Add GPL3 header to avr i2c files (#6332)

[qmk_firmware.git] / drivers / avr / i2c_slave.c

diff --git a/drivers/avr/i2c_slave.c b/drivers/avr/i2c_slave.c
index 27696ca01ab5f99d28faea9c16d6b07654b4b77e..4958a0f8e5a7e77a781ed1f86d92a6a262f4bd45 100755 (executable)
--- a/drivers/avr/i2c_slave.c
+++ b/drivers/avr/i2c_slave.c
@@ -1,3 +1,18 @@
+/*  Copyright (C) 2019 Elia Ritterbusch
+ +
+ *  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 3 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 <https://www.gnu.org/licenses/>.
+ */
 /* Library made by: g4lvanix
  * Github repository: https://github.com/g4lvanix/I2C-slave-lib
  */
@@ -9,23 +24,26 @@
 
 #include "i2c_slave.h"
 
-void i2c_init(uint8_t address){
+volatile uint8_t i2c_slave_reg[I2C_SLAVE_REG_COUNT];
+
+static volatile uint8_t buffer_address;
+static volatile bool slave_has_register_set = false;
+
+void i2c_slave_init(uint8_t address){
     // load address into TWI address register
-    TWAR = (address << 1);
+    TWAR = address;
     // set the TWCR to enable address matching and enable TWI, clear TWINT, enable TWI interrupt
     TWCR = (1 << TWIE) | (1 << TWEA) | (1 << TWINT) | (1 << TWEN);
 }
 
-void i2c_stop(void){
+void i2c_slave_stop(void){
     // clear acknowledge and enable bits
     TWCR &= ~((1 << TWEA) | (1 << TWEN));
 }
 
 ISR(TWI_vect){
     uint8_t ack = 1;
-    // temporary stores the received data
-    //uint8_t data;
-    
+
     switch(TW_STATUS){
         case TW_SR_SLA_ACK:
             // The device is now a slave receiver
@@ -38,13 +56,13 @@ ISR(TWI_vect){
             if(!slave_has_register_set){
                 buffer_address = TWDR;
 
-                if (buffer_address >= RX_BUFFER_SIZE){ // address out of bounds dont ack
-                    ack = 0;
-                    buffer_address = 0;
+                if (buffer_address >= I2C_SLAVE_REG_COUNT) {  // address out of bounds dont ack
+                  ack            = 0;
+                  buffer_address = 0;
                 }
                 slave_has_register_set = true; // address has been receaved now fill in buffer
             } else {
-                rxbuffer[buffer_address] = TWDR;
+                i2c_slave_reg[buffer_address] = TWDR;
                 buffer_address++;
             }
             break;
@@ -52,7 +70,7 @@ ISR(TWI_vect){
         case TW_ST_SLA_ACK:
         case TW_ST_DATA_ACK:
             // This device is a slave transmitter and master has requested data
-            TWDR = txbuffer[buffer_address];
+            TWDR = i2c_slave_reg[buffer_address];
             buffer_address++;
             break;
 
@@ -63,6 +81,6 @@ ISR(TWI_vect){
             break;
     }
 
-    // Reset i2c state mahcine to be ready for next interrupt
+    // Reset i2c state machine to be ready for next interrupt
     TWCR |= (1 << TWIE) | (1 << TWINT) | (ack << TWEA) | (1 << TWEN);
-}
\ No newline at end of file
+}