xref: /linux/Documentation/admin-guide/media/mgb4.rst (revision eb01fe7abbe2d0b38824d2a93fdb4cc3eaf2ccc1)
1.. SPDX-License-Identifier: GPL-2.0
2
3====================
4mgb4 sysfs interface
5====================
6
7The mgb4 driver provides a sysfs interface, that is used to configure video
8stream related parameters (some of them must be set properly before the v4l2
9device can be opened) and obtain the video device/stream status.
10
11There are two types of parameters - global / PCI card related, found under
12``/sys/class/video4linux/videoX/device`` and module specific found under
13``/sys/class/video4linux/videoX``.
14
15
16Global (PCI card) parameters
17============================
18
19**module_type** (R):
20    Module type.
21
22    | 0 - No module present
23    | 1 - FPDL3
24    | 2 - GMSL
25
26**module_version** (R):
27    Module version number. Zero in case of a missing module.
28
29**fw_type** (R):
30    Firmware type.
31
32    | 1 - FPDL3
33    | 2 - GMSL
34
35**fw_version** (R):
36    Firmware version number.
37
38**serial_number** (R):
39    Card serial number. The format is::
40
41        PRODUCT-REVISION-SERIES-SERIAL
42
43    where each component is a 8b number.
44
45
46Common FPDL3/GMSL input parameters
47==================================
48
49**input_id** (R):
50    Input number ID, zero based.
51
52**oldi_lane_width** (RW):
53    Number of deserializer output lanes.
54
55    | 0 - single
56    | 1 - dual (default)
57
58**color_mapping** (RW):
59    Mapping of the incoming bits in the signal to the colour bits of the pixels.
60
61    | 0 - OLDI/JEIDA
62    | 1 - SPWG/VESA (default)
63
64**link_status** (R):
65    Video link status. If the link is locked, chips are properly connected and
66    communicating at the same speed and protocol. The link can be locked without
67    an active video stream.
68
69    A value of 0 is equivalent to the V4L2_IN_ST_NO_SYNC flag of the V4L2
70    VIDIOC_ENUMINPUT status bits.
71
72    | 0 - unlocked
73    | 1 - locked
74
75**stream_status** (R):
76    Video stream status. A stream is detected if the link is locked, the input
77    pixel clock is running and the DE signal is moving.
78
79    A value of 0 is equivalent to the V4L2_IN_ST_NO_SIGNAL flag of the V4L2
80    VIDIOC_ENUMINPUT status bits.
81
82    | 0 - not detected
83    | 1 - detected
84
85**video_width** (R):
86    Video stream width. This is the actual width as detected by the HW.
87
88    The value is identical to what VIDIOC_QUERY_DV_TIMINGS returns in the width
89    field of the v4l2_bt_timings struct.
90
91**video_height** (R):
92    Video stream height. This is the actual height as detected by the HW.
93
94    The value is identical to what VIDIOC_QUERY_DV_TIMINGS returns in the height
95    field of the v4l2_bt_timings struct.
96
97**vsync_status** (R):
98    The type of VSYNC pulses as detected by the video format detector.
99
100    The value is equivalent to the flags returned by VIDIOC_QUERY_DV_TIMINGS in
101    the polarities field of the v4l2_bt_timings struct.
102
103    | 0 - active low
104    | 1 - active high
105    | 2 - not available
106
107**hsync_status** (R):
108    The type of HSYNC pulses as detected by the video format detector.
109
110    The value is equivalent to the flags returned by VIDIOC_QUERY_DV_TIMINGS in
111    the polarities field of the v4l2_bt_timings struct.
112
113    | 0 - active low
114    | 1 - active high
115    | 2 - not available
116
117**vsync_gap_length** (RW):
118    If the incoming video signal does not contain synchronization VSYNC and
119    HSYNC pulses, these must be generated internally in the FPGA to achieve
120    the correct frame ordering. This value indicates, how many "empty" pixels
121    (pixels with deasserted Data Enable signal) are necessary to generate the
122    internal VSYNC pulse.
123
124**hsync_gap_length** (RW):
125    If the incoming video signal does not contain synchronization VSYNC and
126    HSYNC pulses, these must be generated internally in the FPGA to achieve
127    the correct frame ordering. This value indicates, how many "empty" pixels
128    (pixels with deasserted Data Enable signal) are necessary to generate the
129    internal HSYNC pulse. The value must be greater than 1 and smaller than
130    vsync_gap_length.
131
132**pclk_frequency** (R):
133    Input pixel clock frequency in kHz.
134
135    The value is identical to what VIDIOC_QUERY_DV_TIMINGS returns in
136    the pixelclock field of the v4l2_bt_timings struct.
137
138    *Note: The frequency_range parameter must be set properly first to get
139    a valid frequency here.*
140
141**hsync_width** (R):
142    Width of the HSYNC signal in PCLK clock ticks.
143
144    The value is identical to what VIDIOC_QUERY_DV_TIMINGS returns in
145    the hsync field of the v4l2_bt_timings struct.
146
147**vsync_width** (R):
148    Width of the VSYNC signal in PCLK clock ticks.
149
150    The value is identical to what VIDIOC_QUERY_DV_TIMINGS returns in
151    the vsync field of the v4l2_bt_timings struct.
152
153**hback_porch** (R):
154    Number of PCLK pulses between deassertion of the HSYNC signal and the first
155    valid pixel in the video line (marked by DE=1).
156
157    The value is identical to what VIDIOC_QUERY_DV_TIMINGS returns in
158    the hbackporch field of the v4l2_bt_timings struct.
159
160**hfront_porch** (R):
161    Number of PCLK pulses between the end of the last valid pixel in the video
162    line (marked by DE=1) and assertion of the HSYNC signal.
163
164    The value is identical to what VIDIOC_QUERY_DV_TIMINGS returns in
165    the hfrontporch field of the v4l2_bt_timings struct.
166
167**vback_porch** (R):
168    Number of video lines between deassertion of the VSYNC signal and the video
169    line with the first valid pixel (marked by DE=1).
170
171    The value is identical to what VIDIOC_QUERY_DV_TIMINGS returns in
172    the vbackporch field of the v4l2_bt_timings struct.
173
174**vfront_porch** (R):
175    Number of video lines between the end of the last valid pixel line (marked
176    by DE=1) and assertion of the VSYNC signal.
177
178    The value is identical to what VIDIOC_QUERY_DV_TIMINGS returns in
179    the vfrontporch field of the v4l2_bt_timings struct.
180
181**frequency_range** (RW)
182    PLL frequency range of the OLDI input clock generator. The PLL frequency is
183    derived from the Pixel Clock Frequency (PCLK) and is equal to PCLK if
184    oldi_lane_width is set to "single" and PCLK/2 if oldi_lane_width is set to
185    "dual".
186
187    | 0 - PLL < 50MHz (default)
188    | 1 - PLL >= 50MHz
189
190    *Note: This parameter can not be changed while the input v4l2 device is
191    open.*
192
193
194Common FPDL3/GMSL output parameters
195===================================
196
197**output_id** (R):
198    Output number ID, zero based.
199
200**video_source** (RW):
201    Output video source. If set to 0 or 1, the source is the corresponding card
202    input and the v4l2 output devices are disabled. If set to 2 or 3, the source
203    is the corresponding v4l2 video output device. The default is
204    the corresponding v4l2 output, i.e. 2 for OUT1 and 3 for OUT2.
205
206    | 0 - input 0
207    | 1 - input 1
208    | 2 - v4l2 output 0
209    | 3 - v4l2 output 1
210
211    *Note: This parameter can not be changed while ANY of the input/output v4l2
212    devices is open.*
213
214**display_width** (RW):
215    Display width. There is no autodetection of the connected display, so the
216    proper value must be set before the start of streaming. The default width
217    is 1280.
218
219    *Note: This parameter can not be changed while the output v4l2 device is
220    open.*
221
222**display_height** (RW):
223    Display height. There is no autodetection of the connected display, so the
224    proper value must be set before the start of streaming. The default height
225    is 640.
226
227    *Note: This parameter can not be changed while the output v4l2 device is
228    open.*
229
230**frame_rate** (RW):
231    Output video frame rate in frames per second. The default frame rate is
232    60Hz.
233
234**hsync_polarity** (RW):
235    HSYNC signal polarity.
236
237    | 0 - active low (default)
238    | 1 - active high
239
240**vsync_polarity** (RW):
241    VSYNC signal polarity.
242
243    | 0 - active low (default)
244    | 1 - active high
245
246**de_polarity** (RW):
247    DE signal polarity.
248
249    | 0 - active low
250    | 1 - active high (default)
251
252**pclk_frequency** (RW):
253    Output pixel clock frequency. Allowed values are between 25000-190000(kHz)
254    and there is a non-linear stepping between two consecutive allowed
255    frequencies. The driver finds the nearest allowed frequency to the given
256    value and sets it. When reading this property, you get the exact
257    frequency set by the driver. The default frequency is 70000kHz.
258
259    *Note: This parameter can not be changed while the output v4l2 device is
260    open.*
261
262**hsync_width** (RW):
263    Width of the HSYNC signal in pixels. The default value is 16.
264
265**vsync_width** (RW):
266    Width of the VSYNC signal in video lines. The default value is 2.
267
268**hback_porch** (RW):
269    Number of PCLK pulses between deassertion of the HSYNC signal and the first
270    valid pixel in the video line (marked by DE=1). The default value is 32.
271
272**hfront_porch** (RW):
273    Number of PCLK pulses between the end of the last valid pixel in the video
274    line (marked by DE=1) and assertion of the HSYNC signal. The default value
275    is 32.
276
277**vback_porch** (RW):
278    Number of video lines between deassertion of the VSYNC signal and the video
279    line with the first valid pixel (marked by DE=1). The default value is 2.
280
281**vfront_porch** (RW):
282    Number of video lines between the end of the last valid pixel line (marked
283    by DE=1) and assertion of the VSYNC signal. The default value is 2.
284
285
286FPDL3 specific input parameters
287===============================
288
289**fpdl3_input_width** (RW):
290    Number of deserializer input lines.
291
292    | 0 - auto (default)
293    | 1 - single
294    | 2 - dual
295
296FPDL3 specific output parameters
297================================
298
299**fpdl3_output_width** (RW):
300    Number of serializer output lines.
301
302    | 0 - auto (default)
303    | 1 - single
304    | 2 - dual
305
306GMSL specific input parameters
307==============================
308
309**gmsl_mode** (RW):
310    GMSL speed mode.
311
312    | 0 - 12Gb/s (default)
313    | 1 - 6Gb/s
314    | 2 - 3Gb/s
315    | 3 - 1.5Gb/s
316
317**gmsl_stream_id** (RW):
318    The GMSL multi-stream contains up to four video streams. This parameter
319    selects which stream is captured by the video input. The value is the
320    zero-based index of the stream. The default stream id is 0.
321
322    *Note: This parameter can not be changed while the input v4l2 device is
323    open.*
324
325**gmsl_fec** (RW):
326    GMSL Forward Error Correction (FEC).
327
328    | 0 - disabled
329    | 1 - enabled (default)
330
331
332====================
333mgb4 mtd partitions
334====================
335
336The mgb4 driver creates a MTD device with two partitions:
337 - mgb4-fw.X - FPGA firmware.
338 - mgb4-data.X - Factory settings, e.g. card serial number.
339
340The *mgb4-fw* partition is writable and is used for FW updates, *mgb4-data* is
341read-only. The *X* attached to the partition name represents the card number.
342Depending on the CONFIG_MTD_PARTITIONED_MASTER kernel configuration, you may
343also have a third partition named *mgb4-flash* available in the system. This
344partition represents the whole, unpartitioned, card's FLASH memory and one should
345not fiddle with it...
346
347====================
348mgb4 iio (triggers)
349====================
350
351The mgb4 driver creates an Industrial I/O (IIO) device that provides trigger and
352signal level status capability. The following scan elements are available:
353
354**activity**:
355	The trigger levels and pending status.
356
357	| bit 1 - trigger 1 pending
358	| bit 2 - trigger 2 pending
359	| bit 5 - trigger 1 level
360	| bit 6 - trigger 2 level
361
362**timestamp**:
363	The trigger event timestamp.
364
365The iio device can operate either in "raw" mode where you can fetch the signal
366levels (activity bits 5 and 6) using sysfs access or in triggered buffer mode.
367In the triggered buffer mode you can follow the signal level changes (activity
368bits 1 and 2) using the iio device in /dev. If you enable the timestamps, you
369will also get the exact trigger event time that can be matched to a video frame
370(every mgb4 video frame has a timestamp with the same clock source).
371
372*Note: although the activity sample always contains all the status bits, it makes
373no sense to get the pending bits in raw mode or the level bits in the triggered
374buffer mode - the values do not represent valid data in such case.*
375