[PATCH v3] gpio: mxc: map Both Edge pad wakeup to Rising Edge

[Shenwei Wang <shenwei.wang@nxp.com>]

Suspend may fail on i.MX8QM when Falling Edge is used as a pad wakeup
trigger due to a hardware bug in the detection logic. Since the hardware
does not support Both Edge wakeup, remap requests for Both Edge to Rising
Edge by default to avoid hitting this issue.

A warning is emitted when Falling Edge is selected on i.MX8QM.

Fixes: f60c9eac54af ("gpio: mxc: enable pad wakeup on i.MX8x platforms")
cc: stable@vger.kernel.org
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
---
 Changes in V3:
  - improve the warning message per Alexander's feedback.

 Changes in V2:
  - add a check for i.mx8qm and emit a warning when Falling Edge is
    selected.

 drivers/gpio/gpio-mxc.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
index d7666fe9dbf8..647b6f4861b7 100644
--- a/drivers/gpio/gpio-mxc.c
+++ b/drivers/gpio/gpio-mxc.c
@@ -584,12 +584,13 @@ static bool mxc_gpio_set_pad_wakeup(struct mxc_gpio_port *port, bool enable)
 	unsigned long config;
 	bool ret = false;
 	int i, type;
+	bool is_imx8qm = of_device_is_compatible(port->dev->of_node, "fsl,imx8qm-gpio");

 	static const u32 pad_type_map[] = {
 		IMX_SCU_WAKEUP_OFF,		/* 0 */
 		IMX_SCU_WAKEUP_RISE_EDGE,	/* IRQ_TYPE_EDGE_RISING */
 		IMX_SCU_WAKEUP_FALL_EDGE,	/* IRQ_TYPE_EDGE_FALLING */
-		IMX_SCU_WAKEUP_FALL_EDGE,	/* IRQ_TYPE_EDGE_BOTH */
+		IMX_SCU_WAKEUP_RISE_EDGE,	/* IRQ_TYPE_EDGE_BOTH */
 		IMX_SCU_WAKEUP_HIGH_LVL,	/* IRQ_TYPE_LEVEL_HIGH */
 		IMX_SCU_WAKEUP_OFF,		/* 5 */
 		IMX_SCU_WAKEUP_OFF,		/* 6 */
@@ -604,6 +605,13 @@ static bool mxc_gpio_set_pad_wakeup(struct mxc_gpio_port *port, bool enable)
 				config = pad_type_map[type];
 			else
 				config = IMX_SCU_WAKEUP_OFF;
+
+			if (is_imx8qm && config == IMX_SCU_WAKEUP_FALL_EDGE) {
+				dev_warn_once(port->dev,
+					      "No falling-edge support for wakeup on i.MX8QM\n");
+				config = IMX_SCU_WAKEUP_OFF;
+			}
+
 			ret |= mxc_gpio_generic_config(port, i, config);
 		}
 	}
--
2.43.0