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>
This commit is contained in:
Rabin Vincent 2010-05-27 12:29:50 +01:00 committed by Russell King
parent 6647c6c0b6
commit 5b327edf03
2 changed files with 56 additions and 0 deletions

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@ -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)
{

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@ -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);