linux/drivers/nfc/nfcmrvl/main.c

/*
 * Marvell NFC driver: major functions
 *
 * Copyright (C) 2014, Marvell International Ltd.
 *
 * This software file (the "File") is distributed by Marvell International
 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
 * (the "License").  You may use, redistribute and/or modify this File in
 * accordance with the terms and conditions of the License, a copy of which
 * is available on the worldwide web at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 * this warranty disclaimer.
 */

#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/nfc.h>
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>
#include "nfcmrvl.h"

#define VERSION "1.0"

static int nfcmrvl_nci_open(struct nci_dev *ndev)
{
	struct nfcmrvl_private *priv = nci_get_drvdata(ndev);
	int err;

	if (test_and_set_bit(NFCMRVL_NCI_RUNNING, &priv->flags))
		return 0;

	err = priv->if_ops->nci_open(priv);

	if (err)
		clear_bit(NFCMRVL_NCI_RUNNING, &priv->flags);

	return err;
}

static int nfcmrvl_nci_close(struct nci_dev *ndev)
{
	struct nfcmrvl_private *priv = nci_get_drvdata(ndev);

	if (!test_and_clear_bit(NFCMRVL_NCI_RUNNING, &priv->flags))
		return 0;

	priv->if_ops->nci_close(priv);

	return 0;
}

static int nfcmrvl_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
{
	struct nfcmrvl_private *priv = nci_get_drvdata(ndev);

	nfc_info(priv->dev, "send entry, len %d\n", skb->len);

	skb->dev = (void *)ndev;

	if (!test_bit(NFCMRVL_NCI_RUNNING, &priv->flags))
		return -EBUSY;

	if (priv->hci_muxed) {
		unsigned char *hdr;
		unsigned char len = skb->len;

		hdr = (char *) skb_push(skb, NFCMRVL_HCI_EVENT_HEADER_SIZE);
		hdr[0] = NFCMRVL_HCI_COMMAND_CODE;
		hdr[1] = NFCMRVL_HCI_OGF;
		hdr[2] = NFCMRVL_HCI_OCF;
		hdr[3] = len;
	}

	return priv->if_ops->nci_send(priv, skb);
}

static int nfcmrvl_nci_setup(struct nci_dev *ndev)
{
	return 0;
}

static struct nci_ops nfcmrvl_nci_ops = {
	.open = nfcmrvl_nci_open,
	.close = nfcmrvl_nci_close,
	.send = nfcmrvl_nci_send,
	.setup = nfcmrvl_nci_setup,
};

struct nfcmrvl_private *nfcmrvl_nci_register_dev(void *drv_data,
						 struct nfcmrvl_if_ops *ops,
						 struct device *dev,
						 unsigned int flags)
{
	struct nfcmrvl_private *priv;
	int rc;
	int headroom = 0;
	u32 protocols;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return ERR_PTR(-ENOMEM);

	priv->drv_data = drv_data;
	priv->if_ops = ops;
	priv->dev = dev;
	priv->hci_muxed = (flags & NFCMRVL_DEV_FLAG_HCI_MUXED) ? 1 : 0;
	priv->reset_n_io = NFCMRVL_DEV_FLAG_GET_RESET_N_IO(flags);

	if (priv->reset_n_io) {
		rc = devm_gpio_request_one(dev,
					   priv->reset_n_io,
					   GPIOF_OUT_INIT_LOW,
					   "nfcmrvl_reset_n");
		if (rc < 0)
			nfc_err(dev, "failed to request reset_n io\n");
	}

	if (priv->hci_muxed)
		headroom = NFCMRVL_HCI_EVENT_HEADER_SIZE;

	protocols = NFC_PROTO_JEWEL_MASK
		| NFC_PROTO_MIFARE_MASK | NFC_PROTO_FELICA_MASK
		| NFC_PROTO_ISO14443_MASK
		| NFC_PROTO_ISO14443_B_MASK
		| NFC_PROTO_NFC_DEP_MASK;

	priv->ndev = nci_allocate_device(&nfcmrvl_nci_ops, protocols,
					 headroom, 0);
	if (!priv->ndev) {
		nfc_err(dev, "nci_allocate_device failed\n");
		rc = -ENOMEM;
		goto error;
	}

	nci_set_drvdata(priv->ndev, priv);

	nfcmrvl_chip_reset(priv);

	rc = nci_register_device(priv->ndev);
	if (rc) {
		nfc_err(dev, "nci_register_device failed %d\n", rc);
		nci_free_device(priv->ndev);
		goto error;
	}

	nfc_info(dev, "registered with nci successfully\n");
	return priv;

error:
	kfree(priv);
	return ERR_PTR(rc);
}
EXPORT_SYMBOL_GPL(nfcmrvl_nci_register_dev);

void nfcmrvl_nci_unregister_dev(struct nfcmrvl_private *priv)
{
	struct nci_dev *ndev = priv->ndev;

	nci_unregister_device(ndev);
	nci_free_device(ndev);
	kfree(priv);
}
EXPORT_SYMBOL_GPL(nfcmrvl_nci_unregister_dev);

int nfcmrvl_nci_recv_frame(struct nfcmrvl_private *priv, struct sk_buff *skb)
{
	if (priv->hci_muxed) {
		if (skb->data[0] == NFCMRVL_HCI_EVENT_CODE &&
		    skb->data[1] == NFCMRVL_HCI_NFC_EVENT_CODE) {
			/* Data packet, let's extract NCI payload */
			skb_pull(skb, NFCMRVL_HCI_EVENT_HEADER_SIZE);
		} else {
			/* Skip this packet */
			kfree_skb(skb);
			return 0;
		}
	}

	if (test_bit(NFCMRVL_NCI_RUNNING, &priv->flags))
		nci_recv_frame(priv->ndev, skb);
	else {
		/* Drop this packet since nobody wants it */
		kfree_skb(skb);
		return 0;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(nfcmrvl_nci_recv_frame);

void nfcmrvl_chip_reset(struct nfcmrvl_private *priv)
{
	/*
	 * This function does not take care if someone is using the device.
	 * To be improved.
	 */

	if (priv->reset_n_io) {
		nfc_info(priv->dev, "reset the chip\n");
		gpio_set_value(priv->reset_n_io, 0);
		usleep_range(5000, 10000);
		gpio_set_value(priv->reset_n_io, 1);
	} else
		nfc_info(priv->dev, "no reset available on this interface\n");
}

MODULE_AUTHOR("Marvell International Ltd.");
MODULE_DESCRIPTION("Marvell NFC driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL v2");