Not able to get tmp102 to work on beaglebone

General Discussion
1

Hi,

I have one tmp102 sensor from sparkfun-tmp102
I am using an overlay on I2C1 line as below,

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2022 Robert Nelson <robertcnelson@gmail.com>
 */

/dts-v1/;
/plugin/;

#include <dt-bindings/pinctrl/am33xx.h>
#include <dt-bindings/gpio/gpio.h>

/*
 * Helper to show loaded overlays under: /proc/device-tree/chosen/overlays/
 */
&{/chosen} {
	overlays {
		BB-I2C1-TMP102.kernel = __TIMESTAMP__;
	};
};

/*
 * Free up the pins used by the cape from the pinmux helpers.
 */
&ocp {
	P9_17_pinmux { status = "disabled"; };	/* spi0_d1.i2c1_sda */
	P9_18_pinmux { status = "disabled"; };	/* spi0_cs0.i2c1_scl */
};

&am33xx_pinmux {
	bb_i2c1_pins: pinmux_bb_i2c1_pins {
		pinctrl-single,pins = <
			AM33XX_PADCONF(AM335X_PIN_SPI0_D1, SLEWCTRL_SLOW | PIN_INPUT_PULLUP, MUX_MODE2)		/* spi0_d1.i2c1_sda */
			AM33XX_PADCONF(AM335X_PIN_SPI0_CS0, SLEWCTRL_SLOW | PIN_INPUT_PULLUP, MUX_MODE2)	/* spi0_cs0.i2c1_scl */
		>;
	};
};

&i2c1 {
	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&bb_i2c1_pins>;

	clock-frequency = <100000>;

	#address-cells = <1>;
	#size-cells = <0>;

	tmp102@48 {
		status = "okay";
		compatible = "ti,tmp102";
		reg = <0x48>;
	};
};

and trying to use kernelbuildscripts/KERNEL/drivers/hwmon/tmp102.c driver as module.
My uEnv.txt as below,

uname_r=5.10.179
enable_uboot_overlays=1
uenv_root=/dev/mmcblk0p2
enable_uboot_overlays=1
uboot_base_dtb=am335x-boneblack-uboot-univ.dtb
uboot_overlay_addr0=/boot/overlays/BB-I2C1-TMP102-00A0.dtbo
disable_uboot_overlay_video=1
disable_uboot_overlay_adc=1

Overlay loads successfully and I can see i2c address 0x48

# i2cdetect -y -r 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- 48 -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --

and once I load the driver I get below error

# insmod tmp102.ko 
[   25.986815] tmp102 1-0048: error reading config register
[   25.992441] tmp102: probe of 1-0048 failed with error -121

Trying use i2c-utils from this chip manually shows below log,

# i2cdetect -y -r 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- 48 -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --                         
# i2cdump -y 1 0x48
No size specified (using byte-data access)
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: XX 60 4b 50 11 06 00 00 00 60 4b 50 11 06 00 00    X`KP??...`KP??..
10: 00 60 4b 50 11 06 00 00 00 60 4b 50 11 06 00 00    .`KP??...`KP??..
20: 00 60 4b 50 11 06 00 00 00 60 4b 50 11 06 00 00    .`KP??...`KP??..
30: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
40: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
50: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
60: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
70: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
80: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
90: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
a0: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
b0: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
c0: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
d0: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
e0: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
f0: 1b 60 4b 50 11 06 00 00 1b 60 4b 50 11 06 00 00    ?`KP??..?`KP??..
# i2cget -y 1 0x48 0x00
Error: Read failed
# i2cget -y 1 0x48 0x01
Error: Read failed
# i2cget -y 1 0x48 0x02
Error: Read failed
  1. Is this chip faulty?
  2. Am I missing something here?
2

Are you sure you need to insmod the driver?
It should get loaded when the kernel parses the devicetree.
I suspect the error you are getting may be caused by the fact you have a driver loaded already.

Could be wrong though.

Have you checked by doing lsmod after booting to see if the driver has already loaded?

3

Hi

In my setup Kernel modules are not getting loaded after bootup. I have checked lsmod and tmp102 module is not present after bootup.

I also tried without loading the driver, only using only i2c-utils to check if sensor responds to read/write calls and seems, its not responding to i2cget/i2cset calls also.

There are other i2c chips which will work on same i2c1 port, but not this tmp102.

4

If you run i2cdetect without the tmp102 module is it missing ?

5

Yes.

6

Ok strange that i2cdetect can see the device but the driver fails to load. Depending on the protocol for the tmp102 the i2cset/get might not do very much.

7

Yup, I suspected there might be specific way of initialisation of this chip, but if the driver written for this sensor is not able to initialise, read/write then I’ll get another tmp102 and check.

Thanks for looking into the issue.

8

Insmod error 121 looks like the module is invalid.

What is version are you running.
Is the tmp102 module complied by default or did you compile it ?

I don’t have a BBB to hand to check if the module is actually to there

1 Like
9

Nothing special looking at: ti,tmp102.yaml « hwmon « bindings « devicetree « Documentation - kernel/git/torvalds/linux.git - Linux kernel source tree

Regards,

1 Like
10

Bought another tmp102 SparkFun Digital Temperature Sensor - TMP102 (Qwiic) sensor and now I am able to initialize the sensor with tmp102 driver, overlay and using i2c-utils.
Below is log from driver initialization and i2c-utils commands,

[  289.430265] hwmon hwmon0: temp1_input not attached to any thermal zone
[  289.437076] tmp102 1-0048: initialized
[  289.441506] wkup_m3_ipc 44e11324.wkup_m3_ipc: could not get rproc handle
# i2cget -y 1 0x48 0x00
0x1c
# i2cget -y 1 0x48 0x01
0x60
# i2cget -y 1 0x48 0x02

Issue was with previous hw itself.

Thanks & Regards
Mrigendra C.