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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: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
William Breathitt Gray 2017-01-19 10:05:48 -05:00 committed by Linus Walleij
parent 9d7ae8127f
commit 65502a12ad
1 changed files with 39 additions and 0 deletions
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39
drivers/gpio/gpio-gpio-mm.c
View File

@ -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);