1 files changed, 216 insertions, 54 deletions

diff --git a/binding/radio_impl_rtlsdr.c b/binding/radio_impl_rtlsdr.c
index 22d627e..7fd4d69 100644
--- a/binding/radio_impl_rtlsdr.c
+++ b/binding/radio_impl_rtlsdr.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017 Konsulko Group
+ * Copyright (C) 2017,2018 Konsulko Group
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,11 +19,18 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <string.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <sys/stat.h>
+#include <errno.h>
 #include <glib.h>
+#define AFB_BINDING_VERSION 2
+#include <afb/afb-binding.h>
 
 #include "radio_impl.h"
-#include "radio_output.h"
-#include "rtl_fm.h"
+
+#define HELPER_NAME	"rtl_fm_helper"
+#define HELPER_MAX	PATH_MAX + 64
 
 // Structure to describe FM band plans, all values in Hz.
 typedef struct {
@@ -42,27 +49,91 @@ static fm_band_plan_t known_fm_band_plans[5] = {
 };
 
 static unsigned int bandplan;
+static pid_t helper_pid;
+static int helper_in;
+static int helper_out;
+static pthread_mutex_t helper_mutex = PTHREAD_MUTEX_INITIALIZER;
 static bool present;
 static bool active;
+static bool scanning;
 static uint32_t current_frequency;
+static radio_freq_callback_t freq_callback;
+static void *freq_callback_data;
 
 static uint32_t rtlsdr_get_min_frequency(radio_band_t band);
+static void rtlsdr_set_frequency(uint32_t frequency);
 static void rtlsdr_scan_stop(void);
 
-static void rtl_output_callback(int16_t *result, int result_len, void *ctx)
+/*
+ * Bi-directional popen implementation
+ * Based on one of the versions given in:
+ *
+ * https://stackoverflow.com/questions/12778672/killing-process-that-has-been-created-with-popen2
+ */
+static pid_t popen2(char *command, int *in_fd, int *out_fd)
 {
-    if(active)
-	    radio_output_write((char*) result, result_len * 2);
+	int     pin[2], pout[2];
+	pid_t   pid;
+
+	if(out_fd != NULL) {
+		if(pipe(pin) != 0)
+			return -1;
+	}
+	if(in_fd != NULL) {
+		if (pipe(pout) != 0) {
+			if(out_fd != NULL) {
+				close(pin[0]);
+				close(pin[1]);
+			}
+			return -1;
+		}
+	}
+
+	pid = fork();
+	if(pid < 0) {
+		if(out_fd != NULL) {
+			close(pin[0]);
+			close(pin[1]);
+		}
+		if(in_fd != NULL) {
+			close(pout[0]);
+			close(pout[1]);
+		}
+		return pid;
+	}
+	if(pid == 0) {
+		if(out_fd != NULL) {
+			close(pin[1]);
+			dup2(pin[0], 0);
+		}
+		if(in_fd != NULL) {
+			close(pout[0]);
+			dup2(pout[1], 1);
+		}
+		execlp(command, command, NULL);
+		perror("Error:");
+		exit(1);
+	}
+	if(in_fd != NULL) {
+		close(pout[1]);
+		*in_fd = pout[0];
+	}
+	if(out_fd != NULL) {
+		close(pin[0]);
+		*out_fd = pin[1];
+	}
+	return pid;
 }
 
 static int rtlsdr_init(void)
 {
-	GKeyFile* conf_file;
-	int conf_file_present = 0;
+	GKeyFile *conf_file;
 	char *value_str;
+	char *rootdir;
+	char *helper_path;
 
 	if(present)
-		return -1;
+		return 0;
 
 	// Load settings from configuration file if it exists
 	conf_file = g_key_file_new();
@@ -73,7 +144,6 @@ static int rtlsdr_init(void)
 				     NULL,
 				     G_KEY_FILE_KEEP_COMMENTS,
 				     NULL) == TRUE) {
-		conf_file_present = 1;
 
 		// Set band plan if it is specified
 		value_str = g_key_file_get_string(conf_file,
@@ -92,42 +162,43 @@ static int rtlsdr_init(void)
 			}
 		}
 	}
-	fprintf(stderr, "Using FM Bandplan: %s\n", known_fm_band_plans[bandplan].name);
 
+	// Start off with minimum bandplan frequency
 	current_frequency = rtlsdr_get_min_frequency(BAND_FM);
-	if(rtl_fm_init(current_frequency, 200000, 48000, rtl_output_callback, NULL) < 0) {
-		return -1;
-	}
 
-	if(conf_file_present) {
-		GError *error = NULL;
-		int n;
-
-		// Allow over-riding scanning parameters just in case a demo
-		// setup needs to do so to work reliably.
-		n = g_key_file_get_integer(conf_file,
-					   "radio",
-					   "scan_squelch_level",
-					   &error);
-		if(!error) {
-			fprintf(stderr, "Scanning squelch level set to %d\n", n);
-			rtl_fm_scan_set_squelch_level(n);
-		}
+	rootdir = getenv("AFM_APP_INSTALL_DIR");
+	if(!rootdir)
+		return -1;
 
-		error = NULL;
-		n = g_key_file_get_integer(conf_file,
-					   "radio",
-					   "scan_squelch_limit",
-					   &error);
-		if(!error) {
-			fprintf(stderr, "Scanning squelch limit set to %d\n", n);
-			rtl_fm_scan_set_squelch_limit(n);
-		}
+	// Run helper to detect adapter
+	helper_path = malloc(HELPER_MAX);
+	if(!helper_path)
+		return -ENOMEM;
+	if(snprintf(helper_path, HELPER_MAX, "%s/bin/%s --detect", rootdir, HELPER_NAME) == HELPER_MAX) {
+		AFB_ERROR("Could not create command for \"%s --detect\"", HELPER_NAME);
+		return -EINVAL;
+	}
+	if(system(helper_path) != 0) {
+		free(helper_path);
+		return -1;
+	}
 
-		g_key_file_free(conf_file);
+	// Run helper
+	if(snprintf(helper_path, PATH_MAX, "%s/bin/%s", rootdir, HELPER_NAME) == PATH_MAX) {
+		AFB_ERROR("Could not create path to %s", HELPER_NAME);
+		return -EINVAL;
 	}
+	helper_pid = popen2(helper_path, &helper_out, &helper_in);
+	if(helper_pid < 0) {
+		AFB_ERROR("Could not run %s!", HELPER_NAME);
+		return -1;
+	}
+	AFB_DEBUG("%s started", HELPER_NAME);
+	free(helper_path);
 
 	present = true;
+	rtlsdr_set_frequency(current_frequency);
+
 	return 0;
 }
 
@@ -138,6 +209,12 @@ static uint32_t rtlsdr_get_frequency(void)
 
 static void rtlsdr_set_frequency(uint32_t frequency)
 {
+	char cmd[64];
+	char output[128];
+	bool found = false;
+	int rc;
+	uint32_t n;
+
 	if(!present)
 		return;
 
@@ -145,19 +222,45 @@ static void rtlsdr_set_frequency(uint32_t frequency)
 	   frequency > known_fm_band_plans[bandplan].max)
 		return;
 
-	rtlsdr_scan_stop();
+	if(scanning)
+		rtlsdr_scan_stop();
+
 	current_frequency = frequency;
-	rtl_fm_set_freq(frequency);
+	sprintf(cmd, "F=%u\n", frequency);
+	pthread_mutex_lock(&helper_mutex);
+	rc = write(helper_in, cmd, strlen(cmd));
+	if(rc < 0) {
+		pthread_mutex_unlock(&helper_mutex);
+		return;
+	}
+	while(!found) {
+		rc = read(helper_out, output, 128);
+		if(rc <= 0)
+			break;
+		if(rc == 128)
+			rc = 127;
+		output[rc] = '\0';
+		if(output[0] == 'F') {
+			if(sscanf(output, "F=%u\n", &n) == 1) {
+				if(freq_callback)
+					freq_callback(n, freq_callback_data);
+				found = true;
+			}
+		}
+	}
+	pthread_mutex_unlock(&helper_mutex);
 }
 
 static void rtlsdr_set_frequency_callback(radio_freq_callback_t callback,
 					  void *data)
 {
-	rtl_fm_set_freq_callback(callback, data);
+	freq_callback = callback;
+	freq_callback_data = data;
 }
 
 static radio_band_t rtlsdr_get_band(void)
 {
+	// We only support FM
 	return BAND_FM;
 }
 
@@ -206,10 +309,15 @@ static void rtlsdr_start(void)
 		return;
 
 	if(!active) {
-		if(radio_output_start() != 0)
+		int rc;
+		char cmd[64];
+
+		sprintf(cmd, "START\n");
+		pthread_mutex_lock(&helper_mutex);
+		rc = write(helper_in, cmd, strlen(cmd));
+		pthread_mutex_unlock(&helper_mutex);
+		if(rc < 0)
 			return;
-
-		rtl_fm_start();
 		active = true;
 	}
 }
@@ -220,10 +328,14 @@ static void rtlsdr_stop(void)
 		return;
 
 	if(active) {
-		active = false;
-		radio_output_stop();
-		rtl_fm_stop();
+		int rc;
+		char cmd[64];
 
+		active = false;
+		sprintf(cmd, "STOP\n");
+		pthread_mutex_lock(&helper_mutex);
+		write(helper_in, cmd, strlen(cmd));
+		pthread_mutex_unlock(&helper_mutex);
 	}
 }
 
@@ -231,21 +343,71 @@ static void rtlsdr_scan_start(radio_scan_direction_t direction,
 			      radio_scan_callback_t callback,
 			      void *data)
 {
-	rtl_fm_scan_start(direction == SCAN_FORWARD ? 0 : 1,
-			  callback,
-			  data,
-			  rtlsdr_get_frequency_step(BAND_FM),
-			  rtlsdr_get_min_frequency(BAND_FM),
-			  rtlsdr_get_max_frequency(BAND_FM));
+	int rc;
+	char cmd[64];
+	char output[128];
+	bool found = false;
+	uint32_t n;
+
+	if(!active || scanning)
+		return;
+
+	scanning = true;
+	sprintf(cmd, "S=%s\n", direction == SCAN_FORWARD ? "UP" : "DOWN");
+	pthread_mutex_lock(&helper_mutex);
+	if(!scanning) {
+		pthread_mutex_unlock(&helper_mutex);
+		return;
+	}
+	rc = write(helper_in, cmd, strlen(cmd));
+	pthread_mutex_unlock(&helper_mutex);
+	if(rc < 0)
+		return;
+	while(!found) {
+		pthread_mutex_lock(&helper_mutex);
+		if(!scanning) {
+			pthread_mutex_unlock(&helper_mutex);
+			break;
+		}
+		rc = read(helper_out, output, 128);
+		pthread_mutex_unlock(&helper_mutex);
+		if(rc <= 0)
+			break;
+		if(rc == 128)
+			rc = 127;
+		output[rc] = '\0';
+		if(output[0] == 'F') {
+			if(sscanf(output, "F=%u\n", &n) == 1) {
+				current_frequency = n;
+				if(freq_callback)
+					freq_callback(n, freq_callback_data);
+			}
+		}
+		if(output[0] == 'S') {
+			if(sscanf(output, "S=%u\n", &n) == 1) {
+				if(callback)
+					callback(n, data);
+				found = true;
+				scanning = false;
+			}
+		}
+	}
 }
 
 static void rtlsdr_scan_stop(void)
 {
-	rtl_fm_scan_stop();
+	char cmd[64];
+
+	sprintf(cmd, "S=STOP\n");
+	pthread_mutex_lock(&helper_mutex);
+	scanning = false;
+	write(helper_in, cmd, strlen(cmd));
+	pthread_mutex_unlock(&helper_mutex);
 }
 
 static radio_stereo_mode_t rtlsdr_get_stereo_mode(void)
 {
+	// We only support stereo
 	return STEREO;
 }