[PATCH 1/2] pinctrl-amd: enable IRQ for WACF2200 touchscreen on Lenovo Yoga 7 14AGP11

[Hardik Prakash <hardikprakash.official@gmail.com>]

On Lenovo Yoga 7 14AGP11 (83TD), the WACF2200 touchscreen controller
is wired via I2C2 (AMDI0010:02) with its interrupt on GPIO pin 157
(confirmed via ACPI _CRS GpioInt decode). After amd_gpio_irq_init()
clears all GPIO interrupts at boot, pin 157 is never re-enabled,
preventing the touchscreen from signalling the driver.

Windows keeps GPIO 157 INTERRUPT_ENABLE (bit 11) and INTERRUPT_MASK
(bit 12) set after initialisation. Add a DMI quirk to restore these
bits after amd_gpio_irq_init() on this hardware.

Signed-off-by: Hardik Prakash <hardikprakash.official@gmail.com>
---
 drivers/pinctrl/pinctrl-amd.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c
index e3128b0045d22..64315b0edf2a6 100644
--- a/drivers/pinctrl/pinctrl-amd.c
+++ b/drivers/pinctrl/pinctrl-amd.c
@@ -26,6 +26,7 @@
 #include <linux/interrupt.h>
 #include <linux/bitops.h>
 #include <linux/pinctrl/pinconf.h>
+#include <linux/dmi.h>
 #include <linux/pinctrl/pinconf-generic.h>
 #include <linux/pinctrl/pinmux.h>
 #include <linux/string_choices.h>
@@ -39,6 +40,39 @@
 static struct amd_gpio *pinctrl_dev;
 #endif
 
+static const struct dmi_system_id amd_gpio_quirk_yoga7_14agp11[] = {
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "83TD"),
+			DMI_MATCH(DMI_BOARD_NAME, "LNVNB161216"),
+		},
+	},
+	{ }
+};
+
+static void amd_gpio_apply_quirks(struct amd_gpio *gpio_dev)
+{
+	const unsigned int pin = 157; /* WACF2200 GpioInt per ACPI _CRS */
+	unsigned long flags;
+	u32 reg;
+
+	if (!dmi_check_system(amd_gpio_quirk_yoga7_14agp11))
+		return;
+	if (pin >= gpio_dev->gc.ngpio)
+		return;
+
+	raw_spin_lock_irqsave(&gpio_dev->lock, flags);
+	reg = readl(gpio_dev->base + pin * 4);
+	reg |= BIT(INTERRUPT_ENABLE_OFF) | BIT(INTERRUPT_MASK_OFF);
+	writel(reg, gpio_dev->base + pin * 4);
+	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
+
+	dev_info(&gpio_dev->pdev->dev,
+		 "Enabled IRQ for GPIO %u (Yoga 7 14AGP11 touchscreen)\n",
+		 pin);
+}
+
 static int amd_gpio_get_direction(struct gpio_chip *gc, unsigned offset)
 {
 	unsigned long flags;
@@ -1219,6 +1253,7 @@ static int amd_gpio_probe(struct platform_device *pdev)
 
 	/* Disable and mask interrupts */
 	amd_gpio_irq_init(gpio_dev);
+	amd_gpio_apply_quirks(gpio_dev);
 
 	girq = &gpio_dev->gc.irq;
 	gpio_irq_chip_set_chip(girq, &amd_gpio_irqchip);
-- 
2.54.0