[PATCH v1 1/2] pinctrl: baytrail: Do not add all GPIOs to IRQ domain

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

It turns out that for some GPIO pins interrupts are bypassing standard
chain.

Now the reason why some events such as touchscreen communication on ASuS
T100TA does not work if we mask all the interrupts is that in order to
generate either interrupts or GPEs the INTMASK register must have that
particular interrupt unmasked. In case of GPEs the CPU does not trigger
normal interrupt (and thus the GPIO driver does not see it) but instead
it causes SCI (System Control Interrupt) to be triggered with the GPE in
question set.

To make this all work as expected we add those GPIOs to the IRQ
domain that can actually generate interrupts and skip others.

Fixes: 3ae02c14d964 ("pinctrl: intel: set default handler to be handle_bad_irq()")
Reported-by: Robert R. Howell <rhowell@uwyo.edu>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/pinctrl/intel/pinctrl-baytrail.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/pinctrl/intel/pinctrl-baytrail.c b/drivers/pinctrl/intel/pinctrl-baytrail.c
index 67e92699b84e..c123488266ce 100644
--- a/drivers/pinctrl/intel/pinctrl-baytrail.c
+++ b/drivers/pinctrl/intel/pinctrl-baytrail.c
@@ -1623,6 +1623,8 @@ static void byt_gpio_irq_handler(struct irq_desc *desc)
 
 static void byt_gpio_irq_init_hw(struct byt_gpio *vg)
 {
+	struct gpio_chip *gc = &vg->chip;
+	struct device *dev = &vg->pdev->dev;
 	void __iomem *reg;
 	u32 base, value;
 	int i;
@@ -1644,10 +1646,12 @@ static void byt_gpio_irq_init_hw(struct byt_gpio *vg)
 		}
 
 		value = readl(reg);
-		if ((value & BYT_PIN_MUX) == byt_get_gpio_mux(vg, i) &&
-		    !(value & BYT_DIRECT_IRQ_EN)) {
+		if (value & BYT_DIRECT_IRQ_EN) {
+			clear_bit(i, gc->irq_valid_mask);
+			dev_dbg(dev, "excluding GPIO %d from IRQ domain\n", i);
+		} else if ((value & BYT_PIN_MUX) == byt_get_gpio_mux(vg, i)) {
 			byt_gpio_clear_triggering(vg, i);
-			dev_dbg(&vg->pdev->dev, "disabling GPIO %d\n", i);
+			dev_dbg(dev, "disabling GPIO %d\n", i);
 		}
 	}
 
@@ -1686,6 +1690,7 @@ static int byt_gpio_probe(struct byt_gpio *vg)
 	gc->can_sleep	= false;
 	gc->parent	= &vg->pdev->dev;
 	gc->ngpio	= vg->soc_data->npins;
+	gc->irq_need_valid_mask	= true;
 
 #ifdef CONFIG_PM_SLEEP
 	vg->saved_context = devm_kcalloc(&vg->pdev->dev, gc->ngpio,
-- 
2.11.0