Re: [PATCH v2 6/7] iio: adc: ad485x: add ad485x driver

[David Lechner]

On 10/11/24 6:27 AM, Miclaus, Antoniu wrote:
>> On 10/8/24 5:48 AM, Miclaus, Antoniu wrote:
>>>>> +static int ad485x_get_calibscale(struct ad485x_state *st, int ch, int *val,
>> int
>>>> *val2)
>>>>> +{
>>>>> +       unsigned int reg_val;
>>>>> +       int gain;
>>>>
>>>> Should be u8 gain[2] and...
>>>
>>> As discussed in previous patch series, the bulk operations won't work for
>> these
>>> chips. The CS needs to be raised between each byte read/written.
>>>
>>
>> So the datasheet is wrong and Streaming Instruction Mode doesn't actually
>> work?
>>
>> There is also Nonstreaming Instruction Mode if we need to read/write
>> nonconsecutive
>> registers without deasserting CS.
> 
> The chip was set to Nonstreaming Instruction Mode from the start in the ad485x_setup() function.
> 
> And the datasheet specifies (page 49 of 70):
> "In nonstreaming instruction mode, one or more SPI transactions can be provided in
> a single SPI frame."
> 
> So I guess it is an error in the datasheet.

So maybe regmap bulk operations would work if we change it to
Streaming Instruction Mode (along with the correct increment
direction)?