Commit ce284f88 authored by Michal Wilczynski's avatar Michal Wilczynski Committed by Uwe Kleine-König
Browse files

pwm: Export `pwmchip_release` for external use 



The upcoming Rust abstraction layer for the PWM subsystem uses a custom
`dev->release` handler to safely manage the lifetime of its driver
data.

To prevent leaking the memory of the `struct pwm_chip` (allocated by
`pwmchip_alloc`), this custom handler must also call the original
`pwmchip_release` function to complete the cleanup.

Make `pwmchip_release` a global, exported function so that it can be
called from the Rust FFI bridge. This involves removing the `static`
keyword, adding a prototype to the public header, and exporting the
symbol.

Reviewed-by: default avatarElle Rhumsaa <elle@weathered-steel.dev>
Signed-off-by: default avatarMichal Wilczynski <m.wilczynski@samsung.com>
Link: https://patch.msgid.link/20251016-rust-next-pwm-working-fan-for-sending-v16-1-a5df2405d2bd@samsung.com


Signed-off-by: default avatarUwe Kleine-König <ukleinek@kernel.org>
parent 739ad9be

drivers/pwm/core.c

+2 −1
Original line number Diff line number Diff line
@@ -1608,12 +1608,13 @@ void pwmchip_put(struct pwm_chip *chip) 
}

EXPORT_SYMBOL_GPL(pwmchip_put);



static void pwmchip_release(struct device *pwmchip_dev)

void pwmchip_release(struct device *pwmchip_dev)

{

	struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);



	kfree(chip);

}

EXPORT_SYMBOL_GPL(pwmchip_release);



struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv)

{

include/linux/pwm.h

+6 −0
Original line number Diff line number Diff line
@@ -488,6 +488,12 @@ int __pwmchip_add(struct pwm_chip *chip, struct module *owner); 
#define pwmchip_add(chip) __pwmchip_add(chip, THIS_MODULE)

void pwmchip_remove(struct pwm_chip *chip);



/*

 * For FFI wrapper use only:

 * The Rust PWM abstraction needs this to properly free the pwm_chip.

 */

void pwmchip_release(struct device *dev);



int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner);

#define devm_pwmchip_add(dev, chip) __devm_pwmchip_add(dev, chip, THIS_MODULE)