Since it would be dangerous for an ISR or DSR to make a call
that might reschedule the current thread (by trying to lock a mutex
for example) all functions in this API have an associated synchronization
level. These levels are:
Thread
This function may only be called from within threads. This is
usually the client code that makes calls into the device driver.
In a non-kernel configuration, this will be code running at the
default non-interrupt level.
DSR
This function may be called by either DSR or thread code.
ISR
This function may be called from ISR, DSR or thread code.
The following table shows, for each API function, the levels
at which is may be called:
Callable from:
Function ISR DSR Thread
-------------------------------------------------------------------------
cyg_drv_isr_lock X X X
cyg_drv_isr_unlock X X X
cyg_drv_spinlock_init X
cyg_drv_spinlock_destroy X
cyg_drv_spinlock_spin X X X
cyg_drv_spinlock_clear X X X
cyg_drv_spinlock_try X X X
cyg_drv_spinlock_test X X X
cyg_drv_spinlock_spin_intsave X X X
cyg_drv_spinlock_clear_intsave X X X
cyg_drv_dsr_lock X X
cyg_drv_dsr_unlock X X
cyg_drv_mutex_init X
cyg_drv_mutex_destroy X
cyg_drv_mutex_lock X
cyg_drv_mutex_trylock X
cyg_drv_mutex_unlock X
cyg_drv_mutex_release X
cyg_drv_cond_init X
cyg_drv_cond_destroy X
cyg_drv_cond_wait X
cyg_drv_cond_signal X X
cyg_drv_cond_broadcast X X
cyg_drv_interrupt_create X
cyg_drv_interrupt_delete X
cyg_drv_interrupt_attach X X X
cyg_drv_interrupt_detach X X X
cyg_drv_interrupt_mask X X X
cyg_drv_interrupt_unmask X X X
cyg_drv_interrupt_acknowledge X X X
cyg_drv_interrupt_configure X X X
cyg_drv_interrupt_level X X X
cyg_drv_interrupt_set_cpu X X X
cyg_drv_interrupt_get_cpu X X X
