403 | if (dlci->modem_tx & TIOCM_DTR) |
| 404 | modembits |= MDM_RTC; |
| 405 | if (dlci->modem_tx & TIOCM_RTS) |
| 406 | modembits |= MDM_RTR; |
| 407 | if (dlci->modem_tx & TIOCM_RI) |
| 408 | modembits |= MDM_IC; |
| 409 | if (dlci->modem_tx & TIOCM_CD) |
| 410 | modembits |= MDM_DV; |
| 411 | return modembits; |
| 412 | } |
| 413 | |
| 414 | /** |
| 415 | * gsm_print_packet - display a frame for debug |
| 416 | * @hdr: header to print before decode |
| 417 | * @addr: address EA from the frame |
| 418 | * @cr: C/R bit from the frame |
| 419 | * @control: control including PF bit |
| 420 | * @data: following data bytes |
| 421 | * @dlen: length of data |
| 422 | * |
| 423 | * Displays a packet in human readable format for debugging purposes. The |
| 424 | * style is based on amateur radio LAP-B dump display. |
| 425 | */ |
| 426 | |
| 427 | static void gsm_print_packet(const char *hdr, int addr, int cr, |
| 428 | u8 control, const u8 *data, int dlen) |
| 429 | { |
| 430 | if (!(debug & 1)) |
| 431 | return; |
| 432 | |
| 433 | printk(KERN_INFO "%s %d) %c: ", hdr, addr, "RC"[cr]); |
| 434 | |
| 435 | switch (control & ~PF) { |
| 436 | case SABM: |
| 437 | printk(KERN_CONT "SABM"); |
| 438 | break; |
| 439 | case UA: |
| 440 | printk(KERN_CONT "UA"); |
| 441 | break; |
| 442 | case DISC: |
| 443 | printk(KERN_CONT "DISC"); |
| 444 | break; |
| 445 | case DM: |
| 446 | printk(KERN_CONT "DM"); |
| 447 | break; |
| 448 | case UI: |
| 449 | printk(KERN_CONT "UI"); |
| 450 | break; |
| 451 | case UIH: |
| 452 | printk(KERN_CONT "UIH"); |
| 453 | break; |
| 454 | default: |
| 455 | if (!(control & 0x01)) { |
| 456 | printk(KERN_CONT "I N(S)%d N(R)%d", |
| 457 | (control & 0x0E) >> 1, (control & 0xE)>> 5); |
| 458 | } else switch (control & 0x0F) { |
| 459 | case RR: |
| 460 | printk("RR(%d)", (control & 0xE0) >> 5); |
| 461 | break; |
| 462 | case RNR: |
| 463 | printk("RNR(%d)", (control & 0xE0) >> 5); |
| 464 | break; |
| 465 | case REJ: |
| 466 | printk("REJ(%d)", (control & 0xE0) >> 5); |
| 467 | break; |
| 468 | default: |
| 469 | printk(KERN_CONT "[%02X]", control); |
| 470 | } |
| 471 | } |
| 472 | |
| 473 | if (control & PF) |
| 474 | printk(KERN_CONT "(P)"); |
| 475 | else |
| 476 | printk(KERN_CONT "(F)"); |
| 477 | |
| 478 | if (dlen) { |
| 479 | int ct = 0; |
| 480 | while (dlen--) { |
| 481 | if (ct % 8 == 0) |
| 482 | printk(KERN_CONT "\n "); |
| 483 | printk(KERN_CONT "%02X ", *data++); |
| 484 | ct++; |
| 485 | } |
| 486 | } |
| 487 | printk(KERN_CONT "\n"); |
| 488 | } |
| 489 | |
| 490 | |
| 491 | /* |
| 492 | * Link level transmission side |
| 493 | */ |
| 494 | |
| 495 | /** |
| 496 | * gsm_stuff_packet - bytestuff a packet |
| 497 | * @ibuf: input |
| 498 | * @obuf: output |
| 499 | * @len: length of input |
| 500 | * |
| 501 | * Expand a buffer by bytestuffing it. The worst case size change |
| 502 | * is doubling and the caller is responsible for handing out |
| 503 | * suitable sized buffers. |
| 504 | */ |
| 505 | |
| 506 | static int gsm_stuff_frame(const u8 *input, u8 *output, int len) |
| 507 | { |
| 508 | int olen = 0; |
| 509 | while (len--) { |
| 510 | if (*input == GSM1_SOF || *input == GSM1_ESCAPE |
| 511 | || *input == XON || *input == XOFF) { |
| 512 | *output++ = GSM1_ESCAPE; |
| 513 | *output++ = *input++ ^ GSM1_ESCAPE_BITS; |
| 514 | olen++; |
| 515 | } else |
| 516 | *output++ = *input++; |
| 517 | olen++; |
| 518 | } |
| 519 | return olen; |
| 520 | } |
| 521 | |
| 522 | static void hex_packet(const unsigned char *p, int len) |
| 523 | { |
| 524 | int i; |
| 525 | for (i = 0; i < len; i++) { |
| 526 | if (i && (i % 16) == 0) |
| 527 | printk("\n"); |
| 528 | printk("%02X ", *p++); |
| 529 | } |
| 530 | printk("\n"); |
| 531 | } |
| 532 | |
| 533 | /** |
| 534 | * gsm_send - send a control frame |
| 535 | * @gsm: our GSM mux |
| 536 | * @addr: address for control frame |
| 537 | * @cr: command/response bit |
| 538 | * @control: control byte including PF bit |
| 539 | * |
| 540 | * Format up and transmit a control frame. These do not go via the |
| 541 | * queueing logic as they should be transmitted ahead of data when |
| 542 | * they are needed. |
| 543 | * |
| 544 | * FIXME: Lock versus data TX path |
| 545 | */ |
| 546 | |
| 547 | static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control) |
| 548 | { |
| 549 | int len; |
| 550 | u8 cbuf[10]; |
| 551 | u8 ibuf[3]; |
| 552 | |
| 553 | switch (gsm->encoding) { |
| 554 | case 0: |
| 555 | cbuf[0] = GSM0_SOF; |
| 556 | cbuf[1] = (addr << 2) | (cr << 1) | EA; |
| 557 | cbuf[2] = control; |
| 558 | cbuf[3] = EA; /* Length of data = 0 */ |
| 559 | cbuf[4] = 0xFF - gsm_fcs_add_block(INIT_FCS, cbuf + 1, 3); |
| 560 | cbuf[5] = GSM0_SOF; |
| 561 | len = 6; |
| 562 | break; |
| 563 | case 1: |
| 564 | case 2: |
| 565 | /* Control frame + packing (but not frame stuffing) in mode 1 */ |
| 566 | ibuf[0] = (addr << 2) | (cr << 1) | EA; |
| 567 | ibuf[1] = control; |
| 568 | ibuf[2] = 0xFF - gsm_fcs_add_block(INIT_FCS, ibuf, 2); |
| 569 | /* Stuffing may double the size worst case */ |
| 570 | len = gsm_stuff_frame(ibuf, cbuf + 1, 3); |
| 571 | /* Now add the SOF markers */ |
| 572 | cbuf[0] = GSM1_SOF; |
| 573 | cbuf[len + 1] = GSM1_SOF; |
| 574 | /* FIXME: we can omit the lead one in many cases */ |
| 575 | len += 2; |
| 576 | break; |
| 577 | default: |
| 578 | WARN_ON(1); |
| 579 | return; |
| 580 | } |
| 581 | gsm->output(gsm, cbuf, len); |
| 582 | gsm_print_packet("-->", addr, cr, control, NULL, 0); |
| 583 | } |
| 584 | |
| 585 | /** |
| 586 | * gsm_response - send a control response |
| 587 | * @gsm: our GSM mux |
| 588 | * @addr: address for control frame |
| 589 | * @control: control byte including PF bit |
| 590 | * |
| 591 | * Format up and transmit a link level response frame. |
| 592 | */ |
| 593 | |
| 594 | static inline void gsm_response(struct gsm_mux *gsm, int addr, int control) |
| 595 | { |
| 596 | gsm_send(gsm, addr, 0, control); |
| 597 | } |
| 598 | |
| 599 | /** |
| 600 | * gsm_command - send a control command |
| 601 | * @gsm: our GSM mux |
| 602 | * @addr: address for control frame |
| 603 | * @control: control byte including PF bit |
| 604 | * |
| 605 | * Format up and transmit a link level command frame. |
| 606 | */ |
| 607 | |
| 608 | static inline void gsm_command(struct gsm_mux *gsm, int addr, int control) |
| 609 | { |
| 610 | gsm_send(gsm, addr, 1, control); |
| 611 | } |
| 612 | |
| 613 | /* Data transmission */ |
| 614 | |
| 615 | #define HDR_LEN 6 /* ADDR CTRL [LEN.2] DATA FCS */ |
| 616 | |
| 617 | /** |
| 618 | * gsm_data_alloc - allocate data frame |
| 619 | * @gsm: GSM mux |
| 620 | * @addr: DLCI address |
| 621 | * @len: length excluding header and FCS |
| 622 | * @ctrl: control byte |
| 623 | * |
| 624 | * Allocate a new data buffer for sending frames with data. Space is left |
| 625 | * at the front for header bytes but that is treated as an implementation |
| 626 | * detail and not for the high level code to use |
| 627 | */ |
| 628 | |
| 629 | static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, |
| 630 | u8 ctrl) |
| 631 | { |
| 632 | struct gsm_msg *m = kmalloc(sizeof(struct gsm_msg) + len + HDR_LEN, |
| 633 | GFP_ATOMIC); |
| 634 | if (m == NULL) |
| 635 | return NULL; |
| 636 | m->data = m->buffer + HDR_LEN - 1; /* Allow for FCS */ |
| 637 | m->len = len; |
| 638 | m->addr = addr; |
| 639 | m->ctrl = ctrl; |
| 640 | m->next = NULL; |
| 641 | return m; |
| 642 | } |
| 643 | |
| 644 | /** |
| 645 | * gsm_data_kick - poke the queue |
| 646 | * @gsm: GSM Mux |
| 647 | * |
| 648 | * The tty device has called us to indicate that room has appeared in |
| 649 | * the transmit queue. Ram more data into the pipe if we have any |
| 650 | * |
| 651 | * FIXME: lock against link layer control transmissions |
| 652 | */ |
| 653 | |
| 654 | static void gsm_data_kick(struct gsm_mux *gsm) |
| 655 | { |
| 656 | struct gsm_msg *msg = gsm->tx_head; |
| 657 | int len; |
| 658 | int skip_sof = 0; |
| 659 | |
| 660 | /* FIXME: We need to apply this solely to data messages */ |
| 661 | if (gsm->constipated) |
| 662 | return; |
| 663 | |
| 664 | while (gsm->tx_head != NULL) { |
| 665 | msg = gsm->tx_head; |
| 666 | if (gsm->encoding != 0) { |
| 667 | gsm->txframe[0] = GSM1_SOF; |
| 668 | len = gsm_stuff_frame(msg->data, |
| 669 | gsm->txframe + 1, msg->len); |
| 670 | gsm->txframe[len + 1] = GSM1_SOF; |
| 671 | len += 2; |
| 672 | } else { |
| 673 | gsm->txframe[0] = GSM0_SOF; |
| 674 | memcpy(gsm->txframe + 1 , msg->data, msg->len); |
| 675 | gsm->txframe[msg->len + 1] = GSM0_SOF; |
| 676 | len = msg->len + 2; |
| 677 | } |
| 678 | |
| 679 | if (debug & 4) { |
| 680 | printk("gsm_data_kick: \n"); |
| 681 | hex_packet(gsm->txframe, len); |
| 682 | } |
| 683 | |
| 684 | if (gsm->output(gsm, gsm->txframe + skip_sof, |
| 685 | len - skip_sof) < 0) |
| 686 | break; |
| 687 | /* FIXME: Can eliminate one SOF in many more cases */ |
| 688 | gsm->tx_head = msg->next; |
| 689 | if (gsm->tx_head == NULL) |
| 690 | gsm->tx_tail = NULL; |
| 691 | gsm->tx_bytes -= msg->len; |
| 692 | kfree(msg); |
| 693 | /* For a burst of frames skip the extra SOF within the |
| 694 | burst */ |
| 695 | skip_sof = 1; |
| 696 | } |
| 697 | } |
| 698 | |
| 699 | /** |
| 700 | * __gsm_data_queue - queue a UI or UIH frame |
| 701 | * @dlci: DLCI sending the data |
| 702 | * @msg: message queued |
| 703 | * |
| 704 | * Add data to the transmit queue and try and get stuff moving |
| 705 | * out of the mux tty if not already doing so. The Caller must hold |
| 706 | * the gsm tx lock. |
| 707 | */ |
| 708 | |
| 709 | static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) |
| 710 | { |
| 711 | struct gsm_mux *gsm = dlci->gsm; |
| 712 | u8 *dp = msg->data; |
| 713 | u8 *fcs = dp + msg->len; |
| 714 | |
| 715 | /* Fill in the header */ |
| 716 | if (gsm->encoding == 0) { |
| 717 | if (msg->len < 128) |
| 718 | *--dp = (msg->len << 1) | EA; |
| 719 | else { |
| 720 | *--dp = (msg->len >> 6) | EA; |
| 721 | *--dp = (msg->len & 127) << 1; |
| 722 | } |
| 723 | } |
| 724 | |
| 725 | *--dp = msg->ctrl; |
| 726 | if (gsm->initiator) |
| 727 | *--dp = (msg->addr << 2) | 2 | EA; |
| 728 | else |
| 729 | *--dp = (msg->addr << 2) | EA; |
| 730 | *fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp); |
| 731 | /* Ugly protocol layering violation */ |
| 732 | if (msg->ctrl == UI || msg->ctrl == (UI|PF)) |
| 733 | *fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len); |
| 734 | *fcs = 0xFF - *fcs; |
| 735 | |
| 736 | gsm_print_packet("Q> ", msg->addr, gsm->initiator, msg->ctrl, |
| 737 | msg->data, msg->len); |
| 738 | |
| 739 | /* Move the header back and adjust the length, also allow for the FCS |
| 740 | now tacked on the end */ |
| 741 | msg->len += (msg->data - dp) + 1; |
| 742 | msg->data = dp; |
| 743 | |
| 744 | /* Add to the actual output queue */ |
| 745 | if (gsm->tx_tail) |
| 746 | gsm->tx_tail->next = msg; |
| 747 | else |
| 748 | gsm->tx_head = msg; |
| 749 | gsm->tx_tail = msg; |
| 750 | gsm->tx_bytes += msg->len; |
| 751 | gsm_data_kick(gsm); |
| 752 | } |
| 753 | |
| 754 | /** |
| 755 | * gsm_data_queue - queue a UI or UIH frame |
| 756 | * @dlci: DLCI sending the data |
| 757 | * @msg: message queued |
| 758 | * |
| 759 | * Add data to the transmit queue and try and get stuff moving |
| 760 | * out of the mux tty if not already doing so. Take the |
| 761 | * the gsm tx lock and dlci lock. |
| 762 | */ |
| 763 | |
| 764 | static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) |
| 765 | { |
| 766 | unsigned long flags; |
| 767 | spin_lock_irqsave(&dlci->gsm->tx_lock, flags); |
| 768 | __gsm_data_queue(dlci, msg); |
| 769 | spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); |
| 770 | } |
| 771 | |
| 772 | /** |
| 773 | * gsm_dlci_data_output - try and push data out of a DLCI |
| 774 | * @gsm: mux |
| 775 | * @dlci: the DLCI to pull data from |
| 776 | * |
| 777 | * Pull data from a DLCI and send it into the transmit queue if there |
| 778 | * is data. Keep to the MRU of the mux. This path handles the usual tty |
| 779 | * interface which is a byte stream with optional modem data. |
| 780 | * |
| 781 | * Caller must hold the tx_lock of the mux. |
| 782 | */ |
| 783 | |
| 784 | static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci) |
| 785 | { |
| 786 | struct gsm_msg *msg; |
| 787 | u8 *dp; |
| 788 | int len, size; |
| 789 | int h = dlci->adaption - 1; |
| 790 | |
| 791 | len = kfifo_len(dlci->fifo); |
| 792 | if (len == 0) |
| 793 | return 0; |
| 794 | |
| 795 | /* MTU/MRU count only the data bits */ |
| 796 | if (len > gsm->mtu) |
| 797 | len = gsm->mtu; |
| 798 | |
| 799 | size = len + h; |
| 800 | |
| 801 | msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); |
| 802 | /* FIXME: need a timer or something to kick this so it can't |
| 803 | get stuck with no work outstanding and no buffer free */ |
| 804 | if (msg == NULL) |
| 805 | return -ENOMEM; |
| 806 | dp = msg->data; |
| 807 | switch (dlci->adaption) { |
| 808 | case 1: /* Unstructured */ |
| 809 | break; |
| 810 | case 2: /* Unstructed with modem bits. Always one byte as we never |
| 811 | send inline break data */ |
| 812 | *dp += gsm_encode_modem(dlci); |
| 813 | len--; |
| 814 | break; |
| 815 | } |
| 816 | WARN_ON(kfifo_out_locked(dlci->fifo, dp , len, &dlci->lock) != len); |
| 817 | __gsm_data_queue(dlci, msg); |
| 818 | /* Bytes of data we used up */ |
| 819 | return size; |
| 820 | } |
| 821 | |
| 822 | /** |
| 823 | * gsm_dlci_data_output_framed - try and push data out of a DLCI |
| 824 | * @gsm: mux |
| 825 | * @dlci: the DLCI to pull data from |
| 826 | * |
| 827 | * Pull data from a DLCI and send it into the transmit queue if there |
| 828 | * is data. Keep to the MRU of the mux. This path handles framed data |
| 829 | * queued as skbuffs to the DLCI. |
| 830 | * |
| 831 | * Caller must hold the tx_lock of the mux. |
| 832 | */ |
| 833 | |
| 834 | static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, |
| 835 | struct gsm_dlci *dlci) |
| 836 | { |
| 837 | struct gsm_msg *msg; |
| 838 | u8 *dp; |
| 839 | int len, size; |
| 840 | int last = 0, first = 0; |
| 841 | int overhead = 0; |
| 842 | |
| 843 | /* One byte per frame is used for B/F flags */ |
| 844 | if (dlci->adaption == 4) |
| 845 | overhead = 1; |
| 846 | |
| 847 | /* dlci->skb is locked by tx_lock */ |
| 848 | if (dlci->skb == NULL) { |
| 849 | dlci->skb = skb_dequeue(&dlci->skb_list); |
| 850 | if (dlci->skb == NULL) |
| 851 | return 0; |
| 852 | first = 1; |
| 853 | } |
| 854 | len = dlci->skb->len + overhead; |
| 855 | |
| 856 | /* MTU/MRU count only the data bits */ |
| 857 | if (len > gsm->mtu) { |
| 858 | if (dlci->adaption == 3) { |
| 859 | /* Over long frame, bin it */ |
| 860 | kfree_skb(dlci->skb); |
| 861 | dlci->skb = NULL; |
| 862 | return 0; |
| 863 | } |
| 864 | len = gsm->mtu; |
| 865 | } else |
| 866 | last = 1; |
| 867 | |
| 868 | size = len + overhead; |
| 869 | msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); |
| 870 | |
| 871 | /* FIXME: need a timer or something to kick this so it can't |
| 872 | get stuck with no work outstanding and no buffer free */ |
| 873 | if (msg == NULL) |
| 874 | return -ENOMEM; |
| 875 | dp = msg->data; |
| 876 | |
| 877 | if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */ |
| 878 | /* Flag byte to carry the start/end info */ |
| 879 | *dp++ = last << 7 | first << 6 | 1; /* EA */ |
| 880 | len--; |
| 881 | } |
| 882 | memcpy(dp, skb_pull(dlci->skb, len), len); |
| 883 | __gsm_data_queue(dlci, msg); |
| 884 | if (last) |
| 885 | dlci->skb = NULL; |
| 886 | return size; |
| 887 | } |
| 888 | |
| 889 | /** |
| 890 | * gsm_dlci_data_sweep - look for data to send |
| 891 | * @gsm: the GSM mux |
| 892 | * |
| 893 | * Sweep the GSM mux channels in priority order looking for ones with |
| 894 | * data to send. We could do with optimising this scan a bit. We aim |
| 895 | * to fill the queue totally or up to TX_THRESH_HI bytes. Once we hit |
| 896 | * TX_THRESH_LO we get called again |
| 897 | * |
| 898 | * FIXME: We should round robin between groups and in theory you can |
| 899 | * renegotiate DLCI priorities with optional stuff. Needs optimising. |
| 900 | */ |
| 901 | |
| 902 | static void gsm_dlci_data_sweep(struct gsm_mux *gsm) |
| 903 | { |
| 904 | int len; |
| 905 | /* Priority ordering: We should do priority with RR of the groups */ |
| 906 | int i = 1; |
Alan Cox | e1eaea4 | 2010-03-26 11:32:54 +0000 | [diff] [blame] | 907 | |
Alan Cox | e1eaea4 | 2010-03-26 11:32:54 +0000 | [diff] [blame] | 908 | while (i < NUM_DLCI) { |
| 909 | struct gsm_dlci *dlci; |
| 910 | |
| 911 | if (gsm->tx_bytes > TX_THRESH_HI) |
| 912 | break; |
| 913 | dlci = gsm->dlci[i]; |
| 914 | if (dlci == NULL || dlci->constipated) { |
| 915 | i++; |
| 916 | continue; |
| 917 | } |
| 918 | if (dlci->adaption < 3) |
| 919 | len = gsm_dlci_data_output(gsm, dlci); |
| 920 | else |
| 921 | len = gsm_dlci_data_output_framed(gsm, dlci); |
| 922 | if (len < 0) |
| 923 | return; |
| 924 | /* DLCI empty - try the next */ |
| 925 | if (len == 0) |
| 926 | i++; |
| 927 | } |
Alan Cox | e1eaea4 | 2010-03-26 11:32:54 +0000 | [diff] [blame] | 928 | } |
| 929 | |
| 930 | /** |
| 931 | * gsm_dlci_data_kick - transmit if possible |
| 932 | * @dlci: DLCI to kick |
| 933 | * |
| 934 | * Transmit data from this DLCI if the queue is empty. We can't rely on |
| 935 | * a tty wakeup except when we filled the pipe so we need to fire off |
| 936 | * new data ourselves in other cases. |
| 937 | */ |
| 938 | |
| 939 | static void gsm_dlci_data_kick(struct gsm_dlci *dlci) |
| 940 | { |
| 941 | unsigned long flags; |
| 942 | |
| 943 | spin_lock_irqsave(&dlci->gsm->tx_lock, flags); |
| 944 | /* If we have nothing running then we need to fire up */ |
| 945 | if (dlci->gsm->tx_bytes == 0) |
| 946 | gsm_dlci_data_output(dlci->gsm, dlci); |
| 947 | else if (dlci->gsm->tx_bytes < TX_THRESH_LO) |
| 948 | gsm_dlci_data_sweep(dlci->gsm); |
| 949 | spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); |
| 950 | } |
| 951 | |
| 952 | /* |
| 953 | * Control message processing |
| 954 | */ |
| 955 | |
| 956 | |
| 957 | /** |
| 958 | * gsm_control_reply - send a response frame to a control |
| 959 | * @gsm: gsm channel |
| 960 | * @cmd: the command to use |
| 961 | * @data: data to follow encoded info |
| 962 | * @dlen: length of data |
| 963 | * |
| 964 | * Encode up and queue a UI/UIH frame containing our response. |
| 965 | */ |
| 966 | |
| 967 | static void gsm_control_reply(struct gsm_mux *gsm, int cmd, u8 *data, |
| 968 | int dlen) |
| 969 | { |
| 970 | struct gsm_msg *msg; |
| 971 | msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype); |
| 972 | msg->data[0] = (cmd & 0xFE) << 1 | EA; /* Clear C/R */ |
| 973 | msg->data[1] = (dlen << 1) | EA; |
| 974 | memcpy(msg->data + 2, data, dlen); |
| 975 | gsm_data_queue(gsm->dlci[0], msg); |
| 976 | } |
| 977 | |
| 978 | /** |
| 979 | * gsm_process_modem - process received modem status |
| 980 | * @tty: virtual tty bound to the DLCI |
| 981 | * @dlci: DLCI to affect |
| 982 | * @modem: modem bits (full EA) |
| 983 | * |
| 984 | * Used when a modem control message or line state inline in adaption |
| 985 | * layer 2 is processed. Sort out the local modem state and throttles |
| 986 | */ |
| 987 | |
| 988 | static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, |
| 989 | u32 modem) |
| 990 | { |
| 991 | int mlines = 0; |
| 992 | u8 brk = modem >> 6; |
| 993 | |
| 994 | /* Flow control/ready to communicate */ |
| 995 | if (modem & MDM_FC) { |
| 996 | /* Need to throttle our output on this device */ |
| 997 | dlci->constipated = 1; |
| 998 | } |
| 999 | if (modem & MDM_RTC) { |
| 1000 | mlines |= TIOCM_DSR | TIOCM_DTR; |
| 1001 | dlci->constipated = 0; |
| 1002 | gsm_dlci_data_kick(dlci); |
| 1003 | } |
| 1004 | /* Map modem bits */ |
| 1005 | if (modem & MDM_RTR) |
| 1006 | mlines |= TIOCM_RTS | TIOCM_CTS; |
| 1007 | if (modem & MDM_IC) |
| 1008 | mlines |= TIOCM_RI; |
| 1009 | if (modem & MDM_DV) |
| 1010 | mlines |= TIOCM_CD; |
| 1011 | |
| 1012 | /* Carrier drop -> hangup */ |
| 1013 | if (tty) { |
| 1014 | if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD)) |
| 1015 | if (!(tty->termios->c_cflag & CLOCAL)) |
| 1016 | tty_hangup(tty); |
| 1017 | if (brk & 0x01) |
| 1018 | tty_insert_flip_char(tty, 0, TTY_BREAK); |
| 1019 | } |
| 1020 | dlci->modem_rx = mlines; |
| 1021 | } |
| 1022 | |
| 1023 | /** |
| 1024 | * gsm_control_modem - modem status received |
| 1025 | * @gsm: GSM channel |
| 1026 | * @data: data following command |
| 1027 | * @clen: command length |
| 1028 | * |
| 1029 | * We have received a modem status control message. This is used by |
| 1030 | * the GSM mux protocol to pass virtual modem line status and optionally |
| 1031 | * to indicate break signals. Unpack it, convert to Linux representation |
| 1032 | * and if need be stuff a break message down the tty. |
| 1033 | */ |
| 1034 | |
| 1035 | static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen) |
| 1036 | { |
| 1037 | unsigned int addr = 0; |
| 1038 | unsigned int modem = 0; |
| 1039 | struct gsm_dlci *dlci; |
| 1040 | int len = clen; |
| 1041 | u8 *dp = data; |
| 1042 | struct tty_struct *tty; |
| 1043 | |
| 1044 | while (gsm_read_ea(&addr, *dp++) == 0) { |
| 1045 | len--; |
| 1046 | if (len == 0) |
| 1047 | return; |
| 1048 | } |
| 1049 | /* Must be at least one byte following the EA */ |
| 1050 | len--; |
| 1051 | if (len <= 0) |
| 1052 | return; |
| 1053 | |
| 1054 | addr >>= 1; |
| 1055 | /* Closed port, or invalid ? */ |
| 1056 | if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL) |
| 1057 | return; |
| 1058 | dlci = gsm->dlci[addr]; |
| 1059 | |
| 1060 | while (gsm_read_ea(&modem, *dp++) == 0) { |
| 1061 | len--; |
| 1062 | if (len == 0) |
| 1063 | return; |
| 1064 | } |
| 1065 | tty = tty_port_tty_get(&dlci->port); |
| 1066 | gsm_process_modem(tty, dlci, modem); |
| 1067 | if (tty) { |
| 1068 | tty_wakeup(tty); |
| 1069 | tty_kref_put(tty); |
| 1070 | } |
| 1071 | gsm_control_reply(gsm, CMD_MSC, data, clen); |
| 1072 | } |
| 1073 | |
| 1074 | /** |
| 1075 | * gsm_control_rls - remote line status |
| 1076 | * @gsm: GSM channel |
| 1077 | * @data: data bytes |
| 1078 | * @clen: data length |
| 1079 | * |
| 1080 | * The modem sends us a two byte message on the control channel whenever |
| 1081 | * it wishes to send us an error state from the virtual link. Stuff |
| 1082 | * this into the uplink tty if present |
| 1083 | */ |
| 1084 | |
| 1085 | static void gsm_control_rls(struct gsm_mux *gsm, u8 *data, int clen) |
| 1086 | { |
| 1087 | struct tty_struct *tty; |
| 1088 | unsigned int addr = 0 ; |
| 1089 | u8 bits; |
| 1090 | int len = clen; |
| 1091 | u8 *dp = data; |
| 1092 | |
| 1093 | while (gsm_read_ea(&addr, *dp++) == 0) { |
| 1094 | len--; |
| 1095 | if (len == 0) |
| 1096 | return; |
| 1097 | } |
| 1098 | /* Must be at least one byte following ea */ |
| 1099 | len--; |
| 1100 | if (len <= 0) |
| 1101 | return; |
| 1102 | addr >>= 1; |
| 1103 | /* Closed port, or invalid ? */ |
| 1104 | if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL) |
| 1105 | return; |
| 1106 | /* No error ? */ |
| 1107 | bits = *dp; |
| 1108 | if ((bits & 1) == 0) |
| 1109 | return; |
| 1110 | /* See if we have an uplink tty */ |
| 1111 | tty = tty_port_tty_get(&gsm->dlci[addr]->port); |
| 1112 | |
| 1113 | if (tty) { |
| 1114 | if (bits & 2) |
| 1115 | tty_insert_flip_char(tty, 0, TTY_OVERRUN); |
| 1116 | if (bits & 4) |
| 1117 | tty_insert_flip_char(tty, 0, TTY_PARITY); |
| 1118 | if (bits & 8) |
| 1119 | tty_insert_flip_char(tty, 0, TTY_FRAME); |
| 1120 | tty_flip_buffer_push(tty); |
| 1121 | tty_kref_put(tty); |
| 1122 | } |
| 1123 | gsm_control_reply(gsm, CMD_RLS, data, clen); |
| 1124 | } |
| 1125 | |
| 1126 | static void gsm_dlci_begin_close(struct gsm_dlci *dlci); |
| 1127 | |
| 1128 | /** |
| 1129 | * gsm_control_message - DLCI 0 control processing |
| 1130 | * @gsm: our GSM mux |
| 1131 | * @command: the command EA |
| 1132 | * @data: data beyond the command/length EAs |
| 1133 | * @clen: length |
| 1134 | * |
| 1135 | * Input processor for control messages from the other end of the link. |
| 1136 | * Processes the incoming request and queues a response frame or an |
| 1137 | * NSC response if not supported |
| 1138 | */ |
| 1139 | |
| 1140 | static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, |
| 1141 | u8 *data, int clen) |
| 1142 | { |
| 1143 | u8 buf[1]; |
| 1144 | switch (command) { |
| 1145 | case CMD_CLD: { |
| 1146 | struct gsm_dlci *dlci = gsm->dlci[0]; |
| 1147 | /* Modem wishes to close down */ |
| 1148 | if (dlci) { |
| 1149 | dlci->dead = 1; |
| 1150 | gsm->dead = 1; |
| 1151 | gsm_dlci_begin_close(dlci); |
| 1152 | } |
| 1153 | } |
| 1154 | break; |
| 1155 | case CMD_TEST: |
| 1156 | /* Modem wishes to test, reply with the data */ |
| 1157 | gsm_control_reply(gsm, CMD_TEST, data, clen); |
| 1158 | break; |
| 1159 | case CMD_FCON: |
| 1160 | /* Modem wants us to STFU */ |
| 1161 | gsm->constipated = 1; |
| 1162 | gsm_control_reply(gsm, CMD_FCON, NULL, 0); |
| 1163 | break; |
| 1164 | case CMD_FCOFF: |
| 1165 | /* Modem can accept data again */ |
| 1166 | gsm->constipated = 0; |
| 1167 | gsm_control_reply(gsm, CMD_FCOFF, NULL, 0); |
| 1168 | /* Kick the link in case it is idling */ |
| 1169 | gsm_data_kick(gsm); |
| 1170 | break; |
| 1171 | case CMD_MSC: |
| 1172 | /* Out of band modem line change indicator for a DLCI */ |
| 1173 | gsm_control_modem(gsm, data, clen); |
| 1174 | break; |
| 1175 | case CMD_RLS: |
| 1176 | /* Out of band error reception for a DLCI */ |
| 1177 | gsm_control_rls(gsm, data, clen); |
| 1178 | break; |
| 1179 | case CMD_PSC: |
| 1180 | /* Modem wishes to enter power saving state */ |
| 1181 | gsm_control_reply(gsm, CMD_PSC, NULL, 0); |
| 1182 | break; |
| 1183 | /* Optional unsupported commands */ |
| 1184 | case CMD_PN: /* Parameter negotiation */ |
| 1185 | case CMD_RPN: /* Remote port negotation */ |
| 1186 | case CMD_SNC: /* Service negotation command */ |
| 1187 | default: |
| 1188 | /* Reply to bad commands with an NSC */ |
| 1189 | buf[0] = command; |
| 1190 | gsm_control_reply(gsm, CMD_NSC, buf, 1); |
| 1191 | break; |
| 1192 | } |
| 1193 | } |
| 1194 | |
| 1195 | /** |
| 1196 | * gsm_control_response - process a response to our control |
| 1197 | * @gsm: our GSM mux |
| 1198 | * @command: the command (response) EA |
| 1199 | * @data: data beyond the command/length EA |
| 1200 | * @clen: length |
| 1201 | * |
| 1202 | * Process a response to an outstanding command. We only allow a single |
| 1203 | * control message in flight so this is fairly easy. All the clean up |
| 1204 | * is done by the caller, we just update the fields, flag it as done |
| 1205 | * and return |
| 1206 | */ |
| 1207 | |
| 1208 | static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, |
| 1209 | u8 *data, int clen) |
| 1210 | { |
| 1211 | struct gsm_control *ctrl; |
| 1212 | unsigned long flags; |
| 1213 | |
| 1214 | spin_lock_irqsave(&gsm->control_lock, flags); |
| 1215 | |
| 1216 | ctrl = gsm->pending_cmd; |
| 1217 | /* Does the reply match our command */ |
| 1218 | command |= 1; |
| 1219 | if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) { |
| 1220 | /* Our command was replied to, kill the retry timer */ |
| 1221 | del_timer(&gsm->t2_timer); |
| 1222 | gsm->pending_cmd = NULL; |
| 1223 | /* Rejected by the other end */ |
| 1224 | if (command == CMD_NSC) |
| 1225 | ctrl->error = -EOPNOTSUPP; |
| 1226 | ctrl->done = 1; |
| 1227 | wake_up(&gsm->event); |
| 1228 | } |
| 1229 | spin_unlock_irqrestore(&gsm->control_lock, flags); |
| 1230 | } |
| 1231 | |
| 1232 | /** |
| 1233 | * gsm_control_transmit - send control packet |
| 1234 | * @gsm: gsm mux |
| 1235 | * @ctrl: frame to send |
| 1236 | * |
| 1237 | * Send out a pending control command (called under control lock) |
| 1238 | */ |
| 1239 | |
| 1240 | static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl) |
| 1241 | { |
| 1242 | struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 1, |
| 1243 | gsm->ftype|PF); |
| 1244 | if (msg == NULL) |
| 1245 | return; |
| 1246 | msg->data[0] = (ctrl->cmd << 1) | 2 | EA; /* command */ |
| 1247 | memcpy(msg->data + 1, ctrl->data, ctrl->len); |
| 1248 | gsm_data_queue(gsm->dlci[0], msg); |
| 1249 | } |
| 1250 | |
| 1251 | /** |
| 1252 | * gsm_control_retransmit - retransmit a control frame |
| 1253 | * @data: pointer to our gsm object |
| 1254 | * |
| 1255 | * Called off the T2 timer expiry in order to retransmit control frames |
| 1256 | * that have been lost in the system somewhere. The control_lock protects |
| 1257 | * us from colliding with another sender or a receive completion event. |
| 1258 | * In that situation the timer may still occur in a small window but |
| 1259 | * gsm->pending_cmd will be NULL and we just let the timer expire. |
| 1260 | */ |
| 1261 | |
| 1262 | static void gsm_control_retransmit(unsigned long data) |
| 1263 | { |
| 1264 | struct gsm_mux *gsm = (struct gsm_mux *)data; |
| 1265 | struct gsm_control *ctrl; |
| 1266 | unsigned long flags; |
| 1267 | spin_lock_irqsave(&gsm->control_lock, flags); |
| 1268 | ctrl = gsm->pending_cmd; |
| 1269 | if (ctrl) { |
| 1270 | gsm->cretries--; |
| 1271 | if (gsm->cretries == 0) { |
| 1272 | gsm->pending_cmd = NULL; |
| 1273 | ctrl->error = -ETIMEDOUT; |
| 1274 | ctrl->done = 1; |
| 1275 | spin_unlock_irqrestore(&gsm->control_lock, flags); |
| 1276 | wake_up(&gsm->event); |
| 1277 | return; |
| 1278 | } |
| 1279 | gsm_control_transmit(gsm, ctrl); |
| 1280 | mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); |
| 1281 | } |
| 1282 | spin_unlock_irqrestore(&gsm->control_lock, flags); |
| 1283 | } |
| 1284 | |
| 1285 | /** |
| 1286 | * gsm_control_send - send a control frame on DLCI 0 |
| 1287 | * @gsm: the GSM channel |
| 1288 | * @command: command to send including CR bit |
| 1289 | * @data: bytes of data (must be kmalloced) |
| 1290 | * @len: length of the block to send |
| 1291 | * |
| 1292 | * Queue and dispatch a control command. Only one command can be |
| 1293 | * active at a time. In theory more can be outstanding but the matching |
| 1294 | * gets really complicated so for now stick to one outstanding. |
| 1295 | */ |
| 1296 | |
| 1297 | static struct gsm_control *gsm_control_send(struct gsm_mux *gsm, |
| 1298 | unsigned int command, u8 *data, int clen) |
| 1299 | { |
| 1300 | struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control), |
| 1301 | GFP_KERNEL); |
| 1302 | unsigned long flags; |
| 1303 | if (ctrl == NULL) |
| 1304 | return NULL; |
| 1305 | retry: |
| 1306 | wait_event(gsm->event, gsm->pending_cmd == NULL); |
| 1307 | spin_lock_irqsave(&gsm->control_lock, flags); |
| 1308 | if (gsm->pending_cmd != NULL) { |
| 1309 | spin_unlock_irqrestore(&gsm->control_lock, flags); |
| 1310 | goto retry; |
| 1311 | } |
| 1312 | ctrl->cmd = command; |
| 1313 | ctrl->data = data; |
| 1314 | ctrl->len = clen; |
| 1315 | gsm->pending_cmd = ctrl; |
| 1316 | gsm->cretries = gsm->n2; |
| 1317 | mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); |
| 1318 | gsm_control_transmit(gsm, ctrl); |
| 1319 | spin_unlock_irqrestore(&gsm->control_lock, flags); |
| 1320 | return ctrl; |
| 1321 | } |
| 1322 | |
| 1323 | /** |
| 1324 | * gsm_control_wait - wait for a control to finish |
| 1325 | * @gsm: GSM mux |
| 1326 | * @control: control we are waiting on |
| 1327 | * |
| 1328 | * Waits for the control to complete or time out. Frees any used |
| 1329 | * resources and returns 0 for success, or an error if the remote |
| 1330 | * rejected or ignored the request. |
| 1331 | */ |
| 1332 | |
| 1333 | static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control) |
| 1334 | { |
| 1335 | int err; |
| 1336 | wait_event(gsm->event, control->done == 1); |
| 1337 | err = control->error; |
| 1338 | kfree(control); |
| 1339 | return err; |
| 1340 | } |
| 1341 | |
| 1342 | |
| 1343 | /* |
| 1344 | * DLCI level handling: Needs krefs |
| 1345 | */ |
| 1346 | |
| 1347 | /* |
| 1348 | * State transitions and timers |
| 1349 | */ |
| 1350 | |
| 1351 | /** |
| 1352 | * gsm_dlci_close - a DLCI has closed |
| 1353 | * @dlci: DLCI that closed |
| 1354 | * |
| 1355 | * Perform processing when moving a DLCI into closed state. If there |
| 1356 | * is an attached tty this is hung up |
| 1357 | */ |
| 1358 | |
| 1359 | static void gsm_dlci_close(struct gsm_dlci *dlci) |
| 1360 | { |
| 1361 | del_timer(&dlci->t1); |
| 1362 | if (debug & 8) |
| 1363 | printk("DLCI %d goes closed.\n", dlci->addr); |
| 1364 | dlci->state = DLCI_CLOSED; |
| 1365 | if (dlci->addr != 0) { |
| 1366 | struct tty_struct *tty = tty_port_tty_get(&dlci->port); |
| 1367 | if (tty) { |
| 1368 | tty_hangup(tty); |
| 1369 | tty_kref_put(tty); |
| 1370 | } |
| 1371 | kfifo_reset(dlci->fifo); |
| 1372 | } else |
| 1373 | dlci->gsm->dead = 1; |
| 1374 | wake_up(&dlci->gsm->event); |
| 1375 | /* A DLCI 0 close is a MUX termination so we need to kick that |
| 1376 | back to userspace somehow */ |
| 1377 | } |
| 1378 | |
| 1379 | /** |
| 1380 | * gsm_dlci_open - a DLCI has opened |
| 1381 | * @dlci: DLCI that opened |
| 1382 | * |
| 1383 | * Perform processing when moving a DLCI into open state. |
| 1384 | */ |
| 1385 | |
| 1386 | static void gsm_dlci_open(struct gsm_dlci *dlci) |
| 1387 | { |
| 1388 | /* Note that SABM UA .. SABM UA first UA lost can mean that we go |
| 1389 | open -> open */ |
| 1390 | del_timer(&dlci->t1); |
| 1391 | /* This will let a tty open continue */ |
| 1392 | dlci->state = DLCI_OPEN; |
| 1393 | if (debug & 8) |
| 1394 | printk("DLCI %d goes open.\n", dlci->addr); |
| 1395 | wake_up(&dlci->gsm->event); |
| 1396 | } |
| 1397 | |
| 1398 | /** |
| 1399 | * gsm_dlci_t1 - T1 timer expiry |
| 1400 | * @dlci: DLCI that opened |
| 1401 | * |
| 1402 | * The T1 timer handles retransmits of control frames (essentially of |
| 1403 | * SABM and DISC). We resend the command until the retry count runs out |
| 1404 | * in which case an opening port goes back to closed and a closing port |
| 1405 | * is simply put into closed state (any further frames from the other |
| 1406 | * end will get a DM response) |
| 1407 | */ |
| 1408 | |
| 1409 | static void gsm_dlci_t1(unsigned long data) |
| 1410 | { |
| 1411 | struct gsm_dlci *dlci = (struct gsm_dlci *)data; |
| 1412 | struct gsm_mux *gsm = dlci->gsm; |
| 1413 | |
| 1414 | switch (dlci->state) { |
| 1415 | case DLCI_OPENING: |
| 1416 | dlci->retries--; |
| 1417 | if (dlci->retries) { |
| 1418 | gsm_command(dlci->gsm, dlci->addr, SABM|PF); |
| 1419 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); |
| 1420 | } else |
| 1421 | gsm_dlci_close(dlci); |
| 1422 | break; |
| 1423 | case DLCI_CLOSING: |
| 1424 | dlci->retries--; |
| 1425 | if (dlci->retries) { |
| 1426 | gsm_command(dlci->gsm, dlci->addr, DISC|PF); |
| 1427 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); |
| 1428 | } else |
| 1429 | gsm_dlci_close(dlci); |
| 1430 | break; |
| 1431 | } |
| 1432 | } |
| 1433 | |
| 1434 | /** |
| 1435 | * gsm_dlci_begin_open - start channel open procedure |
| 1436 | * @dlci: DLCI to open |
| 1437 | * |
| 1438 | * Commence opening a DLCI from the Linux side. We issue SABM messages |
| 1439 | * to the modem which should then reply with a UA, at which point we |
| 1440 | * will move into open state. Opening is done asynchronously with retry |
| 1441 | * running off timers and the responses. |
| 1442 | */ |
| 1443 | |
| 1444 | static void gsm_dlci_begin_open(struct gsm_dlci *dlci) |
| 1445 | { |
| 1446 | struct gsm_mux *gsm = dlci->gsm; |
| 1447 | if (dlci->state == DLCI_OPEN || dlci->state == DLCI_OPENING) |
| 1448 | return; |
| 1449 | dlci->retries = gsm->n2; |
| 1450 | dlci->state = DLCI_OPENING; |
| 1451 | gsm_command(dlci->gsm, dlci->addr, SABM|PF); |
| 1452 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); |
| 1453 | } |
| 1454 | |
| 1455 | /** |
| 1456 | * gsm_dlci_begin_close - start channel open procedure |
| 1457 | * @dlci: DLCI to open |
| 1458 | * |
| 1459 | * Commence closing a DLCI from the Linux side. We issue DISC messages |
| 1460 | * to the modem which should then reply with a UA, at which point we |
| 1461 | * will move into closed state. Closing is done asynchronously with retry |
| 1462 | * off timers. We may also receive a DM reply from the other end which |
| 1463 | * indicates the channel was already closed. |
| 1464 | */ |
| 1465 | |
| 1466 | static void gsm_dlci_begin_close(struct gsm_dlci *dlci) |
| 1467 | { |
| 1468 | struct gsm_mux *gsm = dlci->gsm; |
| 1469 | if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING) |
| 1470 | return; |
| 1471 | dlci->retries = gsm->n2; |
| 1472 | dlci->state = DLCI_CLOSING; |
| 1473 | gsm_command(dlci->gsm, dlci->addr, DISC|PF); |
| 1474 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); |
| 1475 | } |
| 1476 | |
| 1477 | /** |
| 1478 | * gsm_dlci_data - data arrived |
| 1479 | * @dlci: channel |
| 1480 | * @data: block of bytes received |
| 1481 | * @len: length of received block |
| 1482 | * |
| 1483 | * A UI or UIH frame has arrived which contains data for a channel |
| 1484 | * other than the control channel. If the relevant virtual tty is |
| 1485 | * open we shovel the bits down it, if not we drop them. |
| 1486 | */ |
| 1487 | |
| 1488 | static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int len) |
| 1489 | { |
| 1490 | /* krefs .. */ |
| 1491 | struct tty_port *port = &dlci->port; |
| 1492 | struct tty_struct *tty = tty_port_tty_get(port); |
| 1493 | unsigned int modem = 0; |
| 1494 | |
| 1495 | if (debug & 16) |
| 1496 | printk("%d bytes for tty %p\n", len, tty); |
| 1497 | if (tty) { |
| 1498 | switch (dlci->adaption) { |
| 1499 | /* Unsupported types */ |
| 1500 | /* Packetised interruptible data */ |
| 1501 | case 4: |
| 1502 | break; |
| 1503 | /* Packetised uininterruptible voice/data */ |
| 1504 | case 3: |
| 1505 | break; |
| 1506 | /* Asynchronous serial with line state in each frame */ |
| 1507 | case 2: |
| 1508 | while (gsm_read_ea(&modem, *data++) == 0) { |
| 1509 | len--; |
| 1510 | if (len == 0) |
| 1511 | return; |
| 1512 | } |
| 1513 | gsm_process_modem(tty, dlci, modem); |
| 1514 | /* Line state will go via DLCI 0 controls only */ |
| 1515 | case 1: |
| 1516 | default: |
| 1517 | tty_insert_flip_string(tty, data, len); |
| 1518 | tty_flip_buffer_push(tty); |
| 1519 | } |
| 1520 | tty_kref_put(tty); |
| 1521 | } |
| 1522 | } |
| 1523 | |
| 1524 | /** |
| 1525 | * gsm_dlci_control - data arrived on control channel |
| 1526 | * @dlci: channel |
| 1527 | * @data: block of bytes received |
| 1528 | * @len: length of received block |
| 1529 | * |
| 1530 | * A UI or UIH frame has arrived which contains data for DLCI 0 the |
| 1531 | * control channel. This should contain a command EA followed by |
| 1532 | * control data bytes. The command EA contains a command/response bit |
| 1533 | * and we divide up the work accordingly. |
| 1534 | */ |
| 1535 | |
| 1536 | static void gsm_dlci_command(struct gsm_dlci *dlci, u8 *data, int len) |
| 1537 | { |
| 1538 | /* See what command is involved */ |
| 1539 | unsigned int command = 0; |
| 1540 | while (len-- > 0) { |
| 1541 | if (gsm_read_ea(&command, *data++) == 1) { |
| 1542 | int clen = *data++; |
| 1543 | len--; |
| 1544 | /* FIXME: this is properly an EA */ |
| 1545 | clen >>= 1; |
| 1546 | /* Malformed command ? */ |
| 1547 | if (clen > len) |
| 1548 | return; |
| 1549 | if (command & 1) |
| 1550 | gsm_control_message(dlci->gsm, command, |
| 1551 | data, clen); |
| 1552 | else |
| 1553 | gsm_control_response(dlci->gsm, command, |
| 1554 | data, clen); |
| 1555 | return; |
| 1556 | } |
| 1557 | } |
| 1558 | } |
| 1559 | |
| 1560 | /* |
| 1561 | * Allocate/Free DLCI channels |
| 1562 | */ |
| 1563 | |
| 1564 | /** |
| 1565 | * gsm_dlci_alloc - allocate a DLCI |
| 1566 | * @gsm: GSM mux |
| 1567 | * @addr: address of the DLCI |
| 1568 | * |
| 1569 | * Allocate and install a new DLCI object into the GSM mux. |
| 1570 | * |
| 1571 | * FIXME: review locking races |
| 1572 | */ |
| 1573 | |
| 1574 | static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr) |
| 1575 | { |
| 1576 | struct gsm_dlci *dlci = kzalloc(sizeof(struct gsm_dlci), GFP_ATOMIC); |
| 1577 | if (dlci == NULL) |
| 1578 | return NULL; |
| 1579 | spin_lock_init(&dlci->lock); |
| 1580 | dlci->fifo = &dlci->_fifo; |
| 1581 | if (kfifo_alloc(&dlci->_fifo, 4096, GFP_KERNEL) < 0) { |
| 1582 | kfree(dlci); |
| 1583 | return NULL; |
| 1584 | } |
| 1585 | |
| 1586 | skb_queue_head_init(&dlci->skb_list); |
| 1587 | init_timer(&dlci->t1); |
| 1588 | dlci->t1.function = gsm_dlci_t1; |
| 1589 | dlci->t1.data = (unsigned long)dlci; |
| 1590 | tty_port_init(&dlci->port); |
| 1591 | dlci->port.ops = &gsm_port_ops; |
| 1592 | dlci->gsm = gsm; |
| 1593 | dlci->addr = addr; |
| 1594 | dlci->adaption = gsm->adaption; |
| 1595 | dlci->state = DLCI_CLOSED; |
| 1596 | if (addr) |
| 1597 | dlci->data = gsm_dlci_data; |
| 1598 | else |
| 1599 | dlci->data = gsm_dlci_command; |
| 1600 | gsm->dlci[addr] = dlci; |
| 1601 | return dlci; |
| 1602 | } |
| 1603 | |
| 1604 | /** |
| 1605 | * gsm_dlci_free - release DLCI |
| 1606 | * @dlci: DLCI to destroy |
| 1607 | * |
| 1608 | * Free up a DLCI. Currently to keep the lifetime rules sane we only |
| 1609 | * clean up DLCI objects when the MUX closes rather than as the port |
| 1610 | * is closed down on both the tty and mux levels. |
| 1611 | * |
| 1612 | * Can sleep. |
| 1613 | */ |
| 1614 | static void gsm_dlci_free(struct gsm_dlci *dlci) |
| 1615 | { |
| 1616 | struct tty_struct *tty = tty_port_tty_get(&dlci->port); |
| 1617 | if (tty) { |
| 1618 | tty_vhangup(tty); |
| 1619 | tty_kref_put(tty); |
| 1620 | } |
| 1621 | del_timer_sync(&dlci->t1); |
| 1622 | dlci->gsm->dlci[dlci->addr] = NULL; |
| 1623 | kfifo_free(dlci->fifo); |
| 1624 | kfree(dlci); |
| 1625 | } |
| 1626 | |
| 1627 | |
| 1628 | /* |
| 1629 | * LAPBish link layer logic |
| 1630 | */ |
| 1631 | |
| 1632 | /** |
| 1633 | * gsm_queue - a GSM frame is ready to process |
| 1634 | * @gsm: pointer to our gsm mux |
| 1635 | * |
| 1636 | * At this point in time a frame has arrived and been demangled from |
| 1637 | * the line encoding. All the differences between the encodings have |
| 1638 | * been handled below us and the frame is unpacked into the structures. |
| 1639 | * The fcs holds the header FCS but any data FCS must be added here. |
| 1640 | */ |
| 1641 | |
| 1642 | static void gsm_queue(struct gsm_mux *gsm) |
| 1643 | { |
| 1644 | struct gsm_dlci *dlci; |
| 1645 | u8 cr; |
| 1646 | int address; |
| 1647 | /* We have to sneak a look at the packet body to do the FCS. |
| 1648 | A somewhat layering violation in the spec */ |
| 1649 | |
| 1650 | if ((gsm->control & ~PF) == UI) |
| 1651 | gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len); |
| 1652 | if (gsm->fcs != GOOD_FCS) { |
| 1653 | gsm->bad_fcs++; |
| 1654 | if (debug & 4) |
| 1655 | printk("BAD FCS %02x\n", gsm->fcs); |
| 1656 | return; |
| 1657 | } |
| 1658 | address = gsm->address >> 1; |
| 1659 | if (address >= NUM_DLCI) |
| 1660 | goto invalid; |
| 1661 | |
| 1662 | cr = gsm->address & 1; /* C/R bit */ |
| 1663 | |
| 1664 | gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len); |
| 1665 | |
| 1666 | cr ^= 1 - gsm->initiator; /* Flip so 1 always means command */ |
| 1667 | dlci = gsm->dlci[address]; |
| 1668 | |
| 1669 | switch (gsm->control) { |
| 1670 | case SABM|PF: |
| 1671 | if (cr == 0) |
| 1672 | goto invalid; |
| 1673 | if (dlci == NULL) |
| 1674 | dlci = gsm_dlci_alloc(gsm, address); |
| 1675 | if (dlci == NULL) |
| 1676 | return; |
| 1677 | if (dlci->dead) |
| 1678 | gsm_response(gsm, address, DM); |
| 1679 | else { |
| 1680 | gsm_response(gsm, address, UA); |
| 1681 | gsm_dlci_open(dlci); |
| 1682 | } |
| 1683 | break; |
| 1684 | case DISC|PF: |
| 1685 | if (cr == 0) |
| 1686 | goto invalid; |
| 1687 | if (dlci == NULL || dlci->state == DLCI_CLOSED) { |
| 1688 | gsm_response(gsm, address, DM); |
| 1689 | return; |
| 1690 | } |
| 1691 | /* Real close complete */ |
| 1692 | gsm_response(gsm, address, UA); |
| 1693 | gsm_dlci_close(dlci); |
| 1694 | break; |
| 1695 | case UA: |
| 1696 | case UA|PF: |
| 1697 | if (cr == 0 || dlci == NULL) |
| 1698 | break; |
| 1699 | switch (dlci->state) { |
| 1700 | case DLCI_CLOSING: |
| 1701 | gsm_dlci_close(dlci); |
| 1702 | break; |
| 1703 | case DLCI_OPENING: |
| 1704 | gsm_dlci_open(dlci); |
| 1705 | break; |
| 1706 | } |
| 1707 | break; |
| 1708 | case DM: /* DM can be valid unsolicited */ |
| 1709 | case DM|PF: |
| 1710 | if (cr) |
| 1711 | goto invalid; |
| 1712 | if (dlci == NULL) |
| 1713 | return; |
| 1714 | gsm_dlci_close(dlci); |
| 1715 | break; |
| 1716 | case UI: |
| 1717 | case UI|PF: |
| 1718 | case UIH: |
| 1719 | case UIH|PF: |
| 1720 | #if 0 |
| 1721 | if (cr) |
| 1722 | goto invalid; |
| 1723 | #endif |
| 1724 | if (dlci == NULL || dlci->state != DLCI_OPEN) { |
| 1725 | gsm_command(gsm, address, DM|PF); |
| 1726 | return; |
| 1727 | } |
| 1728 | dlci->data(dlci, gsm->buf, gsm->len); |
| 1729 | break; |
| 1730 | default: |
| 1731 | goto invalid; |
| 1732 | } |
| 1733 | return; |
| 1734 | invalid: |
| 1735 | gsm->malformed++; |
| 1736 | return; |
| 1737 | } |
| 1738 | |
| 1739 | |
| 1740 | /** |
| 1741 | * gsm0_receive - perform processing for non-transparency |
| 1742 | * @gsm: gsm data for this ldisc instance |
| 1743 | * @c: character |
| 1744 | * |
| 1745 | * Receive bytes in gsm mode 0 |
| 1746 | */ |
| 1747 | |
| 1748 | static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) |
| 1749 | { |
| 1750 | switch (gsm->state) { |
| 1751 | case GSM_SEARCH: /* SOF marker */ |
| 1752 | if (c == GSM0_SOF) { |
| 1753 | gsm->state = GSM_ADDRESS; |
| 1754 | gsm->address = 0; |
| 1755 | gsm->len = 0; |
| 1756 | gsm->fcs = INIT_FCS; |
| 1757 | } |
| 1758 | break; /* Address EA */ |
| 1759 | case GSM_ADDRESS: |
| 1760 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
| 1761 | if (gsm_read_ea(&gsm->address, c)) |
| 1762 | gsm->state = GSM_CONTROL; |
| 1763 | break; |
| 1764 | case GSM_CONTROL: /* Control Byte */ |
| 1765 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
| 1766 | gsm->control = c; |
| 1767 | gsm->state = GSM_LEN; |
| 1768 | break; |
| 1769 | case GSM_LEN: /* Length EA */ |
| 1770 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
| 1771 | if (gsm_read_ea(&gsm->len, c)) { |
| 1772 | if (gsm->len > gsm->mru) { |
| 1773 | gsm->bad_size++; |
| 1774 | gsm->state = GSM_SEARCH; |
| 1775 | break; |
| 1776 | } |
| 1777 | gsm->count = 0; |
| 1778 | gsm->state = GSM_DATA; |
| 1779 | } |
| 1780 | break; |
| 1781 | case GSM_DATA: /* Data */ |
| 1782 | gsm->buf[gsm->count++] = c; |
| 1783 | if (gsm->count == gsm->len) |
| 1784 | gsm->state = GSM_FCS; |
| 1785 | break; |
| 1786 | case GSM_FCS: /* FCS follows the packet */ |
| 1787 | gsm->fcs = c; |
| 1788 | gsm_queue(gsm); |
| 1789 | /* And then back for the next frame */ |
| 1790 | gsm->state = GSM_SEARCH; |
| 1791 | break; |
| 1792 | } |
| 1793 | } |
| 1794 | |
| 1795 | /** |
| 1796 | * gsm0_receive - perform processing for non-transparency |
| 1797 | * @gsm: gsm data for this ldisc instance |
| 1798 | * @c: character |
| 1799 | * |
| 1800 | * Receive bytes in mode 1 (Advanced option) |
| 1801 | */ |
| 1802 | |
| 1803 | static void gsm1_receive(struct gsm_mux *gsm, unsigned char c) |
| 1804 | { |
| 1805 | if (c == GSM1_SOF) { |
| 1806 | /* EOF is only valid in frame if we have got to the data state |
| 1807 | and received at least one byte (the FCS) */ |
| 1808 | if (gsm->state == GSM_DATA && gsm->count) { |
| 1809 | /* Extract the FCS */ |
| 1810 | gsm->count--; |
| 1811 | gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]); |
| 1812 | gsm->len = gsm->count; |
| 1813 | gsm_queue(gsm); |
| 1814 | gsm->state = GSM_START; |
| 1815 | return; |
| 1816 | } |
| 1817 | /* Any partial frame was a runt so go back to start */ |
| 1818 | if (gsm->state != GSM_START) { |
| 1819 | gsm->malformed++; |
| 1820 | gsm->state = GSM_START; |
| 1821 | } |
| 1822 | /* A SOF in GSM_START means we are still reading idling or |
| 1823 | framing bytes */ |
| 1824 | return; |
| 1825 | } |
| 1826 | |
| 1827 | if (c == GSM1_ESCAPE) { |
| 1828 | gsm->escape = 1; |
| 1829 | return; |
| 1830 | } |
| 1831 | |
| 1832 | /* Only an unescaped SOF gets us out of GSM search */ |
| 1833 | if (gsm->state == GSM_SEARCH) |
| 1834 | return; |
| 1835 | |
| 1836 | if (gsm->escape) { |
| 1837 | c ^= GSM1_ESCAPE_BITS; |
| 1838 | gsm->escape = 0; |
| 1839 | } |
| 1840 | switch (gsm->state) { |
| 1841 | case GSM_START: /* First byte after SOF */ |
| 1842 | gsm->address = 0; |
| 1843 | gsm->state = GSM_ADDRESS; |
| 1844 | gsm->fcs = INIT_FCS; |
| 1845 | /* Drop through */ |
| 1846 | case GSM_ADDRESS: /* Address continuation */ |
| 1847 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
| 1848 | if (gsm_read_ea(&gsm->address, c)) |
| 1849 | gsm->state = GSM_CONTROL; |
| 1850 | break; |
| 1851 | case GSM_CONTROL: /* Control Byte */ |
| 1852 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
| 1853 | gsm->control = c; |
| 1854 | gsm->count = 0; |
| 1855 | gsm->state = GSM_DATA; |
| 1856 | break; |
| 1857 | case GSM_DATA: /* Data */ |
| 1858 | if (gsm->count > gsm->mru ) { /* Allow one for the FCS */ |
| 1859 | gsm->state = GSM_OVERRUN; |
| 1860 | gsm->bad_size++; |
| 1861 | } else |
| 1862 | gsm->buf[gsm->count++] = c; |
| 1863 | break; |
| 1864 | case GSM_OVERRUN: /* Over-long - eg a dropped SOF */ |
| 1865 | break; |
| 1866 | } |
| 1867 | } |
| 1868 | |
| 1869 | /** |
| 1870 | * gsm_error - handle tty error |
| 1871 | * @gsm: ldisc data |
| 1872 | * @data: byte received (may be invalid) |
| 1873 | * @flag: error received |
| 1874 | * |
| 1875 | * Handle an error in the receipt of data for a frame. Currently we just |
| 1876 | * go back to hunting for a SOF. |
| 1877 | * |
| 1878 | * FIXME: better diagnostics ? |
| 1879 | */ |
| 1880 | |
| 1881 | static void gsm_error(struct gsm_mux *gsm, |
| 1882 | unsigned char data, unsigned char flag) |
| 1883 | { |
| 1884 | gsm->state = GSM_SEARCH; |
| 1885 | gsm->io_error++; |
| 1886 | } |
| 1887 | |
| 1888 | /** |
| 1889 | * gsm_cleanup_mux - generic GSM protocol cleanup |
| 1890 | * @gsm: our mux |
| 1891 | * |
| 1892 | * Clean up the bits of the mux which are the same for all framing |
| 1893 | * protocols. Remove the mux from the mux table, stop all the timers |
| 1894 | * and then shut down each device hanging up the channels as we go. |
| 1895 | */ |
| 1896 | |
| 1897 | void gsm_cleanup_mux(struct gsm_mux *gsm) |
| 1898 | { |
| 1899 | int i; |
| 1900 | struct gsm_dlci *dlci = gsm->dlci[0]; |
| 1901 | struct gsm_msg *txq; |
| 1902 | |
| 1903 | gsm->dead = 1; |
| 1904 | |
| 1905 | spin_lock(&gsm_mux_lock); |
| 1906 | for (i = 0; i < MAX_MUX; i++) { |
| 1907 | if (gsm_mux[i] == gsm) { |
| 1908 | gsm_mux[i] = NULL; |
| 1909 | break; |
| 1910 | } |
| 1911 | } |
| 1912 | spin_unlock(&gsm_mux_lock); |
| 1913 | WARN_ON(i == MAX_MUX); |
| 1914 | |
| 1915 | del_timer_sync(&gsm->t2_timer); |
| 1916 | /* Now we are sure T2 has stopped */ |
| 1917 | if (dlci) { |
| 1918 | dlci->dead = 1; |
| 1919 | gsm_dlci_begin_close(dlci); |
| 1920 | wait_event_interruptible(gsm->event, |
| 1921 | dlci->state == DLCI_CLOSED); |
| 1922 | } |
| 1923 | /* Free up any link layer users */ |
| 1924 | for (i = 0; i < NUM_DLCI; i++) |
| 1925 | if (gsm->dlci[i]) |
| 1926 | gsm_dlci_free(gsm->dlci[i]); |
| 1927 | /* Now wipe the queues */ |
| 1928 | for (txq = gsm->tx_head; txq != NULL; txq = gsm->tx_head) { |
| 1929 | gsm->tx_head = txq->next; |
| 1930 | kfree(txq); |
| 1931 | } |
| 1932 | gsm->tx_tail = NULL; |
| 1933 | } |
| 1934 | EXPORT_SYMBOL_GPL(gsm_cleanup_mux); |
| 1935 | |
| 1936 | /** |
| 1937 | * gsm_activate_mux - generic GSM setup |
| 1938 | * @gsm: our mux |
| 1939 | * |
| 1940 | * Set up the bits of the mux which are the same for all framing |
| 1941 | * protocols. Add the mux to the mux table so it can be opened and |
| 1942 | * finally kick off connecting to DLCI 0 on the modem. |
| 1943 | */ |
| 1944 | |
| 1945 | int gsm_activate_mux(struct gsm_mux *gsm) |
| 1946 | { |
| 1947 | struct gsm_dlci *dlci; |
| 1948 | int i = 0; |
| 1949 | |
| 1950 | init_timer(&gsm->t2_timer); |
| 1951 | gsm->t2_timer.function = gsm_control_retransmit; |
| 1952 | gsm->t2_timer.data = (unsigned long)gsm; |
| 1953 | init_waitqueue_head(&gsm->event); |
| 1954 | spin_lock_init(&gsm->control_lock); |
| 1955 | spin_lock_init(&gsm->tx_lock); |
| 1956 | |
| 1957 | if (gsm->encoding == 0) |
| 1958 | gsm->receive = gsm0_receive; |
| 1959 | else |
| 1960 | gsm->receive = gsm1_receive; |
| 1961 | gsm->error = gsm_error; |
| 1962 | |
| 1963 | spin_lock(&gsm_mux_lock); |
| 1964 | for (i = 0; i < MAX_MUX; i++) { |
| 1965 | if (gsm_mux[i] == NULL) { |
| 1966 | gsm_mux[i] = gsm; |
| 1967 | break; |
| 1968 | } |
| 1969 | } |
| 1970 | spin_unlock(&gsm_mux_lock); |
| 1971 | if (i == MAX_MUX) |
| 1972 | return -EBUSY; |
| 1973 | |
| 1974 | dlci = gsm_dlci_alloc(gsm, 0); |
| 1975 | if (dlci == NULL) |
| 1976 | return -ENOMEM; |
| 1977 | gsm->dead = 0; /* Tty opens are now permissible */ |
| 1978 | return 0; |
| 1979 | } |
| 1980 | EXPORT_SYMBOL_GPL(gsm_activate_mux); |
| 1981 | |
| 1982 | /** |
| 1983 | * gsm_free_mux - free up a mux |
| 1984 | * @mux: mux to free |
| 1985 | * |
| 1986 | * Dispose of allocated resources for a dead mux. No refcounting |
| 1987 | * at present so the mux must be truely dead. |
| 1988 | */ |
| 1989 | void gsm_free_mux(struct gsm_mux *gsm) |
| 1990 | { |
| 1991 | kfree(gsm->txframe); |
| 1992 | kfree(gsm->buf); |
| 1993 | kfree(gsm); |
| 1994 | } |
| 1995 | EXPORT_SYMBOL_GPL(gsm_free_mux); |
| 1996 | |
| 1997 | /** |
| 1998 | * gsm_alloc_mux - allocate a mux |
| 1999 | * |
| 2000 | * Creates a new mux ready for activation. |
| 2001 | */ |
| 2002 | |
| 2003 | struct gsm_mux *gsm_alloc_mux(void) |
| 2004 | { |
| 2005 | struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL); |
| 2006 | if (gsm == NULL) |
| 2007 | return NULL; |
| 2008 | gsm->buf = kmalloc(MAX_MRU + 1, GFP_KERNEL); |
| 2009 | if (gsm->buf == NULL) { |
| 2010 | kfree(gsm); |
| 2011 | return NULL; |
| 2012 | } |
| 2013 | gsm->txframe = kmalloc(2 * MAX_MRU + 2, GFP_KERNEL); |
| 2014 | if (gsm->txframe == NULL) { |
| 2015 | kfree(gsm->buf); |
| 2016 | kfree(gsm); |
| 2017 | return NULL; |
| 2018 | } |
| 2019 | spin_lock_init(&gsm->lock); |
| 2020 | |
| 2021 | gsm->t1 = T1; |
| 2022 | gsm->t2 = T2; |
| 2023 | gsm->n2 = N2; |
| 2024 | gsm->ftype = UIH; |
| 2025 | gsm->initiator = 0; |
| 2026 | gsm->adaption = 1; |
| 2027 | gsm->encoding = 1; |
| 2028 | gsm->mru = 64; /* Default to encoding 1 so these should be 64 */ |
| 2029 | gsm->mtu = 64; |
| 2030 | gsm->dead = 1; /* Avoid early tty opens */ |
| 2031 | |
| 2032 | return gsm; |
| 2033 | } |
| 2034 | EXPORT_SYMBOL_GPL(gsm_alloc_mux); |
| 2035 | |
| 2036 | |
| 2037 | |
| 2038 | |
| 2039 | /** |
| 2040 | * gsmld_output - write to link |
| 2041 | * @gsm: our mux |
| 2042 | * @data: bytes to output |
| 2043 | * @len: size |
| 2044 | * |
| 2045 | * Write a block of data from the GSM mux to the data channel. This |
| 2046 | * will eventually be serialized from above but at the moment isn't. |
| 2047 | */ |
| 2048 | |
| 2049 | static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len) |
| 2050 | { |
| 2051 | if (tty_write_room(gsm->tty) < len) { |
| 2052 | set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags); |
| 2053 | return -ENOSPC; |
| 2054 | } |
| 2055 | if (debug & 4) { |
| 2056 | printk("-->%d bytes out\n", len); |
| 2057 | hex_packet(data, len); |
| 2058 | } |
| 2059 | gsm->tty->ops->write(gsm->tty, data, len); |
| 2060 | return len; |
| 2061 | } |
| 2062 | |
| 2063 | /** |
| 2064 | * gsmld_attach_gsm - mode set up |
| 2065 | * @tty: our tty structure |
| 2066 | * @gsm: our mux |
| 2067 | * |
| 2068 | * Set up the MUX for basic mode and commence connecting to the |
| 2069 | * modem. Currently called from the line discipline set up but |
| 2070 | * will need moving to an ioctl path. |
| 2071 | */ |
| 2072 | |
| 2073 | static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) |
| 2074 | { |
| 2075 | int ret; |
| 2076 | |
| 2077 | gsm->tty = tty_kref_get(tty); |
| 2078 | gsm->output = gsmld_output; |
| 2079 | ret = gsm_activate_mux(gsm); |
| 2080 | if (ret != 0) |
| 2081 | tty_kref_put(gsm->tty); |
| 2082 | return ret; |
| 2083 | } |
| 2084 | |
| 2085 | |
| 2086 | /** |
| 2087 | * gsmld_detach_gsm - stop doing 0710 mux |
| 2088 | * @tty: tty atttached to the mux |
| 2089 | * @gsm: mux |
| 2090 | * |
| 2091 | * Shutdown and then clean up the resources used by the line discipline |
| 2092 | */ |
| 2093 | |
| 2094 | static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) |
| 2095 | { |
| 2096 | WARN_ON(tty != gsm->tty); |
| 2097 | gsm_cleanup_mux(gsm); |
| 2098 | tty_kref_put(gsm->tty); |
| 2099 | gsm->tty = NULL; |
| 2100 | } |
| 2101 | |
| 2102 | static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
| 2103 | char *fp, int count) |
| 2104 | { |
| 2105 | struct gsm_mux *gsm = tty->disc_data; |
| 2106 | const unsigned char *dp; |
| 2107 | char *f; |
| 2108 | int i; |
| 2109 | char buf[64]; |
| 2110 | char flags; |
| 2111 | |
| 2112 | if (debug & 4) { |
| 2113 | printk("Inbytes %dd\n", count); |
| 2114 | hex_packet(cp, count); |
| 2115 | } |
| 2116 | |
| 2117 | for (i = count, dp = cp, f = fp; i; i--, dp++) { |
| 2118 | flags = *f++; |
| 2119 | switch (flags) { |
| 2120 | case TTY_NORMAL: |
| 2121 | gsm->receive(gsm, *dp); |
| 2122 | break; |
| 2123 | case TTY_OVERRUN: |
| 2124 | case TTY_BREAK: |
| 2125 | case TTY_PARITY: |
| 2126 | case TTY_FRAME: |
| 2127 | gsm->error(gsm, *dp, flags); |
| 2128 | break; |
| 2129 | default: |
| 2130 | printk(KERN_ERR "%s: unknown flag %d\n", |
| 2131 | tty_name(tty, buf), flags); |
| 2132 | break; |
| 2133 | } |
| 2134 | } |
| 2135 | /* FASYNC if needed ? */ |
| 2136 | /* If clogged call tty_throttle(tty); */ |
| 2137 | } |
| 2138 | |
| 2139 | /** |
| 2140 | * gsmld_chars_in_buffer - report available bytes |
| 2141 | * @tty: tty device |
| 2142 | * |
| 2143 | * Report the number of characters buffered to be delivered to user |
| 2144 | * at this instant in time. |
| 2145 | * |
| 2146 | * Locking: gsm lock |
| 2147 | */ |
| 2148 | |
| 2149 | static ssize_t gsmld_chars_in_buffer(struct tty_struct *tty) |
| 2150 | { |
| 2151 | return 0; |
| 2152 | } |
| 2153 | |
| 2154 | /** |
| 2155 | * gsmld_flush_buffer - clean input queue |
| 2156 | * @tty: terminal device |
| 2157 | * |
| 2158 | * Flush the input buffer. Called when the line discipline is |
| 2159 | * being closed, when the tty layer wants the buffer flushed (eg |
| 2160 | * at hangup). |
| 2161 | */ |
| 2162 | |
| 2163 | static void gsmld_flush_buffer(struct tty_struct *tty) |
| 2164 | { |
| 2165 | } |
| 2166 | |
| 2167 | /** |
| 2168 | * gsmld_close - close the ldisc for this tty |
| 2169 | * @tty: device |
| 2170 | * |
| 2171 | * Called from the terminal layer when this line discipline is |
| 2172 | * being shut down, either because of a close or becsuse of a |
| 2173 | * discipline change. The function will not be called while other |
| 2174 | * ldisc methods are in progress. |
| 2175 | */ |
| 2176 | |
| 2177 | static void gsmld_close(struct tty_struct *tty) |
| 2178 | { |
| 2179 | struct gsm_mux *gsm = tty->disc_data; |
| 2180 | |
| 2181 | gsmld_detach_gsm(tty, gsm); |
| 2182 | |
| 2183 | gsmld_flush_buffer(tty); |
| 2184 | /* Do other clean up here */ |
| 2185 | gsm_free_mux(gsm); |
| 2186 | } |
| 2187 | |
| 2188 | /** |
| 2189 | * gsmld_open - open an ldisc |
| 2190 | * @tty: terminal to open |
| 2191 | * |
| 2192 | * Called when this line discipline is being attached to the |
| 2193 | * terminal device. Can sleep. Called serialized so that no |
| 2194 | * other events will occur in parallel. No further open will occur |
| 2195 | * until a close. |
| 2196 | */ |
| 2197 | |
| 2198 | static int gsmld_open(struct tty_struct *tty) |
| 2199 | { |
| 2200 | struct gsm_mux *gsm; |
| 2201 | |
| 2202 | if (tty->ops->write == NULL) |
| 2203 | return -EINVAL; |
| 2204 | |
| 2205 | /* Attach our ldisc data */ |
| 2206 | gsm = gsm_alloc_mux(); |
| 2207 | if (gsm == NULL) |
| 2208 | return -ENOMEM; |
| 2209 | |
| 2210 | tty->disc_data = gsm; |
| 2211 | tty->receive_room = 65536; |
| 2212 | |
| 2213 | /* Attach the initial passive connection */ |
| 2214 | gsm->encoding = 1; |
| 2215 | return gsmld_attach_gsm(tty, gsm); |
| 2216 | } |
| 2217 | |
| 2218 | /** |
| 2219 | * gsmld_write_wakeup - asynchronous I/O notifier |
| 2220 | * @tty: tty device |
| 2221 | * |
| 2222 | * Required for the ptys, serial driver etc. since processes |
| 2223 | * that attach themselves to the master and rely on ASYNC |
| 2224 | * IO must be woken up |
| 2225 | */ |
| 2226 | |
| 2227 | static void gsmld_write_wakeup(struct tty_struct *tty) |
| 2228 | { |
| 2229 | struct gsm_mux *gsm = tty->disc_data; |
Dan Carpenter | 328be39 | 2010-05-25 11:37:17 +0200 | [diff] [blame] | 2230 | unsigned long flags; |
Alan Cox | e1eaea4 | 2010-03-26 11:32:54 +0000 | [diff] [blame] | 2231 | |
| 2232 | /* Queue poll */ |
| 2233 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
| 2234 | gsm_data_kick(gsm); |
Dan Carpenter | 328be39 | 2010-05-25 11:37:17 +0200 | [diff] [blame] | 2235 | if (gsm->tx_bytes < TX_THRESH_LO) { |
| 2236 | spin_lock_irqsave(&gsm->tx_lock, flags); |
Alan Cox | e1eaea4 | 2010-03-26 11:32:54 +0000 | [diff] [blame] | 2237 | gsm_dlci_data_sweep(gsm); |
Dan Carpenter | 328be39 | 2010-05-25 11:37:17 +0200 | [diff] [blame] | 2238 | spin_unlock_irqrestore(&gsm->tx_lock, flags); |
| 2239 | } |
Alan Cox | e1eaea4 | 2010-03-26 11:32:54 +0000 | [diff] [blame] | 2240 | } |
| 2241 | |
| 2242 | /** |
| 2243 | * gsmld_read - read function for tty |
| 2244 | * @tty: tty device |
| 2245 | * @file: file object |
| 2246 | * @buf: userspace buffer pointer |
| 2247 | * @nr: size of I/O |
| 2248 | * |
| 2249 | * Perform reads for the line discipline. We are guaranteed that the |
| 2250 | * line discipline will not be closed under us but we may get multiple |
| 2251 | * parallel readers and must handle this ourselves. We may also get |
| 2252 | * a hangup. Always called in user context, may sleep. |
| 2253 | * |
| 2254 | * This code must be sure never to sleep through a hangup. |
| 2255 | */ |
| 2256 | |
| 2257 | static ssize_t gsmld_read(struct tty_struct *tty, struct file *file, |
| 2258 | unsigned char __user *buf, size_t nr) |
| 2259 | { |
| 2260 | return -EOPNOTSUPP; |
| 2261 | } |
| 2262 | |
| 2263 | /** |
| 2264 | * gsmld_write - write function for tty |
| 2265 | * @tty: tty device |
| 2266 | * @file: file object |
| 2267 | * @buf: userspace buffer pointer |
| 2268 | * @nr: size of I/O |
| 2269 | * |
| 2270 | * Called when the owner of the device wants to send a frame |
| 2271 | * itself (or some other control data). The data is transferred |
| 2272 | * as-is and must be properly framed and checksummed as appropriate |
| 2273 | * by userspace. Frames are either sent whole or not at all as this |
| 2274 | * avoids pain user side. |
| 2275 | */ |
| 2276 | |
| 2277 | static ssize_t gsmld_write(struct tty_struct *tty, struct file *file, |
| 2278 | const unsigned char *buf, size_t nr) |
| 2279 | { |
| 2280 | int space = tty_write_room(tty); |
| 2281 | if (space >= nr) |
| 2282 | return tty->ops->write(tty, buf, nr); |
| 2283 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
| 2284 | return -ENOBUFS; |
| 2285 | } |
| 2286 | |
| 2287 | /** |
| 2288 | * gsmld_poll - poll method for N_GSM0710 |
| 2289 | * @tty: terminal device |
| 2290 | * @file: file accessing it |
| 2291 | * @wait: poll table |
| 2292 | * |
| 2293 | * Called when the line discipline is asked to poll() for data or |
| 2294 | * for special events. This code is not serialized with respect to |
| 2295 | * other events save open/close. |
| 2296 | * |
| 2297 | * This code must be sure never to sleep through a hangup. |
| 2298 | * Called without the kernel lock held - fine |
| 2299 | */ |
| 2300 | |
| 2301 | static unsigned int gsmld_poll(struct tty_struct *tty, struct file *file, |
| 2302 | poll_table *wait) |
| 2303 | { |
| 2304 | unsigned int mask = 0; |
| 2305 | struct gsm_mux *gsm = tty->disc_data; |
| 2306 | |
| 2307 | poll_wait(file, &tty->read_wait, wait); |
| 2308 | poll_wait(file, &tty->write_wait, wait); |
| 2309 | if (tty_hung_up_p(file)) |
| 2310 | mask |= POLLHUP; |
| 2311 | if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0) |
| 2312 | mask |= POLLOUT | POLLWRNORM; |
| 2313 | if (gsm->dead) |
| 2314 | mask |= POLLHUP; |
| 2315 | return mask; |
| 2316 | } |
| 2317 | |
| 2318 | static int gsmld_config(struct tty_struct *tty, struct gsm_mux *gsm, |
| 2319 | struct gsm_config *c) |
| 2320 | { |
| 2321 | int need_close = 0; |
| 2322 | int need_restart = 0; |
| 2323 | |
| 2324 | /* Stuff we don't support yet - UI or I frame transport, windowing */ |
| 2325 | if ((c->adaption !=1 && c->adaption != 2) || c->k) |
| 2326 | return -EOPNOTSUPP; |
| 2327 | /* Check the MRU/MTU range looks sane */ |
| 2328 | if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8) |
| 2329 | return -EINVAL; |
| 2330 | if (c->n2 < 3) |
| 2331 | return -EINVAL; |
| 2332 | if (c->encapsulation > 1) /* Basic, advanced, no I */ |
| 2333 | return -EINVAL; |
| 2334 | if (c->initiator > 1) |
| 2335 | return -EINVAL; |
| 2336 | if (c->i == 0 || c->i > 2) /* UIH and UI only */ |
| 2337 | return -EINVAL; |
| 2338 | /* |
| 2339 | * See what is needed for reconfiguration |
| 2340 | */ |
| 2341 | |
| 2342 | /* Timing fields */ |
| 2343 | if (c->t1 != 0 && c->t1 != gsm->t1) |
| 2344 | need_restart = 1; |
| 2345 | if (c->t2 != 0 && c->t2 != gsm->t2) |
| 2346 | need_restart = 1; |
| 2347 | if (c->encapsulation != gsm->encoding) |
| 2348 | need_restart = 1; |
| 2349 | if (c->adaption != gsm->adaption) |
| 2350 | need_restart = 1; |
| 2351 | /* Requires care */ |
| 2352 | if (c->initiator != gsm->initiator) |
| 2353 | need_close = 1; |
| 2354 | if (c->mru != gsm->mru) |
| 2355 | need_restart = 1; |
| 2356 | if (c->mtu != gsm->mtu) |
| 2357 | need_restart = 1; |
| 2358 | |
| 2359 | /* |
| 2360 | * Close down what is needed, restart and initiate the new |
| 2361 | * configuration |
| 2362 | */ |
| 2363 | |
| 2364 | if (need_close || need_restart) { |
| 2365 | gsm_dlci_begin_close(gsm->dlci[0]); |
| 2366 | /* This will timeout if the link is down due to N2 expiring */ |
| 2367 | wait_event_interruptible(gsm->event, |
| 2368 | gsm->dlci[0]->state == DLCI_CLOSED); |
| 2369 | if (signal_pending(current)) |
| 2370 | return -EINTR; |
| 2371 | } |
| 2372 | if (need_restart) |
| 2373 | gsm_cleanup_mux(gsm); |
| 2374 | |
| 2375 | gsm->initiator = c->initiator; |
| 2376 | gsm->mru = c->mru; |
| 2377 | gsm->encoding = c->encapsulation; |
| 2378 | gsm->adaption = c->adaption; |
| 2379 | |
| 2380 | if (c->i == 1) |
| 2381 | gsm->ftype = UIH; |
| 2382 | else if (c->i == 2) |
| 2383 | gsm->ftype = UI; |
| 2384 | |
| 2385 | if (c->t1) |
| 2386 | gsm->t1 = c->t1; |
| 2387 | if (c->t2) |
| 2388 | gsm->t2 = c->t2; |
| 2389 | |
| 2390 | /* FIXME: We need to separate activation/deactivation from adding |
| 2391 | and removing from the mux array */ |
| 2392 | if (need_restart) |
| 2393 | gsm_activate_mux(gsm); |
| 2394 | if (gsm->initiator && need_close) |
| 2395 | gsm_dlci_begin_open(gsm->dlci[0]); |
| 2396 | return 0; |
| 2397 | } |
| 2398 | |
| 2399 | static int gsmld_ioctl(struct tty_struct *tty, struct file *file, |
| 2400 | unsigned int cmd, unsigned long arg) |
| 2401 | { |
| 2402 | struct gsm_config c; |
| 2403 | struct gsm_mux *gsm = tty->disc_data; |
| 2404 | |
| 2405 | switch (cmd) { |
| 2406 | case GSMIOC_GETCONF: |
| 2407 | memset(&c, 0, sizeof(c)); |
| 2408 | c.adaption = gsm->adaption; |
| 2409 | c.encapsulation = gsm->encoding; |
| 2410 | c.initiator = gsm->initiator; |
| 2411 | c.t1 = gsm->t1; |
| 2412 | c.t2 = gsm->t2; |
| 2413 | c.t3 = 0; /* Not supported */ |
| 2414 | c.n2 = gsm->n2; |
| 2415 | if (gsm->ftype == UIH) |
| 2416 | c.i = 1; |
| 2417 | else |
| 2418 | c.i = 2; |
| 2419 | printk("Ftype %d i %d\n", gsm->ftype, c.i); |
| 2420 | c.mru = gsm->mru; |
| 2421 | c.mtu = gsm->mtu; |
| 2422 | c.k = 0; |
| 2423 | if (copy_to_user((void *)arg, &c, sizeof(c))) |
| 2424 | return -EFAULT; |
| 2425 | return 0; |
| 2426 | case GSMIOC_SETCONF: |
| 2427 | if (copy_from_user(&c, (void *)arg, sizeof(c))) |
| 2428 | return -EFAULT; |
| 2429 | return gsmld_config(tty, gsm, &c); |
| 2430 | default: |
| 2431 | return n_tty_ioctl_helper(tty, file, cmd, arg); |
| 2432 | } |
| 2433 | } |
| 2434 | |
| 2435 | |
| 2436 | /* Line discipline for real tty */ |
| 2437 | struct tty_ldisc_ops tty_ldisc_packet = { |
| 2438 | .owner = THIS_MODULE, |
| 2439 | .magic = TTY_LDISC_MAGIC, |
| 2440 | .name = "n_gsm", |
| 2441 | .open = gsmld_open, |
| 2442 | .close = gsmld_close, |
| 2443 | .flush_buffer = gsmld_flush_buffer, |
| 2444 | .chars_in_buffer = gsmld_chars_in_buffer, |
| 2445 | .read = gsmld_read, |
| 2446 | .write = gsmld_write, |
| 2447 | .ioctl = gsmld_ioctl, |
| 2448 | .poll = gsmld_poll, |
| 2449 | .receive_buf = gsmld_receive_buf, |
| 2450 | .write_wakeup = gsmld_write_wakeup |
| 2451 | }; |
| 2452 | |
| 2453 | /* |
| 2454 | * Virtual tty side |
| 2455 | */ |
| 2456 | |
| 2457 | #define TX_SIZE 512 |
| 2458 | |
| 2459 | static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk) |
| 2460 | { |
| 2461 | u8 modembits[5]; |
| 2462 | struct gsm_control *ctrl; |
| 2463 | int len = 2; |
| 2464 | |
| 2465 | if (brk) |
| 2466 | len++; |
| 2467 | |
| 2468 | modembits[0] = len << 1 | EA; /* Data bytes */ |
| 2469 | modembits[1] = dlci->addr << 2 | 3; /* DLCI, EA, 1 */ |
| 2470 | modembits[2] = gsm_encode_modem(dlci) << 1 | EA; |
| 2471 | if (brk) |
| 2472 | modembits[3] = brk << 4 | 2 | EA; /* Valid, EA */ |
| 2473 | ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len + 1); |
| 2474 | if (ctrl == NULL) |
| 2475 | return -ENOMEM; |
| 2476 | return gsm_control_wait(dlci->gsm, ctrl); |
| 2477 | } |
| 2478 | |
| 2479 | static int gsm_carrier_raised(struct tty_port *port) |
| 2480 | { |
| 2481 | struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); |
| 2482 | /* Not yet open so no carrier info */ |
| 2483 | if (dlci->state != DLCI_OPEN) |
| 2484 | return 0; |
| 2485 | if (debug & 2) |
| 2486 | return 1; |
| 2487 | return dlci->modem_rx & TIOCM_CD; |
| 2488 | } |
| 2489 | |
| 2490 | static void gsm_dtr_rts(struct tty_port *port, int onoff) |
| 2491 | { |
| 2492 | struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); |
| 2493 | unsigned int modem_tx = dlci->modem_tx; |
| 2494 | if (onoff) |
| 2495 | modem_tx |= TIOCM_DTR | TIOCM_RTS; |
| 2496 | else |
| 2497 | modem_tx &= ~(TIOCM_DTR | TIOCM_RTS); |
| 2498 | if (modem_tx != dlci->modem_tx) { |
| 2499 | dlci->modem_tx = modem_tx; |
| 2500 | gsmtty_modem_update(dlci, 0); |
| 2501 | } |
| 2502 | } |
| 2503 | |
| 2504 | static const struct tty_port_operations gsm_port_ops = { |
| 2505 | .carrier_raised = gsm_carrier_raised, |
| 2506 | .dtr_rts = gsm_dtr_rts, |
| 2507 | }; |
| 2508 | |
| 2509 | |
| 2510 | static int gsmtty_open(struct tty_struct *tty, struct file *filp) |
| 2511 | { |
| 2512 | struct gsm_mux *gsm; |
| 2513 | struct gsm_dlci *dlci; |
| 2514 | struct tty_port *port; |
| 2515 | unsigned int line = tty->index; |
| 2516 | unsigned int mux = line >> 6; |
| 2517 | |
| 2518 | line = line & 0x3F; |
| 2519 | |
| 2520 | if (mux >= MAX_MUX) |
| 2521 | return -ENXIO; |
| 2522 | /* FIXME: we need to lock gsm_mux for lifetimes of ttys eventually */ |
| 2523 | if (gsm_mux[mux] == NULL) |
| 2524 | return -EUNATCH; |
| 2525 | if (line == 0 || line > 61) /* 62/63 reserved */ |
| 2526 | return -ECHRNG; |
| 2527 | gsm = gsm_mux[mux]; |
| 2528 | if (gsm->dead) |
| 2529 | return -EL2HLT; |
| 2530 | dlci = gsm->dlci[line]; |
| 2531 | if (dlci == NULL) |
| 2532 | dlci = gsm_dlci_alloc(gsm, line); |
| 2533 | if (dlci == NULL) |
| 2534 | return -ENOMEM; |
| 2535 | port = &dlci->port; |
| 2536 | port->count++; |
| 2537 | tty->driver_data = dlci; |
| 2538 | tty_port_tty_set(port, tty); |
| 2539 | |
| 2540 | dlci->modem_rx = 0; |
| 2541 | /* We could in theory open and close before we wait - eg if we get |
| 2542 | a DM straight back. This is ok as that will have caused a hangup */ |
| 2543 | set_bit(ASYNCB_INITIALIZED, &port->flags); |
| 2544 | /* Start sending off SABM messages */ |
| 2545 | gsm_dlci_begin_open(dlci); |
| 2546 | /* And wait for virtual carrier */ |
| 2547 | return tty_port_block_til_ready(port, tty, filp); |
| 2548 | } |
| 2549 | |
| 2550 | static void gsmtty_close(struct tty_struct *tty, struct file *filp) |
| 2551 | { |
| 2552 | struct gsm_dlci *dlci = tty->driver_data; |
| 2553 | if (dlci == NULL) |
| 2554 | return; |
| 2555 | if (tty_port_close_start(&dlci->port, tty, filp) == 0) |
| 2556 | return; |
| 2557 | gsm_dlci_begin_close(dlci); |
| 2558 | tty_port_close_end(&dlci->port, tty); |
| 2559 | tty_port_tty_set(&dlci->port, NULL); |
| 2560 | } |
| 2561 | |
| 2562 | static void gsmtty_hangup(struct tty_struct *tty) |
| 2563 | { |
| 2564 | struct gsm_dlci *dlci = tty->driver_data; |
| 2565 | tty_port_hangup(&dlci->port); |
| 2566 | gsm_dlci_begin_close(dlci); |
| 2567 | } |
| 2568 | |
| 2569 | static int gsmtty_write(struct tty_struct *tty, const unsigned char *buf, |
| 2570 | int len) |
| 2571 | { |
| 2572 | struct gsm_dlci *dlci = tty->driver_data; |
| 2573 | /* Stuff the bytes into the fifo queue */ |
| 2574 | int sent = kfifo_in_locked(dlci->fifo, buf, len, &dlci->lock); |
| 2575 | /* Need to kick the channel */ |
| 2576 | gsm_dlci_data_kick(dlci); |
| 2577 | return sent; |
| 2578 | } |
| 2579 | |
| 2580 | static int gsmtty_write_room(struct tty_struct *tty) |
| 2581 | { |
| 2582 | struct gsm_dlci *dlci = tty->driver_data; |
| 2583 | return TX_SIZE - kfifo_len(dlci->fifo); |
| 2584 | } |
| 2585 | |
| 2586 | static int gsmtty_chars_in_buffer(struct tty_struct *tty) |
| 2587 | { |
| 2588 | struct gsm_dlci *dlci = tty->driver_data; |
| 2589 | return kfifo_len(dlci->fifo); |
| 2590 | } |
| 2591 | |
| 2592 | static void gsmtty_flush_buffer(struct tty_struct *tty) |
| 2593 | { |
| 2594 | struct gsm_dlci *dlci = tty->driver_data; |
| 2595 | /* Caution needed: If we implement reliable transport classes |
| 2596 | then the data being transmitted can't simply be junked once |
| 2597 | it has first hit the stack. Until then we can just blow it |
| 2598 | away */ |
| 2599 | kfifo_reset(dlci->fifo); |
| 2600 | /* Need to unhook this DLCI from the transmit queue logic */ |
| 2601 | } |
| 2602 | |
| 2603 | static void gsmtty_wait_until_sent(struct tty_struct *tty, int timeout) |
| 2604 | { |
| 2605 | /* The FIFO handles the queue so the kernel will do the right |
| 2606 | thing waiting on chars_in_buffer before calling us. No work |
| 2607 | to do here */ |
| 2608 | } |
| 2609 | |
| 2610 | static int gsmtty_tiocmget(struct tty_struct *tty, struct file *filp) |
| 2611 | { |
| 2612 | struct gsm_dlci *dlci = tty->driver_data; |
| 2613 | return dlci->modem_rx; |
| 2614 | } |
| 2615 | |
| 2616 | static int gsmtty_tiocmset(struct tty_struct *tty, struct file *filp, |
| 2617 | unsigned int set, unsigned int clear) |
| 2618 | { |
| 2619 | struct gsm_dlci *dlci = tty->driver_data; |
| 2620 | unsigned int modem_tx = dlci->modem_tx; |
| 2621 | |
| 2622 | modem_tx &= clear; |
| 2623 | modem_tx |= set; |
| 2624 | |
| 2625 | if (modem_tx != dlci->modem_tx) { |
| 2626 | dlci->modem_tx = modem_tx; |
| 2627 | return gsmtty_modem_update(dlci, 0); |
| 2628 | } |
| 2629 | return 0; |
| 2630 | } |
| 2631 | |
| 2632 | |
| 2633 | static int gsmtty_ioctl(struct tty_struct *tty, struct file *filp, |
| 2634 | unsigned int cmd, unsigned long arg) |
| 2635 | { |
| 2636 | return -ENOIOCTLCMD; |
| 2637 | } |
| 2638 | |
| 2639 | static void gsmtty_set_termios(struct tty_struct *tty, struct ktermios *old) |
| 2640 | { |
| 2641 | /* For the moment its fixed. In actual fact the speed information |
| 2642 | for the virtual channel can be propogated in both directions by |
| 2643 | the RPN control message. This however rapidly gets nasty as we |
| 2644 | then have to remap modem signals each way according to whether |
| 2645 | our virtual cable is null modem etc .. */ |
| 2646 | tty_termios_copy_hw(tty->termios, old); |
| 2647 | } |
| 2648 | |
| 2649 | static void gsmtty_throttle(struct tty_struct *tty) |
| 2650 | { |
| 2651 | struct gsm_dlci *dlci = tty->driver_data; |
| 2652 | if (tty->termios->c_cflag & CRTSCTS) |
| 2653 | dlci->modem_tx &= ~TIOCM_DTR; |
| 2654 | dlci->throttled = 1; |
| 2655 | /* Send an MSC with DTR cleared */ |
| 2656 | gsmtty_modem_update(dlci, 0); |
| 2657 | } |
| 2658 | |
| 2659 | static void gsmtty_unthrottle(struct tty_struct *tty) |
| 2660 | { |
| 2661 | struct gsm_dlci *dlci = tty->driver_data; |
| 2662 | if (tty->termios->c_cflag & CRTSCTS) |
| 2663 | dlci->modem_tx |= TIOCM_DTR; |
| 2664 | dlci->throttled = 0; |
| 2665 | /* Send an MSC with DTR set */ |
| 2666 | gsmtty_modem_update(dlci, 0); |
| 2667 | } |
| 2668 | |
| 2669 | static int gsmtty_break_ctl(struct tty_struct *tty, int state) |
| 2670 | { |
| 2671 | struct gsm_dlci *dlci = tty->driver_data; |
| 2672 | int encode = 0; /* Off */ |
| 2673 | |
| 2674 | if (state == -1) /* "On indefinitely" - we can't encode this |
| 2675 | properly */ |
| 2676 | encode = 0x0F; |
| 2677 | else if (state > 0) { |
| 2678 | encode = state / 200; /* mS to encoding */ |
| 2679 | if (encode > 0x0F) |
| 2680 | encode = 0x0F; /* Best effort */ |
| 2681 | } |
| 2682 | return gsmtty_modem_update(dlci, encode); |
| 2683 | } |
| 2684 | |
| 2685 | static struct tty_driver *gsm_tty_driver; |
| 2686 | |
| 2687 | /* Virtual ttys for the demux */ |
| 2688 | static const struct tty_operations gsmtty_ops = { |
| 2689 | .open = gsmtty_open, |
| 2690 | .close = gsmtty_close, |
| 2691 | .write = gsmtty_write, |
| 2692 | .write_room = gsmtty_write_room, |
| 2693 | .chars_in_buffer = gsmtty_chars_in_buffer, |
| 2694 | .flush_buffer = gsmtty_flush_buffer, |
| 2695 | .ioctl = gsmtty_ioctl, |
| 2696 | .throttle = gsmtty_throttle, |
| 2697 | .unthrottle = gsmtty_unthrottle, |
| 2698 | .set_termios = gsmtty_set_termios, |
| 2699 | .hangup = gsmtty_hangup, |
| 2700 | .wait_until_sent = gsmtty_wait_until_sent, |
| 2701 | .tiocmget = gsmtty_tiocmget, |
| 2702 | .tiocmset = gsmtty_tiocmset, |
| 2703 | .break_ctl = gsmtty_break_ctl, |
| 2704 | }; |
| 2705 | |
| 2706 | |
| 2707 | |
| 2708 | static int __init gsm_init(void) |
| 2709 | { |
| 2710 | /* Fill in our line protocol discipline, and register it */ |
| 2711 | int status = tty_register_ldisc(N_GSM0710, &tty_ldisc_packet); |
| 2712 | if (status != 0) { |
| 2713 | printk(KERN_ERR "n_gsm: can't register line discipline (err = %d)\n", status); |
| 2714 | return status; |
| 2715 | } |
| 2716 | |
| 2717 | gsm_tty_driver = alloc_tty_driver(256); |
| 2718 | if (!gsm_tty_driver) { |
| 2719 | tty_unregister_ldisc(N_GSM0710); |
| 2720 | printk(KERN_ERR "gsm_init: tty allocation failed.\n"); |
| 2721 | return -EINVAL; |
| 2722 | } |
| 2723 | gsm_tty_driver->owner = THIS_MODULE; |
| 2724 | gsm_tty_driver->driver_name = "gsmtty"; |
| 2725 | gsm_tty_driver->name = "gsmtty"; |
| 2726 | gsm_tty_driver->major = 0; /* Dynamic */ |
| 2727 | gsm_tty_driver->minor_start = 0; |
| 2728 | gsm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; |
| 2729 | gsm_tty_driver->subtype = SERIAL_TYPE_NORMAL; |
| 2730 | gsm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV |
| 2731 | | TTY_DRIVER_HARDWARE_BREAK; |
| 2732 | gsm_tty_driver->init_termios = tty_std_termios; |
| 2733 | /* Fixme */ |
| 2734 | gsm_tty_driver->init_termios.c_lflag &= ~ECHO; |
| 2735 | tty_set_operations(gsm_tty_driver, &gsmtty_ops); |
| 2736 | |
| 2737 | spin_lock_init(&gsm_mux_lock); |
| 2738 | |
| 2739 | if (tty_register_driver(gsm_tty_driver)) { |
| 2740 | put_tty_driver(gsm_tty_driver); |
| 2741 | tty_unregister_ldisc(N_GSM0710); |
| 2742 | printk(KERN_ERR "gsm_init: tty registration failed.\n"); |
| 2743 | return -EBUSY; |
| 2744 | } |
| 2745 | printk(KERN_INFO "gsm_init: loaded as %d,%d.\n", gsm_tty_driver->major, gsm_tty_driver->minor_start); |
| 2746 | return 0; |
| 2747 | } |
| 2748 | |
| 2749 | static void __exit gsm_exit(void) |
| 2750 | { |
| 2751 | int status = tty_unregister_ldisc(N_GSM0710); |
| 2752 | if (status != 0) |
| 2753 | printk(KERN_ERR "n_gsm: can't unregister line discipline (err = %d)\n", status); |
| 2754 | tty_unregister_driver(gsm_tty_driver); |
| 2755 | put_tty_driver(gsm_tty_driver); |
| 2756 | printk(KERN_INFO "gsm_init: unloaded.\n"); |
| 2757 | } |
| 2758 | |
| 2759 | module_init(gsm_init); |
| 2760 | module_exit(gsm_exit); |
| 2761 | |
| 2762 | |
| 2763 | MODULE_LICENSE("GPL"); |
| 2764 | MODULE_ALIAS_LDISC(N_GSM0710); |