/* Copyright 2022 The ChromiumOS Authors
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 *
 * CAPELLA CM32183 light sensor driver
 */

#include "accelgyro.h"
#include "common.h"
#include "driver/als_cm32183.h"
#include "i2c.h"
#include "math_util.h"

struct cm32183_drv_data {
	int rate;
	int last_value;
	/* the coefficient is scale.uscale */
	int16_t scale;
	uint16_t uscale;
	int16_t offset;
};

#define CM32183_GET_DATA(_s) ((struct cm32183_drv_data *)(_s)->drv_data)

/*
 * Read CM32183 light sensor data.
 */
static int cm32183_read_lux(int *lux)
{
	int ret;
	int data;

	ret = i2c_read16(I2C_PORT_SENSOR, CM32183_I2C_ADDR,
			 CM32183_REG_ALS_RESULT, &data);

	if (ret)
		return ret;

	/*
	 * lux = data * 0.016
	 */
	*lux = (data * 16) / 1000;

	return EC_SUCCESS;
}

/*
 * Read data from CM32183 light sensor, and transfer unit into lux.
 */
static int cm32183_read(const struct motion_sensor_t *s, intv3_t v)
{
	struct cm32183_drv_data *drv_data = CM32183_GET_DATA(s);
	int ret;
	int lux_data;

	ret = cm32183_read_lux(&lux_data);

	if (ret)
		return ret;

	lux_data += drv_data->offset;
	lux_data = lux_data * drv_data->scale +
		   lux_data * drv_data->uscale / 10000;

	v[0] = lux_data;
	v[1] = 0;
	v[2] = 0;

	/*
	 * Return an error when nothing change to prevent filling the
	 * fifo with useless data.
	 */
	if (v[0] == drv_data->last_value)
		return EC_ERROR_UNCHANGED;

	drv_data->last_value = v[0];
	return EC_SUCCESS;
}

static int cm32183_set_range(struct motion_sensor_t *s, int range, int rnd)
{
	return EC_SUCCESS;
}

static int cm32183_set_data_rate(const struct motion_sensor_t *s, int rate,
				 int roundup)
{
	CM32183_GET_DATA(s)->rate = rate;
	return EC_SUCCESS;
}

static int cm32183_get_data_rate(const struct motion_sensor_t *s)
{
	return CM32183_GET_DATA(s)->rate;
}

static int cm32183_set_offset(const struct motion_sensor_t *s,
			      const int16_t *offset, int16_t temp)
{
	/* TODO: check calibration method */
	return EC_SUCCESS;
}

static int cm32183_get_offset(const struct motion_sensor_t *s, int16_t *offset,
			      int16_t *temp)
{
	*offset = CM32183_GET_DATA(s)->offset;
	return EC_SUCCESS;
}

/**
 * Initialise CM32183 light sensor.
 */
static int cm32183_init(struct motion_sensor_t *s)
{
	int ret;
	int data;

	ret = i2c_write16(s->port, s->i2c_spi_addr_flags, CM32183_REG_CONFIGURE,
			  CM32183_REG_CONFIGURE_CH_EN);

	if (ret)
		return ret;

	ret = i2c_read16(s->port, s->i2c_spi_addr_flags, CM32183_REG_ALS_RESULT,
			 &data);

	if (ret)
		return ret;

	return sensor_init_done(s);
}

const struct accelgyro_drv cm32183_drv = {
	.init = cm32183_init,
	.read = cm32183_read,
	.set_range = cm32183_set_range,
	.set_offset = cm32183_set_offset,
	.get_offset = cm32183_get_offset,
	.set_data_rate = cm32183_set_data_rate,
	.get_data_rate = cm32183_get_data_rate,
};