path: root/drivers/nfc/pn544.c

/*
 * Driver for the PN544 NFC chip.
 *
 * Copyright (C) Nokia Corporation
 *
 * Author: Jari Vanhala <ext-jari.vanhala@nokia.com>
 * Contact: Matti Aaltonen <matti.j.aaltonen@nokia.com>
 *
 * 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/completion.h>
#include <linux/crc-ccitt.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/nfc/pn544.h>
#include <linux/poll.h>
#include <linux/regulator/consumer.h>
#include <linux/serial_core.h> /* for TCGETS */
#include <linux/slab.h>

#define DRIVER_CARD	"PN544 NFC"
#define DRIVER_DESC	"NFC driver for PN544"

static struct i2c_device_id pn544_id_table[] = {
	{ PN544_DRIVER_NAME, 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, pn544_id_table);

#define HCI_MODE	0
#define FW_MODE		1

enum pn544_state {
	PN544_ST_COLD,
	PN544_ST_FW_READY,
	PN544_ST_READY,
};

enum pn544_irq {
	PN544_NONE,
	PN544_INT,
};

struct pn544_info {
	struct miscdevice miscdev;
	struct i2c_client *i2c_dev;
	struct regulator_bulk_data regs[3];

	enum pn544_state state;
	wait_queue_head_t read_wait;
	loff_t read_offset;
	enum pn544_irq read_irq;
	struct mutex read_mutex; /* Serialize read_irq access */
	struct mutex mutex; /* Serialize info struct access */
	u8 *buf;
	size_t buflen;
};

static const char reg_vdd_io[]	= "Vdd_IO";
static const char reg_vbat[]	= "VBat";
static const char reg_vsim[]	= "VSim";

/* sysfs interface */
static ssize_t pn544_test(struct device *dev,
			  struct device_attribute *attr, char *buf)
{
	struct pn544_info *info = dev_get_drvdata(dev);
	struct i2c_client *client = info->i2c_dev;
	struct pn544_nfc_platform_data *pdata = client->dev.platform_data;

	return snprintf(buf, PAGE_SIZE, "%d\n", pdata->test());
}

static int pn544_enable(struct pn544_info *info, int mode)
{
	struct pn544_nfc_platform_data *pdata;
	struct i2c_client *client = info->i2c_dev;

	int r;

	r = regulator_bulk_enable(ARRAY_SIZE(info->regs), info->regs);
	if (r < 0)
		return r;

	pdata = client->dev.platform_data;
	info->read_irq = PN544_NONE;
	if (pdata->enable)
		pdata->enable(mode);

	if (mode) {
		info->state = PN544_ST_FW_READY;
		dev_dbg(&client->dev, "now in FW-mode\n");
	} else {
		info->state = PN544_ST_READY;
		dev_dbg(&client->dev, "now in HCI-mode\n");
	}

	usleep_range(10000, 15000);

	return 0;
}

static void pn544_disable(struct pn544_info *info)
{
	struct pn544_nfc_platform_data *pdata;
	struct i2c_client *client = info->i2c_dev;

	pdata = client->dev.platform_data;
	if (pdata->disable)
		pdata->disable();

	info->state = PN544_ST_COLD;

	dev_dbg(&client->dev, "Now in OFF-mode\n");

	msleep(PN544_RESETVEN_TIME);

	info->read_irq = PN544_NONE;
	regulator_bulk_disable(ARRAY_SIZE(info->regs), info->regs);
}

static int check_crc(u8 *buf, int buflen)
{
	u8 len;
	u16 crc;

	len = buf[0] + 1;
	if (len < 4 || len != buflen || len > PN544_MSG_MAX_SIZE) {
		pr_err(PN544_DRIVER_NAME
		       ": CRC; corrupt packet len %u (%d)\n", len, buflen);
		print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
			       16, 2, buf, buflen, false);
		return -EPERM;
	}
	crc = crc_ccitt(0xffff, buf, len - 2);
	crc = ~crc;

	if (buf[len-2] != (crc & 0xff) || buf[len-1] != (crc >> 8)) {
		pr_err(PN544_DRIVER_NAME ": CRC error 0x%x != 0x%x 0x%x\n",
		       crc, buf[len-1], buf[len-2]);

		print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
			       16, 2, buf, buflen, false);
		return -EPERM;
	}
	return 0;
}

static int pn544_i2c_write(struct i2c_client *client, u8 *buf, int len)
{
	int r;

	if (len < 4 || len != (buf[0] + 1)) {
		dev_err(&client->dev, "%s: Illegal message length: %d\n",
			__func__,