[PATCH v2,1/2] wifi: mac80211: Add utilities for converting op_class

[Johannes Berg]

Btw, I ended looking at this again...

On Mon, 2023-11-13 at 10:11 +0800, Michael-CY Lee wrote: 
> +/**
> + * ieee80211_operating_class_to_center_freq - convert operating class to
> + * center frequency
> + *
> + * @operating_class: the operating class to convert
> + * @chan: the ieee80211_channel to convert
> + * @center_freq1: cneter frequency 1 pointer to fill
> + * @center_freq2: cneter frequency 2 pointer to fill

typos here ("center")

But maybe it'd be better to fill (or update, we could pass the channel
pointer in it) a chandef struct? Then it could also be more easily
extended to understand more opclasses in the future, perhaps S1G or DMG?

> + *
> + * Returns %true if the conversion was successful, %false otherwise.
> + */
> +bool ieee80211_operating_class_to_center_freq(u8 operating_class,
> +					      struct ieee80211_channel *chan,
> +					      u32 *center_freq1,
> +					      u32 *center_freq2);
> +
> +/**
> + * ieee80211_operating_class_to_chan_width - convert operating class to
> + * nl80211 channel width
> + *
> + * @operating_class: the operating class to convert
> + */
> +enum nl80211_chan_width
> +ieee80211_operating_class_to_chan_width(u8 operating_class);

And you'd actually get both in one function call? The chan ->
center_freq anyway implies you know the width, no? Is this really needed
separately?

>  /**
>   * ieee8 0211_chandef_to_operating_class - convert chandef to operation class

This also converts the other way around, btw.

> +	case 135: /* 6 GHz band; 80+80 MHz; channels 1,5,..,229 */
> +		/* TODO How to know the center_freq2 of 80+80 MHz?*/
> +		*center_freq1 = 0;

Well, you don't, from this. I'm actually a bit surprised 80+80 exists in
6 GHz, I thought it was treated more or less as a dead end.

johannes