/* This is the serial hardware link layer (HLL) for the Gigaset 307x isdn * DECT base (aka Sinus 45 isdn) using the RS232 DECT data module M101, * written as a line discipline. * * ===================================================================== * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * ===================================================================== */ #include "gigaset.h" #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/platform_device.h> #include <linux/tty.h> #include <linux/completion.h> /* Version Information */ #define DRIVER_AUTHOR "Tilman Schmidt" #define DRIVER_DESC "Serial Driver for Gigaset 307x using Siemens M101" #define GIGASET_MINORS 1 #define GIGASET_MINOR 0 #define GIGASET_MODULENAME "ser_gigaset" #define GIGASET_DEVNAME "ttyGS" /* length limit according to Siemens 3070usb-protokoll.doc ch. 2.1 */ #define IF_WRITEBUF 264 MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL"); MODULE_ALIAS_LDISC(N_GIGASET_M101); static int startmode = SM_ISDN; module_param(startmode, int, S_IRUGO); MODULE_PARM_DESC(startmode, "initial operation mode"); static int cidmode = 1; module_param(cidmode, int, S_IRUGO); MODULE_PARM_DESC(cidmode, "stay in CID mode when idle"); static struct gigaset_driver *driver; struct ser_cardstate { struct platform_device dev; struct tty_struct *tty; atomic_t refcnt; struct completion dead_cmp; }; static struct platform_driver device_driver = { .driver = { .name = GIGASET_MODULENAME, }, }; static void flush_send_queue(struct cardstate *); /* transmit data from current open skb * result: number of bytes sent or error code < 0 */ static int write_modem(struct cardstate *cs) { struct tty_struct *tty = cs->hw.ser->tty; struct bc_state *bcs = &cs->bcs[0]; /* only one channel */ struct sk_buff *skb = bcs->tx_skb; int sent = -EOPNOTSUPP; if (!tty || !tty->driver || !skb) return -EINVAL; if (!skb->len) { dev_kfree_skb_any(skb); bcs->tx_skb = NULL; return -EINVAL; } set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); if (tty->ops->write) sent = tty->ops->write(tty, skb->data, skb->len); gig_dbg(DEBUG_OUTPUT, "write_modem: sent %d", sent); if (sent < 0) { /* error */ flush_send_queue(cs); return sent; } skb_pull(skb, sent); if (!skb->len) { /* skb sent completely */ gigaset_skb_sent(bcs, skb); gig_dbg(DEBUG_INTR, "kfree skb (Adr: %lx)!", (unsigned long) skb); dev_kfree_skb_any(skb); bcs->tx_skb = NULL; } return sent; } /* * transmit first queued command buffer * result: number of bytes sent or error code < 0 */ static int send_cb(struct cardstate *cs) { struct tty_struct *tty = cs->hw.ser->tty; struct cmdbuf_t *cb, *tcb; unsigned long flags; int sent = 0; if (!tty || !tty->driver) return -EFAULT; cb = cs->cmdbuf; if (!cb) return 0; /* nothing to do */ if (cb->len) { set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); sent = tty->ops->write(tty, cb->buf + cb->offset, cb->len); if (sent < 0) { /* error */ gig_dbg(DEBUG_OUTPUT, "send_cb: write error %d", sent); flush_send_queue(cs); return sent; } cb->offset += sent; cb->len -= sent; gig_dbg(DEBUG_OUTPUT, "send_cb: sent %d, left %u, queued %u", sent, cb->len, cs->cmdbytes); } while (cb && !cb->len) { spin_lock_irqsave(&cs->cmdlock, flags); cs->cmdbytes -= cs->curlen; tcb = cb; cs->cmdbuf = cb = cb->next; if (cb) { cb->prev = NULL; cs->curlen = cb->len; } else { cs->lastcmdbuf = NULL; cs->curlen = 0; } spin_unlock_irqrestore(&cs->cmdlock, flags); if (tcb->wake_tasklet) tasklet_schedule(tcb->wake_tasklet); kfree(tcb); } return sent; } /* * send queue tasklet * If there is already a skb opened, put data to the transfer buffer * by calling "write_modem". * Otherwise take a new skb out of the queue. */ static void gigaset_modem_fill(unsigned long data) { struct cardstate *cs = (struct cardstate *) data; struct bc_state *bcs; struct sk_buff *nextskb; int sent = 0; if (!cs) { gig_dbg(DEBUG_OUTPUT, "%s: no cardstate", __func__); return; } bcs = cs->bcs; if (!bcs) { gig_dbg(DEBUG_OUTPUT, "%s: no cardstate", __func__); return; } if (!bcs->tx_skb) { /* no skb is being sent; send command if any */ sent = send_cb(cs); gig_dbg(DEBUG_OUTPUT, "%s: send_cb -> %d", __func__, sent); if (sent) /* something sent or error */ return; /* no command to send; get skb */ nextskb = skb_dequeue(&bcs->squeue); if (!nextskb) /* no skb either, nothing to do */ return; bcs->tx_skb = nextskb; gig_dbg(DEBUG_INTR, "Dequeued skb (Adr: %lx)", (unsigned long) bcs->tx_skb); } /* send skb */ gig_dbg(DEBUG_OUTPUT, "%s: tx_skb", __func__); if (write_modem(cs) < 0) gig_dbg(DEBUG_OUTPUT, "%s: write_modem failed", __func__); } /* * throw away all data queued for sending */ static void flush_send_queue(struct cardstate *cs) { struct sk_buff *skb; struct cmdbuf_t *cb; unsigned long flags; /* command queue */ spin_lock_irqsave(&cs->cmdlock, flags); while ((cb = cs->cmdbuf) != NULL) { cs->cmdbuf = cb->next; if (cb->wake_tasklet) tasklet_schedule(cb->wake_tasklet); kfree(cb); } cs->cmdbuf = cs->lastcmdbuf = NULL; cs->cmdbytes = cs->curlen = 0; spin_unlock_irqrestore(&cs->cmdlock, flags); /* data queue */ if (cs->bcs->tx_skb) dev_kfree_skb_any(cs->bcs->tx_skb); while ((skb = skb_dequeue(&cs->bcs->squeue)) != NULL) dev_kfree_skb_any(skb); } /* Gigaset Driver Interface */ /* ======================== */ /* * queue an AT command string for transmission to the Gigaset device * parameters: * cs controller state structure * buf buffer containing the string to send * len number of characters to send * wake_tasklet tasklet to run when transmission is complete, or NULL * return value: * number of bytes queued, or error code < 0 */ static int gigaset_write_cmd(struct cardstate *cs, const unsigned char *buf, int len, struct tasklet_struct *wake_tasklet) { struct cmdbuf_t *cb; unsigned long flags; gigaset_dbg_buffer(cs->mstate != MS_LOCKED ? DEBUG_TRANSCMD : DEBUG_LOCKCMD, "CMD Transmit", len, buf); if (len <= 0) return 0; cb = kmalloc(sizeof(struct cmdbuf_t) + len, GFP_ATOMIC); if (!cb) { dev_err(cs->dev, "%s: out of memory!\n", __func__); return -ENOMEM; } memcpy(cb->buf, buf, len); cb->len = len; cb->offset = 0; cb->next = NULL; cb->wake_tasklet = wake_tasklet; spin_lock_irqsave(&cs->cmdlock, flags); cb->prev = cs->lastcmdbuf; if (cs->lastcmdbuf) cs->lastcmdbuf->next = cb; else { cs->cmdbuf = cb; cs->curlen = len; } cs->cmdbytes += len; cs->lastcmdbuf = cb; spin_unlock_irqrestore(&cs->cmdlock, flags); spin_lock_irqsave(&cs->lock, flags); if (cs->connected) tasklet_schedule(&cs->write_tasklet); spin_unlock_irqrestore(&cs->lock, flags); return len; } /* * tty_driver.write_room interface routine * return number of characters the driver will accept to be written * parameter: * controller state structure * return value: * number of characters */ static int gigaset_write_room(struct cardstate *cs) { unsigned bytes; bytes = cs->cmdbytes; return bytes < IF_WRITEBUF ? IF_WRITEBUF - bytes : 0; } /* * tty_driver.chars_in_buffer interface routine * return number of characters waiting to be sent * parameter: * controller state structure * return value: * number of characters */ static int gigaset_chars_in_buffer(struct cardstate *cs) { return cs->cmdbytes; } /* * implementation of ioctl(GIGASET_BRKCHARS) * parameter: * controller state structure * return value: * -EINVAL (unimplemented function) */ static int gigaset_brkchars(struct cardstate *cs, const unsigned char buf[6]) { /* not implemented */ return -EINVAL; } /* * Open B channel * Called by "do_action" in ev-layer.c */ static int gigaset_init_bchannel(struct bc_state *bcs) { /* nothing to do for M10x */ gigaset_bchannel_up(bcs); return 0; } /* * Close B channel * Called by "do_action" in ev-layer.c */ static int gigaset_close_bchannel(struct bc_state *bcs) { /* nothing to do for M10x */ gigaset_bchannel_down(bcs); return 0; } /* * Set up B channel structure * This is called by "gigaset_initcs" in common.c */ static int gigaset_initbcshw(struct bc_state *bcs) { /* unused */ bcs->hw.ser = NULL; return 1; } /* * Free B channel structure * Called by "gigaset_freebcs" in common.c */ static int gigaset_freebcshw(struct bc_state *bcs) { /* unused */ return 1; } /* * Reinitialize B channel structure * This is called by "bcs_reinit" in common.c */ static void gigaset_reinitbcshw(struct bc_state *bcs) { /* nothing to do for M10x */ } /* * Free hardware specific device data * This will be called by "gigaset_freecs" in common.c */ static void gigaset_freecshw(struct cardstate *cs) { tasklet_kill(&cs->write_tasklet); if (!cs->hw.ser) return; dev_set_drvdata(&cs->hw.ser->dev.dev, NULL); platform_device_unregister(&cs->hw.ser->dev); kfree(cs->hw.ser); cs->hw.ser = NULL; } static void gigaset_device_release(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); /* adapted from platform_device_release() in drivers/base/platform.c */ kfree(dev->platform_data); kfree(pdev->resource); } /* * Set up hardware specific device data * This is called by "gigaset_initcs" in common.c */ static int gigaset_initcshw(struct cardstate *cs) { int rc; struct ser_cardstate *scs; scs = kzalloc(sizeof(struct ser_cardstate), GFP_KERNEL); if (!scs) { pr_err("out of memory\n"); return 0; } cs->hw.ser = scs; cs->hw.ser->dev.name = GIGASET_MODULENAME; cs->hw.ser->dev.id = cs->minor_index; cs->hw.ser->dev.dev.release = gigaset_device_release; rc = platform_device_register(&cs->hw.ser->dev); if (rc != 0) { pr_err("error %d registering platform device\n", rc); kfree(cs->hw.ser); cs->hw.ser = NULL; return 0; } dev_set_drvdata(&cs->hw.ser->dev.dev, cs); tasklet_init(&cs->write_tasklet, &gigaset_modem_fill, (unsigned long) cs); return 1; } /* * set modem control lines * Parameters: * card state structure * modem control line state ([TIOCM_DTR]|[TIOCM_RTS]) * Called by "gigaset_start" and "gigaset_enterconfigmode" in common.c * and by "if_lock" and "if_termios" in interface.c */ static int gigaset_set_modem_ctrl(struct cardstate *cs, unsigned old_state, unsigned new_state) { struct tty_struct *tty = cs->hw.ser->tty; unsigned int set, clear; if (!tty || !tty->driver || !tty->ops->tiocmset) return -EINVAL; set = new_state & ~old_state; clear = old_state & ~new_state; if (!set && !clear) return 0; gig_dbg(DEBUG_IF, "tiocmset set %x clear %x", set, clear); return tty->ops->tiocmset(tty, NULL, set, clear); } static int gigaset_baud_rate(struct cardstate *cs, unsigned cflag) { return -EINVAL; } static int gigaset_set_line_ctrl(struct cardstate *cs, unsigned cflag) { return -EINVAL; } static const struct gigaset_ops ops = { gigaset_write_cmd, gigaset_write_room, gigaset_chars_in_buffer, gigaset_brkchars, gigaset_init_bchannel, gigaset_close_bchannel, gigaset_initbcshw, gigaset_freebcshw, gigaset_reinitbcshw, gigaset_initcshw, gigaset_freecshw, gigaset_set_modem_ctrl, gigaset_baud_rate, gigaset_set_line_ctrl, gigaset_m10x_send_skb, /* asyncdata.c */ gigaset_m10x_input, /* asyncdata.c */ }; /* Line Discipline Interface */ /* ========================= */ /* helper functions for cardstate refcounting */ static struct cardstate *cs_get(struct tty_struct *tty) { struct cardstate *cs = tty->disc_data; if (!cs || !cs->hw.ser) { gig_dbg(DEBUG_ANY, "%s: no cardstate", __func__); return NULL; } atomic_inc(&cs->hw.ser->refcnt); return cs; } static void cs_put(struct cardstate *cs) { if (atomic_dec_and_test(&cs->hw.ser->refcnt)) complete(&cs->hw.ser->dead_cmp); } /* * Called by the tty driver when the line discipline is pushed onto the tty. * Called in process context. */ static int gigaset_tty_open(struct tty_struct *tty) { struct cardstate *cs; gig_dbg(DEBUG_INIT, "Starting HLL for Gigaset M101"); pr_info(DRIVER_DESC "\n"); if (!driver) { pr_err("%s: no driver structure\n", __func__); return -ENODEV; } /* allocate memory for our device state and intialize it */ cs = gigaset_initcs(driver, 1, 1, 0, cidmode, GIGASET_MODULENAME); if (!cs) goto error; cs->dev = &cs->hw.ser->dev.dev; cs->hw.ser->tty = tty; atomic_set(&cs->hw.ser->refcnt, 1); init_completion(&cs->hw.ser->dead_cmp); tty->disc_data = cs; /* OK.. Initialization of the datastructures and the HW is done.. Now * startup system and notify the LL that we are ready to run */ if (startmode == SM_LOCKED) cs->mstate = MS_LOCKED; if (!gigaset_start(cs)) { tasklet_kill(&cs->write_tasklet); goto error; } gig_dbg(DEBUG_INIT, "Startup of HLL done"); return 0; error: gig_dbg(DEBUG_INIT, "Startup of HLL failed"); tty->disc_data = NULL; gigaset_freecs(cs); return -ENODEV; } /* * Called by the tty driver when the line discipline is removed. * Called from process context. */ static void gigaset_tty_close(struct tty_struct *tty) { struct cardstate *cs = tty->disc_data; gig_dbg(DEBUG_INIT, "Stopping HLL for Gigaset M101"); if (!cs) { gig_dbg(DEBUG_INIT, "%s: no cardstate", __func__); return; } /* prevent other callers from entering ldisc methods */ tty->disc_data = NULL; if (!cs->hw.ser) pr_err("%s: no hw cardstate\n", __func__); else { /* wait for running methods to finish */ if (!atomic_dec_and_test(&cs->hw.ser->refcnt)) wait_for_completion(&cs->hw.ser->dead_cmp); } /* stop operations */ gigaset_stop(cs); tasklet_kill(&cs->write_tasklet); flush_send_queue(cs); cs->dev = NULL; gigaset_freecs(cs); gig_dbg(DEBUG_INIT, "Shutdown of HLL done"); } /* * Called by the tty driver when the tty line is hung up. * Wait for I/O to driver to complete and unregister ISDN device. * This is already done by the close routine, so just call that. * Called from process context. */ static int gigaset_tty_hangup(struct tty_struct *tty) { gigaset_tty_close(tty); return 0; } /* * Read on the tty. * Unused, received data goes only to the Gigaset driver. */ static ssize_t gigaset_tty_read(struct tty_struct *tty, struct file *file, unsigned char __user *buf, size_t count) { return -EAGAIN; } /* * Write on the tty. * Unused, transmit data comes only from the Gigaset driver. */ static ssize_t gigaset_tty_write(struct tty_struct *tty, struct file *file, const unsigned char *buf, size_t count) { return -EAGAIN; } /* * Ioctl on the tty. * Called in process context only. * May be re-entered by multiple ioctl calling threads. */ static int gigaset_tty_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg) { struct cardstate *cs = cs_get(tty); int rc, val; int __user *p = (int __user *)arg; if (!cs) return -ENXIO; switch (cmd) { case FIONREAD: /* unused, always return zero */ val = 0; rc = put_user(val, p); break; case TCFLSH: /* flush our buffers and the serial port's buffer */ switch (arg) { case TCIFLUSH: /* no own input buffer to flush */ break; case TCIOFLUSH: case TCOFLUSH: flush_send_queue(cs); break; } /* Pass through */ default: /* pass through to underlying serial device */ rc = n_tty_ioctl_helper(tty, file, cmd, arg); break; } cs_put(cs); return rc; } /* * Called by the tty driver when a block of data has been received. * Will not be re-entered while running but other ldisc functions * may be called in parallel. * Can be called from hard interrupt level as well as soft interrupt * level or mainline. * Parameters: * tty tty structure * buf buffer containing received characters * cflags buffer containing error flags for received characters (ignored) * count number of received characters */ static void gigaset_tty_receive(struct tty_struct *tty, const unsigned char *buf, char *cflags, int count) { struct cardstate *cs = cs_get(tty); unsigned tail, head, n; struct inbuf_t *inbuf; if (!cs) return; inbuf = cs->inbuf; if (!inbuf) { dev_err(cs->dev, "%s: no inbuf\n", __func__); cs_put(cs); return; } tail = inbuf->tail; head = inbuf->head; gig_dbg(DEBUG_INTR, "buffer state: %u -> %u, receive %u bytes", head, tail, count); if (head <= tail) { /* possible buffer wraparound */ n = min_t(unsigned, count, RBUFSIZE - tail); memcpy(inbuf->data + tail, buf, n); tail = (tail + n) % RBUFSIZE; buf += n; count -= n; } if (count > 0) { /* tail < head and some data left */ n = head - tail - 1; if (count > n) { dev_err(cs->dev, "inbuf overflow, discarding %d bytes\n", count - n); count = n; } memcpy(inbuf->data + tail, buf, count); tail += count; } gig_dbg(DEBUG_INTR, "setting tail to %u", tail); inbuf->tail = tail; /* Everything was received .. Push data into handler */ gig_dbg(DEBUG_INTR, "%s-->BH", __func__); gigaset_schedule_event(cs); cs_put(cs); } /* * Called by the tty driver when there's room for more data to send. */ static void gigaset_tty_wakeup(struct tty_struct *tty) { struct cardstate *cs = cs_get(tty); clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); if (!cs) return; tasklet_schedule(&cs->write_tasklet); cs_put(cs); } static struct tty_ldisc_ops gigaset_ldisc = { .owner = THIS_MODULE, .magic = TTY_LDISC_MAGIC, .name = "ser_gigaset", .open = gigaset_tty_open, .close = gigaset_tty_close, .hangup = gigaset_tty_hangup, .read = gigaset_tty_read, .write = gigaset_tty_write, .ioctl = gigaset_tty_ioctl, .receive_buf = gigaset_tty_receive, .write_wakeup = gigaset_tty_wakeup, }; /* Initialization / Shutdown */ /* ========================= */ static int __init ser_gigaset_init(void) { int rc; gig_dbg(DEBUG_INIT, "%s", __func__); rc = platform_driver_register(&device_driver); if (rc != 0) { pr_err("error %d registering platform driver\n", rc); return rc; } /* allocate memory for our driver state and intialize it */ driver = gigaset_initdriver(GIGASET_MINOR, GIGASET_MINORS, GIGASET_MODULENAME, GIGASET_DEVNAME, &ops, THIS_MODULE); if (!driver) goto error; rc = tty_register_ldisc(N_GIGASET_M101, &gigaset_ldisc); if (rc != 0) { pr_err("error %d registering line discipline\n", rc); goto error; } return 0; error: if (driver) { gigaset_freedriver(driver); driver = NULL; } platform_driver_unregister(&device_driver); return rc; } static void __exit ser_gigaset_exit(void) { int rc; gig_dbg(DEBUG_INIT, "%s", __func__); if (driver) { gigaset_freedriver(driver); driver = NULL; } rc = tty_unregister_ldisc(N_GIGASET_M101); if (rc != 0) pr_err("error %d unregistering line discipline\n", rc); platform_driver_unregister(&device_driver); } module_init(ser_gigaset_init); module_exit(ser_gigaset_exit);