[PATCH] gpiolib: Implement set_debounce for WM831x GPIOs

From: Mark Brown
Date: Sun Jul 04 2010 - 04:38:30 EST


The debounce times are approximate, they can be selected using the two
input functions.

Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
---
drivers/gpio/wm831x-gpio.c | 32 ++++++++++++++++++++++++++++++++
1 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/drivers/gpio/wm831x-gpio.c b/drivers/gpio/wm831x-gpio.c
index 1fa449a..309644c 100644
--- a/drivers/gpio/wm831x-gpio.c
+++ b/drivers/gpio/wm831x-gpio.c
@@ -108,6 +108,37 @@ static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
}

+static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
+ unsigned debounce)
+{
+ struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
+ struct wm831x *wm831x = wm831x_gpio->wm831x;
+ int reg = WM831X_GPIO1_CONTROL + offset;
+ int ret, fn;
+
+ ret = wm831x_reg_read(wm831x, reg);
+ if (ret < 0)
+ return ret;
+
+ switch (ret & WM831X_GPN_FN_MASK) {
+ case 0:
+ case 1:
+ break;
+ default:
+ /* Not in GPIO mode */
+ return -EBUSY;
+ }
+
+ if (debounce >= 32 && debounce <= 64)
+ fn = 0;
+ else if (debounce >= 4000 && debounce <= 8000)
+ fn = 1;
+ else
+ return -EINVAL;
+
+ return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
+}
+
#ifdef CONFIG_DEBUG_FS
static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
@@ -208,6 +239,7 @@ static struct gpio_chip template_chip = {
.direction_output = wm831x_gpio_direction_out,
.set = wm831x_gpio_set,
.to_irq = wm831x_gpio_to_irq,
+ .set_debounce = wm831x_gpio_set_debounce,
.dbg_show = wm831x_gpio_dbg_show,
.can_sleep = 1,
};
--
1.7.1

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