rework towards a library interface

9 files changed, 752 insertions, 428 deletions

diff --git a/src/Makefile b/src/Makefile
index 4f66cf6..09070df 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,9 +1,9 @@
 LDFLAGS=`pkg-config --libs libusb-1.0`
-CFLAGS=-Wall -O2 `pkg-config --cflags libusb-1.0`
+CFLAGS=-Wall -g -O0 `pkg-config --cflags libusb-1.0`
 
 all: rtl-sdr
 
-rtl-sdr: main.o tuner_e4000.o tuner_fc0013.c
+rtl-sdr: main.o rtl-sdr.o tuner_e4000.o tuner_fc0013.c
 	$(CC) -o $@ $^ $(LDFLAGS)
 
 clean:
diff --git a/src/i2c.h b/src/i2c.h
index 31c21bb..0877380 100644
--- a/src/i2c.h
+++ b/src/i2c.h
@@ -1,7 +1,9 @@
 #ifndef __I2C_H
 #define __I2C_H
 
-int rtl_i2c_write(uint8_t i2c_addr, uint8_t *buffer, int len);
-int rtl_i2c_read(uint8_t i2c_addr, uint8_t *buffer, int len);
+typedef int rtlsdr_dev_t;
+
+int rtlsdr_i2c_write(rtlsdr_dev_t *dev, uint8_t i2c_addr, uint8_t *buffer, int len);
+int rtlsdr_i2c_read(rtlsdr_dev_t *dev, uint8_t i2c_addr, uint8_t *buffer, int len);
 
 #endif
diff --git a/src/main.c b/src/main.c
index 2643303..5329676 100644
--- a/src/main.c
+++ b/src/main.c
@@ -24,303 +24,12 @@
 #include <math.h>
 #include <unistd.h>
 
-#include <libusb.h>
-
-#include "tuner_e4000.h"
-#include "tuner_fc0013.h"
+#include "rtl-sdr.h"
 
 #define READLEN		(16 * 16384)
-#define CTRL_IN		(LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN)
-#define CTRL_OUT	(LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_OUT)
-
-/* ezcap USB 2.0 DVB-T/DAB/FM stick */
-#define EZCAP_VID	0x0bda
-#define EZCAP_PID	0x2838
-
-/* Terratec NOXON DAB/DAB+ USB-Stick */
-#define NOXON_VID	0x0ccd
-#define NOXON_PID	0x00b3
-
-#define CRYSTAL_FREQ	28800000
 
-static struct libusb_device_handle *devh = NULL;
 static int do_exit = 0;
 
-enum TUNER_TYPE {
-	TUNER_E4000,
-	TUNER_FC0013
-} tuner_type;
-
-static int find_device(void)
-{
-	devh = libusb_open_device_with_vid_pid(NULL, EZCAP_VID, EZCAP_PID);
-	if (devh > 0) {
-		tuner_type = TUNER_E4000;
-		printf("Found ezcap stick with E4000 tuner\n");
-		return 0;
-	}
-
-	devh = libusb_open_device_with_vid_pid(NULL, NOXON_VID, NOXON_PID);
-	if (devh > 0) {
-		tuner_type = TUNER_FC0013;
-		printf("Found Terratec NOXON stick with FC0013 tuner\n");
-		return 0;
-	}
-
-	return -EIO;
-}
-
-enum usb_reg {
-	USB_SYSCTL		= 0x2000,
-	USB_CTRL		= 0x2010,
-	USB_STAT		= 0x2014,
-	USB_EPA_CFG		= 0x2144,
-	USB_EPA_CTL		= 0x2148,
-	USB_EPA_MAXPKT		= 0x2158,
-	USB_EPA_MAXPKT_2	= 0x215a,
-	USB_EPA_FIFO_CFG	= 0x2160,
-};
-
-enum sys_reg {
-	DEMOD_CTL		= 0x3000,
-	GPO			= 0x3001,
-	GPI			= 0x3002,
-	GPOE			= 0x3003,
-	GPD			= 0x3004,
-	SYSINTE			= 0x3005,
-	SYSINTS			= 0x3006,
-	GP_CFG0			= 0x3007,
-	GP_CFG1			= 0x3008,
-	SYSINTE_1		= 0x3009,
-	SYSINTS_1		= 0x300a,
-	DEMOD_CTL_1		= 0x300b,
-	IR_SUSPEND		= 0x300c,
-};
-
-enum blocks {
-	DEMODB			= 0,
-	USBB			= 1,
-	SYSB			= 2,
-	TUNB			= 3,
-	ROMB			= 4,
-	IRB			= 5,
-	IICB			= 6,
-};
-
-int rtl_read_array(uint8_t block, uint16_t addr, uint8_t *array, uint8_t len)
-{
-	int r;
-	uint16_t index = (block << 8);
-
-	r = libusb_control_transfer(devh, CTRL_IN, 0, addr, index, array, len, 0);
-
-	return r;
-}
-
-int rtl_write_array(uint8_t block, uint16_t addr, uint8_t *array, uint8_t len)
-{
-	int r;
-	uint16_t index = (block << 8) | 0x10;
-
-	r = libusb_control_transfer(devh, CTRL_OUT, 0, addr, index, array, len, 0);
-
-	return r;
-}
-
-int rtl_i2c_write(uint8_t i2c_addr, uint8_t *buffer, int len)
-{
-	uint16_t addr = i2c_addr;
-	return rtl_write_array(IICB, addr, buffer, len);
-}
-
-int rtl_i2c_read(uint8_t i2c_addr, uint8_t *buffer, int len)
-{
-	uint16_t addr = i2c_addr;
-	return rtl_read_array(IICB, addr, buffer, len);
-}
-
-uint16_t rtl_read_reg(uint8_t block, uint16_t addr, uint8_t len)
-{
-	int r;
-	unsigned char data[2];
-	uint16_t index = (block << 8);
-	uint16_t reg;
-
-	r = libusb_control_transfer(devh, CTRL_IN, 0, addr, index, data, len, 0);
-
-	if (r < 0)
-		printf("%s failed\n", __FUNCTION__);
-
-	reg = (data[1] << 8) | data[0];
-
-	return reg;
-}
-
-void rtl_write_reg(uint8_t block, uint16_t addr, uint16_t val, uint8_t len)
-{
-	int r;
-	unsigned char data[2];
-
-	uint16_t index = (block << 8) | 0x10;
-
-	if (len == 1)
-		data[0] = val & 0xff;
-	else
-		data[0] = val >> 8;
-
-	data[1] = val & 0xff;
-
-	r = libusb_control_transfer(devh, CTRL_OUT, 0, addr, index, data, len, 0);
-
-	if (r < 0)
-		printf("%s failed\n", __FUNCTION__);
-}
-
-uint16_t demod_read_reg(uint8_t page, uint8_t addr, uint8_t len)
-{
-	int r;
-	unsigned char data[2];
-
-	uint16_t index = page;
-	uint16_t reg;
-	addr = (addr << 8) | 0x20;
-
-	r = libusb_control_transfer(devh, CTRL_IN, 0, addr, index, data, len, 0);
-
-	if (r < 0)
-		printf("%s failed\n", __FUNCTION__);
-
-	reg = (data[1] << 8) | data[0];
-
-	return reg;
-}
-
-void demod_write_reg(uint8_t page, uint16_t addr, uint16_t val, uint8_t len)
-{
-	int r;
-	unsigned char data[2];
-	uint16_t index = 0x10 | page;
-	addr = (addr << 8) | 0x20;
-
-	if (len == 1)
-		data[0] = val & 0xff;
-	else
-		data[0] = val >> 8;
-
-	data[1] = val & 0xff;
-
-	r = libusb_control_transfer(devh, CTRL_OUT, 0, addr, index, data, len, 0);
-
-	if (r < 0)
-		printf("%s failed\n", __FUNCTION__);
-
-	demod_read_reg(0x0a, 0x01, 1);
-}
-
-void set_samp_rate(uint32_t samp_rate)
-{
-	uint16_t tmp;
-	uint32_t rsamp_ratio;
-	double real_rate;
-
-	/* check for the maximum rate the resampler supports */
-	if (samp_rate > 3200000)
-		samp_rate = 3200000;
-
-	rsamp_ratio = (CRYSTAL_FREQ * pow(2, 22)) / samp_rate;
-	rsamp_ratio &= ~3;
-
-	real_rate = (CRYSTAL_FREQ * pow(2, 22)) / rsamp_ratio;
-	printf("Setting sample rate: %.3f Hz\n", real_rate);
-
-	tmp = (rsamp_ratio >> 16);
-	demod_write_reg(1, 0x9f, tmp, 2);
-	tmp = rsamp_ratio & 0xffff;
-	demod_write_reg(1, 0xa1, tmp, 2);
-}
-
-void set_i2c_repeater(int on)
-{
-	demod_write_reg(1, 0x01, on ? 0x18 : 0x10, 1);
-}
-
-void rtl_init(void)
-{
-	unsigned int i;
-
-	/* default FIR coefficients used for DAB/FM by the Windows driver,
-	 * the DVB driver uses different ones */
-	uint8_t fir_coeff[] = {
-		0xca, 0xdc, 0xd7, 0xd8, 0xe0, 0xf2, 0x0e, 0x35, 0x06, 0x50,
-		0x9c, 0x0d, 0x71, 0x11, 0x14, 0x71, 0x74, 0x19, 0x41, 0x00,
-	};
-
-	/* initialize USB */
-	rtl_write_reg(USBB, USB_SYSCTL, 0x09, 1);
-	rtl_write_reg(USBB, USB_EPA_MAXPKT, 0x0002, 2);
-	rtl_write_reg(USBB, USB_EPA_CTL, 0x1002, 2);
-
-	/* poweron demod */
-	rtl_write_reg(SYSB, DEMOD_CTL_1, 0x22, 1);
-	rtl_write_reg(SYSB, DEMOD_CTL, 0xe8, 1);
-
-	/* reset demod (bit 3, soft_rst) */
-	demod_write_reg(1, 0x01, 0x14, 1);
-	demod_write_reg(1, 0x01, 0x10, 1);
-
-	/* disable spectrum inversion and adjacent channel rejection */
-	demod_write_reg(1, 0x15, 0x00, 1);
-	demod_write_reg(1, 0x16, 0x0000, 2);
-
-	/* set IF-frequency to 0 Hz */
-	demod_write_reg(1, 0x19, 0x0000, 2);
-
-	/* set FIR coefficients */
-	for (i = 0; i < sizeof (fir_coeff); i++)
-		demod_write_reg(1, 0x1c + i, fir_coeff[i], 1);
-
-	demod_write_reg(0, 0x19, 0x25, 1);
-
-	/* init FSM state-holding register */
-	demod_write_reg(1, 0x93, 0xf0, 1);
-
-	/* disable AGC (en_dagc, bit 0) */
-	demod_write_reg(1, 0x11, 0x00, 1);
-
-	/* disable PID filter (enable_PID = 0) */
-	demod_write_reg(0, 0x61, 0x60, 1);
-
-	/* opt_adc_iq = 0, default ADC_I/ADC_Q datapath */
-	demod_write_reg(0, 0x06, 0x80, 1);
-
-	/* Enable Zero-IF mode (en_bbin bit), DC cancellation (en_dc_est),
-	 * IQ estimation/compensation (en_iq_comp, en_iq_est) */
-	demod_write_reg(1, 0xb1, 0x1b, 1);
-}
-
-void tuner_init(int frequency)
-{
-	set_i2c_repeater(1);
-
-	switch (tuner_type) {
-	case TUNER_E4000:
-		e4000_Initialize(1);
-		e4000_SetBandwidthHz(1, 8000000);
-		e4000_SetRfFreqHz(1, frequency);
-		break;
-	case TUNER_FC0013:
-		FC0013_Open();
-		FC0013_SetFrequency(frequency/1000, 8);
-		break;
-	default:
-		printf("No valid tuner available!");
-		break;
-	}
-
-	printf("Tuned to %i Hz\n", frequency);
-	set_i2c_repeater(0);
-}
-
 void usage(void)
 {
 	printf("rtl-sdr, an I/Q recorder for RTL2832 based USB-sticks\n\n"
@@ -342,8 +51,9 @@ int main(int argc, char **argv)
 	char *filename;
 	uint32_t frequency = 0, samp_rate = 2048000;
 	uint8_t buffer[READLEN];
-	int n_read;
+    uint32_t n_read;
 	FILE *file;
+	rtlsdr_dev_t *dev = NULL;
 
 	while ((opt = getopt(argc, argv, "f:s:")) != -1) {
 		switch (opt) {
@@ -365,22 +75,20 @@ int main(int argc, char **argv)
 		filename = argv[optind];
 	}
 
-	r = libusb_init(NULL);
-	if (r < 0) {
-		fprintf(stderr, "Failed to initialize libusb\n");
-		exit(1);
-	}
+    rtlsdr_init();
 
-	r = find_device();
-	if (r < 0) {
-		fprintf(stderr, "Could not find/open device\n");
-		goto out;
-	}
+    int device_count = rtlsdr_get_device_count();
+    if (!device_count) {
+        fprintf(stderr, "No supported devices found.\n");
+        exit(1);
+    }
 
-	r = libusb_claim_interface(devh, 0);
-	if (r < 0) {
-		fprintf(stderr, "usb_claim_interface error %d\n", r);
-		goto out;
+    printf("Found %d device(s).\n", device_count);
+
+    dev = rtlsdr_open(0); /* open the first device */
+	if (NULL == dev) {
+        fprintf(stderr, "Failed to open rtlsdr device.\n");
+		exit(1);
 	}
 
 	sigact.sa_handler = sighandler;
@@ -390,12 +98,17 @@ int main(int argc, char **argv)
 	sigaction(SIGTERM, &sigact, NULL);
 	sigaction(SIGQUIT, &sigact, NULL);
 
-	/* Initialize the RTL2832 */
-	rtl_init();
-	set_samp_rate(samp_rate);
+	/* Set the sample rate */
+    r = rtlsdr_set_sample_rate(dev, samp_rate);
+	if (r < 0) {
+        fprintf(stderr, "WARNING: Failed to set sample rate.\n");
+	}
 
-	/* Initialize tuner & set frequency */
-	tuner_init(frequency);
+	/* Set the frequency */
+	r = rtlsdr_set_center_freq(dev, frequency);
+    if (r < 0) {
+        fprintf(stderr, "WARNING: Failed to set center freq.\n");
+    }
 
 	file = fopen(filename, "wb");
 
@@ -404,27 +117,30 @@ int main(int argc, char **argv)
 		goto out;
 	}
 
-	/* reset endpoint before we start reading */
-	rtl_write_reg(USBB, USB_EPA_CTL, 0x1002, 2);
-	rtl_write_reg(USBB, USB_EPA_CTL, 0x0000, 2);
+	/* Reset endpoint before we start reading from it */
+	r = rtlsdr_reset_buffer(dev);
+    if (r < 0) {
+        fprintf(stderr, "WARNING: Failed to reset buffers.\n");
+    }
 
 	printf("Reading samples...\n");
 	while (!do_exit) {
-		libusb_bulk_transfer(devh, 0x81, buffer, READLEN, &n_read, 3000);
+		r = rtlsdr_read_sync(dev, buffer, READLEN, &n_read);
+        if (r < 0) {
+                fprintf(stderr, "WARNING: sync read failed.\n");
+        }
+
 		fwrite(buffer, n_read, 1, file);
 
 		if (n_read < READLEN) {
-			printf("Short bulk read, samples lost, exiting!\n");
+			printf("Short read, samples lost, exiting!\n");
 			break;
 		}
 	}
 
 	fclose(file);
-	libusb_release_interface(devh, 0);
 
+    rtlsdr_exit();
 out:
-	libusb_close(devh);
-	libusb_exit(NULL);
 	return r >= 0 ? r : -r;
 }
-
diff --git a/src/rtl-sdr.c b/src/rtl-sdr.c
new file mode 100644
index 0000000..cabaa58
--- /dev/null
+++ b/src/rtl-sdr.c
@@ -0,0 +1,539 @@
+/*
+ * rtl-sdr, a poor man's SDR using a Realtek RTL2832 based DVB-stick
+ * 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 <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <unistd.h>
+
+#include <libusb.h>
+
+#include "tuner_e4000.h"
+#include "tuner_fc0013.h"
+
+/* generic tuner interface functions, shall be moved to the tuner implementations */
+int e4k_init(void *dev) { return e4000_Initialize(dev); }
+int e4k_exit(void *dev) { return 0; }
+int e4k_tune(void *dev, int freq) { return e4000_SetRfFreqHz(dev, freq); }
+int e4k_set_bw(void *dev, int bw) { return e4000_SetBandwidthHz(dev, 8000000); }
+
+int fc0012_init(void *dev) { return 0; }
+int fc0012_exit(void *dev) { return 0; }
+int fc0012_tune(void *dev, int freq) { return 0; }
+int fc0012_set_bw(void *dev, int bw) { return 0; }
+
+int fc0013_init(void *dev) { return FC0013_Open(dev); }
+int fc0013_exit(void *dev) { return 0; }
+int fc0013_tune(void *dev, int freq) {
+    /* read bandwidth mode to reapply it */
+    int bw = 0;
+    //fc0013_GetBandwidthMode(dev, &bw); // FIXME: missing
+    return FC0013_SetFrequency(dev, freq/1000, bw & 0xff);
+}
+int fc0013_set_bw(void *dev, int bw) {
+    /* read frequency to reapply it */
+    unsigned long freq = 0;
+    //fc0013_GetRfFreqHz(dev, &freq); // FIXME: missing
+    return FC0013_SetFrequency(dev, freq/1000, 8);
+}
+
+enum rtlsdr_tuners {
+    RTLSDR_TUNER_UNDEF,
+    RTLSDR_TUNER_E4000,
+    RTLSDR_TUNER_FC0012,
+    RTLSDR_TUNER_FC0013
+};
+
+typedef struct rtlsdr_tuner {
+    enum rtlsdr_tuners tuner;
+    int(*init)(void *);
+    int(*exit)(void *);
+    int(*tune)(void *, int freq /* Hz */);
+    int(*set_bw)(void *, int bw /* Hz */);
+    int freq; /* Hz */
+    int corr; /* ppm */
+} rtlsdr_tuner_t;
+
+rtlsdr_tuner_t tuners[] = {
+    { RTLSDR_TUNER_E4000, e4k_init, e4k_exit, e4k_tune, e4k_set_bw, 0, 0 },
+    { RTLSDR_TUNER_FC0012, fc0012_init, fc0012_exit, fc0012_tune, fc0012_set_bw, 0, 0 },
+    { RTLSDR_TUNER_FC0013, fc0013_init, fc0013_exit, fc0013_tune, fc0013_set_bw, 0, 0 },
+};
+
+struct rtlsdr_device {
+	uint16_t vid;
+	uint16_t pid;
+} devices[] = {
+    { 0x0bda, 0x2832, /*RTLSDR_TUNER_E4000,*/ }, /* default RTL2832U vid/pid (eg. hama nano) */
+    { 0x0bda, 0x2838, /*RTLSDR_TUNER_E4000,*/ }, /* ezcap USB 2.0 DVB-T/DAB/FM stick */
+    { 0x0ccd, 0x00b3, /*RTLSDR_TUNER_FC0013,*/ }, /* Terratec NOXON DAB/DAB+ USB-Stick */
+    { 0x1f4d, 0xb803, /*RTLSDR_TUNER_FC0012,*/ }, /* GTek T803 */
+    { 0x1b80, 0xd3a4, /*RTLSDR_TUNER_FC0013,*/ }, /* Twintech UT-40 */
+};
+
+typedef struct {
+	struct libusb_device_handle *devh;
+    rtlsdr_tuner_t *tuner;
+} rtlsdr_dev_t;
+
+#define CRYSTAL_FREQ	28800000
+
+#define CTRL_IN		(LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN)
+#define CTRL_OUT	(LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_OUT)
+
+enum usb_reg {
+	USB_SYSCTL		= 0x2000,
+	USB_CTRL		= 0x2010,
+	USB_STAT		= 0x2014,
+	USB_EPA_CFG		= 0x2144,
+	USB_EPA_CTL		= 0x2148,
+	USB_EPA_MAXPKT		= 0x2158,
+	USB_EPA_MAXPKT_2	= 0x215a,
+	USB_EPA_FIFO_CFG	= 0x2160,
+};
+
+enum sys_reg {
+	DEMOD_CTL		= 0x3000,
+	GPO			= 0x3001,
+	GPI			= 0x3002,
+	GPOE			= 0x3003,
+	GPD			= 0x3004,
+	SYSINTE			= 0x3005,
+	SYSINTS			= 0x3006,
+	GP_CFG0			= 0x3007,
+	GP_CFG1			= 0x3008,
+	SYSINTE_1		= 0x3009,
+	SYSINTS_1		= 0x300a,
+	DEMOD_CTL_1		= 0x300b,
+	IR_SUSPEND		= 0x300c,
+};
+
+enum blocks {
+	DEMODB			= 0,
+	USBB			= 1,
+	SYSB			= 2,
+	TUNB			= 3,
+	ROMB			= 4,
+	IRB			= 5,
+	IICB			= 6,
+};
+
+int rtlsdr_read_array(rtlsdr_dev_t *dev, uint8_t block, uint16_t addr, uint8_t *array, uint8_t len)
+{
+	int r;
+	uint16_t index = (block << 8);
+
+	r = libusb_control_transfer(dev->devh, CTRL_IN, 0, addr, index, array, len, 0);
+
+	return r;
+}
+
+int rtlsdr_write_array(rtlsdr_dev_t *dev, uint8_t block, uint16_t addr, uint8_t *array, uint8_t len)
+{
+	int r;
+	uint16_t index = (block << 8) | 0x10;
+
+	r = libusb_control_transfer(dev->devh, CTRL_OUT, 0, addr, index, array, len, 0);
+
+	return r;
+}
+
+int rtlsdr_i2c_write(rtlsdr_dev_t *dev, uint8_t i2c_addr, uint8_t *buffer, int len)
+{
+	uint16_t addr = i2c_addr;
+	return rtlsdr_write_array(dev, IICB, addr, buffer, len);
+}
+
+int rtlsdr_i2c_read(rtlsdr_dev_t *dev, uint8_t i2c_addr, uint8_t *buffer, int len)
+{
+	uint16_t addr = i2c_addr;
+	return rtlsdr_read_array(dev, IICB, addr, buffer, len);
+}
+
+uint16_t rtlsdr_read_reg(rtlsdr_dev_t *dev, uint8_t block, uint16_t addr, uint8_t len)
+{
+	int r;
+	unsigned char data[2];
+	uint16_t index = (block << 8);
+	uint16_t reg;
+
+	r = libusb_control_transfer(dev->devh, CTRL_IN, 0, addr, index, data, len, 0);
+
+	if (r < 0)
+		printf("%s failed\n", __FUNCTION__);
+
+	reg = (data[1] << 8) | data[0];
+
+	return reg;
+}
+
+void rtlsdr_write_reg(rtlsdr_dev_t *dev, uint8_t block, uint16_t addr, uint16_t val, uint8_t len)
+{
+	int r;
+	unsigned char data[2];
+
+	uint16_t index = (block << 8) | 0x10;
+
+	if (len == 1)
+		data[0] = val & 0xff;
+	else
+		data[0] = val >> 8;
+
+	data[1] = val & 0xff;
+
+	r = libusb_control_transfer(dev->devh, CTRL_OUT, 0, addr, index, data, len, 0);
+
+	if (r < 0)
+		printf("%s failed\n", __FUNCTION__);
+}
+
+uint16_t rtlsdr_demod_read_reg(rtlsdr_dev_t *dev, uint8_t page, uint8_t addr, uint8_t len)
+{
+	int r;
+	unsigned char data[2];
+
+	uint16_t index = page;
+	uint16_t reg;
+	addr = (addr << 8) | 0x20;
+
+	r = libusb_control_transfer(dev->devh, CTRL_IN, 0, addr, index, data, len, 0);
+
+	if (r < 0)
+		printf("%s failed\n", __FUNCTION__);
+
+	reg = (data[1] << 8) | data[0];
+
+	return reg;
+}
+
+void rtlsdr_demod_write_reg(rtlsdr_dev_t *dev, uint8_t page, uint16_t addr, uint16_t val, uint8_t len)
+{
+	int r;
+	unsigned char data[2];
+	uint16_t index = 0x10 | page;
+	addr = (addr << 8) | 0x20;
+
+	if (len == 1)
+		data[0] = val & 0xff;
+	else
+		data[0] = val >> 8;
+
+	data[1] = val & 0xff;
+
+	r = libusb_control_transfer(dev->devh, CTRL_OUT, 0, addr, index, data, len, 0);
+
+	if (r < 0)
+		printf("%s failed\n", __FUNCTION__);
+
+	rtlsdr_demod_read_reg(dev, 0x0a, 0x01, 1);
+}
+
+void rtlsdr_set_i2c_repeater(rtlsdr_dev_t *dev, int on)
+{
+	rtlsdr_demod_write_reg(dev, 1, 0x01, on ? 0x18 : 0x10, 1);
+}
+
+void rtlsdr_init_baseband(rtlsdr_dev_t *dev)
+{
+	unsigned int i;
+
+	/* default FIR coefficients used for DAB/FM by the Windows driver,
+	 * the DVB driver uses different ones */
+	uint8_t fir_coeff[] = {
+		0xca, 0xdc, 0xd7, 0xd8, 0xe0, 0xf2, 0x0e, 0x35, 0x06, 0x50,
+		0x9c, 0x0d, 0x71, 0x11, 0x14, 0x71, 0x74, 0x19, 0x41, 0x00,
+	};
+
+	/* initialize USB */
+	rtlsdr_write_reg(dev, USBB, USB_SYSCTL, 0x09, 1);
+	rtlsdr_write_reg(dev, USBB, USB_EPA_MAXPKT, 0x0002, 2);
+	rtlsdr_write_reg(dev, USBB, USB_EPA_CTL, 0x1002, 2);
+
+	/* poweron demod */
+	rtlsdr_write_reg(dev, SYSB, DEMOD_CTL_1, 0x22, 1);
+	rtlsdr_write_reg(dev, SYSB, DEMOD_CTL, 0xe8, 1);
+
+	/* reset demod (bit 3, soft_rst) */
+	rtlsdr_demod_write_reg(dev, 1, 0x01, 0x14, 1);
+	rtlsdr_demod_write_reg(dev, 1, 0x01, 0x10, 1);
+
+	/* disable spectrum inversion and adjacent channel rejection */
+	rtlsdr_demod_write_reg(dev, 1, 0x15, 0x00, 1);
+	rtlsdr_demod_write_reg(dev, 1, 0x16, 0x0000, 2);
+
+	/* set IF-frequency to 0 Hz */
+	rtlsdr_demod_write_reg(dev, 1, 0x19, 0x0000, 2);
+
+	/* set FIR coefficients */
+	for (i = 0; i < sizeof (fir_coeff); i++)
+		rtlsdr_demod_write_reg(dev, 1, 0x1c + i, fir_coeff[i], 1);
+
+	rtlsdr_demod_write_reg(dev, 0, 0x19, 0x25, 1);
+
+	/* init FSM state-holding register */
+	rtlsdr_demod_write_reg(dev, 1, 0x93, 0xf0, 1);
+
+	/* disable AGC (en_dagc, bit 0) */
+	rtlsdr_demod_write_reg(dev, 1, 0x11, 0x00, 1);
+
+	/* disable PID filter (enable_PID = 0) */
+	rtlsdr_demod_write_reg(dev, 0, 0x61, 0x60, 1);
+
+	/* opt_adc_iq = 0, default ADC_I/ADC_Q datapath */
+	rtlsdr_demod_write_reg(dev, 0, 0x06, 0x80, 1);
+
+	/* Enable Zero-IF mode (en_bbin bit), DC cancellation (en_dc_est),
+	 * IQ estimation/compensation (en_iq_comp, en_iq_est) */
+	rtlsdr_demod_write_reg(dev, 1, 0xb1, 0x1b, 1);
+}
+
+int rtlsdr_set_center_freq(rtlsdr_dev_t *dev, uint32_t freq)
+{
+    rtlsdr_set_i2c_repeater(dev, 1);
+
+    if (dev->tuner) {
+        dev->tuner->freq = freq;
+
+        double f = (double) freq;
+
+        f *= 1.0 + dev->tuner->corr / 1e6;
+
+        dev->tuner->tune((void *)dev, (int) f);
+
+        printf("Tuned to %i Hz\n", freq);
+
+    }
+
+    rtlsdr_set_i2c_repeater(dev, 0);
+
+    return 0;
+}
+
+int rtlsdr_get_center_freq(rtlsdr_dev_t *dev)
+{
+	return 0; // TODO: implement
+}
+
+int rtlsdr_set_freq_correction(rtlsdr_dev_t *dev, int32_t ppm)
+{
+    if (dev->tuner) {
+        if (dev->tuner->corr == ppm)
+            return -1;
+
+        dev->tuner->corr = ppm;
+
+        /* retune to apply new correction value */
+        rtlsdr_set_center_freq(dev, dev->tuner->freq);
+    }
+
+    return 0;
+}
+
+int32_t rtlsdr_get_freq_correction(rtlsdr_dev_t *dev)
+{
+    if (dev->tuner)
+        return dev->tuner->corr;
+    else
+        return 0;
+}
+
+void rtlsdr_set_sample_rate(rtlsdr_dev_t *dev, uint32_t samp_rate)
+{
+    uint16_t tmp;
+    uint32_t rsamp_ratio;
+    double real_rate;
+
+    /* check for the maximum rate the resampler supports */
+    if (samp_rate > 3200000)
+        samp_rate = 3200000;
+
+    rsamp_ratio = (CRYSTAL_FREQ * pow(2, 22)) / samp_rate;
+    rsamp_ratio &= ~3;
+
+    real_rate = (CRYSTAL_FREQ * pow(2, 22)) / rsamp_ratio;
+    printf("Setting sample rate: %.3f Hz\n", real_rate);
+
+    if (dev->tuner)
+        dev->tuner->set_bw((void *)dev, real_rate);
+
+    tmp = (rsamp_ratio >> 16);
+    rtlsdr_demod_write_reg(dev, 1, 0x9f, tmp, 2);
+    tmp = rsamp_ratio & 0xffff;
+    rtlsdr_demod_write_reg(dev, 1, 0xa1, tmp, 2);
+}
+
+int rtlsdr_get_sample_rate(rtlsdr_dev_t *dev)
+{
+    return 0; // TODO: implement
+}
+
+int rtlsdr_init(void)
+{
+    return libusb_init(NULL);
+}
+
+void rtlsdr_exit(void)
+{
+    libusb_exit(NULL);
+}
+
+uint32_t rtlsdr_get_device_count(void)
+{
+    int i, j;
+	libusb_device **list;
+    uint32_t device_count;
+    struct libusb_device_descriptor dd;
+
+	ssize_t cnt = libusb_get_device_list(NULL, &list);
+
+    for (i = 0; i < cnt; i++) {
+        libusb_get_device_descriptor(list[i], &dd);
+
+        for (j = 0; j < sizeof(devices)/sizeof(struct rtlsdr_device); j++ ) {
+            if ( devices[j].vid == dd.idVendor && devices[j].pid == dd.idProduct ) {
+                device_count++;
+            }
+        }
+    }
+
+    libusb_free_device_list(list, 0);
+
+    return device_count;
+}
+
+const char *rtlsdr_get_device_name(uint32_t index)
+{
+	libusb_device **list;
+
+	ssize_t cnt = libusb_get_device_list(NULL, &list);
+	
+	if (index > cnt - 1)
+		return NULL;
+
+    /*libusb_device *device = list[index];*/
+
+
+
+	libusb_free_device_list(list, 0);
+
+    return "TODO: implement";
+}
+
+rtlsdr_dev_t *rtlsdr_open(int index)
+{
+	int r;
+    int i, j;
+    libusb_device **list;
+	rtlsdr_dev_t * dev = NULL;
+    libusb_device *device = NULL;
+    uint32_t device_count = 0;
+    struct libusb_device_descriptor dd;
+
+	dev = malloc(sizeof(rtlsdr_dev_t));
+    memset(dev, 0, sizeof(rtlsdr_dev_t));
+
+	ssize_t cnt = libusb_get_device_list(NULL, &list);
+	
+    for (i = 0; i < cnt; i++) {
+        device = list[i];
+
+        libusb_get_device_descriptor(list[i], &dd);
+
+        for (j = 0; j < sizeof(devices)/sizeof(struct rtlsdr_device); j++ ) {
+            if ( devices[j].vid == dd.idVendor && devices[j].pid == dd.idProduct ) {
+                device_count++;
+
+                if (index == device_count - 1)
+                    break;
+            }
+        }
+
+        if (index == device_count - 1)
+            break;
+
+        device = NULL;
+    }
+
+    if (!device)
+        goto err;
+
+    r = libusb_open(device, &dev->devh);
+    if (r < 0) {
+        libusb_free_device_list(list, 0);
+        fprintf(stderr, "usb_open error %d\n", r);
+        goto err;
+    }
+
+    libusb_free_device_list(list, 0);
+	
+    unsigned char buffer[256];
+
+    libusb_get_string_descriptor_ascii(dev->devh, 0, buffer, sizeof(buffer) );
+    printf("sn#: %s\n", buffer);
+
+    libusb_get_string_descriptor_ascii(dev->devh, 1, buffer, sizeof(buffer) );
+    printf("manufacturer: %s\n", buffer);
+
+    libusb_get_string_descriptor_ascii(dev->devh, 2, buffer, sizeof(buffer) );
+    printf("product: %s\n", buffer);
+
+    r = libusb_claim_interface(dev->devh, 0);
+    if (r < 0) {
+            fprintf(stderr, "usb_claim_interface error %d\n", r);
+            goto err;
+    }
+
+    rtlsdr_init_baseband(dev);
+
+    // TODO: probe the tuner and set dev->tuner member to appropriate tuner object
+    // dev->tuner = &tuners[...];
+
+	return dev;
+err:
+	return NULL;
+}
+
+int rtlsdr_close(rtlsdr_dev_t *dev)
+{
+	libusb_release_interface(dev->devh, 0);
+
+	libusb_close(dev->devh);
+
+	free(dev);
+
+    return 0;
+}
+
+int rtlsdr_reset_buffer(rtlsdr_dev_t *dev)
+{
+	return 0; // TODO: implement
+}
+
+int rtlsdr_read_sync(rtlsdr_dev_t *dev, void *buf, int len, int *n_read)
+{
+	return libusb_bulk_transfer(dev->devh, 0x81, buf, len, n_read, 3000);
+}
+#if 0
+int rtlsdr_async_loop(rtlsdr_dev_t *dev, rtlsdr_async_read_cb_t cb, void *ctx)
+{
+	return 0;
+}
+#endif
diff --git a/src/rtl-sdr.h b/src/rtl-sdr.h
new file mode 100644
index 0000000..0b22eb1
--- /dev/null
+++ b/src/rtl-sdr.h
@@ -0,0 +1,73 @@
+/*
+ * rtl-sdr, a poor man's SDR using a Realtek RTL2832 based DVB-stick
+ * 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/>.
+ */
+
+#ifndef __RTL_SDR_H
+#define __RTL_SDR_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+typedef int rtlsdr_dev_t;
+
+/* must be called once before using any other library functions */
+int rtlsdr_init(void);
+
+/* must be called once at application shutdown */
+void rtlsdr_exit(void);
+
+uint32_t rtlsdr_get_device_count(void);
+
+const char *rtlsdr_get_device_name(uint32_t index);
+
+rtlsdr_dev_t *rtlsdr_open(uint32_t index);
+
+int rtlsdr_close(rtlsdr_dev_t *dev);
+
+/* configuration functions */
+
+int rtlsdr_set_center_freq(rtlsdr_dev_t *dev, uint32_t freq);
+
+int rtlsdr_get_center_freq(rtlsdr_dev_t *dev);
+
+int rtlsdr_set_freq_correction(rtlsdr_dev_t *dev, int32_t ppm);
+
+int32_t rtlsdr_get_freq_correction(rtlsdr_dev_t *dev);
+
+/* this will select the baseband filters according to the requested sample rate */
+int rtlsdr_set_sample_rate(rtlsdr_dev_t *dev, uint32_t rate);
+
+int rtlsdr_get_sample_rate(rtlsdr_dev_t *dev);
+
+/* streaming functions */
+
+int rtlsdr_reset_buffer(rtlsdr_dev_t *dev);
+
+int rtlsdr_read_sync(rtlsdr_dev_t *dev, void *buf, uint32_t len, uint32_t *n_read);
+
+typedef void(*rtlsdr_async_read_cb_t)(const char *buf, uint32_t len, void *ctx);
+
+int rtlsdr_async_loop(rtlsdr_dev_t *dev, rtlsdr_async_read_cb_t cb, void *ctx);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __RTL_SDR_H */
diff --git a/src/tuner_e4000.c b/src/tuner_e4000.c
index 62888e6..7cf7159 100644
--- a/src/tuner_e4000.c
+++ b/src/tuner_e4000.c
@@ -25,7 +25,7 @@
 /* glue functions to rtl-sdr code */
 int
 I2CReadByte(
-	int pTuner,
+    void *pTuner,
 	unsigned char NoUse,
 	unsigned char RegAddr,
 	unsigned char *pReadingByte
@@ -33,10 +33,10 @@ I2CReadByte(
 {
 	uint8_t data = RegAddr;
 
-	if (rtl_i2c_write(E4K_I2C_ADDR, &data, 1) < 0)
+	if (rtlsdr_i2c_write((rtlsdr_dev_t *)pTuner, E4K_I2C_ADDR, &data, 1) < 0)
 		return E4000_I2C_FAIL;
 
-	if (rtl_i2c_read(E4K_I2C_ADDR, &data, 1) < 0)
+	if (rtlsdr_i2c_read((rtlsdr_dev_t *)pTuner, E4K_I2C_ADDR, &data, 1) < 0)
 		return E4000_I2C_FAIL;
 
 	*pReadingByte = data;
@@ -45,19 +45,18 @@ I2CReadByte(
 }
 
 int
-I2CWriteByte(
-	int pTuner,
-	unsigned char NoUse,
-	unsigned char RegAddr,
-	unsigned char WritingByte
-	)
+I2CWriteByte(void *pTuner,
+    unsigned char NoUse,
+    unsigned char RegAddr,
+    unsigned char WritingByte
+    )
 {
 	uint8_t data[2];
 
 	data[0] = RegAddr;
 	data[1] = WritingByte;
 
-	if (rtl_i2c_write(E4K_I2C_ADDR, data, 2) < 0)
+    if (rtlsdr_i2c_write((rtlsdr_dev_t *)pTuner, E4K_I2C_ADDR, data, 2) < 0)
 		return E4000_I2C_FAIL;
 
 	return E4000_I2C_SUCCESS;
@@ -65,7 +64,7 @@ I2CWriteByte(
 
 int
 I2CWriteArray(
-	int pTuner,
+    void *pTuner,
 	unsigned char NoUse,
 	unsigned char RegStartAddr,
 	unsigned char ByteNum,
@@ -80,7 +79,7 @@ I2CWriteArray(
 	for(i = 0; i < ByteNum; i++)
 		WritingBuffer[1 + i] = pWritingBytes[i];
 
-	if (rtl_i2c_write(E4K_I2C_ADDR, WritingBuffer, ByteNum + 1) < 0)
+	if (rtlsdr_i2c_write((rtlsdr_dev_t *)pTuner, E4K_I2C_ADDR, WritingBuffer, ByteNum + 1) < 0)
 		return E4000_I2C_FAIL;
 
 	return E4000_I2C_SUCCESS;
@@ -92,9 +91,8 @@ I2CWriteArray(
 
 */
 int
-e4000_Initialize(
-	int pTuner
-	)
+e4000_Initialize(void *pTuner
+    )
 {
 
 	// Initialize tuner.
@@ -129,7 +127,7 @@ error_status_execute_function:
 */
 int
 e4000_SetRfFreqHz(
-	int pTuner,
+    void *pTuner,
 	unsigned long RfFreqHz
 	)
 {
@@ -182,7 +180,7 @@ error_status_execute_function:
 */
 int
 e4000_SetBandwidthHz(
-	int pTuner,
+    void *pTuner,
 	unsigned long BandwidthHz
 	)
 {
@@ -285,7 +283,7 @@ int GainControlinit();
 *
 \****************************************************************************/
 
-int tunerreset(int pTuner)
+int tunerreset(void *pTuner)
 {
 	unsigned char writearray[5];
 	int status;
@@ -332,7 +330,7 @@ int tunerreset(int pTuner)
 *  Function disables the clock - values can be modified to enable if required.
 \****************************************************************************/
 
-int Tunerclock(int pTuner)
+int Tunerclock(void *pTuner)
 {
 	unsigned char writearray[5];
 	int status;
@@ -364,7 +362,7 @@ int Tunerclock(int pTuner)
 *
 \****************************************************************************/
 /*
-int filtercal(int pTuner)
+int filtercal(void *pTuner)
 {
   //writearray[0] = 1;
  //I2CWriteByte (pTuner, 200,123,writearray[0]);
@@ -382,7 +380,7 @@ int filtercal(int pTuner)
 *
 \****************************************************************************/
 
-int Qpeak(int pTuner)
+int Qpeak(void *pTuner)
 {
 	unsigned char writearray[5];
 	int status;
@@ -431,7 +429,7 @@ int Qpeak(int pTuner)
 *  0xa3 to 0xa7. Also 0x24.
 *
 \****************************************************************************/
-int E4000_gain_freq(int pTuner, int Freq)
+int E4000_gain_freq(void *pTuner, int Freq)
 {
 	unsigned char writearray[5];
 	int status;
@@ -512,7 +510,7 @@ int E4000_gain_freq(int pTuner, int Freq)
 *  Populates DC offset LUT. (Registers 0x2d, 0x70, 0x71).
 *  Turns on DC offset LUT and time varying DC offset.
 \****************************************************************************/
-int DCoffloop(int pTuner)
+int DCoffloop(void *pTuner)
 {
 	unsigned char writearray[5];
 	int status;
@@ -548,7 +546,7 @@ int DCoffloop(int pTuner)
 *
 \****************************************************************************/
 /*
-int commonmode(int pTuner)
+int commonmode(void *pTuner)
 {
      //writearray[0] = 0;
      //I2CWriteByte(Device_address,47,writearray[0]);
@@ -571,7 +569,7 @@ int commonmode(int pTuner)
 *  Sensitivity / Linearity mode: manual switch
 *
 \****************************************************************************/
-int GainControlinit(int pTuner)
+int GainControlinit(void *pTuner)
 {
 	unsigned char writearray[5];
 	unsigned char read1[1];
@@ -808,7 +806,7 @@ int GainControlauto();
 *  Sets Gain control to serial interface control.
 *
 \****************************************************************************/
-int Gainmanual(int pTuner)
+int Gainmanual(void *pTuner)
 {
 	unsigned char writearray[5];
 	int status;
@@ -845,7 +843,7 @@ int Gainmanual(int pTuner)
 *  Configures E4000 PLL divider & sigma delta. 0x0d,0x09, 0x0a, 0x0b).
 *
 \****************************************************************************/
-int PLL(int pTuner, int Ref_clk, int Freq)
+int PLL(void *pTuner, int Ref_clk, int Freq)
 {
 	int VCO_freq;
 	unsigned char writearray[5];
@@ -1185,7 +1183,7 @@ int PLL(int pTuner, int Ref_clk, int Freq)
 *
 \****************************************************************************/
 
-int LNAfilter(int pTuner, int Freq)
+int LNAfilter(void *pTuner, int Freq)
 {
 	unsigned char writearray[5];
 	int status;
@@ -1334,7 +1332,7 @@ int LNAfilter(int pTuner, int Freq)
 *  The function configures the E4000 IF filter. (Register 0x11,0x12).
 *
 \****************************************************************************/
-int IFfilter(int pTuner, int bandwidth, int Ref_clk)
+int IFfilter(void *pTuner, int bandwidth, int Ref_clk)
 {
 	unsigned char writearray[5];
 	int status;
@@ -1524,7 +1522,7 @@ int IFfilter(int pTuner, int bandwidth, int Ref_clk)
 *  Configures the E4000 frequency band. (Registers 0x07, 0x78).
 *
 \****************************************************************************/
-int freqband(int pTuner, int Freq)
+int freqband(void *pTuner, int Freq)
 {
 	unsigned char writearray[5];
 	int status;
@@ -1582,7 +1580,7 @@ int freqband(int pTuner, int Freq)
 *  Populates DC offset LUT. (Registers 0x50 - 0x53, 0x60 - 0x63).
 *
 \****************************************************************************/
-int DCoffLUT(int pTuner)
+int DCoffLUT(void *pTuner)
 {
 	unsigned char writearray[5];
 	int status;
@@ -1856,7 +1854,7 @@ int DCoffLUT(int pTuner)
 *  Configures gain control mode. (Registers 0x1a)
 *
 \****************************************************************************/
-int GainControlauto(int pTuner)
+int GainControlauto(void *pTuner)
 {
 	unsigned char writearray[5];
 	int status;
@@ -1902,7 +1900,7 @@ int main()
 *
 \****************************************************************************/
 
-int E4000_sensitivity(int pTuner, int Freq, int bandwidth)
+int E4000_sensitivity(void *pTuner, int Freq, int bandwidth)
 {
 	unsigned char writearray[2];
 	int status;
@@ -1960,7 +1958,7 @@ int E4000_sensitivity(int pTuner, int Freq, int bandwidth)
 *  The function configures the E4000 for linearity mode.
 *
 \****************************************************************************/
-int E4000_linearity(int pTuner, int Freq, int bandwidth)
+int E4000_linearity(void *pTuner, int Freq, int bandwidth)
 {
 
 	unsigned char writearray[2];
@@ -2019,7 +2017,7 @@ int E4000_linearity(int pTuner, int Freq, int bandwidth)
 *  The function configures the E4000 for nominal
 *
 \****************************************************************************/
-int E4000_nominal(int pTuner, int Freq, int bandwidth)
+int E4000_nominal(void *pTuner, int Freq, int bandwidth)
 {
 	unsigned char writearray[2];
 	int status;
diff --git a/src/tuner_e4000.h b/src/tuner_e4000.h
index f74de17..4c78f3e 100644
--- a/src/tuner_e4000.h
+++ b/src/tuner_e4000.h
@@ -118,52 +118,50 @@ int main(void)
 
 // Function (implemeted for E4000)
 int
-I2CReadByte(
-	int pTuner,
-	unsigned char NoUse,
-	unsigned char RegAddr,
-	unsigned char *pReadingByte
-	);
+I2CReadByte(void *pTuner,
+    unsigned char NoUse,
+    unsigned char RegAddr,
+    unsigned char *pReadingByte
+    );
 
 int
 I2CWriteByte(
-	int pTuner,
+    void *pTuner,
 	unsigned char NoUse,
 	unsigned char RegAddr,
 	unsigned char WritingByte
 	);
 
 int
-I2CWriteArray(
-	int pTuner,
-	unsigned char NoUse,
-	unsigned char RegStartAddr,
-	unsigned char ByteNum,
-	unsigned char *pWritingBytes
-	);
+I2CWriteArray(void *pTuner,
+    unsigned char NoUse,
+    unsigned char RegStartAddr,
+    unsigned char ByteNum,
+    unsigned char *pWritingBytes
+    );
 
 
 
 // Functions (from E4000 source code)
-int tunerreset (int pTuner);
-int Tunerclock(int pTuner);
-int Qpeak(int pTuner);
-int DCoffloop(int pTuner);
-int GainControlinit(int pTuner);
-
-int Gainmanual(int pTuner);
-int E4000_gain_freq(int pTuner, int frequency);
-int PLL(int pTuner, int Ref_clk, int Freq);
-int LNAfilter(int pTuner, int Freq);
-int IFfilter(int pTuner, int bandwidth, int Ref_clk);
-int freqband(int pTuner, int Freq);
-int DCoffLUT(int pTuner);
-int GainControlauto(int pTuner);
-
-int E4000_sensitivity(int pTuner, int Freq, int bandwidth);
-int E4000_linearity(int pTuner, int Freq, int bandwidth);
-int E4000_high_linearity(int pTuner);
-int E4000_nominal(int pTuner, int Freq, int bandwidth);
+int tunerreset (void *pTuner);
+int Tunerclock(void *pTuner);
+int Qpeak(void *pTuner);
+int DCoffloop(void *pTuner);
+int GainControlinit(void *pTuner);
+
+int Gainmanual(void *pTuner);
+int E4000_gain_freq(void *pTuner, int frequency);
+int PLL(void *pTuner, int Ref_clk, int Freq);
+int LNAfilter(void *pTuner, int Freq);
+int IFfilter(void *pTuner, int bandwidth, int Ref_clk);
+int freqband(void *pTuner, int Freq);
+int DCoffLUT(void *pTuner);
+int GainControlauto(void *pTuner);
+
+int E4000_sensitivity(void *pTuner, int Freq, int bandwidth);
+int E4000_linearity(void *pTuner, int Freq, int bandwidth);
+int E4000_high_linearity(void *pTuner);
+int E4000_nominal(void *pTuner, int Freq, int bandwidth);
 
 
 // The following context is E4000 tuner API source code
@@ -182,30 +180,30 @@ enum E4000_BANDWIDTH_HZ
 // Manipulaing functions
 void
 e4000_GetTunerType(
-	int pTuner,
+    void *pTuner,
 	int *pTunerType
 	);
 
 void
 e4000_GetDeviceAddr(
-	int pTuner,
+    void *pTuner,
 	unsigned char *pDeviceAddr
 	);
 
 int
 e4000_Initialize(
-	int pTuner
+    void *pTuner
 	);
 
 int
 e4000_SetRfFreqHz(
-	int pTuner,
+    void *pTuner,
 	unsigned long RfFreqHz
 	);
 
 int
 e4000_GetRfFreqHz(
-	int pTuner,
+    void *pTuner,
 	unsigned long *pRfFreqHz
 	);
 
@@ -216,20 +214,20 @@ e4000_GetRfFreqHz(
 // Extra manipulaing functions
 int
 e4000_GetRegByte(
-	int pTuner,
+    void *pTuner,
 	unsigned char RegAddr,
 	unsigned char *pReadingByte
 	);
 
 int
 e4000_SetBandwidthHz(
-	int pTuner,
+    void *pTuner,
 	unsigned long BandwidthHz
 	);
 
 int
 e4000_GetBandwidthHz(
-	int pTuner,
+    void *pTuner,
 	unsigned long *pBandwidthHz
 	);
 
diff --git a/src/tuner_fc0013.c b/src/tuner_fc0013.c
index 73b1ed9..8da5d06 100644
--- a/src/tuner_fc0013.c
+++ b/src/tuner_fc0013.c
@@ -7,33 +7,34 @@
  */
 
 #include <stdint.h>
+#include "i2c.h"
 #include "tuner_fc0013.h"
 
 #define CRYSTAL_FREQ		28800000
 #define FC0013_I2C_ADDR		0xc6
 
 /* glue functions to rtl-sdr code */
-int FC0013_Write(int pTuner, unsigned char RegAddr, unsigned char Byte)
+int FC0013_Write(void *pTuner, unsigned char RegAddr, unsigned char Byte)
 {
 	uint8_t data[2];
 
 	data[0] = RegAddr;
 	data[1] = Byte;
 
-	if (rtl_i2c_write(FC0013_I2C_ADDR, data, 2) < 0)
+	if (rtlsdr_i2c_write((rtlsdr_dev_t *)pTuner, FC0013_I2C_ADDR, data, 2) < 0)
 		return FC0013_I2C_ERROR;
 
 	return FC0013_I2C_SUCCESS;
 }
 
-int FC0013_Read(int pTuner, unsigned char RegAddr, unsigned char *pByte)
+int FC0013_Read(void *pTuner, unsigned char RegAddr, unsigned char *pByte)
 {
 	uint8_t data = RegAddr;
 
-	if (rtl_i2c_write(FC0013_I2C_ADDR, &data, 1) < 0)
+	if (rtlsdr_i2c_write((rtlsdr_dev_t *)pTuner, FC0013_I2C_ADDR, &data, 1) < 0)
 		return FC0013_I2C_ERROR;
 
-	if (rtl_i2c_read(FC0013_I2C_ADDR, &data, 1) < 0)
+	if (rtlsdr_i2c_read((rtlsdr_dev_t *)pTuner, FC0013_I2C_ADDR, &data, 1) < 0)
 		return FC0013_I2C_ERROR;
 
 	*pByte = data;
@@ -41,7 +42,7 @@ int FC0013_Read(int pTuner, unsigned char RegAddr, unsigned char *pByte)
 	return FC0013_I2C_SUCCESS;
 }
 
-int FC0013_SetVhfTrack(int pTuner, unsigned long FrequencyKHz)
+int FC0013_SetVhfTrack(void *pTuner, unsigned long FrequencyKHz)
 {
 	unsigned char read_byte;
 
@@ -120,9 +121,8 @@ error_status:
 
 // FC0013 Open Function, includes enable/reset pin control and registers initialization.
 //void FC0013_Open()
-int FC0013_Open()
+int FC0013_Open(void *pTuner)
 {
-	int pTuner = 1;
 	// Enable FC0013 Power
 	// (...)
 	// FC0013 Enable = High
@@ -171,7 +171,7 @@ error_status:
 }
 
 
-int FC0013_SetFrequency(unsigned long Frequency, unsigned short Bandwidth)
+int FC0013_SetFrequency(void *pTuner, unsigned long Frequency, unsigned short Bandwidth)
 {
 //    bool VCO1 = false;
 //    unsigned int doubleVCO;
@@ -186,8 +186,6 @@ int FC0013_SetFrequency(unsigned long Frequency, unsigned short Bandwidth)
 
 	unsigned long CrystalFreqKhz;
 
-	int pTuner =1;
-
 	int CrystalFreqHz = CRYSTAL_FREQ;
 
 	// Get tuner crystal frequency in KHz.
diff --git a/src/tuner_fc0013.h b/src/tuner_fc0013.h
index b04d7d1..b405808 100644
--- a/src/tuner_fc0013.h
+++ b/src/tuner_fc0013.h
@@ -39,12 +39,12 @@ enum FC0013_FUNCTION_STATUS
 
 
 // Functions
-int FC0013_Read(int pTuner, unsigned char RegAddr, unsigned char *pByte);
-int FC0013_Write(int pTuner, unsigned char RegAddr, unsigned char Byte);
+int FC0013_Read(void *pTuner, unsigned char RegAddr, unsigned char *pByte);
+int FC0013_Write(void *pTuner, unsigned char RegAddr, unsigned char Byte);
 
 int
 fc0013_SetRegMaskBits(
-	int pTuner,
+    void *pTuner,
 	unsigned char RegAddr,
 	unsigned char Msb,
 	unsigned char Lsb,
@@ -53,18 +53,18 @@ fc0013_SetRegMaskBits(
 
 int
 fc0013_GetRegMaskBits(
-	int pTuner,
+    void *pTuner,
 	unsigned char RegAddr,
 	unsigned char Msb,
 	unsigned char Lsb,
 	unsigned char *pReadingValue
 	);
 
-int FC0013_Open();
-int FC0013_SetFrequency(unsigned long Frequency, unsigned short Bandwidth);
+int FC0013_Open(void *pTuner);
+int FC0013_SetFrequency(void *pTuner, unsigned long Frequency, unsigned short Bandwidth);
 
 // Set VHF Track depends on input frequency
-int FC0013_SetVhfTrack(int pTuner, unsigned long Frequency);
+int FC0013_SetVhfTrack(void *pTuner, unsigned long Frequency);
 
 
 // The following context is FC0013 tuner API source code
@@ -98,54 +98,54 @@ enum FC0013_LNA_GAIN_VALUE
 // Manipulaing functions
 void
 fc0013_GetTunerType(
-	int pTuner,
+    void *pTuner,
 	int *pTunerType
 	);
 
 void
 fc0013_GetDeviceAddr(
-	int pTuner,
+    void *pTuner,
 	unsigned char *pDeviceAddr
 	);
 
 int
 fc0013_Initialize(
-	int pTuner
+    void *pTuner
 	);
 
 int
 fc0013_SetRfFreqHz(
-	int pTuner,
+    void *pTuner,
 	unsigned long RfFreqHz
 	);
 
 int
 fc0013_GetRfFreqHz(
-	int pTuner,
+    void *pTuner,
 	unsigned long *pRfFreqHz
 	);
 
 // Extra manipulaing functions
 int
 fc0013_SetBandwidthMode(
-	int pTuner,
+    void *pTuner,
 	int BandwidthMode
 	);
 
 int
 fc0013_GetBandwidthMode(
-	int pTuner,
+    void *pTuner,
 	int *pBandwidthMode
 	);
 
 int
 fc0013_RcCalReset(
-	int pTuner
+    void *pTuner
 	);
 
 int
 fc0013_RcCalAdd(
-	int pTuner,
+    void *pTuner,
 	int RcValue
 	);