[PATCH v2 2/2] gpio-langwell: implement irq shutdown interface

[David Cohen <david.a.cohen@intel.com>]

From: "Li, Ning" <ning.li@intel.com>

Disable falling/rising edge detection during irq shutdown operation.

Signed-off-by: David Cohen <david.a.cohen@intel.com>
Signed-off-by: Li, Ning <ning.li@intel.com>
---
 drivers/gpio/gpio-langwell.c |   21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/gpio/gpio-langwell.c b/drivers/gpio/gpio-langwell.c
index 2be69fe..10cc520 100644
--- a/drivers/gpio/gpio-langwell.c
+++ b/drivers/gpio/gpio-langwell.c
@@ -225,11 +225,32 @@ static void lnw_irq_mask(struct irq_data *d)
 {
 }
 
+static void lnw_irq_shutdown(struct irq_data *d)
+{
+	struct lnw_gpio *lnw = irq_data_get_irq_chip_data(d);
+	u32 gpio = irqd_to_hwirq(d);
+	unsigned long flags;
+	u32 value;
+	void __iomem *grer = gpio_reg(&lnw->chip, gpio, GRER);
+	void __iomem *gfer = gpio_reg(&lnw->chip, gpio, GFER);
+
+	spin_lock_irqsave(&lnw->lock, flags);
+
+	/* Disable falling/rising edge detection */
+	value = readl(grer) & ~BIT(gpio % 32);
+	writel(value, grer);
+	value = readl(gfer) & ~BIT(gpio % 32);
+	writel(value, gfer);
+
+	spin_unlock_irqrestore(&lnw->lock, flags);
+};
+
 static struct irq_chip lnw_irqchip = {
 	.name		= "LNW-GPIO",
 	.irq_mask	= lnw_irq_mask,
 	.irq_unmask	= lnw_irq_unmask,
 	.irq_set_type	= lnw_irq_type,
+	.irq_shutdown	= lnw_irq_shutdown,
 };
 
 static DEFINE_PCI_DEVICE_TABLE(lnw_gpio_ids) = {   /* pin number */
-- 
1.7.10.4