On 20/10/2023 13:18, Balas, Eliza wrote:
>> -----Original Message-----
>> From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>> Sent: Thursday, October 19, 2023 20:57
>> To: Balas, Eliza <Eliza.Balas@xxxxxxxxxx>
>> Cc: linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; Rob Herring <robh+dt@xxxxxxxxxx>; Krzysztof Kozlowski
>> <krzysztof.kozlowski+dt@xxxxxxxxxx>; Conor Dooley <conor+dt@xxxxxxxxxx>; Derek Kiernan <derek.kiernan@xxxxxxx>; Dragan
>> Cvetic <dragan.cvetic@xxxxxxx>; Arnd Bergmann <arnd@xxxxxxxx>
>> Subject: Re: [PATCH v3 2/2] drivers: misc: adi-axi-tdd: Add TDD engine
>>
>> [External]
>>
>> On Thu, Oct 19, 2023 at 03:56:46PM +0300, Eliza Balas wrote:
>>> +config ADI_AXI_TDD
>>> + tristate "Analog Devices TDD Engine support"
>>> + depends on HAS_IOMEM
>>> + select REGMAP_MMIO
>>> + help
>>> + The ADI AXI TDD core is the reworked and generic TDD engine which
>>> + was developed for general use in Analog Devices HDL projects. Unlike
>>> + the previous TDD engine, this core can only be used standalone mode,
>>> + and is not embedded into other devices.
>>
>> What does "previous" mean here? That's not relevant for a kernel help
>> text, is it?
>>
>> Also, what is the module name? Why would someone enable this? What
>> userspace tools use it?
>>
>>
>>> +
>>> config DUMMY_IRQ
>>> tristate "Dummy IRQ handler"
>>> help
>>
>> Why put your entry in this specific location in the file?
>>
>>> +static int adi_axi_tdd_parse_ms(struct adi_axi_tdd_state *st,
>>> + const char *buf,
>>> + u64 *res)
>>> +{
>>> + u64 clk_rate = READ_ONCE(st->clk.rate);
>>> + char *orig_str, *modf_str, *int_part, frac_part[7];
>>> + long ival, frac;
>>> + int ret;
>>> +
>>> + orig_str = kstrdup(buf, GFP_KERNEL);
>>> + int_part = strsep(&orig_str, ".");
>>
>> Why are we parsing floating point in the kernel? Please just keep the
>> api simple so that we don't have to try to do any type of parsing other
>> than turning a single text number into a value.
>>
>
> The adi_axi_tdd_parse_ms function does almost the same thing as the
> iio_str_to_fixpoint() function which already exists in kernel.
> It parses a fixed-point number from a string.
> The __iio_str_to_fixpoint is used in a similar way, as I intend to use adi_axi_tdd_parse_ms.
> It writes to a channel the corresponding scale (micro,nano) for a value.
>
> Since the device is not an iio device, using an iio function would be confusing.
> That is the reason for creating the adi_axi_tdd_parse_ms function, which is easier
> to understand since I don't have to make all the multiplications that are made
> in the __iio_str_to_fixpoint function.
Why did you skip other comments?
Best regards,
Krzysztof
