rtl_biast: Add rtl_biast

This is an import of the rtl_biast command line tool from the
rtlsdrblog github repository.  It's easier to include it here than
try to package up the separate application because they both
wish to install dynamic libraries.

src/CMakeLists.txt

@@ -91,7 +91,8 @@ add_executable(rtl_fm rtl_fm.c)
 add_executable(rtl_eeprom rtl_eeprom.c)
 add_executable(rtl_adsb rtl_adsb.c)
 add_executable(rtl_power rtl_power.c)
-set(INSTALL_TARGETS rtlsdr_shared rtlsdr_static rtl_sdr rtl_tcp rtl_test rtl_fm rtl_eeprom rtl_adsb rtl_power)
+add_executable(rtl_biast rtl_biast.c)
+set(INSTALL_TARGETS rtlsdr_shared rtlsdr_static rtl_sdr rtl_tcp rtl_test rtl_fm rtl_eeprom rtl_adsb rtl_power rtl_biast)
 
 target_link_libraries(rtl_sdr rtlsdr_shared convenience_static
     ${LIBUSB_LIBRARIES}
@@ -121,6 +122,11 @@ target_link_libraries(rtl_power rtlsdr_shared convenience_static
     ${LIBUSB_LIBRARIES}
     ${CMAKE_THREAD_LIBS_INIT}
 )
+target_link_libraries(rtl_biast rtlsdr_shared convenience_static
+    ${LIBUSB_LIBRARIES}
+    ${CMAKE_THREAD_LIBS_INIT}
+)
+
 if(UNIX)
 target_link_libraries(rtl_fm m)
 target_link_libraries(rtl_adsb m)

src/rtl_biast.c

@@ -0,0 +1,101 @@
+/*
+ * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
+ * rtl_biast, tool to set bias tee gpio output
+ * Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
+ *
+ * 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 2 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/>.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef _WIN32
+#include <unistd.h>
+#else
+#include <windows.h>
+#include "getopt/getopt.h"
+#endif
+
+#include "rtl-sdr.h"
+#include "convenience/convenience.h"
+
+static rtlsdr_dev_t *dev = NULL;
+
+void usage(void)
+{
+	fprintf(stderr,
+		"rtl_biast, a tool for turning the RTL-SDR.com \n"
+		"bias tee or any GPIO ON and OFF. Example to turn on the \n"
+		"bias tee: rtl_biast -d 0 -b 1\n"
+		"Any GPIO: rtl_biast -d 0 -g 1 -b 1\n\n"
+		"Usage:\n"
+		"\t[-d device_index (default: 0)]\n"
+		"\t[-b bias_on (default: 0)]\n"
+		"\t[-g GPIO select (default: 0)]\n");
+	exit(1);
+}
+
+int main(int argc, char **argv)
+{
+	int i, r, opt;
+	int dev_index = 0;
+	int dev_given = 0;
+	uint32_t bias_on = 0;
+	uint32_t gpio_pin = 0;
+	int device_count;
+
+	while ((opt = getopt(argc, argv, "d:b:g:h?")) != -1) {
+		switch (opt) {
+		case 'd':
+			dev_index = verbose_device_search(optarg);
+			dev_given = 1;
+			break;
+		case 'b':
+			bias_on = atoi(optarg);
+			break;
+		case 'g':
+			gpio_pin = atoi(optarg);
+			break;
+		default:
+			usage();
+			break;
+		}
+	}
+
+	if (!dev_given) {
+		dev_index = verbose_device_search("0");
+	}
+
+	if (dev_index < 0) {
+		exit(1);
+	}
+
+	r = rtlsdr_open(&dev, dev_index);
+	rtlsdr_set_bias_tee_gpio(dev, gpio_pin, bias_on);
+
+exit:
+	/*
+	 * Note - rtlsdr_close() in this tree does not clear the bias tee
+	 * GPIO line, so it leaves the bias tee enabled if a client program
+	 * doesn't explictly disable it.
+	 *
+	 * If that behaviour changes then another rtlsdr_close() will be
+	 * needed that takes some extension flags, and one of them should
+	 * be to either explicitly close the biast or leave it alone.
+	 */
+	rtlsdr_close(dev);
+
+	return r >= 0 ? r : -r;
+}