diff options
Diffstat (limited to 'net/nfc/core.c')
-rw-r--r-- | net/nfc/core.c | 468 |
1 files changed, 468 insertions, 0 deletions
diff --git a/net/nfc/core.c b/net/nfc/core.c new file mode 100644 index 000000000000..b6fd4e1f2057 --- /dev/null +++ b/net/nfc/core.c @@ -0,0 +1,468 @@ +/* + * 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. + */ + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> + +#include "nfc.h" + +#define VERSION "0.1" + +int nfc_devlist_generation; +DEFINE_MUTEX(nfc_devlist_mutex); + +int nfc_printk(const char *level, const char *format, ...) +{ + struct va_format vaf; + va_list args; + int r; + + va_start(args, format); + + vaf.fmt = format; + vaf.va = &args; + + r = printk("%sNFC: %pV\n", level, &vaf); + + va_end(args); + + return r; +} +EXPORT_SYMBOL(nfc_printk); + +/** + * nfc_start_poll - start polling for nfc targets + * + * @dev: The nfc device that must start polling + * @protocols: bitset of nfc protocols that must be used for polling + * + * The device remains polling for targets until a target is found or + * the nfc_stop_poll function is called. + */ +int nfc_start_poll(struct nfc_dev *dev, u32 protocols) +{ + int rc; + + nfc_dbg("dev_name=%s protocols=0x%x", dev_name(&dev->dev), protocols); + + if (!protocols) + return -EINVAL; + + device_lock(&dev->dev); + + if (!device_is_registered(&dev->dev)) { + rc = -ENODEV; + goto error; + } + + if (dev->polling) { + rc = -EBUSY; + goto error; + } + + rc = dev->ops->start_poll(dev, protocols); + if (!rc) + dev->polling = true; + +error: + device_unlock(&dev->dev); + return rc; +} + +/** + * nfc_stop_poll - stop polling for nfc targets + * + * @dev: The nfc device that must stop polling + */ +int nfc_stop_poll(struct nfc_dev *dev) +{ + int rc = 0; + + nfc_dbg("dev_name=%s", dev_name(&dev->dev)); + + device_lock(&dev->dev); + + if (!device_is_registered(&dev->dev)) { + rc = -ENODEV; + goto error; + } + + if (!dev->polling) { + rc = -EINVAL; + goto error; + } + + dev->ops->stop_poll(dev); + dev->polling = false; + +error: + device_unlock(&dev->dev); + return rc; +} + +/** + * nfc_activate_target - prepare the target for data exchange + * + * @dev: The nfc device that found the target + * @target_idx: index of the target that must be activated + * @protocol: nfc protocol that will be used for data exchange + */ +int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol) +{ + int rc; + + nfc_dbg("dev_name=%s target_idx=%u protocol=%u", dev_name(&dev->dev), + target_idx, protocol); + + device_lock(&dev->dev); + + if (!device_is_registered(&dev->dev)) { + rc = -ENODEV; + goto error; + } + + rc = dev->ops->activate_target(dev, target_idx, protocol); + +error: + device_unlock(&dev->dev); + return rc; +} + +/** + * nfc_deactivate_target - deactivate a nfc target + * + * @dev: The nfc device that found the target + * @target_idx: index of the target that must be deactivated + */ +int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx) +{ + int rc = 0; + + nfc_dbg("dev_name=%s target_idx=%u", dev_name(&dev->dev), target_idx); + + device_lock(&dev->dev); + + if (!device_is_registered(&dev->dev)) { + rc = -ENODEV; + goto error; + } + + dev->ops->deactivate_target(dev, target_idx); + +error: + device_unlock(&dev->dev); + return rc; +} + +/** + * nfc_data_exchange - transceive data + * + * @dev: The nfc device that found the target + * @target_idx: index of the target + * @skb: data to be sent + * @cb: callback called when the response is received + * @cb_context: parameter for the callback function + * + * The user must wait for the callback before calling this function again. + */ +int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, + struct sk_buff *skb, + data_exchange_cb_t cb, + void *cb_context) +{ + int rc; + + nfc_dbg("dev_name=%s target_idx=%u skb->len=%u", dev_name(&dev->dev), + target_idx, skb->len); + + device_lock(&dev->dev); + + if (!device_is_registered(&dev->dev)) { + rc = -ENODEV; + kfree_skb(skb); + goto error; + } + + rc = dev->ops->data_exchange(dev, target_idx, skb, cb, cb_context); + +error: + device_unlock(&dev->dev); + return rc; +} + +/** + * nfc_alloc_skb - allocate a skb for data exchange responses + * + * @size: size to allocate + * @gfp: gfp flags + */ +struct sk_buff *nfc_alloc_skb(unsigned int size, gfp_t gfp) +{ + struct sk_buff *skb; + unsigned int total_size; + + total_size = size + 1; + skb = alloc_skb(total_size, gfp); + + if (skb) + skb_reserve(skb, 1); + + return skb; +} +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); +} + +struct class nfc_class = { + .name = "nfc", + .dev_release = nfc_release, +}; +EXPORT_SYMBOL(nfc_class); + +static int match_idx(struct device *d, void *data) +{ + struct nfc_dev *dev = to_nfc_dev(d); + unsigned *idx = data; + + return dev->idx == *idx; +} + +struct nfc_dev *nfc_get_device(unsigned idx) +{ + struct device *d; + + d = class_find_device(&nfc_class, NULL, &idx, match_idx); + if (!d) + return NULL; + + return to_nfc_dev(d); +} + +/** + * nfc_allocate_device - allocate a new nfc device + * + * @ops: device operations + * @supported_protocols: NFC protocols supported by the device + */ +struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops, + u32 supported_protocols) +{ + static atomic_t dev_no = ATOMIC_INIT(0); + struct nfc_dev *dev; + + if (!ops->start_poll || !ops->stop_poll || !ops->activate_target || + !ops->deactivate_target || !ops->data_exchange) + return NULL; + + if (!supported_protocols) + return NULL; + + dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL); + if (!dev) + return NULL; + + dev->dev.class = &nfc_class; + dev->idx = atomic_inc_return(&dev_no) - 1; + dev_set_name(&dev->dev, "nfc%d", dev->idx); + device_initialize(&dev->dev); + + 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); + +/** + * nfc_register_device - register a nfc device in the nfc subsystem + * + * @dev: The nfc device to register + */ +int nfc_register_device(struct nfc_dev *dev) +{ + int rc; + + nfc_dbg("dev_name=%s", dev_name(&dev->dev)); + + mutex_lock(&nfc_devlist_mutex); + nfc_devlist_generation++; + rc = device_add(&dev->dev); + mutex_unlock(&nfc_devlist_mutex); + + 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); + +/** + * nfc_unregister_device - unregister a nfc device in the nfc subsystem + * + * @dev: The nfc device to unregister + */ +void nfc_unregister_device(struct nfc_dev *dev) +{ + int rc; + + nfc_dbg("dev_name=%s", dev_name(&dev->dev)); + + mutex_lock(&nfc_devlist_mutex); + nfc_devlist_generation++; + + /* lock to avoid unregistering a device while an operation + is in progress */ + device_lock(&dev->dev); + device_del(&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); + + 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; + + rc = rawsock_init(); + if (rc) + goto err_rawsock; + + rc = af_nfc_init(); + if (rc) + goto err_af_nfc; + + return 0; + +err_af_nfc: + rawsock_exit(); +err_rawsock: + nfc_genl_exit(); +err_genl: + class_unregister(&nfc_class); + return rc; +} + +static void __exit nfc_exit(void) +{ + af_nfc_exit(); + rawsock_exit(); + nfc_genl_exit(); + class_unregister(&nfc_class); +} + +subsys_initcall(nfc_init); +module_exit(nfc_exit); + +MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>"); +MODULE_DESCRIPTION("NFC Core ver " VERSION); +MODULE_VERSION(VERSION); +MODULE_LICENSE("GPL"); |