/* 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;
int sent = 0;
if (!cs || !(bcs = cs->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 */
if (!(bcs->tx_skb = skb_dequeue(&bcs->squeue)))
/* no skb either, nothing to do */
return;
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;
if (!(cb = kmalloc(sizeof(struct cmdbuf_t) + len, GFP_ATOMIC))) {
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 =
container_of(dev, struct platform_device, dev);
/* adapted from platform_device_release() in drivers/base/platform.c */
//FIXME is this actually necessary?
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;
if (!(cs->hw.ser = kzalloc(sizeof(struct ser_cardstate), GFP_KERNEL))) {
pr_err("out of memory\n");
return 0;
}
cs->hw.ser->dev.name = GIGASET_MODULENAME;
cs->hw.ser->dev.id = cs->minor_index;
cs->hw.ser->dev.dev.release = gigaset_device_release;
if ((rc = platform_device_register(&cs->hw.ser->dev)) != 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 */
if (!(cs = gigaset_initcs(driver, 1, 1, 0, cidmode,
GIGASET_MODULENAME)))
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;
if (!(inbuf = cs->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__);
if ((rc = platform_driver_register(&device_driver)) != 0) {
pr_err("error %d registering platform driver\n", rc);
return rc;
}
/* allocate memory for our driver state and intialize it */
if (!(driver = gigaset_initdriver(GIGASET_MINOR, GIGASET_MINORS,
GIGASET_MODULENAME, GIGASET_DEVNAME,
&ops, THIS_MODULE)))
goto error;
if ((rc = tty_register_ldisc(N_GIGASET_M101, &gigaset_ldisc)) != 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;
}
if ((rc = tty_unregister_ldisc(N_GIGASET_M101)) != 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);
