soc/amd/stoneyridge: Add functions for GPIO interrupts

Add a function to configure interrupt settings for a GPIO.  This does
not currently configure GEVENT signals.

The second function returns the GPIO interrupt status and clears the
flag if set.

BUG=b:72838769
BRANCH=none
TEST=Update and test interrupt settings for GPIO_9 on grunt

Change-Id: I1addd3abcb6a57d916b1c93480bacb0450abddf2
Signed-off-by: Chris Ching <chingcodes@chromium.org>
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/23624
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/amd/stoneyridge/Makefile.inc

@@ -40,6 +40,7 @@ subdirs-y += ../../../cpu/x86/smm
 bootblock-$(CONFIG_STONEYRIDGE_UART) += uart.c
 bootblock-y += BiosCallOuts.c
 bootblock-y += bootblock/bootblock.c
+bootblock-y += gpio.c
 bootblock-y += i2c.c
 bootblock-y += monotonic_timer.c
 bootblock-y += pmutil.c
@@ -66,6 +67,7 @@ romstage-$(CONFIG_STONEYRIDGE_UART) += uart.c
 romstage-y += tsc_freq.c
 romstage-y += southbridge.c
 
+verstage-y += gpio.c
 verstage-y += i2c.c
 verstage-y += monotonic_timer.c
 verstage-y += sb_util.c

src/soc/amd/stoneyridge/gpio.c

@@ -106,3 +106,32 @@ uint16_t gpio_acpi_pin(gpio_t gpio)
 {
 	return gpio;
 }
+
+void gpio_set_interrupt(gpio_t gpio, uint32_t flags)
+{
+	uintptr_t gpio_address = gpio_get_address(gpio);
+	uint32_t reg = read32((void *)gpio_address);
+
+	/* Clear registers that are being updated */
+	reg &= ~(GPIO_TRIGGER_MASK | GPIO_ACTIVE_MASK | GPIO_INTERRUPT_MASK);
+
+	/* Clear any extra bits in the flags */
+	flags &= (GPIO_TRIGGER_MASK | GPIO_ACTIVE_MASK | GPIO_INTERRUPT_MASK);
+
+	write32((void *)gpio_address, reg | flags);
+}
+
+int gpio_interrupt_status(gpio_t gpio)
+{
+	uintptr_t gpio_address = gpio_get_address(gpio);
+	uint32_t reg = read32((void *)gpio_address);
+
+	if (reg & GPIO_INT_STATUS) {
+		/* Clear interrupt status, preserve wake status */
+		reg &= ~GPIO_WAKE_STATUS;
+		write32((void *)gpio_address, reg);
+		return 1;
+	}
+
+	return 0;
+}

src/soc/amd/stoneyridge/include/soc/gpio.h

@@ -23,6 +23,19 @@
 #include <soc/iomap.h>
 #include <types.h>
 
+#define GPIO_EDGEL_TRIG		(0 << 8)
+#define GPIO_LEVEL_TRIG		(1 << 8)
+#define GPIO_TRIGGER_MASK	(1 << 8)
+
+#define GPIO_ACTIVE_HIGH	(0 << 9)
+#define GPIO_ACTIVE_LOW		(1 << 9)
+#define GPIO_ACTIVE_BOTH	(2 << 9)
+#define GPIO_ACTIVE_MASK	(3 << 9)
+
+#define GPIO_INT_STATUS_EN	(1 << 11)
+#define GPIO_INT_DELIVERY_EN	(1 << 12)
+#define GPIO_INTERRUPT_MASK	(3 << 11)
+
 #define GPIO_PIN_STS		(1 << 16)
 #define GPIO_PULLUP_ENABLE	(1 << 20)
 #define GPIO_PULLDOWN_ENABLE	(1 << 21)
@@ -30,6 +43,9 @@
 #define GPIO_OUTPUT_MASK	(1 << GPIO_OUTPUT_SHIFT)
 #define GPIO_OUTPUT_ENABLE	(1 << 23)
 
+#define GPIO_INT_STATUS		(1 << 28)
+#define GPIO_WAKE_STATUS	(1 << 29)
+
 /*
  * The definitions below should be used to make GPIO arrays compact and
  * easy to understand.
@@ -143,5 +159,12 @@
 #define GPIO_148			148
 
 typedef uint32_t gpio_t;
+
+/* Update interrupt settings for given GPIO */
+void gpio_set_interrupt(gpio_t gpio, uint32_t flags);
+
+/* Return the interrupt status and clear if set. */
+int gpio_interrupt_status(gpio_t gpio);
+
 #endif /* __ACPI__ */
 #endif /* __STONEYRIDGE_GPIO_H__ */