doc: add texinfodocs and infodocs targets

Sphinx supports generating Texinfo sources and Info documentation,
which can be navigated easily and is convenient to search (via the
indexed nodes or anchors, for example).

Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>
Link: https://lore.kernel.org/r/20221116190210.28407-2-maxim.cournoyer@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/Makefile

@@ -95,6 +95,15 @@ htmldocs:
 	@$(srctree)/scripts/sphinx-pre-install --version-check
 	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,html,$(var),,$(var)))
 
+texinfodocs:
+	@$(srctree)/scripts/sphinx-pre-install --version-check
+	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,texinfo,$(var),texinfo,$(var)))
+
+# Note: the 'info' Make target is generated by sphinx itself when
+# running the texinfodocs target define above.
+infodocs: texinfodocs
+	$(MAKE) -C $(BUILDDIR)/texinfo info
+
 linkcheckdocs:
 	@$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,linkcheck,$(var),,$(var)))
 
@@ -143,6 +152,8 @@ cleandocs:
 dochelp:
 	@echo  ' Linux kernel internal documentation in different formats from ReST:'
 	@echo  '  htmldocs        - HTML'
+	@echo  '  texinfodocs     - Texinfo'
+	@echo  '  infodocs        - Info'
 	@echo  '  latexdocs       - LaTeX'
 	@echo  '  pdfdocs         - PDF'
 	@echo  '  epubdocs        - EPUB'

Documentation/userspace-api/media/Makefile

@@ -47,10 +47,11 @@ $(BUILDDIR)/lirc.h.rst: ${UAPI}/lirc.h ${PARSER} $(SRC_DIR)/lirc.h.rst.exception
 
 # Media build rules
 
-.PHONY: all html epub xml latex
+.PHONY: all html texinfo epub xml latex
 
 all: $(IMGDOT) $(BUILDDIR) ${TARGETS}
 html: all
+texinfo: all
 epub: all
 xml: all
 latex: $(IMGPDF) all

Makefile

@@ -1785,7 +1785,7 @@ $(help-board-dirs): help-%:
 # Documentation targets
 # ---------------------------------------------------------------------------
 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
-	       linkcheckdocs dochelp refcheckdocs
+	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
 PHONY += $(DOC_TARGETS)
 $(DOC_TARGETS):
 	$(Q)$(MAKE) $(build)=Documentation $@