2014-07-01 12:45:15 +07:00
|
|
|
#include <linux/idr.h>
|
|
|
|
#include <linux/mutex.h>
|
|
|
|
#include <linux/device.h>
|
|
|
|
#include <linux/sysfs.h>
|
|
|
|
#include <linux/gpio/consumer.h>
|
|
|
|
#include <linux/gpio/driver.h>
|
|
|
|
#include <linux/interrupt.h>
|
|
|
|
#include <linux/kdev_t.h>
|
|
|
|
|
|
|
|
#include "gpiolib.h"
|
|
|
|
|
|
|
|
static DEFINE_IDR(dirent_idr);
|
|
|
|
|
|
|
|
|
|
|
|
/* lock protects against unexport_gpio() being called while
|
|
|
|
* sysfs files are active.
|
|
|
|
*/
|
|
|
|
static DEFINE_MUTEX(sysfs_lock);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* /sys/class/gpio/gpioN... only for GPIOs that are exported
|
|
|
|
* /direction
|
|
|
|
* * MAY BE OMITTED if kernel won't allow direction changes
|
|
|
|
* * is read/write as "in" or "out"
|
|
|
|
* * may also be written as "high" or "low", initializing
|
|
|
|
* output value as specified ("out" implies "low")
|
|
|
|
* /value
|
|
|
|
* * always readable, subject to hardware behavior
|
|
|
|
* * may be writable, as zero/nonzero
|
|
|
|
* /edge
|
|
|
|
* * configures behavior of poll(2) on /value
|
|
|
|
* * available only if pin can generate IRQs on input
|
|
|
|
* * is read/write as "none", "falling", "rising", or "both"
|
|
|
|
* /active_low
|
|
|
|
* * configures polarity of /value
|
|
|
|
* * is read/write as zero/nonzero
|
|
|
|
* * also affects existing and subsequent "falling" and "rising"
|
|
|
|
* /edge configuration
|
|
|
|
*/
|
|
|
|
|
|
|
|
static ssize_t gpio_direction_show(struct device *dev,
|
|
|
|
struct device_attribute *attr, char *buf)
|
|
|
|
{
|
2014-11-25 15:16:31 +07:00
|
|
|
struct gpio_desc *desc = dev_get_drvdata(dev);
|
2014-07-01 12:45:15 +07:00
|
|
|
ssize_t status;
|
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
|
|
status = -EIO;
|
|
|
|
} else {
|
|
|
|
gpiod_get_direction(desc);
|
|
|
|
status = sprintf(buf, "%s\n",
|
|
|
|
test_bit(FLAG_IS_OUT, &desc->flags)
|
|
|
|
? "out" : "in");
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t gpio_direction_store(struct device *dev,
|
|
|
|
struct device_attribute *attr, const char *buf, size_t size)
|
|
|
|
{
|
|
|
|
struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
|
|
ssize_t status;
|
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags))
|
|
|
|
status = -EIO;
|
|
|
|
else if (sysfs_streq(buf, "high"))
|
|
|
|
status = gpiod_direction_output_raw(desc, 1);
|
|
|
|
else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low"))
|
|
|
|
status = gpiod_direction_output_raw(desc, 0);
|
|
|
|
else if (sysfs_streq(buf, "in"))
|
|
|
|
status = gpiod_direction_input(desc);
|
|
|
|
else
|
|
|
|
status = -EINVAL;
|
|
|
|
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
return status ? : size;
|
|
|
|
}
|
|
|
|
|
|
|
|
static /* const */ DEVICE_ATTR(direction, 0644,
|
|
|
|
gpio_direction_show, gpio_direction_store);
|
|
|
|
|
|
|
|
static ssize_t gpio_value_show(struct device *dev,
|
|
|
|
struct device_attribute *attr, char *buf)
|
|
|
|
{
|
|
|
|
struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
|
|
ssize_t status;
|
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags))
|
|
|
|
status = -EIO;
|
|
|
|
else
|
|
|
|
status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));
|
|
|
|
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t gpio_value_store(struct device *dev,
|
|
|
|
struct device_attribute *attr, const char *buf, size_t size)
|
|
|
|
{
|
|
|
|
struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
|
|
ssize_t status;
|
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags))
|
|
|
|
status = -EIO;
|
|
|
|
else if (!test_bit(FLAG_IS_OUT, &desc->flags))
|
|
|
|
status = -EPERM;
|
|
|
|
else {
|
|
|
|
long value;
|
|
|
|
|
|
|
|
status = kstrtol(buf, 0, &value);
|
|
|
|
if (status == 0) {
|
|
|
|
gpiod_set_value_cansleep(desc, value);
|
|
|
|
status = size;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
|
2015-01-13 19:00:05 +07:00
|
|
|
static DEVICE_ATTR(value, 0644,
|
2014-07-01 12:45:15 +07:00
|
|
|
gpio_value_show, gpio_value_store);
|
|
|
|
|
|
|
|
static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
|
|
|
|
{
|
|
|
|
struct kernfs_node *value_sd = priv;
|
|
|
|
|
|
|
|
sysfs_notify_dirent(value_sd);
|
|
|
|
return IRQ_HANDLED;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
|
|
|
|
unsigned long gpio_flags)
|
|
|
|
{
|
|
|
|
struct kernfs_node *value_sd;
|
|
|
|
unsigned long irq_flags;
|
|
|
|
int ret, irq, id;
|
|
|
|
|
|
|
|
if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
irq = gpiod_to_irq(desc);
|
|
|
|
if (irq < 0)
|
|
|
|
return -EIO;
|
|
|
|
|
|
|
|
id = desc->flags >> ID_SHIFT;
|
|
|
|
value_sd = idr_find(&dirent_idr, id);
|
|
|
|
if (value_sd)
|
|
|
|
free_irq(irq, value_sd);
|
|
|
|
|
|
|
|
desc->flags &= ~GPIO_TRIGGER_MASK;
|
|
|
|
|
|
|
|
if (!gpio_flags) {
|
2014-10-23 15:27:07 +07:00
|
|
|
gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
|
2014-07-01 12:45:15 +07:00
|
|
|
ret = 0;
|
|
|
|
goto free_id;
|
|
|
|
}
|
|
|
|
|
|
|
|
irq_flags = IRQF_SHARED;
|
|
|
|
if (test_bit(FLAG_TRIG_FALL, &gpio_flags))
|
|
|
|
irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
|
|
|
|
IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
|
|
|
|
if (test_bit(FLAG_TRIG_RISE, &gpio_flags))
|
|
|
|
irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
|
|
|
|
IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
|
|
|
|
|
|
|
|
if (!value_sd) {
|
|
|
|
value_sd = sysfs_get_dirent(dev->kobj.sd, "value");
|
|
|
|
if (!value_sd) {
|
|
|
|
ret = -ENODEV;
|
|
|
|
goto err_out;
|
|
|
|
}
|
|
|
|
|
|
|
|
ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL);
|
|
|
|
if (ret < 0)
|
|
|
|
goto free_sd;
|
|
|
|
id = ret;
|
|
|
|
|
|
|
|
desc->flags &= GPIO_FLAGS_MASK;
|
|
|
|
desc->flags |= (unsigned long)id << ID_SHIFT;
|
|
|
|
|
|
|
|
if (desc->flags >> ID_SHIFT != id) {
|
|
|
|
ret = -ERANGE;
|
|
|
|
goto free_id;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2015-05-04 22:10:28 +07:00
|
|
|
/*
|
|
|
|
* FIXME: This should be done in the irq_request_resources callback
|
|
|
|
* when the irq is requested, but a few drivers currently fail
|
|
|
|
* to do so.
|
|
|
|
*
|
|
|
|
* Remove this redundant call (along with the corresponding
|
|
|
|
* unlock) when those drivers have been fixed.
|
|
|
|
*/
|
|
|
|
ret = gpiochip_lock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
|
2014-07-01 12:45:15 +07:00
|
|
|
if (ret < 0)
|
|
|
|
goto free_id;
|
|
|
|
|
2015-05-04 22:10:28 +07:00
|
|
|
ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
|
|
|
|
"gpiolib", value_sd);
|
|
|
|
if (ret < 0)
|
|
|
|
goto err_unlock;
|
2014-07-01 12:45:15 +07:00
|
|
|
|
|
|
|
desc->flags |= gpio_flags;
|
|
|
|
return 0;
|
|
|
|
|
2015-05-04 22:10:28 +07:00
|
|
|
err_unlock:
|
|
|
|
gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
|
2014-07-01 12:45:15 +07:00
|
|
|
free_id:
|
|
|
|
idr_remove(&dirent_idr, id);
|
|
|
|
desc->flags &= GPIO_FLAGS_MASK;
|
|
|
|
free_sd:
|
|
|
|
if (value_sd)
|
|
|
|
sysfs_put(value_sd);
|
|
|
|
err_out:
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static const struct {
|
|
|
|
const char *name;
|
|
|
|
unsigned long flags;
|
|
|
|
} trigger_types[] = {
|
|
|
|
{ "none", 0 },
|
|
|
|
{ "falling", BIT(FLAG_TRIG_FALL) },
|
|
|
|
{ "rising", BIT(FLAG_TRIG_RISE) },
|
|
|
|
{ "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) },
|
|
|
|
};
|
|
|
|
|
|
|
|
static ssize_t gpio_edge_show(struct device *dev,
|
|
|
|
struct device_attribute *attr, char *buf)
|
|
|
|
{
|
|
|
|
const struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
|
|
ssize_t status;
|
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags))
|
|
|
|
status = -EIO;
|
|
|
|
else {
|
|
|
|
int i;
|
|
|
|
|
|
|
|
status = 0;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
|
|
|
|
if ((desc->flags & GPIO_TRIGGER_MASK)
|
|
|
|
== trigger_types[i].flags) {
|
|
|
|
status = sprintf(buf, "%s\n",
|
|
|
|
trigger_types[i].name);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t gpio_edge_store(struct device *dev,
|
|
|
|
struct device_attribute *attr, const char *buf, size_t size)
|
|
|
|
{
|
|
|
|
struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
|
|
ssize_t status;
|
|
|
|
int i;
|
|
|
|
|
|
|
|
for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
|
|
|
|
if (sysfs_streq(trigger_types[i].name, buf))
|
|
|
|
goto found;
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
found:
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags))
|
|
|
|
status = -EIO;
|
|
|
|
else {
|
|
|
|
status = gpio_setup_irq(desc, dev, trigger_types[i].flags);
|
|
|
|
if (!status)
|
|
|
|
status = size;
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
|
|
|
|
static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store);
|
|
|
|
|
|
|
|
static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
|
|
|
|
int value)
|
|
|
|
{
|
|
|
|
int status = 0;
|
|
|
|
|
|
|
|
if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
if (value)
|
|
|
|
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
|
|
else
|
|
|
|
clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
|
|
|
|
|
|
/* reconfigure poll(2) support if enabled on one edge only */
|
|
|
|
if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^
|
|
|
|
!!test_bit(FLAG_TRIG_FALL, &desc->flags))) {
|
|
|
|
unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK;
|
|
|
|
|
|
|
|
gpio_setup_irq(desc, dev, 0);
|
|
|
|
status = gpio_setup_irq(desc, dev, trigger_flags);
|
|
|
|
}
|
|
|
|
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t gpio_active_low_show(struct device *dev,
|
|
|
|
struct device_attribute *attr, char *buf)
|
|
|
|
{
|
|
|
|
const struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
|
|
ssize_t status;
|
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags))
|
|
|
|
status = -EIO;
|
|
|
|
else
|
|
|
|
status = sprintf(buf, "%d\n",
|
|
|
|
!!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
|
|
|
|
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t gpio_active_low_store(struct device *dev,
|
|
|
|
struct device_attribute *attr, const char *buf, size_t size)
|
|
|
|
{
|
|
|
|
struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
|
|
ssize_t status;
|
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
|
|
status = -EIO;
|
|
|
|
} else {
|
|
|
|
long value;
|
|
|
|
|
|
|
|
status = kstrtol(buf, 0, &value);
|
|
|
|
if (status == 0)
|
|
|
|
status = sysfs_set_active_low(desc, dev, value != 0);
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
|
|
|
|
return status ? : size;
|
|
|
|
}
|
|
|
|
|
2015-01-13 19:00:05 +07:00
|
|
|
static DEVICE_ATTR(active_low, 0644,
|
2014-07-01 12:45:15 +07:00
|
|
|
gpio_active_low_show, gpio_active_low_store);
|
|
|
|
|
2015-01-13 19:00:06 +07:00
|
|
|
static umode_t gpio_is_visible(struct kobject *kobj, struct attribute *attr,
|
|
|
|
int n)
|
|
|
|
{
|
|
|
|
struct device *dev = container_of(kobj, struct device, kobj);
|
|
|
|
struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
|
|
umode_t mode = attr->mode;
|
|
|
|
bool show_direction = test_bit(FLAG_SYSFS_DIR, &desc->flags);
|
|
|
|
|
|
|
|
if (attr == &dev_attr_direction.attr) {
|
|
|
|
if (!show_direction)
|
|
|
|
mode = 0;
|
|
|
|
} else if (attr == &dev_attr_edge.attr) {
|
|
|
|
if (gpiod_to_irq(desc) < 0)
|
|
|
|
mode = 0;
|
|
|
|
if (!show_direction && test_bit(FLAG_IS_OUT, &desc->flags))
|
|
|
|
mode = 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
return mode;
|
|
|
|
}
|
|
|
|
|
2015-01-13 19:00:05 +07:00
|
|
|
static struct attribute *gpio_attrs[] = {
|
2015-01-13 19:00:06 +07:00
|
|
|
&dev_attr_direction.attr,
|
|
|
|
&dev_attr_edge.attr,
|
2014-07-01 12:45:15 +07:00
|
|
|
&dev_attr_value.attr,
|
|
|
|
&dev_attr_active_low.attr,
|
|
|
|
NULL,
|
|
|
|
};
|
2015-01-13 19:00:06 +07:00
|
|
|
|
|
|
|
static const struct attribute_group gpio_group = {
|
|
|
|
.attrs = gpio_attrs,
|
|
|
|
.is_visible = gpio_is_visible,
|
|
|
|
};
|
|
|
|
|
|
|
|
static const struct attribute_group *gpio_groups[] = {
|
|
|
|
&gpio_group,
|
|
|
|
NULL
|
|
|
|
};
|
2014-07-01 12:45:15 +07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* /sys/class/gpio/gpiochipN/
|
|
|
|
* /base ... matching gpio_chip.base (N)
|
|
|
|
* /label ... matching gpio_chip.label
|
|
|
|
* /ngpio ... matching gpio_chip.ngpio
|
|
|
|
*/
|
|
|
|
|
|
|
|
static ssize_t chip_base_show(struct device *dev,
|
|
|
|
struct device_attribute *attr, char *buf)
|
|
|
|
{
|
|
|
|
const struct gpio_chip *chip = dev_get_drvdata(dev);
|
|
|
|
|
|
|
|
return sprintf(buf, "%d\n", chip->base);
|
|
|
|
}
|
|
|
|
static DEVICE_ATTR(base, 0444, chip_base_show, NULL);
|
|
|
|
|
|
|
|
static ssize_t chip_label_show(struct device *dev,
|
|
|
|
struct device_attribute *attr, char *buf)
|
|
|
|
{
|
|
|
|
const struct gpio_chip *chip = dev_get_drvdata(dev);
|
|
|
|
|
|
|
|
return sprintf(buf, "%s\n", chip->label ? : "");
|
|
|
|
}
|
|
|
|
static DEVICE_ATTR(label, 0444, chip_label_show, NULL);
|
|
|
|
|
|
|
|
static ssize_t chip_ngpio_show(struct device *dev,
|
|
|
|
struct device_attribute *attr, char *buf)
|
|
|
|
{
|
|
|
|
const struct gpio_chip *chip = dev_get_drvdata(dev);
|
|
|
|
|
|
|
|
return sprintf(buf, "%u\n", chip->ngpio);
|
|
|
|
}
|
|
|
|
static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL);
|
|
|
|
|
2015-01-13 19:00:04 +07:00
|
|
|
static struct attribute *gpiochip_attrs[] = {
|
2014-07-01 12:45:15 +07:00
|
|
|
&dev_attr_base.attr,
|
|
|
|
&dev_attr_label.attr,
|
|
|
|
&dev_attr_ngpio.attr,
|
|
|
|
NULL,
|
|
|
|
};
|
2015-01-13 19:00:04 +07:00
|
|
|
ATTRIBUTE_GROUPS(gpiochip);
|
2014-07-01 12:45:15 +07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* /sys/class/gpio/export ... write-only
|
|
|
|
* integer N ... number of GPIO to export (full access)
|
|
|
|
* /sys/class/gpio/unexport ... write-only
|
|
|
|
* integer N ... number of GPIO to unexport
|
|
|
|
*/
|
|
|
|
static ssize_t export_store(struct class *class,
|
|
|
|
struct class_attribute *attr,
|
|
|
|
const char *buf, size_t len)
|
|
|
|
{
|
|
|
|
long gpio;
|
|
|
|
struct gpio_desc *desc;
|
|
|
|
int status;
|
|
|
|
|
|
|
|
status = kstrtol(buf, 0, &gpio);
|
|
|
|
if (status < 0)
|
|
|
|
goto done;
|
|
|
|
|
|
|
|
desc = gpio_to_desc(gpio);
|
|
|
|
/* reject invalid GPIOs */
|
|
|
|
if (!desc) {
|
|
|
|
pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* No extra locking here; FLAG_SYSFS just signifies that the
|
|
|
|
* request and export were done by on behalf of userspace, so
|
|
|
|
* they may be undone on its behalf too.
|
|
|
|
*/
|
|
|
|
|
|
|
|
status = gpiod_request(desc, "sysfs");
|
|
|
|
if (status < 0) {
|
|
|
|
if (status == -EPROBE_DEFER)
|
|
|
|
status = -ENODEV;
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
status = gpiod_export(desc, true);
|
|
|
|
if (status < 0)
|
|
|
|
gpiod_free(desc);
|
|
|
|
else
|
|
|
|
set_bit(FLAG_SYSFS, &desc->flags);
|
|
|
|
|
|
|
|
done:
|
|
|
|
if (status)
|
|
|
|
pr_debug("%s: status %d\n", __func__, status);
|
|
|
|
return status ? : len;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t unexport_store(struct class *class,
|
|
|
|
struct class_attribute *attr,
|
|
|
|
const char *buf, size_t len)
|
|
|
|
{
|
|
|
|
long gpio;
|
|
|
|
struct gpio_desc *desc;
|
|
|
|
int status;
|
|
|
|
|
|
|
|
status = kstrtol(buf, 0, &gpio);
|
|
|
|
if (status < 0)
|
|
|
|
goto done;
|
|
|
|
|
|
|
|
desc = gpio_to_desc(gpio);
|
|
|
|
/* reject bogus commands (gpio_unexport ignores them) */
|
|
|
|
if (!desc) {
|
|
|
|
pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
status = -EINVAL;
|
|
|
|
|
|
|
|
/* No extra locking here; FLAG_SYSFS just signifies that the
|
|
|
|
* request and export were done by on behalf of userspace, so
|
|
|
|
* they may be undone on its behalf too.
|
|
|
|
*/
|
|
|
|
if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) {
|
|
|
|
status = 0;
|
|
|
|
gpiod_free(desc);
|
|
|
|
}
|
|
|
|
done:
|
|
|
|
if (status)
|
|
|
|
pr_debug("%s: status %d\n", __func__, status);
|
|
|
|
return status ? : len;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct class_attribute gpio_class_attrs[] = {
|
|
|
|
__ATTR(export, 0200, NULL, export_store),
|
|
|
|
__ATTR(unexport, 0200, NULL, unexport_store),
|
|
|
|
__ATTR_NULL,
|
|
|
|
};
|
|
|
|
|
|
|
|
static struct class gpio_class = {
|
|
|
|
.name = "gpio",
|
|
|
|
.owner = THIS_MODULE,
|
|
|
|
|
|
|
|
.class_attrs = gpio_class_attrs,
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
* gpiod_export - export a GPIO through sysfs
|
|
|
|
* @gpio: gpio to make available, already requested
|
|
|
|
* @direction_may_change: true if userspace may change gpio direction
|
|
|
|
* Context: arch_initcall or later
|
|
|
|
*
|
|
|
|
* When drivers want to make a GPIO accessible to userspace after they
|
|
|
|
* have requested it -- perhaps while debugging, or as part of their
|
|
|
|
* public interface -- they may use this routine. If the GPIO can
|
|
|
|
* change direction (some can't) and the caller allows it, userspace
|
|
|
|
* will see "direction" sysfs attribute which may be used to change
|
|
|
|
* the gpio's direction. A "value" attribute will always be provided.
|
|
|
|
*
|
|
|
|
* Returns zero on success, else an error.
|
|
|
|
*/
|
|
|
|
int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
|
|
|
|
{
|
2015-04-21 22:42:09 +07:00
|
|
|
struct gpio_chip *chip;
|
2014-07-01 12:45:15 +07:00
|
|
|
unsigned long flags;
|
|
|
|
int status;
|
|
|
|
const char *ioname = NULL;
|
|
|
|
struct device *dev;
|
|
|
|
int offset;
|
|
|
|
|
|
|
|
/* can't export until sysfs is available ... */
|
|
|
|
if (!gpio_class.p) {
|
|
|
|
pr_debug("%s: called too early!\n", __func__);
|
|
|
|
return -ENOENT;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!desc) {
|
|
|
|
pr_debug("%s: invalid gpio descriptor\n", __func__);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
2015-04-21 22:42:09 +07:00
|
|
|
chip = desc->chip;
|
|
|
|
|
2014-07-01 12:45:15 +07:00
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
2015-04-21 22:42:09 +07:00
|
|
|
/* check if chip is being removed */
|
2015-05-04 22:10:31 +07:00
|
|
|
if (!chip || !chip->cdev) {
|
2015-04-21 22:42:09 +07:00
|
|
|
status = -ENODEV;
|
|
|
|
goto fail_unlock;
|
|
|
|
}
|
|
|
|
|
2014-07-01 12:45:15 +07:00
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
|
|
|
|
test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
gpiod_dbg(desc, "%s: unavailable (requested=%d, exported=%d)\n",
|
|
|
|
__func__,
|
|
|
|
test_bit(FLAG_REQUESTED, &desc->flags),
|
|
|
|
test_bit(FLAG_EXPORT, &desc->flags));
|
|
|
|
status = -EPERM;
|
|
|
|
goto fail_unlock;
|
|
|
|
}
|
|
|
|
|
2015-05-04 22:10:29 +07:00
|
|
|
if (chip->direction_input && chip->direction_output &&
|
2015-01-13 19:00:06 +07:00
|
|
|
direction_may_change) {
|
|
|
|
set_bit(FLAG_SYSFS_DIR, &desc->flags);
|
|
|
|
}
|
|
|
|
|
2014-07-01 12:45:15 +07:00
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
|
|
|
|
offset = gpio_chip_hwgpio(desc);
|
2015-05-04 22:10:29 +07:00
|
|
|
if (chip->names && chip->names[offset])
|
|
|
|
ioname = chip->names[offset];
|
2014-07-01 12:45:15 +07:00
|
|
|
|
2015-05-04 22:10:29 +07:00
|
|
|
dev = device_create_with_groups(&gpio_class, chip->dev,
|
2015-01-13 19:00:05 +07:00
|
|
|
MKDEV(0, 0), desc, gpio_groups,
|
|
|
|
ioname ? ioname : "gpio%u",
|
|
|
|
desc_to_gpio(desc));
|
2014-07-01 12:45:15 +07:00
|
|
|
if (IS_ERR(dev)) {
|
|
|
|
status = PTR_ERR(dev);
|
|
|
|
goto fail_unlock;
|
|
|
|
}
|
|
|
|
|
|
|
|
set_bit(FLAG_EXPORT, &desc->flags);
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
fail_unlock:
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(gpiod_export);
|
|
|
|
|
|
|
|
static int match_export(struct device *dev, const void *data)
|
|
|
|
{
|
|
|
|
return dev_get_drvdata(dev) == data;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* gpiod_export_link - create a sysfs link to an exported GPIO node
|
|
|
|
* @dev: device under which to create symlink
|
|
|
|
* @name: name of the symlink
|
|
|
|
* @gpio: gpio to create symlink to, already exported
|
|
|
|
*
|
|
|
|
* Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN
|
|
|
|
* node. Caller is responsible for unlinking.
|
|
|
|
*
|
|
|
|
* Returns zero on success, else an error.
|
|
|
|
*/
|
|
|
|
int gpiod_export_link(struct device *dev, const char *name,
|
|
|
|
struct gpio_desc *desc)
|
|
|
|
{
|
|
|
|
int status = -EINVAL;
|
|
|
|
|
|
|
|
if (!desc) {
|
|
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
|
|
struct device *tdev;
|
|
|
|
|
|
|
|
tdev = class_find_device(&gpio_class, NULL, desc, match_export);
|
|
|
|
if (tdev != NULL) {
|
|
|
|
status = sysfs_create_link(&dev->kobj, &tdev->kobj,
|
|
|
|
name);
|
2015-01-26 18:02:45 +07:00
|
|
|
put_device(tdev);
|
2014-07-01 12:45:15 +07:00
|
|
|
} else {
|
|
|
|
status = -ENODEV;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (status)
|
|
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(gpiod_export_link);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* gpiod_sysfs_set_active_low - set the polarity of gpio sysfs value
|
|
|
|
* @gpio: gpio to change
|
|
|
|
* @value: non-zero to use active low, i.e. inverted values
|
|
|
|
*
|
|
|
|
* Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute.
|
|
|
|
* The GPIO does not have to be exported yet. If poll(2) support has
|
|
|
|
* been enabled for either rising or falling edge, it will be
|
|
|
|
* reconfigured to follow the new polarity.
|
|
|
|
*
|
|
|
|
* Returns zero on success, else an error.
|
|
|
|
*/
|
|
|
|
int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value)
|
|
|
|
{
|
|
|
|
struct device *dev = NULL;
|
|
|
|
int status = -EINVAL;
|
|
|
|
|
|
|
|
if (!desc) {
|
|
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
|
|
dev = class_find_device(&gpio_class, NULL, desc, match_export);
|
|
|
|
if (dev == NULL) {
|
|
|
|
status = -ENODEV;
|
|
|
|
goto unlock;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
status = sysfs_set_active_low(desc, dev, value);
|
2015-01-26 18:02:46 +07:00
|
|
|
put_device(dev);
|
2014-07-01 12:45:15 +07:00
|
|
|
unlock:
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (status)
|
|
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* gpiod_unexport - reverse effect of gpio_export()
|
|
|
|
* @gpio: gpio to make unavailable
|
|
|
|
*
|
|
|
|
* This is implicit on gpio_free().
|
|
|
|
*/
|
|
|
|
void gpiod_unexport(struct gpio_desc *desc)
|
|
|
|
{
|
|
|
|
int status = 0;
|
|
|
|
struct device *dev = NULL;
|
|
|
|
|
|
|
|
if (!desc) {
|
|
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
|
|
|
|
|
|
dev = class_find_device(&gpio_class, NULL, desc, match_export);
|
|
|
|
if (dev) {
|
|
|
|
gpio_setup_irq(desc, dev, 0);
|
2015-01-13 19:00:06 +07:00
|
|
|
clear_bit(FLAG_SYSFS_DIR, &desc->flags);
|
2014-07-01 12:45:15 +07:00
|
|
|
clear_bit(FLAG_EXPORT, &desc->flags);
|
|
|
|
} else
|
|
|
|
status = -ENODEV;
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
|
|
|
|
if (dev) {
|
|
|
|
device_unregister(dev);
|
|
|
|
put_device(dev);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (status)
|
|
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(gpiod_unexport);
|
|
|
|
|
2015-05-04 22:10:32 +07:00
|
|
|
int gpiochip_sysfs_register(struct gpio_chip *chip)
|
2014-07-01 12:45:15 +07:00
|
|
|
{
|
|
|
|
struct device *dev;
|
|
|
|
|
2015-05-04 22:10:32 +07:00
|
|
|
/*
|
|
|
|
* Many systems add gpio chips for SOC support very early,
|
2014-07-01 12:45:15 +07:00
|
|
|
* before driver model support is available. In those cases we
|
2015-05-04 22:10:32 +07:00
|
|
|
* register later, in gpiolib_sysfs_init() ... here we just
|
2014-07-01 12:45:15 +07:00
|
|
|
* verify that _some_ field of gpio_class got initialized.
|
|
|
|
*/
|
|
|
|
if (!gpio_class.p)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
/* use chip->base for the ID; it's already known to be unique */
|
2015-01-13 19:00:04 +07:00
|
|
|
dev = device_create_with_groups(&gpio_class, chip->dev, MKDEV(0, 0),
|
|
|
|
chip, gpiochip_groups,
|
|
|
|
"gpiochip%d", chip->base);
|
|
|
|
if (IS_ERR(dev))
|
2015-05-04 22:10:31 +07:00
|
|
|
return PTR_ERR(dev);
|
2015-05-04 22:10:30 +07:00
|
|
|
|
|
|
|
mutex_lock(&sysfs_lock);
|
2015-05-04 22:10:31 +07:00
|
|
|
chip->cdev = dev;
|
2014-07-01 12:45:15 +07:00
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
|
2015-05-04 22:10:31 +07:00
|
|
|
return 0;
|
2014-07-01 12:45:15 +07:00
|
|
|
}
|
|
|
|
|
2015-05-04 22:10:32 +07:00
|
|
|
void gpiochip_sysfs_unregister(struct gpio_chip *chip)
|
2014-07-01 12:45:15 +07:00
|
|
|
{
|
2015-04-21 22:42:09 +07:00
|
|
|
struct gpio_desc *desc;
|
|
|
|
unsigned int i;
|
2014-07-01 12:45:15 +07:00
|
|
|
|
2015-05-04 22:10:31 +07:00
|
|
|
if (!chip->cdev)
|
|
|
|
return;
|
2014-07-01 12:45:15 +07:00
|
|
|
|
2015-05-04 22:10:31 +07:00
|
|
|
device_unregister(chip->cdev);
|
|
|
|
|
|
|
|
/* prevent further gpiod exports */
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
chip->cdev = NULL;
|
|
|
|
mutex_unlock(&sysfs_lock);
|
2015-04-21 22:42:09 +07:00
|
|
|
|
|
|
|
/* unregister gpiod class devices owned by sysfs */
|
|
|
|
for (i = 0; i < chip->ngpio; i++) {
|
|
|
|
desc = &chip->desc[i];
|
|
|
|
if (test_and_clear_bit(FLAG_SYSFS, &desc->flags))
|
|
|
|
gpiod_free(desc);
|
|
|
|
}
|
2014-07-01 12:45:15 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
static int __init gpiolib_sysfs_init(void)
|
|
|
|
{
|
|
|
|
int status;
|
|
|
|
unsigned long flags;
|
|
|
|
struct gpio_chip *chip;
|
|
|
|
|
|
|
|
status = class_register(&gpio_class);
|
|
|
|
if (status < 0)
|
|
|
|
return status;
|
|
|
|
|
|
|
|
/* Scan and register the gpio_chips which registered very
|
|
|
|
* early (e.g. before the class_register above was called).
|
|
|
|
*
|
|
|
|
* We run before arch_initcall() so chip->dev nodes can have
|
|
|
|
* registered, and so arch_initcall() can always gpio_export().
|
|
|
|
*/
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
list_for_each_entry(chip, &gpio_chips, list) {
|
2015-05-04 22:10:31 +07:00
|
|
|
if (chip->cdev)
|
2014-07-01 12:45:15 +07:00
|
|
|
continue;
|
|
|
|
|
2014-07-22 14:17:40 +07:00
|
|
|
/*
|
2015-05-04 22:10:32 +07:00
|
|
|
* TODO we yield gpio_lock here because
|
|
|
|
* gpiochip_sysfs_register() acquires a mutex. This is unsafe
|
|
|
|
* and needs to be fixed.
|
2014-07-22 14:17:40 +07:00
|
|
|
*
|
|
|
|
* Also it would be nice to use gpiochip_find() here so we
|
|
|
|
* can keep gpio_chips local to gpiolib.c, but the yield of
|
|
|
|
* gpio_lock prevents us from doing this.
|
|
|
|
*/
|
2014-07-01 12:45:15 +07:00
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
2015-05-04 22:10:32 +07:00
|
|
|
status = gpiochip_sysfs_register(chip);
|
2014-07-01 12:45:15 +07:00
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
}
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
|
|
|
|
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
postcore_initcall(gpiolib_sysfs_init);
|