/*
* 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);
static void nfc_release(struct device *d)
{
struct nfc_dev *dev = to_nfc_dev(d);
nfc_dbg("dev_name=%s", dev_name(&dev->dev));
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;
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);
return rc;
}
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)
{
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);
}
EXPORT_SYMBOL(nfc_unregister_device);
static int __init nfc_init(void)
{
nfc_info("NFC Core ver %s", VERSION);
return class_register(&nfc_class);
}
static void __exit nfc_exit(void)
{
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");
