1 .. SPDX-License-Identifier: GPL-2.0 1 .. SPDX-License-Identifier: GPL-2.0
2 2
3 .. include:: <isonum.txt> 3 .. include:: <isonum.txt>
4 4
5 The Samsung S5P/Exynos4 FIMC driver 5 The Samsung S5P/Exynos4 FIMC driver
6 =================================== 6 ===================================
7 7
8 Copyright |copy| 2012 - 2013 Samsung Electroni 8 Copyright |copy| 2012 - 2013 Samsung Electronics Co., Ltd.
9 9
10 The FIMC (Fully Interactive Mobile Camera) dev 10 The FIMC (Fully Interactive Mobile Camera) device available in Samsung
11 SoC Application Processors is an integrated ca 11 SoC Application Processors is an integrated camera host interface, color
12 space converter, image resizer and rotator. I 12 space converter, image resizer and rotator. It's also capable of capturing
13 data from LCD controller (FIMD) through the So 13 data from LCD controller (FIMD) through the SoC internal writeback data
14 path. There are multiple FIMC instances in th 14 path. There are multiple FIMC instances in the SoCs (up to 4), having
15 slightly different capabilities, like pixel al 15 slightly different capabilities, like pixel alignment constraints, rotator
16 availability, LCD writeback support, etc. The 16 availability, LCD writeback support, etc. The driver is located at
17 drivers/media/platform/samsung/exynos4-is dire 17 drivers/media/platform/samsung/exynos4-is directory.
18 18
19 Supported SoCs 19 Supported SoCs
20 -------------- 20 --------------
21 21
22 S5PC100 (mem-to-mem only), S5PV210, Exynos4210 22 S5PC100 (mem-to-mem only), S5PV210, Exynos4210
23 23
24 Supported features 24 Supported features
25 ------------------ 25 ------------------
26 26
27 - camera parallel interface capture (ITU-R.BT6 27 - camera parallel interface capture (ITU-R.BT601/565);
28 - camera serial interface capture (MIPI-CSI2); 28 - camera serial interface capture (MIPI-CSI2);
29 - memory-to-memory processing (color space con 29 - memory-to-memory processing (color space conversion, scaling, mirror
30 and rotation); 30 and rotation);
31 - dynamic pipeline re-configuration at runtime 31 - dynamic pipeline re-configuration at runtime (re-attachment of any FIMC
32 instance to any parallel video input or any 32 instance to any parallel video input or any MIPI-CSI front-end);
33 - runtime PM and system wide suspend/resume 33 - runtime PM and system wide suspend/resume
34 34
35 Not currently supported 35 Not currently supported
36 ----------------------- 36 -----------------------
37 37
38 - LCD writeback input 38 - LCD writeback input
39 - per frame clock gating (mem-to-mem) 39 - per frame clock gating (mem-to-mem)
40 40
41 User space interfaces 41 User space interfaces
42 --------------------- 42 ---------------------
43 43
44 Media device interface 44 Media device interface
45 ~~~~~~~~~~~~~~~~~~~~~~ 45 ~~~~~~~~~~~~~~~~~~~~~~
46 46
47 The driver supports Media Controller API as de 47 The driver supports Media Controller API as defined at :ref:`media_controller`.
48 The media device driver name is "Samsung S5P F 48 The media device driver name is "Samsung S5P FIMC".
49 49
50 The purpose of this interface is to allow chan 50 The purpose of this interface is to allow changing assignment of FIMC instances
51 to the SoC peripheral camera input at runtime 51 to the SoC peripheral camera input at runtime and optionally to control internal
52 connections of the MIPI-CSIS device(s) to the 52 connections of the MIPI-CSIS device(s) to the FIMC entities.
53 53
54 The media device interface allows to configure 54 The media device interface allows to configure the SoC for capturing image
55 data from the sensor through more than one FIM 55 data from the sensor through more than one FIMC instance (e.g. for simultaneous
56 viewfinder and still capture setup). 56 viewfinder and still capture setup).
57 57
58 Reconfiguration is done by enabling/disabling 58 Reconfiguration is done by enabling/disabling media links created by the driver
59 during initialization. The internal device top 59 during initialization. The internal device topology can be easily discovered
60 through media entity and links enumeration. 60 through media entity and links enumeration.
61 61
62 Memory-to-memory video node 62 Memory-to-memory video node
63 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ 63 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
64 64
65 V4L2 memory-to-memory interface at /dev/video? 65 V4L2 memory-to-memory interface at /dev/video? device node. This is standalone
66 video device, it has no media pads. However pl 66 video device, it has no media pads. However please note the mem-to-mem and
67 capture video node operation on same FIMC inst 67 capture video node operation on same FIMC instance is not allowed. The driver
68 detects such cases but the applications should 68 detects such cases but the applications should prevent them to avoid an
69 undefined behaviour. 69 undefined behaviour.
70 70
71 Capture video node 71 Capture video node
72 ~~~~~~~~~~~~~~~~~~ 72 ~~~~~~~~~~~~~~~~~~
73 73
74 The driver supports V4L2 Video Capture Interfa 74 The driver supports V4L2 Video Capture Interface as defined at
75 :ref:`devices`. 75 :ref:`devices`.
76 76
77 At the capture and mem-to-mem video nodes only 77 At the capture and mem-to-mem video nodes only the multi-planar API is
78 supported. For more details see: :ref:`planar- 78 supported. For more details see: :ref:`planar-apis`.
79 79
80 Camera capture subdevs 80 Camera capture subdevs
81 ~~~~~~~~~~~~~~~~~~~~~~ 81 ~~~~~~~~~~~~~~~~~~~~~~
82 82
83 Each FIMC instance exports a sub-device node ( 83 Each FIMC instance exports a sub-device node (/dev/v4l-subdev?), a sub-device
84 node is also created per each available and en 84 node is also created per each available and enabled at the platform level
85 MIPI-CSI receiver device (currently up to two) 85 MIPI-CSI receiver device (currently up to two).
86 86
87 sysfs 87 sysfs
88 ~~~~~ 88 ~~~~~
89 89
90 In order to enable more precise camera pipelin 90 In order to enable more precise camera pipeline control through the sub-device
91 API the driver creates a sysfs entry associate 91 API the driver creates a sysfs entry associated with "s5p-fimc-md" platform
92 device. The entry path is: /sys/platform/devic 92 device. The entry path is: /sys/platform/devices/s5p-fimc-md/subdev_conf_mode.
93 93
94 In typical use case there could be a following 94 In typical use case there could be a following capture pipeline configuration:
95 sensor subdev -> mipi-csi subdev -> fimc subde 95 sensor subdev -> mipi-csi subdev -> fimc subdev -> video node
96 96
97 When we configure these devices through sub-de 97 When we configure these devices through sub-device API at user space, the
98 configuration flow must be from left to right, 98 configuration flow must be from left to right, and the video node is
99 configured as last one. 99 configured as last one.
100 100
101 When we don't use sub-device user space API th 101 When we don't use sub-device user space API the whole configuration of all
102 devices belonging to the pipeline is done at t 102 devices belonging to the pipeline is done at the video node driver.
103 The sysfs entry allows to instruct the capture 103 The sysfs entry allows to instruct the capture node driver not to configure
104 the sub-devices (format, crop), to avoid reset 104 the sub-devices (format, crop), to avoid resetting the subdevs' configuration
105 when the last configuration steps at the video 105 when the last configuration steps at the video node is performed.
106 106
107 For full sub-device control support (subdevs c 107 For full sub-device control support (subdevs configured at user space before
108 starting streaming): 108 starting streaming):
109 109
110 .. code-block:: none 110 .. code-block:: none
111 111
112 # echo "sub-dev" > /sys/platform/devic 112 # echo "sub-dev" > /sys/platform/devices/s5p-fimc-md/subdev_conf_mode
113 113
114 For V4L2 video node control only (subdevs conf 114 For V4L2 video node control only (subdevs configured internally by the host
115 driver): 115 driver):
116 116
117 .. code-block:: none 117 .. code-block:: none
118 118
119 # echo "vid-dev" > /sys/platform/devic 119 # echo "vid-dev" > /sys/platform/devices/s5p-fimc-md/subdev_conf_mode
120 120
121 This is a default option. 121 This is a default option.
122 122
123 5. Device mapping to video and subdev device n 123 5. Device mapping to video and subdev device nodes
124 ---------------------------------------------- 124 --------------------------------------------------
125 125
126 There are associated two video device nodes wi 126 There are associated two video device nodes with each device instance in
127 hardware - video capture and mem-to-mem and ad 127 hardware - video capture and mem-to-mem and additionally a subdev node for
128 more precise FIMC capture subsystem control. I 128 more precise FIMC capture subsystem control. In addition a separate v4l2
129 sub-device node is created per each MIPI-CSIS 129 sub-device node is created per each MIPI-CSIS device.
130 130
131 How to find out which /dev/video? or /dev/v4l- 131 How to find out which /dev/video? or /dev/v4l-subdev? is assigned to which
132 device? 132 device?
133 133
134 You can either grep through the kernel log to 134 You can either grep through the kernel log to find relevant information, i.e.
135 135
136 .. code-block:: none 136 .. code-block:: none
137 137
138 # dmesg | grep -i fimc 138 # dmesg | grep -i fimc
139 139
140 (note that udev, if present, might still have 140 (note that udev, if present, might still have rearranged the video nodes),
141 141
142 or retrieve the information from /dev/media? w 142 or retrieve the information from /dev/media? with help of the media-ctl tool:
143 143
144 .. code-block:: none 144 .. code-block:: none
145 145
146 # media-ctl -p 146 # media-ctl -p
147 147
148 7. Build 148 7. Build
149 -------- 149 --------
150 150
151 If the driver is built as a loadable kernel mo 151 If the driver is built as a loadable kernel module (CONFIG_VIDEO_SAMSUNG_S5P_FIMC=m)
152 two modules are created (in addition to the co 152 two modules are created (in addition to the core v4l2 modules): s5p-fimc.ko and
153 optional s5p-csis.ko (MIPI-CSI receiver subdev 153 optional s5p-csis.ko (MIPI-CSI receiver subdev).
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