iio: proximity: vl53l0x-i2c: claim direct mode for raw readsgrafted

vl53l0x_read_raw() starts a single-shot ranging measurement and reads
back the result. Once the triggered buffer is enabled the sensor runs in
continuous mode and its data-ready interrupt is routed to the trigger,
so a concurrent in_distance_raw read disturbs the streaming setup and
never gets its completion, returning -ETIMEDOUT.

The original submission claimed direct mode here, but it was dropped
during review because the driver had no buffer support at the time [1].
Continuous (buffered) mode was later added without restoring the
claim [2], reintroducing the conflict.

Reject direct reads while buffered capture is active by claiming direct
mode around the measurement, as the vl53l1x sibling already does.

Fixes: 762186c6e7b1 ("iio: proximity: vl53l0x-i2c: Added continuous mode support")
Link: https://lore.kernel.org/linux-iio/20180911160300.GA9212@himanshu-Vostro-3559/ [1]
Link: https://lore.kernel.org/linux-iio/20240909101508.263085-3-abhashkumarjha123@gmail.com/ [2]
Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

1 files changed, 108 insertions, 0 deletions

diff --git a/Documentation/filesystems/adfs.rst b/Documentation/filesystems/adfs.rst
new file mode 100644
index 000000000..5b22cae38
--- /dev/null
+++ b/Documentation/filesystems/adfs.rst
@@ -0,0 +1,108 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===============================
+Acorn Disc Filing System - ADFS
+===============================
+
+Filesystems supported by ADFS
+-----------------------------
+
+The ADFS module supports the following Filecore formats which have:
+
+- new maps
+- new directories or big directories
+
+In terms of the named formats, this means we support:
+
+- E and E+, with or without boot block
+- F and F+
+
+We fully support reading files from these filesystems, and writing to
+existing files within their existing allocation.  Essentially, we do
+not support changing any of the filesystem metadata.
+
+This is intended to support loopback mounted Linux native filesystems
+on a RISC OS Filecore filesystem, but will allow the data within files
+to be changed.
+
+If write support (ADFS_FS_RW) is configured, we allow rudimentary
+directory updates, specifically updating the access mode and timestamp.
+
+Mount options for ADFS
+----------------------
+
+  ============  ======================================================
+  uid=nnn	All files in the partition will be owned by
+		user id nnn.  Default 0 (root).
+  gid=nnn	All files in the partition will be in group
+		nnn.  Default 0 (root).
+  ownmask=nnn	The permission mask for ADFS 'owner' permissions
+		will be nnn.  Default 0700.
+  othmask=nnn	The permission mask for ADFS 'other' permissions
+		will be nnn.  Default 0077.
+  ftsuffix=n	When ftsuffix=0, no file type suffix will be applied.
+		When ftsuffix=1, a hexadecimal suffix corresponding to
+		the RISC OS file type will be added.  Default 0.
+  ============  ======================================================
+
+Mapping of ADFS permissions to Linux permissions
+------------------------------------------------
+
+  ADFS permissions consist of the following:
+
+	- Owner read
+	- Owner write
+	- Other read
+	- Other write
+
+  (In older versions, an 'execute' permission did exist, but this
+  does not hold the same meaning as the Linux 'execute' permission
+  and is now obsolete).
+
+  The mapping is performed as follows::
+
+	Owner read				-> -r--r--r--
+	Owner write				-> --w--w---w
+	Owner read and filetype UnixExec	-> ---x--x--x
+    These are then masked by ownmask, eg 700	-> -rwx------
+	Possible owner mode permissions		-> -rwx------
+
+	Other read				-> -r--r--r--
+	Other write				-> --w--w--w-
+	Other read and filetype UnixExec	-> ---x--x--x
+    These are then masked by othmask, eg 077	-> ----rwxrwx
+	Possible other mode permissions		-> ----rwxrwx
+
+  Hence, with the default masks, if a file is owner read/write, and
+  not a UnixExec filetype, then the permissions will be::
+
+			-rw-------
+
+  However, if the masks were ownmask=0770,othmask=0007, then this would
+  be modified to::
+
+			-rw-rw----
+
+  There is no restriction on what you can do with these masks.  You may
+  wish that either read bits give read access to the file for all, but
+  keep the default write protection (ownmask=0755,othmask=0577)::
+
+			-rw-r--r--
+
+  You can therefore tailor the permission translation to whatever you
+  desire the permissions should be under Linux.
+
+RISC OS file type suffix
+------------------------
+
+  RISC OS file types are stored in bits 19..8 of the file load address.
+
+  To enable non-RISC OS systems to be used to store files without losing
+  file type information, a file naming convention was devised (initially
+  for use with NFS) such that a hexadecimal suffix of the form ,xyz
+  denoted the file type: e.g. BasicFile,ffb is a BASIC (0xffb) file.  This
+  naming convention is now also used by RISC OS emulators such as RPCEmu.
+
+  Mounting an ADFS disc with option ftsuffix=1 will cause appropriate file
+  type suffixes to be appended to file names read from a directory.  If the
+  ftsuffix option is zero or omitted, no file type suffixes will be added.