[linux-block.git] / drivers / gpu / drm / drm_fbdev_generic.c

// SPDX-License-Identifier: MIT

#include <linux/moduleparam.h>
#include <linux/vmalloc.h>

#include <drm/drm_crtc_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem.h>
#include <drm/drm_print.h>

#include <drm/drm_fbdev_generic.h>

/* @user: 1=userspace, 0=fbcon */
static int drm_fbdev_generic_fb_open(struct fb_info *info, int user)
{
	struct drm_fb_helper *fb_helper = info->par;

	/* No need to take a ref for fbcon because it unbinds on unregister */
	if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
		return -ENODEV;

	return 0;
}

static int drm_fbdev_generic_fb_release(struct fb_info *info, int user)
{
	struct drm_fb_helper *fb_helper = info->par;

	if (user)
		module_put(fb_helper->dev->driver->fops->owner);

	return 0;
}

FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(drm_fbdev_generic,
				   drm_fb_helper_damage_range,
				   drm_fb_helper_damage_area);

static void drm_fbdev_generic_fb_destroy(struct fb_info *info)
{
	struct drm_fb_helper *fb_helper = info->par;
	void *shadow = info->screen_buffer;

	if (!fb_helper->dev)
		return;

	fb_deferred_io_cleanup(info);
	drm_fb_helper_fini(fb_helper);
	vfree(shadow);
	drm_client_framebuffer_delete(fb_helper->buffer);

	drm_client_release(&fb_helper->client);
	drm_fb_helper_unprepare(fb_helper);
	kfree(fb_helper);
}

static const struct fb_ops drm_fbdev_generic_fb_ops = {
	.owner		= THIS_MODULE,
	.fb_open	= drm_fbdev_generic_fb_open,
	.fb_release	= drm_fbdev_generic_fb_release,
	FB_DEFAULT_DEFERRED_OPS(drm_fbdev_generic),
	DRM_FB_HELPER_DEFAULT_OPS,
	.fb_destroy	= drm_fbdev_generic_fb_destroy,
};

/*
 * This function uses the client API to create a framebuffer backed by a dumb buffer.
 */
static int drm_fbdev_generic_helper_fb_probe(struct drm_fb_helper *fb_helper,
					     struct drm_fb_helper_surface_size *sizes)
{
	struct drm_client_dev *client = &fb_helper->client;
	struct drm_device *dev = fb_helper->dev;
	struct drm_client_buffer *buffer;
	struct fb_info *info;
	size_t screen_size;
	void *screen_buffer;
	u32 format;
	int ret;

	drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
		    sizes->surface_width, sizes->surface_height,
		    sizes->surface_bpp);

	format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
	buffer = drm_client_framebuffer_create(client, sizes->surface_width,
					       sizes->surface_height, format);
	if (IS_ERR(buffer))
		return PTR_ERR(buffer);

	fb_helper->buffer = buffer;
	fb_helper->fb = buffer->fb;

	screen_size = buffer->gem->size;
	screen_buffer = vzalloc(screen_size);
	if (!screen_buffer) {
		ret = -ENOMEM;
		goto err_drm_client_framebuffer_delete;
	}

	info = drm_fb_helper_alloc_info(fb_helper);
	if (IS_ERR(info)) {
		ret = PTR_ERR(info);
		goto err_vfree;
	}

	drm_fb_helper_fill_info(info, fb_helper, sizes);

	info->fbops = &drm_fbdev_generic_fb_ops;

	/* screen */
	info->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
	info->screen_buffer = screen_buffer;
	info->fix.smem_start = page_to_phys(vmalloc_to_page(info->screen_buffer));
	info->fix.smem_len = screen_size;

	/* deferred I/O */
	fb_helper->fbdefio.delay = HZ / 20;
	fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;

	info->fbdefio = &fb_helper->fbdefio;
	ret = fb_deferred_io_init(info);
	if (ret)
		goto err_drm_fb_helper_release_info;

	return 0;

err_drm_fb_helper_release_info:
	drm_fb_helper_release_info(fb_helper);
err_vfree:
	vfree(screen_buffer);
err_drm_client_framebuffer_delete:
	fb_helper->fb = NULL;
	fb_helper->buffer = NULL;
	drm_client_framebuffer_delete(buffer);
	return ret;
}

static void drm_fbdev_generic_damage_blit_real(struct drm_fb_helper *fb_helper,
					       struct drm_clip_rect *clip,
					       struct iosys_map *dst)
{
	struct drm_framebuffer *fb = fb_helper->fb;
	size_t offset = clip->y1 * fb->pitches[0];
	size_t len = clip->x2 - clip->x1;
	unsigned int y;
	void *src;

	switch (drm_format_info_bpp(fb->format, 0)) {
	case 1:
		offset += clip->x1 / 8;
		len = DIV_ROUND_UP(len + clip->x1 % 8, 8);
		break;
	case 2:
		offset += clip->x1 / 4;
		len = DIV_ROUND_UP(len + clip->x1 % 4, 4);
		break;
	case 4:
		offset += clip->x1 / 2;
		len = DIV_ROUND_UP(len + clip->x1 % 2, 2);
		break;
	default:
		offset += clip->x1 * fb->format->cpp[0];
		len *= fb->format->cpp[0];
		break;
	}

	src = fb_helper->info->screen_buffer + offset;
	iosys_map_incr(dst, offset); /* go to first pixel within clip rect */

	for (y = clip->y1; y < clip->y2; y++) {
		iosys_map_memcpy_to(dst, 0, src, len);
		iosys_map_incr(dst, fb->pitches[0]);
		src += fb->pitches[0];
	}
}

static int drm_fbdev_generic_damage_blit(struct drm_fb_helper *fb_helper,
					 struct drm_clip_rect *clip)
{
	struct drm_client_buffer *buffer = fb_helper->buffer;
	struct iosys_map map, dst;
	int ret;

	/*
	 * We have to pin the client buffer to its current location while
	 * flushing the shadow buffer. In the general case, concurrent
	 * modesetting operations could try to move the buffer and would
	 * fail. The modeset has to be serialized by acquiring the reservation
	 * object of the underlying BO here.
	 *
	 * For fbdev emulation, we only have to protect against fbdev modeset
	 * operations. Nothing else will involve the client buffer's BO. So it
	 * is sufficient to acquire struct drm_fb_helper.lock here.
	 */
	mutex_lock(&fb_helper->lock);

	ret = drm_client_buffer_vmap(buffer, &map);
	if (ret)
		goto out;

	dst = map;
	drm_fbdev_generic_damage_blit_real(fb_helper, clip, &dst);

	drm_client_buffer_vunmap(buffer);

out:
	mutex_unlock(&fb_helper->lock);

	return ret;
}

static int drm_fbdev_generic_helper_fb_dirty(struct drm_fb_helper *helper,
					     struct drm_clip_rect *clip)
{
	struct drm_device *dev = helper->dev;
	int ret;

	/* Call damage handlers only if necessary */
	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
		return 0;

	ret = drm_fbdev_generic_damage_blit(helper, clip);
	if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
		return ret;

	if (helper->fb->funcs->dirty) {
		ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
		if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
			return ret;
	}

	return 0;
}

static const struct drm_fb_helper_funcs drm_fbdev_generic_helper_funcs = {
	.fb_probe = drm_fbdev_generic_helper_fb_probe,
	.fb_dirty = drm_fbdev_generic_helper_fb_dirty,
};

static void drm_fbdev_generic_client_unregister(struct drm_client_dev *client)
{
	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);

	if (fb_helper->info) {
		drm_fb_helper_unregister_info(fb_helper);
	} else {
		drm_client_release(&fb_helper->client);
		drm_fb_helper_unprepare(fb_helper);
		kfree(fb_helper);
	}
}

static int drm_fbdev_generic_client_restore(struct drm_client_dev *client)
{
	drm_fb_helper_lastclose(client->dev);

	return 0;
}

static int drm_fbdev_generic_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 (dev->fb_helper)
		return drm_fb_helper_hotplug_event(dev->fb_helper);

	ret = drm_fb_helper_init(dev, fb_helper);
	if (ret)
		goto err_drm_err;

	if (!drm_drv_uses_atomic_modeset(dev))
		drm_helper_disable_unused_functions(dev);

	ret = drm_fb_helper_initial_config(fb_helper);
	if (ret)
		goto err_drm_fb_helper_fini;

	return 0;

err_drm_fb_helper_fini:
	drm_fb_helper_fini(fb_helper);
err_drm_err:
	drm_err(dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);
	return ret;
}

static const struct drm_client_funcs drm_fbdev_generic_client_funcs = {
	.owner		= THIS_MODULE,
	.unregister	= drm_fbdev_generic_client_unregister,
	.restore	= drm_fbdev_generic_client_restore,
	.hotplug	= drm_fbdev_generic_client_hotplug,
};

/**
 * drm_fbdev_generic_setup() - Setup generic fbdev emulation
 * @dev: DRM device
 * @preferred_bpp: Preferred bits per pixel for the device.
 *
 * This function sets up generic fbdev emulation for drivers that supports
 * dumb buffers with a virtual address and that can be mmap'ed.
 * drm_fbdev_generic_setup() shall be called after the DRM driver registered
 * the new DRM device with drm_dev_register().
 *
 * 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().
 *
 * In order to provide fixed mmap-able memory ranges, generic fbdev emulation
 * uses a shadow buffer in system memory. The implementation blits the shadow
 * fbdev buffer onto the real buffer in regular intervals.
 *
 * This function is safe to call even when there are no connectors present.
 * Setup will be retried on the next hotplug event.
 *
 * The fbdev is destroyed by drm_dev_unregister().
 */
void drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
{
	struct drm_fb_helper *fb_helper;
	int ret;

	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");

	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
	if (!fb_helper)
		return;
	drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_generic_helper_funcs);

	ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_generic_client_funcs);
	if (ret) {
		drm_err(dev, "Failed to register client: %d\n", ret);
		goto err_drm_client_init;
	}

	drm_client_register(&fb_helper->client);

	return;

err_drm_client_init:
	drm_fb_helper_unprepare(fb_helper);
	kfree(fb_helper);
	return;
}
EXPORT_SYMBOL(drm_fbdev_generic_setup);
Commit	Line	Data
8ab59da2 TZ	1	// SPDX-License-Identifier: MIT
	2
	3	#include <linux/moduleparam.h>
478f6213	4	#include <linux/vmalloc.h>
8ab59da2 TZ	5
	6	#include <drm/drm_crtc_helper.h>
	7	#include <drm/drm_drv.h>
	8	#include <drm/drm_fb_helper.h>
	9	#include <drm/drm_framebuffer.h>
8fbc9af5	10	#include <drm/drm_gem.h>
8ab59da2 TZ	11	#include <drm/drm_print.h>
	12
	13	#include <drm/drm_fbdev_generic.h>
	14
8ab59da2	15	/* @user: 1=userspace, 0=fbcon */
b9c93f4e	16	static int drm_fbdev_generic_fb_open(struct fb_info *info, int user)
8ab59da2 TZ	17	{
	18	struct drm_fb_helper *fb_helper = info->par;
	19
	20	/* No need to take a ref for fbcon because it unbinds on unregister */
	21	if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
	22	return -ENODEV;
	23
	24	return 0;
	25	}
	26
b9c93f4e	27	static int drm_fbdev_generic_fb_release(struct fb_info *info, int user)
8ab59da2 TZ	28	{
	29	struct drm_fb_helper *fb_helper = info->par;
	30
	31	if (user)
	32	module_put(fb_helper->dev->driver->fops->owner);
	33
	34	return 0;
	35	}
	36
744d35d3 TZ	37	FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(drm_fbdev_generic,
	38	drm_fb_helper_damage_range,
	39	drm_fb_helper_damage_area);
c6baad68	40
b9c93f4e	41	static void drm_fbdev_generic_fb_destroy(struct fb_info *info)
8ab59da2	42	{
7f5fe873	43	struct drm_fb_helper *fb_helper = info->par;
a5b44c4a	44	void *shadow = info->screen_buffer;
8ab59da2 TZ	45
	46	if (!fb_helper->dev)
	47	return;
	48
a5b44c4a	49	fb_deferred_io_cleanup(info);
8ab59da2	50	drm_fb_helper_fini(fb_helper);
a5b44c4a	51	vfree(shadow);
8ab59da2	52	drm_client_framebuffer_delete(fb_helper->buffer);
3fb1f62f	53
a5b44c4a	54	drm_client_release(&fb_helper->client);
3fb1f62f	55	drm_fb_helper_unprepare(fb_helper);
8ab59da2 TZ	56	kfree(fb_helper);
	57	}
	58
b9c93f4e	59	static const struct fb_ops drm_fbdev_generic_fb_ops = {
8ab59da2	60	.owner = THIS_MODULE,
b9c93f4e TZ	61	.fb_open = drm_fbdev_generic_fb_open,
b9c93f4e TZ	62	.fb_release = drm_fbdev_generic_fb_release,
c6baad68	63	FB_DEFAULT_DEFERRED_OPS(drm_fbdev_generic),
a5b44c4a	64	DRM_FB_HELPER_DEFAULT_OPS,
b9c93f4e	65	.fb_destroy = drm_fbdev_generic_fb_destroy,
8ab59da2 TZ	66	};
8ab59da2 TZ	67
8ab59da2 TZ	68	/*
	69	* This function uses the client API to create a framebuffer backed by a dumb buffer.
	70	*/
b9c93f4e TZ	71	static int drm_fbdev_generic_helper_fb_probe(struct drm_fb_helper *fb_helper,
b9c93f4e TZ	72	struct drm_fb_helper_surface_size *sizes)
8ab59da2 TZ	73	{
	74	struct drm_client_dev *client = &fb_helper->client;
	75	struct drm_device *dev = fb_helper->dev;
	76	struct drm_client_buffer *buffer;
6ca80b9e	77	struct fb_info *info;
8fbc9af5	78	size_t screen_size;
61b5d007	79	void *screen_buffer;
8ab59da2	80	u32 format;
8ab59da2 TZ	81	int ret;
	82
	83	drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
	84	sizes->surface_width, sizes->surface_height,
	85	sizes->surface_bpp);
	86
	87	format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
	88	buffer = drm_client_framebuffer_create(client, sizes->surface_width,
	89	sizes->surface_height, format);
	90	if (IS_ERR(buffer))
	91	return PTR_ERR(buffer);
	92
	93	fb_helper->buffer = buffer;
	94	fb_helper->fb = buffer->fb;
61b5d007	95
8fbc9af5	96	screen_size = buffer->gem->size;
61b5d007 TZ	97	screen_buffer = vzalloc(screen_size);
	98	if (!screen_buffer) {
	99	ret = -ENOMEM;
	100	goto err_drm_client_framebuffer_delete;
	101	}
8ab59da2	102
6ca80b9e	103	info = drm_fb_helper_alloc_info(fb_helper);
61b5d007 TZ	104	if (IS_ERR(info)) {
	105	ret = PTR_ERR(info);
	106	goto err_vfree;
	107	}
	108
	109	drm_fb_helper_fill_info(info, fb_helper, sizes);
8ab59da2	110
b9c93f4e	111	info->fbops = &drm_fbdev_generic_fb_ops;
8ab59da2	112
61b5d007	113	/* screen */
a5b44c4a	114	info->flags \|= FBINFO_VIRTFB \| FBINFO_READS_FAST;
61b5d007	115	info->screen_buffer = screen_buffer;
a5b44c4a	116	info->fix.smem_start = page_to_phys(vmalloc_to_page(info->screen_buffer));
61b5d007	117	info->fix.smem_len = screen_size;
d6591da5	118
61b5d007	119	/* deferred I/O */
a5b44c4a TZ	120	fb_helper->fbdefio.delay = HZ / 20;
	121	fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
	122
	123	info->fbdefio = &fb_helper->fbdefio;
	124	ret = fb_deferred_io_init(info);
	125	if (ret)
61b5d007	126	goto err_drm_fb_helper_release_info;
8ab59da2 TZ	127
8ab59da2 TZ	128	return 0;
61b5d007 TZ	129
	130	err_drm_fb_helper_release_info:
	131	drm_fb_helper_release_info(fb_helper);
	132	err_vfree:
	133	vfree(screen_buffer);
	134	err_drm_client_framebuffer_delete:
	135	fb_helper->fb = NULL;
	136	fb_helper->buffer = NULL;
	137	drm_client_framebuffer_delete(buffer);
	138	return ret;
8ab59da2 TZ	139	}
8ab59da2 TZ	140
b9c93f4e TZ	141	static void drm_fbdev_generic_damage_blit_real(struct drm_fb_helper *fb_helper,
	142	struct drm_clip_rect *clip,
	143	struct iosys_map *dst)
8ab59da2 TZ	144	{
	145	struct drm_framebuffer *fb = fb_helper->fb;
	146	size_t offset = clip->y1 * fb->pitches[0];
	147	size_t len = clip->x2 - clip->x1;
	148	unsigned int y;
	149	void *src;
	150
	151	switch (drm_format_info_bpp(fb->format, 0)) {
	152	case 1:
	153	offset += clip->x1 / 8;
	154	len = DIV_ROUND_UP(len + clip->x1 % 8, 8);
	155	break;
	156	case 2:
	157	offset += clip->x1 / 4;
	158	len = DIV_ROUND_UP(len + clip->x1 % 4, 4);
	159	break;
	160	case 4:
	161	offset += clip->x1 / 2;
	162	len = DIV_ROUND_UP(len + clip->x1 % 2, 2);
	163	break;
	164	default:
	165	offset += clip->x1 * fb->format->cpp[0];
	166	len *= fb->format->cpp[0];
	167	break;
	168	}
	169
	170	src = fb_helper->info->screen_buffer + offset;
	171	iosys_map_incr(dst, offset); /* go to first pixel within clip rect */
	172
	173	for (y = clip->y1; y < clip->y2; y++) {
	174	iosys_map_memcpy_to(dst, 0, src, len);
	175	iosys_map_incr(dst, fb->pitches[0]);
	176	src += fb->pitches[0];
	177	}
	178	}
	179
b9c93f4e TZ	180	static int drm_fbdev_generic_damage_blit(struct drm_fb_helper *fb_helper,
b9c93f4e TZ	181	struct drm_clip_rect *clip)
8ab59da2 TZ	182	{
	183	struct drm_client_buffer *buffer = fb_helper->buffer;
	184	struct iosys_map map, dst;
	185	int ret;
	186
	187	/*
	188	* We have to pin the client buffer to its current location while
	189	* flushing the shadow buffer. In the general case, concurrent
	190	* modesetting operations could try to move the buffer and would
	191	* fail. The modeset has to be serialized by acquiring the reservation
	192	* object of the underlying BO here.
	193	*
	194	* For fbdev emulation, we only have to protect against fbdev modeset
	195	* operations. Nothing else will involve the client buffer's BO. So it
	196	* is sufficient to acquire struct drm_fb_helper.lock here.
	197	*/
	198	mutex_lock(&fb_helper->lock);
	199
	200	ret = drm_client_buffer_vmap(buffer, &map);
	201	if (ret)
	202	goto out;
	203
	204	dst = map;
b9c93f4e	205	drm_fbdev_generic_damage_blit_real(fb_helper, clip, &dst);
8ab59da2 TZ	206
	207	drm_client_buffer_vunmap(buffer);
	208
	209	out:
	210	mutex_unlock(&fb_helper->lock);
	211
	212	return ret;
	213	}
	214
b9c93f4e TZ	215	static int drm_fbdev_generic_helper_fb_dirty(struct drm_fb_helper *helper,
b9c93f4e TZ	216	struct drm_clip_rect *clip)
8ab59da2 TZ	217	{
	218	struct drm_device *dev = helper->dev;
	219	int ret;
	220
8ab59da2 TZ	221	/* Call damage handlers only if necessary */
	222	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
	223	return 0;
	224
b9c93f4e	225	ret = drm_fbdev_generic_damage_blit(helper, clip);
a5b44c4a TZ	226	if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
a5b44c4a TZ	227	return ret;
8ab59da2 TZ	228
	229	if (helper->fb->funcs->dirty) {
	230	ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
	231	if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
	232	return ret;
	233	}
	234
	235	return 0;
	236	}
	237
b9c93f4e TZ	238	static const struct drm_fb_helper_funcs drm_fbdev_generic_helper_funcs = {
	239	.fb_probe = drm_fbdev_generic_helper_fb_probe,
	240	.fb_dirty = drm_fbdev_generic_helper_fb_dirty,
8ab59da2 TZ	241	};
8ab59da2 TZ	242
b9c93f4e	243	static void drm_fbdev_generic_client_unregister(struct drm_client_dev *client)
8ab59da2 TZ	244	{
	245	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
	246
032116bb	247	if (fb_helper->info) {
8ab59da2	248	drm_fb_helper_unregister_info(fb_helper);
032116bb TZ	249	} else {
	250	drm_client_release(&fb_helper->client);
	251	drm_fb_helper_unprepare(fb_helper);
	252	kfree(fb_helper);
	253	}
8ab59da2 TZ	254	}
8ab59da2 TZ	255
b9c93f4e	256	static int drm_fbdev_generic_client_restore(struct drm_client_dev *client)
8ab59da2 TZ	257	{
	258	drm_fb_helper_lastclose(client->dev);
	259
	260	return 0;
	261	}
	262
b9c93f4e	263	static int drm_fbdev_generic_client_hotplug(struct drm_client_dev *client)
8ab59da2 TZ	264	{
	265	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
	266	struct drm_device *dev = client->dev;
	267	int ret;
	268
8ab59da2 TZ	269	if (dev->fb_helper)
	270	return drm_fb_helper_hotplug_event(dev->fb_helper);
	271
8ab59da2 TZ	272	ret = drm_fb_helper_init(dev, fb_helper);
8ab59da2 TZ	273	if (ret)
643231b2	274	goto err_drm_err;
8ab59da2 TZ	275
	276	if (!drm_drv_uses_atomic_modeset(dev))
	277	drm_helper_disable_unused_functions(dev);
	278
6c80a93b	279	ret = drm_fb_helper_initial_config(fb_helper);
8ab59da2	280	if (ret)
643231b2	281	goto err_drm_fb_helper_fini;
8ab59da2 TZ	282
	283	return 0;
	284
643231b2 TZ	285	err_drm_fb_helper_fini:
	286	drm_fb_helper_fini(fb_helper);
	287	err_drm_err:
8ab59da2	288	drm_err(dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);
8ab59da2 TZ	289	return ret;
	290	}
	291
b9c93f4e	292	static const struct drm_client_funcs drm_fbdev_generic_client_funcs = {
8ab59da2	293	.owner = THIS_MODULE,
b9c93f4e TZ	294	.unregister = drm_fbdev_generic_client_unregister,
	295	.restore = drm_fbdev_generic_client_restore,
	296	.hotplug = drm_fbdev_generic_client_hotplug,
8ab59da2 TZ	297	};
	298
	299	/**
	300	* drm_fbdev_generic_setup() - Setup generic fbdev emulation
	301	* @dev: DRM device
	302	* @preferred_bpp: Preferred bits per pixel for the device.
8ab59da2 TZ	303	*
	304	* This function sets up generic fbdev emulation for drivers that supports
	305	* dumb buffers with a virtual address and that can be mmap'ed.
	306	* drm_fbdev_generic_setup() shall be called after the DRM driver registered
	307	* the new DRM device with drm_dev_register().
	308	*
	309	* Restore, hotplug events and teardown are all taken care of. Drivers that do
	310	* suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
	311	* Simple drivers might use drm_mode_config_helper_suspend().
	312	*
a5b44c4a TZ	313	* In order to provide fixed mmap-able memory ranges, generic fbdev emulation
	314	* uses a shadow buffer in system memory. The implementation blits the shadow
	315	* fbdev buffer onto the real buffer in regular intervals.
8ab59da2 TZ	316	*
	317	* This function is safe to call even when there are no connectors present.
	318	* Setup will be retried on the next hotplug event.
	319	*
	320	* The fbdev is destroyed by drm_dev_unregister().
	321	*/
b9c93f4e	322	void drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
8ab59da2 TZ	323	{
	324	struct drm_fb_helper *fb_helper;
	325	int ret;
	326
	327	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
	328	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
	329
	330	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
	331	if (!fb_helper)
	332	return;
b9c93f4e	333	drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_generic_helper_funcs);
8ab59da2	334
b9c93f4e	335	ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_generic_client_funcs);
8ab59da2	336	if (ret) {
8ab59da2	337	drm_err(dev, "Failed to register client: %d\n", ret);
f73ab51b	338	goto err_drm_client_init;
8ab59da2 TZ	339	}
8ab59da2 TZ	340
8ab59da2	341	drm_client_register(&fb_helper->client);
f73ab51b TZ	342
	343	return;
	344
	345	err_drm_client_init:
	346	drm_fb_helper_unprepare(fb_helper);
	347	kfree(fb_helper);
	348	return;
8ab59da2 TZ	349	}
8ab59da2 TZ	350	EXPORT_SYMBOL(drm_fbdev_generic_setup);