xref: /linux/include/media/v4l2-dv-timings.h (revision fcc79e1714e8c2b8e216dc3149812edd37884eef)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * v4l2-dv-timings - Internal header with dv-timings helper functions
4  *
5  * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
6  */
7 
8 #ifndef __V4L2_DV_TIMINGS_H
9 #define __V4L2_DV_TIMINGS_H
10 
11 #include <linux/debugfs.h>
12 #include <linux/videodev2.h>
13 
14 /**
15  * v4l2_calc_timeperframe - helper function to calculate timeperframe based
16  *	v4l2_dv_timings fields.
17  * @t: Timings for the video mode.
18  *
19  * Calculates the expected timeperframe using the pixel clock value and
20  * horizontal/vertical measures. This means that v4l2_dv_timings structure
21  * must be correctly and fully filled.
22  */
23 struct v4l2_fract v4l2_calc_timeperframe(const struct v4l2_dv_timings *t);
24 
25 /*
26  * v4l2_dv_timings_presets: list of all dv_timings presets.
27  */
28 extern const struct v4l2_dv_timings v4l2_dv_timings_presets[];
29 
30 /**
31  * typedef v4l2_check_dv_timings_fnc - timings check callback
32  *
33  * @t: the v4l2_dv_timings struct.
34  * @handle: a handle from the driver.
35  *
36  * Returns true if the given timings are valid.
37  */
38 typedef bool v4l2_check_dv_timings_fnc(const struct v4l2_dv_timings *t, void *handle);
39 
40 /**
41  * v4l2_valid_dv_timings() - are these timings valid?
42  *
43  * @t:	  the v4l2_dv_timings struct.
44  * @cap: the v4l2_dv_timings_cap capabilities.
45  * @fnc: callback to check if this timing is OK. May be NULL.
46  * @fnc_handle: a handle that is passed on to @fnc.
47  *
48  * Returns true if the given dv_timings struct is supported by the
49  * hardware capabilities and the callback function (if non-NULL), returns
50  * false otherwise.
51  */
52 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
53 			   const struct v4l2_dv_timings_cap *cap,
54 			   v4l2_check_dv_timings_fnc fnc,
55 			   void *fnc_handle);
56 
57 /**
58  * v4l2_enum_dv_timings_cap() - Helper function to enumerate possible DV
59  *	 timings based on capabilities
60  *
61  * @t:	  the v4l2_enum_dv_timings struct.
62  * @cap: the v4l2_dv_timings_cap capabilities.
63  * @fnc: callback to check if this timing is OK. May be NULL.
64  * @fnc_handle: a handle that is passed on to @fnc.
65  *
66  * This enumerates dv_timings using the full list of possible CEA-861 and DMT
67  * timings, filtering out any timings that are not supported based on the
68  * hardware capabilities and the callback function (if non-NULL).
69  *
70  * If a valid timing for the given index is found, it will fill in @t and
71  * return 0, otherwise it returns -EINVAL.
72  */
73 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
74 			     const struct v4l2_dv_timings_cap *cap,
75 			     v4l2_check_dv_timings_fnc fnc,
76 			     void *fnc_handle);
77 
78 /**
79  * v4l2_find_dv_timings_cap() - Find the closest timings struct
80  *
81  * @t:	  the v4l2_enum_dv_timings struct.
82  * @cap: the v4l2_dv_timings_cap capabilities.
83  * @pclock_delta: maximum delta between t->pixelclock and the timing struct
84  *		under consideration.
85  * @fnc: callback to check if a given timings struct is OK. May be NULL.
86  * @fnc_handle: a handle that is passed on to @fnc.
87  *
88  * This function tries to map the given timings to an entry in the
89  * full list of possible CEA-861 and DMT timings, filtering out any timings
90  * that are not supported based on the hardware capabilities and the callback
91  * function (if non-NULL).
92  *
93  * On success it will fill in @t with the found timings and it returns true.
94  * On failure it will return false.
95  */
96 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
97 			      const struct v4l2_dv_timings_cap *cap,
98 			      unsigned pclock_delta,
99 			      v4l2_check_dv_timings_fnc fnc,
100 			      void *fnc_handle);
101 
102 /**
103  * v4l2_find_dv_timings_cea861_vic() - find timings based on CEA-861 VIC
104  * @t:		the timings data.
105  * @vic:	CEA-861 VIC code
106  *
107  * On success it will fill in @t with the found timings and it returns true.
108  * On failure it will return false.
109  */
110 bool v4l2_find_dv_timings_cea861_vic(struct v4l2_dv_timings *t, u8 vic);
111 
112 /**
113  * v4l2_match_dv_timings() - do two timings match?
114  *
115  * @measured:	  the measured timings data.
116  * @standard:	  the timings according to the standard.
117  * @pclock_delta: maximum delta in Hz between standard->pixelclock and
118  *		the measured timings.
119  * @match_reduced_fps: if true, then fail if V4L2_DV_FL_REDUCED_FPS does not
120  * match.
121  *
122  * Returns true if the two timings match, returns false otherwise.
123  */
124 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *measured,
125 			   const struct v4l2_dv_timings *standard,
126 			   unsigned pclock_delta, bool match_reduced_fps);
127 
128 /**
129  * v4l2_print_dv_timings() - log the contents of a dv_timings struct
130  * @dev_prefix:device prefix for each log line.
131  * @prefix:	additional prefix for each log line, may be NULL.
132  * @t:		the timings data.
133  * @detailed:	if true, give a detailed log.
134  */
135 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
136 			   const struct v4l2_dv_timings *t, bool detailed);
137 
138 /**
139  * v4l2_detect_cvt - detect if the given timings follow the CVT standard
140  *
141  * @frame_height: the total height of the frame (including blanking) in lines.
142  * @hfreq: the horizontal frequency in Hz.
143  * @vsync: the height of the vertical sync in lines.
144  * @active_width: active width of image (does not include blanking). This
145  * information is needed only in case of version 2 of reduced blanking.
146  * In other cases, this parameter does not have any effect on timings.
147  * @polarities: the horizontal and vertical polarities (same as struct
148  *		v4l2_bt_timings polarities).
149  * @interlaced: if this flag is true, it indicates interlaced format
150  * @cap: the v4l2_dv_timings_cap capabilities.
151  * @fmt: the resulting timings.
152  *
153  * This function will attempt to detect if the given values correspond to a
154  * valid CVT format. If so, then it will return true, and fmt will be filled
155  * in with the found CVT timings.
156  */
157 bool v4l2_detect_cvt(unsigned int frame_height, unsigned int hfreq,
158 		     unsigned int vsync, unsigned int active_width,
159 		     u32 polarities, bool interlaced,
160 		     const struct v4l2_dv_timings_cap *cap,
161 		     struct v4l2_dv_timings *fmt);
162 
163 /**
164  * v4l2_detect_gtf - detect if the given timings follow the GTF standard
165  *
166  * @frame_height: the total height of the frame (including blanking) in lines.
167  * @hfreq: the horizontal frequency in Hz.
168  * @vsync: the height of the vertical sync in lines.
169  * @polarities: the horizontal and vertical polarities (same as struct
170  *		v4l2_bt_timings polarities).
171  * @interlaced: if this flag is true, it indicates interlaced format
172  * @aspect: preferred aspect ratio. GTF has no method of determining the
173  *		aspect ratio in order to derive the image width from the
174  *		image height, so it has to be passed explicitly. Usually
175  *		the native screen aspect ratio is used for this. If it
176  *		is not filled in correctly, then 16:9 will be assumed.
177  * @cap: the v4l2_dv_timings_cap capabilities.
178  * @fmt: the resulting timings.
179  *
180  * This function will attempt to detect if the given values correspond to a
181  * valid GTF format. If so, then it will return true, and fmt will be filled
182  * in with the found GTF timings.
183  */
184 bool v4l2_detect_gtf(unsigned int frame_height, unsigned int hfreq,
185 		     unsigned int vsync, u32 polarities, bool interlaced,
186 		     struct v4l2_fract aspect,
187 		     const struct v4l2_dv_timings_cap *cap,
188 		     struct v4l2_dv_timings *fmt);
189 
190 /**
191  * v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
192  *	0x15 and 0x16 from the EDID.
193  *
194  * @hor_landscape: byte 0x15 from the EDID.
195  * @vert_portrait: byte 0x16 from the EDID.
196  *
197  * Determines the aspect ratio from the EDID.
198  * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
199  * "Horizontal and Vertical Screen Size or Aspect Ratio"
200  */
201 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait);
202 
203 /**
204  * v4l2_dv_timings_aspect_ratio - calculate the aspect ratio based on the
205  *	v4l2_dv_timings information.
206  *
207  * @t: the timings data.
208  */
209 struct v4l2_fract v4l2_dv_timings_aspect_ratio(const struct v4l2_dv_timings *t);
210 
211 /**
212  * can_reduce_fps - check if conditions for reduced fps are true.
213  * @bt: v4l2 timing structure
214  *
215  * For different timings reduced fps is allowed if the following conditions
216  * are met:
217  *
218  *   - For CVT timings: if reduced blanking v2 (vsync == 8) is true.
219  *   - For CEA861 timings: if %V4L2_DV_FL_CAN_REDUCE_FPS flag is true.
220  */
221 static inline  bool can_reduce_fps(struct v4l2_bt_timings *bt)
222 {
223 	if ((bt->standards & V4L2_DV_BT_STD_CVT) && (bt->vsync == 8))
224 		return true;
225 
226 	if ((bt->standards & V4L2_DV_BT_STD_CEA861) &&
227 	    (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS))
228 		return true;
229 
230 	return false;
231 }
232 
233 /**
234  * struct v4l2_hdmi_colorimetry - describes the HDMI colorimetry information
235  * @colorspace:		enum v4l2_colorspace, the colorspace
236  * @ycbcr_enc:		enum v4l2_ycbcr_encoding, Y'CbCr encoding
237  * @quantization:	enum v4l2_quantization, colorspace quantization
238  * @xfer_func:		enum v4l2_xfer_func, colorspace transfer function
239  */
240 struct v4l2_hdmi_colorimetry {
241 	enum v4l2_colorspace colorspace;
242 	enum v4l2_ycbcr_encoding ycbcr_enc;
243 	enum v4l2_quantization quantization;
244 	enum v4l2_xfer_func xfer_func;
245 };
246 
247 struct hdmi_avi_infoframe;
248 struct hdmi_vendor_infoframe;
249 
250 struct v4l2_hdmi_colorimetry
251 v4l2_hdmi_rx_colorimetry(const struct hdmi_avi_infoframe *avi,
252 			 const struct hdmi_vendor_infoframe *hdmi,
253 			 unsigned int height);
254 
255 u16 v4l2_get_edid_phys_addr(const u8 *edid, unsigned int size,
256 			    unsigned int *offset);
257 void v4l2_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr);
258 u16 v4l2_phys_addr_for_input(u16 phys_addr, u8 input);
259 int v4l2_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port);
260 
261 /* Add support for exporting InfoFrames to debugfs */
262 
263 /*
264  * HDMI InfoFrames start with a 3 byte header, then a checksum,
265  * followed by the actual IF payload.
266  *
267  * The payload length is limited to 30 bytes according to the HDMI spec,
268  * but since the length is encoded in 5 bits, it can be 31 bytes theoretically.
269  * So set the max length as 31 + 3 (header) + 1 (checksum) = 35.
270  */
271 #define V4L2_DEBUGFS_IF_MAX_LEN (35)
272 
273 #define V4L2_DEBUGFS_IF_AVI	BIT(0)
274 #define V4L2_DEBUGFS_IF_AUDIO	BIT(1)
275 #define V4L2_DEBUGFS_IF_SPD	BIT(2)
276 #define V4L2_DEBUGFS_IF_HDMI	BIT(3)
277 
278 typedef ssize_t (*v4l2_debugfs_if_read_t)(u32 type, void *priv,
279 					  struct file *filp, char __user *ubuf,
280 					  size_t count, loff_t *ppos);
281 
282 struct v4l2_debugfs_if {
283 	struct dentry *if_dir;
284 	void *priv;
285 
286 	v4l2_debugfs_if_read_t if_read;
287 };
288 
289 #ifdef CONFIG_DEBUG_FS
290 struct v4l2_debugfs_if *v4l2_debugfs_if_alloc(struct dentry *root, u32 if_types,
291 					      void *priv,
292 					      v4l2_debugfs_if_read_t if_read);
293 void v4l2_debugfs_if_free(struct v4l2_debugfs_if *infoframes);
294 #else
295 static inline
296 struct v4l2_debugfs_if *v4l2_debugfs_if_alloc(struct dentry *root, u32 if_types,
297 					      void *priv,
298 					      v4l2_debugfs_if_read_t if_read)
299 {
300 	return NULL;
301 }
302 
303 static inline void v4l2_debugfs_if_free(struct v4l2_debugfs_if *infoframes)
304 {
305 }
306 #endif
307 
308 #endif
309