qmk_firmware/keyboards/helix/local_drivers/i2c.c
MakotoKurauchi 2d14d12c74
[Keyboard] Helix add split common option (#7718)
* is_master, has_usb() move to rev2.[hc]

* Do recent helix/rev2 changes to helix/pico as well.

helix/pico/matrix.c: remove 'is_master'
helix/pico/pico.c: add 'is_master'
helix/pico/pico.h: add 'has_usb()' macro
helix/pico/split_util.c: remove 'setup_handedness()' 'has_usb()', add 'is_helix_master()' etc

* add HELIX=scan option into {rev2/pico}/local_features.mk

Made DEBUG_MATRIX_SCAN_RATE easy to use.

* Changed rules.mk to link "helix/local_drivers/ssd1306.c" only when OLED_ENABLE = yes.

* Added option to use split_common for helix/rev2, helix/pico keyboard.

how to build:
 ### build helix/pico (HelixPico) with helix current codes
  $ make helix/pico:KEY_MAP
  $ make helix/pico/back:KEY_MAP

 ### build helix/rev2 (Helix or Helix beta) with helix current codes
  $ make helix:KEY_MAP
  $ make helix/rev2/back:KEY_MAP
  $ make helix/rev2/under:KEY_MAP
  $ make helix/rev2/oled:KEY_MAP
  $ make helix/rev2/oled/back:KEY_MAP
  $ make helix/rev2/oled/under:KEY_MAP

 ### build helix/pico (HelixPico) with split_common codes
  $ make helix/pico/sc:KEY_MAP
  $ make helix/pico/sc/back:KEY_MAP
  $ make helix/pico/sc/under:KEY_MAP

 ### build helix/rev2 (Helix) with split_common codes
  $ make helix/rev2/sc:KEY_MAP
  $ make helix/rev2/sc/back:KEY_MAP
  $ make helix/rev2/sc/under:KEY_MAP
  $ make helix/rev2/sc/oled:KEY_MAP
  $ make helix/rev2/sc/oledback:KEY_MAP
  $ make helix/rev2/sc/oledunder:KEY_MAP

* add matrix_slave_scan_user() to helix/rev2/rev2.c, helix/pico/pico.h

* Changed 'helix:xulkal' to always use split_common and removed ad hoc code.

Added the following line to 'helix/rev2/keymaps/xulkal/rules.mk':

        SPLIT_KEYBOARD = yes

Removed the following ad hoc code from 'users/xulkal/custom_oled.c':

        #if KEYBOARD_helix_rev2
        extern uint8_t is_master;
        bool is_keyboard_master(void) { return is_master; }
        #endif

* add '#define DIODE_DIRECTION COL2ROW' into helix/{rev2|pico}/config.h

This commit does not change the build result.

* update helix readme

* keyboards/helix/readme.md
* keyboards/helix/pico/keymaps/default/readme.md
* keyboards/helix/rev2/keymaps/default/readme.md

Co-authored-by: mtei <2170248+mtei@users.noreply.github.com>
2020-03-10 01:33:46 -07:00

160 lines
4.3 KiB
C

#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"
// 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 or 400kHz (see ./i2c.h SCL_CLOCK)
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;
}
// 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;
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);
}