board-i2c.c

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/*
 * Copyright (c) 2014, Texas Instruments Incorporated - http://www.ti.com/
 * Copyright (c) 2017, University of Bristol - http://www.bris.ac.uk/
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*---------------------------------------------------------------------------*/
/**
 * \addtogroup sensortag-cc26xx-i2c
 * @{
 *
 * \file
 * Board-specific I2C driver for the Sensortags
 */
/*---------------------------------------------------------------------------*/
#include "contiki.h"
#include "ti-lib.h"
#include "board-i2c.h"
#include "lpm.h"
#include "rtimer.h"
 
#include <string.h>
#include <stdbool.h>
/*---------------------------------------------------------------------------*/
#define I2C_MAX_WAIT_TIME    (RTIMER_SECOND / 10)
 
#define LIMITED_BUSYWAIT(cond) do {                   \
    rtimer_clock_t end_time = RTIMER_NOW() + I2C_MAX_WAIT_TIME; \
    while(cond) {                                               \
      if(!RTIMER_CLOCK_LT(RTIMER_NOW(), end_time)) {            \
        return false;                                           \
      }                                                         \
    }                                                           \
  } while(0)
/*---------------------------------------------------------------------------*/
#define NO_INTERFACE 0xFF
/*---------------------------------------------------------------------------*/
static uint8_t slave_addr = 0x00;
static uint8_t interface = NO_INTERFACE;
/*---------------------------------------------------------------------------*/
static bool
accessible(void)
{
  /* First, check the PD */
  if(ti_lib_prcm_power_domain_status(PRCM_DOMAIN_SERIAL)
     != PRCM_DOMAIN_POWER_ON) {
    return false;
  }
 
  /* Then check the 'run mode' clock gate */
  if(!(HWREG(PRCM_BASE + PRCM_O_I2CCLKGR) & PRCM_I2CCLKGR_CLK_EN)) {
    return false;
  }
 
  return true;
}
/*---------------------------------------------------------------------------*/
void
board_i2c_wakeup()
{
  /* First, make sure the SERIAL PD is on */
  ti_lib_prcm_power_domain_on(PRCM_DOMAIN_SERIAL);
  while((ti_lib_prcm_power_domain_status(PRCM_DOMAIN_SERIAL)
        != PRCM_DOMAIN_POWER_ON));
 
  /* Enable the clock to I2C */
  ti_lib_prcm_peripheral_run_enable(PRCM_PERIPH_I2C0);
  ti_lib_prcm_load_set();
  while(!ti_lib_prcm_load_get());
 
  /* Enable and initialize the I2C master module */
  ti_lib_i2c_master_init_exp_clk(I2C0_BASE, ti_lib_sys_ctrl_clock_get(),
                                 true);
}
/*---------------------------------------------------------------------------*/
static bool
i2c_status()
{
  uint32_t status;
 
  status = ti_lib_i2c_master_err(I2C0_BASE);
  if(status & (I2C_MSTAT_DATACK_N_M | I2C_MSTAT_ADRACK_N_M)) {
    ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_ERROR_STOP);
  }
 
  return status == I2C_MASTER_ERR_NONE;
}
/*---------------------------------------------------------------------------*/
void
board_i2c_shutdown()
{
  interface = NO_INTERFACE;
 
  if(accessible()) {
    ti_lib_i2c_master_disable(I2C0_BASE);
  }
 
  ti_lib_prcm_peripheral_run_disable(PRCM_PERIPH_I2C0);
  ti_lib_prcm_load_set();
  while(!ti_lib_prcm_load_get());
 
  /*
   * Set all pins to GPIO Input and disable the output driver. Set internal
   * pull to match external pull
   *
   * SDA and SCL: external PU resistor
   * SDA HP and SCL HP: MPU PWR low
   */
  ti_lib_ioc_pin_type_gpio_input(BOARD_IOID_SDA_HP);
  ti_lib_ioc_io_port_pull_set(BOARD_IOID_SDA_HP, IOC_IOPULL_DOWN);
  ti_lib_ioc_pin_type_gpio_input(BOARD_IOID_SCL_HP);
  ti_lib_ioc_io_port_pull_set(BOARD_IOID_SCL_HP, IOC_IOPULL_DOWN);
 
  ti_lib_ioc_pin_type_gpio_input(BOARD_IOID_SDA);
  ti_lib_ioc_io_port_pull_set(BOARD_IOID_SDA, IOC_IOPULL_UP);
  ti_lib_ioc_pin_type_gpio_input(BOARD_IOID_SCL);
  ti_lib_ioc_io_port_pull_set(BOARD_IOID_SCL, IOC_IOPULL_UP);
}
/*---------------------------------------------------------------------------*/
bool
board_i2c_write(uint8_t *data, uint8_t len)
{
  uint32_t i;
  bool success;
 
  /* Write slave address */
  ti_lib_i2c_master_slave_addr_set(I2C0_BASE, slave_addr, false);
 
  /* Write first byte */
  ti_lib_i2c_master_data_put(I2C0_BASE, data[0]);
 
  /* Check if another master has access */
  LIMITED_BUSYWAIT(ti_lib_i2c_master_bus_busy(I2C0_BASE));
 
  /* Assert RUN + START */
  ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_START);
  LIMITED_BUSYWAIT(ti_lib_i2c_master_busy(I2C0_BASE));
  success = i2c_status();
 
  for(i = 1; i < len && success; i++) {
    /* Write next byte */
    ti_lib_i2c_master_data_put(I2C0_BASE, data[i]);
    if(i < len - 1) {
      /* Clear START */
      ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_CONT);
      LIMITED_BUSYWAIT(ti_lib_i2c_master_busy(I2C0_BASE));
      success = i2c_status();
    }
  }
 
  /* Assert stop */
  if(success) {
    /* Assert STOP */
    ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_FINISH);
    LIMITED_BUSYWAIT(ti_lib_i2c_master_busy(I2C0_BASE));
    success = i2c_status();
    LIMITED_BUSYWAIT(ti_lib_i2c_master_bus_busy(I2C0_BASE));
  }
 
  return success;
}
/*---------------------------------------------------------------------------*/
bool
board_i2c_write_single(uint8_t data)
{
  /* Write slave address */
  ti_lib_i2c_master_slave_addr_set(I2C0_BASE, slave_addr, false);
 
  /* Write first byte */
  ti_lib_i2c_master_data_put(I2C0_BASE, data);
 
  /* Check if another master has access */
  LIMITED_BUSYWAIT(ti_lib_i2c_master_bus_busy(I2C0_BASE));
 
  /* Assert RUN + START + STOP */
  ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_SINGLE_SEND);
  LIMITED_BUSYWAIT(ti_lib_i2c_master_busy(I2C0_BASE));
 
  return i2c_status();
}
/*---------------------------------------------------------------------------*/
bool
board_i2c_read(uint8_t *data, uint8_t len)
{
  uint8_t i;
  bool success;
 
  /* Set slave address */
  ti_lib_i2c_master_slave_addr_set(I2C0_BASE, slave_addr, true);
 
  /* Check if another master has access */
  LIMITED_BUSYWAIT(ti_lib_i2c_master_bus_busy(I2C0_BASE));
 
  /* Assert RUN + START + ACK */
  ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START);
 
  i = 0;
  success = true;
  while(i < (len - 1) && success) {
    LIMITED_BUSYWAIT(ti_lib_i2c_master_busy(I2C0_BASE));
    success = i2c_status();
    if(success) {
      data[i] = ti_lib_i2c_master_data_get(I2C0_BASE);
      ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_RECEIVE_CONT);
      i++;
    }
  }
 
  if(success) {
    ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH);
    LIMITED_BUSYWAIT(ti_lib_i2c_master_busy(I2C0_BASE));
    success = i2c_status();
    if(success) {
      data[len - 1] = ti_lib_i2c_master_data_get(I2C0_BASE);
      LIMITED_BUSYWAIT(ti_lib_i2c_master_bus_busy(I2C0_BASE));
    }
  }
 
  return success;
}
/*---------------------------------------------------------------------------*/
bool
board_i2c_write_read(uint8_t *wdata, uint8_t wlen, uint8_t *rdata, uint8_t rlen)
{
  uint32_t i;
  bool success;
 
  /* Set slave address for write */
  ti_lib_i2c_master_slave_addr_set(I2C0_BASE, slave_addr, false);
 
  /* Write first byte */
  ti_lib_i2c_master_data_put(I2C0_BASE, wdata[0]);
 
  /* Check if another master has access */
  LIMITED_BUSYWAIT(ti_lib_i2c_master_bus_busy(I2C0_BASE));
 
  /* Assert RUN + START */
  ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_START);
  LIMITED_BUSYWAIT(ti_lib_i2c_master_busy(I2C0_BASE));
  success = i2c_status();
 
  for(i = 1; i < wlen && success; i++) {
    /* Write next byte */
    ti_lib_i2c_master_data_put(I2C0_BASE, wdata[i]);
 
    /* Clear START */
    ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_CONT);
    LIMITED_BUSYWAIT(ti_lib_i2c_master_busy(I2C0_BASE));
    success = i2c_status();
  }
  if(!success) {
    return false;
  }
 
  /* Set slave address for read */
  ti_lib_i2c_master_slave_addr_set(I2C0_BASE, slave_addr, true);
 
  /* Assert ACK */
  ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START);
 
  i = 0;
  while(i < (rlen - 1) && success) {
    LIMITED_BUSYWAIT(ti_lib_i2c_master_busy(I2C0_BASE));
    success = i2c_status();
    if(success) {
      rdata[i] = ti_lib_i2c_master_data_get(I2C0_BASE);
      ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_RECEIVE_CONT);
      i++;
    }
  }
 
  if(success) {
    ti_lib_i2c_master_control(I2C0_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH);
    LIMITED_BUSYWAIT(ti_lib_i2c_master_busy(I2C0_BASE));
    success = i2c_status();
    if(success) {
      rdata[rlen - 1] = ti_lib_i2c_master_data_get(I2C0_BASE);
      LIMITED_BUSYWAIT(ti_lib_i2c_master_bus_busy(I2C0_BASE));
    }
  }
 
  return success;
}
/*---------------------------------------------------------------------------*/
void
board_i2c_select(uint8_t new_interface, uint8_t address)
{
  slave_addr = address;
 
  if(accessible() == false) {
    board_i2c_wakeup();
  }
 
  if(new_interface != interface) {
    interface = new_interface;
 
    ti_lib_i2c_master_disable(I2C0_BASE);
 
    if(interface == BOARD_I2C_INTERFACE_0) {
      ti_lib_ioc_io_port_pull_set(BOARD_IOID_SDA, IOC_NO_IOPULL);
      ti_lib_ioc_io_port_pull_set(BOARD_IOID_SCL, IOC_NO_IOPULL);
      ti_lib_ioc_pin_type_i2c(I2C0_BASE, BOARD_IOID_SDA, BOARD_IOID_SCL);
      ti_lib_ioc_pin_type_gpio_input(BOARD_IOID_SDA_HP);
      ti_lib_ioc_pin_type_gpio_input(BOARD_IOID_SCL_HP);
    } else if(interface == BOARD_I2C_INTERFACE_1) {
      ti_lib_ioc_io_port_pull_set(BOARD_IOID_SDA_HP, IOC_NO_IOPULL);
      ti_lib_ioc_io_port_pull_set(BOARD_IOID_SCL_HP, IOC_NO_IOPULL);
      ti_lib_ioc_pin_type_i2c(I2C0_BASE, BOARD_IOID_SDA_HP, BOARD_IOID_SCL_HP);
      ti_lib_ioc_pin_type_gpio_input(BOARD_IOID_SDA);
      ti_lib_ioc_pin_type_gpio_input(BOARD_IOID_SCL);
    }
 
    /* Enable and initialize the I2C master module */
    ti_lib_i2c_master_init_exp_clk(I2C0_BASE, ti_lib_sys_ctrl_clock_get(),
                                   true);
  }
}
/*---------------------------------------------------------------------------*/
/** @} */