diff options
Diffstat (limited to 'arch/arm/plat-nomadik/gpio.c')
| -rw-r--r-- | arch/arm/plat-nomadik/gpio.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/arm/plat-nomadik/gpio.c b/arch/arm/plat-nomadik/gpio.c index 13cdbbdc08c..50c49fa9e01 100644 --- a/arch/arm/plat-nomadik/gpio.c +++ b/arch/arm/plat-nomadik/gpio.c @@ -46,6 +46,54 @@ struct nmk_gpio_chip { u32 edge_falling; }; +static void __nmk_gpio_set_pull(struct nmk_gpio_chip *nmk_chip, + unsigned offset, enum nmk_gpio_pull pull) +{ + u32 bit = 1 << offset; + u32 pdis; + + pdis = readl(nmk_chip->addr + NMK_GPIO_PDIS); + if (pull == NMK_GPIO_PULL_NONE) + pdis |= bit; + else + pdis &= ~bit; + writel(pdis, nmk_chip->addr + NMK_GPIO_PDIS); + + if (pull == NMK_GPIO_PULL_UP) + writel(bit, nmk_chip->addr + NMK_GPIO_DATS); + else if (pull == NMK_GPIO_PULL_DOWN) + writel(bit, nmk_chip->addr + NMK_GPIO_DATC); +} + +/** + * nmk_gpio_set_pull() - enable/disable pull up/down on a gpio + * @gpio: pin number + * @pull: one of NMK_GPIO_PULL_DOWN, NMK_GPIO_PULL_UP, and NMK_GPIO_PULL_NONE + * + * Enables/disables pull up/down on a specified pin. This only takes effect if + * the pin is configured as an input (either explicitly or by the alternate + * function). + * + * NOTE: If enabling the pull up/down, the caller must ensure that the GPIO is + * configured as an input. Otherwise, due to the way the controller registers + * work, this function will change the value output on the pin. + */ +int nmk_gpio_set_pull(int gpio, enum nmk_gpio_pull pull) +{ + struct nmk_gpio_chip *nmk_chip; + unsigned long flags; + + nmk_chip = get_irq_chip_data(NOMADIK_GPIO_TO_IRQ(gpio)); + if (!nmk_chip) + return -EINVAL; + + spin_lock_irqsave(&nmk_chip->lock, flags); + __nmk_gpio_set_pull(nmk_chip, gpio - nmk_chip->chip.base, pull); + spin_unlock_irqrestore(&nmk_chip->lock, flags); + + return 0; +} + /* Mode functions */ int nmk_gpio_set_mode(int gpio, int gpio_mode) { |