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Merge tag 'mmc-v4.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc
[mirror_ubuntu-bionic-kernel.git] / drivers / tty / n_gsm.c
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e3b3d0f5 1// SPDX-License-Identifier: GPL-2.0
e1eaea46
AC		 2/*
3 * n_gsm.c GSM 0710 tty multiplexor
4 * Copyright (c) 2009/10 Intel Corporation
5 *
e1eaea46
AC		 6 * * THIS IS A DEVELOPMENT SNAPSHOT IT IS NOT A FINAL RELEASE *
7 *
8 * TO DO:
9 * Mostly done: ioctls for setting modes/timing
5f9a31d6 10 * Partly done: hooks so you can pull off frames to non tty devs
e1eaea46 11 * Restart DLCI 0 when it closes ?
e1eaea46
AC		 12 * Improve the tx engine
13 * Resolve tx side locking by adding a queue_head and routing
14 * all control traffic via it
15 * General tidy/document
16 * Review the locking/move to refcounts more (mux now moved to an
17 * alloc/free model ready)
18 * Use newest tty open/close port helpers and install hooks
19 * What to do about power functions ?
20 * Termios setting and negotiation
21 * Do we need a 'which mux are you' ioctl to correlate mux and tty sets
22 *
23 */
24
25#include <linux/types.h>
26#include <linux/major.h>
27#include <linux/errno.h>
28#include <linux/signal.h>
29#include <linux/fcntl.h>
174cd4b1 30#include <linux/sched/signal.h>
e1eaea46
AC		 31#include <linux/interrupt.h>
32#include <linux/tty.h>
e1eaea46
AC		 33#include <linux/ctype.h>
34#include <linux/mm.h>
35#include <linux/string.h>
36#include <linux/slab.h>
37#include <linux/poll.h>
38#include <linux/bitops.h>
39#include <linux/file.h>
40#include <linux/uaccess.h>
41#include <linux/module.h>
42#include <linux/timer.h>
43#include <linux/tty_flip.h>
44#include <linux/tty_driver.h>
45#include <linux/serial.h>
46#include <linux/kfifo.h>
47#include <linux/skbuff.h>
bcd5abe2
RG		 48#include <net/arp.h>
49#include <linux/ip.h>
50#include <linux/netdevice.h>
51#include <linux/etherdevice.h>
e1eaea46
AC		 52#include <linux/gsmmux.h>
53
54static int debug;
55module_param(debug, int, 0600);
56
a8d12007
AC		 57/* Defaults: these are from the specification */
58
59#define T1 10 /* 100mS */
60#define T2 34 /* 333mS */
61#define N2 3 /* Retry 3 times */
e1eaea46
AC		 62
63/* Use long timers for testing at low speed with debug on */
64#ifdef DEBUG_TIMING
a8d12007
AC		 65#define T1 100
66#define T2 200
e1eaea46
AC		 67#endif
68
5f9a31d6 69/*
25985edc 70 * Semi-arbitrary buffer size limits. 0710 is normally run with 32-64 byte
5f9a31d6
AC		 71 * limits so this is plenty
72 */
bcd5abe2
RG		 73#define MAX_MRU 1500
74#define MAX_MTU 1500
75#define GSM_NET_TX_TIMEOUT (HZ*10)
76
77/**
78 * struct gsm_mux_net - network interface
79 * @struct gsm_dlci* dlci
bcd5abe2
RG		 80 *
81 * Created when net interface is initialized.
82 **/
83struct gsm_mux_net {
84 struct kref ref;
85 struct gsm_dlci *dlci;
bcd5abe2
RG		 86};
87
e1eaea46
AC		 88/*
89 * Each block of data we have queued to go out is in the form of
25985edc 90 * a gsm_msg which holds everything we need in a link layer independent
e1eaea46
AC		 91 * format
92 */
93
94struct gsm_msg {
b4338e1e 95 struct list_head list;
e1eaea46
AC		 96 u8 addr; /* DLCI address + flags */
97 u8 ctrl; /* Control byte + flags */
98 unsigned int len; /* Length of data block (can be zero) */
99 unsigned char *data; /* Points into buffer but not at the start */
100 unsigned char buffer[0];
101};
102
103/*
104 * Each active data link has a gsm_dlci structure associated which ties
105 * the link layer to an optional tty (if the tty side is open). To avoid
106 * complexity right now these are only ever freed up when the mux is
107 * shut down.
108 *
109 * At the moment we don't free DLCI objects until the mux is torn down
110 * this avoid object life time issues but might be worth review later.
111 */
112
113struct gsm_dlci {
114 struct gsm_mux *gsm;
115 int addr;
116 int state;
117#define DLCI_CLOSED 0
118#define DLCI_OPENING 1 /* Sending SABM not seen UA */
119#define DLCI_OPEN 2 /* SABM/UA complete */
120#define DLCI_CLOSING 3 /* Sending DISC not seen UA/DM */
bcd5abe2 121 struct mutex mutex;
e1eaea46
AC		 122
123 /* Link layer */
124 spinlock_t lock; /* Protects the internal state */
125 struct timer_list t1; /* Retransmit timer for SABM and UA */
126 int retries;
127 /* Uplink tty if active */
128 struct tty_port port; /* The tty bound to this DLCI if there is one */
129 struct kfifo *fifo; /* Queue fifo for the DLCI */
130 struct kfifo _fifo; /* For new fifo API porting only */
131 int adaption; /* Adaption layer in use */
bcd5abe2 132 int prev_adaption;
e1eaea46
AC		 133 u32 modem_rx; /* Our incoming virtual modem lines */
134 u32 modem_tx; /* Our outgoing modem lines */
135 int dead; /* Refuse re-open */
136 /* Flow control */
137 int throttled; /* Private copy of throttle state */
138 int constipated; /* Throttle status for outgoing */
139 /* Packetised I/O */
140 struct sk_buff *skb; /* Frame being sent */
141 struct sk_buff_head skb_list; /* Queued frames */
142 /* Data handling callback */
143 void (*data)(struct gsm_dlci *dlci, u8 *data, int len);
bcd5abe2
RG		 144 void (*prev_data)(struct gsm_dlci *dlci, u8 *data, int len);
145 struct net_device *net; /* network interface, if created */
e1eaea46
AC		 146};
147
c33eecc7 148/* DLCI 0, 62/63 are special or reserved see gsmtty_open */
e1eaea46
AC		 149
150#define NUM_DLCI 64
151
152/*
153 * DLCI 0 is used to pass control blocks out of band of the data
154 * flow (and with a higher link priority). One command can be outstanding
155 * at a time and we use this structure to manage them. They are created
156 * and destroyed by the user context, and updated by the receive paths
157 * and timers
158 */
159
160struct gsm_control {
161 u8 cmd; /* Command we are issuing */
162 u8 *data; /* Data for the command in case we retransmit */
163 int len; /* Length of block for retransmission */
164 int done; /* Done flag */
165 int error; /* Error if any */
166};
167
168/*
169 * Each GSM mux we have is represented by this structure. If we are
170 * operating as an ldisc then we use this structure as our ldisc
171 * state. We need to sort out lifetimes and locking with respect
172 * to the gsm mux array. For now we don't free DLCI objects that
173 * have been instantiated until the mux itself is terminated.
174 *
175 * To consider further: tty open versus mux shutdown.
176 */
177
178struct gsm_mux {
179 struct tty_struct *tty; /* The tty our ldisc is bound to */
180 spinlock_t lock;
dfabf7ff 181 struct mutex mutex;
d50f6dca 182 unsigned int num;
6ab8fba7 183 struct kref ref;
e1eaea46
AC		 184
185 /* Events on the GSM channel */
186 wait_queue_head_t event;
187
188 /* Bits for GSM mode decoding */
189
190 /* Framing Layer */
191 unsigned char *buf;
192 int state;
193#define GSM_SEARCH 0
194#define GSM_START 1
195#define GSM_ADDRESS 2
196#define GSM_CONTROL 3
197#define GSM_LEN 4
198#define GSM_DATA 5
199#define GSM_FCS 6
200#define GSM_OVERRUN 7
c2f2f000
AC		 201#define GSM_LEN0 8
202#define GSM_LEN1 9
203#define GSM_SSOF 10
e1eaea46
AC		 204 unsigned int len;
205 unsigned int address;
206 unsigned int count;
207 int escape;
208 int encoding;
209 u8 control;
210 u8 fcs;
c2f2f000 211 u8 received_fcs;
e1eaea46
AC		 212 u8 *txframe; /* TX framing buffer */
213
214 /* Methods for the receiver side */
215 void (*receive)(struct gsm_mux *gsm, u8 ch);
216 void (*error)(struct gsm_mux *gsm, u8 ch, u8 flag);
217 /* And transmit side */
218 int (*output)(struct gsm_mux *mux, u8 *data, int len);
219
220 /* Link Layer */
221 unsigned int mru;
222 unsigned int mtu;
223 int initiator; /* Did we initiate connection */
224 int dead; /* Has the mux been shut down */
225 struct gsm_dlci *dlci[NUM_DLCI];
226 int constipated; /* Asked by remote to shut up */
227
228 spinlock_t tx_lock;
229 unsigned int tx_bytes; /* TX data outstanding */
230#define TX_THRESH_HI 8192
231#define TX_THRESH_LO 2048
b4338e1e 232 struct list_head tx_list; /* Pending data packets */
e1eaea46
AC		 233
234 /* Control messages */
235 struct timer_list t2_timer; /* Retransmit timer for commands */
236 int cretries; /* Command retry counter */
237 struct gsm_control *pending_cmd;/* Our current pending command */
238 spinlock_t control_lock; /* Protects the pending command */
239
240 /* Configuration */
241 int adaption; /* 1 or 2 supported */
242 u8 ftype; /* UI or UIH */
243 int t1, t2; /* Timers in 1/100th of a sec */
244 int n2; /* Retry count */
245
246 /* Statistics (not currently exposed) */
247 unsigned long bad_fcs;
248 unsigned long malformed;
249 unsigned long io_error;
250 unsigned long bad_size;
251 unsigned long unsupported;
252};
253
254
255/*
256 * Mux objects - needed so that we can translate a tty index into the
257 * relevant mux and DLCI.
258 */
259
260#define MAX_MUX 4 /* 256 minors */
261static struct gsm_mux *gsm_mux[MAX_MUX]; /* GSM muxes */
262static spinlock_t gsm_mux_lock;
263
d50f6dca
RG		 264static struct tty_driver *gsm_tty_driver;
265
e1eaea46
AC		 266/*
267 * This section of the driver logic implements the GSM encodings
268 * both the basic and the 'advanced'. Reliable transport is not
269 * supported.
270 */
271
272#define CR 0x02
273#define EA 0x01
274#define PF 0x10
275
276/* I is special: the rest are ..*/
277#define RR 0x01
278#define UI 0x03
279#define RNR 0x05
280#define REJ 0x09
281#define DM 0x0F
282#define SABM 0x2F
283#define DISC 0x43
284#define UA 0x63
285#define UIH 0xEF
286
287/* Channel commands */
288#define CMD_NSC 0x09
289#define CMD_TEST 0x11
290#define CMD_PSC 0x21
291#define CMD_RLS 0x29
292#define CMD_FCOFF 0x31
293#define CMD_PN 0x41
294#define CMD_RPN 0x49
295#define CMD_FCON 0x51
296#define CMD_CLD 0x61
297#define CMD_SNC 0x69
298#define CMD_MSC 0x71
299
300/* Virtual modem bits */
301#define MDM_FC 0x01
302#define MDM_RTC 0x02
303#define MDM_RTR 0x04
304#define MDM_IC 0x20
305#define MDM_DV 0x40
306
307#define GSM0_SOF 0xF9
5f9a31d6 308#define GSM1_SOF 0x7E
e1eaea46
AC		 309#define GSM1_ESCAPE 0x7D
310#define GSM1_ESCAPE_BITS 0x20
311#define XON 0x11
312#define XOFF 0x13
313
314static const struct tty_port_operations gsm_port_ops;
315
316/*
317 * CRC table for GSM 0710
318 */
319
320static const u8 gsm_fcs8[256] = {
321 0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75,
322 0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B,
323 0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69,
324 0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67,
325 0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D,
326 0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43,
327 0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51,
328 0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F,
329 0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05,
330 0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B,
331 0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19,
332 0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17,
333 0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D,
334 0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33,
335 0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21,
336 0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F,
337 0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95,
338 0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B,
339 0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89,
340 0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87,
341 0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD,
342 0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3,
343 0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1,
344 0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF,
345 0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5,
346 0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB,
347 0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9,
348 0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7,
349 0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD,
350 0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3,
351 0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1,
352 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
353};
354
355#define INIT_FCS 0xFF
356#define GOOD_FCS 0xCF
357
358/**
359 * gsm_fcs_add - update FCS
360 * @fcs: Current FCS
361 * @c: Next data
362 *
363 * Update the FCS to include c. Uses the algorithm in the specification
364 * notes.
365 */
366
367static inline u8 gsm_fcs_add(u8 fcs, u8 c)
368{
369 return gsm_fcs8[fcs ^ c];
370}
371
372/**
373 * gsm_fcs_add_block - update FCS for a block
374 * @fcs: Current FCS
375 * @c: buffer of data
376 * @len: length of buffer
377 *
378 * Update the FCS to include c. Uses the algorithm in the specification
379 * notes.
380 */
381
382static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len)
383{
384 while (len--)
385 fcs = gsm_fcs8[fcs ^ *c++];
386 return fcs;
387}
388
389/**
390 * gsm_read_ea - read a byte into an EA
391 * @val: variable holding value
392 * c: byte going into the EA
393 *
394 * Processes one byte of an EA. Updates the passed variable
395 * and returns 1 if the EA is now completely read
396 */
397
398static int gsm_read_ea(unsigned int *val, u8 c)
399{
400 /* Add the next 7 bits into the value */
401 *val <<= 7;
402 *val |= c >> 1;
403 /* Was this the last byte of the EA 1 = yes*/
404 return c & EA;
405}
406
407/**
408 * gsm_encode_modem - encode modem data bits
409 * @dlci: DLCI to encode from
410 *
411 * Returns the correct GSM encoded modem status bits (6 bit field) for
412 * the current status of the DLCI and attached tty object
413 */
414
415static u8 gsm_encode_modem(const struct gsm_dlci *dlci)
416{
417 u8 modembits = 0;
418 /* FC is true flow control not modem bits */
419 if (dlci->throttled)
420 modembits |= MDM_FC;
421 if (dlci->modem_tx & TIOCM_DTR)
422 modembits |= MDM_RTC;
423 if (dlci->modem_tx & TIOCM_RTS)
424 modembits |= MDM_RTR;
425 if (dlci->modem_tx & TIOCM_RI)
426 modembits |= MDM_IC;
427 if (dlci->modem_tx & TIOCM_CD)
428 modembits |= MDM_DV;
429 return modembits;
430}
431
432/**
433 * gsm_print_packet - display a frame for debug
434 * @hdr: header to print before decode
435 * @addr: address EA from the frame
436 * @cr: C/R bit from the frame
437 * @control: control including PF bit
438 * @data: following data bytes
439 * @dlen: length of data
440 *
441 * Displays a packet in human readable format for debugging purposes. The
442 * style is based on amateur radio LAP-B dump display.
443 */
444
445static void gsm_print_packet(const char *hdr, int addr, int cr,
446 u8 control, const u8 *data, int dlen)
447{
448 if (!(debug & 1))
449 return;
450
5f9a31d6 451 pr_info("%s %d) %c: ", hdr, addr, "RC"[cr]);
e1eaea46
AC		 452
453 switch (control & ~PF) {
454 case SABM:
5f9a31d6 455 pr_cont("SABM");
e1eaea46
AC		 456 break;
457 case UA:
5f9a31d6 458 pr_cont("UA");
e1eaea46
AC		 459 break;
460 case DISC:
5f9a31d6 461 pr_cont("DISC");
e1eaea46
AC		 462 break;
463 case DM:
5f9a31d6 464 pr_cont("DM");
e1eaea46
AC		 465 break;
466 case UI:
5f9a31d6 467 pr_cont("UI");
e1eaea46
AC		 468 break;
469 case UIH:
5f9a31d6 470 pr_cont("UIH");
e1eaea46
AC		 471 break;
472 default:
473 if (!(control & 0x01)) {
5f9a31d6 474 pr_cont("I N(S)%d N(R)%d",
47fdd641 475 (control & 0x0E) >> 1, (control & 0xE0) >> 5);
e1eaea46 476 } else switch (control & 0x0F) {
5f9a31d6
AC		 477 case RR:
478 pr_cont("RR(%d)", (control & 0xE0) >> 5);
479 break;
480 case RNR:
481 pr_cont("RNR(%d)", (control & 0xE0) >> 5);
482 break;
483 case REJ:
484 pr_cont("REJ(%d)", (control & 0xE0) >> 5);
485 break;
486 default:
487 pr_cont("[%02X]", control);
e1eaea46
AC		 488 }
489 }
490
491 if (control & PF)
5f9a31d6 492 pr_cont("(P)");
e1eaea46 493 else
5f9a31d6 494 pr_cont("(F)");
e1eaea46
AC		 495
496 if (dlen) {
497 int ct = 0;
498 while (dlen--) {
5f9a31d6
AC		 499 if (ct % 8 == 0) {
500 pr_cont("\n");
501 pr_debug(" ");
502 }
503 pr_cont("%02X ", *data++);
e1eaea46
AC		 504 ct++;
505 }
506 }
5f9a31d6 507 pr_cont("\n");
e1eaea46
AC		 508}
509
510
511/*
512 * Link level transmission side
513 */
514
515/**
516 * gsm_stuff_packet - bytestuff a packet
517 * @ibuf: input
518 * @obuf: output
519 * @len: length of input
520 *
521 * Expand a buffer by bytestuffing it. The worst case size change
522 * is doubling and the caller is responsible for handing out
523 * suitable sized buffers.
524 */
525
526static int gsm_stuff_frame(const u8 *input, u8 *output, int len)
527{
528 int olen = 0;
529 while (len--) {
530 if (*input == GSM1_SOF || *input == GSM1_ESCAPE
531 || *input == XON || *input == XOFF) {
532 *output++ = GSM1_ESCAPE;
533 *output++ = *input++ ^ GSM1_ESCAPE_BITS;
534 olen++;
535 } else
536 *output++ = *input++;
537 olen++;
538 }
539 return olen;
540}
541
e1eaea46
AC		 542/**
543 * gsm_send - send a control frame
544 * @gsm: our GSM mux
545 * @addr: address for control frame
546 * @cr: command/response bit
547 * @control: control byte including PF bit
548 *
549 * Format up and transmit a control frame. These do not go via the
550 * queueing logic as they should be transmitted ahead of data when
551 * they are needed.
552 *
553 * FIXME: Lock versus data TX path
554 */
555
556static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
557{
558 int len;
559 u8 cbuf[10];
560 u8 ibuf[3];
561
562 switch (gsm->encoding) {
563 case 0:
564 cbuf[0] = GSM0_SOF;
565 cbuf[1] = (addr << 2) | (cr << 1) | EA;
566 cbuf[2] = control;
567 cbuf[3] = EA; /* Length of data = 0 */
568 cbuf[4] = 0xFF - gsm_fcs_add_block(INIT_FCS, cbuf + 1, 3);
569 cbuf[5] = GSM0_SOF;
570 len = 6;
571 break;
572 case 1:
573 case 2:
574 /* Control frame + packing (but not frame stuffing) in mode 1 */
575 ibuf[0] = (addr << 2) | (cr << 1) | EA;
576 ibuf[1] = control;
577 ibuf[2] = 0xFF - gsm_fcs_add_block(INIT_FCS, ibuf, 2);
578 /* Stuffing may double the size worst case */
579 len = gsm_stuff_frame(ibuf, cbuf + 1, 3);
580 /* Now add the SOF markers */
581 cbuf[0] = GSM1_SOF;
582 cbuf[len + 1] = GSM1_SOF;
583 /* FIXME: we can omit the lead one in many cases */
584 len += 2;
585 break;
586 default:
587 WARN_ON(1);
588 return;
589 }
590 gsm->output(gsm, cbuf, len);
591 gsm_print_packet("-->", addr, cr, control, NULL, 0);
592}
593
594/**
595 * gsm_response - send a control response
596 * @gsm: our GSM mux
597 * @addr: address for control frame
598 * @control: control byte including PF bit
599 *
600 * Format up and transmit a link level response frame.
601 */
602
603static inline void gsm_response(struct gsm_mux *gsm, int addr, int control)
604{
605 gsm_send(gsm, addr, 0, control);
606}
607
608/**
609 * gsm_command - send a control command
610 * @gsm: our GSM mux
611 * @addr: address for control frame
612 * @control: control byte including PF bit
613 *
614 * Format up and transmit a link level command frame.
615 */
616
617static inline void gsm_command(struct gsm_mux *gsm, int addr, int control)
618{
619 gsm_send(gsm, addr, 1, control);
620}
621
622/* Data transmission */
623
624#define HDR_LEN 6 /* ADDR CTRL [LEN.2] DATA FCS */
625
626/**
627 * gsm_data_alloc - allocate data frame
628 * @gsm: GSM mux
629 * @addr: DLCI address
630 * @len: length excluding header and FCS
631 * @ctrl: control byte
632 *
633 * Allocate a new data buffer for sending frames with data. Space is left
634 * at the front for header bytes but that is treated as an implementation
635 * detail and not for the high level code to use
636 */
637
638static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len,
639 u8 ctrl)
640{
641 struct gsm_msg *m = kmalloc(sizeof(struct gsm_msg) + len + HDR_LEN,
642 GFP_ATOMIC);
643 if (m == NULL)
644 return NULL;
645 m->data = m->buffer + HDR_LEN - 1; /* Allow for FCS */
646 m->len = len;
647 m->addr = addr;
648 m->ctrl = ctrl;
b4338e1e 649 INIT_LIST_HEAD(&m->list);
e1eaea46
AC		 650 return m;
651}
652
653/**
654 * gsm_data_kick - poke the queue
655 * @gsm: GSM Mux
656 *
657 * The tty device has called us to indicate that room has appeared in
658 * the transmit queue. Ram more data into the pipe if we have any
c01af4fe
FB		 659 * If we have been flow-stopped by a CMD_FCOFF, then we can only
660 * send messages on DLCI0 until CMD_FCON
e1eaea46
AC		 661 *
662 * FIXME: lock against link layer control transmissions
663 */
664
665static void gsm_data_kick(struct gsm_mux *gsm)
666{
b4338e1e 667 struct gsm_msg *msg, *nmsg;
e1eaea46
AC		 668 int len;
669 int skip_sof = 0;
670
b4338e1e
RG		 671 list_for_each_entry_safe(msg, nmsg, &gsm->tx_list, list) {
672 if (gsm->constipated && msg->addr)
c01af4fe 673 continue;
e1eaea46
AC		 674 if (gsm->encoding != 0) {
675 gsm->txframe[0] = GSM1_SOF;
676 len = gsm_stuff_frame(msg->data,
677 gsm->txframe + 1, msg->len);
678 gsm->txframe[len + 1] = GSM1_SOF;
679 len += 2;
680 } else {
681 gsm->txframe[0] = GSM0_SOF;
682 memcpy(gsm->txframe + 1 , msg->data, msg->len);
683 gsm->txframe[msg->len + 1] = GSM0_SOF;
684 len = msg->len + 2;
685 }
686
0a77c4f9
JP		 687 if (debug & 4)
688 print_hex_dump_bytes("gsm_data_kick: ",
689 DUMP_PREFIX_OFFSET,
690 gsm->txframe, len);
e1eaea46
AC		 691
692 if (gsm->output(gsm, gsm->txframe + skip_sof,
693 len - skip_sof) < 0)
694 break;
695 /* FIXME: Can eliminate one SOF in many more cases */
e1eaea46 696 gsm->tx_bytes -= msg->len;
e1eaea46
AC		 697 /* For a burst of frames skip the extra SOF within the
698 burst */
699 skip_sof = 1;
c01af4fe 700
b4338e1e
RG		 701 list_del(&msg->list);
702 kfree(msg);
e1eaea46
AC		 703 }
704}
705
706/**
707 * __gsm_data_queue - queue a UI or UIH frame
708 * @dlci: DLCI sending the data
709 * @msg: message queued
710 *
711 * Add data to the transmit queue and try and get stuff moving
712 * out of the mux tty if not already doing so. The Caller must hold
713 * the gsm tx lock.
714 */
715
716static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
717{
718 struct gsm_mux *gsm = dlci->gsm;
719 u8 *dp = msg->data;
720 u8 *fcs = dp + msg->len;
721
722 /* Fill in the header */
723 if (gsm->encoding == 0) {
724 if (msg->len < 128)
725 *--dp = (msg->len << 1) | EA;
726 else {
be7a7411
KM		 727 *--dp = (msg->len >> 7); /* bits 7 - 15 */
728 *--dp = (msg->len & 127) << 1; /* bits 0 - 6 */
e1eaea46
AC		 729 }
730 }
731
732 *--dp = msg->ctrl;
733 if (gsm->initiator)
734 *--dp = (msg->addr << 2) | 2 | EA;
735 else
736 *--dp = (msg->addr << 2) | EA;
737 *fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp);
738 /* Ugly protocol layering violation */
739 if (msg->ctrl == UI || msg->ctrl == (UI|PF))
740 *fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len);
741 *fcs = 0xFF - *fcs;
742
743 gsm_print_packet("Q> ", msg->addr, gsm->initiator, msg->ctrl,
744 msg->data, msg->len);
745
746 /* Move the header back and adjust the length, also allow for the FCS
747 now tacked on the end */
748 msg->len += (msg->data - dp) + 1;
749 msg->data = dp;
750
751 /* Add to the actual output queue */
b4338e1e 752 list_add_tail(&msg->list, &gsm->tx_list);
e1eaea46
AC		 753 gsm->tx_bytes += msg->len;
754 gsm_data_kick(gsm);
755}
756
757/**
758 * gsm_data_queue - queue a UI or UIH frame
759 * @dlci: DLCI sending the data
760 * @msg: message queued
761 *
762 * Add data to the transmit queue and try and get stuff moving
763 * out of the mux tty if not already doing so. Take the
764 * the gsm tx lock and dlci lock.
765 */
766
767static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
768{
769 unsigned long flags;
770 spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
771 __gsm_data_queue(dlci, msg);
772 spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
773}
774
775/**
776 * gsm_dlci_data_output - try and push data out of a DLCI
777 * @gsm: mux
778 * @dlci: the DLCI to pull data from
779 *
780 * Pull data from a DLCI and send it into the transmit queue if there
781 * is data. Keep to the MRU of the mux. This path handles the usual tty
782 * interface which is a byte stream with optional modem data.
783 *
784 * Caller must hold the tx_lock of the mux.
785 */
786
787static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
788{
789 struct gsm_msg *msg;
790 u8 *dp;
268e526b 791 int len, total_size, size;
e1eaea46
AC		 792 int h = dlci->adaption - 1;
793
268e526b 794 total_size = 0;
f3c909b4 795 while (1) {
268e526b
MK		 796 len = kfifo_len(dlci->fifo);
797 if (len == 0)
798 return total_size;
799
800 /* MTU/MRU count only the data bits */
801 if (len > gsm->mtu)
802 len = gsm->mtu;
803
804 size = len + h;
805
806 msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype);
807 /* FIXME: need a timer or something to kick this so it can't
808 get stuck with no work outstanding and no buffer free */
809 if (msg == NULL)
810 return -ENOMEM;
811 dp = msg->data;
812 switch (dlci->adaption) {
813 case 1: /* Unstructured */
814 break;
f3c909b4
AI		 815 case 2: /* Unstructed with modem bits.
816 Always one byte as we never send inline break data */
268e526b
MK		 817 *dp++ = gsm_encode_modem(dlci);
818 break;
819 }
820 WARN_ON(kfifo_out_locked(dlci->fifo, dp , len, &dlci->lock) != len);
821 __gsm_data_queue(dlci, msg);
822 total_size += size;
e1eaea46 823 }
e1eaea46 824 /* Bytes of data we used up */
268e526b 825 return total_size;
e1eaea46
AC		 826}
827
828/**
829 * gsm_dlci_data_output_framed - try and push data out of a DLCI
830 * @gsm: mux
831 * @dlci: the DLCI to pull data from
832 *
833 * Pull data from a DLCI and send it into the transmit queue if there
834 * is data. Keep to the MRU of the mux. This path handles framed data
835 * queued as skbuffs to the DLCI.
836 *
837 * Caller must hold the tx_lock of the mux.
838 */
839
840static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
841 struct gsm_dlci *dlci)
842{
843 struct gsm_msg *msg;
844 u8 *dp;
845 int len, size;
846 int last = 0, first = 0;
847 int overhead = 0;
848
849 /* One byte per frame is used for B/F flags */
850 if (dlci->adaption == 4)
851 overhead = 1;
852
853 /* dlci->skb is locked by tx_lock */
854 if (dlci->skb == NULL) {
88ed2a60 855 dlci->skb = skb_dequeue_tail(&dlci->skb_list);
e1eaea46
AC		 856 if (dlci->skb == NULL)
857 return 0;
858 first = 1;
859 }
860 len = dlci->skb->len + overhead;
861
862 /* MTU/MRU count only the data bits */
863 if (len > gsm->mtu) {
864 if (dlci->adaption == 3) {
865 /* Over long frame, bin it */
329e5678 866 dev_kfree_skb_any(dlci->skb);
e1eaea46
AC		 867 dlci->skb = NULL;
868 return 0;
869 }
870 len = gsm->mtu;
871 } else
872 last = 1;
873
874 size = len + overhead;
875 msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype);
876
877 /* FIXME: need a timer or something to kick this so it can't
878 get stuck with no work outstanding and no buffer free */
88ed2a60
RG		 879 if (msg == NULL) {
880 skb_queue_tail(&dlci->skb_list, dlci->skb);
881 dlci->skb = NULL;
e1eaea46 882 return -ENOMEM;
88ed2a60 883 }
e1eaea46
AC		 884 dp = msg->data;
885
886 if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */
887 /* Flag byte to carry the start/end info */
888 *dp++ = last << 7 | first << 6 | 1; /* EA */
889 len--;
890 }
57f2104f
RG		 891 memcpy(dp, dlci->skb->data, len);
892 skb_pull(dlci->skb, len);
e1eaea46 893 __gsm_data_queue(dlci, msg);
bcd5abe2 894 if (last) {
329e5678 895 dev_kfree_skb_any(dlci->skb);
e1eaea46 896 dlci->skb = NULL;
bcd5abe2 897 }
e1eaea46
AC		 898 return size;
899}
900
901/**
902 * gsm_dlci_data_sweep - look for data to send
903 * @gsm: the GSM mux
904 *
905 * Sweep the GSM mux channels in priority order looking for ones with
906 * data to send. We could do with optimising this scan a bit. We aim
907 * to fill the queue totally or up to TX_THRESH_HI bytes. Once we hit
908 * TX_THRESH_LO we get called again
909 *
910 * FIXME: We should round robin between groups and in theory you can
911 * renegotiate DLCI priorities with optional stuff. Needs optimising.
912 */
913
914static void gsm_dlci_data_sweep(struct gsm_mux *gsm)
915{
916 int len;
917 /* Priority ordering: We should do priority with RR of the groups */
918 int i = 1;
e1eaea46 919
e1eaea46
AC		 920 while (i < NUM_DLCI) {
921 struct gsm_dlci *dlci;
922
923 if (gsm->tx_bytes > TX_THRESH_HI)
924 break;
925 dlci = gsm->dlci[i];
926 if (dlci == NULL || dlci->constipated) {
927 i++;
928 continue;
929 }
bcd5abe2 930 if (dlci->adaption < 3 && !dlci->net)
e1eaea46
AC		 931 len = gsm_dlci_data_output(gsm, dlci);
932 else
933 len = gsm_dlci_data_output_framed(gsm, dlci);
934 if (len < 0)
e73790a5 935 break;
e1eaea46
AC		 936 /* DLCI empty - try the next */
937 if (len == 0)
938 i++;
939 }
e1eaea46
AC		 940}
941
942/**
943 * gsm_dlci_data_kick - transmit if possible
944 * @dlci: DLCI to kick
945 *
946 * Transmit data from this DLCI if the queue is empty. We can't rely on
947 * a tty wakeup except when we filled the pipe so we need to fire off
948 * new data ourselves in other cases.
949 */
950
951static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
952{
953 unsigned long flags;
192b6041 954 int sweep;
e1eaea46 955
f3c909b4 956 if (dlci->constipated)
c01af4fe 957 return;
c01af4fe 958
e1eaea46
AC		 959 spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
960 /* If we have nothing running then we need to fire up */
192b6041 961 sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO);
bcd5abe2
RG		 962 if (dlci->gsm->tx_bytes == 0) {
963 if (dlci->net)
964 gsm_dlci_data_output_framed(dlci->gsm, dlci);
965 else
966 gsm_dlci_data_output(dlci->gsm, dlci);
192b6041
RG		 967 }
968 if (sweep)
f3c909b4 969 gsm_dlci_data_sweep(dlci->gsm);
e1eaea46
AC		 970 spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
971}
972
973/*
974 * Control message processing
975 */
976
977
978/**
979 * gsm_control_reply - send a response frame to a control
980 * @gsm: gsm channel
981 * @cmd: the command to use
982 * @data: data to follow encoded info
983 * @dlen: length of data
984 *
985 * Encode up and queue a UI/UIH frame containing our response.
986 */
987
988static void gsm_control_reply(struct gsm_mux *gsm, int cmd, u8 *data,
989 int dlen)
990{
991 struct gsm_msg *msg;
992 msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype);
093d8046
KM		 993 if (msg == NULL)
994 return;
e1eaea46
AC		 995 msg->data[0] = (cmd & 0xFE) << 1 | EA; /* Clear C/R */
996 msg->data[1] = (dlen << 1) | EA;
997 memcpy(msg->data + 2, data, dlen);
998 gsm_data_queue(gsm->dlci[0], msg);
999}
1000
1001/**
1002 * gsm_process_modem - process received modem status
1003 * @tty: virtual tty bound to the DLCI
1004 * @dlci: DLCI to affect
1005 * @modem: modem bits (full EA)
1006 *
1007 * Used when a modem control message or line state inline in adaption
1008 * layer 2 is processed. Sort out the local modem state and throttles
1009 */
1010
1011static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci,
7263287a 1012 u32 modem, int clen)
e1eaea46
AC		 1013{
1014 int mlines = 0;
7263287a 1015 u8 brk = 0;
c01af4fe 1016 int fc;
7263287a
RG		 1017
1018 /* The modem status command can either contain one octet (v.24 signals)
1019 or two octets (v.24 signals + break signals). The length field will
1020 either be 2 or 3 respectively. This is specified in section
1021 5.4.6.3.7 of the 27.010 mux spec. */
1022
1023 if (clen == 2)
1024 modem = modem & 0x7f;
1025 else {
1026 brk = modem & 0x7f;
1027 modem = (modem >> 7) & 0x7f;
c01af4fe 1028 }
e1eaea46
AC		 1029
1030 /* Flow control/ready to communicate */
c01af4fe
FB		 1031 fc = (modem & MDM_FC) || !(modem & MDM_RTR);
1032 if (fc && !dlci->constipated) {
e1eaea46
AC		 1033 /* Need to throttle our output on this device */
1034 dlci->constipated = 1;
c01af4fe 1035 } else if (!fc && dlci->constipated) {
e1eaea46
AC		 1036 dlci->constipated = 0;
1037 gsm_dlci_data_kick(dlci);
1038 }
c01af4fe 1039
e1eaea46 1040 /* Map modem bits */
c01af4fe
FB		 1041 if (modem & MDM_RTC)
1042 mlines |= TIOCM_DSR | TIOCM_DTR;
e1eaea46
AC		 1043 if (modem & MDM_RTR)
1044 mlines |= TIOCM_RTS | TIOCM_CTS;
1045 if (modem & MDM_IC)
1046 mlines |= TIOCM_RI;
1047 if (modem & MDM_DV)
1048 mlines |= TIOCM_CD;
1049
1050 /* Carrier drop -> hangup */
1051 if (tty) {
1052 if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD))
9db276f8 1053 if (!C_CLOCAL(tty))
e1eaea46 1054 tty_hangup(tty);
e1eaea46 1055 }
92a19f9c
JS		 1056 if (brk & 0x01)
1057 tty_insert_flip_char(&dlci->port, 0, TTY_BREAK);
e1eaea46
AC		 1058 dlci->modem_rx = mlines;
1059}
1060
1061/**
1062 * gsm_control_modem - modem status received
1063 * @gsm: GSM channel
1064 * @data: data following command
1065 * @clen: command length
1066 *
1067 * We have received a modem status control message. This is used by
1068 * the GSM mux protocol to pass virtual modem line status and optionally
1069 * to indicate break signals. Unpack it, convert to Linux representation
1070 * and if need be stuff a break message down the tty.
1071 */
1072
1073static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen)
1074{
1075 unsigned int addr = 0;
1076 unsigned int modem = 0;
3ac06b90 1077 unsigned int brk = 0;
e1eaea46
AC		 1078 struct gsm_dlci *dlci;
1079 int len = clen;
1080 u8 *dp = data;
1081 struct tty_struct *tty;
1082
1083 while (gsm_read_ea(&addr, *dp++) == 0) {
1084 len--;
1085 if (len == 0)
1086 return;
1087 }
1088 /* Must be at least one byte following the EA */
1089 len--;
1090 if (len <= 0)
1091 return;
1092
1093 addr >>= 1;
1094 /* Closed port, or invalid ? */
1095 if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL)
1096 return;
1097 dlci = gsm->dlci[addr];
1098
1099 while (gsm_read_ea(&modem, *dp++) == 0) {
1100 len--;
1101 if (len == 0)
1102 return;
1103 }
3ac06b90
LP		 1104 len--;
1105 if (len > 0) {
1106 while (gsm_read_ea(&brk, *dp++) == 0) {
1107 len--;
1108 if (len == 0)
1109 return;
1110 }
1111 modem <<= 7;
1112 modem |= (brk & 0x7f);
1113 }
e1eaea46 1114 tty = tty_port_tty_get(&dlci->port);
7263287a 1115 gsm_process_modem(tty, dlci, modem, clen);
e1eaea46
AC		 1116 if (tty) {
1117 tty_wakeup(tty);
1118 tty_kref_put(tty);
1119 }
1120 gsm_control_reply(gsm, CMD_MSC, data, clen);
1121}
1122
1123/**
1124 * gsm_control_rls - remote line status
1125 * @gsm: GSM channel
1126 * @data: data bytes
1127 * @clen: data length
1128 *
1129 * The modem sends us a two byte message on the control channel whenever
1130 * it wishes to send us an error state from the virtual link. Stuff
1131 * this into the uplink tty if present
1132 */
1133
1134static void gsm_control_rls(struct gsm_mux *gsm, u8 *data, int clen)
1135{
92a19f9c 1136 struct tty_port *port;
f3c909b4 1137 unsigned int addr = 0;
e1eaea46
AC		 1138 u8 bits;
1139 int len = clen;
1140 u8 *dp = data;
1141
1142 while (gsm_read_ea(&addr, *dp++) == 0) {
1143 len--;
1144 if (len == 0)
1145 return;
1146 }
1147 /* Must be at least one byte following ea */
1148 len--;
1149 if (len <= 0)
1150 return;
1151 addr >>= 1;
1152 /* Closed port, or invalid ? */
1153 if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL)
1154 return;
1155 /* No error ? */
1156 bits = *dp;
1157 if ((bits & 1) == 0)
1158 return;
e1eaea46 1159
92a19f9c
JS		 1160 port = &gsm->dlci[addr]->port;
1161
1162 if (bits & 2)
1163 tty_insert_flip_char(port, 0, TTY_OVERRUN);
1164 if (bits & 4)
1165 tty_insert_flip_char(port, 0, TTY_PARITY);
1166 if (bits & 8)
1167 tty_insert_flip_char(port, 0, TTY_FRAME);
1168
2e124b4a
JS		 1169 tty_flip_buffer_push(port);
1170
e1eaea46
AC		 1171 gsm_control_reply(gsm, CMD_RLS, data, clen);
1172}
1173
1174static void gsm_dlci_begin_close(struct gsm_dlci *dlci);
1175
1176/**
1177 * gsm_control_message - DLCI 0 control processing
1178 * @gsm: our GSM mux
1179 * @command: the command EA
1180 * @data: data beyond the command/length EAs
1181 * @clen: length
1182 *
1183 * Input processor for control messages from the other end of the link.
1184 * Processes the incoming request and queues a response frame or an
1185 * NSC response if not supported
1186 */
1187
1188static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
1189 u8 *data, int clen)
1190{
1191 u8 buf[1];
5e44708f
RG		 1192 unsigned long flags;
1193
e1eaea46
AC		 1194 switch (command) {
1195 case CMD_CLD: {
1196 struct gsm_dlci *dlci = gsm->dlci[0];
1197 /* Modem wishes to close down */
1198 if (dlci) {
1199 dlci->dead = 1;
1200 gsm->dead = 1;
1201 gsm_dlci_begin_close(dlci);
1202 }
1203 }
1204 break;
1205 case CMD_TEST:
1206 /* Modem wishes to test, reply with the data */
1207 gsm_control_reply(gsm, CMD_TEST, data, clen);
1208 break;
1209 case CMD_FCON:
e1eaea46
AC		 1210 /* Modem can accept data again */
1211 gsm->constipated = 0;
c01af4fe 1212 gsm_control_reply(gsm, CMD_FCON, NULL, 0);
e1eaea46 1213 /* Kick the link in case it is idling */
5e44708f 1214 spin_lock_irqsave(&gsm->tx_lock, flags);
e1eaea46 1215 gsm_data_kick(gsm);
5e44708f 1216 spin_unlock_irqrestore(&gsm->tx_lock, flags);
e1eaea46 1217 break;
c01af4fe
FB		 1218 case CMD_FCOFF:
1219 /* Modem wants us to STFU */
c01af4fe
FB		 1220 gsm->constipated = 1;
1221 gsm_control_reply(gsm, CMD_FCOFF, NULL, 0);
1222 break;
e1eaea46
AC		 1223 case CMD_MSC:
1224 /* Out of band modem line change indicator for a DLCI */
1225 gsm_control_modem(gsm, data, clen);
1226 break;
1227 case CMD_RLS:
1228 /* Out of band error reception for a DLCI */
1229 gsm_control_rls(gsm, data, clen);
1230 break;
1231 case CMD_PSC:
1232 /* Modem wishes to enter power saving state */
1233 gsm_control_reply(gsm, CMD_PSC, NULL, 0);
1234 break;
1235 /* Optional unsupported commands */
1236 case CMD_PN: /* Parameter negotiation */
25985edc
LDM		 1237 case CMD_RPN: /* Remote port negotiation */
1238 case CMD_SNC: /* Service negotiation command */
e1eaea46
AC		 1239 default:
1240 /* Reply to bad commands with an NSC */
1241 buf[0] = command;
1242 gsm_control_reply(gsm, CMD_NSC, buf, 1);
1243 break;
1244 }
1245}
1246
1247/**
1248 * gsm_control_response - process a response to our control
1249 * @gsm: our GSM mux
1250 * @command: the command (response) EA
1251 * @data: data beyond the command/length EA
1252 * @clen: length
1253 *
1254 * Process a response to an outstanding command. We only allow a single
1255 * control message in flight so this is fairly easy. All the clean up
1256 * is done by the caller, we just update the fields, flag it as done
1257 * and return
1258 */
1259
1260static void gsm_control_response(struct gsm_mux *gsm, unsigned int command,
1261 u8 *data, int clen)
1262{
1263 struct gsm_control *ctrl;
1264 unsigned long flags;
1265
1266 spin_lock_irqsave(&gsm->control_lock, flags);
1267
1268 ctrl = gsm->pending_cmd;
1269 /* Does the reply match our command */
1270 command |= 1;
1271 if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) {
1272 /* Our command was replied to, kill the retry timer */
1273 del_timer(&gsm->t2_timer);
1274 gsm->pending_cmd = NULL;
1275 /* Rejected by the other end */
1276 if (command == CMD_NSC)
1277 ctrl->error = -EOPNOTSUPP;
1278 ctrl->done = 1;
1279 wake_up(&gsm->event);
1280 }
1281 spin_unlock_irqrestore(&gsm->control_lock, flags);
1282}
1283
1284/**
5f9a31d6 1285 * gsm_control_transmit - send control packet
e1eaea46
AC		 1286 * @gsm: gsm mux
1287 * @ctrl: frame to send
1288 *
1289 * Send out a pending control command (called under control lock)
1290 */
1291
1292static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl)
1293{
ed43b47b 1294 struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 1, gsm->ftype);
e1eaea46
AC		 1295 if (msg == NULL)
1296 return;
1297 msg->data[0] = (ctrl->cmd << 1) | 2 | EA; /* command */
1298 memcpy(msg->data + 1, ctrl->data, ctrl->len);
1299 gsm_data_queue(gsm->dlci[0], msg);
1300}
1301
1302/**
1303 * gsm_control_retransmit - retransmit a control frame
1304 * @data: pointer to our gsm object
1305 *
1306 * Called off the T2 timer expiry in order to retransmit control frames
1307 * that have been lost in the system somewhere. The control_lock protects
1308 * us from colliding with another sender or a receive completion event.
1309 * In that situation the timer may still occur in a small window but
1310 * gsm->pending_cmd will be NULL and we just let the timer expire.
1311 */
1312
e99e88a9 1313static void gsm_control_retransmit(struct timer_list *t)
e1eaea46 1314{
e99e88a9 1315 struct gsm_mux *gsm = from_timer(gsm, t, t2_timer);
e1eaea46
AC		 1316 struct gsm_control *ctrl;
1317 unsigned long flags;
1318 spin_lock_irqsave(&gsm->control_lock, flags);
1319 ctrl = gsm->pending_cmd;
1320 if (ctrl) {
1321 gsm->cretries--;
1322 if (gsm->cretries == 0) {
1323 gsm->pending_cmd = NULL;
1324 ctrl->error = -ETIMEDOUT;
1325 ctrl->done = 1;
1326 spin_unlock_irqrestore(&gsm->control_lock, flags);
1327 wake_up(&gsm->event);
1328 return;
1329 }
1330 gsm_control_transmit(gsm, ctrl);
1331 mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
1332 }
1333 spin_unlock_irqrestore(&gsm->control_lock, flags);
1334}
1335
1336/**
1337 * gsm_control_send - send a control frame on DLCI 0
1338 * @gsm: the GSM channel
1339 * @command: command to send including CR bit
1340 * @data: bytes of data (must be kmalloced)
1341 * @len: length of the block to send
1342 *
1343 * Queue and dispatch a control command. Only one command can be
1344 * active at a time. In theory more can be outstanding but the matching
1345 * gets really complicated so for now stick to one outstanding.
1346 */
1347
1348static struct gsm_control *gsm_control_send(struct gsm_mux *gsm,
1349 unsigned int command, u8 *data, int clen)
1350{
1351 struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control),
1352 GFP_KERNEL);
1353 unsigned long flags;
1354 if (ctrl == NULL)
1355 return NULL;
1356retry:
1357 wait_event(gsm->event, gsm->pending_cmd == NULL);
1358 spin_lock_irqsave(&gsm->control_lock, flags);
1359 if (gsm->pending_cmd != NULL) {
1360 spin_unlock_irqrestore(&gsm->control_lock, flags);
1361 goto retry;
1362 }
1363 ctrl->cmd = command;
1364 ctrl->data = data;
1365 ctrl->len = clen;
1366 gsm->pending_cmd = ctrl;
1367 gsm->cretries = gsm->n2;
1368 mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
1369 gsm_control_transmit(gsm, ctrl);
1370 spin_unlock_irqrestore(&gsm->control_lock, flags);
1371 return ctrl;
1372}
1373
1374/**
1375 * gsm_control_wait - wait for a control to finish
1376 * @gsm: GSM mux
1377 * @control: control we are waiting on
1378 *
1379 * Waits for the control to complete or time out. Frees any used
1380 * resources and returns 0 for success, or an error if the remote
1381 * rejected or ignored the request.
1382 */
1383
1384static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control)
1385{
1386 int err;
1387 wait_event(gsm->event, control->done == 1);
1388 err = control->error;
1389 kfree(control);
1390 return err;
1391}
1392
1393
1394/*
1395 * DLCI level handling: Needs krefs
1396 */
1397
1398/*
1399 * State transitions and timers
1400 */
1401
1402/**
1403 * gsm_dlci_close - a DLCI has closed
1404 * @dlci: DLCI that closed
1405 *
1406 * Perform processing when moving a DLCI into closed state. If there
1407 * is an attached tty this is hung up
1408 */
1409
1410static void gsm_dlci_close(struct gsm_dlci *dlci)
1411{
1412 del_timer(&dlci->t1);
1413 if (debug & 8)
5f9a31d6 1414 pr_debug("DLCI %d goes closed.\n", dlci->addr);
e1eaea46
AC		 1415 dlci->state = DLCI_CLOSED;
1416 if (dlci->addr != 0) {
aa27a094 1417 tty_port_tty_hangup(&dlci->port, false);
e1eaea46
AC		 1418 kfifo_reset(dlci->fifo);
1419 } else
1420 dlci->gsm->dead = 1;
1421 wake_up(&dlci->gsm->event);
1422 /* A DLCI 0 close is a MUX termination so we need to kick that
1423 back to userspace somehow */
1424}
1425
1426/**
1427 * gsm_dlci_open - a DLCI has opened
1428 * @dlci: DLCI that opened
1429 *
1430 * Perform processing when moving a DLCI into open state.
1431 */
1432
1433static void gsm_dlci_open(struct gsm_dlci *dlci)
1434{
1435 /* Note that SABM UA .. SABM UA first UA lost can mean that we go
1436 open -> open */
1437 del_timer(&dlci->t1);
1438 /* This will let a tty open continue */
1439 dlci->state = DLCI_OPEN;
1440 if (debug & 8)
5f9a31d6 1441 pr_debug("DLCI %d goes open.\n", dlci->addr);
e1eaea46
AC		 1442 wake_up(&dlci->gsm->event);
1443}
1444
1445/**
1446 * gsm_dlci_t1 - T1 timer expiry
1447 * @dlci: DLCI that opened
1448 *
1449 * The T1 timer handles retransmits of control frames (essentially of
1450 * SABM and DISC). We resend the command until the retry count runs out
1451 * in which case an opening port goes back to closed and a closing port
1452 * is simply put into closed state (any further frames from the other
1453 * end will get a DM response)
1454 */
1455
e99e88a9 1456static void gsm_dlci_t1(struct timer_list *t)
e1eaea46 1457{
e99e88a9 1458 struct gsm_dlci *dlci = from_timer(dlci, t, t1);
e1eaea46
AC		 1459 struct gsm_mux *gsm = dlci->gsm;
1460
1461 switch (dlci->state) {
1462 case DLCI_OPENING:
1463 dlci->retries--;
1464 if (dlci->retries) {
1465 gsm_command(dlci->gsm, dlci->addr, SABM|PF);
1466 mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
1467 } else
1468 gsm_dlci_close(dlci);
1469 break;
1470 case DLCI_CLOSING:
1471 dlci->retries--;
1472 if (dlci->retries) {
1473 gsm_command(dlci->gsm, dlci->addr, DISC|PF);
1474 mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
1475 } else
1476 gsm_dlci_close(dlci);
1477 break;
1478 }
1479}
1480
1481/**
1482 * gsm_dlci_begin_open - start channel open procedure
1483 * @dlci: DLCI to open
1484 *
1485 * Commence opening a DLCI from the Linux side. We issue SABM messages
1486 * to the modem which should then reply with a UA, at which point we
1487 * will move into open state. Opening is done asynchronously with retry
1488 * running off timers and the responses.
1489 */
1490
1491static void gsm_dlci_begin_open(struct gsm_dlci *dlci)
1492{
1493 struct gsm_mux *gsm = dlci->gsm;
1494 if (dlci->state == DLCI_OPEN || dlci->state == DLCI_OPENING)
1495 return;
1496 dlci->retries = gsm->n2;
1497 dlci->state = DLCI_OPENING;
1498 gsm_command(dlci->gsm, dlci->addr, SABM|PF);
1499 mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
1500}
1501
1502/**
1503 * gsm_dlci_begin_close - start channel open procedure
1504 * @dlci: DLCI to open
1505 *
1506 * Commence closing a DLCI from the Linux side. We issue DISC messages
1507 * to the modem which should then reply with a UA, at which point we
1508 * will move into closed state. Closing is done asynchronously with retry
1509 * off timers. We may also receive a DM reply from the other end which
1510 * indicates the channel was already closed.
1511 */
1512
1513static void gsm_dlci_begin_close(struct gsm_dlci *dlci)
1514{
1515 struct gsm_mux *gsm = dlci->gsm;
1516 if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING)
1517 return;
1518 dlci->retries = gsm->n2;
1519 dlci->state = DLCI_CLOSING;
1520 gsm_command(dlci->gsm, dlci->addr, DISC|PF);
1521 mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
1522}
1523
1524/**
1525 * gsm_dlci_data - data arrived
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 a channel
1531 * other than the control channel. If the relevant virtual tty is
1532 * open we shovel the bits down it, if not we drop them.
1533 */
1534
7263287a 1535static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int clen)
e1eaea46
AC		 1536{
1537 /* krefs .. */
1538 struct tty_port *port = &dlci->port;
2e124b4a 1539 struct tty_struct *tty;
e1eaea46 1540 unsigned int modem = 0;
7263287a 1541 int len = clen;
e1eaea46
AC		 1542
1543 if (debug & 16)
2e124b4a
JS		 1544 pr_debug("%d bytes for tty\n", len);
1545 switch (dlci->adaption) {
1546 /* Unsupported types */
1547 /* Packetised interruptible data */
1548 case 4:
1549 break;
1550 /* Packetised uininterruptible voice/data */
1551 case 3:
1552 break;
1553 /* Asynchronous serial with line state in each frame */
1554 case 2:
1555 while (gsm_read_ea(&modem, *data++) == 0) {
1556 len--;
1557 if (len == 0)
1558 return;
1559 }
1560 tty = tty_port_tty_get(port);
1561 if (tty) {
7263287a 1562 gsm_process_modem(tty, dlci, modem, clen);
2e124b4a 1563 tty_kref_put(tty);
e1eaea46 1564 }
2e124b4a
JS		 1565 /* Line state will go via DLCI 0 controls only */
1566 case 1:
1567 default:
1568 tty_insert_flip_string(port, data, len);
1569 tty_flip_buffer_push(port);
e1eaea46
AC		 1570 }
1571}
1572
1573/**
1574 * gsm_dlci_control - data arrived on control channel
1575 * @dlci: channel
1576 * @data: block of bytes received
1577 * @len: length of received block
1578 *
1579 * A UI or UIH frame has arrived which contains data for DLCI 0 the
1580 * control channel. This should contain a command EA followed by
1581 * control data bytes. The command EA contains a command/response bit
1582 * and we divide up the work accordingly.
1583 */
1584
1585static void gsm_dlci_command(struct gsm_dlci *dlci, u8 *data, int len)
1586{
1587 /* See what command is involved */
1588 unsigned int command = 0;
1589 while (len-- > 0) {
1590 if (gsm_read_ea(&command, *data++) == 1) {
1591 int clen = *data++;
1592 len--;
1593 /* FIXME: this is properly an EA */
1594 clen >>= 1;
1595 /* Malformed command ? */
1596 if (clen > len)
1597 return;
1598 if (command & 1)
1599 gsm_control_message(dlci->gsm, command,
1600 data, clen);
1601 else
1602 gsm_control_response(dlci->gsm, command,
1603 data, clen);
1604 return;
1605 }
1606 }
1607}
1608
1609/*
1610 * Allocate/Free DLCI channels
1611 */
1612
1613/**
1614 * gsm_dlci_alloc - allocate a DLCI
1615 * @gsm: GSM mux
1616 * @addr: address of the DLCI
1617 *
1618 * Allocate and install a new DLCI object into the GSM mux.
1619 *
1620 * FIXME: review locking races
1621 */
1622
1623static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr)
1624{
1625 struct gsm_dlci *dlci = kzalloc(sizeof(struct gsm_dlci), GFP_ATOMIC);
1626 if (dlci == NULL)
1627 return NULL;
1628 spin_lock_init(&dlci->lock);
bcd5abe2 1629 mutex_init(&dlci->mutex);
e1eaea46
AC		 1630 dlci->fifo = &dlci->_fifo;
1631 if (kfifo_alloc(&dlci->_fifo, 4096, GFP_KERNEL) < 0) {
1632 kfree(dlci);
1633 return NULL;
1634 }
1635
1636 skb_queue_head_init(&dlci->skb_list);
e99e88a9 1637 timer_setup(&dlci->t1, gsm_dlci_t1, 0);
e1eaea46
AC		 1638 tty_port_init(&dlci->port);
1639 dlci->port.ops = &gsm_port_ops;
1640 dlci->gsm = gsm;
1641 dlci->addr = addr;
1642 dlci->adaption = gsm->adaption;
1643 dlci->state = DLCI_CLOSED;
1644 if (addr)
1645 dlci->data = gsm_dlci_data;
1646 else
1647 dlci->data = gsm_dlci_command;
1648 gsm->dlci[addr] = dlci;
1649 return dlci;
1650}
1651
1652/**
6ab8fba7
RG		 1653 * gsm_dlci_free - free DLCI
1654 * @dlci: DLCI to free
1655 *
1656 * Free up a DLCI.
1657 *
1658 * Can sleep.
1659 */
9a8e62bc 1660static void gsm_dlci_free(struct tty_port *port)
6ab8fba7 1661{
9a8e62bc 1662 struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
6ab8fba7
RG		 1663
1664 del_timer_sync(&dlci->t1);
1665 dlci->gsm->dlci[dlci->addr] = NULL;
1666 kfifo_free(dlci->fifo);
1667 while ((dlci->skb = skb_dequeue(&dlci->skb_list)))
329e5678 1668 dev_kfree_skb(dlci->skb);
6ab8fba7
RG		 1669 kfree(dlci);
1670}
1671
1672static inline void dlci_get(struct gsm_dlci *dlci)
1673{
9a8e62bc 1674 tty_port_get(&dlci->port);
6ab8fba7
RG		 1675}
1676
1677static inline void dlci_put(struct gsm_dlci *dlci)
1678{
9a8e62bc 1679 tty_port_put(&dlci->port);
6ab8fba7
RG		 1680}
1681
4d9b1090
DB		 1682static void gsm_destroy_network(struct gsm_dlci *dlci);
1683
6ab8fba7
RG		 1684/**
1685 * gsm_dlci_release - release DLCI
e1eaea46
AC		 1686 * @dlci: DLCI to destroy
1687 *
6ab8fba7
RG		 1688 * Release a DLCI. Actual free is deferred until either
1689 * mux is closed or tty is closed - whichever is last.
e1eaea46
AC		 1690 *
1691 * Can sleep.
1692 */
6ab8fba7 1693static void gsm_dlci_release(struct gsm_dlci *dlci)
e1eaea46
AC		 1694{
1695 struct tty_struct *tty = tty_port_tty_get(&dlci->port);
1696 if (tty) {
4d9b1090
DB		 1697 mutex_lock(&dlci->mutex);
1698 gsm_destroy_network(dlci);
1699 mutex_unlock(&dlci->mutex);
1700
e1eaea46 1701 tty_vhangup(tty);
be706572 1702
4d9b1090 1703 tty_port_tty_set(&dlci->port, NULL);
e1eaea46
AC		 1704 tty_kref_put(tty);
1705 }
4d9b1090 1706 dlci->state = DLCI_CLOSED;
6ab8fba7 1707 dlci_put(dlci);
e1eaea46
AC		 1708}
1709
e1eaea46
AC		 1710/*
1711 * LAPBish link layer logic
1712 */
1713
1714/**
1715 * gsm_queue - a GSM frame is ready to process
1716 * @gsm: pointer to our gsm mux
1717 *
1718 * At this point in time a frame has arrived and been demangled from
1719 * the line encoding. All the differences between the encodings have
1720 * been handled below us and the frame is unpacked into the structures.
1721 * The fcs holds the header FCS but any data FCS must be added here.
1722 */
1723
1724static void gsm_queue(struct gsm_mux *gsm)
1725{
1726 struct gsm_dlci *dlci;
1727 u8 cr;
1728 int address;
1729 /* We have to sneak a look at the packet body to do the FCS.
1730 A somewhat layering violation in the spec */
1731
1732 if ((gsm->control & ~PF) == UI)
1733 gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len);
f3c909b4
AI		 1734 if (gsm->encoding == 0) {
1735 /* WARNING: gsm->received_fcs is used for
1736 gsm->encoding = 0 only.
1737 In this case it contain the last piece of data
1738 required to generate final CRC */
9db4e438
MK		 1739 gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->received_fcs);
1740 }
e1eaea46
AC		 1741 if (gsm->fcs != GOOD_FCS) {
1742 gsm->bad_fcs++;
1743 if (debug & 4)
5f9a31d6 1744 pr_debug("BAD FCS %02x\n", gsm->fcs);
e1eaea46
AC		 1745 return;
1746 }
1747 address = gsm->address >> 1;
1748 if (address >= NUM_DLCI)
1749 goto invalid;
1750
1751 cr = gsm->address & 1; /* C/R bit */
1752
1753 gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len);
1754
1755 cr ^= 1 - gsm->initiator; /* Flip so 1 always means command */
1756 dlci = gsm->dlci[address];
1757
1758 switch (gsm->control) {
1759 case SABM|PF:
1760 if (cr == 0)
1761 goto invalid;
1762 if (dlci == NULL)
1763 dlci = gsm_dlci_alloc(gsm, address);
1764 if (dlci == NULL)
1765 return;
1766 if (dlci->dead)
1767 gsm_response(gsm, address, DM);
1768 else {
1769 gsm_response(gsm, address, UA);
1770 gsm_dlci_open(dlci);
1771 }
1772 break;
1773 case DISC|PF:
1774 if (cr == 0)
1775 goto invalid;
1776 if (dlci == NULL || dlci->state == DLCI_CLOSED) {
1777 gsm_response(gsm, address, DM);
1778 return;
1779 }
1780 /* Real close complete */
1781 gsm_response(gsm, address, UA);
1782 gsm_dlci_close(dlci);
1783 break;
1784 case UA:
1785 case UA|PF:
1786 if (cr == 0 || dlci == NULL)
1787 break;
1788 switch (dlci->state) {
1789 case DLCI_CLOSING:
1790 gsm_dlci_close(dlci);
1791 break;
1792 case DLCI_OPENING:
1793 gsm_dlci_open(dlci);
1794 break;
1795 }
1796 break;
1797 case DM: /* DM can be valid unsolicited */
1798 case DM|PF:
1799 if (cr)
1800 goto invalid;
1801 if (dlci == NULL)
1802 return;
1803 gsm_dlci_close(dlci);
1804 break;
1805 case UI:
1806 case UI|PF:
1807 case UIH:
1808 case UIH|PF:
1809#if 0
1810 if (cr)
1811 goto invalid;
1812#endif
1813 if (dlci == NULL || dlci->state != DLCI_OPEN) {
1814 gsm_command(gsm, address, DM|PF);
1815 return;
1816 }
1817 dlci->data(dlci, gsm->buf, gsm->len);
1818 break;
1819 default:
1820 goto invalid;
1821 }
1822 return;
1823invalid:
1824 gsm->malformed++;
1825 return;
1826}
1827
1828
1829/**
1830 * gsm0_receive - perform processing for non-transparency
1831 * @gsm: gsm data for this ldisc instance
1832 * @c: character
1833 *
1834 * Receive bytes in gsm mode 0
1835 */
1836
1837static void gsm0_receive(struct gsm_mux *gsm, unsigned char c)
1838{
c2f2f000
AC		 1839 unsigned int len;
1840
e1eaea46
AC		 1841 switch (gsm->state) {
1842 case GSM_SEARCH: /* SOF marker */
1843 if (c == GSM0_SOF) {
1844 gsm->state = GSM_ADDRESS;
1845 gsm->address = 0;
1846 gsm->len = 0;
1847 gsm->fcs = INIT_FCS;
1848 }
c2f2f000
AC		 1849 break;
1850 case GSM_ADDRESS: /* Address EA */
e1eaea46
AC		 1851 gsm->fcs = gsm_fcs_add(gsm->fcs, c);
1852 if (gsm_read_ea(&gsm->address, c))
1853 gsm->state = GSM_CONTROL;
1854 break;
1855 case GSM_CONTROL: /* Control Byte */
1856 gsm->fcs = gsm_fcs_add(gsm->fcs, c);
1857 gsm->control = c;
c2f2f000 1858 gsm->state = GSM_LEN0;
e1eaea46 1859 break;
c2f2f000 1860 case GSM_LEN0: /* Length EA */
e1eaea46
AC		 1861 gsm->fcs = gsm_fcs_add(gsm->fcs, c);
1862 if (gsm_read_ea(&gsm->len, c)) {
1863 if (gsm->len > gsm->mru) {
1864 gsm->bad_size++;
1865 gsm->state = GSM_SEARCH;
1866 break;
1867 }
1868 gsm->count = 0;
c2f2f000
AC		 1869 if (!gsm->len)
1870 gsm->state = GSM_FCS;
1871 else
1872 gsm->state = GSM_DATA;
1873 break;
e1eaea46 1874 }
c2f2f000
AC		 1875 gsm->state = GSM_LEN1;
1876 break;
1877 case GSM_LEN1:
1878 gsm->fcs = gsm_fcs_add(gsm->fcs, c);
1879 len = c;
1880 gsm->len |= len << 7;
1881 if (gsm->len > gsm->mru) {
1882 gsm->bad_size++;
1883 gsm->state = GSM_SEARCH;
1884 break;
e1eaea46 1885 }
c2f2f000
AC		 1886 gsm->count = 0;
1887 if (!gsm->len)
1888 gsm->state = GSM_FCS;
1889 else
1890 gsm->state = GSM_DATA;
e1eaea46
AC		 1891 break;
1892 case GSM_DATA: /* Data */
1893 gsm->buf[gsm->count++] = c;
1894 if (gsm->count == gsm->len)
1895 gsm->state = GSM_FCS;
1896 break;
1897 case GSM_FCS: /* FCS follows the packet */
c2f2f000 1898 gsm->received_fcs = c;
e1eaea46 1899 gsm_queue(gsm);
c2f2f000
AC		 1900 gsm->state = GSM_SSOF;
1901 break;
1902 case GSM_SSOF:
1903 if (c == GSM0_SOF) {
1904 gsm->state = GSM_SEARCH;
1905 break;
1906 }
e1eaea46
AC		 1907 break;
1908 }
1909}
1910
1911/**
c2f2f000 1912 * gsm1_receive - perform processing for non-transparency
e1eaea46
AC		 1913 * @gsm: gsm data for this ldisc instance
1914 * @c: character
1915 *
1916 * Receive bytes in mode 1 (Advanced option)
1917 */
1918
1919static void gsm1_receive(struct gsm_mux *gsm, unsigned char c)
1920{
1921 if (c == GSM1_SOF) {
1922 /* EOF is only valid in frame if we have got to the data state
1923 and received at least one byte (the FCS) */
1924 if (gsm->state == GSM_DATA && gsm->count) {
1925 /* Extract the FCS */
1926 gsm->count--;
1927 gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]);
1928 gsm->len = gsm->count;
1929 gsm_queue(gsm);
1930 gsm->state = GSM_START;
1931 return;
1932 }
1933 /* Any partial frame was a runt so go back to start */
1934 if (gsm->state != GSM_START) {
1935 gsm->malformed++;
1936 gsm->state = GSM_START;
1937 }
1938 /* A SOF in GSM_START means we are still reading idling or
1939 framing bytes */
1940 return;
1941 }
1942
1943 if (c == GSM1_ESCAPE) {
1944 gsm->escape = 1;
1945 return;
1946 }
1947
1948 /* Only an unescaped SOF gets us out of GSM search */
1949 if (gsm->state == GSM_SEARCH)
1950 return;
1951
1952 if (gsm->escape) {
1953 c ^= GSM1_ESCAPE_BITS;
1954 gsm->escape = 0;
1955 }
1956 switch (gsm->state) {
1957 case GSM_START: /* First byte after SOF */
1958 gsm->address = 0;
1959 gsm->state = GSM_ADDRESS;
1960 gsm->fcs = INIT_FCS;
1961 /* Drop through */
1962 case GSM_ADDRESS: /* Address continuation */
1963 gsm->fcs = gsm_fcs_add(gsm->fcs, c);
1964 if (gsm_read_ea(&gsm->address, c))
1965 gsm->state = GSM_CONTROL;
1966 break;
1967 case GSM_CONTROL: /* Control Byte */
1968 gsm->fcs = gsm_fcs_add(gsm->fcs, c);
1969 gsm->control = c;
1970 gsm->count = 0;
1971 gsm->state = GSM_DATA;
1972 break;
1973 case GSM_DATA: /* Data */
5f9a31d6 1974 if (gsm->count > gsm->mru) { /* Allow one for the FCS */
e1eaea46
AC		 1975 gsm->state = GSM_OVERRUN;
1976 gsm->bad_size++;
1977 } else
1978 gsm->buf[gsm->count++] = c;
1979 break;
1980 case GSM_OVERRUN: /* Over-long - eg a dropped SOF */
1981 break;
1982 }
1983}
1984
1985/**
1986 * gsm_error - handle tty error
1987 * @gsm: ldisc data
1988 * @data: byte received (may be invalid)
1989 * @flag: error received
1990 *
1991 * Handle an error in the receipt of data for a frame. Currently we just
1992 * go back to hunting for a SOF.
1993 *
1994 * FIXME: better diagnostics ?
1995 */
1996
1997static void gsm_error(struct gsm_mux *gsm,
1998 unsigned char data, unsigned char flag)
1999{
2000 gsm->state = GSM_SEARCH;
2001 gsm->io_error++;
2002}
2003
71e07791
SH		 2004static int gsm_disconnect(struct gsm_mux *gsm)
2005{
2006 struct gsm_dlci *dlci = gsm->dlci[0];
2007 struct gsm_control *gc;
2008
2009 if (!dlci)
2010 return 0;
2011
2012 /* In theory disconnecting DLCI 0 is sufficient but for some
2013 modems this is apparently not the case. */
2014 gc = gsm_control_send(gsm, CMD_CLD, NULL, 0);
2015 if (gc)
2016 gsm_control_wait(gsm, gc);
2017
2018 del_timer_sync(&gsm->t2_timer);
2019 /* Now we are sure T2 has stopped */
2020
2021 gsm_dlci_begin_close(dlci);
2022 wait_event_interruptible(gsm->event,
2023 dlci->state == DLCI_CLOSED);
2024
2025 if (signal_pending(current))
2026 return -EINTR;
2027
2028 return 0;
2029}
2030
e1eaea46
AC		 2031/**
2032 * gsm_cleanup_mux - generic GSM protocol cleanup
2033 * @gsm: our mux
2034 *
2035 * Clean up the bits of the mux which are the same for all framing
2036 * protocols. Remove the mux from the mux table, stop all the timers
2037 * and then shut down each device hanging up the channels as we go.
2038 */
2039
54af5836 2040static void gsm_cleanup_mux(struct gsm_mux *gsm)
e1eaea46
AC		 2041{
2042 int i;
2043 struct gsm_dlci *dlci = gsm->dlci[0];
329e5678 2044 struct gsm_msg *txq, *ntxq;
e1eaea46
AC		 2045
2046 gsm->dead = 1;
2047
2048 spin_lock(&gsm_mux_lock);
2049 for (i = 0; i < MAX_MUX; i++) {
2050 if (gsm_mux[i] == gsm) {
2051 gsm_mux[i] = NULL;
2052 break;
2053 }
2054 }
2055 spin_unlock(&gsm_mux_lock);
d175feca
JS		 2056 /* open failed before registering => nothing to do */
2057 if (i == MAX_MUX)
2058 return;
e1eaea46
AC		 2059
2060 del_timer_sync(&gsm->t2_timer);
2061 /* Now we are sure T2 has stopped */
71e07791 2062 if (dlci)
e1eaea46 2063 dlci->dead = 1;
71e07791 2064
e1eaea46 2065 /* Free up any link layer users */
dfabf7ff 2066 mutex_lock(&gsm->mutex);
e1eaea46
AC		 2067 for (i = 0; i < NUM_DLCI; i++)
2068 if (gsm->dlci[i])
6ab8fba7 2069 gsm_dlci_release(gsm->dlci[i]);
dfabf7ff 2070 mutex_unlock(&gsm->mutex);
e1eaea46 2071 /* Now wipe the queues */
b4338e1e 2072 list_for_each_entry_safe(txq, ntxq, &gsm->tx_list, list)
e1eaea46 2073 kfree(txq);
b4338e1e 2074 INIT_LIST_HEAD(&gsm->tx_list);
e1eaea46 2075}
e1eaea46
AC		 2076
2077/**
2078 * gsm_activate_mux - generic GSM setup
2079 * @gsm: our mux
2080 *
2081 * Set up the bits of the mux which are the same for all framing
2082 * protocols. Add the mux to the mux table so it can be opened and
2083 * finally kick off connecting to DLCI 0 on the modem.
2084 */
2085
54af5836 2086static int gsm_activate_mux(struct gsm_mux *gsm)
e1eaea46
AC		 2087{
2088 struct gsm_dlci *dlci;
2089 int i = 0;
2090
e99e88a9 2091 timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0);
e1eaea46
AC		 2092 init_waitqueue_head(&gsm->event);
2093 spin_lock_init(&gsm->control_lock);
2094 spin_lock_init(&gsm->tx_lock);
2095
2096 if (gsm->encoding == 0)
2097 gsm->receive = gsm0_receive;
2098 else
2099 gsm->receive = gsm1_receive;
2100 gsm->error = gsm_error;
2101
2102 spin_lock(&gsm_mux_lock);
2103 for (i = 0; i < MAX_MUX; i++) {
2104 if (gsm_mux[i] == NULL) {
d50f6dca 2105 gsm->num = i;
e1eaea46
AC		 2106 gsm_mux[i] = gsm;
2107 break;
2108 }
2109 }
2110 spin_unlock(&gsm_mux_lock);
2111 if (i == MAX_MUX)
2112 return -EBUSY;
2113
2114 dlci = gsm_dlci_alloc(gsm, 0);
2115 if (dlci == NULL)
2116 return -ENOMEM;
2117 gsm->dead = 0; /* Tty opens are now permissible */
2118 return 0;
2119}
e1eaea46
AC		 2120
2121/**
2122 * gsm_free_mux - free up a mux
2123 * @mux: mux to free
2124 *
6ab8fba7 2125 * Dispose of allocated resources for a dead mux
e1eaea46 2126 */
54af5836 2127static void gsm_free_mux(struct gsm_mux *gsm)
e1eaea46
AC		 2128{
2129 kfree(gsm->txframe);
2130 kfree(gsm->buf);
2131 kfree(gsm);
2132}
e1eaea46 2133
6ab8fba7
RG		 2134/**
2135 * gsm_free_muxr - free up a mux
2136 * @mux: mux to free
2137 *
2138 * Dispose of allocated resources for a dead mux
2139 */
2140static void gsm_free_muxr(struct kref *ref)
2141{
2142 struct gsm_mux *gsm = container_of(ref, struct gsm_mux, ref);
2143 gsm_free_mux(gsm);
2144}
2145
2146static inline void mux_get(struct gsm_mux *gsm)
2147{
2148 kref_get(&gsm->ref);
2149}
2150
2151static inline void mux_put(struct gsm_mux *gsm)
2152{
2153 kref_put(&gsm->ref, gsm_free_muxr);
2154}
2155
e1eaea46
AC		 2156/**
2157 * gsm_alloc_mux - allocate a mux
2158 *
2159 * Creates a new mux ready for activation.
2160 */
2161
54af5836 2162static struct gsm_mux *gsm_alloc_mux(void)
e1eaea46
AC		 2163{
2164 struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL);
2165 if (gsm == NULL)
2166 return NULL;
2167 gsm->buf = kmalloc(MAX_MRU + 1, GFP_KERNEL);
2168 if (gsm->buf == NULL) {
2169 kfree(gsm);
2170 return NULL;
2171 }
2172 gsm->txframe = kmalloc(2 * MAX_MRU + 2, GFP_KERNEL);
2173 if (gsm->txframe == NULL) {
2174 kfree(gsm->buf);
2175 kfree(gsm);
2176 return NULL;
2177 }
2178 spin_lock_init(&gsm->lock);
dfabf7ff 2179 mutex_init(&gsm->mutex);
6ab8fba7 2180 kref_init(&gsm->ref);
b4338e1e 2181 INIT_LIST_HEAD(&gsm->tx_list);
e1eaea46
AC		 2182
2183 gsm->t1 = T1;
2184 gsm->t2 = T2;
2185 gsm->n2 = N2;
2186 gsm->ftype = UIH;
e1eaea46
AC		 2187 gsm->adaption = 1;
2188 gsm->encoding = 1;
2189 gsm->mru = 64; /* Default to encoding 1 so these should be 64 */
2190 gsm->mtu = 64;
2191 gsm->dead = 1; /* Avoid early tty opens */
2192
2193 return gsm;
2194}
e1eaea46 2195
e1eaea46
AC		 2196/**
2197 * gsmld_output - write to link
2198 * @gsm: our mux
2199 * @data: bytes to output
2200 * @len: size
2201 *
2202 * Write a block of data from the GSM mux to the data channel. This
2203 * will eventually be serialized from above but at the moment isn't.
2204 */
2205
2206static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len)
2207{
2208 if (tty_write_room(gsm->tty) < len) {
2209 set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags);
2210 return -ENOSPC;
2211 }
0a77c4f9
JP		 2212 if (debug & 4)
2213 print_hex_dump_bytes("gsmld_output: ", DUMP_PREFIX_OFFSET,
2214 data, len);
e1eaea46
AC		 2215 gsm->tty->ops->write(gsm->tty, data, len);
2216 return len;
2217}
2218
2219/**
2220 * gsmld_attach_gsm - mode set up
2221 * @tty: our tty structure
2222 * @gsm: our mux
2223 *
2224 * Set up the MUX for basic mode and commence connecting to the
2225 * modem. Currently called from the line discipline set up but
2226 * will need moving to an ioctl path.
2227 */
2228
2229static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
2230{
850e93eb 2231 int ret, i, base;
e1eaea46
AC		 2232
2233 gsm->tty = tty_kref_get(tty);
2234 gsm->output = gsmld_output;
2235 ret = gsm_activate_mux(gsm);
2236 if (ret != 0)
2237 tty_kref_put(gsm->tty);
d50f6dca
RG		 2238 else {
2239 /* Don't register device 0 - this is the control channel and not
2240 a usable tty interface */
850e93eb 2241 base = gsm->num << 6; /* Base for this MUX */
d50f6dca
RG		 2242 for (i = 1; i < NUM_DLCI; i++)
2243 tty_register_device(gsm_tty_driver, base + i, NULL);
2244 }
e1eaea46
AC		 2245 return ret;
2246}
2247
2248
2249/**
2250 * gsmld_detach_gsm - stop doing 0710 mux
70f23fd6 2251 * @tty: tty attached to the mux
e1eaea46
AC		 2252 * @gsm: mux
2253 *
2254 * Shutdown and then clean up the resources used by the line discipline
2255 */
2256
2257static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
2258{
d50f6dca
RG		 2259 int i;
2260 int base = gsm->num << 6; /* Base for this MUX */
2261
e1eaea46 2262 WARN_ON(tty != gsm->tty);
d50f6dca
RG		 2263 for (i = 1; i < NUM_DLCI; i++)
2264 tty_unregister_device(gsm_tty_driver, base + i);
e1eaea46
AC		 2265 gsm_cleanup_mux(gsm);
2266 tty_kref_put(gsm->tty);
2267 gsm->tty = NULL;
2268}
2269
55db4c64
LT		 2270static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
2271 char *fp, int count)
e1eaea46
AC		 2272{
2273 struct gsm_mux *gsm = tty->disc_data;
2274 const unsigned char *dp;
2275 char *f;
2276 int i;
82f91fe0 2277 char flags = TTY_NORMAL;
e1eaea46 2278
0a77c4f9
JP		 2279 if (debug & 4)
2280 print_hex_dump_bytes("gsmld_receive: ", DUMP_PREFIX_OFFSET,
2281 cp, count);
e1eaea46
AC		 2282
2283 for (i = count, dp = cp, f = fp; i; i--, dp++) {
82f91fe0
PH		 2284 if (f)
2285 flags = *f++;
e1eaea46
AC		 2286 switch (flags) {
2287 case TTY_NORMAL:
2288 gsm->receive(gsm, *dp);
2289 break;
2290 case TTY_OVERRUN:
2291 case TTY_BREAK:
2292 case TTY_PARITY:
2293 case TTY_FRAME:
2294 gsm->error(gsm, *dp, flags);
2295 break;
2296 default:
c01af4fe 2297 WARN_ONCE(1, "%s: unknown flag %d\n",
429b4749 2298 tty_name(tty), flags);
e1eaea46
AC		 2299 break;
2300 }
2301 }
2302 /* FASYNC if needed ? */
2303 /* If clogged call tty_throttle(tty); */
2304}
2305
e1eaea46
AC		 2306/**
2307 * gsmld_flush_buffer - clean input queue
2308 * @tty: terminal device
2309 *
2310 * Flush the input buffer. Called when the line discipline is
2311 * being closed, when the tty layer wants the buffer flushed (eg
2312 * at hangup).
2313 */
2314
2315static void gsmld_flush_buffer(struct tty_struct *tty)
2316{
2317}
2318
2319/**
2320 * gsmld_close - close the ldisc for this tty
2321 * @tty: device
2322 *
2323 * Called from the terminal layer when this line discipline is
2324 * being shut down, either because of a close or becsuse of a
2325 * discipline change. The function will not be called while other
2326 * ldisc methods are in progress.
2327 */
2328
2329static void gsmld_close(struct tty_struct *tty)
2330{
2331 struct gsm_mux *gsm = tty->disc_data;
2332
2333 gsmld_detach_gsm(tty, gsm);
2334
2335 gsmld_flush_buffer(tty);
2336 /* Do other clean up here */
6ab8fba7 2337 mux_put(gsm);
e1eaea46
AC		 2338}
2339
2340/**
2341 * gsmld_open - open an ldisc
2342 * @tty: terminal to open
2343 *
2344 * Called when this line discipline is being attached to the
2345 * terminal device. Can sleep. Called serialized so that no
2346 * other events will occur in parallel. No further open will occur
2347 * until a close.
2348 */
2349
2350static int gsmld_open(struct tty_struct *tty)
2351{
2352 struct gsm_mux *gsm;
5a640967 2353 int ret;
e1eaea46
AC		 2354
2355 if (tty->ops->write == NULL)
2356 return -EINVAL;
2357
2358 /* Attach our ldisc data */
2359 gsm = gsm_alloc_mux();
2360 if (gsm == NULL)
2361 return -ENOMEM;
2362
2363 tty->disc_data = gsm;
2364 tty->receive_room = 65536;
2365
2366 /* Attach the initial passive connection */
2367 gsm->encoding = 1;
5a640967 2368
2369 ret = gsmld_attach_gsm(tty, gsm);
2370 if (ret != 0) {
2371 gsm_cleanup_mux(gsm);
2372 mux_put(gsm);
2373 }
2374 return ret;
e1eaea46
AC		 2375}
2376
2377/**
2378 * gsmld_write_wakeup - asynchronous I/O notifier
2379 * @tty: tty device
2380 *
2381 * Required for the ptys, serial driver etc. since processes
2382 * that attach themselves to the master and rely on ASYNC
2383 * IO must be woken up
2384 */
2385
2386static void gsmld_write_wakeup(struct tty_struct *tty)
2387{
2388 struct gsm_mux *gsm = tty->disc_data;
328be395 2389 unsigned long flags;
e1eaea46
AC		 2390
2391 /* Queue poll */
2392 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
5e44708f 2393 spin_lock_irqsave(&gsm->tx_lock, flags);
e1eaea46 2394 gsm_data_kick(gsm);
328be395 2395 if (gsm->tx_bytes < TX_THRESH_LO) {
e1eaea46 2396 gsm_dlci_data_sweep(gsm);
328be395 2397 }
5e44708f 2398 spin_unlock_irqrestore(&gsm->tx_lock, flags);
e1eaea46
AC		 2399}
2400
2401/**
2402 * gsmld_read - read function for tty
2403 * @tty: tty device
2404 * @file: file object
2405 * @buf: userspace buffer pointer
2406 * @nr: size of I/O
2407 *
2408 * Perform reads for the line discipline. We are guaranteed that the
2409 * line discipline will not be closed under us but we may get multiple
2410 * parallel readers and must handle this ourselves. We may also get
2411 * a hangup. Always called in user context, may sleep.
2412 *
2413 * This code must be sure never to sleep through a hangup.
2414 */
2415
2416static ssize_t gsmld_read(struct tty_struct *tty, struct file *file,
2417 unsigned char __user *buf, size_t nr)
2418{
2419 return -EOPNOTSUPP;
2420}
2421
2422/**
2423 * gsmld_write - write function for tty
2424 * @tty: tty device
2425 * @file: file object
2426 * @buf: userspace buffer pointer
2427 * @nr: size of I/O
2428 *
2429 * Called when the owner of the device wants to send a frame
2430 * itself (or some other control data). The data is transferred
2431 * as-is and must be properly framed and checksummed as appropriate
2432 * by userspace. Frames are either sent whole or not at all as this
2433 * avoids pain user side.
2434 */
2435
2436static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
2437 const unsigned char *buf, size_t nr)
2438{
2439 int space = tty_write_room(tty);
2440 if (space >= nr)
2441 return tty->ops->write(tty, buf, nr);
2442 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
2443 return -ENOBUFS;
2444}
2445
2446/**
2447 * gsmld_poll - poll method for N_GSM0710
2448 * @tty: terminal device
2449 * @file: file accessing it
2450 * @wait: poll table
2451 *
2452 * Called when the line discipline is asked to poll() for data or
2453 * for special events. This code is not serialized with respect to
2454 * other events save open/close.
2455 *
2456 * This code must be sure never to sleep through a hangup.
2457 * Called without the kernel lock held - fine
2458 */
2459
2460static unsigned int gsmld_poll(struct tty_struct *tty, struct file *file,
2461 poll_table *wait)
2462{
2463 unsigned int mask = 0;
2464 struct gsm_mux *gsm = tty->disc_data;
2465
2466 poll_wait(file, &tty->read_wait, wait);
2467 poll_wait(file, &tty->write_wait, wait);
2468 if (tty_hung_up_p(file))
2469 mask |= POLLHUP;
2470 if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0)
2471 mask |= POLLOUT | POLLWRNORM;
2472 if (gsm->dead)
2473 mask |= POLLHUP;
2474 return mask;
2475}
2476
2477static int gsmld_config(struct tty_struct *tty, struct gsm_mux *gsm,
2478 struct gsm_config *c)
2479{
2480 int need_close = 0;
2481 int need_restart = 0;
2482
2483 /* Stuff we don't support yet - UI or I frame transport, windowing */
5f9a31d6 2484 if ((c->adaption != 1 && c->adaption != 2) || c->k)
e1eaea46
AC		 2485 return -EOPNOTSUPP;
2486 /* Check the MRU/MTU range looks sane */
2487 if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8)
2488 return -EINVAL;
2489 if (c->n2 < 3)
2490 return -EINVAL;
2491 if (c->encapsulation > 1) /* Basic, advanced, no I */
2492 return -EINVAL;
2493 if (c->initiator > 1)
2494 return -EINVAL;
2495 if (c->i == 0 || c->i > 2) /* UIH and UI only */
2496 return -EINVAL;
2497 /*
2498 * See what is needed for reconfiguration
2499 */
2500
2501 /* Timing fields */
2502 if (c->t1 != 0 && c->t1 != gsm->t1)
2503 need_restart = 1;
2504 if (c->t2 != 0 && c->t2 != gsm->t2)
2505 need_restart = 1;
2506 if (c->encapsulation != gsm->encoding)
2507 need_restart = 1;
2508 if (c->adaption != gsm->adaption)
2509 need_restart = 1;
2510 /* Requires care */
2511 if (c->initiator != gsm->initiator)
2512 need_close = 1;
2513 if (c->mru != gsm->mru)
2514 need_restart = 1;
2515 if (c->mtu != gsm->mtu)
2516 need_restart = 1;
2517
2518 /*
2519 * Close down what is needed, restart and initiate the new
2520 * configuration
2521 */
2522
2523 if (need_close || need_restart) {
71e07791
SH		 2524 int ret;
2525
2526 ret = gsm_disconnect(gsm);
2527
2528 if (ret)
2529 return ret;
e1eaea46
AC		 2530 }
2531 if (need_restart)
2532 gsm_cleanup_mux(gsm);
2533
2534 gsm->initiator = c->initiator;
2535 gsm->mru = c->mru;
91f78f36 2536 gsm->mtu = c->mtu;
e1eaea46
AC		 2537 gsm->encoding = c->encapsulation;
2538 gsm->adaption = c->adaption;
820e62ef 2539 gsm->n2 = c->n2;
e1eaea46
AC		 2540
2541 if (c->i == 1)
2542 gsm->ftype = UIH;
2543 else if (c->i == 2)
2544 gsm->ftype = UI;
2545
2546 if (c->t1)
2547 gsm->t1 = c->t1;
2548 if (c->t2)
2549 gsm->t2 = c->t2;
2550
2551 /* FIXME: We need to separate activation/deactivation from adding
2552 and removing from the mux array */
2553 if (need_restart)
2554 gsm_activate_mux(gsm);
2555 if (gsm->initiator && need_close)
2556 gsm_dlci_begin_open(gsm->dlci[0]);
2557 return 0;
2558}
2559
2560static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
2561 unsigned int cmd, unsigned long arg)
2562{
2563 struct gsm_config c;
2564 struct gsm_mux *gsm = tty->disc_data;
2565
2566 switch (cmd) {
2567 case GSMIOC_GETCONF:
2568 memset(&c, 0, sizeof(c));
2569 c.adaption = gsm->adaption;
2570 c.encapsulation = gsm->encoding;
2571 c.initiator = gsm->initiator;
2572 c.t1 = gsm->t1;
2573 c.t2 = gsm->t2;
2574 c.t3 = 0; /* Not supported */
2575 c.n2 = gsm->n2;
2576 if (gsm->ftype == UIH)
2577 c.i = 1;
2578 else
2579 c.i = 2;
5f9a31d6 2580 pr_debug("Ftype %d i %d\n", gsm->ftype, c.i);
e1eaea46
AC		 2581 c.mru = gsm->mru;
2582 c.mtu = gsm->mtu;
2583 c.k = 0;
2584 if (copy_to_user((void *)arg, &c, sizeof(c)))
2585 return -EFAULT;
2586 return 0;
2587 case GSMIOC_SETCONF:
2588 if (copy_from_user(&c, (void *)arg, sizeof(c)))
2589 return -EFAULT;
2590 return gsmld_config(tty, gsm, &c);
2591 default:
2592 return n_tty_ioctl_helper(tty, file, cmd, arg);
2593 }
2594}
2595
199e717f
LP		 2596#ifdef CONFIG_COMPAT
2597static long gsmld_compat_ioctl(struct tty_struct *tty, struct file *file,
2598 unsigned int cmd, unsigned long arg)
2599{
2600 return gsmld_ioctl(tty, file, cmd, arg);
2601}
2602#endif
2603
bcd5abe2
RG		 2604/*
2605 * Network interface
2606 *
2607 */
2608
2609static int gsm_mux_net_open(struct net_device *net)
2610{
2611 pr_debug("%s called\n", __func__);
2612 netif_start_queue(net);
2613 return 0;
2614}
2615
2616static int gsm_mux_net_close(struct net_device *net)
2617{
2618 netif_stop_queue(net);
2619 return 0;
2620}
2621
bcd5abe2
RG		 2622static void dlci_net_free(struct gsm_dlci *dlci)
2623{
2624 if (!dlci->net) {
2625 WARN_ON(1);
2626 return;
2627 }
2628 dlci->adaption = dlci->prev_adaption;
2629 dlci->data = dlci->prev_data;
2630 free_netdev(dlci->net);
2631 dlci->net = NULL;
2632}
2633static void net_free(struct kref *ref)
2634{
2635 struct gsm_mux_net *mux_net;
2636 struct gsm_dlci *dlci;
2637
2638 mux_net = container_of(ref, struct gsm_mux_net, ref);
2639 dlci = mux_net->dlci;
2640
2641 if (dlci->net) {
2642 unregister_netdev(dlci->net);
2643 dlci_net_free(dlci);
2644 }
2645}
2646
6ab8fba7
RG		 2647static inline void muxnet_get(struct gsm_mux_net *mux_net)
2648{
2649 kref_get(&mux_net->ref);
2650}
2651
2652static inline void muxnet_put(struct gsm_mux_net *mux_net)
2653{
2654 kref_put(&mux_net->ref, net_free);
2655}
2656
bcd5abe2
RG		 2657static int gsm_mux_net_start_xmit(struct sk_buff *skb,
2658 struct net_device *net)
2659{
5dbc32a8 2660 struct gsm_mux_net *mux_net = netdev_priv(net);
bcd5abe2 2661 struct gsm_dlci *dlci = mux_net->dlci;
6ab8fba7 2662 muxnet_get(mux_net);
bcd5abe2
RG		 2663
2664 skb_queue_head(&dlci->skb_list, skb);
47baf1ad
TK		 2665 net->stats.tx_packets++;
2666 net->stats.tx_bytes += skb->len;
bcd5abe2
RG		 2667 gsm_dlci_data_kick(dlci);
2668 /* And tell the kernel when the last transmit started. */
860e9538 2669 netif_trans_update(net);
6ab8fba7 2670 muxnet_put(mux_net);
bcd5abe2
RG		 2671 return NETDEV_TX_OK;
2672}
2673
2674/* called when a packet did not ack after watchdogtimeout */
2675static void gsm_mux_net_tx_timeout(struct net_device *net)
2676{
2677 /* Tell syslog we are hosed. */
2678 dev_dbg(&net->dev, "Tx timed out.\n");
2679
2680 /* Update statistics */
47baf1ad 2681 net->stats.tx_errors++;
bcd5abe2
RG		 2682}
2683
2684static void gsm_mux_rx_netchar(struct gsm_dlci *dlci,
2685 unsigned char *in_buf, int size)
2686{
2687 struct net_device *net = dlci->net;
2688 struct sk_buff *skb;
5dbc32a8 2689 struct gsm_mux_net *mux_net = netdev_priv(net);
6ab8fba7 2690 muxnet_get(mux_net);
bcd5abe2
RG		 2691
2692 /* Allocate an sk_buff */
2693 skb = dev_alloc_skb(size + NET_IP_ALIGN);
2694 if (!skb) {
2695 /* We got no receive buffer. */
47baf1ad 2696 net->stats.rx_dropped++;
6ab8fba7 2697 muxnet_put(mux_net);
bcd5abe2
RG		 2698 return;
2699 }
2700 skb_reserve(skb, NET_IP_ALIGN);
59ae1d12 2701 skb_put_data(skb, in_buf, size);
bcd5abe2
RG		 2702
2703 skb->dev = net;
75406b3b 2704 skb->protocol = htons(ETH_P_IP);
bcd5abe2
RG		 2705
2706 /* Ship it off to the kernel */
2707 netif_rx(skb);
2708
2709 /* update out statistics */
47baf1ad
TK		 2710 net->stats.rx_packets++;
2711 net->stats.rx_bytes += size;
6ab8fba7 2712 muxnet_put(mux_net);
bcd5abe2
RG		 2713 return;
2714}
2715
bcd5abe2
RG		 2716static void gsm_mux_net_init(struct net_device *net)
2717{
2718 static const struct net_device_ops gsm_netdev_ops = {
2719 .ndo_open = gsm_mux_net_open,
2720 .ndo_stop = gsm_mux_net_close,
2721 .ndo_start_xmit = gsm_mux_net_start_xmit,
2722 .ndo_tx_timeout = gsm_mux_net_tx_timeout,
bcd5abe2
RG		 2723 };
2724
2725 net->netdev_ops = &gsm_netdev_ops;
2726
2727 /* fill in the other fields */
2728 net->watchdog_timeo = GSM_NET_TX_TIMEOUT;
2729 net->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
2730 net->type = ARPHRD_NONE;
2731 net->tx_queue_len = 10;
2732}
2733
2734
2735/* caller holds the dlci mutex */
2736static void gsm_destroy_network(struct gsm_dlci *dlci)
2737{
2738 struct gsm_mux_net *mux_net;
2739
2740 pr_debug("destroy network interface");
2741 if (!dlci->net)
2742 return;
5dbc32a8 2743 mux_net = netdev_priv(dlci->net);
6ab8fba7 2744 muxnet_put(mux_net);
bcd5abe2
RG		 2745}
2746
2747
2748/* caller holds the dlci mutex */
2749static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc)
2750{
2751 char *netname;
2752 int retval = 0;
2753 struct net_device *net;
2754 struct gsm_mux_net *mux_net;
2755
2756 if (!capable(CAP_NET_ADMIN))
2757 return -EPERM;
2758
2759 /* Already in a non tty mode */
2760 if (dlci->adaption > 2)
2761 return -EBUSY;
2762
2763 if (nc->protocol != htons(ETH_P_IP))
2764 return -EPROTONOSUPPORT;
2765
2766 if (nc->adaption != 3 && nc->adaption != 4)
2767 return -EPROTONOSUPPORT;
2768
2769 pr_debug("create network interface");
2770
2771 netname = "gsm%d";
2772 if (nc->if_name[0] != '\0')
2773 netname = nc->if_name;
c835a677
TG		 2774 net = alloc_netdev(sizeof(struct gsm_mux_net), netname,
2775 NET_NAME_UNKNOWN, gsm_mux_net_init);
bcd5abe2
RG		 2776 if (!net) {
2777 pr_err("alloc_netdev failed");
2778 return -ENOMEM;
2779 }
2780 net->mtu = dlci->gsm->mtu;
9c22b4a3
JW		 2781 net->min_mtu = 8;
2782 net->max_mtu = dlci->gsm->mtu;
5dbc32a8 2783 mux_net = netdev_priv(net);
bcd5abe2
RG		 2784 mux_net->dlci = dlci;
2785 kref_init(&mux_net->ref);
2786 strncpy(nc->if_name, net->name, IFNAMSIZ); /* return net name */
2787
2788 /* reconfigure dlci for network */
2789 dlci->prev_adaption = dlci->adaption;
2790 dlci->prev_data = dlci->data;
2791 dlci->adaption = nc->adaption;
2792 dlci->data = gsm_mux_rx_netchar;
2793 dlci->net = net;
2794
2795 pr_debug("register netdev");
2796 retval = register_netdev(net);
2797 if (retval) {
2798 pr_err("network register fail %d\n", retval);
2799 dlci_net_free(dlci);
2800 return retval;
2801 }
2802 return net->ifindex; /* return network index */
2803}
e1eaea46
AC		 2804
2805/* Line discipline for real tty */
d3157b2c 2806static struct tty_ldisc_ops tty_ldisc_packet = {
e1eaea46
AC		 2807 .owner = THIS_MODULE,
2808 .magic = TTY_LDISC_MAGIC,
2809 .name = "n_gsm",
2810 .open = gsmld_open,
2811 .close = gsmld_close,
2812 .flush_buffer = gsmld_flush_buffer,
e1eaea46
AC		 2813 .read = gsmld_read,
2814 .write = gsmld_write,
199e717f
LP		 2815#ifdef CONFIG_COMPAT
2816 .compat_ioctl = gsmld_compat_ioctl,
2817#endif
e1eaea46
AC		 2818 .ioctl = gsmld_ioctl,
2819 .poll = gsmld_poll,
2820 .receive_buf = gsmld_receive_buf,
2821 .write_wakeup = gsmld_write_wakeup
2822};
2823
2824/*
2825 * Virtual tty side
2826 */
2827
2828#define TX_SIZE 512
2829
2830static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk)
2831{
2832 u8 modembits[5];
2833 struct gsm_control *ctrl;
2834 int len = 2;
2835
2836 if (brk)
2837 len++;
2838
2839 modembits[0] = len << 1 | EA; /* Data bytes */
2840 modembits[1] = dlci->addr << 2 | 3; /* DLCI, EA, 1 */
2841 modembits[2] = gsm_encode_modem(dlci) << 1 | EA;
2842 if (brk)
2843 modembits[3] = brk << 4 | 2 | EA; /* Valid, EA */
2844 ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len + 1);
2845 if (ctrl == NULL)
2846 return -ENOMEM;
2847 return gsm_control_wait(dlci->gsm, ctrl);
2848}
2849
2850static int gsm_carrier_raised(struct tty_port *port)
2851{
2852 struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
2853 /* Not yet open so no carrier info */
2854 if (dlci->state != DLCI_OPEN)
2855 return 0;
2856 if (debug & 2)
2857 return 1;
2858 return dlci->modem_rx & TIOCM_CD;
2859}
2860
2861static void gsm_dtr_rts(struct tty_port *port, int onoff)
2862{
2863 struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
2864 unsigned int modem_tx = dlci->modem_tx;
2865 if (onoff)
2866 modem_tx |= TIOCM_DTR | TIOCM_RTS;
2867 else
2868 modem_tx &= ~(TIOCM_DTR | TIOCM_RTS);
2869 if (modem_tx != dlci->modem_tx) {
2870 dlci->modem_tx = modem_tx;
2871 gsmtty_modem_update(dlci, 0);
2872 }
2873}
2874
2875static const struct tty_port_operations gsm_port_ops = {
2876 .carrier_raised = gsm_carrier_raised,
2877 .dtr_rts = gsm_dtr_rts,
9a8e62bc 2878 .destruct = gsm_dlci_free,
e1eaea46
AC		 2879};
2880
86176ed9 2881static int gsmtty_install(struct tty_driver *driver, struct tty_struct *tty)
e1eaea46
AC		 2882{
2883 struct gsm_mux *gsm;
2884 struct gsm_dlci *dlci;
e1eaea46
AC		 2885 unsigned int line = tty->index;
2886 unsigned int mux = line >> 6;
86176ed9
JS		 2887 bool alloc = false;
2888 int ret;
e1eaea46
AC		 2889
2890 line = line & 0x3F;
2891
2892 if (mux >= MAX_MUX)
2893 return -ENXIO;
2894 /* FIXME: we need to lock gsm_mux for lifetimes of ttys eventually */
2895 if (gsm_mux[mux] == NULL)
2896 return -EUNATCH;
2897 if (line == 0 || line > 61) /* 62/63 reserved */
2898 return -ECHRNG;
2899 gsm = gsm_mux[mux];
2900 if (gsm->dead)
2901 return -EL2HLT;
f3c909b4
AI		 2902 /* If DLCI 0 is not yet fully open return an error.
2903 This is ok from a locking
2904 perspective as we don't have to worry about this
2905 if DLCI0 is lost */
dfabf7ff
CB		 2906 mutex_lock(&gsm->mutex);
2907 if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN) {
2908 mutex_unlock(&gsm->mutex);
7e8ac7b2 2909 return -EL2NSYNC;
dfabf7ff 2910 }
e1eaea46 2911 dlci = gsm->dlci[line];
86176ed9
JS		 2912 if (dlci == NULL) {
2913 alloc = true;
e1eaea46 2914 dlci = gsm_dlci_alloc(gsm, line);
86176ed9 2915 }
dfabf7ff
CB		 2916 if (dlci == NULL) {
2917 mutex_unlock(&gsm->mutex);
e1eaea46 2918 return -ENOMEM;
dfabf7ff 2919 }
86176ed9
JS		 2920 ret = tty_port_install(&dlci->port, driver, tty);
2921 if (ret) {
2922 if (alloc)
2923 dlci_put(dlci);
dfabf7ff 2924 mutex_unlock(&gsm->mutex);
86176ed9
JS		 2925 return ret;
2926 }
2927
dfabf7ff
CB		 2928 dlci_get(dlci);
2929 dlci_get(gsm->dlci[0]);
2930 mux_get(gsm);
e1eaea46 2931 tty->driver_data = dlci;
dfabf7ff 2932 mutex_unlock(&gsm->mutex);
86176ed9
JS		 2933
2934 return 0;
2935}
2936
2937static int gsmtty_open(struct tty_struct *tty, struct file *filp)
2938{
2939 struct gsm_dlci *dlci = tty->driver_data;
2940 struct tty_port *port = &dlci->port;
2941
2942 port->count++;
e1eaea46
AC		 2943 tty_port_tty_set(port, tty);
2944
2945 dlci->modem_rx = 0;
2946 /* We could in theory open and close before we wait - eg if we get
2947 a DM straight back. This is ok as that will have caused a hangup */
d41861ca 2948 tty_port_set_initialized(port, 1);
e1eaea46
AC		 2949 /* Start sending off SABM messages */
2950 gsm_dlci_begin_open(dlci);
2951 /* And wait for virtual carrier */
2952 return tty_port_block_til_ready(port, tty, filp);
2953}
2954
2955static void gsmtty_close(struct tty_struct *tty, struct file *filp)
2956{
2957 struct gsm_dlci *dlci = tty->driver_data;
6ab8fba7
RG		 2958 struct gsm_mux *gsm;
2959
e1eaea46
AC		 2960 if (dlci == NULL)
2961 return;
4d9b1090
DB		 2962 if (dlci->state == DLCI_CLOSED)
2963 return;
bcd5abe2
RG		 2964 mutex_lock(&dlci->mutex);
2965 gsm_destroy_network(dlci);
2966 mutex_unlock(&dlci->mutex);
6ab8fba7 2967 gsm = dlci->gsm;
e1eaea46 2968 if (tty_port_close_start(&dlci->port, tty, filp) == 0)
dfabf7ff 2969 return;
e1eaea46 2970 gsm_dlci_begin_close(dlci);
d41861ca
PH		 2971 if (tty_port_initialized(&dlci->port) && C_HUPCL(tty))
2972 tty_port_lower_dtr_rts(&dlci->port);
e1eaea46
AC		 2973 tty_port_close_end(&dlci->port, tty);
2974 tty_port_tty_set(&dlci->port, NULL);
dfabf7ff 2975 return;
e1eaea46
AC		 2976}
2977
2978static void gsmtty_hangup(struct tty_struct *tty)
2979{
2980 struct gsm_dlci *dlci = tty->driver_data;
4d9b1090
DB		 2981 if (dlci->state == DLCI_CLOSED)
2982 return;
e1eaea46
AC		 2983 tty_port_hangup(&dlci->port);
2984 gsm_dlci_begin_close(dlci);
2985}
2986
2987static int gsmtty_write(struct tty_struct *tty, const unsigned char *buf,
2988 int len)
2989{
4d9b1090 2990 int sent;
e1eaea46 2991 struct gsm_dlci *dlci = tty->driver_data;
4d9b1090
DB		 2992 if (dlci->state == DLCI_CLOSED)
2993 return -EINVAL;
e1eaea46 2994 /* Stuff the bytes into the fifo queue */
4d9b1090 2995 sent = kfifo_in_locked(dlci->fifo, buf, len, &dlci->lock);
e1eaea46
AC		 2996 /* Need to kick the channel */
2997 gsm_dlci_data_kick(dlci);
2998 return sent;
2999}
3000
3001static int gsmtty_write_room(struct tty_struct *tty)
3002{
3003 struct gsm_dlci *dlci = tty->driver_data;
4d9b1090
DB		 3004 if (dlci->state == DLCI_CLOSED)
3005 return -EINVAL;
e1eaea46
AC		 3006 return TX_SIZE - kfifo_len(dlci->fifo);
3007}
3008
3009static int gsmtty_chars_in_buffer(struct tty_struct *tty)
3010{
3011 struct gsm_dlci *dlci = tty->driver_data;
4d9b1090
DB		 3012 if (dlci->state == DLCI_CLOSED)
3013 return -EINVAL;
e1eaea46
AC		 3014 return kfifo_len(dlci->fifo);
3015}
3016
3017static void gsmtty_flush_buffer(struct tty_struct *tty)
3018{
3019 struct gsm_dlci *dlci = tty->driver_data;
4d9b1090
DB		 3020 if (dlci->state == DLCI_CLOSED)
3021 return;
e1eaea46
AC		 3022 /* Caution needed: If we implement reliable transport classes
3023 then the data being transmitted can't simply be junked once
3024 it has first hit the stack. Until then we can just blow it
3025 away */
3026 kfifo_reset(dlci->fifo);
3027 /* Need to unhook this DLCI from the transmit queue logic */
3028}
3029
3030static void gsmtty_wait_until_sent(struct tty_struct *tty, int timeout)
3031{
3032 /* The FIFO handles the queue so the kernel will do the right
3033 thing waiting on chars_in_buffer before calling us. No work
3034 to do here */
3035}
3036
60b33c13 3037static int gsmtty_tiocmget(struct tty_struct *tty)
e1eaea46
AC		 3038{
3039 struct gsm_dlci *dlci = tty->driver_data;
4d9b1090
DB		 3040 if (dlci->state == DLCI_CLOSED)
3041 return -EINVAL;
e1eaea46
AC		 3042 return dlci->modem_rx;
3043}
3044
20b9d177 3045static int gsmtty_tiocmset(struct tty_struct *tty,
e1eaea46
AC		 3046 unsigned int set, unsigned int clear)
3047{
3048 struct gsm_dlci *dlci = tty->driver_data;
3049 unsigned int modem_tx = dlci->modem_tx;
3050
4d9b1090
DB		 3051 if (dlci->state == DLCI_CLOSED)
3052 return -EINVAL;
cf16807b 3053 modem_tx &= ~clear;
e1eaea46
AC		 3054 modem_tx |= set;
3055
3056 if (modem_tx != dlci->modem_tx) {
3057 dlci->modem_tx = modem_tx;
3058 return gsmtty_modem_update(dlci, 0);
3059 }
3060 return 0;
3061}
3062
3063
6caa76b7 3064static int gsmtty_ioctl(struct tty_struct *tty,
e1eaea46
AC		 3065 unsigned int cmd, unsigned long arg)
3066{
bcd5abe2
RG		 3067 struct gsm_dlci *dlci = tty->driver_data;
3068 struct gsm_netconfig nc;
3069 int index;
3070
4d9b1090
DB		 3071 if (dlci->state == DLCI_CLOSED)
3072 return -EINVAL;
bcd5abe2
RG		 3073 switch (cmd) {
3074 case GSMIOC_ENABLE_NET:
3075 if (copy_from_user(&nc, (void __user *)arg, sizeof(nc)))
3076 return -EFAULT;
3077 nc.if_name[IFNAMSIZ-1] = '\0';
3078 /* return net interface index or error code */
3079 mutex_lock(&dlci->mutex);
3080 index = gsm_create_network(dlci, &nc);
3081 mutex_unlock(&dlci->mutex);
3082 if (copy_to_user((void __user *)arg, &nc, sizeof(nc)))
3083 return -EFAULT;
3084 return index;
3085 case GSMIOC_DISABLE_NET:
3086 if (!capable(CAP_NET_ADMIN))
3087 return -EPERM;
3088 mutex_lock(&dlci->mutex);
3089 gsm_destroy_network(dlci);
3090 mutex_unlock(&dlci->mutex);
3091 return 0;
3092 default:
3093 return -ENOIOCTLCMD;
3094 }
e1eaea46
AC		 3095}
3096
3097static void gsmtty_set_termios(struct tty_struct *tty, struct ktermios *old)
3098{
4d9b1090
DB		 3099 struct gsm_dlci *dlci = tty->driver_data;
3100 if (dlci->state == DLCI_CLOSED)
3101 return;
e1eaea46
AC		 3102 /* For the moment its fixed. In actual fact the speed information
3103 for the virtual channel can be propogated in both directions by
3104 the RPN control message. This however rapidly gets nasty as we
3105 then have to remap modem signals each way according to whether
3106 our virtual cable is null modem etc .. */
adc8d746 3107 tty_termios_copy_hw(&tty->termios, old);
e1eaea46
AC		 3108}
3109
3110static void gsmtty_throttle(struct tty_struct *tty)
3111{
3112 struct gsm_dlci *dlci = tty->driver_data;
4d9b1090
DB		 3113 if (dlci->state == DLCI_CLOSED)
3114 return;
9db276f8 3115 if (C_CRTSCTS(tty))
e1eaea46
AC		 3116 dlci->modem_tx &= ~TIOCM_DTR;
3117 dlci->throttled = 1;
3118 /* Send an MSC with DTR cleared */
3119 gsmtty_modem_update(dlci, 0);
3120}
3121
3122static void gsmtty_unthrottle(struct tty_struct *tty)
3123{
3124 struct gsm_dlci *dlci = tty->driver_data;
4d9b1090
DB		 3125 if (dlci->state == DLCI_CLOSED)
3126 return;
9db276f8 3127 if (C_CRTSCTS(tty))
e1eaea46
AC		 3128 dlci->modem_tx |= TIOCM_DTR;
3129 dlci->throttled = 0;
3130 /* Send an MSC with DTR set */
3131 gsmtty_modem_update(dlci, 0);
3132}
3133
3134static int gsmtty_break_ctl(struct tty_struct *tty, int state)
3135{
3136 struct gsm_dlci *dlci = tty->driver_data;
3137 int encode = 0; /* Off */
4d9b1090
DB		 3138 if (dlci->state == DLCI_CLOSED)
3139 return -EINVAL;
e1eaea46
AC		 3140
3141 if (state == -1) /* "On indefinitely" - we can't encode this
3142 properly */
3143 encode = 0x0F;
3144 else if (state > 0) {
3145 encode = state / 200; /* mS to encoding */
3146 if (encode > 0x0F)
3147 encode = 0x0F; /* Best effort */
3148 }
3149 return gsmtty_modem_update(dlci, encode);
3150}
3151
8f9cfeed 3152static void gsmtty_cleanup(struct tty_struct *tty)
dfabf7ff
CB		 3153{
3154 struct gsm_dlci *dlci = tty->driver_data;
3155 struct gsm_mux *gsm = dlci->gsm;
3156
3157 dlci_put(dlci);
3158 dlci_put(gsm->dlci[0]);
3159 mux_put(gsm);
dfabf7ff 3160}
e1eaea46
AC		 3161
3162/* Virtual ttys for the demux */
3163static const struct tty_operations gsmtty_ops = {
86176ed9 3164 .install = gsmtty_install,
e1eaea46
AC		 3165 .open = gsmtty_open,
3166 .close = gsmtty_close,
3167 .write = gsmtty_write,
3168 .write_room = gsmtty_write_room,
3169 .chars_in_buffer = gsmtty_chars_in_buffer,
3170 .flush_buffer = gsmtty_flush_buffer,
3171 .ioctl = gsmtty_ioctl,
3172 .throttle = gsmtty_throttle,
3173 .unthrottle = gsmtty_unthrottle,
3174 .set_termios = gsmtty_set_termios,
3175 .hangup = gsmtty_hangup,
3176 .wait_until_sent = gsmtty_wait_until_sent,
3177 .tiocmget = gsmtty_tiocmget,
3178 .tiocmset = gsmtty_tiocmset,
3179 .break_ctl = gsmtty_break_ctl,
8f9cfeed 3180 .cleanup = gsmtty_cleanup,
e1eaea46
AC		 3181};
3182
3183
3184
3185static int __init gsm_init(void)
3186{
3187 /* Fill in our line protocol discipline, and register it */
3188 int status = tty_register_ldisc(N_GSM0710, &tty_ldisc_packet);
3189 if (status != 0) {
5f9a31d6
AC		 3190 pr_err("n_gsm: can't register line discipline (err = %d)\n",
3191 status);
e1eaea46
AC		 3192 return status;
3193 }
3194
3195 gsm_tty_driver = alloc_tty_driver(256);
3196 if (!gsm_tty_driver) {
3197 tty_unregister_ldisc(N_GSM0710);
5f9a31d6 3198 pr_err("gsm_init: tty allocation failed.\n");
e1eaea46
AC		 3199 return -EINVAL;
3200 }
e1eaea46
AC		 3201 gsm_tty_driver->driver_name = "gsmtty";
3202 gsm_tty_driver->name = "gsmtty";
3203 gsm_tty_driver->major = 0; /* Dynamic */
3204 gsm_tty_driver->minor_start = 0;
3205 gsm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
3206 gsm_tty_driver->subtype = SERIAL_TYPE_NORMAL;
3207 gsm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV
5f9a31d6 3208 | TTY_DRIVER_HARDWARE_BREAK;
e1eaea46
AC		 3209 gsm_tty_driver->init_termios = tty_std_termios;
3210 /* Fixme */
3211 gsm_tty_driver->init_termios.c_lflag &= ~ECHO;
3212 tty_set_operations(gsm_tty_driver, &gsmtty_ops);
3213
3214 spin_lock_init(&gsm_mux_lock);
3215
3216 if (tty_register_driver(gsm_tty_driver)) {
3217 put_tty_driver(gsm_tty_driver);
3218 tty_unregister_ldisc(N_GSM0710);
5f9a31d6 3219 pr_err("gsm_init: tty registration failed.\n");
e1eaea46
AC		 3220 return -EBUSY;
3221 }
5f9a31d6
AC		 3222 pr_debug("gsm_init: loaded as %d,%d.\n",
3223 gsm_tty_driver->major, gsm_tty_driver->minor_start);
e1eaea46
AC		 3224 return 0;
3225}
3226
3227static void __exit gsm_exit(void)
3228{
3229 int status = tty_unregister_ldisc(N_GSM0710);
3230 if (status != 0)
5f9a31d6
AC		 3231 pr_err("n_gsm: can't unregister line discipline (err = %d)\n",
3232 status);
e1eaea46
AC		 3233 tty_unregister_driver(gsm_tty_driver);
3234 put_tty_driver(gsm_tty_driver);
e1eaea46
AC		 3235}
3236
3237module_init(gsm_init);
3238module_exit(gsm_exit);
3239
3240
3241MODULE_LICENSE("GPL");
3242MODULE_ALIAS_LDISC(N_GSM0710);
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