diff options
Diffstat (limited to 'nuttx/configs/px4io/include/drv_pwm_servo.h')
| -rw-r--r-- | nuttx/configs/px4io/include/drv_pwm_servo.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/nuttx/configs/px4io/include/drv_pwm_servo.h b/nuttx/configs/px4io/include/drv_pwm_servo.h new file mode 100644 index 000000000..663468404 --- /dev/null +++ b/nuttx/configs/px4io/include/drv_pwm_servo.h @@ -0,0 +1,94 @@ +/**************************************************************************** + * + * 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 PWM servo driver. + * + * The pwm_servo driver supports servos connected to STM32 timer + * blocks. + * + * Servo values can be set either with the PWM_SERVO_SET ioctl, or + * by writing an array of servo_position_t values to the device. + * Writing a value of 0 to a channel suppresses any output for that + * channel. + * + * Servo values can be read back either with the PWM_SERVO_GET + * ioctl, or by reading an array of servo_position_t values + * from the device. + * + * Attempts to set a channel that is not configured are ignored, + * and unconfigured channels always read zero. + * + * The PWM_SERVO_ARM / PWM_SERVO_DISARM calls globally arm + * (enable) and disarm (disable) all servo outputs. + */ + +#include <sys/ioctl.h> + +#define _PWM_SERVO_BASE 0x7500 +#define PWM_SERVO_ARM _IOC(_PWM_SERVO_BASE, 0) +#define PWM_SERVO_DISARM _IOC(_PWM_SERVO_BASE, 1) + +#define PWM_SERVO_SET(_servo) _IOC(_PWM_SERVO_BASE, 0x20 + _servo) +#define PWM_SERVO_GET(_servo) _IOC(_PWM_SERVO_BASE, 0x40 + _servo) + +typedef uint16_t servo_position_t; + +/* configuration limits */ +#define PWM_SERVO_MAX_TIMERS 3 +#define PWM_SERVO_MAX_CHANNELS 8 + +struct pwm_servo_config { + /* rate (in Hz) of PWM updates */ + uint32_t update_rate; + + /* array of timers dedicated to PWM servo use */ + struct pwm_servo_timer { + uint32_t base; + uint32_t clock_register; + uint32_t clock_bit; + uint32_t clock_freq; + } timers[PWM_SERVO_MAX_TIMERS]; + + /* array of channels in logical order */ + struct pwm_servo_channel { + uint32_t gpio; + uint8_t timer_index; + uint8_t timer_channel; + servo_position_t default_value; + } channels[PWM_SERVO_MAX_CHANNELS]; +}; + +extern int pwm_servo_init(const struct pwm_servo_config *config); + + |