/**
*
* Run a self-test on the timer. This test clears the timer enable bit in
* the control register, writes to the timer load register and verifies the
* value read back matches the value written and restores the control register
* and the timer load register.
*
* @param InstancePtr is a pointer to the XScuTimer instance.
*
* @return
* - XST_SUCCESS if self-test was successful.
* - XST_FAILURE if self test was not successful.
*
* @note None.
*
******************************************************************************/
s32 XScuTimer_SelfTest(XScuTimer *InstancePtr)
{
u32 Register;
u32 CtrlOrig;
u32 LoadOrig;
s32 Status;
/*
* Assert to ensure the inputs are valid and the instance has been
* initialized.
*/
Xil_AssertNonvoid(InstancePtr != NULL);
Xil_AssertNonvoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
/*
* Save the contents of the Control Register and stop the timer.
*/
CtrlOrig = XScuTimer_ReadReg(InstancePtr->Config.BaseAddr,
XSCUTIMER_CONTROL_OFFSET);
Register = CtrlOrig & (u32)(~XSCUTIMER_CONTROL_ENABLE_MASK);
XScuTimer_WriteReg(InstancePtr->Config.BaseAddr,
XSCUTIMER_CONTROL_OFFSET, Register);
/*
* Save the contents of the Load Register.
* Load a new test value in the Load Register, read it back and
* compare it with the written value.
*/
LoadOrig = XScuTimer_ReadReg((InstancePtr)->Config.BaseAddr,
XSCUTIMER_LOAD_OFFSET);
XScuTimer_LoadTimer(InstancePtr, XSCUTIMER_SELFTEST_VALUE);
Register = XScuTimer_ReadReg((InstancePtr)->Config.BaseAddr,
XSCUTIMER_LOAD_OFFSET);
/*
* Restore the contents of the Load Register and Control Register.
*/
XScuTimer_LoadTimer(InstancePtr, LoadOrig);
XScuTimer_WriteReg(InstancePtr->Config.BaseAddr,
XSCUTIMER_CONTROL_OFFSET, CtrlOrig);
/*
* Return a Failure if the contents of the Load Register do not
* match with the value written to it.
*/
if (Register != XSCUTIMER_SELFTEST_VALUE) {
Status = (s32)XST_FAILURE;
}
else {
Status = (s32)XST_SUCCESS;
}
return Status;
}
/**
*
* Stop the timer.
*
* @param InstancePtr is a pointer to the XScuTimer instance.
*
* @return None.
*
* @note None.
*
******************************************************************************/
void XScuTimer_Stop(XScuTimer *InstancePtr)
{
u32 Register;
Xil_AssertVoid(InstancePtr != NULL);
Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
/*
* Read the contents of the Control register.
*/
Register = XScuTimer_ReadReg(InstancePtr->Config.BaseAddr,
XSCUTIMER_CONTROL_OFFSET);
/*
* Clear the 'timer enable' bit in the register.
*/
Register &= (u32)(~XSCUTIMER_CONTROL_ENABLE_MASK);
/*
* Update the Control register with the new value.
*/
XScuTimer_WriteReg(InstancePtr->Config.BaseAddr,
XSCUTIMER_CONTROL_OFFSET, Register);
/*
* Indicate that the device is stopped.
*/
InstancePtr->IsStarted = (u32)0;
}
/**
*
* This function sets the prescaler bits in the timer control register.
*
* @param InstancePtr is a pointer to the XScuTimer instance.
* @param PrescalerValue is a 8 bit value that sets the prescaler to use.
*
* @return None
*
* @note None
*
****************************************************************************/
void XScuTimer_SetPrescaler(XScuTimer *InstancePtr, u8 PrescalerValue)
{
u32 ControlReg;
/*
* Assert to validate input arguments.
*/
Xil_AssertVoid(InstancePtr != NULL);
Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
/*
* Read the Timer control register.
*/
ControlReg = XScuTimer_ReadReg(InstancePtr->Config.BaseAddr,
XSCUTIMER_CONTROL_OFFSET);
/*
* Clear all of the prescaler control bits in the register.
*/
ControlReg &= (u32)(~XSCUTIMER_CONTROL_PRESCALER_MASK);
/*
* Set the prescaler value.
*/
ControlReg |= (((u32)PrescalerValue) << XSCUTIMER_CONTROL_PRESCALER_SHIFT);
/*
* Write the register with the new values.
*/
XScuTimer_WriteReg(InstancePtr->Config.BaseAddr,
XSCUTIMER_CONTROL_OFFSET, ControlReg);
}
int timer_init()
{
u32 val;
/*
* Load the timer counter register.
*/
XScuTimer_WriteReg(XSCUTIMER_LOAD_OFFSET, 0xFFFFFFFF);
/*
* Start the A9Timer device.
*/
val = XScuTimer_ReadReg(XSCUTIMER_CONTROL_OFFSET);
/* Enable Auto reload mode. */
val |= XSCUTIMER_CONTROL_AUTO_RELOAD_MASK;
/* Clear prescaler control bits */
val &= ~XSCUTIMER_CONTROL_PRESCALER_MASK;
/* Set prescaler value */
val |= (CONFIG_TIMER_PRESCALE << XSCUTIMER_CONTROL_PRESCALER_SHIFT);
/* Enable the decrementer */
val |= XSCUTIMER_CONTROL_ENABLE_MASK;
XScuTimer_WriteReg(XSCUTIMER_CONTROL_OFFSET, val);
/* This must not be called before relocation */
/*reset_timer_masked();*/
return 0;
}
/**
*
* This function returns the current prescaler value.
*
* @param InstancePtr is a pointer to the XScuTimer instance.
*
* @return The prescaler value.
*
* @note None.
*
****************************************************************************/
u8 XScuTimer_GetPrescaler(XScuTimer *InstancePtr)
{
u32 ControlReg;
/*
* Assert to validate input arguments.
*/
Xil_AssertNonvoid(InstancePtr != NULL);
Xil_AssertNonvoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
/*
* Read the Timer control register.
*/
ControlReg = XScuTimer_ReadReg(InstancePtr->Config.BaseAddr,
XSCUTIMER_CONTROL_OFFSET);
ControlReg &= XSCUTIMER_CONTROL_PRESCALER_MASK;
return (u8)(ControlReg >> XSCUTIMER_CONTROL_PRESCALER_SHIFT);
}
