diff options
| -rw-r--r-- | software/watchdog/.gitignore | 1 | ||||
| -rw-r--r-- | software/watchdog/Makefile | 9 | ||||
| -rw-r--r-- | software/watchdog/watchdog.c | 221 |
3 files changed, 231 insertions, 0 deletions
diff --git a/software/watchdog/.gitignore b/software/watchdog/.gitignore new file mode 100644 index 0000000..35566c7 --- /dev/null +++ b/software/watchdog/.gitignore @@ -0,0 +1 @@ +demo_gpio diff --git a/software/watchdog/Makefile b/software/watchdog/Makefile new file mode 100644 index 0000000..f614a4e --- /dev/null +++ b/software/watchdog/Makefile @@ -0,0 +1,9 @@ +TARGET = watchdog +CFLAGS += -O2 -fno-builtin-printf -DUSE_PLIC -DUSE_M_TIME + +BSP_BASE = ../../bsp + +C_SRCS += watchdog.c +C_SRCS += $(BSP_BASE)/drivers/plic/plic_driver.c + +include $(BSP_BASE)/env/common.mk diff --git a/software/watchdog/watchdog.c b/software/watchdog/watchdog.c new file mode 100644 index 0000000..672ed68 --- /dev/null +++ b/software/watchdog/watchdog.c @@ -0,0 +1,221 @@ +// See LICENSE for license details. + +#include <stdio.h> +#include <stdlib.h> +#include "platform.h" +#include <string.h> +#include "plic/plic_driver.h" +#include "encoding.h" +#include <unistd.h> +#include "stdatomic.h" + +void reset_demo (void); + +// Structures for registering different interrupt handlers +// for different parts of the application. +typedef void (*function_ptr_t) (void); +void no_interrupt_handler (void) {}; +function_ptr_t g_ext_interrupt_handlers[PLIC_NUM_INTERRUPTS]; + + +// Instance data for the PLIC. +plic_instance_t g_plic; + + +/** +* use mtime to wait for a specified number of ticks. +* async determins if this is a busy wait, or if +* an irq is scheduled +*/ +void mtime_wait( uint64_t ticks, uint32_t async) +{ + + volatile uint64_t * mtime = (uint64_t*) (CLINT_CTRL_ADDR + CLINT_MTIME); + uint64_t now = *mtime; + + //if async, schedule irq + if(async) { + volatile uint64_t * mtimecmp = (uint64_t*) (CLINT_CTRL_ADDR + CLINT_MTIMECMP); + uint64_t then = now + ticks; + *mtimecmp = then; + set_csr(mie, MIP_MTIP); + + } else { + //else busy wait + uint64_t then = now + ticks; + while(*mtime<then) {} + + } + +} + +/*Entry Point for PLIC Interrupt Handler*/ +void handle_m_ext_interrupt(){ + plic_source int_num = PLIC_claim_interrupt(&g_plic); + if ((int_num >=1 ) && (int_num < PLIC_NUM_INTERRUPTS)) { + g_ext_interrupt_handlers[int_num](); + } + else { + exit(1 + (uintptr_t) int_num); + } + PLIC_complete_interrupt(&g_plic, int_num); +} + +//global countdown timer +static uint32_t countdown = 10; +/*Entry Point for Machine Timer Interrupt Handler*/ +void handle_m_time_interrupt(){ + + //cleare the timer irq + clear_csr(mie, MIP_MTIP); + + //schedule next timer irq for 1 second + mtime_wait(1*RTC_FREQ, 1); + + //flash a led + GPIO_REG(GPIO_OUTPUT_VAL) ^= (0x1 << BLUE_LED_OFFSET); + + //print the count + printf("watchdog reset in %d\n", countdown--); +} + + +const char * instructions_msg = " \ +\n\ + SIFIVE, INC.\n\ +\n\ + 5555555555555555555555555\n\ + 5555 5555\n\ + 5555 5555\n\ + 5555 5555\n\ + 5555 5555555555555555555555\n\ + 5555 555555555555555555555555\n\ + 5555 5555\n\ + 5555 5555\n\ + 5555 5555\n\ +5555555555555555555555555555 55555\n\ + 55555 555555555 55555\n\ + 55555 55555 55555\n\ + 55555 5 55555\n\ + 55555 55555\n\ + 55555 55555\n\ + 55555 55555\n\ + 55555 55555\n\ + 55555 55555\n\ + 555555555\n\ + 55555\n\ + 5\n\ +\n\ +This application demonstrates the functionality of\n\ +the watchdog timer present in the HiFive1 AON peripheral.\n\ +\n\ +The Watchdog timer will expire in 10 seconds resulting in\n\ +a software reset.\n\ +\n\ +Press a key to prevent a reset\n\ +"; + +void print_instructions() { + + write (STDOUT_FILENO, instructions_msg, strlen(instructions_msg)); + +} + + +/** +* Flash the red led for a second, then set up +* blue for blinking during mtime irq +*/ +void led_init() { + + + // Set up the GPIOs such that the LED GPIO + // can be used as both Inputs and 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<< RED_LED_OFFSET) | (0x1<< GREEN_LED_OFFSET) | (0x1<< BLUE_LED_OFFSET)); + + //flash red led to indicate reset + GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << RED_LED_OFFSET) ; + mtime_wait(1*RTC_FREQ,0); + GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << RED_LED_OFFSET) ; +} + +/** +* initialize the watchdog to reset in +* 5 seconds +**/ +void watchdog_init() { + + +//reset in 10 seconds +AON_REG(AON_WDOGKEY) = AON_WDOGKEY_VALUE; +AON_REG(AON_WDOGCMP) = 11; +//wdogconfig: : wdogrsten | enablealways | reset to 0 | max scale +AON_REG(AON_WDOGKEY) = AON_WDOGKEY_VALUE; +AON_REG(AON_WDOGCFG) |= (AON_WDOGCFG_RSTEN | AON_WDOGCFG_ENALWAYS |\ + AON_WDOGCFG_ZEROCMP | AON_WDOGCFG_SCALE) ; + +} + +void reset_demo () { + + // Disable the machine & timer interrupts until setup is done. + clear_csr(mie, MIP_MEIP); + clear_csr(mie, MIP_MTIP); + + //enable uart input + UART0_REG(UART_REG_RXCTRL) = UART_RXEN; + + /************************************************************************** + * Set up the PLIC + *************************************************************************/ + PLIC_init(&g_plic, + PLIC_CTRL_ADDR, + PLIC_NUM_INTERRUPTS, + PLIC_NUM_PRIORITIES); + + for (int ii = 0; ii < PLIC_NUM_INTERRUPTS; ii ++){ + g_ext_interrupt_handlers[ii] = no_interrupt_handler; + } + + + led_init(); + print_instructions(); + watchdog_init(); + + // Enable the Machine-External bit in MIE + set_csr(mie, MIP_MEIP); + // Enable interrupts in general. + set_csr(mstatus, MSTATUS_MIE); +} + +int main(int argc, char **argv) +{ + + reset_demo(); + //schedule a 1 second timer + mtime_wait(1*RTC_FREQ,1); + + + while (1){ + char c; + if(((int32_t) UART0_REG(UART_REG_RXFIFO)) > 0){ + //flash green led to indicate Kick + GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << GREEN_LED_OFFSET) ; + + printf("Feeding Watchdog.\nHiFive1 will reset in 10 seconds.\n"); + countdown = 10; + AON_REG(AON_WDOGKEY) = AON_WDOGKEY_VALUE; + AON_REG(AON_WDOGFEED) = AON_WDOGFEED_VALUE; + + //busy wait a bit so the user sees the led blink + mtime_wait(5000, 0); + //turn off led + GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << GREEN_LED_OFFSET) ; + } + } + + return 0; + +} |