diff options
Diffstat (limited to 'nuttx/configs/px4io/include/drv_ppm_input.h')
-rw-r--r-- | nuttx/configs/px4io/include/drv_ppm_input.h | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/nuttx/configs/px4io/include/drv_ppm_input.h b/nuttx/configs/px4io/include/drv_ppm_input.h new file mode 100644 index 000000000..78c424154 --- /dev/null +++ b/nuttx/configs/px4io/include/drv_ppm_input.h @@ -0,0 +1,100 @@ +/**************************************************************************** + * + * 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 PPM input decoder. + * + * Works in conjunction with the HRT driver, exports a device node + * and a message queue (if message queues are enabled). + * + * Note that the device node supports both blocking and non-blocking + * opens, but actually never blocks. A nonblocking open will return + * EWOULDBLOCK if there has not been an update since the last read, + * while a blocking open will always return the most recent data. + */ + +#include <sys/ioctl.h> + +#define _PPM_INPUT_BASE 0x7600 + +/* + * Fetch the state of the PPM input detector. + */ +#define PPM_INPUT_STATUS _IOC(_PPM_INPUT_BASE, 0) + +typedef enum { + PPM_STATUS_NO_SIGNAL = 0, + PPM_STATUS_SIGNAL_CURRENT = 1, +} ppm_input_status_t; + +/* + * Fetch the number of channels decoded (only valid when PPM_STATUS_SIGNAL_CURRENT). + */ +#define PPM_INPUT_CHANNELS _IOC(_PPM_INPUT_BASE, 1) + +typedef int ppm_input_channel_count_t; + +/* + * Device node + */ +#define PPM_DEVICE_NODE "/dev/ppm_input" + +/* + * Message queue; if message queues are supported, PPM input data is + * supplied to the queue when a frame is decoded. + */ +#ifndef CONFIG_DISABLE_MQUEUE +# define PPM_MESSAGE_QUEUE "ppm_input" +#endif + +/* + * Private hook from the HRT driver to the PPM decoder. + * + * This function is called for every edge of the incoming PPM + * signal. + * + * @param reset If true, the decoder should be reset (e.g.) + * capture failure was detected. + * @param count The counter value at which the edge + * was captured. + */ + +void ppm_input_decode(bool reset, uint16_t count); + +/* + * PPM input initialisation function. + * + * If message queues are enabled, and mq_name is not NULL, received input + * is posted to the message queue as an array of 16-bit unsigned channel values. + */ +int ppm_input_init(const char *mq_name);
\ No newline at end of file |