This commit adds comprehensive signal notification support to the capture
driver, enabling applications to be asynchronously notified when capture
edge events occur on any channel, rather than having to poll for events.
Background:
The capture driver is used to measure frequency and duty cycle of external
signals by detecting edges (rising/falling). Previously, applications could
only retrieve captured values through periodic polling via CAPIOC_GETDUTY
and CAPIOC_GETFREQ ioctl commands, which is inefficient for event-driven
applications.
Problem:
Without event notification, applications must:
- Continuously poll the capture device to check for new events
- Waste CPU cycles in polling loops
- Experience higher latency in responding to capture events
- Cannot efficiently handle multiple capture channels simultaneously
Solution:
This commit adds a signal-based notification mechanism that allows
applications to register callbacks for specific capture channels and
edge types (rising, falling, or both). When the hardware detects the
configured edge, a signal is sent to the registered task.
Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
This patch fixes an incorrect call to stm32_cap_initialize() in
stm32_bringup.c: the call was made without the channel parameter.
Instead of adding the channel in the call, the channel is selected by
stm32_cap_gpio() (first available channel).
This patch also fixes incorrect driver registration in
drivers/timers/capture.c: the driver was registered with the wrong
name (/dev/cap -> /dev/capture). Also added more error checking in
cap_register_multiple().
Signed-off-by: Côme VINCENT <44554692+comejv@users.noreply.github.com>
This commit introduces a timer capture driver for the STM32H7 series
ported from the STM32 F series.
The main changes include:
- A new generic timer capture driver for STM32H7.
- A lower-half driver to integrate with the NuttX capture subsystem.
- Kconfig options to enable and configure capture for various timers.
- Pin definitions for TIM1-4 capture inputs on the nucleo-h743zi.
- An update to `cap_register_multiple` to handle multiple device registration.
- An update to `stm32_bringup` to register the capture drivers.
The current implementation is based on a driver originally for PWM input,
and as such, it calculates duty cycle and frequency. It is also limited
to a single capture channel per timer.
The original implementation's `stm32_cap_init` in
`arch/arm/src/stm32h7/stm32_capture.c` has been modified to accept a
channel number instead of using a hardcoded 0 through
`STM32_CAP_CHANNEL_COUNTER`.
This serves as a foundation for future development of more comprehensive
input capture capabilities on STM32H7 platforms.
Tested by polling and reading `/dev/cap0-4` with
`ioctl(fds[i], CAPIOC_FREQUENCE, freq)` while sending a square wave signal to
appropriate pins and checking frequency.
Also tested by bypassing upper half driver and setting up capture on
TIM4 channels 1-4 as explained in #16762.
Signed-off-by: Côme VINCENT <44554692+comejv@users.noreply.github.com>
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
When monitoring multiple capture channels, the `ioctl` function
is called three times, leading to significant overhead mainly due
to VFS and `nxmutex_lock/unlock`. Adding a new interface can save
the overhead of two `ioctl` calls.
Signed-off-by: yangguangcai <yangguangcai@xiaomi.com>
