qmk_firmware/quantum/joystick.c

131 lines
3.8 KiB
C

/* 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},
.axes = {
#if JOYSTICK_AXES_COUNT > 0
0
#endif
},
.status = 0
};
// clang-format on
// array defining the reading of analog values for each axis
__attribute__((weak)) joystick_config_t joystick_axes[JOYSTICK_AXES_COUNT] = {};
__attribute__((weak)) void joystick_task(void) {
joystick_read_axes();
}
void joystick_flush(void) {
if ((joystick_status.status & JS_UPDATED) > 0) {
host_joystick_send(&joystick_status);
joystick_status.status &= ~JS_UPDATED;
}
}
void register_joystick_button(uint8_t button) {
joystick_status.buttons[button / 8] |= 1 << (button % 8);
joystick_status.status |= JS_UPDATED;
joystick_flush();
}
void unregister_joystick_button(uint8_t button) {
joystick_status.buttons[button / 8] &= ~(1 << (button % 8));
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;
}
}