Sylwester Nawrocki | 1b741bc | 2012-01-30 11:38:21 -0300 | [diff] [blame] | 1 | Samsung S5P/EXYNOS4 FIMC driver |
| 2 | |
| 3 | Copyright (C) 2012 Samsung Electronics Co., Ltd. |
| 4 | --------------------------------------------------------------------------- |
| 5 | |
| 6 | The FIMC (Fully Interactive Mobile Camera) device available in Samsung |
| 7 | SoC Application Processors is an integrated camera host interface, color |
| 8 | space converter, image resizer and rotator. It's also capable of capturing |
| 9 | data from LCD controller (FIMD) through the SoC internal writeback data |
| 10 | path. There are multiple FIMC instances in the SoCs (up to 4), having |
| 11 | slightly different capabilities, like pixel alignment constraints, rotator |
| 12 | availability, LCD writeback support, etc. The driver is located at |
Lad, Prabhakar | 83c7353 | 2012-09-14 05:17:52 -0300 | [diff] [blame^] | 13 | drivers/media/platform/s5p-fimc directory. |
Sylwester Nawrocki | 1b741bc | 2012-01-30 11:38:21 -0300 | [diff] [blame] | 14 | |
| 15 | 1. Supported SoCs |
| 16 | ================= |
| 17 | |
| 18 | S5PC100 (mem-to-mem only), S5PV210, EXYNOS4210 |
| 19 | |
| 20 | 2. Supported features |
| 21 | ===================== |
| 22 | |
| 23 | - camera parallel interface capture (ITU-R.BT601/565); |
| 24 | - camera serial interface capture (MIPI-CSI2); |
| 25 | - memory-to-memory processing (color space conversion, scaling, mirror |
| 26 | and rotation); |
| 27 | - dynamic pipeline re-configuration at runtime (re-attachment of any FIMC |
| 28 | instance to any parallel video input or any MIPI-CSI front-end); |
| 29 | - runtime PM and system wide suspend/resume |
| 30 | |
| 31 | Not currently supported: |
| 32 | - LCD writeback input |
| 33 | - per frame clock gating (mem-to-mem) |
| 34 | |
| 35 | 3. Files partitioning |
| 36 | ===================== |
| 37 | |
| 38 | - media device driver |
Lad, Prabhakar | 83c7353 | 2012-09-14 05:17:52 -0300 | [diff] [blame^] | 39 | drivers/media/platform/s5p-fimc/fimc-mdevice.[ch] |
Sylwester Nawrocki | 1b741bc | 2012-01-30 11:38:21 -0300 | [diff] [blame] | 40 | |
| 41 | - camera capture video device driver |
Lad, Prabhakar | 83c7353 | 2012-09-14 05:17:52 -0300 | [diff] [blame^] | 42 | drivers/media/platform/s5p-fimc/fimc-capture.c |
Sylwester Nawrocki | 1b741bc | 2012-01-30 11:38:21 -0300 | [diff] [blame] | 43 | |
| 44 | - MIPI-CSI2 receiver subdev |
Lad, Prabhakar | 83c7353 | 2012-09-14 05:17:52 -0300 | [diff] [blame^] | 45 | drivers/media/platform/s5p-fimc/mipi-csis.[ch] |
Sylwester Nawrocki | 1b741bc | 2012-01-30 11:38:21 -0300 | [diff] [blame] | 46 | |
| 47 | - video post-processor (mem-to-mem) |
Lad, Prabhakar | 83c7353 | 2012-09-14 05:17:52 -0300 | [diff] [blame^] | 48 | drivers/media/platform/s5p-fimc/fimc-core.c |
Sylwester Nawrocki | 1b741bc | 2012-01-30 11:38:21 -0300 | [diff] [blame] | 49 | |
| 50 | - common files |
Lad, Prabhakar | 83c7353 | 2012-09-14 05:17:52 -0300 | [diff] [blame^] | 51 | drivers/media/platform/s5p-fimc/fimc-core.h |
| 52 | drivers/media/platform/s5p-fimc/fimc-reg.h |
| 53 | drivers/media/platform/s5p-fimc/regs-fimc.h |
Sylwester Nawrocki | 1b741bc | 2012-01-30 11:38:21 -0300 | [diff] [blame] | 54 | |
| 55 | 4. User space interfaces |
| 56 | ======================== |
| 57 | |
| 58 | 4.1. Media device interface |
| 59 | |
| 60 | The driver supports Media Controller API as defined at |
| 61 | http://http://linuxtv.org/downloads/v4l-dvb-apis/media_common.html |
| 62 | The media device driver name is "SAMSUNG S5P FIMC". |
| 63 | |
| 64 | The purpose of this interface is to allow changing assignment of FIMC instances |
| 65 | to the SoC peripheral camera input at runtime and optionally to control internal |
| 66 | connections of the MIPI-CSIS device(s) to the FIMC entities. |
| 67 | |
| 68 | The media device interface allows to configure the SoC for capturing image |
| 69 | data from the sensor through more than one FIMC instance (e.g. for simultaneous |
| 70 | viewfinder and still capture setup). |
| 71 | Reconfiguration is done by enabling/disabling media links created by the driver |
| 72 | during initialization. The internal device topology can be easily discovered |
| 73 | through media entity and links enumeration. |
| 74 | |
| 75 | 4.2. Memory-to-memory video node |
| 76 | |
| 77 | V4L2 memory-to-memory interface at /dev/video? device node. This is standalone |
| 78 | video device, it has no media pads. However please note the mem-to-mem and |
| 79 | capture video node operation on same FIMC instance is not allowed. The driver |
| 80 | detects such cases but the applications should prevent them to avoid an |
| 81 | undefined behaviour. |
| 82 | |
| 83 | 4.3. Capture video node |
| 84 | |
| 85 | The driver supports V4L2 Video Capture Interface as defined at: |
| 86 | http://linuxtv.org/downloads/v4l-dvb-apis/devices.html |
| 87 | |
| 88 | At the capture and mem-to-mem video nodes only the multi-planar API is |
| 89 | supported. For more details see: |
| 90 | http://linuxtv.org/downloads/v4l-dvb-apis/planar-apis.html |
| 91 | |
| 92 | 4.4. Camera capture subdevs |
| 93 | |
| 94 | Each FIMC instance exports a sub-device node (/dev/v4l-subdev?), a sub-device |
| 95 | node is also created per each available and enabled at the platform level |
| 96 | MIPI-CSI receiver device (currently up to two). |
| 97 | |
| 98 | 4.5. sysfs |
| 99 | |
| 100 | In order to enable more precise camera pipeline control through the sub-device |
| 101 | API the driver creates a sysfs entry associated with "s5p-fimc-md" platform |
| 102 | device. The entry path is: /sys/platform/devices/s5p-fimc-md/subdev_conf_mode. |
| 103 | |
| 104 | In typical use case there could be a following capture pipeline configuration: |
| 105 | sensor subdev -> mipi-csi subdev -> fimc subdev -> video node |
| 106 | |
| 107 | When we configure these devices through sub-device API at user space, the |
| 108 | configuration flow must be from left to right, and the video node is |
| 109 | configured as last one. |
| 110 | When we don't use sub-device user space API the whole configuration of all |
| 111 | devices belonging to the pipeline is done at the video node driver. |
| 112 | The sysfs entry allows to instruct the capture node driver not to configure |
| 113 | the sub-devices (format, crop), to avoid resetting the subdevs' configuration |
| 114 | when the last configuration steps at the video node is performed. |
| 115 | |
| 116 | For full sub-device control support (subdevs configured at user space before |
| 117 | starting streaming): |
| 118 | # echo "sub-dev" > /sys/platform/devices/s5p-fimc-md/subdev_conf_mode |
| 119 | |
| 120 | For V4L2 video node control only (subdevs configured internally by the host |
| 121 | driver): |
| 122 | # echo "vid-dev" > /sys/platform/devices/s5p-fimc-md/subdev_conf_mode |
| 123 | This is a default option. |
| 124 | |
| 125 | 5. Device mapping to video and subdev device nodes |
| 126 | ================================================== |
| 127 | |
| 128 | There are associated two video device nodes with each device instance in |
| 129 | hardware - video capture and mem-to-mem and additionally a subdev node for |
| 130 | more precise FIMC capture subsystem control. In addition a separate v4l2 |
| 131 | sub-device node is created per each MIPI-CSIS device. |
| 132 | |
| 133 | How to find out which /dev/video? or /dev/v4l-subdev? is assigned to which |
| 134 | device? |
| 135 | |
| 136 | You can either grep through the kernel log to find relevant information, i.e. |
| 137 | # dmesg | grep -i fimc |
| 138 | (note that udev, if present, might still have rearranged the video nodes), |
| 139 | |
| 140 | or retrieve the information from /dev/media? with help of the media-ctl tool: |
| 141 | # media-ctl -p |
| 142 | |
| 143 | 6. Platform support |
| 144 | =================== |
| 145 | |
| 146 | The machine code (plat-s5p and arch/arm/mach-*) must select following options |
| 147 | |
| 148 | CONFIG_S5P_DEV_FIMC0 mandatory |
| 149 | CONFIG_S5P_DEV_FIMC1 \ |
| 150 | CONFIG_S5P_DEV_FIMC2 | optional |
| 151 | CONFIG_S5P_DEV_FIMC3 | |
| 152 | CONFIG_S5P_SETUP_FIMC / |
| 153 | CONFIG_S5P_SETUP_MIPIPHY \ |
| 154 | CONFIG_S5P_DEV_CSIS0 | optional for MIPI-CSI interface |
| 155 | CONFIG_S5P_DEV_CSIS1 / |
| 156 | |
| 157 | Except that, relevant s5p_device_fimc? should be registered in the machine code |
| 158 | in addition to a "s5p-fimc-md" platform device to which the media device driver |
| 159 | is bound. The "s5p-fimc-md" device instance is required even if only mem-to-mem |
| 160 | operation is used. |
| 161 | |
| 162 | The description of sensor(s) attached to FIMC/MIPI-CSIS camera inputs should be |
| 163 | passed as the "s5p-fimc-md" device platform_data. The platform data structure |
| 164 | is defined in file include/media/s5p_fimc.h. |
| 165 | |
| 166 | 7. Build |
| 167 | ======== |
| 168 | |
| 169 | This driver depends on following config options: |
| 170 | PLAT_S5P, |
| 171 | PM_RUNTIME, |
| 172 | I2C, |
| 173 | REGULATOR, |
| 174 | VIDEO_V4L2_SUBDEV_API, |
| 175 | |
| 176 | If the driver is built as a loadable kernel module (CONFIG_VIDEO_SAMSUNG_S5P_FIMC=m) |
| 177 | two modules are created (in addition to the core v4l2 modules): s5p-fimc.ko and |
| 178 | optional s5p-csis.ko (MIPI-CSI receiver subdev). |