diff --git a/src/board/system76/galp3-c/include/board/power.h b/src/board/system76/galp3-c/include/board/power.h
new file mode 100644
index 0000000..504ed64
--- /dev/null
+++ b/src/board/system76/galp3-c/include/board/power.h
@@ -0,0 +1,6 @@
+#ifndef _BOARD_POWER_H
+#define _BOARD_POWER_H
+
+void power_event(void);
+
+#endif // _BOARD_POWER_H
diff --git a/src/board/system76/galp3-c/power.c b/src/board/system76/galp3-c/power.c
index 6d9c3c2..e06ec04 100644
--- a/src/board/system76/galp3-c/power.c
+++ b/src/board/system76/galp3-c/power.c
@@ -1,4 +1,7 @@
 #include <arch/delay.h>
+#include <board/power.h>
+#include <board/pnp.h>
+#include <common/debug.h>
 #include <ec/gpio.h>
 
 // Platform does not currently support Deep Sx
@@ -48,11 +51,19 @@ static struct Gpio __code SUS_PWR_ACK =     GPIO(J, 0);
 #define tPCH11 delay_ns(100)
 // RSMRST# asserting to VccPRIM dropping 5%
 #define tPCH12 delay_ns(400)
+// DSW_PWROK falling to any of VccDSW, VccPRIM dropping 5%
+#define tPCH14 delay_ns(400)
+// De-assertion of RSMRST# to de-assertion of ESPI_RESET#
+#if DEEP_SX
+    #define tPCH18 delay_us(90)
+#else
+    #define tPCH18 delay_ms(95)
+#endif
 // DSW_PWROK assertion to SLP_SUS# de-assertion
 #define tPCH32 delay_ms(95)
 
 // Enable deep sleep well power
-int power_on_dsw() {
+void power_on_ds5() {
 #if DEEP_SX
     // See Figure 12-18 in Whiskey Lake Platform Design Guide
     // | VCCRTC | RTCRST# | VCCDSW_3P3 | DSW_PWROK |
@@ -78,9 +89,6 @@ int power_on_dsw() {
     // tPCH04 is the ideal delay
     tPCH04;
 #endif // DEEP_SX
-
-    // We are ready to move on to the next stage
-    return 0;
 }
 
 // Enable S5 power
@@ -88,27 +96,160 @@ void power_on_s5() {
 #if DEEP_SX
     // See Figure 12-18 in Whiskey Lake Platform Design Guide
 
-    // RTC stage
-    {
-        // | VCCRTC | RTCRST# | VCCDSW_3P3 | DSW_PWROK |
-        // | tPCH01---------- |            |           |
-        // | tPCH04----------------------- |           |
-        // |        | tPCH05-------------------------- |
-        // |        |         | tPCH02---------------- |
-        // tPCH01 and tPCH02 combined make the longest delay
-        tPCH01;
-        tPCH02;
-    }
-
-    // Deep sleep well is a-ok
-    gpio_set(PCH_DPWROK_EC, true);
-    tPCH32;
-
-
     // TODO
 #else // DEEP_SX
     // See Figure 12-19 in Whiskey Lake Platform Design Guide
+    // TODO - signal timing graph
+    // See Figure 12-25 in Whiskey Lake Platform Design Guide
+    // TODO - rail timing graph
 
-    // TODO
+    // Enable VCCPRIM_* planes - must be enabled prior to USB power in order to
+    // avoid leakage
+    gpio_set(&VA_EC_EN, true);
+    tPCH06;
+
+    // Enable VDD5
+    gpio_set(&DD_ON, true);
+
+    // De-assert SUS_ACK# - TODO is this needed on non-dsx?
+    gpio_set(&SUS_PWR_ACK, true);
+    tPCH03;
+
+    // Assert DSW_PWROK
+    gpio_set(&PCH_DPWROK_EC, true);
+
+    // De-assert RSMRST#
+    gpio_set(&EC_RSMRST_N, true);
+
+    // Wait for PCH stability
+    tPCH18;
+
+    // Allow processor to control SUSB# and SUSC#
+    gpio_set(&EC_EN, true);
+#endif // DEEP_SX
+}
+
+void power_off_s5() {
+#if DEEP_SX
+    // TODO
+#else // DEEP_SX
+    // De-assert SYS_PWROK
+    gpio_set(&PCH_PWROK_EC, false);
+
+    // De-assert PCH_PWROK
+    gpio_set(&PM_PWROK, false);
+
+    // Block processor from controlling SUSB# and SUSC#
+    gpio_set(&EC_EN, false);
+
+    // De-assert RSMRST#
+    gpio_set(&EC_RSMRST_N, false);
+
+    // Disable VDD5
+    gpio_set(&DD_ON, false);
+    tPCH12;
+
+    // Disable VCCPRIM_* planes
+    gpio_set(&VA_EC_EN, false);
+
+    // De-assert DSW_PWROK
+    gpio_set(&PCH_DPWROK_EC, false);
+    tPCH14;
+#endif // DEEP_SX
+}
+
+enum PowerState {
+    POWER_STATE_DEFAULT,
+    POWER_STATE_DS5,
+    POWER_STATE_S5,
+    POWER_STATE_DS3,
+    POWER_STATE_S3,
+    POWER_STATE_S0,
+};
+
+void power_event(void) {
+    static enum PowerState state = POWER_STATE_DEFAULT;
+
+    // Always switch to ds5 if EC is running
+    if (state == POWER_STATE_DEFAULT) {
+        power_on_ds5();
+        state = POWER_STATE_DS5;
+
+        //TODO: Logic for switching from ds5 to s5
+        power_on_s5();
+        state = POWER_STATE_S5;
+    }
+
+    // Read power button state
+    static bool last = true;
+    bool new = gpio_get(&PWR_SW_N);
+    if (!new && last) {
+        // Ensure press is not spurious
+        delay_ms(10);
+        if (gpio_get(&PWR_SW_N) != new) {
+            DEBUG("Spurious press\n");
+            return;
+        }
+
+        DEBUG("Power switch press\n");
+    }
+    #if LEVEL >= LEVEL_DEBUG
+        else if (new && !last) {
+            DEBUG("Power switch release\n");
+        }
+    #endif
+
+    // Send power signal to PCH
+    gpio_set(&PWR_BTN_N, new);
+
+#if DEEP_SX
+    //TODO
+#else // DEEP_SX
+    //TODO: set power state as necessary
+
+    // If system power is good
+    if (gpio_get(&ALL_SYS_PWRGD)) {
+        DEBUG("ALL_SYS_PWRGD asserted\n");
+
+        // Allow H_VR_READY to set PCH_PWROK
+        gpio_set(&PM_PWROK, true);
+
+        // OEM defined delay from ALL_SYS_PWRGD to SYS_PWROK - TODO
+        delay_ms(10);
+
+        // Assert SYS_PWROK, system can finally perform PLT_RST# and boot
+        gpio_set(&PCH_PWROK_EC, true);
+    } else {
+        DEBUG("ALL_SYS_PWRGD de-asserted\n");
+
+        // De-assert SYS_PWROK
+        gpio_set(&PCH_PWROK_EC, false);
+
+        // De-assert PCH_PWROK
+        gpio_set(&PM_PWROK, false);
+    }
+
+    static bool rst_old = false;
+    bool rst_new = gpio_get(&BUF_PLT_RST_N);
+    if (!rst_old && rst_new) {
+        // LPC was just reset, enable PNP devices
+        pnp_enable();
+        //TODO: reset KBC and touchpad states
+    }
+
+    // EC must keep VccPRIM powered if SUSPWRDNACK is de-asserted low or system
+    // state is S3
+    bool primary = !gpio_get(&SUSWARN_N) || !gpio_get(&SUSB_N_PCH);
+    if (primary) {
+        if (state == POWER_STATE_DS5) {
+            power_on_s5();
+            state = POWER_STATE_DS5;
+        }
+    } else {
+        if (state == POWER_STATE_S5) {
+            power_off_s5();
+            state = POWER_STATE_DS5;
+        }
+    }
 #endif // DEEP_SX
 }