zephyr/drivers/clock_control/clock_control_nrf2_hsfll.c

/*
 * Copyright (c) 2024 Nordic Semiconductor ASA
 * SPDX-License-Identifier: Apache-2.0
 */

#define DT_DRV_COMPAT nordic_nrf_hsfll

#include "clock_control_nrf2_common.h"
#include <zephyr/devicetree.h>
#include <zephyr/drivers/clock_control/nrf_clock_control.h>
#include <hal/nrf_hsfll.h>

#include <zephyr/logging/log.h>
LOG_MODULE_DECLARE(clock_control_nrf2, CONFIG_CLOCK_CONTROL_LOG_LEVEL);

/* TODO: add support for other HSFLLs */
BUILD_ASSERT(DT_NUM_INST_STATUS_OKAY(DT_DRV_COMPAT) == 1,
	     "multiple instances not supported");

#ifdef CONFIG_NRFS_DVFS_LOCAL_DOMAIN
#include <ld_dvfs_handler.h>

#define FLAG_FREQ_CHANGE_CB_EXPECTED BIT(FLAGS_COMMON_BITS)

#define HSFLL_FREQ_LOW    MHZ(64)
#define HSFLL_FREQ_MEDLOW MHZ(128)
#define HSFLL_FREQ_HIGH   MHZ(320)

#define NRFS_DVFS_TIMEOUT K_MSEC(CONFIG_CLOCK_CONTROL_NRF2_NRFS_DVFS_TIMEOUT_MS)

/* Clock options sorted from lowest to highest frequency */
static const struct clock_options {
	uint32_t frequency;
	enum dvfs_frequency_setting setting;
} clock_options[] = {
	{
		.frequency = HSFLL_FREQ_LOW,
		.setting = DVFS_FREQ_LOW,
	},
	{
		.frequency = HSFLL_FREQ_MEDLOW,
		.setting = DVFS_FREQ_MEDLOW,
	},
	{
		.frequency = HSFLL_FREQ_HIGH,
		.setting = DVFS_FREQ_HIGH,
	},
};

struct hsfll_dev_data {
	STRUCT_CLOCK_CONFIG(hsfll, ARRAY_SIZE(clock_options)) clk_cfg;
	struct k_timer timer;
};

static void freq_setting_applied_cb(enum dvfs_frequency_setting new_setting)
{
	ARG_UNUSED(new_setting);

	const struct device *dev = DEVICE_DT_INST_GET(0);
	struct hsfll_dev_data *dev_data = dev->data;
	atomic_val_t prev_flags;

	/* Process only expected notifications (after sent requests). */
	prev_flags = atomic_and(&dev_data->clk_cfg.flags,
				~FLAG_FREQ_CHANGE_CB_EXPECTED);
	if (prev_flags & FLAG_FREQ_CHANGE_CB_EXPECTED) {
		k_timer_stop(&dev_data->timer);

		clock_config_update_end(&dev_data->clk_cfg, 0);
	}
}

static void hsfll_update_timeout_handler(struct k_timer *timer)
{
	struct hsfll_dev_data *dev_data =
		CONTAINER_OF(timer, struct hsfll_dev_data, timer);

	clock_config_update_end(&dev_data->clk_cfg, -ETIMEDOUT);
}

static void hsfll_work_handler(struct k_work *work)
{
	struct hsfll_dev_data *dev_data =
		CONTAINER_OF(work, struct hsfll_dev_data, clk_cfg.work);
	enum dvfs_frequency_setting required_setting;
	uint8_t to_activate_idx;
	int rc;

	to_activate_idx = clock_config_update_begin(work);
	required_setting = clock_options[to_activate_idx].setting;

	/* Notify the DVFS service about the required setting. */
	rc = dvfs_service_handler_change_freq_setting(required_setting);
	if (rc < 0) {
		clock_config_update_end(&dev_data->clk_cfg, rc);
		return;
	}

	/* And expect a confirmation that the setting is ready to be used. */
	(void)atomic_or(&dev_data->clk_cfg.flags, FLAG_FREQ_CHANGE_CB_EXPECTED);
	k_timer_start(&dev_data->timer, NRFS_DVFS_TIMEOUT, K_NO_WAIT);
}

static struct onoff_manager *hsfll_find_mgr(const struct device *dev,
					    const struct nrf_clock_spec *spec)
{
	struct hsfll_dev_data *dev_data = dev->data;
	uint32_t frequency;

	if (!spec) {
		return &dev_data->clk_cfg.onoff[0].mgr;
	}

	if (spec->accuracy || spec->precision) {
		LOG_ERR("invalid specification of accuracy or precision");
		return NULL;
	}

	frequency = spec->frequency == NRF_CLOCK_CONTROL_FREQUENCY_MAX
		  ? HSFLL_FREQ_HIGH
		  : spec->frequency;

	for (int i = 0; i < ARRAY_SIZE(clock_options); ++i) {
		if (frequency > clock_options[i].frequency) {
			continue;
		}

		return &dev_data->clk_cfg.onoff[i].mgr;
	}

	LOG_ERR("invalid frequency");
	return NULL;
}
#endif /* CONFIG_NRFS_DVFS_LOCAL_DOMAIN */

static int api_request_hsfll(const struct device *dev,
			     const struct nrf_clock_spec *spec,
			     struct onoff_client *cli)
{
#ifdef CONFIG_NRFS_DVFS_LOCAL_DOMAIN
	struct onoff_manager *mgr = hsfll_find_mgr(dev, spec);

	if (mgr) {
		return onoff_request(mgr, cli);
	}

	return -EINVAL;
#else
	return -ENOTSUP;
#endif
}

static int api_release_hsfll(const struct device *dev,
			     const struct nrf_clock_spec *spec)
{
#ifdef CONFIG_NRFS_DVFS_LOCAL_DOMAIN
	struct onoff_manager *mgr = hsfll_find_mgr(dev, spec);

	if (mgr) {
		return onoff_release(mgr);
	}

	return -EINVAL;
#else
	return -ENOTSUP;
#endif
}

static int api_cancel_or_release_hsfll(const struct device *dev,
				       const struct nrf_clock_spec *spec,
				       struct onoff_client *cli)
{
#ifdef CONFIG_NRFS_DVFS_LOCAL_DOMAIN
	struct onoff_manager *mgr = hsfll_find_mgr(dev, spec);

	if (mgr) {
		return onoff_cancel_or_release(mgr, cli);
	}

	return -EINVAL;
#else
	return -ENOTSUP;
#endif
}

static int api_get_rate_hsfll(const struct device *dev,
			      clock_control_subsys_t sys,
			      uint32_t *rate)
{
	ARG_UNUSED(dev);
	ARG_UNUSED(sys);

	*rate = nrf_hsfll_clkctrl_mult_get(NRF_HSFLL) * MHZ(16);

	return 0;
}

static int hsfll_init(const struct device *dev)
{
#ifdef CONFIG_NRFS_DVFS_LOCAL_DOMAIN
	struct hsfll_dev_data *dev_data = dev->data;
	int rc;

	rc = clock_config_init(&dev_data->clk_cfg,
			       ARRAY_SIZE(dev_data->clk_cfg.onoff),
			       hsfll_work_handler);
	if (rc < 0) {
		return rc;
	}

	k_timer_init(&dev_data->timer, hsfll_update_timeout_handler, NULL);

	dvfs_service_handler_register_freq_setting_applied_callback(
		freq_setting_applied_cb);
#endif

	return 0;
}

static struct nrf_clock_control_driver_api hsfll_drv_api = {
	.std_api = {
		.on = api_nosys_on_off,
		.off = api_nosys_on_off,
		.get_rate = api_get_rate_hsfll,
	},
	.request = api_request_hsfll,
	.release = api_release_hsfll,
	.cancel_or_release = api_cancel_or_release_hsfll,
};

#ifdef CONFIG_NRFS_DVFS_LOCAL_DOMAIN
static struct hsfll_dev_data hsfll_data;
#endif

DEVICE_DT_INST_DEFINE(0, hsfll_init, NULL,
		      COND_CODE_1(CONFIG_NRFS_DVFS_LOCAL_DOMAIN,
				  (&hsfll_data),
				  (NULL)),
		      NULL,
		      PRE_KERNEL_1, CONFIG_CLOCK_CONTROL_INIT_PRIORITY,
		      &hsfll_drv_api);