aerofc: Implement ADC

Measure the battery voltage of Aero RTF kit will be done by FPGA
and read by AeroFC using I2C bus.

The protocol is a little bit odd, it have different I2C slave
address for each "register", in future the FPGA RTL will
have a protocol more similar to other I2C sensors.

Also Aero RTF don't have a ADC line to measure current consumption.

ROMFS/px4fmu_common/init.d/rc.sensors

@@ -52,8 +52,13 @@ else
 	fi
 fi
 
-if adc start
+if ver hwcmp AEROFC_V1
 then
+	# Aero FC uses separate driver
+else
+	if adc start
+	then
+	fi
 fi
 
 if ver hwcmp AUAV_X21
@@ -344,6 +349,10 @@ then
 	if hmc5883 -X start
 	then
 	fi
+
+	if aerofc_adc start
+	then
+	fi
 fi
 
 if meas_airspeed start

cmake/configs/nuttx_aerofc-v1_default.cmake

@@ -12,7 +12,6 @@ set(config_module_list
 	#
 	drivers/device
 	drivers/stm32
-	drivers/stm32/adc
 	drivers/led
 	drivers/px4fmu
 	drivers/boards/aerofc-v1
@@ -22,6 +21,7 @@ set(config_module_list
 	drivers/hmc5883
 	drivers/gps
 	drivers/ist8310
+	drivers/aerofc_adc
 	modules/sensors
 	# dummy tone alarm
 	modules/dummy

src/drivers/aerofc_adc/CMakeLists.txt

@@ -0,0 +1,43 @@
+############################################################################
+#
+#   Copyright (C) 2016  Intel Corporation. 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.
+#
+############################################################################
+px4_add_module(
+	MODULE drivers__aerofc_adc
+	MAIN aerofc_adc
+	COMPILE_FLAGS
+		-Os
+	SRCS
+		aerofc_adc.cpp
+	DEPENDS
+		platforms__common
+	)
+# vim: set noet ft=cmake fenc=utf-8 ff=unix : 

src/drivers/aerofc_adc/aerofc_adc.cpp

@@ -0,0 +1,231 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2016  Intel Corporation. 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 <px4_config.h>
+#include <px4_defines.h>
+
+#include <arch/board/board.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/wqueue.h>
+
+#include <board_config.h>
+
+#include <drivers/device/i2c.h>
+#include <drivers/drv_adc.h>
+
+#include <systemlib/err.h>
+
+#define SLAVE_ADDR 0x50
+#define ENABLE_ADC_REG 0x00
+#define ADC_CHANNEL_1_REG 0x01
+#define ADC_CHANNEL_2_REG 0x02
+#define ADC_CHANNEL_3_REG 0x03
+#define ADC_CHANNEL_4_REG 0x04
+#define ADC_CHANNEL_5_REG 0x05
+#define MAX_CHANNEL 5
+
+// 10Hz
+#define CYCLE_TICKS_DELAY MSEC2TICK(100)
+
+extern "C" { __EXPORT int aerofc_adc_main(int argc, char *argv[]); }
+
+class AEROFC_ADC : public device::I2C
+{
+public:
+	AEROFC_ADC(uint8_t bus);
+	virtual ~AEROFC_ADC();
+
+	virtual int init();
+	virtual int ioctl(file *filp, int cmd, unsigned long arg);
+	virtual ssize_t read(file *filp, char *buffer, size_t len);
+
+private:
+	virtual int probe();
+
+	void cycle();
+	static void cycle_trampoline(void *arg);
+
+	struct work_s _work;
+	adc_msg_s _samples[MAX_CHANNEL];
+	pthread_mutex_t _samples_mutex;
+};
+
+static AEROFC_ADC *instance = nullptr;
+
+int aerofc_adc_main(int argc, char *argv[])
+{
+	if (argc < 2) {
+		warn("Missing action <start>");
+		return PX4_OK;
+	}
+
+	if (!strcmp(argv[1], "start")) {
+		if (instance) {
+			warn("AEROFC_ADC was already started");
+		}
+
+		instance = new AEROFC_ADC(PX4_I2C_BUS_EXPANSION);
+
+		if (!instance) {
+			warn("No memory to instance AEROFC_ADC");
+			return PX4_OK;
+		}
+
+		if (instance->init() != PX4_OK) {
+			delete instance;
+			instance = nullptr;
+		}
+
+	} else {
+		warn("Action not supported");
+	}
+
+	return PX4_OK;
+}
+
+AEROFC_ADC::AEROFC_ADC(uint8_t bus) :
+	I2C("AEROFC_ADC", ADC0_DEVICE_PATH, bus, 0, 400000)
+{
+	for (unsigned i = 0; i < MAX_CHANNEL; i++) {
+		_samples[i].am_channel = i + 1;
+	}
+
+	pthread_mutex_init(&_samples_mutex, NULL);
+}
+
+AEROFC_ADC::~AEROFC_ADC()
+{
+	work_cancel(HPWORK, &_work);
+}
+
+int AEROFC_ADC::init()
+{
+	int ret = I2C::init();
+
+	if (ret != PX4_OK) {
+		return ret;
+	}
+
+	work_queue(HPWORK, &_work, (worker_t)&AEROFC_ADC::cycle_trampoline, this,
+		   CYCLE_TICKS_DELAY);
+
+	return PX4_OK;
+}
+
+int AEROFC_ADC::probe()
+{
+	uint8_t buffer[1];
+	int ret;
+
+	_retries = 3;
+
+	set_address(SLAVE_ADDR | ENABLE_ADC_REG);
+	buffer[0] = 1;
+	ret = transfer(buffer, sizeof(buffer), NULL, 0);
+
+	if (ret != PX4_OK) {
+		goto error;
+	}
+
+	buffer[0] = 0;
+	ret = transfer(0, 0, buffer, sizeof(buffer));
+
+	if (ret != PX4_OK || buffer[0] != 1) {
+		goto error;
+	}
+
+	return PX4_OK;
+
+error:
+	warn("AEROFC_ADC not found");
+	return -EIO;
+}
+
+int
+AEROFC_ADC::ioctl(file *filp, int cmd, unsigned long arg)
+{
+	return -ENOTTY;
+}
+
+ssize_t
+AEROFC_ADC::read(file *filp, char *buffer, size_t len)
+{
+	if (len > sizeof(_samples)) {
+		len = sizeof(_samples);
+	}
+
+	pthread_mutex_lock(&_samples_mutex);
+	memcpy(buffer, _samples, len);
+	pthread_mutex_unlock(&_samples_mutex);
+
+	return len;
+}
+
+void
+AEROFC_ADC::cycle_trampoline(void *arg)
+{
+	AEROFC_ADC *dev = reinterpret_cast<AEROFC_ADC * >(arg);
+	dev->cycle();
+}
+
+void
+AEROFC_ADC::cycle()
+{
+	int32_t value[MAX_CHANNEL];
+
+	for (uint8_t i = 0; i < MAX_CHANNEL; i++) {
+		int ret;
+		uint8_t buffer[2];
+
+		set_address(SLAVE_ADDR | (ADC_CHANNEL_1_REG + i));
+		ret = transfer(0, 0, buffer, sizeof(buffer));
+
+		if (ret != PX4_OK) {
+			warn("Error reading channel %u", i + 1);
+		}
+
+		value[i] = (int32_t)(buffer[0] | (buffer[1] << 8));
+	}
+
+	pthread_mutex_lock(&_samples_mutex);
+
+	for (uint8_t i = 0; i < MAX_CHANNEL; i++) {
+		_samples[i].am_data = value[i];
+	}
+
+	pthread_mutex_unlock(&_samples_mutex);
+
+	work_queue(HPWORK, &_work, (worker_t)&AEROFC_ADC::cycle_trampoline, this,
+		   CYCLE_TICKS_DELAY);
+}

src/drivers/boards/aerofc-v1/board_config.h

@@ -99,7 +99,7 @@
  * ADC defines just to not break sensors.cpp build, battery voltage and current
  * will be read in another way in future.
  */
-#define ADC_BATTERY_VOLTAGE_CHANNEL    0
+#define ADC_BATTERY_VOLTAGE_CHANNEL    5
 #define ADC_BATTERY_CURRENT_CHANNEL    ((uint8_t)(-1))
 
 #define DIRECT_PWM_OUTPUT_CHANNELS	1