From e24328974a88aa8541e94e8bb8dfa2ade1b3c45d Mon Sep 17 00:00:00 2001 From: Donggeun Yoo Date: Wed, 2 Sep 2026 00:21:26 +0900 Subject: iio: proximity: vl53l0x-i2c: claim direct mode for raw reads 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 Cc: stable@vger.kernel.org Signed-off-by: Jonathan Cameron --- Documentation/arch/arc/arc.rst | 85 +++++++++++++++++++++++++++++++++++++ Documentation/arch/arc/features.rst | 3 ++ Documentation/arch/arc/index.rst | 10 +++++ 3 files changed, 98 insertions(+) create mode 100644 Documentation/arch/arc/arc.rst create mode 100644 Documentation/arch/arc/features.rst create mode 100644 Documentation/arch/arc/index.rst (limited to 'Documentation/arch/arc') diff --git a/Documentation/arch/arc/arc.rst b/Documentation/arch/arc/arc.rst new file mode 100644 index 000000000..5923dee37 --- /dev/null +++ b/Documentation/arch/arc/arc.rst @@ -0,0 +1,85 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Linux kernel for ARC processors +******************************* + +Other sources of information +############################ + +Below are some resources where more information can be found on +ARC processors and relevant open source projects. + +- ``_ - Community portal for open source on ARC. + Good place to start to find relevant FOSS projects, toolchain releases, + news items and more. + +- ``_ - + Home for all development activities regarding open source projects for + ARC processors. Some of the projects are forks of various upstream projects, + where "work in progress" is hosted prior to submission to upstream projects. + Other projects are developed by Synopsys and made available to community + as open source for use on ARC Processors. + +- `Official Synopsys ARC Processors website + `_ - + location, with access to some IP documentation (`Programmer's Reference + Manual, AKA PRM for ARC HS processors + `_) + and free versions of some commercial tools (`Free nSIM + `_ and + `MetaWare Light Edition `_). + Please note though, registration is required to access both the documentation and + the tools. + +Important note on ARC processors configurability +################################################ + +ARC processors are highly configurable and several configurable options +are supported in Linux. Some options are transparent to software +(e.g., cache geometries), some can be detected at runtime and configured +and used accordingly, while some need to be explicitly selected or configured +in the kernel's configuration utility (AKA "make menuconfig"). + +However not all configurable options are supported when an ARC processor +is to run Linux. SoC design teams should refer to "Appendix E: +Configuration for ARC Linux" in the ARC HS Databook for configurability +guidelines. + +Following these guidelines and selecting valid configuration options +up front is critical to help prevent any unwanted issues during +SoC bringup and software development in general. + +Building the Linux kernel for ARC processors +############################################ + +The process of kernel building for ARC processors is the same as for any other +architecture and could be done in 2 ways: + +- Cross-compilation: process of compiling for ARC targets on a development + host with a different processor architecture (generally x86_64/amd64). +- Native compilation: process of compiling for ARC on a ARC platform + (hardware board or a simulator like QEMU) with complete development environment + (GNU toolchain, dtc, make etc) installed on the platform. + +In both cases, up-to-date GNU toolchain for ARC for the host is needed. +Synopsys offers prebuilt toolchain releases which can be used for this purpose, +available from: + +- Synopsys GNU toolchain releases: + ``_ + +- Linux kernel compilers collection: + ``_ + +- Bootlin's toolchain collection: ``_ + +Once the toolchain is installed in the system, make sure its "bin" folder +is added in your ``PATH`` environment variable. Then set ``ARCH=arc`` & +``CROSS_COMPILE=arc-linux`` (or whatever matches installed ARC toolchain prefix) +and then as usual ``make defconfig && make``. + +This will produce "vmlinux" file in the root of the kernel source tree +usable for loading on the target system via JTAG. +If you need to get an image usable with U-Boot bootloader, +type ``make uImage`` and ``uImage`` will be produced in ``arch/arc/boot`` +folder. diff --git a/Documentation/arch/arc/features.rst b/Documentation/arch/arc/features.rst new file mode 100644 index 000000000..49ff446ff --- /dev/null +++ b/Documentation/arch/arc/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: features arc diff --git a/Documentation/arch/arc/index.rst b/Documentation/arch/arc/index.rst new file mode 100644 index 000000000..10bf8c270 --- /dev/null +++ b/Documentation/arch/arc/index.rst @@ -0,0 +1,10 @@ +=================== +ARC architecture +=================== + +.. toctree:: + :maxdepth: 1 + + arc + + features -- cgit v1.3.1