GPIO: gpio-dwapb: Support Debounce
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@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Weike Chen <alvin.chen@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
index 551eaf7..db059bb 100644
--- a/drivers/gpio/gpio-dwapb.c
+++ b/drivers/gpio/gpio-dwapb.c
@@ -37,6 +37,7 @@
#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 +65,12 @@
struct irq_domain *domain;
};
+static inline struct dwapb_gpio_port *
+to_dwapb_gpio_port(struct bgpio_chip *bgc)
+{
+ return container_of(bgc, struct dwapb_gpio_port, bgc);
+}
+
static inline u32 dwapb_read(struct dwapb_gpio *gpio, unsigned int offset)
{
struct bgpio_chip *bgc = &gpio->ports[0].bgc;
@@ -84,8 +91,7 @@
static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct bgpio_chip *bgc = to_bgpio_chip(gc);
- struct dwapb_gpio_port *port = container_of(bgc, struct
- dwapb_gpio_port, bgc);
+ struct dwapb_gpio_port *port = to_dwapb_gpio_port(bgc);
struct dwapb_gpio *gpio = port->gpio;
return irq_find_mapping(gpio->domain, offset);
@@ -235,6 +241,28 @@
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 = to_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, val_deb | mask);
+ else
+ dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, val_deb & ~mask);
+
+ spin_unlock_irqrestore(&bgc->lock, flags);
+
+ return 0;
+}
+
static irqreturn_t dwapb_irq_handler_mfd(int irq, void *dev_id)
{
u32 worked;
@@ -373,6 +401,10 @@
port->bgc.gc.ngpio = pp->ngpio;
port->bgc.gc.base = pp->gpio_base;
+ /* Only port A support debounce */
+ if (pp->idx == 0)
+ port->bgc.gc.set_debounce = dwapb_gpio_set_debounce;
+
if (pp->irq)
dwapb_configure_irqs(gpio, port, pp);