AP_RangeFinder: Add support for HC-SR04 Range Finder connected to BBB

libraries/AP_RangeFinder/AP_RangeFinder_BBB_PRU.cpp

@@ -0,0 +1,102 @@
+/*
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+   HC-SR04 Ultrasonic Distance Sensor connected to BeagleBone Black
+   by Mirko Denecke <mirkix@gmail.com>
+ */
+
+#include <AP_HAL.h>
+#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BBBMINI
+
+#include "AP_RangeFinder_BBB_PRU.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+
+extern const AP_HAL::HAL& hal;
+
+volatile struct range *rangerpru;
+
+/*
+   The constructor also initialises the rangefinder. Note that this
+   constructor is not called until detect() returns true, so we
+   already know that we should setup the rangefinder
+*/
+AP_RangeFinder_BBB_PRU::AP_RangeFinder_BBB_PRU(RangeFinder &_ranger, uint8_t instance, RangeFinder::RangeFinder_State &_state) :
+    AP_RangeFinder_Backend(_ranger, instance, _state)
+{
+}
+
+/*
+   Stop PRU, load firmware (check if firmware is present), start PRU.
+   If we get a result the sensor seems to be there.
+*/
+bool AP_RangeFinder_BBB_PRU::detect(RangeFinder &_ranger, uint8_t instance)
+{
+    bool result = true;
+    uint32_t mem_fd;
+    uint32_t *ctrl;
+    void *ram;
+
+    mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
+    ctrl = (uint32_t*)mmap(0, 0x1000, PROT_READ | PROT_WRITE, MAP_SHARED, mem_fd, PRU0_CTRL_BASE);
+    ram = mmap(0, PRU0_IRAM_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, mem_fd, PRU0_IRAM_BASE);
+
+    // Reset PRU 0
+    *ctrl = 0;
+    hal.scheduler->delay(1);
+
+    // Load firmware
+    FILE *file = fopen("/lib/firmware/rangefinderprutext.bin", "rb");
+    if(file == NULL)
+    {
+        result = false;
+    }
+
+    if(fread(ram, PRU0_IRAM_SIZE, 1, file) != 1)
+    {
+        result = false;
+    }
+
+    fclose(file);
+
+    munmap(ram, PRU0_IRAM_SIZE);
+
+    // Map PRU RAM
+    ram = mmap(0, 0x1000, PROT_READ | PROT_WRITE, MAP_SHARED, mem_fd, PRU0_DRAM_BASE);
+    close(mem_fd);
+
+    // Start PRU 0
+    *ctrl = 2;
+
+    rangerpru = (volatile struct range*)ram;
+
+    return result;
+}
+
+/*
+   update the state of the sensor
+*/
+void AP_RangeFinder_BBB_PRU::update(void)
+{
+    state.status = (RangeFinder::RangeFinder_Status)rangerpru->status;
+    state.distance_cm = rangerpru->distance;
+}
+#endif // CONFIG_HAL_BOARD_SUBTYPE

libraries/AP_RangeFinder/AP_RangeFinder_BBB_PRU.h

@@ -0,0 +1,35 @@
+#ifndef __AP_RANGEFINDER_PRU_H__
+#define __AP_RANGEFINDER_PRU_H__
+
+#include "RangeFinder.h"
+#include "RangeFinder_Backend.h"
+
+
+#define PRU0_CTRL_BASE 0x4a322000
+
+#define PRU0_IRAM_BASE 0x4a334000
+#define PRU0_IRAM_SIZE 0x2000
+
+#define PRU0_DRAM_BASE 0x4a300000
+
+struct range {
+        uint32_t distance;
+	uint32_t status;
+};
+
+class AP_RangeFinder_BBB_PRU : public AP_RangeFinder_Backend
+{
+public:
+    // constructor
+    AP_RangeFinder_BBB_PRU(RangeFinder &ranger, uint8_t instance, RangeFinder::RangeFinder_State &_state);
+
+    // static detection function
+    static bool detect(RangeFinder &ranger, uint8_t instance);
+
+    // update state
+    void update(void);
+
+private:
+
+};
+#endif  // __AP_RANGEFINDER_PRU_H__

libraries/AP_RangeFinder/RangeFinder.cpp

@@ -20,13 +20,14 @@
 #include "AP_RangeFinder_MaxsonarI2CXL.h"
 #include "AP_RangeFinder_PX4.h"
 #include "AP_RangeFinder_PX4_PWM.h"
+#include "AP_RangeFinder_BBB_PRU.h"
 
 // table of user settable parameters
 const AP_Param::GroupInfo RangeFinder::var_info[] PROGMEM = {
     // @Param: _TYPE
     // @DisplayName: Rangefinder type
     // @Description: What type of rangefinder device that is connected
-    // @Values: 0:None,1:Analog,2:APM2-MaxbotixI2C,3:APM2-PulsedLightI2C,4:PX4-I2C,5:PX4-PWM
+    // @Values: 0:None,1:Analog,2:APM2-MaxbotixI2C,3:APM2-PulsedLightI2C,4:PX4-I2C,5:PX4-PWM,6:BBB-PRU
     AP_GROUPINFO("_TYPE",    0, RangeFinder, _type[0], 0),
 
     // @Param: _PIN
@@ -110,7 +111,7 @@ const AP_Param::GroupInfo RangeFinder::var_info[] PROGMEM = {
     // @Param: 2_TYPE
     // @DisplayName: Second Rangefinder type
     // @Description: What type of rangefinder device that is connected
-    // @Values: 0:None,1:Analog,2:APM2-MaxbotixI2C,3:APM2-PulsedLightI2C,4:PX4-I2C,5:PX4-PWM
+    // @Values: 0:None,1:Analog,2:APM2-MaxbotixI2C,3:APM2-PulsedLightI2C,4:PX4-I2C,5:PX4-PWM,6:BBB-PRU
     AP_GROUPINFO("2_TYPE",    12, RangeFinder, _type[1], 0),
 
     // @Param: 2_PIN
@@ -295,6 +296,15 @@ void RangeFinder::detect_instance(uint8_t instance)
             return;
         }
     }
+#endif
+#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BBBMINI
+    if (type == RangeFinder_TYPE_BBB_PRU) {
+        if (AP_RangeFinder_BBB_PRU::detect(*this, instance)) {
+            state[instance].instance = instance;
+            drivers[instance] = new AP_RangeFinder_BBB_PRU(*this, instance, state[instance]);
+            return;
+        }
+    }
 #endif
     if (type == RangeFinder_TYPE_ANALOG) {
         // note that analog must be the last to be checked, as it will

libraries/AP_RangeFinder/RangeFinder.h

@@ -44,7 +44,8 @@ public:
         RangeFinder_TYPE_MBI2C  = 2,
         RangeFinder_TYPE_PLI2C  = 3,
         RangeFinder_TYPE_PX4    = 4,
-        RangeFinder_TYPE_PX4_PWM= 5
+        RangeFinder_TYPE_PX4_PWM= 5,
+        RangeFinder_TYPE_BBB_PRU= 6
     };
 
     enum RangeFinder_Function {