EPICS Device Support Library

1
EPICS Device Support Library

• Motivating factors
• Quick tour of the API
• Some examples

2
Motivating Factors

• Detect conflicting use of memory mapped IO and
  interrupt resources
• Print address maps and interrupt vector maps
• Abstract interface improves portability of device
  drivers

3
Type Codes for Address Spaces We Use

• typedef enum
• atVMEA16,
• atVMEA24,
• atVMEA32,
• atISA, / memory mapped ISA access (until now
  only on PC) /
• atLast / atLast must be the last enum in this
  list /
• epicsAddressType

4
Register / Map Address Range of Memory Mapped IO

• long devRegisterAddress(
• const char pOwnerName,
• epicsAddressType addrType,
• void baseAddress,
• unsigned long size, / bytes /
• void pLocalAddress)

5
Unregister Address Range of Memory Mapped IO

• long devUnregisterAddress(
• epicsAddressType addrType,
• void baseAddress,
• const char pOwnerName)

6
Type Codes For Interrupt Vector Spaces

• typedef enum intCPU, intVME, intVXI
  epicsInterruptType

7
Connect to an Interrupt

• long devConnectInterrupt(
• epicsInterruptType intType,
• unsigned vectorNumber,
• void (pFunction)(),
• void parameter)

8
Disconnect from an Interrupt

• /
• The parameter pFunction should be set to the C
  function pointer that
• was connected. It is used as a key to prevent
  a driver from inadvertently
• removing an interrupt handler that it didn't
  install
• /
• long devDisconnectInterrupt(
• epicsInterruptType intType,
• unsigned vectorNumber,
• void (pFunction)())

9
Enable and Disable Interrupt Levels

• long devEnableInterruptLevel(
• epicsInterruptType intType,
• unsigned level)
• long devDisableInterruptLevel(
• epicsInterruptType intType, unsigned level)
  

10
Print Address Map

• long devAddressMap(void)

11
Print Interrupt Vector Map

• veclist()

12
Examples (Unfortunately Only a Few in EPICS Base)

• ltepicsgt\base\src\drv\ansi\drvAb.c(895)
  status devRegisterAddress("drvAb",atVMEA24,(void
  )p6008,
• ltepicsgt\base\src\drv\ansi\drvEpvxi.c(513) status
  devRegisterAddress(
• ltepicsgt\base\src\drv\ansi\drvEpvxi.c(525) status
  devRegisterAddress(
• ltepicsgt\base\src\drv\old\drvBitBus.c(317) if
  (devRegisterAddress("Xycom Bitbus", atVMEA16,
  (void)BaseAddr, sizeof(XycomBBRegsStruct), NULL)
  ! 0)
• ltepicsgt\base\src\drv\old\drvBitBus.c(327) if
  (devRegisterAddress("PEP Bitbus", atVMEA16,
  (void)BaseAddr, sizeof(PepBBRegsStruct), NULL)
  ! 0)