X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=drivers%2Favr%2Fi2c_master.c;h=0acc246426460815776263780d0d2f960f36a6c8;hb=ff0cb0cf9dc81db11459e7e59c01adadca3ec2b8;hp=19bae33e9f174c31e60133b8ab83925713afb983;hpb=d28684da90536b54ff7d145decb80e0bd9290996;p=qmk_firmware.git

diff --git a/drivers/avr/i2c_master.c b/drivers/avr/i2c_master.c
index 19bae33e9..0acc24642 100755
--- a/drivers/avr/i2c_master.c
+++ b/drivers/avr/i2c_master.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-master-lib
  */
@@ -7,43 +22,56 @@
 
 #include "i2c_master.h"
 #include "timer.h"
+#include "wait.h"
 
 #ifndef F_SCL
-#define F_SCL 400000UL // SCL frequency
+#  define F_SCL 400000UL  // SCL frequency
 #endif
 #define Prescaler 1
-#define TWBR_val ((((F_CPU / F_SCL) / Prescaler) - 16 ) / 2)
+#define TWBR_val ((((F_CPU / F_SCL) / Prescaler) - 16) / 2)
 
-void i2c_init(void)
-{
-  TWSR = 0;     /* no prescaler */
+void i2c_init(void) {
+  TWSR = 0; /* no prescaler */
   TWBR = (uint8_t)TWBR_val;
+
+  #ifdef __AVR_ATmega32A__
+  // set pull-up resistors on I2C bus pins
+  PORTC |= 0b11;
+
+  // enable TWI (two-wire interface)
+  TWCR |= (1 << TWEN);
+
+  // enable TWI interrupt and slave address ACK
+  TWCR |= (1 << TWIE);
+  TWCR |= (1 << TWEA);
+  #endif
 }
 
-i2c_status_t i2c_start(uint8_t address, uint16_t timeout)
-{
+i2c_status_t i2c_start(uint8_t address, uint16_t timeout) {
   // reset TWI control register
   TWCR = 0;
   // transmit START condition
-  TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
+  TWCR = (1 << TWINT) | (1 << TWSTA) | (1 << TWEN);
 
   uint16_t timeout_timer = timer_read();
-  while( !(TWCR & (1<<TWINT)) ) {
+  while (!(TWCR & (1 << TWINT))) {
     if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
 
   // check if the start condition was successfully transmitted
-  if(((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)){ return I2C_STATUS_ERROR; }
+  if (((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)) {
+    return I2C_STATUS_ERROR;
+  }
 
   // load slave address into data register
   TWDR = address;
   // start transmission of address
-  TWCR = (1<<TWINT) | (1<<TWEN);
+  TWCR = (1 << TWINT) | (1 << TWEN);
 
   timeout_timer = timer_read();
-  while( !(TWCR & (1<<TWINT)) ) {
+  while (!(TWCR & (1 << TWINT))) {
     if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
@@ -51,38 +79,39 @@ i2c_status_t i2c_start(uint8_t address, uint16_t timeout)
 
   // 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 I2C_STATUS_ERROR;
+  if ((twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK)) {
+    return I2C_STATUS_ERROR;
+  }
 
   return I2C_STATUS_SUCCESS;
 }
 
-i2c_status_t i2c_write(uint8_t data, uint16_t timeout)
-{
+i2c_status_t i2c_write(uint8_t data, uint16_t timeout) {
   // load data into data register
   TWDR = data;
   // start transmission of data
-  TWCR = (1<<TWINT) | (1<<TWEN);
+  TWCR = (1 << TWINT) | (1 << TWEN);
 
   uint16_t timeout_timer = timer_read();
-  while( !(TWCR & (1<<TWINT)) ) {
+  while (!(TWCR & (1 << TWINT))) {
     if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
 
-  if( (TW_STATUS & 0xF8) != TW_MT_DATA_ACK ){ return I2C_STATUS_ERROR; }
+  if ((TW_STATUS & 0xF8) != TW_MT_DATA_ACK) {
+    return I2C_STATUS_ERROR;
+  }
 
   return I2C_STATUS_SUCCESS;
 }
 
-int16_t i2c_read_ack(uint16_t timeout)
-{
-
+int16_t i2c_read_ack(uint16_t timeout) {
   // start TWI module and acknowledge data after reception
-  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
+  TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWEA);
 
   uint16_t timeout_timer = timer_read();
-  while( !(TWCR & (1<<TWINT)) ) {
+  while (!(TWCR & (1 << TWINT))) {
     if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
@@ -92,14 +121,12 @@ int16_t i2c_read_ack(uint16_t timeout)
   return TWDR;
 }
 
-int16_t i2c_read_nack(uint16_t timeout)
-{
-
+int16_t i2c_read_nack(uint16_t timeout) {
   // start receiving without acknowledging reception
-  TWCR = (1<<TWINT) | (1<<TWEN);
+  TWCR = (1 << TWINT) | (1 << TWEN);
 
   uint16_t timeout_timer = timer_read();
-  while( !(TWCR & (1<<TWINT)) ) {
+  while (!(TWCR & (1 << TWINT))) {
     if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
@@ -109,115 +136,89 @@ int16_t i2c_read_nack(uint16_t timeout)
   return TWDR;
 }
 
-i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)
-{
+i2c_status_t i2c_transmit(uint8_t address, const uint8_t* data, uint16_t length, uint16_t timeout) {
   i2c_status_t status = i2c_start(address | I2C_WRITE, timeout);
-  if (status) return status;
 
-  for (uint16_t i = 0; i < length; i++) {
+  for (uint16_t i = 0; i < length && status >= 0; i++) {
     status = i2c_write(data[i], timeout);
-    if (status) return status;
   }
 
-  status = i2c_stop(timeout);
-  if (status) return status;
+  i2c_stop();
 
-  return I2C_STATUS_SUCCESS;
+  return status;
 }
 
-i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)
-{
+i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) {
   i2c_status_t status = i2c_start(address | I2C_READ, timeout);
-  if (status) return status;
 
-  for (uint16_t i = 0; i < (length-1); i++) {
+  for (uint16_t i = 0; i < (length - 1) && status >= 0; i++) {
     status = i2c_read_ack(timeout);
     if (status >= 0) {
       data[i] = status;
-    } else {
-      return status;
     }
   }
 
-  status = i2c_read_nack(timeout);
-  if (status >= 0 ) {
-    data[(length-1)] = status;
-  } else {
-    return status;
+  if (status >= 0) {
+    status = i2c_read_nack(timeout);
+    if (status >= 0) {
+      data[(length - 1)] = status;
+    }
   }
 
-  status = i2c_stop(timeout);
-  if (status) return status;
+  i2c_stop();
 
-  return I2C_STATUS_SUCCESS;
+  return (status < 0) ? status : I2C_STATUS_SUCCESS;
 }
 
-i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
-{
+i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, const uint8_t* data, uint16_t length, uint16_t timeout) {
   i2c_status_t status = i2c_start(devaddr | 0x00, timeout);
-  if (status) return status;
-
-  status = i2c_write(regaddr, timeout);
-  if (status) return status;
+  if (status >= 0) {
+    status = i2c_write(regaddr, timeout);
 
-  for (uint16_t i = 0; i < length; i++) {
-    status = i2c_write(data[i], timeout);
-    if (status) return status;
+    for (uint16_t i = 0; i < length && status >= 0; i++) {
+      status = i2c_write(data[i], timeout);
+    }
   }
 
-  status = i2c_stop(timeout);
-  if (status) return status;
+  i2c_stop();
 
-  return I2C_STATUS_SUCCESS;
+  return status;
 }
 
-i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
-{
+i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) {
   i2c_status_t status = i2c_start(devaddr, timeout);
-  if (status) return status;
+  if (status < 0) {
+    goto error;
+  }
 
   status = i2c_write(regaddr, timeout);
-  if (status) return status;
-
-  status = i2c_stop(timeout);
-  if (status) return status;
+  if (status < 0) {
+    goto error;
+  }
 
   status = i2c_start(devaddr | 0x01, timeout);
-  if (status) return status;
 
-  for (uint16_t i = 0; i < (length-1); i++) {
+  for (uint16_t i = 0; i < (length - 1) && status >= 0; i++) {
     status = i2c_read_ack(timeout);
     if (status >= 0) {
       data[i] = status;
-    } else {
-      return status;
     }
   }
 
-  status = i2c_read_nack(timeout);
-  if (status >= 0 ) {
-    data[(length-1)] = status;
-  } else {
-    return status;
+  if (status >= 0) {
+    status = i2c_read_nack(timeout);
+    if (status >= 0) {
+      data[(length - 1)] = status;
+    }
   }
 
-  status = i2c_stop(timeout);
-  if (status) return status;
+error:
+  i2c_stop();
 
-  return I2C_STATUS_SUCCESS;
+  return (status < 0) ? status : I2C_STATUS_SUCCESS;
 }
 
-i2c_status_t i2c_stop(uint16_t timeout)
-{
+void i2c_stop(void) {
   // transmit STOP condition
-  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
-
-  uint16_t timeout_timer = timer_read();
-  while(TWCR & (1<<TWSTO)) {
-    if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
-      return I2C_STATUS_TIMEOUT;
-    }
-  }
-
-  return I2C_STATUS_SUCCESS;
+  TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);
 }