Commit 8a00a61b authored by Frederic Danis's avatar Frederic Danis Committed by Samuel Ortiz

NFC: Add basic NCI over SPI

The NFC Forum defines a transport interface based on
Serial Peripheral Interface (SPI) for the NFC Controller
Interface (NCI).

This module implements the SPI transport of NCI, calling SPI module
directly to read/write data to NFC controller (NFCC).

NFCC driver should provide functions performing device open and close.
It should also provide functions asserting/de-asserting interruption
to prevent TX/RX race conditions.
NFCC driver can also fix a delay between transactions if needed by
the hardware.
Signed-off-by: default avatarFrederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent a395298c
......@@ -3,6 +3,7 @@
* NFC Controller (NFCC) and a Device Host (DH).
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2013 Intel Corporation. All rights reserved.
*
* Written by Ilan Elias <ilane@ti.com>
*
......@@ -202,4 +203,52 @@ void nci_req_complete(struct nci_dev *ndev, int result);
/* ----- NCI status code ----- */
int nci_to_errno(__u8 code);
/* ----- NCI over SPI acknowledge modes ----- */
#define NCI_SPI_CRC_DISABLED 0x00
#define NCI_SPI_CRC_ENABLED 0x01
/* ----- NCI SPI structures ----- */
struct nci_spi_dev;
struct nci_spi_ops {
int (*open)(struct nci_spi_dev *ndev);
int (*close)(struct nci_spi_dev *ndev);
void (*assert_int)(struct nci_spi_dev *ndev);
void (*deassert_int)(struct nci_spi_dev *ndev);
};
struct nci_spi_dev {
struct nci_dev *nci_dev;
struct spi_device *spi;
struct nci_spi_ops *ops;
unsigned int xfer_udelay; /* microseconds delay between
transactions */
u8 acknowledge_mode;
void *driver_data;
};
/* ----- NCI SPI Devices ----- */
struct nci_spi_dev *nci_spi_allocate_device(struct spi_device *spi,
struct nci_spi_ops *ops,
u32 supported_protocols,
u32 supported_se,
u8 acknowledge_mode,
unsigned int delay);
void nci_spi_free_device(struct nci_spi_dev *ndev);
int nci_spi_register_device(struct nci_spi_dev *ndev);
void nci_spi_unregister_device(struct nci_spi_dev *ndev);
static inline void nci_spi_set_drvdata(struct nci_spi_dev *ndev,
void *data)
{
ndev->driver_data = data;
}
static inline void *nci_spi_get_drvdata(struct nci_spi_dev *ndev)
{
return ndev->driver_data;
}
#endif /* __NCI_CORE_H */
......@@ -8,3 +8,13 @@ config NFC_NCI
Say Y here to compile NCI support into the kernel or say M to
compile it as module (nci).
config NFC_NCI_SPI
depends on NFC_NCI && SPI
bool "NCI over SPI protocol support"
default n
help
NCI (NFC Controller Interface) is a communication protocol between
an NFC Controller (NFCC) and a Device Host (DH).
Say yes if you use an NCI driver that requires SPI link layer.
......@@ -5,3 +5,5 @@
obj-$(CONFIG_NFC_NCI) += nci.o
nci-objs := core.o data.o lib.o ntf.o rsp.o
nci-$(CONFIG_NFC_NCI_SPI) += spi.o
/*
* Copyright (C) 2013 Intel Corporation. All rights reserved.
*
* 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.
*
* 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.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#define pr_fmt(fmt) "nci_spi: %s: " fmt, __func__
#include <linux/export.h>
#include <linux/spi/spi.h>
#include <linux/nfc.h>
#include <net/nfc/nci_core.h>
#define NCI_SPI_HDR_LEN 4
#define NCI_SPI_CRC_LEN 2
static int nci_spi_open(struct nci_dev *nci_dev)
{
struct nci_spi_dev *ndev = nci_get_drvdata(nci_dev);
return ndev->ops->open(ndev);
}
static int nci_spi_close(struct nci_dev *nci_dev)
{
struct nci_spi_dev *ndev = nci_get_drvdata(nci_dev);
return ndev->ops->close(ndev);
}
static int nci_spi_send(struct nci_dev *nci_dev, struct sk_buff *skb)
{
return 0;
}
static struct nci_ops nci_spi_ops = {
.open = nci_spi_open,
.close = nci_spi_close,
.send = nci_spi_send,
};
/* ---- Interface to NCI SPI drivers ---- */
/**
* nci_spi_allocate_device - allocate a new nci spi device
*
* @spi: SPI device
* @ops: device operations
* @supported_protocols: NFC protocols supported by the device
* @supported_se: NFC Secure Elements supported by the device
* @acknowledge_mode: Acknowledge mode used by the device
* @delay: delay between transactions in us
*/
struct nci_spi_dev *nci_spi_allocate_device(struct spi_device *spi,
struct nci_spi_ops *ops,
u32 supported_protocols,
u32 supported_se,
u8 acknowledge_mode,
unsigned int delay)
{
struct nci_spi_dev *ndev;
int tailroom = 0;
if (!ops->open || !ops->close || !ops->assert_int || !ops->deassert_int)
return NULL;
if (!supported_protocols)
return NULL;
ndev = devm_kzalloc(&spi->dev, sizeof(struct nci_dev), GFP_KERNEL);
if (!ndev)
return NULL;
ndev->ops = ops;
ndev->acknowledge_mode = acknowledge_mode;
ndev->xfer_udelay = delay;
if (acknowledge_mode == NCI_SPI_CRC_ENABLED)
tailroom += NCI_SPI_CRC_LEN;
ndev->nci_dev = nci_allocate_device(&nci_spi_ops, supported_protocols,
supported_se, NCI_SPI_HDR_LEN,
tailroom);
if (!ndev->nci_dev)
return NULL;
nci_set_drvdata(ndev->nci_dev, ndev);
return ndev;
}
EXPORT_SYMBOL_GPL(nci_spi_allocate_device);
/**
* nci_spi_free_device - deallocate nci spi device
*
* @ndev: The nci spi device to deallocate
*/
void nci_spi_free_device(struct nci_spi_dev *ndev)
{
nci_free_device(ndev->nci_dev);
}
EXPORT_SYMBOL_GPL(nci_spi_free_device);
/**
* nci_spi_register_device - register a nci spi device in the nfc subsystem
*
* @pdev: The nci spi device to register
*/
int nci_spi_register_device(struct nci_spi_dev *ndev)
{
return nci_register_device(ndev->nci_dev);
}
EXPORT_SYMBOL_GPL(nci_spi_register_device);
/**
* nci_spi_unregister_device - unregister a nci spi device in the nfc subsystem
*
* @dev: The nci spi device to unregister
*/
void nci_spi_unregister_device(struct nci_spi_dev *ndev)
{
nci_unregister_device(ndev->nci_dev);
}
EXPORT_SYMBOL_GPL(nci_spi_unregister_device);
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