/*
 * drm_sysfs.c - Modifications to drm_sysfs_class.c to support
 *               extra sysfs attribute from DRM. Normal drm_sysfs_class
 *               does not allow adding attributes.
 *
 * Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
 * Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
 * Copyright (c) 2003-2004 IBM Corp.
 *
 * This file is released under the GPLv2
 *
 */

#include <linux/device.h>
#include <linux/kdev_t.h>
#include <linux/gfp.h>
#include <linux/err.h>
#include <linux/export.h>

#include <drm/drm_sysfs.h>
#include <drm/drm_core.h>
#include <drm/drmP.h>
#include "drm_internal.h"

#define to_drm_minor(d) dev_get_drvdata(d)
#define to_drm_connector(d) dev_get_drvdata(d)

static struct device_type drm_sysfs_device_minor = {
        .name = "drm_minor"
};

struct class *drm_class;

static char *drm_devnode(struct device *dev, umode_t *mode)
{
        return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
}

static CLASS_ATTR_STRING(version, S_IRUGO,
                CORE_NAME " "
                __stringify(CORE_MAJOR) "."
                __stringify(CORE_MINOR) "."
                __stringify(CORE_PATCHLEVEL) " "
                CORE_DATE);

/**
 * drm_sysfs_init - initialize sysfs helpers
 *
 * This is used to create the DRM class, which is the implicit parent of any
 * other top-level DRM sysfs objects.
 *
 * You must call drm_sysfs_destroy() to release the allocated resources.
 *
 * Return: 0 on success, negative error code on failure.
 */
int drm_sysfs_init(void)
{
        int err;

        drm_class = class_create(THIS_MODULE, "drm");
        if (IS_ERR(drm_class))
                return PTR_ERR(drm_class);

        err = class_create_file(drm_class, &class_attr_version.attr);
        if (err) {
                class_destroy(drm_class);
                drm_class = NULL;
                return err;
        }

        drm_class->devnode = drm_devnode;
        return 0;
}

/**
 * drm_sysfs_destroy - destroys DRM class
 *
 * Destroy the DRM device class.
 */
void drm_sysfs_destroy(void)
{
        if (IS_ERR_OR_NULL(drm_class))
                return;
        class_remove_file(drm_class, &class_attr_version.attr);
        class_destroy(drm_class);
        drm_class = NULL;
}

/*
 * Connector properties
 */
static ssize_t status_store(struct device *device,
                           struct device_attribute *attr,
                           const char *buf, size_t count)
{
        struct drm_connector *connector = to_drm_connector(device);
        struct drm_device *dev = connector->dev;
        enum drm_connector_force old_force;
        int ret;

        ret = mutex_lock_interruptible(&dev->mode_config.mutex);
        if (ret)
                return ret;

        old_force = connector->force;

        if (sysfs_streq(buf, "detect"))
                connector->force = 0;
        else if (sysfs_streq(buf, "on"))
                connector->force = DRM_FORCE_ON;
        else if (sysfs_streq(buf, "on-digital"))
                connector->force = DRM_FORCE_ON_DIGITAL;
        else if (sysfs_streq(buf, "off"))
                connector->force = DRM_FORCE_OFF;
        else
                ret = -EINVAL;

        if (old_force != connector->force || !connector->force) {
                DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
                              connector->base.id,
                              connector->name,
                              old_force, connector->force);

                connector->funcs->fill_modes(connector,
                                             dev->mode_config.max_width,
                                             dev->mode_config.max_height);
        }

        mutex_unlock(&dev->mode_config.mutex);

        return ret ? ret : count;
}

static ssize_t status_show(struct device *device,
                           struct device_attribute *attr,
                           char *buf)
{
        struct drm_connector *connector = to_drm_connector(device);
        enum drm_connector_status status;

        status = READ_ONCE(connector->status);

        return snprintf(buf, PAGE_SIZE, "%s\n",
                        drm_get_connector_status_name(status));
}

static ssize_t dpms_show(struct device *device,
                           struct device_attribute *attr,
                           char *buf)
{
        struct drm_connector *connector = to_drm_connector(device);
        int dpms;

        dpms = READ_ONCE(connector->dpms);

        return snprintf(buf, PAGE_SIZE, "%s\n",
                        drm_get_dpms_name(dpms));
}

static ssize_t enabled_show(struct device *device,
                            struct device_attribute *attr,
                           char *buf)
{
        struct drm_connector *connector = to_drm_connector(device);
        bool enabled;

        enabled = READ_ONCE(connector->encoder);

        return snprintf(buf, PAGE_SIZE, enabled ? "enabled\n" : "disabled\n");
}

static ssize_t edid_show(struct file *filp, struct kobject *kobj,
                         struct bin_attribute *attr, char *buf, loff_t off,
                         size_t count)
{
        struct device *connector_dev = kobj_to_dev(kobj);
        struct drm_connector *connector = to_drm_connector(connector_dev);
        unsigned char *edid;
        size_t size;
        ssize_t ret = 0;

        mutex_lock(&connector->dev->mode_config.mutex);
        if (!connector->edid_blob_ptr)
                goto unlock;

        edid = connector->edid_blob_ptr->data;
        size = connector->edid_blob_ptr->length;
        if (!edid)
                goto unlock;

        if (off >= size)
                goto unlock;

        if (off + count > size)
                count = size - off;
        memcpy(buf, edid + off, count);

        ret = count;
unlock:
        mutex_unlock(&connector->dev->mode_config.mutex);

        return ret;
}

static ssize_t modes_show(struct device *device,
                           struct device_attribute *attr,
                           char *buf)
{
        struct drm_connector *connector = to_drm_connector(device);
        struct drm_display_mode *mode;
        int written = 0;

        mutex_lock(&connector->dev->mode_config.mutex);
        list_for_each_entry(mode, &connector->modes, head) {
                written += snprintf(buf + written, PAGE_SIZE - written, "%s\n",
                                    mode->name);
        }
        mutex_unlock(&connector->dev->mode_config.mutex);

        return written;
}

static DEVICE_ATTR_RW(status);
static DEVICE_ATTR_RO(enabled);
static DEVICE_ATTR_RO(dpms);
static DEVICE_ATTR_RO(modes);

static struct attribute *connector_dev_attrs[] = {
        &dev_attr_status.attr,
        &dev_attr_enabled.attr,
        &dev_attr_dpms.attr,
        &dev_attr_modes.attr,
        NULL
};

static struct bin_attribute edid_attr = {
        .attr.name = "edid",
        .attr.mode = 0444,
        .size = 0,
        .read = edid_show,
};

static struct bin_attribute *connector_bin_attrs[] = {
        &edid_attr,
        NULL
};

static const struct attribute_group connector_dev_group = {
        .attrs = connector_dev_attrs,
        .bin_attrs = connector_bin_attrs,
};

static const struct attribute_group *connector_dev_groups[] = {
        &connector_dev_group,
        NULL
};

/**
 * drm_sysfs_connector_add - add a connector to sysfs
 * @connector: connector to add
 *
 * Create a connector device in sysfs, along with its associated connector
 * properties (so far, connection status, dpms, mode list & edid) and
 * generate a hotplug event so userspace knows there's a new connector
 * available.
 */
int drm_sysfs_connector_add(struct drm_connector *connector)
{
        struct drm_device *dev = connector->dev;

        if (connector->kdev)
                return 0;

        connector->kdev =
                device_create_with_groups(drm_class, dev->primary->kdev, 0,
                                          connector, connector_dev_groups,
                                          "card%d-%s", dev->primary->index,
                                          connector->name);
        DRM_DEBUG("adding \"%s\" to sysfs\n",
                  connector->name);

        if (IS_ERR(connector->kdev)) {
                DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
                return PTR_ERR(connector->kdev);
        }

        /* Let userspace know we have a new connector */
        drm_sysfs_hotplug_event(dev);

        return 0;
}

/**
 * drm_sysfs_connector_remove - remove an connector device from sysfs
 * @connector: connector to remove
 *
 * Remove @connector and its associated attributes from sysfs.  Note that
 * the device model core will take care of sending the "remove" uevent
 * at this time, so we don't need to do it.
 *
 * Note:
 * This routine should only be called if the connector was previously
 * successfully registered.  If @connector hasn't been registered yet,
 * you'll likely see a panic somewhere deep in sysfs code when called.
 */
void drm_sysfs_connector_remove(struct drm_connector *connector)
{
        if (!connector->kdev)
                return;
        DRM_DEBUG("removing \"%s\" from sysfs\n",
                  connector->name);

        device_unregister(connector->kdev);
        connector->kdev = NULL;
}

/**
 * drm_sysfs_hotplug_event - generate a DRM uevent
 * @dev: DRM device
 *
 * Send a uevent for the DRM device specified by @dev.  Currently we only
 * set HOTPLUG=1 in the uevent environment, but this could be expanded to
 * deal with other types of events.
 */
void drm_sysfs_hotplug_event(struct drm_device *dev)
{
        char *event_string = "HOTPLUG=1";
        char *envp[] = { event_string, NULL };

        DRM_DEBUG("generating hotplug event\n");

        kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
}
EXPORT_SYMBOL(drm_sysfs_hotplug_event);

static void drm_sysfs_release(struct device *dev)
{
        kfree(dev);
}

/**
 * drm_sysfs_minor_alloc() - Allocate sysfs device for given minor
 * @minor: minor to allocate sysfs device for
 *
 * This allocates a new sysfs device for @minor and returns it. The device is
 * not registered nor linked. The caller has to use device_add() and
 * device_del() to register and unregister it.
 *
 * Note that dev_get_drvdata() on the new device will return the minor.
 * However, the device does not hold a ref-count to the minor nor to the
 * underlying drm_device. This is unproblematic as long as you access the
 * private data only in sysfs callbacks. device_del() disables those
 * synchronously, so they cannot be called after you cleanup a minor.
 */
struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
{
        const char *minor_str;
        struct device *kdev;
        int r;

        if (minor->type == DRM_MINOR_CONTROL)
                minor_str = "controlD%d";
        else if (minor->type == DRM_MINOR_RENDER)
                minor_str = "renderD%d";
        else
                minor_str = "card%d";

        kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
        if (!kdev)
                return ERR_PTR(-ENOMEM);

        device_initialize(kdev);
        kdev->devt = MKDEV(DRM_MAJOR, minor->index);
        kdev->class = drm_class;
        kdev->type = &drm_sysfs_device_minor;
        kdev->parent = minor->dev->dev;
        kdev->release = drm_sysfs_release;
        dev_set_drvdata(kdev, minor);

        r = dev_set_name(kdev, minor_str, minor->index);
        if (r < 0)
                goto err_free;

        return kdev;

err_free:
        put_device(kdev);
        return ERR_PTR(r);
}

/**
 * drm_class_device_register - Register a struct device in the drm class.
 *
 * @dev: pointer to struct device to register.
 *
 * @dev should have all relevant members pre-filled with the exception
 * of the class member. In particular, the device_type member must
 * be set.
 */

int drm_class_device_register(struct device *dev)
{
        if (!drm_class || IS_ERR(drm_class))
                return -ENOENT;

        dev->class = drm_class;
        return device_register(dev);
}
EXPORT_SYMBOL_GPL(drm_class_device_register);

void drm_class_device_unregister(struct device *dev)
{
        return device_unregister(dev);
}
EXPORT_SYMBOL_GPL(drm_class_device_unregister);