arm: omap: gpio: implement set_debounce method

OMAP supports debouncing of gpio lines, implement the method using
gpiolib.

Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Felipe Balbi 2010-05-26 14:42:23 -07:00 committed by Linus Torvalds
parent c4b5be98fe
commit 168ef3d9a5
1 changed files with 68 additions and 0 deletions

View File

@ -624,6 +624,59 @@ do { \
__raw_writel(l, base + reg); \
} while(0)
/**
* _set_gpio_debounce - low level gpio debounce time
* @bank: the gpio bank we're acting upon
* @gpio: the gpio number on this @gpio
* @debounce: debounce time to use
*
* OMAP's debounce time is in 31us steps so we need
* to convert and round up to the closest unit.
*/
static void _set_gpio_debounce(struct gpio_bank *bank, unsigned gpio,
unsigned debounce)
{
void __iomem *reg = bank->base;
u32 val;
u32 l;
if (debounce < 32)
debounce = 0x01;
else if (debounce > 7936)
debounce = 0xff;
else
debounce = (debounce / 0x1f) - 1;
l = 1 << get_gpio_index(gpio);
if (cpu_is_omap44xx())
reg += OMAP4_GPIO_DEBOUNCINGTIME;
else
reg += OMAP24XX_GPIO_DEBOUNCE_VAL;
__raw_writel(debounce, reg);
reg = bank->base;
if (cpu_is_omap44xx())
reg += OMAP4_GPIO_DEBOUNCENABLE;
else
reg += OMAP24XX_GPIO_DEBOUNCE_EN;
val = __raw_readl(reg);
if (debounce) {
val |= l;
if (cpu_is_omap34xx() || cpu_is_omap44xx())
clk_enable(bank->dbck);
} else {
val &= ~l;
if (cpu_is_omap34xx() || cpu_is_omap44xx())
clk_disable(bank->dbck);
}
__raw_writel(val, reg);
}
void omap_set_gpio_debounce(int gpio, int enable)
{
struct gpio_bank *bank;
@ -1656,6 +1709,20 @@ static int gpio_output(struct gpio_chip *chip, unsigned offset, int value)
return 0;
}
static int gpio_debounce(struct gpio_chip *chip, unsigned offset,
unsigned debounce)
{
struct gpio_bank *bank;
unsigned long flags;
bank = container_of(chip, struct gpio_bank, chip);
spin_lock_irqsave(&bank->lock, flags);
_set_gpio_debounce(bank, offset, debounce);
spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
static void gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct gpio_bank *bank;
@ -1909,6 +1976,7 @@ static int __init _omap_gpio_init(void)
bank->chip.direction_input = gpio_input;
bank->chip.get = gpio_get;
bank->chip.direction_output = gpio_output;
bank->chip.set_debounce = gpio_debounce;
bank->chip.set = gpio_set;
bank->chip.to_irq = gpio_2irq;
if (bank_is_mpuio(bank)) {