Please add support for the TI TMP117 I2C Sensor

[RussellSenior]

Describe the bug

Please add support for ti,tmp117 in i2c-sensors.dtsi and in the kernel configs to provide the tmp117 module.

The default kernel config, e.g. arch/arm/configs/bcmrpi_defconfig, does not include CONFIG_TMP117=m, and arch/arm/boot/dts/overlays/i2c-sensor-common.dtsi does not include support for the tmp117 sensor.

Steps to reproduce the behaviour

After make bcmpi_defconfig:

$ grep TMP117 .config

Device (s)

Raspberry Pi Zero

System

$ cat /etc/rpi-issue
Raspberry Pi reference 2025-10-01
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, 7385adde4cd7a2bfcf6e6ef0e5b790391c172a8d, stage2

$ vcgencmd version
Aug 20 2025 17:04:09
Copyright (c) 2012 Broadcom
version cd866525580337c0aee4b25880e1f5f9f674fb24 (clean) (release) (start)

$ uname -a
Linux pi0-ir 6.12.47+rpt-rpi-v6 #1 Raspbian 1:6.12.47-1+rpt1 (2025-09-16) armv6l GNU/Linux

Logs

No response

Additional context

No response

[pelwell]

You can do some of the work by saying which I2C addresses the device can use, which is the logical default address if more than one, and whether it supports or needs an interrupt signal.

[RussellSenior]

The TMP117 does support an interrupt, but I don't know how that works. I have an untested patch here I've built locally, but not yet booted, that ignores the interrupt part. Here's the most significant bit, based on cargo-cult cribbing:

diff --git a/arch/arm/boot/dts/overlays/i2c-sensor-common.dtsi b/arch/arm/boot/dts/overlays/i2c-sensor-common.dtsi
index 84b090e80..5a2315d2d 100755
--- a/arch/arm/boot/dts/overlays/i2c-sensor-common.dtsi
+++ b/arch/arm/boot/dts/overlays/i2c-sensor-common.dtsi
@@ -789,6 +789,22 @@ veml6030: veml6030@48 {
                };
        };
 
+       fragment@51 {
+               target = <&i2cbus>;
+               __dormant__ {
+                       #address-cells = <1>;
+                       #size-cells = <0>;
+                       status = "okay";
+
+                       tmp117: tmp117@48 {
+                               compatible = "ti,tmp117";
+                               reg = <0x48>;
+                               vcc-supply = <&pmic_reg_3v3>;
+                               status = "okay";
+                       };
+               };
+       };
+
        fragment@99 {
                target = <&gpio>;
                __dormant__ {

[nbuchwitz]

The usual evb from adafruit or sparkfun come with interrupt pin, which is internally named alert. Adaik it's only used for optional threshold based notifications.

[pelwell]

See #7083. After about half an hour you should be able to install a trial kernel build with sudo rpi-update pulls/7083. Back up any important data first, and be careful if you think you might be using an initramfs (test by commenting out auto_initramfs=1 in config.txt, and confirming that the Pi still boots).