dvb_ca_en50221.c

linux-2.6.15.6

/* EN50221 IO interface functions */

/**
 * Real ioctl implementation.
 * NOTE: CA_SEND_MSG/CA_GET_MSG ioctls have userspace buffers passed to them.
 *
 * @param inode Inode concerned.
 * @param file File concerned.
 * @param cmd IOCTL command.
 * @param arg Associated argument.
 *
 * @return 0 on success, <0 on error.
 */
static int dvb_ca_en50221_io_do_ioctl(struct inode *inode, struct file *file,
				      unsigned int cmd, void *parg)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	int err = 0;
	int slot;

	dprintk("%s\n", __FUNCTION__);

	switch (cmd) {
	case CA_RESET:
		for (slot = 0; slot < ca->slot_count; slot++) {
			if (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_NONE) {
				dvb_ca_en50221_slot_shutdown(ca, slot);
				if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)
					dvb_ca_en50221_camchange_irq(ca->pub,
								     slot,
								     DVB_CA_EN50221_CAMCHANGE_INSERTED);
			}
		}
		ca->next_read_slot = 0;
		dvb_ca_en50221_thread_wakeup(ca);
		break;

	case CA_GET_CAP: {
		struct ca_caps *caps = parg;

		caps->slot_num = ca->slot_count;
		caps->slot_type = CA_CI_LINK;
		caps->descr_num = 0;
		caps->descr_type = 0;
		break;
	}

	case CA_GET_SLOT_INFO: {
		struct ca_slot_info *info = parg;

		if ((info->num > ca->slot_count) || (info->num < 0))
			return -EINVAL;

		info->type = CA_CI_LINK;
		info->flags = 0;
		if ((ca->slot_info[info->num].slot_state != DVB_CA_SLOTSTATE_NONE)
			&& (ca->slot_info[info->num].slot_state != DVB_CA_SLOTSTATE_INVALID)) {
			info->flags = CA_CI_MODULE_PRESENT;
		}
		if (ca->slot_info[info->num].slot_state == DVB_CA_SLOTSTATE_RUNNING) {
			info->flags |= CA_CI_MODULE_READY;
		}
		break;
	}

	default:
		err = -EINVAL;
		break;
	}

	return err;
}


/**
 * Wrapper for ioctl implementation.
 *
 * @param inode Inode concerned.
 * @param file File concerned.
 * @param cmd IOCTL command.
 * @param arg Associated argument.
 *
 * @return 0 on success, <0 on error.
 */
static int dvb_ca_en50221_io_ioctl(struct inode *inode, struct file *file,
				   unsigned int cmd, unsigned long arg)
{
	return dvb_usercopy(inode, file, cmd, arg, dvb_ca_en50221_io_do_ioctl);
}


/**
 * Implementation of write() syscall.
 *
 * @param file File structure.
 * @param buf Source buffer.
 * @param count Size of source buffer.
 * @param ppos Position in file (ignored).
 *
 * @return Number of bytes read, or <0 on error.
 */
static ssize_t dvb_ca_en50221_io_write(struct file *file,
				       const char __user * buf, size_t count, loff_t * ppos)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	u8 slot, connection_id;
	int status;
	char fragbuf[HOST_LINK_BUF_SIZE];
	int fragpos = 0;
	int fraglen;
	unsigned long timeout;
	int written;

	dprintk("%s\n", __FUNCTION__);

	/* Incoming packet has a 2 byte header. hdr[0] = slot_id, hdr[1] = connection_id */
	if (count < 2)
		return -EINVAL;

	/* extract slot & connection id */
	if (copy_from_user(&slot, buf, 1))
		return -EFAULT;
	if (copy_from_user(&connection_id, buf + 1, 1))
		return -EFAULT;
	buf += 2;
	count -= 2;

	/* check if the slot is actually running */
	if (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_RUNNING)
		return -EINVAL;

	/* fragment the packets & store in the buffer */
	while (fragpos < count) {
		fraglen = ca->slot_info[slot].link_buf_size - 2;
		if ((count - fragpos) < fraglen)
			fraglen = count - fragpos;

		fragbuf[0] = connection_id;
		fragbuf[1] = ((fragpos + fraglen) < count) ? 0x80 : 0x00;
		if ((status = copy_from_user(fragbuf + 2, buf + fragpos, fraglen)) != 0)
			goto exit;

		timeout = jiffies + HZ / 2;
		written = 0;
		while (!time_after(jiffies, timeout)) {
			/* check the CAM hasn't been removed/reset in the meantime */
			if (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_RUNNING) {
				status = -EIO;
				goto exit;
			}

			status = dvb_ca_en50221_write_data(ca, slot, fragbuf, fraglen + 2);
			if (status == (fraglen + 2)) {
				written = 1;
				break;
			}
			if (status != -EAGAIN)
				goto exit;

			msleep(1);
		}
		if (!written) {
			status = -EIO;
			goto exit;
		}

		fragpos += fraglen;
	}
	status = count + 2;

exit:
	return status;
}


/**
 * Condition for waking up in dvb_ca_en50221_io_read_condition
 */
static int dvb_ca_en50221_io_read_condition(struct dvb_ca_private *ca,
					    int *result, int *_slot)
{
	int slot;
	int slot_count = 0;
	int idx;
	size_t fraglen;
	int connection_id = -1;
	int found = 0;
	u8 hdr[2];

	slot = ca->next_read_slot;
	while ((slot_count < ca->slot_count) && (!found)) {
		if (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_RUNNING)
			goto nextslot;

		if (ca->slot_info[slot].rx_buffer.data == NULL) {
			return 0;
		}

		idx = dvb_ringbuffer_pkt_next(&ca->slot_info[slot].rx_buffer, -1, &fraglen);
		while (idx != -1) {
			dvb_ringbuffer_pkt_read(&ca->slot_info[slot].rx_buffer, idx, 0, hdr, 2, 0);
			if (connection_id == -1)
				connection_id = hdr[0];
			if ((hdr[0] == connection_id) && ((hdr[1] & 0x80) == 0)) {
				*_slot = slot;
				found = 1;
				break;
			}

			idx = dvb_ringbuffer_pkt_next(&ca->slot_info[slot].rx_buffer, idx, &fraglen);
		}

nextslot:
		slot = (slot + 1) % ca->slot_count;
		slot_count++;
	}

	ca->next_read_slot = slot;
	return found;
}


/**
 * Implementation of read() syscall.
 *
 * @param file File structure.
 * @param buf Destination buffer.
 * @param count Size of destination buffer.
 * @param ppos Position in file (ignored).
 *
 * @return Number of bytes read, or <0 on error.
 */
static ssize_t dvb_ca_en50221_io_read(struct file *file, char __user * buf,
				      size_t count, loff_t * ppos)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	int status;
	int result = 0;
	u8 hdr[2];
	int slot;
	int connection_id = -1;
	size_t idx, idx2;
	int last_fragment = 0;
	size_t fraglen;
	int pktlen;
	int dispose = 0;

	dprintk("%s\n", __FUNCTION__);

	/* Outgoing packet has a 2 byte header. hdr[0] = slot_id, hdr[1] = connection_id */
	if (count < 2)
		return -EINVAL;

	/* wait for some data */
	if ((status = dvb_ca_en50221_io_read_condition(ca, &result, &slot)) == 0) {

		/* if we're in nonblocking mode, exit immediately */
		if (file->f_flags & O_NONBLOCK)
			return -EWOULDBLOCK;

		/* wait for some data */
		status = wait_event_interruptible(ca->wait_queue,
						  dvb_ca_en50221_io_read_condition
						  (ca, &result, &slot));
	}
	if ((status < 0) || (result < 0)) {
		if (result)
			return result;
		return status;
	}

	idx = dvb_ringbuffer_pkt_next(&ca->slot_info[slot].rx_buffer, -1, &fraglen);
	pktlen = 2;
	do {
		if (idx == -1) {
			printk("dvb_ca adapter %d: BUG: read packet ended before last_fragment encountered\n", ca->dvbdev->adapter->num);
			status = -EIO;
			goto exit;
		}

		dvb_ringbuffer_pkt_read(&ca->slot_info[slot].rx_buffer, idx, 0, hdr, 2, 0);
		if (connection_id == -1)
			connection_id = hdr[0];
		if (hdr[0] == connection_id) {
			if (pktlen < count) {
				if ((pktlen + fraglen - 2) > count) {
					fraglen = count - pktlen;
				} else {
					fraglen -= 2;
				}

				if ((status = dvb_ringbuffer_pkt_read(&ca->slot_info[slot].rx_buffer, idx, 2,
								      buf + pktlen, fraglen, 1)) < 0) {
					goto exit;
				}
				pktlen += fraglen;
			}

			if ((hdr[1] & 0x80) == 0)
				last_fragment = 1;
			dispose = 1;
		}

		idx2 = dvb_ringbuffer_pkt_next(&ca->slot_info[slot].rx_buffer, idx, &fraglen);
		if (dispose)
			dvb_ringbuffer_pkt_dispose(&ca->slot_info[slot].rx_buffer, idx);
		idx = idx2;
		dispose = 0;
	} while (!last_fragment);

	hdr[0] = slot;
	hdr[1] = connection_id;
	if ((status = copy_to_user(buf, hdr, 2)) != 0)
		goto exit;
	status = pktlen;

exit:
	return status;
}


/**
 * Implementation of file open syscall.
 *
 * @param inode Inode concerned.
 * @param file File concerned.
 *
 * @return 0 on success, <0 on failure.
 */
static int dvb_ca_en50221_io_open(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	int err;
	int i;

	dprintk("%s\n", __FUNCTION__);

	if (!try_module_get(ca->pub->owner))
		return -EIO;

	err = dvb_generic_open(inode, file);
	if (err < 0)
		return err;

	for (i = 0; i < ca->slot_count; i++) {

		if (ca->slot_info[i].slot_state == DVB_CA_SLOTSTATE_RUNNING) {
			if (ca->slot_info[i].rx_buffer.data != NULL) {
				/* it is safe to call this here without locks because
				 * ca->open == 0. Data is not read in this case */
				dvb_ringbuffer_flush(&ca->slot_info[i].rx_buffer);
			}
		}
	}

	ca->open = 1;
	dvb_ca_en50221_thread_update_delay(ca);
	dvb_ca_en50221_thread_wakeup(ca);

	return 0;
}


/**
 * Implementation of file close syscall.
 *
 * @param inode Inode concerned.
 * @param file File concerned.
 *
 * @return 0 on success, <0 on failure.
 */
static int dvb_ca_en50221_io_release(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	int err = 0;

	dprintk("%s\n", __FUNCTION__);

	/* mark the CA device as closed */
	ca->open = 0;
	dvb_ca_en50221_thread_update_delay(ca);

	err = dvb_generic_release(inode, file);

	module_put(ca->pub->owner);

	return 0;
}


/**
 * Implementation of poll() syscall.
 *
 * @param file File concerned.
 * @param wait poll wait table.
 *
 * @return Standard poll mask.
 */
static unsigned int dvb_ca_en50221_io_poll(struct file *file, poll_table * wait)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_ca_private *ca = dvbdev->priv;
	unsigned int mask = 0;
	int slot;
	int result = 0;

	dprintk("%s\n", __FUNCTION__);

	if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1) {
		mask |= POLLIN;
	}

	/* if there is something, return now */
	if (mask)
		return mask;

	/* wait for something to happen */
	poll_wait(file, &ca->wait_queue, wait);

	if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1) {
		mask |= POLLIN;
	}

	return mask;
}
EXPORT_SYMBOL(dvb_ca_en50221_init);


static struct file_operations dvb_ca_fops = {
	.owner = THIS_MODULE,
	.read = dvb_ca_en50221_io_read,
	.write = dvb_ca_en50221_io_write,
	.ioctl = dvb_ca_en50221_io_ioctl,
	.open = dvb_ca_en50221_io_open,
	.release = dvb_ca_en50221_io_release,
	.poll = dvb_ca_en50221_io_poll,
};

static struct dvb_device dvbdev_ca = {
	.priv = NULL,
	.users = 1,
	.readers = 1,
	.writers = 1,
	.fops = &dvb_ca_fops,
};


/* ******************************************************************************** */
/* Initialisation/shutdown functions */


/**
 * Initialise a new DVB CA EN50221 interface device.
 *
 * @param dvb_adapter DVB adapter to attach the new CA device to.
 * @param ca The dvb_ca instance.
 * @param flags Flags describing the CA device (DVB_CA_FLAG_*).
 * @param slot_count Number of slots supported.
 *
 * @return 0 on success, nonzero on failure
 */
int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
			struct dvb_ca_en50221 *pubca, int flags, int slot_count)
{
	int ret;
	struct dvb_ca_private *ca = NULL;
	int i;

	dprintk("%s\n", __FUNCTION__);

	if (slot_count < 1)
		return -EINVAL;

	/* initialise the system data */
	if ((ca =
	     (struct dvb_ca_private *) kmalloc(sizeof(struct dvb_ca_private),
					       GFP_KERNEL)) == NULL) {
		ret = -ENOMEM;
		goto error;
	}
	memset(ca, 0, sizeof(struct dvb_ca_private));
	ca->pub = pubca;
	ca->flags = flags;
	ca->slot_count = slot_count;
	if ((ca->slot_info = kmalloc(sizeof(struct dvb_ca_slot) * slot_count, GFP_KERNEL)) == NULL) {
		ret = -ENOMEM;
		goto error;
	}
	memset(ca->slot_info, 0, sizeof(struct dvb_ca_slot) * slot_count);
	init_waitqueue_head(&ca->wait_queue);
	ca->thread_pid = 0;
	init_waitqueue_head(&ca->thread_queue);
	ca->exit = 0;
	ca->open = 0;
	ca->wakeup = 0;
	ca->next_read_slot = 0;
	pubca->private = ca;

	/* register the DVB device */
	ret = dvb_register_device(dvb_adapter, &ca->dvbdev, &dvbdev_ca, ca, DVB_DEVICE_CA);
	if (ret)
		goto error;

	/* now initialise each slot */
	for (i = 0; i < slot_count; i++) {
		memset(&ca->slot_info[i], 0, sizeof(struct dvb_ca_slot));
		ca->slot_info[i].slot_state = DVB_CA_SLOTSTATE_NONE;
		atomic_set(&ca->slot_info[i].camchange_count, 0);
		ca->slot_info[i].camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
	}

	if (signal_pending(current)) {
		ret = -EINTR;
		goto error;
	}
	mb();

	/* create a kthread for monitoring this CA device */

	ret = kernel_thread(dvb_ca_en50221_thread, ca, 0);

	if (ret < 0) {
		printk("dvb_ca_init: failed to start kernel_thread (%d)\n", ret);
		goto error;
	}
	ca->thread_pid = ret;
	return 0;

error:
	if (ca != NULL) {
		if (ca->dvbdev != NULL)
			dvb_unregister_device(ca->dvbdev);
		kfree(ca->slot_info);
		kfree(ca);
	}
	pubca->private = NULL;
	return ret;
}
EXPORT_SYMBOL(dvb_ca_en50221_release);



/**
 * Release a DVB CA EN50221 interface device.
 *
 * @param ca_dev The dvb_device_t instance for the CA device.
 * @param ca The associated dvb_ca instance.
 */
void dvb_ca_en50221_release(struct dvb_ca_en50221 *pubca)
{
	struct dvb_ca_private *ca = pubca->private;
	int i;

	dprintk("%s\n", __FUNCTION__);

	/* shutdown the thread if there was one */
	if (ca->thread_pid) {
		if (kill_proc(ca->thread_pid, 0, 1) == -ESRCH) {
			printk("dvb_ca_release adapter %d: thread PID %d already died\n",
			       ca->dvbdev->adapter->num, ca->thread_pid);
		} else {
			ca->exit = 1;
			mb();
			dvb_ca_en50221_thread_wakeup(ca);
			wait_event_interruptible(ca->thread_queue, ca->thread_pid == 0);
		}
	}

	for (i = 0; i < ca->slot_count; i++) {
		dvb_ca_en50221_slot_shutdown(ca, i);
		if (ca->slot_info[i].rx_buffer.data != NULL) {
			vfree(ca->slot_info[i].rx_buffer.data);
		}
	}
	kfree(ca->slot_info);
	dvb_unregister_device(ca->dvbdev);
	kfree(ca);
	pubca->private = NULL;
}