Boot Linux faster!

Check our new training course

Boot Linux faster!

Check our new training course
and Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

  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
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
/*
 * Copyright (c) 2017 Jan Van Winkel <jan.van_winkel@dxplore.eu>
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @file
 * @brief Public API for display drivers and applications
 */

#ifndef ZEPHYR_INCLUDE_DRIVERS_DISPLAY_H_
#define ZEPHYR_INCLUDE_DRIVERS_DISPLAY_H_

/**
 * @brief Display Interface
 * @defgroup display_interface Display Interface
 * @ingroup display_interfaces
 * @{
 */

#include <device.h>
#include <stddef.h>
#include <zephyr/types.h>

#ifdef __cplusplus
extern "C" {
#endif

enum display_pixel_format {
	PIXEL_FORMAT_RGB_888		= BIT(0),
	PIXEL_FORMAT_MONO01		= BIT(1), /* 0=Black 1=White */
	PIXEL_FORMAT_MONO10		= BIT(2), /* 1=Black 0=White */
	PIXEL_FORMAT_ARGB_8888		= BIT(3),
	PIXEL_FORMAT_RGB_565		= BIT(4),
};

enum display_screen_info {
	/**
	 * If selected, one octet represents 8 pixels ordered vertically,
	 * otherwise ordered horizontally.
	 */
	SCREEN_INFO_MONO_VTILED		= BIT(0),
	/**
	 * If selected, the MSB represents the first pixel,
	 * otherwise MSB represents the last pixel.
	 */
	SCREEN_INFO_MONO_MSB_FIRST	= BIT(1),
	/**
	 * Electrophoretic Display.
	 */
	SCREEN_INFO_EPD			= BIT(2),
	/**
	 * Screen has two alternating ram buffers
	 */
	SCREEN_INFO_DOUBLE_BUFFER	= BIT(3),
};

/**
 * @enum display_orientation
 * @brief Enumeration with possible display orientation
 *
 */
enum display_orientation {
	DISPLAY_ORIENTATION_NORMAL,
	DISPLAY_ORIENTATION_ROTATED_90,
	DISPLAY_ORIENTATION_ROTATED_180,
	DISPLAY_ORIENTATION_ROTATED_270,
};

/**
 * @struct display_capabilities
 * @brief Structure holding display capabilities
 *
 * @var u16_t display_capabilities::x_resolution
 * Display resolution in the X direction
 *
 * @var u16_t display_capabilities::y_resolution
 * Display resolution in the Y direction
 *
 * @var u32_t display_capabilities::supported_pixel_formats
 * Bitwise or of pixel formats supported by the display
 *
 * @var u32_t display_capabilities::screen_info
 * Information about display panel
 *
 * @var enum display_pixel_format display_capabilities::current_pixel_format
 * Currently active pixel format for the display
 *
 * @var enum display_orientation display_capabilities::current_orientation
 * Current display orientation
 *
 */
struct display_capabilities {
	u16_t x_resolution;
	u16_t y_resolution;
	u32_t supported_pixel_formats;
	u32_t screen_info;
	enum display_pixel_format current_pixel_format;
	enum display_orientation current_orientation;
};

/**
 * @struct display_buffer_descriptor
 * @brief Structure to describe display data buffer layout
 *
 * @var u32_t display_buffer_descriptor::buf_size
 * Data buffer size in bytes
 *
 * @var u16_t display_buffer_descriptor::width
 * Data buffer row width in pixels
 *
 * @var u16_t display_buffer_descriptor::height
 * Data buffer column height in pixels
 *
 * @var u16_t display_buffer_descriptor::pitch
 * Number of pixels between consecutive rows in the data buffer
 *
 */
struct display_buffer_descriptor {
	u32_t buf_size;
	u16_t width;
	u16_t height;
	u16_t pitch;
};

/**
 * @typedef display_blanking_on_api
 * @brief Callback API to turn on display blanking
 * See display_blanking_on() for argument description
 */
typedef int (*display_blanking_on_api)(const struct device *dev);

/**
 * @typedef display_blanking_off_api
 * @brief Callback API to turn off display blanking
 * See display_blanking_off() for argument description
 */
typedef int (*display_blanking_off_api)(const struct device *dev);

/**
 * @typedef display_write_api
 * @brief Callback API for writing data to the display
 * See display_write() for argument description
 */
typedef int (*display_write_api)(const struct device *dev, const u16_t x,
				 const u16_t y,
				 const struct display_buffer_descriptor *desc,
				 const void *buf);

/**
 * @typedef display_read_api
 * @brief Callback API for reading data from the display
 * See display_read() for argument description
 */
typedef int (*display_read_api)(const struct device *dev, const u16_t x,
				const u16_t y,
				const struct display_buffer_descriptor *desc,
				void *buf);

/**
 * @typedef display_get_framebuffer_api
 * @brief Callback API to get framebuffer pointer
 * See display_get_framebuffer() for argument description
 */
typedef void *(*display_get_framebuffer_api)(const struct device *dev);

/**
 * @typedef display_set_brightness_api
 * @brief Callback API to set display brightness
 * See display_set_brightness() for argument description
 */
typedef int (*display_set_brightness_api)(const struct device *dev,
					  const u8_t brightness);

/**
 * @typedef display_set_contrast_api
 * @brief Callback API to set display contrast
 * See display_set_contrast() for argument description
 */
typedef int (*display_set_contrast_api)(const struct device *dev,
					const u8_t contrast);

/**
 * @typedef display_get_capabilities_api
 * @brief Callback API to get display capabilities
 * See display_get_capabilities() for argument description
 */
typedef void (*display_get_capabilities_api)(const struct device *dev,
					     struct display_capabilities *
					     capabilities);

/**
 * @typedef display_set_pixel_format_api
 * @brief Callback API to set pixel format used by the display
 * See display_set_pixel_format() for argument description
 */
typedef int (*display_set_pixel_format_api)(const struct device *dev,
					    const enum display_pixel_format
					    pixel_format);

/**
 * @typedef display_set_orientation_api
 * @brief Callback API to set orientation used by the display
 * See display_set_orientation() for argument description
 */
typedef int (*display_set_orientation_api)(const struct device *dev,
					   const enum display_orientation
					   orientation);

/**
 * @brief Display driver API
 * API which a display driver should expose
 */
struct display_driver_api {
	display_blanking_on_api blanking_on;
	display_blanking_off_api blanking_off;
	display_write_api write;
	display_read_api read;
	display_get_framebuffer_api get_framebuffer;
	display_set_brightness_api set_brightness;
	display_set_contrast_api set_contrast;
	display_get_capabilities_api get_capabilities;
	display_set_pixel_format_api set_pixel_format;
	display_set_orientation_api set_orientation;
};

/**
 * @brief Write data to display
 *
 * @param dev Pointer to device structure
 * @param x x Coordinate of the upper left corner where to write the buffer
 * @param y y Coordinate of the upper left corner where to write the buffer
 * @param desc Pointer to a structure describing the buffer layout
 * @param buf Pointer to buffer array
 *
 * @retval 0 on success else negative errno code.
 */
static inline int display_write(const struct device *dev, const u16_t x,
				const u16_t y,
				const struct display_buffer_descriptor *desc,
				const void *buf)
{
	struct display_driver_api *api =
		(struct display_driver_api *)dev->driver_api;

	return api->write(dev, x, y, desc, buf);
}

/**
 * @brief Read data from display
 *
 * @param dev Pointer to device structure
 * @param x x Coordinate of the upper left corner where to read from
 * @param y y Coordinate of the upper left corner where to read from
 * @param desc Pointer to a structure describing the buffer layout
 * @param buf Pointer to buffer array
 *
 * @retval 0 on success else negative errno code.
 */
static inline int display_read(const struct device *dev, const u16_t x,
			       const u16_t y,
			       const struct display_buffer_descriptor *desc,
			       void *buf)
{
	struct display_driver_api *api =
		(struct display_driver_api *)dev->driver_api;

	return api->read(dev, x, y, desc, buf);
}

/**
 * @brief Get pointer to framebuffer for direct access
 *
 * @param dev Pointer to device structure
 *
 * @retval Pointer to frame buffer or NULL if direct framebuffer access
 * is not supported
 *
 */
static inline void *display_get_framebuffer(const struct device *dev)
{
	struct display_driver_api *api =
		(struct display_driver_api *)dev->driver_api;

	return api->get_framebuffer(dev);
}

/**
 * @brief Turn display blanking on
 *
 * This function blanks the complete display.
 * The content of the frame buffer will be retained while blanking is enabled
 * and the frame buffer will be accessible for read and write operations.
 *
 * In case backlight control is supported by the driver the backlight is
 * turned off. The backlight configuration is retained and accessible for
 * configuration.
 *
 * In case the driver supports display blanking the initial state of the driver
 * would be the same as if this function was called.
 *
 * @param dev Pointer to device structure
 *
 * @retval 0 on success else negative errno code.
 */
static inline int display_blanking_on(const struct device *dev)
{
	struct display_driver_api *api =
		(struct display_driver_api *)dev->driver_api;

	return api->blanking_on(dev);
}

/**
 * @brief Turn display blanking off
 *
 * Restore the frame buffer content to the display.
 * In case backlight control is supported by the driver the backlight
 * configuration is restored.
 *
 * @param dev Pointer to device structure
 *
 * @retval 0 on success else negative errno code.
 */
static inline int display_blanking_off(const struct device *dev)
{
	struct display_driver_api *api =
		(struct display_driver_api *)dev->driver_api;

	return api->blanking_off(dev);
}

/**
 * @brief Set the brightness of the display
 *
 * Set the brightness of the display in steps of 1/256, where 255 is full
 * brightness and 0 is minimal.
 *
 * @param dev Pointer to device structure
 * @param brightness Brightness in steps of 1/256
 *
 * @retval 0 on success else negative errno code.
 */
static inline int display_set_brightness(const struct device *dev,
					 u8_t brightness)
{
	struct display_driver_api *api =
		(struct display_driver_api *)dev->driver_api;

	return api->set_brightness(dev, brightness);
}

/**
 * @brief Set the contrast of the display
 *
 * Set the contrast of the display in steps of 1/256, where 255 is maximum
 * difference and 0 is minimal.
 *
 * @param dev Pointer to device structure
 * @param contrast Contrast in steps of 1/256
 *
 * @retval 0 on success else negative errno code.
 */
static inline int display_set_contrast(const struct device *dev, u8_t contrast)
{
	struct display_driver_api *api =
		(struct display_driver_api *)dev->driver_api;

	return api->set_contrast(dev, contrast);
}

/**
 * @brief Get display capabilities
 *
 * @param dev Pointer to device structure
 * @param capabilities Pointer to capabilities structure to populate
 */
static inline void display_get_capabilities(const struct device *dev,
					    struct display_capabilities *
					    capabilities)
{
	struct display_driver_api *api =
		(struct display_driver_api *)dev->driver_api;

	api->get_capabilities(dev, capabilities);
}

/**
 * @brief Set pixel format used by the display
 *
 * @param dev Pointer to device structure
 * @param pixel_format Pixel format to be used by display
 *
 * @retval 0 on success else negative errno code.
 */
static inline int
display_set_pixel_format(const struct device *dev,
			 const enum display_pixel_format pixel_format)
{
	struct display_driver_api *api =
		(struct display_driver_api *)dev->driver_api;

	return api->set_pixel_format(dev, pixel_format);
}

/**
 * @brief Set display orientation
 *
 * @param dev Pointer to device structure
 * @param orientation Orientation to be used by display
 *
 * @retval 0 on success else negative errno code.
 */
static inline int display_set_orientation(const struct device *dev,
					  const enum display_orientation
					  orientation)
{
	struct display_driver_api *api =
		(struct display_driver_api *)dev->driver_api;

	return api->set_orientation(dev, orientation);
}

#ifdef __cplusplus
}
#endif

/**
 * @}
 */

#endif /* ZEPHYR_INCLUDE_DRIVERS_DISPLAY_H_ */