xref: /linux/drivers/gpu/drm/vkms/vkms_drv.h (revision 2c1ed907520c50326b8f604907a8478b27881a2e)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 
3 #ifndef _VKMS_DRV_H_
4 #define _VKMS_DRV_H_
5 
6 #include <linux/hrtimer.h>
7 
8 #include <drm/drm.h>
9 #include <drm/drm_framebuffer.h>
10 #include <drm/drm_gem.h>
11 #include <drm/drm_gem_atomic_helper.h>
12 #include <drm/drm_encoder.h>
13 #include <drm/drm_writeback.h>
14 
15 #define XRES_MIN    10
16 #define YRES_MIN    10
17 
18 #define XRES_DEF  1024
19 #define YRES_DEF   768
20 
21 #define XRES_MAX  8192
22 #define YRES_MAX  8192
23 
24 #define NUM_OVERLAY_PLANES 8
25 
26 #define VKMS_LUT_SIZE 256
27 
28 /**
29  * struct vkms_frame_info - Structure to store the state of a frame
30  *
31  * @fb: backing drm framebuffer
32  * @src: source rectangle of this frame in the source framebuffer, stored in 16.16 fixed-point form
33  * @dst: destination rectangle in the crtc buffer, stored in whole pixel units
34  * @map: see @drm_shadow_plane_state.data
35  * @rotation: rotation applied to the source.
36  *
37  * @src and @dst should have the same size modulo the rotation.
38  */
39 struct vkms_frame_info {
40 	struct drm_framebuffer *fb;
41 	struct drm_rect src, dst;
42 	struct iosys_map map[DRM_FORMAT_MAX_PLANES];
43 	unsigned int rotation;
44 };
45 
46 struct pixel_argb_u16 {
47 	u16 a, r, g, b;
48 };
49 
50 struct line_buffer {
51 	size_t n_pixels;
52 	struct pixel_argb_u16 *pixels;
53 };
54 
55 /**
56  * typedef pixel_write_t - These functions are used to read a pixel from a
57  * &struct pixel_argb_u16, convert it in a specific format and write it in the @out_pixel
58  * buffer.
59  *
60  * @out_pixel: destination address to write the pixel
61  * @in_pixel: pixel to write
62  */
63 typedef void (*pixel_write_t)(u8 *out_pixel, const struct pixel_argb_u16 *in_pixel);
64 
65 struct vkms_writeback_job {
66 	struct iosys_map data[DRM_FORMAT_MAX_PLANES];
67 	struct vkms_frame_info wb_frame_info;
68 	pixel_write_t pixel_write;
69 };
70 
71 /**
72  * enum pixel_read_direction - Enum used internally by VKMS to represent a reading direction in a
73  * plane.
74  */
75 enum pixel_read_direction {
76 	READ_BOTTOM_TO_TOP,
77 	READ_TOP_TO_BOTTOM,
78 	READ_RIGHT_TO_LEFT,
79 	READ_LEFT_TO_RIGHT
80 };
81 
82 struct vkms_plane_state;
83 
84 /**
85  * typedef pixel_read_line_t - These functions are used to read a pixel line in the source frame,
86  * convert it to `struct pixel_argb_u16` and write it to @out_pixel.
87  *
88  * @plane: plane used as source for the pixel value
89  * @x_start: X (width) coordinate of the first pixel to copy. The caller must ensure that x_start
90  * is non-negative and smaller than @plane->frame_info->fb->width.
91  * @y_start: Y (height) coordinate of the first pixel to copy. The caller must ensure that y_start
92  * is non-negative and smaller than @plane->frame_info->fb->height.
93  * @direction: direction to use for the copy, starting at @x_start/@y_start
94  * @count: number of pixels to copy
95  * @out_pixel: pointer where to write the pixel values. They will be written from @out_pixel[0]
96  * (included) to @out_pixel[@count] (excluded). The caller must ensure that out_pixel have a
97  * length of at least @count.
98  */
99 typedef void (*pixel_read_line_t)(const struct vkms_plane_state *plane, int x_start,
100 				  int y_start, enum pixel_read_direction direction, int count,
101 				  struct pixel_argb_u16 out_pixel[]);
102 
103 /**
104  * struct vkms_plane_state - Driver specific plane state
105  * @base: base plane state
106  * @frame_info: data required for composing computation
107  * @pixel_read_line: function to read a pixel line in this plane. The creator of a
108  *		     struct vkms_plane_state must ensure that this pointer is valid
109  */
110 struct vkms_plane_state {
111 	struct drm_shadow_plane_state base;
112 	struct vkms_frame_info *frame_info;
113 	pixel_read_line_t pixel_read_line;
114 };
115 
116 struct vkms_plane {
117 	struct drm_plane base;
118 };
119 
120 struct vkms_color_lut {
121 	struct drm_color_lut *base;
122 	size_t lut_length;
123 	s64 channel_value2index_ratio;
124 };
125 
126 /**
127  * struct vkms_crtc_state - Driver specific CRTC state
128  *
129  * @base: base CRTC state
130  * @composer_work: work struct to compose and add CRC entries
131  *
132  * @num_active_planes: Number of active planes
133  * @active_planes: List containing all the active planes (counted by
134  *		   @num_active_planes). They should be stored in z-order.
135  * @active_writeback: Current active writeback job
136  * @gamma_lut: Look up table for gamma used in this CRTC
137  * @crc_pending: Protected by @vkms_output.composer_lock, true when the frame CRC is not computed
138  *		 yet. Used by vblank to detect if the composer is too slow.
139  * @wb_pending: Protected by @vkms_output.composer_lock, true when a writeback frame is requested.
140  * @frame_start: Protected by @vkms_output.composer_lock, saves the frame number before the start
141  *		 of the composition process.
142  * @frame_end: Protected by @vkms_output.composer_lock, saves the last requested frame number.
143  *	       This is used to generate enough CRC entries when the composition worker is too slow.
144  */
145 struct vkms_crtc_state {
146 	struct drm_crtc_state base;
147 	struct work_struct composer_work;
148 
149 	int num_active_planes;
150 	struct vkms_plane_state **active_planes;
151 	struct vkms_writeback_job *active_writeback;
152 	struct vkms_color_lut gamma_lut;
153 
154 	bool crc_pending;
155 	bool wb_pending;
156 	u64 frame_start;
157 	u64 frame_end;
158 };
159 
160 /**
161  * struct vkms_output - Internal representation of all output components in VKMS
162  *
163  * @crtc: Base CRTC in DRM
164  * @encoder: DRM encoder used for this output
165  * @connector: DRM connector used for this output
166  * @wb_connecter: DRM writeback connector used for this output
167  * @vblank_hrtimer: Timer used to trigger the vblank
168  * @period_ns: vblank period, in nanoseconds, used to configure @vblank_hrtimer and to compute
169  *	       vblank timestamps
170  * @composer_workq: Ordered workqueue for @composer_state.composer_work.
171  * @lock: Lock used to protect concurrent access to the composer
172  * @composer_enabled: Protected by @lock, true when the VKMS composer is active (crc needed or
173  *		      writeback)
174  * @composer_state: Protected by @lock, current state of this VKMS output
175  * @composer_lock: Lock used internally to protect @composer_state members
176  */
177 struct vkms_output {
178 	struct drm_crtc crtc;
179 	struct drm_encoder encoder;
180 	struct drm_connector connector;
181 	struct drm_writeback_connector wb_connector;
182 	struct hrtimer vblank_hrtimer;
183 	ktime_t period_ns;
184 	struct workqueue_struct *composer_workq;
185 	spinlock_t lock;
186 
187 	bool composer_enabled;
188 	struct vkms_crtc_state *composer_state;
189 
190 	spinlock_t composer_lock;
191 };
192 
193 /**
194  * struct vkms_config - General configuration for VKMS driver
195  *
196  * @writeback: If true, a writeback buffer can be attached to the CRTC
197  * @cursor: If true, a cursor plane is created in the VKMS device
198  * @overlay: If true, NUM_OVERLAY_PLANES will be created for the VKMS device
199  * @dev: Used to store the current VKMS device. Only set when the device is instantiated.
200  */
201 struct vkms_config {
202 	bool writeback;
203 	bool cursor;
204 	bool overlay;
205 	struct vkms_device *dev;
206 };
207 
208 /**
209  * struct vkms_device - Description of a VKMS device
210  *
211  * @drm - Base device in DRM
212  * @platform - Associated platform device
213  * @output - Configuration and sub-components of the VKMS device
214  * @config: Configuration used in this VKMS device
215  */
216 struct vkms_device {
217 	struct drm_device drm;
218 	struct platform_device *platform;
219 	struct vkms_output output;
220 	const struct vkms_config *config;
221 };
222 
223 /*
224  * The following helpers are used to convert a member of a struct into its parent.
225  */
226 
227 #define drm_crtc_to_vkms_output(target) \
228 	container_of(target, struct vkms_output, crtc)
229 
230 #define drm_device_to_vkms_device(target) \
231 	container_of(target, struct vkms_device, drm)
232 
233 #define to_vkms_crtc_state(target)\
234 	container_of(target, struct vkms_crtc_state, base)
235 
236 #define to_vkms_plane_state(target)\
237 	container_of(target, struct vkms_plane_state, base.base)
238 
239 /**
240  * vkms_crtc_init() - Initialize a CRTC for VKMS
241  * @dev: DRM device associated with the VKMS buffer
242  * @crtc: uninitialized CRTC device
243  * @primary: primary plane to attach to the CRTC
244  * @cursor: plane to attach to the CRTC
245  */
246 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
247 		   struct drm_plane *primary, struct drm_plane *cursor);
248 
249 /**
250  * vkms_output_init() - Initialize all sub-components needed for a VKMS device.
251  *
252  * @vkmsdev: VKMS device to initialize
253  */
254 int vkms_output_init(struct vkms_device *vkmsdev);
255 
256 /**
257  * vkms_plane_init() - Initialize a plane
258  *
259  * @vkmsdev: VKMS device containing the plane
260  * @type: type of plane to initialize
261  */
262 struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
263 				   enum drm_plane_type type);
264 
265 /* CRC Support */
266 const char *const *vkms_get_crc_sources(struct drm_crtc *crtc,
267 					size_t *count);
268 int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name);
269 int vkms_verify_crc_source(struct drm_crtc *crtc, const char *source_name,
270 			   size_t *values_cnt);
271 
272 /* Composer Support */
273 void vkms_composer_worker(struct work_struct *work);
274 void vkms_set_composer(struct vkms_output *out, bool enabled);
275 void vkms_writeback_row(struct vkms_writeback_job *wb, const struct line_buffer *src_buffer, int y);
276 
277 /* Writeback */
278 int vkms_enable_writeback_connector(struct vkms_device *vkmsdev);
279 
280 #endif /* _VKMS_DRV_H_ */
281