On Mon, 14 Dec 2020 01:40:32 +0530 Puranjay Mohan <puranjay12@xxxxxxxxx> wrote: > On Sun, Dec 13, 2020 at 9:38 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > > > > On 12/13/20 7:12 AM, Jonathan Cameron wrote: > > > On Wed, 9 Dec 2020 11:48:40 -0800 > > > Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > > > > > >> On 12/9/20 12:11 AM, Alexandru Ardelean wrote: > > >>> On Tue, Dec 8, 2020 at 6:10 PM Puranjay Mohan <puranjay12@xxxxxxxxx> wrote: > > >>>> > > >>>> I have this TI's TMP117 sensor with me and I was thinking about writing an > > >>>> IIO driver for it as a hobby project. Is the IIO subsystem the correct > > >>>> place for this driver? if yes, can someone help me get started with this, > > >>>> I haven't written an IIO driver before. I have this sensor and also a > > >>>> raspberry pi with me for testing. > > >>> > > >>> This could also fit into drivers/hwmon. > > >>> Looking at the HWMON subsystem there are more TMP drivers there > > >>> (TMP102/103/108/401/513). > > >>> The first 3 seem a bit more similar to TMP117 (in terms of register map). > > >>> > > >> > > >> It would probably be better suited for hwmon (it has limit registers, > > >> suggesting a common use as hardware monitoring device). > > > It is a curious part. I suspect TI based their design for a medical grade > > > digital thermometer chip on an existing hwmon part. > > > > > > The limit registers are very simple so could be supported by IIO. > > > This sits somewhere in the middle of high end thermocouple chips which > > > tend to be in IIO and typically lower accuracy / range hwmon parts. > > > > > > It's in the fuzzy borderline region so I doubt anyone would raise strong > > > objections to which subsystem it was in. Guenter has fallen on the > > > hwmon side of things and I'm fine with that. > > > > > > > On the other side, it turns out that there is already tmp107 support > > in iio, and tmp107 is pretty much the spi equivalent of the same chip. > > Yes, you are right, tmp107 is very similar to tmp117, but it is less accurate > and it doesn't include the OFFSET functionality. Actually, I had seen the > tmp107 register in IIO and thought that tmp117 should go in IIO, > hence, I wrote this email. > > So, is it fine if I write the IIO driver for this sensor? Actually, > this will just > be a hobby project for me so It doesn't bother me if it goes in hwmon or IIO. Sounds good to me. Jonathan > > > So it really depends on the use case. If the user wants to use the iio > > subsystem, I am fine with it. We just need to remind people that this > > implies no or only limited hwmon support. > > > > [ I really need to spend the time to write a hwmon->iio bridge. > > The iio->hwmon bridge is a bit limited - I have not been able to > > figure out how to support limit registers (or event values) > > and events, and I don't think it is possible. ] > > > > Guenter > > > > > Jonathan > > > > > >> > > >>> Let's see what others have to add. > > >>> But, all-in-all whatever driver you end up writing, the easiest method > > >>> is to copy an existing similar driver and extend it. > > >>> Sometimes, a part can be added to an existing driver. > > >>> At a quick scan through existing drivers, it doesn't look like TMP117 > > >>> is similar to existing drivers, so it may require a new driver > > >>> altogether. > > >> > > >> I don't see an immediate match either, but the tmp102 hwmon driver > > >> might be a good start. > > >> > > >> Guenter > > >> > > >>> I may have missed something though. > > >>> > > >>> Thanks > > >>> Alex > > >>> > > >>>> > > >>>> -- > > >>>> Thanks and Regards > > >>>> > > >>>> Yours Truly, > > >>>> > > >>>> Puranjay Mohan > > >> > > > > > > >
