diff options
| author | Uwe Kleine-König <u.kleine-koenig@baylibre.com> | 2025-07-17 17:11:16 +0200 |
|---|---|---|
| committer | Uwe Kleine-König <ukleinek@kernel.org> | 2025-09-15 11:39:44 +0200 |
| commit | e7c9b66b106989aeb17b167f5bbea9a108d26c0d (patch) | |
| tree | cac64067492ab8042205b9641198e409bfbdb733 /include/linux | |
| parent | b871d093f1caebeb39b12136a33e7529b8fdea50 (diff) | |
pwm: Provide a gpio device for waveform drivers
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>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/pwm.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 8cafc483db53..549ac4aaad59 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -5,6 +5,7 @@ #include <linux/cdev.h> #include <linux/device.h> #include <linux/err.h> +#include <linux/gpio/driver.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of.h> @@ -321,6 +322,7 @@ struct pwm_ops { * @npwm: number of PWMs controlled by this chip * @of_xlate: request a PWM device given a device tree PWM specifier * @atomic: can the driver's ->apply() be called in atomic context + * @gpio: &struct gpio_chip to operate this PWM chip's lines as GPO * @uses_pwmchip_alloc: signals if pwmchip_allow was used to allocate this chip * @operational: signals if the chip can be used (or is already deregistered) * @nonatomic_lock: mutex for nonatomic chips @@ -340,6 +342,7 @@ struct pwm_chip { bool atomic; /* only used internally by the PWM framework */ + struct gpio_chip gpio; bool uses_pwmchip_alloc; bool operational; union { |