summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/drm_plane_helper.c
blob: d966afa7ecae66e620cf38a1ec237a6b47b08b68 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
/*
 * Copyright (C) 2014 Intel Corporation
 *
 * DRM universal plane helper functions
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/list.h>
#include <drm/drmP.h>
#include <drm/drm_rect.h>

#define SUBPIXEL_MASK 0xffff

/*
 * This is the minimal list of formats that seem to be safe for modeset use
 * with all current DRM drivers.  Most hardware can actually support more
 * formats than this and drivers may specify a more accurate list when
 * creating the primary plane.  However drivers that still call
 * drm_plane_init() will use this minimal format list as the default.
 */
const static uint32_t safe_modeset_formats[] = {
       DRM_FORMAT_XRGB8888,
       DRM_FORMAT_ARGB8888,
};

/*
 * Returns the connectors currently associated with a CRTC.  This function
 * should be called twice:  once with a NULL connector list to retrieve
 * the list size, and once with the properly allocated list to be filled in.
 */
static int get_connectors_for_crtc(struct drm_crtc *crtc,
				   struct drm_connector **connector_list,
				   int num_connectors)
{
	struct drm_device *dev = crtc->dev;
	struct drm_connector *connector;
	int count = 0;

	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
		if (connector->encoder && connector->encoder->crtc == crtc) {
			if (connector_list != NULL && count < num_connectors)
				*(connector_list++) = connector;

			count++;
		}

	return count;
}

/**
 * drm_primary_helper_update() - Helper for primary plane update
 * @plane: plane object to update
 * @crtc: owning CRTC of owning plane
 * @fb: framebuffer to flip onto plane
 * @crtc_x: x offset of primary plane on crtc
 * @crtc_y: y offset of primary plane on crtc
 * @crtc_w: width of primary plane rectangle on crtc
 * @crtc_h: height of primary plane rectangle on crtc
 * @src_x: x offset of @fb for panning
 * @src_y: y offset of @fb for panning
 * @src_w: width of source rectangle in @fb
 * @src_h: height of source rectangle in @fb
 *
 * Provides a default plane update handler for primary planes.  This is handler
 * is called in response to a userspace SetPlane operation on the plane with a
 * non-NULL framebuffer.  We call the driver's modeset handler to update the
 * framebuffer.
 *
 * SetPlane() on a primary plane of a disabled CRTC is not supported, and will
 * return an error.
 *
 * Note that we make some assumptions about hardware limitations that may not be
 * true for all hardware --
 *   1) Primary plane cannot be repositioned.
 *   2) Primary plane cannot be scaled.
 *   3) Primary plane must cover the entire CRTC.
 *   4) Subpixel positioning is not supported.
 * Drivers for hardware that don't have these restrictions can provide their
 * own implementation rather than using this helper.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
			      struct drm_framebuffer *fb,
			      int crtc_x, int crtc_y,
			      unsigned int crtc_w, unsigned int crtc_h,
			      uint32_t src_x, uint32_t src_y,
			      uint32_t src_w, uint32_t src_h)
{
	struct drm_mode_set set = {
		.crtc = crtc,
		.fb = fb,
		.mode = &crtc->mode,
		.x = src_x >> 16,
		.y = src_y >> 16,
	};
	struct drm_rect dest = {
		.x1 = crtc_x,
		.y1 = crtc_y,
		.x2 = crtc_x + crtc_w,
		.y2 = crtc_y + crtc_h,
	};
	struct drm_rect clip = {
		.x2 = crtc->mode.hdisplay,
		.y2 = crtc->mode.vdisplay,
	};
	struct drm_connector **connector_list;
	int num_connectors, ret;

	if (!crtc->enabled) {
		DRM_DEBUG_KMS("Cannot update primary plane of a disabled CRTC.\n");
		return -EINVAL;
	}

	/* Disallow subpixel positioning */
	if ((src_x | src_y | src_w | src_h) & SUBPIXEL_MASK) {
		DRM_DEBUG_KMS("Primary plane does not support subpixel positioning\n");
		return -EINVAL;
	}

	/* Primary planes are locked to their owning CRTC */
	if (plane->possible_crtcs != drm_crtc_mask(crtc)) {
		DRM_DEBUG_KMS("Cannot change primary plane CRTC\n");
		return -EINVAL;
	}

	/* Disallow scaling */
	src_w >>= 16;
	src_h >>= 16;
	if (crtc_w != src_w || crtc_h != src_h) {
		DRM_DEBUG_KMS("Can't scale primary plane\n");
		return -EINVAL;
	}

	/* Make sure primary plane covers entire CRTC */
	drm_rect_intersect(&dest, &clip);
	if (dest.x1 != 0 || dest.y1 != 0 ||
	    dest.x2 != crtc->mode.hdisplay || dest.y2 != crtc->mode.vdisplay) {
		DRM_DEBUG_KMS("Primary plane must cover entire CRTC\n");
		return -EINVAL;
	}

	/* Framebuffer must be big enough to cover entire plane */
	ret = drm_crtc_check_viewport(crtc, crtc_x, crtc_y, &crtc->mode, fb);
	if (ret)
		return ret;

	/* Find current connectors for CRTC */
	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
	BUG_ON(num_connectors == 0);
	connector_list = kzalloc(num_connectors * sizeof(*connector_list),
				 GFP_KERNEL);
	if (!connector_list)
		return -ENOMEM;
	get_connectors_for_crtc(crtc, connector_list, num_connectors);

	set.connectors = connector_list;
	set.num_connectors = num_connectors;

	/*
	 * We call set_config() directly here rather than using
	 * drm_mode_set_config_internal.  We're reprogramming the same
	 * connectors that were already in use, so we shouldn't need the extra
	 * cross-CRTC fb refcounting to accomodate stealing connectors.
	 * drm_mode_setplane() already handles the basic refcounting for the
	 * framebuffers involved in this operation.
	 */
	ret = crtc->funcs->set_config(&set);

	kfree(connector_list);
	return ret;
}
EXPORT_SYMBOL(drm_primary_helper_update);

/**
 * drm_primary_helper_disable() - Helper for primary plane disable
 * @plane: plane to disable
 *
 * Provides a default plane disable handler for primary planes.  This is handler
 * is called in response to a userspace SetPlane operation on the plane with a
 * NULL framebuffer parameter.  It unconditionally fails the disable call with
 * -EINVAL the only way to disable the primary plane without driver support is
 * to disable the entier CRTC. Which does not match the plane ->disable hook.
 *
 * Note that some hardware may be able to disable the primary plane without
 * disabling the whole CRTC.  Drivers for such hardware should provide their
 * own disable handler that disables just the primary plane (and they'll likely
 * need to provide their own update handler as well to properly re-enable a
 * disabled primary plane).
 *
 * RETURNS:
 * Unconditionally returns -EINVAL.
 */
int drm_primary_helper_disable(struct drm_plane *plane)
{
	return -EINVAL;
}
EXPORT_SYMBOL(drm_primary_helper_disable);

/**
 * drm_primary_helper_destroy() - Helper for primary plane destruction
 * @plane: plane to destroy
 *
 * Provides a default plane destroy handler for primary planes.  This handler
 * is called during CRTC destruction.  We disable the primary plane, remove
 * it from the DRM plane list, and deallocate the plane structure.
 */
void drm_primary_helper_destroy(struct drm_plane *plane)
{
	drm_plane_cleanup(plane);
	kfree(plane);
}
EXPORT_SYMBOL(drm_primary_helper_destroy);

const struct drm_plane_funcs drm_primary_helper_funcs = {
	.update_plane = drm_primary_helper_update,
	.disable_plane = drm_primary_helper_disable,
	.destroy = drm_primary_helper_destroy,
};
EXPORT_SYMBOL(drm_primary_helper_funcs);

/**
 * drm_primary_helper_create_plane() - Create a generic primary plane
 * @dev: drm device
 * @formats: pixel formats supported, or NULL for a default safe list
 * @num_formats: size of @formats; ignored if @formats is NULL
 *
 * Allocates and initializes a primary plane that can be used with the primary
 * plane helpers.  Drivers that wish to use driver-specific plane structures or
 * provide custom handler functions may perform their own allocation and
 * initialization rather than calling this function.
 */
struct drm_plane *drm_primary_helper_create_plane(struct drm_device *dev,
						  const uint32_t *formats,
						  int num_formats)
{
	struct drm_plane *primary;
	int ret;

	primary = kzalloc(sizeof(*primary), GFP_KERNEL);
	if (primary == NULL) {
		DRM_DEBUG_KMS("Failed to allocate primary plane\n");
		return NULL;
	}

	if (formats == NULL) {
		formats = safe_modeset_formats;
		num_formats = ARRAY_SIZE(safe_modeset_formats);
	}

	/* possible_crtc's will be filled in later by crtc_init */
	ret = drm_plane_init(dev, primary, 0, &drm_primary_helper_funcs,
			     formats, num_formats,
			     DRM_PLANE_TYPE_PRIMARY);
	if (ret) {
		kfree(primary);
		primary = NULL;
	}

	return primary;
}
EXPORT_SYMBOL(drm_primary_helper_create_plane);

/**
 * drm_crtc_init - Legacy CRTC initialization function
 * @dev: DRM device
 * @crtc: CRTC object to init
 * @funcs: callbacks for the new CRTC
 *
 * Initialize a CRTC object with a default helper-provided primary plane and no
 * cursor plane.
 *
 * Returns:
 * Zero on success, error code on failure.
 */
int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
		  const struct drm_crtc_funcs *funcs)
{
	struct drm_plane *primary;

	primary = drm_primary_helper_create_plane(dev, NULL, 0);
	return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs);
}
EXPORT_SYMBOL(drm_crtc_init);