[PATCH v5 02/11] pinctrl: Reformat documentation in dm/pinctrl.h

[Sean Anderson <seanga2@gmail.com>]

On 9/2/20 8:26 AM, Heinrich Schuchardt wrote:
> On 15.08.20 17:52, Sean Anderson wrote:
>> This normalizes the documentatation to conform to kernel-doc style [1]. It
> 
> Nits:
> %s/documentatation/documentation/
> 
>> also moves the documentation for pinctrl_ops inline, and adds argument and
>> return-value documentation. I have kept the usual function style for these
>> comments. I could not find any existing examples of function documentation
>> inside structs.
>>
>> [1] https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html
>>
>> Signed-off-by: Sean Anderson <seanga2@gmail.com>
>> Reviewed-by: Simon Glass <sjg@chromium.org>
> 
> 
> Before and after this patch the documentation format is incorrect. See
> output below for the situation after the patch.
> 
> Please include include/dm/pinctrl.h into doc/api/index.rst via a new
> file doc/api/pnctrl.rst.
> 
> A documentation style accepted by 'make htmldocs' is:
> 
> struct pinctrl_ops {
>     /**
>      * @get_pins_count:           Get the number of selectable pins
>      *
>      * @get_pins_count.dev:       Pinctrl device to use
>      *
>      * This function is necessary to parse the "pins" property
>      * in DTS.
>      *
>      * @get_pins_count.Return:    number of selectable named pins
>      *                            available in this driver
>      */
>     int (*get_pins_count)(struct udevice *dev);
> 
> See the nested structures in
> 
> https://www.kernel.org/doc/html/v5.7/doc-guide/kernel-doc.html#in-line-member-documentation-comments
> and
> https://www.kernel.org/doc/html/v5.7/doc-guide/kernel-doc.html#nested-structs-unions

Thanks for suggesting those changes. This works better. As far as I can
tell, fully-qualified members are only necessary when documenting nested
structs at the top-level. When using in-line documentation, members are
automatically nested. With that in mind, I am using the following format

	/**
	 * @pinmux_property_set: Enable a pinmux group
	 *
	 * @dev: Pinctrl device to use
	 *
	 * @pinmux_group: A u32 representing the pin identifier and mux
	 *                settings. The exact format of a pinmux group is left
	 *                up to the driver.
	 *
	 * Mux a single pin to a single function based on a driver-specific
	 * pinmux group. This function is necessary for parsing the "pinmux"
	 * property in DTS, and for pin-muxing against a pinmux group.
	 *
	 * @Return:
	 *	Pin selector for the muxed pin if OK, or negative error code on
	 *	failure
	 */
	int (*pinmux_property_set)(struct udevice *dev, u32 pinmux_group);

However, I am having some problems with multi-line descriptions. In the
example above, the desciption for @pinmux_group has the first line
bolded and the rest of the description is typeset as normal, but is
indented. The generated html is

<dl class="docutils">
<dt><strong>pinmux_group</strong>: A u32 representing the pin identifier
and mux</dt>
<dd>settings. The exact format of a pinmux group is left up to the
driver.</dd>
</dl>

However, it should be something like

<p><strong>pinmux_group</strong>: A u32 representing the pin identifier
and mux settings. The exact format of a pinmux group is left up to the
driver.</p>

I have also tried an alternate style, as shown for @Return. However,
this too generated the wrong html:

<dl class="last docutils">
<dt><strong>Return</strong>:</dt>
<dd>Pin selector for the muxed pin if OK, or negative error code on
failure</dd>
</dl>

where it should generate something like

<p class="last"><strong>Return</strong>: Pin selector for the muxed pin
if OK, or negative error code on failure</p>

Do you have any suggestions for generating the latter forms? My current
work is at [1].

--Sean

[1] https://github.com/Forty-Bot/u-boot/commit/e835cf9552dc96438699806731a208b40daead7b