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GPIO_CLX_AcquireInterruptLock method

The GPIO_CLX_AcquireInterruptLock method acquires an interrupt lock on a bank of pins in the general-purpose I/O (GPIO) controller.

Syntax


VOID GPIO_CLX_AcquireInterruptLock(
  [in]  PVOID Context,
  [in]  BANK_ID BankId
);

Parameters

Context [in]

A pointer to the GPIO controller driver's device context. The GPIO framework extension (GpioClx) passes this pointer value as a parameter to the callback functions that are implemented by the GPIO controller driver.

BankId [in]

The identifier for this bank of GPIO pins. If N is the number of banks in the GPIO controller, BankId is an integer in the range 0 to N–1.

Return value

None.

Remarks

A GPIO controller driver thread calls this method to synchronize to the interrupt service routine (ISR) in GpioClx. While the caller holds the interrupt lock, the ISR cannot call driver-implemented callback functions to access GPIO registers in the specified bank. A GPIO controller driver should call this method before it tries to access GPIO registers that might be accessed by the GpioClx ISR.

The GpioClx ISR calls driver-implemented callback functions to access interrupt status and enable registers in the GPIO controller. Depending on the capabilities of the GPIO controller, the ISR is called either at DIRQL or at PASSIVE_LEVEL. For more information, see Interrupt-Related Callbacks.

If the GpioClx ISR accesses these interrupt registers at DIRQL, GPIO_CLX_AcquireInterruptLock raises the calling thread's IRQL to the DIRQL at which the ISR runs. If the ISR runs at PASSIVE_LEVEL, this method does not change the calling thread's IRQL.

The GPIO_CLX_ReleaseInterruptLock method releases an interrupt lock that was acquired in a previous call to GPIO_CLX_AcquireInterruptLock. The BankId parameter specifies the bank that is affected by the lock. To release a lock on a bank, the BankId parameter of the GPIO_CLX_ReleaseInterruptLock call must match the BankId parameter of the GPIO_CLX_AcquireInterruptLock call that acquired the lock. If the GPIO_CLX_AcquireInterruptLock call raised the calling thread's IRQL, GPIO_CLX_ReleaseInterruptLock restores this thread's original IRQL.

The GPIO controller driver can independently acquire and release interrupt locks on the various banks in the GPIO controller. However, it is a fatal error for the driver to try to acquire a lock on a particular bank if the driver already holds a lock on this bank.

If the Context parameter is NULL or points to an invalid GPIO device context, this method causes a bug check in debug builds of GpioClx.

Requirements

Version

Available starting with Windows 8.

Header

Gpioclx.h

IRQL

See Remarks.

See also

GPIO_CLX_ReleaseInterruptLock

 

 

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