AS621x driver

AS621x driver

[Joseph Strauss]

The AS621x is a digital temperature sensor chip with an I2C interface. It has applications in electronic equipment, personal computers, wearables, and HVAC. The datasheet can be found here: https://ams.com/documents/20143/36005/AS621x_DS000677_4-00.pdf

I wish to write a driver for this device and contribute it to the kernel, as my first module. It being my first module, I wanted to make sure that this was a worthy use of everyone's time and that it could be useful at some point. Sparkfun provides a convenient breakout board already, which is the one that I will be using.

After searching through the mailing list archive, I found a set of patches from 2016 for the AS6200 as part of the iio subsystem. For reasons I could not find, the driver never got merged. I guess the original developers moved on to something else. Additionally, they were discussing towards the end how the hwmon subsystem may have been a better fit for the driver. Therefore, I wanted to hear everyone's thoughts on writing this driver before I get started on it. From what I can tell, it does not seem much more complex than some other temperature sensor drivers in the kernel, such as the tmp102.

Regards,
Joe Strauss

Re: AS621x driver

[Guenter Roeck]

On Sun, Aug 14, 2022 at 07:08:18PM +0000, Joseph Strauss wrote:
> The AS621x is a digital temperature sensor chip with an I2C interface. It has applications in electronic equipment, personal computers, wearables, and HVAC. The datasheet can be found here: https://ams.com/documents/20143/36005/AS621x_DS000677_4-00.pdf
> 
> I wish to write a driver for this device and contribute it to the kernel, as my first module. It being my first module, I wanted to make sure that this was a worthy use of everyone's time and that it could be useful at some point. Sparkfun provides a convenient breakout board already, which is the one that I will be using.
> 
> After searching through the mailing list archive, I found a set of patches from 2016 for the AS6200 as part of the iio subsystem. For reasons I could not find, the driver never got merged. I guess the original developers moved on to something else. Additionally, they were discussing towards the end how the hwmon subsystem may have been a better fit for the driver. Therefore, I wanted to hear everyone's thoughts on writing this driver before I get started on it. From what I can tell, it does not seem much more complex than some other temperature sensor drivers in the kernel, such as the tmp102.
> 

If you look really closely, you'll notice that the chip is LM75 compatible.
Except for the resolution it seems to be fully compatible to TPM112.
Given that, there is no need for a new driver. Extending the lm75 driver
should be sufficient.

Guenter