Re: [1/2] pmbus: added tps544c20 driver with trimming support

From: Romain Porte
Date: Mon Oct 23 2017 - 09:34:39 EST


On 21/10/2017 18:20, Guenter Roeck wrote:
This should be part of device programming in manufacturing, just like,
say, current calibration. It should not be user programmable, even less so
runtime programmable. On top of that, we definitely don't want to make
STORE_USER_ALL available to user space. Both can too easily result in
a bricked device (bad enough that the register values are writable using
i2cset).
After some work, I have tested accessing these registers using i2cget and i2cset and I can reproduce all the features I have implemented in this driver. I think am going to re-implement my calibration procedure using i2cget and i2cset in userspace.

I thought it could be a good idea to make this accessible by sysfs entries. Since one must read the datasheet for calibrating the component, I guess it is not a big deal to have users to find register addresses/sizes and write to them using userspace commands instead of (over?)simplifying it by providing dedicated sysfs entries.

Romain.