Diff: targets/hal/TARGET_NXP/TARGET_LPC11UXX/i2c_api.c

Revision:

43:b3acfef78949

Parent:

42:7ca0bbba899b

--- a/targets/hal/TARGET_NXP/TARGET_LPC11UXX/i2c_api.c	Sun Oct 27 16:30:04 2013 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,387 +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 PinMap PinMap_I2C_SDA[] = {
-    {P0_5, I2C_0, 1},
-    {NC  , NC   , 0}
-};
-
-static const PinMap PinMap_I2C_SCL[] = {
-    {P0_4, I2C_0, 1},
-    {NC  , NC,    0}
-};
-
-#define I2C_CONSET(x)       (x->i2c->CONSET)
-#define I2C_CONCLR(x)       (x->i2c->CONCLR)
-#define I2C_STAT(x)         (x->i2c->STAT)
-#define I2C_DAT(x)          (x->i2c->DAT)
-#define I2C_SCLL(x, val)    (x->i2c->SCLL = val)
-#define I2C_SCLH(x, val)    (x->i2c->SCLH = val)
-
-static const uint32_t I2C_addr_offset[2][4] = {
-    {0x0C, 0x20, 0x24, 0x28},
-    {0x30, 0x34, 0x38, 0x3C}
-};
-
-static inline void i2c_conclr(i2c_t *obj, int start, int stop, int interrupt, int acknowledge) {
-    I2C_CONCLR(obj) = (start << 5)
-                    | (stop << 4)
-                    | (interrupt << 3)
-                    | (acknowledge << 2);
-}
-
-static inline void i2c_conset(i2c_t *obj, int start, int stop, int interrupt, int acknowledge) {
-    I2C_CONSET(obj) = (start << 5)
-                    | (stop << 4)
-                    | (interrupt << 3)
-                    | (acknowledge << 2);
-}
-
-// Clear the Serial Interrupt (SI)
-static inline void i2c_clear_SI(i2c_t *obj) {
-    i2c_conclr(obj, 0, 0, 1, 0);
-}
-
-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 (!(I2C_CONSET(obj) & (1 << 3))) {
-        timeout++;
-        if (timeout > 100000) return -1;
-    }
-    return 0;
-}
-
-static inline void i2c_interface_enable(i2c_t *obj) {
-    I2C_CONSET(obj) = 0x40;
-}
-
-static inline void i2c_power_enable(i2c_t *obj) {
-    LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 5);
-    LPC_SYSCON->PRESETCTRL |= 1 << 1;
-}
-
-void i2c_init(i2c_t *obj, PinName sda, PinName scl) {
-    // determine the SPI to use
-    I2CName i2c_sda = (I2CName)pinmap_peripheral(sda, PinMap_I2C_SDA);
-    I2CName i2c_scl = (I2CName)pinmap_peripheral(scl, PinMap_I2C_SCL);
-    obj->i2c = (LPC_I2C_Type *)pinmap_merge(i2c_sda, i2c_scl);
-    
-    if ((int)obj->i2c == NC) {
-        error("I2C pin mapping failed");
-    }
-    
-    // enable power
-    i2c_power_enable(obj);
-    
-    // set default frequency at 100k
-    i2c_frequency(obj, 100000);
-    i2c_conclr(obj, 1, 1, 1, 1);
-    i2c_interface_enable(obj);
-    
-    pinmap_pinout(sda, PinMap_I2C_SDA);
-    pinmap_pinout(scl, PinMap_I2C_SCL);
-}
-
-inline int i2c_start(i2c_t *obj) {
-    int status = 0;
-    // 8.1 Before master mode can be entered, I2CON must be initialised to:
-    //  - I2EN STA STO SI AA - -
-    //  -  1    0   0   0  x - -
-    // if AA = 0, it can't enter slave mode
-    i2c_conclr(obj, 1, 1, 1, 1);
-    
-    // The master mode may now be entered by setting the STA bit
-    // this will generate a start condition when the bus becomes free
-    i2c_conset(obj, 1, 0, 0, 1);
-    
-    i2c_wait_SI(obj);
-    status = i2c_status(obj);
-    
-    // Clear start bit now transmitted, and interrupt bit
-    i2c_conclr(obj, 1, 0, 0, 0);
-    return status;
-}
-
-inline int i2c_stop(i2c_t *obj) {
-    int timeout = 0;
-
-    // write the stop bit
-    i2c_conset(obj, 0, 1, 0, 0);
-    i2c_clear_SI(obj);
-    
-    // wait for STO bit to reset
-    while(I2C_CONSET(obj) & (1 << 4)) {
-        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;
-    
-    // clear SI to init a send
-    i2c_clear_SI(obj);
-    
-    // wait and return status
-    i2c_wait_SI(obj);
-    return i2c_status(obj);
-}
-
-static inline int i2c_do_read(i2c_t *obj, int last) {
-    // we are in state 0x40 (SLA+R tx'd) or 0x50 (data rx'd and ack)
-    if (last) {
-        i2c_conclr(obj, 0, 0, 0, 1); // send a NOT ACK
-    } else {
-        i2c_conset(obj, 0, 0, 0, 1); // send a ACK
-    }
-    
-    // accept byte
-    i2c_clear_SI(obj);
-    
-    // wait for it to arrive
-    i2c_wait_SI(obj);
-    
-    // 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 pulse = PCLK / (hz * 2);
-    
-    // I2C Rate
-    I2C_SCLL(obj, pulse);
-    I2C_SCLH(obj, pulse);
-}
-
-// 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;
-    
-    status = i2c_start(obj);
-    
-    if ((status != 0x10) && (status != 0x08)) {
-        i2c_stop(obj);
-        return I2C_ERROR_BUS_BUSY;
-    }
-    
-    status = i2c_do_write(obj, (address | 0x01), 1);
-    if (status != 0x40) {
-        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 != 0x50) {
-            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 != 0x58) {
-        i2c_stop(obj);
-        return length - 1;
-    }
-    
-    data[count] = (char) value;
-    
-    // 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) {
-    int i, status;
-    
-    status = i2c_start(obj);
-    
-    if ((status != 0x10) && (status != 0x08)) {
-        i2c_stop(obj);
-        return I2C_ERROR_BUS_BUSY;
-    }
-    
-    status = i2c_do_write(obj, (address & 0xFE), 1);
-    if (status != 0x18) {
-        i2c_stop(obj);
-        return I2C_ERROR_NO_SLAVE;
-    }
-    
-    for (i=0; i<length; i++) {
-        status = i2c_do_write(obj, data[i], 0);
-        if(status != 0x28) {
-            i2c_stop(obj);
-            return i;
-        }
-    }
-    
-    // clearing the serial interrupt here might cause an unintended rewrite of the last byte
-    // see also issue report https://mbed.org/users/mbed_official/code/mbed/issues/1
-    // i2c_clear_SI(obj);
-    
-    // If not repeated start, send stop.
-    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) {
-    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 0x18: case 0x28:       // Master transmit ACKs
-            ack = 1;
-            break;
-        case 0x40:                  // Master receive address transmitted ACK
-            ack = 1;
-            break;
-        case 0xB8:                  // Slave transmit ACK
-            ack = 1;
-            break;
-        default:
-            ack = 0;
-            break;
-    }
-
-    return ack;
-}
-
-void i2c_slave_mode(i2c_t *obj, int enable_slave) {
-    if (enable_slave != 0) {
-        i2c_conclr(obj, 1, 1, 1, 0);
-        i2c_conset(obj, 0, 0, 0, 1);
-    } else {
-        i2c_conclr(obj, 1, 1, 1, 1);
-    }
-}
-
-int i2c_slave_receive(i2c_t *obj) {
-    int status;
-    int retval;
-    
-    status = i2c_status(obj);
-    switch(status) {
-        case 0x60: retval = 3; break;
-        case 0x70: retval = 2; break;
-        case 0xA8: retval = 1; break;
-        default  : retval = 0; break;
-    }
-    
-    return(retval);
-}
-
-int i2c_slave_read(i2c_t *obj, char *data, int length) {
-    int count = 0;
-    int status;
-    
-    do {
-        i2c_clear_SI(obj);
-        i2c_wait_SI(obj);
-        status = i2c_status(obj);
-        if((status == 0x80) || (status == 0x90)) {
-            data[count] = I2C_DAT(obj) & 0xFF;
-        }
-        count++;
-    } while (((status == 0x80) || (status == 0x90) ||
-            (status == 0x060) || (status == 0x70)) && (count < length));
-    
-    if(status != 0xA0) {
-        i2c_stop(obj);
-    }
-    
-    i2c_clear_SI(obj);
-    
-    return count;
-}
-
-int i2c_slave_write(i2c_t *obj, const char *data, int length) {
-    int count = 0;
-    int status;
-    
-    if(length <= 0) {
-        return(0);
-    }
-    
-    do {
-        status = i2c_do_write(obj, data[count], 0);
-        count++;
-    } while ((count < length) && (status == 0xB8));
-    
-    if((status != 0xC0) && (status != 0xC8)) {
-        i2c_stop(obj);
-    }
-    
-    i2c_clear_SI(obj);
-    
-    return(count);
-}
-
-void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask) {
-    uint32_t addr;
-    
-    if ((idx >= 0) && (idx <= 3)) {
-        addr = ((uint32_t)obj->i2c) + I2C_addr_offset[0][idx];
-        *((uint32_t *) addr) = address & 0xFF;
-    }
-}