Increase matrix scanning speed on xd84 (#7517)

* Increase matrix scanning speed

* Fix func name in failure output

drivers/gpio/pca9555.c

@@ -76,3 +76,20 @@ uint8_t pca9555_readPins(uint8_t slave_addr, uint8_t port) {
     }
     return data;
 }
+
+uint16_t pca9555_readAllPins(uint8_t slave_addr) {
+    uint8_t addr = SLAVE_TO_ADDR(slave_addr);
+
+    typedef union {
+        uint8_t  u8[2];
+        uint16_t u16;
+    } data16;
+
+    data16 data;
+
+    i2c_status_t ret = i2c_readReg(addr, CMD_INPUT_0, &data.u8[0], sizeof(data), TIMEOUT);
+    if (ret != I2C_STATUS_SUCCESS) {
+        print("pca9555_readAllPins::FAILED\n");
+    }
+    return data.u16;
+}

drivers/gpio/pca9555.h

@@ -53,3 +53,5 @@ void pca9555_set_config(uint8_t slave_addr, uint8_t port, uint8_t conf);
 void pca9555_set_output(uint8_t slave_addr, uint8_t port, uint8_t conf);
 
 uint8_t pca9555_readPins(uint8_t slave_addr, uint8_t port);
+
+uint16_t pca9555_readAllPins(uint8_t slave_addr);

keyboards/xd84/matrix.c

@@ -30,65 +30,69 @@
 //_____Utility funcs___________________________________________________________
 
 static void init_pins(void) {
-  // init all cols high - IC2 all input
-  pca9555_set_config(IC2, PCA9555_PORT0, ALL_INPUT);//same as initial state
-  pca9555_set_config(IC2, PCA9555_PORT1, ALL_INPUT);//same as initial state
+    // init all cols high - IC2 all input
+    pca9555_set_config(IC2, PCA9555_PORT0, ALL_INPUT);  // same as initial state
+    pca9555_set_config(IC2, PCA9555_PORT1, ALL_INPUT);  // same as initial state
 
-  // init all rows - IC1 port0 input
-  pca9555_set_config(IC1, PCA9555_PORT0, ALL_INPUT);//same as initial state
+    // init all rows - IC1 port0 input
+    pca9555_set_config(IC1, PCA9555_PORT0, ALL_INPUT);  // same as initial state
+    pca9555_set_output(IC1, PCA9555_PORT0, ALL_LOW);
 }
 
 static void select_row(uint8_t row) {
-  // For the XD84 all rows are on the same IC and port
-  // so its safe enough to assume here row == pin
-  uint8_t pin = row;
-  uint8_t mask = 1 << pin;
-
-  pca9555_set_output(IC1, PCA9555_PORT0, ALL_HIGH & (~mask));
-  pca9555_set_config(IC1, PCA9555_PORT0, ALL_INPUT & (~mask));
+    // For the XD84 all rows are on the same IC and port
+    // so its safe enough to assume here row == pin
+    uint8_t pin  = row;
+    uint8_t mask = 1 << pin;
+
+    // we configure output once in init, as pca9555 remembers state when flipping between input/output 
+    // pca9555_set_output(IC1, PCA9555_PORT0, ALL_HIGH & (~mask));
+    pca9555_set_config(IC1, PCA9555_PORT0, ALL_INPUT & (~mask));
 }
 
 static uint16_t read_cols(void) {
-  uint16_t state_1 = pca9555_readPins(IC2, PCA9555_PORT0);
-  uint16_t state_2 = pca9555_readPins(IC2, PCA9555_PORT1);
-
-  // For the XD84 all cols are on the same IC and mapped sequentially
-  // while this technically gives 16 column reads,
-  // the 16th column can never be set so is safely ignored
-  return ~((state_2 << 8) | state_1);
+    // uint16_t state_1 = pca9555_readPins(IC2, PCA9555_PORT0);
+    // uint16_t state_2 = pca9555_readPins(IC2, PCA9555_PORT1);
+    uint16_t state = pca9555_readAllPins(IC2);
+
+    // For the XD84 all cols are on the same IC and mapped sequentially
+    // while this technically gives 16 column reads,
+    // the 16th column can never be set so is safely ignored
+    // return ~((state_2 << 8) | state_1);
+    return ~state;
 }
 
 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];
+    // 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;
+    // 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);
+    // Select row and wait for row selection to stabilize
+    select_row(current_row);
+    // Skip the wait_us(30); as i2c is slow enough to debounce the io changes
 
-  current_matrix[current_row] = read_cols();
+    current_matrix[current_row] = read_cols();
 
-  // No need to Unselect row as the next `select_row` will blank everything
+    // No need to Unselect row as the next `select_row` will blank everything
 
-  return (last_row_value != current_matrix[current_row]);
+    return (last_row_value != current_matrix[current_row]);
 }
 
 //_____CUSTOM MATRIX IMPLEMENTATION____________________________________________________
 
 void custom_matrix_init(void) {
-  pca9555_init(IC1);
-  pca9555_init(IC2);
+    pca9555_init(IC1);
+    pca9555_init(IC2);
 
-  init_pins();
+    init_pins();
 }
 
 bool custom_matrix_scan(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;
-}
+    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;
+}