Skip to content

dts: comma: pin i2c bus numbers for openpilot via aliases #116

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
greatgitsby wants to merge 1 commit into
base: master
Choose a base branch
from
Draft

dts: comma: pin i2c bus numbers for openpilot via aliases #116

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
33 changes: 33 additions & 0 deletions kernel/dts/sdm845-comma-common.dtsi
View file
Open in desktop

@adeebshihadeh adeebshihadeh Jun 13, 2026

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

should we just give these nice alias names instead? we'll be shipping a new kernel anyway in the next release

@okias okias Jun 22, 2026

Copy link
Copy Markdown

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

yeah, this is good hack, but proper alias won't hurt :)

Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,26 @@
/ {
aliases {
serial0 = &uart9;

/*
* openpilot opens fixed i2c bus numbers: IMU on bus 1
* (sensord.py I2C_BUS_IMU=1), ina231 power monitor on bus 0,
* touch on bus 2. Linux derives the adapter number from these
* aliases (of_alias_get_id). Upstream sdm845.dtsi ships identity
* aliases (i2cN=&i2cN), so without this override the IMU node
* (i2c@890000 = i2c4) would be bus 4. Remap the three buses we
* use to the legacy numbers and park the displaced identity
* aliases on unused nodes so no two aliases target one node.
*
* Matches agnos legacy DTS: se10=/dev/i2c-0 (power),
* se4=IMU bus 1, se5=/dev/i2c-2 (touch).
*/
i2c0 = &i2c10; /* i2c@a88000 legacy /dev/i2c-0 (no devices on mici) */
i2c1 = &i2c4; /* i2c@890000 IMU */
i2c2 = &i2c5; /* i2c@894000 touch */
i2c4 = &i2c0;
i2c5 = &i2c1;
i2c10 = &i2c2;
};

chosen {
Expand Down Expand Up @@ -379,6 +399,19 @@
clock-frequency = <100000>;
};

/*
* Legacy /dev/i2c-0 (SE10, a88000) -> aliased to bus 0 above. On the comma
* four this bus carries no devices openpilot uses: there is NO ina231 (legacy
* comma_mici.dts /delete-node's it as "not populated on mici" — confirmed on
* device: probe of 0x40 returns -ENXIO, bus scan empty). openpilot reads power
* from the PMIC bms power_supply, not this bus. Kept enabled only to preserve
* bus-0 numbering parity with legacy.
*/
&i2c10 {
status = "okay";
clock-frequency = <100000>;
Comment on lines +411 to +412

@okias okias Jun 22, 2026 •
edited
Loading

Copy link
Copy Markdown

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

to have the patch ready for the mainline coding style 😉

Suggested change
status = "okay";
clock-frequency = <100000>;
clock-frequency = <100000>;
status = "okay";

};

&mdss {
status = "okay";
};
Expand Down
Loading