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Diff: targets/TARGET_Maxim/TARGET_MAX32625/i2c_api.c
- Revision:
- 150:02e0a0aed4ec
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/TARGET_Maxim/TARGET_MAX32625/i2c_api.c Tue Nov 08 17:45:16 2016 +0000 @@ -0,0 +1,214 @@ +/******************************************************************************* + * 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 "i2cm_regs.h" +#include "i2cm.h" +#include "pinmap.h" +#include "PeripheralPins.h" + +#ifndef MXC_I2CM_RX_TIMEOUT +#define MXC_I2CM_RX_TIMEOUT 0x5000 +#endif + +#define MBED_NAK 0 +#define MBED_ACK 1 +#define MBED_TIMEOUT 2 + +//****************************************************************************** +void i2c_init(i2c_t *obj, PinName sda, PinName scl) +{ + // SDA and SCL must map to same peripheral instance + 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->fifo = MXC_I2CM_GET_FIFO(MXC_I2CM_GET_IDX(i2c)); + obj->start_pending = 0; + + // Merge pin function requests for use with CMSIS init func + ioman_req_t io_req; + pin_function_t *pin_func; + pin_func = (pin_function_t *)pinmap_find_function(sda, PinMap_I2C_SDA); + io_req.value = pin_func->req_val; + pin_func = (pin_function_t *)pinmap_find_function(scl, PinMap_I2C_SCL); + io_req.value |= pin_func->req_val; + + sys_cfg_i2cm_t sys_cfg; + sys_cfg.io_cfg.req_reg = pin_func->reg_req; + sys_cfg.io_cfg.ack_reg = pin_func->reg_ack; + sys_cfg.io_cfg.req_val = io_req; + sys_cfg.clk_scale = CLKMAN_SCALE_DIV_1; + + I2CM_Init(obj->i2c, &sys_cfg, I2CM_SPEED_400KHZ); +} + +//****************************************************************************** +void i2c_frequency(i2c_t *obj, int hz) +{ + I2CM_SetFrequency(obj->i2c, hz); +} + +//****************************************************************************** +int i2c_start(i2c_t *obj) +{ + obj->start_pending = 1; + return 0; +} + +//****************************************************************************** +int i2c_stop(i2c_t *obj) +{ + obj->start_pending = 0; + I2CM_WriteTxFifo(obj->i2c, obj->fifo, MXC_S_I2CM_TRANS_TAG_STOP); + I2CM_TxInProgress(obj->i2c); + return 0; +} + +//****************************************************************************** +int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) +{ + MBED_ASSERT(stop != 0); + return I2CM_Read(obj->i2c, address >> 1, NULL, 0, (uint8_t *)data, length); +} + +//****************************************************************************** +int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop) +{ + mxc_i2cm_regs_t *i2cm = obj->i2c; + mxc_i2cm_fifo_regs_t *fifo = obj->fifo; + + if (stop) { + return I2CM_Write(i2cm, address >> 1, NULL, 0, (uint8_t *)data, length); + } + + i2cm->inten = 0; + i2cm->intfl = i2cm->intfl; + if (I2CM_Tx(i2cm, fifo, address >> 1, (uint8_t *)data, length, 0) == E_NO_ERROR) { + return length; + } else { + return -1; + } +} + +//****************************************************************************** +void i2c_reset(i2c_t *obj) +{ + I2CM_Recover(obj->i2c); +} + +//****************************************************************************** +int i2c_byte_read(i2c_t *obj, int last) +{ + mxc_i2cm_regs_t *i2cm = obj->i2c; + mxc_i2cm_fifo_regs_t *fifo = obj->fifo; + int tmp; + + // Start the transaction if it is not currently ongoing + if (!(i2cm->trans & MXC_F_I2CM_TRANS_TX_IN_PROGRESS)) { + i2cm->trans |= MXC_F_I2CM_TRANS_TX_START; + } + + if (last) { + // NACK the last read byte + if (I2CM_WriteTxFifo(i2cm, fifo, MXC_S_I2CM_TRANS_TAG_RXDATA_NACK) != E_NO_ERROR) { + goto byte_write_err; + } + + // Send the stop condition + if (I2CM_WriteTxFifo(i2cm, fifo, MXC_S_I2CM_TRANS_TAG_STOP) != E_NO_ERROR) { + goto byte_write_err; + } + } else { + if (I2CM_WriteTxFifo(i2cm, fifo, MXC_S_I2CM_TRANS_TAG_RXDATA_COUNT) != E_NO_ERROR) { + goto byte_write_err; + } + } + + do { + // Wait for data in RX FIFO + int timeout = MXC_I2CM_RX_TIMEOUT; + while (!(i2cm->intfl & MXC_F_I2CM_INTFL_RX_FIFO_NOT_EMPTY) && + ((i2cm->bb & MXC_F_I2CM_BB_RX_FIFO_CNT) == 0)) { + + if((timeout-- < 0) || (i2cm->trans & MXC_F_I2CM_TRANS_TX_TIMEOUT)) { + goto byte_write_err; + } + + if (i2cm->trans & (MXC_F_I2CM_TRANS_TX_LOST_ARBITR | MXC_F_I2CM_TRANS_TX_NACKED)) { + goto byte_write_err; + } + } + i2cm->intfl = MXC_F_I2CM_INTFL_RX_FIFO_NOT_EMPTY; + + } while ((tmp = fifo->rx) & MXC_S_I2CM_RSTLS_TAG_EMPTY); + + return (uint8_t)tmp; + +byte_write_err: + i2c_reset(obj); + return -1; +} + +//****************************************************************************** +int i2c_byte_write(i2c_t *obj, int data) +{ + mxc_i2cm_regs_t *i2cm = obj->i2c; + mxc_i2cm_fifo_regs_t *fifo = obj->fifo; + int result; + + if (obj->start_pending) { + obj->start_pending = 0; + data |= MXC_S_I2CM_TRANS_TAG_START; + } else { + data |= MXC_S_I2CM_TRANS_TAG_TXDATA_ACK; + } + + if ((result = I2CM_WriteTxFifo(i2cm, fifo, data)) != E_NO_ERROR) { + i2c_reset(obj); + if (result == E_COMM_ERR) { + return MBED_NAK; + } + return MBED_TIMEOUT; + } + + // Start the transaction if it is not currently ongoing + if (!(i2cm->trans & MXC_F_I2CM_TRANS_TX_IN_PROGRESS)) { + i2cm->trans |= MXC_F_I2CM_TRANS_TX_START; + } + + return MBED_ACK; +}