AVR I2C driver.
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@4380 35acf78f-673a-0410-8e92-d51de3d6d3f4
This commit is contained in:
gdisirio
parent
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commit
076b5bbb9a
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/*
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ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
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2011,2012 Giovanni Di Sirio.
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This file is part of ChibiOS/RT.
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ChibiOS/RT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
|
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(at your option) any later version.
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ChibiOS/RT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
|
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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* @file AVR/i2c_lld.c
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* @brief AVR I2C subsystem low level driver source.
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*
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* @addtogroup I2C
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* @{
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*/
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#include "ch.h"
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#include "hal.h"
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#if HAL_USE_I2C || defined(__DOXYGEN__)
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/*===========================================================================*/
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/* Driver local definitions. */
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/*===========================================================================*/
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/*===========================================================================*/
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/* Driver exported variables. */
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/*===========================================================================*/
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/** @brief I2C driver identifier.*/
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#if USE_AVR_I2C || defined(__DOXYGEN__)
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I2CDriver I2CD;
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#endif
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/*===========================================================================*/
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/* Driver local variables. */
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/*===========================================================================*/
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/*===========================================================================*/
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/* Driver local functions. */
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/*===========================================================================*/
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/**
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* @brief Wakes up the waiting thread.
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*
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* @param[in] i2cp pointer to the @p I2CDriver object
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* @param[in] msg wakeup message
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*
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* @notapi
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*/
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#define wakeup_isr(i2cp, msg) { \
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chSysLockFromIsr(); \
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if ((i2cp)->thread != NULL) { \
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Thread *tp = (i2cp)->thread; \
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(i2cp)->thread = NULL; \
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tp->p_u.rdymsg = (msg); \
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chSchReadyI(tp); \
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} \
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chSysUnlockFromIsr(); \
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}
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/*===========================================================================*/
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/* Driver interrupt handlers. */
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/*===========================================================================*/
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#if USE_AVR_I2C || defined(__DOXYGEN__)
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/**
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* @brief I2C event interrupt handler.
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*
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* @notapi
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*/
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CH_IRQ_HANDLER(TWI_vect) {
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CH_IRQ_PROLOGUE();
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I2CDriver *i2cp = &I2CD;
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switch (TWSR & 0xF8) {
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case TWI_START:
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case TWI_REPEAT_START:
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TWDR = (i2cp->addr << 1);
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if ((i2cp->txbuf == NULL) || (i2cp->txbytes == 0) || (i2cp->txidx == i2cp->txbytes)) {
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TWDR |= 0x01;
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}
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TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
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break;
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case TWI_MASTER_TX_ADDR_ACK:
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case TWI_MASTER_TX_DATA_ACK:
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if (i2cp->txidx < i2cp->txbytes) {
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TWDR = i2cp->txbuf[i2cp->txidx++];
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TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
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} else {
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if (i2cp->rxbuf && i2cp->rxbytes) {
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TWCR = ((1 << TWSTA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
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} else {
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TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
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wakeup_isr(i2cp, RDY_OK);
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}
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}
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break;
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case TWI_MASTER_RX_ADDR_ACK:
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if (i2cp->rxidx == (i2cp->rxbytes - 1)) {
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TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
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} else {
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TWCR = ((1 << TWEA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
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}
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break;
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case TWI_MASTER_RX_DATA_ACK:
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i2cp->rxbuf[i2cp->rxidx++] = TWDR;
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if (i2cp->rxidx == (i2cp->rxbytes - 1)) {
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TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
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} else {
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TWCR = ((1 << TWEA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
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}
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break;
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case TWI_MASTER_RX_DATA_NACK:
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i2cp->rxbuf[i2cp->rxidx] = TWDR;
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TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
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wakeup_isr(i2cp, RDY_OK);
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case TWI_MASTER_TX_ADDR_NACK:
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case TWI_MASTER_TX_DATA_NACK:
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case TWI_MASTER_RX_ADDR_NACK:
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i2cp->errors |= I2CD_ACK_FAILURE;
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break;
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case TWI_ARBITRATION_LOST:
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i2cp->errors |= I2CD_ARBITRATION_LOST;
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break;
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case TWI_BUS_ERROR:
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i2cp->errors |= I2CD_BUS_ERROR;
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break;
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default:
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/* FIXME: only gets here if there are other MASTERs in the bus */
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TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
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wakeup_isr(i2cp, RDY_RESET);
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}
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if (i2cp->errors != I2CD_NO_ERROR) {
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TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
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wakeup_isr(i2cp, RDY_RESET);
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}
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CH_IRQ_EPILOGUE();
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}
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#endif /* USE_AVR_I2C */
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/*===========================================================================*/
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/* Driver exported functions. */
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/*===========================================================================*/
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/**
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* @brief Low level I2C driver initialization.
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*
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* @notapi
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*/
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void i2c_lld_init(void) {
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i2cObjectInit(&I2CD);
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}
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/**
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* @brief Configures and activates the I2C peripheral.
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*
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* @param[in] i2cp pointer to the @p I2CDriver object
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*
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* @notapi
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*/
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void i2c_lld_start(I2CDriver *i2cp) {
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/* TODO: Test TWI without external pull-ups (use internal) */
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/* Configure prescaler to 1 */
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TWSR &= 0xF8;
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/* Configure baudrate */
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TWBR = ((F_CPU / i2cp->config->clock_speed) - 16) / 2;
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}
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/**
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* @brief Deactivates the I2C peripheral.
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*
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* @param[in] i2cp pointer to the @p I2CDriver object
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*
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* @notapi
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*/
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void i2c_lld_stop(I2CDriver *i2cp) {
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if (i2cp->state != I2C_STOP) {
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/* Disable TWI subsystem and stop all operations */
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TWCR &= ~(1 << TWEN);
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}
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}
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/**
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* @brief Receives data via the I2C bus as master.
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*
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* @param[in] i2cp pointer to the @p I2CDriver object
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* @param[in] addr slave device address
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* @param[out] rxbuf pointer to the receive buffer
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* @param[in] rxbytes number of bytes to be received
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* @param[in] timeout the number of ticks before the operation timeouts,
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* the following special values are allowed:
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* - @a TIME_INFINITE no timeout.
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* .
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* @return The operation status.
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* @retval RDY_OK if the function succeeded.
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* @retval RDY_RESET if one or more I2C errors occurred, the errors can
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* be retrieved using @p i2cGetErrors().
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* @retval RDY_TIMEOUT if a timeout occurred before operation end. <b>After a
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* timeout the driver must be stopped and restarted
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* because the bus is in an uncertain state</b>.
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*
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* @notapi
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*/
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msg_t i2c_lld_master_receive_timeout(I2CDriver *i2cp, i2caddr_t addr,
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uint8_t *rxbuf, size_t rxbytes,
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systime_t timeout) {
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i2cp->addr = addr;
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i2cp->txbuf = NULL;
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i2cp->txbytes = 0;
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i2cp->txidx = 0;
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i2cp->rxbuf = rxbuf;
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i2cp->rxbytes = rxbytes;
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i2cp->rxidx = 0;
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/* Send START */
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TWCR = ((1 << TWSTA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
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chSysLock();
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i2cp->thread = chThdSelf();
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chSchGoSleepS(THD_STATE_SUSPENDED);
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chSysUnlock();
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return chThdSelf()->p_u.rdymsg;
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}
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/**
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* @brief Transmits data via the I2C bus as master.
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*
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* @param[in] i2cp pointer to the @p I2CDriver object
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* @param[in] addr slave device address
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* @param[in] txbuf pointer to the transmit buffer
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* @param[in] txbytes number of bytes to be transmitted
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* @param[out] rxbuf pointer to the receive buffer
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* @param[in] rxbytes number of bytes to be received
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* @param[in] timeout the number of ticks before the operation timeouts,
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* the following special values are allowed:
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* - @a TIME_INFINITE no timeout.
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* .
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* @return The operation status.
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* @retval RDY_OK if the function succeeded.
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* @retval RDY_RESET if one or more I2C errors occurred, the errors can
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* be retrieved using @p i2cGetErrors().
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* @retval RDY_TIMEOUT if a timeout occurred before operation end. <b>After a
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* timeout the driver must be stopped and restarted
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* because the bus is in an uncertain state</b>.
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*
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* @notapi
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*/
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msg_t i2c_lld_master_transmit_timeout(I2CDriver *i2cp, i2caddr_t addr,
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const uint8_t *txbuf, size_t txbytes,
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uint8_t *rxbuf, size_t rxbytes,
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systime_t timeout) {
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i2cp->addr = addr;
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i2cp->txbuf = txbuf;
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i2cp->txbytes = txbytes;
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i2cp->txidx = 0;
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i2cp->rxbuf = rxbuf;
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i2cp->rxbytes = rxbytes;
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i2cp->rxidx = 0;
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TWCR = ((1 << TWSTA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
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chSysLock();
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i2cp->thread = chThdSelf();
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chSchGoSleepS(THD_STATE_SUSPENDED);
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chSysUnlock();
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return chThdSelf()->p_u.rdymsg;
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}
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#endif /* HAL_USE_I2C */
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/** @} */
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@ -0,0 +1,227 @@
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/*
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ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
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2011,2012 Giovanni Di Sirio.
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This file is part of ChibiOS/RT.
|
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|
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ChibiOS/RT is free software; you can redistribute it and/or modify
|
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it under the terms of the GNU General Public License as published by
|
||||
the Free Software Foundation; either version 3 of the License, or
|
||||
(at your option) any later version.
|
||||
|
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ChibiOS/RT is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
GNU General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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* @file AVR/i2c_lld.h
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* @brief AVR I2C subsystem low level driver header.
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*
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* @addtogroup I2C
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* @{
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*/
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#ifndef _I2C_LLD_H_
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#define _I2C_LLD_H_
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#if HAL_USE_I2C || defined(__DOXYGEN__)
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/*===========================================================================*/
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/* Driver constants. */
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/*===========================================================================*/
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/** START transmitted */
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#define TWI_START 0x08
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/** Repeated START transmitted */
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#define TWI_REPEAT_START 0x10
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/** Arbitration Lost */
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#define TWI_ARBITRATION_LOST 0x38
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/** Bus errors */
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#define TWI_BUS_ERROR 0x00
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/** SLA+W transmitted with ACK response */
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#define TWI_MASTER_TX_ADDR_ACK 0x18
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/** SLA+W transmitted with NACK response */
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#define TWI_MASTER_TX_ADDR_NACK 0x20
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/** DATA transmitted with ACK response */
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#define TWI_MASTER_TX_DATA_ACK 0x28
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/** DATA transmitted with NACK response */
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#define TWI_MASTER_TX_DATA_NACK 0x30
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/** SLA+R transmitted with ACK response */
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#define TWI_MASTER_RX_ADDR_ACK 0x40
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/** SLA+R transmitted with NACK response */
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#define TWI_MASTER_RX_ADDR_NACK 0x48
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/** DATA received with ACK response */
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#define TWI_MASTER_RX_DATA_ACK 0x50
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/** DATA received with NACK response */
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#define TWI_MASTER_RX_DATA_NACK 0x58
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/*===========================================================================*/
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/* Driver pre-compile time settings. */
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/*===========================================================================*/
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/**
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* @name Configuration options
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* @{
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*/
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/**
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* @brief I2C driver enable switch.
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* @details If set to @p TRUE the support for I2C is included.
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* @note The default is @p FALSE.
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*/
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#if !defined(USE_AVR_I2C) || defined(__DOXYGEN__)
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#define USE_AVR_I2C FALSE
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#endif
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/*===========================================================================*/
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/* Derived constants and error checks. */
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/*===========================================================================*/
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/*===========================================================================*/
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/* Driver data structures and types. */
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/*===========================================================================*/
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/**
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* @brief Type representing I2C address.
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*/
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typedef uint8_t i2caddr_t;
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/**
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* @brief I2C Driver condition flags type.
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*/
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typedef uint8_t i2cflags_t;
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/**
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* @brief Driver configuration structure.
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* @note Implementations may extend this structure to contain more,
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* architecture dependent, fields.
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*/
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typedef struct {
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/**
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* @brief Specifies the I2C clock frequency.
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*/
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uint32_t clock_speed;
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} I2CConfig;
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/**
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* @brief Structure representing an I2C driver.
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*/
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struct I2CDriver {
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/**
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* @brief Driver state.
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*/
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i2cstate_t state;
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/**
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* @brief Current configuration data.
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*/
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const I2CConfig *config;
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/**
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* @brief Error flags.
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*/
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i2cflags_t errors;
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#if I2C_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
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#if CH_USE_MUTEXES || defined(__DOXYGEN__)
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/**
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* @brief Mutex protecting the bus.
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*/
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Mutex mutex;
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#elif CH_USE_SEMAPHORES
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Semaphore semaphore;
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#endif
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#endif /* I2C_USE_MUTUAL_EXCLUSION */
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#if defined(I2C_DRIVER_EXT_FIELDS)
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I2C_DRIVER_EXT_FIELDS
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#endif
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/* End of the mandatory fields.*/
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/**
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* @brief Thread waiting for I/O completion.
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*/
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Thread *thread;
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/**
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* @brief Address of slave device
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*/
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i2caddr_t addr;
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/**
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* @brief Pointer to the buffer with data to send.
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*/
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const uint8_t *txbuf;
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/**
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* @brief Number of bytes of data to send.
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*/
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size_t txbytes;
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/**
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* @brief Current index in buffer when sending data.
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*/
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size_t txidx;
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/**
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* @brief Pointer to the buffer to put received data.
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*/
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uint8_t *rxbuf;
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/**
|
||||
* @brief Number of bytes of data to receive.
|
||||
*/
|
||||
size_t rxbytes;
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||||
/**
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||||
* @brief Current index in buffer when receiving data.
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||||
*/
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||||
size_t rxidx;
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};
|
||||
|
||||
/**
|
||||
* @brief Type of a structure representing an I2C driver.
|
||||
*/
|
||||
typedef struct I2CDriver I2CDriver;
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/*===========================================================================*/
|
||||
/* Driver macros. */
|
||||
/*===========================================================================*/
|
||||
|
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/**
|
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* @brief Get errors from I2C driver.
|
||||
*
|
||||
* @param[in] i2cp pointer to the @p I2CDriver object
|
||||
*
|
||||
* @notapi
|
||||
*/
|
||||
#define i2c_lld_get_errors(i2cp) ((i2cp)->errors)
|
||||
|
||||
/*===========================================================================*/
|
||||
/* External declarations. */
|
||||
/*===========================================================================*/
|
||||
|
||||
#if !defined(__DOXYGEN__)
|
||||
#if USE_AVR_I2C
|
||||
extern I2CDriver I2CD;
|
||||
#endif
|
||||
#endif /* !defined(__DOXYGEN__) */
|
||||
|
||||
#ifdef __cplusplus
|
||||
extern "C" {
|
||||
#endif
|
||||
void i2c_lld_init(void);
|
||||
void i2c_lld_start(I2CDriver *i2cp);
|
||||
void i2c_lld_stop(I2CDriver *i2cp);
|
||||
msg_t i2c_lld_master_transmit_timeout(I2CDriver *i2cp, i2caddr_t addr,
|
||||
const uint8_t *txbuf, size_t txbytes,
|
||||
uint8_t *rxbuf, size_t rxbytes,
|
||||
systime_t timeout);
|
||||
msg_t i2c_lld_master_receive_timeout(I2CDriver *i2cp, i2caddr_t addr,
|
||||
uint8_t *rxbuf, size_t rxbytes,
|
||||
systime_t timeout);
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif /* HAL_USE_I2C */
|
||||
|
||||
#endif /* _I2C_LLD_H_ */
|
||||
|
||||
/** @} */
|
||||
|
|
@ -100,3 +100,15 @@
|
|||
* .
|
||||
* @ingroup AVR_DRIVERS
|
||||
*/
|
||||
|
||||
/**
|
||||
* @defgroup AVR_I2C AVR I2C Support
|
||||
* @details The AVR I2C driver uses the TWI peripheral in an interrupt
|
||||
* driven, implementation.
|
||||
*
|
||||
* @section avr_i2c Supported HW resources
|
||||
* The i2c driver can support the following hardware resource:
|
||||
* - I2C.
|
||||
* .
|
||||
* @ingroup AVR_DRIVERS
|
||||
*/
|
||||
|
|
|
|||
|
|
@ -1,7 +1,8 @@
|
|||
# List of all the AVR platform files.
|
||||
PLATFORMSRC = ${CHIBIOS}/os/hal/platforms/AVR/hal_lld.c \
|
||||
${CHIBIOS}/os/hal/platforms/AVR/pal_lld.c \
|
||||
${CHIBIOS}/os/hal/platforms/AVR/serial_lld.c
|
||||
${CHIBIOS}/os/hal/platforms/AVR/serial_lld.c \
|
||||
${CHIBIOS}/os/hal/platforms/AVR/i2c_lld.c
|
||||
|
||||
# Required include directories
|
||||
PLATFORMINC = ${CHIBIOS}/os/hal/platforms/AVR
|
||||
|
|
|
|||
|
|
@ -163,6 +163,7 @@
|
|||
to 2.4.1).
|
||||
- NEW: Added demo for Arduino Mega, contributed by Fabio Utzig.
|
||||
- NEW: Added support for ATmega1280, contributed by Fabio Utzig.
|
||||
- NEW: Added I2C driver for AVR, contributed by Fabio Utzig.
|
||||
- NEW: Added FatFs demo for the Olimex STM32-P107 board.
|
||||
- NEW: Added support for the Olimex STM32-E407 board. Added an integrated
|
||||
demo including USB-CDC, lwIP with web server, FatFs and shell, all running
|
||||
|
|
|
|||
Loading…
Reference in New Issue