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AVR I2C driver. 

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@4380 35acf78f-673a-0410-8e92-d51de3d6d3f4
master
gdisirio 2012-07-01 15:25:03 +00:00
parent 21b907c946
commit 076b5bbb9a
5 changed files with 535 additions and 1 deletions
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293
os/hal/platforms/AVR/i2c_lld.c Normal file
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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
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.
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/>.
*/
/**
* @file AVR/i2c_lld.c
* @brief AVR I2C subsystem low level driver source.
*
* @addtogroup I2C
* @{
*/
#include "ch.h"
#include "hal.h"
#if HAL_USE_I2C || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/** @brief I2C driver identifier.*/
#if USE_AVR_I2C || defined(__DOXYGEN__)
I2CDriver I2CD;
#endif
/*===========================================================================*/
/* Driver local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/**
* @brief Wakes up the waiting thread.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] msg wakeup message
*
* @notapi
*/
#define wakeup_isr(i2cp, msg) { \
chSysLockFromIsr(); \
if ((i2cp)->thread != NULL) { \
Thread *tp = (i2cp)->thread; \
(i2cp)->thread = NULL; \
tp->p_u.rdymsg = (msg); \
chSchReadyI(tp); \
} \
chSysUnlockFromIsr(); \
}
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
#if USE_AVR_I2C || defined(__DOXYGEN__)
/**
* @brief I2C event interrupt handler.
*
* @notapi
*/
CH_IRQ_HANDLER(TWI_vect) {
CH_IRQ_PROLOGUE();
I2CDriver *i2cp = &I2CD;
switch (TWSR & 0xF8) {
case TWI_START:
case TWI_REPEAT_START:
TWDR = (i2cp->addr << 1);
if ((i2cp->txbuf == NULL) || (i2cp->txbytes == 0) || (i2cp->txidx == i2cp->txbytes)) {
TWDR |= 0x01;
}
TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
break;
case TWI_MASTER_TX_ADDR_ACK:
case TWI_MASTER_TX_DATA_ACK:
if (i2cp->txidx < i2cp->txbytes) {
TWDR = i2cp->txbuf[i2cp->txidx++];
TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
} else {
if (i2cp->rxbuf && i2cp->rxbytes) {
TWCR = ((1 << TWSTA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
} else {
TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
wakeup_isr(i2cp, RDY_OK);
}
}
break;
case TWI_MASTER_RX_ADDR_ACK:
if (i2cp->rxidx == (i2cp->rxbytes - 1)) {
TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
} else {
TWCR = ((1 << TWEA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
}
break;
case TWI_MASTER_RX_DATA_ACK:
i2cp->rxbuf[i2cp->rxidx++] = TWDR;
if (i2cp->rxidx == (i2cp->rxbytes - 1)) {
TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
} else {
TWCR = ((1 << TWEA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
}
break;
case TWI_MASTER_RX_DATA_NACK:
i2cp->rxbuf[i2cp->rxidx] = TWDR;
TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
wakeup_isr(i2cp, RDY_OK);
case TWI_MASTER_TX_ADDR_NACK:
case TWI_MASTER_TX_DATA_NACK:
case TWI_MASTER_RX_ADDR_NACK:
i2cp->errors |= I2CD_ACK_FAILURE;
break;
case TWI_ARBITRATION_LOST:
i2cp->errors |= I2CD_ARBITRATION_LOST;
break;
case TWI_BUS_ERROR:
i2cp->errors |= I2CD_BUS_ERROR;
break;
default:
/* FIXME: only gets here if there are other MASTERs in the bus */
TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
wakeup_isr(i2cp, RDY_RESET);
}
if (i2cp->errors != I2CD_NO_ERROR) {
TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
wakeup_isr(i2cp, RDY_RESET);
}
CH_IRQ_EPILOGUE();
}
#endif /* USE_AVR_I2C */
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level I2C driver initialization.
*
* @notapi
*/
void i2c_lld_init(void) {
i2cObjectInit(&I2CD);
}
/**
* @brief Configures and activates the I2C peripheral.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
void i2c_lld_start(I2CDriver *i2cp) {
/* TODO: Test TWI without external pull-ups (use internal) */
/* Configure prescaler to 1 */
TWSR &= 0xF8;
/* Configure baudrate */
TWBR = ((F_CPU / i2cp->config->clock_speed) - 16) / 2;
}
/**
* @brief Deactivates the I2C peripheral.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
void i2c_lld_stop(I2CDriver *i2cp) {
if (i2cp->state != I2C_STOP) {
/* Disable TWI subsystem and stop all operations */
TWCR &= ~(1 << TWEN);
}
}
/**
* @brief Receives data via the I2C bus as master.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] addr slave device address
* @param[out] rxbuf pointer to the receive buffer
* @param[in] rxbytes number of bytes to be received
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval RDY_OK if the function succeeded.
* @retval RDY_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
* @retval RDY_TIMEOUT if a timeout occurred before operation end. <b>After a
* timeout the driver must be stopped and restarted
* because the bus is in an uncertain state</b>.
*
* @notapi
*/
msg_t i2c_lld_master_receive_timeout(I2CDriver *i2cp, i2caddr_t addr,
uint8_t *rxbuf, size_t rxbytes,
systime_t timeout) {
i2cp->addr = addr;
i2cp->txbuf = NULL;
i2cp->txbytes = 0;
i2cp->txidx = 0;
i2cp->rxbuf = rxbuf;
i2cp->rxbytes = rxbytes;
i2cp->rxidx = 0;
/* Send START */
TWCR = ((1 << TWSTA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
chSysLock();
i2cp->thread = chThdSelf();
chSchGoSleepS(THD_STATE_SUSPENDED);
chSysUnlock();
return chThdSelf()->p_u.rdymsg;
}
/**
* @brief Transmits data via the I2C bus as master.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] addr slave device address
* @param[in] txbuf pointer to the transmit buffer
* @param[in] txbytes number of bytes to be transmitted
* @param[out] rxbuf pointer to the receive buffer
* @param[in] rxbytes number of bytes to be received
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval RDY_OK if the function succeeded.
* @retval RDY_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
* @retval RDY_TIMEOUT if a timeout occurred before operation end. <b>After a
* timeout the driver must be stopped and restarted
* because the bus is in an uncertain state</b>.
*
* @notapi
*/
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) {
i2cp->addr = addr;
i2cp->txbuf = txbuf;
i2cp->txbytes = txbytes;
i2cp->txidx = 0;
i2cp->rxbuf = rxbuf;
i2cp->rxbytes = rxbytes;
i2cp->rxidx = 0;
TWCR = ((1 << TWSTA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
chSysLock();
i2cp->thread = chThdSelf();
chSchGoSleepS(THD_STATE_SUSPENDED);
chSysUnlock();
return chThdSelf()->p_u.rdymsg;
}
#endif /* HAL_USE_I2C */
/** @} */

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os/hal/platforms/AVR/i2c_lld.h Normal file
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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
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.
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/>.
*/
/**
* @file AVR/i2c_lld.h
* @brief AVR I2C subsystem low level driver header.
*
* @addtogroup I2C
* @{
*/
#ifndef _I2C_LLD_H_
#define _I2C_LLD_H_
#if HAL_USE_I2C || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver constants. */
/*===========================================================================*/
/** START transmitted */
#define TWI_START 0x08
/** Repeated START transmitted */
#define TWI_REPEAT_START 0x10
/** Arbitration Lost */
#define TWI_ARBITRATION_LOST 0x38
/** Bus errors */
#define TWI_BUS_ERROR 0x00
/** SLA+W transmitted with ACK response */
#define TWI_MASTER_TX_ADDR_ACK 0x18
/** SLA+W transmitted with NACK response */
#define TWI_MASTER_TX_ADDR_NACK 0x20
/** DATA transmitted with ACK response */
#define TWI_MASTER_TX_DATA_ACK 0x28
/** DATA transmitted with NACK response */
#define TWI_MASTER_TX_DATA_NACK 0x30
/** SLA+R transmitted with ACK response */
#define TWI_MASTER_RX_ADDR_ACK 0x40
/** SLA+R transmitted with NACK response */
#define TWI_MASTER_RX_ADDR_NACK 0x48
/** DATA received with ACK response */
#define TWI_MASTER_RX_DATA_ACK 0x50
/** DATA received with NACK response */
#define TWI_MASTER_RX_DATA_NACK 0x58
/*===========================================================================*/
/* Driver pre-compile time settings. */
/*===========================================================================*/
/**
* @name Configuration options
* @{
*/
/**
* @brief I2C driver enable switch.
* @details If set to @p TRUE the support for I2C is included.
* @note The default is @p FALSE.
*/
#if !defined(USE_AVR_I2C) || defined(__DOXYGEN__)
#define USE_AVR_I2C FALSE
#endif
/*===========================================================================*/
/* Derived constants and error checks. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver data structures and types. */
/*===========================================================================*/
/**
* @brief Type representing I2C address.
*/
typedef uint8_t i2caddr_t;
/**
* @brief I2C Driver condition flags type.
*/
typedef uint8_t i2cflags_t;
/**
* @brief Driver configuration structure.
* @note Implementations may extend this structure to contain more,
* architecture dependent, fields.
*/
typedef struct {
/**
* @brief Specifies the I2C clock frequency.
*/
uint32_t clock_speed;
} I2CConfig;
/**
* @brief Structure representing an I2C driver.
*/
struct I2CDriver {
/**
* @brief Driver state.
*/
i2cstate_t state;
/**
* @brief Current configuration data.
*/
const I2CConfig *config;
/**
* @brief Error flags.
*/
i2cflags_t errors;
#if I2C_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
#if CH_USE_MUTEXES || defined(__DOXYGEN__)
/**
* @brief Mutex protecting the bus.
*/
Mutex mutex;
#elif CH_USE_SEMAPHORES
Semaphore semaphore;
#endif
#endif /* I2C_USE_MUTUAL_EXCLUSION */
#if defined(I2C_DRIVER_EXT_FIELDS)
I2C_DRIVER_EXT_FIELDS
#endif
/* End of the mandatory fields.*/
/**
* @brief Thread waiting for I/O completion.
*/
Thread *thread;
/**
* @brief Address of slave device
*/
i2caddr_t addr;
/**
* @brief Pointer to the buffer with data to send.
*/
const uint8_t *txbuf;
/**
* @brief Number of bytes of data to send.
*/
size_t txbytes;
/**
* @brief Current index in buffer when sending data.
*/
size_t txidx;
/**
* @brief Pointer to the buffer to put received data.
*/
uint8_t *rxbuf;
/**
* @brief Number of bytes of data to receive.
*/
size_t rxbytes;
/**
* @brief Current index in buffer when receiving data.
*/
size_t rxidx;
};
/**
* @brief Type of a structure representing an I2C driver.
*/
typedef struct I2CDriver I2CDriver;
/*===========================================================================*/
/* Driver macros. */
/*===========================================================================*/
/**
* @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_ */
/** @} */

12
os/hal/platforms/AVR/platform.dox
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@ -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
*/

3
os/hal/platforms/AVR/platform.mk
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@ -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

1
readme.txt
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@ -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