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path: root/drivers/gpio/gpiolib.c
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Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 51a8d4103be5..aef6b3d8e2cf 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -505,6 +505,51 @@ static int match_export(struct device *dev, void *data)
505} 505}
506 506
507/** 507/**
508 * gpio_export_link - create a sysfs link to an exported GPIO node
509 * @dev: device under which to create symlink
510 * @name: name of the symlink
511 * @gpio: gpio to create symlink to, already exported
512 *
513 * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN
514 * node. Caller is responsible for unlinking.
515 *
516 * Returns zero on success, else an error.
517 */
518int gpio_export_link(struct device *dev, const char *name, unsigned gpio)
519{
520 struct gpio_desc *desc;
521 int status = -EINVAL;
522
523 if (!gpio_is_valid(gpio))
524 goto done;
525
526 mutex_lock(&sysfs_lock);
527
528 desc = &gpio_desc[gpio];
529
530 if (test_bit(FLAG_EXPORT, &desc->flags)) {
531 struct device *tdev;
532
533 tdev = class_find_device(&gpio_class, NULL, desc, match_export);
534 if (tdev != NULL) {
535 status = sysfs_create_link(&dev->kobj, &tdev->kobj,
536 name);
537 } else {
538 status = -ENODEV;
539 }
540 }
541
542 mutex_unlock(&sysfs_lock);
543
544done:
545 if (status)
546 pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
547
548 return status;
549}
550EXPORT_SYMBOL_GPL(gpio_export_link);
551
552/**
508 * gpio_unexport - reverse effect of gpio_export() 553 * gpio_unexport - reverse effect of gpio_export()
509 * @gpio: gpio to make unavailable 554 * @gpio: gpio to make unavailable
510 * 555 *