I2C (DDC)

[victor910]

My system Freebsd 12.0
My processor:
Intel(R) Core(TM) i7-7500U CPU @ 2.70GHz (kaby lake)
Internal video card HD Graphics 620

I had installed port drm-kmod"
The question, how to enable "gmbus " support?
My final target will have access to HDMI DDC - (I2C).

I believe something wrong with GMBus.

I had to try to install Debian on the same machine, HDMI I2C has been detected&working correctly.
For example a report from Debian:
`test@debian# i2cdetect -l

i2c-0 i2c i915 gmbus dpa i2c adapter

i2c-1 i2c i915 gmbus dpb i2c adapter

i2c-2 i2c i915 gmbus dpc i2c adapter

i2c-3 i2c i915 gmbus dpd i2c adapter

i2c-4 i2c i915 DPDDC-C i2c adapter`

I have only this in my Freebsd Log:
[drm:drm_dp_aux_register_devnode] drm_dp_aux_dev: aux [DPDDC-C] registered as minor 0`

But anyway I do not have any I2C controller under FreeBSD

Dmesg | grep drm

[drm:drm_core_init] Initialized
drmn0: on vgapci0
vgapci0: child drmn0 requested pci_enable_io
vgapci0: child drmn0 requested pci_enable_io
[drm] Unable to create a private tmpfs mount, hugepage support will be disabled(-19).
[drm:__intel_uncore_early_sanitize] unclaimed mmio detected on uncore init, clearing
[drm] Got stolen memory base 0x8e000000, size 0x2000000
[drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[drm] Driver supports precise vblank timestamp query.
[drm:drm_irq_install] irq=16
[drm] Connector HDMI-A-1: get mode from tunables:
[drm] - kern.vt.fb.modes.HDMI-A-1
[drm] - kern.vt.fb.default_mode
[drm] Connector DP-1: get mode from tunables:
[drm] - kern.vt.fb.modes.DP-1
[drm] - kern.vt.fb.default_mode
[drm:drm_calc_timestamping_constants] crtc 37: hwmode: htotal 2720, vtotal 1481, vdisplay 1440
[drm:drm_calc_timestamping_constants] crtc 37: clock 241500 kHz framedur 16680414 linedur 11262
[drm:drm_mode_object_get] OBJ ID: 59 (2)
[drm:drm_mode_object_get] OBJ ID: 59 (3)
[drm:drm_mode_object_get] OBJ ID: 64 (2)
[drm:drm_minor_register]
[drm:drm_minor_register]
[drm:drm_minor_register] new minor registered 128
[drm:drm_minor_register]
[drm:drm_minor_register] new minor registered 0
[drm:drm_sysfs_connector_add] adding "HDMI-A-1" to sysfs
[drm:drm_sysfs_hotplug_event] generating hotplug event
[drm:drm_sysfs_connector_add] adding "DP-1" to sysfs
[drm:drm_sysfs_hotplug_event] generating hotplug event
[drm:drm_dp_aux_register_devnode] drm_dp_aux_dev: aux [DPDDC-C] registered as minor 0
[drm] Initialized i915 1.6.0 20171222 for drmn0 on minor 0
[drm:drm_sysfs_hotplug_event] generating hotplug event
[drm:drm_mode_object_get] OBJ ID: 59 (3)
[drm:drm_mode_object_get] OBJ ID: 68 (1)
[drm:drm_mode_object_put] OBJ ID: 68 (2)
[drm:drm_mode_object_get] OBJ ID: 85 (1)
[drm:drm_mode_object_get] OBJ ID: 59 (5)
[drm:drm_mode_object_get] OBJ ID: 59 (6)
[drm:drm_mode_object_put] OBJ ID: 59 (6)
[drm:drm_mode_object_get] OBJ ID: 59 (5)
[drm:drm_calc_timestamping_constants] crtc 37: hwmode: htotal 2720, vtotal 1481, vdisplay 1440
[drm:drm_calc_timestamping_constants] crtc 37: clock 241500 kHz framedur 16680414 linedur 11262
[drm] Reducing the compressed framebuffer size. This may lead to less power savings than a non-reduced-size. Try to increase stolen memory size if available in BIOS.
[drm:drm_vblank_enable] enabling vblank on crtc 0, ret: 0
name=drmn0 flags=0x0 stride=10240 bpp=32
drmn0: fb0: inteldrmfb frame buffer device
[drm:drm_handle_vblank_events] vblank event on 5, current 5
[drm:drm_mode_object_put] OBJ ID: 68 (1)
[drm:drm_mode_object_get] OBJ ID: 85 (2)
[drm:drm_mode_object_put] OBJ ID: 59 (6)
[drm:drm_mode_object_put] OBJ ID: 59 (5)
[drm:vblank_disable_fn] disabling vblank on crtc 0
drmn0: successfully loaded firmware image with name: i915/kbl_dmc_ver1_04.bin
[drm] Finished loading DMC firmware i915/kbl_dmc_ver1_04.bin (v1.4)

how you see right now, I do not have to detect HDMI I2C in my log.

[valpackett]

Yes, these devices are not exposed, this is a known issue: #10

[victor910]

Are they not exposed because it wasn't implemented?
Or, because there is an error in code?