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authorThat-Canadian <Poole.Chris.11@gmail.com>2018-07-16 19:25:02 -0700
committerJack Humbert <jack.humb@gmail.com>2018-07-16 22:25:02 -0400
commit0fab3bbde33f82301a8c5e177c3c0ceb7ad2219c (patch)
tree15a411d5ed6ad203982337448cfde11ed26ce7b7 /quantum/split_common/i2c.c
parentb2877470ced1deb9651ecb39f6a82f5ef380b399 (diff)
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"
Diffstat (limited to 'quantum/split_common/i2c.c')
-rw-r--r--quantum/split_common/i2c.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/quantum/split_common/i2c.c b/quantum/split_common/i2c.c
new file mode 100644
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+++ b/quantum/split_common/i2c.c
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+#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"
+
+#if defined(USE_I2C) || defined(EH)
+
+// 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);
+}
+#endif