Commit 65502a12 authored by William Breathitt Gray's avatar William Breathitt Gray Committed by Linus Walleij
Browse files

gpio: gpio-mm: Add set_multiple callback function support 



The Diamond Systems GPIO-MM series provides registers where 8 lines of
GPIO may be set at a time. This patch add support for the set_multiple
callback function, thus allowing multiple GPIO output lines to be set
more efficiently in groups.

Signed-off-by: default avatarWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 9d7ae812

drivers/gpio/gpio-gpio-mm.c

+39 −0
Original line number Diff line number Diff line
@@ -192,6 +192,44 @@ static void gpiomm_gpio_set(struct gpio_chip *chip, unsigned int offset, 
	spin_unlock_irqrestore(&gpiommgpio->lock, flags);

}



static void gpiomm_gpio_set_multiple(struct gpio_chip *chip,

	unsigned long *mask, unsigned long *bits)

{

	struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);

	unsigned int i;

	const unsigned int gpio_reg_size = 8;

	unsigned int port;

	unsigned int out_port;

	unsigned int bitmask;

	unsigned long flags;



	/* set bits are evaluated a gpio register size at a time */

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

		/* no more set bits in this mask word; skip to the next word */

		if (!mask[BIT_WORD(i)]) {

			i = (BIT_WORD(i) + 1) * BITS_PER_LONG - gpio_reg_size;

			continue;

		}



		port = i / gpio_reg_size;

		out_port = (port > 2) ? port + 1 : port;

		bitmask = mask[BIT_WORD(i)] & bits[BIT_WORD(i)];



		spin_lock_irqsave(&gpiommgpio->lock, flags);



		/* update output state data and set device gpio register */

		gpiommgpio->out_state[port] &= ~mask[BIT_WORD(i)];

		gpiommgpio->out_state[port] |= bitmask;

		outb(gpiommgpio->out_state[port], gpiommgpio->base + out_port);



		spin_unlock_irqrestore(&gpiommgpio->lock, flags);



		/* prepare for next gpio register set */

		mask[BIT_WORD(i)] >>= gpio_reg_size;

		bits[BIT_WORD(i)] >>= gpio_reg_size;

	}

}



static int gpiomm_probe(struct device *dev, unsigned int id)

{

	struct gpiomm_gpio *gpiommgpio;
@@ -218,6 +256,7 @@ static int gpiomm_probe(struct device *dev, unsigned int id) 
	gpiommgpio->chip.direction_output = gpiomm_gpio_direction_output;

	gpiommgpio->chip.get = gpiomm_gpio_get;

	gpiommgpio->chip.set = gpiomm_gpio_set;

	gpiommgpio->chip.set_multiple = gpiomm_gpio_set_multiple;

	gpiommgpio->base = base[id];



	spin_lock_init(&gpiommgpio->lock);

CRA Git | Maintained and supported by SUSTech CRA and CCSE