drivers/ieee802154: IEEE 802.15.4 loopback driver

Add support for IEEE 802.15.4 loopback driver - useful development
and debugging tool.
Signed-off-by: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/ieee802154/Kconfig

@@ -19,4 +19,12 @@ config IEEE802154_FAKEHARD
 
           This driver can also be built as a module. To do so say M here.
 	  The module will be called 'fakehard'.
+config IEEE802154_FAKELB
+	depends on IEEE802154_DRIVERS && MAC802154
+	tristate "IEEE 802.15.4 loopback driver"
+	---help---
+	  Say Y here to enable the fake driver that can emulate a net
+	  of several interconnected radio devices.
 
+	  This driver can also be built as a module. To do so say M here.
+	  The module will be called 'fakelb'.

drivers/ieee802154/Makefile

 obj-$(CONFIG_IEEE802154_FAKEHARD) += fakehard.o
+obj-$(CONFIG_IEEE802154_FAKELB) += fakelb.o

drivers/ieee802154/fakelb.c

+/*
+ * Loopback IEEE 802.15.4 interface
+ *
+ * Copyright 2007-2012 Siemens AG
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Written by:
+ * Sergey Lapin <slapin@ossfans.org>
+ * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
+ * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
+ */
+
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/platform_device.h>
+#include <linux/netdevice.h>
+#include <linux/spinlock.h>
+#include <net/mac802154.h>
+#include <net/wpan-phy.h>
+
+static int numlbs = 1;
+
+struct fakelb_dev_priv {
+	struct ieee802154_dev *dev;
+
+	struct list_head list;
+	struct fakelb_priv *fake;
+
+	spinlock_t lock;
+	bool working;
+};
+
+struct fakelb_priv {
+	struct list_head list;
+	rwlock_t lock;
+};
+
+static int
+fakelb_hw_ed(struct ieee802154_dev *dev, u8 *level)
+{
+	might_sleep();
+	BUG_ON(!level);
+	*level = 0xbe;
+
+	return 0;
+}
+
+static int
+fakelb_hw_channel(struct ieee802154_dev *dev, int page, int channel)
+{
+	pr_debug("set channel to %d\n", channel);
+
+	might_sleep();
+	dev->phy->current_page = page;
+	dev->phy->current_channel = channel;
+
+	return 0;
+}
+
+static void
+fakelb_hw_deliver(struct fakelb_dev_priv *priv, struct sk_buff *skb)
+{
+	struct sk_buff *newskb;
+
+	spin_lock(&priv->lock);
+	if (priv->working) {
+		newskb = pskb_copy(skb, GFP_ATOMIC);
+		ieee802154_rx_irqsafe(priv->dev, newskb, 0xcc);
+	}
+	spin_unlock(&priv->lock);
+}
+
+static int
+fakelb_hw_xmit(struct ieee802154_dev *dev, struct sk_buff *skb)
+{
+	struct fakelb_dev_priv *priv = dev->priv;
+	struct fakelb_priv *fake = priv->fake;
+
+	might_sleep();
+
+	read_lock_bh(&fake->lock);
+	if (priv->list.next == priv->list.prev) {
+		/* we are the only one device */
+		fakelb_hw_deliver(priv, skb);
+	} else {
+		struct fakelb_dev_priv *dp;
+		list_for_each_entry(dp, &priv->fake->list, list) {
+			if (dp != priv &&
+			    (dp->dev->phy->current_channel ==
+			     priv->dev->phy->current_channel))
+				fakelb_hw_deliver(dp, skb);
+		}
+	}
+	read_unlock_bh(&fake->lock);
+
+	return 0;
+}
+
+static int
+fakelb_hw_start(struct ieee802154_dev *dev) {
+	struct fakelb_dev_priv *priv = dev->priv;
+	int ret = 0;
+
+	spin_lock(&priv->lock);
+	if (priv->working)
+		ret = -EBUSY;
+	else
+		priv->working = 1;
+	spin_unlock(&priv->lock);
+
+	return ret;
+}
+
+static void
+fakelb_hw_stop(struct ieee802154_dev *dev) {
+	struct fakelb_dev_priv *priv = dev->priv;
+
+	spin_lock(&priv->lock);
+	priv->working = 0;
+	spin_unlock(&priv->lock);
+}
+
+static struct ieee802154_ops fakelb_ops = {
+	.owner = THIS_MODULE,
+	.xmit = fakelb_hw_xmit,
+	.ed = fakelb_hw_ed,
+	.set_channel = fakelb_hw_channel,
+	.start = fakelb_hw_start,
+	.stop = fakelb_hw_stop,
+};
+
+/* Number of dummy devices to be set up by this module. */
+module_param(numlbs, int, 0);
+MODULE_PARM_DESC(numlbs, " number of pseudo devices");
+
+static int fakelb_add_one(struct device *dev, struct fakelb_priv *fake)
+{
+	struct fakelb_dev_priv *priv;
+	int err;
+	struct ieee802154_dev *ieee;
+
+	ieee = ieee802154_alloc_device(sizeof(*priv), &fakelb_ops);
+	if (!ieee)
+		return -ENOMEM;
+
+	priv = ieee->priv;
+	priv->dev = ieee;
+
+	/* 868 MHz BPSK	802.15.4-2003 */
+	ieee->phy->channels_supported[0] |= 1;
+	/* 915 MHz BPSK	802.15.4-2003 */
+	ieee->phy->channels_supported[0] |= 0x7fe;
+	/* 2.4 GHz O-QPSK 802.15.4-2003 */
+	ieee->phy->channels_supported[0] |= 0x7FFF800;
+	/* 868 MHz ASK 802.15.4-2006 */
+	ieee->phy->channels_supported[1] |= 1;
+	/* 915 MHz ASK 802.15.4-2006 */
+	ieee->phy->channels_supported[1] |= 0x7fe;
+	/* 868 MHz O-QPSK 802.15.4-2006 */
+	ieee->phy->channels_supported[2] |= 1;
+	/* 915 MHz O-QPSK 802.15.4-2006 */
+	ieee->phy->channels_supported[2] |= 0x7fe;
+	/* 2.4 GHz CSS 802.15.4a-2007 */
+	ieee->phy->channels_supported[3] |= 0x3fff;
+	/* UWB Sub-gigahertz 802.15.4a-2007 */
+	ieee->phy->channels_supported[4] |= 1;
+	/* UWB Low band 802.15.4a-2007 */
+	ieee->phy->channels_supported[4] |= 0x1e;
+	/* UWB High band 802.15.4a-2007 */
+	ieee->phy->channels_supported[4] |= 0xffe0;
+	/* 750 MHz O-QPSK 802.15.4c-2009 */
+	ieee->phy->channels_supported[5] |= 0xf;
+	/* 750 MHz MPSK 802.15.4c-2009 */
+	ieee->phy->channels_supported[5] |= 0xf0;
+	/* 950 MHz BPSK 802.15.4d-2009 */
+	ieee->phy->channels_supported[6] |= 0x3ff;
+	/* 950 MHz GFSK 802.15.4d-2009 */
+	ieee->phy->channels_supported[6] |= 0x3ffc00;
+
+	INIT_LIST_HEAD(&priv->list);
+	priv->fake = fake;
+
+	spin_lock_init(&priv->lock);
+
+	ieee->parent = dev;
+
+	err = ieee802154_register_device(ieee);
+	if (err)
+		goto err_reg;
+
+	write_lock_bh(&fake->lock);
+	list_add_tail(&priv->list, &fake->list);
+	write_unlock_bh(&fake->lock);
+
+	return 0;
+
+err_reg:
+	ieee802154_free_device(priv->dev);
+	return err;
+}
+
+static void fakelb_del(struct fakelb_dev_priv *priv)
+{
+	write_lock_bh(&priv->fake->lock);
+	list_del(&priv->list);
+	write_unlock_bh(&priv->fake->lock);
+
+	ieee802154_unregister_device(priv->dev);
+	ieee802154_free_device(priv->dev);
+}
+
+static int __devinit fakelb_probe(struct platform_device *pdev)
+{
+	struct fakelb_priv *priv;
+	struct fakelb_dev_priv *dp;
+	int err = -ENOMEM;
+	int i;
+
+	priv = kzalloc(sizeof(struct fakelb_priv), GFP_KERNEL);
+	if (!priv)
+		goto err_alloc;
+
+	INIT_LIST_HEAD(&priv->list);
+	rwlock_init(&priv->lock);
+
+	for (i = 0; i < numlbs; i++) {
+		err = fakelb_add_one(&pdev->dev, priv);
+		if (err < 0)
+			goto err_slave;
+	}
+
+	platform_set_drvdata(pdev, priv);
+	dev_info(&pdev->dev, "added ieee802154 hardware\n");
+	return 0;
+
+err_slave:
+	list_for_each_entry(dp, &priv->list, list)
+		fakelb_del(dp);
+	kfree(priv);
+err_alloc:
+	return err;
+}
+
+static int __devexit fakelb_remove(struct platform_device *pdev)
+{
+	struct fakelb_priv *priv = platform_get_drvdata(pdev);
+	struct fakelb_dev_priv *dp, *temp;
+
+	list_for_each_entry_safe(dp, temp, &priv->list, list)
+		fakelb_del(dp);
+	kfree(priv);
+
+	return 0;
+}
+
+static struct platform_device *ieee802154fake_dev;
+
+static struct platform_driver ieee802154fake_driver = {
+	.probe = fakelb_probe,
+	.remove = __devexit_p(fakelb_remove),
+	.driver = {
+			.name = "ieee802154fakelb",
+			.owner = THIS_MODULE,
+	},
+};
+
+static __init int fakelb_init_module(void)
+{
+	ieee802154fake_dev = platform_device_register_simple(
+			     "ieee802154fakelb", -1, NULL, 0);
+	return platform_driver_register(&ieee802154fake_driver);
+}
+
+static __exit void fake_remove_module(void)
+{
+	platform_driver_unregister(&ieee802154fake_driver);
+	platform_device_unregister(ieee802154fake_dev);
+}
+
+module_init(fakelb_init_module);
+module_exit(fake_remove_module);
+MODULE_LICENSE("GPL");