// SPDX-License-Identifier: MIT
/*
 * Copyright © 2022 Intel Corporation
 */

#include <drm/drm_device.h>
#include <linux/device.h>
#include <linux/kobject.h>
#include <linux/printk.h>
#include <linux/sysfs.h>

#include "i915_drv.h"
#include "i915_sysfs.h"
#include "intel_gt.h"
#include "intel_gt_print.h"
#include "intel_gt_sysfs.h"
#include "intel_gt_sysfs_pm.h"
#include "intel_gt_types.h"
#include "intel_rc6.h"

bool is_object_gt(struct kobject *kobj)
{
        return !strncmp(kobj->name, "gt", 2);
}

struct intel_gt *intel_gt_sysfs_get_drvdata(struct kobject *kobj,
                                            const char *name)
{
        /*
         * We are interested at knowing from where the interface
         * has been called, whether it's called from gt/ or from
         * the parent directory.
         * From the interface position it depends also the value of
         * the private data.
         * If the interface is called from gt/ then private data is
         * of the "struct intel_gt *" type, otherwise it's * a
         * "struct drm_i915_private *" type.
         */
        if (!is_object_gt(kobj)) {
                struct device *dev = kobj_to_dev(kobj);
                struct drm_i915_private *i915 = kdev_minor_to_i915(dev);

                return to_gt(i915);
        }

        return kobj_to_gt(kobj);
}

static struct kobject *gt_get_parent_obj(struct intel_gt *gt)
{
        return &gt->i915->drm.primary->kdev->kobj;
}

static ssize_t id_show(struct kobject *kobj,
                       struct kobj_attribute *attr,
                       char *buf)
{
        struct intel_gt *gt = intel_gt_sysfs_get_drvdata(kobj, attr->attr.name);

        return sysfs_emit(buf, "%u\n", gt->info.id);
}
static struct kobj_attribute attr_id = __ATTR_RO(id);

static struct attribute *id_attrs[] = {
        &attr_id.attr,
        NULL,
};
ATTRIBUTE_GROUPS(id);

/* A kobject needs a release() method even if it does nothing */
static void kobj_gt_release(struct kobject *kobj)
{
}

static const struct kobj_type kobj_gt_type = {
        .release = kobj_gt_release,
        .sysfs_ops = &kobj_sysfs_ops,
        .default_groups = id_groups,
};

void intel_gt_sysfs_register(struct intel_gt *gt)
{
        /*
         * We need to make things right with the
         * ABI compatibility. The files were originally
         * generated under the parent directory.
         *
         * We generate the files only for gt 0
         * to avoid duplicates.
         */
        if (gt_is_root(gt))
                intel_gt_sysfs_pm_init(gt, gt_get_parent_obj(gt));

        /* init and xfer ownership to sysfs tree */
        if (kobject_init_and_add(&gt->sysfs_gt, &kobj_gt_type,
                                 gt->i915->sysfs_gt, "gt%d", gt->info.id))
                goto exit_fail;

        gt->sysfs_defaults = kobject_create_and_add(".defaults", &gt->sysfs_gt);
        if (!gt->sysfs_defaults)
                goto exit_fail;

        intel_gt_sysfs_pm_init(gt, &gt->sysfs_gt);

        return;

exit_fail:
        kobject_put(&gt->sysfs_gt);
        gt_warn(gt, "failed to initialize sysfs root\n");
}

void intel_gt_sysfs_unregister(struct intel_gt *gt)
{
        kobject_put(gt->sysfs_defaults);
        kobject_put(&gt->sysfs_gt);
}