From e7a718f9b1c106dc7705d96cf0fe2e2f69089cf9 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Thu, 1 Dec 2016 17:45:51 +0200 Subject: [PATCH] gpio: merrifield: Add support for hardware debouncer By default all pins are configured to use a glitch filter. Writing 1 to the certain bit of the specific register might be useful in case someone needs to bypass the glitch filter completely for a given GPIO pin. This patch adds support for that in the Intel Merrifield GPIO driver. Signed-off-by: Andy Shevchenko Signed-off-by: Linus Walleij --- drivers/gpio/gpio-merrifield.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/gpio/gpio-merrifield.c b/drivers/gpio/gpio-merrifield.c index 82cdcdc779bb..d7cbbc0fc47b 100644 --- a/drivers/gpio/gpio-merrifield.c +++ b/drivers/gpio/gpio-merrifield.c @@ -161,6 +161,27 @@ static int mrfld_gpio_direction_output(struct gpio_chip *chip, return 0; } +static int mrfld_gpio_set_debounce(struct gpio_chip *chip, unsigned int offset, + unsigned int debounce) +{ + struct mrfld_gpio *priv = gpiochip_get_data(chip); + void __iomem *gfbr = gpio_reg(chip, offset, GFBR); + unsigned long flags; + u32 value; + + raw_spin_lock_irqsave(&priv->lock, flags); + + if (debounce) + value = readl(gfbr) & ~BIT(offset % 32); + else + value = readl(gfbr) | BIT(offset % 32); + writel(value, gfbr); + + raw_spin_unlock_irqrestore(&priv->lock, flags); + + return 0; +} + static void mrfld_irq_ack(struct irq_data *d) { struct mrfld_gpio *priv = irq_data_get_irq_chip_data(d); @@ -384,6 +405,7 @@ static int mrfld_gpio_probe(struct pci_dev *pdev, const struct pci_device_id *id priv->chip.direction_output = mrfld_gpio_direction_output; priv->chip.get = mrfld_gpio_get; priv->chip.set = mrfld_gpio_set; + priv->chip.set_debounce = mrfld_gpio_set_debounce; priv->chip.base = gpio_base; priv->chip.ngpio = MRFLD_NGPIO; priv->chip.can_sleep = false; -- 2.20.1