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/videodev2.h>
12 
13 /**
14  * v4l2_calc_timeperframe - helper function to calculate timeperframe based
15  *	v4l2_dv_timings fields.
16  * @t: Timings for the video mode.
17  *
18  * Calculates the expected timeperframe using the pixel clock value and
19  * horizontal/vertical measures. This means that v4l2_dv_timings structure
20  * must be correctly and fully filled.
21  */
22 struct v4l2_fract v4l2_calc_timeperframe(const struct v4l2_dv_timings *t);
23 
24 /*
25  * v4l2_dv_timings_presets: list of all dv_timings presets.
26  */
27 extern const struct v4l2_dv_timings v4l2_dv_timings_presets[];
28 
29 /**
30  * typedef v4l2_check_dv_timings_fnc - timings check callback
31  *
32  * @t: the v4l2_dv_timings struct.
33  * @handle: a handle from the driver.
34  *
35  * Returns true if the given timings are valid.
36  */
37 typedef bool v4l2_check_dv_timings_fnc(const struct v4l2_dv_timings *t, void *handle);
38 
39 /**
40  * v4l2_valid_dv_timings() - are these timings valid?
41  *
42  * @t:	  the v4l2_dv_timings struct.
43  * @cap: the v4l2_dv_timings_cap capabilities.
44  * @fnc: callback to check if this timing is OK. May be NULL.
45  * @fnc_handle: a handle that is passed on to @fnc.
46  *
47  * Returns true if the given dv_timings struct is supported by the
48  * hardware capabilities and the callback function (if non-NULL), returns
49  * false otherwise.
50  */
51 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
52 			   const struct v4l2_dv_timings_cap *cap,
53 			   v4l2_check_dv_timings_fnc fnc,
54 			   void *fnc_handle);
55 
56 /**
57  * v4l2_enum_dv_timings_cap() - Helper function to enumerate possible DV
58  *	 timings based on capabilities
59  *
60  * @t:	  the v4l2_enum_dv_timings struct.
61  * @cap: the v4l2_dv_timings_cap capabilities.
62  * @fnc: callback to check if this timing is OK. May be NULL.
63  * @fnc_handle: a handle that is passed on to @fnc.
64  *
65  * This enumerates dv_timings using the full list of possible CEA-861 and DMT
66  * timings, filtering out any timings that are not supported based on the
67  * hardware capabilities and the callback function (if non-NULL).
68  *
69  * If a valid timing for the given index is found, it will fill in @t and
70  * return 0, otherwise it returns -EINVAL.
71  */
72 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
73 			     const struct v4l2_dv_timings_cap *cap,
74 			     v4l2_check_dv_timings_fnc fnc,
75 			     void *fnc_handle);
76 
77 /**
78  * v4l2_find_dv_timings_cap() - Find the closest timings struct
79  *
80  * @t:	  the v4l2_enum_dv_timings struct.
81  * @cap: the v4l2_dv_timings_cap capabilities.
82  * @pclock_delta: maximum delta between t->pixelclock and the timing struct
83  *		under consideration.
84  * @fnc: callback to check if a given timings struct is OK. May be NULL.
85  * @fnc_handle: a handle that is passed on to @fnc.
86  *
87  * This function tries to map the given timings to an entry in the
88  * full list of possible CEA-861 and DMT timings, filtering out any timings
89  * that are not supported based on the hardware capabilities and the callback
90  * function (if non-NULL).
91  *
92  * On success it will fill in @t with the found timings and it returns true.
93  * On failure it will return false.
94  */
95 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
96 			      const struct v4l2_dv_timings_cap *cap,
97 			      unsigned pclock_delta,
98 			      v4l2_check_dv_timings_fnc fnc,
99 			      void *fnc_handle);
100 
101 /**
102  * v4l2_find_dv_timings_cea861_vic() - find timings based on CEA-861 VIC
103  * @t:		the timings data.
104  * @vic:	CEA-861 VIC code
105  *
106  * On success it will fill in @t with the found timings and it returns true.
107  * On failure it will return false.
108  */
109 bool v4l2_find_dv_timings_cea861_vic(struct v4l2_dv_timings *t, u8 vic);
110 
111 /**
112  * v4l2_match_dv_timings() - do two timings match?
113  *
114  * @measured:	  the measured timings data.
115  * @standard:	  the timings according to the standard.
116  * @pclock_delta: maximum delta in Hz between standard->pixelclock and
117  *		the measured timings.
118  * @match_reduced_fps: if true, then fail if V4L2_DV_FL_REDUCED_FPS does not
119  * match.
120  *
121  * Returns true if the two timings match, returns false otherwise.
122  */
123 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *measured,
124 			   const struct v4l2_dv_timings *standard,
125 			   unsigned pclock_delta, bool match_reduced_fps);
126 
127 /**
128  * v4l2_print_dv_timings() - log the contents of a dv_timings struct
129  * @dev_prefix:device prefix for each log line.
130  * @prefix:	additional prefix for each log line, may be NULL.
131  * @t:		the timings data.
132  * @detailed:	if true, give a detailed log.
133  */
134 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
135 			   const struct v4l2_dv_timings *t, bool detailed);
136 
137 /**
138  * v4l2_detect_cvt - detect if the given timings follow the CVT standard
139  *
140  * @frame_height: the total height of the frame (including blanking) in lines.
141  * @hfreq: the horizontal frequency in Hz.
142  * @vsync: the height of the vertical sync in lines.
143  * @active_width: active width of image (does not include blanking). This
144  * information is needed only in case of version 2 of reduced blanking.
145  * In other cases, this parameter does not have any effect on timings.
146  * @polarities: the horizontal and vertical polarities (same as struct
147  *		v4l2_bt_timings polarities).
148  * @interlaced: if this flag is true, it indicates interlaced format
149  * @fmt: the resulting timings.
150  *
151  * This function will attempt to detect if the given values correspond to a
152  * valid CVT format. If so, then it will return true, and fmt will be filled
153  * in with the found CVT timings.
154  */
155 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
156 		unsigned active_width, u32 polarities, bool interlaced,
157 		struct v4l2_dv_timings *fmt);
158 
159 /**
160  * v4l2_detect_gtf - detect if the given timings follow the GTF standard
161  *
162  * @frame_height: the total height of the frame (including blanking) in lines.
163  * @hfreq: the horizontal frequency in Hz.
164  * @vsync: the height of the vertical sync in lines.
165  * @polarities: the horizontal and vertical polarities (same as struct
166  *		v4l2_bt_timings polarities).
167  * @interlaced: if this flag is true, it indicates interlaced format
168  * @aspect: preferred aspect ratio. GTF has no method of determining the
169  *		aspect ratio in order to derive the image width from the
170  *		image height, so it has to be passed explicitly. Usually
171  *		the native screen aspect ratio is used for this. If it
172  *		is not filled in correctly, then 16:9 will be assumed.
173  * @fmt: the resulting timings.
174  *
175  * This function will attempt to detect if the given values correspond to a
176  * valid GTF format. If so, then it will return true, and fmt will be filled
177  * in with the found GTF timings.
178  */
179 bool v4l2_detect_gtf(unsigned frame_height, unsigned hfreq, unsigned vsync,
180 		u32 polarities, bool interlaced, struct v4l2_fract aspect,
181 		struct v4l2_dv_timings *fmt);
182 
183 /**
184  * v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
185  *	0x15 and 0x16 from the EDID.
186  *
187  * @hor_landscape: byte 0x15 from the EDID.
188  * @vert_portrait: byte 0x16 from the EDID.
189  *
190  * Determines the aspect ratio from the EDID.
191  * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
192  * "Horizontal and Vertical Screen Size or Aspect Ratio"
193  */
194 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait);
195 
196 /**
197  * v4l2_dv_timings_aspect_ratio - calculate the aspect ratio based on the
198  *	v4l2_dv_timings information.
199  *
200  * @t: the timings data.
201  */
202 struct v4l2_fract v4l2_dv_timings_aspect_ratio(const struct v4l2_dv_timings *t);
203 
204 /**
205  * can_reduce_fps - check if conditions for reduced fps are true.
206  * @bt: v4l2 timing structure
207  *
208  * For different timings reduced fps is allowed if the following conditions
209  * are met:
210  *
211  *   - For CVT timings: if reduced blanking v2 (vsync == 8) is true.
212  *   - For CEA861 timings: if %V4L2_DV_FL_CAN_REDUCE_FPS flag is true.
213  */
214 static inline  bool can_reduce_fps(struct v4l2_bt_timings *bt)
215 {
216 	if ((bt->standards & V4L2_DV_BT_STD_CVT) && (bt->vsync == 8))
217 		return true;
218 
219 	if ((bt->standards & V4L2_DV_BT_STD_CEA861) &&
220 	    (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS))
221 		return true;
222 
223 	return false;
224 }
225 
226 /**
227  * struct v4l2_hdmi_rx_colorimetry - describes the HDMI colorimetry information
228  * @colorspace:		enum v4l2_colorspace, the colorspace
229  * @ycbcr_enc:		enum v4l2_ycbcr_encoding, Y'CbCr encoding
230  * @quantization:	enum v4l2_quantization, colorspace quantization
231  * @xfer_func:		enum v4l2_xfer_func, colorspace transfer function
232  */
233 struct v4l2_hdmi_colorimetry {
234 	enum v4l2_colorspace colorspace;
235 	enum v4l2_ycbcr_encoding ycbcr_enc;
236 	enum v4l2_quantization quantization;
237 	enum v4l2_xfer_func xfer_func;
238 };
239 
240 struct hdmi_avi_infoframe;
241 struct hdmi_vendor_infoframe;
242 
243 struct v4l2_hdmi_colorimetry
244 v4l2_hdmi_rx_colorimetry(const struct hdmi_avi_infoframe *avi,
245 			 const struct hdmi_vendor_infoframe *hdmi,
246 			 unsigned int height);
247 
248 u16 v4l2_get_edid_phys_addr(const u8 *edid, unsigned int size,
249 			    unsigned int *offset);
250 void v4l2_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr);
251 u16 v4l2_phys_addr_for_input(u16 phys_addr, u8 input);
252 int v4l2_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port);
253 
254 #endif
255