[PATCH 4.9 144/310] pinctrl: baytrail: Enable glitch filter for GPIOs used as interrupts

From: Greg Kroah-Hartman
Date: Wed Apr 11 2018 - 15:42:32 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Hans de Goede <hdegoede@xxxxxxxxxx>


[ Upstream commit 9291c65b01d1c67ebd56644cb19317ad665c44b3 ]

On some systems, some PCB traces attached to GpioInts are routed in such
a way that they pick up enough interference to constantly (many times per
second) trigger.

Enabling glitch-filtering fixes this.

Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pinctrl/intel/pinctrl-baytrail.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/pinctrl/intel/pinctrl-baytrail.c
+++ b/drivers/pinctrl/intel/pinctrl-baytrail.c
@@ -46,6 +46,9 @@
#define BYT_TRIG_POS BIT(25)
#define BYT_TRIG_LVL BIT(24)
#define BYT_DEBOUNCE_EN BIT(20)
+#define BYT_GLITCH_FILTER_EN BIT(19)
+#define BYT_GLITCH_F_SLOW_CLK BIT(17)
+#define BYT_GLITCH_F_FAST_CLK BIT(16)
#define BYT_PULL_STR_SHIFT 9
#define BYT_PULL_STR_MASK (3 << BYT_PULL_STR_SHIFT)
#define BYT_PULL_STR_2K (0 << BYT_PULL_STR_SHIFT)
@@ -1579,6 +1582,9 @@ static int byt_irq_type(struct irq_data
*/
value &= ~(BYT_DIRECT_IRQ_EN | BYT_TRIG_POS | BYT_TRIG_NEG |
BYT_TRIG_LVL);
+ /* Enable glitch filtering */
+ value |= BYT_GLITCH_FILTER_EN | BYT_GLITCH_F_SLOW_CLK |
+ BYT_GLITCH_F_FAST_CLK;

writel(value, reg);