f4da9b9705
This commit introduces a new Sensor Clock API, enabling the retrieval of cycle counts and conversion to nanoseconds based on the system or external clock. The API includes: - `sensor_clock_get_cycles()` to get the current cycle count from the sensor clock. - `sensor_clock_cycles_to_ns()` to convert cycles to nanoseconds using the clock's frequency. The implementation supports both system clocks and external clocks defined in the device tree, making the sensor clock integration more flexible for various sensor use cases. Signed-off-by: Mark Chen <mark.chen@cienet.com>
63 lines
1.4 KiB
C
63 lines
1.4 KiB
C
/*
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* Copyright (c) 2024 Cienet
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr/device.h>
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#include <zephyr/sys/util.h>
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#include <zephyr/sys_clock.h>
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#include <zephyr/drivers/counter.h>
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#include <zephyr/logging/log.h>
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#include <zephyr/init.h>
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LOG_MODULE_REGISTER(sensor_clock, CONFIG_SENSOR_LOG_LEVEL);
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static const struct device *external_sensor_clock = DEVICE_DT_GET(DT_CHOSEN(zephyr_sensor_clock));
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static uint32_t freq;
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static int external_sensor_clock_init(void)
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{
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int rc;
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rc = counter_start(external_sensor_clock);
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if (rc != 0) {
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LOG_ERR("Failed to start sensor clock counter: %d\n", rc);
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return rc;
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}
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freq = counter_get_frequency(external_sensor_clock);
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if (freq == 0) {
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LOG_ERR("Sensor clock %s has no fixed frequency\n", external_sensor_clock->name);
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return -EINVAL;
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}
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return 0;
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}
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int sensor_clock_get_cycles(uint64_t *cycles)
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{
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__ASSERT_NO_MSG(counter_is_counting_up(external_sensor_clock));
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int rc;
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const struct counter_driver_api *api =
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(const struct counter_driver_api *)external_sensor_clock->api;
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if (api->get_value_64) {
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rc = counter_get_value_64(external_sensor_clock, cycles);
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} else {
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uint32_t result_32;
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rc = counter_get_value(external_sensor_clock, &result_32);
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*cycles = (uint64_t)result_32;
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}
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return rc;
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}
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uint64_t sensor_clock_cycles_to_ns(uint64_t cycles)
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{
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return (cycles * NSEC_PER_SEC) / freq;
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}
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SYS_INIT(external_sensor_clock_init, POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE);
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