linux/net/nfc/digital_core.c

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NFC: Digital Protocol stack implementation This is the initial commit of the NFC Digital Protocol stack implementation. It offers an interface for devices that don't have an embedded NFC Digital protocol stack. The driver instantiates the digital stack by calling nfc_digital_allocate_device(). Within the nfc_digital_ops structure, the driver specifies a set of function pointers for driver operations. These functions must be implemented by the driver and are: in_configure_hw: Hardware configuration for RF technology and communication framing in initiator mode. This is a synchronous function. in_send_cmd: Initiator mode data exchange using RF technology and framing previously set with in_configure_hw. The peer response is returned through callback cb. If an io error occurs or the peer didn't reply within the specified timeout (ms), the error code is passed back through the resp pointer. This is an asynchronous function. tg_configure_hw: Hardware configuration for RF technology and communication framing in target mode. This is a synchronous function. tg_send_cmd: Target mode data exchange using RF technology and framing previously set with tg_configure_hw. The peer next command is returned through callback cb. If an io error occurs or the peer didn't reply within the specified timeout (ms), the error code is passed back through the resp pointer. This is an asynchronous function. tg_listen: Put the device in listen mode waiting for data from the peer device. This is an asynchronous function. tg_listen_mdaa: If supported, put the device in automatic listen mode with mode detection and automatic anti-collision. In this mode, the device automatically detects the RF technology and executes the anti-collision detection using the command responses specified in mdaa_params. The mdaa_params structure contains SENS_RES, NFCID1, and SEL_RES for 106A RF tech. NFCID2 and system code (sc) for 212F and 424F. The driver returns the NFC-DEP ATR_REQ command through cb. The digital stack deducts the RF tech by analyzing the SoD of the frame containing the ATR_REQ command. This is an asynchronous function. switch_rf: Turns device radio on or off. The stack does not call explicitly switch_rf to turn the radio on. A call to in|tg_configure_hw must turn the device radio on. abort_cmd: Discard the last sent command. Then the driver registers itself against the digital stack by using nfc_digital_register_device() which in turn registers the digital stack against the NFC core layer. The digital stack implements common NFC operations like dev_up(), dev_down(), start_poll(), stop_poll(), etc. This patch is only a skeleton and NFC operations are just stubs. Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2013-09-19 15:55:25 +00:00
/*
* NFC Digital Protocol stack
* Copyright (c) 2013, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
*/
#include <linux/module.h>
#include "digital.h"
static int digital_start_poll(struct nfc_dev *nfc_dev, __u32 im_protocols,
__u32 tm_protocols)
{
return -EOPNOTSUPP;
}
static void digital_stop_poll(struct nfc_dev *nfc_dev)
{
}
static int digital_dev_up(struct nfc_dev *nfc_dev)
{
return -EOPNOTSUPP;
}
static int digital_dev_down(struct nfc_dev *nfc_dev)
{
return -EOPNOTSUPP;
}
static int digital_dep_link_up(struct nfc_dev *nfc_dev,
struct nfc_target *target,
__u8 comm_mode, __u8 *gb, size_t gb_len)
{
return -EOPNOTSUPP;
}
static int digital_dep_link_down(struct nfc_dev *nfc_dev)
{
return -EOPNOTSUPP;
}
static int digital_activate_target(struct nfc_dev *nfc_dev,
struct nfc_target *target, __u32 protocol)
{
return -EOPNOTSUPP;
}
static void digital_deactivate_target(struct nfc_dev *nfc_dev,
struct nfc_target *target)
{
}
static int digital_tg_send(struct nfc_dev *dev, struct sk_buff *skb)
{
return -EOPNOTSUPP;
}
static int digital_in_send(struct nfc_dev *nfc_dev, struct nfc_target *target,
struct sk_buff *skb, data_exchange_cb_t cb,
void *cb_context)
{
return -EOPNOTSUPP;
}
static struct nfc_ops digital_nfc_ops = {
.dev_up = digital_dev_up,
.dev_down = digital_dev_down,
.start_poll = digital_start_poll,
.stop_poll = digital_stop_poll,
.dep_link_up = digital_dep_link_up,
.dep_link_down = digital_dep_link_down,
.activate_target = digital_activate_target,
.deactivate_target = digital_deactivate_target,
.tm_send = digital_tg_send,
.im_transceive = digital_in_send,
};
struct nfc_digital_dev *nfc_digital_allocate_device(struct nfc_digital_ops *ops,
__u32 supported_protocols,
__u32 driver_capabilities,
int tx_headroom, int tx_tailroom)
{
struct nfc_digital_dev *ddev;
if (!ops->in_configure_hw || !ops->in_send_cmd || !ops->tg_listen ||
!ops->tg_configure_hw || !ops->tg_send_cmd || !ops->abort_cmd ||
!ops->switch_rf)
return NULL;
ddev = kzalloc(sizeof(struct nfc_digital_dev), GFP_KERNEL);
if (!ddev) {
PR_ERR("kzalloc failed");
return NULL;
}
ddev->driver_capabilities = driver_capabilities;
ddev->ops = ops;
ddev->tx_headroom = tx_headroom;
ddev->tx_tailroom = tx_tailroom;
ddev->nfc_dev = nfc_allocate_device(&digital_nfc_ops, ddev->protocols,
ddev->tx_headroom,
ddev->tx_tailroom);
if (!ddev->nfc_dev) {
PR_ERR("nfc_allocate_device failed");
goto free_dev;
}
nfc_set_drvdata(ddev->nfc_dev, ddev);
return ddev;
free_dev:
kfree(ddev);
return NULL;
}
EXPORT_SYMBOL(nfc_digital_allocate_device);
void nfc_digital_free_device(struct nfc_digital_dev *ddev)
{
nfc_free_device(ddev->nfc_dev);
kfree(ddev);
}
EXPORT_SYMBOL(nfc_digital_free_device);
int nfc_digital_register_device(struct nfc_digital_dev *ddev)
{
return nfc_register_device(ddev->nfc_dev);
}
EXPORT_SYMBOL(nfc_digital_register_device);
void nfc_digital_unregister_device(struct nfc_digital_dev *ddev)
{
nfc_unregister_device(ddev->nfc_dev);
}
EXPORT_SYMBOL(nfc_digital_unregister_device);
MODULE_LICENSE("GPL");