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LibrePilot/flight/pios/common/pios_com.c

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/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_COM COM layer functions
* @brief Hardware communication layer
* @{
*
* @file pios_com.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief COM layer functions
* @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
*/
#include "pios.h"
#ifdef PIOS_INCLUDE_COM
#include "fifo_buffer.h"
#include <pios_com_priv.h>
#ifndef PIOS_INCLUDE_FREERTOS
#include "pios_delay.h" /* PIOS_DELAY_WaitmS */
#endif
enum pios_com_dev_magic {
PIOS_COM_DEV_MAGIC = 0xaa55aa55,
};
struct pios_com_dev {
enum pios_com_dev_magic magic;
uint32_t lower_id;
const struct pios_com_driver *driver;
#if defined(PIOS_INCLUDE_FREERTOS)
xSemaphoreHandle tx_sem;
xSemaphoreHandle rx_sem;
xSemaphoreHandle sendbuffer_sem;
#endif
bool has_rx;
bool has_tx;
t_fifo_buffer rx;
t_fifo_buffer tx;
};
static bool PIOS_COM_validate(struct pios_com_dev *com_dev)
{
return com_dev && (com_dev->magic == PIOS_COM_DEV_MAGIC);
}
#if defined(PIOS_INCLUDE_FREERTOS)
static struct pios_com_dev *PIOS_COM_alloc(void)
{
struct pios_com_dev *com_dev;
com_dev = (struct pios_com_dev *)pios_malloc(sizeof(struct pios_com_dev));
if (!com_dev) {
return NULL;
}
memset(com_dev, 0, sizeof(struct pios_com_dev));
com_dev->magic = PIOS_COM_DEV_MAGIC;
return com_dev;
}
#else
static struct pios_com_dev pios_com_devs[PIOS_COM_MAX_DEVS];
static uint8_t pios_com_num_devs;
static struct pios_com_dev *PIOS_COM_alloc(void)
{
struct pios_com_dev *com_dev;
if (pios_com_num_devs >= PIOS_COM_MAX_DEVS) {
return NULL;
}
com_dev = &pios_com_devs[pios_com_num_devs++];
memset(com_dev, 0, sizeof(struct pios_com_dev));
com_dev->magic = PIOS_COM_DEV_MAGIC;
return com_dev;
}
#endif /* if defined(PIOS_INCLUDE_FREERTOS) */
static uint16_t PIOS_COM_TxOutCallback(uint32_t context, uint8_t *buf, uint16_t buf_len, uint16_t *headroom, bool *need_yield);
static uint16_t PIOS_COM_RxInCallback(uint32_t context, uint8_t *buf, uint16_t buf_len, uint16_t *headroom, bool *need_yield);
static void PIOS_COM_UnblockRx(struct pios_com_dev *com_dev, bool *need_yield);
static void PIOS_COM_UnblockTx(struct pios_com_dev *com_dev, bool *need_yield);
/**
* Initialises COM layer
* \param[out] handle
* \param[in] driver
* \param[in] id
* \return < 0 if initialisation failed
*/
int32_t PIOS_COM_Init(uint32_t *com_id, const struct pios_com_driver *driver, uint32_t lower_id, uint8_t *rx_buffer, uint16_t rx_buffer_len, uint8_t *tx_buffer, uint16_t tx_buffer_len)
{
PIOS_Assert(com_id);
PIOS_Assert(driver);
bool has_rx = (rx_buffer && rx_buffer_len > 0);
bool has_tx = (tx_buffer && tx_buffer_len > 0);
PIOS_Assert(has_rx || has_tx);
PIOS_Assert(driver->bind_tx_cb || !has_tx);
PIOS_Assert(driver->bind_rx_cb || !has_rx);
struct pios_com_dev *com_dev;
com_dev = (struct pios_com_dev *)PIOS_COM_alloc();
if (!com_dev) {
goto out_fail;
}
com_dev->driver = driver;
com_dev->lower_id = lower_id;
com_dev->has_rx = has_rx;
com_dev->has_tx = has_tx;
if (has_rx) {
fifoBuf_init(&com_dev->rx, rx_buffer, rx_buffer_len);
#if defined(PIOS_INCLUDE_FREERTOS)
vSemaphoreCreateBinary(com_dev->rx_sem);
#endif /* PIOS_INCLUDE_FREERTOS */
(com_dev->driver->bind_rx_cb)(lower_id, PIOS_COM_RxInCallback, (uint32_t)com_dev);
if (com_dev->driver->rx_start) {
/* Start the receiver */
(com_dev->driver->rx_start)(com_dev->lower_id,
fifoBuf_getFree(&com_dev->rx));
}
}
if (has_tx) {
fifoBuf_init(&com_dev->tx, tx_buffer, tx_buffer_len);
#if defined(PIOS_INCLUDE_FREERTOS)
vSemaphoreCreateBinary(com_dev->tx_sem);
#endif /* PIOS_INCLUDE_FREERTOS */
(com_dev->driver->bind_tx_cb)(lower_id, PIOS_COM_TxOutCallback, (uint32_t)com_dev);
}
#if defined(PIOS_INCLUDE_FREERTOS)
com_dev->sendbuffer_sem = xSemaphoreCreateMutex();
#endif /* PIOS_INCLUDE_FREERTOS */
*com_id = (uint32_t)com_dev;
return 0;
out_fail:
return -1;
}
#if defined(PIOS_INCLUDE_FREERTOS)
static void PIOS_COM_UnblockRx(struct pios_com_dev *com_dev, bool *need_yield)
{
static signed portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
xSemaphoreGiveFromISR(com_dev->rx_sem, &xHigherPriorityTaskWoken);
if (xHigherPriorityTaskWoken != pdFALSE) {
*need_yield = true;
} else {
*need_yield = false;
}
}
#else
static void PIOS_COM_UnblockRx(__attribute__((unused)) struct pios_com_dev *com_dev, bool *need_yield)
{
*need_yield = false;
}
#endif
#if defined(PIOS_INCLUDE_FREERTOS)
static void PIOS_COM_UnblockTx(struct pios_com_dev *com_dev, bool *need_yield)
{
static signed portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
xSemaphoreGiveFromISR(com_dev->tx_sem, &xHigherPriorityTaskWoken);
if (xHigherPriorityTaskWoken != pdFALSE) {
*need_yield = true;
} else {
*need_yield = false;
}
}
#else
static void PIOS_COM_UnblockTx(__attribute__((unused)) struct pios_com_dev *com_dev, bool *need_yield)
{
*need_yield = false;
}
#endif
static uint16_t PIOS_COM_RxInCallback(uint32_t context, uint8_t *buf, uint16_t buf_len, uint16_t *headroom, bool *need_yield)
{
struct pios_com_dev *com_dev = (struct pios_com_dev *)context;
bool valid = PIOS_COM_validate(com_dev);
PIOS_Assert(valid);
PIOS_Assert(com_dev->has_rx);
uint16_t bytes_into_fifo;
if (buf_len == 1) {
bytes_into_fifo = fifoBuf_putByte(&com_dev->rx, buf[0]);
} else {
bytes_into_fifo = fifoBuf_putData(&com_dev->rx, buf, buf_len);
}
if (bytes_into_fifo > 0) {
/* Data has been added to the buffer */
PIOS_COM_UnblockRx(com_dev, need_yield);
}
if (headroom) {
*headroom = fifoBuf_getFree(&com_dev->rx);
}
return bytes_into_fifo;
}
static uint16_t PIOS_COM_TxOutCallback(uint32_t context, uint8_t *buf, uint16_t buf_len, uint16_t *headroom, bool *need_yield)
{
struct pios_com_dev *com_dev = (struct pios_com_dev *)context;
bool valid = PIOS_COM_validate(com_dev);
PIOS_Assert(valid);
PIOS_Assert(buf);
PIOS_Assert(buf_len);
PIOS_Assert(com_dev->has_tx);
uint16_t bytes_from_fifo = fifoBuf_getData(&com_dev->tx, buf, buf_len);
if (bytes_from_fifo > 0) {
/* More space has been made in the buffer */
PIOS_COM_UnblockTx(com_dev, need_yield);
}
if (headroom) {
*headroom = fifoBuf_getUsed(&com_dev->tx);
}
return bytes_from_fifo;
}
/**
* Change the port speed without re-initializing
* \param[in] port COM port
* \param[in] baud Requested baud rate
* \return -1 if port not available
* \return 0 on success
*/
int32_t PIOS_COM_ChangeBaud(uint32_t com_id, uint32_t baud)
{
struct pios_com_dev *com_dev = (struct pios_com_dev *)com_id;
if (!PIOS_COM_validate(com_dev)) {
/* Undefined COM port for this board (see pios_board.c) */
return -1;
}
/* Invoke the driver function if it exists */
if (com_dev->driver->set_baud) {
com_dev->driver->set_baud(com_dev->lower_id, baud);
}
return 0;
}
static int32_t PIOS_COM_SendBufferNonBlockingInternal(struct pios_com_dev *com_dev, const uint8_t *buffer, uint16_t len)
{
PIOS_Assert(com_dev);
PIOS_Assert(com_dev->has_tx);
if (com_dev->driver->available && !com_dev->driver->available(com_dev->lower_id)) {
/*
* Underlying device is down/unconnected.
* Dump our fifo contents and act like an infinite data sink.
* Failure to do this results in stale data in the fifo as well as
* possibly having the caller block trying to send to a device that's
* no longer accepting data.
*/
fifoBuf_clearData(&com_dev->tx);
return len;
}
if (len > fifoBuf_getFree(&com_dev->tx)) {
/* Buffer cannot accept all requested bytes (retry) */
return -2;
}
uint16_t bytes_into_fifo = fifoBuf_putData(&com_dev->tx, buffer, len);
if (bytes_into_fifo > 0) {
/* More data has been put in the tx buffer, make sure the tx is started */
if (com_dev->driver->tx_start) {
com_dev->driver->tx_start(com_dev->lower_id,
fifoBuf_getUsed(&com_dev->tx));
}
}
return bytes_into_fifo;
}
/**
* Sends a package over given port
* \param[in] port COM port
* \param[in] buffer character buffer
* \param[in] len buffer length
* \return -1 if port not available
* \return -2 if non-blocking mode activated: buffer is full
* caller should retry until buffer is free again
* \return -3 another thread is already sending, caller should
* retry until com is available again
* \return number of bytes transmitted on success
*/
int32_t PIOS_COM_SendBufferNonBlocking(uint32_t com_id, const uint8_t *buffer, uint16_t len)
{
struct pios_com_dev *com_dev = (struct pios_com_dev *)com_id;
if (!PIOS_COM_validate(com_dev)) {
/* Undefined COM port for this board (see pios_board.c) */
return -1;
}
#if defined(PIOS_INCLUDE_FREERTOS)
if (xSemaphoreTake(com_dev->sendbuffer_sem, 0) != pdTRUE) {
return -3;
}
#endif /* PIOS_INCLUDE_FREERTOS */
int32_t ret = PIOS_COM_SendBufferNonBlockingInternal(com_dev, buffer, len);
#if defined(PIOS_INCLUDE_FREERTOS)
xSemaphoreGive(com_dev->sendbuffer_sem);
#endif /* PIOS_INCLUDE_FREERTOS */
return ret;
}
/**
* Sends a package over given port
* (blocking function)
* \param[in] port COM port
* \param[in] buffer character buffer
* \param[in] len buffer length
* \return -1 if port not available
* \return -2 if mutex can't be taken;
* \return -3 if data cannot be sent in the max allotted time of 5000msec
* \return number of bytes transmitted on success
*/
int32_t PIOS_COM_SendBuffer(uint32_t com_id, const uint8_t *buffer, uint16_t len)
{
struct pios_com_dev *com_dev = (struct pios_com_dev *)com_id;
if (!PIOS_COM_validate(com_dev)) {
/* Undefined COM port for this board (see pios_board.c) */
return -1;
}
PIOS_Assert(com_dev->has_tx);
#if defined(PIOS_INCLUDE_FREERTOS)
if (xSemaphoreTake(com_dev->sendbuffer_sem, 5) != pdTRUE) {
return -2;
}
#endif /* PIOS_INCLUDE_FREERTOS */
uint32_t max_frag_len = fifoBuf_getSize(&com_dev->tx);
uint32_t bytes_to_send = len;
while (bytes_to_send) {
uint32_t frag_size;
if (bytes_to_send > max_frag_len) {
frag_size = max_frag_len;
} else {
frag_size = bytes_to_send;
}
int32_t rc = PIOS_COM_SendBufferNonBlockingInternal(com_dev, buffer, frag_size);
if (rc >= 0) {
bytes_to_send -= rc;
buffer += rc;
} else {
switch (rc) {
case -1:
#if defined(PIOS_INCLUDE_FREERTOS)
xSemaphoreGive(com_dev->sendbuffer_sem);
#endif /* PIOS_INCLUDE_FREERTOS */
/* Device is invalid, this will never work */
return -1;
case -2:
/* Device is busy, wait for the underlying device to free some space and retry */
/* Make sure the transmitter is running while we wait */
if (com_dev->driver->tx_start) {
(com_dev->driver->tx_start)(com_dev->lower_id,
fifoBuf_getUsed(&com_dev->tx));
}
#if defined(PIOS_INCLUDE_FREERTOS)
if (xSemaphoreTake(com_dev->tx_sem, 5000) != pdTRUE) {
xSemaphoreGive(com_dev->sendbuffer_sem);
return -3;
}
#endif
continue;
default:
/* Unhandled return code */
#if defined(PIOS_INCLUDE_FREERTOS)
xSemaphoreGive(com_dev->sendbuffer_sem);
#endif /* PIOS_INCLUDE_FREERTOS */
return rc;
}
}
}
#if defined(PIOS_INCLUDE_FREERTOS)
xSemaphoreGive(com_dev->sendbuffer_sem);
#endif /* PIOS_INCLUDE_FREERTOS */
return len;
}
/**
* Sends a single character over given port
* \param[in] port COM port
* \param[in] c character
* \return -1 if port not available
* \return -2 buffer is full
* caller should retry until buffer is free again
* \return 0 on success
*/
int32_t PIOS_COM_SendCharNonBlocking(uint32_t com_id, char c)
{
return PIOS_COM_SendBufferNonBlocking(com_id, (uint8_t *)&c, 1);
}
/**
* Sends a single character over given port
* (blocking function)
* \param[in] port COM port
* \param[in] c character
* \return -1 if port not available
* \return 0 on success
*/
int32_t PIOS_COM_SendChar(uint32_t com_id, char c)
{
return PIOS_COM_SendBuffer(com_id, (uint8_t *)&c, 1);
}
/**
* Sends a string over given port
* \param[in] port COM port
* \param[in] str zero-terminated string
* \return -1 if port not available
* \return -2 buffer is full
* caller should retry until buffer is free again
* \return 0 on success
*/
int32_t PIOS_COM_SendStringNonBlocking(uint32_t com_id, const char *str)
{
return PIOS_COM_SendBufferNonBlocking(com_id, (uint8_t *)str, (uint16_t)strlen(str));
}
/**
* Sends a string over given port
* (blocking function)
* \param[in] port COM port
* \param[in] str zero-terminated string
* \return -1 if port not available
* \return 0 on success
*/
int32_t PIOS_COM_SendString(uint32_t com_id, const char *str)
{
return PIOS_COM_SendBuffer(com_id, (uint8_t *)str, strlen(str));
}
/**
* Sends a formatted string (-> printf) over given port
* \param[in] port COM port
* \param[in] *format zero-terminated format string - 128 characters supported maximum!
* \param[in] ... optional arguments,
* 128 characters supported maximum!
* \return -2 if non-blocking mode activated: buffer is full
* caller should retry until buffer is free again
* \return 0 on success
*/
int32_t PIOS_COM_SendFormattedStringNonBlocking(uint32_t com_id, const char *format, ...)
{
uint8_t buffer[128]; // TODO: tmp!!! Provide a streamed COM method later!
va_list args;
va_start(args, format);
vsprintf((char *)buffer, format, args);
return PIOS_COM_SendBufferNonBlocking(com_id, buffer, (uint16_t)strlen((char *)buffer));
}
/**
* Sends a formatted string (-> printf) over given port
* (blocking function)
* \param[in] port COM port
* \param[in] *format zero-terminated format string - 128 characters supported maximum!
* \param[in] ... optional arguments,
* \return -1 if port not available
* \return 0 on success
*/
int32_t PIOS_COM_SendFormattedString(uint32_t com_id, const char *format, ...)
{
uint8_t buffer[128]; // TODO: tmp!!! Provide a streamed COM method later!
va_list args;
va_start(args, format);
vsprintf((char *)buffer, format, args);
return PIOS_COM_SendBuffer(com_id, buffer, (uint16_t)strlen((char *)buffer));
}
/**
* Transfer bytes from port buffers into another buffer
* \param[in] port COM port
* \returns Byte from buffer
*/
uint16_t PIOS_COM_ReceiveBuffer(uint32_t com_id, uint8_t *buf, uint16_t buf_len, uint32_t timeout_ms)
{
PIOS_Assert(buf);
PIOS_Assert(buf_len);
uint16_t bytes_from_fifo;
struct pios_com_dev *com_dev = (struct pios_com_dev *)com_id;
if (!PIOS_COM_validate(com_dev)) {
/* Undefined COM port for this board (see pios_board.c) */
PIOS_Assert(0);
}
PIOS_Assert(com_dev->has_rx);
check_again:
bytes_from_fifo = fifoBuf_getData(&com_dev->rx, buf, buf_len);
if (bytes_from_fifo == 0) {
/* No more bytes in receive buffer */
/* Make sure the receiver is running while we wait */
if (com_dev->driver->rx_start) {
/* Notify the lower layer that there is now room in the rx buffer */
(com_dev->driver->rx_start)(com_dev->lower_id,
fifoBuf_getFree(&com_dev->rx));
}
if (timeout_ms > 0) {
#if defined(PIOS_INCLUDE_FREERTOS)
if (xSemaphoreTake(com_dev->rx_sem, timeout_ms / portTICK_RATE_MS) == pdTRUE) {
/* Make sure we don't come back here again */
timeout_ms = 0;
goto check_again;
}
#else
PIOS_DELAY_WaitmS(1);
timeout_ms--;
goto check_again;
#endif
}
}
/* Return received byte */
return bytes_from_fifo;
}
/**
* Query if a com port is available for use. That can be
* used to check a link is established even if the device
* is valid.
*/
bool PIOS_COM_Available(uint32_t com_id)
{
struct pios_com_dev *com_dev = (struct pios_com_dev *)com_id;
if (!PIOS_COM_validate(com_dev)) {
return false;
}
// If a driver does not provide a query method assume always
// available if valid
if (com_dev->driver->available == NULL) {
return true;
}
return (com_dev->driver->available)(com_dev->lower_id);
}
#endif /* PIOS_INCLUDE_COM */
/**
* @}
* @}
*/