keyboard/qmk/keyboards/ferris/0_1/matrix.c

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2020-10-29 21:04:34 +00:00
/*
Copyright 2013 Oleg Kostyuk <cub.uanic@gmail.com>
2020 Pierre Chevalier <pierrechevalier83@gmail.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/>.
*/
/*
* This code was heavily inspired by the ergodox_ez keymap, and modernized
* to take advantage of the quantum.h microcontroller agnostics gpio control
* abstractions and use the macros defined in config.h for the wiring as opposed
* to repeating that information all over the place.
*/
#include QMK_KEYBOARD_H
#include "i2c_master.h"
extern i2c_status_t mcp23017_status;
#define I2C_TIMEOUT 1000
// For a better understanding of the i2c protocol, this is a good read:
// https://www.robot-electronics.co.uk/i2c-tutorial
// I2C address:
// See the datasheet, section 3.3.1 on addressing I2C devices and figure 3-6 for an
// illustration
// http://ww1.microchip.com/downloads/en/devicedoc/20001952c.pdf
// All address pins of the mcp23017 are connected to the ground on the ferris
// | 0 | 1 | 0 | 0 | A2 | A1 | A0 |
// | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
#define I2C_ADDR 0b0100000
#define I2C_ADDR_WRITE ((I2C_ADDR << 1) | I2C_WRITE)
#define I2C_ADDR_READ ((I2C_ADDR << 1) | I2C_READ)
// Register addresses
// See https://github.com/adafruit/Adafruit-MCP23017-Arduino-Library/blob/master/Adafruit_MCP23017.h
#define IODIRA 0x00 // i/o direction register
#define IODIRB 0x01
#define GPPUA 0x0C // GPIO pull-up resistor register
#define GPPUB 0x0D
#define GPIOA 0x12 // general purpose i/o port register (write modifies OLAT)
#define GPIOB 0x13
#define OLATA 0x14 // output latch register
#define OLATB 0x15
bool i2c_initialized = 0;
i2c_status_t mcp23017_status = I2C_ADDR;
uint8_t init_mcp23017(void) {
print("starting init");
mcp23017_status = I2C_ADDR;
// I2C subsystem
if (i2c_initialized == 0) {
i2c_init(); // on pins D(1,0)
i2c_initialized = true;
wait_ms(I2C_TIMEOUT);
}
// set pin direction
// - unused : input : 1
// - input : input : 1
// - driving : output : 0
mcp23017_status = i2c_start(I2C_ADDR_WRITE, I2C_TIMEOUT);
if (mcp23017_status) goto out;
mcp23017_status = i2c_write(IODIRA, I2C_TIMEOUT);
if (mcp23017_status) goto out;
// This means: we will read all the bits on GPIOA
mcp23017_status = i2c_write(0b11111111, I2C_TIMEOUT);
if (mcp23017_status) goto out;
// This means: we will write to the pins 0-4 on GPIOB (in select_rows)
mcp23017_status = i2c_write(0b11110000, I2C_TIMEOUT);
if (mcp23017_status) goto out;
i2c_stop();
// set pull-up
// - unused : on : 1
// - input : on : 1
// - driving : off : 0
mcp23017_status = i2c_start(I2C_ADDR_WRITE, I2C_TIMEOUT);
if (mcp23017_status) goto out;
mcp23017_status = i2c_write(GPPUA, I2C_TIMEOUT);
if (mcp23017_status) goto out;
// This means: we will read all the bits on GPIOA
mcp23017_status = i2c_write(0b11111111, I2C_TIMEOUT);
if (mcp23017_status) goto out;
// This means: we will write to the pins 0-4 on GPIOB (in select_rows)
mcp23017_status = i2c_write(0b11110000, I2C_TIMEOUT);
if (mcp23017_status) goto out;
out:
i2c_stop();
return mcp23017_status;
}
/* matrix state(1:on, 0:off) */
static matrix_row_t matrix[MATRIX_ROWS]; // debounced values
static matrix_row_t read_cols(uint8_t row);
static void init_cols(void);
static void unselect_rows(void);
static void select_row(uint8_t row);
static uint8_t mcp23017_reset_loop;
void matrix_init_custom(void) {
// initialize row and col
mcp23017_status = init_mcp23017();
unselect_rows();
init_cols();
// initialize matrix state: all keys off
for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
matrix[i] = 0;
}
}
void matrix_power_up(void) {
mcp23017_status = init_mcp23017();
unselect_rows();
init_cols();
// initialize matrix state: all keys off
for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
matrix[i] = 0;
}
}
// Reads and stores a row, returning
// whether a change occurred.
static inline bool store_matrix_row(matrix_row_t current_matrix[], uint8_t index) {
matrix_row_t temp = read_cols(index);
if (current_matrix[index] != temp) {
current_matrix[index] = temp;
return true;
}
return false;
}
bool matrix_scan_custom(matrix_row_t current_matrix[]) {
if (mcp23017_status) { // if there was an error
if (++mcp23017_reset_loop == 0) {
// if (++mcp23017_reset_loop >= 1300) {
// since mcp23017_reset_loop is 8 bit - we'll try to reset once in 255 matrix scans
// this will be approx bit more frequent than once per second
dprint("trying to reset mcp23017\n");
mcp23017_status = init_mcp23017();
if (mcp23017_status) {
dprint("right side not responding\n");
} else {
dprint("right side attached\n");
}
}
}
bool changed = false;
for (uint8_t i = 0; i < MATRIX_ROWS_PER_SIDE; i++) {
// select rows from left and right hands
uint8_t left_index = i;
uint8_t right_index = i + MATRIX_ROWS_PER_SIDE;
select_row(left_index);
select_row(right_index);
// we don't need a 30us delay anymore, because selecting a
// left-hand row requires more than 30us for i2c.
changed |= store_matrix_row(current_matrix, left_index);
changed |= store_matrix_row(current_matrix, right_index);
unselect_rows();
}
return changed;
}
static void init_cols(void) {
// init on mcp23017
// not needed, already done as part of init_mcp23017()
// init on mcu
pin_t matrix_col_pins_mcu[MATRIX_COLS_PER_SIDE] = MATRIX_COL_PINS_MCU;
for (int pin_index = 0; pin_index < MATRIX_COLS_PER_SIDE; pin_index++) {
pin_t pin = matrix_col_pins_mcu[pin_index];
setPinInput(pin);
writePinHigh(pin);
}
}
static matrix_row_t read_cols(uint8_t row) {
if (row < MATRIX_ROWS_PER_SIDE) {
pin_t matrix_col_pins_mcu[MATRIX_COLS_PER_SIDE] = MATRIX_COL_PINS_MCU;
matrix_row_t current_row_value = 0;
// For each col...
for (uint8_t col_index = 0; col_index < MATRIX_COLS_PER_SIDE; col_index++) {
// Select the col pin to read (active low)
uint8_t pin_state = readPin(matrix_col_pins_mcu[col_index]);
// Populate the matrix row with the state of the col pin
current_row_value |= pin_state ? 0 : (MATRIX_ROW_SHIFTER << col_index);
}
return current_row_value;
} else {
if (mcp23017_status) { // if there was an error
return 0;
} else {
uint8_t data = 0;
mcp23017_status = i2c_start(I2C_ADDR_WRITE, I2C_TIMEOUT);
if (mcp23017_status) goto out;
mcp23017_status = i2c_write(GPIOA, I2C_TIMEOUT);
if (mcp23017_status) goto out;
mcp23017_status = i2c_start(I2C_ADDR_READ, I2C_TIMEOUT);
if (mcp23017_status) goto out;
mcp23017_status = i2c_read_nack(I2C_TIMEOUT);
if (mcp23017_status < 0) goto out;
// We read all the pins on GPIOA.
// The initial state was all ones and any depressed key at a given column for the currently selected row will have its bit flipped to zero.
// The return value is a row as represented in the generic matrix code were the rightmost bits represent the lower columns and zeroes represent non-depressed keys while ones represent depressed keys.
// Since the pins connected to eact columns are sequential, and counting from zero up (col 5 -> GPIOA0, col 6 -> GPIOA1 and so on), the only transformation needed is a bitwise not to swap all zeroes and ones.
data = ~((uint8_t)mcp23017_status);
mcp23017_status = I2C_STATUS_SUCCESS;
out:
i2c_stop();
// return reverse_bits(data, MATRIX_COLS_PER_SIDE);
return data;
}
}
}
static void unselect_rows(void) {
// no need to unselect on mcp23017, because the select step sets all
// the other row bits high, and it's not changing to a different
// direction
// unselect rows on microcontroller
pin_t matrix_row_pins_mcu[MATRIX_ROWS_PER_SIDE] = MATRIX_ROW_PINS_MCU;
for (int pin_index = 0; pin_index < MATRIX_ROWS_PER_SIDE; pin_index++) {
pin_t pin = matrix_row_pins_mcu[pin_index];
setPinInput(pin);
writePinLow(pin);
}
}
static void select_row(uint8_t row) {
if (row < MATRIX_ROWS_PER_SIDE) {
// select on atmega32u4
pin_t matrix_row_pins_mcu[MATRIX_ROWS_PER_SIDE] = MATRIX_ROW_PINS_MCU;
pin_t pin = matrix_row_pins_mcu[row];
setPinOutput(pin);
writePinLow(pin);
} else {
// select on mcp23017
if (mcp23017_status) { // if there was an error
// do nothing
} else {
mcp23017_status = i2c_start(I2C_ADDR_WRITE, I2C_TIMEOUT);
if (mcp23017_status) goto out;
mcp23017_status = i2c_write(GPIOB, I2C_TIMEOUT);
if (mcp23017_status) goto out;
// Select the desired row by writing a byte for the entire GPIOB bus where only the bit representing the row we want to select is a zero (write instruction) and every other bit is a one.
// Note that the row - MATRIX_ROWS_PER_SIDE reflects the fact that being on the right hand, the columns are numbered from MATRIX_ROWS_PER_SIDE to MATRIX_ROWS, but the pins we want to write to are indexed from zero up on the GPIOB bus.
mcp23017_status = i2c_write(0xFF & ~(1 << (row - MATRIX_ROWS_PER_SIDE)), I2C_TIMEOUT);
if (mcp23017_status) goto out;
out:
i2c_stop();
}
}
}