+++ /dev/null
-/* 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 "mbed_assert.h"
-#include "i2c_api.h"
-#include "cmsis.h"
-#include "pinmap.h"
-
-static uint8_t repeated_start = 0;
-
-#define I2C_STAT(x) ((LPC_I2C0->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) {
- volatile int timeout = 0;
- while (!(LPC_I2C0->STAT & (1 << 0))) {
- timeout++;
- if (timeout > 100000) return -1;
- }
- return 0;
-}
-
-static inline void i2c_interface_enable(i2c_t *obj) {
- LPC_I2C0->CFG |= (1 << 0);
-}
-
-void i2c_init(i2c_t *obj, PinName sda, PinName scl) {
- MBED_ASSERT((sda == P0_23) && (scl == P0_22));
-
- // Enables clock for I2C0
- LPC_SYSCON->SYSAHBCLKCTRL1 |= (1 << 13);
-
- LPC_SYSCON->PRESETCTRL1 |= (1 << 13);
- LPC_SYSCON->PRESETCTRL1 &= ~(1 << 13);
-
- // pin enable
- LPC_SWM->PINENABLE1 &= ~(0x3 << 3);
-
- // set default frequency at 100kHz
- i2c_frequency(obj, 100000);
- i2c_interface_enable(obj);
-}
-
-inline int i2c_start(i2c_t *obj) {
- int status = 0;
- if (repeated_start) {
- LPC_I2C0->MSTCTL = (1 << 1) | (1 << 0);
- repeated_start = 0;
- } else {
- LPC_I2C0->MSTCTL = (1 << 1);
- }
- return status;
-}
-
-inline int i2c_stop(i2c_t *obj) {
- volatile int timeout = 0;
-
- LPC_I2C0->MSTCTL = (1 << 2) | (1 << 0);
- while ((LPC_I2C0->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
- LPC_I2C0->MSTDAT = value;
-
- if (!addr)
- LPC_I2C0->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)
- LPC_I2C0->MSTCTL = (1 << 0);
-
- // return the data
- return (LPC_I2C0->MSTDAT & 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;
-
- LPC_I2C0->DIV = clkdiv;
- LPC_I2C0->MSTTIME = 0;
-}
-
-int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) {
- int count, status;
-
- i2c_start(obj);
-
- LPC_I2C0->MSTDAT = (address | 0x01);
- LPC_I2C0->MSTCTL |= 0x20;
- if (i2c_wait_SI(obj) == -1)
- return -1;
-
- status = ((LPC_I2C0->STAT >> 1) & (0x07));
- if (status != 0x01) {
- i2c_stop(obj);
- return I2C_ERROR_NO_SLAVE;
- }
-
- // Read in all except last byte
- for (count = 0; count < (length - 1); count++) {
- if (i2c_wait_SI(obj) == -1)
- return -1;
- LPC_I2C0->MSTCTL = (1 << 0);
- data[count] = (LPC_I2C0->MSTDAT & 0xFF);
- status = ((LPC_I2C0->STAT >> 1) & (0x07));
- if (status != 0x01) {
- i2c_stop(obj);
- return count;
- }
- }
-
- // read in last byte
- if (i2c_wait_SI(obj) == -1)
- return -1;
-
- data[count] = (LPC_I2C0->MSTDAT & 0xFF);
- status = i2c_status(obj);
- if (status != 0x01) {
- i2c_stop(obj);
- return length - 1;
- }
- // 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);
-
- LPC_I2C0->MSTDAT = (address & 0xFE);
- LPC_I2C0->MSTCTL |= 0x20;
- if (i2c_wait_SI(obj) == -1)
- return -1;
-
- status = ((LPC_I2C0->STAT >> 1) & (0x07));
- if (status != 0x02) {
- i2c_stop(obj);
- return I2C_ERROR_NO_SLAVE;
- }
-
- for (i=0; i<length; i++) {
- LPC_I2C0->MSTDAT = data[i];
- LPC_I2C0->MSTCTL = (1 << 0);
- if (i2c_wait_SI(obj) == -1)
- return -1;
-
- status = ((LPC_I2C0->STAT >> 1) & (0x07));
- 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) {
- if (i2c_do_write(obj, (data & 0xFF), 0) == 2) {
- return 1;
- } else {
- return 0;
- }
-}