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Commit 93aead46 authored by Ilan Elias's avatar Ilan Elias Committed by John W. Linville
Browse files

NFC: driver for TI shared transport 



Signed-off-by: default avatarIlan Elias <ilane@ti.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 6a2968aa

drivers/nfc/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -27,4 +27,15 @@ config NFC_PN533 
	  Say Y here to compile support for PN533 devices into the

	  kernel or say M to compile it as module (pn533).



config NFC_WILINK

	tristate "Texas Instruments NFC WiLink driver"

	depends on TI_ST

	help

	  This enables the NFC driver for Texas Instrument's BT/FM/GPS/NFC

	  combo devices. This makes use of shared transport line discipline

	  core driver to communicate with the NFC core of the combo chip.



	  Say Y here to compile support for Texas Instrument's NFC WiLink driver

	  into the kernel or say M to compile it as module.



endmenu

drivers/nfc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -4,5 +4,6 @@ 


obj-$(CONFIG_PN544_NFC)		+= pn544.o

obj-$(CONFIG_NFC_PN533)		+= pn533.o

obj-$(CONFIG_NFC_WILINK)	+= nfcwilink.o



ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG

drivers/nfc/nfcwilink.c

0 → 100644
+342 −0
Original line number Diff line number Diff line 
/*

 *  Texas Instrument's NFC Driver For Shared Transport.

 *

 *  NFC Driver acts as interface between NCI core and

 *  TI Shared Transport Layer.

 *

 *  Copyright (C) 2011 Texas Instruments, Inc.

 *

 *  Written by Ilan Elias <ilane@ti.com>

 *

 *  Acknowledgements:

 *  This file is based on btwilink.c, which was written

 *  by Raja Mani and Pavan Savoy.

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License version 2 as

 *  published by the Free Software Foundation.

 *

 *  This program is distributed in the hope that 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

#include <linux/platform_device.h>

#include <linux/nfc.h>

#include <net/nfc/nci.h>

#include <net/nfc/nci_core.h>

#include <linux/ti_wilink_st.h>



#define NFCWILINK_CHNL			12

#define NFCWILINK_OPCODE		7

#define NFCWILINK_MAX_FRAME_SIZE	300

#define NFCWILINK_HDR_LEN		4

#define NFCWILINK_OFFSET_LEN_IN_HDR	1

#define NFCWILINK_LEN_SIZE		2

#define NFCWILINK_REGISTER_TIMEOUT	8000	/* 8 sec */



struct nfcwilink_hdr {

	u8 chnl;

	u8 opcode;

	u16 len;

} __packed;



struct nfcwilink {

	struct platform_device		*pdev;

	struct nci_dev			*ndev;

	unsigned long			flags;



	char				st_register_cb_status;

	long				(*st_write) (struct sk_buff *);

	struct completion		st_register_completed;

};



/* NFCWILINK driver flags */

enum {

	NFCWILINK_RUNNING,

};



/* Called by ST when registration is complete */

static void nfcwilink_register_complete(void *priv_data, char data)

{

	struct nfcwilink *drv = priv_data;



	nfc_dev_dbg(&drv->pdev->dev, "register_complete entry");



	/* store ST registration status */

	drv->st_register_cb_status = data;



	/* complete the wait in nfc_st_open() */

	complete(&drv->st_register_completed);

}



/* Called by ST when receive data is available */

static long nfcwilink_receive(void *priv_data, struct sk_buff *skb)

{

	struct nfcwilink *drv = priv_data;

	int rc;



	nfc_dev_dbg(&drv->pdev->dev, "receive entry, len %d", skb->len);



	if (!skb)

		return -EFAULT;



	if (!drv) {

		kfree_skb(skb);

		return -EFAULT;

	}



	/* strip the ST header

	(apart for the chnl byte, which is not received in the hdr) */

	skb_pull(skb, (NFCWILINK_HDR_LEN-1));



	skb->dev = (void *) drv->ndev;



	/* Forward skb to NCI core layer */

	rc = nci_recv_frame(skb);

	if (rc < 0) {

		nfc_dev_err(&drv->pdev->dev, "nci_recv_frame failed %d", rc);

		return rc;

	}



	return 0;

}



/* protocol structure registered with ST */

static struct st_proto_s nfcwilink_proto = {

	.chnl_id = NFCWILINK_CHNL,

	.max_frame_size = NFCWILINK_MAX_FRAME_SIZE,

	.hdr_len = (NFCWILINK_HDR_LEN-1),	/* not including chnl byte */

	.offset_len_in_hdr = NFCWILINK_OFFSET_LEN_IN_HDR,

	.len_size = NFCWILINK_LEN_SIZE,

	.reserve = 0,

	.recv = nfcwilink_receive,

	.reg_complete_cb = nfcwilink_register_complete,

	.write = NULL,

};



static int nfcwilink_open(struct nci_dev *ndev)

{

	struct nfcwilink *drv = nci_get_drvdata(ndev);

	unsigned long comp_ret;

	int rc;



	nfc_dev_dbg(&drv->pdev->dev, "open entry");



	if (test_and_set_bit(NFCWILINK_RUNNING, &drv->flags)) {

		rc = -EBUSY;

		goto exit;

	}



	nfcwilink_proto.priv_data = drv;



	init_completion(&drv->st_register_completed);

	drv->st_register_cb_status = -EINPROGRESS;



	rc = st_register(&nfcwilink_proto);

	if (rc < 0) {

		if (rc == -EINPROGRESS) {

			comp_ret = wait_for_completion_timeout(

			&drv->st_register_completed,

			msecs_to_jiffies(NFCWILINK_REGISTER_TIMEOUT));



			nfc_dev_dbg(&drv->pdev->dev,

			"wait_for_completion_timeout returned %ld",

			comp_ret);



			if (comp_ret == 0) {

				/* timeout */

				rc = -ETIMEDOUT;

				goto clear_exit;

			} else if (drv->st_register_cb_status != 0) {

				rc = drv->st_register_cb_status;

				nfc_dev_err(&drv->pdev->dev,

				"st_register_cb failed %d", rc);

				goto clear_exit;

			}

		} else {

			nfc_dev_err(&drv->pdev->dev,

				"st_register failed %d", rc);

			goto clear_exit;

		}

	}



	/* st_register MUST fill the write callback */

	BUG_ON(nfcwilink_proto.write == NULL);

	drv->st_write = nfcwilink_proto.write;



	goto exit;



clear_exit:

	clear_bit(NFCWILINK_RUNNING, &drv->flags);



exit:

	return rc;

}



static int nfcwilink_close(struct nci_dev *ndev)

{

	struct nfcwilink *drv = nci_get_drvdata(ndev);

	int rc;



	nfc_dev_dbg(&drv->pdev->dev, "close entry");



	if (!test_and_clear_bit(NFCWILINK_RUNNING, &drv->flags))

		return 0;



	rc = st_unregister(&nfcwilink_proto);

	if (rc)

		nfc_dev_err(&drv->pdev->dev, "st_unregister failed %d", rc);



	drv->st_write = NULL;



	return rc;

}



static int nfcwilink_send(struct sk_buff *skb)

{

	struct nci_dev *ndev = (struct nci_dev *)skb->dev;

	struct nfcwilink *drv = nci_get_drvdata(ndev);

	struct nfcwilink_hdr hdr = {NFCWILINK_CHNL, NFCWILINK_OPCODE, 0x0000};

	long len;



	nfc_dev_dbg(&drv->pdev->dev, "send entry, len %d", skb->len);



	if (!test_bit(NFCWILINK_RUNNING, &drv->flags))

		return -EBUSY;



	/* add the ST hdr to the start of the buffer */

	hdr.len = skb->len;

	memcpy(skb_push(skb, NFCWILINK_HDR_LEN), &hdr, NFCWILINK_HDR_LEN);



	/* Insert skb to shared transport layer's transmit queue.

	 * Freeing skb memory is taken care in shared transport layer,

	 * so don't free skb memory here.

	 */

	len = drv->st_write(skb);

	if (len < 0) {

		kfree_skb(skb);

		nfc_dev_err(&drv->pdev->dev, "st_write failed %ld", len);

		return -EFAULT;

	}



	return 0;

}



static struct nci_ops nfcwilink_ops = {

	.open = nfcwilink_open,

	.close = nfcwilink_close,

	.send = nfcwilink_send,

};



static int nfcwilink_probe(struct platform_device *pdev)

{

	static struct nfcwilink *drv;

	int rc;

	u32 protocols;



	nfc_dev_dbg(&pdev->dev, "probe entry");



	drv = kzalloc(sizeof(struct nfcwilink), GFP_KERNEL);

	if (!drv) {

		rc = -ENOMEM;

		goto exit;

	}



	drv->pdev = pdev;



	protocols = NFC_PROTO_JEWEL_MASK

			| NFC_PROTO_MIFARE_MASK | NFC_PROTO_FELICA_MASK

			| NFC_PROTO_ISO14443_MASK

			| NFC_PROTO_NFC_DEP_MASK;



	drv->ndev = nci_allocate_device(&nfcwilink_ops,

					protocols,

					NFCWILINK_HDR_LEN,

					0);

	if (!drv->ndev) {

		nfc_dev_err(&pdev->dev, "nci_allocate_device failed");

		rc = -ENOMEM;

		goto free_exit;

	}



	nci_set_parent_dev(drv->ndev, &pdev->dev);

	nci_set_drvdata(drv->ndev, drv);



	rc = nci_register_device(drv->ndev);

	if (rc < 0) {

		nfc_dev_err(&pdev->dev, "nci_register_device failed %d", rc);

		goto free_dev_exit;

	}



	dev_set_drvdata(&pdev->dev, drv);



	goto exit;



free_dev_exit:

	nci_free_device(drv->ndev);



free_exit:

	kfree(drv);



exit:

	return rc;

}



static int nfcwilink_remove(struct platform_device *pdev)

{

	struct nfcwilink *drv = dev_get_drvdata(&pdev->dev);

	struct nci_dev *ndev;



	nfc_dev_dbg(&pdev->dev, "remove entry");



	if (!drv)

		return -EFAULT;



	ndev = drv->ndev;



	nci_unregister_device(ndev);

	nci_free_device(ndev);



	kfree(drv);



	dev_set_drvdata(&pdev->dev, NULL);



	return 0;

}



static struct platform_driver nfcwilink_driver = {

	.probe = nfcwilink_probe,

	.remove = nfcwilink_remove,

	.driver = {

		.name = "nfcwilink",

		.owner = THIS_MODULE,

	},

};



/* ------- Module Init/Exit interfaces ------ */

static int __init nfcwilink_init(void)

{

	printk(KERN_INFO "NFC Driver for TI WiLink");



	return platform_driver_register(&nfcwilink_driver);

}



static void __exit nfcwilink_exit(void)

{

	platform_driver_unregister(&nfcwilink_driver);

}



module_init(nfcwilink_init);

module_exit(nfcwilink_exit);



/* ------ Module Info ------ */



MODULE_AUTHOR("Ilan Elias <ilane@ti.com>");

MODULE_DESCRIPTION("NFC Driver for TI Shared Transport");

MODULE_LICENSE("GPL");