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Updated corresponding to - NFC_AR_00_6000_11.02.00_OpnSrc

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Nanjesh
2020-04-24 23:24:40 +05:30
parent cb2bb40fc5
commit 25c57d3a9e
16 changed files with 2259 additions and 2390 deletions
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667
nfc/common.c
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@@ -1,667 +0,0 @@
/******************************************************************************
* Copyright (C) 2019-2020 NXP
* *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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/of_gpio.h>
#include <linux/of_device.h>
#include <linux/delay.h>
#include "../nfc/cold_reset.h"
#include "common.h"
nfc_dev_t *nfc_dev_platform = NULL;
int nfc_parse_dt(struct device *dev, platform_gpio_t *nfc_gpio,
uint8_t interface)
{
struct device_node *np = dev->of_node;
if (!np) {
pr_err("nfc of_node NULL\n");
return -EINVAL;
}
//required for i2c based chips only
if (interface == PLATFORM_IF_I2C) {
nfc_gpio->irq = of_get_named_gpio(np, DTS_IRQ_GPIO_STR, 0);
if ((!gpio_is_valid(nfc_gpio->irq))) {
pr_err("nfc irq gpio invalid %d\n", nfc_gpio->irq);
return -EINVAL;
}
pr_info("%s: irq %d\n", __func__, nfc_gpio->irq);
}
nfc_gpio->ven = of_get_named_gpio(np, DTS_VEN_GPIO_STR, 0);
if ((!gpio_is_valid(nfc_gpio->ven))) {
pr_err("nfc ven gpio invalid %d\n", nfc_gpio->ven);
return -EINVAL;
}
nfc_gpio->dwl_req = of_get_named_gpio(np, DTS_FWDN_GPIO_STR, 0);
if ((!gpio_is_valid(nfc_gpio->dwl_req))) {
pr_err("nfc dwl_req gpio invalid %d\n", nfc_gpio->dwl_req);
return -EINVAL;
}
//required for old platform only
nfc_gpio->ese_pwr = of_get_named_gpio(np, DTS_ESE_GPIO_STR, 0);
if ((!gpio_is_valid(nfc_gpio->ese_pwr))) {
pr_err("nfc ese_pwr gpio invalid %d\n", nfc_gpio->ese_pwr);
nfc_gpio->ese_pwr = -EINVAL;
}
pr_info("%s: %d, %d, %d, %d\n", __func__,
nfc_gpio->irq, nfc_gpio->ven, nfc_gpio->dwl_req,
nfc_gpio->ese_pwr);
return 0;
}
void gpio_set_ven(nfc_dev_t *nfc_dev, int value)
{
if (nfc_dev->ven_policy == VEN_ALWAYS_ENABLED) {
value |= 1;
}
if (gpio_get_value(nfc_dev->gpio.ven) != value) {
gpio_set_value(nfc_dev->gpio.ven, value);
/* hardware dependent delay */
usleep_range(10000, 10100);
}
}
int configure_gpio(unsigned int gpio, int flag)
{
int ret;
pr_debug("%s: nfc gpio [%d] flag [%01x]\n", __func__, gpio, flag);
if (gpio_is_valid(gpio)) {
ret = gpio_request(gpio, "nfc_gpio");
if (ret) {
pr_err("%s: unable to request nfc gpio [%d]\n",
__func__, gpio);
return ret;
}
/*set direction and value for output pin */
if (flag & GPIO_OUTPUT)
ret = gpio_direction_output(gpio, (GPIO_HIGH & flag));
else
ret = gpio_direction_input(gpio);
if (ret) {
pr_err
("%s: unable to set direction for nfc gpio [%d]\n",
__func__, gpio);
gpio_free(gpio);
return ret;
}
/*Consider value as control for input IRQ pin */
if (flag & GPIO_IRQ) {
ret = gpio_to_irq(gpio);
if (ret < 0) {
pr_err
("%s: unable to set irq for nfc gpio [%d]\n",
__func__, gpio);
gpio_free(gpio);
return ret;
}
pr_debug
("%s: gpio_to_irq successful [%d]\n",
__func__, gpio);
return ret;
}
} else {
pr_err("%s: invalid gpio\n", __func__);
ret = -EINVAL;
}
return ret;
}
void gpio_free_all(nfc_dev_t *nfc_dev)
{
if (gpio_is_valid(nfc_dev->gpio.ese_pwr)) {
gpio_free(nfc_dev->gpio.ese_pwr);
}
if (gpio_is_valid(nfc_dev->gpio.dwl_req)) {
gpio_free(nfc_dev->gpio.dwl_req);
}
if (gpio_is_valid(nfc_dev->gpio.irq)) {
gpio_free(nfc_dev->gpio.irq);
}
if (gpio_is_valid(nfc_dev->gpio.ven)) {
gpio_free(nfc_dev->gpio.ven);
}
}
void nfc_misc_unregister(nfc_dev_t *nfc_dev, int count)
{
pr_debug("%s: entry\n", __func__);
device_destroy(nfc_dev->nfc_class, nfc_dev->devno);
cdev_del(&nfc_dev->c_dev);
class_destroy(nfc_dev->nfc_class);
unregister_chrdev_region(nfc_dev->devno, count);
}
int nfc_misc_register(nfc_dev_t *nfc_dev,
const struct file_operations *nfc_fops,
int count, char *devname, char *classname)
{
int ret = 0;
ret = alloc_chrdev_region(&nfc_dev->devno, 0, count, devname);
if (ret < 0) {
pr_err("%s: failed to alloc chrdev region ret %d\n",
__func__, ret);
return ret;
}
nfc_dev->nfc_class = class_create(THIS_MODULE, classname);
if (IS_ERR(nfc_dev->nfc_class)) {
ret = PTR_ERR(nfc_dev->nfc_class);
pr_err("%s: failed to register device class ret %d\n",
__func__, ret);
unregister_chrdev_region(nfc_dev->devno, count);
return ret;
}
cdev_init(&nfc_dev->c_dev, nfc_fops);
ret = cdev_add(&nfc_dev->c_dev, nfc_dev->devno, count);
if (ret < 0) {
pr_err("%s: failed to add cdev ret %d\n", __func__, ret);
class_destroy(nfc_dev->nfc_class);
unregister_chrdev_region(nfc_dev->devno, count);
return ret;
}
nfc_dev->nfc_device = device_create(nfc_dev->nfc_class, NULL,
nfc_dev->devno, nfc_dev, devname);
if (IS_ERR(nfc_dev->nfc_device)) {
ret = PTR_ERR(nfc_dev->nfc_device);
pr_err("%s: failed to create the device ret %d\n",
__func__, ret);
cdev_del(&nfc_dev->c_dev);
class_destroy(nfc_dev->nfc_class);
unregister_chrdev_region(nfc_dev->devno, count);
return ret;
}
return 0;
}
static void enable_interrupt(nfc_dev_t *nfc_dev)
{
if (nfc_dev->interface == PLATFORM_IF_I2C)
i2c_enable_irq(&nfc_dev->i2c_dev);
else {
#ifdef CONFIG_NXP_NFC_I3C
i3c_enable_ibi(&nfc_dev->i3c_dev);
#endif //CONFIG_NXP_NFC_I3C
}
}
static void disable_interrupt(nfc_dev_t *nfc_dev)
{
if (nfc_dev->interface == PLATFORM_IF_I2C)
i2c_disable_irq(&nfc_dev->i2c_dev);
else {
#ifdef CONFIG_NXP_NFC_I3C
i3c_disable_ibi(&nfc_dev->i3c_dev);
#endif //CONFIG_NXP_NFC_I3C
}
}
static int send_cold_reset_cmd(nfc_dev_t *nfc_dev)
{
int ret = 0;
char cmd[COLD_RESET_CMD_LEN];
cmd[0] = COLD_RESET_CMD_GID;
cmd[1] = COLD_RESET_OID;
cmd[2] = COLD_RESET_CMD_PAYLOAD_LEN;
if (nfc_dev->interface == PLATFORM_IF_I2C) {
ret = i2c_write(&nfc_dev->i2c_dev, cmd,
COLD_RESET_CMD_LEN, MAX_RETRY_COUNT);
} else {
//TODO: Handling Cold reset for I3C
//ret = i3c_write(nfc_dev->i3c_dev, cmd, COLD_RESET_CMD_LEN);
}
if (ret != COLD_RESET_CMD_LEN) {
pr_err("%s : i2c_master_send returned %d\n", __func__, ret);
nfc_dev->cold_reset.timer_started = false;
return -EIO;
}
pr_info("%s: NxpNciX: %d > %02X%02X%02X \n", __func__, ret, cmd[0],
cmd[1], cmd[2]);
return ret;
}
void read_cold_reset_rsp(nfc_dev_t *nfc_dev, char *buf)
{
int ret = -1;
char rsp[COLD_RESET_RSP_LEN];
i2c_dev_t *i2c_dev = &nfc_dev->i2c_dev;
cold_reset_t *cold_reset = &nfc_dev->cold_reset;
cold_reset->status = -EIO;
/*
* read header also if NFC is disabled
* for enable case, will be taken care by nfc read thread
*/
if (!cold_reset->nfc_enabled) {
if (nfc_dev->interface == PLATFORM_IF_I2C) {
ret = i2c_read(i2c_dev, rsp, NCI_HDR_LEN);
} else {
//TODO: Handling Cold reset for I3C
//ret = i3c_read(i3c_dev, rsp, NCI_HDR_LEN);
}
if (ret != NCI_HDR_LEN) {
pr_err("%s: failure to read cold reset rsp header\n",
__func__);
return;
}
} else {
memcpy(rsp, buf, NCI_HDR_LEN);
}
if ((NCI_HDR_LEN + rsp[NCI_PAYLOAD_LEN_OFFSET]) != COLD_RESET_RSP_LEN) {
pr_err("%s: - invalid response for cold_reset\n", __func__);
return;
}
if (nfc_dev->interface == PLATFORM_IF_I2C) {
ret = i2c_read(i2c_dev, &rsp[NCI_PAYLOAD_IDX], rsp[2]);
} else {
//TODO:Handling Cold Reset for I3C
//ret = i3c_read(nfc_dev->i3c_dev, &rsp[NCI_PAYLOAD_IDX], rsp[2]);
}
if (ret != rsp[2]) {
pr_err("%s: failure to read cold reset rsp header\n", __func__);
return;
}
pr_info("%s NxpNciR : len = 4 > %02X%02X%02X%02X\n", __func__, rsp[0],
rsp[1], rsp[2], rsp[3]);
cold_reset->status = rsp[NCI_PAYLOAD_IDX];
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,14,0)
static void ese_cold_reset_gaurd_timer_callback(unsigned long data)
{
(void)data;
#else
static void ese_cold_reset_gaurd_timer_callback(struct timer_list *unused)
{
#endif
pr_info("%s: Enter\n",__func__);
nfc_dev_platform->cold_reset.timer_started = false;
return;
}
static long start_ese_cold_reset_guard_timer(void)
{
long ret = -EINVAL;
if (timer_pending(&nfc_dev_platform->cold_reset.timer) == 1) {
pr_info("ese_cold_reset_guard_timer: delete pending timer \n");
/* delete timer if already pending */
del_timer(&nfc_dev_platform->cold_reset.timer);
}
nfc_dev_platform->cold_reset.timer_started = true;
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,14,0)
init_timer(&nfc_dev_platform->cold_reset.timer);
setup_timer( &nfc_dev_platform->cold_reset.timer, ese_cold_reset_gaurd_timer_callback, 0);
#else
timer_setup(&nfc_dev_platform->cold_reset.timer, ese_cold_reset_gaurd_timer_callback, 0);
#endif
ret = mod_timer(&nfc_dev_platform->cold_reset.timer,
jiffies + msecs_to_jiffies(ESE_COLD_RESET_GUARD_TIME));
return ret;
}
static int perform_ese_cold_reset(nfc_dev_t *nfc_dev,
ese_cold_reset_origin_t origin)
{
int ret = 0;
if (gpio_get_value(nfc_dev->gpio.dwl_req)) {
pr_err("FW download in-progress\n");
return -EBUSY;
}
if (!gpio_get_value(nfc_dev->gpio.ven)) {
pr_err("VEN LOW - NFCC powered off\n");
return -ENODEV;
}
mutex_lock(&nfc_dev->cold_reset.sync_mutex);
if (!nfc_dev->cold_reset.timer_started) {
ret = start_ese_cold_reset_guard_timer();
if (ret) {
pr_err("%s: Error in mod_timer\n", __func__);
mutex_unlock(&nfc_dev->cold_reset.sync_mutex);
return ret;
}
/* set default value for status as failure */
nfc_dev->cold_reset.status = -EIO;
ret = send_cold_reset_cmd(nfc_dev);
if (ret <= 0) {
pr_err("failed to send cold reset command\n");
mutex_unlock(&nfc_dev->cold_reset.sync_mutex);
return ret;
}
ret = 0;
nfc_dev->cold_reset.rsp_pending = true;
/* check if NFC is enabled */
if (nfc_dev->cold_reset.nfc_enabled) {
/* Pending read from NFC_HAL will read the cold reset rsp and signal read_wq */
if (!wait_event_interruptible_timeout
(nfc_dev->cold_reset.read_wq,
nfc_dev->cold_reset.rsp_pending == false,
msecs_to_jiffies(ESE_COLD_RESET_CMD_RSP_TIMEOUT)))
{
pr_err("%s:Cold Reset Response Timeout\n",
__func__);
}
} else {
/* Read data as NFC thread is not active */
enable_interrupt(nfc_dev);
read_cold_reset_rsp(nfc_dev, NULL);
nfc_dev->cold_reset.rsp_pending = false;
// TODO: Handling Cold reset for I3C
// ret = i3c_read(i3c_dev, rsp, NCI_HDR_LEN);
}
if (!ret) { /* wait for reboot guard timer */
if (wait_event_interruptible_timeout
(nfc_dev->cold_reset.read_wq, true,
msecs_to_jiffies(ESE_COLD_RESET_REBOOT_GUARD_TIME))
== 0) {
pr_err("%s: guard Timeout interrupted",
__func__);
}
}
}
mutex_unlock(&nfc_dev->cold_reset.sync_mutex);
if (ret == 0) /* success case */
ret = nfc_dev->cold_reset.status;
return ret;
}
/*
* Power management of the eSE
* eSE and NFCC both are powered using VEN gpio,
* VEN HIGH - eSE and NFCC both are powered on
* VEN LOW - eSE and NFCC both are power down
*/
int nfc_ese_pwr(nfc_dev_t *nfc_dev, unsigned long arg)
{
int ret = 0;
if (arg == ESE_POWER_ON) {
/**
* Let's store the NFC VEN pin state
* will check stored value in case of eSE power off request,
* to find out if NFC MW also sent request to set VEN HIGH
* VEN state will remain HIGH if NFC is enabled otherwise
* it will be set as LOW
*/
nfc_dev->nfc_ven_enabled = gpio_get_value(nfc_dev->gpio.ven);
if (!nfc_dev->nfc_ven_enabled) {
pr_debug("eSE HAL service setting ven HIGH\n");
gpio_set_ven(nfc_dev, 1);
} else {
pr_debug("ven already HIGH\n");
}
} else if (arg == ESE_POWER_OFF) {
if (!nfc_dev->nfc_ven_enabled) {
pr_debug("NFC not enabled, disabling ven\n");
gpio_set_ven(nfc_dev, 0);
} else {
pr_debug("keep ven high as NFC is enabled\n");
}
} else if (IS_COLD_RESET_REQ(arg) &&
nfc_dev->interface == PLATFORM_IF_I2C) {
ret = perform_ese_cold_reset(nfc_dev, arg);
} else if (arg == ESE_POWER_STATE) {
// eSE power state
ret = gpio_get_value(nfc_dev->gpio.ven);
} else {
pr_err("%s bad arg %lu\n", __func__, arg);
ret = -ENOIOCTLCMD;
}
return ret;
}
EXPORT_SYMBOL(nfc_ese_pwr);
/*
* This function shall be called from SPI, UWB, NFC driver to perform eSE cold reset.
*/
int ese_cold_reset(ese_cold_reset_origin_t origin)
{
int ret = 0;
unsigned long arg;
pr_info("%s: Enter origin:%d", __func__, origin);
switch (origin) {
case ESE_COLD_RESET_SOURCE_SPI:
arg = ESE_COLD_RESET_SPI;
break;
case ESE_COLD_RESET_SOURCE_UWB:
arg = ESE_COLD_RESET_UWB;
break;
default:
pr_info("%s: Invalid argument", __func__);
return -EINVAL;
}
if (nfc_dev_platform == NULL)
return -ENODEV;
ret = nfc_ese_pwr(nfc_dev_platform, arg);
pr_info("%s:%d exit, Status:%d", __func__, origin, ret);
return ret;
}
EXPORT_SYMBOL(ese_cold_reset);
/*
* nfc_ioctl_power_states() - power control
* @filp: pointer to the file descriptor
* @arg: mode that we want to move to
*
* Device power control. Depending on the arg value, device moves to
* different states
* (arg = 0): NFC_ENABLE GPIO = 0, FW_DL GPIO = 0
* (arg = 1): NFC_ENABLE GPIO = 1, FW_DL GPIO = 0
* (arg = 2): FW_DL GPIO = 1
*
* Return: -ENOIOCTLCMD if arg is not supported, 0 in any other case
*/
static int nfc_ioctl_power_states(nfc_dev_t *nfc_dev, unsigned long arg)
{
int ret = 0;
if (arg == NFC_POWER_OFF) {
/*
* We are attempting a hardware reset so let us disable
* interrupts to avoid spurious notifications to upper
* layers.
*/
disable_interrupt(nfc_dev);
pr_debug("gpio firm disable\n");
if (gpio_is_valid(nfc_dev->gpio.dwl_req)) {
gpio_set_value(nfc_dev->gpio.dwl_req, 0);
usleep_range(10000, 10100);
}
if (gpio_is_valid(nfc_dev->gpio.ese_pwr)) {
if (!gpio_get_value(nfc_dev->gpio.ese_pwr)) {
pr_debug("disabling ven\n");
gpio_set_ven(nfc_dev, 0);
} else {
pr_debug("keeping ven high\n");
}
} else {
pr_debug("ese_pwr invalid, set ven to low\n");
gpio_set_ven(nfc_dev, 0);
}
nfc_dev->nfc_ven_enabled = false;
} else if (arg == NFC_POWER_ON) {
enable_interrupt(nfc_dev);
pr_debug("gpio_set_value enable: %s:\n", __func__);
if (gpio_is_valid(nfc_dev->gpio.dwl_req)) {
gpio_set_value(nfc_dev->gpio.dwl_req, 0);
usleep_range(10000, 10100);
}
gpio_set_ven(nfc_dev, 1);
nfc_dev->nfc_ven_enabled = true;
#ifdef CONFIG_NXP_NFC_I3C
if (nfc_dev->interface == PLATFORM_IF_I3C)
nfc_dev->i3c_dev.read_hdr = NCI_HDR_LEN;
#endif //CONFIG_NXP_NFC_I3C
} else if (arg == NFC_FW_DWL_VEN_TOGGLE) {
/*
* We are switching to Dowload Mode, toggle the enable pin
* in order to set the NFCC in the new mode
*/
if (gpio_is_valid(nfc_dev->gpio.ese_pwr)) {
if (gpio_get_value(nfc_dev->gpio.ese_pwr)) {
pr_err
("FW download forbidden while ese is on\n");
return -EBUSY; /* Device or resource busy */
}
}
gpio_set_value(nfc_dev->gpio.ven, 1);
if (gpio_is_valid(nfc_dev->gpio.dwl_req)) {
gpio_set_value(nfc_dev->gpio.dwl_req, 1);
usleep_range(10000, 10100);
}
if (nfc_dev->interface == PLATFORM_IF_I2C) {
gpio_set_value(nfc_dev->gpio.ven, 0);
usleep_range(10000, 10100);
}
gpio_set_value(nfc_dev->gpio.ven, 1);
usleep_range(10000, 10100);
} else if (arg == NFC_FW_DWL_HIGH) {
/*
* Setting firmware download gpio to HIGH
* before FW download start
*/
pr_debug("set fw gpio high\n");
if (gpio_is_valid(nfc_dev->gpio.dwl_req)) {
gpio_set_value(nfc_dev->gpio.dwl_req, 1);
usleep_range(10000, 10100);
} else
pr_debug("gpio.dwl_req is invalid\n");
} else if (arg == NFC_VEN_FORCED_HARD_RESET
&& nfc_dev->interface == PLATFORM_IF_I2C) {
/*
* TODO: Enable Ven reset for I3C, after hot join integration
*/
gpio_set_value(nfc_dev->gpio.ven, 0);
usleep_range(10000, 10100);
gpio_set_value(nfc_dev->gpio.ven, 1);
usleep_range(10000, 10100);
pr_info("%s VEN forced reset done\n", __func__);
} else if (arg == NFC_FW_DWL_LOW) {
/*
* Setting firmware download gpio to LOW
* FW download finished
*/
pr_debug("set fw gpio LOW\n");
if (gpio_is_valid(nfc_dev->gpio.dwl_req)) {
gpio_set_value(nfc_dev->gpio.dwl_req, 0);
usleep_range(10000, 10100);
} else {
pr_debug("gpio.dwl_req is invalid\n");
}
#ifdef CONFIG_NXP_NFC_I3C
if (nfc_dev->interface == PLATFORM_IF_I3C)
nfc_dev->i3c_dev.read_hdr = NCI_HDR_LEN;
#endif //CONFIG_NXP_NFC_I3C
#ifdef CONFIG_NXP_NFC_I3C
} else if (arg == NFC_FW_HDR_LEN) {
if (nfc_dev->interface == PLATFORM_IF_I3C)
nfc_dev->i3c_dev.read_hdr = FW_HDR_LEN;
#endif //CONFIG_NXP_NFC_I3C
} else {
pr_err("%s bad arg %lu\n", __func__, arg);
ret = -ENOIOCTLCMD;
}
return ret;
}
/** @brief IOCTL function to be used to set or get data from upper layer.
*
* @param pfile fil node for opened device.
* @cmd IOCTL type from upper layer.
* @arg IOCTL arg from upper layer.
*
* @return 0 on success, error code for failures.
*/
long nfc_dev_ioctl(struct file *pfile, unsigned int cmd, unsigned long arg)
{
int ret = 0;
struct nfc_dev *nfc_dev = pfile->private_data;
if (!nfc_dev)
return -ENODEV;
pr_debug("%s cmd = %x arg = %zx\n", __func__, cmd, arg);
switch (cmd) {
case NFC_SET_PWR:
ret = nfc_ioctl_power_states(nfc_dev, arg);
break;
case ESE_SET_PWR:
ret = nfc_ese_pwr(nfc_dev, arg);
break;
case ESE_GET_PWR:
ret = nfc_ese_pwr(nfc_dev, 3);
break;
case NFC_GET_PLATFORM_TYPE:
ret = nfc_dev->interface;
break;
default:
pr_err("%s bad cmd %lu\n", __func__, arg);
ret = -ENOIOCTLCMD;
};
return ret;
}
int nfc_dev_open(struct inode *inode, struct file *filp)
{
nfc_dev_t *nfc_dev = container_of(inode->i_cdev, nfc_dev_t, c_dev);
if (!nfc_dev)
return -ENODEV;
pr_debug("%s: %d, %d\n", __func__, imajor(inode), iminor(inode));
mutex_lock(&nfc_dev->dev_ref_mutex);
filp->private_data = nfc_dev;
if (nfc_dev->dev_ref_count == 0) {
if (gpio_is_valid(nfc_dev->gpio.dwl_req)) {
gpio_set_value(nfc_dev->gpio.dwl_req, 0);
usleep_range(10000, 10100);
}
nfc_dev->cold_reset.nfc_enabled = true;
enable_interrupt(nfc_dev);
}
nfc_dev->dev_ref_count = nfc_dev->dev_ref_count + 1;
mutex_unlock(&nfc_dev->dev_ref_mutex);
return 0;
}
int nfc_dev_close(struct inode *inode, struct file *filp)
{
nfc_dev_t *nfc_dev = container_of(inode->i_cdev, nfc_dev_t, c_dev);
if (!nfc_dev)
return -ENODEV;
pr_debug("%s: %d, %d\n", __func__, imajor(inode), iminor(inode));
mutex_lock(&nfc_dev->dev_ref_mutex);
if (nfc_dev->dev_ref_count == 1) {
disable_interrupt(nfc_dev);
if (gpio_is_valid(nfc_dev->gpio.dwl_req)) {
gpio_set_value(nfc_dev->gpio.dwl_req, 0);
usleep_range(10000, 10100);
}
nfc_dev->cold_reset.nfc_enabled = false;
}
if (nfc_dev->dev_ref_count > 0)
nfc_dev->dev_ref_count = nfc_dev->dev_ref_count - 1;
filp->private_data = NULL;
mutex_unlock(&nfc_dev->dev_ref_mutex);
return 0;
}