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add i2c code from Hedde Bosman

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Mariano Alvira 2011-07-18 07:11:05 -04:00
parent 4c36473ff5
commit 76a8e49262
5 changed files with 471 additions and 0 deletions
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331
lib/i2c.c Normal file
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/*
* Copyright (c) 2011, Hedde Bosman <heddebosman@incas3.eu>
*
* I2C communication device drivers for mc1322x
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id$
*/
#include "i2c.h"
#include <stdio.h>
static int8_t tx_byte_ctr;
static int8_t rx_byte_ctr;
static uint8_t* tx_buf_ptr;
static uint8_t* rx_buf_ptr;
volatile unsigned int i; // volatile to prevent optimization
static inline void i2c_send_byte(void) {
*I2CDR = *(tx_buf_ptr++); // set new byte, MCF is automatically cleared
tx_byte_ctr--;
}
static inline void i2c_recv_byte(void) {
*(rx_buf_ptr++) = *I2CDR;
rx_byte_ctr--;
}
//------------------------------------------------------------------------------
// void i2c_receiveinit(uint8_t slave_address,
// uint8_t prescale)
//
// This function initializes the USCI module for master-receive operation.
//
// IN: uint8_t slave_address => Slave Address
// uint8_t prescale => SCL clock adjustment
//-----------------------------------------------------------------------------
//static volatile uint8_t rx_byte_tot = 0;
void i2c_receiveinit(uint8_t slave_address, uint8_t byte_ctr, uint8_t *rx_buf) {
// wait for bus to be free before setting MSTA (assuming we're in a multi-master environment or still sending something else)
while(i2c_busy()) /* wait */;
// assert: rx_byte_ctr <= 0
// assert: tx_byte_ctr <= 0
tx_buf_ptr = 0;
tx_byte_ctr = 0; // indicate that nothing is to be received
rx_byte_ctr = byte_ctr;
rx_buf_ptr = rx_buf;
// clockdiv
//*I2CFDR = 0x20; // 150 khz for redbee econotag
// assume being master, thus no addres has to be set
*I2CCR = I2C_MEN |
#ifdef I2C_NON_BLOCKING
I2C_MIEN |
#endif
I2C_MSTA | I2C_MTX | I2C_RXAK; // start condition is triggered
// write out address of slave
*I2CDR = (slave_address & 0x7f) <<1 | 0x01;
#ifndef I2C_NON_BLOCKING
i2c_receive();
#endif
}
//------------------------------------------------------------------------------
// void i2c_transmitinit(uint8_t slave_address,
// uint8_t prescale)
//
// Initializes USCI for master-transmit operation.
//
// IN: uint8_t slave_address => Slave Address
// uint8_t prescale => SCL clock adjustment
//------------------------------------------------------------------------------
//static volatile uint8_t tx_byte_tot = 0;
void i2c_transmitinit(uint8_t slave_address, uint8_t byte_ctr, uint8_t *tx_buf) {
// wait for bus to be free before setting MSTA (assuming we're in a multi-master environment or still sending something else)
while(i2c_busy()) /* wait */;
// assert: rx_byte_ctr <= 0
// assert: tx_byte_ctr <= 0
rx_buf_ptr = 0;
rx_byte_ctr = 0; // indicate that nothing is to be received
tx_byte_ctr = byte_ctr;
tx_buf_ptr = tx_buf;
// clockdiv
//*I2CFDR = 0x20; // 150 khz for redbee econotag
// assume being master, thus no addres has to be set
*I2CCR = I2C_MEN |
#ifdef I2C_NON_BLOCKING
I2C_MIEN |
#endif
I2C_MSTA | I2C_MTX ; // start condition is triggered
// write out address of slave
*I2CDR = (slave_address & 0x7f) <<1;
#ifndef I2C_NON_BLOCKING
i2c_transmit();
#endif
}
/*----------------------------------------------------------------------------*/
/*- blocking counterparts of interrupt hanlder function ---------------------*/
/*----------------------------------------------------------------------------*/
#ifndef I2C_NON_BLOCKING
/*----------------------------------------------------------------------------*/
uint8_t i2c_receive() {
while(rx_byte_ctr > 0) {
// busy wait
while(!(*I2CSR & I2C_MCF) || !(*I2CSR & I2C_MIF)) /*wait*/;
if (rx_byte_ctr == 1) { // receiving next-to-last byte, thus turn off auto-ack for stop condition
*I2CCR |= I2C_TXAK;
}
if (*I2CSR & I2C_MCF) {
i2c_recv_byte(); // read new byte
}
if (*I2CSR & I2C_MAL) {
*I2CSR &= ~I2C_MAL; // should be cleared in software
printf("*** ERROR I2C: Arbitration lost\n");
// Arbitration lost; ERROR?
}
}
while(!(*I2CSR & I2C_MCF) || !(*I2CSR & I2C_MIF)) /*wait*/;
if (*I2CSR & I2C_RXAK) {
// NO acknoledge byte received
printf("*** ERROR I2C: No ack received\n");
}
if (*I2CSR & I2C_MAL) {
*I2CSR &= ~I2C_MAL; // should be cleared in software
printf("*** ERROR I2C: Arbitration lost\n");
// Arbitration lost; ERROR?
}
*I2CCR &= ~I2C_MSTA; // stop condition
}
/*----------------------------------------------------------------------------*/
void i2c_transmit() {
while(tx_byte_ctr > 0) {
// busy wait
while(!(*I2CSR & I2C_MCF) || !(*I2CSR & I2C_MIF)) /*wait*/;
if (*I2CSR & I2C_RXAK) {
// NO acknoledge byte received
printf("*** ERROR I2C: No ack received\n");
}
if (*I2CSR & I2C_MCF) {
i2c_send_byte();
}
if (*I2CSR & I2C_MAL) {
*I2CSR &= ~I2C_MAL; // should be cleared in software
printf("*** ERROR I2C: Arbitration lost\n");
// Arbitration lost; ERROR?
}
// clear MIF
*I2CSR &= ~I2C_MIF;
}
while(!(*I2CSR & I2C_MCF) || !(*I2CSR & I2C_MIF)) /*wait*/;
if (*I2CSR & I2C_RXAK) {
// NO acknoledge byte received
printf("*** ERROR I2C: No ack received\n");
}
if (*I2CSR & I2C_MAL) {
*I2CSR &= ~I2C_MAL; // should be cleared in software
printf("*** ERROR I2C: Arbitration lost\n");
// Arbitration lost; ERROR?
}
*I2CCR &= ~I2C_MSTA; // stop condition
}
#endif
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
/* force SCL to become bus master when sda is still low (can occur after sys reset */
/*----------------------------------------------------------------------------*/
void i2c_force_reset(void) {
uint8_t tmp;
*I2CCR = 0x20;
*I2CCR = 0xA0;
tmp = *I2CDR;
// return to module state Master?
}
/*----------------------------------------------------------------------------*/
/*- check if we're still in the process of sending something ----------------*/
/*----------------------------------------------------------------------------*/
uint8_t i2c_transferred(void) {
return (!i2c_busy() && rx_byte_ctr == 0 && tx_byte_ctr == 0);
}
/*----------------------------------------------------------------------------*/
/* check if there is communication in progress on the i2c bus. */
/*----------------------------------------------------------------------------*/
uint8_t i2c_busy(void) {
return ((*I2CSR & I2C_MBB) > 0); // bit 5 high = busy
}
/*----------------------------------------------------------------------------*/
/* Setup ports and pins for I2C use. */
/*----------------------------------------------------------------------------*/
void i2c_enable(void) {
// enable clock signal to i2c module
*I2CCKER = I2C_CKEN; // enable
enable_irq(I2C);
*I2CFDR = 0x20; // clockdiv: 150 khz for redbee econotag
*I2CADR = 0x01; // our slave address (not used; we're master)
// then enable i2c module
*I2CCR |= I2C_MEN | // module-enable, auto-ack = on
#ifdef I2C_NON_BLOCKING
I2C_MIEN | //module-interrupt-enable
#endif
0;
// then switch gpio pins to i2c
*GPIO_FUNC_SEL0 |= (0x01 << (I2C_SCL*2)) | (0x01 << (I2C_SDA*2)); // GPIO 12, 13 to i2c
// and enable pull-up resistors
*GPIO_PAD_PU_EN0 |= (0x01 << I2C_SCL) | (0x01 << I2C_SDA); // Activate internal pull-up/-down resistors
*GPIO_PAD_PU_SEL0 |= (0x01 << I2C_SCL) | (0x01 << I2C_SDA); // select pull-up resistors for ports
}
/*----------------------------------------------------------------------------*/
/* Reset ports and pins for GPIO use. */
/*----------------------------------------------------------------------------*/
void i2c_disable(void) {
// all control values are set off
*I2CCR = 0;
// clock is turned off
*I2CCKER = ~I2C_CKEN;
// then switch gpio pins to gpio
*GPIO_FUNC_SEL0 &= ~(0x01 << (I2C_SCL*2)) | (0x01 << (I2C_SDA*2)); // GPIO 12, 13 to i2c
// and disable resistors
*GPIO_PAD_PU_EN0 &= ~(0x01 << I2C_SCL) | (0x01 << I2C_SDA); // Deactivate internal pull-up/-down resistors
disable_irq(I2C);
}
/*----------------------------------------------------------------------------*/
/*- i2c interrupt handler --------------------------------------------------*/
/*----------------------------------------------------------------------------*/
#ifdef I2C_NON_BLOCKING
void i2c_isr (void) {
uint8_t dummy;
if (*I2CSR & I2C_MIF) { // interrupt is from i2c
if (*I2CSR & I2C_MCF) { // one byte transferred/received. will be cleared automatically when I2CDR is written or I2CSR read
if (tx_buf_ptr != 0) { // we're sending
if (*I2CSR & I2C_RXAK) {
// NO acknoledge byte received
printf("*** ERROR I2C: No ack received\n");
}
if (tx_byte_ctr > 0) { // tx
i2c_send_byte(); // set new byte, MCF is automatically cleared
} else {
*I2CCR &= ~I2C_MSTA; // generate stop condition
}
} else { //if (rx_buf_ptr != 0) { // receive
if (rx_byte_ctr == 1) { // receiving next-to-last byte, thus turn off auto-ack for stop condition
*I2CCR |= I2C_TXAK;
}
if (*I2CCR & I2C_MTX) { // address byte was just sent
*I2CCR &= ~I2C_MTX; // switch to receive mode
dummy = *I2CDR; // dummy read to throw away the address from register
} else if (rx_byte_ctr > 0) {
i2c_recv_byte(); // read new byte
} else {
*I2CCR &= ~I2C_MSTA; // generate stop condition
}
}
}
if (*I2CSR & I2C_MAL) {
*I2CSR &= ~I2C_MAL; // should be cleared in software
printf("*** ERROR I2C: Arbitration lost\n");
// Arbitration lost; reset..
rx_byte_ctr = tx_byte_ctr = 0;
*I2CCR &= ~I2C_MSTA; // generate stop condition
}
// clear MIF
*I2CSR &= ~I2C_MIF;
}
}
#endif

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lib/include/i2c.h Normal file
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/*
* Copyright (c) 2011, Hedde Bosman <heddebosman@incas3.eu>
*
* I2C communication device drivers for mc1322x
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id$
*/
#ifndef I2C_H
#define I2C_H
#include <stdint.h>
#include "isr.h"
#include "gpio.h"
#define I2C_NON_BLOCKING 1
/* The I2C Interrupt Service Routine */
void i2c_isr (void);
/* Enable the I2C module */
void i2c_enable(void);
/* Disable the I2C module */
void i2c_disable(void);
/* Returns 1 if the I2C bus is active (we or some other device are transferring data) */
uint8_t i2c_busy(void);
/* Returns 1 if our data is sent or received */
uint8_t i2c_transferred(void); // indicates success of data last transfer (send or receive)
/* start receiving data from 'slave_address' of length 'byte_ctr' and store it in 'rx_buf'
* @parameter slave_addr 7bits (and will be padded with the 'receive bit')
* @parameter byte_ctr the number of bytes expected to be received
* @parameter rx_buf the buffer in which the received bytes will be stored.
*
* IFDEF I2C_NON_BLOCKING THEN THIS FUNCTION RETURNS IMMEDIATLY BUT THE TRANSFER WILL ONLY
* BE COMPLETE WHEN i2c_transferred IS 1
*/
void i2c_receiveinit( uint8_t slave_address, uint8_t byte_ctr, uint8_t *rx_buf);
/* start sending data to 'slave_address' of length 'byte_ctr' found in the buffer 'rx_buf'
* @parameter slave_addr 7bits (and will be padded with the 'send bit')
* @parameter byte_ctr the number of bytes to be sent
* @parameter tx_buf the buffer in which the bytes to be sent are stored
*
* IFDEF I2C_NON_BLOCKING THEN THIS FUNCTION RETURNS IMMEDIATLY BUT THE TRANSFER WILL ONLY
* BE COMPLETE WHEN i2c_transferred IS 1
*/
void i2c_transmitinit(uint8_t slave_address, uint8_t byte_ctr, uint8_t *tx_buf);
#ifndef I2C_NON_BLOCKING
#define I2C_NON_BLOCKING 1
#endif
#if I2C_NON_BLOCKING
uint8_t i2c_receive(void);
void i2c_transmit(void);
#endif
// TODO: see if this is better fit in platform definition
#define I2C_SDA 13 //SDA == P5.1 // GPIO 13
#define I2C_SCL 12 //SCL == P5.2 // GPIO 12
// TODO: this could use a nice struct with bit members...
#define I2C_BASE (0x80006000)
#define I2CADR ((volatile uint8_t *) ( I2C_BASE + 0x00 ))
#define I2CFDR ((volatile uint8_t *) ( I2C_BASE + 0x04 ))
#define I2CCR ((volatile uint8_t *) ( I2C_BASE + 0x08 ))
#define I2CSR ((volatile uint8_t *) ( I2C_BASE + 0x0C ))
#define I2CDR ((volatile uint8_t *) ( I2C_BASE + 0x10 ))
#define I2CDFSRR ((volatile uint8_t *) ( I2C_BASE + 0x14 ))
#define I2CCKER ((volatile uint8_t *) ( I2C_BASE + 0x18 ))
// TODO: fix nice structs
// i2c CR
#define I2C_MEN 0x80
#define I2C_MIEN 0x40
#define I2C_MSTA 0x20
#define I2C_MTX 0x10
#define I2C_TXAK 0x08
#define I2C_RSTA 0x04
#define I2C_BCST 0x01
// i2c SR
#define I2C_MCF 0x80
#define I2C_MAAS 0x40
#define I2C_MBB 0x20
#define I2C_MAL 0x10
#define I2C_BCSTM 0x08
#define I2C_SRW 0x04
#define I2C_MIF 0x02
#define I2C_RXAK 0x01
// i2c digital filter sample rate register
#define I2C_DFSR 0x3f // default = 0x10
// i2c CKER
#define I2C_CKEN 0x01
#endif

1
lib/include/isr.h
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@ -169,5 +169,6 @@ extern void maca_isr(void) __attribute__((weak));
extern void asm_isr(void) __attribute__((weak));
extern void i2c_isr(void) __attribute__((weak));
#endif

1
lib/include/mc1322x.h
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@ -47,5 +47,6 @@
#include "uart.h"
#include "utils.h"
#include "asm.h"
#include "i2c.h"
#endif

3
src/isr.c
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@ -92,6 +92,9 @@ void irq(void)
if(bit_is_set(pending, INT_NUM_ASM)) {
if(asm_isr != 0) { asm_isr(); }
}
if (bit_is_set(pending, INT_NUM_I2C)) {
if (i2c_isr != 0) { i2c_isr(); }
}
*INTFRC = 0; /* stop forcing interrupts */