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; }
/** * * 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; }
/** * * 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); }
/** * * 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; }