ec/ite: Add WUC 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

@@ -9,6 +9,7 @@ ec-y += kbc.c
 ec-y += pmc.c
 ec-y += ps2.c
 ec-y += signature.c
+ec-y += wuc.c
 
 ifeq ($(CONFIG_EC_ITE_IT8587E), y)
 CFLAGS+=-DCONFIG_EC_ITE_IT8587E=1

src/ec/ite/include/ec/wuc.h

@@ -55,4 +55,14 @@ volatile uint8_t __xdata __at(0x1B2D) WUESR13;
 volatile uint8_t __xdata __at(0x1B30) WUEMR14;
 volatile uint8_t __xdata __at(0x1B31) WUESR14;
 
+enum WucEdgeMode {
+    EDGE_RISING,
+    EDGE_FALLING,
+    EDGE_BOTH,
+};
+
+void wuc_enable(uint8_t nr, enum WucEdgeMode detect);
+void wuc_disable(uint8_t nr);
+void wuc_clear(uint8_t nr);
+
 #endif // _EC_WUC_H

src/ec/ite/wuc.c

@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-3.0-only
+
+#include <ec/wuc.h>
+#include <common/macro.h>
+#include <stddef.h>
+
+struct WucGroup {
+    volatile uint8_t *edge;
+    volatile uint8_t *sense;
+    volatile uint8_t *enable;
+};
+
+// clang-format off
+
+// Only groups 1, 3, and 4 have WUENR.
+#define WUC_GROUP_EN(nr) { \
+    .edge = &WUEMR ## nr, \
+    .sense = &WUESR ## nr, \
+    .enable = &WUENR ## nr, \
+}
+
+#define WUC_GROUP(nr) { \
+    .edge = &WUEMR ## nr, \
+    .sense = &WUESR ## nr, \
+    .enable = NULL, \
+}
+
+static const struct WucGroup wuc[] = {
+    // Group 0 unused
+    WUC_GROUP_EN(1),
+    WUC_GROUP(2),
+    WUC_GROUP_EN(3),
+    WUC_GROUP_EN(4),
+    // Group 5 unused
+    WUC_GROUP(6),
+    WUC_GROUP(7),
+    WUC_GROUP(8),
+    WUC_GROUP(9),
+    WUC_GROUP(10),
+    WUC_GROUP(11),
+    WUC_GROUP(12),
+    WUC_GROUP(13),
+    WUC_GROUP(14),
+};
+
+// clang-format on
+
+void wuc_enable(uint8_t nr, enum WucEdgeMode detect) {
+    // XXX: SDCC doesn't optimize division with power-of-2.
+    const uint8_t group = nr >> 3U;
+    const uint8_t bit = nr % 8U;
+
+    if (detect == EDGE_RISING) {
+        *(wuc[group].edge) &= ~BIT(bit);
+    } else if (detect == EDGE_FALLING || detect == EDGE_BOTH) {
+        *(wuc[group].edge) |= BIT(bit);
+    }
+
+    *(wuc[group].sense) = BIT(bit);
+
+    if (wuc[group].enable) {
+        *(wuc[group].enable) |= BIT(bit);
+    }
+}
+
+void wuc_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;
+
+    if (wuc[group].enable) {
+        *(wuc[group].enable) &= ~BIT(bit);
+    }
+}
+
+void wuc_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;
+
+    *(wuc[group].sense) = BIT(bit);
+}