marlin/Marlin/src/HAL/HAL_LPC1768/include/digipot_mcp4451_I2C_routines.c

/**
  * Marlin 3D Printer Firmware
  * Copyright (C) 2016, 2017 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
  *
  * Based on Sprinter and grbl.
  * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
*/

// adapted from  I2C/master/master.c example
//   https://www-users.cs.york.ac.uk/~pcc/MCP/HAPR-Course-web/CMSIS/examples/html/master_8c_source.html



#ifdef TARGET_LPC1768

  #ifdef __cplusplus
    extern "C" {
  #endif

  #include <lpc17xx_i2c.h>
  #include <lpc17xx_pinsel.h>
  #include <lpc17xx_libcfg_default.h>

  //////////////////////////////////////////////////////////////////////////////////////

  // These two routines are exact copies of the lpc17xx_i2c.c routines.  Couldn't link to
  // to the lpc17xx_i2c.c routines so had to copy them into this file & rename them.

  static uint32_t _I2C_Start (LPC_I2C_TypeDef *I2Cx)
  {
    // Reset STA, STO, SI
    I2Cx->I2CONCLR = I2C_I2CONCLR_SIC|I2C_I2CONCLR_STOC|I2C_I2CONCLR_STAC;

    // Enter to Master Transmitter mode
    I2Cx->I2CONSET = I2C_I2CONSET_STA;

    // Wait for complete
    while (!(I2Cx->I2CONSET & I2C_I2CONSET_SI));
    I2Cx->I2CONCLR = I2C_I2CONCLR_STAC;
    return (I2Cx->I2STAT & I2C_STAT_CODE_BITMASK);
  }

  static void _I2C_Stop (LPC_I2C_TypeDef *I2Cx)
  {

    /* Make sure start bit is not active */
    if (I2Cx->I2CONSET & I2C_I2CONSET_STA)
    {
      I2Cx->I2CONCLR = I2C_I2CONCLR_STAC;
    }

    I2Cx->I2CONSET = I2C_I2CONSET_STO|I2C_I2CONSET_AA;

    I2Cx->I2CONCLR = I2C_I2CONCLR_SIC;
  }


  //////////////////////////////////////////////////////////////////////////////////////


  #define USEDI2CDEV_M  1  // use I2C1 controller

  #if (USEDI2CDEV_M == 0)
    #define I2CDEV_M LPC_I2C0
  #elif (USEDI2CDEV_M == 1)
    #define I2CDEV_M LPC_I2C1
  #elif (USEDI2CDEV_M == 2)
    #define I2CDEV_M LPC_I2C2
  #else
    #error "Master I2C device not defined!"
  #endif


  PINSEL_CFG_Type PinCfg;
  I2C_M_SETUP_Type transferMCfg;

  #define I2C_status (LPC_I2C1->I2STAT & I2C_STAT_CODE_BITMASK)


  uint8_t digipot_mcp4451_start(uint8_t sla) {  // send slave address and write bit
    // Sometimes TX data ACK or NAK status is returned.  That mean the start state didn't
    // happen which means only the value of the slave address was send.  Keep looping until
    // the slave address and write bit are actually sent.
    do{
      _I2C_Stop(I2CDEV_M); // output stop state on I2C bus
      _I2C_Start(I2CDEV_M); // output start state on I2C bus
      while ((I2C_status != I2C_I2STAT_M_TX_START)
          && (I2C_status != I2C_I2STAT_M_TX_RESTART)
          && (I2C_status != I2C_I2STAT_M_TX_DAT_ACK)
          && (I2C_status != I2C_I2STAT_M_TX_DAT_NACK));  //wait for start to be asserted

      LPC_I2C1->I2CONCLR = I2C_I2CONCLR_STAC; // clear start state before tansmitting slave address
      LPC_I2C1->I2DAT = (sla <<1) & I2C_I2DAT_BITMASK; // transmit slave address & write bit
      LPC_I2C1->I2CONSET = I2C_I2CONSET_AA;
      LPC_I2C1->I2CONCLR = I2C_I2CONCLR_SIC;
      while ((I2C_status != I2C_I2STAT_M_TX_SLAW_ACK)
          && (I2C_status != I2C_I2STAT_M_TX_SLAW_NACK)
          && (I2C_status != I2C_I2STAT_M_TX_DAT_ACK)
          && (I2C_status != I2C_I2STAT_M_TX_DAT_NACK));  //wait for slaw to finish
    }while ( (I2C_status == I2C_I2STAT_M_TX_DAT_ACK) ||  (I2C_status == I2C_I2STAT_M_TX_DAT_NACK));
    return 1;
  }


  void digipot_mcp4451_init(void) {

    /*
      * Init I2C pin connect
    */
    PinCfg.OpenDrain = 0;
    PinCfg.Pinmode = 0;
    #if ((USEDI2CDEV_M == 0))
      PinCfg.Funcnum = 1;
      PinCfg.Pinnum = 27;
      PinCfg.Portnum = 0;
      PINSEL_ConfigPin(&PinCfg); // SDA0 / D57  AUX-1
      PinCfg.Pinnum = 28;
      PINSEL_ConfigPin(&PinCfg); // SCL0 / D58  AUX-1
    #endif
    #if ((USEDI2CDEV_M == 1))
      PinCfg.Funcnum = 3;
      PinCfg.Pinnum = 0;
      PinCfg.Portnum = 0;
      PINSEL_ConfigPin(&PinCfg);  // SDA1 / D20 SCA
      PinCfg.Pinnum = 1;
      PINSEL_ConfigPin(&PinCfg);  // SCL1 / D21 SCL
    #endif
    #if ((USEDI2CDEV_M == 2))
      PinCfg.Funcnum = 2;
      PinCfg.Pinnum = 10;
      PinCfg.Portnum = 0;
      PINSEL_ConfigPin(&PinCfg); // SDA2 / D38  X_ENABLE_PIN
      PinCfg.Pinnum = 11;
      PINSEL_ConfigPin(&PinCfg); // SCL2 / D55  X_DIR_PIN
    #endif
    // Initialize I2C peripheral
    I2C_Init(I2CDEV_M, 400000);  // hardwired to 400KHz bit rate, 100KHz is the other option

    /* Enable Master I2C operation */
    I2C_Cmd(I2CDEV_M, I2C_MASTER_MODE, ENABLE);
  }


  uint8_t digipot_mcp4451_send_byte(uint8_t data) {

    LPC_I2C1->I2DAT = data & I2C_I2DAT_BITMASK; // transmit data
    LPC_I2C1->I2CONSET = I2C_I2CONSET_AA;
    LPC_I2C1->I2CONCLR = I2C_I2CONCLR_SIC;
    while ((I2C_status != I2C_I2STAT_M_TX_DAT_ACK) && (I2C_status != I2C_I2STAT_M_TX_DAT_NACK));  // wait for xmit to finish
    return 1;
  }


  #ifdef __cplusplus
    }
  #endif
#endif