/* Copyright 2016 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

/**
 * LSM6DSx (x is L or M) accelerometer and gyro module for Chrome EC
 * 3D digital accelerometer & 3D digital gyroscope
 * This driver supports both devices LSM6DSM and LSM6DSL
 */

#include "driver/accelgyro_lsm6dsm.h"
#include "hooks.h"
#include "hwtimer.h"
#include "math_util.h"
#include "task.h"
#include "timer.h"

#define CPUTS(outstr) cputs(CC_ACCEL, outstr)
#define CPRINTF(format, args...) cprintf(CC_ACCEL, format, ## args)
#define CPRINTS(format, args...) cprints(CC_ACCEL, format, ## args)

#ifdef CONFIG_ACCEL_FIFO
static uint32_t last_interrupt_timestamp;
#endif

/**
 * @return output base register for sensor
 */
static inline int get_xyz_reg(enum motionsensor_type type)
{
	return LSM6DSM_ACCEL_OUT_X_L_ADDR -
		(LSM6DSM_ACCEL_OUT_X_L_ADDR - LSM6DSM_GYRO_OUT_X_L_ADDR) * type;
}

#ifdef CONFIG_ACCEL_INTERRUPTS
/**
 * Configure interrupt int 1 to fire handler for:
 *
 * FIFO threshold on watermark
 *
 * @s: Motion sensor pointer
 */
static int config_interrupt(const struct motion_sensor_t *s)
{
	int ret = EC_SUCCESS;
	int int1_ctrl_val;

	ret = st_raw_read8(s->port, s->addr, LSM6DSM_INT1_CTRL, &int1_ctrl_val);
	if (ret != EC_SUCCESS)
		return ret;

#ifdef CONFIG_ACCEL_FIFO
	/* As soon as one sample is ready, trigger an interrupt. */
	ret = st_raw_write8(s->port, s->addr, LSM6DSM_FIFO_CTRL1_ADDR,
			 OUT_XYZ_SIZE / sizeof(uint16_t));
	if (ret != EC_SUCCESS)
		return ret;
	int1_ctrl_val |= LSM6DSM_INT_FIFO_TH | LSM6DSM_INT_FIFO_OVR |
		LSM6DSM_INT_FIFO_FULL;
#endif /* CONFIG_ACCEL_FIFO */

	return st_raw_write8(
		s->port, s->addr, LSM6DSM_INT1_CTRL, int1_ctrl_val);
}


#ifdef CONFIG_ACCEL_FIFO
/**
 * fifo_disable - set fifo mode
 * @s: Motion sensor pointer: must be MOTIONSENSE_TYPE_ACCEL.
 * @fmode: BYPASS or CONTINUOUS
 */
static int fifo_disable(const struct motion_sensor_t *s)
{
	return st_raw_write8(s->port, s->addr, LSM6DSM_FIFO_CTRL5_ADDR, 0x00);
}

/**
 * fifo_reset_pattern: called at each new FIFO pattern.
 */
static void fifo_reset_pattern(struct lsm6dsm_data *private)
{
	/* The fifo is ready to run. */
	memcpy(&private->current, &private->config,
	       sizeof(struct lsm6dsm_fifo_data));
	private->next_in_patten = FIFO_DEV_INVALID;
}

/**
 * set_fifo_params - Configure internal FIFO parameters
 *
 * Configure FIFO decimator to have every time the right pattern
 * with acc/gyro
 */
static int fifo_enable(const struct motion_sensor_t *accel)
{
	int err, i, rate;
	uint8_t decimator[FIFO_DEV_NUM] = { 0 };
	unsigned int min_odr = LSM6DSM_ODR_MAX_VAL;
	unsigned int max_odr = 0;
	struct lsm6dsm_data *private = accel->drv_data;
	/* In FIFO sensors are mapped in a different way. */
	uint8_t agm_maps[] = {
		MOTIONSENSE_TYPE_GYRO,
		MOTIONSENSE_TYPE_ACCEL,
		MOTIONSENSE_TYPE_MAG,
	};


	/* Search for min and max odr values for acc, gyro. */
	for (i = FIFO_DEV_GYRO; i < FIFO_DEV_NUM; i++) {
		/* Check if sensor enabled with ODR. */
		rate = st_get_data_rate(accel + agm_maps[i]);
		if (rate > 0) {
			min_odr = MIN(min_odr, rate);
			max_odr = MAX(max_odr, rate);
		}
	}

	if (max_odr == 0) {
		/* Leave FIFO disabled. */
		return EC_SUCCESS;
	}

	/* Scan all sensors configuration to calculate FIFO decimator. */
	private->config.total_samples_in_pattern = 0;
	for (i = FIFO_DEV_GYRO; i < FIFO_DEV_NUM; i++) {
		rate = st_get_data_rate(accel + agm_maps[i]);
		if (rate > 0) {
			private->config.samples_in_pattern[i] = rate / min_odr;
			decimator[i] = LSM6DSM_FIFO_DECIMATOR(max_odr / rate);
			private->config.total_samples_in_pattern +=
				private->config.samples_in_pattern[i];
		} else {
			/* Not in FIFO if sensor disabled. */
			private->config.samples_in_pattern[i] = 0;
		}
	}
	st_raw_write8(accel->port, accel->addr, LSM6DSM_FIFO_CTRL3_ADDR,
			(decimator[FIFO_DEV_GYRO] << LSM6DSM_FIFO_DEC_G_OFF) |
			(decimator[FIFO_DEV_ACCEL] << LSM6DSM_FIFO_DEC_XL_OFF));
#ifdef CONFIG_MAG_LSM6DSM_LIS2MDL
	st_raw_write8(accel->port, accel->addr, LSM6DSM_FIFO_CTRL4_ADDR,
			decimator[FIFO_DEV_MAG]);
#endif /* CONFIG_MAG_LSM6DSM_LIS2MDL */
	err = st_raw_write8(accel->port, accel->addr, LSM6DSM_FIFO_CTRL5_ADDR,
			 (LSM6DSM_ODR_TO_REG(max_odr) <<
			  LSM6DSM_FIFO_CTRL5_ODR_OFF) |
			 LSM6DSM_FIFO_MODE_CONTINUOUS_VAL);
	if (err != EC_SUCCESS)
		return err;
	fifo_reset_pattern(private);
	return EC_SUCCESS;
}

/*
 * Must order FIFO read based on ODR:
 * For example Acc @ 52 Hz, Gyro @ 26 Hz Mag @ 13 Hz in FIFO we have
 * for each pattern this data samples:
 *  ________ _______ _______ _______ ________ _______ _______
 * | Gyro_0 | Acc_0 | Mag_0 | Acc_1 | Gyro_1 | Acc_2 | Acc_3 |
 * |________|_______|_______|_______|________|_______|_______|
 *
 * Total samples for each pattern: 2 Gyro, 4 Acc, 1 Mag.
 */
static int fifo_next(struct lsm6dsm_data *private)
{
	int next_id;

	if (private->current.total_samples_in_pattern == 0)
		fifo_reset_pattern(private);

	if (private->current.total_samples_in_pattern == 0) {
		/*
		 * Not expected we are supposed to be called to process FIFO
		 * data.
		 */
		CPRINTF("[%T FIFO empty pattern]\n");
		return FIFO_DEV_INVALID;
	}

	for (next_id = private->next_in_patten + 1; 1; next_id++) {
		if (next_id == FIFO_DEV_NUM)
			next_id = FIFO_DEV_GYRO;
		if (private->current.samples_in_pattern[next_id] != 0) {
			private->current.samples_in_pattern[next_id]--;
			private->current.total_samples_in_pattern--;
			private->next_in_patten = next_id;
			return next_id;
		}
	}
	/* Will never happen. */
	return FIFO_DEV_INVALID;
}

/**
 * push_fifo_data - Scan data pattern and push upside
 */
static void push_fifo_data(struct motion_sensor_t *accel, uint8_t *fifo,
			   uint16_t flen)
{
	struct lsm6dsm_data *private = accel->drv_data;
	/* In FIFO sensors are mapped in a different way. */
	uint8_t agm_maps[] = {
		MOTIONSENSE_TYPE_GYRO,
		MOTIONSENSE_TYPE_ACCEL,
		MOTIONSENSE_TYPE_MAG,
	};

	while (flen > 0) {
		struct ec_response_motion_sensor_data vect;
		int id;
		int *axis;
		int next_fifo = fifo_next(private);
		/*
		 * This should never happen, but it could. There will be a
		 * report from inside fifo_next about it, so no extra message
		 * required here.
		 */
		if (next_fifo == FIFO_DEV_INVALID) {
			return;
		}
		id = agm_maps[next_fifo];
		axis = (accel + id)->raw_xyz;

		/* Apply precision, sensitivity and rotation. */
		st_normalize(accel + id, axis, fifo);
		vect.data[X] = axis[X];
		vect.data[Y] = axis[Y];
		vect.data[Z] = axis[Z];

		vect.flags = 0;
		vect.sensor_num = accel - motion_sensors + id;
		motion_sense_fifo_add_data(&vect, accel + id, 3,
					   last_interrupt_timestamp);

		fifo += OUT_XYZ_SIZE;
		flen -= OUT_XYZ_SIZE;
	}
}

static int load_fifo(struct motion_sensor_t *s, const struct fstatus *fsts)
{
	int err, left, length;
	uint8_t fifo[FIFO_READ_LEN];

	/*
	 * DIFF[9:0] are number of unread uint16 in FIFO
	 * mask DIFF and compute total byte len to read from FIFO.
	 */
	left = fsts->len & LSM6DSM_FIFO_DIFF_MASK;
	left *= sizeof(uint16_t);
	left = (left / OUT_XYZ_SIZE) * OUT_XYZ_SIZE;

	/* Push all data on upper side. */
	do {
		/* Fit len to pre-allocated static buffer. */
		if (left > FIFO_READ_LEN)
			length = FIFO_READ_LEN;
		else
			length = left;

		/* Read data and copy in buffer. */
		err = st_raw_read_n_noinc(s->port, s->addr,
					  LSM6DSM_FIFO_DATA_ADDR,
					  fifo, length);
		if (err != EC_SUCCESS)
			return err;

		/* Manage patterns and push data. */
		push_fifo_data(s, fifo, length);
		left -= length;
	} while (left > 0);

	return EC_SUCCESS;
}

/**
 * accelgyro_config_fifo - update mode and ODR for FIFO decimator
 */
int accelgyro_config_fifo(const struct motion_sensor_t *accel)
{
	int err;

	/* Changing in ODR must stop FIFO. */
	err = fifo_disable(accel);
	if (err != EC_SUCCESS)
		return err;


	return fifo_enable(accel);
}
#endif /* CONFIG_ACCEL_FIFO */

/**
 * lsm6dsm_interrupt - interrupt from int1/2 pin of sensor
 */
void lsm6dsm_interrupt(enum gpio_signal signal)
{
#ifdef CONFIG_ACCEL_FIFO
	last_interrupt_timestamp = __hw_clock_source_read();
#endif
	task_set_event(TASK_ID_MOTIONSENSE,
		       CONFIG_ACCEL_LSM6DSM_INT_EVENT, 0);
}

/**
 * irq_handler - bottom half of the interrupt stack
 */
static int irq_handler(struct motion_sensor_t *s, uint32_t *event)
{
	int ret = EC_SUCCESS;

	if ((s->type != MOTIONSENSE_TYPE_ACCEL) ||
	    (!(*event & CONFIG_ACCEL_LSM6DSM_INT_EVENT)))
		return EC_ERROR_NOT_HANDLED;

#ifdef CONFIG_ACCEL_FIFO
	{
		struct fstatus fsts;
		/* Read how many data pattern on FIFO to read and pattern. */
		ret = st_raw_read_n_noinc(s->port, s->addr,
				LSM6DSM_FIFO_STS1_ADDR,
				(uint8_t *)&fsts, sizeof(fsts));
		if (ret != EC_SUCCESS)
			return ret;
		if (fsts.len & (LSM6DSM_FIFO_DATA_OVR | LSM6DSM_FIFO_FULL)) {
			CPRINTF("[%T %s FIFO Overrun: %04x]\n",
				s->name, fsts.len);
		}
		if (!(fsts.len & LSM6DSM_FIFO_EMPTY))
			ret = load_fifo(s, &fsts);
	}
#endif
	return ret;
}
#endif /* CONFIG_ACCEL_INTERRUPTS */

/**
 * set_range - set full scale range
 * @s: Motion sensor pointer
 * @range: Range
 * @rnd: Round up/down flag
 * Note: Range is sensitivity/gain for speed purpose
 */
static int set_range(const struct motion_sensor_t *s, int range, int rnd)
{
	int err;
	uint8_t ctrl_reg, reg_val;
	/*
	 * Since 'stprivate_data a_data;' is the first member of lsm6dsm_data,
	 * the address of lsm6dsm_data is the same as a_data's. Using this
	 * fact, we can do the following conversion. This conversion is equal
	 * to:
	 *     struct lsm6dsm_data *lsm_data = s->drv_data;
	 *     struct stprivate_data *data = &lsm_data->a_data;
	 */
	struct stprivate_data *data = s->drv_data;
	int newrange = range;

	ctrl_reg = LSM6DSM_RANGE_REG(s->type);
	if (s->type == MOTIONSENSE_TYPE_ACCEL) {
		/* Adjust and check rounded value for acc. */
		if (rnd && (newrange < LSM6DSM_ACCEL_NORMALIZE_FS(newrange)))
			newrange *= 2;

		if (newrange > LSM6DSM_ACCEL_FS_MAX_VAL)
			newrange = LSM6DSM_ACCEL_FS_MAX_VAL;

		reg_val = LSM6DSM_ACCEL_FS_REG(newrange);
	} else {
		/* Adjust and check rounded value for gyro. */
		if (rnd && (newrange < LSM6DSM_GYRO_NORMALIZE_FS(newrange)))
			newrange *= 2;

		if (newrange > LSM6DSM_GYRO_FS_MAX_VAL)
			newrange = LSM6DSM_GYRO_FS_MAX_VAL;

		reg_val = LSM6DSM_GYRO_FS_REG(newrange);
	}

	mutex_lock(s->mutex);
	err = st_write_data_with_mask(s, ctrl_reg, LSM6DSM_RANGE_MASK, reg_val);
	if (err == EC_SUCCESS)
		/* Save internally gain for speed optimization. */
		data->base.range = (s->type == MOTIONSENSE_TYPE_ACCEL ?
				    newrange :
				    LSM6DSM_GYRO_FS_GAIN(newrange));
	mutex_unlock(s->mutex);

	return EC_SUCCESS;
}

/**
 * get_range - get full scale range
 * @s: Motion sensor pointer
 *
 * For mag range is fixed to LIS2MDL_RANGE by hardware
 */
static int get_range(const struct motion_sensor_t *s)
{
	/*
	 * Since 'stprivate_data a_data;' is the first member of lsm6dsm_data,
	 * the address of lsm6dsm_data is the same as a_data's. Using this
	 * fact, we can do the following conversion. This conversion is equal
	 * to:
	 *     struct lsm6dsm_data *lsm_data = s->drv_data;
	 *     struct stprivate_data *data = &lsm_data->a_data;
	 */
	struct stprivate_data *data = s->drv_data;

	if (s->type == MOTIONSENSE_TYPE_ACCEL)
		return data->base.range;
	return LSM6DSM_GYRO_GAIN_FS(data->base.range);
}

/**
 * set_data_rate
 * @s: Motion sensor pointer
 * @range: Rate (mHz)
 * @rnd: Round up/down flag
 *
 * For mag in cascade with lsm6dsm/l we use acc trigger and FIFO decimator
 */
static int set_data_rate(const struct motion_sensor_t *s, int rate, int rnd)
{
	int ret, normalized_rate = 0;
	/*
	 * Since 'stprivate_data a_data;' is the first member of lsm6dsm_data,
	 * the address of lsm6dsm_data is the same as a_data's. Using this
	 * fact, we can do the following conversion. This conversion is equal
	 * to:
	 *     struct lsm6dsm_data *lsm_data = s->drv_data;
	 *     struct stprivate_data *data = &lsm_data->a_data;
	 */
	struct stprivate_data *data = s->drv_data;
	uint8_t ctrl_reg, reg_val = 0;

	ctrl_reg = LSM6DSM_ODR_REG(s->type);
	if (rate > 0) {
		reg_val = LSM6DSM_ODR_TO_REG(rate);
		normalized_rate = LSM6DSM_REG_TO_ODR(reg_val);

		if (rnd && (normalized_rate < rate)) {
			reg_val++;
			normalized_rate = LSM6DSM_REG_TO_ODR(reg_val);
		}
		if (normalized_rate < LSM6DSM_ODR_MIN_VAL ||
		    normalized_rate > MIN(LSM6DSM_ODR_MAX_VAL,
			    CONFIG_EC_MAX_SENSOR_FREQ_MILLIHZ))
			return EC_RES_INVALID_PARAM;
	}

	mutex_lock(s->mutex);
	ret = st_write_data_with_mask(s, ctrl_reg, LSM6DSM_ODR_MASK, reg_val);
	if (ret == EC_SUCCESS) {
		data->base.odr = normalized_rate;
#ifdef CONFIG_ACCEL_FIFO
		accelgyro_config_fifo(LSM6DSM_MAIN_SENSOR(s));
#endif
	}

	mutex_unlock(s->mutex);
	return ret;
}

static int is_data_ready(const struct motion_sensor_t *s, int *ready)
{
	int ret, tmp;

	ret = st_raw_read8(s->port, s->addr, LSM6DSM_STATUS_REG, &tmp);
	if (ret != EC_SUCCESS) {
		CPRINTF("[%T %s type:0x%X RS Error]", s->name, s->type);
		return ret;
	}

	if (MOTIONSENSE_TYPE_ACCEL == s->type)
		*ready = (LSM6DSM_STS_XLDA_UP == (tmp & LSM6DSM_STS_XLDA_MASK));
	else
		*ready = (LSM6DSM_STS_GDA_UP == (tmp & LSM6DSM_STS_GDA_MASK));

	return EC_SUCCESS;
}

/*
 * Is not very efficient to collect the data in read: better have an interrupt
 * and collect the FIFO, even if it has one item: we don't have to check if the
 * sensor is ready (minimize I2C access).
 */
static int read(const struct motion_sensor_t *s, intv3_t v)
{
	uint8_t raw[OUT_XYZ_SIZE];
	uint8_t xyz_reg;
	int ret, tmp = 0;

	ret = is_data_ready(s, &tmp);
	if (ret != EC_SUCCESS)
		return ret;

	/*
	 * If sensor data is not ready, return the previous read data.
	 * Note: return success so that motion senor task can read again
	 * to get the latest updated sensor data quickly.
	 */
	if (!tmp) {
		if (v != s->raw_xyz)
			memcpy(v, s->raw_xyz, sizeof(s->raw_xyz));
		return EC_SUCCESS;
	}

	xyz_reg = get_xyz_reg(s->type);

	/* Read data bytes starting at xyz_reg. */
	ret = st_raw_read_n_noinc(s->port, s->addr, xyz_reg, raw, OUT_XYZ_SIZE);
	if (ret != EC_SUCCESS)
		return ret;

	/* Apply precision, sensitivity and rotation vector. */
	st_normalize(s, v, raw);

	return EC_SUCCESS;
}

static int init(const struct motion_sensor_t *s)
{
	int ret = 0, tmp;
	/*
	 * Since 'stprivate_data a_data;' is the first member of lsm6dsm_data,
	 * the address of lsm6dsm_data is the same as a_data's. Using this
	 * fact, we can do the following conversion. This conversion is equal
	 * to:
	 *     struct lsm6dsm_data *lsm_data = s->drv_data;
	 *     struct stprivate_data *data = &lsm_data->a_data;
	 */
	struct stprivate_data *data = s->drv_data;

	ret = st_raw_read8(s->port, s->addr, LSM6DSM_WHO_AM_I_REG, &tmp);
	if (ret != EC_SUCCESS)
		return EC_ERROR_UNKNOWN;

	if (tmp != LSM6DSM_WHO_AM_I)
		return EC_ERROR_ACCESS_DENIED;

	/*
	 * This sensor can be powered through an EC reboot, so the state of the
	 * sensor is unknown here so reset it
	 * LSM6DSM/L supports both accel & gyro features
	 * Board will see two virtual sensor devices: accel & gyro
	 * Requirement: Accel need be init before gyro and mag
	 */
	if (s->type == MOTIONSENSE_TYPE_ACCEL) {
		mutex_lock(s->mutex);

		/* Software reset. */
		ret = st_raw_write8(s->port, s->addr, LSM6DSM_CTRL3_ADDR,
				LSM6DSM_SW_RESET);
		if (ret != EC_SUCCESS)
			goto err_unlock;

		/*
		 * Output data not updated until have been read.
		 * Prefer interrupt to be active low.
		 */
		ret = st_raw_write8(s->port, s->addr, LSM6DSM_CTRL3_ADDR,
				LSM6DSM_BDU | LSM6DSM_H_L_ACTIVE |
				LSM6DSM_IF_INC);
		if (ret != EC_SUCCESS)
			goto err_unlock;

#ifdef CONFIG_ACCEL_FIFO
		ret = fifo_disable(s);
		if (ret != EC_SUCCESS)
			goto err_unlock;
#endif /* CONFIG_ACCEL_FIFO */

#ifdef CONFIG_ACCEL_INTERRUPTS
		ret = config_interrupt(s);
		if (ret != EC_SUCCESS)
			goto err_unlock;
#endif /* CONFIG_ACCEL_INTERRUPTS */

		mutex_unlock(s->mutex);
	}

	/* Set default resolution common to acc and gyro. */
	data->resol = LSM6DSM_RESOLUTION;
	return sensor_init_done(s);

err_unlock:
	mutex_unlock(s->mutex);
	CPRINTF("[%T %s: MS Init type:0x%X Error]\n", s->name, s->type);

	return ret;
}

const struct accelgyro_drv lsm6dsm_drv = {
	.init = init,
	.read = read,
	.set_range = set_range,
	.get_range = get_range,
	.get_resolution = st_get_resolution,
	.set_data_rate = set_data_rate,
	.get_data_rate = st_get_data_rate,
	.set_offset = st_set_offset,
	.get_offset = st_get_offset,
#ifdef CONFIG_ACCEL_INTERRUPTS
	.irq_handler = irq_handler,
#endif /* CONFIG_ACCEL_INTERRUPTS */
};