// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/* Copyright (c) 2020 Marvell International Ltd. All rights reserved */

#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/string.h>

#include "prestera_dsa.h"

#define PRESTERA_DSA_W0_CMD             GENMASK(31, 30)
#define PRESTERA_DSA_W0_IS_TAGGED       BIT(29)
#define PRESTERA_DSA_W0_DEV_NUM         GENMASK(28, 24)
#define PRESTERA_DSA_W0_PORT_NUM        GENMASK(23, 19)
#define PRESTERA_DSA_W0_VPT             GENMASK(15, 13)
#define PRESTERA_DSA_W0_EXT_BIT         BIT(12)
#define PRESTERA_DSA_W0_VID             GENMASK(11, 0)

#define PRESTERA_DSA_W1_EXT_BIT         BIT(31)
#define PRESTERA_DSA_W1_CFI_BIT         BIT(30)
#define PRESTERA_DSA_W1_PORT_NUM        GENMASK(11, 10)
#define PRESTERA_DSA_W1_MASK_CPU_CODE   GENMASK(7, 0)

#define PRESTERA_DSA_W2_EXT_BIT         BIT(31)
#define PRESTERA_DSA_W2_PORT_NUM        BIT(20)

#define PRESTERA_DSA_W3_VID             GENMASK(30, 27)
#define PRESTERA_DSA_W3_DST_EPORT       GENMASK(23, 7)
#define PRESTERA_DSA_W3_DEV_NUM         GENMASK(6, 0)

#define PRESTERA_DSA_VID                GENMASK(15, 12)
#define PRESTERA_DSA_DEV_NUM            GENMASK(11, 5)

int prestera_dsa_parse(struct prestera_dsa *dsa, const u8 *dsa_buf)
{
        __be32 *dsa_words = (__be32 *)dsa_buf;
        enum prestera_dsa_cmd cmd;
        u32 words[4];
        u32 field;

        words[0] = ntohl(dsa_words[0]);
        words[1] = ntohl(dsa_words[1]);
        words[2] = ntohl(dsa_words[2]);
        words[3] = ntohl(dsa_words[3]);

        /* set the common parameters */
        cmd = (enum prestera_dsa_cmd)FIELD_GET(PRESTERA_DSA_W0_CMD, words[0]);

        /* only to CPU is supported */
        if (unlikely(cmd != PRESTERA_DSA_CMD_TO_CPU))
                return -EINVAL;

        if (FIELD_GET(PRESTERA_DSA_W0_EXT_BIT, words[0]) == 0)
                return -EINVAL;
        if (FIELD_GET(PRESTERA_DSA_W1_EXT_BIT, words[1]) == 0)
                return -EINVAL;
        if (FIELD_GET(PRESTERA_DSA_W2_EXT_BIT, words[2]) == 0)
                return -EINVAL;

        field = FIELD_GET(PRESTERA_DSA_W3_VID, words[3]);

        dsa->vlan.is_tagged = FIELD_GET(PRESTERA_DSA_W0_IS_TAGGED, words[0]);
        dsa->vlan.cfi_bit = FIELD_GET(PRESTERA_DSA_W1_CFI_BIT, words[1]);
        dsa->vlan.vpt = FIELD_GET(PRESTERA_DSA_W0_VPT, words[0]);
        dsa->vlan.vid = FIELD_GET(PRESTERA_DSA_W0_VID, words[0]);
        dsa->vlan.vid &= ~PRESTERA_DSA_VID;
        dsa->vlan.vid |= FIELD_PREP(PRESTERA_DSA_VID, field);

        field = FIELD_GET(PRESTERA_DSA_W3_DEV_NUM, words[3]);

        dsa->hw_dev_num = FIELD_GET(PRESTERA_DSA_W0_DEV_NUM, words[0]);
        dsa->hw_dev_num |= FIELD_PREP(PRESTERA_DSA_DEV_NUM, field);

        dsa->port_num = (FIELD_GET(PRESTERA_DSA_W0_PORT_NUM, words[0]) << 0) |
                        (FIELD_GET(PRESTERA_DSA_W1_PORT_NUM, words[1]) << 5) |
                        (FIELD_GET(PRESTERA_DSA_W2_PORT_NUM, words[2]) << 7);

        dsa->cpu_code = FIELD_GET(PRESTERA_DSA_W1_MASK_CPU_CODE, words[1]);

        return 0;
}

int prestera_dsa_build(const struct prestera_dsa *dsa, u8 *dsa_buf)
{
        __be32 *dsa_words = (__be32 *)dsa_buf;
        u32 dev_num = dsa->hw_dev_num;
        u32 words[4] = { 0 };

        words[0] |= FIELD_PREP(PRESTERA_DSA_W0_CMD, PRESTERA_DSA_CMD_FROM_CPU);

        words[0] |= FIELD_PREP(PRESTERA_DSA_W0_DEV_NUM, dev_num);
        dev_num = FIELD_GET(PRESTERA_DSA_DEV_NUM, dev_num);
        words[3] |= FIELD_PREP(PRESTERA_DSA_W3_DEV_NUM, dev_num);

        words[3] |= FIELD_PREP(PRESTERA_DSA_W3_DST_EPORT, dsa->port_num);

        words[0] |= FIELD_PREP(PRESTERA_DSA_W0_EXT_BIT, 1);
        words[1] |= FIELD_PREP(PRESTERA_DSA_W1_EXT_BIT, 1);
        words[2] |= FIELD_PREP(PRESTERA_DSA_W2_EXT_BIT, 1);

        dsa_words[0] = htonl(words[0]);
        dsa_words[1] = htonl(words[1]);
        dsa_words[2] = htonl(words[2]);
        dsa_words[3] = htonl(words[3]);

        return 0;
}