From 4d5cbec9118cbedf2d4ae5b54acaa22862245a4c Mon Sep 17 00:00:00 2001 From: Megan Wachs Date: Thu, 4 May 2017 05:46:05 -0700 Subject: Update SDK For E31/E51 Coreplex IP Evaluation --- software/local_interrupts/local_interrupts.c | 216 +++++++++++++++++++++++++++ 1 file changed, 216 insertions(+) create mode 100644 software/local_interrupts/local_interrupts.c (limited to 'software/local_interrupts/local_interrupts.c') diff --git a/software/local_interrupts/local_interrupts.c b/software/local_interrupts/local_interrupts.c new file mode 100644 index 0000000..cb2aca3 --- /dev/null +++ b/software/local_interrupts/local_interrupts.c @@ -0,0 +1,216 @@ +// See LICENSE for license details. + +#include +#include +#include "platform.h" +#include +#include "encoding.h" +#include + +#ifndef _SIFIVE_COREPLEXIP_ARTY_H +#error 'local_interrupts' demo only supported for Coreplex IP Eval Kits +#endif + +// Global Variable used to show +// software interrupts. +volatile uint32_t g_debouncing; + +void debounce(); + +// Structures for registering different interrupt handlers +// for different parts of the application. +typedef void (*interrupt_function_ptr_t) (void); + +// This function enables some of the local interrupts sources +// used in this demo -- just those for the buttons and +// Switch 3. + +void enable_local_interrupts(){ + + // lowest priority + set_csr(mie, MIP_MLIP(LOCAL_INT_SW_3 )); + set_csr(mie, MIP_MLIP(LOCAL_INT_BTN_0)); + set_csr(mie, MIP_MLIP(LOCAL_INT_BTN_1)); + set_csr(mie, MIP_MLIP(LOCAL_INT_BTN_2)); + set_csr(mie, MIP_MLIP(LOCAL_INT_BTN_3)); + // highest priority + +} + +void disable_local_interrupts() { + + // lowest priority + clear_csr(mie, MIP_MLIP(LOCAL_INT_SW_3 )); + clear_csr(mie, MIP_MLIP(LOCAL_INT_BTN_0)); + clear_csr(mie, MIP_MLIP(LOCAL_INT_BTN_1)); + clear_csr(mie, MIP_MLIP(LOCAL_INT_BTN_2)); + clear_csr(mie, MIP_MLIP(LOCAL_INT_BTN_3)); + // highest priority + +} + +/*Entry Point for Machine Software Interrupt Handler*/ +void msi_isr() { + + const char msi_msg[] = " Debouncing: (this message due to Software Interrupt))\n\n"; + write (STDOUT_FILENO, msi_msg, strlen(msi_msg)); + + //clear the SW interrupt + CLINT_REG(CLINT_MSIP) = 0; + +} + +/*Entry Point for Machine Timer Interrupt Handler*/ +void mti_isr(){ + + // Disable the timer interrupt. The Debounce logic sets it. + clear_csr(mie, MIP_MTIP); + + // Enable all the local interrupts + enable_local_interrupts(); +} + + +const char * instructions_msg = " \ +\n\ + SiFive, Inc\n\ + E31/E51 Coreplex IP Eval Kit 'local_interrupts' demo.\n\ +\n\ +The Buttons 0-3 and Switch 3 are enabled as local\n\ +interrupts sources. A .5 s 'debounce' timer is used \n\ +between these interrupts. Software interrupts are +used to print a message while debouncing.\n\ +Note the priority of the interrupts sources.\n\ +\n"; + +void print_instructions() { + + write (STDERR_FILENO, instructions_msg, strlen(instructions_msg)); + +} + +void button_0_isr(void) { + + // Toggle Red LED + const char button_0_msg[] = "Button 0 was pressed. Toggle Red.\n"; + write (STDOUT_FILENO, button_0_msg, strlen(button_0_msg)); + GPIO_REG(GPIO_OUTPUT_VAL) = GPIO_REG(GPIO_OUTPUT_VAL) ^ (0x1 << RED_LED_OFFSET); + debounce(); +}; + +void button_1_isr(void) { + + // Toggle Green LED + const char button_1_msg[] = "Button 1 was pressed. Toggle Green.\n"; + write (STDOUT_FILENO, button_1_msg, strlen(button_1_msg)); + GPIO_REG(GPIO_OUTPUT_VAL) = GPIO_REG(GPIO_OUTPUT_VAL) ^ (0x1 << GREEN_LED_OFFSET); + debounce(); +}; + + +void button_2_isr(void) { + + // Toggle Blue LED + const char button_2_msg[] = "Button 2 was pressed. Toggle Blue.\n"; + write (STDOUT_FILENO, button_2_msg, strlen(button_2_msg)); + GPIO_REG(GPIO_OUTPUT_VAL) = GPIO_REG(GPIO_OUTPUT_VAL) ^ (0x1 << BLUE_LED_OFFSET); + debounce(); + +}; + +void button_3_isr(void) { + const char button_3_msg[] = "Button 3 was pressed! (No LEDs change).\n"; + write (STDOUT_FILENO, button_3_msg, strlen(button_3_msg)); + debounce(); +} + +void switch_3_isr(void) { + const char sw_3_msg[] = "Switch 3 is on! But buttons have higher priority.\n"; + write (STDOUT_FILENO, sw_3_msg, strlen(sw_3_msg)); + debounce(); +} + +void debounce(int local_interrupt_num) { + + // Disable the most recent interrupt. + // Don't enable it again until the timer goes off, + // in .5 second. + + // Set the machine timer to go off in .5 seconds. + // If the timer was already set to go off, this "cancels" + // the current one. + + volatile uint64_t * mtime = (uint64_t*) (CLINT_CTRL_ADDR + CLINT_MTIME); + volatile uint64_t * mtimecmp = (uint64_t*) (CLINT_CTRL_ADDR + CLINT_MTIMECMP); + uint64_t now = *mtime; + uint64_t then = now + .5*RTC_FREQ; + *mtimecmp = then; + + disable_local_interrupts(); + g_debouncing = 1; + + // Enable the Machine-Timer bit in MIE + set_csr(mie, MIP_MTIP); + +} + +// See bsp/env//init.c for how this +// interrupt vector is used. + +interrupt_function_ptr_t localISR[32]; + +int main(int argc, char **argv) +{ + + // Configure LEDs as outputs. + GPIO_REG(GPIO_INPUT_EN) &= ~((0x1<< RED_LED_OFFSET) | (0x1<< GREEN_LED_OFFSET) | (0x1 << BLUE_LED_OFFSET)) ; + GPIO_REG(GPIO_OUTPUT_EN) |= ((0x1<< RED_LED_OFFSET)| (0x1<< GREEN_LED_OFFSET) | (0x1 << BLUE_LED_OFFSET)) ; + GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << BLUE_LED_OFFSET) ; + GPIO_REG(GPIO_OUTPUT_VAL) &= ~((0x1<< RED_LED_OFFSET) | (0x1<< GREEN_LED_OFFSET)) ; + + // The Buttons and Switches which are used as local interrupt sources + // do not go through the GPIO peripheral, so they do not need to + // be configured as inputs. + + // Disable the timer & local interrupts until setup is done (they're + // not reset by default) + + // Disable all interrupts. MIE is not reset. + write_csr(mie, 0); + + for (int isr = 0; isr < 32; isr++){ + localISR[isr] = 0; + } + + localISR[IRQ_M_SOFT] = msi_isr; + localISR[IRQ_M_TIMER] = mti_isr; + localISR[IRQ_M_LOCAL + LOCAL_INT_SW_3] = switch_3_isr; + localISR[IRQ_M_LOCAL + LOCAL_INT_BTN_0] = button_0_isr; + localISR[IRQ_M_LOCAL + LOCAL_INT_BTN_1] = button_1_isr; + localISR[IRQ_M_LOCAL + LOCAL_INT_BTN_2] = button_2_isr; + localISR[IRQ_M_LOCAL + LOCAL_INT_BTN_3] = button_3_isr; + + print_instructions(); + + enable_local_interrupts(); + + g_debouncing = 0; + + // Enable SW interrupts as well in this demo. + set_csr(mie, MIP_MSIP); + + // Enable all global interrupts + set_csr(mstatus, MSTATUS_MIE); + + volatile int foo = 1; + while(foo){ + if (g_debouncing){ + //Trigger a SW interrupt + CLINT_REG(CLINT_MSIP) = 1; + g_debouncing = 0; + } + } + + return 0; + +} -- cgit v1.2.1-18-gbd029