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// Copyright 2019 Mathias Andersson <[email protected]>
// SPDX-License-Identifier: GPL-2.0-or-later
#include "matrix.h"
#include "pca9555.h"
#include "wait.h"
/*
* IC1 (PCA9555) IC2 (PCA9555)
* ,----------. ,----------.
* SDA --| SDA P00 |-- P1 SDA --| SDA P00 |-- P17
* SCL --| SCL P01 |-- P2 SCL --| SCL P01 |-- P18
* INT --| INT P02 |-- P3 INT --| INT P02 |-- P19
* | P03 |-- P4 | P03 |-- P20
* GND --| A0 P04 |-- P5 VCC --| A0 P04 |-- P21
* SJ1 --| A1 P05 |-- P6 SJ1 --| A1 P05 |-- P22
* GND --| A2 P06 |-- P7 GND --| A2 P06 |-- P23
* | P07 |-- P8 | P07 |-- P24
* | | | |
* | P10 |-- P9 | P10 |-- P25
* | P11 |-- P10 | P11 |-- P26
* | P12 |-- P11 | P12 |-- P27
* | P13 |-- P12 | P13 |-- P28
* | P14 |-- P13 | P14 |-- P29
* | P15 |-- P14 | P15 |-- P30
* | P16 |-- P15 | P16 |-- P31
* | P17 |-- P16 | P17 |-- P32
* `----------' `----------'
*/
/*
* | Row | Pin | | Col | Pin |
* | --- | --- | | --- | --- |
* | 0 | P1 | | 0 | P25 |
* | 1 | P2 | | 1 | P26 |
* | 2 | P3 | | 2 | P27 |
* | 3 | P4 | | 3 | P28 |
* | 4 | P5 | | 4 | P29 |
* | 5 | P6 | | 5 | P30 |
* | 6 | P7 | | 6 | P20 |
* | 7 | P8 | | 7 | P21 |
* | 8 | P22 |
* | 9 | P23 |
* | A | P24 |
*/
// PCA9555 slave addresses
#define IC1 0x20
#define IC2 0x21
// PCA9555 column pin masks
#define PORT0_COLS_MASK 0b11111000
#define PORT1_COLS_MASK 0b00111111
#define COLS_MASK 0b0000011111111111
static void init_pins(void) {
// init cols - IC2 port0 & IC2 port1 input
pca9555_set_config(IC2, PCA9555_PORT0, ALL_INPUT);
pca9555_set_config(IC2, PCA9555_PORT1, ALL_INPUT);
// init rows - IC1 port0 output
pca9555_set_config(IC1, PCA9555_PORT0, ALL_OUTPUT);
pca9555_set_output(IC1, PCA9555_PORT0, ALL_HIGH);
}
static void select_row(uint8_t row) {
// All rows are on the same IC and port
uint8_t mask = 1 << row;
// set active row low : 0
// set other rows hi-Z : 1
pca9555_set_output(IC1, PCA9555_PORT0, ALL_HIGH & (~mask));
}
static uint16_t read_cols(void) {
uint8_t state_1 = 0;
uint8_t state_2 = 0;
pca9555_read_pins(IC2, PCA9555_PORT0, &state_1);
pca9555_read_pins(IC2, PCA9555_PORT1, &state_2);
uint16_t state = (((uint16_t)state_1 & PORT0_COLS_MASK) << 3) | (((uint16_t)state_2 & PORT1_COLS_MASK));
// A low pin indicates an active column
return (~state) & COLS_MASK;
}
static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) {
// Store last value of row prior to reading
matrix_row_t last_row_value = current_matrix[current_row];
// Clear data in matrix row
current_matrix[current_row] = 0;
// Select row and wait for row selection to stabilize
select_row(current_row);
wait_us(30);
current_matrix[current_row] = read_cols();
// No need to unselect as `select_row` sets all the pins.
return (last_row_value != current_matrix[current_row]);
}
void matrix_init_custom(void) {
pca9555_init(IC1);
pca9555_init(IC2);
init_pins();
}
bool matrix_scan_custom(matrix_row_t current_matrix[]) {
bool changed = false;
for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) {
changed |= read_cols_on_row(current_matrix, current_row);
}
return changed;
}
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