[PATCH 3/4 v4] GPIO: gpio-dwapb: Support Debounce
From: Weike Chen <hidden>
Date: 2014-09-16 01:29:36
Also in:
linux-gpio, lkml
Subsystem:
gpio subsystem, synopsys designware apb gpio driver, the rest · Maintainers:
Linus Walleij, Bartosz Golaszewski, Hoan Tran, Linus Torvalds
This patch enables 'debounce' for the designware GPIO, and it is based on Josef Ahmad's previous work. Reviewed-by: Hock Leong Kweh <redacted> Reviewed-by: Shevchenko, Andriy <redacted> Signed-off-by: Weike Chen <redacted> --- drivers/gpio/gpio-dwapb.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
index 534945c..9a76e3c 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
@@ -235,6 +236,29 @@ 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) { u32 worked;
@@ -373,6 +397,10 @@ static int dwapb_gpio_add_port(struct dwapb_gpio *gpio, 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);
--
1.7.9.5