diff options
Diffstat (limited to 'drivers/char/n_gsm.c')
| -rw-r--r-- | drivers/char/n_gsm.c | 2763 |
1 files changed, 0 insertions, 2763 deletions
diff --git a/drivers/char/n_gsm.c b/drivers/char/n_gsm.c deleted file mode 100644 index 04ef3ef0a422..000000000000 --- a/drivers/char/n_gsm.c +++ /dev/null @@ -1,2763 +0,0 @@ -/* - * n_gsm.c GSM 0710 tty multiplexor - * Copyright (c) 2009/10 Intel Corporation - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - * - * * THIS IS A DEVELOPMENT SNAPSHOT IT IS NOT A FINAL RELEASE * - * - * TO DO: - * Mostly done: ioctls for setting modes/timing - * Partly done: hooks so you can pull off frames to non tty devs - * Restart DLCI 0 when it closes ? - * Test basic encoding - * Improve the tx engine - * Resolve tx side locking by adding a queue_head and routing - * all control traffic via it - * General tidy/document - * Review the locking/move to refcounts more (mux now moved to an - * alloc/free model ready) - * Use newest tty open/close port helpers and install hooks - * What to do about power functions ? - * Termios setting and negotiation - * Do we need a 'which mux are you' ioctl to correlate mux and tty sets - * - */ - -#include <linux/types.h> -#include <linux/major.h> -#include <linux/errno.h> -#include <linux/signal.h> -#include <linux/fcntl.h> -#include <linux/sched.h> -#include <linux/interrupt.h> -#include <linux/tty.h> -#include <linux/ctype.h> -#include <linux/mm.h> -#include <linux/string.h> -#include <linux/slab.h> -#include <linux/poll.h> -#include <linux/bitops.h> -#include <linux/file.h> -#include <linux/uaccess.h> -#include <linux/module.h> -#include <linux/timer.h> -#include <linux/tty_flip.h> -#include <linux/tty_driver.h> -#include <linux/serial.h> -#include <linux/kfifo.h> -#include <linux/skbuff.h> -#include <linux/gsmmux.h> - -static int debug; -module_param(debug, int, 0600); - -#define T1 (HZ/10) -#define T2 (HZ/3) -#define N2 3 - -/* Use long timers for testing at low speed with debug on */ -#ifdef DEBUG_TIMING -#define T1 HZ -#define T2 (2 * HZ) -#endif - -/* Semi-arbitary buffer size limits. 0710 is normally run with 32-64 byte - limits so this is plenty */ -#define MAX_MRU 512 -#define MAX_MTU 512 - -/* - * Each block of data we have queued to go out is in the form of - * a gsm_msg which holds everything we need in a link layer independant - * format - */ - -struct gsm_msg { - struct gsm_msg *next; - u8 addr; /* DLCI address + flags */ - u8 ctrl; /* Control byte + flags */ - unsigned int len; /* Length of data block (can be zero) */ - unsigned char *data; /* Points into buffer but not at the start */ - unsigned char buffer[0]; -}; - -/* - * Each active data link has a gsm_dlci structure associated which ties - * the link layer to an optional tty (if the tty side is open). To avoid - * complexity right now these are only ever freed up when the mux is - * shut down. - * - * At the moment we don't free DLCI objects until the mux is torn down - * this avoid object life time issues but might be worth review later. - */ - -struct gsm_dlci { - struct gsm_mux *gsm; - int addr; - int state; -#define DLCI_CLOSED 0 -#define DLCI_OPENING 1 /* Sending SABM not seen UA */ -#define DLCI_OPEN 2 /* SABM/UA complete */ -#define DLCI_CLOSING 3 /* Sending DISC not seen UA/DM */ - - /* Link layer */ - spinlock_t lock; /* Protects the internal state */ - struct timer_list t1; /* Retransmit timer for SABM and UA */ - int retries; - /* Uplink tty if active */ - struct tty_port port; /* The tty bound to this DLCI if there is one */ - struct kfifo *fifo; /* Queue fifo for the DLCI */ - struct kfifo _fifo; /* For new fifo API porting only */ - int adaption; /* Adaption layer in use */ - u32 modem_rx; /* Our incoming virtual modem lines */ - u32 modem_tx; /* Our outgoing modem lines */ - int dead; /* Refuse re-open */ - /* Flow control */ - int throttled; /* Private copy of throttle state */ - int constipated; /* Throttle status for outgoing */ - /* Packetised I/O */ - struct sk_buff *skb; /* Frame being sent */ - struct sk_buff_head skb_list; /* Queued frames */ - /* Data handling callback */ - void (*data)(struct gsm_dlci *dlci, u8 *data, int len); -}; - -/* DLCI 0, 62/63 are special or reseved see gsmtty_open */ - -#define NUM_DLCI 64 - -/* - * DLCI 0 is used to pass control blocks out of band of the data - * flow (and with a higher link priority). One command can be outstanding - * at a time and we use this structure to manage them. They are created - * and destroyed by the user context, and updated by the receive paths - * and timers - */ - -struct gsm_control { - u8 cmd; /* Command we are issuing */ - u8 *data; /* Data for the command in case we retransmit */ - int len; /* Length of block for retransmission */ - int done; /* Done flag */ - int error; /* Error if any */ -}; - -/* - * Each GSM mux we have is represented by this structure. If we are - * operating as an ldisc then we use this structure as our ldisc - * state. We need to sort out lifetimes and locking with respect - * to the gsm mux array. For now we don't free DLCI objects that - * have been instantiated until the mux itself is terminated. - * - * To consider further: tty open versus mux shutdown. - */ - -struct gsm_mux { - struct tty_struct *tty; /* The tty our ldisc is bound to */ - spinlock_t lock; - - /* Events on the GSM channel */ - wait_queue_head_t event; - - /* Bits for GSM mode decoding */ - - /* Framing Layer */ - unsigned char *buf; - int state; -#define GSM_SEARCH 0 -#define GSM_START 1 -#define GSM_ADDRESS 2 -#define GSM_CONTROL 3 -#define GSM_LEN 4 -#define GSM_DATA 5 -#define GSM_FCS 6 -#define GSM_OVERRUN 7 - unsigned int len; - unsigned int address; - unsigned int count; - int escape; - int encoding; - u8 control; - u8 fcs; - u8 *txframe; /* TX framing buffer */ - - /* Methods for the receiver side */ - void (*receive)(struct gsm_mux *gsm, u8 ch); - void (*error)(struct gsm_mux *gsm, u8 ch, u8 flag); - /* And transmit side */ - int (*output)(struct gsm_mux *mux, u8 *data, int len); - - /* Link Layer */ - unsigned int mru; - unsigned int mtu; - int initiator; /* Did we initiate connection */ - int dead; /* Has the mux been shut down */ - struct gsm_dlci *dlci[NUM_DLCI]; - int constipated; /* Asked by remote to shut up */ - - spinlock_t tx_lock; - unsigned int tx_bytes; /* TX data outstanding */ -#define TX_THRESH_HI 8192 -#define TX_THRESH_LO 2048 - struct gsm_msg *tx_head; /* Pending data packets */ - struct gsm_msg *tx_tail; - - /* Control messages */ - struct timer_list t2_timer; /* Retransmit timer for commands */ - int cretries; /* Command retry counter */ - struct gsm_control *pending_cmd;/* Our current pending command */ - spinlock_t control_lock; /* Protects the pending command */ - - /* Configuration */ - int adaption; /* 1 or 2 supported */ - u8 ftype; /* UI or UIH */ - int t1, t2; /* Timers in 1/100th of a sec */ - int n2; /* Retry count */ - - /* Statistics (not currently exposed) */ - unsigned long bad_fcs; - unsigned long malformed; - unsigned long io_error; - unsigned long bad_size; - unsigned long unsupported; -}; - - -/* - * Mux objects - needed so that we can translate a tty index into the - * relevant mux and DLCI. - */ - -#define MAX_MUX 4 /* 256 minors */ -static struct gsm_mux *gsm_mux[MAX_MUX]; /* GSM muxes */ -static spinlock_t gsm_mux_lock; - -/* - * This section of the driver logic implements the GSM encodings - * both the basic and the 'advanced'. Reliable transport is not - * supported. - */ - -#define CR 0x02 -#define EA 0x01 -#define PF 0x10 - -/* I is special: the rest are ..*/ -#define RR 0x01 -#define UI 0x03 -#define RNR 0x05 -#define REJ 0x09 -#define DM 0x0F -#define SABM 0x2F -#define DISC 0x43 -#define UA 0x63 -#define UIH 0xEF - -/* Channel commands */ -#define CMD_NSC 0x09 -#define CMD_TEST 0x11 -#define CMD_PSC 0x21 -#define CMD_RLS 0x29 -#define CMD_FCOFF 0x31 -#define CMD_PN 0x41 -#define CMD_RPN 0x49 -#define CMD_FCON 0x51 -#define CMD_CLD 0x61 -#define CMD_SNC 0x69 -#define CMD_MSC 0x71 - -/* Virtual modem bits */ -#define MDM_FC 0x01 -#define MDM_RTC 0x02 -#define MDM_RTR 0x04 -#define MDM_IC 0x20 -#define MDM_DV 0x40 - -#define GSM0_SOF 0xF9 -#define GSM1_SOF 0x7E -#define GSM1_ESCAPE 0x7D -#define GSM1_ESCAPE_BITS 0x20 -#define XON 0x11 -#define XOFF 0x13 - -static const struct tty_port_operations gsm_port_ops; - -/* - * CRC table for GSM 0710 - */ - -static const u8 gsm_fcs8[256] = { - 0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75, - 0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B, - 0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69, - 0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67, - 0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D, - 0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43, - 0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51, - 0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F, - 0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05, - 0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B, - 0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19, - 0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17, - 0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D, - 0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33, - 0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21, - 0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F, - 0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95, - 0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B, - 0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89, - 0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87, - 0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD, - 0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3, - 0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1, - 0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF, - 0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5, - 0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB, - 0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9, - 0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7, - 0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD, - 0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3, - 0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1, - 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF -}; - -#define INIT_FCS 0xFF -#define GOOD_FCS 0xCF - -/** - * gsm_fcs_add - update FCS - * @fcs: Current FCS - * @c: Next data - * - * Update the FCS to include c. Uses the algorithm in the specification - * notes. - */ - -static inline u8 gsm_fcs_add(u8 fcs, u8 c) -{ - return gsm_fcs8[fcs ^ c]; -} - -/** - * gsm_fcs_add_block - update FCS for a block - * @fcs: Current FCS - * @c: buffer of data - * @len: length of buffer - * - * Update the FCS to include c. Uses the algorithm in the specification - * notes. - */ - -static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len) -{ - while (len--) - fcs = gsm_fcs8[fcs ^ *c++]; - return fcs; -} - -/** - * gsm_read_ea - read a byte into an EA - * @val: variable holding value - * c: byte going into the EA - * - * Processes one byte of an EA. Updates the passed variable - * and returns 1 if the EA is now completely read - */ - -static int gsm_read_ea(unsigned int *val, u8 c) -{ - /* Add the next 7 bits into the value */ - *val <<= 7; - *val |= c >> 1; - /* Was this the last byte of the EA 1 = yes*/ - return c & EA; -} - -/** - * gsm_encode_modem - encode modem data bits - * @dlci: DLCI to encode from - * - * Returns the correct GSM encoded modem status bits (6 bit field) for - * the current status of the DLCI and attached tty object - */ - -static u8 gsm_encode_modem(const struct gsm_dlci *dlci) -{ - u8 modembits = 0; - /* FC is true flow control not modem bits */ - if (dlci->throttled) - modembits |= MDM_FC; - if (dlci->modem_tx & TIOCM_DTR) - modembits |= MDM_RTC; - if (dlci->modem_tx & TIOCM_RTS) - modembits |= MDM_RTR; - if (dlci->modem_tx & TIOCM_RI) - modembits |= MDM_IC; - if (dlci->modem_tx & TIOCM_CD) - modembits |= MDM_DV; - return modembits; -} - -/** - * gsm_print_packet - display a frame for debug - * @hdr: header to print before decode - * @addr: address EA from the frame - * @cr: C/R bit from the frame - * @control: control including PF bit - * @data: following data bytes - * @dlen: length of data - * - * Displays a packet in human readable format for debugging purposes. The - * style is based on amateur radio LAP-B dump display. - */ - -static void gsm_print_packet(const char *hdr, int addr, int cr, - u8 control, const u8 *data, int dlen) -{ - if (!(debug & 1)) - return; - - printk(KERN_INFO "%s %d) %c: ", hdr, addr, "RC"[cr]); - - switch (control & ~PF) { - case SABM: - printk(KERN_CONT "SABM"); - break; - case UA: - printk(KERN_CONT "UA"); - break; - case DISC: - printk(KERN_CONT "DISC"); - break; - case DM: - printk(KERN_CONT "DM"); - break; - case UI: - printk(KERN_CONT "UI"); - break; - case UIH: - printk(KERN_CONT "UIH"); - break; - default: - if (!(control & 0x01)) { - printk(KERN_CONT "I N(S)%d N(R)%d", - (control & 0x0E) >> 1, (control & 0xE)>> 5); - } else switch (control & 0x0F) { - case RR: - printk("RR(%d)", (control & 0xE0) >> 5); - break; - case RNR: - printk("RNR(%d)", (control & 0xE0) >> 5); - break; - case REJ: - printk("REJ(%d)", (control & 0xE0) >> 5); - break; - default: - printk(KERN_CONT "[%02X]", control); - } - } - - if (control & PF) - printk(KERN_CONT "(P)"); - else - printk(KERN_CONT "(F)"); - - if (dlen) { - int ct = 0; - while (dlen--) { - if (ct % 8 == 0) - printk(KERN_CONT "\n "); - printk(KERN_CONT "%02X ", *data++); - ct++; - } - } - printk(KERN_CONT "\n"); -} - - -/* - * Link level transmission side - */ - -/** - * gsm_stuff_packet - bytestuff a packet - * @ibuf: input - * @obuf: output - * @len: length of input - * - * Expand a buffer by bytestuffing it. The worst case size change - * is doubling and the caller is responsible for handing out - * suitable sized buffers. - */ - -static int gsm_stuff_frame(const u8 *input, u8 *output, int len) -{ - int olen = 0; - while (len--) { - if (*input == GSM1_SOF || *input == GSM1_ESCAPE - || *input == XON || *input == XOFF) { - *output++ = GSM1_ESCAPE; - *output++ = *input++ ^ GSM1_ESCAPE_BITS; - olen++; - } else - *output++ = *input++; - olen++; - } - return olen; -} - -static void hex_packet(const unsigned char *p, int len) -{ - int i; - for (i = 0; i < len; i++) { - if (i && (i % 16) == 0) - printk("\n"); - printk("%02X ", *p++); - } - printk("\n"); -} - -/** - * gsm_send - send a control frame - * @gsm: our GSM mux - * @addr: address for control frame - * @cr: command/response bit - * @control: control byte including PF bit - * - * Format up and transmit a control frame. These do not go via the - * queueing logic as they should be transmitted ahead of data when - * they are needed. - * - * FIXME: Lock versus data TX path - */ - -static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control) -{ - int len; - u8 cbuf[10]; - u8 ibuf[3]; - - switch (gsm->encoding) { - case 0: - cbuf[0] = GSM0_SOF; - cbuf[1] = (addr << 2) | (cr << 1) | EA; - cbuf[2] = control; - cbuf[3] = EA; /* Length of data = 0 */ - cbuf[4] = 0xFF - gsm_fcs_add_block(INIT_FCS, cbuf + 1, 3); - cbuf[5] = GSM0_SOF; - len = 6; - break; - case 1: - case 2: - /* Control frame + packing (but not frame stuffing) in mode 1 */ - ibuf[0] = (addr << 2) | (cr << 1) | EA; - ibuf[1] = control; - ibuf[2] = 0xFF - gsm_fcs_add_block(INIT_FCS, ibuf, 2); - /* Stuffing may double the size worst case */ - len = gsm_stuff_frame(ibuf, cbuf + 1, 3); - /* Now add the SOF markers */ - cbuf[0] = GSM1_SOF; - cbuf[len + 1] = GSM1_SOF; - /* FIXME: we can omit the lead one in many cases */ - len += 2; - break; - default: - WARN_ON(1); - return; - } - gsm->output(gsm, cbuf, len); - gsm_print_packet("-->", addr, cr, control, NULL, 0); -} - -/** - * gsm_response - send a control response - * @gsm: our GSM mux - * @addr: address for control frame - * @control: control byte including PF bit - * - * Format up and transmit a link level response frame. - */ - -static inline void gsm_response(struct gsm_mux *gsm, int addr, int control) -{ - gsm_send(gsm, addr, 0, control); -} - -/** - * gsm_command - send a control command - * @gsm: our GSM mux - * @addr: address for control frame - * @control: control byte including PF bit - * - * Format up and transmit a link level command frame. - */ - -static inline void gsm_command(struct gsm_mux *gsm, int addr, int control) -{ - gsm_send(gsm, addr, 1, control); -} - -/* Data transmission */ - -#define HDR_LEN 6 /* ADDR CTRL [LEN.2] DATA FCS */ - -/** - * gsm_data_alloc - allocate data frame - * @gsm: GSM mux - * @addr: DLCI address - * @len: length excluding header and FCS - * @ctrl: control byte - * - * Allocate a new data buffer for sending frames with data. Space is left - * at the front for header bytes but that is treated as an implementation - * detail and not for the high level code to use - */ - -static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, - u8 ctrl) -{ - struct gsm_msg *m = kmalloc(sizeof(struct gsm_msg) + len + HDR_LEN, - GFP_ATOMIC); - if (m == NULL) - return NULL; - m->data = m->buffer + HDR_LEN - 1; /* Allow for FCS */ - m->len = len; - m->addr = addr; - m->ctrl = ctrl; - m->next = NULL; - return m; -} - -/** - * gsm_data_kick - poke the queue - * @gsm: GSM Mux - * - * The tty device has called us to indicate that room has appeared in - * the transmit queue. Ram more data into the pipe if we have any - * - * FIXME: lock against link layer control transmissions - */ - -static void gsm_data_kick(struct gsm_mux *gsm) -{ - struct gsm_msg *msg = gsm->tx_head; - int len; - int skip_sof = 0; - - /* FIXME: We need to apply this solely to data messages */ - if (gsm->constipated) - return; - - while (gsm->tx_head != NULL) { - msg = gsm->tx_head; - if (gsm->encoding != 0) { - gsm->txframe[0] = GSM1_SOF; - len = gsm_stuff_frame(msg->data, - gsm->txframe + 1, msg->len); - gsm->txframe[len + 1] = GSM1_SOF; - len += 2; - } else { - gsm->txframe[0] = GSM0_SOF; - memcpy(gsm->txframe + 1 , msg->data, msg->len); - gsm->txframe[msg->len + 1] = GSM0_SOF; - len = msg->len + 2; - } - - if (debug & 4) { - printk("gsm_data_kick: \n"); - hex_packet(gsm->txframe, len); - } - - if (gsm->output(gsm, gsm->txframe + skip_sof, - len - skip_sof) < 0) - break; - /* FIXME: Can eliminate one SOF in many more cases */ - gsm->tx_head = msg->next; - if (gsm->tx_head == NULL) - gsm->tx_tail = NULL; - gsm->tx_bytes -= msg->len; - kfree(msg); - /* For a burst of frames skip the extra SOF within the - burst */ - skip_sof = 1; - } -} - -/** - * __gsm_data_queue - queue a UI or UIH frame - * @dlci: DLCI sending the data - * @msg: message queued - * - * Add data to the transmit queue and try and get stuff moving - * out of the mux tty if not already doing so. The Caller must hold - * the gsm tx lock. - */ - -static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) -{ - struct gsm_mux *gsm = dlci->gsm; - u8 *dp = msg->data; - u8 *fcs = dp + msg->len; - - /* Fill in the header */ - if (gsm->encoding == 0) { - if (msg->len < 128) - *--dp = (msg->len << 1) | EA; - else { - *--dp = (msg->len >> 6) | EA; - *--dp = (msg->len & 127) << 1; - } - } - - *--dp = msg->ctrl; - if (gsm->initiator) - *--dp = (msg->addr << 2) | 2 | EA; - else - *--dp = (msg->addr << 2) | EA; - *fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp); - /* Ugly protocol layering violation */ - if (msg->ctrl == UI || msg->ctrl == (UI|PF)) - *fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len); - *fcs = 0xFF - *fcs; - - gsm_print_packet("Q> ", msg->addr, gsm->initiator, msg->ctrl, - msg->data, msg->len); - - /* Move the header back and adjust the length, also allow for the FCS - now tacked on the end */ - msg->len += (msg->data - dp) + 1; - msg->data = dp; - - /* Add to the actual output queue */ - if (gsm->tx_tail) - gsm->tx_tail->next = msg; - else - gsm->tx_head = msg; - gsm->tx_tail = msg; - gsm->tx_bytes += msg->len; - gsm_data_kick(gsm); -} - -/** - * gsm_data_queue - queue a UI or UIH frame - * @dlci: DLCI sending the data - * @msg: message queued - * - * Add data to the transmit queue and try and get stuff moving - * out of the mux tty if not already doing so. Take the - * the gsm tx lock and dlci lock. - */ - -static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) -{ - unsigned long flags; - spin_lock_irqsave(&dlci->gsm->tx_lock, flags); - __gsm_data_queue(dlci, msg); - spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); -} - -/** - * gsm_dlci_data_output - try and push data out of a DLCI - * @gsm: mux - * @dlci: the DLCI to pull data from - * - * Pull data from a DLCI and send it into the transmit queue if there - * is data. Keep to the MRU of the mux. This path handles the usual tty - * interface which is a byte stream with optional modem data. - * - * Caller must hold the tx_lock of the mux. - */ - -static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci) -{ - struct gsm_msg *msg; - u8 *dp; - int len, size; - int h = dlci->adaption - 1; - - len = kfifo_len(dlci->fifo); - if (len == 0) - return 0; - - /* MTU/MRU count only the data bits */ - if (len > gsm->mtu) - len = gsm->mtu; - - size = len + h; - - msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); - /* FIXME: need a timer or something to kick this so it can't - get stuck with no work outstanding and no buffer free */ - if (msg == NULL) - return -ENOMEM; - dp = msg->data; - switch (dlci->adaption) { - case 1: /* Unstructured */ - break; - case 2: /* Unstructed with modem bits. Always one byte as we never - send inline break data */ - *dp += gsm_encode_modem(dlci); - len--; - break; - } - WARN_ON(kfifo_out_locked(dlci->fifo, dp , len, &dlci->lock) != len); - __gsm_data_queue(dlci, msg); - /* Bytes of data we used up */ - return size; -} - -/** - * gsm_dlci_data_output_framed - try and push data out of a DLCI - * @gsm: mux - * @dlci: the DLCI to pull data from - * - * Pull data from a DLCI and send it into the transmit queue if there - * is data. Keep to the MRU of the mux. This path handles framed data - * queued as skbuffs to the DLCI. - * - * Caller must hold the tx_lock of the mux. - */ - -static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, - struct gsm_dlci *dlci) -{ - struct gsm_msg *msg; - u8 *dp; - int len, size; - int last = 0, first = 0; - int overhead = 0; - - /* One byte per frame is used for B/F flags */ - if (dlci->adaption == 4) - overhead = 1; - - /* dlci->skb is locked by tx_lock */ - if (dlci->skb == NULL) { - dlci->skb = skb_dequeue(&dlci->skb_list); - if (dlci->skb == NULL) - return 0; - first = 1; - } - len = dlci->skb->len + overhead; - - /* MTU/MRU count only the data bits */ - if (len > gsm->mtu) { - if (dlci->adaption == 3) { - /* Over long frame, bin it */ - kfree_skb(dlci->skb); - dlci->skb = NULL; - return 0; - } - len = gsm->mtu; - } else - last = 1; - - size = len + overhead; - msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); - - /* FIXME: need a timer or something to kick this so it can't - get stuck with no work outstanding and no buffer free */ - if (msg == NULL) - return -ENOMEM; - dp = msg->data; - - if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */ - /* Flag byte to carry the start/end info */ - *dp++ = last << 7 | first << 6 | 1; /* EA */ - len--; - } - memcpy(dp, skb_pull(dlci->skb, len), len); - __gsm_data_queue(dlci, msg); - if (last) - dlci->skb = NULL; - return size; -} - -/** - * gsm_dlci_data_sweep - look for data to send - * @gsm: the GSM mux - * - * Sweep the GSM mux channels in priority order looking for ones with - * data to send. We could do with optimising this scan a bit. We aim - * to fill the queue totally or up to TX_THRESH_HI bytes. Once we hit - * TX_THRESH_LO we get called again - * - * FIXME: We should round robin between groups and in theory you can - * renegotiate DLCI priorities with optional stuff. Needs optimising. - */ - -static void gsm_dlci_data_sweep(struct gsm_mux *gsm) -{ - int len; - /* Priority ordering: We should do priority with RR of the groups */ - int i = 1; - - while (i < NUM_DLCI) { - struct gsm_dlci *dlci; - - if (gsm->tx_bytes > TX_THRESH_HI) - break; - dlci = gsm->dlci[i]; - if (dlci == NULL || dlci->constipated) { - i++; - continue; - } - if (dlci->adaption < 3) - len = gsm_dlci_data_output(gsm, dlci); - else - len = gsm_dlci_data_output_framed(gsm, dlci); - if (len < 0) - break; - /* DLCI empty - try the next */ - if (len == 0) - i++; - } -} - -/** - * gsm_dlci_data_kick - transmit if possible - * @dlci: DLCI to kick - * - * Transmit data from this DLCI if the queue is empty. We can't rely on - * a tty wakeup except when we filled the pipe so we need to fire off - * new data ourselves in other cases. - */ - -static void gsm_dlci_data_kick(struct gsm_dlci *dlci) -{ - unsigned long flags; - - spin_lock_irqsave(&dlci->gsm->tx_lock, flags); - /* If we have nothing running then we need to fire up */ - if (dlci->gsm->tx_bytes == 0) - gsm_dlci_data_output(dlci->gsm, dlci); - else if (dlci->gsm->tx_bytes < TX_THRESH_LO) - gsm_dlci_data_sweep(dlci->gsm); - spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); -} - -/* - * Control message processing - */ - - -/** - * gsm_control_reply - send a response frame to a control - * @gsm: gsm channel - * @cmd: the command to use - * @data: data to follow encoded info - * @dlen: length of data - * - * Encode up and queue a UI/UIH frame containing our response. - */ - -static void gsm_control_reply(struct gsm_mux *gsm, int cmd, u8 *data, - int dlen) -{ - struct gsm_msg *msg; - msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype); - msg->data[0] = (cmd & 0xFE) << 1 | EA; /* Clear C/R */ - msg->data[1] = (dlen << 1) | EA; - memcpy(msg->data + 2, data, dlen); - gsm_data_queue(gsm->dlci[0], msg); -} - -/** - * gsm_process_modem - process received modem status - * @tty: virtual tty bound to the DLCI - * @dlci: DLCI to affect - * @modem: modem bits (full EA) - * - * Used when a modem control message or line state inline in adaption - * layer 2 is processed. Sort out the local modem state and throttles - */ - -static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, - u32 modem) -{ - int mlines = 0; - u8 brk = modem >> 6; - - /* Flow control/ready to communicate */ - if (modem & MDM_FC) { - /* Need to throttle our output on this device */ - dlci->constipated = 1; - } - if (modem & MDM_RTC) { - mlines |= TIOCM_DSR | TIOCM_DTR; - dlci->constipated = 0; - gsm_dlci_data_kick(dlci); - } - /* Map modem bits */ - if (modem & MDM_RTR) - mlines |= TIOCM_RTS | TIOCM_CTS; - if (modem & MDM_IC) - mlines |= TIOCM_RI; - if (modem & MDM_DV) - mlines |= TIOCM_CD; - - /* Carrier drop -> hangup */ - if (tty) { - if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD)) - if (!(tty->termios->c_cflag & CLOCAL)) - tty_hangup(tty); - if (brk & 0x01) - tty_insert_flip_char(tty, 0, TTY_BREAK); - } - dlci->modem_rx = mlines; -} - -/** - * gsm_control_modem - modem status received - * @gsm: GSM channel - * @data: data following command - * @clen: command length - * - * We have received a modem status control message. This is used by - * the GSM mux protocol to pass virtual modem line status and optionally - * to indicate break signals. Unpack it, convert to Linux representation - * and if need be stuff a break message down the tty. - */ - -static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen) -{ - unsigned int addr = 0; - unsigned int modem = 0; - struct gsm_dlci *dlci; - int len = clen; - u8 *dp = data; - struct tty_struct *tty; - - while (gsm_read_ea(&addr, *dp++) == 0) { - len--; - if (len == 0) - return; - } - /* Must be at least one byte following the EA */ - len--; - if (len <= 0) - return; - - addr >>= 1; - /* Closed port, or invalid ? */ - if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL) - return; - dlci = gsm->dlci[addr]; - - while (gsm_read_ea(&modem, *dp++) == 0) { - len--; - if (len == 0) - return; - } - tty = tty_port_tty_get(&dlci->port); - gsm_process_modem(tty, dlci, modem); - if (tty) { - tty_wakeup(tty); - tty_kref_put(tty); - } - gsm_control_reply(gsm, CMD_MSC, data, clen); -} - -/** - * gsm_control_rls - remote line status - * @gsm: GSM channel - * @data: data bytes - * @clen: data length - * - * The modem sends us a two byte message on the control channel whenever - * it wishes to send us an error state from the virtual link. Stuff - * this into the uplink tty if present - */ - -static void gsm_control_rls(struct gsm_mux *gsm, u8 *data, int clen) -{ - struct tty_struct *tty; - unsigned int addr = 0 ; - u8 bits; - int len = clen; - u8 *dp = data; - - while (gsm_read_ea(&addr, *dp++) == 0) { - len--; - if (len == 0) - return; - } - /* Must be at least one byte following ea */ - len--; - if (len <= 0) - return; - addr >>= 1; - /* Closed port, or invalid ? */ - if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL) - return; - /* No error ? */ - bits = *dp; - if ((bits & 1) == 0) - return; - /* See if we have an uplink tty */ - tty = tty_port_tty_get(&gsm->dlci[addr]->port); - - if (tty) { - if (bits & 2) - tty_insert_flip_char(tty, 0, TTY_OVERRUN); - if (bits & 4) - tty_insert_flip_char(tty, 0, TTY_PARITY); - if (bits & 8) - tty_insert_flip_char(tty, 0, TTY_FRAME); - tty_flip_buffer_push(tty); - tty_kref_put(tty); - } - gsm_control_reply(gsm, CMD_RLS, data, clen); -} - -static void gsm_dlci_begin_close(struct gsm_dlci *dlci); - -/** - * gsm_control_message - DLCI 0 control processing - * @gsm: our GSM mux - * @command: the command EA - * @data: data beyond the command/length EAs - * @clen: length - * - * Input processor for control messages from the other end of the link. - * Processes the incoming request and queues a response frame or an - * NSC response if not supported - */ - -static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, - u8 *data, int clen) -{ - u8 buf[1]; - switch (command) { - case CMD_CLD: { - struct gsm_dlci *dlci = gsm->dlci[0]; - /* Modem wishes to close down */ - if (dlci) { - dlci->dead = 1; - gsm->dead = 1; - gsm_dlci_begin_close(dlci); - } - } - break; - case CMD_TEST: - /* Modem wishes to test, reply with the data */ - gsm_control_reply(gsm, CMD_TEST, data, clen); - break; - case CMD_FCON: - /* Modem wants us to STFU */ - gsm->constipated = 1; - gsm_control_reply(gsm, CMD_FCON, NULL, 0); - break; - case CMD_FCOFF: - /* Modem can accept data again */ - gsm->constipated = 0; - gsm_control_reply(gsm, CMD_FCOFF, NULL, 0); - /* Kick the link in case it is idling */ - gsm_data_kick(gsm); - break; - case CMD_MSC: - /* Out of band modem line change indicator for a DLCI */ - gsm_control_modem(gsm, data, clen); - break; - case CMD_RLS: - /* Out of band error reception for a DLCI */ - gsm_control_rls(gsm, data, clen); - break; - case CMD_PSC: - /* Modem wishes to enter power saving state */ - gsm_control_reply(gsm, CMD_PSC, NULL, 0); - break; - /* Optional unsupported commands */ - case CMD_PN: /* Parameter negotiation */ - case CMD_RPN: /* Remote port negotation */ - case CMD_SNC: /* Service negotation command */ - default: - /* Reply to bad commands with an NSC */ - buf[0] = command; - gsm_control_reply(gsm, CMD_NSC, buf, 1); - break; - } -} - -/** - * gsm_control_response - process a response to our control - * @gsm: our GSM mux - * @command: the command (response) EA - * @data: data beyond the command/length EA - * @clen: length - * - * Process a response to an outstanding command. We only allow a single - * control message in flight so this is fairly easy. All the clean up - * is done by the caller, we just update the fields, flag it as done - * and return - */ - -static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, - u8 *data, int clen) -{ - struct gsm_control *ctrl; - unsigned long flags; - - spin_lock_irqsave(&gsm->control_lock, flags); - - ctrl = gsm->pending_cmd; - /* Does the reply match our command */ - command |= 1; - if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) { - /* Our command was replied to, kill the retry timer */ - del_timer(&gsm->t2_timer); - gsm->pending_cmd = NULL; - /* Rejected by the other end */ - if (command == CMD_NSC) - ctrl->error = -EOPNOTSUPP; - ctrl->done = 1; - wake_up(&gsm->event); - } - spin_unlock_irqrestore(&gsm->control_lock, flags); -} - -/** - * gsm_control_transmit - send control packet - * @gsm: gsm mux - * @ctrl: frame to send - * - * Send out a pending control command (called under control lock) - */ - -static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl) -{ - struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 1, - gsm->ftype|PF); - if (msg == NULL) - return; - msg->data[0] = (ctrl->cmd << 1) | 2 | EA; /* command */ - memcpy(msg->data + 1, ctrl->data, ctrl->len); - gsm_data_queue(gsm->dlci[0], msg); -} - -/** - * gsm_control_retransmit - retransmit a control frame - * @data: pointer to our gsm object - * - * Called off the T2 timer expiry in order to retransmit control frames - * that have been lost in the system somewhere. The control_lock protects - * us from colliding with another sender or a receive completion event. - * In that situation the timer may still occur in a small window but - * gsm->pending_cmd will be NULL and we just let the timer expire. - */ - -static void gsm_control_retransmit(unsigned long data) -{ - struct gsm_mux *gsm = (struct gsm_mux *)data; - struct gsm_control *ctrl; - unsigned long flags; - spin_lock_irqsave(&gsm->control_lock, flags); - ctrl = gsm->pending_cmd; - if (ctrl) { - gsm->cretries--; - if (gsm->cretries == 0) { - gsm->pending_cmd = NULL; - ctrl->error = -ETIMEDOUT; - ctrl->done = 1; - spin_unlock_irqrestore(&gsm->control_lock, flags); - wake_up(&gsm->event); - return; - } - gsm_control_transmit(gsm, ctrl); - mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); - } - spin_unlock_irqrestore(&gsm->control_lock, flags); -} - -/** - * gsm_control_send - send a control frame on DLCI 0 - * @gsm: the GSM channel - * @command: command to send including CR bit - * @data: bytes of data (must be kmalloced) - * @len: length of the block to send - * - * Queue and dispatch a control command. Only one command can be - * active at a time. In theory more can be outstanding but the matching - * gets really complicated so for now stick to one outstanding. - */ - -static struct gsm_control *gsm_control_send(struct gsm_mux *gsm, - unsigned int command, u8 *data, int clen) -{ - struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control), - GFP_KERNEL); - unsigned long flags; - if (ctrl == NULL) - return NULL; -retry: - wait_event(gsm->event, gsm->pending_cmd == NULL); - spin_lock_irqsave(&gsm->control_lock, flags); - if (gsm->pending_cmd != NULL) { - spin_unlock_irqrestore(&gsm->control_lock, flags); - goto retry; - } - ctrl->cmd = command; - ctrl->data = data; - ctrl->len = clen; - gsm->pending_cmd = ctrl; - gsm->cretries = gsm->n2; - mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); - gsm_control_transmit(gsm, ctrl); - spin_unlock_irqrestore(&gsm->control_lock, flags); - return ctrl; -} - -/** - * gsm_control_wait - wait for a control to finish - * @gsm: GSM mux - * @control: control we are waiting on - * - * Waits for the control to complete or time out. Frees any used - * resources and returns 0 for success, or an error if the remote - * rejected or ignored the request. - */ - -static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control) -{ - int err; - wait_event(gsm->event, control->done == 1); - err = control->error; - kfree(control); - return err; -} - - -/* - * DLCI level handling: Needs krefs - */ - -/* - * State transitions and timers - */ - -/** - * gsm_dlci_close - a DLCI has closed - * @dlci: DLCI that closed - * - * Perform processing when moving a DLCI into closed state. If there - * is an attached tty this is hung up - */ - -static void gsm_dlci_close(struct gsm_dlci *dlci) -{ - del_timer(&dlci->t1); - if (debug & 8) - printk("DLCI %d goes closed.\n", dlci->addr); - dlci->state = DLCI_CLOSED; - if (dlci->addr != 0) { - struct tty_struct *tty = tty_port_tty_get(&dlci->port); - if (tty) { - tty_hangup(tty); - tty_kref_put(tty); - } - kfifo_reset(dlci->fifo); - } else - dlci->gsm->dead = 1; - wake_up(&dlci->gsm->event); - /* A DLCI 0 close is a MUX termination so we need to kick that - back to userspace somehow */ -} - -/** - * gsm_dlci_open - a DLCI has opened - * @dlci: DLCI that opened - * - * Perform processing when moving a DLCI into open state. - */ - -static void gsm_dlci_open(struct gsm_dlci *dlci) -{ - /* Note that SABM UA .. SABM UA first UA lost can mean that we go - open -> open */ - del_timer(&dlci->t1); - /* This will let a tty open continue */ - dlci->state = DLCI_OPEN; - if (debug & 8) - printk("DLCI %d goes open.\n", dlci->addr); - wake_up(&dlci->gsm->event); -} - -/** - * gsm_dlci_t1 - T1 timer expiry - * @dlci: DLCI that opened - * - * The T1 timer handles retransmits of control frames (essentially of - * SABM and DISC). We resend the command until the retry count runs out - * in which case an opening port goes back to closed and a closing port - * is simply put into closed state (any further frames from the other - * end will get a DM response) - */ - -static void gsm_dlci_t1(unsigned long data) -{ - struct gsm_dlci *dlci = (struct gsm_dlci *)data; - struct gsm_mux *gsm = dlci->gsm; - - switch (dlci->state) { - case DLCI_OPENING: - dlci->retries--; - if (dlci->retries) { - gsm_command(dlci->gsm, dlci->addr, SABM|PF); - mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); - } else - gsm_dlci_close(dlci); - break; - case DLCI_CLOSING: - dlci->retries--; - if (dlci->retries) { - gsm_command(dlci->gsm, dlci->addr, DISC|PF); - mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); - } else - gsm_dlci_close(dlci); - break; - } -} - -/** - * gsm_dlci_begin_open - start channel open procedure - * @dlci: DLCI to open - * - * Commence opening a DLCI from the Linux side. We issue SABM messages - * to the modem which should then reply with a UA, at which point we - * will move into open state. Opening is done asynchronously with retry - * running off timers and the responses. - */ - -static void gsm_dlci_begin_open(struct gsm_dlci *dlci) -{ - struct gsm_mux *gsm = dlci->gsm; - if (dlci->state == DLCI_OPEN || dlci->state == DLCI_OPENING) - return; - dlci->retries = gsm->n2; - dlci->state = DLCI_OPENING; - gsm_command(dlci->gsm, dlci->addr, SABM|PF); - mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); -} - -/** - * gsm_dlci_begin_close - start channel open procedure - * @dlci: DLCI to open - * - * Commence closing a DLCI from the Linux side. We issue DISC messages - * to the modem which should then reply with a UA, at which point we - * will move into closed state. Closing is done asynchronously with retry - * off timers. We may also receive a DM reply from the other end which - * indicates the channel was already closed. - */ - -static void gsm_dlci_begin_close(struct gsm_dlci *dlci) -{ - struct gsm_mux *gsm = dlci->gsm; - if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING) - return; - dlci->retries = gsm->n2; - dlci->state = DLCI_CLOSING; - gsm_command(dlci->gsm, dlci->addr, DISC|PF); - mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); -} - -/** - * gsm_dlci_data - data arrived - * @dlci: channel - * @data: block of bytes received - * @len: length of received block - * - * A UI or UIH frame has arrived which contains data for a channel - * other than the control channel. If the relevant virtual tty is - * open we shovel the bits down it, if not we drop them. - */ - -static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int len) -{ - /* krefs .. */ - struct tty_port *port = &dlci->port; - struct tty_struct *tty = tty_port_tty_get(port); - unsigned int modem = 0; - - if (debug & 16) - printk("%d bytes for tty %p\n", len, tty); - if (tty) { - switch (dlci->adaption) { - /* Unsupported types */ - /* Packetised interruptible data */ - case 4: - break; - /* Packetised uininterruptible voice/data */ - case 3: - break; - /* Asynchronous serial with line state in each frame */ - case 2: - while (gsm_read_ea(&modem, *data++) == 0) { - len--; - if (len == 0) - return; - } - gsm_process_modem(tty, dlci, modem); - /* Line state will go via DLCI 0 controls only */ - case 1: - default: - tty_insert_flip_string(tty, data, len); - tty_flip_buffer_push(tty); - } - tty_kref_put(tty); - } -} - -/** - * gsm_dlci_control - data arrived on control channel - * @dlci: channel - * @data: block of bytes received - * @len: length of received block - * - * A UI or UIH frame has arrived which contains data for DLCI 0 the - * control channel. This should contain a command EA followed by - * control data bytes. The command EA contains a command/response bit - * and we divide up the work accordingly. - */ - -static void gsm_dlci_command(struct gsm_dlci *dlci, u8 *data, int len) -{ - /* See what command is involved */ - unsigned int command = 0; - while (len-- > 0) { - if (gsm_read_ea(&command, *data++) == 1) { - int clen = *data++; - len--; - /* FIXME: this is properly an EA */ - clen >>= 1; - /* Malformed command ? */ - if (clen > len) - return; - if (command & 1) - gsm_control_message(dlci->gsm, command, - data, clen); - else - gsm_control_response(dlci->gsm, command, - data, clen); - return; - } - } -} - -/* - * Allocate/Free DLCI channels - */ - -/** - * gsm_dlci_alloc - allocate a DLCI - * @gsm: GSM mux - * @addr: address of the DLCI - * - * Allocate and install a new DLCI object into the GSM mux. - * - * FIXME: review locking races - */ - -static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr) -{ - struct gsm_dlci *dlci = kzalloc(sizeof(struct gsm_dlci), GFP_ATOMIC); - if (dlci == NULL) - return NULL; - spin_lock_init(&dlci->lock); - dlci->fifo = &dlci->_fifo; - if (kfifo_alloc(&dlci->_fifo, 4096, GFP_KERNEL) < 0) { - kfree(dlci); - return NULL; - } - - skb_queue_head_init(&dlci->skb_list); - init_timer(&dlci->t1); - dlci->t1.function = gsm_dlci_t1; - dlci->t1.data = (unsigned long)dlci; - tty_port_init(&dlci->port); - dlci->port.ops = &gsm_port_ops; - dlci->gsm = gsm; - dlci->addr = addr; - dlci->adaption = gsm->adaption; - dlci->state = DLCI_CLOSED; - if (addr) - dlci->data = gsm_dlci_data; - else - dlci->data = gsm_dlci_command; - gsm->dlci[addr] = dlci; - return dlci; -} - -/** - * gsm_dlci_free - release DLCI - * @dlci: DLCI to destroy - * - * Free up a DLCI. Currently to keep the lifetime rules sane we only - * clean up DLCI objects when the MUX closes rather than as the port - * is closed down on both the tty and mux levels. - * - * Can sleep. - */ -static void gsm_dlci_free(struct gsm_dlci *dlci) -{ - struct tty_struct *tty = tty_port_tty_get(&dlci->port); - if (tty) { - tty_vhangup(tty); - tty_kref_put(tty); - } - del_timer_sync(&dlci->t1); - dlci->gsm->dlci[dlci->addr] = NULL; - kfifo_free(dlci->fifo); - kfree(dlci); -} - - -/* - * LAPBish link layer logic - */ - -/** - * gsm_queue - a GSM frame is ready to process - * @gsm: pointer to our gsm mux - * - * At this point in time a frame has arrived and been demangled from - * the line encoding. All the differences between the encodings have - * been handled below us and the frame is unpacked into the structures. - * The fcs holds the header FCS but any data FCS must be added here. - */ - -static void gsm_queue(struct gsm_mux *gsm) -{ - struct gsm_dlci *dlci; - u8 cr; - int address; - /* We have to sneak a look at the packet body to do the FCS. - A somewhat layering violation in the spec */ - - if ((gsm->control & ~PF) == UI) - gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len); - if (gsm->fcs != GOOD_FCS) { - gsm->bad_fcs++; - if (debug & 4) - printk("BAD FCS %02x\n", gsm->fcs); - return; - } - address = gsm->address >> 1; - if (address >= NUM_DLCI) - goto invalid; - - cr = gsm->address & 1; /* C/R bit */ - - gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len); - - cr ^= 1 - gsm->initiator; /* Flip so 1 always means command */ - dlci = gsm->dlci[address]; - - switch (gsm->control) { - case SABM|PF: - if (cr == 0) - goto invalid; - if (dlci == NULL) - dlci = gsm_dlci_alloc(gsm, address); - if (dlci == NULL) - return; - if (dlci->dead) - gsm_response(gsm, address, DM); - else { - gsm_response(gsm, address, UA); - gsm_dlci_open(dlci); - } - break; - case DISC|PF: - if (cr == 0) - goto invalid; - if (dlci == NULL || dlci->state == DLCI_CLOSED) { - gsm_response(gsm, address, DM); - return; - } - /* Real close complete */ - gsm_response(gsm, address, UA); - gsm_dlci_close(dlci); - break; - case UA: - case UA|PF: - if (cr == 0 || dlci == NULL) - break; - switch (dlci->state) { - case DLCI_CLOSING: - gsm_dlci_close(dlci); - break; - case DLCI_OPENING: - gsm_dlci_open(dlci); - break; - } - break; - case DM: /* DM can be valid unsolicited */ - case DM|PF: - if (cr) - goto invalid; - if (dlci == NULL) - return; - gsm_dlci_close(dlci); - break; - case UI: - case UI|PF: - case UIH: - case UIH|PF: -#if 0 - if (cr) - goto invalid; -#endif - if (dlci == NULL || dlci->state != DLCI_OPEN) { - gsm_command(gsm, address, DM|PF); - return; - } - dlci->data(dlci, gsm->buf, gsm->len); - break; - default: - goto invalid; - } - return; -invalid: - gsm->malformed++; - return; -} - - -/** - * gsm0_receive - perform processing for non-transparency - * @gsm: gsm data for this ldisc instance - * @c: character - * - * Receive bytes in gsm mode 0 - */ - -static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) -{ - switch (gsm->state) { - case GSM_SEARCH: /* SOF marker */ - if (c == GSM0_SOF) { - gsm->state = GSM_ADDRESS; - gsm->address = 0; - gsm->len = 0; - gsm->fcs = INIT_FCS; - } - break; /* Address EA */ - case GSM_ADDRESS: - gsm->fcs = gsm_fcs_add(gsm->fcs, c); - if (gsm_read_ea(&gsm->address, c)) - gsm->state = GSM_CONTROL; - break; - case GSM_CONTROL: /* Control Byte */ - gsm->fcs = gsm_fcs_add(gsm->fcs, c); - gsm->control = c; - gsm->state = GSM_LEN; - break; - case GSM_LEN: /* Length EA */ - gsm->fcs = gsm_fcs_add(gsm->fcs, c); - if (gsm_read_ea(&gsm->len, c)) { - if (gsm->len > gsm->mru) { - gsm->bad_size++; - gsm->state = GSM_SEARCH; - break; - } - gsm->count = 0; - gsm->state = GSM_DATA; - } - break; - case GSM_DATA: /* Data */ - gsm->buf[gsm->count++] = c; - if (gsm->count == gsm->len) - gsm->state = GSM_FCS; - break; - case GSM_FCS: /* FCS follows the packet */ - gsm->fcs = c; - gsm_queue(gsm); - /* And then back for the next frame */ - gsm->state = GSM_SEARCH; - break; - } -} - -/** - * gsm0_receive - perform processing for non-transparency - * @gsm: gsm data for this ldisc instance - * @c: character - * - * Receive bytes in mode 1 (Advanced option) - */ - -static void gsm1_receive(struct gsm_mux *gsm, unsigned char c) -{ - if (c == GSM1_SOF) { - /* EOF is only valid in frame if we have got to the data state - and received at least one byte (the FCS) */ - if (gsm->state == GSM_DATA && gsm->count) { - /* Extract the FCS */ - gsm->count--; - gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]); - gsm->len = gsm->count; - gsm_queue(gsm); - gsm->state = GSM_START; - return; - } - /* Any partial frame was a runt so go back to start */ - if (gsm->state != GSM_START) { - gsm->malformed++; - gsm->state = GSM_START; - } - /* A SOF in GSM_START means we are still reading idling or - framing bytes */ - return; - } - - if (c == GSM1_ESCAPE) { - gsm->escape = 1; - return; - } - - /* Only an unescaped SOF gets us out of GSM search */ - if (gsm->state == GSM_SEARCH) - return; - - if (gsm->escape) { - c ^= GSM1_ESCAPE_BITS; - gsm->escape = 0; - } - switch (gsm->state) { - case GSM_START: /* First byte after SOF */ - gsm->address = 0; - gsm->state = GSM_ADDRESS; - gsm->fcs = INIT_FCS; - /* Drop through */ - case GSM_ADDRESS: /* Address continuation */ - gsm->fcs = gsm_fcs_add(gsm->fcs, c); - if (gsm_read_ea(&gsm->address, c)) - gsm->state = GSM_CONTROL; - break; - case GSM_CONTROL: /* Control Byte */ - gsm->fcs = gsm_fcs_add(gsm->fcs, c); - gsm->control = c; - gsm->count = 0; - gsm->state = GSM_DATA; - break; - case GSM_DATA: /* Data */ - if (gsm->count > gsm->mru ) { /* Allow one for the FCS */ - gsm->state = GSM_OVERRUN; - gsm->bad_size++; - } else - gsm->buf[gsm->count++] = c; - break; - case GSM_OVERRUN: /* Over-long - eg a dropped SOF */ - break; - } -} - -/** - * gsm_error - handle tty error - * @gsm: ldisc data - * @data: byte received (may be invalid) - * @flag: error received - * - * Handle an error in the receipt of data for a frame. Currently we just - * go back to hunting for a SOF. - * - * FIXME: better diagnostics ? - */ - -static void gsm_error(struct gsm_mux *gsm, - unsigned char data, unsigned char flag) -{ - gsm->state = GSM_SEARCH; - gsm->io_error++; -} - -/** - * gsm_cleanup_mux - generic GSM protocol cleanup - * @gsm: our mux - * - * Clean up the bits of the mux which are the same for all framing - * protocols. Remove the mux from the mux table, stop all the timers - * and then shut down each device hanging up the channels as we go. - */ - -void gsm_cleanup_mux(struct gsm_mux *gsm) -{ - int i; - struct gsm_dlci *dlci = gsm->dlci[0]; - struct gsm_msg *txq; - - gsm->dead = 1; - - spin_lock(&gsm_mux_lock); - for (i = 0; i < MAX_MUX; i++) { - if (gsm_mux[i] == gsm) { - gsm_mux[i] = NULL; - break; - } - } - spin_unlock(&gsm_mux_lock); - WARN_ON(i == MAX_MUX); - - del_timer_sync(&gsm->t2_timer); - /* Now we are sure T2 has stopped */ - if (dlci) { - dlci->dead = 1; - gsm_dlci_begin_close(dlci); - wait_event_interruptible(gsm->event, - dlci->state == DLCI_CLOSED); - } - /* Free up any link layer users */ - for (i = 0; i < NUM_DLCI; i++) - if (gsm->dlci[i]) - gsm_dlci_free(gsm->dlci[i]); - /* Now wipe the queues */ - for (txq = gsm->tx_head; txq != NULL; txq = gsm->tx_head) { - gsm->tx_head = txq->next; - kfree(txq); - } - gsm->tx_tail = NULL; -} -EXPORT_SYMBOL_GPL(gsm_cleanup_mux); - -/** - * gsm_activate_mux - generic GSM setup - * @gsm: our mux - * - * Set up the bits of the mux which are the same for all framing - * protocols. Add the mux to the mux table so it can be opened and - * finally kick off connecting to DLCI 0 on the modem. - */ - -int gsm_activate_mux(struct gsm_mux *gsm) -{ - struct gsm_dlci *dlci; - int i = 0; - - init_timer(&gsm->t2_timer); - gsm->t2_timer.function = gsm_control_retransmit; - gsm->t2_timer.data = (unsigned long)gsm; - init_waitqueue_head(&gsm->event); - spin_lock_init(&gsm->control_lock); - spin_lock_init(&gsm->tx_lock); - - if (gsm->encoding == 0) - gsm->receive = gsm0_receive; - else - gsm->receive = gsm1_receive; - gsm->error = gsm_error; - - spin_lock(&gsm_mux_lock); - for (i = 0; i < MAX_MUX; i++) { - if (gsm_mux[i] == NULL) { - gsm_mux[i] = gsm; - break; - } - } - spin_unlock(&gsm_mux_lock); - if (i == MAX_MUX) - return -EBUSY; - - dlci = gsm_dlci_alloc(gsm, 0); - if (dlci == NULL) - return -ENOMEM; - gsm->dead = 0; /* Tty opens are now permissible */ - return 0; -} -EXPORT_SYMBOL_GPL(gsm_activate_mux); - -/** - * gsm_free_mux - free up a mux - * @mux: mux to free - * - * Dispose of allocated resources for a dead mux. No refcounting - * at present so the mux must be truely dead. - */ -void gsm_free_mux(struct gsm_mux *gsm) -{ - kfree(gsm->txframe); - kfree(gsm->buf); - kfree(gsm); -} -EXPORT_SYMBOL_GPL(gsm_free_mux); - -/** - * gsm_alloc_mux - allocate a mux - * - * Creates a new mux ready for activation. - */ - -struct gsm_mux *gsm_alloc_mux(void) -{ - struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL); - if (gsm == NULL) - return NULL; - gsm->buf = kmalloc(MAX_MRU + 1, GFP_KERNEL); - if (gsm->buf == NULL) { - kfree(gsm); - return NULL; - } - gsm->txframe = kmalloc(2 * MAX_MRU + 2, GFP_KERNEL); - if (gsm->txframe == NULL) { - kfree(gsm->buf); - kfree(gsm); - return NULL; - } - spin_lock_init(&gsm->lock); - - gsm->t1 = T1; - gsm->t2 = T2; - gsm->n2 = N2; - gsm->ftype = UIH; - gsm->initiator = 0; - gsm->adaption = 1; - gsm->encoding = 1; - gsm->mru = 64; /* Default to encoding 1 so these should be 64 */ - gsm->mtu = 64; - gsm->dead = 1; /* Avoid early tty opens */ - - return gsm; -} -EXPORT_SYMBOL_GPL(gsm_alloc_mux); - - - - -/** - * gsmld_output - write to link - * @gsm: our mux - * @data: bytes to output - * @len: size - * - * Write a block of data from the GSM mux to the data channel. This - * will eventually be serialized from above but at the moment isn't. - */ - -static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len) -{ - if (tty_write_room(gsm->tty) < len) { - set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags); - return -ENOSPC; - } - if (debug & 4) { - printk("-->%d bytes out\n", len); - hex_packet(data, len); - } - gsm->tty->ops->write(gsm->tty, data, len); - return len; -} - -/** - * gsmld_attach_gsm - mode set up - * @tty: our tty structure - * @gsm: our mux - * - * Set up the MUX for basic mode and commence connecting to the - * modem. Currently called from the line discipline set up but - * will need moving to an ioctl path. - */ - -static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) -{ - int ret; - - gsm->tty = tty_kref_get(tty); - gsm->output = gsmld_output; - ret = gsm_activate_mux(gsm); - if (ret != 0) - tty_kref_put(gsm->tty); - return ret; -} - - -/** - * gsmld_detach_gsm - stop doing 0710 mux - * @tty: tty atttached to the mux - * @gsm: mux - * - * Shutdown and then clean up the resources used by the line discipline - */ - -static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) -{ - WARN_ON(tty != gsm->tty); - gsm_cleanup_mux(gsm); - tty_kref_put(gsm->tty); - gsm->tty = NULL; -} - -static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp, - char *fp, int count) -{ - struct gsm_mux *gsm = tty->disc_data; - const unsigned char *dp; - char *f; - int i; - char buf[64]; - char flags; - - if (debug & 4) { - printk("Inbytes %dd\n", count); - hex_packet(cp, count); - } - - for (i = count, dp = cp, f = fp; i; i--, dp++) { - flags = *f++; - switch (flags) { - case TTY_NORMAL: - gsm->receive(gsm, *dp); - break; - case TTY_OVERRUN: - case TTY_BREAK: - case TTY_PARITY: - case TTY_FRAME: - gsm->error(gsm, *dp, flags); - break; - default: - printk(KERN_ERR "%s: unknown flag %d\n", - tty_name(tty, buf), flags); - break; - } - } - /* FASYNC if needed ? */ - /* If clogged call tty_throttle(tty); */ -} - -/** - * gsmld_chars_in_buffer - report available bytes - * @tty: tty device - * - * Report the number of characters buffered to be delivered to user - * at this instant in time. - * - * Locking: gsm lock - */ - -static ssize_t gsmld_chars_in_buffer(struct tty_struct *tty) -{ - return 0; -} - -/** - * gsmld_flush_buffer - clean input queue - * @tty: terminal device - * - * Flush the input buffer. Called when the line discipline is - * being closed, when the tty layer wants the buffer flushed (eg - * at hangup). - */ - -static void gsmld_flush_buffer(struct tty_struct *tty) -{ -} - -/** - * gsmld_close - close the ldisc for this tty - * @tty: device - * - * Called from the terminal layer when this line discipline is - * being shut down, either because of a close or becsuse of a - * discipline change. The function will not be called while other - * ldisc methods are in progress. - */ - -static void gsmld_close(struct tty_struct *tty) -{ - struct gsm_mux *gsm = tty->disc_data; - - gsmld_detach_gsm(tty, gsm); - - gsmld_flush_buffer(tty); - /* Do other clean up here */ - gsm_free_mux(gsm); -} - -/** - * gsmld_open - open an ldisc - * @tty: terminal to open - * - * Called when this line discipline is being attached to the - * terminal device. Can sleep. Called serialized so that no - * other events will occur in parallel. No further open will occur - * until a close. - */ - -static int gsmld_open(struct tty_struct *tty) -{ - struct gsm_mux *gsm; - - if (tty->ops->write == NULL) - return -EINVAL; - - /* Attach our ldisc data */ - gsm = gsm_alloc_mux(); - if (gsm == NULL) - return -ENOMEM; - - tty->disc_data = gsm; - tty->receive_room = 65536; - - /* Attach the initial passive connection */ - gsm->encoding = 1; - return gsmld_attach_gsm(tty, gsm); -} - -/** - * gsmld_write_wakeup - asynchronous I/O notifier - * @tty: tty device - * - * Required for the ptys, serial driver etc. since processes - * that attach themselves to the master and rely on ASYNC - * IO must be woken up - */ - -static void gsmld_write_wakeup(struct tty_struct *tty) -{ - struct gsm_mux *gsm = tty->disc_data; - unsigned long flags; - - /* Queue poll */ - clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); - gsm_data_kick(gsm); - if (gsm->tx_bytes < TX_THRESH_LO) { - spin_lock_irqsave(&gsm->tx_lock, flags); - gsm_dlci_data_sweep(gsm); - spin_unlock_irqrestore(&gsm->tx_lock, flags); - } -} - -/** - * gsmld_read - read function for tty - * @tty: tty device - * @file: file object - * @buf: userspace buffer pointer - * @nr: size of I/O - * - * Perform reads for the line discipline. We are guaranteed that the - * line discipline will not be closed under us but we may get multiple - * parallel readers and must handle this ourselves. We may also get - * a hangup. Always called in user context, may sleep. - * - * This code must be sure never to sleep through a hangup. - */ - -static ssize_t gsmld_read(struct tty_struct *tty, struct file *file, - unsigned char __user *buf, size_t nr) -{ - return -EOPNOTSUPP; -} - -/** - * gsmld_write - write function for tty - * @tty: tty device - * @file: file object - * @buf: userspace buffer pointer - * @nr: size of I/O - * - * Called when the owner of the device wants to send a frame - * itself (or some other control data). The data is transferred - * as-is and must be properly framed and checksummed as appropriate - * by userspace. Frames are either sent whole or not at all as this - * avoids pain user side. - */ - -static ssize_t gsmld_write(struct tty_struct *tty, struct file *file, - const unsigned char *buf, size_t nr) -{ - int space = tty_write_room(tty); - if (space >= nr) - return tty->ops->write(tty, buf, nr); - set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); - return -ENOBUFS; -} - -/** - * gsmld_poll - poll method for N_GSM0710 - * @tty: terminal device - * @file: file accessing it - * @wait: poll table - * - * Called when the line discipline is asked to poll() for data or - * for special events. This code is not serialized with respect to - * other events save open/close. - * - * This code must be sure never to sleep through a hangup. - * Called without the kernel lock held - fine - */ - -static unsigned int gsmld_poll(struct tty_struct *tty, struct file *file, - poll_table *wait) -{ - unsigned int mask = 0; - struct gsm_mux *gsm = tty->disc_data; - - poll_wait(file, &tty->read_wait, wait); - poll_wait(file, &tty->write_wait, wait); - if (tty_hung_up_p(file)) - mask |= POLLHUP; - if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0) - mask |= POLLOUT | POLLWRNORM; - if (gsm->dead) - mask |= POLLHUP; - return mask; -} - -static int gsmld_config(struct tty_struct *tty, struct gsm_mux *gsm, - struct gsm_config *c) -{ - int need_close = 0; - int need_restart = 0; - - /* Stuff we don't support yet - UI or I frame transport, windowing */ - if ((c->adaption !=1 && c->adaption != 2) || c->k) - return -EOPNOTSUPP; - /* Check the MRU/MTU range looks sane */ - if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8) - return -EINVAL; - if (c->n2 < 3) - return -EINVAL; - if (c->encapsulation > 1) /* Basic, advanced, no I */ - return -EINVAL; - if (c->initiator > 1) - return -EINVAL; - if (c->i == 0 || c->i > 2) /* UIH and UI only */ - return -EINVAL; - /* - * See what is needed for reconfiguration - */ - - /* Timing fields */ - if (c->t1 != 0 && c->t1 != gsm->t1) - need_restart = 1; - if (c->t2 != 0 && c->t2 != gsm->t2) - need_restart = 1; - if (c->encapsulation != gsm->encoding) - need_restart = 1; - if (c->adaption != gsm->adaption) - need_restart = 1; - /* Requires care */ - if (c->initiator != gsm->initiator) - need_close = 1; - if (c->mru != gsm->mru) - need_restart = 1; - if (c->mtu != gsm->mtu) - need_restart = 1; - - /* - * Close down what is needed, restart and initiate the new - * configuration - */ - - if (need_close || need_restart) { - gsm_dlci_begin_close(gsm->dlci[0]); - /* This will timeout if the link is down due to N2 expiring */ - wait_event_interruptible(gsm->event, - gsm->dlci[0]->state == DLCI_CLOSED); - if (signal_pending(current)) - return -EINTR; - } - if (need_restart) - gsm_cleanup_mux(gsm); - - gsm->initiator = c->initiator; - gsm->mru = c->mru; - gsm->encoding = c->encapsulation; - gsm->adaption = c->adaption; - - if (c->i == 1) - gsm->ftype = UIH; - else if (c->i == 2) - gsm->ftype = UI; - - if (c->t1) - gsm->t1 = c->t1; - if (c->t2) - gsm->t2 = c->t2; - - /* FIXME: We need to separate activation/deactivation from adding - and removing from the mux array */ - if (need_restart) - gsm_activate_mux(gsm); - if (gsm->initiator && need_close) - gsm_dlci_begin_open(gsm->dlci[0]); - return 0; -} - -static int gsmld_ioctl(struct tty_struct *tty, struct file *file, - unsigned int cmd, unsigned long arg) -{ - struct gsm_config c; - struct gsm_mux *gsm = tty->disc_data; - - switch (cmd) { - case GSMIOC_GETCONF: - memset(&c, 0, sizeof(c)); - c.adaption = gsm->adaption; - c.encapsulation = gsm->encoding; - c.initiator = gsm->initiator; - c.t1 = gsm->t1; - c.t2 = gsm->t2; - c.t3 = 0; /* Not supported */ - c.n2 = gsm->n2; - if (gsm->ftype == UIH) - c.i = 1; - else - c.i = 2; - printk("Ftype %d i %d\n", gsm->ftype, c.i); - c.mru = gsm->mru; - c.mtu = gsm->mtu; - c.k = 0; - if (copy_to_user((void *)arg, &c, sizeof(c))) - return -EFAULT; - return 0; - case GSMIOC_SETCONF: - if (copy_from_user(&c, (void *)arg, sizeof(c))) - return -EFAULT; - return gsmld_config(tty, gsm, &c); - default: - return n_tty_ioctl_helper(tty, file, cmd, arg); - } -} - - -/* Line discipline for real tty */ -struct tty_ldisc_ops tty_ldisc_packet = { - .owner = THIS_MODULE, - .magic = TTY_LDISC_MAGIC, - .name = "n_gsm", - .open = gsmld_open, - .close = gsmld_close, - .flush_buffer = gsmld_flush_buffer, - .chars_in_buffer = gsmld_chars_in_buffer, - .read = gsmld_read, - .write = gsmld_write, - .ioctl = gsmld_ioctl, - .poll = gsmld_poll, - .receive_buf = gsmld_receive_buf, - .write_wakeup = gsmld_write_wakeup -}; - -/* - * Virtual tty side - */ - -#define TX_SIZE 512 - -static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk) -{ - u8 modembits[5]; - struct gsm_control *ctrl; - int len = 2; - - if (brk) - len++; - - modembits[0] = len << 1 | EA; /* Data bytes */ - modembits[1] = dlci->addr << 2 | 3; /* DLCI, EA, 1 */ - modembits[2] = gsm_encode_modem(dlci) << 1 | EA; - if (brk) - modembits[3] = brk << 4 | 2 | EA; /* Valid, EA */ - ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len + 1); - if (ctrl == NULL) - return -ENOMEM; - return gsm_control_wait(dlci->gsm, ctrl); -} - -static int gsm_carrier_raised(struct tty_port *port) -{ - struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); - /* Not yet open so no carrier info */ - if (dlci->state != DLCI_OPEN) - return 0; - if (debug & 2) - return 1; - return dlci->modem_rx & TIOCM_CD; -} - -static void gsm_dtr_rts(struct tty_port *port, int onoff) -{ - struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); - unsigned int modem_tx = dlci->modem_tx; - if (onoff) - modem_tx |= TIOCM_DTR | TIOCM_RTS; - else - modem_tx &= ~(TIOCM_DTR | TIOCM_RTS); - if (modem_tx != dlci->modem_tx) { - dlci->modem_tx = modem_tx; - gsmtty_modem_update(dlci, 0); - } -} - -static const struct tty_port_operations gsm_port_ops = { - .carrier_raised = gsm_carrier_raised, - .dtr_rts = gsm_dtr_rts, -}; - - -static int gsmtty_open(struct tty_struct *tty, struct file *filp) -{ - struct gsm_mux *gsm; - struct gsm_dlci *dlci; - struct tty_port *port; - unsigned int line = tty->index; - unsigned int mux = line >> 6; - - line = line & 0x3F; - - if (mux >= MAX_MUX) - return -ENXIO; - /* FIXME: we need to lock gsm_mux for lifetimes of ttys eventually */ - if (gsm_mux[mux] == NULL) - return -EUNATCH; - if (line == 0 || line > 61) /* 62/63 reserved */ - return -ECHRNG; - gsm = gsm_mux[mux]; - if (gsm->dead) - return -EL2HLT; - dlci = gsm->dlci[line]; - if (dlci == NULL) - dlci = gsm_dlci_alloc(gsm, line); - if (dlci == NULL) - return -ENOMEM; - port = &dlci->port; - port->count++; - tty->driver_data = dlci; - tty_port_tty_set(port, tty); - - dlci->modem_rx = 0; - /* We could in theory open and close before we wait - eg if we get - a DM straight back. This is ok as that will have caused a hangup */ - set_bit(ASYNCB_INITIALIZED, &port->flags); - /* Start sending off SABM messages */ - gsm_dlci_begin_open(dlci); - /* And wait for virtual carrier */ - return tty_port_block_til_ready(port, tty, filp); -} - -static void gsmtty_close(struct tty_struct *tty, struct file *filp) -{ - struct gsm_dlci *dlci = tty->driver_data; - if (dlci == NULL) - return; - if (tty_port_close_start(&dlci->port, tty, filp) == 0) - return; - gsm_dlci_begin_close(dlci); - tty_port_close_end(&dlci->port, tty); - tty_port_tty_set(&dlci->port, NULL); -} - -static void gsmtty_hangup(struct tty_struct *tty) -{ - struct gsm_dlci *dlci = tty->driver_data; - tty_port_hangup(&dlci->port); - gsm_dlci_begin_close(dlci); -} - -static int gsmtty_write(struct tty_struct *tty, const unsigned char *buf, - int len) -{ - struct gsm_dlci *dlci = tty->driver_data; - /* Stuff the bytes into the fifo queue */ - int sent = kfifo_in_locked(dlci->fifo, buf, len, &dlci->lock); - /* Need to kick the channel */ - gsm_dlci_data_kick(dlci); - return sent; -} - -static int gsmtty_write_room(struct tty_struct *tty) -{ - struct gsm_dlci *dlci = tty->driver_data; - return TX_SIZE - kfifo_len(dlci->fifo); -} - -static int gsmtty_chars_in_buffer(struct tty_struct *tty) -{ - struct gsm_dlci *dlci = tty->driver_data; - return kfifo_len(dlci->fifo); -} - -static void gsmtty_flush_buffer(struct tty_struct *tty) -{ - struct gsm_dlci *dlci = tty->driver_data; - /* Caution needed: If we implement reliable transport classes - then the data being transmitted can't simply be junked once - it has first hit the stack. Until then we can just blow it - away */ - kfifo_reset(dlci->fifo); - /* Need to unhook this DLCI from the transmit queue logic */ -} - -static void gsmtty_wait_until_sent(struct tty_struct *tty, int timeout) -{ - /* The FIFO handles the queue so the kernel will do the right - thing waiting on chars_in_buffer before calling us. No work - to do here */ -} - -static int gsmtty_tiocmget(struct tty_struct *tty, struct file *filp) -{ - struct gsm_dlci *dlci = tty->driver_data; - return dlci->modem_rx; -} - -static int gsmtty_tiocmset(struct tty_struct *tty, struct file *filp, - unsigned int set, unsigned int clear) -{ - struct gsm_dlci *dlci = tty->driver_data; - unsigned int modem_tx = dlci->modem_tx; - - modem_tx &= clear; - modem_tx |= set; - - if (modem_tx != dlci->modem_tx) { - dlci->modem_tx = modem_tx; - return gsmtty_modem_update(dlci, 0); - } - return 0; -} - - -static int gsmtty_ioctl(struct tty_struct *tty, struct file *filp, - unsigned int cmd, unsigned long arg) -{ - return -ENOIOCTLCMD; -} - -static void gsmtty_set_termios(struct tty_struct *tty, struct ktermios *old) -{ - /* For the moment its fixed. In actual fact the speed information - for the virtual channel can be propogated in both directions by - the RPN control message. This however rapidly gets nasty as we - then have to remap modem signals each way according to whether - our virtual cable is null modem etc .. */ - tty_termios_copy_hw(tty->termios, old); -} - -static void gsmtty_throttle(struct tty_struct *tty) -{ - struct gsm_dlci *dlci = tty->driver_data; - if (tty->termios->c_cflag & CRTSCTS) - dlci->modem_tx &= ~TIOCM_DTR; - dlci->throttled = 1; - /* Send an MSC with DTR cleared */ - gsmtty_modem_update(dlci, 0); -} - -static void gsmtty_unthrottle(struct tty_struct *tty) -{ - struct gsm_dlci *dlci = tty->driver_data; - if (tty->termios->c_cflag & CRTSCTS) - dlci->modem_tx |= TIOCM_DTR; - dlci->throttled = 0; - /* Send an MSC with DTR set */ - gsmtty_modem_update(dlci, 0); -} - -static int gsmtty_break_ctl(struct tty_struct *tty, int state) -{ - struct gsm_dlci *dlci = tty->driver_data; - int encode = 0; /* Off */ - - if (state == -1) /* "On indefinitely" - we can't encode this - properly */ - encode = 0x0F; - else if (state > 0) { - encode = state / 200; /* mS to encoding */ - if (encode > 0x0F) - encode = 0x0F; /* Best effort */ - } - return gsmtty_modem_update(dlci, encode); -} - -static struct tty_driver *gsm_tty_driver; - -/* Virtual ttys for the demux */ -static const struct tty_operations gsmtty_ops = { - .open = gsmtty_open, - .close = gsmtty_close, - .write = gsmtty_write, - .write_room = gsmtty_write_room, - .chars_in_buffer = gsmtty_chars_in_buffer, - .flush_buffer = gsmtty_flush_buffer, - .ioctl = gsmtty_ioctl, - .throttle = gsmtty_throttle, - .unthrottle = gsmtty_unthrottle, - .set_termios = gsmtty_set_termios, - .hangup = gsmtty_hangup, - .wait_until_sent = gsmtty_wait_until_sent, - .tiocmget = gsmtty_tiocmget, - .tiocmset = gsmtty_tiocmset, - .break_ctl = gsmtty_break_ctl, -}; - - - -static int __init gsm_init(void) -{ - /* Fill in our line protocol discipline, and register it */ - int status = tty_register_ldisc(N_GSM0710, &tty_ldisc_packet); - if (status != 0) { - printk(KERN_ERR "n_gsm: can't register line discipline (err = %d)\n", status); - return status; - } - - gsm_tty_driver = alloc_tty_driver(256); - if (!gsm_tty_driver) { - tty_unregister_ldisc(N_GSM0710); - printk(KERN_ERR "gsm_init: tty allocation failed.\n"); - return -EINVAL; - } - gsm_tty_driver->owner = THIS_MODULE; - gsm_tty_driver->driver_name = "gsmtty"; - gsm_tty_driver->name = "gsmtty"; - gsm_tty_driver->major = 0; /* Dynamic */ - gsm_tty_driver->minor_start = 0; - gsm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; - gsm_tty_driver->subtype = SERIAL_TYPE_NORMAL; - gsm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV - | TTY_DRIVER_HARDWARE_BREAK; - gsm_tty_driver->init_termios = tty_std_termios; - /* Fixme */ - gsm_tty_driver->init_termios.c_lflag &= ~ECHO; - tty_set_operations(gsm_tty_driver, &gsmtty_ops); - - spin_lock_init(&gsm_mux_lock); - - if (tty_register_driver(gsm_tty_driver)) { - put_tty_driver(gsm_tty_driver); - tty_unregister_ldisc(N_GSM0710); - printk(KERN_ERR "gsm_init: tty registration failed.\n"); - return -EBUSY; - } - printk(KERN_INFO "gsm_init: loaded as %d,%d.\n", gsm_tty_driver->major, gsm_tty_driver->minor_start); - return 0; -} - -static void __exit gsm_exit(void) -{ - int status = tty_unregister_ldisc(N_GSM0710); - if (status != 0) - printk(KERN_ERR "n_gsm: can't unregister line discipline (err = %d)\n", status); - tty_unregister_driver(gsm_tty_driver); - put_tty_driver(gsm_tty_driver); - printk(KERN_INFO "gsm_init: unloaded.\n"); -} - -module_init(gsm_init); -module_exit(gsm_exit); - - -MODULE_LICENSE("GPL"); -MODULE_ALIAS_LDISC(N_GSM0710); |
