1 files changed, 95 insertions, 3 deletions

diff --git a/quantum/joystick.c b/quantum/joystick.c
index 86b2c64036..d285dcdb5e 100644
--- a/quantum/joystick.c
+++ b/quantum/joystick.c
@@ -1,5 +1,24 @@
+/* Copyright 2022
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include "joystick.h"
 
+#include "analog.h"
+#include "wait.h"
+
 // clang-format off
 joystick_t joystick_status = {
     .buttons = {0},
@@ -15,12 +34,13 @@ joystick_t joystick_status = {
 // array defining the reading of analog values for each axis
 __attribute__((weak)) joystick_config_t joystick_axes[JOYSTICK_AXES_COUNT] = {};
 
-// to be implemented in the hid protocol library
-void send_joystick_packet(joystick_t *joystick);
+__attribute__((weak)) void joystick_task(void) {
+    joystick_read_axes();
+}
 
 void joystick_flush(void) {
     if ((joystick_status.status & JS_UPDATED) > 0) {
-        send_joystick_packet(&joystick_status);
+        host_joystick_send(&joystick_status);
         joystick_status.status &= ~JS_UPDATED;
     }
 }
@@ -36,3 +56,75 @@ void unregister_joystick_button(uint8_t button) {
     joystick_status.status |= JS_UPDATED;
     joystick_flush();
 }
+
+int16_t joystick_read_axis(uint8_t axis) {
+    // disable pull-up resistor
+    writePinLow(joystick_axes[axis].input_pin);
+
+    // if pin was a pull-up input, we need to uncharge it by turning it low
+    // before making it a low input
+    setPinOutput(joystick_axes[axis].input_pin);
+
+    wait_us(10);
+
+    if (joystick_axes[axis].output_pin != JS_VIRTUAL_AXIS) {
+        setPinOutput(joystick_axes[axis].output_pin);
+        writePinHigh(joystick_axes[axis].output_pin);
+    }
+
+    if (joystick_axes[axis].ground_pin != JS_VIRTUAL_AXIS) {
+        setPinOutput(joystick_axes[axis].ground_pin);
+        writePinLow(joystick_axes[axis].ground_pin);
+    }
+
+    wait_us(10);
+
+    setPinInput(joystick_axes[axis].input_pin);
+
+    wait_us(10);
+
+#if defined(ANALOG_JOYSTICK_ENABLE) && (defined(__AVR__) || defined(PROTOCOL_CHIBIOS))
+    int16_t axis_val = analogReadPin(joystick_axes[axis].input_pin);
+#else
+    // default to resting position
+    int16_t axis_val = joystick_axes[axis].mid_digit;
+#endif
+
+    // test the converted value against the lower range
+    int32_t ref        = joystick_axes[axis].mid_digit;
+    int32_t range      = joystick_axes[axis].min_digit;
+    int32_t ranged_val = ((axis_val - ref) * -JOYSTICK_RESOLUTION) / (range - ref);
+
+    if (ranged_val > 0) {
+        // the value is in the higher range
+        range      = joystick_axes[axis].max_digit;
+        ranged_val = ((axis_val - ref) * JOYSTICK_RESOLUTION) / (range - ref);
+    }
+
+    // clamp the result in the valid range
+    ranged_val = ranged_val < -JOYSTICK_RESOLUTION ? -JOYSTICK_RESOLUTION : ranged_val;
+    ranged_val = ranged_val > JOYSTICK_RESOLUTION ? JOYSTICK_RESOLUTION : ranged_val;
+
+    return ranged_val;
+}
+
+void joystick_read_axes() {
+#if JOYSTICK_AXES_COUNT > 0
+    for (int i = 0; i < JOYSTICK_AXES_COUNT; ++i) {
+        if (joystick_axes[i].input_pin == JS_VIRTUAL_AXIS) {
+            continue;
+        }
+
+        joystick_set_axis(i, joystick_read_axis(i));
+    }
+
+    joystick_flush();
+#endif
+}
+
+void joystick_set_axis(uint8_t axis, int16_t value) {
+    if (value != joystick_status.axes[axis]) {
+        joystick_status.axes[axis] = value;
+        joystick_status.status |= JS_UPDATED;
+    }
+}