gpio: gpio-mm: Implement get_multiple callback

 * This driver supports the following Diamond Systems devices: GPIO-MM and

 * GPIO-MM-12.

 */

#include <linux/bitmap.h>

#include <linux/bitops.h>

#include <linux/device.h>

#include <linux/errno.h>

	return !!(port_state & mask);

}

static int gpiomm_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,

	unsigned long *bits)

{

	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);

	size_t i;

	const size_t ports[] = { 0, 1, 2, 4, 5, 6 };

	const unsigned int gpio_reg_size = 8;

	unsigned int bits_offset;

	size_t word_index;

	unsigned int word_offset;

	unsigned long word_mask;

	const unsigned long port_mask = GENMASK(gpio_reg_size - 1, 0);

	unsigned long port_state;

	/* clear bits array to a clean slate */

	bitmap_zero(bits, chip->ngpio);

	/* get bits are evaluated a gpio port register at a time */

	for (i = 0; i < ARRAY_SIZE(ports); i++) {

		/* gpio offset in bits array */

		bits_offset = i * gpio_reg_size;

		/* word index for bits array */

		word_index = BIT_WORD(bits_offset);

		/* gpio offset within current word of bits array */

		word_offset = bits_offset % BITS_PER_LONG;

		/* mask of get bits for current gpio within current word */

		word_mask = mask[word_index] & (port_mask << word_offset);

		if (!word_mask) {

			/* no get bits in this port so skip to next one */

			continue;

		}

		/* read bits from current gpio port */

		port_state = inb(gpiommgpio->base + ports[i]);

		/* store acquired bits at respective bits array offset */

		bits[word_index] |= port_state << word_offset;

	}

	return 0;

}

static void gpiomm_gpio_set(struct gpio_chip *chip, unsigned int offset,

	int value)

{

	gpiommgpio->chip.direction_input = gpiomm_gpio_direction_input;

	gpiommgpio->chip.direction_output = gpiomm_gpio_direction_output;

	gpiommgpio->chip.get = gpiomm_gpio_get;

	gpiommgpio->chip.get_multiple = gpiomm_gpio_get_multiple;

	gpiommgpio->chip.set = gpiomm_gpio_set;

	gpiommgpio->chip.set_multiple = gpiomm_gpio_set_multiple;

	gpiommgpio->base = base[id];