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: Frederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/include/net/nfc/nci_core.h b/include/net/nfc/nci_core.h
index 1009d3d..3b05beb 100644
--- a/include/net/nfc/nci_core.h
+++ b/include/net/nfc/nci_core.h
@@ -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 @@
/* ----- 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 */
diff --git a/net/nfc/nci/Kconfig b/net/nfc/nci/Kconfig
index 6d69b5f..2a24160 100644
--- a/net/nfc/nci/Kconfig
+++ b/net/nfc/nci/Kconfig
@@ -8,3 +8,13 @@
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.
diff --git a/net/nfc/nci/Makefile b/net/nfc/nci/Makefile
index cdb3a2e..7aeedc4 100644
--- a/net/nfc/nci/Makefile
+++ b/net/nfc/nci/Makefile
@@ -4,4 +4,6 @@
obj-$(CONFIG_NFC_NCI) += nci.o
-nci-objs := core.o data.o lib.o ntf.o rsp.o
\ No newline at end of file
+nci-objs := core.o data.o lib.o ntf.o rsp.o
+
+nci-$(CONFIG_NFC_NCI_SPI) += spi.o
diff --git a/net/nfc/nci/spi.c b/net/nfc/nci/spi.c
new file mode 100644
index 0000000..ebcdba5
--- /dev/null
+++ b/net/nfc/nci/spi.c
@@ -0,0 +1,136 @@
+/*
+ * 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);