blob: 8f132fd689b5d3abe6f4f7ca403595493d258e16 [file] [log] [blame]
/* drivers/gpio/gpio-msm-smp2p.c
*
* Copyright (c) 2013-2014, 2016 The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only 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.
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/bitmap.h>
#include <linux/of.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/ipc_logging.h>
#include "../soc/qcom/smp2p_private_api.h"
#include "../soc/qcom/smp2p_private.h"
/* GPIO device - one per SMP2P entry. */
struct smp2p_chip_dev {
struct list_head entry_list;
char name[SMP2P_MAX_ENTRY_NAME];
int remote_pid;
bool is_inbound;
bool is_open;
bool in_shadow;
uint32_t shadow_value;
struct work_struct shadow_work;
spinlock_t shadow_lock;
struct notifier_block out_notifier;
struct notifier_block in_notifier;
struct msm_smp2p_out *out_handle;
struct gpio_chip gpio;
struct irq_domain *irq_domain;
int irq_base;
spinlock_t irq_lock;
DECLARE_BITMAP(irq_enabled, SMP2P_BITS_PER_ENTRY);
DECLARE_BITMAP(irq_rising_edge, SMP2P_BITS_PER_ENTRY);
DECLARE_BITMAP(irq_falling_edge, SMP2P_BITS_PER_ENTRY);
};
static struct platform_driver smp2p_gpio_driver;
static struct lock_class_key smp2p_gpio_lock_class;
static struct irq_chip smp2p_gpio_irq_chip;
static DEFINE_SPINLOCK(smp2p_entry_lock_lha1);
static LIST_HEAD(smp2p_entry_list);
/* Used for mapping edge to name for logging. */
static const char * const edge_names[] = {
"-",
"0->1",
"1->0",
"-",
};
/* Used for mapping edge to value for logging. */
static const char * const edge_name_rising[] = {
"-",
"0->1",
};
/* Used for mapping edge to value for logging. */
static const char * const edge_name_falling[] = {
"-",
"1->0",
};
static int smp2p_gpio_to_irq(struct gpio_chip *cp,
unsigned int offset);
/**
* smp2p_get_value - Retrieves GPIO value.
*
* @cp: GPIO chip pointer
* @offset: Pin offset
* @returns: >=0: value of GPIO Pin; < 0 for error
*
* Error codes:
* -ENODEV - chip/entry invalid
* -ENETDOWN - valid entry, but entry not yet created
*/
static int smp2p_get_value(struct gpio_chip *cp,
unsigned int offset)
{
struct smp2p_chip_dev *chip;
int ret = 0;
uint32_t data;
if (!cp)
return -ENODEV;
chip = container_of(cp, struct smp2p_chip_dev, gpio);
if (!chip->is_open)
return -ENETDOWN;
if (chip->is_inbound)
ret = msm_smp2p_in_read(chip->remote_pid, chip->name, &data);
else
ret = msm_smp2p_out_read(chip->out_handle, &data);
if (!ret)
ret = (data & (1 << offset)) ? 1 : 0;
return ret;
}
/**
* smp2p_set_value - Sets GPIO value.
*
* @cp: GPIO chip pointer
* @offset: Pin offset
* @value: New value
*/
static void smp2p_set_value(struct gpio_chip *cp, unsigned int offset,
int value)
{
struct smp2p_chip_dev *chip;
uint32_t data_set;
uint32_t data_clear;
bool send_irq;
int ret;
unsigned long flags;
if (!cp)
return;
chip = container_of(cp, struct smp2p_chip_dev, gpio);
if (chip->is_inbound) {
SMP2P_INFO("%s: '%s':%d virq %d invalid operation\n",
__func__, chip->name, chip->remote_pid,
chip->irq_base + offset);
return;
}
if (value & SMP2P_GPIO_NO_INT) {
value &= ~SMP2P_GPIO_NO_INT;
send_irq = false;
} else {
send_irq = true;
}
if (value) {
data_set = 1 << offset;
data_clear = 0;
} else {
data_set = 0;
data_clear = 1 << offset;
}
spin_lock_irqsave(&chip->shadow_lock, flags);
if (!chip->is_open) {
chip->in_shadow = true;
chip->shadow_value &= ~data_clear;
chip->shadow_value |= data_set;
spin_unlock_irqrestore(&chip->shadow_lock, flags);
return;
}
if (chip->in_shadow) {
chip->in_shadow = false;
chip->shadow_value &= ~data_clear;
chip->shadow_value |= data_set;
ret = msm_smp2p_out_modify(chip->out_handle,
chip->shadow_value, 0x0, send_irq);
chip->shadow_value = 0x0;
} else {
ret = msm_smp2p_out_modify(chip->out_handle,
data_set, data_clear, send_irq);
}
spin_unlock_irqrestore(&chip->shadow_lock, flags);
if (ret)
SMP2P_GPIO("'%s':%d gpio %d set to %d failed (%d)\n",
chip->name, chip->remote_pid,
chip->gpio.base + offset, value, ret);
else
SMP2P_GPIO("'%s':%d gpio %d set to %d\n",
chip->name, chip->remote_pid,
chip->gpio.base + offset, value);
}
/**
* smp2p_direction_input - Sets GPIO direction to input.
*
* @cp: GPIO chip pointer
* @offset: Pin offset
* @returns: 0 for success; < 0 for failure
*/
static int smp2p_direction_input(struct gpio_chip *cp, unsigned int offset)
{
struct smp2p_chip_dev *chip;
if (!cp)
return -ENODEV;
chip = container_of(cp, struct smp2p_chip_dev, gpio);
if (!chip->is_inbound)
return -EPERM;
return 0;
}
/**
* smp2p_direction_output - Sets GPIO direction to output.
*
* @cp: GPIO chip pointer
* @offset: Pin offset
* @value: Direction
* @returns: 0 for success; < 0 for failure
*/
static int smp2p_direction_output(struct gpio_chip *cp,
unsigned int offset, int value)
{
struct smp2p_chip_dev *chip;
if (!cp)
return -ENODEV;
chip = container_of(cp, struct smp2p_chip_dev, gpio);
if (chip->is_inbound)
return -EPERM;
return 0;
}
/**
* smp2p_gpio_to_irq - Convert GPIO pin to virtual IRQ pin.
*
* @cp: GPIO chip pointer
* @offset: Pin offset
* @returns: >0 for virtual irq value; < 0 for failure
*/
static int smp2p_gpio_to_irq(struct gpio_chip *cp, unsigned int offset)
{
struct smp2p_chip_dev *chip;
chip = container_of(cp, struct smp2p_chip_dev, gpio);
if (!cp || chip->irq_base <= 0)
return -ENODEV;
return chip->irq_base + offset;
}
/**
* smp2p_gpio_irq_mask_helper - Mask/Unmask interrupt.
*
* @d: IRQ data
* @mask: true to mask (disable), false to unmask (enable)
*/
static void smp2p_gpio_irq_mask_helper(struct irq_data *d, bool mask)
{
struct smp2p_chip_dev *chip;
int offset;
unsigned long flags;
chip = (struct smp2p_chip_dev *)irq_get_chip_data(d->irq);
if (!chip || chip->irq_base <= 0)
return;
offset = d->irq - chip->irq_base;
spin_lock_irqsave(&chip->irq_lock, flags);
if (mask)
clear_bit(offset, chip->irq_enabled);
else
set_bit(offset, chip->irq_enabled);
spin_unlock_irqrestore(&chip->irq_lock, flags);
}
/**
* smp2p_gpio_irq_mask - Mask interrupt.
*
* @d: IRQ data
*/
static void smp2p_gpio_irq_mask(struct irq_data *d)
{
smp2p_gpio_irq_mask_helper(d, true);
}
/**
* smp2p_gpio_irq_unmask - Unmask interrupt.
*
* @d: IRQ data
*/
static void smp2p_gpio_irq_unmask(struct irq_data *d)
{
smp2p_gpio_irq_mask_helper(d, false);
}
/**
* smp2p_gpio_irq_set_type - Set interrupt edge type.
*
* @d: IRQ data
* @type: Edge type for interrupt
* @returns 0 for success; < 0 for failure
*/
static int smp2p_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
struct smp2p_chip_dev *chip;
int offset;
unsigned long flags;
int ret = 0;
chip = (struct smp2p_chip_dev *)irq_get_chip_data(d->irq);
if (!chip)
return -ENODEV;
if (chip->irq_base <= 0) {
SMP2P_ERR("%s: '%s':%d virqbase %d invalid\n",
__func__, chip->name, chip->remote_pid,
chip->irq_base);
return -ENODEV;
}
offset = d->irq - chip->irq_base;
spin_lock_irqsave(&chip->irq_lock, flags);
clear_bit(offset, chip->irq_rising_edge);
clear_bit(offset, chip->irq_falling_edge);
switch (type) {
case IRQ_TYPE_EDGE_RISING:
set_bit(offset, chip->irq_rising_edge);
break;
case IRQ_TYPE_EDGE_FALLING:
set_bit(offset, chip->irq_falling_edge);
break;
case IRQ_TYPE_NONE:
case IRQ_TYPE_DEFAULT:
case IRQ_TYPE_EDGE_BOTH:
set_bit(offset, chip->irq_rising_edge);
set_bit(offset, chip->irq_falling_edge);
break;
default:
SMP2P_ERR("%s: unsupported interrupt type 0x%x\n",
__func__, type);
ret = -EINVAL;
break;
}
spin_unlock_irqrestore(&chip->irq_lock, flags);
return ret;
}
/**
* smp2p_irq_map - Creates or updates binding of virtual IRQ
*
* @domain_ptr: Interrupt domain pointer
* @virq: Virtual IRQ
* @hw: Hardware IRQ (same as virq for nomap)
* @returns: 0 for success
*/
static int smp2p_irq_map(struct irq_domain *domain_ptr, unsigned int virq,
irq_hw_number_t hw)
{
struct smp2p_chip_dev *chip;
chip = domain_ptr->host_data;
if (!chip) {
SMP2P_ERR("%s: invalid domain ptr\n", __func__);
return -ENODEV;
}
/* map chip structures to device */
irq_set_lockdep_class(virq, &smp2p_gpio_lock_class);
irq_set_chip_and_handler(virq, &smp2p_gpio_irq_chip,
handle_level_irq);
irq_set_chip_data(virq, chip);
return 0;
}
static struct irq_chip smp2p_gpio_irq_chip = {
.name = "smp2p_gpio",
.irq_mask = smp2p_gpio_irq_mask,
.irq_unmask = smp2p_gpio_irq_unmask,
.irq_set_type = smp2p_gpio_irq_set_type,
};
/* No-map interrupt Domain */
static const struct irq_domain_ops smp2p_irq_domain_ops = {
.map = smp2p_irq_map,
};
/**
* msm_summary_irq_handler - Handles inbound entry change notification.
*
* @chip: GPIO chip pointer
* @entry: Change notification data
*
* Whenever an entry changes, this callback is triggered to determine
* which bits changed and if the corresponding interrupts need to be
* triggered.
*/
static void msm_summary_irq_handler(struct smp2p_chip_dev *chip,
struct msm_smp2p_update_notif *entry)
{
int i;
uint32_t cur_val;
uint32_t prev_val;
uint32_t edge;
unsigned long flags;
bool trigger_interrupt;
bool irq_rising;
bool irq_falling;
cur_val = entry->current_value;
prev_val = entry->previous_value;
if (chip->irq_base <= 0)
return;
SMP2P_GPIO("'%s':%d GPIO Summary IRQ Change %08x->%08x\n",
chip->name, chip->remote_pid, prev_val, cur_val);
for (i = 0; i < SMP2P_BITS_PER_ENTRY; ++i) {
spin_lock_irqsave(&chip->irq_lock, flags);
trigger_interrupt = false;
edge = (prev_val & 0x1) << 1 | (cur_val & 0x1);
irq_rising = test_bit(i, chip->irq_rising_edge);
irq_falling = test_bit(i, chip->irq_falling_edge);
if (test_bit(i, chip->irq_enabled)) {
if (edge == 0x1 && irq_rising)
/* 0->1 transition */
trigger_interrupt = true;
else if (edge == 0x2 && irq_falling)
/* 1->0 transition */
trigger_interrupt = true;
} else {
SMP2P_GPIO(
"'%s':%d GPIO bit %d virq %d (%s,%s) - edge %s disabled\n",
chip->name, chip->remote_pid, i,
chip->irq_base + i,
edge_name_rising[irq_rising],
edge_name_falling[irq_falling],
edge_names[edge]);
}
spin_unlock_irqrestore(&chip->irq_lock, flags);
if (trigger_interrupt) {
SMP2P_INFO(
"'%s':%d GPIO bit %d virq %d (%s,%s) - edge %s triggering\n",
chip->name, chip->remote_pid, i,
chip->irq_base + i,
edge_name_rising[irq_rising],
edge_name_falling[irq_falling],
edge_names[edge]);
(void)generic_handle_irq(chip->irq_base + i);
}
cur_val >>= 1;
prev_val >>= 1;
}
}
/**
* Adds an interrupt domain based upon the DT node.
*
* @chip: pointer to GPIO chip
* @node: pointer to Device Tree node
*/
static void smp2p_add_irq_domain(struct smp2p_chip_dev *chip,
struct device_node *node)
{
int irq_base;
/* map GPIO pins to interrupts */
chip->irq_domain = irq_domain_add_linear(node, SMP2P_BITS_PER_ENTRY,
&smp2p_irq_domain_ops, chip);
if (!chip->irq_domain) {
SMP2P_ERR("%s: unable to create interrupt domain '%s':%d\n",
__func__, chip->name, chip->remote_pid);
goto domain_fail;
}
/* alloc a contiguous set of virt irqs from anywhere in the irq space */
irq_base = irq_alloc_descs_from(0, SMP2P_BITS_PER_ENTRY, of_node_to_nid(
irq_domain_get_of_node(chip->irq_domain)));
if (irq_base < 0) {
SMP2P_ERR("alloc virt irqs failed:%d name:%s pid%d\n", irq_base,
chip->name, chip->remote_pid);
goto irq_alloc_fail;
}
/* map the allocated irqs to gpios */
irq_domain_associate_many(chip->irq_domain, irq_base, 0,
SMP2P_BITS_PER_ENTRY);
chip->irq_base = irq_base;
SMP2P_DBG("create mapping:%d naem:%s pid:%d\n", chip->irq_base,
chip->name, chip->remote_pid);
return;
irq_alloc_fail:
irq_domain_remove(chip->irq_domain);
domain_fail:
return;
}
/**
* Notifier function passed into smp2p API for out bound entries.
*
* @self: Pointer to calling notifier block
* @event: Event
* @data: Event-specific data
* @returns: 0
*/
static int smp2p_gpio_out_notify(struct notifier_block *self,
unsigned long event, void *data)
{
struct smp2p_chip_dev *chip;
chip = container_of(self, struct smp2p_chip_dev, out_notifier);
switch (event) {
case SMP2P_OPEN:
chip->is_open = 1;
SMP2P_GPIO("%s: Opened out '%s':%d in_shadow[%d]\n", __func__,
chip->name, chip->remote_pid, chip->in_shadow);
if (chip->in_shadow)
schedule_work(&chip->shadow_work);
break;
case SMP2P_ENTRY_UPDATE:
break;
default:
SMP2P_ERR("%s: Unknown event\n", __func__);
break;
}
return 0;
}
/**
* Notifier function passed into smp2p API for in bound entries.
*
* @self: Pointer to calling notifier block
* @event: Event
* @data: Event-specific data
* @returns: 0
*/
static int smp2p_gpio_in_notify(struct notifier_block *self,
unsigned long event, void *data)
{
struct smp2p_chip_dev *chip;
chip = container_of(self, struct smp2p_chip_dev, in_notifier);
switch (event) {
case SMP2P_OPEN:
chip->is_open = 1;
SMP2P_GPIO("%s: Opened in '%s':%d\n", __func__,
chip->name, chip->remote_pid);
break;
case SMP2P_ENTRY_UPDATE:
msm_summary_irq_handler(chip, data);
break;
default:
SMP2P_ERR("%s: Unknown event\n", __func__);
break;
}
return 0;
}
/**
* smp2p_gpio_shadow_worker - Handles shadow updates of an entry.
*
* @work: Work Item scheduled to handle the shadow updates.
*/
static void smp2p_gpio_shadow_worker(struct work_struct *work)
{
struct smp2p_chip_dev *chip;
int ret;
unsigned long flags;
chip = container_of(work, struct smp2p_chip_dev, shadow_work);
spin_lock_irqsave(&chip->shadow_lock, flags);
if (chip->in_shadow) {
ret = msm_smp2p_out_modify(chip->out_handle,
chip->shadow_value, 0x0, true);
if (ret)
SMP2P_GPIO("'%s':%d shadow val[0x%x] failed(%d)\n",
chip->name, chip->remote_pid,
chip->shadow_value, ret);
else
SMP2P_GPIO("'%s':%d shadow val[0x%x]\n",
chip->name, chip->remote_pid,
chip->shadow_value);
chip->shadow_value = 0;
chip->in_shadow = false;
}
spin_unlock_irqrestore(&chip->shadow_lock, flags);
}
/**
* Device tree probe function.
*
* @pdev: Pointer to device tree data.
* @returns: 0 on success; -ENODEV otherwise
*
* Called for each smp2pgpio entry in the device tree.
*/
static int smp2p_gpio_probe(struct platform_device *pdev)
{
struct device_node *node;
char *key;
struct smp2p_chip_dev *chip;
const char *name_tmp;
unsigned long flags;
bool is_test_entry = false;
int ret;
chip = kzalloc(sizeof(struct smp2p_chip_dev), GFP_KERNEL);
if (!chip) {
SMP2P_ERR("%s: out of memory\n", __func__);
ret = -ENOMEM;
goto fail;
}
spin_lock_init(&chip->irq_lock);
spin_lock_init(&chip->shadow_lock);
INIT_WORK(&chip->shadow_work, smp2p_gpio_shadow_worker);
/* parse device tree */
node = pdev->dev.of_node;
key = "qcom,entry-name";
ret = of_property_read_string(node, key, &name_tmp);
if (ret) {
SMP2P_ERR("%s: missing DT key '%s'\n", __func__, key);
goto fail;
}
strlcpy(chip->name, name_tmp, sizeof(chip->name));
key = "qcom,remote-pid";
ret = of_property_read_u32(node, key, &chip->remote_pid);
if (ret) {
SMP2P_ERR("%s: missing DT key '%s'\n", __func__, key);
goto fail;
}
key = "qcom,is-inbound";
chip->is_inbound = of_property_read_bool(node, key);
/* create virtual GPIO controller */
chip->gpio.label = chip->name;
chip->gpio.parent = &pdev->dev;
chip->gpio.owner = THIS_MODULE;
chip->gpio.direction_input = smp2p_direction_input,
chip->gpio.get = smp2p_get_value;
chip->gpio.direction_output = smp2p_direction_output,
chip->gpio.set = smp2p_set_value;
chip->gpio.to_irq = smp2p_gpio_to_irq,
chip->gpio.base = -1; /* use dynamic GPIO pin allocation */
chip->gpio.ngpio = SMP2P_BITS_PER_ENTRY;
ret = gpiochip_add(&chip->gpio);
if (ret) {
SMP2P_ERR("%s: unable to register GPIO '%s' ret %d\n",
__func__, chip->name, ret);
goto fail;
}
/*
* Test entries opened by GPIO Test conflict with loopback
* support, so the test entries must be explicitly opened
* in the unit test framework.
*/
if (strcmp("smp2p", chip->name) == 0)
is_test_entry = true;
if (!chip->is_inbound) {
chip->out_notifier.notifier_call = smp2p_gpio_out_notify;
if (!is_test_entry) {
ret = msm_smp2p_out_open(chip->remote_pid, chip->name,
&chip->out_notifier,
&chip->out_handle);
if (ret < 0)
goto error;
}
} else {
chip->in_notifier.notifier_call = smp2p_gpio_in_notify;
if (!is_test_entry) {
ret = msm_smp2p_in_register(chip->remote_pid,
chip->name,
&chip->in_notifier);
if (ret < 0)
goto error;
}
}
spin_lock_irqsave(&smp2p_entry_lock_lha1, flags);
list_add(&chip->entry_list, &smp2p_entry_list);
spin_unlock_irqrestore(&smp2p_entry_lock_lha1, flags);
/*
* Create interrupt domain - note that chip can't be removed from the
* interrupt domain, so chip cannot be deleted after this point.
*/
if (chip->is_inbound)
smp2p_add_irq_domain(chip, node);
else
chip->irq_base = -1;
SMP2P_GPIO("%s: added %s%s entry '%s':%d gpio %d irq %d",
__func__,
is_test_entry ? "test " : "",
chip->is_inbound ? "in" : "out",
chip->name, chip->remote_pid,
chip->gpio.base, chip->irq_base);
return 0;
error:
gpiochip_remove(&chip->gpio);
fail:
kfree(chip);
return ret;
}
/**
* smp2p_gpio_open_close - Opens or closes entry.
*
* @entry: Entry to open or close
* @do_open: true = open port; false = close
*/
static void smp2p_gpio_open_close(struct smp2p_chip_dev *entry,
bool do_open)
{
int ret;
if (do_open) {
/* open entry */
if (entry->is_inbound)
ret = msm_smp2p_in_register(entry->remote_pid,
entry->name, &entry->in_notifier);
else
ret = msm_smp2p_out_open(entry->remote_pid,
entry->name, &entry->out_notifier,
&entry->out_handle);
SMP2P_GPIO("%s: opened %s '%s':%d ret %d\n",
__func__,
entry->is_inbound ? "in" : "out",
entry->name, entry->remote_pid,
ret);
} else {
/* close entry */
if (entry->is_inbound)
ret = msm_smp2p_in_unregister(entry->remote_pid,
entry->name, &entry->in_notifier);
else
ret = msm_smp2p_out_close(&entry->out_handle);
entry->is_open = false;
SMP2P_GPIO("%s: closed %s '%s':%d ret %d\n",
__func__,
entry->is_inbound ? "in" : "out",
entry->name, entry->remote_pid, ret);
}
}
/**
* smp2p_gpio_open_test_entry - Opens or closes test entries for unit testing.
*
* @name: Name of the entry
* @remote_pid: Remote processor ID
* @do_open: true = open port; false = close
*/
void smp2p_gpio_open_test_entry(const char *name, int remote_pid, bool do_open)
{
struct smp2p_chip_dev *entry;
struct smp2p_chip_dev *start_entry;
unsigned long flags;
spin_lock_irqsave(&smp2p_entry_lock_lha1, flags);
if (list_empty(&smp2p_entry_list)) {
spin_unlock_irqrestore(&smp2p_entry_lock_lha1, flags);
return;
}
start_entry = list_first_entry(&smp2p_entry_list,
struct smp2p_chip_dev,
entry_list);
entry = start_entry;
do {
if (!strcmp(entry->name, name)
&& entry->remote_pid == remote_pid) {
/* found entry to change */
spin_unlock_irqrestore(&smp2p_entry_lock_lha1, flags);
smp2p_gpio_open_close(entry, do_open);
spin_lock_irqsave(&smp2p_entry_lock_lha1, flags);
}
list_rotate_left(&smp2p_entry_list);
entry = list_first_entry(&smp2p_entry_list,
struct smp2p_chip_dev,
entry_list);
} while (entry != start_entry);
spin_unlock_irqrestore(&smp2p_entry_lock_lha1, flags);
}
static const struct of_device_id msm_smp2p_match_table[] = {
{.compatible = "qcom,smp2pgpio", },
{},
};
static struct platform_driver smp2p_gpio_driver = {
.probe = smp2p_gpio_probe,
.driver = {
.name = "smp2pgpio",
.owner = THIS_MODULE,
.of_match_table = msm_smp2p_match_table,
},
};
static int smp2p_init(void)
{
INIT_LIST_HEAD(&smp2p_entry_list);
return platform_driver_register(&smp2p_gpio_driver);
}
module_init(smp2p_init);
static void __exit smp2p_exit(void)
{
platform_driver_unregister(&smp2p_gpio_driver);
}
module_exit(smp2p_exit);
MODULE_DESCRIPTION("SMP2P GPIO");
MODULE_LICENSE("GPL v2");