matrix.c
4472 bytes
1/*
2Copyright 2012-2018 Jun Wako, Jack Humbert, Yiancar
3Copyright 2022 jun10000
4
5This program is free software: you can redistribute it and/or modify
6it under the terms of the GNU General Public License as published by
7the Free Software Foundation, either version 2 of the License, or
8(at your option) any later version.
9
10This program is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with this program. If not, see <http://www.gnu.org/licenses/>.
17*/
18#include "matrix.h"
19#include "wait.h"
20
21#if (MATRIX_COLS <= 8)
22# define ROW_SHIFTER ((uint8_t)1)
23#elif (MATRIX_COLS <= 16)
24# define ROW_SHIFTER ((uint16_t)1)
25#elif (MATRIX_COLS <= 32)
26# define ROW_SHIFTER ((uint32_t)1)
27#endif
28
29static const pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
30static const pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
31
32static void select_row(uint8_t row)
33{
34 gpio_set_pin_output(row_pins[row]);
35 gpio_write_pin_low(row_pins[row]);
36}
37
38static void unselect_row(uint8_t row)
39{
40 gpio_set_pin_input_high(row_pins[row]);
41}
42
43static void unselect_rows(void)
44{
45 for(uint8_t x = 0; x < MATRIX_ROWS; x++) {
46 gpio_set_pin_input_high(row_pins[x]);
47 }
48}
49
50static void select_col(uint8_t col)
51{
52 gpio_set_pin_output(col_pins[col]);
53 gpio_write_pin_low(col_pins[col]);
54}
55
56static void unselect_col(uint8_t col)
57{
58 gpio_set_pin_input_high(col_pins[col]);
59}
60
61static void unselect_cols(void)
62{
63 for(uint8_t x = 0; x < MATRIX_COLS; x++) {
64 gpio_set_pin_input_high(col_pins[x]);
65 }
66}
67
68static void init_pins(void) {
69 unselect_rows();
70 unselect_cols();
71 for (uint8_t x = 0; x < MATRIX_COLS; x++) {
72 gpio_set_pin_input_high(col_pins[x]);
73 }
74 for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
75 gpio_set_pin_input_high(row_pins[x]);
76 }
77}
78
79static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row)
80{
81 // Store last value of row prior to reading
82 matrix_row_t last_row_value = current_matrix[current_row];
83
84 // Clear data in matrix row
85 current_matrix[current_row] = 0;
86
87 // Select row and wait for row selecton to stabilize
88 select_row(current_row);
89 wait_us(30);
90
91 // For each col...
92 for(uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++) {
93
94 // Select the col pin to read (active low)
95 uint8_t pin_state = gpio_read_pin(col_pins[col_index]);
96
97 // Populate the matrix row with the state of the col pin
98 current_matrix[current_row] |= pin_state ? 0 : (ROW_SHIFTER << col_index);
99 }
100
101 // Unselect row
102 unselect_row(current_row);
103
104 return (last_row_value != current_matrix[current_row]);
105}
106
107static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col)
108{
109 bool matrix_changed = false;
110
111 // Select col and wait for col selecton to stabilize
112 select_col(current_col);
113 wait_us(30);
114
115 // For each row...
116 for(uint8_t row_index = 0; row_index < MATRIX_ROWS/2; row_index++)
117 {
118 uint8_t tmp = row_index + MATRIX_ROWS/2;
119 // Store last value of row prior to reading
120 matrix_row_t last_row_value = current_matrix[tmp];
121
122 // Check row pin state
123 if (gpio_read_pin(row_pins[row_index]) == 0)
124 {
125 // Pin LO, set col bit
126 current_matrix[tmp] |= (ROW_SHIFTER << current_col);
127 }
128 else
129 {
130 // Pin HI, clear col bit
131 current_matrix[tmp] &= ~(ROW_SHIFTER << current_col);
132 }
133
134 // Determine if the matrix changed state
135 if ((last_row_value != current_matrix[tmp]) && !(matrix_changed))
136 {
137 matrix_changed = true;
138 }
139 }
140
141 // Unselect col
142 unselect_col(current_col);
143
144 return matrix_changed;
145}
146
147void matrix_init_custom(void) {
148 // initialize key pins
149 init_pins();
150}
151
152bool matrix_scan_custom(matrix_row_t current_matrix[])
153{
154 bool changed = false;
155
156 // Set row, read cols
157 for (uint8_t current_row = 0; current_row < MATRIX_ROWS / 2; current_row++) {
158 changed |= read_cols_on_row(current_matrix, current_row);
159 }
160 //else
161 // Set col, read rows
162 for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) {
163 changed |= read_rows_on_col(current_matrix, current_col);
164 }
165
166 return (uint8_t)changed;
167}