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
......@@ -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
......@@ -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
/*
* 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");
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