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targets/TARGET_Maxim/TARGET_MAX32625/i2c_api.c
- Committer:
- amithy
- Date:
- 2017-11-09
- Revision:
- 178:c26431f84b0d
- Parent:
- 150:02e0a0aed4ec
File content as of revision 178:c26431f84b0d:
/******************************************************************************* * 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; }