pinctrl: baytrail: Do not clear IRQ flags on direct-irq enabled pins

Suspending Goodix touchscreens requires changing the interrupt pin to
output before sending them a power-down command. Followed by wiggling
the interrupt pin to wake the device up, after which it is put back
in input mode.

On Bay Trail devices with a Goodix touchscreen direct-irq mode is used
in combination with listing the pin as a normal GpioIo resource.

This works fine, until the goodix driver gets rmmod-ed and then insmod-ed
again. In this case byt_gpio_disable_free() calls
byt_gpio_clear_triggering() which clears the IRQ flags and after that the
(direct) IRQ no longer triggers.

This commit fixes this by adding a check for the BYT_DIRECT_IRQ_EN flag
to byt_gpio_clear_triggering().

Note that byt_gpio_clear_triggering() only gets called from
byt_gpio_disable_free() for direct-irq enabled pins, as these are excluded
from the irq_valid mask by byt_init_irq_valid_mask().
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/pinctrl/intel/pinctrl-baytrail.c

@@ -742,7 +742,13 @@ static void byt_gpio_clear_triggering(struct intel_pinctrl *vg, unsigned int off
 
 	raw_spin_lock_irqsave(&byt_lock, flags);
 	value = readl(reg);
+
+	/* Do not clear direct-irq enabled IRQs (from gpio_disable_free) */
+	if (value & BYT_DIRECT_IRQ_EN)
+		/* nothing to do */ ;
+	else
 		value &= ~(BYT_TRIG_POS | BYT_TRIG_NEG | BYT_TRIG_LVL);
+
 	writel(value, reg);
 	raw_spin_unlock_irqrestore(&byt_lock, flags);
 }