Diff: targets/hal/TARGET_NXP/TARGET_LPC81X/i2c_api.c

Revision:

20:4263a77256ae

Parent:

19:398f4c622e1b

Child:

21:67d3158c7b56

--- a/targets/hal/TARGET_NXP/TARGET_LPC81X/i2c_api.c	Mon Aug 19 18:17:02 2013 +0300
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,242 +0,0 @@
-/* mbed Microcontroller Library
- * Copyright (c) 2006-2013 ARM Limited
- *
- * 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"
-#include "cmsis.h"
-#include "pinmap.h"
-#include "error.h"
-
-static const SWM_Map SWM_I2C_SDA[] = {
-    {7, 24},
-};
-
-static const SWM_Map SWM_I2C_SCL[] = {
-    {8, 0},
-};
-
-static uint8_t repeated_start = 0;
-
-#define I2C_DAT(x)          (x->i2c->MSTDAT)
-#define I2C_STAT(x)         ((x->i2c->STAT >> 1) & (0x07))
-
-static inline int i2c_status(i2c_t *obj) {
-    return I2C_STAT(obj);
-}
-
-// Wait until the Serial Interrupt (SI) is set
-static int i2c_wait_SI(i2c_t *obj) {
-    int timeout = 0;
-    while (!(obj->i2c->STAT & (1 << 0))) {
-        timeout++;
-        if (timeout > 100000) return -1;
-    }
-    return 0;
-}
-
-static inline void i2c_interface_enable(i2c_t *obj) {
-    obj->i2c->CFG |= (1 << 0);
-}
-
-static inline void i2c_power_enable(i2c_t *obj) {
-    LPC_SYSCON->SYSAHBCLKCTRL |= (1<<5);	
-    LPC_SYSCON->PRESETCTRL &= ~(0x1<<6);
-    LPC_SYSCON->PRESETCTRL |= (0x1<<6);
-}
-
-void i2c_init(i2c_t *obj, PinName sda, PinName scl) {
-    obj->i2c = (LPC_I2C_TypeDef *)LPC_I2C;
-    
-    const SWM_Map *swm;
-    uint32_t regVal;
-    
-    swm = &SWM_I2C_SDA[0];
-    regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
-    LPC_SWM->PINASSIGN[swm->n] = regVal |  (sda   << swm->offset);
-    
-    swm = &SWM_I2C_SCL[0];
-    regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
-    LPC_SWM->PINASSIGN[swm->n] = regVal |  (scl   << swm->offset);
-    
-    // enable power
-    i2c_power_enable(obj);
-    // set default frequency at 100k
-    i2c_frequency(obj, 100000);
-    i2c_interface_enable(obj);
-}
-
-inline int i2c_start(i2c_t *obj) {
-    int status = 0;
-    if (repeated_start) {
-        obj->i2c->MSTCTL = (1 << 1) | (1 << 0);
-        repeated_start = 0;
-    } else {
-        obj->i2c->MSTCTL = (1 << 1);
-    }
-    return status;
-}
-
-inline int i2c_stop(i2c_t *obj) {
-    int timeout = 0;
-
-    obj->i2c->MSTCTL = (1 << 2) | (1 << 0);
-    while ((obj->i2c->STAT & ((1 << 0) | (7 << 1))) != ((1 << 0) | (0 << 1))) {
-        timeout ++;
-        if (timeout > 100000) return 1;
-    }
-
-    return 0;
-}
-
-
-static inline int i2c_do_write(i2c_t *obj, int value, uint8_t addr) {
-    // write the data
-    I2C_DAT(obj) = value;
-    
-    if (!addr)
-        obj->i2c->MSTCTL = (1 << 0);
-    
-    // wait and return status
-    i2c_wait_SI(obj);
-    return i2c_status(obj);
-}
-
-static inline int i2c_do_read(i2c_t *obj, int last) {
-    // wait for it to arrive
-    i2c_wait_SI(obj);
-    if (!last)
-        obj->i2c->MSTCTL = (1 << 0);
-    
-    // return the data
-    return (I2C_DAT(obj) & 0xFF);
-}
-
-void i2c_frequency(i2c_t *obj, int hz) {
-    // No peripheral clock divider on the M0
-    uint32_t PCLK = SystemCoreClock;
-    
-    uint32_t clkdiv = PCLK / (hz * 4) - 1;
-    
-    obj->i2c->DIV = clkdiv;
-    obj->i2c->MSTTIME = 0;
-}
-
-// The I2C does a read or a write as a whole operation
-// There are two types of error conditions it can encounter
-//  1) it can not obtain the bus
-//  2) it gets error responses at part of the transmission
-//
-// We tackle them as follows:
-//  1) we retry until we get the bus. we could have a "timeout" if we can not get it
-//      which basically turns it in to a 2)
-//  2) on error, we use the standard error mechanisms to report/debug
-//
-// Therefore an I2C transaction should always complete. If it doesn't it is usually
-// because something is setup wrong (e.g. wiring), and we don't need to programatically
-// check for that
-
-int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) {
-    int count, status;
-    
-    i2c_start(obj);
-    
-    status = i2c_do_write(obj, (address | 0x01), 1);
-    if (status != 0x01) {
-        i2c_stop(obj);
-        return I2C_ERROR_NO_SLAVE;
-    }
-    
-    // Read in all except last byte
-    for (count = 0; count < (length - 1); count++) {
-        int value = i2c_do_read(obj, 0);
-        status = i2c_status(obj);
-        if (status != 0x00) {
-            i2c_stop(obj);
-            return count;
-        }
-        data[count] = (char) value;
-    }
-    
-    // read in last byte
-    int value = i2c_do_read(obj, 1);
-    status = i2c_status(obj);
-    if (status != 0x01) {
-        i2c_stop(obj);
-        return length - 1;
-    }
-    
-    data[count] = (char) value;
-    
-    // If not repeated start, send stop.
-    if (stop) {
-        i2c_stop(obj);
-    } else {
-        repeated_start = 1;
-    }
-    
-    return length;
-}
-
-int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop) {
-    int i, status;
-    
-    i2c_start(obj);
-    
-    status = i2c_do_write(obj, (address & 0xFE), 1);
-    if (status != 0x02) {
-        i2c_stop(obj);
-        return I2C_ERROR_NO_SLAVE;
-    }
-    
-    for (i=0; i<length; i++) {
-        status = i2c_do_write(obj, data[i], 0);
-        if (status != 0x02) {
-            i2c_stop(obj);
-            return i;
-        }
-    }
-    
-    // If not repeated start, send stop.
-    if (stop) {
-        i2c_stop(obj);
-    } else {
-        repeated_start = 1;
-    }
-    
-    return length;
-}
-
-void i2c_reset(i2c_t *obj) {
-    i2c_stop(obj);
-}
-
-int i2c_byte_read(i2c_t *obj, int last) {
-    return (i2c_do_read(obj, last) & 0xFF);
-}
-
-int i2c_byte_write(i2c_t *obj, int data) {
-    int ack;
-    int status = i2c_do_write(obj, (data & 0xFF), 0);
-    
-    switch(status) {
-        case 2:
-            ack = 1;
-            break;
-        default:
-            ack = 0;
-            break;
-    }
-
-    return ack;
-}