mediatek: Share GPIO external interrupts (EINT) code among similar SoCs

Refactor GPIO EINT code which can be reused among similar SoCs.

BUG=b:80501386
BRANCH=none
TEST=emerge-elm coreboot; emerge-kukui coreboot

Change-Id: Ib01b43cf1aa4082d7d968fe1ef82f75e8cf05b8b
Signed-off-by: Chuanjia Liu <Chuanjia.Liu@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/29837
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

2 files changed, 120 insertions, 0 deletions

diff --git a/src/soc/mediatek/common/gpio.c b/src/soc/mediatek/common/gpio.c
index 590f8ea461..371ff266d7 100644
--- a/src/soc/mediatek/common/gpio.c
+++ b/src/soc/mediatek/common/gpio.c
@@ -126,3 +126,64 @@ void gpio_output(gpio_t gpio, int value)
 	gpio_set_dir(gpio, GPIO_DIRECTION_OUT);
 	gpio_set_mode(gpio, GPIO_MODE);
 }
+
+enum {
+	MAX_EINT_REG_BITS = 32,
+};
+
+static void pos_bit_calc_for_eint(gpio_t gpio, u32 *pos, u32 *bit)
+{
+	*pos = gpio.id / MAX_EINT_REG_BITS;
+	*bit = gpio.id % MAX_EINT_REG_BITS;
+}
+
+int gpio_eint_poll(gpio_t gpio)
+{
+	u32 pos;
+	u32 bit;
+	u32 status;
+
+	pos_bit_calc_for_eint(gpio, &pos, &bit);
+
+	status = (read32(&mtk_eint->sta.regs[pos]) >> bit) & 0x1;
+
+	if (status)
+		write32(&mtk_eint->ack.regs[pos], 1 << bit);
+
+	return status;
+}
+
+void gpio_eint_configure(gpio_t gpio, enum gpio_irq_type type)
+{
+	u32 pos;
+	u32 bit, mask;
+
+	pos_bit_calc_for_eint(gpio, &pos, &bit);
+	mask = 1 << bit;
+
+	/* Make it an input first. */
+	gpio_input_pullup(gpio);
+
+	write32(&mtk_eint->d0en[pos], mask);
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_FALLING:
+		write32(&mtk_eint->sens_clr.regs[pos], mask);
+		write32(&mtk_eint->pol_clr.regs[pos], mask);
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		write32(&mtk_eint->sens_clr.regs[pos], mask);
+		write32(&mtk_eint->pol_set.regs[pos], mask);
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		write32(&mtk_eint->sens_set.regs[pos], mask);
+		write32(&mtk_eint->pol_clr.regs[pos], mask);
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		write32(&mtk_eint->sens_set.regs[pos], mask);
+		write32(&mtk_eint->pol_set.regs[pos], mask);
+		break;
+	}
+
+	write32(&mtk_eint->mask_clr.regs[pos], mask);
+}
diff --git a/src/soc/mediatek/common/include/soc/gpio_common.h b/src/soc/mediatek/common/include/soc/gpio_common.h
index 22acd92fe6..374c810313 100644
--- a/src/soc/mediatek/common/include/soc/gpio_common.h
+++ b/src/soc/mediatek/common/include/soc/gpio_common.h
@@ -16,6 +16,10 @@
 #ifndef SOC_MEDIATEK_COMMON_GPIO_H
 #define SOC_MEDIATEK_COMMON_GPIO_H
 
+#include <soc/gpio_base.h>
+#include <stddef.h>
+#include <stdint.h>
+
 enum pull_enable {
 	GPIO_PULL_DISABLE = 0,
 	GPIO_PULL_ENABLE = 1,
@@ -26,4 +30,59 @@ enum pull_select {
 	GPIO_PULL_UP = 1,
 };
 
+void gpio_set_pull(gpio_t gpio, enum pull_enable enable,
+		   enum pull_select select);
+void gpio_set_mode(gpio_t gpio, int mode);
+
+enum gpio_irq_type {
+	IRQ_TYPE_EDGE_RISING,
+	IRQ_TYPE_EDGE_FALLING,
+	IRQ_TYPE_LEVEL_HIGH,
+	IRQ_TYPE_LEVEL_LOW,
+};
+
+struct eint_section {
+	uint32_t	regs[7];
+	uint32_t	align1[9];
+};
+
+struct eint_regs {
+	struct eint_section sta;
+	struct eint_section ack;
+	struct eint_section mask;
+	struct eint_section mask_set;
+	struct eint_section mask_clr;
+	struct eint_section sens;
+	struct eint_section sens_set;
+	struct eint_section sens_clr;
+	struct eint_section soft;
+	struct eint_section soft_set;
+	struct eint_section soft_clr;
+	struct eint_section rsv00;
+	struct eint_section pol;
+	struct eint_section pol_set;
+	struct eint_section pol_clr;
+	struct eint_section rsv01;
+	uint32_t	    d0en[7];
+	uint32_t	    rsv02;
+	uint32_t	    d1en[7];
+};
+
+check_member(eint_regs, d1en, 0x420);
+
+static struct eint_regs *const mtk_eint = (void *)(EINT_BASE);
+
+/*
+ * Firmware never enables interrupts on this platform.  This function
+ * reads current EINT status and clears the pending interrupt.
+ *
+ * Returns 1 if the interrupt was pending, else 0.
+ */
+int gpio_eint_poll(gpio_t gpio);
+
+/*
+ * Configure a GPIO to handle external interrupts (EINT) of given irq type.
+ */
+void gpio_eint_configure(gpio_t gpio, enum gpio_irq_type type);
+
 #endif