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author | Felipe Balbi <felipe.balbi@nokia.com> | 2010-05-26 23:42:23 +0200 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-27 18:12:42 +0200 |
commit | 168ef3d9a56bd8bffe0ef4189c450888b4aefefe (patch) | |
tree | 13f3d29419be6a8853f7cce807658a42a3d2f22a /arch/arm/plat-omap/gpio.c | |
parent | gpiolib: introduce set_debounce method (diff) | |
download | linux-168ef3d9a56bd8bffe0ef4189c450888b4aefefe.tar.xz linux-168ef3d9a56bd8bffe0ef4189c450888b4aefefe.zip |
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>
Diffstat (limited to 'arch/arm/plat-omap/gpio.c')
-rw-r--r-- | 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 dc2ac42d6319..1a65865fcfb6 100644 --- a/arch/arm/plat-omap/gpio.c +++ b/arch/arm/plat-omap/gpio.c @@ -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)) { |