Commit 99c8ac95 authored by William Breathitt Gray's avatar William Breathitt Gray Committed by Linus Walleij
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gpio: ws16c48: Add set_multiple callback function support 



The WinSystems WS16C48 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 65502a12

drivers/gpio/gpio-ws16c48.c

+41 −0
Original line number Diff line number Diff line
@@ -155,6 +155,46 @@ static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 
	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);

}



static void ws16c48_gpio_set_multiple(struct gpio_chip *chip,

	unsigned long *mask, unsigned long *bits)

{

	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);

	unsigned int i;

	const unsigned int gpio_reg_size = 8;

	unsigned int port;

	unsigned int iomask;

	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;



		/* mask out GPIO configured for input */

		iomask = mask[BIT_WORD(i)] & ~ws16c48gpio->io_state[port];

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



		spin_lock_irqsave(&ws16c48gpio->lock, flags);



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

		ws16c48gpio->out_state[port] &= ~iomask;

		ws16c48gpio->out_state[port] |= bitmask;

		outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);



		spin_unlock_irqrestore(&ws16c48gpio->lock, flags);



		/* prepare for next gpio register set */

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

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

	}

}



static void ws16c48_irq_ack(struct irq_data *data)

{

	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
@@ -329,6 +369,7 @@ static int ws16c48_probe(struct device *dev, unsigned int id) 
	ws16c48gpio->chip.direction_output = ws16c48_gpio_direction_output;

	ws16c48gpio->chip.get = ws16c48_gpio_get;

	ws16c48gpio->chip.set = ws16c48_gpio_set;

	ws16c48gpio->chip.set_multiple = ws16c48_gpio_set_multiple;

	ws16c48gpio->base = base[id];

	ws16c48gpio->irq = irq[id];

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