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Commit bb1e88cc authored by Alexandre Courbot's avatar Alexandre Courbot Committed by Linus Walleij
Browse files

gpiolib: add gpiochip_get_desc() driver function 



Some drivers dealing with a gpio_chip might need to act on its
descriptors directly; one example is pinctrl drivers that need to lock a
GPIO for being used as IRQ using gpiod_lock_as_irq().

This patch exports a gpiochip_get_desc() function that returns the
GPIO descriptor at the requested index. It also sweeps the
gpio_to_chip() function out of the consumer interface since any holder
of a gpio_chip reference can manipulate its GPIOs way beyond what a
consumer should be allowed to do.

As a result, gpio_chip is not visible anymore to simple GPIO consumers.

Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: default avatarJean-Jacques Hiblot <jjhiblot@traphandler.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 90df4fe0

drivers/gpio/gpiolib.c

+9 −8
Original line number Diff line number Diff line
@@ -164,16 +164,17 @@ struct gpio_desc *gpio_to_desc(unsigned gpio) 
EXPORT_SYMBOL_GPL(gpio_to_desc);



/**

 * Convert an offset on a certain chip to a corresponding descriptor

 * Get the GPIO descriptor corresponding to the given hw number for this chip.

 */

static struct gpio_desc *gpiochip_offset_to_desc(struct gpio_chip *chip,

						 unsigned int offset)

struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,

				    u16 hwnum)

{

	if (offset >= chip->ngpio)

	if (hwnum >= chip->ngpio)

		return ERR_PTR(-EINVAL);



	return &chip->desc[offset];

	return &chip->desc[hwnum];

}

EXPORT_SYMBOL_GPL(gpiochip_get_desc);



/**

 * Convert a GPIO descriptor to the integer namespace.
@@ -2190,7 +2191,7 @@ EXPORT_SYMBOL_GPL(gpiod_lock_as_irq); 


int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset)

{

	return gpiod_lock_as_irq(gpiochip_offset_to_desc(chip, offset));

	return gpiod_lock_as_irq(gpiochip_get_desc(chip, offset));

}

EXPORT_SYMBOL_GPL(gpio_lock_as_irq);
@@ -2212,7 +2213,7 @@ EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq); 


void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)

{

	return gpiod_unlock_as_irq(gpiochip_offset_to_desc(chip, offset));

	return gpiod_unlock_as_irq(gpiochip_get_desc(chip, offset));

}

EXPORT_SYMBOL_GPL(gpio_unlock_as_irq);
@@ -2433,7 +2434,7 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, 
			return ERR_PTR(-EINVAL);

		}



		desc = gpiochip_offset_to_desc(chip, p->chip_hwnum);

		desc = gpiochip_get_desc(chip, p->chip_hwnum);

		*flags = p->flags;



		return desc;

include/linux/gpio/consumer.h

+0 −8
Original line number Diff line number Diff line
@@ -7,7 +7,6 @@ 
#ifdef CONFIG_GPIOLIB



struct device;

struct gpio_chip;



/**

 * Opaque descriptor for a GPIO. These are obtained using gpiod_get() and are
@@ -60,7 +59,6 @@ int gpiod_to_irq(const struct gpio_desc *desc); 
/* Convert between the old gpio_ and new gpiod_ interfaces */

struct gpio_desc *gpio_to_desc(unsigned gpio);

int desc_to_gpio(const struct gpio_desc *desc);

struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);



#else /* CONFIG_GPIOLIB */
@@ -214,12 +212,6 @@ static inline int desc_to_gpio(const struct gpio_desc *desc) 
	WARN_ON(1);

	return -EINVAL;

}

static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)

{

	/* GPIO can never have been requested */

	WARN_ON(1);

	return ERR_PTR(-ENODEV);

}





#endif /* CONFIG_GPIOLIB */

include/linux/gpio/driver.h

+18 −0
Original line number Diff line number Diff line
@@ -10,6 +10,8 @@ struct of_phandle_args; 
struct device_node;

struct seq_file;



#ifdef CONFIG_GPIOLIB



/**

 * struct gpio_chip - abstract a GPIO controller

 * @label: for diagnostics
@@ -129,6 +131,11 @@ extern struct gpio_chip *gpiochip_find(void *data, 
int gpiod_lock_as_irq(struct gpio_desc *desc);

void gpiod_unlock_as_irq(struct gpio_desc *desc);



struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);



struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,

				    u16 hwnum);



enum gpio_lookup_flags {

	GPIO_ACTIVE_HIGH = (0 << 0),

	GPIO_ACTIVE_LOW = (1 << 0),
@@ -183,4 +190,15 @@ struct gpiod_lookup_table { 


void gpiod_add_lookup_table(struct gpiod_lookup_table *table);



#else /* CONFIG_GPIOLIB */



static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)

{

	/* GPIO can never have been requested */

	WARN_ON(1);

	return ERR_PTR(-ENODEV);

}



#endif /* CONFIG_GPIOLIB */



#endif