Introduce a PWM driver for the T-HEAD TH1520 SoC, written in Rust and
utilizing the safe PWM abstractions from the preceding commit.
The driver implements the pwm::PwmOps trait using the modern waveform
API (round_waveform_tohw, write_waveform, etc.) to support configuration
of period, duty cycle, and polarity for the TH1520's PWM channels.
Resource management is handled using idiomatic Rust patterns. The PWM
chip object is allocated via pwm::Chip::new and its registration with
the PWM core is managed by the pwm::Registration RAII guard. This
ensures pwmchip_remove is always called when the driver unbinds,
preventing resource leaks. Device managed resources are used for the
MMIO region, and the clock lifecycle is correctly managed in the
driver's private data Drop implementation.
The driver's core logic is written entirely in safe Rust, with no unsafe
blocks, except for the Send and Sync implementations for the driver
data, which are explained in the comments.
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
Link: https://patch.msgid.link/20251016-rust-next-pwm-working-fan-for-sending-v16-4-a5df2405d2bd@samsung.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Introduce the foundational support for PWM abstractions in Rust.
This commit adds the `RUST_PWM_ABSTRACTIONS` Kconfig option to enable
the feature, along with the necessary build-system support and C
helpers.
It also introduces the first set of safe wrappers for the PWM
subsystem, covering the basic data carrying C structs and enums:
- `Polarity`: A safe wrapper for `enum pwm_polarity`.
- `Waveform`: A wrapper for `struct pwm_waveform`.
- `State`: A wrapper for `struct pwm_state`.
These types provide memory safe, idiomatic Rust representations of the
core PWM data structures and form the building blocks for the
abstractions that will follow.
Tested-by: Drew Fustini <fustini@kernel.org>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
Link: https://patch.msgid.link/20251016-rust-next-pwm-working-fan-for-sending-v16-2-a5df2405d2bd@samsung.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Pull gpio updates from Bartosz Golaszewski:
"There are two new drivers and support for more models in existing
ones.
The generic GPIO API has been reworked and all users converted
which allowed us to move the fields specific to the generic GPIO
implementation out of the high-level struct gpio_chip into its own
structure that wraps the gpio_chip.
Other than that, there's nothing too exciting. Mostly minor tweaks and
fixes all over the place, some refactoring and some small new features
in helper modules.
GPIO core:
- add support for sparse pin ranges to the glue between GPIO and
pinctrl
- use a common prefix across all GPIO descriptor flags for improved
namespacing
New drivers:
- add new GPIO driver for the Nuvoton NCT6694
- add new GPIO driver for MAX7360
Driver improvements:
- add support for Tegra 256 to the gpio-tegra186 driver
- add support for Loongson-2K0300 to the gpio-loongson-64bit driver
- refactor the gpio-aggregator module to expose its GPIO forwarder
API to other in-kernel users (to enable merging of a new pinctrl
driver that uses it)
- convert all remaining drivers to using the modernized generic GPIO
chip API and remove the old interface
- stop displaying global GPIO numbers in debugfs output of controller
drivers
- extend the gpio-regmap helper with a new config option and improve
its support for GPIO interrupts
- remove redundant fast_io parameter from regmap configs in GPIO
drivers that already use MMIO regmaps which imply it
- add support for a new model in gpio-mmio: ixp4xx expansion bus
- order includes alphabetically in a few drivers for better
readability
- use generic device properties where applicable
- use devm_mutex_init() where applicable
- extend build coverage of drivers by enabling more to be compiled
with COMPILE_TEST enabled
- allow building gpio-stmpe as a module
- use dev_err_probe() where it makes sense in drivers
Late driver fixes:
- fix setting GPIO direction to output in gpio-mpfs
Documentation:
- document the usage of software nodes with GPIO chips
Device-tree bindings:
- Add DT bindings documents for new hardware: Tegra256, MAX7360
- Document a new model in Loongson bindings: LS2K0300
- Document a new model using the generic GPIO binding: IXP4xx
- Convert the DT binding for fsl,mxs-pinctrl to YAML
- fix the schema ID in the "trivial" GPIO schema
- describe GPIO hogs in the generic GPIO binding"
* tag 'gpio-updates-for-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (122 commits)
gpio: mpfs: fix setting gpio direction to output
gpio: generic: move GPIO_GENERIC_ flags to the correct header
gpio: generic: rename BGPIOF_ flags to GPIO_GENERIC_
gpio: nomadik: fix the debugfs helper stub
MAINTAINERS: Add entry on MAX7360 driver
input: misc: Add support for MAX7360 rotary
input: keyboard: Add support for MAX7360 keypad
gpio: max7360: Add MAX7360 gpio support
gpio: regmap: Allow to provide init_valid_mask callback
gpio: regmap: Allow to allocate regmap-irq device
pwm: max7360: Add MAX7360 PWM support
pinctrl: Add MAX7360 pinctrl driver
mfd: Add max7360 support
dt-bindings: mfd: gpio: Add MAX7360
rtc: Add Nuvoton NCT6694 RTC support
hwmon: Add Nuvoton NCT6694 HWMON support
watchdog: Add Nuvoton NCT6694 WDT support
can: Add Nuvoton NCT6694 CANFD support
i2c: Add Nuvoton NCT6694 I2C support
gpio: Add Nuvoton NCT6694 GPIO support
...
A PWM is a more general concept than an output-only GPIO. When using
duty_length = period_length the PWM looks like an active GPIO, with
duty_length = 0 like an inactive GPIO. With the waveform abstraction
there is enough control over the configuration to ensure that PWMs that
cannot generate a constant signal at both levels error out.
The pwm-pca9685 driver already provides a gpio chip. When this driver is
converted to the waveform callbacks, the gpio part can just be dropped.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20250717151117.1828585-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Because current PWM Kconfig is sorting by symbol name,
it looks strange ordering in menuconfig.
=> [ ] Renesas R-Car PWM support
=> [ ] Renesas TPU PWM support
[ ] Rockchip PWM support
=> [ ] Renesas RZ/G2L General PWM Timer support
=> [ ] Renesas RZ/G2L MTU3a PWM Timer support
Let's use common CONFIG_PWM_RENESAS_xxx symbol name for Renesas,
and sort it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/877c2mxrrr.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
RZ/G2L General PWM Timer (GPT) composed of 8 channels with 32-bit timer
(GPT32E). It supports the following functions
* 32 bits x 8 channels
* Up-counting or down-counting (saw waves) or up/down-counting
(triangle waves) for each counter.
* Clock sources independently selectable for each channel
* Two I/O pins per channel
* Two output compare/input capture registers per channel
* For the two output compare/input capture registers of each channel,
four registers are provided as buffer registers and are capable of
operating as comparison registers when buffering is not in use.
* In output compare operation, buffer switching can be at crests or
troughs, enabling the generation of laterally asymmetric PWM waveforms.
* Registers for setting up frame cycles in each channel (with capability
for generating interrupts at overflow or underflow)
* Generation of dead times in PWM operation
* Synchronous starting, stopping and clearing counters for arbitrary
channels
* Starting, stopping, clearing and up/down counters in response to input
level comparison
* Starting, clearing, stopping and up/down counters in response to a
maximum of four external triggers
* Output pin disable function by dead time error and detected
short-circuits between output pins
* A/D converter start triggers can be generated (GPT32E0 to GPT32E3)
* Enables the noise filter for input capture and external trigger
operation
Add basic pwm support for RZ/G2L GPT driver by creating separate
logical channels for each IOs.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20250226144531.176819-4-biju.das.jz@bp.renesas.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Add a software PWM which toggles a GPIO from a high-resolution timer.
This will naturally not be as accurate or as efficient as a hardware
PWM, but it is useful in some cases. I have for example used it for
evaluating LED brightness handling (via leds-pwm) on a board where the
LED was just hooked up to a GPIO, and for a simple verification of the
timer frequency on another platform.
Since high-resolution timers are used, sleeping GPIO chips are not
supported and are rejected in the probe function.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Co-developed-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Co-developed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20240604-pwm-gpio-v7-2-6b67cf60db92@linaro.org
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
With the upcoming restructuring having all in a single file simplifies
things a bit. The relevant and somewhat visible changes are:
- Some dropped prototypes from include/linux/pwm.h that were only
necessary that core.c has a declaration of the symbols defined in
sysfs.c. The respective functions are static now.
- The pwm class now also exists if CONFIG_SYSFS isn't enabled. Having
CONFIG_SYSFS is not very relevant today, but even without it the
class and device stuff still provides lifetime tracking.
- Both files had an initcall, these are merged into a single one now.
Instead of a big #ifdef block for CONFIG_DEBUG_FS, a single
if (IS_ENABLED(CONFIG_DEBUG_FS)) is used now. This increases compile
coverage a bit and is a tad nicer on the eyes.
Link: https://lore.kernel.org/r/9e2d39a5280d7dda5bfc6682a8aef510148635b2.1710670958.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Michal Wilczynski
Uwe Kleine-König
Benjamin Larsson
Linus Torvalds
Kamel Bouhara
Uwe Kleine-König
Colin Ian King
Dimitri Fedrau
Marek Vasut
Guodong Xu
Kuninori Morimoto
Biju Das
Binbin Zhou
Chen Wang
Clark Wang
Vincent Whitchurch
Drew Fustini
Uwe Kleine-König
Ben Dooks