[PATCH 3/3] Input: ti_am335x_tsc - Ack pending IRQs at probe and before suspend

[Vignesh R]

From: Grygorii Strashko <grygorii.strashko@xxxxxx>

It is seen that just enabling the TSC module triggers a HW_PEN IRQ
without any interaction with touchscreen by user. This results in first
suspend/resume sequence to fail as system immediately wakes up from
suspend as soon as HW_PEN IRQ is enabled in suspend handler. due to the
pending IRQ. Therefore clear all IRQs at probe and also in suspend
callback for sanity.

Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
Signed-off-by: Vignesh R <vigneshr@xxxxxx>
---
 drivers/input/touchscreen/ti_am335x_tsc.c | 2 ++
 include/linux/mfd/ti_am335x_tscadc.h      | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index 4683ed18b9f8..d2c55b5730e6 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -441,6 +441,7 @@ static int titsc_probe(struct platform_device *pdev)
 			dev_err(&pdev->dev, "irq wake enable failed.\n");
 	}
 
+	titsc_writel(ts_dev, REG_IRQSTATUS, IRQENB_MASK);
 	titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
 	titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_EOS);
 	err = titsc_config_wires(ts_dev);
@@ -506,6 +507,7 @@ static int __maybe_unused titsc_suspend(struct device *dev)
 
 	tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
 	if (device_may_wakeup(tscadc_dev->dev)) {
+		titsc_writel(ts_dev, REG_IRQSTATUS, IRQENB_MASK);
 		idle = titsc_readl(ts_dev, REG_IRQENABLE);
 		titsc_writel(ts_dev, REG_IRQENABLE,
 				(idle | IRQENB_HW_PEN));
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index 1fd50dcfe47c..a7ca0f908ba8 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -60,6 +60,7 @@
 #define IRQENB_FIFO1OVRRUN	BIT(6)
 #define IRQENB_FIFO1UNDRFLW	BIT(7)
 #define IRQENB_PENUP		BIT(9)
+#define IRQENB_MASK		(0x7FF)
 
 /* Step Configuration */
 #define STEPCONFIG_MODE_MASK	(3 << 0)
-- 
2.8.2