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, 66 insertions, 0 deletions

diff --git a/Documentation/fb/pvr2fb.rst b/Documentation/fb/pvr2fb.rst
new file mode 100644
index 000000000..315ce085a
--- /dev/null
+++ b/Documentation/fb/pvr2fb.rst
@@ -0,0 +1,66 @@
+===============================================
+pvr2fb - PowerVR 2 graphics frame buffer driver
+===============================================
+
+This is a driver for PowerVR 2 based graphics frame buffers, such as the
+one found in the Dreamcast.
+
+Advantages:
+
+ * It provides a nice large console (128 cols + 48 lines with 1024x768)
+   without using tiny, unreadable fonts (NOT on the Dreamcast)
+ * You can run XF86_FBDev on top of /dev/fb0
+ * Most important: boot logo :-)
+
+Disadvantages:
+
+ * Driver is largely untested on non-Dreamcast systems.
+
+Configuration
+=============
+
+You can pass kernel command line options to pvr2fb with
+`video=pvr2fb:option1,option2:value2,option3` (multiple options should be
+separated by comma, values are separated from options by `:`).
+
+Accepted options:
+
+==========  ==================================================================
+font:X      default font to use. All fonts are supported, including the
+	    SUN12x22 font which is very nice at high resolutions.
+
+
+mode:X      default video mode with format [xres]x[yres]-<bpp>@<refresh rate>
+	    The following video modes are supported:
+	    640x640-16@60, 640x480-24@60, 640x480-32@60. The Dreamcast
+	    defaults to 640x480-16@60. At the time of writing the
+	    24bpp and 32bpp modes function poorly. Work to fix that is
+	    ongoing
+
+	    Note: the 640x240 mode is currently broken, and should not be
+	    used for any reason. It is only mentioned here as a reference.
+
+inverse     invert colors on screen (for LCD displays)
+
+nomtrr      disables write combining on frame buffer. This slows down driver
+	    but there is reported minor incompatibility between GUS DMA and
+	    XFree under high loads if write combining is enabled (sound
+	    dropouts). MTRR is enabled by default on systems that have it
+	    configured and that support it.
+
+cable:X     cable type. This can be any of the following: vga, rgb, and
+	    composite. If none is specified, we guess.
+
+output:X    output type. This can be any of the following: pal, ntsc, and
+	    vga. If none is specified, we guess.
+==========  ==================================================================
+
+X11
+===
+
+XF86_FBDev has been shown to work on the Dreamcast in the past - though not yet
+on any 2.6 series kernel.
+
+Paul Mundt <lethal@linuxdc.org>
+
+Updated by Adrian McMenamin <adrian@mcmen.demon.co.uk>