Commit aa4858eb authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Bartosz Golaszewski
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gpio: aggregator: Wrap access to gpiochip_fwd.tmp[] 



The tmp[] member of the gpiochip_fwd structure is used to store both the
temporary values bitmap and the desc pointers for operations on multiple
GPIOs.  As both are arrays with sizes unknown at compile-time, accessing
them requires offset calculations, which are currently duplicated in
gpio_fwd_get_multiple() and gpio_fwd_set_multiple().

Introduce (a) accessors for both arrays and (b) a macro to calculate the
needed storage size.  This confines the layout of the tmp[] member into
a single spot, to ease maintenance.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarBartosz Golaszewski <brgl@bgdev.pl>
parent 7687a5b0

drivers/gpio/gpio-aggregator.c

+11 −14
Original line number Diff line number Diff line
@@ -247,6 +247,11 @@ struct gpiochip_fwd { 
	unsigned long tmp[];		/* values and descs for multiple ops */

};



#define fwd_tmp_values(fwd)	&(fwd)->tmp[0]

#define fwd_tmp_descs(fwd)	(void *)&(fwd)->tmp[BITS_TO_LONGS((fwd)->chip.ngpio)]



#define fwd_tmp_size(ngpios)	(BITS_TO_LONGS((ngpios)) + (ngpios))



static int gpio_fwd_get_direction(struct gpio_chip *chip, unsigned int offset)

{

	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
@@ -279,15 +284,11 @@ static int gpio_fwd_get(struct gpio_chip *chip, unsigned int offset) 
static int gpio_fwd_get_multiple(struct gpiochip_fwd *fwd, unsigned long *mask,

				 unsigned long *bits)

{

	struct gpio_desc **descs;

	unsigned long *values;

	struct gpio_desc **descs = fwd_tmp_descs(fwd);

	unsigned long *values = fwd_tmp_values(fwd);

	unsigned int i, j = 0;

	int error;



	/* Both values bitmap and desc pointers are stored in tmp[] */

	values = &fwd->tmp[0];

	descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)];



	bitmap_clear(values, 0, fwd->chip.ngpio);

	for_each_set_bit(i, mask, fwd->chip.ngpio)

		descs[j++] = fwd->descs[i];
@@ -333,14 +334,10 @@ static void gpio_fwd_set(struct gpio_chip *chip, unsigned int offset, int value) 
static void gpio_fwd_set_multiple(struct gpiochip_fwd *fwd, unsigned long *mask,

				  unsigned long *bits)

{

	struct gpio_desc **descs;

	unsigned long *values;

	struct gpio_desc **descs = fwd_tmp_descs(fwd);

	unsigned long *values = fwd_tmp_values(fwd);

	unsigned int i, j = 0;



	/* Both values bitmap and desc pointers are stored in tmp[] */

	values = &fwd->tmp[0];

	descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)];



	for_each_set_bit(i, mask, fwd->chip.ngpio) {

		__assign_bit(j, values, test_bit(i, bits));

		descs[j++] = fwd->descs[i];
@@ -398,8 +395,8 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev, 
	unsigned int i;

	int error;



	fwd = devm_kzalloc(dev, struct_size(fwd, tmp,

			   BITS_TO_LONGS(ngpios) + ngpios), GFP_KERNEL);

	fwd = devm_kzalloc(dev, struct_size(fwd, tmp, fwd_tmp_size(ngpios)),

			   GFP_KERNEL);

	if (!fwd)

		return ERR_PTR(-ENOMEM);