Commit 6c0b4e6c authored by Alexandre Courbot's avatar Alexandre Courbot Committed by Grant Likely
Browse files

gpiolib: let gpio_chip reference its descriptors 



Add a pointer to the gpio_chip structure that references the array of
GPIO descriptors belonging to the chip, and update gpiolib code to use
this pointer instead of the global gpio_desc[] array. This is another
step towards the removal of the gpio_desc[] global array.

Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.orh>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 372e722e

drivers/gpio/gpiolib.c

+23 −16
Original line number Diff line number Diff line
@@ -72,6 +72,8 @@ struct gpio_desc { 
};

static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];



#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio)



static LIST_HEAD(gpio_chips);



#ifdef CONFIG_GPIO_SYSFS
@@ -112,7 +114,7 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) 
 */

static int gpio_chip_hwgpio(const struct gpio_desc *desc)

{

	return (desc - &gpio_desc[0]) - desc->chip->base;

	return desc - &desc->chip->desc[0];

}



/**
@@ -133,7 +135,7 @@ static struct gpio_desc *gpio_to_desc(unsigned gpio) 
 */

static int desc_to_gpio(const struct gpio_desc *desc)

{

	return desc - &gpio_desc[0];

	return desc->chip->base + gpio_chip_hwgpio(desc);

}
@@ -1007,9 +1009,9 @@ static int gpiochip_export(struct gpio_chip *chip) 
		unsigned	gpio;



		spin_lock_irqsave(&gpio_lock, flags);

		gpio = chip->base;

		while (gpio_desc[gpio].chip == chip)

			gpio_desc[gpio++].chip = NULL;

		gpio = 0;

		while (gpio < chip->ngpio)

			chip->desc[gpio++].chip = NULL;

		spin_unlock_irqrestore(&gpio_lock, flags);



		pr_debug("%s: chip %s status %d\n", __func__,
@@ -1186,8 +1188,11 @@ int gpiochip_add(struct gpio_chip *chip) 
	status = gpiochip_add_to_list(chip);



	if (status == 0) {

		for (id = base; id < base + chip->ngpio; id++) {

			gpio_desc[id].chip = chip;

		chip->desc = &gpio_desc[chip->base];



		for (id = 0; id < chip->ngpio; id++) {

			struct gpio_desc *desc = &chip->desc[id];

			desc->chip = chip;



			/* REVISIT:  most hardware initializes GPIOs as

			 * inputs (often with pullups enabled) so power
@@ -1196,7 +1201,7 @@ int gpiochip_add(struct gpio_chip *chip) 
			 * and in case chip->get_direction is not set,

			 * we may expose the wrong direction in sysfs.

			 */

			gpio_desc[id].flags = !chip->direction_input

			desc->flags = !chip->direction_input

				? (1 << FLAG_IS_OUT)

				: 0;

		}
@@ -1249,15 +1254,15 @@ int gpiochip_remove(struct gpio_chip *chip) 
	gpiochip_remove_pin_ranges(chip);

	of_gpiochip_remove(chip);



	for (id = chip->base; id < chip->base + chip->ngpio; id++) {

		if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) {

	for (id = 0; id < chip->ngpio; id++) {

		if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {

			status = -EBUSY;

			break;

		}

	}

	if (status == 0) {

		for (id = chip->base; id < chip->base + chip->ngpio; id++)

			gpio_desc[id].chip = NULL;

		for (id = 0; id < chip->ngpio; id++)

			chip->desc[id].chip = NULL;



		list_del(&chip->list);

	}
@@ -1582,11 +1587,13 @@ EXPORT_SYMBOL_GPL(gpio_free_array); 
 */

const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)

{

	unsigned gpio = chip->base + offset;

	struct gpio_desc *desc = &gpio_desc[gpio];

	struct gpio_desc *desc;



	if (!gpio_is_valid(gpio) || desc->chip != chip)

	if (!GPIO_OFFSET_VALID(chip, offset))

		return NULL;



	desc = &chip->desc[offset];



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

		return NULL;

#ifdef CONFIG_DEBUG_FS
@@ -2025,7 +2032,7 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) 
{

	unsigned		i;

	unsigned		gpio = chip->base;

	struct gpio_desc	*gdesc = &gpio_desc[gpio];

	struct gpio_desc	*gdesc = &chip->desc[0];

	int			is_out;



	for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {

include/asm-generic/gpio.h

+3 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ struct gpio; 
struct seq_file;

struct module;

struct device_node;

struct gpio_desc;



/**

 * struct gpio_chip - abstract a GPIO controller
@@ -76,6 +77,7 @@ struct device_node; 
 *	negative during registration, requests dynamic ID allocation.

 * @ngpio: the number of GPIOs handled by this controller; the last GPIO

 *	handled is (base + ngpio - 1).

 * @desc: array of ngpio descriptors. Private.

 * @can_sleep: flag must be set iff get()/set() methods sleep, as they

 *	must while accessing GPIO expander chips over I2C or SPI

 * @names: if set, must be an array of strings to use as alternative
@@ -126,6 +128,7 @@ struct gpio_chip { 
						struct gpio_chip *chip);

	int			base;

	u16			ngpio;

	struct gpio_desc	*desc;

	const char		*const *names;

	unsigned		can_sleep:1;

	unsigned		exported:1;

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