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qmk_firmware/quantum/split_common/i2c.c

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Lets split eh (#3120) * Line ending stuff again * Added Let's Split Eh? Files and updated #USE_IC2 checks to also include th EH revision (can only be used in I2C) * Added personal keymap, updated some of the EH files * Created new keyboard file for testing "lets_split_eh" will merge into lets_split once fully functional * Added split code from lets_split, removed pro micro imports and LED code THIS IS WORKING CODE, WITHOUT RGB AND BACKLIGHT * Took back original Lets Slit files for the lets_split keyboard, working in the lets_split_eh folder for now * Updated eh.c * More rework of the I2C code, added global flags for split boards. * Introduced RGB over I2C, having weird edge case issues at the moment though * Fixed weird I2C edgecase with RGB, although still would like to track down route cause.. * Changed RGB keycodes (static ones) to activate on key-up instead of key-down to elimate weird ghosting issue over I2C * Lots of changes, mainly externalized the Split keyboard code and added logic for only including when needed. - Added makefile option "SPLIT_KEYBOARD" that when = yes will include the split keyboard files and custom matrix - Split keyboard files placed into quantum/split_common/ - Added define option for config files "SPLIT_HAND_PIN" FOr using high/low pin to determine handedness, low = right hand, high = left hand - Cleaned up split logic for RGB and Backlight so it is only exectuted / included when needed * Updated documentation for the new makefile options and #defines specific to split keyboards * Added a bit more info to docs, so people aren't confused * Modifed Let's Split to use externalized code, also added left and right hand eeprom files to the split_common folder * Removed some debugging from eh.c * Small changes to keyboard configs. Also added a default keymap (just a copy of my that_canadian keymap). * Added a README file to the Let's Split Eh? * Changed it so RGB static updates are done on key-up ONLY for split boards rather than all boards. Also fixed leftover un-used variable in rgblight.c * Updated default keymap and my keymap for Let's Split Eh? Updated the comments so it reflects RGB control, and removed audio functions. * Fixed lets_split_eh not having a default version * Removed "eh" references from lets_split folder for now * Took lets_split folder from master to fix travis build errors, weird my local was overriding. * Changed LAYOUT_ortho_4x12_kc -> LAYOUT_kc_ortho_4x12 to match bakingpy and others * Removed rules.mk from my lets_split keymap, not needed * Updated the config_options doc to better explain the usage of "#define SPLIT_HAND_PIN"
2018-07-17 02:25:02 +00:00
#include <util/twi.h>
#include <avr/io.h>
#include <stdlib.h>
#include <avr/interrupt.h>
#include <util/twi.h>
#include <stdbool.h>
#include "i2c.h"
#include "split_flags.h"
// Limits the amount of we wait for any one i2c transaction.
// Since were running SCL line 100kHz (=> 10μs/bit), and each transactions is
// 9 bits, a single transaction will take around 90μs to complete.
//
// (F_CPU/SCL_CLOCK) => # of μC cycles to transfer a bit
// poll loop takes at least 8 clock cycles to execute
#define I2C_LOOP_TIMEOUT (9+1)*(F_CPU/SCL_CLOCK)/8
#define BUFFER_POS_INC() (slave_buffer_pos = (slave_buffer_pos+1)%SLAVE_BUFFER_SIZE)
volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
static volatile uint8_t slave_buffer_pos;
static volatile bool slave_has_register_set = false;
// Wait for an i2c operation to finish
inline static
void i2c_delay(void) {
uint16_t lim = 0;
while(!(TWCR & (1<<TWINT)) && lim < I2C_LOOP_TIMEOUT)
lim++;
// easier way, but will wait slightly longer
// _delay_us(100);
}
// Setup twi to run at 100kHz
void i2c_master_init(void) {
// no prescaler
TWSR = 0;
// Set TWI clock frequency to SCL_CLOCK. Need TWBR>10.
// Check datasheets for more info.
TWBR = ((F_CPU/SCL_CLOCK)-16)/2;
}
// Start a transaction with the given i2c slave address. The direction of the
// transfer is set with I2C_READ and I2C_WRITE.
// returns: 0 => success
// 1 => error
uint8_t i2c_master_start(uint8_t address) {
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTA);
i2c_delay();
// check that we started successfully
if ( (TW_STATUS != TW_START) && (TW_STATUS != TW_REP_START))
return 1;
TWDR = address;
TWCR = (1<<TWINT) | (1<<TWEN);
i2c_delay();
if ( (TW_STATUS != TW_MT_SLA_ACK) && (TW_STATUS != TW_MR_SLA_ACK) )
return 1; // slave did not acknowledge
else
return 0; // success
}
// Finish the i2c transaction.
void i2c_master_stop(void) {
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
uint16_t lim = 0;
while(!(TWCR & (1<<TWSTO)) && lim < I2C_LOOP_TIMEOUT)
lim++;
}
// Write one byte to the i2c slave.
// returns 0 => slave ACK
// 1 => slave NACK
uint8_t i2c_master_write(uint8_t data) {
TWDR = data;
TWCR = (1<<TWINT) | (1<<TWEN);
i2c_delay();
// check if the slave acknowledged us
return (TW_STATUS == TW_MT_DATA_ACK) ? 0 : 1;
}
uint8_t i2c_master_write_data(void *const TXdata, uint8_t dataLen) {
uint8_t *data = (uint8_t *)TXdata;
int err = 0;
for (int i = 0; i < dataLen; i++) {
err = i2c_master_write(data[i]);
if ( err )
return err;
}
return err;
}
// Read one byte from the i2c slave. If ack=1 the slave is acknowledged,
// if ack=0 the acknowledge bit is not set.
// returns: byte read from i2c device
uint8_t i2c_master_read(int ack) {
TWCR = (1<<TWINT) | (1<<TWEN) | (ack<<TWEA);
i2c_delay();
return TWDR;
}
void i2c_reset_state(void) {
TWCR = 0;
}
void i2c_slave_init(uint8_t address) {
TWAR = address << 0; // slave i2c address
// TWEN - twi enable
// TWEA - enable address acknowledgement
// TWINT - twi interrupt flag
// TWIE - enable the twi interrupt
TWCR = (1<<TWIE) | (1<<TWEA) | (1<<TWINT) | (1<<TWEN);
}
ISR(TWI_vect);
ISR(TWI_vect) {
uint8_t ack = 1;
switch(TW_STATUS) {
case TW_SR_SLA_ACK:
// this device has been addressed as a slave receiver
slave_has_register_set = false;
break;
case TW_SR_DATA_ACK:
// this device has received data as a slave receiver
// The first byte that we receive in this transaction sets the location
// of the read/write location of the slaves memory that it exposes over
// i2c. After that, bytes will be written at slave_buffer_pos, incrementing
// slave_buffer_pos after each write.
if(!slave_has_register_set) {
slave_buffer_pos = TWDR;
// don't acknowledge the master if this memory loctaion is out of bounds
if ( slave_buffer_pos >= SLAVE_BUFFER_SIZE ) {
ack = 0;
slave_buffer_pos = 0;
}
slave_has_register_set = true;
} else {
i2c_slave_buffer[slave_buffer_pos] = TWDR;
if ( slave_buffer_pos == I2C_BACKLIT_START) {
BACKLIT_DIRTY = true;
} else if ( slave_buffer_pos == (I2C_RGB_START+3)) {
RGB_DIRTY = true;
}
BUFFER_POS_INC();
}
break;
case TW_ST_SLA_ACK:
case TW_ST_DATA_ACK:
// master has addressed this device as a slave transmitter and is
// requesting data.
TWDR = i2c_slave_buffer[slave_buffer_pos];
BUFFER_POS_INC();
break;
case TW_BUS_ERROR: // something went wrong, reset twi state
TWCR = 0;
default:
break;
}
// Reset everything, so we are ready for the next TWI interrupt
TWCR |= (1<<TWIE) | (1<<TWINT) | (ack<<TWEA) | (1<<TWEN);
}