/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Rockchip Video Decoder bit writer
 *
 * Copyright (C) 2026 Collabora, Ltd.
 *      Detlev Casanova <detlev.casanova@collabora.com>
 * Copyright (C) 2019 Collabora, Ltd.
 *      Boris Brezillon <boris.brezillon@collabora.com>
 */

#ifndef RKVDEC_BIT_WRITER_H_
#define RKVDEC_BIT_WRITER_H_

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

struct rkvdec_bw_field {
        u16 offset;
        u8 len;
};

#define BW_FIELD(_offset, _len) ((struct rkvdec_bw_field){ _offset, _len })

static inline void rkvdec_set_bw_field(u32 *buf, struct rkvdec_bw_field field, u32 value)
{
        u8 bit = field.offset % 32;
        u16 word = field.offset / 32;
        u64 mask = GENMASK_ULL(bit + field.len - 1, bit);
        u64 val = ((u64)value << bit) & mask;

        buf[word] &= ~mask;
        buf[word] |= val;
        if (bit + field.len > 32) {
                buf[word + 1] &= ~(mask >> 32);
                buf[word + 1] |= val >> 32;
        }
}

#endif /* RKVDEC_BIT_WRITER_H_ */