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

#define DT_DRV_COMPAT nordic_nrf_fll16m

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

#include <soc_lrcconf.h>
#include <hal/nrf_bicr.h>

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

BUILD_ASSERT(DT_NUM_INST_STATUS_OKAY(DT_DRV_COMPAT) == 1,
	     "multiple instances not supported");

#define FLAG_HFXO_STARTED BIT(FLAGS_COMMON_BITS)

#define FLL16M_MODE_OPEN_LOOP   0
#define FLL16M_MODE_CLOSED_LOOP 1
#define FLL16M_MODE_BYPASS      2
#define FLL16M_MODE_DEFAULT     FLL16M_MODE_OPEN_LOOP

#define FLL16M_HFXO_NODE DT_INST_PHANDLE_BY_NAME(0, clocks, hfxo)

#define FLL16M_HFXO_ACCURACY DT_PROP(FLL16M_HFXO_NODE, accuracy_ppm)
#define FLL16M_OPEN_LOOP_ACCURACY DT_INST_PROP(0, open_loop_accuracy_ppm)
#define FLL16M_CLOSED_LOOP_BASE_ACCURACY DT_INST_PROP(0, closed_loop_base_accuracy_ppm)
#define FLL16M_MAX_ACCURACY FLL16M_HFXO_ACCURACY

#define BICR (NRF_BICR_Type *)DT_REG_ADDR(DT_NODELABEL(bicr))

/* Clock options sorted from lowest to highest accuracy */
static struct clock_options {
	uint16_t accuracy;
	uint8_t mode;
} clock_options[] = {
	{
		.accuracy = FLL16M_OPEN_LOOP_ACCURACY,
		.mode = FLL16M_MODE_OPEN_LOOP,
	},
	{
		.mode = FLL16M_MODE_CLOSED_LOOP,
	},
	{
		/* Bypass mode uses HFXO */
		.accuracy = FLL16M_HFXO_ACCURACY,
		.mode = FLL16M_MODE_BYPASS,
	},
};

struct fll16m_dev_data {
	STRUCT_CLOCK_CONFIG(fll16m, ARRAY_SIZE(clock_options)) clk_cfg;
	struct onoff_client hfxo_cli;
	sys_snode_t fll16m_node;
};

struct fll16m_dev_config {
	uint32_t fixed_frequency;
};

static void activate_fll16m_mode(struct fll16m_dev_data *dev_data, uint8_t mode)
{
	/* TODO: change to nrf_lrcconf_* function when such is available. */

	if (mode != FLL16M_MODE_DEFAULT) {
		soc_lrcconf_poweron_request(&dev_data->fll16m_node, NRF_LRCCONF_POWER_MAIN);
	}

	NRF_LRCCONF010->CLKCTRL[0].SRC = mode;

	if (mode == FLL16M_MODE_DEFAULT) {
		soc_lrcconf_poweron_release(&dev_data->fll16m_node, NRF_LRCCONF_POWER_MAIN);
	}

	nrf_lrcconf_task_trigger(NRF_LRCCONF010, NRF_LRCCONF_TASK_CLKSTART_0);

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

static void hfxo_cb(struct onoff_manager *mgr,
		    struct onoff_client *cli,
		    uint32_t state,
		    int res)
{
	ARG_UNUSED(mgr);
	ARG_UNUSED(state);

	struct fll16m_dev_data *dev_data =
		CONTAINER_OF(cli, struct fll16m_dev_data, hfxo_cli);

	if (res < 0) {
		clock_config_update_end(&dev_data->clk_cfg, res);
	} else {
		(void)atomic_or(&dev_data->clk_cfg.flags, FLAG_HFXO_STARTED);

		activate_fll16m_mode(dev_data, FLL16M_MODE_BYPASS);
	}
}

static void fll16m_work_handler(struct k_work *work)
{
	const struct device *hfxo = DEVICE_DT_GET(FLL16M_HFXO_NODE);
	struct fll16m_dev_data *dev_data =
		CONTAINER_OF(work, struct fll16m_dev_data, clk_cfg.work);
	uint8_t to_activate_idx;

	to_activate_idx = clock_config_update_begin(work);
	if (clock_options[to_activate_idx].mode == FLL16M_MODE_BYPASS) {
		int rc;

		/* Bypass mode requires HFXO to be running first. */
		sys_notify_init_callback(&dev_data->hfxo_cli.notify, hfxo_cb);
		rc = nrf_clock_control_request(hfxo, NULL, &dev_data->hfxo_cli);
		if (rc < 0) {
			clock_config_update_end(&dev_data->clk_cfg, rc);
		}
	} else {
		atomic_val_t prev_flags;

		prev_flags = atomic_and(&dev_data->clk_cfg.flags,
					~FLAG_HFXO_STARTED);
		if (prev_flags & FLAG_HFXO_STARTED) {
			(void)nrf_clock_control_release(hfxo, NULL);
		}

		activate_fll16m_mode(dev_data,
				     clock_options[to_activate_idx].mode);
	}
}

static struct onoff_manager *fll16m_find_mgr(const struct device *dev,
					     const struct nrf_clock_spec *spec)
{
	struct fll16m_dev_data *dev_data = dev->data;
	const struct fll16m_dev_config *dev_config = dev->config;
	uint16_t accuracy;

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

	if (spec->frequency > dev_config->fixed_frequency) {
		LOG_ERR("invalid frequency");
		return NULL;
	}

	if (spec->precision) {
		LOG_ERR("invalid precision");
		return NULL;
	}

	accuracy = spec->accuracy == NRF_CLOCK_CONTROL_ACCURACY_MAX
		 ? FLL16M_MAX_ACCURACY
		 : spec->accuracy;

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

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

	LOG_ERR("invalid accuracy");
	return NULL;
}

static int api_request_fll16m(const struct device *dev,
			      const struct nrf_clock_spec *spec,
			      struct onoff_client *cli)
{
	struct onoff_manager *mgr = fll16m_find_mgr(dev, spec);

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

	return -EINVAL;
}

static int api_release_fll16m(const struct device *dev,
			      const struct nrf_clock_spec *spec)
{
	struct onoff_manager *mgr = fll16m_find_mgr(dev, spec);

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

	return -EINVAL;
}

static int api_cancel_or_release_fll16m(const struct device *dev,
					const struct nrf_clock_spec *spec,
					struct onoff_client *cli)
{
	struct onoff_manager *mgr = fll16m_find_mgr(dev, spec);

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

	return -EINVAL;
}

static int api_get_rate_fll16m(const struct device *dev,
			       clock_control_subsys_t sys,
			       uint32_t *rate)
{
	ARG_UNUSED(sys);

	const struct fll16m_dev_config *dev_config = dev->config;

	*rate = dev_config->fixed_frequency;

	return 0;
}

static int fll16m_init(const struct device *dev)
{
	struct fll16m_dev_data *dev_data = dev->data;
	nrf_bicr_lfosc_mode_t lfosc_mode;

	clock_options[1].accuracy = FLL16M_CLOSED_LOOP_BASE_ACCURACY;

	/* Closed-loop mode uses LFXO as source if present, HFXO otherwise */
	lfosc_mode = nrf_bicr_lfosc_mode_get(BICR);

	if (lfosc_mode != NRF_BICR_LFOSC_MODE_UNCONFIGURED &&
	    lfosc_mode != NRF_BICR_LFOSC_MODE_DISABLED) {
		int ret;
		uint16_t accuracy;

		ret = lfosc_get_accuracy(&accuracy);
		if (ret < 0) {
			return ret;
		}

		clock_options[1].accuracy += accuracy;
	} else {
		clock_options[1].accuracy += FLL16M_HFXO_ACCURACY;
	}

	return clock_config_init(&dev_data->clk_cfg,
				 ARRAY_SIZE(dev_data->clk_cfg.onoff),
				 fll16m_work_handler);
}

static DEVICE_API(nrf_clock_control, fll16m_drv_api) = {
	.std_api = {
		.on = api_nosys_on_off,
		.off = api_nosys_on_off,
		.get_rate = api_get_rate_fll16m,
	},
	.request = api_request_fll16m,
	.release = api_release_fll16m,
	.cancel_or_release = api_cancel_or_release_fll16m,
};

static struct fll16m_dev_data fll16m_data;

static const struct fll16m_dev_config fll16m_config = {
	.fixed_frequency = DT_INST_PROP(0, clock_frequency),
};

DEVICE_DT_INST_DEFINE(0, fll16m_init, NULL,
		      &fll16m_data, &fll16m_config,
		      PRE_KERNEL_1, CONFIG_CLOCK_CONTROL_INIT_PRIORITY,
		      &fll16m_drv_api);