Re: [PATCH v2 4/5] drivers: iio: adc: LTC2499 support

[Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>]

On Thu, 1 Sep 2022 16:23:09 +0300
Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote:

> On 01/09/2022 15:16, Ciprian Regus wrote:
> > The LTC2499 is a 16-channel (eight differential), 24-bit,
> > ADC with Easy Drive technology and a 2-wire, I2C interface.
> > 
> > Implement support for the LTC2499 ADC by extending the LTC2497
> > driver. A new chip_info struct is added to differentiate between
> > chip types and resolutions when reading data from the device.
> > 
> > Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/2499fe.pdf  
> 
> Missing blank line. Use standard Git tools for handling your patches or
> be sure you produce the same result when using some custom process.

My understanding is Datasheet is a standard tag as part of the main tag block.
There should not be a blank line between that and the Sign off.

+CC Andy who can probably point to a reference for that...

> 
> > Signed-off-by: Ciprian Regus <ciprian.regus@xxxxxxxxxx>  
> 
> (...)
> 
> > +};
> > +
> >  static const struct i2c_device_id ltc2497_id[] = {
> > -	{ "ltc2497", 0 },
> > +	{ "ltc2497", (kernel_ulong_t)&ltc2497_info[TYPE_LTC2497] },
> > +	{ "ltc2499", (kernel_ulong_t)&ltc2497_info[TYPE_LTC2497] },  
> 
> So they are the same, aren't they?
> 
> >  	{ }
> >  };
> >  MODULE_DEVICE_TABLE(i2c, ltc2497_id);
> >  
> >  static const struct of_device_id ltc2497_of_match[] = {
> > -	{ .compatible = "lltc,ltc2497", },
> > +	{ .compatible = "lltc,ltc2497", .data = &ltc2497_info[TYPE_LTC2497] },
> > +	{ .compatible = "lltc,ltc2499", .data = &ltc2497_info[TYPE_LTC2499] },  
> 
> I think this should be split into two patches for easier review - one
> working on driver data for existing variant and second for adding new
> variant 2499.
> 
> >  	{},
> >  };
> >  MODULE_DEVICE_TABLE(of, ltc2497_of_match);
> > diff --git a/drivers/iio/adc/ltc2497.h b/drivers/iio/adc/ltc2497.h
> > index d0b42dd6b8ad..95f6a5f4d4a6 100644
> > --- a/drivers/iio/adc/ltc2497.h
> > +++ b/drivers/iio/adc/ltc2497.h
> > @@ -4,9 +4,20 @@
> >  #define LTC2497_CONFIG_DEFAULT		LTC2497_ENABLE
> >  #define LTC2497_CONVERSION_TIME_MS	150ULL
> >  
> > +enum ltc2497_chip_type {
> > +	TYPE_LTC2496,  
> 
> Why having here 2496 and not using it?
> 
> > +	TYPE_LTC2497,
> > +	TYPE_LTC2499,
> > +};
> > +  
> Krzysztof