keyscan.h File Reference

Define functions to access Keyscan driver. More...

Data Structures
struct	KeyscanQueueState
	Keyscan circular event queue state. More...
struct	KeyscanRegistration
	Keyscan event notification registration structure. Internal. More...
struct	KeyscanState
	Keyscan driver state. More...

Typedefs
struct {
BYTE   keyCode
	Key code. More...
BYTE   reserved: 6
	Reserved bits.
BYTE   upDownFlag: 1
	Up/down flag.
BYTE   scanCycleFlag: 1
	Should be toggled for every scan cycle in which a new event is queued. More...
}	KeyEvent
	Definition of a key event.
typedef struct KeyscanRegistration	KeyscanRegistration
	Keyscan event notification registration structure. Internal.

Enumerations
enum	{ KEY_DOWN = 0x0, KEY_UP = 0x1 }
	Defines a keyscan driver. More...
enum	{ ROLLOVER = 0xff, END_OF_SCAN_CYCLE = 0xfe }
	Special event codes used internally by the driver. More...
enum	{ MIA_KEY_EVENT_FIFO_SIZE = 20, KEYSCAN_FW_FIFO_SIZE = (2*MIA_KEY_EVENT_FIFO_SIZE + 6) }
	Keyscan driver constants. More...
enum	{ EVENT_NONE = 0xfd }
	Defines the standard keyscan driver. More...
enum	{   HW_CTRL_SCAN_CTRL_MASK = 0x00001, HW_CTRL_GHOST_DETECT_MASK = 0x00004, HW_CTRL_INTERRUPT_CTRL_MASK = 0x00008, HW_CTRL_RESET_MASK = 0x00010,   HW_CTRL_RC_EXT_MASK = 0x000C0, HW_CTRL_ROW_MASK = 0x00700, HW_CTRL_COL_MASK = 0x0F800, HW_CTRL_COL_DRIVE_CTRL_MASK = 0x10000,   HW_CTRL_ROW_DRIVE_CTRL_MASK = 0x20000, HW_CTRL_SCAN_ENABLE = 0x00001, HW_CTRL_GHOST_ENABLE = 0x00004, HW_CTRL_KS_INTERRUPT_ENABLE = 0x00008,   HW_CTRL_RESET_ENABLE = 0x00010, HW_CTRL_CLK_ALWAYS_ON = 0x40000, HW_CTRL_RC_DEFAULT = 0x000C0, HW_CTRL_ROW_SHIFT = 8,   HW_CTRL_COL_SHIFT = 11, HW_CTRL_COL_ACTIVE_DRIVE = 0x10000, HW_CTRL_ROW_ACTIVE_DRIVE = 0x20000, HW_CTRL_SCAN_DISABLE = 0x00000,   HW_CTRL_GHOST_DISABLE = 0x00000, HW_CTRL_INTERRUPT_DISABLE = 0x00000, HW_CTRL_RESET_DISABLE = 0x00000, HW_CTRL_CLK_AUTO_CTRL = 0x00000,   HW_CTRL_COLUMN_PASSIVE_DRIVE = 0x00000, HW_CTRL_ROW_PASSIVE_DRIVE = 0x00000 }
	Internal HW control and status bits.
enum	{ HW_MIA_STATUS_KEYSCAN_INT_SET_MASK = 0x00040 }
	Keyscan interrupt mask. Internal.
enum	{ HW_LHL_CTRL_CLR_KEYS = 0x0002, HW_LHL_STATUS_GHOST = 0x0008, HW_LHL_STATUS_KEY_FIFO_OVERFLOW = 0x0004, HW_LHL_STATUS_KEYCODE = 0x0002 }
	Keyscan HW status bits. Internal.
enum	{   HW_KEYCODE_MASK = 0x000000ff, HW_SCAN_CYCLE_MASK = 0x40000000, HW_KEY_UP_DOWN_MASK = (int)0x80000000, HW_KEYCODE_SHIFT_COUNT = 0,   HW_SCAN_CYCLE_SHIFT_COUNT = 30, HW_KEY_UP_DOWN_SHIFT_COUNT = 31, HW_KEYCODE_GHOST = 0xf5, HW_KEYCODE_INIT = 0xff,   HW_KEY_UP = (int)0x80000000, HW_KEY_DOWN = 0x00000000 }
	Keyscan configuration and status bits.
enum	{ CH_SEL_KEYSCAN_ROW_INPUT_50_57 = 0x0000, CH_SEL_KEYSCAN_ROW_INPUT_16_23 = 0x0001 }

Functions
void	ksq_init (void *buffer, BYTE elementSize, BYTE maxElements)
	Initialize the keyscan queue. More...
void	ksq_flush (void)
	Flush all elements from the keyscan queue.
BYTE	ksq_getCurNumElements (void)
	Get the number of elements currently in the queue. More...
BOOL32	ksq_putExcludeOverflowSlot (void *elm, BYTE len)
	Add the given element (by copying into) to the queue, leaving one slot for an overflow indicator. More...
BOOL32	ksq_putIncludeOverflowSlot (void *elm, BYTE len)
	Add the given element (by copying into) to the queue. More...
void *	ksq_getCurElmPtr (void)
	Get element at the front of the queue. More...
void	ksq_removeCurElement (void)
	Remove the element at the front of the queue.
BOOL32	ksq_put (void *elm, BYTE len)
	Puts an element into the queue. More...
void	ksq_markCurrentEventForRollBack (void)
	Mark current events to save them when an atomic add is required. More...
void	ksq_rollbackUptoMarkedEvents (void)
	Rollback to marked item on error when using atomic adds.
void	ksq_putEvent (KeyEvent *event)
	Put a key event into the keyscan data queue. More...
void	ksq_getEvent (KeyEvent *event)
	Copy over the keyscan event at the front of the queue and delete from the queue. More...
INLINE BOOLEAN	ksq_isEmpty (void)
	Check if the KeyscanQueue is empty. More...
void	keyscan_init (void)
	Keyscan driver initialization function. More...
void	keyscan_reset (void)
	Reset the keyscan HW. Any existing events will be thrown away.
BOOL32	keyscan_eventsPending (void)
	Check if there are any pending key events. More...
BOOL32	keyscan_getNextEvent (KeyEvent *event)
	Get next key event. More...
void	keyscan_turnOff (void)
	Disables keyscanning and and any associated wakeup.
void	keyscan_turnOn (void)
	Enabled keyscanning and and any associated wakeup functionality. More...
void	keyscan_registerForEventNotification (void(*userfn)(void *), void *userdata)
	Register for notification of changes. More...
void	keyscan_enableEventDetection (void)
	Configures the interrupt source from Keyscan HW and enables event detection. More...
void	keyscan_flushHwEvents (void)
	Clears the keys in the HW queue.
void	keyscan_miaFreezeCallBack (void)
	MIA clock freeze notification. More...
void	keyscan_miaUnfreezeCallBack (void)
	MIA clock unfreeze notification. Internal.
void	keyscan_enableInterrupt (void)
	Enables the interrupts from Keyscan HW. More...
void	keyscan_disableInterrupt (void)
	Disables interrupts from the keyscan HW block.
void	keyscan_ksInterrupt (void)
	Thread context interrupt handler. Internal.
void	keyscan_restoreActivity (void)
	Reenables keyscan after a soft power up. Internal.
void	keyscan_clearKeysPressedCount (void)
	Clear the count of unmatched key down events. Internal.
UINT8	keyscan_getKeysPressedCount (void)
	Get count of unmatched key down events.
void	keyscan_enableGhostDetection (BOOL32 enable)
	Enable/disable keyscan ghost detection.
void	keyscan_hwResetOnce (void)
	Soft Reset the keyscan HW once.
void	keyscan_initHW (void)
	Initialize the keyscan HE. Internal.
void	keyscan_configGpios (void)
	Configure the GPIOs used by the keyscan HW based on keyscan config.
void	keyscan_getEventsFromHWFifo (void)
	Retrieve events from the HW fifo and places them in the FW fifo. More...

Detailed Description

Define functions to access Keyscan driver.

Variable Documentation

BYTE keyCode

Key code.

This is the location in the keyscan matrix that is pressed/released. May be implemented as ((row * numCols) + col) or ((col * numRows) + row.

BYTE scanCycleFlag

Should be toggled for every scan cycle in which a new event is queued.

Use of this flag is optional. If used, it allows the consumer to determine whether an event is detected in the same scan cycle as the previous event or a different one. Note that this flag does not indicate any separation in time.