This patch enables 'debounce' for the designware GPIO, and
it is based on Josef Ahmad's previous work.
Reviewed-by: Hock Leong Kweh <hock.leong.kweh@xxxxxxxxx>
Reviewed-by: Shevchenko, Andriy <andriy.shevchenko@xxxxxxxxx>
Signed-off-by: Weike Chen <alvin.chen@xxxxxxxxx>
---
drivers/gpio/gpio-dwapb.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
index 155a64b..e0ab988 100644
--- a/drivers/gpio/gpio-dwapb.c
+++ b/drivers/gpio/gpio-dwapb.c
@@ -36,6 +36,7 @@
#define GPIO_INTTYPE_LEVEL 0x38
#define GPIO_INT_POLARITY 0x3c
#define GPIO_INTSTATUS 0x40
+#define GPIO_PORTA_DEBOUNCE 0x48
#define GPIO_PORTA_EOI 0x4c
#define GPIO_EXT_PORTA 0x50
#define GPIO_EXT_PORTB 0x54
@@ -64,6 +65,23 @@ struct dwapb_gpio {
const struct dwapb_gpio_platform_data *pdata;
};
+static inline u32 dwapb_read(struct dwapb_gpio *gpio, unsigned int offset)
+{
+ struct bgpio_chip *bgc = &gpio->ports[0].bgc;
+ void __iomem *reg_base = gpio->regs;
+
+ return bgc->read_reg(reg_base + offset);
+}
+
+static inline void dwapb_write(struct dwapb_gpio *gpio, unsigned int offset,
+ u32 val)
+{
+ struct bgpio_chip *bgc = &gpio->ports[0].bgc;
+ void __iomem *reg_base = gpio->regs;
+
+ bgc->write_reg(reg_base + offset, val);
+}
+
static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct bgpio_chip *bgc = to_bgpio_chip(gc);
@@ -209,6 +227,29 @@ static int dwapb_irq_set_type(struct irq_data *d, u32 type)
return 0;
}
+static int dwapb_gpio_set_debounce(struct gpio_chip *gc,
+ unsigned offset, unsigned debounce)
+{
+ struct bgpio_chip *bgc = to_bgpio_chip(gc);
+ struct dwapb_gpio_port *port =
+ container_of(bgc, struct dwapb_gpio_port, bgc);
+ struct dwapb_gpio *gpio = port->gpio;
+ unsigned long flags, val_deb;
+ unsigned long mask = bgc->pin2mask(bgc, offset);
+
+ spin_lock_irqsave(&bgc->lock, flags);
+
+ val_deb = dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
+ if (debounce)
+ dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, mask | val_deb);
+ else
+ dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, ~mask & val_deb);
+
+ spin_unlock_irqrestore(&bgc->lock, flags);
+
+ return 0;
+}
+
static irqreturn_t dwapb_irq_handler_mfd(int irq, void *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
@@ -342,6 +383,7 @@ static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
port->bgc.gc.ngpio = pp->ngpio;
port->bgc.gc.base = pp->gpio_base;
+ port->bgc.gc.set_debounce = dwapb_gpio_set_debounce;
/*
* Only port A can provide interrupts in all configurations of the IP.
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
