Unverified Commit 0edb040d authored by Linus Walleij's avatar Linus Walleij Committed by Mark Brown
Browse files

regulator: core: Track dangling GPIO descriptors 



If a GPIO descriptor is passed to the regulator_register()
function inside the config->ena_gpiod callers must be
sure that once they call this API the regulator core
owns that descriptor and will make sure to issue
gpiod_put() on it, no matter whether the call is
successful or not.

For device tree regulators, the regulator core will
automatically set up regulator init data from the device
tree when registering a regulator by calling
regulator_of_get_init_data() which in turn calls down to
the regulator driver's .of_parse_cb() callback.
This callback (in drivers such as for max77686) may also
choose to fill in the config->ena_gpiod field with a GPIO
descriptor.

Harden the errorpath of regulator_register() to
properly gpiod_put() any passed in cfg->ena_gpiod
or any gpiod coming from the device tree on any type
of error.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: default avatarCharles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent c32569e3

drivers/regulator/core.c

+45 −10
Original line number Diff line number Diff line
@@ -4868,21 +4868,33 @@ regulator_register(const struct regulator_desc *regulator_desc, 
	struct regulator_config *config = NULL;

	static atomic_t regulator_no = ATOMIC_INIT(-1);

	struct regulator_dev *rdev;

	bool dangling_cfg_gpiod = false;

	bool dangling_of_gpiod = false;

	struct device *dev;

	int ret, i;



	if (regulator_desc == NULL || cfg == NULL)

	if (cfg == NULL)

		return ERR_PTR(-EINVAL);

	if (cfg->ena_gpiod)

		dangling_cfg_gpiod = true;

	if (regulator_desc == NULL) {

		ret = -EINVAL;

		goto rinse;

	}



	dev = cfg->dev;

	WARN_ON(!dev);



	if (regulator_desc->name == NULL || regulator_desc->ops == NULL)

		return ERR_PTR(-EINVAL);

	if (regulator_desc->name == NULL || regulator_desc->ops == NULL) {

		ret = -EINVAL;

		goto rinse;

	}



	if (regulator_desc->type != REGULATOR_VOLTAGE &&

	    regulator_desc->type != REGULATOR_CURRENT)

		return ERR_PTR(-EINVAL);

	    regulator_desc->type != REGULATOR_CURRENT) {

		ret = -EINVAL;

		goto rinse;

	}



	/* Only one of each should be implemented */

	WARN_ON(regulator_desc->ops->get_voltage &&
@@ -4893,16 +4905,20 @@ regulator_register(const struct regulator_desc *regulator_desc, 
	/* If we're using selectors we must implement list_voltage. */

	if (regulator_desc->ops->get_voltage_sel &&

	    !regulator_desc->ops->list_voltage) {

		return ERR_PTR(-EINVAL);

		ret = -EINVAL;

		goto rinse;

	}

	if (regulator_desc->ops->set_voltage_sel &&

	    !regulator_desc->ops->list_voltage) {

		return ERR_PTR(-EINVAL);

		ret = -EINVAL;

		goto rinse;

	}



	rdev = kzalloc(sizeof(struct regulator_dev), GFP_KERNEL);

	if (rdev == NULL)

		return ERR_PTR(-ENOMEM);

	if (rdev == NULL) {

		ret = -ENOMEM;

		goto rinse;

	}



	/*

	 * Duplicate the config so the driver could override it after
@@ -4911,11 +4927,22 @@ regulator_register(const struct regulator_desc *regulator_desc, 
	config = kmemdup(cfg, sizeof(*cfg), GFP_KERNEL);

	if (config == NULL) {

		kfree(rdev);

		return ERR_PTR(-ENOMEM);

		ret = -ENOMEM;

		goto rinse;

	}



	init_data = regulator_of_get_init_data(dev, regulator_desc, config,

					       &rdev->dev.of_node);

	/*

	 * We need to keep track of any GPIO descriptor coming from the

	 * device tree until we have handled it over to the core. If the

	 * config that was passed in to this function DOES NOT contain

	 * a descriptor, and the config after this call DOES contain

	 * a descriptor, we definately got one from parsing the device

	 * tree.

	 */

	if (!cfg->ena_gpiod && config->ena_gpiod)

		dangling_of_gpiod = true;

	if (!init_data) {

		init_data = config->init_data;

		rdev->dev.of_node = of_node_get(config->of_node);
@@ -4954,6 +4981,9 @@ regulator_register(const struct regulator_desc *regulator_desc, 
				 config->ena_gpio, ret);

			goto clean;

		}

		/* The regulator core took over the GPIO descriptor */

		dangling_cfg_gpiod = false;

		dangling_of_gpiod = false;

	}



	/* register with sysfs */
@@ -5039,8 +5069,13 @@ wash: 
	regulator_ena_gpio_free(rdev);

	mutex_unlock(&regulator_list_mutex);

clean:

	if (dangling_of_gpiod)

		gpiod_put(config->ena_gpiod);

	kfree(rdev);

	kfree(config);

rinse:

	if (dangling_cfg_gpiod)

		gpiod_put(cfg->ena_gpiod);

	return ERR_PTR(ret);

}

EXPORT_SYMBOL_GPL(regulator_register);

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