Commit d82da797 authored by Alexandre Courbot's avatar Alexandre Courbot Committed by Linus Walleij
Browse files

gpio: move gpio_ensure_requested() into legacy C file 



gpio_ensure_requested() only makes sense when using the integer-based
GPIO API, so make sure it is called from there instead of the gpiod
API which we know cannot be called with a non-requested GPIO anyway.

The uses of gpio_ensure_requested() in the gpiod API were kind of
out-of-place anyway, so putting them in gpio-legacy.c helps clearing the
code.

Actually, considering the time this ensure_requested mechanism has been
around, maybe we should just turn this patch into "remove
gpio_ensure_requested()" if we know for sure that no user depend on it
anymore?

Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent d74be6df

drivers/gpio/gpiolib-legacy.c

+106 −0
Original line number Diff line number Diff line
@@ -5,6 +5,64 @@ 


#include "gpiolib.h"



/* Warn when drivers omit gpio_request() calls -- legal but ill-advised

 * when setting direction, and otherwise illegal.  Until board setup code

 * and drivers use explicit requests everywhere (which won't happen when

 * those calls have no teeth) we can't avoid autorequesting.  This nag

 * message should motivate switching to explicit requests... so should

 * the weaker cleanup after faults, compared to gpio_request().

 *

 * NOTE: the autorequest mechanism is going away; at this point it's

 * only "legal" in the sense that (old) code using it won't break yet,

 * but instead only triggers a WARN() stack dump.

 */

static int gpio_ensure_requested(struct gpio_desc *desc)

{

	struct gpio_chip *chip = desc->chip;

	unsigned long flags;

	bool request = false;

	int err = 0;



	spin_lock_irqsave(&gpio_lock, flags);



	if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0,

			"autorequest GPIO-%d\n", desc_to_gpio(desc))) {

		if (!try_module_get(chip->owner)) {

			gpiod_err(desc, "%s: module can't be gotten\n",

					__func__);

			clear_bit(FLAG_REQUESTED, &desc->flags);

			/* lose */

			err = -EIO;

			goto end;

		}

		desc->label = "[auto]";

		/* caller must chip->request() w/o spinlock */

		if (chip->request)

			request = true;

	}



end:

	spin_unlock_irqrestore(&gpio_lock, flags);



	if (request) {

		might_sleep_if(chip->can_sleep);

		err = chip->request(chip, gpio_chip_hwgpio(desc));



		if (err < 0) {

			gpiod_dbg(desc, "%s: chip request fail, %d\n",

					__func__, err);

			spin_lock_irqsave(&gpio_lock, flags);



			desc->label = NULL;

			clear_bit(FLAG_REQUESTED, &desc->flags);



			spin_unlock_irqrestore(&gpio_lock, flags);

		}

	}



	return err;

}



void gpio_free(unsigned gpio)

{

	gpiod_free(gpio_to_desc(gpio));
@@ -100,3 +158,51 @@ void gpio_free_array(const struct gpio *array, size_t num) 
		gpio_free((array++)->gpio);

}

EXPORT_SYMBOL_GPL(gpio_free_array);



int gpio_direction_input(unsigned gpio)

{

	struct gpio_desc *desc = gpio_to_desc(gpio);

	int err;



	if (!desc)

		return -EINVAL;



	err = gpio_ensure_requested(desc);

	if (err < 0)

		return err;



	return gpiod_direction_input(desc);

}

EXPORT_SYMBOL_GPL(gpio_direction_input);



int gpio_direction_output(unsigned gpio, int value)

{

	struct gpio_desc *desc = gpio_to_desc(gpio);

	int err;



	if (!desc)

		return -EINVAL;



	err = gpio_ensure_requested(desc);

	if (err < 0)

		return err;



	return gpiod_direction_output_raw(desc, value);

}

EXPORT_SYMBOL_GPL(gpio_direction_output);



int gpio_set_debounce(unsigned gpio, unsigned debounce)

{

	struct gpio_desc *desc = gpio_to_desc(gpio);

	int err;



	if (!desc)

		return -EINVAL;



	err = gpio_ensure_requested(desc);

	if (err < 0)

		return err;



	return gpiod_set_debounce(desc, debounce);

}

EXPORT_SYMBOL_GPL(gpio_set_debounce);

drivers/gpio/gpiolib.c

+4 −125
Original line number Diff line number Diff line
@@ -95,39 +95,6 @@ int desc_to_gpio(const struct gpio_desc *desc) 
EXPORT_SYMBOL_GPL(desc_to_gpio);





/* Warn when drivers omit gpio_request() calls -- legal but ill-advised

 * when setting direction, and otherwise illegal.  Until board setup code

 * and drivers use explicit requests everywhere (which won't happen when

 * those calls have no teeth) we can't avoid autorequesting.  This nag

 * message should motivate switching to explicit requests... so should

 * the weaker cleanup after faults, compared to gpio_request().

 *

 * NOTE: the autorequest mechanism is going away; at this point it's

 * only "legal" in the sense that (old) code using it won't break yet,

 * but instead only triggers a WARN() stack dump.

 */

static int gpio_ensure_requested(struct gpio_desc *desc)

{

	const struct gpio_chip *chip = desc->chip;

	const int gpio = desc_to_gpio(desc);



	if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0,

			"autorequest GPIO-%d\n", gpio)) {

		if (!try_module_get(chip->owner)) {

			gpiod_err(desc, "%s: module can't be gotten\n",

					__func__);

			clear_bit(FLAG_REQUESTED, &desc->flags);

			/* lose */

			return -EIO;

		}

		desc_set_label(desc, "[auto]");

		/* caller must chip->request() w/o spinlock */

		if (chip->request)

			return 1;

	}

	return 0;

}



/**

 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs

 * @desc:	descriptor to return the chip of
@@ -964,10 +931,8 @@ void gpiochip_free_own_desc(struct gpio_desc *desc) 
 */

int gpiod_direction_input(struct gpio_desc *desc)

{

	unsigned long		flags;

	struct gpio_chip	*chip;

	int			status = -EINVAL;

	int			offset;



	if (!desc || !desc->chip) {

		pr_warn("%s: invalid GPIO\n", __func__);
@@ -982,52 +947,20 @@ int gpiod_direction_input(struct gpio_desc *desc) 
		return -EIO;

	}



	spin_lock_irqsave(&gpio_lock, flags);



	status = gpio_ensure_requested(desc);

	if (status < 0)

		goto fail;



	/* now we know the gpio is valid and chip won't vanish */



	spin_unlock_irqrestore(&gpio_lock, flags);



	might_sleep_if(chip->can_sleep);



	offset = gpio_chip_hwgpio(desc);

	if (status) {

		status = chip->request(chip, offset);

		if (status < 0) {

			gpiod_dbg(desc, "%s: chip request fail, %d\n",

					__func__, status);

			/* and it's not available to anyone else ...

			 * gpio_request() is the fully clean solution.

			 */

			goto lose;

		}

	}



	status = chip->direction_input(chip, offset);

	status = chip->direction_input(chip, gpio_chip_hwgpio(desc));

	if (status == 0)

		clear_bit(FLAG_IS_OUT, &desc->flags);



	trace_gpio_direction(desc_to_gpio(desc), 1, status);

lose:

	return status;

fail:

	spin_unlock_irqrestore(&gpio_lock, flags);

	if (status)

		gpiod_dbg(desc, "%s: status %d\n", __func__, status);



	return status;

}

EXPORT_SYMBOL_GPL(gpiod_direction_input);



static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)

{

	unsigned long		flags;

	struct gpio_chip	*chip;

	int			status = -EINVAL;

	int offset;



	/* GPIOs used for IRQs shall not be set as output */

	if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
@@ -1053,42 +986,11 @@ static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value) 
		return -EIO;

	}



	spin_lock_irqsave(&gpio_lock, flags);



	status = gpio_ensure_requested(desc);

	if (status < 0)

		goto fail;



	/* now we know the gpio is valid and chip won't vanish */



	spin_unlock_irqrestore(&gpio_lock, flags);



	might_sleep_if(chip->can_sleep);



	offset = gpio_chip_hwgpio(desc);

	if (status) {

		status = chip->request(chip, offset);

		if (status < 0) {

			gpiod_dbg(desc, "%s: chip request fail, %d\n",

					__func__, status);

			/* and it's not available to anyone else ...

			 * gpio_request() is the fully clean solution.

			 */

			goto lose;

		}

	}



	status = chip->direction_output(chip, offset, value);

	status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);

	if (status == 0)

		set_bit(FLAG_IS_OUT, &desc->flags);

	trace_gpio_value(desc_to_gpio(desc), 0, value);

	trace_gpio_direction(desc_to_gpio(desc), 0, status);

lose:

	return status;

fail:

	spin_unlock_irqrestore(&gpio_lock, flags);

	if (status)

		gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status);

	return status;

}
@@ -1147,10 +1049,7 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output); 
 */

int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)

{

	unsigned long		flags;

	struct gpio_chip	*chip;

	int			status = -EINVAL;

	int			offset;



	if (!desc || !desc->chip) {

		pr_warn("%s: invalid GPIO\n", __func__);
@@ -1165,27 +1064,7 @@ int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) 
		return -ENOTSUPP;

	}



	spin_lock_irqsave(&gpio_lock, flags);



	status = gpio_ensure_requested(desc);

	if (status < 0)

		goto fail;



	/* now we know the gpio is valid and chip won't vanish */



	spin_unlock_irqrestore(&gpio_lock, flags);



	might_sleep_if(chip->can_sleep);



	offset = gpio_chip_hwgpio(desc);

	return chip->set_debounce(chip, offset, debounce);



fail:

	spin_unlock_irqrestore(&gpio_lock, flags);

	if (status)

		gpiod_dbg(desc, "%s: status %d\n", __func__, status);



	return status;

	return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);

}

EXPORT_SYMBOL_GPL(gpiod_set_debounce);

include/asm-generic/gpio.h

+3 −12
Original line number Diff line number Diff line
@@ -63,19 +63,10 @@ static inline struct gpio_chip *gpio_to_chip(unsigned gpio) 
extern int gpio_request(unsigned gpio, const char *label);

extern void gpio_free(unsigned gpio);



static inline int gpio_direction_input(unsigned gpio)

{

	return gpiod_direction_input(gpio_to_desc(gpio));

}

static inline int gpio_direction_output(unsigned gpio, int value)

{

	return gpiod_direction_output_raw(gpio_to_desc(gpio), value);

}

extern int gpio_direction_input(unsigned gpio);

extern int gpio_direction_output(unsigned gpio, int value);



static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)

{

	return gpiod_set_debounce(gpio_to_desc(gpio), debounce);

}

extern int gpio_set_debounce(unsigned gpio, unsigned debounce);



static inline int gpio_get_value_cansleep(unsigned gpio)

{

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