gnu: linux-libre: Enable building info doc.

* gnu/packages/patches/linux-libre-infodocs-target.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/linux.scm (linux-libre-6.0-source, linux-libre-5.15-source)
(linux-libre-5.10-source): Apply above patch.
(doc-supported?): New procedure.
(make-linux-libre) [DOC-SUPPORTED?]: Add new patch in
the default patches used.  Add a BUILD-DOC? argument.
(make-linux-libre*): Add a BUILD-DOC? argument.  Validate BUILD-DOC? for
supported VERSION.
[arguments]: Conditionally add the build-doc and install-doc phases.
[native-inputs]: Conditionally add fontconfig, graphviz, python-wrapper,
python-sphinx, texinfo and which.

1 files changed, 88 insertions, 0 deletions

diff --git a/gnu/packages/patches/linux-libre-infodocs-target.patch b/gnu/packages/patches/linux-libre-infodocs-target.patch
new file mode 100644
index 0000000000..e9e6495c26
--- /dev/null
+++ b/gnu/packages/patches/linux-libre-infodocs-target.patch
@@ -0,0 +1,88 @@
+Upstream status: https://marc.info/?l=linux-doc&m=166861669723994&w=2
+
+From 7edb5b278ee383ff9bed525329b2cdbe22317bf2 Mon Sep 17 00:00:00 2001
+From: Maxim Cournoyer <maxim.cournoyer@gmail.com>
+Date: Mon, 14 Nov 2022 22:51:11 -0500
+Subject: [PATCH] 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).
+
+This change also causes the html output to appear under its own output
+sub-directory, which makes it easier to install, since it's clean from
+.doctrees or other output formats.
+
+Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>
+---
+ Documentation/Makefile                     | 13 ++++++++++++-
+ Documentation/userspace-api/media/Makefile |  3 ++-
+ Makefile                                   |  2 +-
+ 3 files changed, 15 insertions(+), 3 deletions(-)
+
+diff --git a/Documentation/Makefile b/Documentation/Makefile
+index 64d44c1ecad3..bd8dac560633 100644
+--- a/Documentation/Makefile
++++ b/Documentation/Makefile
+@@ -93,7 +93,16 @@ quiet_cmd_sphinx = SPHINX  $@ --> file://$(abspath $(BUILDDIR)/$3/$4)
+ 
+ htmldocs:
+ 	@$(srctree)/scripts/sphinx-pre-install --version-check
+-	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,html,$(var),,$(var)))
++	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,html,$(var),html,$(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'
+diff --git a/Documentation/userspace-api/media/Makefile b/Documentation/userspace-api/media/Makefile
+index 00922aa7efde..3d8aaf5c253b 100644
+--- a/Documentation/userspace-api/media/Makefile
++++ b/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
+diff --git a/Makefile b/Makefile
+index 58cd4f5e1c3a..b3266c408b6c 100644
+--- a/Makefile
++++ b/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 $@
+
+base-commit: 81e7cfa3a9eb4ba6993a9c71772fdab21bc5d870
+-- 
+2.38.1
+