drm/linux-core/drm_sysfs.c

/*
 * 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/err.h>

#include "drm_core.h"
#include "drmP.h"

#define to_drm_minor(d) container_of(d, struct drm_minor, kdev)

/**
 * drm_sysfs_suspend - DRM class suspend hook
 * @dev: Linux device to suspend
 * @state: power state to enter
 *
 * Just figures out what the actual struct drm_device associated with
 * @dev is and calls its suspend hook, if present.
 */
static int drm_sysfs_suspend(struct device *dev, pm_message_t state)
{
	struct drm_minor *drm_minor = to_drm_minor(dev);
	struct drm_device *drm_dev = drm_minor->dev;

	printk(KERN_ERR "%s\n", __FUNCTION__);

	if (drm_minor->type == DRM_MINOR_CONTROL)
		if (drm_dev->driver->suspend)
			return drm_dev->driver->suspend(drm_dev, state);

	return 0;
}

/**
 * drm_sysfs_resume - DRM class resume hook
 * @dev: Linux device to resume
 *
 * Just figures out what the actual struct drm_device associated with
 * @dev is and calls its resume hook, if present.
 */
static int drm_sysfs_resume(struct device *dev)
{
	struct drm_minor *drm_minor = to_drm_minor(dev);
	struct drm_device *drm_dev = drm_minor->dev;

	if (drm_minor->type == DRM_MINOR_CONTROL)
		if (drm_dev->driver->resume)
			return drm_dev->driver->resume(drm_dev);

	return 0;
}

/* Display the version of drm_core. This doesn't work right in current design */
static ssize_t version_show(struct class *dev, char *buf)
{
	return sprintf(buf, "%s %d.%d.%d %s\n", CORE_NAME, CORE_MAJOR,
		       CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
}

static CLASS_ATTR(version, S_IRUGO, version_show, NULL);

/**
 * drm_sysfs_create - create a struct drm_sysfs_class structure
 * @owner: pointer to the module that is to "own" this struct drm_sysfs_class
 * @name: pointer to a string for the name of this class.
 *
 * This is used to create DRM class pointer that can then be used
 * in calls to drm_sysfs_device_add().
 *
 * Note, the pointer created here is to be destroyed when finished by making a
 * call to drm_sysfs_destroy().
 */
struct class *drm_sysfs_create(struct module *owner, char *name)
{
	struct class *class;
	int err;

	class = class_create(owner, name);
	if (IS_ERR(class)) {
		err = PTR_ERR(class);
		goto err_out;
	}

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22))
	class->suspend = drm_sysfs_suspend;
	class->resume = drm_sysfs_resume;
#endif

	err = class_create_file(class, &class_attr_version);
	if (err)
		goto err_out_class;

	return class;

err_out_class:
	class_destroy(class);
err_out:
	return ERR_PTR(err);
}

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

static ssize_t show_dri(struct device *device, struct device_attribute *attr,
			char *buf)
{
	struct drm_minor *drm_minor = to_drm_minor(device);
	struct drm_device *drm_dev = drm_minor->dev;
	if (drm_dev->driver->dri_library_name)
		return drm_dev->driver->dri_library_name(drm_dev, buf);
	return snprintf(buf, PAGE_SIZE, "%s\n", drm_dev->driver->pci_driver.name);
}

/**
 * drm_sysfs_device_release - do nothing
 * @dev: Linux device
 *
 * Normally, this would free the DRM device associated with @dev, along
 * with cleaning up any other stuff.  But we do that in the DRM core, so
 * this function can just return and hope that the core does its job.
 */
static void drm_sysfs_device_release(struct device *dev)
{
	return;
}

/*
 * Connector properties
 */
static ssize_t status_show(struct device *device,
			   struct device_attribute *attr,
			   char *buf)
{
	struct drm_connector *connector = container_of(device, struct drm_connector, kdev);
	return snprintf(buf, PAGE_SIZE, "%s",
			drm_get_connector_status_name(connector->funcs->detect(connector)));
}

static ssize_t dpms_show(struct device *device,
			   struct device_attribute *attr,
			   char *buf)
{
	struct drm_connector *connector = container_of(device, struct drm_connector, kdev);
	struct drm_device *dev = connector->dev;
	uint64_t dpms_status;
	int ret;

	ret = drm_connector_property_get_value(connector,
					    dev->mode_config.dpms_property,
					    &dpms_status);
	if (ret)
		return 0;
	
	return snprintf(buf, PAGE_SIZE, "%s", drm_get_dpms_name((int)dpms_status));
}

static ssize_t edid_show(struct kobject *kobj, struct bin_attribute *attr,
			 char *buf, loff_t off, size_t count)
{
	struct device *connector_dev = container_of(kobj, struct device, kobj);
	struct drm_connector *connector = container_of(connector_dev, struct drm_connector,
						 kdev);
	unsigned char *edid;
	size_t size;

	if (!connector->edid_blob_ptr)
		return 0;

	edid = connector->edid_blob_ptr->data;
	size = connector->edid_blob_ptr->length;
	if (!edid)
		return 0;
		
	if (off >= size)
		return 0;

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

	return count;
}

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

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

	return written;
}

static struct device_attribute connector_attrs[] = {
	__ATTR_RO(status),
	__ATTR_RO(dpms),
	__ATTR_RO(modes),
};

static struct bin_attribute edid_attr = {
	.attr.name = "edid",
	.size = 128,
	.read = edid_show,
};

/**
 * drm_sysfs_connector_add - add an connector to sysfs
 * @connector: connector to add
 *
 * Create an 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.
 *
 * Note:
 * This routine should only be called *once* for each DRM minor registered.
 * A second call for an already registered device will trigger the BUG_ON
 * below.
 */
int drm_sysfs_connector_add(struct drm_connector *connector)
{
	struct drm_device *dev = connector->dev;
	int ret = 0, i, j;

	/* We shouldn't get called more than once for the same connector */
	BUG_ON(device_is_registered(&connector->kdev));

	connector->kdev.parent = &dev->primary->kdev;
	connector->kdev.class = drm_class;
	connector->kdev.release = drm_sysfs_device_release;

	DRM_DEBUG("adding \"%s\" to sysfs\n",
		  drm_get_connector_name(connector));

	snprintf(connector->kdev.bus_id, BUS_ID_SIZE, "card%d-%s",
		 dev->primary->index, drm_get_connector_name(connector));
	ret = device_register(&connector->kdev);

	if (ret) {
		DRM_ERROR("failed to register connector device: %d\n", ret);
		goto out;
	}

	for (i = 0; i < ARRAY_SIZE(connector_attrs); i++) {
		ret = device_create_file(&connector->kdev, &connector_attrs[i]);
		if (ret)
			goto err_out_files;
	}

	ret = sysfs_create_bin_file(&connector->kdev.kobj, &edid_attr);
	if (ret)
		goto err_out_files;

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

	return 0;

err_out_files:
	if (i > 0)
		for (j = 0; j < i; j++)
			device_remove_file(&connector->kdev, &connector_attrs[i]);
	device_unregister(&connector->kdev);

out:
	return ret;
}
EXPORT_SYMBOL(drm_sysfs_connector_add);

/**
 * 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)
{
	int i;

	DRM_DEBUG("removing \"%s\" from sysfs\n",
		  drm_get_connector_name(connector));

	for (i = 0; i < ARRAY_SIZE(connector_attrs); i++)
		device_remove_file(&connector->kdev, &connector_attrs[i]);
	sysfs_remove_bin_file(&connector->kdev.kobj, &edid_attr);
	device_unregister(&connector->kdev);
}
EXPORT_SYMBOL(drm_sysfs_connector_remove);

/**
 * 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);
}

static struct device_attribute dri_attrs[] = {
	__ATTR(dri_library_name, S_IRUGO, show_dri, NULL),
};

/**
 * drm_sysfs_device_add - adds a class device to sysfs for a character driver
 * @dev: DRM device to be added
 * @head: DRM head in question
 *
 * Add a DRM device to the DRM's device model class.  We use @dev's PCI device
 * as the parent for the Linux device, and make sure it has a file containing
 * the driver we're using (for userspace compatibility).
 *
 * Note:
 * This routine should only be called *once* for each DRM minor registered.
 * A second call for an already registered device will trigger the BUG_ON
 * below.
 */
int drm_sysfs_device_add(struct drm_minor *minor)
{
	int err;
	int i, j;
	char *minor_str;

	minor->kdev.parent = &minor->dev->pdev->dev;
	minor->kdev.class = drm_class;
	minor->kdev.release = drm_sysfs_device_release;
	minor->kdev.devt = minor->device;
	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";
	
	snprintf(minor->kdev.bus_id, BUS_ID_SIZE, minor_str, minor->index);

	/* Shouldn't register more than once */
	BUG_ON(device_is_registered(&minor->kdev));

	DRM_DEBUG("registering DRM device \"%s\"\n", minor->kdev.bus_id);

	err = device_register(&minor->kdev);
	if (err) {
		DRM_ERROR("device add failed: %d\n", err);
		goto err_out;
	}

	for (i = 0; i < ARRAY_SIZE(dri_attrs); i++) {
		err = device_create_file(&minor->kdev, &dri_attrs[i]);
		if (err)
			goto err_out_files;
	}

	return 0;

err_out_files:
	if (i > 0)
		for (j = 0; j < i; j++)
			device_remove_file(&minor->kdev, &dri_attrs[i]);
	device_unregister(&minor->kdev);
err_out:

	return err;
}

/**
 * drm_sysfs_device_remove - remove DRM device
 * @dev: DRM device to remove
 *
 * This call unregisters and cleans up a class device that was created with a
 * call to drm_sysfs_device_add()
 */
void drm_sysfs_device_remove(struct drm_minor *minor)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(dri_attrs); i++)
		device_remove_file(&minor->kdev, &dri_attrs[i]);
	device_unregister(&minor->kdev);
}