diff options
Diffstat (limited to 'bsps/riscv/riscv/clock/clockdrv.c')
| -rw-r--r-- | bsps/riscv/riscv/clock/clockdrv.c | 108 |
1 files changed, 67 insertions, 41 deletions
diff --git a/bsps/riscv/riscv/clock/clockdrv.c b/bsps/riscv/riscv/clock/clockdrv.c index 340e158489..8be203757c 100644 --- a/bsps/riscv/riscv/clock/clockdrv.c +++ b/bsps/riscv/riscv/clock/clockdrv.c @@ -7,8 +7,7 @@ */ /* - * riscv_generic Clock driver - * + * Copyright (c) 2018 embedded brains GmbH * COPYRIGHT (c) 2015 Hesham Alatary <hesham@alumni.york.ac.uk> * * Redistribution and use in source and binary forms, with or without @@ -33,75 +32,102 @@ * SUCH DAMAGE. */ -#include <rtems.h> +#include <rtems/timecounter.h> + #include <bsp.h> +#include <bsp/fatal.h> +#include <bsp/fdt.h> #include <bsp/irq.h> -#include <rtems/score/riscv-utility.h> -#include <rtems/score/cpu.h> -#include <rtems/timecounter.h> -/* The number of clock cycles before generating a tick timer interrupt. */ -#define TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT 1000 -#define RISCV_CLOCK_CYCLE_TIME_NANOSECONDS 1 +#include <dev/irq/clint.h> -static struct timecounter riscv_generic_tc; +#include <libfdt.h> -/* CPU counter */ -static CPU_Counter_ticks cpu_counter_ticks; +#define CLINT ((volatile clint_regs *) 0x02000000) -/* This prototype is added here to Avoid warnings */ +/* This is defined in dev/clock/clockimpl.h */ void Clock_isr(void *arg); -static void riscv_generic_clock_at_tick(void) +static struct timecounter riscv_clock_tc; + +static uint32_t riscv_clock_interval; + +static void riscv_clock_at_tick(void) { - REG(MTIME_MM) = 0; - REG(MTIMECMP_MM) = TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT; + volatile clint_regs *clint; + uint64_t cmp; + + clint = CLINT; + + cmp = clint->mtimecmp[0].val_64; + cmp += riscv_clock_interval; - cpu_counter_ticks += TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT * 10000; +#if __riscv_xlen == 32 + clint->mtimecmp[0].val_32[0] = 0xffffffff; + clint->mtimecmp[0].val_32[1] = (uint32_t) (cmp >> 32); + clint->mtimecmp[0].val_32[0] = (uint32_t) cmp; +#elif __riscv_xlen == 64 + clint->mtimecmp[0].val_64 = cmp; +#endif } -static void riscv_generic_clock_handler_install(proc_ptr new_isr) +static void riscv_clock_handler_install(proc_ptr new_isr) { - rtems_status_code sc = RTEMS_SUCCESSFUL; _CPU_ISR_install_vector(RISCV_MACHINE_TIMER_INTERRUPT, new_isr, NULL); - - if (sc != RTEMS_SUCCESSFUL) { - rtems_fatal_error_occurred(0xdeadbeef); - } } -static uint32_t riscv_generic_get_timecount(struct timecounter *tc) +static uint32_t riscv_clock_get_timecount(struct timecounter *tc) { - uint32_t ticks_since_last_timer_interrupt = REG(MTIME_MM); + volatile clint_regs *clint; - return cpu_counter_ticks + ticks_since_last_timer_interrupt; + clint = CLINT; + return clint->mtime.val_32[0]; } CPU_Counter_ticks _CPU_Counter_read(void) { - return riscv_generic_get_timecount(NULL); + return riscv_clock_get_timecount(NULL); +} + +static uint32_t riscv_clock_get_timebase_frequency(const void *fdt) +{ + int node; + const uint32_t *val; + int len; + + node = fdt_path_offset(fdt, "/cpus"); + val = fdt_getprop(fdt, node, "timebase-frequency", &len); + if (val == NULL || len < 4) { + bsp_fatal(RISCV_FATAL_NO_TIMEBASE_FREQUENCY_IN_DEVICE_TREE); + } + + return fdt32_to_cpu(*val); } -static void riscv_generic_clock_initialize(void) +static void riscv_clock_initialize(void) { - uint32_t mtimecmp = TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT; - uint64_t frequency = (1000000000 / RISCV_CLOCK_CYCLE_TIME_NANOSECONDS); + const char *fdt; + uint32_t tb_freq; + uint64_t us_per_tick; + + fdt = bsp_fdt_get(); + tb_freq = riscv_clock_get_timebase_frequency(fdt); + us_per_tick = rtems_configuration_get_microseconds_per_tick(); + riscv_clock_interval = (uint32_t) ((tb_freq * us_per_tick) / 1000000); - REG(MTIME_MM) = 0; - REG(MTIMECMP_MM) = TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT; + riscv_clock_at_tick(); /* Enable mtimer interrupts */ set_csr(mie, MIP_MTIP); - set_csr(mip, MIP_MTIP); /* Initialize timecounter */ - riscv_generic_tc.tc_get_timecount = riscv_generic_get_timecount; - riscv_generic_tc.tc_counter_mask = 0xffffffff; - riscv_generic_tc.tc_frequency = frequency; - riscv_generic_tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER; - rtems_timecounter_install(&riscv_generic_tc); + riscv_clock_tc.tc_get_timecount = riscv_clock_get_timecount; + riscv_clock_tc.tc_counter_mask = 0xffffffff; + riscv_clock_tc.tc_frequency = tb_freq; + riscv_clock_tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER; + rtems_timecounter_install(&riscv_clock_tc); } CPU_Counter_ticks _CPU_Counter_difference( @@ -112,11 +138,11 @@ CPU_Counter_ticks _CPU_Counter_difference( return second - first; } -#define Clock_driver_support_at_tick() riscv_generic_clock_at_tick() +#define Clock_driver_support_at_tick() riscv_clock_at_tick() -#define Clock_driver_support_initialize_hardware() riscv_generic_clock_initialize() +#define Clock_driver_support_initialize_hardware() riscv_clock_initialize() #define Clock_driver_support_install_isr(isr) \ - riscv_generic_clock_handler_install(isr) + riscv_clock_handler_install(isr) #include "../../../shared/dev/clock/clockimpl.h" |