1 files changed, 140 insertions, 0 deletions
diff --git a/drivers/sensors/pimoroni_trackball.c b/drivers/sensors/pimoroni_trackball.c
new file mode 100644
index 0000000000..c0ac644f70
--- /dev/null
+++ b/drivers/sensors/pimoroni_trackball.c
@@ -0,0 +1,140 @@
+/* Copyright 2020 Christopher Courtney, aka Drashna Jael're  (@drashna) <drashna@live.com>
+ *
+ * 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 "pimoroni_trackball.h"
+#include "i2c_master.h"
+
+static uint8_t scrolling      = 0;
+static int16_t x_offset       = 0;
+static int16_t y_offset       = 0;
+static int16_t h_offset       = 0;
+static int16_t v_offset       = 0;
+static float   precisionSpeed = 1;
+
+static uint16_t i2c_timeout_timer;
+
+#ifndef PIMORONI_I2C_TIMEOUT
+#    define PIMORONI_I2C_TIMEOUT 100
+#endif
+#ifndef I2C_WAITCHECK
+#    define I2C_WAITCHECK 1000
+#endif
+#ifndef MOUSE_DEBOUNCE
+#    define MOUSE_DEBOUNCE 5
+#endif
+
+void trackball_set_rgbw(uint8_t red, uint8_t green, uint8_t blue, uint8_t white) {
+    uint8_t data[] = {0x00, red, green, blue, white};
+    i2c_transmit(TRACKBALL_WRITE, data, sizeof(data), PIMORONI_I2C_TIMEOUT);
+}
+
+int16_t mouse_offset(uint8_t positive, uint8_t negative, int16_t scale) {
+    int16_t offset    = (int16_t)positive - (int16_t)negative;
+    int16_t magnitude = (int16_t)(scale * offset * offset * precisionSpeed);
+    return offset < 0 ? -magnitude : magnitude;
+}
+
+void update_member(int8_t* member, int16_t* offset) {
+    if (*offset > 127) {
+        *member = 127;
+        *offset -= 127;
+    } else if (*offset < -127) {
+        *member = -127;
+        *offset += 127;
+    } else {
+        *member = *offset;
+        *offset = 0;
+    }
+}
+
+__attribute__((weak)) void trackball_check_click(bool pressed, report_mouse_t* mouse) {
+    if (pressed) {
+        mouse->buttons |= MOUSE_BTN1;
+    } else {
+        mouse->buttons &= ~MOUSE_BTN1;
+    }
+}
+
+float trackball_get_precision(void) { return precisionSpeed; }
+void  trackball_set_precision(float precision) { precisionSpeed = precision; }
+bool  trackball_is_scrolling(void) { return scrolling; }
+void  trackball_set_scrolling(bool scroll) { scrolling = scroll; }
+
+__attribute__((weak)) void pointing_device_init(void) { i2c_init(); trackball_set_rgbw(0x00, 0x00, 0x00, 0x00); }
+
+void pointing_device_task(void) {
+    static bool     debounce;
+    static uint16_t debounce_timer;
+    uint8_t         state[5] = {};
+    if (timer_elapsed(i2c_timeout_timer) > I2C_WAITCHECK) {
+        if (i2c_readReg(TRACKBALL_READ, 0x04, state, 5, PIMORONI_I2C_TIMEOUT) == I2C_STATUS_SUCCESS) {
+            if (!state[4] && !debounce) {
+                if (scrolling) {
+#ifdef PIMORONI_TRACKBALL_INVERT_X
+                    h_offset += mouse_offset(state[2], state[3], 1);
+#else
+                    h_offset -= mouse_offset(state[2], state[3], 1);
+#endif
+#ifdef PIMORONI_TRACKBALL_INVERT_Y
+                    v_offset += mouse_offset(state[1], state[0], 1);
+#else
+                    v_offset -= mouse_offset(state[1], state[0], 1);
+#endif
+                } else {
+#ifdef PIMORONI_TRACKBALL_INVERT_X
+                    x_offset -= mouse_offset(state[2], state[3], 5);
+#else
+                    x_offset += mouse_offset(state[2], state[3], 5);
+#endif
+#ifdef PIMORONI_TRACKBALL_INVERT_Y
+                    y_offset -= mouse_offset(state[1], state[0], 5);
+#else
+                    y_offset += mouse_offset(state[1], state[0], 5);
+#endif
+                }
+            } else {
+                if (state[4]) {
+                    debounce       = true;
+                    debounce_timer = timer_read();
+                }
+            }
+        } else {
+            i2c_timeout_timer = timer_read();
+        }
+    }
+
+    if (timer_elapsed(debounce_timer) > MOUSE_DEBOUNCE) debounce = false;
+
+    report_mouse_t mouse = pointing_device_get_report();
+
+#ifdef PIMORONI_TRACKBALL_CLICK
+    trackball_check_click(state[4] & (1 << 7), &mouse);
+#endif
+
+#ifndef PIMORONI_TRACKBALL_ROTATE
+    update_member(&mouse.x, &x_offset);
+    update_member(&mouse.y, &y_offset);
+    update_member(&mouse.h, &h_offset);
+    update_member(&mouse.v, &v_offset);
+#else
+    update_member(&mouse.x, &y_offset);
+    update_member(&mouse.y, &x_offset);
+    update_member(&mouse.h, &v_offset);
+    update_member(&mouse.v, &h_offset);
+#endif
+    pointing_device_set_report(mouse);
+    pointing_device_send();
+}