TX2 OV5693 no Video0 on custom board

We made a custom TX2 board, with identical CSI connection from TX2 carrier with TX2’s OV5693. However, the Ubuntu system couldn’t probe the sensor to be Video0. We tested and confirmed hardware wiring is correct. Is there any prerequisites before system probes the sensor? So we’ll compile the kernel at first to make it work? Thanks in advance! Jetpack 3.1 R28.1

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By default the sensor is not on /dev/video* , unless you utilize the v4l2loopback module function.
You may find more details in case I .

Install the OV5693 cam back to TX2 carrier, post info shows:

dmesg |grep v4l

2.758640[OV5693]: probing V4L2 sensor

ls /dev:

Video0
V4l
V4l-subdev0
V4l-subdev1

However, on my custom board, post info doesn’t contain anything related with “V4L”. I think the system didn’t detect the sensor because our board lacks something on hardware so a kernel recompilation is needed?

Does anyone know what camera module could be used as substitution for OV5693 at the devkit board or where a spare OV5693 can be ordered?

hello kaosun,

please refer to [OEM product design guide] for your custom board development,
also, please configure the pinmux spreadsheet to update the *.cfg files, please check [TX2 Configuring Pinmux GPIO and PAD] chapter in the release documentation for more details.
thanks

Thank you Jerry!
I downloaded the file “OEM product design guide” but unfortunately I didn’t find the chapter you mentioned: “TX2 Configuring Pinmux GPIO and PAD”. Does it exist in any other guide?

My question is, our carrier board couldn’t load OV5693; however, we have identical design withe the TX2 original carrier board. We exchanged the EEPROM 24C02 from another working OV5693 board, the non-working 24C02 works on the original board but the working 24C02 doesn’t work on our carrier board either. Pins of TX2 module C6(CAM_I2C_SCL) and D6(CAM_I2C_SDA) connects well with the 24C02 chip(confirmed correct device address by A0, A1 and A2 pins).

I tried “i2cdetect” but didn’t find any devices, is there any method I can read the content from 24C02 to show it’s also an “E3326”? So I guess there might be something wrong before camera plugin manager starts to detect camera???

dmesg |grep cam
[    0.146856] node /plugin-manager/fragment-p3310-c00-camera match with board >=3310-1000-800
[    0.262646] GPIO line 461 (cam0-rst) hogged as output/low
[    0.262707] GPIO line 456 (cam0-pwdn) hogged as output/low
[    0.262781] GPIO line 457 (cam1-rst) hogged as output/low
[    0.262833] GPIO line 426 (cam1-pwdn) hogged as output/low
[    0.450117] tegra_camera_platform tegra-camera-platform: tegra_camera_probe:camera_platform_driver probe
[    0.450211] misc tegra_camera_ctrl: tegra_camera_isomgr_register tpg_max_iso = 3916800KBs
[    0.450215] misc tegra_camera_ctrl: tegra_camera_isomgr_register isp_iso_bw=4687500, vi_iso_bw=1500000, max_bw=4687500
[    2.736236] tegra186-cam-rtcpu b000000.rtcpu: Trace buffer configured at IOVA=0xa0000000
[    2.737920] tegra186-cam-rtcpu b000000.rtcpu: already unhalted
[    2.738972] tegra186-cam-rtcpu b000000.rtcpu: using cam RTCPU IRQ (52)
[    2.738975] tegra186-cam-rtcpu b000000.rtcpu: tegra_camrtc_mon_create is successful
[    2.739660] tegra186-cam-rtcpu b000000.rtcpu: firmware version cpu=sce cmd=4 sha1=a8b1ecdd9615cd817a56df035be363fce3b0b88f

dmesg |grep plugin-manager
[    0.139204] Initializing plugin-manager
[    0.139661] node /plugin-manager/soc-prod-a02-fragment match with chip-id A02P
[    0.139997] node /plugin-manager/fragement@0 match with odm-data enable-denver-wdt
[    0.140602] node /plugin-manager/fragement@4 match with odm-data enable-denver-wdt
[    0.141781] node /plugin-manager/fragment-sdwake-p3310-1000-300 match with board >=3310-1000-300
[    0.142137] node /plugin-manager/fragement-pmon-p3310-1000-300 match with board >=3310-1000-300
[    0.142391] node /plugin-manager/fragement-pmon-p3310-1000-800 match with board >=3310-1000-800
[    0.142612] node /plugin-manager/fragment-devslp@0 match with board >=3310-1000-200
[    0.143031] node /plugin-manager/fragment-500-pcie-config match with board >=3310-1000-500
[    0.143468] node /plugin-manager/fragment-500-xusb-config match with board >=3310-1000-500
[    0.143748] node /plugin-manager/fragment-500-e3325-pcie match with board >=3310-1000-500
[    0.144128] node /plugin-manager/fragment-p3310-c00-comm match with board >=3310-1000-800
[    0.144381] node /plugin-manager/fragment-p3310-c00-pmic match with board >=3310-1000-800
[    0.144606] node /plugin-manager/fragment-p3310-c01 match with board >=3310-1000-900
[    0.144867] node /plugin-manager/fragment-p3310-c03 match with board >=3310-1000-B00
[    0.146856] node /plugin-manager/fragment-p3310-c00-camera match with board >=3310-1000-800

Want any more info?

THX!

I might found the issue.

The board id from the 24C02 is: 3310-1000-800

However, in the

“tegra186-quill-camera-plugin-manager.dtsi” says:

fragment-p3310-c00-camera{
     ids=">=3310-1000-800",">=3489-0000-200";
     overide@1{
               target=<${/i2c@240000/ov23850_c@36}>;

Which means the plugin-manage will load ov23850 for board-id:“3310-1000-800”??

IS it also possible I don’t have “vana_supply” and “vif_supply”? Something like USB2 doesn’t work you’ll have to modify "Battery_reg"to turn on USB power. I designed two separate 1.8V and 2.8V LDO power supply which don’t feedback to TX2 module. IS this the reason?

hello kaosun,

…I didn’t find the chapter you mentioned: “TX2 Configuring Pinmux GPIO and PAD”.
please check [TX2 Configuring Pinmux GPIO and PAD] chapter in the [Release 28.2 Development Guide]

since our design would detect the device by reading the EEPROM in the bootloader stage,
please have a quick try to disable the plugin-manager to include the ov5693’s DTS only.
you could also refer to [Sensor Driver Programming Guide] in the [Release 28.2 Development Guide].
thanks

Hi Jerry,

I followed the “Sensor Driver Programming Guide”, disabled the camera plugin-manager and enabled the ee3326, still no VIDEO0… I’m analyzing the override code in the pluging-manager. Any suggestion and example? Or, which part of the code lines should be directly modified?

Guide mentions use “trgea18x-quill-cv-camera-modules.dtsi” as a model for generating your DTSI, and change status “disable” to “okey”. But where is the file??

Thanks!

hello kaosun,

FYI, we fix ov5693 cannot detect issue on TX1/R28.1
please also refer to this topic for more details: https://devtalk.nvidia.com/default/topic/1019986/jetson-tx1/getting-errors-in-using-onboard-camera-jetpack-3-1-/post/5203796/#5203796

since we had release JetPack-3.2, could you please take a try with latest release?
moreover, are you able to gather bootloader message through serial port? bootloader messages also helpful with this issue.
thanks

Hi Jerry,

R28.2 installed but camera plugin-manager cannot detect OV5693 automatically as usually in R28.1.

I’d like to change corresponding “disable” to “okey” but have to research the plugin-manager to see how many variables to be modified. “override” is Not easy for me. Trying to find all 15 variables for E3326 in plugin-manager but couldn’t find them all yet.

I tried the “cboot.bin” method in your post but doesn’t work. The “sudo ./flash.sh -r -k ETB jetson-tx2 mmcblk0p1” failed to upload the cboot.bin. I guess it might different with TX2.

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nvidia@tegra-ubuntu:~$ dmesg |grep cam
[    0.146402] node /plugin-manager/fragment-p3310-c00-camera match with board >=3310-1000-800
[    0.262977] GPIO line 461 (cam0-rst) hogged as output/low
[    0.263040] GPIO line 456 (cam0-pwdn) hogged as output/low
[    0.263136] GPIO line 457 (cam1-rst) hogged as output/low
[    0.263184] GPIO line 426 (cam1-pwdn) hogged as output/low
[    0.441738] tegra_camera_platform tegra-camera-platform: tegra_camera_probe:camera_platform_driver probe
[    0.441833] misc tegra_camera_ctrl: tegra_camera_isomgr_register tpg_max_iso = 3916800KBs
[    0.441863] misc tegra_camera_ctrl: tegra_camera_isomgr_register isp_iso_bw=4687500, vi_iso_bw=1500000, max_bw=4687500
[    2.782195] tegra186-cam-rtcpu b000000.rtcpu: Trace buffer configured at IOVA=0xa0000000
[    2.783515] tegra186-cam-rtcpu b000000.rtcpu: already unhalted
[    2.784396] tegra186-cam-rtcpu b000000.rtcpu: using cam RTCPU IRQ (52)
[    2.784398] tegra186-cam-rtcpu b000000.rtcpu: tegra_camrtc_mon_create is successful
[    2.785031] tegra186-cam-rtcpu b000000.rtcpu: firmware version cpu=sce cmd=4 sha1=a8b1ecdd9615cd817a56df035be363fce3b0b88f
[    2.789094] tegra-ivc-cdev ivc-b000000.rtcpu:echo@0: probing /dev/camchar-echo
[    2.789842] tegra-ivc-cdev ivc-b000000.rtcpu:dbg@7c00: probing /dev/camchar-dbg
[    2.789953] camchar: rtcpu character device driver loaded

Seems like the plugin-manager read the EEPROM successfully “3310-1000-800”, but didn’t probe OV5693?

hello kaosun,

could you please share the part# and S/N number of your camera sensor board,
for example,
part#: 690-83326-1000-000 M.1
S/N: P3326-A01-P2387

plugin-manager read the EEPROM from camera sensor board, for example, it should be “3326-1000-000” to probe ov5693.

S/N:032197015823
699-83326-1000-100 M

Disabled plugin-manager and manually enabled corresponding variables “okay”, seems going to work.

Now, issues are VANA and VIF error:

nvidia@tegra-ubuntu:~$ dmesg |grep 5693
[    2.684730] [OV5693]: probing v4l2 sensor.
[    2.685146] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    2.685193] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    4.596504] [OV5693]: probing v4l2 sensor.
[    4.596651] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    4.596681] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    4.598983] [OV5693]: probing v4l2 sensor.
[    4.599112] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    4.599139] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    4.675610] [OV5693]: probing v4l2 sensor.
[    4.675798] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    4.675831] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    6.963101] [OV5693]: probing v4l2 sensor.
[    6.963255] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    6.963285] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    7.571924] [OV5693]: probing v4l2 sensor.
[    7.579117] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    7.590246] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    7.997499] [OV5693]: probing v4l2 sensor.
[    7.997789] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    7.997835] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    7.999214] [OV5693]: probing v4l2 sensor.
[    7.999439] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    7.999474] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    8.015825] [OV5693]: probing v4l2 sensor.
[    8.016141] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    8.016188] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    8.249688] [OV5693]: probing v4l2 sensor.
[    8.256353] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    8.256394] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    8.679512] [OV5693]: probing v4l2 sensor.
[    8.679766] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    8.679799] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    8.698939] [OV5693]: probing v4l2 sensor.
[    8.699139] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    8.699169] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.196895] [OV5693]: probing v4l2 sensor.
[    9.197232] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.197275] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.601557] [OV5693]: probing v4l2 sensor.
[    9.601807] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.601847] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.603592] [OV5693]: probing v4l2 sensor.
[    9.603752] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.603785] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.720133] [OV5693]: probing v4l2 sensor.
[    9.722182] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.722307] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.730676] [OV5693]: probing v4l2 sensor.
[    9.730916] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.730954] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.740815] [OV5693]: probing v4l2 sensor.
[    9.741390] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.741658] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.746431] [OV5693]: probing v4l2 sensor.
[    9.746832] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.746900] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[   33.545535] [OV5693]: probing v4l2 sensor.
[   33.550072] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[   33.557652] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[   34.555670] [OV5693]: probing v4l2 sensor.
[   34.558101] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[   34.558155] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb

Someone mentioned these power checks can be disabled if you directly power cameras but where and how?

Any document guides? THX!

hello kaosun,

there’s some module specific regulator definitions,
had you try to disable plugin-manager and include camera module device tree directly?
for example,

diff --git a/kernel-dts/tegra186-quill-p3310-1000-a00-00-base.dts b/kernel-dts/tegra186-quill-p3310-1000-a00-00-base.dts
index d79f701..8010734 100644
--- a/kernel-dts/tegra186-quill-p3310-1000-a00-00-base.dts
+++ b/kernel-dts/tegra186-quill-p3310-1000-a00-00-base.dts
@@ -24,7 +24,7 @@
 #include <t18x-common-modules/tegra186-super-module-e2614-p2597-1000-a00.dtsi>
 #include <t18x-common-plugin-manager/tegra186-quill-display-plugin-manager.dtsi>
 #include <t18x-common-prod/tegra186-priv-quill-p3310-1000-a00-prod.dtsi>
-#include <t18x-common-plugin-manager/tegra186-quill-camera-plugin-manager.dtsi>
+#include <t18x-common-modules/tegra186-camera-e3326-a00.dtsi>

Previously I did remove plugin-manager, didn’t remove “tegra186-quill-camera-modules.dtsi” but changing corresponding variables to be “okay”.

I also tried your method, in “tegra186-quill-p3310-1000-a00-00-base.dts”,
I removed “tegra186-quill-camera-modules.dtsi” and added “tegra186-camera-e3326-a00.dtsi”
I compiled DT and flash.sh to TX2

Now, I checked my post info:

[2.862435] [OV5693]:Probing V4l2 sensor.
[2.862463] ov5693 2-0036:Failed to find clocks
[2.862466] ov5693 2-0036: unable to get platform data
[2.862493] ov5693:probe of 2-0036 failed with error -14

Any suggestion?

hello kaosun,

since you’re working on developing your custom board, you should treat this as bring-up new sensors.
please check you’re using correct mclk clock source in the e3326’s device tree.
thanks

Hello Jerry!

I handled the clocks issue and later pwdn-gpios issue. Now come back again to VANA and VIF issues.

nvidia@tegra-ubuntu:~$ dmesg |grep 5693
[    2.849930] [OV5693]: probing v4l2 sensor.
[    2.850324] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    2.850362] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    3.068059] [OV5693]: probing v4l2 sensor.
[    3.068208] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    3.068233] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    3.070228] [OV5693]: probing v4l2 sensor.
[    3.070738] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    3.070763] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    3.162743] [OV5693]: probing v4l2 sensor.
[    3.162874] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    3.162900] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    6.808615] [OV5693]: probing v4l2 sensor.
[    6.808743] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    6.808769] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    7.314460] [OV5693]: probing v4l2 sensor.
[    7.323503] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    7.335079] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    7.757584] [OV5693]: probing v4l2 sensor.
[    7.757821] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    7.757856] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    7.759180] [OV5693]: probing v4l2 sensor.
[    7.759369] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    7.759404] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    7.775601] [OV5693]: probing v4l2 sensor.
[    7.775854] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    7.775888] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    7.983939] [OV5693]: probing v4l2 sensor.
[    7.984177] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    7.984212] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    7.985550] [OV5693]: probing v4l2 sensor.
[    7.985737] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    7.985762] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    8.414784] [OV5693]: probing v4l2 sensor.
[    8.414991] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    8.415020] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    8.433705] [OV5693]: probing v4l2 sensor.
[    8.433898] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    8.433926] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    8.879646] [OV5693]: probing v4l2 sensor.
[    8.879941] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    8.879993] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.279582] [OV5693]: probing v4l2 sensor.
[    9.279800] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.279854] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.281468] [OV5693]: probing v4l2 sensor.
[    9.281600] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.281624] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.401960] [OV5693]: probing v4l2 sensor.
[    9.402222] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.402268] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.414215] [OV5693]: probing v4l2 sensor.
[    9.414449] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.414493] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.420962] [OV5693]: probing v4l2 sensor.
[    9.422390] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.422444] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.426339] [OV5693]: probing v4l2 sensor.
[    9.426574] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.426624] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[    9.583696] [OV5693]: probing v4l2 sensor.
[    9.585540] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[    9.585609] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb
[   10.602581] [OV5693]: probing v4l2 sensor.
[   10.602800] ov5693 2-0036: camera_common_regulator_get vana ERR: fffffffffffffdfb
[   10.602827] ov5693 2-0036: camera_common_regulator_get vif ERR: fffffffffffffdfb

Please help!

hello kaosun,

please check your regulators of analog 2.8v (AVDD_CAM) and IO 1.8v (DVDD_CAM).
please also refer to [Jetson TX2/TX2i OEM Product Design Guide] for more details.
thanks

Hello Jerry,

I install two LM1117 adjustable LDO to generate 1.8V and 2.8V directly to OV5693 module without control of enable signal.

I also checked OEM design guide, found these two regulators but nothing helps.

DVDD_CAM_IO_1V8, 1.8V rail for camera i/o; 1.8V; load switch; from VDD_1V8; controlled by GPIO expander U28 P11

AVDD_CAM, High voltage rail for cameras; 2.8V; load switch; from VDD_3V3_SLP; controlled by GPIO Expander U29, P15