lotus: Add host SLEEP# detection

Signed-off-by: Daniel Schaefer <git@danielschaefer.me>

keyboards/lotus/lotus.c

@@ -4,16 +4,6 @@
 #include "quantum.h"
 #include "lotus.h"
 
-#define MUX_ENABLE_GPIO GP4
-#define BOOT_DONE_GPIO GP5
-// Pin SDB to enable the RGB controller
-#ifdef PICO_LOTUS
-// 22 only on RPi Pico because it doesn't have GP29
-#define IS31FL3743A_ENABLE_GPIO GP22
-#else
-#define IS31FL3743A_ENABLE_GPIO GP29
-#endif
-
 void keyboard_post_init_kb(void) {
   keyboard_post_init_user();
 
@@ -40,7 +30,30 @@ void keyboard_pre_init_kb(void) {
     writePinHigh(MUX_ENABLE_GPIO);
 
 #ifdef RGB_MATRIX_ENABLE
-    //// TODO: Do we ever need to disable it to save power?
+    setPinOutput(IS31FL3743A_ENABLE_GPIO);
+    writePinHigh(IS31FL3743A_ENABLE_GPIO);
+#endif
+    setPinInput(SLEEP_GPIO);
+}
+
+/**
+ * Called by QMK when the keyboard suspends
+ */
+void suspend_power_down_kb(void) {
+  suspend_power_down_user();
+
+#ifdef RGB_MATRIX_ENABLE
+  writePinLow(IS31FL3743A_ENABLE_GPIO);
+#endif
+}
+
+/**
+ * Called by QMK when the keyboard wakes up from suspend
+ */
+void suspend_wakeup_init_kb(void) {
+  suspend_wakeup_init_user();
+
+#ifdef RGB_MATRIX_ENABLE
     setPinOutput(IS31FL3743A_ENABLE_GPIO);
     writePinHigh(IS31FL3743A_ENABLE_GPIO);
 #endif

keyboards/lotus/lotus.h

@@ -21,3 +21,15 @@ enum lotus_keycodes {
   // Custom keycode to change screen modes (e.g. enable external screen)
   KC_SCRN = SAFE_RANGE,
 };
+
+#define SLEEP_GPIO GP0
+#define MUX_ENABLE_GPIO GP4
+#define BOOT_DONE_GPIO GP5
+// Pin SDB to enable the RGB controller
+#ifdef PICO_LOTUS
+// 22 only on RPi Pico because it doesn't have GP29
+#define IS31FL3743A_ENABLE_GPIO GP22
+#else
+#define IS31FL3743A_ENABLE_GPIO GP29
+#endif
+

keyboards/lotus/matrix.c

@@ -4,13 +4,14 @@
 #include <stdio.h>
 #include <stdint.h>
 #include "debug.h"
-#include "matrix.h"
 #include "analog.h"
 #include "print.h"
 #include "quantum.h"
 #include "hal_adc.h"
 #include "chprintf.h"
+
 #include "matrix.h"
+#include "lotus.h"
 
 // Use raw ChibiOS ADC functions instead of those from QMK
 // Using the QMK functions doesn't work yet
@@ -361,6 +362,19 @@ static void read_adc(void) {
     print_float(adc_voltage);
 }
 
+/**
+ * Handle the host going to sleep or the keyboard being idle
+ * If the host is asleep the keyboard should reduce the scan rate and turn backlight off.
+ *
+ * If the host is awake but the keyboard is idle it should enter a low-power state
+ */
+void handle_idle(void) {
+    bool asleep = readPin(SLEEP_GPIO);
+    uprintf("Host asleep: %d\n", asleep);
+
+    // TODO: Implement idle behavior
+}
+
 /**
  * Overriding behavior of matrix_scan from quantum/matrix.c
 */
@@ -369,6 +383,8 @@ bool matrix_scan_custom(matrix_row_t current_matrix[]) {
 
     print("scan\n");
 
+    handle_idle();
+
     for (int col = 0; col < MATRIX_COLS; col++) {
         // Drive column low so we can measure the resistors on each row in this column
         drive_col(col, false);