[RFC net-next 06/15] net: lora: Prepare for device drivers

["Andreas Färber" <afaerber@suse.de>]

Implement helper functions for use by LoRa device drivers.

Signed-off-by: Andreas Färber <afaerber@suse.de>
---
 drivers/net/Makefile      |   1 +
 drivers/net/lora/Kconfig  |  18 +++++++
 drivers/net/lora/Makefile |  10 ++++
 drivers/net/lora/dev.c    | 125 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/lora/dev.h  |  23 +++++++++
 net/lora/Kconfig          |   6 +++
 6 files changed, 183 insertions(+)
 create mode 100644 drivers/net/lora/Kconfig
 create mode 100644 drivers/net/lora/Makefile
 create mode 100644 drivers/net/lora/dev.c
 create mode 100644 include/linux/lora/dev.h

diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 21cde7e78621..9819bf28633d 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -45,6 +45,7 @@ obj-$(CONFIG_ETHERNET) += ethernet/
 obj-$(CONFIG_FDDI) += fddi/
 obj-$(CONFIG_HIPPI) += hippi/
 obj-$(CONFIG_HAMRADIO) += hamradio/
+obj-$(CONFIG_LORA) += lora/
 obj-$(CONFIG_PLIP) += plip/
 obj-$(CONFIG_PPP) += ppp/
 obj-$(CONFIG_PPP_ASYNC) += ppp/
diff --git a/drivers/net/lora/Kconfig b/drivers/net/lora/Kconfig
new file mode 100644
index 000000000000..40969b148a50
--- /dev/null
+++ b/drivers/net/lora/Kconfig
@@ -0,0 +1,18 @@
+#
+# LoRa
+#
+
+menu "LoRa Device Drivers"
+
+config LORA_DEV
+	tristate "LoRa drivers"
+	default y
+	help
+	  LoRa ...
+	  If unsure, say Y.
+
+#
+# Alphabetically sorted.
+#
+
+endmenu
diff --git a/drivers/net/lora/Makefile b/drivers/net/lora/Makefile
new file mode 100644
index 000000000000..8f9d25ea4e70
--- /dev/null
+++ b/drivers/net/lora/Makefile
@@ -0,0 +1,10 @@
+#
+# LoRa
+#
+
+obj-$(CONFIG_LORA_DEV) += lora-dev.o
+lora-dev-y := dev.o
+
+#
+# Alphabetically sorted.
+#
diff --git a/drivers/net/lora/dev.c b/drivers/net/lora/dev.c
new file mode 100644
index 000000000000..8c01106008be
--- /dev/null
+++ b/drivers/net/lora/dev.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2017-2018 Andreas Färber
+ */
+
+#include <linux/if_arp.h>
+#include <linux/lora.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/lora/dev.h>
+#include <linux/lora/skb.h>
+#include <net/rtnetlink.h>
+
+#define LORA_MTU 256 /* XXX */
+
+struct sk_buff *alloc_lora_skb(struct net_device *dev, u8 **data)
+{
+	struct sk_buff *skb;
+
+	skb = netdev_alloc_skb(dev, sizeof(struct lora_skb_priv) + LORA_MTU);
+	if (unlikely(!skb))
+		return NULL;
+
+	skb->protocol = htons(ETH_P_LORA);
+	skb->pkt_type = PACKET_BROADCAST;
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
+	lora_skb_reserve(skb);
+	lora_skb_prv(skb)->ifindex = dev->ifindex;
+
+	return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_lora_skb);
+
+int open_loradev(struct net_device *dev)
+{
+	if (!netif_carrier_ok(dev))
+		netif_carrier_on(dev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(open_loradev);
+
+void close_loradev(struct net_device *dev)
+{
+}
+EXPORT_SYMBOL_GPL(close_loradev);
+
+static void lora_setup(struct net_device *dev)
+{
+	dev->type = ARPHRD_LORA;
+	dev->mtu = LORA_MTU;
+	dev->hard_header_len = 0;
+	dev->addr_len = 0;
+	dev->tx_queue_len = 10;
+
+	dev->flags = IFF_NOARP;
+	dev->features = 0;
+}
+
+struct net_device *alloc_loradev(int sizeof_priv)
+{
+	struct net_device *dev;
+	struct lora_priv *priv;
+
+	dev = alloc_netdev(sizeof_priv, "lora%d", NET_NAME_UNKNOWN, lora_setup);
+	if (!dev)
+		return NULL;
+
+	priv = netdev_priv(dev);
+	priv->dev = dev;
+
+	return dev;
+}
+EXPORT_SYMBOL_GPL(alloc_loradev);
+
+void free_loradev(struct net_device *dev)
+{
+	free_netdev(dev);
+}
+EXPORT_SYMBOL_GPL(free_loradev);
+
+static struct rtnl_link_ops lora_link_ops __read_mostly = {
+	.kind = "lora",
+	.setup = lora_setup,
+};
+
+int register_loradev(struct net_device *dev)
+{
+	dev->rtnl_link_ops = &lora_link_ops;
+	return register_netdev(dev);
+}
+EXPORT_SYMBOL_GPL(register_loradev);
+
+void unregister_loradev(struct net_device *dev)
+{
+	unregister_netdev(dev);
+}
+EXPORT_SYMBOL_GPL(unregister_loradev);
+
+static int __init lora_dev_init(void)
+{
+	printk("lora-dev: init\n");
+
+	return rtnl_link_register(&lora_link_ops);
+}
+
+static void __exit lora_dev_exit(void)
+{
+	printk("lora-dev: exit\n");
+
+	rtnl_link_unregister(&lora_link_ops);
+}
+
+module_init(lora_dev_init);
+module_exit(lora_dev_exit);
+
+MODULE_DESCRIPTION("LoRa device driver interface");
+MODULE_ALIAS_RTNL_LINK("lora");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andreas Färber");
diff --git a/include/linux/lora/dev.h b/include/linux/lora/dev.h
new file mode 100644
index 000000000000..531e68f0c9a6
--- /dev/null
+++ b/include/linux/lora/dev.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * linux/lora/dev.h
+ *
+ * Copyright (c) 2017-2018 Andreas Färber
+ */
+#ifndef _LORA_DEV_H
+#define _LORA_DEV_H
+
+#include <linux/netdevice.h>
+
+struct net_device *alloc_loradev(int sizeof_priv);
+void free_loradev(struct net_device *dev);
+int register_loradev(struct net_device *dev);
+void unregister_loradev(struct net_device *dev);
+int open_loradev(struct net_device *dev);
+void close_loradev(struct net_device *dev);
+
+struct lora_priv {
+	struct net_device *dev;
+};
+
+#endif /* _LORA_DEV_H */
diff --git a/net/lora/Kconfig b/net/lora/Kconfig
index 44972ea8769f..20658fea3c7c 100644
--- a/net/lora/Kconfig
+++ b/net/lora/Kconfig
@@ -7,3 +7,9 @@ menuconfig LORA
 	tristate "LoRa subsystem support"
 	help
 	  LoRa ...
+
+if LORA
+
+source "drivers/net/lora/Kconfig"
+
+endif
-- 
2.16.4