diff options
Diffstat (limited to 'drivers/tty/n_gsm.c')
| -rw-r--r-- | drivers/tty/n_gsm.c | 477 |
1 files changed, 276 insertions, 201 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index fa92f727fdf8..a38b922bcbc1 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -73,6 +73,8 @@ module_param(debug, int, 0600); */ #define MAX_MRU 1500 #define MAX_MTU 1500 +/* SOF, ADDR, CTRL, LEN1, LEN2, ..., FCS, EOF */ +#define PROT_OVERHEAD 7 #define GSM_NET_TX_TIMEOUT (HZ*10) /* @@ -219,7 +221,6 @@ struct gsm_mux { int encoding; u8 control; u8 fcs; - u8 received_fcs; u8 *txframe; /* TX framing buffer */ /* Method for the receiver side */ @@ -231,6 +232,7 @@ struct gsm_mux { int initiator; /* Did we initiate connection */ bool dead; /* Has the mux been shut down */ struct gsm_dlci *dlci[NUM_DLCI]; + int old_c_iflag; /* termios c_iflag value before attach */ bool constipated; /* Asked by remote to shut up */ spinlock_t tx_lock; @@ -271,10 +273,6 @@ static DEFINE_SPINLOCK(gsm_mux_lock); static struct tty_driver *gsm_tty_driver; -/* Save dlci open address */ -static int addr_open[256] = { 0 }; -/* Save dlci open count */ -static int addr_cnt; /* * This section of the driver logic implements the GSM encodings * both the basic and the 'advanced'. Reliable transport is not @@ -369,6 +367,7 @@ static const u8 gsm_fcs8[256] = { #define GOOD_FCS 0xCF static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len); +static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk); /** * gsm_fcs_add - update FCS @@ -832,7 +831,7 @@ static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci) break; case 2: /* Unstructed with modem bits. Always one byte as we never send inline break data */ - *dp++ = gsm_encode_modem(dlci); + *dp++ = (gsm_encode_modem(dlci) << 1) | EA; break; } WARN_ON(kfifo_out_locked(&dlci->fifo, dp , len, &dlci->lock) != len); @@ -917,6 +916,66 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, } /** + * gsm_dlci_modem_output - try and push modem status out of a DLCI + * @gsm: mux + * @dlci: the DLCI to pull modem status from + * @brk: break signal + * + * Push an empty frame in to the transmit queue to update the modem status + * bits and to transmit an optional break. + * + * Caller must hold the tx_lock of the mux. + */ + +static int gsm_dlci_modem_output(struct gsm_mux *gsm, struct gsm_dlci *dlci, + u8 brk) +{ + u8 *dp = NULL; + struct gsm_msg *msg; + int size = 0; + + /* for modem bits without break data */ + switch (dlci->adaption) { + case 1: /* Unstructured */ + break; + case 2: /* Unstructured with modem bits. */ + size++; + if (brk > 0) + size++; + break; + default: + pr_err("%s: unsupported adaption %d\n", __func__, + dlci->adaption); + return -EINVAL; + } + + msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); + if (!msg) { + pr_err("%s: gsm_data_alloc error", __func__); + return -ENOMEM; + } + dp = msg->data; + switch (dlci->adaption) { + case 1: /* Unstructured */ + break; + case 2: /* Unstructured with modem bits. */ + if (brk == 0) { + *dp++ = (gsm_encode_modem(dlci) << 1) | EA; + } else { + *dp++ = gsm_encode_modem(dlci) << 1; + *dp++ = (brk << 4) | 2 | EA; /* Length, Break, EA */ + } + break; + default: + /* Handled above */ + break; + } + + __gsm_data_queue(dlci, msg); + return size; +} + +/** * gsm_dlci_data_sweep - look for data to send * @gsm: the GSM mux * @@ -1093,7 +1152,6 @@ static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen) { unsigned int addr = 0; unsigned int modem = 0; - unsigned int brk = 0; struct gsm_dlci *dlci; int len = clen; int slen; @@ -1123,17 +1181,8 @@ static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen) return; } len--; - if (len > 0) { - while (gsm_read_ea(&brk, *dp++) == 0) { - len--; - if (len == 0) - return; - } - modem <<= 7; - modem |= (brk & 0x7f); - } tty = tty_port_tty_get(&dlci->port); - gsm_process_modem(tty, dlci, modem, slen); + gsm_process_modem(tty, dlci, modem, slen - len); if (tty) { tty_wakeup(tty); tty_kref_put(tty); @@ -1193,7 +1242,6 @@ static void gsm_control_rls(struct gsm_mux *gsm, const u8 *data, int clen) } static void gsm_dlci_begin_close(struct gsm_dlci *dlci); -static void gsm_dlci_close(struct gsm_dlci *dlci); /** * gsm_control_message - DLCI 0 control processing @@ -1212,28 +1260,15 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, { u8 buf[1]; unsigned long flags; - struct gsm_dlci *dlci; - int i; - int address; switch (command) { case CMD_CLD: { - if (addr_cnt > 0) { - for (i = 0; i < addr_cnt; i++) { - address = addr_open[i]; - dlci = gsm->dlci[address]; - gsm_dlci_close(dlci); - addr_open[i] = 0; - } - } + struct gsm_dlci *dlci = gsm->dlci[0]; /* Modem wishes to close down */ - dlci = gsm->dlci[0]; if (dlci) { dlci->dead = true; gsm->dead = true; - gsm_dlci_close(dlci); - addr_cnt = 0; - gsm_response(gsm, 0, UA|PF); + gsm_dlci_begin_close(dlci); } } break; @@ -1326,11 +1361,12 @@ static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, 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); + struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 2, gsm->ftype); if (msg == NULL) return; - msg->data[0] = (ctrl->cmd << 1) | 2 | EA; /* command */ - memcpy(msg->data + 1, ctrl->data, ctrl->len); + msg->data[0] = (ctrl->cmd << 1) | CR | EA; /* command */ + msg->data[1] = (ctrl->len << 1) | EA; + memcpy(msg->data + 2, ctrl->data, ctrl->len); gsm_data_queue(gsm->dlci[0], msg); } @@ -1353,7 +1389,6 @@ static void gsm_control_retransmit(struct timer_list *t) 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; @@ -1362,6 +1397,7 @@ static void gsm_control_retransmit(struct timer_list *t) wake_up(&gsm->event); return; } + gsm->cretries--; gsm_control_transmit(gsm, ctrl); mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); } @@ -1402,7 +1438,7 @@ retry: /* If DLCI0 is in ADM mode skip retries, it won't respond */ if (gsm->dlci[0]->mode == DLCI_MODE_ADM) - gsm->cretries = 1; + gsm->cretries = 0; else gsm->cretries = gsm->n2; @@ -1450,20 +1486,22 @@ static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control) static void gsm_dlci_close(struct gsm_dlci *dlci) { + unsigned long flags; + del_timer(&dlci->t1); if (debug & 8) pr_debug("DLCI %d goes closed.\n", dlci->addr); dlci->state = DLCI_CLOSED; if (dlci->addr != 0) { tty_port_tty_hangup(&dlci->port, false); + spin_lock_irqsave(&dlci->lock, flags); kfifo_reset(&dlci->fifo); + spin_unlock_irqrestore(&dlci->lock, flags); /* Ensure that gsmtty_open() can return. */ tty_port_set_initialized(&dlci->port, 0); wake_up_interruptible(&dlci->port.open_wait); } else dlci->gsm->dead = true; - /* Unregister gsmtty driver,report gsmtty dev remove uevent for user */ - tty_unregister_device(gsm_tty_driver, dlci->addr); wake_up(&dlci->gsm->event); /* A DLCI 0 close is a MUX termination so we need to kick that back to userspace somehow */ @@ -1485,8 +1523,9 @@ static void gsm_dlci_open(struct gsm_dlci *dlci) dlci->state = DLCI_OPEN; if (debug & 8) pr_debug("DLCI %d goes open.\n", dlci->addr); - /* Register gsmtty driver,report gsmtty dev add uevent for user */ - tty_register_device(gsm_tty_driver, dlci->addr, NULL); + /* Send current modem state */ + if (dlci->addr) + gsm_modem_update(dlci, 0); wake_up(&dlci->gsm->event); } @@ -1623,6 +1662,7 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen) tty = tty_port_tty_get(port); if (tty) { gsm_process_modem(tty, dlci, modem, slen); + tty_wakeup(tty); tty_kref_put(tty); } fallthrough; @@ -1793,19 +1833,7 @@ static void gsm_queue(struct gsm_mux *gsm) struct gsm_dlci *dlci; u8 cr; int address; - int i, j, k, address_tmp; - /* 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->encoding == 0) { - /* WARNING: gsm->received_fcs is used for - gsm->encoding = 0 only. - In this case it contain the last piece of data - required to generate final CRC */ - gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->received_fcs); - } if (gsm->fcs != GOOD_FCS) { gsm->bad_fcs++; if (debug & 4) @@ -1836,11 +1864,6 @@ static void gsm_queue(struct gsm_mux *gsm) else { gsm_response(gsm, address, UA|PF); gsm_dlci_open(dlci); - /* Save dlci open address */ - if (address) { - addr_open[addr_cnt] = address; - addr_cnt++; - } } break; case DISC|PF: @@ -1851,35 +1874,9 @@ static void gsm_queue(struct gsm_mux *gsm) return; } /* Real close complete */ - if (!address) { - if (addr_cnt > 0) { - for (i = 0; i < addr_cnt; i++) { - address = addr_open[i]; - dlci = gsm->dlci[address]; - gsm_dlci_close(dlci); - addr_open[i] = 0; - } - } - dlci = gsm->dlci[0]; - gsm_dlci_close(dlci); - addr_cnt = 0; - gsm_response(gsm, 0, UA|PF); - } else { - gsm_response(gsm, address, UA|PF); - gsm_dlci_close(dlci); - /* clear dlci address */ - for (j = 0; j < addr_cnt; j++) { - address_tmp = addr_open[j]; - if (address_tmp == address) { - for (k = j; k < addr_cnt; k++) - addr_open[k] = addr_open[k+1]; - addr_cnt--; - break; - } - } - } + gsm_response(gsm, address, UA|PF); + gsm_dlci_close(dlci); break; - case UA: case UA|PF: if (cr == 0 || dlci == NULL) break; @@ -1993,19 +1990,25 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) break; case GSM_DATA: /* Data */ gsm->buf[gsm->count++] = c; - if (gsm->count == gsm->len) + if (gsm->count == gsm->len) { + /* Calculate final FCS for UI frames over all data */ + if ((gsm->control & ~PF) != UIH) { + gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, + gsm->count); + } gsm->state = GSM_FCS; + } break; case GSM_FCS: /* FCS follows the packet */ - gsm->received_fcs = c; - gsm_queue(gsm); + gsm->fcs = gsm_fcs_add(gsm->fcs, c); gsm->state = GSM_SSOF; break; case GSM_SSOF: - if (c == GSM0_SOF) { - gsm->state = GSM_SEARCH; - break; - } + gsm->state = GSM_SEARCH; + if (c == GSM0_SOF) + gsm_queue(gsm); + else + gsm->bad_size++; break; default: pr_debug("%s: unhandled state: %d\n", __func__, gsm->state); @@ -2023,12 +2026,35 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) static void gsm1_receive(struct gsm_mux *gsm, unsigned char c) { + /* handle XON/XOFF */ + if ((c & ISO_IEC_646_MASK) == XON) { + gsm->constipated = true; + return; + } else if ((c & ISO_IEC_646_MASK) == XOFF) { + gsm->constipated = false; + /* Kick the link in case it is idling */ + gsm_data_kick(gsm, NULL); + return; + } 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 */ + /* EOF is only valid in frame if we have got to the data state */ + if (gsm->state == GSM_DATA) { + if (gsm->count < 1) { + /* Missing FSC */ + gsm->malformed++; + gsm->state = GSM_START; + return; + } + /* Remove the FCS from data */ gsm->count--; + if ((gsm->control & ~PF) != UIH) { + /* Calculate final FCS for UI frames over all + * data but FCS + */ + gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, + gsm->count); + } + /* Add the FCS itself to test against GOOD_FCS */ gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]); gsm->len = gsm->count; gsm_queue(gsm); @@ -2037,7 +2063,8 @@ static void gsm1_receive(struct gsm_mux *gsm, unsigned char c) } /* Any partial frame was a runt so go back to start */ if (gsm->state != GSM_START) { - gsm->malformed++; + if (gsm->state != GSM_SEARCH) + gsm->malformed++; gsm->state = GSM_START; } /* A SOF in GSM_START means we are still reading idling or @@ -2106,74 +2133,43 @@ static void gsm_error(struct gsm_mux *gsm) gsm->io_error++; } -static int gsm_disconnect(struct gsm_mux *gsm) -{ - struct gsm_dlci *dlci = gsm->dlci[0]; - struct gsm_control *gc; - - if (!dlci) - return 0; - - /* In theory disconnecting DLCI 0 is sufficient but for some - modems this is apparently not the case. */ - gc = gsm_control_send(gsm, CMD_CLD, NULL, 0); - if (gc) - gsm_control_wait(gsm, gc); - - del_timer_sync(&gsm->t2_timer); - /* Now we are sure T2 has stopped */ - - gsm_dlci_begin_close(dlci); - wait_event_interruptible(gsm->event, - dlci->state == DLCI_CLOSED); - - if (signal_pending(current)) - return -EINTR; - - return 0; -} - /** * gsm_cleanup_mux - generic GSM protocol cleanup * @gsm: our mux + * @disc: disconnect link? * * 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. */ -static void gsm_cleanup_mux(struct gsm_mux *gsm) +static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc) { int i; struct gsm_dlci *dlci = gsm->dlci[0]; struct gsm_msg *txq, *ntxq; gsm->dead = true; + mutex_lock(&gsm->mutex); - spin_lock(&gsm_mux_lock); - for (i = 0; i < MAX_MUX; i++) { - if (gsm_mux[i] == gsm) { - gsm_mux[i] = NULL; - break; + if (dlci) { + if (disc && dlci->state != DLCI_CLOSED) { + gsm_dlci_begin_close(dlci); + wait_event(gsm->event, dlci->state == DLCI_CLOSED); } + dlci->dead = true; } - spin_unlock(&gsm_mux_lock); - /* open failed before registering => nothing to do */ - if (i == MAX_MUX) - return; + /* Finish outstanding timers, making sure they are done */ del_timer_sync(&gsm->t2_timer); - /* Now we are sure T2 has stopped */ - if (dlci) - dlci->dead = true; - /* Free up any link layer users */ - mutex_lock(&gsm->mutex); - for (i = 0; i < NUM_DLCI; i++) + /* Free up any link layer users and finally the control channel */ + for (i = NUM_DLCI - 1; i >= 0; i--) if (gsm->dlci[i]) gsm_dlci_release(gsm->dlci[i]); mutex_unlock(&gsm->mutex); /* Now wipe the queues */ + tty_ldisc_flush(gsm->tty); list_for_each_entry_safe(txq, ntxq, &gsm->tx_list, list) kfree(txq); INIT_LIST_HEAD(&gsm->tx_list); @@ -2191,7 +2187,6 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm) static int gsm_activate_mux(struct gsm_mux *gsm) { struct gsm_dlci *dlci; - int i = 0; timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0); init_waitqueue_head(&gsm->event); @@ -2203,18 +2198,6 @@ static int gsm_activate_mux(struct gsm_mux *gsm) else gsm->receive = gsm1_receive; - spin_lock(&gsm_mux_lock); - for (i = 0; i < MAX_MUX; i++) { - if (gsm_mux[i] == NULL) { - gsm->num = i; - 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; @@ -2230,6 +2213,15 @@ static int gsm_activate_mux(struct gsm_mux *gsm) */ static void gsm_free_mux(struct gsm_mux *gsm) { + int i; + + for (i = 0; i < MAX_MUX; i++) { + if (gsm == gsm_mux[i]) { + gsm_mux[i] = NULL; + break; + } + } + mutex_destroy(&gsm->mutex); kfree(gsm->txframe); kfree(gsm->buf); kfree(gsm); @@ -2249,12 +2241,20 @@ static void gsm_free_muxr(struct kref *ref) static inline void mux_get(struct gsm_mux *gsm) { + unsigned long flags; + + spin_lock_irqsave(&gsm_mux_lock, flags); kref_get(&gsm->ref); + spin_unlock_irqrestore(&gsm_mux_lock, flags); } static inline void mux_put(struct gsm_mux *gsm) { + unsigned long flags; + + spin_lock_irqsave(&gsm_mux_lock, flags); kref_put(&gsm->ref, gsm_free_muxr); + spin_unlock_irqrestore(&gsm_mux_lock, flags); } static inline unsigned int mux_num_to_base(struct gsm_mux *gsm) @@ -2275,6 +2275,7 @@ static inline unsigned int mux_line_to_num(unsigned int line) static struct gsm_mux *gsm_alloc_mux(void) { + int i; struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL); if (gsm == NULL) return NULL; @@ -2283,7 +2284,7 @@ static struct gsm_mux *gsm_alloc_mux(void) kfree(gsm); return NULL; } - gsm->txframe = kmalloc(2 * MAX_MRU + 2, GFP_KERNEL); + gsm->txframe = kmalloc(2 * (MAX_MTU + PROT_OVERHEAD - 1), GFP_KERNEL); if (gsm->txframe == NULL) { kfree(gsm->buf); kfree(gsm); @@ -2304,6 +2305,26 @@ static struct gsm_mux *gsm_alloc_mux(void) gsm->mtu = 64; gsm->dead = true; /* Avoid early tty opens */ + /* Store the instance to the mux array or abort if no space is + * available. + */ + spin_lock(&gsm_mux_lock); + for (i = 0; i < MAX_MUX; i++) { + if (!gsm_mux[i]) { + gsm_mux[i] = gsm; + gsm->num = i; + break; + } + } + spin_unlock(&gsm_mux_lock); + if (i == MAX_MUX) { + mutex_destroy(&gsm->mutex); + kfree(gsm->txframe); + kfree(gsm->buf); + kfree(gsm); + return NULL; + } + return gsm; } @@ -2339,7 +2360,7 @@ static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c) /* 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) + if (c->n2 > 255) return -EINVAL; if (c->encapsulation > 1) /* Basic, advanced, no I */ return -EINVAL; @@ -2370,19 +2391,11 @@ static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c) /* * Close down what is needed, restart and initiate the new - * configuration + * configuration. On the first time there is no DLCI[0] + * and closing or cleaning up is not necessary. */ - - if (gsm->initiator && (need_close || need_restart)) { - int ret; - - ret = gsm_disconnect(gsm); - - if (ret) - return ret; - } - if (need_restart) - gsm_cleanup_mux(gsm); + if (need_close || need_restart) + gsm_cleanup_mux(gsm, true); gsm->initiator = c->initiator; gsm->mru = c->mru; @@ -2450,25 +2463,26 @@ static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) int ret, i; gsm->tty = tty_kref_get(tty); + /* Turn off tty XON/XOFF handling to handle it explicitly. */ + gsm->old_c_iflag = tty->termios.c_iflag; + tty->termios.c_iflag &= (IXON | IXOFF); ret = gsm_activate_mux(gsm); if (ret != 0) tty_kref_put(gsm->tty); else { /* Don't register device 0 - this is the control channel and not a usable tty interface */ - if (gsm->initiator) { - base = mux_num_to_base(gsm); /* Base for this MUX */ - for (i = 1; i < NUM_DLCI; i++) { - struct device *dev; + base = mux_num_to_base(gsm); /* Base for this MUX */ + for (i = 1; i < NUM_DLCI; i++) { + struct device *dev; - dev = tty_register_device(gsm_tty_driver, + dev = tty_register_device(gsm_tty_driver, base + i, NULL); - if (IS_ERR(dev)) { - for (i--; i >= 1; i--) - tty_unregister_device(gsm_tty_driver, - base + i); - return PTR_ERR(dev); - } + if (IS_ERR(dev)) { + for (i--; i >= 1; i--) + tty_unregister_device(gsm_tty_driver, + base + i); + return PTR_ERR(dev); } } } @@ -2490,11 +2504,10 @@ static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) int i; WARN_ON(tty != gsm->tty); - if (gsm->initiator) { - for (i = 1; i < NUM_DLCI; i++) - tty_unregister_device(gsm_tty_driver, base + i); - } - gsm_cleanup_mux(gsm); + for (i = 1; i < NUM_DLCI; i++) + tty_unregister_device(gsm_tty_driver, base + i); + /* Restore tty XON/XOFF handling. */ + gsm->tty->termios.c_iflag = gsm->old_c_iflag; tty_kref_put(gsm->tty); gsm->tty = NULL; } @@ -2559,6 +2572,12 @@ static void gsmld_close(struct tty_struct *tty) { struct gsm_mux *gsm = tty->disc_data; + /* The ldisc locks and closes the port before calling our close. This + * means we have no way to do a proper disconnect. We will not bother + * to do one. + */ + gsm_cleanup_mux(gsm, false); + gsmld_detach_gsm(tty, gsm); gsmld_flush_buffer(tty); @@ -2597,7 +2616,7 @@ static int gsmld_open(struct tty_struct *tty) ret = gsmld_attach_gsm(tty, gsm); if (ret != 0) { - gsm_cleanup_mux(gsm); + gsm_cleanup_mux(gsm, false); mux_put(gsm); } return ret; @@ -2954,26 +2973,78 @@ static struct tty_ldisc_ops tty_ldisc_packet = { #define TX_SIZE 512 -static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk) +/** + * gsm_modem_upd_via_data - send modem bits via convergence layer + * @dlci: channel + * @brk: break signal + * + * Send an empty frame to signal mobile state changes and to transmit the + * break signal for adaption 2. + */ + +static void gsm_modem_upd_via_data(struct gsm_dlci *dlci, u8 brk) { - u8 modembits[5]; + struct gsm_mux *gsm = dlci->gsm; + unsigned long flags; + + if (dlci->state != DLCI_OPEN || dlci->adaption != 2) + return; + + spin_lock_irqsave(&gsm->tx_lock, flags); + gsm_dlci_modem_output(gsm, dlci, brk); + spin_unlock_irqrestore(&gsm->tx_lock, flags); +} + +/** + * gsm_modem_upd_via_msc - send modem bits via control frame + * @dlci: channel + * @brk: break signal + */ + +static int gsm_modem_upd_via_msc(struct gsm_dlci *dlci, u8 brk) +{ + u8 modembits[3]; struct gsm_control *ctrl; int len = 2; - if (brk) - len++; + if (dlci->gsm->encoding != 0) + return 0; - 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); + modembits[0] = (dlci->addr << 2) | 2 | EA; /* DLCI, Valid, EA */ + if (!brk) { + modembits[1] = (gsm_encode_modem(dlci) << 1) | EA; + } else { + modembits[1] = gsm_encode_modem(dlci) << 1; + modembits[2] = (brk << 4) | 2 | EA; /* Length, Break, EA */ + len++; + } + ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len); if (ctrl == NULL) return -ENOMEM; return gsm_control_wait(dlci->gsm, ctrl); } +/** + * gsm_modem_update - send modem status line state + * @dlci: channel + * @brk: break signal + */ + +static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk) +{ + if (dlci->adaption == 2) { + /* Send convergence layer type 2 empty data frame. */ + gsm_modem_upd_via_data(dlci, brk); + return 0; + } else if (dlci->gsm->encoding == 0) { + /* Send as MSC control message. */ + return gsm_modem_upd_via_msc(dlci, brk); + } + + /* Modem status lines are not supported. */ + return -EPROTONOSUPPORT; +} + static int gsm_carrier_raised(struct tty_port *port) { struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); @@ -3006,7 +3077,7 @@ static void gsm_dtr_rts(struct tty_port *port, int onoff) modem_tx &= ~(TIOCM_DTR | TIOCM_RTS); if (modem_tx != dlci->modem_tx) { dlci->modem_tx = modem_tx; - gsmtty_modem_update(dlci, 0); + gsm_modem_update(dlci, 0); } } @@ -3155,13 +3226,17 @@ static unsigned int gsmtty_chars_in_buffer(struct tty_struct *tty) static void gsmtty_flush_buffer(struct tty_struct *tty) { struct gsm_dlci *dlci = tty->driver_data; + unsigned long flags; + if (dlci->state == DLCI_CLOSED) return; /* 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 */ + spin_lock_irqsave(&dlci->lock, flags); kfifo_reset(&dlci->fifo); + spin_unlock_irqrestore(&dlci->lock, flags); /* Need to unhook this DLCI from the transmit queue logic */ } @@ -3193,7 +3268,7 @@ static int gsmtty_tiocmset(struct tty_struct *tty, if (modem_tx != dlci->modem_tx) { dlci->modem_tx = modem_tx; - return gsmtty_modem_update(dlci, 0); + return gsm_modem_update(dlci, 0); } return 0; } @@ -3254,7 +3329,7 @@ static void gsmtty_throttle(struct tty_struct *tty) dlci->modem_tx &= ~TIOCM_RTS; dlci->throttled = true; /* Send an MSC with RTS cleared */ - gsmtty_modem_update(dlci, 0); + gsm_modem_update(dlci, 0); } static void gsmtty_unthrottle(struct tty_struct *tty) @@ -3266,7 +3341,7 @@ static void gsmtty_unthrottle(struct tty_struct *tty) dlci->modem_tx |= TIOCM_RTS; dlci->throttled = false; /* Send an MSC with RTS set */ - gsmtty_modem_update(dlci, 0); + gsm_modem_update(dlci, 0); } static int gsmtty_break_ctl(struct tty_struct *tty, int state) @@ -3284,7 +3359,7 @@ static int gsmtty_break_ctl(struct tty_struct *tty, int state) if (encode > 0x0F) encode = 0x0F; /* Best effort */ } - return gsmtty_modem_update(dlci, encode); + return gsm_modem_update(dlci, encode); } static void gsmtty_cleanup(struct tty_struct *tty) |