From 8a00a61b0ef2bfd1b468dd20c0d0b1a94a8f7475 Mon Sep 17 00:00:00 2001 From: Frederic Danis Date: Wed, 29 May 2013 15:35:02 +0200 Subject: [PATCH] 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 Signed-off-by: Samuel Ortiz --- include/net/nfc/nci_core.h | 49 +++++++++++++ net/nfc/nci/Kconfig | 10 +++ net/nfc/nci/Makefile | 4 +- net/nfc/nci/spi.c | 136 +++++++++++++++++++++++++++++++++++++ 4 files changed, 198 insertions(+), 1 deletion(-) create mode 100644 net/nfc/nci/spi.c diff --git a/include/net/nfc/nci_core.h b/include/net/nfc/nci_core.h index 1009d3dcb316..3b05bebd8235 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 * @@ -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 */ diff --git a/net/nfc/nci/Kconfig b/net/nfc/nci/Kconfig index 6d69b5f0f19b..2a2416080b4f 100644 --- a/net/nfc/nci/Kconfig +++ b/net/nfc/nci/Kconfig @@ -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. diff --git a/net/nfc/nci/Makefile b/net/nfc/nci/Makefile index cdb3a2e44471..7aeedc43187d 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 000000000000..ebcdba51418c --- /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 +#include +#include +#include + +#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); -- 2.30.2