/* Wire Library for Teensy LC & 3.X * Copyright (c) 2014-2017, Paul Stoffregen, paul@pjrc.com * * Development of this I2C library was funded by PJRC.COM, LLC by sales of * Teensy and related products. Please support PJRC's efforts to develop * open source software by purchasing Teensy or other PJRC products. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice, development funding notice, and this permission * notice shall be included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "Wire.h" #if defined(__arm__) && defined(TEENSYDUINO) #include "kinetis.h" #include // for memcpy #include "core_pins.h" #include "Wire.h" // undefine these, so we can't accidentally access the hardware directly. #undef I2C0_A1 #undef I2C0_F #undef I2C0_C1 #undef I2C0_S #undef I2C0_D #undef I2C0_C2 #undef I2C0_FLT #undef I2C0_RA #undef I2C0_SMB #undef I2C0_A2 #undef I2C0_SLTH #undef I2C0_SLTL void sda_rising_isr(void); void TwoWire::begin(void) { //serial_begin(BAUD2DIV(115200)); //serial_print("\nWire Begin\n"); rxBufferIndex = 0; rxBufferLength = 0; txBufferIndex = 0; txBufferLength = 0; transmitting = 0; user_onRequest = NULL; user_onReceive = NULL; slave_mode = 0; hardware.clock_gate_register |= hardware.clock_gate_mask; port.C1 = 0; // On Teensy 3.0 external pullup resistors *MUST* be used // the PORT_PCR_PE bit is ignored when in I2C mode // I2C will not work at all without pullup resistors // It might seem like setting PORT_PCR_PE & PORT_PCR_PS // would enable pullup resistors. However, there seems // to be a bug in chip while I2C is enabled, where setting // those causes the port to be driven strongly high. uint32_t mux; volatile uint32_t *reg; reg = portConfigRegister(hardware.sda_pin[sda_pin_index]); mux = PORT_PCR_MUX(hardware.sda_mux[sda_pin_index]); *reg = mux|PORT_PCR_ODE|PORT_PCR_SRE|PORT_PCR_DSE; reg = portConfigRegister(hardware.scl_pin[scl_pin_index]); mux = PORT_PCR_MUX(hardware.scl_mux[scl_pin_index]); *reg = mux|PORT_PCR_ODE|PORT_PCR_SRE|PORT_PCR_DSE; setClock(100000); port.C2 = I2C_C2_HDRS; port.C1 = I2C_C1_IICEN; //pinMode(3, OUTPUT); //pinMode(4, OUTPUT); } void TwoWire::setClock(uint32_t frequency) { if (!(hardware.clock_gate_register & hardware.clock_gate_mask)) return; #if F_BUS == 120000000 if (frequency < 400000) { port.F = I2C_F_DIV1152; // 104 kHz } else if (frequency < 1000000) { port.F = I2C_F_DIV288; // 416 kHz } else { port.F = I2C_F_DIV128; // 0.94 MHz } port.FLT = 4; #elif F_BUS == 108000000 if (frequency < 400000) { port.F = I2C_F_DIV1024; // 105 kHz } else if (frequency < 1000000) { port.F = I2C_F_DIV256; // 422 kHz } else { port.F = I2C_F_DIV112; // 0.96 MHz } port.FLT = 4; #elif F_BUS == 96000000 if (frequency < 400000) { port.F = I2C_F_DIV960; // 100 kHz } else if (frequency < 1000000) { port.F = I2C_F_DIV240; // 400 kHz } else { port.F = I2C_F_DIV96; // 1.0 MHz } port.FLT = 4; #elif F_BUS == 90000000 if (frequency < 400000) { port.F = I2C_F_DIV896; // 100 kHz } else if (frequency < 1000000) { port.F = I2C_F_DIV224; // 402 kHz } else { port.F = I2C_F_DIV88; // 1.02 MHz } port.FLT = 4; #elif F_BUS == 80000000 if (frequency < 400000) { port.F = I2C_F_DIV768; // 104 kHz } else if (frequency < 1000000) { port.F = I2C_F_DIV192; // 416 kHz } else { port.F = I2C_F_DIV80; // 1.0 MHz } port.FLT = 4; #elif F_BUS == 72000000 if (frequency < 400000) { port.F = I2C_F_DIV640; // 112 kHz } else if (frequency < 1000000) { port.F = I2C_F_DIV192; // 375 kHz } else { port.F = I2C_F_DIV72; // 1.0 MHz } port.FLT = 4; #elif F_BUS == 64000000 if (frequency < 400000) { port.F = I2C_F_DIV640; // 100 kHz } else if (frequency < 1000000) { port.F = I2C_F_DIV160; // 400 kHz } else { port.F = I2C_F_DIV64; // 1.0 MHz } port.FLT = 4; #elif F_BUS == 60000000 if (frequency < 400000) { port.F = 0x2C; // 104 kHz } else if (frequency < 1000000) { port.F = 0x1C; // 416 kHz } else { port.F = 0x12; // 938 kHz } port.FLT = 4; #elif F_BUS == 56000000 if (frequency < 400000) { port.F = 0x2B; // 109 kHz } else if (frequency < 1000000) { port.F = 0x1C; // 389 kHz } else { port.F = 0x0E; // 1 MHz } port.FLT = 4; #elif F_BUS == 54000000 if (frequency < 400000) { port.F = I2C_F_DIV512; // 105 kHz } else if (frequency < 1000000) { port.F = I2C_F_DIV128; // 422 kHz } else { port.F = I2C_F_DIV56; // 0.96 MHz } port.FLT = 4; #elif F_BUS == 48000000 if (frequency < 400000) { port.F = 0x27; // 100 kHz } else if (frequency < 1000000) { port.F = 0x1A; // 400 kHz } else { port.F = 0x0D; // 1 MHz } port.FLT = 4; #elif F_BUS == 40000000 if (frequency < 400000) { port.F = 0x29; // 104 kHz } else if (frequency < 1000000) { port.F = 0x19; // 416 kHz } else { port.F = 0x0B; // 1 MHz } port.FLT = 3; #elif F_BUS == 36000000 if (frequency < 400000) { port.F = 0x28; // 113 kHz } else if (frequency < 1000000) { port.F = 0x19; // 375 kHz } else { port.F = 0x0A; // 1 MHz } port.FLT = 3; #elif F_BUS == 24000000 if (frequency < 400000) { port.F = 0x1F; // 100 kHz } else if (frequency < 1000000) { port.F = 0x12; // 375 kHz } else { port.F = 0x02; // 1 MHz } port.FLT = 2; #elif F_BUS == 16000000 if (frequency < 400000) { port.F = 0x20; // 100 kHz } else if (frequency < 1000000) { port.F = 0x07; // 400 kHz } else { port.F = 0x00; // 800 MHz } port.FLT = 1; #elif F_BUS == 8000000 if (frequency < 400000) { port.F = 0x14; // 100 kHz } else { port.F = 0x00; // 400 kHz } port.FLT = 1; #elif F_BUS == 4000000 if (frequency < 400000) { port.F = 0x07; // 100 kHz } else { port.F = 0x00; // 200 kHz } port.FLT = 1; #elif F_BUS == 2000000 port.F = 0x00; // 100 kHz port.FLT = 1; #else #error "F_BUS must be 120, 108, 96, 90, 80, 72, 64, 60, 56, 54, 48, 40, 36, 24, 16, 8, 4 or 2 MHz" #endif } void TwoWire::setSDA(uint8_t pin) { if (pin == hardware.sda_pin[sda_pin_index]) return; uint32_t newindex=0; while (1) { uint32_t sda_pin = hardware.sda_pin[newindex]; if (sda_pin == 255) return; if (sda_pin == pin) break; if (++newindex >= sizeof(hardware.sda_pin)) return; } if ((hardware.clock_gate_register & hardware.clock_gate_mask)) { volatile uint32_t *reg; reg = portConfigRegister(hardware.sda_pin[sda_pin_index]); *reg = 0; reg = portConfigRegister(hardware.sda_pin[newindex]); uint32_t mux = PORT_PCR_MUX(hardware.sda_mux[newindex]); *reg = mux|PORT_PCR_ODE|PORT_PCR_SRE|PORT_PCR_DSE; } sda_pin_index = newindex; } void TwoWire::setSCL(uint8_t pin) { if (pin == hardware.scl_pin[scl_pin_index]) return; uint32_t newindex=0; while (1) { uint32_t scl_pin = hardware.scl_pin[newindex]; if (scl_pin == 255) return; if (scl_pin == pin) break; if (++newindex >= sizeof(hardware.scl_pin)) return; } if ((hardware.clock_gate_register & hardware.clock_gate_mask)) { volatile uint32_t *reg; reg = portConfigRegister(hardware.scl_pin[scl_pin_index]); *reg = 0; reg = portConfigRegister(hardware.scl_pin[newindex]); uint32_t mux = PORT_PCR_MUX(hardware.scl_mux[newindex]); *reg = mux|PORT_PCR_ODE|PORT_PCR_SRE|PORT_PCR_DSE; } scl_pin_index = newindex; } void TwoWire::begin(uint8_t address) { begin(); port.A1 = address << 1; slave_mode = 1; port.C1 = I2C_C1_IICEN | I2C_C1_IICIE; NVIC_ENABLE_IRQ(IRQ_I2C0); } void TwoWire::end() { if (!(hardware.clock_gate_register & hardware.clock_gate_mask)) return; NVIC_DISABLE_IRQ(IRQ_I2C0); // TODO: should this try to create a stop condition?? port.C1 = 0; volatile uint32_t *reg; reg = portConfigRegister(hardware.scl_pin[scl_pin_index]); *reg = 0; reg = portConfigRegister(hardware.sda_pin[sda_pin_index]); *reg = 0; hardware.clock_gate_register &= ~hardware.clock_gate_mask; } void i2c0_isr(void) { uint8_t status, c1, data; static uint8_t receiving=0; status = Wire.port.S; //serial_print("."); if (status & I2C_S_ARBL) { // Arbitration Lost Wire.port.S = I2C_S_ARBL; //serial_print("a"); if (receiving && Wire.rxBufferLength > 0) { // TODO: does this detect the STOP condition in slave receive mode? } if (!(status & I2C_S_IAAS)) return; } if (status & I2C_S_IAAS) { //serial_print("\n"); // Addressed As A Slave if (status & I2C_S_SRW) { //serial_print("T"); // Begin Slave Transmit receiving = 0; Wire.txBufferLength = 0; if (Wire.user_onRequest != NULL) { Wire.user_onRequest(); } if (Wire.txBufferLength == 0) { // is this correct, transmitting a single zero // when we should send nothing? Arduino's AVR // implementation does this, but is it ok? Wire.txBufferLength = 1; Wire.txBuffer[0] = 0; } Wire.port.C1 = I2C_C1_IICEN | I2C_C1_IICIE | I2C_C1_TX; Wire.port.D = Wire.txBuffer[0]; Wire.txBufferIndex = 1; } else { // Begin Slave Receive //serial_print("R"); receiving = 1; Wire.rxBufferLength = 0; Wire.port.C1 = I2C_C1_IICEN | I2C_C1_IICIE; data = Wire.port.D; } Wire.port.S = I2C_S_IICIF; return; } #if defined(KINETISL) c1 = Wire.port.FLT; if ((c1 & I2C_FLT_STOPF) && (c1 & I2C_FLT_STOPIE)) { Wire.port.FLT = c1 & ~I2C_FLT_STOPIE; if (Wire.user_onReceive != NULL) { Wire.rxBufferIndex = 0; Wire.user_onReceive(Wire.rxBufferLength); } } #endif c1 = Wire.port.C1; if (c1 & I2C_C1_TX) { // Continue Slave Transmit //serial_print("t"); if ((status & I2C_S_RXAK) == 0) { //serial_print("."); // Master ACK'd previous byte if (Wire.txBufferIndex < Wire.txBufferLength) { Wire.port.D = Wire.txBuffer[Wire.txBufferIndex++]; } else { Wire.port.D = 0; } Wire.port.C1 = I2C_C1_IICEN | I2C_C1_IICIE | I2C_C1_TX; } else { //serial_print("*"); // Master did not ACK previous byte Wire.port.C1 = I2C_C1_IICEN | I2C_C1_IICIE; data = Wire.port.D; } } else { // Continue Slave Receive Wire.irqcount = 0; #if defined(KINETISK) attachInterrupt(18, sda_rising_isr, RISING); #elif defined(KINETISL) Wire.port.FLT |= I2C_FLT_STOPIE; #endif //digitalWriteFast(4, HIGH); data = Wire.port.D; //serial_phex(data); if (Wire.rxBufferLength < BUFFER_LENGTH && receiving) { Wire.rxBuffer[Wire.rxBufferLength++] = data; } //digitalWriteFast(4, LOW); } Wire.port.S = I2C_S_IICIF; } // Detects the stop condition that terminates a slave receive transfer. // Sadly, the I2C in Kinetis K series lacks the stop detect interrupt // This pin change interrupt hack is needed to detect the stop condition void sda_rising_isr(void) { //digitalWrite(3, HIGH); if (!(Wire.port.S & I2C_S_BUSY)) { detachInterrupt(18); if (Wire.user_onReceive != NULL) { Wire.rxBufferIndex = 0; Wire.user_onReceive(Wire.rxBufferLength); } //delayMicroseconds(100); } else { if (++Wire.irqcount >= 2 || !Wire.slave_mode) { detachInterrupt(18); } } //digitalWrite(3, LOW); } // Chapter 44: Inter-Integrated Circuit (I2C) - Page 1012 // I2C0_A1 // I2C Address Register 1 // I2C0_F // I2C Frequency Divider register // I2C0_C1 // I2C Control Register 1 // I2C0_S // I2C Status register // I2C0_D // I2C Data I/O register // I2C0_C2 // I2C Control Register 2 // I2C0_FLT // I2C Programmable Input Glitch Filter register size_t TwoWire::write(uint8_t data) { if (transmitting || slave_mode) { if (txBufferLength >= BUFFER_LENGTH+1) { setWriteError(); return 0; } txBuffer[txBufferLength++] = data; return 1; } return 0; } size_t TwoWire::write(const uint8_t *data, size_t quantity) { if (transmitting || slave_mode) { size_t avail = BUFFER_LENGTH+1 - txBufferLength; if (quantity > avail) { quantity = avail; setWriteError(); } memcpy(txBuffer + txBufferLength, data, quantity); txBufferLength += quantity; return quantity; } return 0; } uint8_t TwoWire::endTransmission(uint8_t sendStop) { uint8_t i, status, ret=0; // clear the status flags port.S = I2C_S_IICIF | I2C_S_ARBL; // now take control of the bus... if (port.C1 & I2C_C1_MST) { // we are already the bus master, so send a repeated start //Serial.print("rstart:"); port.C1 = I2C_C1_IICEN | I2C_C1_MST | I2C_C1_RSTA | I2C_C1_TX; } else { // we are not currently the bus master, so wait for bus ready //Serial.print("busy:"); uint32_t wait_begin = millis(); while (i2c_status() & I2C_S_BUSY) { //Serial.write('.') ; if (millis() - wait_begin > 15) { // bus stuck busy too long port.C1 = 0; port.C1 = I2C_C1_IICEN; //Serial.println("abort"); return 4; } } // become the bus master in transmit mode (send start) slave_mode = 0; port.C1 = I2C_C1_IICEN | I2C_C1_MST | I2C_C1_TX; } // wait until start condition establishes control of the bus while (1) { status = i2c_status(); if ((status & I2C_S_BUSY)) break; } // transmit the address and data for (i=0; i < txBufferLength; i++) { port.D = txBuffer[i]; //Serial.write('^'); while (1) { status = i2c_status(); if ((status & I2C_S_IICIF)) break; if (!(status & I2C_S_BUSY)) break; } port.S = I2C_S_IICIF; //Serial.write('$'); status = i2c_status(); if ((status & I2C_S_ARBL)) { // we lost bus arbitration to another master // TODO: what is the proper thing to do here?? //Serial.printf(" c1=%02X ", port.C1); port.C1 = I2C_C1_IICEN; ret = 4; // 4:other error break; } if (!(status & I2C_S_BUSY)) { // suddenly lost control of the bus! port.C1 = I2C_C1_IICEN; ret = 4; // 4:other error break; } if (status & I2C_S_RXAK) { // the slave device did not acknowledge if (i == 0) { ret = 2; // 2:received NACK on transmit of address } else { ret = 3; // 3:received NACK on transmit of data } sendStop = 1; break; } } if (sendStop) { // send the stop condition port.C1 = I2C_C1_IICEN; // TODO: do we wait for this somehow? } transmitting = 0; //Serial.print(" ret="); //Serial.println(ret); return ret; } uint8_t TwoWire::requestFrom(uint8_t address, uint8_t length, uint8_t sendStop) { uint8_t tmp __attribute__((unused)); uint8_t status, count=0; rxBufferIndex = 0; rxBufferLength = 0; //serial_print("requestFrom\n"); // clear the status flags port.S = I2C_S_IICIF | I2C_S_ARBL; // now take control of the bus... if (port.C1 & I2C_C1_MST) { // we are already the bus master, so send a repeated start port.C1 = I2C_C1_IICEN | I2C_C1_MST | I2C_C1_RSTA | I2C_C1_TX; } else { // we are not currently the bus master, so wait for bus ready while (i2c_status() & I2C_S_BUSY) ; // become the bus master in transmit mode (send start) slave_mode = 0; port.C1 = I2C_C1_IICEN | I2C_C1_MST | I2C_C1_TX; } // send the address port.D = (address << 1) | 1; i2c_wait(); status = i2c_status(); if ((status & I2C_S_RXAK) || (status & I2C_S_ARBL)) { // the slave device did not acknowledge // or we lost bus arbitration to another master port.C1 = I2C_C1_IICEN; return 0; } if (length == 0) { // TODO: does anybody really do zero length reads? // if so, does this code really work? port.C1 = I2C_C1_IICEN | (sendStop ? 0 : I2C_C1_MST); return 0; } else if (length == 1) { port.C1 = I2C_C1_IICEN | I2C_C1_MST | I2C_C1_TXAK; } else { port.C1 = I2C_C1_IICEN | I2C_C1_MST; } tmp = port.D; // initiate the first receive while (length > 1) { i2c_wait(); length--; if (length == 1) port.C1 = I2C_C1_IICEN | I2C_C1_MST | I2C_C1_TXAK; if (count < BUFFER_LENGTH) { rxBuffer[count++] = port.D; } else { tmp = port.D; } } i2c_wait(); port.C1 = I2C_C1_IICEN | I2C_C1_MST | I2C_C1_TX; if (count < BUFFER_LENGTH) { rxBuffer[count++] = port.D; } else { tmp = port.D; } if (sendStop) port.C1 = I2C_C1_IICEN; rxBufferLength = count; return count; } const TwoWire::I2C_Hardware_t TwoWire::i2c0_hardware = { SIM_SCGC4, SIM_SCGC4_I2C0, #if defined(__MKL26Z64__) || defined(__MK20DX128__) || defined(__MK20DX256__) 18, 17, 255, 255, 255, 2, 2, 0, 0, 0, 19, 16, 255, 255, 255, 2, 2, 0, 0, 0, #elif defined(__MK64FX512__) || defined(__MK66FX1M0__) 18, 17, 34, 8, 48, 2, 2, 5, 7, 2, 19, 16, 33, 7, 47, 2, 2, 5, 7, 2, #endif }; const TwoWire::I2C_Hardware_t TwoWire::i2c1_hardware = { SIM_SCGC4, SIM_SCGC4_I2C1, #if defined(__MKL26Z64__) 23, 255, 255, 255, 255, 2, 0, 0, 0, 0, 22, 255, 255, 255, 255, 2, 0, 0, 0, 0, #elif defined(__MK20DX256__) 30, 255, 255, 255, 255, 2, 0, 0, 0, 0, 29, 255, 255, 255, 255, 2, 0, 0, 0, 0, #elif defined(__MK64FX512__) || defined(__MK66FX1M0__) 38, 255, 255, 255, 255, 2, 0, 0, 0, 0, 37, 255, 255, 255, 255, 2, 0, 0, 0, 0, #else 255, 255, 255, 255, 255, 0, 0, 0, 0, 0, 255, 255, 255, 255, 255, 0, 0, 0, 0, 0, #endif }; const TwoWire::I2C_Hardware_t TwoWire::i2c2_hardware = { SIM_SCGC1, SIM_SCGC1_I2C2, #if defined(__MK64FX512__) || defined(__MK66FX1M0__) 4, 255, 255, 255, 255, 5, 0, 0, 0, 0, 3, 26, 255, 255, 255, 5, 5, 0, 0, 0, #else 255, 255, 255, 255, 255, 0, 0, 0, 0, 0, 255, 255, 255, 255, 255, 0, 0, 0, 0, 0, #endif }; const TwoWire::I2C_Hardware_t TwoWire::i2c3_hardware = { SIM_SCGC1, SIM_SCGC1_I2C3, #if defined(__MK66FX1M0__) 56, 255, 255, 255, 255, 2, 0, 0, 0, 0, 57, 255, 255, 255, 255, 2, 0, 0, 0, 0, #else 255, 255, 255, 255, 255, 0, 0, 0, 0, 0, 255, 255, 255, 255, 255, 0, 0, 0, 0, 0, #endif }; TwoWire Wire(KINETIS_I2C0, TwoWire::i2c0_hardware); TwoWire Wire1(KINETIS_I2C1, TwoWire::i2c1_hardware); #endif // __arm__ && TEENSYDUINO