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/*
* Copyright (c) 2013 - 2014, Freescale Semiconductor, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* o Redistributions of source code must retain the above copyright notice, this list
* of conditions and the following disclaimer.
*
* o 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.
*
* o Neither the name of Freescale Semiconductor, Inc. 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.
*/
#include "fsl_i2c_hal.h"
#include "fsl_misc_utilities.h" /* For ARRAY_SIZE*/
/*******************************************************************************
* Definitions
******************************************************************************/
/*!
* @brief An entry in the I2C divider table.
*
* This struct pairs the value of the I2C_F.ICR bitfield with the resulting
* clock divider value.
*/
typedef struct I2CDividerTableEntry {
uint8_t icr; /*!< F register ICR value.*/
uint16_t sclDivider; /*!< SCL clock divider.*/
} i2c_divider_table_entry_t;
/*******************************************************************************
* Variables
******************************************************************************/
/*!
* @brief I2C divider values.
*
* This table is taken from the I2C Divider and Hold values section of the
* reference manual. In the original table there are, in some cases, multiple
* entries with the same divider but different hold values. This table
* includes only one entry for every divider, selecting the lowest hold value.
*/
const i2c_divider_table_entry_t kI2CDividerTable[] = {
/* ICR Divider*/
{ 0x00, 20 },
{ 0x01, 22 },
{ 0x02, 24 },
{ 0x03, 26 },
{ 0x04, 28 },
{ 0x05, 30 },
{ 0x09, 32 },
{ 0x06, 34 },
{ 0x0a, 36 },
{ 0x07, 40 },
{ 0x0c, 44 },
{ 0x0d, 48 },
{ 0x0e, 56 },
{ 0x12, 64 },
{ 0x0f, 68 },
{ 0x13, 72 },
{ 0x14, 80 },
{ 0x15, 88 },
{ 0x19, 96 },
{ 0x16, 104 },
{ 0x1a, 112 },
{ 0x17, 128 },
{ 0x1c, 144 },
{ 0x1d, 160 },
{ 0x1e, 192 },
{ 0x22, 224 },
{ 0x1f, 240 },
{ 0x23, 256 },
{ 0x24, 288 },
{ 0x25, 320 },
{ 0x26, 384 },
{ 0x2a, 448 },
{ 0x27, 480 },
{ 0x2b, 512 },
{ 0x2c, 576 },
{ 0x2d, 640 },
{ 0x2e, 768 },
{ 0x32, 896 },
{ 0x2f, 960 },
{ 0x33, 1024 },
{ 0x34, 1152 },
{ 0x35, 1280 },
{ 0x36, 1536 },
{ 0x3a, 1792 },
{ 0x37, 1920 },
{ 0x3b, 2048 },
{ 0x3c, 2304 },
{ 0x3d, 2560 },
{ 0x3e, 3072 },
{ 0x3f, 3840 }
};
/*******************************************************************************
* Code
******************************************************************************/
/*FUNCTION**********************************************************************
*
* Function Name : I2C_HAL_Init
* Description : Initialize I2C peripheral to reset state.
*
*END**************************************************************************/
void I2C_HAL_Init(uint32_t baseAddr)
{
HW_I2C_A1_WR(baseAddr, 0u);
HW_I2C_F_WR(baseAddr, 0u);
HW_I2C_C1_WR(baseAddr, 0u);
HW_I2C_S_WR(baseAddr, 0u);
HW_I2C_D_WR(baseAddr, 0u);
HW_I2C_C2_WR(baseAddr, 0u);
HW_I2C_FLT_WR(baseAddr, 0u);
HW_I2C_RA_WR(baseAddr, 0u);
#if FSL_FEATURE_I2C_HAS_SMBUS
HW_I2C_SMB_WR(baseAddr, 0u);
HW_I2C_A2_WR(baseAddr, 0xc2u);
HW_I2C_SLTH_WR(baseAddr, 0u);
HW_I2C_SLTL_WR(baseAddr, 0u);
#endif /* FSL_FEATURE_I2C_HAS_SMBUS*/
}
/*FUNCTION**********************************************************************
*
* Function Name : I2C_HAL_SetBaudRate
* Description : Sets the I2C bus frequency for master transactions.
*
*END**************************************************************************/
i2c_status_t I2C_HAL_SetBaudRate(uint32_t baseAddr, uint32_t sourceClockInHz, uint32_t kbps,
uint32_t * absoluteError_Hz)
{
uint32_t mult, i, multiplier;
uint32_t hz = kbps * 1000u;
uint32_t bestError = 0xffffffffu;
uint32_t bestMult = 0u;
uint32_t bestIcr = 0u;
/* Check if the requested frequency is greater than the max supported baud.*/
if ((kbps * 1000U) > (sourceClockInHz / (1U * 20U)))
{
return kStatus_I2C_OutOfRange;
}
/* Search for the settings with the lowest error.
* mult is the MULT field of the I2C_F register, and ranges from 0-2. It selects the
* multiplier factor for the divider. */
for (mult = 0u; (mult <= 2u) && (bestError != 0); ++mult)
{
multiplier = 1u << mult;
/* Scan table to find best match.*/
for (i = 0u; i < ARRAY_SIZE(kI2CDividerTable); ++i)
{
uint32_t computedRate = sourceClockInHz / (multiplier * kI2CDividerTable[i].sclDivider);
uint32_t absError = hz > computedRate ? hz - computedRate : computedRate - hz;
if (absError < bestError)
{
bestMult = mult;
bestIcr = kI2CDividerTable[i].icr;
bestError = absError;
/* If the error is 0, then we can stop searching
* because we won't find a better match.*/
if (absError == 0)
{
break;
}
}
}
}
/* Set the resulting error.*/
if (absoluteError_Hz)
{
*absoluteError_Hz = bestError;
}
/* Set frequency register based on best settings.*/
HW_I2C_F_WR(baseAddr, BF_I2C_F_MULT(bestMult) | BF_I2C_F_ICR(bestIcr));
return kStatus_I2C_Success;
}
/*FUNCTION**********************************************************************
*
* Function Name : I2C_HAL_SendStart
* Description : Send a START or Repeated START signal on the I2C bus.
* This function is used to initiate a new master mode transfer by sending the
* START signal. It is also used to send a Repeated START signal when a transfer
* is already in progress.
*
*END**************************************************************************/
void I2C_HAL_SendStart(uint32_t baseAddr)
{
/* Check if we're in a master mode transfer.*/
if (BR_I2C_C1_MST(baseAddr))
{
#if FSL_FEATURE_I2C_HAS_ERRATA_6070
/* Errata 6070: Repeat start cannot be generated if the I2Cx_F[MULT] field is set to a
* non- zero value.
* The workaround is to either always keep MULT set to 0, or to temporarily set it to
* 0 while performing the repeated start and then restore it.*/
uint32_t savedMult = 0;
if (BR_I2C_F_MULT(baseAddr) != 0)
{
savedMult = BR_I2C_F_MULT(baseAddr);
BW_I2C_F_MULT(baseAddr, 0U);
}
#endif /* FSL_FEATURE_I2C_HAS_ERRATA_6070*/
/* We are already in a transfer, so send a repeated start.*/
BW_I2C_C1_RSTA(baseAddr, 1U);
#if FSL_FEATURE_I2C_HAS_ERRATA_6070
if (savedMult)
{
BW_I2C_F_MULT(baseAddr, savedMult);
}
#endif /* FSL_FEATURE_I2C_HAS_ERRATA_6070*/
}
else
{
/* Initiate a transfer by sending the start signal.*/
HW_I2C_C1_SET(baseAddr, BM_I2C_C1_MST | BM_I2C_C1_TX);
}
}
/*FUNCTION**********************************************************************
*
* Function Name : I2C_HAL_SetAddress7bit
* Description : Sets the primary 7-bit slave address.
*
*END**************************************************************************/
void I2C_HAL_SetAddress7bit(uint32_t baseAddr, uint8_t address)
{
/* Set 7-bit slave address.*/
HW_I2C_A1_WR(baseAddr, address << 1U);
/* Disable the address extension option, selecting 7-bit mode.*/
BW_I2C_C2_ADEXT(baseAddr, 0U);
}
/*FUNCTION**********************************************************************
*
* Function Name : I2C_HAL_SetAddress10bit
* Description : Sets the primary slave address and enables 10-bit address mode.
*
*END**************************************************************************/
void I2C_HAL_SetAddress10bit(uint32_t baseAddr, uint16_t address)
{
uint8_t temp;
/* Set bottom 7 bits of slave address.*/
temp = address & 0x7FU;
HW_I2C_A1_WR(baseAddr, temp << 1U);
/* Enable 10-bit address extension.*/
BW_I2C_C2_ADEXT(baseAddr, 1U);
/* Set top 3 bits of slave address.*/
BW_I2C_C2_AD(baseAddr, (address & 0x0380U) >> 7U);
}
/*******************************************************************************
* EOF
******************************************************************************/
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