diff options
| author | William Breathitt Gray <vilhelm.gray@gmail.com> | 2017-01-19 10:05:59 -0500 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2017-01-26 10:57:39 +0100 |
| commit | 99c8ac957e6b7c670b78ad7b8667051de8624d37 (patch) | |
| tree | fd7a7739fb9dbeadcb5a10ea7b635e810db4a6b9 /drivers/gpio | |
| parent | 65502a12adc343037e8a1e6e936dd8c01f4117b2 (diff) | |
| download | linux-99c8ac957e6b7c670b78ad7b8667051de8624d37.tar.bz2 | |
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: 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-ws16c48.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-ws16c48.c b/drivers/gpio/gpio-ws16c48.c index eaa71d440ccf..25e539530c08 100644 --- a/drivers/gpio/gpio-ws16c48.c +++ b/drivers/gpio/gpio-ws16c48.c @@ -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]; |