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@@ -6,14 +6,29 @@
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#include <linux/gpio/driver.h>
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#include <linux/interrupt.h>
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#include <linux/kdev_t.h>
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+#include <linux/slab.h>
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#include "gpiolib.h"
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-static DEFINE_IDR(dirent_idr);
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+#define GPIO_IRQF_TRIGGER_FALLING BIT(0)
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+#define GPIO_IRQF_TRIGGER_RISING BIT(1)
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+#define GPIO_IRQF_TRIGGER_BOTH (GPIO_IRQF_TRIGGER_FALLING | \
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+ GPIO_IRQF_TRIGGER_RISING)
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+struct gpiod_data {
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+ struct gpio_desc *desc;
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+
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+ struct mutex mutex;
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+ struct kernfs_node *value_kn;
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+ int irq;
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+ unsigned char irq_flags;
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-/* lock protects against unexport_gpio() being called while
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- * sysfs files are active.
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+ bool direction_can_change;
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+};
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+
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+/*
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+ * Lock to serialise gpiod export and unexport, and prevent re-export of
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+ * gpiod whose chip is being unregistered.
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*/
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static DEFINE_MUTEX(sysfs_lock);
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@@ -38,38 +53,35 @@ static DEFINE_MUTEX(sysfs_lock);
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* /edge configuration
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*/
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-static ssize_t gpio_direction_show(struct device *dev,
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+static ssize_t direction_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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- struct gpio_desc *desc = dev_get_drvdata(dev);
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+ struct gpiod_data *data = dev_get_drvdata(dev);
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+ struct gpio_desc *desc = data->desc;
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ssize_t status;
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- mutex_lock(&sysfs_lock);
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+ mutex_lock(&data->mutex);
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- if (!test_bit(FLAG_EXPORT, &desc->flags)) {
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- status = -EIO;
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- } else {
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- gpiod_get_direction(desc);
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- status = sprintf(buf, "%s\n",
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+ gpiod_get_direction(desc);
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+ status = sprintf(buf, "%s\n",
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test_bit(FLAG_IS_OUT, &desc->flags)
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? "out" : "in");
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- }
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- mutex_unlock(&sysfs_lock);
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+ mutex_unlock(&data->mutex);
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+
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return status;
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}
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-static ssize_t gpio_direction_store(struct device *dev,
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+static ssize_t direction_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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- struct gpio_desc *desc = dev_get_drvdata(dev);
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+ struct gpiod_data *data = dev_get_drvdata(dev);
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+ struct gpio_desc *desc = data->desc;
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ssize_t status;
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- mutex_lock(&sysfs_lock);
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+ mutex_lock(&data->mutex);
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- if (!test_bit(FLAG_EXPORT, &desc->flags))
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- status = -EIO;
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- else if (sysfs_streq(buf, "high"))
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+ if (sysfs_streq(buf, "high"))
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status = gpiod_direction_output_raw(desc, 1);
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else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low"))
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status = gpiod_direction_output_raw(desc, 0);
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@@ -78,43 +90,40 @@ static ssize_t gpio_direction_store(struct device *dev,
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else
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status = -EINVAL;
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- mutex_unlock(&sysfs_lock);
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+ mutex_unlock(&data->mutex);
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+
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return status ? : size;
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}
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+static DEVICE_ATTR_RW(direction);
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-static /* const */ DEVICE_ATTR(direction, 0644,
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- gpio_direction_show, gpio_direction_store);
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-
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-static ssize_t gpio_value_show(struct device *dev,
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+static ssize_t value_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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- struct gpio_desc *desc = dev_get_drvdata(dev);
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+ struct gpiod_data *data = dev_get_drvdata(dev);
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+ struct gpio_desc *desc = data->desc;
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ssize_t status;
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- mutex_lock(&sysfs_lock);
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+ mutex_lock(&data->mutex);
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- if (!test_bit(FLAG_EXPORT, &desc->flags))
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- status = -EIO;
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- else
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- status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));
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+ status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));
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+
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+ mutex_unlock(&data->mutex);
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- mutex_unlock(&sysfs_lock);
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return status;
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}
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-static ssize_t gpio_value_store(struct device *dev,
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+static ssize_t value_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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- struct gpio_desc *desc = dev_get_drvdata(dev);
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+ struct gpiod_data *data = dev_get_drvdata(dev);
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+ struct gpio_desc *desc = data->desc;
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ssize_t status;
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- mutex_lock(&sysfs_lock);
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+ mutex_lock(&data->mutex);
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- if (!test_bit(FLAG_EXPORT, &desc->flags))
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- status = -EIO;
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- else if (!test_bit(FLAG_IS_OUT, &desc->flags))
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+ if (!test_bit(FLAG_IS_OUT, &desc->flags)) {
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status = -EPERM;
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- else {
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+ } else {
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long value;
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status = kstrtol(buf, 0, &value);
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@@ -124,172 +133,168 @@ static ssize_t gpio_value_store(struct device *dev,
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}
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}
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- mutex_unlock(&sysfs_lock);
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+ mutex_unlock(&data->mutex);
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+
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return status;
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}
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-
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-static DEVICE_ATTR(value, 0644,
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- gpio_value_show, gpio_value_store);
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+static DEVICE_ATTR_RW(value);
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static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
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{
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- struct kernfs_node *value_sd = priv;
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+ struct gpiod_data *data = priv;
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+
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+ sysfs_notify_dirent(data->value_kn);
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- sysfs_notify_dirent(value_sd);
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return IRQ_HANDLED;
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}
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-static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
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- unsigned long gpio_flags)
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+/* Caller holds gpiod-data mutex. */
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+static int gpio_sysfs_request_irq(struct device *dev, unsigned char flags)
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{
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- struct kernfs_node *value_sd;
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+ struct gpiod_data *data = dev_get_drvdata(dev);
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+ struct gpio_desc *desc = data->desc;
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unsigned long irq_flags;
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- int ret, irq, id;
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+ int ret;
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- if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags)
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- return 0;
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-
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- irq = gpiod_to_irq(desc);
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- if (irq < 0)
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+ data->irq = gpiod_to_irq(desc);
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+ if (data->irq < 0)
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return -EIO;
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- id = desc->flags >> ID_SHIFT;
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- value_sd = idr_find(&dirent_idr, id);
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- if (value_sd)
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- free_irq(irq, value_sd);
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-
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- desc->flags &= ~GPIO_TRIGGER_MASK;
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-
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- if (!gpio_flags) {
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- gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
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- ret = 0;
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- goto free_id;
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- }
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+ data->value_kn = sysfs_get_dirent(dev->kobj.sd, "value");
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+ if (!data->value_kn)
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+ return -ENODEV;
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irq_flags = IRQF_SHARED;
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- if (test_bit(FLAG_TRIG_FALL, &gpio_flags))
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+ if (flags & GPIO_IRQF_TRIGGER_FALLING)
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irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
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IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
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- if (test_bit(FLAG_TRIG_RISE, &gpio_flags))
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+ if (flags & GPIO_IRQF_TRIGGER_RISING)
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irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
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IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
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- if (!value_sd) {
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- value_sd = sysfs_get_dirent(dev->kobj.sd, "value");
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- if (!value_sd) {
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- ret = -ENODEV;
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- goto err_out;
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- }
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-
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- ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL);
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- if (ret < 0)
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- goto free_sd;
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- id = ret;
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-
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- desc->flags &= GPIO_FLAGS_MASK;
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- desc->flags |= (unsigned long)id << ID_SHIFT;
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-
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- if (desc->flags >> ID_SHIFT != id) {
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- ret = -ERANGE;
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- goto free_id;
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- }
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- }
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+ /*
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+ * FIXME: This should be done in the irq_request_resources callback
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+ * when the irq is requested, but a few drivers currently fail
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+ * to do so.
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+ *
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+ * Remove this redundant call (along with the corresponding
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+ * unlock) when those drivers have been fixed.
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+ */
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+ ret = gpiochip_lock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
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+ if (ret < 0)
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+ goto err_put_kn;
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- ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
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- "gpiolib", value_sd);
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+ ret = request_any_context_irq(data->irq, gpio_sysfs_irq, irq_flags,
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+ "gpiolib", data);
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if (ret < 0)
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- goto free_id;
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+ goto err_unlock;
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- ret = gpiochip_lock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
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- if (ret < 0) {
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- gpiod_warn(desc, "failed to flag the GPIO for IRQ\n");
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- goto free_id;
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- }
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+ data->irq_flags = flags;
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- desc->flags |= gpio_flags;
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return 0;
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-free_id:
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- idr_remove(&dirent_idr, id);
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- desc->flags &= GPIO_FLAGS_MASK;
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-free_sd:
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- if (value_sd)
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- sysfs_put(value_sd);
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-err_out:
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+err_unlock:
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+ gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
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+err_put_kn:
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+ sysfs_put(data->value_kn);
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+
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return ret;
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}
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+/*
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+ * Caller holds gpiod-data mutex (unless called after class-device
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+ * deregistration).
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+ */
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+static void gpio_sysfs_free_irq(struct device *dev)
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+{
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+ struct gpiod_data *data = dev_get_drvdata(dev);
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+ struct gpio_desc *desc = data->desc;
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+
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+ data->irq_flags = 0;
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+ free_irq(data->irq, data);
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+ gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
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+ sysfs_put(data->value_kn);
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+}
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+
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static const struct {
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const char *name;
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- unsigned long flags;
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+ unsigned char flags;
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} trigger_types[] = {
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{ "none", 0 },
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- { "falling", BIT(FLAG_TRIG_FALL) },
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- { "rising", BIT(FLAG_TRIG_RISE) },
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- { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) },
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+ { "falling", GPIO_IRQF_TRIGGER_FALLING },
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+ { "rising", GPIO_IRQF_TRIGGER_RISING },
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+ { "both", GPIO_IRQF_TRIGGER_BOTH },
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};
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-static ssize_t gpio_edge_show(struct device *dev,
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+static ssize_t edge_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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- const struct gpio_desc *desc = dev_get_drvdata(dev);
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- ssize_t status;
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+ struct gpiod_data *data = dev_get_drvdata(dev);
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+ ssize_t status = 0;
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+ int i;
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- mutex_lock(&sysfs_lock);
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-
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- if (!test_bit(FLAG_EXPORT, &desc->flags))
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- status = -EIO;
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- else {
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- int i;
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+ mutex_lock(&data->mutex);
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- status = 0;
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- for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
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- if ((desc->flags & GPIO_TRIGGER_MASK)
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- == trigger_types[i].flags) {
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- status = sprintf(buf, "%s\n",
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- trigger_types[i].name);
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- break;
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- }
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+ for (i = 0; i < ARRAY_SIZE(trigger_types); i++) {
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+ if (data->irq_flags == trigger_types[i].flags) {
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+ status = sprintf(buf, "%s\n", trigger_types[i].name);
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+ break;
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+ }
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}
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- mutex_unlock(&sysfs_lock);
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+ mutex_unlock(&data->mutex);
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+
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return status;
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}
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-static ssize_t gpio_edge_store(struct device *dev,
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+static ssize_t edge_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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- struct gpio_desc *desc = dev_get_drvdata(dev);
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- ssize_t status;
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- int i;
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+ struct gpiod_data *data = dev_get_drvdata(dev);
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+ unsigned char flags;
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+ ssize_t status = size;
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+ int i;
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- for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
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+ for (i = 0; i < ARRAY_SIZE(trigger_types); i++) {
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if (sysfs_streq(trigger_types[i].name, buf))
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- goto found;
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- return -EINVAL;
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+ break;
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+ }
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-found:
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- mutex_lock(&sysfs_lock);
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+ if (i == ARRAY_SIZE(trigger_types))
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+ return -EINVAL;
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- if (!test_bit(FLAG_EXPORT, &desc->flags))
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- status = -EIO;
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- else {
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- status = gpio_setup_irq(desc, dev, trigger_types[i].flags);
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+ flags = trigger_types[i].flags;
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+
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+ mutex_lock(&data->mutex);
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+
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+ if (flags == data->irq_flags) {
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+ status = size;
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+ goto out_unlock;
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+ }
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+
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+ if (data->irq_flags)
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+ gpio_sysfs_free_irq(dev);
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+
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+ if (flags) {
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+ status = gpio_sysfs_request_irq(dev, flags);
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if (!status)
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status = size;
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}
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- mutex_unlock(&sysfs_lock);
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+out_unlock:
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+ mutex_unlock(&data->mutex);
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return status;
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}
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+static DEVICE_ATTR_RW(edge);
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-static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store);
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-
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-static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
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- int value)
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+/* Caller holds gpiod-data mutex. */
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+static int gpio_sysfs_set_active_low(struct device *dev, int value)
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{
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+ struct gpiod_data *data = dev_get_drvdata(dev);
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|
+ 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;
|
|
@@ -300,69 +305,59 @@ static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
|
|
|
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)
|
|
@@ -402,32 +397,32 @@ static const struct attribute_group *gpio_groups[] = {
|
|
|
* /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,
|
|
@@ -552,6 +547,7 @@ static struct class gpio_class = {
|
|
|
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;
|
|
@@ -574,9 +570,9 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
|
|
|
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);
|
|
@@ -588,43 +584,54 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
|
|
|
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;
|
|
|
}
|
|
|
|
|
|
/**
|
|
@@ -641,81 +648,25 @@ static int match_export(struct device *dev, const void *data)
|
|
|
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
|
|
@@ -724,8 +675,8 @@ EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low);
|
|
|
*/
|
|
|
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__);
|
|
@@ -734,82 +685,79 @@ void gpiod_unexport(struct gpio_desc *desc)
|
|
|
|
|
|
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)
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+void gpiochip_sysfs_unregister(struct gpio_chip *chip)
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{
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- int status;
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- struct device *dev;
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struct gpio_desc *desc;
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unsigned int i;
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+ if (!chip->cdev)
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+ return;
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+
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+ device_unregister(chip->cdev);
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+
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+ /* prevent further gpiod exports */
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mutex_lock(&sysfs_lock);
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- dev = class_find_device(&gpio_class, NULL, chip, match_export);
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- if (dev) {
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- put_device(dev);
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- device_unregister(dev);
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- /* prevent further gpiod exports */
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- chip->exported = false;
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- status = 0;
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- } else
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- status = -ENODEV;
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+ chip->cdev = NULL;
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mutex_unlock(&sysfs_lock);
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- if (status)
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- chip_dbg(chip, "%s: status %d\n", __func__, status);
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-
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/* unregister gpiod class devices owned by sysfs */
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for (i = 0; i < chip->ngpio; i++) {
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desc = &chip->desc[i];
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@@ -836,19 +784,20 @@ static int __init gpiolib_sysfs_init(void)
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*/
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spin_lock_irqsave(&gpio_lock, flags);
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list_for_each_entry(chip, &gpio_chips, list) {
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- if (chip->exported)
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+ if (chip->cdev)
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continue;
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/*
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- * TODO we yield gpio_lock here because gpiochip_export()
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- * acquires a mutex. This is unsafe and needs to be fixed.
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+ * TODO we yield gpio_lock here because
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+ * gpiochip_sysfs_register() acquires a mutex. This is unsafe
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+ * and needs to be fixed.
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*
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* Also it would be nice to use gpiochip_find() here so we
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* can keep gpio_chips local to gpiolib.c, but the yield of
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* gpio_lock prevents us from doing this.
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*/
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spin_unlock_irqrestore(&gpio_lock, flags);
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- status = gpiochip_export(chip);
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+ status = gpiochip_sysfs_register(chip);
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spin_lock_irqsave(&gpio_lock, flags);
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}
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spin_unlock_irqrestore(&gpio_lock, flags);
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