Commit 4c56b143 authored by Uwe Kleine-König's avatar Uwe Kleine-König
Browse files

pwm: Add a struct device to struct pwm_chip 

This replaces the formerly dynamically allocated struct device. This
allows to additionally use it to track the lifetime of the struct
pwm_chip. Otherwise the new struct device provides the same sysfs API as
was provided by the dynamic device before.

Link: https://lore.kernel.org/r/35c65ea7f6de789a568ff39d7b6b4ce80de4b7dc.1710670958.git.u.kleine-koenig@pengutronix.de


Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
parent ee37bf50

drivers/pwm/core.c

+51 −42
Original line number Diff line number Diff line
@@ -343,9 +343,16 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) 
	if (!try_module_get(chip->owner))

		return -ENODEV;



	if (!get_device(&chip->dev)) {

		err = -ENODEV;

		goto err_get_device;

	}



	if (ops->request) {

		err = ops->request(chip, pwm);

		if (err) {

			put_device(&chip->dev);

err_get_device:

			module_put(chip->owner);

			return err;

		}
@@ -463,7 +470,7 @@ struct pwm_export { 


static inline struct pwm_chip *pwmchip_from_dev(struct device *pwmchip_dev)

{

	return dev_get_drvdata(pwmchip_dev);

	return container_of(pwmchip_dev, struct pwm_chip, dev);

}



static inline struct pwm_export *pwmexport_from_dev(struct device *pwm_dev)
@@ -941,46 +948,16 @@ static struct class pwm_class = { 
	.pm = pm_sleep_ptr(&pwm_class_pm_ops),

};



static int pwmchip_sysfs_match(struct device *pwmchip_dev, const void *data)

{

	return pwmchip_from_dev(pwmchip_dev) == data;

}



static void pwmchip_sysfs_export(struct pwm_chip *chip)

{

	struct device *pwmchip_dev;



	/*

	 * If device_create() fails the pwm_chip is still usable by

	 * the kernel it's just not exported.

	 */

	pwmchip_dev = device_create(&pwm_class, pwmchip_parent(chip), MKDEV(0, 0), chip,

			       "pwmchip%d", chip->id);

	if (IS_ERR(pwmchip_dev)) {

		dev_warn(pwmchip_parent(chip),

			 "device_create failed for pwm_chip sysfs export\n");

	}

}



static void pwmchip_sysfs_unexport(struct pwm_chip *chip)

{

	struct device *pwmchip_dev;

	unsigned int i;



	pwmchip_dev = class_find_device(&pwm_class, NULL, chip,

					pwmchip_sysfs_match);

	if (!pwmchip_dev)

		return;



	for (i = 0; i < chip->npwm; i++) {

		struct pwm_device *pwm = &chip->pwms[i];



		if (test_bit(PWMF_EXPORTED, &pwm->flags))

			pwm_unexport_child(pwmchip_dev, pwm);

			pwm_unexport_child(&chip->dev, pwm);

	}



	put_device(pwmchip_dev);

	device_unregister(pwmchip_dev);

}



#define PWMCHIP_ALIGN ARCH_DMA_MINALIGN
@@ -993,13 +970,21 @@ static void *pwmchip_priv(struct pwm_chip *chip) 
/* This is the counterpart to pwmchip_alloc() */

void pwmchip_put(struct pwm_chip *chip)

{

	kfree(chip);

	put_device(&chip->dev);

}

EXPORT_SYMBOL_GPL(pwmchip_put);



static void pwmchip_release(struct device *pwmchip_dev)

{

	struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);



	kfree(chip);

}



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

{

	struct pwm_chip *chip;

	struct device *pwmchip_dev;

	size_t alloc_size;

	unsigned int i;
@@ -1010,10 +995,15 @@ struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t 
	if (!chip)

		return ERR_PTR(-ENOMEM);



	chip->dev = parent;

	chip->npwm = npwm;

	chip->uses_pwmchip_alloc = true;



	pwmchip_dev = &chip->dev;

	device_initialize(pwmchip_dev);

	pwmchip_dev->class = &pwm_class;

	pwmchip_dev->parent = parent;

	pwmchip_dev->release = pwmchip_release;



	pwmchip_set_drvdata(chip, pwmchip_priv(chip));



	for (i = 0; i < chip->npwm; i++) {
@@ -1115,21 +1105,34 @@ int __pwmchip_add(struct pwm_chip *chip, struct module *owner) 
	mutex_lock(&pwm_lock);



	ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL);

	if (ret < 0) {

		mutex_unlock(&pwm_lock);

		return ret;

	}

	if (ret < 0)

		goto err_idr_alloc;



	chip->id = ret;



	mutex_unlock(&pwm_lock);

	dev_set_name(&chip->dev, "pwmchip%u", chip->id);



	if (IS_ENABLED(CONFIG_OF))

		of_pwmchip_add(chip);



	pwmchip_sysfs_export(chip);

	ret = device_add(&chip->dev);

	if (ret)

		goto err_device_add;



	mutex_unlock(&pwm_lock);



	return 0;



err_device_add:

	if (IS_ENABLED(CONFIG_OF))

		of_pwmchip_remove(chip);



	idr_remove(&pwm_chips, chip->id);

err_idr_alloc:



	mutex_unlock(&pwm_lock);



	return ret;

}

EXPORT_SYMBOL_GPL(__pwmchip_add);
@@ -1151,6 +1154,8 @@ void pwmchip_remove(struct pwm_chip *chip) 
	idr_remove(&pwm_chips, chip->id);



	mutex_unlock(&pwm_lock);



	device_del(&chip->dev);

}

EXPORT_SYMBOL_GPL(pwmchip_remove);
@@ -1520,6 +1525,8 @@ EXPORT_SYMBOL_GPL(pwm_get); 
 */

void pwm_put(struct pwm_device *pwm)

{

	struct pwm_chip *chip = pwm->chip;



	if (!pwm)

		return;
@@ -1530,12 +1537,14 @@ void pwm_put(struct pwm_device *pwm) 
		goto out;

	}



	if (pwm->chip->ops->free)

	if (chip->ops->free)

		pwm->chip->ops->free(pwm->chip, pwm);



	pwm->label = NULL;



	module_put(pwm->chip->owner);

	put_device(&chip->dev);



	module_put(chip->owner);

out:

	mutex_unlock(&pwm_lock);

}

include/linux/pwm.h

+3 −2
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#ifndef __LINUX_PWM_H

#define __LINUX_PWM_H



#include <linux/device.h>

#include <linux/err.h>

#include <linux/mutex.h>

#include <linux/of.h>
@@ -277,7 +278,7 @@ struct pwm_ops { 
 * @pwms: array of PWM devices allocated by the framework

 */

struct pwm_chip {

	struct device *dev;

	struct device dev;

	const struct pwm_ops *ops;

	struct module *owner;

	unsigned int id;
@@ -295,7 +296,7 @@ struct pwm_chip { 


static inline struct device *pwmchip_parent(const struct pwm_chip *chip)

{

	return chip->dev;

	return chip->dev.parent;

}



static inline void *pwmchip_get_drvdata(struct pwm_chip *chip)