diff options
| author | William Breathitt Gray <vilhelm.gray@gmail.com> | 2017-01-19 18:05:48 +0300 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2017-01-26 12:56:37 +0300 |
| commit | 65502a12adc343037e8a1e6e936dd8c01f4117b2 (patch) | |
| tree | f6351c4e3877b9c0ff3cf045667b45147b927cbf /drivers/gpio | |
| parent | 9d7ae8127ff9eea84375dd8d962ce776a3734119 (diff) | |
| download | linux-65502a12adc343037e8a1e6e936dd8c01f4117b2.tar.xz | |
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>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpio-gpio-mm.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-gpio-mm.c b/drivers/gpio/gpio-gpio-mm.c index 1e7def9449ce..093489556c54 100644 --- a/drivers/gpio/gpio-gpio-mm.c +++ b/drivers/gpio/gpio-gpio-mm.c @@ -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); |