6802d3510b
This patch extends CLOCKFD support to clock_getres(), allowing
applications to query the resolution of PTP clocks through file
descriptors using the standard POSIX clock API.
Key changes include:
1. Move clock_getres() from libc to kernel:
- Relocated from libs/libc/sched/clock_getres.c to sched/clock/
- Enables direct kernel-level file descriptor handling
- Maintains POSIX compliance while adding CLOCKFD support
2. CLOCKFD support in clock_getres():
- Detects CLOCKFD-encoded clockids using CLOCKFD_TO_FD() check
- Extracts file descriptor from clockid parameter
- Validates file descriptor through fs_getfilep()
- Issues PTP_CLOCK_GETRES ioctl to query clock resolution
3. PTP clock resolution query:
- Retrieves resolution from PTP clock device via ioctl
- Returns nanosecond-precision timing resolution
- Enables applications to determine clock accuracy capabilities
- Falls back to standard clock resolution for non-CLOCKFD clockids
4. Error handling:
- Returns EINVAL for invalid CLOCKFD file descriptors
- Properly manages file reference counting with fs_putfilep()
- Maintains backward compatibility with existing clock types
5. Build system updates:
- Updated libs/libc/sched/CMakeLists.txt and Make.defs
- Updated sched/clock/CMakeLists.txt to include clock_getres.c
- Ensures proper compilation in kernel context
Usage example:
int fd = open("/dev/ptp0", O_RDONLY);
struct timespec res;
clock_getres(CLOCKFD(fd), &res); /* Query PTP clock resolution */
printf("Resolution: %ld.%09ld sec\n", res.tv_sec, res.tv_nsec);
close(fd);
This completes the basic POSIX clock API support for dynamic PTP clocks,
providing applications with comprehensive clock information access.
Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
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| arch | ||
| audio | ||
| binfmt | ||
| boards | ||
| cmake | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| dummy | ||
| fs | ||
| graphics | ||
| include | ||
| libs | ||
| mm | ||
| net | ||
| openamp | ||
| pass1 | ||
| sched | ||
| syscall | ||
| tools | ||
| video | ||
| wireless | ||
| .asf.yaml | ||
| .codespell-ignore-lines | ||
| .codespellrc | ||
| .editorconfig | ||
| .gitignore | ||
| .gitmessage | ||
| .pre-commit-config.yaml | ||
| .yamllint | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| INVIOLABLES.md | ||
| Kconfig | ||
| LICENSE | ||
| Makefile | ||
| NOTICE | ||
| README.md | ||
| ReleaseNotes | ||
Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).
For brevity, many parts of the documentation will refer to Apache NuttX as simply NuttX.
Getting Started
First time on NuttX? Read the Getting Started guide! If you don't have a board available, NuttX has its own simulator that you can run on terminal.
Documentation
You can find the current NuttX documentation on the Documentation Page.
Alternatively, you can build the documentation yourself by following the Documentation Build Instructions.
The old NuttX documentation is still available in the Apache wiki.
Supported Boards
NuttX supports a wide variety of platforms. See the full list on the Supported Platforms page.
Contributing
If you wish to contribute to the NuttX project, read the Contributing guidelines for information on Git usage, coding standard, workflow and the NuttX principles.
License
The code in this repository is under either the Apache 2 license, or a license compatible with the Apache 2 license. See the License Page for more information.