Problems with ads1115 installation on Raspberry Pi

I’m trying to install ads1115 on two versions of Raspbian, the latest, 5.4.83+, and an old one, 4.4.10+, both on a Raspberry Pi Zero. I’m having trouble with both.

Let’s take the latest OS first. I followed the instructions in a Seeed doc about using the ads1115. I edited /boot/config.txt and get the proper results with lsmod | grep ads once I reboot. The device is present in i2cdetect -y 1, at address 0x49. But the /sys/bus/iio/devices folder, where there should be industrial_io files that access the device, is empty. How do I fix this ?

Now let’s take the older OS, where I need to update some running systems. Following the same Seeed doc, I edited /boot/config.txt and rebooted. The device is present at 0x49. But the driver must be missing since I don’t get anything when I do lsmod | grep ads. I know the driver for the ads1115 was available for this older OS, but either I don’t have it or it’s not active. How do I fix this ?

Thank you in advance for your help.