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

[Hans de Goede <hdegoede@xxxxxxxxxx>]

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@xxxxxxxxxx>
---
 drivers/pinctrl/intel/pinctrl-baytrail.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/pinctrl/intel/pinctrl-baytrail.c b/drivers/pinctrl/intel/pinctrl-baytrail.c
index db55761c90cc..844b89f230d7 100644
--- a/drivers/pinctrl/intel/pinctrl-baytrail.c
+++ b/drivers/pinctrl/intel/pinctrl-baytrail.c
@@ -742,8 +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)
+		goto out;
+
 	value &= ~(BYT_TRIG_POS | BYT_TRIG_NEG | BYT_TRIG_LVL);
 	writel(value, reg);
+out:
 	raw_spin_unlock_irqrestore(&byt_lock, flags);
 }
 
-- 
2.24.1