Fixed issue #34, #23 - added DMA support

Fixed issue #56 - added support for playlsits
markondej · Jan 5, 2019 · 11fcc4c · 11fcc4c
1 parent ea843ab
commit 11fcc4c
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diff --git a/README.md b/README.md
@@ -1,7 +1,7 @@
 # fm_transmitter
 Use Raspberry Pi as FM transmitter. Works on any Raspberry Pi board.
 
-This project uses the general clock output to produce frequency modulated radio communication. It is based on idea originaly posted here: [http://icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter](http://icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter), but does not use DMA controller in order to distribute samples to output (clock generator), so sound quality is worse as in PiFm project and only mono transmition is available but this makes possible to run it on all kind of boards.
+This project uses the general clock output to produce frequency modulated radio communication. It is based on idea originaly presented by Oliver Mattos and Oskar Weigl on [http://icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter](PiFM project).
 
 ## How to use it
 To use this project You will have to build it. First, clone this repository, then use "make" command as shown below:
@@ -15,9 +15,13 @@ After successful build You can start transmitting by typing:
 sudo ./fm_transmitter -f 102.0 acoustic_guitar_duet.wav
 ```
 Where:
-* -f 102.0 - Specifies the frequency in MHz, if not passed default is 100.0
+* -f <frequency> - Specifies the frequency in MHz, 100.0 by default if not passed
 * acoustic_guitar_duet.wav - Sample WAVE file, You can use your own
 
+Other options:
+* -d <dma_channel> - Specifies the used DMA channel (0 by default), pass 255 in order to disable DMA and use CPU
+* -r - Loops the playback
+
 ### Supported audio formats
 You can transmitt uncompressed WAVE (.wav) files directly or read audio data from stdin, eg.:
 ```
@@ -28,8 +32,8 @@ Please note only uncompressed WAVE files are supported. If You expire "corrupted
 sox my-audio.mp3 -r 22050 -c 1 -b 16 -t wav my-converted-audio.wav
 sudo ./fm_transmitter -f 100.6 my-converted-audio.wav
 ```
-### USB microphone
-To use a USB sound card microphone input use arecord, eg.:
+### USB microphone support
+In order to use a USB microphone input use arecord command, eg.:
 ```
 arecord -D hw:1,0 -c1 -d 0 -r 22050 -f S16_LE | sudo ./fm_transmitter -f 100.6 -
 ```
@@ -39,9 +43,9 @@ In case of performance drop down use ```plughw:1,0``` instead of ```hw:1,0```.
 Please keep in mind that transmitting on certain frequencies without special permissions may be illegal in your country.
 
 ## New features
+* DMA engine support
 * works on any Raspberry Pi model
 * reads mono and stereo files
 * reads data from stdin
-* based on threads
 
 Included sample audio was created by [graham_makes](https://freesound.org/people/graham_makes/sounds/449409/) and published on [freesound.org](https://freesound.org/)
diff --git a/error_reporter.cpp b/error_reporter.cpp
@@ -1,7 +1,7 @@
 /*
     fm_transmitter - use Raspberry Pi as FM transmitter
 
-    Copyright (c) 2018, Marcin Kondej
+    Copyright (c) 2019, Marcin Kondej
     All rights reserved.
 
     See https://github.com/markondej/fm_transmitter
@@ -42,7 +42,7 @@ ErrorReporter::~ErrorReporter() throw()
 {
 }
 
-const char* ErrorReporter::what() const throw()
+const char *ErrorReporter::what() const throw()
 {
 	return errorMessage.c_str();
 }
diff --git a/error_reporter.h b/error_reporter.h
@@ -1,7 +1,7 @@
 /*
     fm_transmitter - use Raspberry Pi as FM transmitter
 
-    Copyright (c) 2018, Marcin Kondej
+    Copyright (c) 2019, Marcin Kondej
     All rights reserved.
 
     See https://github.com/markondej/fm_transmitter
@@ -46,7 +46,7 @@ class ErrorReporter : public exception
         explicit ErrorReporter(string message);
         virtual ~ErrorReporter() throw();
 
-        virtual const char* what() const throw();
+        virtual const char *what() const throw();
     protected:
         string errorMessage;
 };

diff --git a/mailbox.c b/mailbox.c
@@ -0,0 +1,262 @@
+/*
+Copyright (c) 2012, Broadcom Europe Ltd.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * 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.
+    * Neither the name of the copyright holder 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 HOLDER 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 <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <assert.h>
+#include <stdint.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+
+#include "mailbox.h"
+
+#define PAGE_SIZE (4*1024)
+
+void *mapmem(unsigned base, unsigned size)
+{
+   int mem_fd;
+   unsigned offset = base % PAGE_SIZE;
+   base = base - offset;
+   size = size + offset;
+   /* open /dev/mem */
+   if ((mem_fd = open("/dev/mem", O_RDWR|O_SYNC) ) < 0) {
+      printf("can't open /dev/mem\nThis program should be run as root. Try prefixing command with: sudo\n");
+      exit (-1);
+   }
+   void *mem = mmap(
+      0,
+      size,
+      PROT_READ|PROT_WRITE,
+      MAP_SHARED/*|MAP_FIXED*/,
+      mem_fd,
+      base);
+#ifdef DEBUG
+   printf("base=0x%x, mem=%p\n", base, mem);
+#endif
+   if (mem == MAP_FAILED) {
+      printf("mmap error %d\n", (int)mem);
+      exit (-1);
+   }
+   close(mem_fd);
+   return (char *)mem + offset;
+}
+
+void unmapmem(void *addr, unsigned size)
+{
+   const intptr_t offset = (intptr_t)addr % PAGE_SIZE;
+   addr = (char *)addr - offset;
+   size = size + offset;
+   int s = munmap(addr, size);
+   if (s != 0) {
+      printf("munmap error %d\n", s);
+      exit (-1);
+   }
+}
+
+/*
+ * use ioctl to send mbox property message
+ */
+
+static int mbox_property(int file_desc, void *buf)
+{
+   int ret_val = ioctl(file_desc, IOCTL_MBOX_PROPERTY, buf);
+
+   if (ret_val < 0) {
+      printf("ioctl_set_msg failed:%d\n", ret_val);
+   }
+
+#ifdef DEBUG
+   unsigned *p = buf; int i; unsigned size = *(unsigned *)buf;
+   for (i=0; i<size/4; i++)
+      printf("%04x: 0x%08x\n", i*sizeof *p, p[i]);
+#endif
+   return ret_val;
+}
+
+unsigned mem_alloc(int file_desc, unsigned size, unsigned align, unsigned flags)
+{
+   int i=0;
+   unsigned p[32];
+   p[i++] = 0; // size
+   p[i++] = 0x00000000; // process request
+
+   p[i++] = 0x3000c; // (the tag id)
+   p[i++] = 12; // (size of the buffer)
+   p[i++] = 12; // (size of the data)
+   p[i++] = size; // (num bytes? or pages?)
+   p[i++] = align; // (alignment)
+   p[i++] = flags; // (MEM_FLAG_L1_NONALLOCATING)
+
+   p[i++] = 0x00000000; // end tag
+   p[0] = i*sizeof *p; // actual size
+
+   mbox_property(file_desc, p);
+   return p[5];
+}
+
+unsigned mem_free(int file_desc, unsigned handle)
+{
+   int i=0;
+   unsigned p[32];
+   p[i++] = 0; // size
+   p[i++] = 0x00000000; // process request
+
+   p[i++] = 0x3000f; // (the tag id)
+   p[i++] = 4; // (size of the buffer)
+   p[i++] = 4; // (size of the data)
+   p[i++] = handle;
+
+   p[i++] = 0x00000000; // end tag
+   p[0] = i*sizeof *p; // actual size
+
+   mbox_property(file_desc, p);
+   return p[5];
+}
+
+unsigned mem_lock(int file_desc, unsigned handle)
+{
+   int i=0;
+   unsigned p[32];
+   p[i++] = 0; // size
+   p[i++] = 0x00000000; // process request
+
+   p[i++] = 0x3000d; // (the tag id)
+   p[i++] = 4; // (size of the buffer)
+   p[i++] = 4; // (size of the data)
+   p[i++] = handle;
+
+   p[i++] = 0x00000000; // end tag
+   p[0] = i*sizeof *p; // actual size
+
+   mbox_property(file_desc, p);
+   return p[5];
+}
+
+unsigned mem_unlock(int file_desc, unsigned handle)
+{
+   int i=0;
+   unsigned p[32];
+   p[i++] = 0; // size
+   p[i++] = 0x00000000; // process request
+
+   p[i++] = 0x3000e; // (the tag id)
+   p[i++] = 4; // (size of the buffer)
+   p[i++] = 4; // (size of the data)
+   p[i++] = handle;
+
+   p[i++] = 0x00000000; // end tag
+   p[0] = i*sizeof *p; // actual size
+
+   mbox_property(file_desc, p);
+   return p[5];
+}
+
+unsigned execute_code(int file_desc, unsigned code, unsigned r0, unsigned r1, unsigned r2, unsigned r3, unsigned r4, unsigned r5)
+{
+   int i=0;
+   unsigned p[32];
+   p[i++] = 0; // size
+   p[i++] = 0x00000000; // process request
+
+   p[i++] = 0x30010; // (the tag id)
+   p[i++] = 28; // (size of the buffer)
+   p[i++] = 28; // (size of the data)
+   p[i++] = code;
+   p[i++] = r0;
+   p[i++] = r1;
+   p[i++] = r2;
+   p[i++] = r3;
+   p[i++] = r4;
+   p[i++] = r5;
+
+   p[i++] = 0x00000000; // end tag
+   p[0] = i*sizeof *p; // actual size
+
+   mbox_property(file_desc, p);
+   return p[5];
+}
+
+unsigned qpu_enable(int file_desc, unsigned enable)
+{
+   int i=0;
+   unsigned p[32];
+
+   p[i++] = 0; // size
+   p[i++] = 0x00000000; // process request
+
+   p[i++] = 0x30012; // (the tag id)
+   p[i++] = 4; // (size of the buffer)
+   p[i++] = 4; // (size of the data)
+   p[i++] = enable;
+
+   p[i++] = 0x00000000; // end tag
+   p[0] = i*sizeof *p; // actual size
+
+   mbox_property(file_desc, p);
+   return p[5];
+}
+
+unsigned execute_qpu(int file_desc, unsigned num_qpus, unsigned control, unsigned noflush, unsigned timeout) {
+   int i=0;
+   unsigned p[32];
+
+   p[i++] = 0; // size
+   p[i++] = 0x00000000; // process request
+   p[i++] = 0x30011; // (the tag id)
+   p[i++] = 16; // (size of the buffer)
+   p[i++] = 16; // (size of the data)
+   p[i++] = num_qpus;
+   p[i++] = control;
+   p[i++] = noflush;
+   p[i++] = timeout; // ms
+
+   p[i++] = 0x00000000; // end tag
+   p[0] = i*sizeof *p; // actual size
+
+   mbox_property(file_desc, p);
+   return p[5];
+}
+
+int mbox_open() {
+   int file_desc;
+
+   // open a char device file used for communicating with kernel mbox driver
+   file_desc = open(DEVICE_FILE_NAME, 0);
+   if (file_desc < 0) {
+      printf("Can't open device file: %s\n", DEVICE_FILE_NAME);
+      printf("Try creating a device file with: sudo mknod %s c %d 0\n", DEVICE_FILE_NAME, MAJOR_NUM);
+      exit(-1);
+   }
+   return file_desc;
+}
+
+void mbox_close(int file_desc) {
+  close(file_desc);
+}
diff --git a/mailbox.h b/mailbox.h
@@ -0,0 +1,47 @@
+/*
+Copyright (c) 2012, Broadcom Europe Ltd.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * 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.
+    * Neither the name of the copyright holder 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 HOLDER 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 <linux/ioctl.h>
+
+#define MAJOR_NUM 100
+#define IOCTL_MBOX_PROPERTY _IOWR(MAJOR_NUM, 0, char *)
+#define DEVICE_FILE_NAME "/dev/vcio"
+
+int mbox_open();
+void mbox_close(int file_desc);
+
+unsigned get_version(int file_desc);
+unsigned mem_alloc(int file_desc, unsigned size, unsigned align, unsigned flags);
+unsigned mem_free(int file_desc, unsigned handle);
+unsigned mem_lock(int file_desc, unsigned handle);
+unsigned mem_unlock(int file_desc, unsigned handle);
+void *mapmem(unsigned base, unsigned size);
+void unmapmem(void *addr, unsigned size);
+
+unsigned execute_code(int file_desc, unsigned code, unsigned r0, unsigned r1, unsigned r2, unsigned r3, unsigned r4, unsigned r5);
+unsigned execute_qpu(int file_desc, unsigned num_qpus, unsigned control, unsigned noflush, unsigned timeout);
+unsigned qpu_enable(int file_desc, unsigned enable);