This patch enables 'debounce' for the designware GPIO, and it is based on Josef Ahmad's previous work.
Reviewed-by: Hock Leong Kweh <[email protected]> Reviewed-by: Shevchenko, Andriy <[email protected]> Signed-off-by: Weike Chen <[email protected]> --- 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
