i2c.c 32.36 KiB
/* ****************************************************************************
* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
*
* 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 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 MAXIM INTEGRATED 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.
*
* Except as contained in this notice, the name of Maxim Integrated
* Products, Inc. shall not be used except as stated in the Maxim Integrated
* Products, Inc. Branding Policy.
*
* The mere transfer of this software does not imply any licenses
* of trade secrets, proprietary technology, copyrights, patents,
* trademarks, maskwork rights, or any other form of intellectual
* property whatsoever. Maxim Integrated Products, Inc. retains all
* ownership rights.
*
* $Date: 2020-02-03 10:17:47 -0600 (Mon, 03 Feb 2020) $
* $Revision: 51324 $
*
*************************************************************************** */
#include <stddef.h>
#include <stdint.h>
#include "mxc_config.h"
#include "mxc_assert.h"
#include "mxc_lock.h"
#include "mxc_sys.h"
#include "i2c.h"
#include <stdio.h>
#include "mxc_delay.h"
/* **** Definitions **** */
#define I2C_ERROR (MXC_F_I2C_INT_FL0_ARB_ER | MXC_F_I2C_INT_FL0_TO_ER | MXC_F_I2C_INT_FL0_ADDR_NACK_ER | \
MXC_F_I2C_INT_FL0_DATA_ER | MXC_F_I2C_INT_FL0_DO_NOT_RESP_ER | MXC_F_I2C_INT_FL0_START_ER | \
MXC_F_I2C_INT_FL0_STOP_ER)
#define MASTER 1
#define SLAVE 0
/* For high speed mode, if the I2C bus capacitance is greater than 100pF, set this value to ((capacitance - 100) / 3).
Otherwise leave it at 0. */
#define HS_SCALE_FACTOR (0)
#define T_LOW_MIN (160 + (160 * HS_SCALE_FACTOR / 100)) /* tLOW minimum in nanoseconds */
#define T_HIGH_MIN (60 + (60 * HS_SCALE_FACTOR / 100)) /* tHIGH minimum in nanoseconds */
#define T_R_MAX_HS (40 + (40 * HS_SCALE_FACTOR / 100)) /* tR maximum for high speed mode in nanoseconds */
#define T_F_MAX_HS (40 + (40 * HS_SCALE_FACTOR / 100)) /* tF maximum for high speed mode in nanoseconds */
#define T_AF_MIN (10 + (10 * HS_SCALE_FACTOR / 100)) /* tAF minimun in nanoseconds */
/* **** Variable Declaration **** */
// Saves the state of the non-blocking requests
typedef struct {
i2c_req_t *req;
i2c_state_t state; uint8_t num_wr; // keep track of number of bytes loaded in the fifo during slave transmit
} i2c_req_state_t;
static i2c_req_state_t states[MXC_I2C_INSTANCES];
/* **** Function Prototypes **** */
static void I2C_MasterHandler(mxc_i2c_regs_t *i2c);
static void I2C_SlaveHandler(mxc_i2c_regs_t *i2c);
static void I2C_FreeCallback(int i2c_num, int error);
static void I2C_Recover(mxc_i2c_regs_t *i2c);
/* ************************************************************************** */
static int I2C_Setspeed(mxc_i2c_regs_t * i2c, i2c_speed_t i2cspeed)
{
uint32_t ticks, ticks_lo, ticks_hi;
if (i2cspeed == I2C_HS_MODE) {
uint32_t sys_freq, tPCLK, targBusFreq, tSCLmin, cklMin, ckhMin, ckh_cklMin;
/* Compute dividers for high speed mode. */
sys_freq = SYS_I2C_GetFreq(i2c);
MXC_ASSERT(sys_freq >= 1000);
tPCLK = 1000000 / (sys_freq / 1000);
MXC_ASSERT(tPCLK > 0)
targBusFreq = i2cspeed - ((i2cspeed/2) * HS_SCALE_FACTOR / 100);
if(targBusFreq < 1000) {
return E_BAD_PARAM;
}
tSCLmin = 1000000 / (targBusFreq / 1000);
cklMin = ((T_LOW_MIN + T_F_MAX_HS + (tPCLK - 1) - T_AF_MIN) / tPCLK) - 1;
ckhMin = ((T_HIGH_MIN + T_R_MAX_HS + (tPCLK - 1) - T_AF_MIN) / tPCLK) - 1;
ckh_cklMin = ((tSCLmin + (tPCLK - 1)) / tPCLK) - 2;
ticks_lo = (cklMin > (ckh_cklMin - ckhMin)) ? (cklMin) : (ckh_cklMin - ckhMin);
ticks_hi = ckhMin;
if((ticks_lo > (MXC_F_I2C_HS_CLK_HS_CLK_LO >> MXC_F_I2C_HS_CLK_HS_CLK_LO_POS)) ||
(ticks_hi > (MXC_F_I2C_HS_CLK_HS_CLK_HI >> MXC_F_I2C_HS_CLK_HS_CLK_HI_POS))) {
return E_BAD_PARAM;
}
/* Write results to destination registers. */
i2c->hs_clk = ((ticks_lo-1) << MXC_F_I2C_HS_CLK_HS_CLK_LO_POS) | (ticks_hi <<
MXC_F_I2C_HS_CLK_HS_CLK_HI_POS);
/* Still need to load dividers for the preamble that each high-speed transaction starts with.
Switch setting to fast mode and fall out of if statement. */
i2cspeed = I2C_FAST_MODE;
}
/* Get the number of periph clocks needed to achieve selected speed. */
ticks = SYS_I2C_GetFreq(i2c) / i2cspeed;
/* For a 50% duty cycle, half the ticks will be spent high and half will be low. */
ticks_hi = (ticks >> 1) - 1;
ticks_lo = (ticks >> 1) - 1;
/* Account for rounding error in odd tick counts. */
if (ticks & 1) {
ticks_hi++;
}
/* Will results fit into 9 bit registers? (ticks_hi will always be >= ticks_lo. No need to check ticks_lo.) */
if (ticks_hi > 0x1FF) {
return E_BAD_PARAM;
}
/* 0 is an invalid value for the destination registers. (ticks_hi will always be >= ticks_lo. No need to check ticks_hi.) */
if (ticks_lo == 0) {
return E_BAD_PARAM;
}
/* Write results to destination registers. */
i2c->clk_lo = ticks_lo;
i2c->clk_hi = ticks_hi;
return E_NO_ERROR;
}
/* ************************************************************************** */
int I2C_Init(mxc_i2c_regs_t *i2c, i2c_speed_t i2cspeed, const sys_cfg_i2c_t* sys_cfg)
{
int err;
int idx = MXC_I2C_GET_IDX(i2c);
// Check the base pointer
MXC_ASSERT(idx >= 0);
// Set system level configurations
if ((err = SYS_I2C_Init(i2c, sys_cfg)) != E_NO_ERROR) {
return err;
}
// Always disable the HW autoflush on data NACK and let the SW handle the flushing.
i2c->tx_ctrl0 |= 0x20;
states[idx].num_wr = 0;
i2c->ctrl = 0; // clear configuration bits
i2c->ctrl = MXC_F_I2C_CTRL_I2C_EN; // Enable I2C
i2c->master_ctrl = 0; // clear master configuration bits
i2c->status = 0; // clear status bits
/* If either SDA or SCL is already low, there is a problem.
* Try reclaiming the bus by sending clocks until we have control of the SDA line.
* Follow procedure defined in i2c spec.
*/
if ((i2c->ctrl & (MXC_F_I2C_CTRL_SCL | MXC_F_I2C_CTRL_SDA)) !=
(MXC_F_I2C_CTRL_SCL | MXC_F_I2C_CTRL_SDA)) {
int i, have_control;
// Set SCL/SDA as software controlled.
i2c->ctrl |= MXC_F_I2C_CTRL_SW_OUT_EN;
// Try to get control of SDA.
for (i = 0; i < 16; i++) {
have_control = 1;
// Drive SCL low and check its state.
i2c->ctrl &= ~(MXC_F_I2C_CTRL_SCL_OUT);
mxc_delay(MXC_DELAY_USEC(5));
if ((i2c->ctrl & MXC_F_I2C_CTRL_SCL) == MXC_F_I2C_CTRL_SCL) {
have_control = 0;
}
// Drive SDA low and check its state.
i2c->ctrl &= ~(MXC_F_I2C_CTRL_SDA_OUT);
mxc_delay(MXC_DELAY_USEC(5));
if ((i2c->ctrl & MXC_F_I2C_CTRL_SDA) == MXC_F_I2C_CTRL_SDA) {
have_control = 0;
}
// Release SDA and check its state.
i2c->ctrl |= (MXC_F_I2C_CTRL_SDA_OUT);
mxc_delay(MXC_DELAY_USEC(5));
if ((i2c->ctrl & MXC_F_I2C_CTRL_SDA) != MXC_F_I2C_CTRL_SDA) {
have_control = 0; }
// Release SCL and check its state.
i2c->ctrl |= (MXC_F_I2C_CTRL_SCL_OUT);
mxc_delay(MXC_DELAY_USEC(5));
if ((i2c->ctrl & MXC_F_I2C_CTRL_SCL) != MXC_F_I2C_CTRL_SCL) {
have_control = 0;
}
if (have_control) {
// Issue stop
// Drive SDA low.
i2c->ctrl &= ~(MXC_F_I2C_CTRL_SDA_OUT);
mxc_delay(MXC_DELAY_USEC(5));
// Release SDA.
i2c->ctrl |= (MXC_F_I2C_CTRL_SDA_OUT);
mxc_delay(MXC_DELAY_USEC(5));
break;
}
}
if (!have_control) {
return E_COMM_ERR;
}
}
i2c->ctrl = 0; // clear configuration bits
i2c->ctrl = MXC_F_I2C_CTRL_I2C_EN; // Enable I2C
i2c->master_ctrl = 0; // clear master configuration bits
i2c->status= 0; // clear status bits
// Check for HS mode
if (i2cspeed == I2C_HS_MODE) {
i2c->ctrl |= MXC_F_I2C_CTRL_HS_MODE; // Enable HS mode
}
// Disable and clear interrupts
i2c->int_en0 = 0;
i2c->int_en1 = 0;
i2c->int_fl0 = i2c->int_fl0;
i2c->int_fl1 = i2c->int_fl1;
i2c->timeout = 0x0; // set timeout
i2c->rx_ctrl0 |= MXC_F_I2C_RX_CTRL0_RX_FLUSH; // clear the RX FIFO
i2c->tx_ctrl0 |= MXC_F_I2C_TX_CTRL0_TX_FLUSH; // clear the TX FIFO
return I2C_Setspeed(i2c, i2cspeed);
}
/* ************************************************************************** */
int I2C_Shutdown(mxc_i2c_regs_t *i2c)
{
int i2c_num, err;
// Check the base pointer
i2c_num = MXC_I2C_GET_IDX(i2c);
MXC_ASSERT(i2c_num >= 0);
// Disable and clear interrupts
i2c->int_en0 = 0;
i2c->int_en1 = 0;
i2c->int_fl0 = i2c->int_fl0;
i2c->int_fl1 = i2c->int_fl1;
i2c->rx_ctrl0 |= MXC_F_I2C_RX_CTRL0_RX_FLUSH; // clear the RX FIFO
i2c->tx_ctrl0 |= MXC_F_I2C_TX_CTRL0_TX_FLUSH; // clear the TX FIFO
// Call all of the pending callbacks for this I2C
if (states[i2c_num].req != NULL) {
I2C_Recover(i2c);
I2C_FreeCallback(i2c_num, E_SHUTDOWN); }
i2c->ctrl = 0;
// Clears system level configurations
if ((err = SYS_I2C_Shutdown(i2c)) != E_NO_ERROR) {
return err;
}
return E_NO_ERROR;
}
/* ************************************************************************** */
int I2C_MasterWrite(mxc_i2c_regs_t *i2c, uint8_t addr, const uint8_t* data, int len, int restart)
{
int save_len = len;
if (len == 0) {
return E_NO_ERROR;
}
// Clear the lock out bit (W1C) in case it is set.
i2c->int_fl0 = MXC_F_I2C_INT_FL0_TX_LOCK_OUT;
i2c->int_fl0 = i2c->int_fl0;
// Enable master mode
i2c->ctrl |= MXC_F_I2C_CTRL_MST;
// Load FIFO with slave address for WRITE and as much data as we can
while (i2c->status & MXC_F_I2C_STATUS_TX_FULL) {}
i2c->fifo = addr & ~(0x1);
while ((len > 0) && !(i2c->status & MXC_F_I2C_STATUS_TX_FULL)) {
i2c->fifo = *data++;
len--;
}
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_START;
// Write remaining data to FIFO
while (len > 0) {
// Check for errors
if (i2c->int_fl0 & I2C_ERROR) {
// Set the stop bit
i2c->master_ctrl &= ~(MXC_F_I2C_MASTER_CTRL_RESTART);
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_STOP;
while (!(i2c->int_fl0 & (MXC_F_I2C_INT_FL0_STOP))) {}
return E_COMM_ERR;
}
if (!(i2c->status & MXC_F_I2C_STATUS_TX_FULL)) {
i2c->fifo = *data++;
len--;
}
}
if (restart) {
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_RESTART;
} else {
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_STOP;
}
// Wait for Done
while (!(i2c->int_fl0 & (MXC_F_I2C_INT_FL0_DONE | I2C_ERROR))) {}
i2c->int_fl0 = MXC_F_I2C_INT_FL0_DONE;
// Wait for Stop
if (!restart) {
while (!(i2c->int_fl0 & (MXC_F_I2C_INT_FL0_STOP ))) {}
i2c->int_fl0 = MXC_F_I2C_INT_FL0_STOP;
}
// Check for errors
if (i2c->int_fl0 & I2C_ERROR) {
return E_COMM_ERR;
}
return save_len;
}
/* ************************************************************************** */
int I2C_MasterRead(mxc_i2c_regs_t *i2c, uint8_t addr, uint8_t* data, int len, int restart)
{
int save_len = len;
if (len == 0) {
return E_NO_ERROR;
}
if (len > 256) {
return E_BAD_PARAM;
}
i2c->int_fl0 = MXC_F_I2C_INT_FL0_TX_LOCK_OUT;
i2c->int_fl0 = i2c->int_fl0;
// Make sure the I2C has been initialized
if (!(i2c->ctrl & MXC_F_I2C_CTRL_I2C_EN)) {
return E_UNINITIALIZED;
}
// Enable master mode
i2c->ctrl |= MXC_F_I2C_CTRL_MST;
// Set receive count
i2c->rx_ctrl1= len;
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_START;
// Load FIFO with slave address
while (i2c->status & MXC_F_I2C_STATUS_TX_FULL) {}
i2c->fifo = (addr | 1);
// Wait for all data to be received or error
while (len > 0) {
// Check for errors
if (i2c->int_fl0 & I2C_ERROR) {
// Set the stop bit
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_STOP;
while (!(i2c->int_fl0 & (MXC_F_I2C_INT_FL0_STOP))) {}
return E_COMM_ERR;
}
if (!(i2c->status & MXC_F_I2C_STATUS_RX_EMPTY)) {
*data++ = i2c->fifo;
len--;
}
}
if (i2c->int_fl0 & I2C_ERROR) {
// Set the stop bit
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_STOP;
while (!(i2c->int_fl0 & (MXC_F_I2C_INT_FL0_STOP))) {} return E_COMM_ERR;
}
if (restart) {
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_RESTART;
} else {
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_STOP;
}
// Wait for Done
while (!(i2c->int_fl0 & (MXC_F_I2C_INT_FL0_DONE | I2C_ERROR))) {
}
i2c->int_fl0 = MXC_F_I2C_INT_FL0_DONE;
// Wait for Stop
if (!restart) {
while (!(i2c->int_fl0 &( MXC_F_I2C_INT_FL0_STOP | I2C_ERROR))) {
}
i2c->int_fl0 = MXC_F_I2C_INT_FL0_STOP;
}
// Check for errors
if (i2c->int_fl0 & I2C_ERROR) {
return E_COMM_ERR;
}
return save_len;
}
/* ************************************************************************** */
int I2C_Slave(mxc_i2c_regs_t *i2c, uint8_t addr, const uint8_t* read_data, int read_len,
uint8_t* write_data, int write_len, int* tx_num, int* rx_num,
i2c_autoflush_disable_t sw_autoflush_disable)
{
int i2c_num;
i2c_num = MXC_I2C_GET_IDX(i2c);
if ((read_data == NULL) && (write_data == NULL)) {
return E_NULL_PTR;
}
// Make sure the I2C has been initialized
if (!(i2c->ctrl & MXC_F_I2C_CTRL_I2C_EN)) {
return E_UNINITIALIZED;
}
if ((read_len == 0) && (write_len == 0)) {
return E_NO_ERROR;
}
if (mxc_get_lock((uint32_t*)&states[i2c_num].req, 1) != E_NO_ERROR) {
return E_BUSY;
}
// Disable master mode
i2c->ctrl &= ~MXC_F_I2C_CTRL_MST;
// Clear any previous errors
i2c->int_fl0 = i2c->int_fl0;
i2c->int_fl1 = i2c->int_fl1;
// Set the slave address
i2c->slave_addr = (addr >> 1);
// Wait for address match
while (!(i2c->int_fl0 & MXC_F_I2C_INT_FL0_ADDR_MATCH) && !(i2c->int_fl0 & I2C_ERROR)) {
}
i2c->int_fl0 = MXC_F_I2C_INT_FL0_ADDR_MATCH;
i2c->int_fl0 = MXC_F_I2C_INT_FL0_TX_LOCK_OUT;
if (i2c->int_fl0 & I2C_ERROR) {
if (!sw_autoflush_disable) {
i2c->tx_ctrl0 |= MXC_F_I2C_TX_CTRL0_TX_FLUSH;
i2c->rx_ctrl0 |= MXC_F_I2C_RX_CTRL0_RX_FLUSH;
}
mxc_free_lock((uint32_t*)&states[i2c_num]);
return E_COMM_ERR;
}
// See if we're reading or writing
if (i2c->ctrl & MXC_F_I2C_CTRL_READ) {
// This is the master read/slave write case
if (read_data == NULL || read_len == 0) {
mxc_free_lock((uint32_t*)&states[i2c_num]);
return E_NULL_PTR;
}
// Wait for all data to be received or error
while (read_len > 0) {
// Check for errors
if (i2c->int_fl0 & I2C_ERROR) {
*tx_num = states[i2c_num].num_wr - ((i2c->tx_ctrl1 & MXC_F_I2C_TX_CTRL1_TX_FIFO) >> MXC_F_I2C_TX_CTRL1_TX_FIFO_POS);
states[i2c_num].num_wr = 0;
if (!sw_autoflush_disable) {
i2c->tx_ctrl0 |= MXC_F_I2C_TX_CTRL0_TX_FLUSH;
}
mxc_free_lock((uint32_t*)&states[i2c_num]);
return E_COMM_ERR;
}
// Check for nack from master
if (i2c->int_fl0 & MXC_F_I2C_INT_FL0_TX_LOCK_OUT) {
break;
}
// Check for done bit
if (i2c->int_fl0 & MXC_F_I2C_INT_FL0_DONE) {
break;
}
if (!(i2c->status & MXC_F_I2C_STATUS_TX_FULL)) {
i2c->fifo = *read_data++;
states[i2c_num].num_wr++;
read_len--;
}
}
// Wait for Done
while (!(i2c->int_fl0 & MXC_F_I2C_INT_FL0_DONE)) {}
// Calculate number of bytes sent by the slave
*tx_num = states[i2c_num].num_wr - ((i2c->tx_ctrl1 & MXC_F_I2C_TX_CTRL1_TX_FIFO) >> MXC_F_I2C_TX_CTRL1_TX_FIFO_POS);
states[i2c_num].num_wr = 0;
if (!sw_autoflush_disable) {
// Flush the TX FIFO
i2c->tx_ctrl0 |= MXC_F_I2C_TX_CTRL0_TX_FLUSH;
}
} else {
// This is the master write/slave read case
if (write_data == NULL || write_len == 0) {
mxc_free_lock((uint32_t*)&states[i2c_num]);
return E_NULL_PTR;
}
// Wait for all data to be written or error
while (write_len > 0) {
// Check for errors
if (i2c->int_fl0 & I2C_ERROR) {
if (!sw_autoflush_disable) {
i2c->rx_ctrl0 |= MXC_F_I2C_RX_CTRL0_RX_FLUSH;
}
mxc_free_lock((uint32_t*)&states[i2c_num]);
return E_COMM_ERR;
}
// Check for done bit
if (i2c->int_fl0 & MXC_F_I2C_INT_FL0_DONE) {
break;
}
if (!(i2c->status & MXC_F_I2C_STATUS_RX_EMPTY)) {
*write_data++ = i2c->fifo;
(*rx_num)++;
write_len--;
}
}
// Wait for done
while (!(i2c->int_fl0 & MXC_F_I2C_INT_FL0_DONE)) {
}
// Flush the FIFO
if (!sw_autoflush_disable) {
i2c->rx_ctrl0 |= MXC_F_I2C_RX_CTRL0_RX_FLUSH;
}
}
// Check for errors
if (i2c->int_fl0 & I2C_ERROR) {
// Flush the FIFO
if (!sw_autoflush_disable) {
i2c->tx_ctrl0 |= MXC_F_I2C_TX_CTRL0_TX_FLUSH;
i2c->rx_ctrl0 |= MXC_F_I2C_RX_CTRL0_RX_FLUSH;
}
mxc_free_lock((uint32_t*)&states[i2c_num]);
return E_COMM_ERR;
}
mxc_free_lock((uint32_t*)&states[i2c_num]);
return E_NO_ERROR;
}
/* ************************************************************************** */
int I2C_MasterAsync(mxc_i2c_regs_t *i2c, i2c_req_t *req)
{
int i2c_num;
i2c_num = MXC_I2C_GET_IDX(i2c);
if (req->state == I2C_STATE_READING) {
// Check the parameters
if (req->rx_len == 0) {
return E_NO_ERROR;
}
if (req->rx_data == NULL) {
return E_NULL_PTR;
}
} else {
// Check the parameters
if (req->tx_len == 0) {
return E_NO_ERROR;
}
if (req->tx_data == NULL) { return E_NULL_PTR;
}
}
// Make sure the I2C has been initialized
if (!(i2c->ctrl & MXC_F_I2C_CTRL_I2C_EN)) {
return E_UNINITIALIZED;
}
// Attempt to register this request
if (mxc_get_lock((uint32_t*)&states[i2c_num].req, (uint32_t)req) != E_NO_ERROR) {
return E_BUSY;
}
states[i2c_num].state = req->state;
states[i2c_num].req = req;
// Enable master mode
i2c->ctrl |= MXC_F_I2C_CTRL_MST;
// Clear the byte counters
req->tx_num = 0;
req->rx_num = 0;
// Disable and clear the interrupts
i2c->int_en0 = 0;
i2c->int_en1 = 0;
i2c->int_fl0 = i2c->int_fl0;
i2c->int_fl1 = i2c->int_fl1;
// Start the transaction
I2C_MasterHandler(i2c);
return E_NO_ERROR;
}
/* ************************************************************************** */
static void I2C_MasterHandler(mxc_i2c_regs_t *i2c)
{
uint32_t int0, inten0 = 0;
int i2c_num;
unsigned rx_remain, tx_remain;
i2c_req_t *req;
i2c_num = MXC_I2C_GET_IDX(i2c);
req = states[i2c_num].req;
// Check for errors
int0 = i2c->int_fl0;
if (int0 & I2C_ERROR) {
// Set the stop bit
i2c->master_ctrl &= ~(MXC_F_I2C_MASTER_CTRL_RESTART);
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_STOP;
i2c->int_en0 = 0;
if (req->callback != NULL) {
I2C_Recover(i2c);
I2C_FreeCallback(i2c_num, E_COMM_ERR);
}
return;
}
rx_remain = req->rx_len - req->rx_num;
tx_remain = req->tx_len - req->tx_num;
if (states[i2c_num].state == I2C_STATE_READING) {
// Read out any data in the RX FIFO while (rx_remain && !(i2c->status & MXC_F_I2C_STATUS_RX_EMPTY)) {
*(req->rx_data)++ = i2c->fifo;
req->rx_num++;
rx_remain--;
}
// Load the slave address if we haven't already started reading the data
if (rx_remain == req->rx_len) {
i2c->fifo = (req->addr | 1);
// Set the RX Count
i2c->rx_ctrl1 = req->rx_len;
// Start transmission if idle
if (!(i2c->status & MXC_F_I2C_STATUS_BUS)) {
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_START;
}
// Set restart or stop
if (req->restart) {
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_RESTART;
} else {
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_STOP;
inten0 |= MXC_F_I2C_INT_EN0_STOP;
}
}
// Set the RX threshold interrupt level
if (rx_remain >= (MXC_I2C_FIFO_DEPTH - 1)) {
i2c->rx_ctrl0 = ((i2c->rx_ctrl0 & ~(MXC_F_I2C_RX_CTRL0_RX_THRESH)) |
(MXC_I2C_FIFO_DEPTH - 1) << MXC_F_I2C_RX_CTRL0_RX_THRESH_POS);
inten0 |= MXC_F_I2C_INT_EN0_RX_THRESH;
}
} else {
// Load the slave address if we haven't already started writing the data
if (tx_remain == req->tx_len) {
i2c->fifo = req->addr;
// Start transmission if idle
if (!(i2c->status & MXC_F_I2C_STATUS_BUS)) {
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_START;
}
}
// Fill the FIFO
while ((tx_remain > 0) && !(i2c->status & MXC_F_I2C_STATUS_TX_FULL)) {
i2c->fifo = *(req->tx_data)++;
req->tx_num++;
tx_remain--;
}
// Set the TX threshold interrupt level, or restart/stop
if (tx_remain) {
i2c->tx_ctrl0 = ((i2c->tx_ctrl0 & ~(MXC_F_I2C_TX_CTRL0_TX_THRESH)) | (1 << MXC_F_I2C_TX_CTRL0_TX_THRESH_POS));
inten0 |= MXC_F_I2C_INT_EN0_TX_THRESH;
}
// Set restart or stop if at the end of the transaction since these actions happen at the moment the bit is set.
else if (req->restart) {
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_RESTART;
} else {
i2c->master_ctrl |= MXC_F_I2C_MASTER_CTRL_STOP;
inten0 |= MXC_F_I2C_INT_EN0_STOP;
}
}
if (req->restart) {
// Check for DONE interrupt
if ((int0 & MXC_F_I2C_INT_FL0_DONE)) { // Read out any data in the RX FIFO
while (rx_remain && !(i2c->status & MXC_F_I2C_STATUS_RX_EMPTY)) {
*(req->rx_data)++ = i2c->fifo;
req->rx_num++;
rx_remain--;
}
i2c->int_en0 = 0;
if (req->callback != NULL) {
I2C_Recover(i2c);
I2C_FreeCallback(i2c_num, E_NO_ERROR);
}
return;
}
} else {
// Check for STOP interrupt
if ((int0 & MXC_F_I2C_INT_FL0_STOP)) {
i2c->int_en0 = 0;
if (req->callback != NULL) {
I2C_Recover(i2c);
I2C_FreeCallback(i2c_num, E_NO_ERROR);
}
return;
}
// Check for DONE interrupt
if ((int0 & MXC_F_I2C_INT_FL0_DONE)) {
// Read out any data in the RX FIFO
while (rx_remain && !(i2c->status & MXC_F_I2C_STATUS_RX_EMPTY)) {
*(req->rx_data)++ = i2c->fifo;
req->rx_num++;
rx_remain--;
}
return;
}
}
// Clear the interrupts
i2c->int_fl0 = int0;
inten0 |= (MXC_F_I2C_INT_EN0_DONE | I2C_ERROR);
i2c->int_en0 = inten0;
}
/* ************************************************************************** */
int I2C_SlaveAsync(mxc_i2c_regs_t *i2c, i2c_req_t *req)
{
int i2c_num;
i2c_num = MXC_I2C_GET_IDX(i2c);
// Make sure the I2C has been initialized
if (!(i2c->ctrl & MXC_F_I2C_CTRL_I2C_EN)) {
return E_UNINITIALIZED;
}
// Attempt to register this request
if (mxc_get_lock((uint32_t*)&states[i2c_num].req, (uint32_t)req) != E_NO_ERROR) {
return E_BUSY;
}
states[i2c_num].req = req;
// Set Slave Address
i2c->slave_addr = (req->addr >> 1);
// Clear the byte counters
req->tx_num = 0;
req->rx_num = 0;
// Disable and clear the interrupts
i2c->int_en0 = 0;
i2c->int_en1 = 0;
i2c->int_fl0 = i2c->int_fl0;
i2c->int_fl1 = i2c->int_fl1;
i2c->int_en0 |= MXC_F_I2C_INT_EN0_ADDR_MATCH;
return E_NO_ERROR;
}
/* ************************************************************************** */
static void I2C_SlaveHandler(mxc_i2c_regs_t *i2c)
{
uint32_t int0, inten0 = 0;
int rx_remain, tx_remain, i2c_num;
i2c_req_t *req;
i2c_num = MXC_I2C_GET_IDX(i2c);
req = states[i2c_num].req;
if ( i2c->int_fl0 & MXC_F_I2C_INT_FL0_ADDR_MATCH ) {
i2c->int_fl0 |=MXC_F_I2C_INT_EN0_STOP;
}
// Check for errors
int0 = i2c->int_fl0;
if (int0 & I2C_ERROR) {
i2c->int_en0 = 0;
// Calculate the number of bytes sent by the slave
req->tx_num = states[i2c_num].num_wr - ((i2c->tx_ctrl1 & MXC_F_I2C_TX_CTRL1_TX_FIFO) >> MXC_F_I2C_TX_CTRL1_TX_FIFO_POS);
if (!req->sw_autoflush_disable) {
// Manually clear the TXFIFO
i2c->tx_ctrl0 |= MXC_F_I2C_TX_CTRL0_TX_FLUSH;
}
states[i2c_num].num_wr = 0;
if (req->callback != NULL) {
I2C_Recover(i2c);
I2C_FreeCallback(i2c_num, E_COMM_ERR);
}
return;
}
rx_remain = req->rx_len - req->rx_num;
tx_remain = req->tx_len - states[i2c_num].num_wr;
//Check if Master Write has been called and if there is a rx_data buffer
if ((i2c->int_fl0 & MXC_F_I2C_INT_FL0_TX_LOCK_OUT) && !(i2c->ctrl & MXC_F_I2C_CTRL_READ)) {
i2c->int_en0 = 0;
if (req->rx_data == NULL) {
I2C_Recover(i2c);
I2C_FreeCallback(i2c_num, E_NULL_PTR);
return;
}
}
// Check for DONE interrupt
if (int0 & MXC_F_I2C_INT_EN0_DONE) {
// Read out any data in the RX FIFO
while (rx_remain && !(i2c->status & MXC_F_I2C_STATUS_RX_EMPTY)) {
*(req->rx_data)++ = i2c->fifo;
req->rx_num++;
rx_remain--;
}
// Calculate the number of bytes sent by the slave
req->tx_num = states[i2c_num].num_wr - ((i2c->tx_ctrl1 & MXC_F_I2C_TX_CTRL1_TX_FIFO) >> MXC_F_I2C_TX_CTRL1_TX_FIFO_POS);
if (!req->sw_autoflush_disable) {
// Manually clear the TXFIFO i2c->tx_ctrl0 |= MXC_F_I2C_TX_CTRL0_TX_FLUSH;
}
states[i2c_num].num_wr = 0;
i2c->int_en0 = 0;
if (req->callback != NULL) {
if (i2c->int_fl0 & MXC_F_I2C_INT_FL0_STOP) {
I2C_Recover(i2c);
} else {
i2c->int_fl0 = i2c->int_fl0;
i2c->int_fl1 = i2c->int_fl1;
}
I2C_FreeCallback(i2c_num, E_NO_ERROR);
}
return;
}
// Clear the interrupts
i2c->int_fl0 = int0;
if (i2c->ctrl & MXC_F_I2C_CTRL_READ) {
i2c->int_en0 = 0;
if (req->tx_data == NULL) {
I2C_Recover(i2c);
I2C_FreeCallback(i2c_num, E_NULL_PTR);
return;
}
// Fill the FIFO
while ((tx_remain > 0) && !(i2c->status & MXC_F_I2C_STATUS_TX_FULL)) {
i2c->fifo = *(req->tx_data)++;
states[i2c_num].num_wr++;
tx_remain--;
}
// Set the TX threshold interrupt level
if (tx_remain) {
i2c->tx_ctrl0 = ((i2c->tx_ctrl0 & ~(MXC_F_I2C_TX_CTRL0_TX_THRESH)) | (1 << MXC_F_I2C_TX_CTRL0_TX_THRESH_POS));
inten0 |= MXC_F_I2C_INT_EN0_TX_THRESH;
}
} else {
// Read out any data in the RX FIFO
while (rx_remain && !(i2c->status & MXC_F_I2C_STATUS_RX_EMPTY)) {
*(req->rx_data)++ = i2c->fifo;
req->rx_num++;
rx_remain--;
}
// Set the RX threshold interrupt level
if (rx_remain >= (MXC_I2C_FIFO_DEPTH - 1)) {
i2c->rx_ctrl0 = ((i2c->rx_ctrl0 & ~(MXC_F_I2C_RX_CTRL0_RX_THRESH)) |
(MXC_I2C_FIFO_DEPTH - 1) << MXC_F_I2C_RX_CTRL0_RX_THRESH_POS);
inten0 |= MXC_F_I2C_INT_EN0_RX_THRESH;
}else{
i2c->rx_ctrl0 = ((i2c->rx_ctrl0 & ~(MXC_F_I2C_RX_CTRL0_RX_THRESH)) |
(rx_remain) << MXC_F_I2C_RX_CTRL0_RX_THRESH_POS);
inten0 |= MXC_F_I2C_INT_EN0_RX_THRESH;
}
}
inten0 |= (MXC_F_I2C_INT_EN0_DONE | I2C_ERROR | MXC_F_I2C_INT_EN0_TX_LOCK_OUT);
i2c->int_en0 = inten0;
}
/* ************************************************************************** */
void I2C_Handler(mxc_i2c_regs_t *i2c)
{
if (i2c->ctrl & MXC_F_I2C_CTRL_MST && i2c->int_fl0) {
// Service master interrupts if we're in master mode I2C_MasterHandler(i2c);
} else if (i2c->int_fl0 || i2c->int_fl1) {
// Service the slave interrupts
I2C_SlaveHandler(i2c);
}
}
/* ************************************************************************** */
void I2C_DrainRX(mxc_i2c_regs_t *i2c)
{
i2c->rx_ctrl0 |= MXC_F_I2C_RX_CTRL0_RX_FLUSH;
}
/* ************************************************************************** */
void I2C_DrainTX(mxc_i2c_regs_t *i2c)
{
i2c->tx_ctrl0 |= MXC_F_I2C_TX_CTRL0_TX_FLUSH;
}
/* ************************************************************************* */
static void I2C_FreeCallback(int i2c_num, int error)
{
// Save the request
i2c_req_t *temp_req = states[i2c_num].req;
mxc_free_lock((uint32_t*)&states[i2c_num].req);
// Callback if not NULL
if (temp_req->callback != NULL) {
temp_req->callback(temp_req, error);
}
}
/* ************************************************************************* */
static void I2C_Recover(mxc_i2c_regs_t *i2c)
{
// Disable and clear interrupts
i2c->int_en0 = 0;
i2c->int_en1 = 0;
i2c->int_fl0 = i2c->int_fl0;
i2c->int_fl1 = i2c->int_fl1;
i2c->ctrl = 0;
i2c->ctrl = MXC_F_I2C_CTRL_I2C_EN;
}
/* ************************************************************************* */
int I2C_AbortAsync(i2c_req_t *req)
{
int i2c_num;
mxc_i2c_regs_t *i2c;
// Find the request, set to NULL
for (i2c_num = 0; i2c_num < MXC_I2C_INSTANCES; i2c_num++) {
if (req == states[i2c_num].req) {
i2c = MXC_I2C_GET_I2C(i2c_num);
I2C_Recover(i2c);
I2C_FreeCallback(i2c_num, E_ABORT);
return E_NO_ERROR;
}
}
return E_BAD_PARAM;
}
/* ************************************************************************* */
int I2C_SetTimeout(mxc_i2c_regs_t *i2c, int us){
uint32_t timeout;
timeout = (PeripheralClock/1000000) * us;
if(timeout > 0xFFFF){ return E_BAD_PARAM;
}
i2c->timeout = timeout;
return E_NO_ERROR;
}
/* ************************************************************************* */
void I2C_ClearTimeout (mxc_i2c_regs_t *i2c)
{
i2c->timeout = 0;
}