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author | px4dev <px4@purgatory.org> | 2012-08-04 15:12:36 -0700 |
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committer | px4dev <px4@purgatory.org> | 2012-08-04 15:12:36 -0700 |
commit | 8a365179eafdf3aea98e60ab9f5882b200d4c759 (patch) | |
tree | 4f38d6d4cd80bd0b6e22e2bb534c3f117ce44e56 /apps/drivers/device/i2c.cpp | |
download | px4-firmware-8a365179eafdf3aea98e60ab9f5882b200d4c759.tar.gz px4-firmware-8a365179eafdf3aea98e60ab9f5882b200d4c759.tar.bz2 px4-firmware-8a365179eafdf3aea98e60ab9f5882b200d4c759.zip |
Fresh import of the PX4 firmware sources.
Diffstat (limited to 'apps/drivers/device/i2c.cpp')
-rw-r--r-- | apps/drivers/device/i2c.cpp | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/apps/drivers/device/i2c.cpp b/apps/drivers/device/i2c.cpp new file mode 100644 index 000000000..8489db4bb --- /dev/null +++ b/apps/drivers/device/i2c.cpp @@ -0,0 +1,149 @@ +/**************************************************************************** + * + * Copyright (C) 2012 PX4 Development Team. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name PX4 nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/** + * @file Base class for devices attached via the I2C bus. + * + * @todo Bus frequency changes; currently we do nothing with the value + * that is supplied. Should we just depend on the bus knowing? + */ + +#include "i2c.h" + +namespace device +{ + +I2C::I2C(const char *name, + const char *devname, + int bus, + uint16_t address, + uint32_t frequency, + int irq) : + // base class + CDev(name, devname, irq), + // public + // protected + // private + _bus(bus), + _address(address), + _frequency(frequency), + _dev(nullptr) +{ +} + +I2C::~I2C() +{ + if (_dev) + up_i2cuninitialize(_dev); +} + +int +I2C::init() +{ + int ret = OK; + + // attach to the i2c bus + _dev = up_i2cinitialize(_bus); + + if (_dev == nullptr) { + debug("failed to init I2C"); + ret = -ENOENT; + goto out; + } + + // call the probe function to check whether the device is present + ret = probe(); + + if (ret != OK) { + debug("probe failed"); + goto out; + } + + // do base class init, which will create device node, etc + ret = CDev::init(); + + if (ret != OK) { + debug("cdev init failed"); + goto out; + } + + // tell the world where we are + log("on bus %d at 0x%02x", _bus, _address); + +out: + return ret; +} + +int +I2C::probe() +{ + // Assume the device is too stupid to be discoverable. + return OK; +} + +int +I2C::transfer(uint8_t *send, unsigned send_len, uint8_t *recv, unsigned recv_len) +{ + struct i2c_msg_s msgv[2]; + unsigned msgs; + int ret; + +// debug("transfer out %p/%u in %p/%u", send, send_len, recv, recv_len); + + msgs = 0; + + if (send_len > 0) { + msgv[msgs].addr = _address; + msgv[msgs].flags = 0; + msgv[msgs].buffer = send; + msgv[msgs].length = send_len; + msgs++; + } + + if (recv_len > 0) { + msgv[msgs].addr = _address; + msgv[msgs].flags = I2C_M_READ; + msgv[msgs].buffer = recv; + msgv[msgs].length = recv_len; + msgs++; + } + + if (msgs == 0) + return -EINVAL; + + ret = I2C_TRANSFER(_dev, &msgv[0], msgs); + + return ret; +} + +} // namespace device
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