linux_pwm_out: add ocpoc_mmap mode

2026-10-22 10:33:33 +08:00 · 2017-07-13 16:53:28 +02:00
parent 8527c8276f
commit d17a7b46e8
4 changed files with 193 additions and 4 deletions
@@ -0,0 +1,108 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2017 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.
+ *
+ ****************************************************************************/
+
+#include "ocpoc_mmap.h"
+
+#include <px4_log.h>
+
+#include <fcntl.h>
+#include <sys/mman.h>
+
+using namespace linux_pwm_out;
+
+#define RCOUT_ZYNQ_PWM_BASE	    0x43c00000
+static const int TICK_PER_US   =  50;
+static const int FREQUENCY_PWM = 400;
+static const int TICK_PER_S  = 50000000;
+
+OcpocMmapPWMOut::OcpocMmapPWMOut(int max_num_outputs)
+{
+	_num_outputs = max_num_outputs;
+
+	if (_num_outputs > MAX_ZYNQ_PWMS) {
+		PX4_WARN("number of outputs too large. Setting to %i", MAX_ZYNQ_PWMS);
+		_num_outputs = MAX_ZYNQ_PWMS;
+	}
+}
+
+OcpocMmapPWMOut::~OcpocMmapPWMOut()
+{
+	if (_shared_mem_cmd) {
+		munmap((void *)_shared_mem_cmd, 0x1000);
+	}
+}
+
+unsigned long OcpocMmapPWMOut::freq2tick(uint16_t freq_hz)
+{
+	unsigned long duty = TICK_PER_S / (unsigned long)freq_hz;
+	return duty;
+}
+
+int OcpocMmapPWMOut::init()
+{
+	uint32_t mem_fd = open(_device, O_RDWR | O_SYNC);
+	_shared_mem_cmd = (struct pwm_cmd *) mmap(0, 0x1000, PROT_READ | PROT_WRITE,
+			  MAP_SHARED, mem_fd, RCOUT_ZYNQ_PWM_BASE);
+	close(mem_fd);
+
+	if (_shared_mem_cmd == nullptr) {
+		PX4_ERR("initialize pwm pointer failed.");
+		return -1;
+	}
+
+	for (int i = 0; i < _num_outputs; ++i) {
+		_shared_mem_cmd->periodhi[i].period   =  freq2tick(FREQUENCY_PWM);
+		_shared_mem_cmd->periodhi[i].hi = freq2tick(FREQUENCY_PWM) / 2;
+		PX4_DEBUG("Output values: %d, %d", _shared_mem_cmd->periodhi[i].period, _shared_mem_cmd->periodhi[i].hi);
+	}
+
+	return 0;
+}
+
+int OcpocMmapPWMOut::send_output_pwm(const uint16_t *pwm, int num_outputs)
+{
+	if (num_outputs > _num_outputs) {
+		num_outputs = _num_outputs;
+	}
+
+	//convert this to duty_cycle in ns
+	for (int i = 0; i < num_outputs; ++i) {
+		//n = ::asprintf(&data, "%u", pwm[i] * 1000);
+		//::write(_pwm_fd[i], data, n);
+		_shared_mem_cmd->periodhi[i].hi = TICK_PER_US * pwm[i];
+		//printf("ch:%d, val:%d*%d ", ch, period_us, TICK_PER_US);
+	}
+
+	return 0;
+}
+