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LibrePilot/flight/PiOS/STM32F10x/pios_i2c.c
stac 88e73906d0 i2c: Add recovery code for i2c bus errors 
I2C bus errors are now recoverable.  The bus is properly reset
and an error indication is now provided to the caller whenever
a bus error occurs during processing of the transaction list.

For now, the users of the I2C layer just retry infinitely on
failure.  The BMP085 and HMC5843 code should be changed to
report errors to its callers to allow a more sensible retry
strategy.

git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@1625 ebee16cc-31ac-478f-84a7-5cbb03baadba
2010-09-15 14:20:57 +00:00

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/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_I2C I2C Functions
* @brief STM32 Hardware dependent I2C functionality
* @{
*
* @file pios_i2c.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* Parts by Thorsten Klose (tk@midibox.org) (tk@midibox.org)
* @brief I2C Enable/Disable routines
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* This program 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.
*
* This program 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, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* Project Includes */
#include "pios.h"
#if defined(PIOS_INCLUDE_I2C)
#if defined(PIOS_INCLUDE_FREERTOS)
#define USE_FREERTOS
#endif
#include <pios_i2c_priv.h>
enum i2c_adapter_event {
I2C_EVENT_BUS_ERROR,
I2C_EVENT_START,
I2C_EVENT_STARTED_MORE_TXN_READ,
I2C_EVENT_STARTED_MORE_TXN_WRITE,
I2C_EVENT_STARTED_LAST_TXN_READ,
I2C_EVENT_STARTED_LAST_TXN_WRITE,
I2C_EVENT_ADDR_SENT_LEN_EQ_0,
I2C_EVENT_ADDR_SENT_LEN_EQ_1,
I2C_EVENT_ADDR_SENT_LEN_EQ_2,
I2C_EVENT_ADDR_SENT_LEN_GT_2,
I2C_EVENT_TRANSFER_DONE_LEN_EQ_0,
I2C_EVENT_TRANSFER_DONE_LEN_EQ_1,
I2C_EVENT_TRANSFER_DONE_LEN_EQ_2,
I2C_EVENT_TRANSFER_DONE_LEN_GT_2,
I2C_EVENT_STOPPED,
I2C_EVENT_AUTO, /* FIXME: remove this */
I2C_EVENT_NUM_EVENTS /* Must be last */
};
static void go_fsm_fault (struct pios_i2c_adapter * i2c_adapter);
static void go_bus_error (struct pios_i2c_adapter * i2c_adapter);
static void go_stopping (struct pios_i2c_adapter * i2c_adapter);
static void go_stopped (struct pios_i2c_adapter * i2c_adapter);
static void go_starting (struct pios_i2c_adapter * i2c_adapter);
static void go_r_any_txn_addr (struct pios_i2c_adapter * i2c_adapter);
static void go_r_more_txn_pre_one (struct pios_i2c_adapter * i2c_adapter);
static void go_r_any_txn_pre_first (struct pios_i2c_adapter * i2c_adapter);
static void go_r_any_txn_pre_middle (struct pios_i2c_adapter * i2c_adapter);
static void go_r_more_txn_pre_last (struct pios_i2c_adapter * i2c_adapter);
static void go_r_any_txn_post_last (struct pios_i2c_adapter * i2c_adapter);
static void go_r_any_txn_addr (struct pios_i2c_adapter * i2c_adapter);
static void go_r_last_txn_pre_one (struct pios_i2c_adapter * i2c_adapter);
static void go_r_any_txn_pre_first (struct pios_i2c_adapter * i2c_adapter);
static void go_r_any_txn_pre_middle (struct pios_i2c_adapter * i2c_adapter);
static void go_r_last_txn_pre_last (struct pios_i2c_adapter * i2c_adapter);
static void go_r_any_txn_post_last (struct pios_i2c_adapter * i2c_adapter);
static void go_w_any_txn_addr (struct pios_i2c_adapter * i2c_adapter);
static void go_w_any_txn_middle (struct pios_i2c_adapter * i2c_adapter);
static void go_w_more_txn_last (struct pios_i2c_adapter * i2c_adapter);
static void go_w_any_txn_addr (struct pios_i2c_adapter * i2c_adapter);
static void go_w_any_txn_middle (struct pios_i2c_adapter * i2c_adapter);
static void go_w_last_txn_last (struct pios_i2c_adapter * i2c_adapter);
struct i2c_adapter_transition {
void (*entry_fn)(struct pios_i2c_adapter * i2c_adapter);
enum i2c_adapter_state next_state[I2C_EVENT_NUM_EVENTS];
};
static void i2c_adapter_process_auto(struct pios_i2c_adapter * i2c_adapter);
static void i2c_adapter_inject_event(struct pios_i2c_adapter * i2c_adapter, enum i2c_adapter_event event);
static void i2c_adapter_fsm_init(struct pios_i2c_adapter * i2c_adapter);
static bool i2c_adapter_wait_for_stopped(struct pios_i2c_adapter * i2c_adapter);
static void i2c_adapter_reset_bus(struct pios_i2c_adapter * i2c_adapter);
const static struct i2c_adapter_transition i2c_adapter_transitions[I2C_STATE_NUM_STATES] = {
[I2C_STATE_FSM_FAULT] = {
.entry_fn = go_fsm_fault,
},
[I2C_STATE_BUS_ERROR] = {
.entry_fn = go_bus_error,
.next_state = {
[I2C_EVENT_AUTO] = I2C_STATE_STOPPING,
},
},
[I2C_STATE_STOPPED] = {
.entry_fn = go_stopped,
.next_state = {
[I2C_EVENT_START] = I2C_STATE_STARTING,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_STOPPING] = {
.entry_fn = go_stopping,
.next_state = {
[I2C_EVENT_STOPPED] = I2C_STATE_STOPPED,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_STARTING] = {
.entry_fn = go_starting,
.next_state = {
[I2C_EVENT_STARTED_MORE_TXN_READ] = I2C_STATE_R_MORE_TXN_ADDR,
[I2C_EVENT_STARTED_MORE_TXN_WRITE] = I2C_STATE_W_MORE_TXN_ADDR,
[I2C_EVENT_STARTED_LAST_TXN_READ] = I2C_STATE_R_LAST_TXN_ADDR,
[I2C_EVENT_STARTED_LAST_TXN_WRITE] = I2C_STATE_W_LAST_TXN_ADDR,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
/*
* Read with restart
*/
[I2C_STATE_R_MORE_TXN_ADDR] = {
.entry_fn = go_r_any_txn_addr,
.next_state = {
[I2C_EVENT_ADDR_SENT_LEN_EQ_1] = I2C_STATE_R_MORE_TXN_PRE_ONE,
[I2C_EVENT_ADDR_SENT_LEN_EQ_2] = I2C_STATE_R_MORE_TXN_PRE_FIRST,
[I2C_EVENT_ADDR_SENT_LEN_GT_2] = I2C_STATE_R_MORE_TXN_PRE_FIRST,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_R_MORE_TXN_PRE_ONE] = {
.entry_fn = go_r_more_txn_pre_one,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_1] = I2C_STATE_R_MORE_TXN_POST_LAST,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_R_MORE_TXN_PRE_FIRST] = {
.entry_fn = go_r_any_txn_pre_first,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_2] = I2C_STATE_R_MORE_TXN_PRE_LAST,
[I2C_EVENT_TRANSFER_DONE_LEN_GT_2] = I2C_STATE_R_MORE_TXN_PRE_MIDDLE,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_R_MORE_TXN_PRE_MIDDLE] = {
.entry_fn = go_r_any_txn_pre_middle,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_2] = I2C_STATE_R_MORE_TXN_PRE_LAST,
[I2C_EVENT_TRANSFER_DONE_LEN_GT_2] = I2C_STATE_R_MORE_TXN_PRE_MIDDLE,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_R_MORE_TXN_PRE_LAST] = {
.entry_fn = go_r_more_txn_pre_last,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_1] = I2C_STATE_R_MORE_TXN_POST_LAST,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_R_MORE_TXN_POST_LAST] = {
.entry_fn = go_r_any_txn_post_last,
.next_state = {
[I2C_EVENT_AUTO] = I2C_STATE_STARTING,
},
},
/*
* Read
*/
[I2C_STATE_R_LAST_TXN_ADDR] = {
.entry_fn = go_r_any_txn_addr,
.next_state = {
[I2C_EVENT_ADDR_SENT_LEN_EQ_1] = I2C_STATE_R_LAST_TXN_PRE_ONE,
[I2C_EVENT_ADDR_SENT_LEN_EQ_2] = I2C_STATE_R_LAST_TXN_PRE_FIRST,
[I2C_EVENT_ADDR_SENT_LEN_GT_2] = I2C_STATE_R_LAST_TXN_PRE_FIRST,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_R_LAST_TXN_PRE_ONE] = {
.entry_fn = go_r_last_txn_pre_one,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_1] = I2C_STATE_R_LAST_TXN_POST_LAST,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_R_LAST_TXN_PRE_FIRST] = {
.entry_fn = go_r_any_txn_pre_first,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_2] = I2C_STATE_R_LAST_TXN_PRE_LAST,
[I2C_EVENT_TRANSFER_DONE_LEN_GT_2] = I2C_STATE_R_LAST_TXN_PRE_MIDDLE,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_R_LAST_TXN_PRE_MIDDLE] = {
.entry_fn = go_r_any_txn_pre_middle,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_2] = I2C_STATE_R_LAST_TXN_PRE_LAST,
[I2C_EVENT_TRANSFER_DONE_LEN_GT_2] = I2C_STATE_R_LAST_TXN_PRE_MIDDLE,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_R_LAST_TXN_PRE_LAST] = {
.entry_fn = go_r_last_txn_pre_last,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_1] = I2C_STATE_R_LAST_TXN_POST_LAST,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_R_LAST_TXN_POST_LAST] = {
.entry_fn = go_r_any_txn_post_last,
.next_state = {
[I2C_EVENT_AUTO] = I2C_STATE_STOPPING,
},
},
/*
* Write with restart
*/
[I2C_STATE_W_MORE_TXN_ADDR] = {
.entry_fn = go_w_any_txn_addr,
.next_state = {
[I2C_EVENT_ADDR_SENT_LEN_EQ_1] = I2C_STATE_W_MORE_TXN_LAST,
[I2C_EVENT_ADDR_SENT_LEN_EQ_2] = I2C_STATE_W_MORE_TXN_MIDDLE,
[I2C_EVENT_ADDR_SENT_LEN_GT_2] = I2C_STATE_W_MORE_TXN_MIDDLE,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_W_MORE_TXN_MIDDLE] = {
.entry_fn = go_w_any_txn_middle,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_1] = I2C_STATE_W_MORE_TXN_LAST,
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_2] = I2C_STATE_W_MORE_TXN_MIDDLE,
[I2C_EVENT_TRANSFER_DONE_LEN_GT_2] = I2C_STATE_W_MORE_TXN_MIDDLE,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_W_MORE_TXN_LAST] = {
.entry_fn = go_w_more_txn_last,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_0] = I2C_STATE_STARTING,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
/*
* Write
*/
[I2C_STATE_W_LAST_TXN_ADDR] = {
.entry_fn = go_w_any_txn_addr,
.next_state = {
[I2C_EVENT_ADDR_SENT_LEN_EQ_1] = I2C_STATE_W_LAST_TXN_LAST,
[I2C_EVENT_ADDR_SENT_LEN_EQ_2] = I2C_STATE_W_LAST_TXN_MIDDLE,
[I2C_EVENT_ADDR_SENT_LEN_GT_2] = I2C_STATE_W_LAST_TXN_MIDDLE,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_W_LAST_TXN_MIDDLE] = {
.entry_fn = go_w_any_txn_middle,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_1] = I2C_STATE_W_LAST_TXN_LAST,
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_2] = I2C_STATE_W_LAST_TXN_MIDDLE,
[I2C_EVENT_TRANSFER_DONE_LEN_GT_2] = I2C_STATE_W_LAST_TXN_MIDDLE,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
[I2C_STATE_W_LAST_TXN_LAST] = {
.entry_fn = go_w_last_txn_last,
.next_state = {
[I2C_EVENT_TRANSFER_DONE_LEN_EQ_0] = I2C_STATE_STOPPING,
[I2C_EVENT_BUS_ERROR] = I2C_STATE_BUS_ERROR,
},
},
};
static void go_fsm_fault (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(0);
}
static void go_bus_error (struct pios_i2c_adapter * i2c_adapter)
{
/* Note that this transfer has hit a bus error */
i2c_adapter->bus_error = true;
i2c_adapter_reset_bus (i2c_adapter);
}
static void go_stopping (struct pios_i2c_adapter * i2c_adapter)
{
#ifdef USE_FREERTOS
signed portBASE_TYPE pxHigherPriorityTaskWoken = pdFALSE;
#endif
I2C_ITConfig(i2c_adapter->cfg->regs, I2C_IT_EVT | I2C_IT_BUF | I2C_IT_ERR, DISABLE);
#ifdef USE_FREERTOS
if (xSemaphoreGiveFromISR(i2c_adapter->sem_ready, &pxHigherPriorityTaskWoken) != pdTRUE) {
PIOS_DEBUG_Assert(0);
}
portEND_SWITCHING_ISR(pxHigherPriorityTaskWoken); /* FIXME: is this the right place for this? */
#endif /* USE_FREERTOS */
}
static void go_stopped (struct pios_i2c_adapter * i2c_adapter)
{
I2C_ITConfig(i2c_adapter->cfg->regs, I2C_IT_EVT | I2C_IT_BUF | I2C_IT_ERR, DISABLE);
I2C_AcknowledgeConfig(i2c_adapter->cfg->regs, ENABLE);
}
static void go_starting (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(i2c_adapter->active_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn >= i2c_adapter->first_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn <= i2c_adapter->last_txn);
i2c_adapter->active_byte = &(i2c_adapter->active_txn->buf[0]);
i2c_adapter->last_byte = &(i2c_adapter->active_txn->buf[i2c_adapter->active_txn->len - 1]);
I2C_GenerateSTART(i2c_adapter->cfg->regs, ENABLE);
I2C_ITConfig(i2c_adapter->cfg->regs, I2C_IT_EVT | I2C_IT_BUF | I2C_IT_ERR, ENABLE);
}
/* Common to 'more' and 'last' transaction */
static void go_r_any_txn_addr (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(i2c_adapter->active_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn >= i2c_adapter->first_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn <= i2c_adapter->last_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn->rw == PIOS_I2C_TXN_READ);
I2C_Send7bitAddress(i2c_adapter->cfg->regs, (i2c_adapter->active_txn->addr)<<1, I2C_Direction_Receiver);
}
static void go_r_more_txn_pre_one (struct pios_i2c_adapter * i2c_adapter)
{
I2C_AcknowledgeConfig(i2c_adapter->cfg->regs, DISABLE);
I2C_GenerateSTART(i2c_adapter->cfg->regs, ENABLE);
}
static void go_r_last_txn_pre_one (struct pios_i2c_adapter * i2c_adapter)
{
I2C_AcknowledgeConfig(i2c_adapter->cfg->regs, DISABLE);
I2C_GenerateSTOP(i2c_adapter->cfg->regs, ENABLE);
}
/* Common to 'more' and 'last' transaction */
static void go_r_any_txn_pre_first (struct pios_i2c_adapter * i2c_adapter)
{
I2C_AcknowledgeConfig(i2c_adapter->cfg->regs, ENABLE);
}
/* Common to 'more' and 'last' transaction */
static void go_r_any_txn_pre_middle (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(i2c_adapter->active_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_byte <= i2c_adapter->last_byte);
*(i2c_adapter->active_byte) = I2C_ReceiveData(i2c_adapter->cfg->regs);
/* Move to the next byte */
i2c_adapter->active_byte++;
PIOS_DEBUG_Assert(i2c_adapter->active_byte <= i2c_adapter->last_byte);
}
static void go_r_more_txn_pre_last (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(i2c_adapter->active_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_byte <= i2c_adapter->last_byte);
I2C_AcknowledgeConfig(i2c_adapter->cfg->regs, DISABLE);
PIOS_IRQ_Disable();
I2C_ITConfig(i2c_adapter->cfg->regs, I2C_IT_EVT | I2C_IT_BUF | I2C_IT_ERR, DISABLE);
I2C_GenerateSTART(i2c_adapter->cfg->regs, ENABLE);
*(i2c_adapter->active_byte) = I2C_ReceiveData(i2c_adapter->cfg->regs);
I2C_ITConfig(i2c_adapter->cfg->regs, I2C_IT_EVT | I2C_IT_BUF | I2C_IT_ERR, ENABLE);
PIOS_IRQ_Enable();
/* Move to the next byte */
i2c_adapter->active_byte++;
PIOS_DEBUG_Assert(i2c_adapter->active_byte <= i2c_adapter->last_byte);
}
static void go_r_last_txn_pre_last (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(i2c_adapter->active_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_byte <= i2c_adapter->last_byte);
I2C_AcknowledgeConfig(i2c_adapter->cfg->regs, DISABLE);
PIOS_IRQ_Disable();
I2C_ITConfig(i2c_adapter->cfg->regs, I2C_IT_EVT | I2C_IT_BUF | I2C_IT_ERR, DISABLE);
I2C_GenerateSTOP(i2c_adapter->cfg->regs, ENABLE);
*(i2c_adapter->active_byte) = I2C_ReceiveData(i2c_adapter->cfg->regs);
I2C_ITConfig(i2c_adapter->cfg->regs, I2C_IT_EVT | I2C_IT_BUF | I2C_IT_ERR, ENABLE);
PIOS_IRQ_Enable();
/* Move to the next byte */
i2c_adapter->active_byte++;
PIOS_DEBUG_Assert(i2c_adapter->active_byte <= i2c_adapter->last_byte);
}
/* Common to 'more' and 'last' transaction */
static void go_r_any_txn_post_last (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(i2c_adapter->active_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_byte == i2c_adapter->last_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn >= i2c_adapter->first_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn <= i2c_adapter->last_txn);
*(i2c_adapter->active_byte) = I2C_ReceiveData(i2c_adapter->cfg->regs);
/* Move to the next byte */
i2c_adapter->active_byte++;
/* Move to the next transaction */
i2c_adapter->active_txn++;
}
/* Common to 'more' and 'last' transaction */
static void go_w_any_txn_addr (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(i2c_adapter->active_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn >= i2c_adapter->first_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn <= i2c_adapter->last_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn->rw == PIOS_I2C_TXN_WRITE);
I2C_Send7bitAddress(i2c_adapter->cfg->regs, (i2c_adapter->active_txn->addr)<<1, I2C_Direction_Transmitter);
}
static void go_w_any_txn_middle (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(i2c_adapter->active_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_byte < i2c_adapter->last_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn >= i2c_adapter->first_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn <= i2c_adapter->last_txn);
I2C_SendData(i2c_adapter->cfg->regs, *(i2c_adapter->active_byte));
/* Move to the next byte */
i2c_adapter->active_byte++;
PIOS_DEBUG_Assert(i2c_adapter->active_byte <= i2c_adapter->last_byte);
}
static void go_w_more_txn_last (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(i2c_adapter->active_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_byte == i2c_adapter->last_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn >= i2c_adapter->first_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn <= i2c_adapter->last_txn);
I2C_SendData(i2c_adapter->cfg->regs, *(i2c_adapter->active_byte));
/* Move to the next byte */
i2c_adapter->active_byte++;
/* Move to the next transaction */
i2c_adapter->active_txn++;
PIOS_DEBUG_Assert(i2c_adapter->active_txn <= i2c_adapter->last_txn);
}
static void go_w_last_txn_last (struct pios_i2c_adapter * i2c_adapter)
{
PIOS_DEBUG_Assert(i2c_adapter->active_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_byte == i2c_adapter->last_byte);
PIOS_DEBUG_Assert(i2c_adapter->active_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn >= i2c_adapter->first_txn);
PIOS_DEBUG_Assert(i2c_adapter->active_txn <= i2c_adapter->last_txn);
I2C_ITConfig(i2c_adapter->cfg->regs, I2C_IT_BUF, DISABLE);
I2C_SendData(i2c_adapter->cfg->regs, *(i2c_adapter->active_byte));
// SHOULD MOVE THIS INTO A STOPPING STATE AND SET IT ONLY AFTER THE BYTE WAS SENT
I2C_GenerateSTOP(i2c_adapter->cfg->regs, ENABLE);
/* Move to the next byte */
i2c_adapter->active_byte++;
}
static void i2c_adapter_inject_event(struct pios_i2c_adapter * i2c_adapter, enum i2c_adapter_event event)
{
PIOS_IRQ_Disable();
/*
* Move to the next state
*
* This is done prior to calling the new state's entry function to
* guarantee that the entry function never depends on the previous
* state. This way, it cannot ever know what the previous state was.
*/
enum i2c_adapter_state prev_state = i2c_adapter->curr_state;
if (prev_state);
i2c_adapter->curr_state = i2c_adapter_transitions[i2c_adapter->curr_state].next_state[event];
/* Call the entry function (if any) for the next state. */
if (i2c_adapter_transitions[i2c_adapter->curr_state].entry_fn) {
i2c_adapter_transitions[i2c_adapter->curr_state].entry_fn(i2c_adapter);
}
/* Process any AUTO transitions in the FSM */
i2c_adapter_process_auto(i2c_adapter);
PIOS_IRQ_Enable();
}
static void i2c_adapter_process_auto(struct pios_i2c_adapter * i2c_adapter)
{
PIOS_IRQ_Disable();
enum i2c_adapter_state prev_state = i2c_adapter->curr_state;
if (prev_state);
while (i2c_adapter_transitions[i2c_adapter->curr_state].next_state[I2C_EVENT_AUTO]) {
i2c_adapter->curr_state = i2c_adapter_transitions[i2c_adapter->curr_state].next_state[I2C_EVENT_AUTO];
/* Call the entry function (if any) for the next state. */
if (i2c_adapter_transitions[i2c_adapter->curr_state].entry_fn) {
i2c_adapter_transitions[i2c_adapter->curr_state].entry_fn(i2c_adapter);
}
}
PIOS_IRQ_Enable();
}
static void i2c_adapter_fsm_init(struct pios_i2c_adapter * i2c_adapter)
{
i2c_adapter_reset_bus(i2c_adapter);
i2c_adapter->curr_state = I2C_STATE_STOPPED;
}
static bool i2c_adapter_wait_for_stopped(struct pios_i2c_adapter * i2c_adapter)
{
uint32_t guard;
/*
* Wait for the bus to return to the stopped state.
* This was pulled out of the FSM due to occasional
* failures at this transition which previously resulted
* in spinning on this bit in the ISR forever.
*/
#define I2C_CR1_STOP_REQUESTED 0x0200
for (guard = 1e6; /* FIXME: should use the configured bus timeout */
guard && (i2c_adapter->cfg->regs->CR1 & I2C_CR1_STOP_REQUESTED);
guard--) continue;
if (!guard) {
/* We timed out waiting for the stop condition */
return false;
}
return true;
}
static void i2c_adapter_reset_bus(struct pios_i2c_adapter * i2c_adapter)
{
/* Reset the I2C block */
I2C_DeInit(i2c_adapter->cfg->regs);
/* Make sure the bus is free by clocking it until any slaves release the bus. */
GPIO_InitTypeDef scl_gpio_init;
scl_gpio_init = i2c_adapter->cfg->scl.init;
scl_gpio_init.GPIO_Mode = GPIO_Mode_Out_OD;
GPIO_SetBits(i2c_adapter->cfg->scl.gpio, i2c_adapter->cfg->scl.init.GPIO_Pin);
GPIO_Init(i2c_adapter->cfg->scl.gpio, &scl_gpio_init);
GPIO_InitTypeDef sda_gpio_init;
sda_gpio_init = i2c_adapter->cfg->sda.init;
sda_gpio_init.GPIO_Mode = GPIO_Mode_Out_OD;
GPIO_SetBits(i2c_adapter->cfg->sda.gpio, i2c_adapter->cfg->sda.init.GPIO_Pin);
GPIO_Init(i2c_adapter->cfg->sda.gpio, &sda_gpio_init);
for (uint8_t i = 0; i < 9; i++) {
/* Set clock high and wait for any clock stretching to finish. */
GPIO_SetBits(i2c_adapter->cfg->scl.gpio, i2c_adapter->cfg->scl.init.GPIO_Pin);
while (GPIO_ReadInputDataBit(i2c_adapter->cfg->scl.gpio, i2c_adapter->cfg->scl.init.GPIO_Pin) == Bit_RESET);
PIOS_DELAY_WaituS(2);
/* Set clock low */
GPIO_ResetBits(i2c_adapter->cfg->scl.gpio, i2c_adapter->cfg->scl.init.GPIO_Pin);
PIOS_DELAY_WaituS(2);
}
/* Set data and clock high and wait for any clock stretching to finish. */
GPIO_SetBits(i2c_adapter->cfg->sda.gpio, i2c_adapter->cfg->sda.init.GPIO_Pin);
GPIO_SetBits(i2c_adapter->cfg->scl.gpio, i2c_adapter->cfg->scl.init.GPIO_Pin);
while (GPIO_ReadInputDataBit(i2c_adapter->cfg->scl.gpio, i2c_adapter->cfg->scl.init.GPIO_Pin) == Bit_RESET);
/* Wait for data to be high */
while (GPIO_ReadInputDataBit(i2c_adapter->cfg->sda.gpio, i2c_adapter->cfg->sda.init.GPIO_Pin) != Bit_SET);
/* Bus signals are guaranteed to be high (ie. free) after this point */
/* Initialize the GPIO pins to the peripheral function */
GPIO_Init(i2c_adapter->cfg->scl.gpio, &(i2c_adapter->cfg->scl.init));
GPIO_Init(i2c_adapter->cfg->sda.gpio, &(i2c_adapter->cfg->sda.init));
/* Reset the I2C block */
I2C_DeInit(i2c_adapter->cfg->regs);
/* Initialize the I2C block */
I2C_Init(i2c_adapter->cfg->regs, &(i2c_adapter->cfg->init));
#define I2C_BUSY 0x20
if (i2c_adapter->cfg->regs->SR2 & I2C_BUSY) {
/* Reset the I2C block */
I2C_SoftwareResetCmd(i2c_adapter->cfg->regs, ENABLE);
I2C_SoftwareResetCmd(i2c_adapter->cfg->regs, DISABLE);
}
}
#include <pios_i2c_priv.h>
static struct pios_i2c_adapter * find_i2c_adapter_by_id (uint8_t adapter)
{
if (adapter >= pios_i2c_num_adapters) {
/* Undefined I2C adapter for this board (see pios_board.c) */
return NULL;
}
/* Get a handle for the device configuration */
return &(pios_i2c_adapters[adapter]);
}
/* Return true if the FSM is in a terminal state */
static bool i2c_adapter_fsm_terminated(struct pios_i2c_adapter * i2c_adapter)
{
switch (i2c_adapter->curr_state) {
case I2C_STATE_STOPPING:
case I2C_STATE_STOPPED:
return (true);
default:
return (false);
}
}
/**
* Initializes IIC driver
* \param[in] mode currently only mode 0 supported
* \return < 0 if initialisation failed
*/
int32_t PIOS_I2C_Init(void)
{
struct pios_i2c_adapter * i2c_adapter;
for (uint8_t i = 0; i < pios_i2c_num_adapters; i++) {
/* Get a handle for the device configuration */
i2c_adapter = find_i2c_adapter_by_id(i);
PIOS_DEBUG_Assert(i2c_adapter);
#ifdef USE_FREERTOS
/*
* Must be done prior to calling i2c_adapter_fsm_init()
* since the sem_ready mutex is used in the initial state.
*/
vSemaphoreCreateBinary(i2c_adapter->sem_ready);
i2c_adapter->sem_busy = xSemaphoreCreateMutex();
#endif // USE_FREERTOS
/* Enable the associated peripheral clock */
switch ((uint32_t)i2c_adapter->cfg->regs) {
case (uint32_t)I2C1:
/* Enable I2C peripheral clock (APB1 == slow speed) */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
break;
case (uint32_t)I2C2:
/* Enable I2C peripheral clock (APB1 == slow speed) */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);
break;
}
/* Initialize the state machine */
i2c_adapter_fsm_init(i2c_adapter);
/* Configure and enable I2C interrupts */
NVIC_Init(&(i2c_adapter->cfg->event.init));
NVIC_Init(&(i2c_adapter->cfg->error.init));
}
/* No error */
return 0;
}
bool PIOS_I2C_Transfer(uint8_t i2c, const struct pios_i2c_txn txn_list[], uint32_t num_txns)
{
PIOS_DEBUG_Assert(txn_list);
PIOS_DEBUG_Assert(num_txns);
struct pios_i2c_adapter * i2c_adapter;
i2c_adapter = find_i2c_adapter_by_id(i2c);
PIOS_DEBUG_Assert(i2c_adapter);
#ifdef USE_FREERTOS
/* Lock the bus */
xSemaphoreTake(i2c_adapter->sem_busy, portMAX_DELAY);
#endif /* USE_FREERTOS */
PIOS_DEBUG_Assert(i2c_adapter->curr_state == I2C_STATE_STOPPED);
i2c_adapter->first_txn = &txn_list[0];
i2c_adapter->last_txn = &txn_list[num_txns - 1];
i2c_adapter->active_txn = i2c_adapter->first_txn;
#ifdef USE_FREERTOS
/* Make sure the done/ready semaphore is consumed before we start */
xSemaphoreTake(i2c_adapter->sem_ready, portMAX_DELAY);
#endif
i2c_adapter->bus_error = false;
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_START);
/* Wait for the transfer to complete */
#ifdef USE_FREERTOS
xSemaphoreTake(i2c_adapter->sem_ready, portMAX_DELAY);
xSemaphoreGive(i2c_adapter->sem_ready);
#endif /* USE_FREERTOS */
/* Spin waiting for the transfer to finish */
while (!i2c_adapter_fsm_terminated(i2c_adapter));
if (i2c_adapter_wait_for_stopped(i2c_adapter)) {
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_STOPPED);
} else {
i2c_adapter_fsm_init(i2c_adapter);
}
#ifdef USE_FREERTOS
/* Unlock the bus */
xSemaphoreGive(i2c_adapter->sem_busy);
#endif /* USE_FREERTOS */
return (!i2c_adapter->bus_error);
}
#endif
void PIOS_I2C_EV_IRQ_Handler(uint8_t i2c)
{
struct pios_i2c_adapter * i2c_adapter;
i2c_adapter = find_i2c_adapter_by_id(i2c);
PIOS_DEBUG_Assert(i2c_adapter);
uint32_t event = I2C_GetLastEvent(i2c_adapter->cfg->regs);
switch (event) {
case (I2C_EVENT_MASTER_MODE_SELECT | 0x40):
/* Unexplained event: EV5 + RxNE : Extraneous Rx. Probably a late NACK from previous read. */
/* Clean up the extra Rx until the root cause is identified and just keep going */
(void) I2C_ReceiveData(i2c_adapter->cfg->regs);
/* Fall through */
case I2C_EVENT_MASTER_MODE_SELECT: /* EV5 */
switch (i2c_adapter->active_txn->rw) {
case PIOS_I2C_TXN_READ:
if (i2c_adapter->active_txn == i2c_adapter->last_txn) {
/* Final transaction */
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_STARTED_LAST_TXN_READ);
} else if (i2c_adapter->active_txn < i2c_adapter->last_txn) {
/* More transactions follow */
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_STARTED_MORE_TXN_READ);
} else {
PIOS_DEBUG_Assert(0);
}
break;
case PIOS_I2C_TXN_WRITE:
if (i2c_adapter->active_txn == i2c_adapter->last_txn) {
/* Final transaction */
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_STARTED_LAST_TXN_WRITE);
} else if (i2c_adapter->active_txn < i2c_adapter->last_txn) {
/* More transactions follow */
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_STARTED_MORE_TXN_WRITE);
} else {
PIOS_DEBUG_Assert(0);
}
break;
default:
PIOS_DEBUG_Assert(0);
break;
}
break;
case I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED: /* EV6 */
case I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED: /* EV6 */
switch (i2c_adapter->last_byte - i2c_adapter->active_byte + 1) {
case 0:
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_ADDR_SENT_LEN_EQ_0);
break;
case 1:
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_ADDR_SENT_LEN_EQ_1);
break;
case 2:
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_ADDR_SENT_LEN_EQ_2);
break;
default:
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_ADDR_SENT_LEN_GT_2);
break;
}
break;
case 0x80: /* TxE only. TRA + MSL + BUSY have been cleared before we got here. */
/* Ignore */
{
static volatile bool halt = FALSE;
while (halt);
}
break;
case 0: /* Unexplained spurious event. Not sure what to do here. */
case 0x40: /* RxNE only. MSL + BUSY have already been cleared by HW. */
case 0x44: /* RxNE + BTF. MSL + BUSY have already been cleared by HW. */
case I2C_EVENT_MASTER_BYTE_RECEIVED: /* EV7 */
case (I2C_EVENT_MASTER_BYTE_RECEIVED | 0x4): /* EV7 + BTF */
case I2C_EVENT_MASTER_BYTE_TRANSMITTED: /* EV8_2 */
case 0x84: /* TxE + BTF. EV8_2 but TRA + MSL + BUSY have already been cleared by HW. */
switch (i2c_adapter->last_byte - i2c_adapter->active_byte + 1) {
case 0:
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_TRANSFER_DONE_LEN_EQ_0);
break;
case 1:
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_TRANSFER_DONE_LEN_EQ_1);
break;
case 2:
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_TRANSFER_DONE_LEN_EQ_2);
break;
default:
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_TRANSFER_DONE_LEN_GT_2);
break;
}
break;
case I2C_EVENT_MASTER_BYTE_TRANSMITTING: /* EV8 */
/* Ignore this event and wait for TRANSMITTED in case we can't keep up */
goto skip_event;
break;
default:
PIOS_DEBUG_Assert(0);
break;
}
skip_event:
;
}
void PIOS_I2C_ER_IRQ_Handler(uint8_t i2c)
{
struct pios_i2c_adapter * i2c_adapter;
i2c_adapter = find_i2c_adapter_by_id(i2c);
PIOS_DEBUG_Assert(i2c_adapter);
/* Fail hard on any errors for now */
i2c_adapter_inject_event(i2c_adapter, I2C_EVENT_BUS_ERROR);
}
/**
* @}
* @}
*/
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