drivers/gpio/gpiolib-shared.h

File Facts

System

Linux kernel

Corpus path

drivers/gpio/gpiolib-shared.h

Extension

.h

Size

1810 bytes

Lines

77

Domain

Driver Families

Bucket

drivers/gpio

Inferred role

Driver Families: implementation source

Status

source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

• Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/cleanup.h
• linux/lockdep.h
• linux/mutex.h
• linux/spinlock.h

Detected Declarations

• struct gpio_device
• struct gpio_desc
• struct device
• struct fwnode_handle
• struct gpio_shared_desc
• function gpiochip_setup_shared
• function gpio_device_teardown_shared
• function spin_unlock_irqrestore

Annotated Snippet

struct gpio_shared_desc {
	struct gpio_desc *desc;
	bool can_sleep;
	unsigned long cfg;
	unsigned int usecnt;
	unsigned int highcnt;
	union {
		struct mutex mutex;
		spinlock_t spinlock;
	};
};

struct gpio_shared_desc *devm_gpiod_shared_get(struct device *dev);

DEFINE_LOCK_GUARD_1(gpio_shared_desc_lock, struct gpio_shared_desc,
	if (_T->lock->can_sleep)
		mutex_lock(&_T->lock->mutex);
	else
		spin_lock_irqsave(&_T->lock->spinlock, _T->flags),
	if (_T->lock->can_sleep)
		mutex_unlock(&_T->lock->mutex);
	else
		spin_unlock_irqrestore(&_T->lock->spinlock, _T->flags),
	unsigned long flags)

static inline void gpio_shared_lockdep_assert(struct gpio_shared_desc *shared_desc)
{
	if (shared_desc->can_sleep)
		lockdep_assert_held(&shared_desc->mutex);
	else
		lockdep_assert_held(&shared_desc->spinlock);
}

#endif /* __LINUX_GPIO_SHARED_H */

Annotation

• Immediate include surface: `linux/cleanup.h`, `linux/lockdep.h`, `linux/mutex.h`, `linux/spinlock.h`.
• Detected declarations: `struct gpio_device`, `struct gpio_desc`, `struct device`, `struct fwnode_handle`, `struct gpio_shared_desc`, `function gpiochip_setup_shared`, `function gpio_device_teardown_shared`, `function spin_unlock_irqrestore`.
• Atlas domain: Driver Families / drivers/gpio.
• Implementation status: source implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.