diff options
Diffstat (limited to 'source/hal/source/platform/mps3/source/timer_mps3.c')
| -rw-r--r-- | source/hal/source/platform/mps3/source/timer_mps3.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/source/hal/source/platform/mps3/source/timer_mps3.c b/source/hal/source/platform/mps3/source/timer_mps3.c new file mode 100644 index 0000000..3511883 --- /dev/null +++ b/source/hal/source/platform/mps3/source/timer_mps3.c @@ -0,0 +1,193 @@ +/* + * Copyright (c) 2022 Arm Limited. All rights reserved. + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#include "timer_mps3.h" + +#include "log_macros.h" +#include "smm_mps3.h" /* Memory map for MPS3. */ + +static uint64_t cpu_cycle_count = 0; /* 64-bit cpu cycle counter */ + +/** + * @brief Gets the system tick triggered cycle counter for the CPU. + * @return 64-bit counter value. + **/ +static uint64_t Get_SysTick_Cycle_Count(void); + +/** + * SysTick initialisation + */ +static int Init_SysTick(void); + +void timer_reset(void) +{ + MPS3_FPGAIO->CLK1HZ = 0; + MPS3_FPGAIO->CLK100HZ = 0; + MPS3_FPGAIO->COUNTER = 0; + + if (0 != Init_SysTick()) { + printf_err("Failed to initialise system tick config\n"); + } + debug("system tick config ready\n"); +} + +base_time_counter get_time_counter(void) +{ + base_time_counter t = { + .counter_1Hz = MPS3_FPGAIO->CLK1HZ, + .counter_100Hz = MPS3_FPGAIO->CLK100HZ, + .counter_fpga = MPS3_FPGAIO->COUNTER, + .counter_systick = Get_SysTick_Cycle_Count() + }; + debug("Timestamp:\n"); + debug("\tCounter 1 Hz: %" PRIu32 "\n", t.counter_1Hz); + debug("\tCounter 100 Hz: %" PRIu32 "\n", t.counter_100Hz); + debug("\tCounter FPGA: %" PRIu32 "\n", t.counter_fpga); + debug("\tCounter CPU: %" PRIu64 "\n", t.counter_systick); + return t; +} + +/** + * Please note, that there are no checks for overflow in this function => if + * the time elapsed has been big (in days) this could happen and is currently + * not handled. + **/ +uint32_t get_duration_milliseconds(base_time_counter *start, + base_time_counter *end) +{ + uint32_t time_elapsed = 0; + if (end->counter_100Hz > start->counter_100Hz) { + time_elapsed = (end->counter_100Hz - start->counter_100Hz) * 10; + } else { + time_elapsed = (end->counter_1Hz - start->counter_1Hz) * 1000 + + ((0xFFFFFFFF - start->counter_100Hz) + end->counter_100Hz + 1) * 10; + } + + /* If the time elapsed is less than 100ms, use microseconds count to be + * more precise */ + if (time_elapsed < 100) { + debug("Using the microsecond function instead..\n"); + return get_duration_microseconds(start, end)/1000; + } + + return time_elapsed; +} + +/** + * Like the microsecond counterpart, this function could return wrong results when + * the counter (MAINCLK) overflows. There are no overflow counters available. + **/ +uint32_t get_duration_microseconds(base_time_counter *start, + base_time_counter *end) +{ + const int divisor = get_mps3_core_clock()/1000000; + uint32_t time_elapsed = 0; + if (end->counter_fpga > start->counter_fpga) { + time_elapsed = (end->counter_fpga - start->counter_fpga)/divisor; + } else { + time_elapsed = ((0xFFFFFFFF - end->counter_fpga) + + start->counter_fpga + 1)/divisor; + } + return time_elapsed; +} + +uint64_t get_cycle_count_diff(base_time_counter *start, + base_time_counter *end) +{ + if (start->counter_systick > end->counter_systick) { + warn("start > end; counter might have overflown\n"); + } + return end->counter_systick - start->counter_systick; +} + +void start_cycle_counter(void) +{ + /* Nothing to do for FPGA */ +} + +void stop_cycle_counter(void) +{ + /* Nothing to do for FPGA */ +} + +void SysTick_Handler(void) +{ + /* Increment the cycle counter based on load value. */ + cpu_cycle_count += SysTick->LOAD + 1; +} + +/** + * Gets the current SysTick derived counter value + */ +static uint64_t Get_SysTick_Cycle_Count(void) +{ + uint32_t systick_val; + + NVIC_DisableIRQ(SysTick_IRQn); + systick_val = SysTick->VAL & SysTick_VAL_CURRENT_Msk; + NVIC_EnableIRQ(SysTick_IRQn); + + return cpu_cycle_count + (SysTick->LOAD - systick_val); +} + + +/** + * SysTick initialisation + */ +static int Init_SysTick(void) +{ + const uint32_t ticks_10ms = get_mps3_core_clock()/100 + 1; + int err = 0; + + /* Reset CPU cycle count value. */ + cpu_cycle_count = 0; + + /* Changing configuration for sys tick => guard from being + * interrupted. */ + NVIC_DisableIRQ(SysTick_IRQn); + + /* SysTick init - this will enable interrupt too. */ + err = SysTick_Config(ticks_10ms); + + /* Enable interrupt again. */ + NVIC_EnableIRQ(SysTick_IRQn); + + /* Wait for SysTick to kick off */ + while (!err && !SysTick->VAL) { + __NOP(); + } + + return err; +} + +uint32_t get_mps3_core_clock(void) +{ + const uint32_t default_clock = 32000000 /* 32 MHz clock */; + static int warned_once = 0; + if (0 != MPS3_SCC->CFG_ACLK) { + if (default_clock != MPS3_SCC->CFG_ACLK) { + warn("System clock is different to the MPS3 config set clock.\n"); + } + return MPS3_SCC->CFG_ACLK; + } + + if (!warned_once) { + warn("MPS3_SCC->CFG_ACLK reads 0. Assuming default clock of %" PRIu32 "\n", + default_clock); + warned_once = 1; + } + return default_clock; +}
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