Add ability to poweroff ADNS5050 sensor (#24223)

* Add ability to poweroff ADNS5050 sensor

* ploopyco/trackball_nano: Poweroff ADNS5050 on suspend

drivers/sensors/adns5050.c

@@ -45,6 +45,8 @@
 #define REG_MOTION_BURST   0x63
 // clang-format on
 
+static bool powered_down = false;
+
 void adns5050_init(void) {
     // Initialize the ADNS serial pins.
     gpio_set_pin_output(ADNS5050_SCLK_PIN);
@@ -59,6 +61,8 @@ void adns5050_init(void) {
     // this ensures that the adns is actuall ready after reset.
     wait_ms(55);
 
+    powered_down = false;
+
     // read a burst from the adns and then discard it.
     // gets the adns ready for write commands
     // (for example, setting the dpi).
@@ -163,6 +167,10 @@ report_adns5050_t adns5050_read_burst(void) {
     data.dx = 0;
     data.dy = 0;
 
+    if (powered_down) {
+        return data;
+    }
+
     adns5050_serial_write(REG_MOTION_BURST);
 
     // We don't need a minimum tSRAD here. That's because a 4ms wait time is
@@ -211,3 +219,10 @@ bool adns5050_check_signature(void) {
 
     return (pid == 0x12 && rid == 0x01 && pid2 == 0x26);
 }
+
+void adns5050_power_down(void) {
+    if (!powered_down) {
+        powered_down = true;
+        adns5050_write_reg(REG_MOUSE_CONTROL, 0b10);
+    }
+}

drivers/sensors/adns5050.h

@@ -83,3 +83,4 @@ void              adns5050_set_cpi(uint16_t cpi);
 uint16_t          adns5050_get_cpi(void);
 int8_t            convert_twoscomp(uint8_t data);
 bool              adns5050_check_signature(void);
+void              adns5050_power_down(void);

keyboards/ploopyco/trackball_nano/keymaps/default/keymap.c

@@ -20,3 +20,12 @@
 
 // Dummy
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {{{ KC_NO }}};
+
+void suspend_power_down_user(void) {
+    // Switch off sensor + LED making trackball unable to wake host
+    adns5050_power_down();
+}
+
+void suspend_wakeup_init_user(void) {
+    adns5050_init();
+}