NFC: add nfc generic netlink interface

The NFC generic netlink interface exports the NFC control operations
to the user space.

Signed-off-by: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Signed-off-by: Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Author: Lauro Ramos Venancio

include/linux/nfc.h

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2011 Instituto Nokia de Tecnologia
+ *
+ * Authors:
+ *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
+ *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
+ *
+ * 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.
+ *
+ * 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.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __LINUX_NFC_H
+#define __LINUX_NFC_H
+
+#define NFC_GENL_NAME "nfc"
+#define NFC_GENL_VERSION 1
+
+#define NFC_GENL_MCAST_EVENT_NAME "events"
+
+/**
+ * enum nfc_commands - supported nfc commands
+ *
+ * @NFC_CMD_UNSPEC: unspecified command
+ *
+ * @NFC_CMD_GET_DEVICE: request information about a device (requires
+ *	%NFC_ATTR_DEVICE_INDEX) or dump request to get a list of all nfc devices
+ * @NFC_CMD_START_POLL: start polling for targets using the given protocols
+ *	(requires %NFC_ATTR_DEVICE_INDEX and %NFC_ATTR_PROTOCOLS)
+ * @NFC_CMD_STOP_POLL: stop polling for targets (requires
+ *	%NFC_ATTR_DEVICE_INDEX)
+ * @NFC_CMD_GET_TARGET: dump all targets found by the previous poll (requires
+ *	%NFC_ATTR_DEVICE_INDEX)
+ * @NFC_EVENT_TARGETS_FOUND: event emitted when a new target is found
+ *	(it sends %NFC_ATTR_DEVICE_INDEX)
+ * @NFC_EVENT_DEVICE_ADDED: event emitted when a new device is registred
+ *	(it sends %NFC_ATTR_DEVICE_NAME, %NFC_ATTR_DEVICE_INDEX and
+ *	%NFC_ATTR_PROTOCOLS)
+ * @NFC_EVENT_DEVICE_REMOVED: event emitted when a device is removed
+ *	(it sends %NFC_ATTR_DEVICE_INDEX)
+ */
+enum nfc_commands {
+	NFC_CMD_UNSPEC,
+	NFC_CMD_GET_DEVICE,
+	NFC_CMD_START_POLL,
+	NFC_CMD_STOP_POLL,
+	NFC_CMD_GET_TARGET,
+	NFC_EVENT_TARGETS_FOUND,
+	NFC_EVENT_DEVICE_ADDED,
+	NFC_EVENT_DEVICE_REMOVED,
+/* private: internal use only */
+	__NFC_CMD_AFTER_LAST
+};
+#define NFC_CMD_MAX (__NFC_CMD_AFTER_LAST - 1)
+
+/**
+ * enum nfc_attrs - supported nfc attributes
+ *
+ * @NFC_ATTR_UNSPEC: unspecified attribute
+ *
+ * @NFC_ATTR_DEVICE_INDEX: index of nfc device
+ * @NFC_ATTR_DEVICE_NAME: device name, max 8 chars
+ * @NFC_ATTR_PROTOCOLS: nfc protocols - bitwise or-ed combination from
+ *	NFC_PROTO_*_MASK constants
+ * @NFC_ATTR_TARGET_INDEX: index of the nfc target
+ * @NFC_ATTR_TARGET_SENS_RES: NFC-A targets extra information such as NFCID
+ * @NFC_ATTR_TARGET_SEL_RES: NFC-A targets extra information (useful if the
+ *	target is not NFC-Forum compliant)
+ */
+enum nfc_attrs {
+	NFC_ATTR_UNSPEC,
+	NFC_ATTR_DEVICE_INDEX,
+	NFC_ATTR_DEVICE_NAME,
+	NFC_ATTR_PROTOCOLS,
+	NFC_ATTR_TARGET_INDEX,
+	NFC_ATTR_TARGET_SENS_RES,
+	NFC_ATTR_TARGET_SEL_RES,
+/* private: internal use only */
+	__NFC_ATTR_AFTER_LAST
+};
+#define NFC_ATTR_MAX (__NFC_ATTR_AFTER_LAST - 1)
+
+#define NFC_DEVICE_NAME_MAXSIZE 8
+
+/* NFC protocols */
+#define NFC_PROTO_JEWEL		1
+#define NFC_PROTO_MIFARE	2
+#define NFC_PROTO_FELICA	3
+#define NFC_PROTO_ISO14443	4
+#define NFC_PROTO_NFC_DEP	5
+
+#define NFC_PROTO_MAX		6
+
+/* NFC protocols masks used in bitsets */
+#define NFC_PROTO_JEWEL_MASK	(1 << NFC_PROTO_JEWEL)
+#define NFC_PROTO_MIFARE_MASK	(1 << NFC_PROTO_MIFARE)
+#define NFC_PROTO_FELICA_MASK	(1 << NFC_PROTO_FELICA)
+#define NFC_PROTO_ISO14443_MASK	(1 << NFC_PROTO_ISO14443)
+#define NFC_PROTO_NFC_DEP_MASK	(1 << NFC_PROTO_NFC_DEP)
+
+#endif /*__LINUX_NFC_H */

include/net/nfc.h

@@ -58,10 +58,28 @@ struct nfc_ops {
 							void *cb_context);
 };
 
+struct nfc_target {
+	u32 idx;
+	u32 supported_protocols;
+	u16 sens_res;
+	u8 sel_res;
+};
+
+struct nfc_genl_data {
+	u32 poll_req_pid;
+	struct mutex genl_data_mutex;
+};
+
 struct nfc_dev {
 	unsigned idx;
+	unsigned target_idx;
+	struct nfc_target *targets;
+	int n_targets;
+	int targets_generation;
+	spinlock_t targets_lock;
 	struct device dev;
 	bool polling;
+	struct nfc_genl_data genl_data;
 	u32 supported_protocols;
 
 	struct nfc_ops *ops;
@@ -132,4 +150,7 @@ static inline const char *nfc_device_name(struct nfc_dev *dev)
 
 struct sk_buff *nfc_alloc_skb(unsigned int size, gfp_t gfp);
 
+int nfc_targets_found(struct nfc_dev *dev, struct nfc_target *targets,
+							int ntargets);
+
 #endif /* __NET_NFC_H */

net/nfc/Makefile

@@ -4,4 +4,4 @@
 
 obj-$(CONFIG_NFC) += nfc.o
 
-nfc-objs := core.o
+nfc-objs := core.o netlink.o

net/nfc/core.c

@@ -233,12 +233,60 @@ struct sk_buff *nfc_alloc_skb(unsigned int size, gfp_t gfp)
 }
 EXPORT_SYMBOL(nfc_alloc_skb);
 
+/**
+ * nfc_targets_found - inform that targets were found
+ *
+ * @dev: The nfc device that found the targets
+ * @targets: array of nfc targets found
+ * @ntargets: targets array size
+ *
+ * The device driver must call this function when one or many nfc targets
+ * are found. After calling this function, the device driver must stop
+ * polling for targets.
+ */
+int nfc_targets_found(struct nfc_dev *dev, struct nfc_target *targets,
+							int n_targets)
+{
+	int i;
+
+	nfc_dbg("dev_name=%s n_targets=%d", dev_name(&dev->dev), n_targets);
+
+	dev->polling = false;
+
+	for (i = 0; i < n_targets; i++)
+		targets[i].idx = dev->target_idx++;
+
+	spin_lock_bh(&dev->targets_lock);
+
+	dev->targets_generation++;
+
+	kfree(dev->targets);
+	dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target),
+								GFP_ATOMIC);
+
+	if (!dev->targets) {
+		dev->n_targets = 0;
+		spin_unlock_bh(&dev->targets_lock);
+		return -ENOMEM;
+	}
+
+	dev->n_targets = n_targets;
+	spin_unlock_bh(&dev->targets_lock);
+
+	nfc_genl_targets_found(dev);
+
+	return 0;
+}
+EXPORT_SYMBOL(nfc_targets_found);
+
 static void nfc_release(struct device *d)
 {
 	struct nfc_dev *dev = to_nfc_dev(d);
 
 	nfc_dbg("dev_name=%s", dev_name(&dev->dev));
 
+	nfc_genl_data_exit(&dev->genl_data);
+	kfree(dev->targets);
 	kfree(dev);
 }
 
@@ -298,6 +346,12 @@ struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
 	dev->ops = ops;
 	dev->supported_protocols = supported_protocols;
 
+	spin_lock_init(&dev->targets_lock);
+	nfc_genl_data_init(&dev->genl_data);
+
+	/* first generation must not be 0 */
+	dev->targets_generation = 1;
+
 	return dev;
 }
 EXPORT_SYMBOL(nfc_allocate_device);
@@ -318,7 +372,16 @@ int nfc_register_device(struct nfc_dev *dev)
 	rc = device_add(&dev->dev);
 	mutex_unlock(&nfc_devlist_mutex);
 
-	return rc;
+	if (rc < 0)
+		return rc;
+
+	rc = nfc_genl_device_added(dev);
+	if (rc)
+		nfc_dbg("The userspace won't be notified that the device %s was"
+						" added", dev_name(&dev->dev));
+
+
+	return 0;
 }
 EXPORT_SYMBOL(nfc_register_device);
 
@@ -329,6 +392,8 @@ EXPORT_SYMBOL(nfc_register_device);
  */
 void nfc_unregister_device(struct nfc_dev *dev)
 {
+	int rc;
+
 	nfc_dbg("dev_name=%s", dev_name(&dev->dev));
 
 	mutex_lock(&nfc_devlist_mutex);
@@ -341,18 +406,42 @@ void nfc_unregister_device(struct nfc_dev *dev)
 	device_unlock(&dev->dev);
 
 	mutex_unlock(&nfc_devlist_mutex);
+
+	rc = nfc_genl_device_removed(dev);
+	if (rc)
+		nfc_dbg("The userspace won't be notified that the device %s"
+					" was removed", dev_name(&dev->dev));
+
 }
 EXPORT_SYMBOL(nfc_unregister_device);
 
 static int __init nfc_init(void)
 {
+	int rc;
+
 	nfc_info("NFC Core ver %s", VERSION);
 
-	return class_register(&nfc_class);
+	rc = class_register(&nfc_class);
+	if (rc)
+		return rc;
+
+	rc = nfc_genl_init();
+	if (rc)
+		goto err_genl;
+
+	/* the first generation must not be 0 */
+	nfc_devlist_generation = 1;
+
+	return 0;
+
+err_genl:
+	class_unregister(&nfc_class);
+	return rc;
 }
 
 static void __exit nfc_exit(void)
 {
+	nfc_genl_exit();
 	class_unregister(&nfc_class);
 }