{
unsigned long flags;
struct gpio_desc *desc;
- int status = -EINVAL;
+ int status;
const char *ioname = NULL;
+ struct device *dev;
/* can't export until sysfs is available ... */
if (!gpio_class.p) {
return -ENOENT;
}
- if (!gpio_is_valid(gpio))
- goto done;
+ if (!gpio_is_valid(gpio)) {
+ pr_debug("%s: gpio %d is not valid\n", __func__, gpio);
+ return -EINVAL;
+ }
mutex_lock(&sysfs_lock);
spin_lock_irqsave(&gpio_lock, flags);
desc = &gpio_desc[gpio];
- if (test_bit(FLAG_REQUESTED, &desc->flags)
- && !test_bit(FLAG_EXPORT, &desc->flags)) {
- status = 0;
- if (!desc->chip->direction_input
- || !desc->chip->direction_output)
- direction_may_change = false;
+ if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
+ test_bit(FLAG_EXPORT, &desc->flags)) {
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ pr_debug("%s: gpio %d unavailable (requested=%d, exported=%d)\n",
+ __func__, gpio,
+ test_bit(FLAG_REQUESTED, &desc->flags),
+ test_bit(FLAG_EXPORT, &desc->flags));
+ return -EPERM;
}
+
+ if (!desc->chip->direction_input || !desc->chip->direction_output)
+ direction_may_change = false;
spin_unlock_irqrestore(&gpio_lock, flags);
if (desc->chip->names && desc->chip->names[gpio - desc->chip->base])
ioname = desc->chip->names[gpio - desc->chip->base];
- if (status == 0) {
- struct device *dev;
-
- dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
- desc, ioname ? ioname : "gpio%u", gpio);
- if (!IS_ERR(dev)) {
- status = sysfs_create_group(&dev->kobj,
- &gpio_attr_group);
-
- if (!status && direction_may_change)
- status = device_create_file(dev,
- &dev_attr_direction);
-
- if (!status && gpio_to_irq(gpio) >= 0
- && (direction_may_change
- || !test_bit(FLAG_IS_OUT,
- &desc->flags)))
- status = device_create_file(dev,
- &dev_attr_edge);
-
- if (status != 0)
- device_unregister(dev);
- } else
- status = PTR_ERR(dev);
- if (status == 0)
- set_bit(FLAG_EXPORT, &desc->flags);
+ dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
+ desc, ioname ? ioname : "gpio%u", gpio);
+ if (IS_ERR(dev)) {
+ status = PTR_ERR(dev);
+ goto fail_unlock;
}
- mutex_unlock(&sysfs_lock);
-
-done:
+ status = sysfs_create_group(&dev->kobj, &gpio_attr_group);
if (status)
- pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
+ goto fail_unregister_device;
+
+ if (direction_may_change) {
+ status = device_create_file(dev, &dev_attr_direction);
+ if (status)
+ goto fail_unregister_device;
+ }
+ if (gpio_to_irq(gpio) >= 0 && (direction_may_change ||
+ !test_bit(FLAG_IS_OUT, &desc->flags))) {
+ status = device_create_file(dev, &dev_attr_edge);
+ if (status)
+ goto fail_unregister_device;
+ }
+
+ set_bit(FLAG_EXPORT, &desc->flags);
+ mutex_unlock(&sysfs_lock);
+ return 0;
+
+fail_unregister_device:
+ device_unregister(dev);
+fail_unlock:
+ mutex_unlock(&sysfs_lock);
+ pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
return status;
}
EXPORT_SYMBOL_GPL(gpio_export);
}
}
-static int gpiolib_show(struct seq_file *s, void *unused)
+static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
{
- struct gpio_chip *chip = NULL;
- unsigned gpio;
- int started = 0;
+ struct gpio_chip *chip = NULL;
+ unsigned int gpio;
+ void *ret = NULL;
+ loff_t index = 0;
/* REVISIT this isn't locked against gpio_chip removal ... */
for (gpio = 0; gpio_is_valid(gpio); gpio++) {
- struct device *dev;
-
- if (chip == gpio_desc[gpio].chip)
+ if (gpio_desc[gpio].chip == chip)
continue;
+
chip = gpio_desc[gpio].chip;
if (!chip)
continue;
- seq_printf(s, "%sGPIOs %d-%d",
- started ? "\n" : "",
- chip->base, chip->base + chip->ngpio - 1);
- dev = chip->dev;
- if (dev)
- seq_printf(s, ", %s/%s",
- dev->bus ? dev->bus->name : "no-bus",
- dev_name(dev));
- if (chip->label)
- seq_printf(s, ", %s", chip->label);
- if (chip->can_sleep)
- seq_printf(s, ", can sleep");
- seq_printf(s, ":\n");
-
- started = 1;
- if (chip->dbg_show)
- chip->dbg_show(s, chip);
- else
- gpiolib_dbg_show(s, chip);
+ if (index++ >= *pos) {
+ ret = chip;
+ break;
+ }
+ }
+
+ s->private = "";
+
+ return ret;
+}
+
+static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+ struct gpio_chip *chip = v;
+ unsigned int gpio;
+ void *ret = NULL;
+
+ /* skip GPIOs provided by the current chip */
+ for (gpio = chip->base + chip->ngpio; gpio_is_valid(gpio); gpio++) {
+ chip = gpio_desc[gpio].chip;
+ if (chip) {
+ ret = chip;
+ break;
+ }
}
+
+ s->private = "\n";
+ ++*pos;
+
+ return ret;
+}
+
+static void gpiolib_seq_stop(struct seq_file *s, void *v)
+{
+}
+
+static int gpiolib_seq_show(struct seq_file *s, void *v)
+{
+ struct gpio_chip *chip = v;
+ struct device *dev;
+
+ seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
+ chip->base, chip->base + chip->ngpio - 1);
+ dev = chip->dev;
+ if (dev)
+ seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
+ dev_name(dev));
+ if (chip->label)
+ seq_printf(s, ", %s", chip->label);
+ if (chip->can_sleep)
+ seq_printf(s, ", can sleep");
+ seq_printf(s, ":\n");
+
+ if (chip->dbg_show)
+ chip->dbg_show(s, chip);
+ else
+ gpiolib_dbg_show(s, chip);
+
return 0;
}
+static const struct seq_operations gpiolib_seq_ops = {
+ .start = gpiolib_seq_start,
+ .next = gpiolib_seq_next,
+ .stop = gpiolib_seq_stop,
+ .show = gpiolib_seq_show,
+};
+
static int gpiolib_open(struct inode *inode, struct file *file)
{
- return single_open(file, gpiolib_show, NULL);
+ return seq_open(file, &gpiolib_seq_ops);
}
static const struct file_operations gpiolib_operations = {
+ .owner = THIS_MODULE,
.open = gpiolib_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = single_release,
+ .release = seq_release,
};
static int __init gpiolib_debugfs_init(void)