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, 100 insertions, 0 deletions

diff --git a/Documentation/admin-guide/media/technisat.rst b/Documentation/admin-guide/media/technisat.rst
new file mode 100644
index 000000000..9eaa12366
--- /dev/null
+++ b/Documentation/admin-guide/media/technisat.rst
@@ -0,0 +1,100 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+How to set up the Technisat/B2C2 Flexcop devices
+================================================
+
+.. note::
+
+   This documentation is outdated.
+
+Author: Uwe Bugla <uwe.bugla@gmx.de> August 2009
+
+Find out what device you have
+-----------------------------
+
+Important Notice: The driver does NOT support Technisat USB 2 devices!
+
+First start your linux box with a shipped kernel:
+
+.. code-block:: none
+
+	lspci -vvv for a PCI device (lsusb -vvv for an USB device) will show you for example:
+	02:0b.0 Network controller: Techsan Electronics Co Ltd B2C2 FlexCopII DVB chip /
+	Technisat SkyStar2 DVB card (rev 02)
+
+	dmesg | grep frontend may show you for example:
+	DVB: registering frontend 0 (Conexant CX24123/CX24109)...
+
+Kernel compilation:
+-------------------
+
+If the Flexcop / Technisat is the only DVB / TV / Radio device in your box
+get rid of unnecessary modules and check this one:
+
+``Multimedia support`` => ``Customise analog and hybrid tuner modules to build``
+
+In this directory uncheck every driver which is activated there
+(except ``Simple tuner support`` for ATSC 3rd generation only -> see case 9 please).
+
+Then please activate:
+
+- Main module part:
+
+  ``Multimedia support`` => ``DVB/ATSC adapters`` => ``Technisat/B2C2 FlexcopII(b) and FlexCopIII adapters``
+
+  #) => ``Technisat/B2C2 Air/Sky/Cable2PC PCI`` (PCI card) or
+  #) => ``Technisat/B2C2 Air/Sky/Cable2PC USB`` (USB 1.1 adapter)
+     and for troubleshooting purposes:
+  #) => ``Enable debug for the B2C2 FlexCop drivers``
+
+- Frontend / Tuner / Demodulator module part:
+
+  ``Multimedia support`` => ``DVB/ATSC adapters``
+   => ``Customise the frontend modules to build`` ``Customise DVB frontends`` =>
+
+  - SkyStar DVB-S Revision 2.3:
+
+    #) => ``Zarlink VP310/MT312/ZL10313 based``
+    #) => ``Generic I2C PLL based tuners``
+
+  - SkyStar DVB-S Revision 2.6:
+
+    #) => ``ST STV0299 based``
+    #) => ``Generic I2C PLL based tuners``
+
+  - SkyStar DVB-S Revision 2.7:
+
+    #) => ``Samsung S5H1420 based``
+    #) => ``Integrant ITD1000 Zero IF tuner for DVB-S/DSS``
+    #) => ``ISL6421 SEC controller``
+
+  - SkyStar DVB-S Revision 2.8:
+
+    #) => ``Conexant CX24123 based``
+    #) => ``Conexant CX24113/CX24128 tuner for DVB-S/DSS``
+    #) => ``ISL6421 SEC controller``
+
+  - AirStar DVB-T card:
+
+    #) => ``Zarlink MT352 based``
+    #) => ``Generic I2C PLL based tuners``
+
+  - CableStar DVB-C card:
+
+    #) => ``ST STV0297 based``
+    #) => ``Generic I2C PLL based tuners``
+
+  - AirStar ATSC card 1st generation:
+
+    #) => ``Broadcom BCM3510``
+
+  - AirStar ATSC card 2nd generation:
+
+    #) => ``NxtWave Communications NXT2002/NXT2004 based``
+    #) => ``Generic I2C PLL based tuners``
+
+  - AirStar ATSC card 3rd generation:
+
+    #) => ``LG Electronics LGDT3302/LGDT3303 based``
+    #) ``Multimedia support`` => ``Customise analog and hybrid tuner modules to build`` => ``Simple tuner support``
+