ec/ite: Add INTC functions to handle interrupts

Add functions to enable, disable, and clear an interrupt.

Signed-off-by: Tim Crawford <tcrawford@system76.com>

src/ec/ite/ec.mk

@@ -4,6 +4,7 @@ ec-y += ec.c
 ec-$(CONFIG_BUS_ESPI) += espi.c
 ec-y += gpio.c
 ec-y += i2c.c
+ec-y += intc.c
 ec-y += kbc.c
 ec-y += pmc.c
 ec-y += ps2.c

src/ec/ite/include/ec/intc.h

@@ -134,4 +134,8 @@ static inline uint8_t intc_get_irq(void) {
     return IVCT - 0x10;
 }
 
+void intc_enable(uint8_t nr);
+void intc_disable(uint8_t nr);
+void intc_clear(uint8_t nr);
+
 #endif // _EC_INTC_H

src/ec/ite/intc.c

@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-3.0-only
+
+#include <ec/intc.h>
+#include <common/macro.h>
+
+struct IrqGroup {
+    volatile uint8_t *status;
+    volatile uint8_t *enable;
+    volatile uint8_t *level;
+    volatile uint8_t *polarity;
+};
+
+// clang-format off
+#define IRQ_GROUP(nr) { \
+    .status = &ISR ## nr, \
+    .enable = &IER ## nr, \
+    .level = &IELMR ## nr, \
+    .polarity = &IPOLR ## nr, \
+}
+
+static const struct IrqGroup irqs[] = {
+    IRQ_GROUP(0),
+    IRQ_GROUP(1),
+    IRQ_GROUP(2),
+    IRQ_GROUP(3),
+    IRQ_GROUP(4),
+    IRQ_GROUP(5),
+    IRQ_GROUP(6),
+    IRQ_GROUP(7),
+    IRQ_GROUP(8),
+    IRQ_GROUP(9),
+    IRQ_GROUP(10),
+    IRQ_GROUP(11),
+    IRQ_GROUP(12),
+    IRQ_GROUP(13),
+    IRQ_GROUP(14),
+    IRQ_GROUP(15),
+    IRQ_GROUP(16),
+    IRQ_GROUP(17),
+    IRQ_GROUP(18),
+#if CONFIG_EC_ITE_IT5570E
+    IRQ_GROUP(19),
+    IRQ_GROUP(20),
+    IRQ_GROUP(21),
+#endif
+};
+// clang-format on
+
+void intc_enable(uint8_t nr) {
+    // XXX: SDCC doesn't optimize division with power-of-2.
+    const uint8_t group = nr >> 3U;
+    const uint8_t bit = nr % 8U;
+
+    *(irqs[group].status) = BIT(bit);
+    *(irqs[group].enable) |= BIT(bit);
+}
+
+void intc_disable(uint8_t nr) {
+    // XXX: SDCC doesn't optimize division with power-of-2.
+    const uint8_t group = nr >> 3U;
+    const uint8_t bit = nr % 8U;
+
+    *(irqs[group].enable) &= ~BIT(bit);
+}
+
+void intc_clear(uint8_t nr) {
+    // XXX: SDCC doesn't optimize division with power-of-2.
+    const uint8_t group = nr >> 3U;
+    const uint8_t bit = nr % 8U;
+
+    *(irqs[group].status) = BIT(bit);
+}