/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2020 Invensense, Inc.
 */

#ifndef INV_ICM42600_BUFFER_H_
#define INV_ICM42600_BUFFER_H_

#include <linux/kernel.h>
#include <linux/bits.h>

struct inv_icm42600_state;

#define INV_ICM42600_SENSOR_GYRO        BIT(0)
#define INV_ICM42600_SENSOR_ACCEL       BIT(1)
#define INV_ICM42600_SENSOR_TEMP        BIT(2)

/**
 * struct inv_icm42600_fifo - FIFO state variables
 * @on:         reference counter for FIFO on.
 * @en:         bits field of INV_ICM42600_SENSOR_* for FIFO EN bits.
 * @period:     FIFO internal period.
 * @watermark:  watermark configuration values for accel and gyro.
 * @count:      number of bytes in the FIFO data buffer.
 * @nb:         gyro, accel and total samples in the FIFO data buffer.
 * @data:       FIFO data buffer aligned for DMA (2kB + 32 bytes of read cache).
 */
struct inv_icm42600_fifo {
        unsigned int on;
        unsigned int en;
        u32 period;
        struct {
                unsigned int gyro;
                unsigned int accel;
                unsigned int eff_gyro;
                unsigned int eff_accel;
        } watermark;
        size_t count;
        struct {
                size_t gyro;
                size_t accel;
                size_t total;
        } nb;
        u8 data[2080] __aligned(IIO_DMA_MINALIGN);
};

/* FIFO data packet */
struct inv_icm42600_fifo_sensor_data {
        __be16 x;
        __be16 y;
        __be16 z;
} __packed;
#define INV_ICM42600_FIFO_DATA_INVALID          -32768

static inline s16 inv_icm42600_fifo_get_sensor_data(__be16 d)
{
        return be16_to_cpu(d);
}

static inline bool
inv_icm42600_fifo_is_data_valid(const struct inv_icm42600_fifo_sensor_data *s)
{
        s16 x, y, z;

        x = inv_icm42600_fifo_get_sensor_data(s->x);
        y = inv_icm42600_fifo_get_sensor_data(s->y);
        z = inv_icm42600_fifo_get_sensor_data(s->z);

        if (x == INV_ICM42600_FIFO_DATA_INVALID &&
            y == INV_ICM42600_FIFO_DATA_INVALID &&
            z == INV_ICM42600_FIFO_DATA_INVALID)
                return false;

        return true;
}

ssize_t inv_icm42600_fifo_decode_packet(const void *packet, const void **accel,
                                        const void **gyro, const s8 **temp,
                                        const void **timestamp, unsigned int *odr);

extern const struct iio_buffer_setup_ops inv_icm42600_buffer_ops;

int inv_icm42600_buffer_init(struct inv_icm42600_state *st);

void inv_icm42600_buffer_update_fifo_period(struct inv_icm42600_state *st);

int inv_icm42600_buffer_set_fifo_en(struct inv_icm42600_state *st,
                                    unsigned int fifo_en);

int inv_icm42600_buffer_update_watermark(struct inv_icm42600_state *st);

int inv_icm42600_buffer_fifo_read(struct inv_icm42600_state *st,
                                  unsigned int max);

int inv_icm42600_buffer_fifo_parse(struct inv_icm42600_state *st);

int inv_icm42600_buffer_hwfifo_flush(struct inv_icm42600_state *st,
                                     unsigned int count);

#endif