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Commit 9060d7f4 authored by Noralf Trønnes's avatar Noralf Trønnes
Browse files

drm/fb-helper: Finish the generic fbdev emulation 



This adds a drm_fbdev_generic_setup() function that sets up generic
fbdev emulation with client callbacks for restore, hotplug and
unregister.

Signed-off-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180703160354.59955-7-noralf@tronnes.org
parent e896c132

drivers/gpu/drm/drm_fb_helper.c

+117 −0
Original line number Diff line number Diff line
@@ -67,6 +67,9 @@ static DEFINE_MUTEX(kernel_fb_helper_lock); 
 * helper functions used by many drivers to implement the kernel mode setting

 * interfaces.

 *

 * Drivers that support a dumb buffer with a virtual address and mmap support,

 * should try out the generic fbdev emulation using drm_fbdev_generic_setup().

 *

 * Setup fbdev emulation by calling drm_fb_helper_fbdev_setup() and tear it

 * down by calling drm_fb_helper_fbdev_teardown().

 *
@@ -3118,6 +3121,120 @@ int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper, 
}

EXPORT_SYMBOL(drm_fb_helper_generic_probe);



static const struct drm_fb_helper_funcs drm_fb_helper_generic_funcs = {

	.fb_probe = drm_fb_helper_generic_probe,

};



static void drm_fbdev_client_unregister(struct drm_client_dev *client)

{

	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);



	if (fb_helper->fbdev) {

		drm_fb_helper_unregister_fbi(fb_helper);

		/* drm_fbdev_fb_destroy() takes care of cleanup */

		return;

	}



	/* Did drm_fb_helper_fbdev_setup() run? */

	if (fb_helper->dev)

		drm_fb_helper_fini(fb_helper);



	drm_client_release(client);

	kfree(fb_helper);

}



static int drm_fbdev_client_restore(struct drm_client_dev *client)

{

	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);



	drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);



	return 0;

}



static int drm_fbdev_client_hotplug(struct drm_client_dev *client)

{

	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);

	struct drm_device *dev = client->dev;

	int ret;



	/* If drm_fb_helper_fbdev_setup() failed, we only try once */

	if (!fb_helper->dev && fb_helper->funcs)

		return 0;



	if (dev->fb_helper)

		return drm_fb_helper_hotplug_event(dev->fb_helper);



	if (!dev->mode_config.num_connector)

		return 0;



	ret = drm_fb_helper_fbdev_setup(dev, fb_helper, &drm_fb_helper_generic_funcs,

					fb_helper->preferred_bpp, 0);

	if (ret) {

		fb_helper->dev = NULL;

		fb_helper->fbdev = NULL;

		return ret;

	}



	return 0;

}



static const struct drm_client_funcs drm_fbdev_client_funcs = {

	.owner		= THIS_MODULE,

	.unregister	= drm_fbdev_client_unregister,

	.restore	= drm_fbdev_client_restore,

	.hotplug	= drm_fbdev_client_hotplug,

};



/**

 * drm_fb_helper_generic_fbdev_setup() - Setup generic fbdev emulation

 * @dev: DRM device

 * @preferred_bpp: Preferred bits per pixel for the device.

 *                 @dev->mode_config.preferred_depth is used if this is zero.

 *

 * This function sets up generic fbdev emulation for drivers that supports

 * dumb buffers with a virtual address and that can be mmap'ed.

 *

 * Restore, hotplug events and teardown are all taken care of. Drivers that do

 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.

 * Simple drivers might use drm_mode_config_helper_suspend().

 *

 * Drivers that set the dirty callback on their framebuffer will get a shadow

 * fbdev buffer that is blitted onto the real buffer. This is done in order to

 * make deferred I/O work with all kinds of buffers.

 *

 * This function is safe to call even when there are no connectors present.

 * Setup will be retried on the next hotplug event.

 *

 * Returns:

 * Zero on success or negative error code on failure.

 */

int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)

{

	struct drm_fb_helper *fb_helper;

	int ret;



	if (!drm_fbdev_emulation)

		return 0;



	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);

	if (!fb_helper)

		return -ENOMEM;



	ret = drm_client_new(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);

	if (ret) {

		kfree(fb_helper);

		return ret;

	}



	fb_helper->preferred_bpp = preferred_bpp;



	drm_fbdev_client_hotplug(&fb_helper->client);



	return 0;

}

EXPORT_SYMBOL(drm_fbdev_generic_setup);



/* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)

 * but the module doesn't depend on any fb console symbols.  At least

 * attempt to load fbcon to avoid leaving the system without a usable console.

include/drm/drm_fb_helper.h

+7 −0
Original line number Diff line number Diff line
@@ -354,6 +354,7 @@ void drm_fb_helper_output_poll_changed(struct drm_device *dev); 


int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,

				struct drm_fb_helper_surface_size *sizes);

int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp);

#else

static inline void drm_fb_helper_prepare(struct drm_device *dev,

					struct drm_fb_helper *helper,
@@ -595,6 +596,12 @@ drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper, 
	return 0;

}



static inline int

drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)

{

	return 0;

}



#endif



static inline int