[Keyboard] revert back to the old custom i2c code for bmc (qmk#5501)

keyboards/exclusive/e6v2/bmc/bmc.c

@@ -15,7 +15,7 @@
  */
 #include "bmc.h"
 #include "rgblight.h"
-#include "i2c_master.h"
+#include "i2c.h"
 
 void matrix_init_kb(void) {
  // put your keyboard start-up code here
@@ -57,7 +57,7 @@ void rgblight_set(void) {
  }
 
  i2c_init();
- i2c_transmit(0xb0, (uint8_t*)led, 3 * RGBLED_NUM, 100);
+ i2c_send(0xb0, (uint8_t*)led, 3 * RGBLED_NUM);
 }
 #endif
 

keyboards/exclusive/e6v2/bmc/i2c.c

@@ -0,0 +1,106 @@
+/*
+Copyright 2016 Luiz Ribeiro <[email protected]>
+
+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:https://www.gnu.org/licenses/>.
+*/
+
+// Please do not modify this file 
+
+#include <avr/io.h>
+#include <util/twi.h>
+
+#include "i2c.h"
+
+void i2c_set_bitrate(uint16_t bitrate_khz) {
+ uint8_t bitrate_div = ((F_CPU / 1000l) / bitrate_khz);
+ if (bitrate_div >= 16) {
+ bitrate_div = (bitrate_div - 16) / 2;
+ }
+ TWBR = bitrate_div;
+}
+
+void i2c_init(void) {
+ // set pull-up resistors on I2C bus pins
+ PORTC |= 0b11;
+
+ i2c_set_bitrate(400);
+
+ // enable TWI (two-wire interface)
+ TWCR |= (1 << TWEN);
+
+ // enable TWI interrupt and slave address ACK
+ TWCR |= (1 << TWIE);
+ TWCR |= (1 << TWEA);
+}
+
+uint8_t i2c_start(uint8_t address) {
+ // reset TWI control register
+ TWCR = 0;
+
+ // begin transmission and wait for it to end
+ TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
+ while (!(TWCR & (1<<TWINT)));
+
+ // check if the start condition was successfully transmitted
+ if ((TWSR & 0xF8) != TW_START) {
+ return 1;
+ }
+
+ // transmit address and wait
+ TWDR = address;
+ TWCR = (1<<TWINT) | (1<<TWEN);
+ while (!(TWCR & (1<<TWINT)));
+
+ // check if the device has acknowledged the READ / WRITE mode
+ uint8_t twst = TW_STATUS & 0xF8;
+ if ((twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK)) {
+ return 1;
+ }
+
+ return 0;
+}
+
+void i2c_stop(void) {
+ TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
+}
+
+uint8_t i2c_write(uint8_t data) {
+ TWDR = data;
+
+ // transmit data and wait
+ TWCR = (1<<TWINT) | (1<<TWEN);
+ while (!(TWCR & (1<<TWINT)));
+
+ if ((TWSR & 0xF8) != TW_MT_DATA_ACK) {
+ return 1;
+ }
+
+ return 0;
+}
+
+uint8_t i2c_send(uint8_t address, uint8_t *data, uint16_t length) {
+ if (i2c_start(address)) {
+ return 1;
+ }
+
+ for (uint16_t i = 0; i < length; i++) {
+ if (i2c_write(data[i])) {
+ return 1;
+ }
+ }
+
+ i2c_stop();
+
+ return 0;
+}

keyboards/exclusive/e6v2/bmc/i2c.h

@@ -0,0 +1,24 @@
+/*
+Copyright 2016 Luiz Ribeiro <[email protected]>
+
+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:https://www.gnu.org/licenses/>.
+*/
+
+// Please do not modify this file 
+
+#pragma once
+
+void i2c_init(void);
+void i2c_set_bitrate(uint16_t bitrate_khz);
+uint8_t i2c_send(uint8_t address, uint8_t *data, uint16_t length);

keyboards/exclusive/e6v2/bmc/rules.mk

@@ -85,6 +85,6 @@ AUDIO_ENABLE = no # Audio output on port C6
 FAUXCLICKY_ENABLE = no # Use buzzer to emulate clicky switches
 HD44780_ENABLE = no # Enable support for HD44780 based LCDs (+400)
 
-SRC += i2c_master.c
+SRC += i2c.c
 
 PROGRAM_CMD = ./util/atmega32a_program.py $(TARGET).hex