7 files changed, 288 insertions, 0 deletions

diff --git a/quantum/joystick.c b/quantum/joystick.c
new file mode 100644
index 000000000..7b87201ae
--- /dev/null
+++ b/quantum/joystick.c
@@ -0,0 +1,13 @@
+#include "joystick.h"
+
+joystick_t joystick_status = {.buttons = {0},
+                              .axes =
+                                  {
+#if JOYSTICK_AXES_COUNT > 0
+                                      0
+#endif
+                                  },
+                              .status = 0};
+
+// array defining the reading of analog values for each axis
+__attribute__((weak)) joystick_config_t joystick_axes[JOYSTICK_AXES_COUNT] = {};
diff --git a/quantum/joystick.h b/quantum/joystick.h
new file mode 100644
index 000000000..a95472b9f
--- /dev/null
+++ b/quantum/joystick.h
@@ -0,0 +1,54 @@
+#pragma once
+
+#ifndef JOYSTICK_BUTTON_COUNT
+#    define JOYSTICK_BUTTON_COUNT 8
+#endif
+
+#ifndef JOYSTICK_AXES_COUNT
+#    define JOYSTICK_AXES_COUNT 4
+#endif
+
+#include "quantum.h"
+
+#include <stdint.h>
+
+// configure on input_pin of the joystick_axes array entry to JS_VIRTUAL_AXIS
+// to prevent it from being read from the ADC. This allows outputing forged axis value.
+//
+#define JS_VIRTUAL_AXIS 0xFF
+
+#define JOYSTICK_AXIS_VIRTUAL \
+    { JS_VIRTUAL_AXIS, JS_VIRTUAL_AXIS, JS_VIRTUAL_AXIS, 0, 1023 }
+#define JOYSTICK_AXIS_IN(INPUT_PIN, LOW, REST, HIGH) \
+    { JS_VIRTUAL_AXIS, INPUT_PIN, JS_VIRTUAL_AXIS, LOW, REST, HIGH }
+#define JOYSTICK_AXIS_IN_OUT(INPUT_PIN, OUTPUT_PIN, LOW, REST, HIGH) \
+    { OUTPUT_PIN, INPUT_PIN, JS_VIRTUAL_AXIS, LOW, REST, HIGH }
+#define JOYSTICK_AXIS_IN_OUT_GROUND(INPUT_PIN, OUTPUT_PIN, GROUND_PIN, LOW, REST, HIGH) \
+    { OUTPUT_PIN, INPUT_PIN, GROUND_PIN, LOW, REST, HIGH }
+
+typedef struct {
+    pin_t output_pin;
+    pin_t input_pin;
+    pin_t ground_pin;
+
+    // the AVR ADC offers 10 bit precision, with significant bits on the higher part
+    uint16_t min_digit;
+    uint16_t mid_digit;
+    uint16_t max_digit;
+} joystick_config_t;
+
+extern joystick_config_t joystick_axes[JOYSTICK_AXES_COUNT];
+
+enum joystick_status { JS_INITIALIZED = 1, JS_UPDATED = 2 };
+
+typedef struct {
+    uint8_t buttons[JOYSTICK_BUTTON_COUNT / 8 + 1];
+
+    int16_t axes[JOYSTICK_AXES_COUNT];
+    uint8_t status : 2;
+} joystick_t;
+
+extern joystick_t joystick_status;
+
+// to be implemented in the hid protocol library
+void send_joystick_packet(joystick_t *joystick);
diff --git a/quantum/process_keycode/process_joystick.c b/quantum/process_keycode/process_joystick.c
new file mode 100644
index 000000000..c12f75685
--- /dev/null
+++ b/quantum/process_keycode/process_joystick.c
@@ -0,0 +1,168 @@
+#include "joystick.h"
+#include "process_joystick.h"
+
+#include "analog.h"
+
+#include <string.h>
+#include <math.h>
+
+bool process_joystick_buttons(uint16_t keycode, keyrecord_t *record);
+
+bool process_joystick(uint16_t keycode, keyrecord_t *record) {
+    if (process_joystick_buttons(keycode, record) && (joystick_status.status & JS_UPDATED) > 0) {
+        send_joystick_packet(&joystick_status);
+        joystick_status.status &= ~JS_UPDATED;
+    }
+
+    return true;
+}
+
+__attribute__((weak))
+void joystick_task(void) {
+    if (process_joystick_analogread() && (joystick_status.status & JS_UPDATED)) {
+        send_joystick_packet(&joystick_status);
+        joystick_status.status &= ~JS_UPDATED;
+    }
+}
+
+bool process_joystick_buttons(uint16_t keycode, keyrecord_t *record) {
+    if (keycode < JS_BUTTON0 || keycode > JS_BUTTON_MAX) {
+        return true;
+    } else {
+        if (record->event.pressed) {
+            joystick_status.buttons[(keycode - JS_BUTTON0) / 8] |= 1 << (keycode % 8);
+        } else {
+            joystick_status.buttons[(keycode - JS_BUTTON0) / 8] &= ~(1 << (keycode % 8));
+        }
+
+        joystick_status.status |= JS_UPDATED;
+    }
+
+    return true;
+}
+
+uint16_t savePinState(pin_t pin) {
+#ifdef __AVR__
+    uint8_t pinNumber = pin & 0xF;
+    return ((PORTx_ADDRESS(pin) >> pinNumber) & 0x1) << 1 | ((DDRx_ADDRESS(pin) >> pinNumber) & 0x1);
+#elif defined(PROTOCOL_CHIBIOS)
+    /*
+    The pin configuration is backed up in the following format : 
+ bit  15    9  8   7   6  5  4   3     2    1 0
+      |unused|ODR|IDR|PUPDR|OSPEEDR|OTYPER|MODER|
+    */
+    return  (( PAL_PORT(pin)->MODER   >> (2*PAL_PAD(pin))) & 0x3)
+          | (((PAL_PORT(pin)->OTYPER  >> (1*PAL_PAD(pin))) & 0x1) << 2) 
+          | (((PAL_PORT(pin)->OSPEEDR >> (2*PAL_PAD(pin))) & 0x3) << 3)
+          | (((PAL_PORT(pin)->PUPDR   >> (2*PAL_PAD(pin))) & 0x3) << 5)
+          | (((PAL_PORT(pin)->IDR     >> (1*PAL_PAD(pin))) & 0x1) << 7)
+          | (((PAL_PORT(pin)->ODR     >> (1*PAL_PAD(pin))) & 0x1) << 8);
+#else
+    return 0;
+#endif
+}
+
+void restorePinState(pin_t pin, uint16_t restoreState) {
+#if defined(PROTOCOL_LUFA)
+    uint8_t pinNumber  = pin & 0xF;
+    PORTx_ADDRESS(pin) = (PORTx_ADDRESS(pin) & ~_BV(pinNumber)) | (((restoreState >> 1) & 0x1) << pinNumber);
+    DDRx_ADDRESS(pin)  = (DDRx_ADDRESS(pin) & ~_BV(pinNumber)) | ((restoreState & 0x1) << pinNumber);
+#elif defined(PROTOCOL_CHIBIOS)
+    PAL_PORT(pin)->MODER  =  (PAL_PORT(pin)->MODER   & ~(0x3<< (2*PAL_PAD(pin)))) | (restoreState & 0x3)     << (2*PAL_PAD(pin));
+    PAL_PORT(pin)->OTYPER =  (PAL_PORT(pin)->OTYPER  & ~(0x1<< (1*PAL_PAD(pin)))) | ((restoreState>>2) & 0x1) << (1*PAL_PAD(pin));
+    PAL_PORT(pin)->OSPEEDR=  (PAL_PORT(pin)->OSPEEDR & ~(0x3<< (2*PAL_PAD(pin)))) | ((restoreState>>3) & 0x3) << (2*PAL_PAD(pin));
+    PAL_PORT(pin)->PUPDR  =  (PAL_PORT(pin)->PUPDR   & ~(0x3<< (2*PAL_PAD(pin)))) | ((restoreState>>5) & 0x3) << (2*PAL_PAD(pin));
+    PAL_PORT(pin)->IDR    =  (PAL_PORT(pin)->IDR     & ~(0x1<< (1*PAL_PAD(pin)))) | ((restoreState>>7) & 0x1) << (1*PAL_PAD(pin));
+    PAL_PORT(pin)->ODR    =  (PAL_PORT(pin)->ODR     & ~(0x1<< (1*PAL_PAD(pin)))) | ((restoreState>>8) & 0x1) << (1*PAL_PAD(pin));
+#else
+    return;
+#endif
+}
+
+__attribute__((weak)) bool process_joystick_analogread() { return process_joystick_analogread_quantum(); }
+
+bool process_joystick_analogread_quantum() {
+#if JOYSTICK_AXES_COUNT > 0
+    for (int axis_index = 0; axis_index < JOYSTICK_AXES_COUNT; ++axis_index) {
+        if (joystick_axes[axis_index].input_pin == JS_VIRTUAL_AXIS) {
+            continue;
+        }
+
+        // save previous input pin status as well
+        uint16_t inputSavedState = savePinState(joystick_axes[axis_index].input_pin);
+
+        // disable pull-up resistor
+        writePinLow(joystick_axes[axis_index].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_index].input_pin);
+
+        wait_us(10);
+
+        // save and apply output pin status
+        uint16_t outputSavedState = 0;
+        if (joystick_axes[axis_index].output_pin != JS_VIRTUAL_AXIS) {
+            // save previous output pin status
+            outputSavedState = savePinState(joystick_axes[axis_index].output_pin);
+
+            setPinOutput(joystick_axes[axis_index].output_pin);
+            writePinHigh(joystick_axes[axis_index].output_pin);
+        }
+
+        uint16_t groundSavedState = 0;
+        if (joystick_axes[axis_index].ground_pin != JS_VIRTUAL_AXIS) {
+            // save previous output pin status
+            groundSavedState = savePinState(joystick_axes[axis_index].ground_pin);
+
+            setPinOutput(joystick_axes[axis_index].ground_pin);
+            writePinLow(joystick_axes[axis_index].ground_pin);
+        }
+
+        wait_us(10);
+
+        setPinInput(joystick_axes[axis_index].input_pin);
+
+        wait_us(10);
+
+#    if defined(__AVR__) || defined(PROTOCOL_CHIBIOS)
+        int16_t axis_val = analogReadPin(joystick_axes[axis_index].input_pin);
+#    else
+        // default to resting position
+        int16_t axis_val = joystick_axes[axis_index].mid_digit;
+#    endif
+
+        //test the converted value against the lower range
+        int32_t ref = joystick_axes[axis_index].mid_digit;
+        int32_t range = joystick_axes[axis_index].min_digit;
+        int32_t ranged_val = ((axis_val - ref) * -127) / (range - ref) ;
+
+        if (ranged_val > 0) {
+            //the value is in the higher range
+            range = joystick_axes[axis_index].max_digit;
+            ranged_val = ((axis_val - ref) * 127) / (range - ref);
+        }
+        
+        //clamp the result in the valid range
+        ranged_val = ranged_val < -127 ? -127 : ranged_val;
+        ranged_val = ranged_val > 127 ? 127 : ranged_val;
+        
+        if (ranged_val != joystick_status.axes[axis_index]) {
+            joystick_status.axes[axis_index] = ranged_val;
+            joystick_status.status |= JS_UPDATED;
+        }
+
+        // restore output, ground and input status
+        if (joystick_axes[axis_index].output_pin != JS_VIRTUAL_AXIS) {
+            restorePinState(joystick_axes[axis_index].output_pin, outputSavedState);
+        }
+        if (joystick_axes[axis_index].ground_pin != JS_VIRTUAL_AXIS) {
+            restorePinState(joystick_axes[axis_index].ground_pin, groundSavedState);
+        }
+
+        restorePinState(joystick_axes[axis_index].input_pin, inputSavedState);
+    }
+
+#endif
+    return true;
+}
diff --git a/quantum/process_keycode/process_joystick.h b/quantum/process_keycode/process_joystick.h
new file mode 100644
index 000000000..7a8b82913
--- /dev/null
+++ b/quantum/process_keycode/process_joystick.h
@@ -0,0 +1,11 @@
+#pragma once
+
+#include <stdint.h>
+#include "quantum.h"
+
+bool process_joystick(uint16_t keycode, keyrecord_t *record);
+
+void joystick_task(void);
+
+bool process_joystick_analogread(void);
+bool process_joystick_analogread_quantum(void);
diff --git a/quantum/quantum.c b/quantum/quantum.c
index 9d63f4de2..dab6c9172 100644
--- a/quantum/quantum.c
+++ b/quantum/quantum.c
@@ -277,6 +277,9 @@ bool process_record_quantum(keyrecord_t *record) {
 #if defined(RGBLIGHT_ENABLE) || defined(RGB_MATRIX_ENABLE)
             process_rgb(keycode, record) &&
 #endif
+#ifdef JOYSTICK_ENABLE
+            process_joystick(keycode, record) &&
+#endif
             true)) {
         return false;
     }
diff --git a/quantum/quantum.h b/quantum/quantum.h
index 51deac0cd..a2c0ec9a2 100644
--- a/quantum/quantum.h
+++ b/quantum/quantum.h
@@ -142,6 +142,10 @@ extern layer_state_t layer_state;
 #    include "process_magic.h"
 #endif
 
+#ifdef JOYSTICK_ENABLE
+#    include "process_joystick.h"
+#endif
+
 #ifdef GRAVE_ESC_ENABLE
 #    include "process_grave_esc.h"
 #endif
diff --git a/quantum/quantum_keycodes.h b/quantum/quantum_keycodes.h
index 437921aeb..5e7c9ad33 100644
--- a/quantum/quantum_keycodes.h
+++ b/quantum/quantum_keycodes.h
@@ -512,6 +512,41 @@ enum quantum_keycodes {
     DYN_MACRO_PLAY1,
     DYN_MACRO_PLAY2,
 
+    JS_BUTTON0,
+    JS_BUTTON_MIN = JS_BUTTON0,
+    JS_BUTTON1,
+    JS_BUTTON2,
+    JS_BUTTON3,
+    JS_BUTTON4,
+    JS_BUTTON5,
+    JS_BUTTON6,
+    JS_BUTTON7,
+    JS_BUTTON8,
+    JS_BUTTON9,
+    JS_BUTTON10,
+    JS_BUTTON11,
+    JS_BUTTON12,
+    JS_BUTTON13,
+    JS_BUTTON14,
+    JS_BUTTON15,
+    JS_BUTTON16,
+    JS_BUTTON17,
+    JS_BUTTON18,
+    JS_BUTTON19,
+    JS_BUTTON20,
+    JS_BUTTON21,
+    JS_BUTTON22,
+    JS_BUTTON23,
+    JS_BUTTON24,
+    JS_BUTTON25,
+    JS_BUTTON26,
+    JS_BUTTON27,
+    JS_BUTTON28,
+    JS_BUTTON29,
+    JS_BUTTON30,
+    JS_BUTTON31,
+    JS_BUTTON_MAX = JS_BUTTON31,
+
     // always leave at the end
     SAFE_RANGE
 };