366 lines
7.5 KiB
C
366 lines
7.5 KiB
C
![]() |
/*
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* Copyright (C) 2011 Instituto Nokia de Tecnologia
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*
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* Authors:
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* Lauro Ramos Venancio <lauro.venancio@openbossa.org>
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* Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the
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* Free Software Foundation, Inc.,
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* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include "nfc.h"
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#define VERSION "0.1"
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int nfc_devlist_generation;
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DEFINE_MUTEX(nfc_devlist_mutex);
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int nfc_printk(const char *level, const char *format, ...)
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{
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struct va_format vaf;
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va_list args;
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int r;
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va_start(args, format);
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vaf.fmt = format;
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vaf.va = &args;
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r = printk("%sNFC: %pV\n", level, &vaf);
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va_end(args);
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return r;
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}
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EXPORT_SYMBOL(nfc_printk);
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/**
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* nfc_start_poll - start polling for nfc targets
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*
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* @dev: The nfc device that must start polling
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* @protocols: bitset of nfc protocols that must be used for polling
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*
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* The device remains polling for targets until a target is found or
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* the nfc_stop_poll function is called.
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*/
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int nfc_start_poll(struct nfc_dev *dev, u32 protocols)
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{
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int rc;
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nfc_dbg("dev_name=%s protocols=0x%x", dev_name(&dev->dev), protocols);
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if (!protocols)
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return -EINVAL;
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device_lock(&dev->dev);
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if (!device_is_registered(&dev->dev)) {
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rc = -ENODEV;
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goto error;
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}
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if (dev->polling) {
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rc = -EBUSY;
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goto error;
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}
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rc = dev->ops->start_poll(dev, protocols);
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if (!rc)
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dev->polling = true;
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error:
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device_unlock(&dev->dev);
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return rc;
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}
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/**
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* nfc_stop_poll - stop polling for nfc targets
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*
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* @dev: The nfc device that must stop polling
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*/
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int nfc_stop_poll(struct nfc_dev *dev)
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{
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int rc = 0;
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nfc_dbg("dev_name=%s", dev_name(&dev->dev));
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device_lock(&dev->dev);
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if (!device_is_registered(&dev->dev)) {
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rc = -ENODEV;
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goto error;
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}
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if (!dev->polling) {
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rc = -EINVAL;
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goto error;
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}
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dev->ops->stop_poll(dev);
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dev->polling = false;
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error:
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device_unlock(&dev->dev);
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return rc;
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}
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/**
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* nfc_activate_target - prepare the target for data exchange
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*
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* @dev: The nfc device that found the target
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* @target_idx: index of the target that must be activated
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* @protocol: nfc protocol that will be used for data exchange
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*/
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int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
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{
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int rc;
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nfc_dbg("dev_name=%s target_idx=%u protocol=%u", dev_name(&dev->dev),
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target_idx, protocol);
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device_lock(&dev->dev);
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if (!device_is_registered(&dev->dev)) {
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rc = -ENODEV;
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goto error;
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}
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rc = dev->ops->activate_target(dev, target_idx, protocol);
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error:
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device_unlock(&dev->dev);
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return rc;
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}
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/**
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* nfc_deactivate_target - deactivate a nfc target
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*
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* @dev: The nfc device that found the target
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* @target_idx: index of the target that must be deactivated
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*/
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int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx)
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{
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int rc = 0;
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nfc_dbg("dev_name=%s target_idx=%u", dev_name(&dev->dev), target_idx);
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device_lock(&dev->dev);
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if (!device_is_registered(&dev->dev)) {
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rc = -ENODEV;
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goto error;
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}
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dev->ops->deactivate_target(dev, target_idx);
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error:
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device_unlock(&dev->dev);
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return rc;
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}
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/**
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* nfc_data_exchange - transceive data
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*
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* @dev: The nfc device that found the target
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* @target_idx: index of the target
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* @skb: data to be sent
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* @cb: callback called when the response is received
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* @cb_context: parameter for the callback function
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*
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* The user must wait for the callback before calling this function again.
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*/
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int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx,
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struct sk_buff *skb,
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data_exchange_cb_t cb,
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void *cb_context)
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{
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int rc;
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nfc_dbg("dev_name=%s target_idx=%u skb->len=%u", dev_name(&dev->dev),
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target_idx, skb->len);
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device_lock(&dev->dev);
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if (!device_is_registered(&dev->dev)) {
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rc = -ENODEV;
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kfree_skb(skb);
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goto error;
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}
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rc = dev->ops->data_exchange(dev, target_idx, skb, cb, cb_context);
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error:
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device_unlock(&dev->dev);
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return rc;
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}
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/**
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* nfc_alloc_skb - allocate a skb for data exchange responses
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*
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* @size: size to allocate
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* @gfp: gfp flags
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*/
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struct sk_buff *nfc_alloc_skb(unsigned int size, gfp_t gfp)
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{
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struct sk_buff *skb;
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unsigned int total_size;
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total_size = size + 1;
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skb = alloc_skb(total_size, gfp);
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if (skb)
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skb_reserve(skb, 1);
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return skb;
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}
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EXPORT_SYMBOL(nfc_alloc_skb);
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static void nfc_release(struct device *d)
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{
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struct nfc_dev *dev = to_nfc_dev(d);
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nfc_dbg("dev_name=%s", dev_name(&dev->dev));
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kfree(dev);
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}
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struct class nfc_class = {
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.name = "nfc",
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.dev_release = nfc_release,
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};
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EXPORT_SYMBOL(nfc_class);
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static int match_idx(struct device *d, void *data)
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{
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struct nfc_dev *dev = to_nfc_dev(d);
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unsigned *idx = data;
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return dev->idx == *idx;
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}
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struct nfc_dev *nfc_get_device(unsigned idx)
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{
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struct device *d;
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d = class_find_device(&nfc_class, NULL, &idx, match_idx);
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if (!d)
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return NULL;
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return to_nfc_dev(d);
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}
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/**
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* nfc_allocate_device - allocate a new nfc device
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*
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* @ops: device operations
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* @supported_protocols: NFC protocols supported by the device
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*/
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struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
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u32 supported_protocols)
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{
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static atomic_t dev_no = ATOMIC_INIT(0);
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struct nfc_dev *dev;
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if (!ops->start_poll || !ops->stop_poll || !ops->activate_target ||
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!ops->deactivate_target || !ops->data_exchange)
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return NULL;
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if (!supported_protocols)
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return NULL;
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dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
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if (!dev)
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return NULL;
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dev->dev.class = &nfc_class;
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dev->idx = atomic_inc_return(&dev_no) - 1;
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dev_set_name(&dev->dev, "nfc%d", dev->idx);
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device_initialize(&dev->dev);
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dev->ops = ops;
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dev->supported_protocols = supported_protocols;
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return dev;
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}
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EXPORT_SYMBOL(nfc_allocate_device);
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/**
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* nfc_register_device - register a nfc device in the nfc subsystem
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*
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* @dev: The nfc device to register
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*/
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int nfc_register_device(struct nfc_dev *dev)
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{
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int rc;
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nfc_dbg("dev_name=%s", dev_name(&dev->dev));
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mutex_lock(&nfc_devlist_mutex);
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nfc_devlist_generation++;
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rc = device_add(&dev->dev);
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mutex_unlock(&nfc_devlist_mutex);
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return rc;
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}
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EXPORT_SYMBOL(nfc_register_device);
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/**
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* nfc_unregister_device - unregister a nfc device in the nfc subsystem
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*
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* @dev: The nfc device to unregister
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*/
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void nfc_unregister_device(struct nfc_dev *dev)
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{
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nfc_dbg("dev_name=%s", dev_name(&dev->dev));
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mutex_lock(&nfc_devlist_mutex);
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nfc_devlist_generation++;
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/* lock to avoid unregistering a device while an operation
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is in progress */
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device_lock(&dev->dev);
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device_del(&dev->dev);
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device_unlock(&dev->dev);
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mutex_unlock(&nfc_devlist_mutex);
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}
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EXPORT_SYMBOL(nfc_unregister_device);
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static int __init nfc_init(void)
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{
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nfc_info("NFC Core ver %s", VERSION);
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return class_register(&nfc_class);
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}
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static void __exit nfc_exit(void)
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{
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class_unregister(&nfc_class);
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}
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subsys_initcall(nfc_init);
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module_exit(nfc_exit);
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MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
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MODULE_DESCRIPTION("NFC Core ver " VERSION);
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MODULE_VERSION(VERSION);
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MODULE_LICENSE("GPL");
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