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mbed-os/targets/TARGET_Maxim/TARGET_MAX32620/i2c_api.c

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/*******************************************************************************
* 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.
*******************************************************************************
*/
#include "mbed_assert.h"
#include "i2c_api.h"
#include "cmsis.h"
#include "i2cm_regs.h"
#include "clkman_regs.h"
#include "ioman_regs.h"
#include "PeripheralPins.h"
#define I2C_SLAVE_ADDR_READ_BIT 0x0001
#ifndef MXC_I2CM_TX_TIMEOUT
#define MXC_I2CM_TX_TIMEOUT 0x5000
#endif
#ifndef MXC_I2CM_RX_TIMEOUT
#define MXC_I2CM_RX_TIMEOUT 0x5000
#endif
typedef enum {
/** 100KHz */
MXC_E_I2CM_SPEED_100KHZ = 0,
/** 400KHz */
MXC_E_I2CM_SPEED_400KHZ
} i2cm_speed_t;
/* Clock divider lookup table */
static const uint32_t clk_div_table[2][8] = {
/* MXC_E_I2CM_SPEED_100KHZ */
{
/* 0: 12MHz */ ((6 << MXC_F_I2CM_FS_CLK_DIV_FS_FILTER_CLK_DIV_POS) |
(17 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_HI_CNT_POS) |
(72 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_LO_CNT_POS)),
/* 1: 24MHz */ ((12 << MXC_F_I2CM_FS_CLK_DIV_FS_FILTER_CLK_DIV_POS) |
(38 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_HI_CNT_POS) |
(144 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_LO_CNT_POS)),
/* 2: */ 0, /* not supported */
/* 3: 48MHz */ ((24 << MXC_F_I2CM_FS_CLK_DIV_FS_FILTER_CLK_DIV_POS) |
(80 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_HI_CNT_POS) |
(288 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_LO_CNT_POS)),
/* 4: */ 0, /* not supported */
/* 5: */ 0, /* not supported */
/* 6: */ 0, /* not supported */
/* 7: 96MHz */ ((48 << MXC_F_I2CM_FS_CLK_DIV_FS_FILTER_CLK_DIV_POS) |
(164 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_HI_CNT_POS) |
(576 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_LO_CNT_POS)),
},
/* MXC_E_I2CM_SPEED_400KHZ */
{
/* 0: 12MHz */ ((2 << MXC_F_I2CM_FS_CLK_DIV_FS_FILTER_CLK_DIV_POS) |
(1 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_HI_CNT_POS) |
(18 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_LO_CNT_POS)),
/* 1: 24MHz */ ((3 << MXC_F_I2CM_FS_CLK_DIV_FS_FILTER_CLK_DIV_POS) |
(5 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_HI_CNT_POS) |
(36 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_LO_CNT_POS)),
/* 2: */ 0, /* not supported */
/* 3: 48MHz */ ((6 << MXC_F_I2CM_FS_CLK_DIV_FS_FILTER_CLK_DIV_POS) |
(15 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_HI_CNT_POS) |
(72 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_LO_CNT_POS)),
/* 4: */ 0, /* not supported */
/* 5: */ 0, /* not supported */
/* 6: */ 0, /* not supported */
/* 7: 96MHz */ ((12 << MXC_F_I2CM_FS_CLK_DIV_FS_FILTER_CLK_DIV_POS) |
(33 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_HI_CNT_POS) |
(144 << MXC_F_I2CM_FS_CLK_DIV_FS_SCL_LO_CNT_POS)),
},
};
void i2c_init(i2c_t *obj, PinName sda, PinName scl)
{
// determine the I2C to use
I2CName i2c_sda = (I2CName)pinmap_peripheral(sda, PinMap_I2C_SDA);
I2CName i2c_scl = (I2CName)pinmap_peripheral(scl, PinMap_I2C_SCL);
mxc_i2cm_regs_t *i2c = (mxc_i2cm_regs_t*)pinmap_merge(i2c_sda, i2c_scl);
MBED_ASSERT((int)i2c != NC);
obj->i2c = i2c;
obj->fifos = (mxc_i2cm_fifo_regs_t*)MXC_I2CM_GET_BASE_FIFO(MXC_I2CM_GET_IDX(i2c));
obj->start_pending = 0;
obj->stop_pending = 0;
// configure the pins
pinmap_pinout(sda, PinMap_I2C_SDA);
pinmap_pinout(scl, PinMap_I2C_SCL);
// enable the clock
MXC_CLKMAN->sys_clk_ctrl_9_i2cm = MXC_S_CLKMAN_CLK_SCALE_DIV_1;
// reset module
i2c->ctrl = MXC_F_I2CM_CTRL_MSTR_RESET_EN;
i2c->ctrl = 0;
// set default frequency at 100k
i2c_frequency(obj, 100000);
// set timeout to 255 ms and turn on the auto-stop option
i2c->timeout = (0xFF << MXC_F_I2CM_TIMEOUT_TX_TIMEOUT_POS) | MXC_F_I2CM_TIMEOUT_AUTO_STOP_EN;
// enable tx_fifo and rx_fifo
i2c->ctrl |= (MXC_F_I2CM_CTRL_TX_FIFO_EN | MXC_F_I2CM_CTRL_RX_FIFO_EN);
}
void i2c_frequency(i2c_t *obj, int hz)
{
// compute clock array index
// (96Mhz/12M) -1 = 7
// (48Mhz/12M) -1 = 3
// (24Mhz/12M) -1 = 1
// (12Mhz/12M) -1 = 0
int clki = (SystemCoreClock / 12000000) - 1;
// get clock divider settings from lookup table
if ((hz < 400000) && (clk_div_table[MXC_E_I2CM_SPEED_100KHZ][clki] > 0)) {
obj->i2c->fs_clk_div = clk_div_table[MXC_E_I2CM_SPEED_100KHZ][clki];
} else if ((hz >= 400000) && (clk_div_table[MXC_E_I2CM_SPEED_400KHZ][clki] > 0)) {
obj->i2c->fs_clk_div = clk_div_table[MXC_E_I2CM_SPEED_400KHZ][clki];
}
}
static int write_tx_fifo(i2c_t *obj, const uint16_t data)
{
int timeout = MXC_I2CM_TX_TIMEOUT;
while (*obj->fifos->trans) {
uint32_t intfl = obj->i2c->intfl;
if (intfl & MXC_F_I2CM_INTFL_TX_NACKED) {
return I2C_ERROR_NO_SLAVE;
}
if (!timeout || (intfl & (MXC_F_I2CM_INTFL_TX_TIMEOUT | MXC_F_I2CM_INTFL_TX_LOST_ARBITR))) {
return I2C_ERROR_BUS_BUSY;
}
timeout--;
}
*obj->fifos->trans = data;
return 0;
}
static int wait_tx_in_progress(i2c_t *obj)
{
int timeout = MXC_I2CM_TX_TIMEOUT;
while ((obj->i2c->trans & MXC_F_I2CM_TRANS_TX_IN_PROGRESS) && --timeout);
uint32_t intfl = obj->i2c->intfl;
if (intfl & MXC_F_I2CM_INTFL_TX_NACKED) {
i2c_reset(obj);
return I2C_ERROR_NO_SLAVE;
}
if (!timeout || (intfl & (MXC_F_I2CM_INTFL_TX_TIMEOUT | MXC_F_I2CM_INTFL_TX_LOST_ARBITR))) {
i2c_reset(obj);
return I2C_ERROR_BUS_BUSY;
}
return 0;
}
int i2c_start(i2c_t *obj)
{
obj->start_pending = 1;
return 0;
}
int i2c_stop(i2c_t *obj)
{
obj->start_pending = 0;
write_tx_fifo(obj, MXC_S_I2CM_TRANS_TAG_STOP);
return wait_tx_in_progress(obj);
}
void i2c_reset(i2c_t *obj)
{
obj->i2c->ctrl = MXC_F_I2CM_CTRL_MSTR_RESET_EN;
obj->i2c->intfl = 0x3FF; // clear all interrupts
obj->i2c->ctrl = MXC_F_I2CM_CTRL_TX_FIFO_EN | MXC_F_I2CM_CTRL_RX_FIFO_EN;
obj->start_pending = 0;
}
int i2c_byte_write(i2c_t *obj, int data)
{
int err;
// clear all interrupts
obj->i2c->intfl = 0x3FF;
if (obj->start_pending) {
obj->start_pending = 0;
data = (data & 0xFF) | MXC_S_I2CM_TRANS_TAG_START;
} else {
data = (data & 0xFF) | MXC_S_I2CM_TRANS_TAG_TXDATA_ACK;
}
if ((err = write_tx_fifo(obj, data)) != 0) {
return err;
}
obj->i2c->trans |= MXC_F_I2CM_TRANS_TX_START;
// Wait for the FIFO to be empty
while (!(obj->i2c->intfl & MXC_F_I2CM_INTFL_TX_FIFO_EMPTY));
if (obj->i2c->intfl & MXC_F_I2CM_INTFL_TX_NACKED) {
i2c_reset(obj);
return 0;
}
if (obj->i2c->intfl & (MXC_F_I2CM_INTFL_TX_TIMEOUT | MXC_F_I2CM_INTFL_TX_LOST_ARBITR)) {
i2c_reset(obj);
return 2;
}
return 1;
}
int i2c_byte_read(i2c_t *obj, int last)
{
uint16_t fifo_value;
int err;
// clear all interrupts
obj->i2c->intfl = 0x3FF;
if (last) {
fifo_value = MXC_S_I2CM_TRANS_TAG_RXDATA_NACK;
} else {
fifo_value = MXC_S_I2CM_TRANS_TAG_RXDATA_COUNT;
}
if ((err = write_tx_fifo(obj, fifo_value)) != 0) {
i2c_reset(obj);
return err;
}
obj->i2c->trans |= MXC_F_I2CM_TRANS_TX_START;
int timeout = MXC_I2CM_RX_TIMEOUT;
while (!(obj->i2c->intfl & MXC_F_I2CM_INTFL_RX_FIFO_NOT_EMPTY) &&
(!(obj->i2c->bb & MXC_F_I2CM_BB_RX_FIFO_CNT))) {
if ((--timeout < 0) || (obj->i2c->trans & (MXC_F_I2CM_TRANS_TX_TIMEOUT |
MXC_F_I2CM_TRANS_TX_LOST_ARBITR | MXC_F_I2CM_TRANS_TX_NACKED))) {
break;
}
}
if (obj->i2c->intfl & MXC_F_I2CM_INTFL_RX_FIFO_NOT_EMPTY) {
obj->i2c->intfl = MXC_F_I2CM_INTFL_RX_FIFO_NOT_EMPTY;
return *obj->fifos->rslts;
}
i2c_reset(obj);
return -1;
}
int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop)
{
int err, retval = 0;
int i;
if (!(obj->stop_pending) && (obj->i2c->trans & MXC_F_I2CM_TRANS_TX_IN_PROGRESS)) {
return 0;
}
// clear all interrupts
obj->i2c->intfl = 0x3FF;
// write the address to the fifo
if ((err = write_tx_fifo(obj, (MXC_S_I2CM_TRANS_TAG_START | address))) != 0) { // start + addr (write)
i2c_reset(obj);
return err;
}
obj->start_pending = 0;
// start the transaction
obj->i2c->trans |= MXC_F_I2CM_TRANS_TX_START;
// load as much of the cmd into the FIFO as possible
for (i = 0; i < length; i++) {
if ((err = write_tx_fifo(obj, (MXC_S_I2CM_TRANS_TAG_TXDATA_ACK | data[i]))) != 0) { // cmd (expect ACK)
retval = (retval ? retval : err);
break;
}
}
if (stop) {
obj->stop_pending = 0;
if ((err = write_tx_fifo(obj, MXC_S_I2CM_TRANS_TAG_STOP)) != 0) { // stop condition
retval = (retval ? retval : err);
}
if ((err = wait_tx_in_progress(obj)) != 0) {
retval = (retval ? retval : err);
}
} else {
obj->stop_pending = 1;
int timeout = MXC_I2CM_TX_TIMEOUT;
// Wait for TX fifo to be empty
while (!(obj->i2c->intfl & MXC_F_I2CM_INTFL_TX_FIFO_EMPTY) && timeout--);
}
if (retval == 0) {
return length;
}
i2c_reset(obj);
return retval;
}
int i2c_read(i2c_t *obj, int address, char *data, int length, int stop)
{
int err, retval = 0;
int i = length;
int timeout;
if (!(obj->stop_pending) && (obj->i2c->trans & MXC_F_I2CM_TRANS_TX_IN_PROGRESS)) {
return 0;
}
// clear all interrupts
obj->i2c->intfl = 0x3FF;
// start + addr (read)
if ((retval = write_tx_fifo(obj, (MXC_S_I2CM_TRANS_TAG_START | address | I2C_SLAVE_ADDR_READ_BIT))) != 0) {
goto read_done;
}
obj->start_pending = 0;
while (i > 256) {
if ((retval = write_tx_fifo(obj, (MXC_S_I2CM_TRANS_TAG_RXDATA_COUNT | 255))) != 0) {
goto read_done;
}
i -= 256;
}
if (i > 1) {
if ((retval = write_tx_fifo(obj, (MXC_S_I2CM_TRANS_TAG_RXDATA_COUNT | (i - 2)))) != 0) {
goto read_done;
}
}
// start the transaction
obj->i2c->trans |= MXC_F_I2CM_TRANS_TX_START;
if ((retval = write_tx_fifo(obj, MXC_S_I2CM_TRANS_TAG_RXDATA_NACK)) != 0) { // NACK last data byte
goto read_done;
}
if (stop) {
if ((retval = write_tx_fifo(obj, MXC_S_I2CM_TRANS_TAG_STOP)) != 0) { // stop condition
goto read_done;
}
}
timeout = MXC_I2CM_RX_TIMEOUT;
i = 0;
while (i < length) {
while (!(obj->i2c->intfl & MXC_F_I2CM_INTFL_RX_FIFO_NOT_EMPTY) &&
(!(obj->i2c->bb & MXC_F_I2CM_BB_RX_FIFO_CNT))) {
if ((--timeout < 0) || (obj->i2c->trans & (MXC_F_I2CM_TRANS_TX_TIMEOUT |
MXC_F_I2CM_TRANS_TX_LOST_ARBITR | MXC_F_I2CM_TRANS_TX_NACKED))) {
retval = -3;
goto read_done;
}
}
timeout = MXC_I2CM_RX_TIMEOUT;
obj->i2c->intfl = MXC_F_I2CM_INTFL_RX_FIFO_NOT_EMPTY;
uint16_t temp = *obj->fifos->rslts;
if (temp & MXC_S_I2CM_RSTLS_TAG_EMPTY) {
continue;
}
data[i++] = (uint8_t) temp;
}
read_done:
if (stop) {
obj->stop_pending = 0;
if ((err = wait_tx_in_progress(obj)) != 0) {
retval = (retval ? retval : err);
}
} else {
obj->stop_pending = 1;
}
if (retval == 0) {
return length;
}
i2c_reset(obj);
return retval;
}
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