/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Intel Core SoC Power Management Controller Header File
 *
 * Copyright (c) 2025, Intel Corporation.
 * All Rights Reserved.
 *
 */
#ifndef INTEL_PMC_IPC_H
#define INTEL_PMC_IPC_H
#include <linux/acpi.h>
#include <linux/cleanup.h>

#define IPC_SOC_REGISTER_ACCESS                 0xAA
#define IPC_SOC_SUB_CMD_READ                    0x00
#define IPC_SOC_SUB_CMD_WRITE                   0x01
#define PMC_IPCS_PARAM_COUNT                    7
#define VALID_IPC_RESPONSE                      5

struct pmc_ipc_cmd {
        u32 cmd;
        u32 sub_cmd;
        u32 size;
        u32 wbuf[4];
};

struct pmc_ipc_rbuf {
        u32 buf[4];
};

/**
 * intel_pmc_ipc() - PMC IPC Mailbox accessor
 * @ipc_cmd:  Prepared input command to send
 * @rbuf:     Allocated array for returned IPC data
 *
 * Return: 0 on success. Non-zero on mailbox error
 */
static inline int intel_pmc_ipc(struct pmc_ipc_cmd *ipc_cmd, struct pmc_ipc_rbuf *rbuf)
{
#ifdef CONFIG_ACPI
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object params[PMC_IPCS_PARAM_COUNT] = {
                {.type = ACPI_TYPE_INTEGER,},
                {.type = ACPI_TYPE_INTEGER,},
                {.type = ACPI_TYPE_INTEGER,},
                {.type = ACPI_TYPE_INTEGER,},
                {.type = ACPI_TYPE_INTEGER,},
                {.type = ACPI_TYPE_INTEGER,},
                {.type = ACPI_TYPE_INTEGER,},
        };
        struct acpi_object_list arg_list = { PMC_IPCS_PARAM_COUNT, params };
        int status;

        if (!ipc_cmd || !rbuf)
                return -EINVAL;

        /*
         * 0: IPC Command
         * 1: IPC Sub Command
         * 2: Size
         * 3-6: Write Buffer for offset
         */
        params[0].integer.value = ipc_cmd->cmd;
        params[1].integer.value = ipc_cmd->sub_cmd;
        params[2].integer.value = ipc_cmd->size;
        params[3].integer.value = ipc_cmd->wbuf[0];
        params[4].integer.value = ipc_cmd->wbuf[1];
        params[5].integer.value = ipc_cmd->wbuf[2];
        params[6].integer.value = ipc_cmd->wbuf[3];

        status = acpi_evaluate_object(NULL, "\\IPCS", &arg_list, &buffer);
        if (ACPI_FAILURE(status))
                return -ENODEV;

        union acpi_object *obj __free(kfree) = buffer.pointer;

        if (obj && obj->type == ACPI_TYPE_PACKAGE &&
            obj->package.count == VALID_IPC_RESPONSE) {
                const union acpi_object *objs = obj->package.elements;

                if ((u8)objs[0].integer.value != 0)
                        return -EINVAL;

                rbuf->buf[0] = objs[1].integer.value;
                rbuf->buf[1] = objs[2].integer.value;
                rbuf->buf[2] = objs[3].integer.value;
                rbuf->buf[3] = objs[4].integer.value;
        } else {
                return -EINVAL;
        }

        return 0;
#else
        return -ENODEV;
#endif /* CONFIG_ACPI */
}

#endif /* INTEL_PMC_IPC_H */