Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6354316d authored by Alexandre Courbot's avatar Alexandre Courbot Committed by Thierry Reding
Browse files

pwm: add devm_pwm_get() and devm_pwm_put() 



Add resource managed variants of pwm_get() and pwm_put() for
convenience. Code is largely inspired by the equivalent devm functions
of the regulator framework.

Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@avionic-design.de>
parent 0aa0869c

Documentation/driver-model/devres.txt

+4 −0
Original line number Diff line number Diff line
@@ -284,3 +284,7 @@ CLOCK 
PINCTRL

  devm_pinctrl_get()

  devm_pinctrl_put()



PWM

  devm_pwm_get()

  devm_pwm_put()

Documentation/pwm.txt

+2 −1
Original line number Diff line number Diff line
@@ -36,7 +36,8 @@ Legacy users can request a PWM device using pwm_request() and free it 
after usage with pwm_free().



New users should use the pwm_get() function and pass to it the consumer

device or a consumer name. pwm_put() is used to free the PWM device.

device or a consumer name. pwm_put() is used to free the PWM device. Managed

variants of these functions, devm_pwm_get() and devm_pwm_put(), also exist.



After being requested a PWM has to be configured using:

drivers/pwm/core.c

+58 −0
Original line number Diff line number Diff line
@@ -646,6 +646,64 @@ void pwm_put(struct pwm_device *pwm) 
}

EXPORT_SYMBOL_GPL(pwm_put);



static void devm_pwm_release(struct device *dev, void *res)

{

	pwm_put(*(struct pwm_device **)res);

}



/**

 * devm_pwm_get() - resource managed pwm_get()

 * @dev: device for PWM consumer

 * @con_id: consumer name

 *

 * This function performs like pwm_get() but the acquired PWM device will

 * automatically be released on driver detach.

 */

struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)

{

	struct pwm_device **ptr, *pwm;



	ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL);

	if (!ptr)

		return ERR_PTR(-ENOMEM);



	pwm = pwm_get(dev, con_id);

	if (!IS_ERR(pwm)) {

		*ptr = pwm;

		devres_add(dev, ptr);

	} else {

		devres_free(ptr);

	}



	return pwm;

}

EXPORT_SYMBOL_GPL(devm_pwm_get);



static int devm_pwm_match(struct device *dev, void *res, void *data)

{

	struct pwm_device **p = res;



	if (WARN_ON(!p || !*p))

		return 0;



	return *p == data;

}



/**

 * devm_pwm_put() - resource managed pwm_put()

 * @dev: device for PWM consumer

 * @pwm: PWM device

 *

 * Release a PWM previously allocated using devm_pwm_get(). Calling this

 * function is usually not needed because devm-allocated resources are

 * automatically released on driver detach.

 */

void devm_pwm_put(struct device *dev, struct pwm_device *pwm)

{

	WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));

}

EXPORT_SYMBOL_GPL(devm_pwm_put);



#ifdef CONFIG_DEBUG_FS

static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)

{

include/linux/pwm.h

+3 −0
Original line number Diff line number Diff line
@@ -148,6 +148,9 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, 
struct pwm_device *pwm_get(struct device *dev, const char *consumer);

void pwm_put(struct pwm_device *pwm);



struct pwm_device *devm_pwm_get(struct device *dev, const char *consumer);

void devm_pwm_put(struct device *dev, struct pwm_device *pwm);



struct pwm_lookup {

	struct list_head list;

	const char *provider;