#include <linux/gpio/driver.h>
#include <linux/interrupt.h>
#include <linux/kdev_t.h>
+#include <linux/slab.h>
#include "gpiolib.h"
-static DEFINE_IDR(dirent_idr);
+#define GPIO_IRQF_TRIGGER_FALLING BIT(0)
+#define GPIO_IRQF_TRIGGER_RISING BIT(1)
+#define GPIO_IRQF_TRIGGER_BOTH (GPIO_IRQF_TRIGGER_FALLING | \
+ GPIO_IRQF_TRIGGER_RISING)
+struct gpiod_data {
+ struct gpio_desc *desc;
+
+ struct mutex mutex;
+ struct kernfs_node *value_kn;
+ int irq;
+ unsigned char irq_flags;
-/* lock protects against unexport_gpio() being called while
- * sysfs files are active.
+ bool direction_can_change;
+};
+
+/*
+ * Lock to serialise gpiod export and unexport, and prevent re-export of
+ * gpiod whose chip is being unregistered.
*/
static DEFINE_MUTEX(sysfs_lock);
* /edge configuration
*/
-static ssize_t gpio_direction_show(struct device *dev,
+static ssize_t direction_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct gpio_desc *desc = dev_get_drvdata(dev);
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ struct gpio_desc *desc = data->desc;
ssize_t status;
- mutex_lock(&sysfs_lock);
+ mutex_lock(&data->mutex);
- if (!test_bit(FLAG_EXPORT, &desc->flags)) {
- status = -EIO;
- } else {
- gpiod_get_direction(desc);
- status = sprintf(buf, "%s\n",
+ gpiod_get_direction(desc);
+ status = sprintf(buf, "%s\n",
test_bit(FLAG_IS_OUT, &desc->flags)
? "out" : "in");
- }
- mutex_unlock(&sysfs_lock);
+ mutex_unlock(&data->mutex);
+
return status;
}
-static ssize_t gpio_direction_store(struct device *dev,
+static ssize_t direction_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
- struct gpio_desc *desc = dev_get_drvdata(dev);
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ struct gpio_desc *desc = data->desc;
ssize_t status;
- mutex_lock(&sysfs_lock);
+ mutex_lock(&data->mutex);
- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else if (sysfs_streq(buf, "high"))
+ 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
status = -EINVAL;
- mutex_unlock(&sysfs_lock);
+ mutex_unlock(&data->mutex);
+
return status ? : size;
}
+static DEVICE_ATTR_RW(direction);
-static /* const */ DEVICE_ATTR(direction, 0644,
- gpio_direction_show, gpio_direction_store);
-
-static ssize_t gpio_value_show(struct device *dev,
+static ssize_t value_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct gpio_desc *desc = dev_get_drvdata(dev);
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ struct gpio_desc *desc = data->desc;
ssize_t status;
- mutex_lock(&sysfs_lock);
+ mutex_lock(&data->mutex);
- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else
- status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));
+ status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));
+
+ mutex_unlock(&data->mutex);
- mutex_unlock(&sysfs_lock);
return status;
}
-static ssize_t gpio_value_store(struct device *dev,
+static ssize_t value_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
- struct gpio_desc *desc = dev_get_drvdata(dev);
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ struct gpio_desc *desc = data->desc;
ssize_t status;
- mutex_lock(&sysfs_lock);
+ mutex_lock(&data->mutex);
- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else if (!test_bit(FLAG_IS_OUT, &desc->flags))
+ if (!test_bit(FLAG_IS_OUT, &desc->flags)) {
status = -EPERM;
- else {
+ } else {
long value;
status = kstrtol(buf, 0, &value);
}
}
- mutex_unlock(&sysfs_lock);
+ mutex_unlock(&data->mutex);
+
return status;
}
-
-static DEVICE_ATTR(value, 0644,
- gpio_value_show, gpio_value_store);
+static DEVICE_ATTR_RW(value);
static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
{
- struct kernfs_node *value_sd = priv;
+ struct gpiod_data *data = priv;
+
+ sysfs_notify_dirent(data->value_kn);
- sysfs_notify_dirent(value_sd);
return IRQ_HANDLED;
}
-static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
- unsigned long gpio_flags)
+/* Caller holds gpiod-data mutex. */
+static int gpio_sysfs_request_irq(struct device *dev, unsigned char flags)
{
- struct kernfs_node *value_sd;
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ struct gpio_desc *desc = data->desc;
unsigned long irq_flags;
- int ret, irq, id;
+ int ret;
- if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags)
- return 0;
-
- irq = gpiod_to_irq(desc);
- if (irq < 0)
+ data->irq = gpiod_to_irq(desc);
+ if (data->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) {
- gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
- ret = 0;
- goto free_id;
- }
+ data->value_kn = sysfs_get_dirent(dev->kobj.sd, "value");
+ if (!data->value_kn)
+ return -ENODEV;
irq_flags = IRQF_SHARED;
- if (test_bit(FLAG_TRIG_FALL, &gpio_flags))
+ if (flags & GPIO_IRQF_TRIGGER_FALLING)
irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
- if (test_bit(FLAG_TRIG_RISE, &gpio_flags))
+ if (flags & GPIO_IRQF_TRIGGER_RISING)
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;
- }
- }
+ /*
+ * 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));
+ if (ret < 0)
+ goto err_put_kn;
- ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
- "gpiolib", value_sd);
+ ret = request_any_context_irq(data->irq, gpio_sysfs_irq, irq_flags,
+ "gpiolib", data);
if (ret < 0)
- goto free_id;
+ goto err_unlock;
- ret = gpiochip_lock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
- if (ret < 0) {
- gpiod_warn(desc, "failed to flag the GPIO for IRQ\n");
- goto free_id;
- }
+ data->irq_flags = flags;
- desc->flags |= gpio_flags;
return 0;
-free_id:
- idr_remove(&dirent_idr, id);
- desc->flags &= GPIO_FLAGS_MASK;
-free_sd:
- if (value_sd)
- sysfs_put(value_sd);
-err_out:
+err_unlock:
+ gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
+err_put_kn:
+ sysfs_put(data->value_kn);
+
return ret;
}
+/*
+ * Caller holds gpiod-data mutex (unless called after class-device
+ * deregistration).
+ */
+static void gpio_sysfs_free_irq(struct device *dev)
+{
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ struct gpio_desc *desc = data->desc;
+
+ data->irq_flags = 0;
+ free_irq(data->irq, data);
+ gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
+ sysfs_put(data->value_kn);
+}
+
static const struct {
const char *name;
- unsigned long flags;
+ unsigned char flags;
} trigger_types[] = {
{ "none", 0 },
- { "falling", BIT(FLAG_TRIG_FALL) },
- { "rising", BIT(FLAG_TRIG_RISE) },
- { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) },
+ { "falling", GPIO_IRQF_TRIGGER_FALLING },
+ { "rising", GPIO_IRQF_TRIGGER_RISING },
+ { "both", GPIO_IRQF_TRIGGER_BOTH },
};
-static ssize_t gpio_edge_show(struct device *dev,
+static ssize_t edge_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- const struct gpio_desc *desc = dev_get_drvdata(dev);
- ssize_t status;
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ ssize_t status = 0;
+ int i;
- mutex_lock(&sysfs_lock);
-
- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else {
- int i;
+ mutex_lock(&data->mutex);
- 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;
- }
+ for (i = 0; i < ARRAY_SIZE(trigger_types); i++) {
+ if (data->irq_flags == trigger_types[i].flags) {
+ status = sprintf(buf, "%s\n", trigger_types[i].name);
+ break;
+ }
}
- mutex_unlock(&sysfs_lock);
+ mutex_unlock(&data->mutex);
+
return status;
}
-static ssize_t gpio_edge_store(struct device *dev,
+static ssize_t 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;
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ unsigned char flags;
+ ssize_t status = size;
+ int i;
- for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
+ for (i = 0; i < ARRAY_SIZE(trigger_types); i++) {
if (sysfs_streq(trigger_types[i].name, buf))
- goto found;
- return -EINVAL;
+ break;
+ }
-found:
- mutex_lock(&sysfs_lock);
+ if (i == ARRAY_SIZE(trigger_types))
+ return -EINVAL;
- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else {
- status = gpio_setup_irq(desc, dev, trigger_types[i].flags);
+ flags = trigger_types[i].flags;
+
+ mutex_lock(&data->mutex);
+
+ if (flags == data->irq_flags) {
+ status = size;
+ goto out_unlock;
+ }
+
+ if (data->irq_flags)
+ gpio_sysfs_free_irq(dev);
+
+ if (flags) {
+ status = gpio_sysfs_request_irq(dev, flags);
if (!status)
status = size;
}
- mutex_unlock(&sysfs_lock);
+out_unlock:
+ mutex_unlock(&data->mutex);
return status;
}
+static DEVICE_ATTR_RW(edge);
-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)
+/* Caller holds gpiod-data mutex. */
+static int gpio_sysfs_set_active_low(struct device *dev, int value)
{
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ struct gpio_desc *desc = data->desc;
int status = 0;
+ unsigned int flags = data->irq_flags;
if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value)
return 0;
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);
+ if (flags == GPIO_IRQF_TRIGGER_FALLING ||
+ flags == GPIO_IRQF_TRIGGER_RISING) {
+ gpio_sysfs_free_irq(dev);
+ status = gpio_sysfs_request_irq(dev, flags);
}
return status;
}
-static ssize_t gpio_active_low_show(struct device *dev,
+static ssize_t active_low_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- const struct gpio_desc *desc = dev_get_drvdata(dev);
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ struct gpio_desc *desc = data->desc;
ssize_t status;
- mutex_lock(&sysfs_lock);
+ mutex_lock(&data->mutex);
- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else
- status = sprintf(buf, "%d\n",
+ status = sprintf(buf, "%d\n",
!!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
- mutex_unlock(&sysfs_lock);
+ mutex_unlock(&data->mutex);
return status;
}
-static ssize_t gpio_active_low_store(struct device *dev,
+static ssize_t active_low_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
- struct gpio_desc *desc = dev_get_drvdata(dev);
+ struct gpiod_data *data = dev_get_drvdata(dev);
ssize_t status;
+ long value;
- mutex_lock(&sysfs_lock);
+ mutex_lock(&data->mutex);
- if (!test_bit(FLAG_EXPORT, &desc->flags)) {
- status = -EIO;
- } else {
- long value;
+ status = kstrtol(buf, 0, &value);
+ if (status == 0)
+ status = gpio_sysfs_set_active_low(dev, value);
- status = kstrtol(buf, 0, &value);
- if (status == 0)
- status = sysfs_set_active_low(desc, dev, value != 0);
- }
-
- mutex_unlock(&sysfs_lock);
+ mutex_unlock(&data->mutex);
return status ? : size;
}
-
-static DEVICE_ATTR(active_low, 0644,
- gpio_active_low_show, gpio_active_low_store);
+static DEVICE_ATTR_RW(active_low);
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);
+ struct gpiod_data *data = dev_get_drvdata(dev);
+ struct gpio_desc *desc = data->desc;
umode_t mode = attr->mode;
- bool show_direction = test_bit(FLAG_SYSFS_DIR, &desc->flags);
+ bool show_direction = data->direction_can_change;
if (attr == &dev_attr_direction.attr) {
if (!show_direction)
* /ngpio ... matching gpio_chip.ngpio
*/
-static ssize_t chip_base_show(struct device *dev,
+static ssize_t 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 DEVICE_ATTR_RO(base);
-static ssize_t chip_label_show(struct device *dev,
+static ssize_t 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 DEVICE_ATTR_RO(label);
-static ssize_t chip_ngpio_show(struct device *dev,
+static ssize_t 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);
+static DEVICE_ATTR_RO(ngpio);
static struct attribute *gpiochip_attrs[] = {
&dev_attr_base.attr,
int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
{
struct gpio_chip *chip;
+ struct gpiod_data *data;
unsigned long flags;
int status;
const char *ioname = NULL;
mutex_lock(&sysfs_lock);
/* check if chip is being removed */
- if (!chip || !chip->exported) {
+ if (!chip || !chip->cdev) {
status = -ENODEV;
- goto fail_unlock;
+ goto err_unlock;
}
spin_lock_irqsave(&gpio_lock, flags);
test_bit(FLAG_REQUESTED, &desc->flags),
test_bit(FLAG_EXPORT, &desc->flags));
status = -EPERM;
- goto fail_unlock;
+ goto err_unlock;
}
+ spin_unlock_irqrestore(&gpio_lock, flags);
- if (desc->chip->direction_input && desc->chip->direction_output &&
- direction_may_change) {
- set_bit(FLAG_SYSFS_DIR, &desc->flags);
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data) {
+ status = -ENOMEM;
+ goto err_unlock;
}
- spin_unlock_irqrestore(&gpio_lock, flags);
+ data->desc = desc;
+ mutex_init(&data->mutex);
+ if (chip->direction_input && chip->direction_output)
+ data->direction_can_change = direction_may_change;
+ else
+ data->direction_can_change = false;
offset = gpio_chip_hwgpio(desc);
- if (desc->chip->names && desc->chip->names[offset])
- ioname = desc->chip->names[offset];
+ if (chip->names && chip->names[offset])
+ ioname = chip->names[offset];
- dev = device_create_with_groups(&gpio_class, desc->chip->dev,
- MKDEV(0, 0), desc, gpio_groups,
+ dev = device_create_with_groups(&gpio_class, chip->dev,
+ MKDEV(0, 0), data, gpio_groups,
ioname ? ioname : "gpio%u",
desc_to_gpio(desc));
if (IS_ERR(dev)) {
status = PTR_ERR(dev);
- goto fail_unlock;
+ goto err_free_data;
}
set_bit(FLAG_EXPORT, &desc->flags);
mutex_unlock(&sysfs_lock);
return 0;
-fail_unlock:
+err_free_data:
+ kfree(data);
+err_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)
+static int match_export(struct device *dev, const void *desc)
{
- return dev_get_drvdata(dev) == data;
+ struct gpiod_data *data = dev_get_drvdata(dev);
+
+ return data->desc == desc;
}
/**
int gpiod_export_link(struct device *dev, const char *name,
struct gpio_desc *desc)
{
- int status = -EINVAL;
+ struct device *cdev;
+ int ret;
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);
- put_device(tdev);
- } else {
- status = -ENODEV;
- }
- }
-
- mutex_unlock(&sysfs_lock);
+ cdev = class_find_device(&gpio_class, NULL, desc, match_export);
+ if (!cdev)
+ return -ENODEV;
- if (status)
- gpiod_dbg(desc, "%s: status %d\n", __func__, status);
+ ret = sysfs_create_link(&dev->kobj, &cdev->kobj, name);
+ put_device(cdev);
- return status;
+ return ret;
}
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);
- put_device(dev);
-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
*/
void gpiod_unexport(struct gpio_desc *desc)
{
- int status = 0;
- struct device *dev = NULL;
+ struct gpiod_data *data;
+ struct device *dev;
if (!desc) {
pr_warn("%s: invalid GPIO\n", __func__);
mutex_lock(&sysfs_lock);
- if (test_bit(FLAG_EXPORT, &desc->flags)) {
+ if (!test_bit(FLAG_EXPORT, &desc->flags))
+ goto err_unlock;
- dev = class_find_device(&gpio_class, NULL, desc, match_export);
- if (dev) {
- gpio_setup_irq(desc, dev, 0);
- clear_bit(FLAG_SYSFS_DIR, &desc->flags);
- clear_bit(FLAG_EXPORT, &desc->flags);
- } else
- status = -ENODEV;
- }
+ dev = class_find_device(&gpio_class, NULL, desc, match_export);
+ if (!dev)
+ goto err_unlock;
+
+ data = dev_get_drvdata(dev);
+
+ clear_bit(FLAG_EXPORT, &desc->flags);
+
+ device_unregister(dev);
+
+ /*
+ * Release irq after deregistration to prevent race with edge_store.
+ */
+ if (data->irq_flags)
+ gpio_sysfs_free_irq(dev);
mutex_unlock(&sysfs_lock);
- if (dev) {
- device_unregister(dev);
- put_device(dev);
- }
+ put_device(dev);
+ kfree(data);
- if (status)
- gpiod_dbg(desc, "%s: status %d\n", __func__, status);
+ return;
+
+err_unlock:
+ mutex_unlock(&sysfs_lock);
}
EXPORT_SYMBOL_GPL(gpiod_unexport);
-int gpiochip_export(struct gpio_chip *chip)
+int gpiochip_sysfs_register(struct gpio_chip *chip)
{
- int status;
struct device *dev;
- /* Many systems register gpio chips for SOC support very early,
+ /*
+ * Many systems add gpio chips for SOC support very early,
* before driver model support is available. In those cases we
- * export this later, in gpiolib_sysfs_init() ... here we just
+ * register later, in gpiolib_sysfs_init() ... here we just
* 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 */
- mutex_lock(&sysfs_lock);
dev = device_create_with_groups(&gpio_class, chip->dev, MKDEV(0, 0),
chip, gpiochip_groups,
"gpiochip%d", chip->base);
if (IS_ERR(dev))
- status = PTR_ERR(dev);
- else
- status = 0;
- chip->exported = (status == 0);
- mutex_unlock(&sysfs_lock);
+ return PTR_ERR(dev);
- if (status)
- chip_dbg(chip, "%s: status %d\n", __func__, status);
+ mutex_lock(&sysfs_lock);
+ chip->cdev = dev;
+ mutex_unlock(&sysfs_lock);
- return status;
+ return 0;
}
-void gpiochip_unexport(struct gpio_chip *chip)
+void gpiochip_sysfs_unregister(struct gpio_chip *chip)
{
- int status;
- struct device *dev;
struct gpio_desc *desc;
unsigned int i;
+ if (!chip->cdev)
+ return;
+
+ device_unregister(chip->cdev);
+
+ /* prevent further gpiod exports */
mutex_lock(&sysfs_lock);
- dev = class_find_device(&gpio_class, NULL, chip, match_export);
- if (dev) {
- put_device(dev);
- device_unregister(dev);
- /* prevent further gpiod exports */
- chip->exported = false;
- status = 0;
- } else
- status = -ENODEV;
+ chip->cdev = NULL;
mutex_unlock(&sysfs_lock);
- if (status)
- chip_dbg(chip, "%s: status %d\n", __func__, status);
-
/* unregister gpiod class devices owned by sysfs */
for (i = 0; i < chip->ngpio; i++) {
desc = &chip->desc[i];
*/
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(chip, &gpio_chips, list) {
- if (chip->exported)
+ if (chip->cdev)
continue;
/*
- * TODO we yield gpio_lock here because gpiochip_export()
- * acquires a mutex. This is unsafe and needs to be fixed.
+ * TODO we yield gpio_lock here because
+ * gpiochip_sysfs_register() acquires a mutex. This is unsafe
+ * and needs to be fixed.
*
* 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.
*/
spin_unlock_irqrestore(&gpio_lock, flags);
- status = gpiochip_export(chip);
+ status = gpiochip_sysfs_register(chip);
spin_lock_irqsave(&gpio_lock, flags);
}
spin_unlock_irqrestore(&gpio_lock, flags);
Code Review / kvmfornfv.git / blobdiff