// SPDX-License-Identifier: GPL-2.0+
/*
 * Core driver model support for ACPI table generation
 *
 * Copyright 2019 Google LLC
 * Written by Simon Glass <sjg@chromium.org>
 */

#define LOG_CATEOGRY    LOGC_ACPI

#include <common.h>
#include <display_options.h>
#include <dm.h>
#include <log.h>
#include <malloc.h>
#include <mapmem.h>
#include <acpi/acpi_device.h>
#include <dm/acpi.h>
#include <dm/device-internal.h>
#include <dm/root.h>

#define MAX_ACPI_ITEMS  100

/**
 * Type of table that we collected
 *
 * @TYPE_NONE: Not yet known
 * @TYPE_SSDT: Items in the Secondary System Description Table
 * @TYPE_DSDT: Items in the Differentiated System Description Table
 * @TYPE_OTHER: Other (whole)
 */
enum gen_type_t {
        TYPE_NONE,
        TYPE_SSDT,
        TYPE_DSDT,
        TYPE_OTHER,
};

const char *gen_type_str[] = {
        "-",
        "ssdt",
        "dsdt",
        "other",
};

/* Type of method to call */
enum method_t {
        METHOD_WRITE_TABLES,
        METHOD_FILL_SSDT,
        METHOD_INJECT_DSDT,
        METHOD_SETUP_NHLT,
};

/* Prototype for all methods */
typedef int (*acpi_method)(const struct udevice *dev, struct acpi_ctx *ctx);

/**
 * struct acpi_item - Holds info about ACPI data generated by a driver method
 *
 * @dev: Device that generated this data
 * @type: Table type it refers to
 * @writer: Writer that wrote this table
 * @base: Pointer to base of table in its original location
 * @buf: Buffer allocated to contain the data (NULL if not allocated)
 * @size: Size of the data in bytes
 */
struct acpi_item {
        struct udevice *dev;
        const struct acpi_writer *writer;
        enum gen_type_t type;
        const char *base;
        char *buf;
        int size;
};

/* List of ACPI items collected */
static struct acpi_item acpi_item[MAX_ACPI_ITEMS];
static int item_count;

int acpi_copy_name(char *out_name, const char *name)
{
        strncpy(out_name, name, ACPI_NAME_LEN);
        out_name[ACPI_NAME_LEN] = '\0';

        return 0;
}

int acpi_get_name(const struct udevice *dev, char *out_name)
{
        struct acpi_ops *aops;
        const char *name;
        int ret;

        aops = device_get_acpi_ops(dev);
        if (aops && aops->get_name)
                return aops->get_name(dev, out_name);
        name = dev_read_string(dev, "acpi,name");
        if (name)
                return acpi_copy_name(out_name, name);
        ret = acpi_device_infer_name(dev, out_name);
        if (ret)
                return log_msg_ret("dev", ret);

        return 0;
}

int acpi_get_path(const struct udevice *dev, char *out_path, int maxlen)
{
        const char *path;
        int ret;

        path = dev_read_string(dev, "acpi,path");
        if (path) {
                if (strlen(path) >= maxlen)
                        return -ENOSPC;
                strcpy(out_path, path);
                return 0;
        }
        ret = acpi_device_path(dev, out_path, maxlen);
        if (ret)
                return log_msg_ret("dev", ret);

        return 0;
}

/**
 * add_item() - Add a new item to the list of data collected
 *
 * @ctx: ACPI context
 * @dev: Device that generated the data, if type != TYPE_OTHER
 * @writer: Writer entry that generated the data, if type == TYPE_OTHER
 * @type: Table type it refers to
 * @start: The start of the data (the end is obtained from ctx->current)
 * Return: 0 if OK, -ENOSPC if too many items, -ENOMEM if out of memory
 */
static int add_item(struct acpi_ctx *ctx, struct udevice *dev,
                    const struct acpi_writer *writer, enum gen_type_t type,
                    void *start)
{
        struct acpi_item *item;
        void *end = ctx->current;

        if (item_count == MAX_ACPI_ITEMS) {
                log_err("Too many items\n");
                return log_msg_ret("mem", -ENOSPC);
        }

        item = &acpi_item[item_count];
        item->dev = dev;
        item->writer = writer;
        item->type = type;
        item->size = end - start;
        item->base = start;
        if (!item->size)
                return 0;
        if (type != TYPE_OTHER) {
                item->buf = malloc(item->size);
                if (!item->buf)
                        return log_msg_ret("mem", -ENOMEM);
                memcpy(item->buf, start, item->size);
        }
        item_count++;
        log_debug("* %s: Added type %d, %p, size %x\n",
                  dev ? dev->name : "other", type, start, item->size);

        return 0;
}

int acpi_add_other_item(struct acpi_ctx *ctx, const struct acpi_writer *writer,
                        void *start)
{
        return add_item(ctx, NULL, writer, TYPE_OTHER, start);
}

void acpi_dump_items(enum acpi_dump_option option)
{
        int i;

        printf("Seq  Type       Base   Size  Device/Writer\n");
        printf("---  -----  --------   ----  -------------\n");
        for (i = 0; i < item_count; i++) {
                struct acpi_item *item = &acpi_item[i];

                printf("%3x  %-5s  %8lx  %5x  %s\n", i,
                       gen_type_str[item->type],
                       (ulong)map_to_sysmem(item->base), item->size,
                       item->dev ? item->dev->name : item->writer->name);
                if (option == ACPI_DUMP_CONTENTS) {
                        print_buffer(0, item->buf ? item->buf : item->base, 1,
                                     item->size, 0);
                        printf("\n");
                }
        }
}

static struct acpi_item *find_acpi_item(const char *devname)
{
        int i;

        for (i = 0; i < item_count; i++) {
                struct acpi_item *item = &acpi_item[i];

                if (item->dev && !strcmp(devname, item->dev->name))
                        return item;
        }

        return NULL;
}

/**
 * sort_acpi_item_type - Sort the ACPI items into the desired order
 *
 * This looks up the ordering in the device tree and then adds each item one by
 * one into the supplied buffer
 *
 * @ctx: ACPI context
 * @start: Start position to put the sorted items. The items will follow each
 *      other in sorted order
 * @type: Type of items to sort
 * Return: 0 if OK, -ve on error
 */
static int sort_acpi_item_type(struct acpi_ctx *ctx, void *start,
                               enum gen_type_t type)
{
        const u32 *order;
        int size;
        int count;
        void *ptr;
        void *end = ctx->current;

        ptr = start;
        order = ofnode_read_chosen_prop(type == TYPE_DSDT ?
                                        "u-boot,acpi-dsdt-order" :
                                        "u-boot,acpi-ssdt-order", &size);
        if (!order) {
                log_debug("Failed to find ordering, leaving as is\n");
                return 0;
        }

        /*
         * This algorithm rewrites the context buffer without changing its
         * length. So there is no need to update ctx-current
         */
        count = size / sizeof(u32);
        while (count--) {
                struct acpi_item *item;
                const char *name;
                ofnode node;

                node = ofnode_get_by_phandle(fdt32_to_cpu(*order++));
                name = ofnode_get_name(node);
                item = find_acpi_item(name);
                if (!item) {
                        log_err("Failed to find item '%s'\n", name);
                        return log_msg_ret("find", -ENOENT);
                }
                if (item->type == type) {
                        log_debug("   - add %s\n", item->dev->name);
                        memcpy(ptr, item->buf, item->size);
                        ptr += item->size;
                }
        }

        /*
         * If the sort order is missing an item then the output will be too
         * small. Report this error since the item needs to be added to the
         * ordering for the ACPI tables to be complete.
         */
        if (ptr != end) {
                log_warning("*** Missing bytes: ptr=%p, end=%p\n", ptr, end);
                return -ENXIO;
        }

        return 0;
}

acpi_method acpi_get_method(struct udevice *dev, enum method_t method)
{
        struct acpi_ops *aops;

        aops = device_get_acpi_ops(dev);
        if (aops) {
                switch (method) {
                case METHOD_WRITE_TABLES:
                        return aops->write_tables;
                case METHOD_FILL_SSDT:
                        return aops->fill_ssdt;
                case METHOD_INJECT_DSDT:
                        return aops->inject_dsdt;
                case METHOD_SETUP_NHLT:
                        return aops->setup_nhlt;
                }
        }

        return NULL;
}

int acpi_recurse_method(struct acpi_ctx *ctx, struct udevice *parent,
                        enum method_t method, enum gen_type_t type)
{
        struct udevice *dev;
        acpi_method func;
        int ret;

        func = acpi_get_method(parent, method);
        if (func) {
                log_debug("- method %d, %s %p\n", method, parent->name, func);
                ret = device_of_to_plat(parent);
                if (ret)
                        return log_msg_ret("ofdata", ret);
                ctx->tab_start = ctx->current;
                ret = func(parent, ctx);
                if (ret)
                        return log_msg_ret("func", ret);

                /* Add the item to the internal list */
                if (type != TYPE_NONE) {
                        ret = add_item(ctx, parent, NULL, type, ctx->tab_start);
                        if (ret)
                                return log_msg_ret("add", ret);
                }
        }
        device_foreach_child(dev, parent) {
                ret = acpi_recurse_method(ctx, dev, method, type);
                if (ret)
                        return log_msg_ret("recurse", ret);
        }

        return 0;
}

int acpi_fill_ssdt(struct acpi_ctx *ctx)
{
        void *start = ctx->current;
        int ret;

        log_debug("Writing SSDT tables\n");
        ret = acpi_recurse_method(ctx, dm_root(), METHOD_FILL_SSDT, TYPE_SSDT);
        log_debug("Writing SSDT finished, err=%d\n", ret);
        ret = sort_acpi_item_type(ctx, start, TYPE_SSDT);
        if (ret)
                return log_msg_ret("build", ret);

        return ret;
}

int acpi_inject_dsdt(struct acpi_ctx *ctx)
{
        void *start = ctx->current;
        int ret;

        log_debug("Writing DSDT tables\n");
        ret = acpi_recurse_method(ctx, dm_root(), METHOD_INJECT_DSDT,
                                  TYPE_DSDT);
        log_debug("Writing DSDT finished, err=%d\n", ret);
        ret = sort_acpi_item_type(ctx, start, TYPE_DSDT);
        if (ret)
                return log_msg_ret("build", ret);

        return ret;
}

void acpi_reset_items(void)
{
        item_count = 0;
}

int acpi_write_dev_tables(struct acpi_ctx *ctx)
{
        int ret;

        log_debug("Writing device tables\n");
        ret = acpi_recurse_method(ctx, dm_root(), METHOD_WRITE_TABLES,
                                  TYPE_NONE);
        log_debug("Writing finished, err=%d\n", ret);

        return ret;
}

int acpi_setup_nhlt(struct acpi_ctx *ctx, struct nhlt *nhlt)
{
        int ret;

        log_debug("Setup NHLT\n");
        ctx->nhlt = nhlt;
        ret = acpi_recurse_method(ctx, dm_root(), METHOD_SETUP_NHLT, TYPE_NONE);
        log_debug("Setup finished, err=%d\n", ret);

        return ret;
}