[PATCH AUTOSEL for 4.15 061/124] pinctrl: baytrail: Enable glitch filter for GPIOs used as interrupts

Sasha Levin
2018-03-19T22:27:54Z

From: Hans de Goede <hdegoede@redhat.com>

[ 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@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/pinctrl/intel/pinctrl-baytrail.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/pinctrl/intel/pinctrl-baytrail.c b/drivers/pinctrl/intel/pinctrl-baytrail.c
index 9c1ca29c60b7..6b52ea1440a6 100644
--- 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 *d, unsigned int type)
*/
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);

--
2.14.1