/*
 * Copyright (c) 2023 SILA Embedded Solutions GmbH
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/i2c/stm32.h>
#include <zephyr/drivers/pinctrl.h>
#include <zephyr/drivers/smbus.h>
#include <zephyr/logging/log.h>
#include <zephyr/sys/byteorder.h>
#include <soc.h>

#include "smbus_utils.h"

LOG_MODULE_REGISTER(stm32_smbus, CONFIG_SMBUS_LOG_LEVEL);

struct smbus_stm32_config {
	const struct pinctrl_dev_config *pcfg;
	const struct device *i2c_dev;
};

struct smbus_stm32_data {
	uint32_t config;
	const struct device *dev;
#ifdef CONFIG_SMBUS_STM32_SMBALERT
	sys_slist_t smbalert_callbacks;
	struct k_work smbalert_work;
#endif /* CONFIG_SMBUS_STM32_SMBALERT */
};

#ifdef CONFIG_SMBUS_STM32_SMBALERT
static void smbus_stm32_smbalert_isr(const struct device *dev)
{
	struct smbus_stm32_data *data = dev->data;

	k_work_submit(&data->smbalert_work);
}

static void smbus_stm32_smbalert_work(struct k_work *work)
{
	struct smbus_stm32_data *data = CONTAINER_OF(work, struct smbus_stm32_data, smbalert_work);
	const struct device *dev = data->dev;

	LOG_DBG("%s: got SMB alert", dev->name);

	smbus_loop_alert_devices(dev, &data->smbalert_callbacks);
}

static int smbus_stm32_smbalert_set_cb(const struct device *dev, struct smbus_callback *cb)
{
	struct smbus_stm32_data *data = dev->data;

	return smbus_callback_set(&data->smbalert_callbacks, cb);
}

static int smbus_stm32_smbalert_remove_cb(const struct device *dev, struct smbus_callback *cb)
{
	struct smbus_stm32_data *data = dev->data;

	return smbus_callback_remove(&data->smbalert_callbacks, cb);
}
#endif /* CONFIG_SMBUS_STM32_SMBALERT */

static int smbus_stm32_init(const struct device *dev)
{
	const struct smbus_stm32_config *config = dev->config;
	struct smbus_stm32_data *data = dev->data;
	int result;

	data->dev = dev;

	if (!device_is_ready(config->i2c_dev)) {
		LOG_ERR("%s: I2C device is not ready", dev->name);
		return -ENODEV;
	}

	result = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
	if (result < 0) {
		LOG_ERR("%s: pinctrl setup failed (%d)", dev->name, result);
		return result;
	}

#ifdef CONFIG_SMBUS_STM32_SMBALERT
	k_work_init(&data->smbalert_work, smbus_stm32_smbalert_work);

	i2c_stm32_smbalert_set_callback(config->i2c_dev, smbus_stm32_smbalert_isr, dev);
#endif /* CONFIG_SMBUS_STM32_SMBALERT */

	return 0;
}

static int smbus_stm32_configure(const struct device *dev, uint32_t config_value)
{
	const struct smbus_stm32_config *config = dev->config;
	struct smbus_stm32_data *data = dev->data;

	if (config_value & SMBUS_MODE_PEC) {
		LOG_ERR("%s: not implemented", dev->name);
		return -EINVAL;
	}

	if (config_value & SMBUS_MODE_HOST_NOTIFY) {
		LOG_ERR("%s: not available", dev->name);
		return -EINVAL;
	}

	if (config_value & SMBUS_MODE_CONTROLLER) {
		LOG_DBG("%s: configuring SMB in host mode", dev->name);
		i2c_stm32_set_smbus_mode(config->i2c_dev, I2CSTM32MODE_SMBUSHOST);
	} else {
		LOG_DBG("%s: configuring SMB in device mode", dev->name);
		i2c_stm32_set_smbus_mode(config->i2c_dev, I2CSTM32MODE_SMBUSDEVICE);
	}

	if (config_value & SMBUS_MODE_SMBALERT) {
		LOG_DBG("%s: activating SMB alert", dev->name);
		i2c_stm32_smbalert_enable(config->i2c_dev);
	} else {
		LOG_DBG("%s: deactivating SMB alert", dev->name);
		i2c_stm32_smbalert_disable(config->i2c_dev);
	}

	data->config = config_value;
	return 0;
}

static int smbus_stm32_get_config(const struct device *dev, uint32_t *config)
{
	struct smbus_stm32_data *data = dev->data;
	*config = data->config;
	return 0;
}

static int smbus_stm32_quick(const struct device *dev, uint16_t periph_addr,
			     enum smbus_direction rw)
{
	const struct smbus_stm32_config *config = dev->config;

	switch (rw) {
	case SMBUS_MSG_WRITE:
		return i2c_write(config->i2c_dev, NULL, 0, periph_addr);
	case SMBUS_MSG_READ:
		return i2c_read(config->i2c_dev, NULL, 0, periph_addr);
	default:
		LOG_ERR("%s: invalid smbus direction %i", dev->name, rw);
		return -EINVAL;
	}
}

static int smbus_stm32_byte_write(const struct device *dev, uint16_t periph_addr, uint8_t command)
{
	const struct smbus_stm32_config *config = dev->config;

	return i2c_write(config->i2c_dev, &command, sizeof(command), periph_addr);
}

static int smbus_stm32_byte_read(const struct device *dev, uint16_t periph_addr, uint8_t *byte)
{
	const struct smbus_stm32_config *config = dev->config;

	return i2c_read(config->i2c_dev, byte, sizeof(*byte), periph_addr);
}

static int smbus_stm32_byte_data_write(const struct device *dev, uint16_t periph_addr,
				       uint8_t command, uint8_t byte)
{
	const struct smbus_stm32_config *config = dev->config;
	uint8_t buffer[] = {
		command,
		byte,
	};

	return i2c_write(config->i2c_dev, buffer, ARRAY_SIZE(buffer), periph_addr);
}

static int smbus_stm32_byte_data_read(const struct device *dev, uint16_t periph_addr,
				      uint8_t command, uint8_t *byte)
{
	const struct smbus_stm32_config *config = dev->config;

	return i2c_write_read(config->i2c_dev, periph_addr, &command, sizeof(command), byte,
			      sizeof(*byte));
}

static int smbus_stm32_word_data_write(const struct device *dev, uint16_t periph_addr,
				       uint8_t command, uint16_t word)
{
	const struct smbus_stm32_config *config = dev->config;
	uint8_t buffer[sizeof(command) + sizeof(word)];

	buffer[0] = command;
	sys_put_le16(word, buffer + 1);

	return i2c_write(config->i2c_dev, buffer, ARRAY_SIZE(buffer), periph_addr);
}

static int smbus_stm32_word_data_read(const struct device *dev, uint16_t periph_addr,
				      uint8_t command, uint16_t *word)
{
	const struct smbus_stm32_config *config = dev->config;
	int result;

	result = i2c_write_read(config->i2c_dev, periph_addr, &command, sizeof(command), word,
			      sizeof(*word));
	*word = sys_le16_to_cpu(*word);

	return result;
}

static int smbus_stm32_pcall(const struct device *dev, uint16_t periph_addr, uint8_t command,
			     uint16_t send_word, uint16_t *recv_word)
{
	const struct smbus_stm32_config *config = dev->config;
	uint8_t buffer[sizeof(command) + sizeof(send_word)];
	int result;

	buffer[0] = command;
	sys_put_le16(send_word, buffer + 1);

	result = i2c_write_read(config->i2c_dev, periph_addr, buffer, ARRAY_SIZE(buffer), recv_word,
			      sizeof(*recv_word));
	*recv_word = sys_le16_to_cpu(*recv_word);

	return result;
}

static int smbus_stm32_block_write(const struct device *dev, uint16_t periph_addr, uint8_t command,
				   uint8_t count, uint8_t *buf)
{
	const struct smbus_stm32_config *config = dev->config;
	struct i2c_msg messages[] = {
		{
			.buf = &command,
			.len = sizeof(command),
			.flags = 0,
		},
		{
			.buf = buf,
			.len = count,
			.flags = 0,
		},
	};

	return i2c_transfer(config->i2c_dev, messages, ARRAY_SIZE(messages), periph_addr);
}

static DEVICE_API(smbus, smbus_stm32_api) = {
	.configure = smbus_stm32_configure,
	.get_config = smbus_stm32_get_config,
	.smbus_quick = smbus_stm32_quick,
	.smbus_byte_write = smbus_stm32_byte_write,
	.smbus_byte_read = smbus_stm32_byte_read,
	.smbus_byte_data_write = smbus_stm32_byte_data_write,
	.smbus_byte_data_read = smbus_stm32_byte_data_read,
	.smbus_word_data_write = smbus_stm32_word_data_write,
	.smbus_word_data_read = smbus_stm32_word_data_read,
	.smbus_pcall = smbus_stm32_pcall,
	.smbus_block_write = smbus_stm32_block_write,
#ifdef CONFIG_SMBUS_STM32_SMBALERT
	.smbus_smbalert_set_cb = smbus_stm32_smbalert_set_cb,
	.smbus_smbalert_remove_cb = smbus_stm32_smbalert_remove_cb,
#else
	.smbus_smbalert_set_cb = NULL,
	.smbus_smbalert_remove_cb = NULL,
#endif /* CONFIG_SMBUS_STM32_SMBALERT */
	.smbus_block_read = NULL,
	.smbus_block_pcall = NULL,
	.smbus_host_notify_set_cb = NULL,
	.smbus_host_notify_remove_cb = NULL,
};

#define DT_DRV_COMPAT st_stm32_smbus

#define SMBUS_STM32_DEVICE_INIT(n)                                                                 \
	PINCTRL_DT_INST_DEFINE(n);                                                                 \
	static struct smbus_stm32_config smbus_stm32_config_##n = {                                \
		.i2c_dev = DEVICE_DT_GET(DT_INST_PROP(n, i2c)),                                    \
		.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(n),                                         \
	};                                                                                         \
                                                                                                   \
	static struct smbus_stm32_data smbus_stm32_data_##n;                                       \
                                                                                                   \
	SMBUS_DEVICE_DT_INST_DEFINE(n, smbus_stm32_init, NULL, &smbus_stm32_data_##n,              \
				    &smbus_stm32_config_##n, POST_KERNEL,                          \
				    CONFIG_SMBUS_INIT_PRIORITY, &smbus_stm32_api);

DT_INST_FOREACH_STATUS_OKAY(SMBUS_STM32_DEVICE_INIT)