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;
+}