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Add i2c capability for AVR

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This commit is contained in:
Jeremy Soller
2019-10-01 14:20:35 -06:00
parent f50b8feb83
commit 044584e96e
7 changed files with 245 additions and 0 deletions
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163
src/arch/avr/i2c.c Normal file
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@@ -0,0 +1,163 @@
#include <stdio.h>
#include <avr/io.h>
#include <util/twi.h>
#include <arch/i2c.h>
#include <board/cpu.h>
#define TIMEOUT (F_CPU/1000)
#define I2C_READ 0x01
#define I2C_WRITE 0x00
uint8_t i2c_start(uint8_t addr, uint8_t rw) {
uint32_t count;
// reset TWI control register
TWCR = 0;
// transmit START condition
TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
// wait for end of transmission
count = TIMEOUT;
while(!(TWCR & (1<<TWINT)) && count > 0) count -= 1;
if (count == 0) {
printf("i2c_start timed out waiting to send start to 0x%X\n", addr);
return 1;
}
// check if the start condition was successfully transmitted
if((TWSR & 0xF8) != TW_START){
printf("i2c_start failed to send start condition to 0x%X\n", addr);
return 1;
}
// load slave addr into data register
TWDR = ((addr << 1) | rw);
// start transmission of addr
TWCR = (1<<TWINT) | (1<<TWEN);
// wait for end of transmission
count = TIMEOUT;
while(!(TWCR & (1<<TWINT)) && count > 0) count -= 1;
if (count == 0) {
printf("i2c_start timed out waiting to send addr to 0x%X\n", addr);
return 1;
}
// 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)) {
printf("i2c_start failed to receive ack from 0x%X\n", addr);
return 1;
}
return 0;
}
void i2c_stop() {
// transmit STOP condition
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
}
uint8_t i2c_write(uint8_t data) {
uint32_t count;
// load data into data register
TWDR = data;
// start transmission of data
TWCR = (1<<TWINT) | (1<<TWEN);
// wait for end of transmission
count = TIMEOUT;
while(!(TWCR & (1<<TWINT)) && count > 0) count -= 1;
if (count == 0) {
printf("i2c_write timed out waiting to send 0x%X\n", data);
return 1;
}
if( (TWSR & 0xF8) != TW_MT_DATA_ACK ){
printf("i2c_write failed to receive ack for 0x%X\n", data);
return 1;
}
return 0;
}
uint8_t i2c_read_ack() {
// start TWI module and acknowledge data after reception
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
// wait for end of transmission
while( !(TWCR & (1<<TWINT)) );
// return received data from TWDR
return TWDR;
}
uint8_t i2c_read_nack() {
// start receiving without acknowledging reception
TWCR = (1<<TWINT) | (1<<TWEN);
// wait for end of transmission
while( !(TWCR & (1<<TWINT)) );
// return received data from TWDR
return TWDR;
}
uint8_t i2c_recv(uint8_t addr, uint8_t* data, uint16_t length) {
if (i2c_start(addr, I2C_READ)) return 1;
uint16_t i;
for (i = 0; i < (length-1); i++)
{
data[i] = i2c_read_ack();
}
data[(length-1)] = i2c_read_nack();
i2c_stop();
return 0;
}
uint8_t i2c_send(uint8_t addr, uint8_t* data, uint16_t length) {
if (i2c_start(addr, I2C_WRITE)) return 1;
uint16_t i;
for (i = 0; i < length; i++) {
if (i2c_write(data[i])) return 1;
}
i2c_stop();
return 0;
}
uint8_t i2c_get(uint8_t addr, uint8_t reg, uint8_t* data, uint16_t length) {
if (i2c_start(addr, I2C_WRITE)) return 1;
if (i2c_write(reg)) return 1;
if (i2c_start(addr, I2C_READ)) return 1;
uint16_t i;
for (i = 0; i < (length-1); i++)
{
data[i] = i2c_read_ack();
}
data[(length-1)] = i2c_read_nack();
i2c_stop();
return 0;
}
uint8_t i2c_set(uint8_t addr, uint8_t reg, uint8_t* data, uint16_t length) {
if (i2c_start(addr, I2C_WRITE)) return 1;
if(i2c_write(reg)) return 1;
uint16_t i;
for (i = 0; i < length; i++)
{
if (i2c_write(data[i])) return 1;
}
i2c_stop();
return 0;
}

10
src/arch/avr/include/arch/i2c.h Normal file
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@@ -0,0 +1,10 @@
#ifndef _ARCH_I2C_H
#define _ARCH_I2C_H
uint8_t i2c_recv(uint8_t addr, uint8_t* data, uint16_t length);
uint8_t i2c_send(uint8_t addr, uint8_t* data, uint16_t length);
uint8_t i2c_get(uint8_t addr, uint8_t reg, uint8_t* data, uint16_t length);
uint8_t i2c_set(uint8_t addr, uint8_t reg, uint8_t* data, uint16_t length);
#endif // _ARCH_I2C_H

43
src/board/arduino/mega2560/battery.c Normal file
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@@ -0,0 +1,43 @@
#include <stdio.h>
#include <board/i2c.h>
uint8_t smbus_read(uint8_t address, uint8_t command, uint16_t * data) {
return i2c_get(address, command, (uint8_t *)data, 2);
}
void battery_debug(void) {
uint16_t data = 0;
uint8_t err = 0;
#define command(N, A, V) { \
printf(#N ": "); \
err = smbus_read(A, V, &data); \
if (err) { \
printf("ERROR %02X\n", err); \
return; \
} \
printf("%04X\n", data); \
}
printf("Battery:\n");
command(Temperature, 0x0B, 0x08);
command(Voltage, 0x0B, 0x09);
command(Current, 0x0B, 0x0A);
command(Charge, 0x0B, 0x0D);
printf("Charger:\n");
command(ChargeOption0, 0x09, 0x12);
command(ChargeOption1, 0x09, 0x3B);
command(ChargeOption2, 0x09, 0x38);
command(ChargeOption3, 0x09, 0x37);
command(ChargeCurrent, 0x09, 0x14);
command(ChargeVoltage, 0x09, 0x15);
command(DishargeCurrent, 0x09, 0x39);
command(InputCurrent, 0x09, 0x3F);
command(ProchotOption0, 0x09, 0x3C);
command(ProchotOption1, 0x09, 0x3D);
command(ProchotStatus, 0x09, 0x3A);
#undef command
}

10
src/board/arduino/mega2560/i2c.c Normal file
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@@ -0,0 +1,10 @@
#include <avr/io.h>
#include <board/cpu.h>
#include <board/i2c.h>
void i2c_init(unsigned long baud) {
TWAR = 0;
TWBR = (uint8_t)(((F_CPU / baud) - 16 ) / 2);
TWCR = 0;
}

6
src/board/arduino/mega2560/include/board/battery.h Normal file
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@@ -0,0 +1,6 @@
#ifndef _BOARD_BATTERY_H
#define _BOARD_BATTERY_H
void battery_debug(void);
#endif // _BOARD_BATTERY_H

6
src/board/arduino/mega2560/include/board/i2c.h Normal file
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@@ -0,0 +1,6 @@
#ifndef _BOARD_I2C_H
#define _BOARD_I2C_H
void i2c_init(unsigned long baud);
#endif // _BOARD_I2C_H

7
src/board/arduino/mega2560/main.c
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@@ -2,9 +2,12 @@
#include <arch/gpio.h>
#include <arch/uart.h>
#include <board/battery.h>
#include <board/i2c.h>
void init(void) {
uart_stdio_init(0, __CONSOLE_BAUD__);
i2c_init(50000);
}
struct Gpio LED = GPIO(B, 7);
@@ -15,10 +18,14 @@ int main(void) {
gpio_set_dir(&LED, true);
gpio_set(&LED, false);
printf("Hello from System76 EC for the Arduino Mega 2560!\n");
battery_debug();
for (;;) {
int c = getchar();
if (c == '\r') {
putchar('\n');
battery_debug();
} else if (c > 0) {
putchar(c);
}