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Subject[PATCH 2/5] arm: omap: gpio: implement set_debounce method
Date
From: Felipe Balbi <felipe.balbi@nokia.com>

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

Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
---
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


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