Merge tag 'docs-5.4' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "It's a somewhat calmer cycle for docs this time, as the churn of the
  mass RST conversion is happily mostly behind us.

   - A new document on reproducible builds.

   - We finally got around to zapping the documentation for hardware
     support that was removed in 2004; one doesn't want to rush these
     things.

   - The usual assortment of fixes, typo corrections, etc"

* tag 'docs-5.4' of git://git.lwn.net/linux: (67 commits)
  Documentation: kbuild: Add document about reproducible builds
  docs: printk-formats: Stop encouraging use of unnecessary %h[xudi] and %hh[xudi]
  Documentation: Add "earlycon=sbi" to the admin guide
  doc:lock: remove reference to clever use of read-write lock
  devices.txt: improve entry for comedi (char major 98)
  docs: mtd: Update spi nor reference driver
  doc: arm64: fix grammar dtb placed in no attributes region
  Documentation: sysrq: don't recommend 'S' 'U' before 'B'
  mailmap: Update email address for Quentin Perret
  docs: ftrace: clarify when tracing is disabled by the trace file
  docs: process: fix broken link
  Documentation/arm/samsung-s3c24xx: Remove stray U+FEFF character to fix title
  Documentation/arm/sa1100/assabet: Fix 'make assabet_defconfig' command
  Documentation/arm/sa1100: Remove some obsolete documentation
  docs/zh_CN: update Chinese howto.rst for latexdocs making
  Documentation: virt: Fix broken reference to virt tree's index
  docs: Fix typo on pull requests guide
  kernel-doc: Allow anonymous enum
  Documentation: sphinx: Don't parse socket() as identifier reference
  Documentation: sphinx: Add missing comma to list of strings
  ...

1 files changed, 27 insertions, 0 deletions

diff --git a/Documentation/w1/slaves/w1_ds2406.rst b/Documentation/w1/slaves/w1_ds2406.rst
new file mode 100644
index 000000000000..d3e68266084f
--- /dev/null
+++ b/Documentation/w1/slaves/w1_ds2406.rst
@@ -0,0 +1,27 @@
+=======================
+w1_ds2406 kernel driver
+=======================
+
+Supported chips:
+
+  * Maxim DS2406 (and other family 0x12) addressable switches
+
+Author: Scott Alfter <scott@alfter.us>
+
+Description
+-----------
+
+The w1_ds2406 driver allows connected devices to be switched on and off.
+These chips also provide 128 bytes of OTP EPROM, but reading/writing it is
+not supported.  In TSOC-6 form, the DS2406 provides two switch outputs and
+can be provided with power on a dedicated input.  In TO-92 form, it provides
+one output and uses parasitic power only.
+
+The driver provides two sysfs files.  state is readable; it gives the
+current state of each switch, with PIO A in bit 0 and PIO B in bit 1.  The
+driver ORs this state with 0x30, so shell scripts get an ASCII 0/1/2/3 to
+work with.  output is writable; bits 0 and 1 control PIO A and B,
+respectively.  Bits 2-7 are ignored, so it's safe to write ASCII data.
+
+CRCs are checked on read and write.  Failed checks cause an I/O error to be
+returned.  On a failed write, the switch status is not changed.