diff options
| author | Rabin Vincent <rabin.vincent@stericsson.com> | 2010-05-27 12:29:50 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-06-16 22:26:10 +0100 |
| commit | 5b327edf03c037ea6dc49a98a2b7f7186298ad1e (patch) | |
| tree | e971eed0cbd971dd30f821b4d32f4bf0fb848541 /arch/arm | |
| parent | 6647c6c0b62ae14ca994c5776ddb084820bea808 (diff) | |
ARM: 6148/1: nomadik-gpio: add function to configure pullup/pulldown
Cc: Alessandro Rubini <rubini@unipv.it>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/plat-nomadik/gpio.c | 48 | ||||
| -rw-r--r-- | arch/arm/plat-nomadik/include/plat/gpio.h | 8 |
2 files changed, 56 insertions, 0 deletions
diff --git a/arch/arm/plat-nomadik/gpio.c b/arch/arm/plat-nomadik/gpio.c index 13cdbbdc08ca..50c49fa9e01a 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) { diff --git a/arch/arm/plat-nomadik/include/plat/gpio.h b/arch/arm/plat-nomadik/include/plat/gpio.h index 4200811249ca..1d97e96ad1f4 100644 --- a/arch/arm/plat-nomadik/include/plat/gpio.h +++ b/arch/arm/plat-nomadik/include/plat/gpio.h @@ -55,6 +55,14 @@ #define NMK_GPIO_ALT_B 2 #define NMK_GPIO_ALT_C (NMK_GPIO_ALT_A | NMK_GPIO_ALT_B) +/* Pull up/down values */ +enum nmk_gpio_pull { + NMK_GPIO_PULL_NONE, + NMK_GPIO_PULL_UP, + NMK_GPIO_PULL_DOWN, +}; + +extern int nmk_gpio_set_pull(int gpio, enum nmk_gpio_pull pull); extern int nmk_gpio_set_mode(int gpio, int gpio_mode); extern int nmk_gpio_get_mode(int gpio); |