mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by mbed official

Revision:
153:9398a535854b
Parent:
152:9a67f0b066fc
diff -r 9a67f0b066fc -r 9398a535854b targets/TARGET_NUVOTON/TARGET_M451/i2c_api.c
--- a/targets/TARGET_NUVOTON/TARGET_M451/i2c_api.c	Thu Dec 15 11:48:27 2016 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1017 +0,0 @@
-/* mbed Microcontroller Library
- * Copyright (c) 2015-2016 Nuvoton
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- 
-#include "i2c_api.h"
-
-#if DEVICE_I2C
-
-#include "cmsis.h"
-#include "pinmap.h"
-#include "PeripheralPins.h"
-#include "nu_modutil.h"
-#include "nu_miscutil.h"
-#include "nu_bitutil.h"
-#include "critical.h"
-
-#define NU_I2C_DEBUG    0
-
-#if NU_I2C_DEBUG
-struct i2c_s MY_I2C;
-struct i2c_s MY_I2C_2;
-char MY_I2C_STATUS[64];
-int MY_I2C_STATUS_POS = 0;
-uint32_t MY_I2C_TIMEOUT;
-uint32_t MY_I2C_ELAPSED;
-uint32_t MY_I2C_T1;
-uint32_t MY_I2C_T2;
-#endif
-
-struct nu_i2c_var {
-    i2c_t *     obj;
-    void        (*vec)(void);
-};
-
-static void i2c0_vec(void);
-static void i2c1_vec(void);
-static void i2c_irq(i2c_t *obj);
-static void i2c_fsm_reset(i2c_t *obj, uint32_t i2c_ctl);
-
-static struct nu_i2c_var i2c0_var = {
-    .obj                =   NULL,
-    .vec                =   i2c0_vec,
-};
-static struct nu_i2c_var i2c1_var = {
-    .obj                =   NULL,
-    .vec                =   i2c1_vec,
-};
-
-static uint32_t i2c_modinit_mask = 0;
-
-static const struct nu_modinit_s i2c_modinit_tab[] = {
-    {I2C_0, I2C0_MODULE, 0, 0, I2C0_RST, I2C0_IRQn, &i2c0_var},
-    {I2C_1, I2C1_MODULE, 0, 0, I2C1_RST, I2C1_IRQn, &i2c1_var},
-    
-    {NC, 0, 0, 0, 0, (IRQn_Type) 0, NULL}
-};
-
-static int i2c_do_tran(i2c_t *obj, char *buf, int length, int read, int naklastdata);
-static int i2c_do_write(i2c_t *obj, char data, int naklastdata);
-static int i2c_do_read(i2c_t *obj, char *data, int naklastdata);
-static int i2c_do_trsn(i2c_t *obj, uint32_t i2c_ctl, int sync);
-#define NU_I2C_TIMEOUT_STAT_INT     500000
-#define NU_I2C_TIMEOUT_STOP         500000
-static int i2c_poll_status_timeout(i2c_t *obj, int (*is_status)(i2c_t *obj), uint32_t timeout);
-static int i2c_poll_tran_heatbeat_timeout(i2c_t *obj, uint32_t timeout);
-//static int i2c_is_stat_int(i2c_t *obj);
-//static int i2c_is_stop_det(i2c_t *obj);
-static int i2c_is_trsn_done(i2c_t *obj);
-static int i2c_is_tran_started(i2c_t *obj);
-static int i2c_addr2data(int address, int read);
-#if DEVICE_I2CSLAVE
-// Convert mbed address to BSP address.
-static int i2c_addr2bspaddr(int address);
-#endif  // #if DEVICE_I2CSLAVE
-static void i2c_enable_int(i2c_t *obj);
-static void i2c_disable_int(i2c_t *obj);
-static int i2c_set_int(i2c_t *obj, int inten);
-
-
-#if DEVICE_I2C_ASYNCH
-static void i2c_buffer_set(i2c_t *obj, const void *tx, size_t tx_length, void *rx, size_t rx_length);
-static void i2c_enable_vector_interrupt(i2c_t *obj, uint32_t handler, int enable);
-static void i2c_rollback_vector_interrupt(i2c_t *obj);
-#endif
-
-#define TRANCTRL_STARTED        (1)
-#define TRANCTRL_NAKLASTDATA    (1 << 1)
-
-uint32_t us_ticker_read(void);
-
-void i2c_init(i2c_t *obj, PinName sda, PinName scl)
-{
-    uint32_t i2c_sda = pinmap_peripheral(sda, PinMap_I2C_SDA);
-    uint32_t i2c_scl = pinmap_peripheral(scl, PinMap_I2C_SCL);
-    obj->i2c.i2c = (I2CName) pinmap_merge(i2c_sda, i2c_scl);
-    MBED_ASSERT((int)obj->i2c.i2c != NC);
-    
-    const struct nu_modinit_s *modinit = get_modinit(obj->i2c.i2c, i2c_modinit_tab);
-    MBED_ASSERT(modinit != NULL);
-    MBED_ASSERT(modinit->modname == obj->i2c.i2c);
-    
-    // Reset this module
-    SYS_ResetModule(modinit->rsetidx);
-    
-    // Enable IP clock
-    CLK_EnableModuleClock(modinit->clkidx);
-
-    pinmap_pinout(sda, PinMap_I2C_SDA);
-    pinmap_pinout(scl, PinMap_I2C_SCL);
-    
-#if DEVICE_I2C_ASYNCH
-    obj->i2c.dma_usage = DMA_USAGE_NEVER;
-    obj->i2c.event = 0;
-    obj->i2c.stop = 0;
-    obj->i2c.address = 0;
-#endif
-
-    // NOTE: Setting I2C bus clock to 100 KHz is required. See I2C::I2C in common/I2C.cpp.
-    I2C_Open((I2C_T *) NU_MODBASE(obj->i2c.i2c), 100000);
-    // NOTE: INTEN bit and FSM control bits (STA, STO, SI, AA) are packed in one register CTL. We cannot control interrupt through 
-    //       INTEN bit without impacting FSM control bits. Use NVIC_EnableIRQ/NVIC_DisableIRQ instead for interrupt control.
-    I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-    i2c_base->CTL |= (I2C_CTL_INTEN_Msk | I2C_CTL_I2CEN_Msk);
-
-    // Enable sync-moce vector interrupt.
-    struct nu_i2c_var *var = (struct nu_i2c_var *) modinit->var;
-    var->obj = obj;
-    obj->i2c.tran_ctrl = 0;
-    obj->i2c.stop = 0;
-    i2c_enable_vector_interrupt(obj, (uint32_t) var->vec, 1);
-    
-    // Mark this module to be inited.
-    int i = modinit - i2c_modinit_tab;
-    i2c_modinit_mask |= 1 << i;
-}
-
-int i2c_start(i2c_t *obj)
-{
-    return i2c_do_trsn(obj, I2C_CTL_STA_Msk | I2C_CTL_SI_Msk, 1);
-}
-
-int i2c_stop(i2c_t *obj)
-{
-    return i2c_do_trsn(obj, I2C_CTL_STO_Msk | I2C_CTL_SI_Msk, 1);
-}
-
-void i2c_frequency(i2c_t *obj, int hz)
-{
-    I2C_SetBusClockFreq((I2C_T *) NU_MODBASE(obj->i2c.i2c), hz);
-}
-
-int i2c_read(i2c_t *obj, int address, char *data, int length, int stop)
-{
-    if (i2c_start(obj)) {
-        i2c_stop(obj);
-        return I2C_ERROR_BUS_BUSY;
-    }
-
-    if (i2c_do_write(obj, i2c_addr2data(address, 1), 0)) {
-        i2c_stop(obj);
-        return I2C_ERROR_NO_SLAVE;
-    }
-
-    // Read in bytes
-    length = i2c_do_tran(obj, data, length, 1, 1);
-
-    // If not repeated start, send stop.
-    if (stop) {
-        i2c_stop(obj);
-    }
-
-    return length;
-}
-
-int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop)
-{
-    if (i2c_start(obj)) {
-        i2c_stop(obj);
-        return I2C_ERROR_BUS_BUSY;
-    }
-
-    if (i2c_do_write(obj, i2c_addr2data(address, 0), 0)) {
-        i2c_stop(obj);
-        return I2C_ERROR_NO_SLAVE;
-    }
-
-    // Write out bytes
-    length = i2c_do_tran(obj, (char *) data, length, 0, 1);
-
-    if (stop) {
-        i2c_stop(obj);
-    }
-
-    return length;
-}
-
-void i2c_reset(i2c_t *obj)
-{
-    i2c_stop(obj);
-}
-
-int i2c_byte_read(i2c_t *obj, int last)
-{
-    char data = 0;
-    
-    i2c_do_read(obj, &data, last);
-    return data;
-}
-
-int i2c_byte_write(i2c_t *obj, int data)
-{
-    return i2c_do_write(obj, (data & 0xFF), 0);
-}
-
-#if DEVICE_I2CSLAVE
-
-// See I2CSlave.h
-#define NoData         0    // the slave has not been addressed
-#define ReadAddressed  1    // the master has requested a read from this slave (slave = transmitter)
-#define WriteGeneral   2    // the master is writing to all slave
-#define WriteAddressed 3    // the master is writing to this slave (slave = receiver)
-
-void i2c_slave_mode(i2c_t *obj, int enable_slave)
-{
-    I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-    
-    i2c_disable_int(obj);
-
-    obj->i2c.slaveaddr_state = NoData;
-    
-    // Switch to not addressed mode
-    I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_SI_Msk | I2C_CTL_AA_Msk);
-    
-    i2c_enable_int(obj);
-}
-
-int i2c_slave_receive(i2c_t *obj)
-{
-    int slaveaddr_state;
-    
-    i2c_disable_int(obj);
-    slaveaddr_state = obj->i2c.slaveaddr_state;
-    i2c_enable_int(obj);
-    
-    return slaveaddr_state;
-}
-
-int i2c_slave_read(i2c_t *obj, char *data, int length)
-{
-    return i2c_do_tran(obj, data, length, 1, 1);
-}
-
-int i2c_slave_write(i2c_t *obj, const char *data, int length)
-{
-    return i2c_do_tran(obj, (char *) data, length, 0, 1);
-}
-
-void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask)
-{
-    I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-    
-    i2c_disable_int(obj);
-    
-    I2C_SetSlaveAddr(i2c_base, 0, i2c_addr2bspaddr(address), I2C_GCMODE_ENABLE);
-    
-    i2c_enable_int(obj);
-}
-
-static int i2c_addr2bspaddr(int address)
-{
-    return (address >> 1);
-}
-
-#endif // #if DEVICE_I2CSLAVE
-
-static void i2c_enable_int(i2c_t *obj)
-{
-    const struct nu_modinit_s *modinit = get_modinit(obj->i2c.i2c, i2c_modinit_tab);
-    
-    core_util_critical_section_enter();
-    
-    // Enable I2C interrupt
-    NVIC_EnableIRQ(modinit->irq_n);
-    obj->i2c.inten = 1;
-    
-    core_util_critical_section_exit();
-}
-
-static void i2c_disable_int(i2c_t *obj)
-{
-    const struct nu_modinit_s *modinit = get_modinit(obj->i2c.i2c, i2c_modinit_tab);
-    
-    core_util_critical_section_enter();
-    
-    // Disable I2C interrupt
-    NVIC_DisableIRQ(modinit->irq_n);
-    obj->i2c.inten = 0;
-    
-    core_util_critical_section_exit();
-}
-
-static int i2c_set_int(i2c_t *obj, int inten)
-{
-    int inten_back;
-    
-    core_util_critical_section_enter();
-    
-    inten_back = obj->i2c.inten;
-    
-    core_util_critical_section_exit();
-    
-    if (inten) {
-        i2c_enable_int(obj);
-    }
-    else {
-        i2c_disable_int(obj);
-    }
-    
-    return inten_back;
-}
-
-int i2c_allow_powerdown(void)
-{
-    uint32_t modinit_mask = i2c_modinit_mask;
-    while (modinit_mask) {
-        int i2c_idx = nu_ctz(modinit_mask);
-        const struct nu_modinit_s *modinit = i2c_modinit_tab + i2c_idx;
-        struct nu_i2c_var *var = (struct nu_i2c_var *) modinit->var;
-        if (var->obj) {
-            // Disallow entering power-down mode if I2C transfer is enabled.
-            if (i2c_active(var->obj)) {
-                return 0;
-            }
-        }
-        modinit_mask &= ~(1 << i2c_idx);
-    }
-    
-    return 1;
-}
-
-static int i2c_do_tran(i2c_t *obj, char *buf, int length, int read, int naklastdata)
-{
-    int tran_len = 0;
-    
-    i2c_disable_int(obj);
-    obj->i2c.tran_ctrl = naklastdata ? (TRANCTRL_STARTED | TRANCTRL_NAKLASTDATA) : TRANCTRL_STARTED;
-    obj->i2c.tran_beg = buf;
-    obj->i2c.tran_pos = buf;
-    obj->i2c.tran_end = buf + length;
-    i2c_enable_int(obj);
-    
-    if (i2c_poll_tran_heatbeat_timeout(obj, NU_I2C_TIMEOUT_STAT_INT)) {
-#if NU_I2C_DEBUG
-        MY_I2C_2 = obj->i2c;
-        while (1);
-#endif
-    }
-    else {
-        i2c_disable_int(obj);
-        obj->i2c.tran_ctrl = 0;
-        tran_len = obj->i2c.tran_pos - obj->i2c.tran_beg;
-        obj->i2c.tran_beg = NULL;
-        obj->i2c.tran_pos = NULL;
-        obj->i2c.tran_end = NULL;
-        i2c_enable_int(obj);
-    }
-    
-    return tran_len;
-}
-
-static int i2c_do_write(i2c_t *obj, char data, int naklastdata)
-{
-    char data_[1];
-    data_[0] = data;
-    return i2c_do_tran(obj, data_, 1, 0, naklastdata) == 1 ? 0 : I2C_ERROR_BUS_BUSY;
-}
-
-static int i2c_do_read(i2c_t *obj, char *data, int naklastdata)
-{
-    return i2c_do_tran(obj, data, 1, 1, naklastdata) == 1 ? 0 : I2C_ERROR_BUS_BUSY;
-}
-
-static int i2c_do_trsn(i2c_t *obj, uint32_t i2c_ctl, int sync)
-{
-    I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-    int err = 0;
-    
-    i2c_disable_int(obj);
-
-    if (i2c_poll_status_timeout(obj, i2c_is_trsn_done, NU_I2C_TIMEOUT_STAT_INT)) {
-        err = I2C_ERROR_BUS_BUSY;
-#if NU_I2C_DEBUG
-        MY_I2C_2 = obj->i2c;
-        while (1);
-#endif
-    }
-    else {
-#if 1
-        // NOTE: Avoid duplicate Start/Stop. Otherwise, we may meet strange error.
-        uint32_t status = I2C_GET_STATUS(i2c_base);
-        
-        switch (status) {
-        case 0x08:  // Start
-        case 0x10:  // Master Repeat Start
-            if (i2c_ctl & I2C_CTL_STA_Msk) {
-                return 0;
-            }
-            else {
-                break;
-            }
-        case 0xF8:  // Bus Released
-            if (i2c_ctl & (I2C_CTL_STA_Msk | I2C_CTL_STO_Msk) == I2C_CTL_STO_Msk) {
-                return 0;
-            }
-            else {
-                break;
-            }
-        }
-#endif        
-        I2C_SET_CONTROL_REG(i2c_base, i2c_ctl);
-        if (sync && i2c_poll_status_timeout(obj, i2c_is_trsn_done, NU_I2C_TIMEOUT_STAT_INT)) {
-            err = I2C_ERROR_BUS_BUSY;
-#if NU_I2C_DEBUG
-            MY_I2C_2 = obj->i2c;
-            while (1);
-#endif
-        }
-    }
-
-    i2c_enable_int(obj);
-    
-    return err;
-}
-
-static int i2c_poll_status_timeout(i2c_t *obj, int (*is_status)(i2c_t *obj), uint32_t timeout)
-{
-    uint32_t t1, t2, elapsed = 0;
-    int status_assert = 0;
-    
-    t1 = us_ticker_read();
-    while (1) {
-        status_assert = is_status(obj);
-        if (status_assert) {
-            break;
-        }
-        
-        t2 = us_ticker_read();
-        elapsed = (t2 > t1) ? (t2 - t1) : ((uint64_t) t2 + 0xFFFFFFFF - t1 + 1);
-        if (elapsed >= timeout) {
-#if NU_I2C_DEBUG
-            MY_I2C_T1 = t1;
-            MY_I2C_T2 = t2;
-            MY_I2C_ELAPSED = elapsed;
-            MY_I2C_TIMEOUT = timeout;
-            MY_I2C_2 = obj->i2c;
-            while (1);
-#endif
-            break;
-        }
-    }
-    
-    return (elapsed >= timeout);
-}
-
-static int i2c_poll_tran_heatbeat_timeout(i2c_t *obj, uint32_t timeout)
-{
-    uint32_t t1, t2, elapsed = 0;
-    int tran_started;
-    char *tran_pos = NULL;
-    char *tran_pos2 = NULL;
-    
-    i2c_disable_int(obj);
-    tran_pos = obj->i2c.tran_pos;
-    i2c_enable_int(obj);
-    t1 = us_ticker_read();
-    while (1) {
-        i2c_disable_int(obj);
-        tran_started = i2c_is_tran_started(obj);
-        i2c_enable_int(obj);
-        if (! tran_started) {    // Transfer completed or stopped
-            break;
-        }
-        
-        i2c_disable_int(obj);
-        tran_pos2 = obj->i2c.tran_pos;
-        i2c_enable_int(obj);
-        t2 = us_ticker_read();
-        if (tran_pos2 != tran_pos) {    // Transfer on-going
-            t1 = t2;
-            tran_pos = tran_pos2;
-            continue;
-        }
-        
-        elapsed = (t2 > t1) ? (t2 - t1) : ((uint64_t) t2 + 0xFFFFFFFF - t1 + 1);
-        if (elapsed >= timeout) {   // Transfer idle
-#if NU_I2C_DEBUG
-            MY_I2C = obj->i2c;
-            MY_I2C_T1 = t1;
-            MY_I2C_T2 = t2;
-            MY_I2C_ELAPSED = elapsed;
-            MY_I2C_TIMEOUT = timeout;
-            MY_I2C_2 = obj->i2c;
-            while (1);
-#endif
-            break;
-        }
-    }
-    
-    return (elapsed >= timeout);
-}
-
-#if 0
-static int i2c_is_stat_int(i2c_t *obj)
-{
-    I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-
-    return !! (i2c_base->CTL & I2C_CTL_SI_Msk);
-}
-
-static int i2c_is_stop_det(i2c_t *obj)
-{
-    I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-
-    return ! (i2c_base->CTL & I2C_CTL_STO_Msk);
-}
-#endif
-
-static int i2c_is_trsn_done(i2c_t *obj)
-{
-    I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-    int i2c_int;
-    uint32_t status;
-    int inten_back;
-    
-    inten_back = i2c_set_int(obj, 0);
-    i2c_int = !! (i2c_base->CTL & I2C_CTL_SI_Msk);
-    status = I2C_GET_STATUS(i2c_base);
-    i2c_set_int(obj, inten_back);
-    
-    return (i2c_int || status == 0xF8);
-}
-
-static int i2c_is_tran_started(i2c_t *obj)
-{
-    int started;
-    int inten_back;
-    
-    inten_back = i2c_set_int(obj, 0);
-    started = !! (obj->i2c.tran_ctrl & TRANCTRL_STARTED);
-    i2c_set_int(obj, inten_back);
-    
-    return started;
-}
-
-static int i2c_addr2data(int address, int read)
-{
-    return read ? (address | 1) : (address & 0xFE);
-}
-
-static void i2c0_vec(void)
-{
-    i2c_irq(i2c0_var.obj);
-}
-static void i2c1_vec(void)
-{
-    i2c_irq(i2c1_var.obj);
-}
-
-static void i2c_irq(i2c_t *obj)
-{
-    I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-    uint32_t status;
-    
-    if (I2C_GET_TIMEOUT_FLAG(i2c_base)) {
-        I2C_ClearTimeoutFlag(i2c_base);
-        return;
-    }
-    
-    status = I2C_GET_STATUS(i2c_base);
-#if NU_I2C_DEBUG
-    if (MY_I2C_STATUS_POS < (sizeof (MY_I2C_STATUS) / sizeof (MY_I2C_STATUS[0]))) {
-        MY_I2C_STATUS[MY_I2C_STATUS_POS ++] = status;
-    }
-    else {
-        memset(MY_I2C_STATUS, 0x00, sizeof (MY_I2C_STATUS));
-        MY_I2C_STATUS_POS = 0;
-    }
-#endif
-    
-    switch (status) {
-        // Master Transmit
-        case 0x28:  // Master Transmit Data ACK
-        case 0x18:  // Master Transmit Address ACK
-        case 0x08:  // Start
-        case 0x10:  // Master Repeat Start
-            if ((obj->i2c.tran_ctrl & TRANCTRL_STARTED) && obj->i2c.tran_pos) {
-                if (obj->i2c.tran_pos < obj->i2c.tran_end) {
-                    I2C_SET_DATA(i2c_base, *obj->i2c.tran_pos ++);
-                    I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_SI_Msk | I2C_CTL_AA_Msk);
-                }
-                else {
-                    if (status == 0x18) {
-                        obj->i2c.tran_ctrl &= ~TRANCTRL_STARTED;
-                        i2c_disable_int(obj);
-                        break;
-                    }
-                    // Go Master Repeat Start
-                    i2c_fsm_reset(obj, I2C_CTL_STA_Msk | I2C_CTL_SI_Msk);
-                }
-            }
-            else {
-                i2c_disable_int(obj);
-            }
-            break;
-        case 0x30:  // Master Transmit Data NACK
-        case 0x20:  // Master Transmit Address NACK
-            // Go Master Repeat Start
-            i2c_fsm_reset(obj, I2C_CTL_STA_Msk | I2C_CTL_SI_Msk);
-            break;
-        case 0x38:  // Master Arbitration Lost
-            i2c_fsm_reset(obj, I2C_CTL_SI_Msk | I2C_CTL_AA_Msk);
-            break;
-        
-        case 0x48:  // Master Receive Address NACK
-            // Go Master Repeat Start
-            i2c_fsm_reset(obj, I2C_CTL_STA_Msk | I2C_CTL_SI_Msk);
-            break;
-        case 0x40:  // Master Receive Address ACK
-        case 0x50:  // Master Receive Data ACK
-        case 0x58:  // Master Receive Data NACK
-            if ((obj->i2c.tran_ctrl & TRANCTRL_STARTED) && obj->i2c.tran_pos) {
-                if (obj->i2c.tran_pos < obj->i2c.tran_end) {
-                    if (status == 0x50 || status == 0x58) {
-                        *obj->i2c.tran_pos ++ = I2C_GET_DATA(i2c_base);
-                    }
-                    
-                    if (status == 0x58) {
-#if NU_I2C_DEBUG
-                        if (obj->i2c.tran_pos != obj->i2c.tran_end) {
-                            MY_I2C = obj->i2c;
-                            while (1);
-                        }
-#endif
-                        // Go Master Repeat Start
-                        i2c_fsm_reset(obj, I2C_CTL_STA_Msk | I2C_CTL_SI_Msk);
-                    }
-                    else {
-                        uint32_t i2c_ctl = I2C_CTL_SI_Msk | I2C_CTL_AA_Msk;
-                        if ((obj->i2c.tran_end - obj->i2c.tran_pos) == 1 &&
-                            obj->i2c.tran_ctrl & TRANCTRL_NAKLASTDATA) {
-                            // Last data
-                            i2c_ctl &= ~I2C_CTL_AA_Msk;
-                        }
-                        I2C_SET_CONTROL_REG(i2c_base, i2c_ctl);
-                    }
-                }
-                else {
-                    obj->i2c.tran_ctrl &= ~TRANCTRL_STARTED;
-                    i2c_disable_int(obj);
-                    break;
-                }
-            }
-            else {
-                i2c_disable_int(obj);
-            }
-            break;
-            
-        //case 0x00:  // Bus error
-        
-        // Slave Transmit
-        case 0xB8:  // Slave Transmit Data ACK
-        case 0xA8:  // Slave Transmit Address ACK
-        case 0xB0:  // Slave Transmit Arbitration Lost
-            if ((obj->i2c.tran_ctrl & TRANCTRL_STARTED) && obj->i2c.tran_pos) {
-                if (obj->i2c.tran_pos < obj->i2c.tran_end) {
-                    uint32_t i2c_ctl = I2C_CTL_SI_Msk | I2C_CTL_AA_Msk;
-                    
-                    I2C_SET_DATA(i2c_base, *obj->i2c.tran_pos ++);
-                    if (obj->i2c.tran_pos == obj->i2c.tran_end &&
-                        obj->i2c.tran_ctrl & TRANCTRL_NAKLASTDATA) {
-                        // Last data
-                        i2c_ctl &= ~I2C_CTL_AA_Msk;
-                    }
-                    I2C_SET_CONTROL_REG(i2c_base, i2c_ctl);
-                }
-                else {
-                    obj->i2c.tran_ctrl &= ~TRANCTRL_STARTED;
-                    i2c_disable_int(obj);
-                    break;
-                }
-            }
-            else {
-                i2c_disable_int(obj);
-            }
-            obj->i2c.slaveaddr_state = ReadAddressed;
-            break;
-        //case 0xA0:  // Slave Transmit Repeat Start or Stop
-        case 0xC0:  // Slave Transmit Data NACK
-        case 0xC8:  // Slave Transmit Last Data ACK
-            obj->i2c.slaveaddr_state = NoData;
-            i2c_fsm_reset(obj, I2C_CTL_SI_Msk | I2C_CTL_AA_Msk);
-            break;
-        
-        // Slave Receive
-        case 0x80:  // Slave Receive Data ACK
-        case 0x88:  // Slave Receive Data NACK
-        case 0x60:  // Slave Receive Address ACK    
-        case 0x68:  // Slave Receive Arbitration Lost
-            obj->i2c.slaveaddr_state = WriteAddressed;
-            if ((obj->i2c.tran_ctrl & TRANCTRL_STARTED) && obj->i2c.tran_pos) {
-                if (obj->i2c.tran_pos < obj->i2c.tran_end) {
-                    if (status == 0x80 || status == 0x88) {
-                        *obj->i2c.tran_pos ++ = I2C_GET_DATA(i2c_base);
-                    }
-                    
-                    if (status == 0x88) {
-#if NU_I2C_DEBUG
-                        if (obj->i2c.tran_pos != obj->i2c.tran_end) {
-                            MY_I2C = obj->i2c;
-                            while (1);
-                        }
-#endif
-                        obj->i2c.slaveaddr_state = NoData;
-                        i2c_fsm_reset(obj, I2C_CTL_SI_Msk | I2C_CTL_AA_Msk);
-                    }
-                    else {
-                        uint32_t i2c_ctl = I2C_CTL_SI_Msk | I2C_CTL_AA_Msk;
-                        if ((obj->i2c.tran_end - obj->i2c.tran_pos) == 1 &&
-                            obj->i2c.tran_ctrl & TRANCTRL_NAKLASTDATA) {
-                            // Last data
-                            i2c_ctl &= ~I2C_CTL_AA_Msk;
-                        }
-                        I2C_SET_CONTROL_REG(i2c_base, i2c_ctl);
-                    }
-                }
-                else {
-                    obj->i2c.tran_ctrl &= ~TRANCTRL_STARTED;
-                    i2c_disable_int(obj);
-                    break;
-                }
-            }
-            else {
-                i2c_disable_int(obj);
-            }
-            break;
-        //case 0xA0:  // Slave Receive Repeat Start or Stop
-        
-        // GC mode
-        //case 0xA0:  // GC mode Repeat Start or Stop
-        case 0x90:  // GC mode Data ACK
-        case 0x98:  // GC mode Data NACK
-        case 0x70:  // GC mode Address ACK
-        case 0x78:  // GC mode Arbitration Lost
-            obj->i2c.slaveaddr_state = WriteAddressed;
-            if ((obj->i2c.tran_ctrl & TRANCTRL_STARTED) && obj->i2c.tran_pos) {
-                if (obj->i2c.tran_pos < obj->i2c.tran_end) {
-                    if (status == 0x90 || status == 0x98) {
-                        *obj->i2c.tran_pos ++ = I2C_GET_DATA(i2c_base);
-                    }
-                    
-                    if (status == 0x98) {
-#if NU_I2C_DEBUG
-                        if (obj->i2c.tran_pos != obj->i2c.tran_end) {
-                            MY_I2C = obj->i2c;
-                            while (1);
-                        }
-#endif
-                        obj->i2c.slaveaddr_state = NoData;
-                        i2c_fsm_reset(obj, I2C_CTL_SI_Msk | I2C_CTL_AA_Msk);
-                    }
-                    else {
-                        uint32_t i2c_ctl = I2C_CTL_SI_Msk | I2C_CTL_AA_Msk;
-                        if ((obj->i2c.tran_end - obj->i2c.tran_pos) == 1 &&
-                            obj->i2c.tran_ctrl & TRANCTRL_NAKLASTDATA) {
-                            // Last data
-                            i2c_ctl &= ~I2C_CTL_AA_Msk;
-                        }
-                        I2C_SET_CONTROL_REG(i2c_base, i2c_ctl);
-                    }
-                }
-                else {
-                    obj->i2c.tran_ctrl &= ~TRANCTRL_STARTED;
-                    i2c_disable_int(obj);
-                    break;
-                }
-            }
-            else {
-                i2c_disable_int(obj);
-            }
-            break;
-        
-        case 0xF8:  // Bus Released
-            break;
-            
-        default:
-            i2c_fsm_reset(obj, I2C_CTL_SI_Msk | I2C_CTL_AA_Msk);
-    }
-}
-
-static void i2c_fsm_reset(i2c_t *obj, uint32_t i2c_ctl)
-{
-    I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-
-    obj->i2c.stop = 0;
-    
-    obj->i2c.tran_ctrl = 0;
-            
-    I2C_SET_CONTROL_REG(i2c_base, i2c_ctl);
-    obj->i2c.slaveaddr_state = NoData;
-}
-
-#if DEVICE_I2C_ASYNCH
-
-void i2c_transfer_asynch(i2c_t *obj, const void *tx, size_t tx_length, void *rx, size_t rx_length, uint32_t address, uint32_t stop, uint32_t handler, uint32_t event, DMAUsage hint)
-{
-    // NOTE: M451 I2C only supports 7-bit slave address. The mbed I2C address passed in is shifted left by 1 bit (7-bit addr << 1).
-    MBED_ASSERT((address & 0xFFFFFF00) == 0);
-    
-    // NOTE: First transmit and then receive.
-    
-    (void) hint;
-    obj->i2c.dma_usage = DMA_USAGE_NEVER;
-    obj->i2c.stop = stop;
-    obj->i2c.address = address;
-    obj->i2c.event = event;
-    i2c_buffer_set(obj, tx, tx_length, rx, rx_length);
-
-    //I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-    
-    i2c_enable_vector_interrupt(obj, handler, 1);
-    i2c_start(obj);
-}
-
-uint32_t i2c_irq_handler_asynch(i2c_t *obj)
-{
-    int event = 0;
-
-    I2C_T *i2c_base = (I2C_T *) NU_MODBASE(obj->i2c.i2c);
-    uint32_t status = I2C_GET_STATUS(i2c_base);
-    switch (status) {
-        case 0x08:  // Start
-        case 0x10: {// Master Repeat Start
-            if (obj->tx_buff.buffer && obj->tx_buff.pos < obj->tx_buff.length) {
-                I2C_SET_DATA(i2c_base, (i2c_addr2data(obj->i2c.address, 0)));
-                I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_SI_Msk);
-            }
-            else if (obj->rx_buff.buffer && obj->rx_buff.pos < obj->rx_buff.length) {
-                I2C_SET_DATA(i2c_base, (i2c_addr2data(obj->i2c.address, 1)));
-                I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_SI_Msk);
-            }
-            else {
-                event = I2C_EVENT_TRANSFER_COMPLETE;
-                if (obj->i2c.stop) {
-                    I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_STO_Msk | I2C_CTL_SI_Msk);
-                }
-            }
-            break;
-        }
-        
-        case 0x18:  // Master Transmit Address ACK
-        case 0x28:  // Master Transmit Data ACK
-            if (obj->tx_buff.buffer && obj->tx_buff.pos < obj->tx_buff.length) {
-                uint8_t *tx = (uint8_t *)obj->tx_buff.buffer;
-                I2C_SET_DATA(i2c_base, tx[obj->tx_buff.pos ++]);
-                I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_SI_Msk);
-            }
-            else if (obj->rx_buff.buffer && obj->rx_buff.pos < obj->rx_buff.length) {
-                I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_STA_Msk | I2C_CTL_SI_Msk);
-            }
-            else {
-                event = I2C_EVENT_TRANSFER_COMPLETE;
-                if (obj->i2c.stop) {
-                    I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_STO_Msk | I2C_CTL_SI_Msk);
-                }
-            }
-            break;
-            
-        case 0x20:  // Master Transmit Address NACK
-            event = I2C_EVENT_ERROR_NO_SLAVE;
-            if (obj->i2c.stop) {
-                I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_STO_Msk | I2C_CTL_SI_Msk);
-            }
-            break;
-            
-        case 0x30:  // Master Transmit Data NACK
-            if (obj->tx_buff.buffer && obj->tx_buff.pos < obj->tx_buff.length) {
-                event = I2C_EVENT_TRANSFER_EARLY_NACK;
-                I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_STO_Msk | I2C_CTL_SI_Msk);
-            }
-            else if (obj->rx_buff.buffer && obj->rx_buff.pos < obj->rx_buff.length) {
-                I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_STA_Msk | I2C_CTL_SI_Msk);
-            }
-            else {
-                event = I2C_EVENT_TRANSFER_COMPLETE;
-                if (obj->i2c.stop) {
-                    I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_STO_Msk | I2C_CTL_SI_Msk);
-                }
-            }
-            break;
-                
-        case 0x38:  // Master Arbitration Lost
-            I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_SI_Msk);  // Enter not addressed SLV mode
-            event = I2C_EVENT_ERROR;
-            break;
-            
-        case 0x50:  // Master Receive Data ACK
-            if (obj->rx_buff.buffer && obj->rx_buff.pos < obj->rx_buff.length) {
-                uint8_t *rx = (uint8_t *) obj->rx_buff.buffer;
-                rx[obj->rx_buff.pos ++] = I2C_GET_DATA(((I2C_T *) NU_MODBASE(obj->i2c.i2c)));
-            }
-        case 0x40:  // Master Receive Address ACK
-            I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_SI_Msk | ((obj->rx_buff.pos != obj->rx_buff.length - 1) ? I2C_CTL_AA_Msk : 0));
-            break;
-            
-        case 0x48:  // Master Receive Address NACK    
-            event = I2C_EVENT_ERROR_NO_SLAVE;
-            if (obj->i2c.stop) {
-                I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_STO_Msk | I2C_CTL_SI_Msk);
-            }
-            break;
-            
-        case 0x58:  // Master Receive Data NACK
-            if (obj->rx_buff.buffer && obj->rx_buff.pos < obj->rx_buff.length) {
-                uint8_t *rx = (uint8_t *) obj->rx_buff.buffer;
-                rx[obj->rx_buff.pos ++] = I2C_GET_DATA(((I2C_T *) NU_MODBASE(obj->i2c.i2c)));
-            }
-            I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_STA_Msk | I2C_CTL_SI_Msk);
-            break;
-            
-        case 0x00:  // Bus error
-            event = I2C_EVENT_ERROR;
-            i2c_reset(obj);
-            break;
-            
-        default:
-            event = I2C_EVENT_ERROR;
-            if (obj->i2c.stop) {
-                I2C_SET_CONTROL_REG(i2c_base, I2C_CTL_STO_Msk | I2C_CTL_SI_Msk);
-            }
-    }
-    
-    if (event) {
-        i2c_rollback_vector_interrupt(obj);
-    }
-
-    return (event & obj->i2c.event);
-}
-
-uint8_t i2c_active(i2c_t *obj)
-{   
-    const struct nu_modinit_s *modinit = get_modinit(obj->i2c.i2c, i2c_modinit_tab);
-    MBED_ASSERT(modinit != NULL);
-    MBED_ASSERT(modinit->modname == obj->i2c.i2c);
-    
-    // Vector will be changed for async transfer. Use it to judge if async transfer is on-going.
-    uint32_t vec = NVIC_GetVector(modinit->irq_n);
-    struct nu_i2c_var *var = (struct nu_i2c_var *) modinit->var;
-    return (vec && vec != (uint32_t) var->vec);
-}
-
-void i2c_abort_asynch(i2c_t *obj)
-{
-    i2c_rollback_vector_interrupt(obj);
-    i2c_stop(obj);
-}
-
-static void i2c_buffer_set(i2c_t *obj, const void *tx, size_t tx_length, void *rx, size_t rx_length)
-{
-    obj->tx_buff.buffer = (void *) tx;
-    obj->tx_buff.length = tx_length;
-    obj->tx_buff.pos = 0;
-    obj->rx_buff.buffer = rx;
-    obj->rx_buff.length = rx_length;
-    obj->rx_buff.pos = 0;
-}
-
-static void i2c_enable_vector_interrupt(i2c_t *obj, uint32_t handler, int enable)
-{
-    const struct nu_modinit_s *modinit = get_modinit(obj->i2c.i2c, i2c_modinit_tab);
-    MBED_ASSERT(modinit != NULL);
-    MBED_ASSERT(modinit->modname == obj->i2c.i2c);
-    
-    if (enable) {
-        NVIC_SetVector(modinit->irq_n, handler);
-        i2c_enable_int(obj);
-    }
-    else {
-        i2c_disable_int(obj);
-    }
-
-}
-
-static void i2c_rollback_vector_interrupt(i2c_t *obj)
-{
-    const struct nu_modinit_s *modinit = get_modinit(obj->i2c.i2c, i2c_modinit_tab);
-    MBED_ASSERT(modinit != NULL);
-    MBED_ASSERT(modinit->modname == obj->i2c.i2c);
-    
-    struct nu_i2c_var *var = (struct nu_i2c_var *) modinit->var;
-    i2c_enable_vector_interrupt(obj, (uint32_t) var->vec, 1);
-}
-
-#endif
-
-#endif