px4_autopilot/boards/bitcraze/crazyflie/syslink/syslink_memory.cpp

/****************************************************************************
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 *   Copyright (c) 2016 PX4 Development Team. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *    used to endorse or promote products derived from this software
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#include "syslink_main.h"

#include "drv_deck.h"

#include <cstring>


SyslinkMemory::SyslinkMemory(Syslink *link) :
	CDev(DECK_DEVICE_PATH),
	_link(link),
	_activeI(0)
{
}


int
SyslinkMemory::init()
{
	int ret = CDev::init();

	/* if init failed, bail now */
	if (ret != OK) {
		PX4_DEBUG("CDev init failed");
		return ret;
	}


	return ret;
}

ssize_t
SyslinkMemory::read(struct file *filp, char *buffer, size_t buflen)
{
	return read(_activeI, 0, buffer, buflen);
}

ssize_t
SyslinkMemory::write(struct file *filp, const char *buffer, size_t buflen)
{
	// For now, unsupported
	return -1;
//	return buflen;
}

int
SyslinkMemory::ioctl(struct file *filp, int cmd, unsigned long arg)
{
	switch (cmd) {
	case DECKIOGNUM:
		*((int *) arg) = scan();
		return 0;

	case DECKIOSNUM:
		_activeI = *((int *) arg);
		return 0;

	case DECKIOID: {
			syslink_ow_getinfo_t *data = (syslink_ow_getinfo_t *) &msgbuf.data;
			getinfo(_activeI);
			*((uint8_t **)arg) = data->id;
			return 8;
		}

	default:
		CDev::ioctl(filp, cmd, arg);
		return 0;
	}
}


uint8_t
SyslinkMemory::scan()
{
	syslink_ow_scan_t *data = (syslink_ow_scan_t *) &msgbuf.data;
	msgbuf.type = SYSLINK_OW_SCAN;
	msgbuf.length = 0;
	sendAndWait();

	return data->nmems;
}

void
SyslinkMemory::getinfo(int i)
{
	syslink_ow_getinfo_t *data = (syslink_ow_getinfo_t *) &msgbuf.data;
	msgbuf.type = SYSLINK_OW_GETINFO;
	msgbuf.length = 1;
	data->idx = i;
	sendAndWait();
}

int
SyslinkMemory::read(int i, uint16_t addr, char *buf, int length)
{
	syslink_ow_read_t *data = (syslink_ow_read_t *) &msgbuf.data;
	msgbuf.type = SYSLINK_OW_READ;

	int nread = 0;

	while (nread < length) {

		msgbuf.length = 3;
		data->idx = i;
		data->addr = addr;
		sendAndWait();

		// Number of bytes actually read
		int n = MIN(length - nread, msgbuf.length - 3);

		if (n == 0) {
			break;
		}

		memcpy(buf, data->data, n);
		nread += n;
		buf += n;
		addr += n;
	}

	return nread;
}

int
SyslinkMemory::write(int i, uint16_t addr, const char *buf, int length)
{
	// TODO: Unimplemented
	return -1;
}

void
SyslinkMemory::sendAndWait()
{
	// TODO: Force the syslink thread to wake up
	_link->_queue.force(&msgbuf, sizeof(msgbuf));
	px4_sem_wait(&_link->memory_sem);
}