From: Felipe Balbi <[email protected]> OMAP support debouncing of gpio lines, implement the method using gpiolib.
Signed-off-by: Felipe Balbi <[email protected]> --- arch/arm/plat-omap/gpio.c | 68 +++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 68 insertions(+), 0 deletions(-) diff --git a/arch/arm/plat-omap/gpio.c b/arch/arm/plat-omap/gpio.c index 45a225d..4a17dc4 100644 --- a/arch/arm/plat-omap/gpio.c +++ b/arch/arm/plat-omap/gpio.c @@ -612,6 +612,59 @@ 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; @@ -1608,6 +1661,20 @@ 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; @@ -1860,6 +1927,7 @@ 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)) { -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
