rename rtl-sdr.c to librtlsdr.c

Having rtl_sdr.c for the application and rtl-sdr.c for the lib
caused a bit of confusion...

Signed-off-by: Steve Markgraf <steve@steve-m.de>

1 files changed, 1153 insertions, 0 deletions

diff --git a/src/librtlsdr.c b/src/librtlsdr.c
new file mode 100644
index 0000000..6a9539b
--- /dev/null
+++ b/src/librtlsdr.c
@@ -0,0 +1,1153 @@
+/*
+ * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
+ * Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
+ * Copyright (C) 2012 by Dimitri Stolnikov <horiz0n@gmx.net>
+ *
+ * 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>
+#ifndef _WIN32
+#include <unistd.h>
+#define min(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+
+#include <libusb.h>
+
+/*
+ * All libusb callback functions should be marked with the LIBUSB_CALL macro
+ * to ensure that they are compiled with the same calling convention as libusb.
+ *
+ * If the macro isn't available in older libusb versions, we simply define it.
+ */
+#ifndef LIBUSB_CALL
+#define LIBUSB_CALL
+#endif
+
+#include "rtl-sdr.h"
+#include "tuner_e4k.h"
+#include "tuner_fc0012.h"
+#include "tuner_fc0013.h"
+#include "tuner_fc2580.h"
+
+typedef struct rtlsdr_tuner {
+	/* tuner interface */
+	int (*init)(void *);
+	int (*exit)(void *);
+	int (*set_freq)(void *, uint32_t freq /* Hz */);
+	int (*set_bw)(void *, int bw /* Hz */);
+	int (*set_gain)(void *, int gain /* dB */);
+	int (*set_gain_mode)(void *, int manual);
+} rtlsdr_tuner_t;
+
+enum rtlsdr_async_status {
+	RTLSDR_INACTIVE = 0,
+	RTLSDR_CANCELING,
+	RTLSDR_RUNNING
+};
+
+struct rtlsdr_dev {
+	libusb_context *ctx;
+	struct libusb_device_handle *devh;
+	uint32_t xfer_buf_num;
+	uint32_t xfer_buf_len;
+	struct libusb_transfer **xfer;
+	unsigned char **xfer_buf;
+	rtlsdr_read_async_cb_t cb;
+	void *cb_ctx;
+	enum rtlsdr_async_status async_status;
+	/* rtl demod context */
+	uint32_t rate; /* Hz */
+	uint32_t rtl_xtal; /* Hz */
+	/* tuner context */
+	rtlsdr_tuner_t *tuner;
+	uint32_t tun_xtal; /* Hz */
+	uint32_t freq; /* Hz */
+	int corr; /* ppm */
+	int gain; /* dB */
+	struct e4k_state e4k_s;
+};
+
+void rtlsdr_set_gpio_bit(rtlsdr_dev_t *dev, uint8_t gpio, int val);
+
+/* generic tuner interface functions, shall be moved to the tuner implementations */
+int e4000_init(void *dev) {
+	rtlsdr_dev_t* devt = (rtlsdr_dev_t*)dev;
+	devt->e4k_s.i2c_addr = E4K_I2C_ADDR;
+	devt->e4k_s.vco.fosc = devt->tun_xtal;
+	devt->e4k_s.rtl_dev = dev;
+	return e4k_init(&devt->e4k_s);
+}
+int e4000_exit(void *dev) { return 0; }
+int e4000_set_freq(void *dev, uint32_t freq) {
+	rtlsdr_dev_t* devt = (rtlsdr_dev_t*)dev;
+	return e4k_tune_freq(&devt->e4k_s, freq);
+}
+int e4000_set_bw(void *dev, int bw) {
+	return 0;
+}
+int e4000_set_gain(void *dev, int gain) {
+	int rc;
+	rtlsdr_dev_t* devt = (rtlsdr_dev_t*)dev;
+	int mixgain = (gain > 340) ? 12 : 4;
+	int enhgain = (gain - 420);
+	if(e4k_set_lna_gain(&devt->e4k_s, min(300, gain - 40)) == -EINVAL)
+		return -1;
+	if(e4k_mixer_gain_set(&devt->e4k_s, mixgain) == -EINVAL)
+		return -1;
+	if(enhgain >= 0)
+		if(e4k_set_enh_gain(&devt->e4k_s, enhgain) == -EINVAL)
+			return -1;
+
+	return 0;
+}
+
+int e4000_set_gain_mode(void *dev, int manual) {
+	rtlsdr_dev_t* devt = (rtlsdr_dev_t*)dev;
+	e4k_enable_manual_gain(&devt->e4k_s, manual);
+	return 0;
+}
+
+int fc0012_init(void *dev) { return FC0012_Open(dev); }
+int fc0012_exit(void *dev) { return 0; }
+int fc0012_set_freq(void *dev, uint32_t freq) {
+	/* select V-band/U-band filter */
+	rtlsdr_set_gpio_bit(dev, 6, (freq > 300000000) ? 1 : 0);
+	return FC0012_SetFrequency(dev, freq/1000, 6);
+}
+int fc0012_set_bw(void *dev, int bw) {
+	return FC0012_SetFrequency(dev, ((rtlsdr_dev_t *) dev)->freq/1000, 6);
+}
+int fc0012_set_gain(void *dev, int gain) { return 0; }
+int fc0012_set_gain_mode(void *dev, int manual) { return 0; }
+
+int fc0013_init(void *dev) { return FC0013_Open(dev); }
+int fc0013_exit(void *dev) { return 0; }
+int fc0013_set_freq(void *dev, uint32_t freq) {
+	return FC0013_SetFrequency(dev, freq/1000, 6);
+}
+int fc0013_set_bw(void *dev, int bw) {
+	return FC0013_SetFrequency(dev, ((rtlsdr_dev_t *) dev)->freq/1000, 6);
+}
+int fc0013_set_gain(void *dev, int gain) { return 0; }
+int fc0013_set_gain_mode(void *dev, int manual) { return 0; }
+
+int fc2580_init(void *dev) { return fc2580_Initialize(dev); }
+int fc2580_exit(void *dev) { return 0; }
+int _fc2580_set_freq(void *dev, uint32_t freq) {
+	return fc2580_SetRfFreqHz(dev, freq);
+}
+int fc2580_set_bw(void *dev, int bw) {
+	return fc2580_SetBandwidthMode(dev, 1);
+}
+int fc2580_set_gain(void *dev, int gain) { return 0; }
+int fc2580_set_gain_mode(void *dev, int manual) { return 0; }
+
+enum rtlsdr_tuners {
+	RTLSDR_TUNER_E4000,
+	RTLSDR_TUNER_FC0012,
+	RTLSDR_TUNER_FC0013,
+	RTLSDR_TUNER_FC2580
+};
+
+static rtlsdr_tuner_t tuners[] = {
+	{
+		e4000_init, e4000_exit,
+		e4000_set_freq, e4000_set_bw, e4000_set_gain,
+		e4000_set_gain_mode
+	},
+	{
+		fc0012_init, fc0012_exit,
+		fc0012_set_freq, fc0012_set_bw, fc0012_set_gain,
+		fc0012_set_gain_mode
+	},
+	{
+		fc0013_init, fc0013_exit,
+		fc0013_set_freq, fc0013_set_bw, fc0013_set_gain,
+		fc0013_set_gain_mode
+	},
+	{
+		fc2580_init, fc2580_exit,
+		_fc2580_set_freq, fc2580_set_bw, fc2580_set_gain,
+		fc2580_set_gain_mode
+	},
+};
+
+typedef struct rtlsdr_dongle {
+	uint16_t vid;
+	uint16_t pid;
+	const char *name;
+} rtlsdr_dongle_t;
+
+/*
+ * Please add your device here and send a patch to osmocom-sdr@lists.osmocom.org
+ */
+static rtlsdr_dongle_t known_devices[] = {
+	{ 0x0bda, 0x2832, "Generic RTL2832U (e.g. hama nano)" },
+	{ 0x0bda, 0x2838, "ezcap USB 2.0 DVB-T/DAB/FM dongle" },
+	{ 0x0ccd, 0x00a9, "Terratec Cinergy T Stick Black (rev 1)" },
+	{ 0x0ccd, 0x00b3, "Terratec NOXON DAB/DAB+ USB dongle (rev 1)" },
+	{ 0x0ccd, 0x00d3, "Terratec Cinergy T Stick RC (Rev.3)" },
+	{ 0x0ccd, 0x00d7, "Terratec T Stick PLUS" },
+	{ 0x0ccd, 0x00e0, "Terratec NOXON DAB/DAB+ USB dongle (rev 2)" },
+	{ 0x185b, 0x0620, "Compro Videomate U620F"},
+	{ 0x185b, 0x0650, "Compro Videomate U650F"},
+	{ 0x185b, 0x0680, "Compro Videomate U680F"},
+	{ 0x1f4d, 0xb803, "GTek T803" },
+	{ 0x1f4d, 0xc803, "Lifeview LV5TDeluxe" },
+	{ 0x1b80, 0xd3a4, "Twintech UT-40" },
+	{ 0x1d19, 0x1101, "Dexatek DK DVB-T Dongle (Logilink VG0002A)" },
+	{ 0x1d19, 0x1102, "Dexatek DK DVB-T Dongle (MSI DigiVox mini II V3.0)" },
+	{ 0x1d19, 0x1103, "Dexatek Technology Ltd. DK 5217 DVB-T Dongle" },
+	{ 0x0458, 0x707f, "Genius TVGo DVB-T03 USB dongle (Ver. B)" },
+	{ 0x1b80, 0xd393, "GIGABYTE GT-U7300" },
+	{ 0x1b80, 0xd394, "DIKOM USB-DVBT HD" },
+	{ 0x1b80, 0xd395, "Peak 102569AGPK" },
+	{ 0x1b80, 0xd39d, "SVEON STV20 DVB-T USB & FM" },
+};
+
+#define DEFAULT_BUF_NUMBER	32
+#define DEFAULT_BUF_LENGTH	(16 * 32 * 512)
+
+#define DEF_RTL_XTAL_FREQ	28800000
+#define MIN_RTL_XTAL_FREQ	(DEF_RTL_XTAL_FREQ - 1000)
+#define MAX_RTL_XTAL_FREQ	(DEF_RTL_XTAL_FREQ + 1000)
+
+#define MAX_SAMP_RATE		3200000
+
+#define CTRL_IN		(LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN)
+#define CTRL_OUT	(LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_OUT)
+#define CTRL_TIMEOUT	300
+#define BULK_TIMEOUT	0
+
+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, CTRL_TIMEOUT);
+
+	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, CTRL_TIMEOUT);
+
+	return r;
+}
+
+int rtlsdr_i2c_write_reg(rtlsdr_dev_t *dev, uint8_t i2c_addr, uint8_t reg, uint8_t val)
+{
+	uint16_t addr = i2c_addr;
+	uint8_t data[2];
+
+	data[0] = reg;
+	data[1] = val;
+	return rtlsdr_write_array(dev, IICB, addr, (uint8_t *)&data, 2);
+}
+
+uint8_t rtlsdr_i2c_read_reg(rtlsdr_dev_t *dev, uint8_t i2c_addr, uint8_t reg)
+{
+	uint16_t addr = i2c_addr;
+	uint8_t data;
+
+	rtlsdr_write_array(dev, IICB, addr, &reg, 1);
+	rtlsdr_read_array(dev, IICB, addr, &data, 1);
+
+	return data;
+}
+
+/* TODO clean this up again */
+int e4k_reg_write(struct e4k_state *e4k, uint8_t reg, uint8_t val)
+{
+	return rtlsdr_i2c_write_reg((rtlsdr_dev_t*)e4k->rtl_dev, e4k->i2c_addr, reg, val);}
+
+uint8_t e4k_reg_read(struct e4k_state *e4k, uint8_t reg)
+{
+	return rtlsdr_i2c_read_reg((rtlsdr_dev_t*)e4k->rtl_dev, e4k->i2c_addr, reg);
+}
+
+int rtlsdr_i2c_write(rtlsdr_dev_t *dev, uint8_t i2c_addr, uint8_t *buffer, int len)
+{
+	uint16_t addr = i2c_addr;
+
+	if (!dev)
+		return -1;
+
+	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;
+
+	if (!dev)
+		return -1;
+
+	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, CTRL_TIMEOUT);
+
+	if (r < 0)
+		fprintf(stderr, "%s failed with %d\n", __FUNCTION__, r);
+
+	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, CTRL_TIMEOUT);
+
+	if (r < 0)
+		fprintf(stderr, "%s failed with %d\n", __FUNCTION__, r);
+}
+
+uint16_t rtlsdr_demod_read_reg(rtlsdr_dev_t *dev, uint8_t page, uint16_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, CTRL_TIMEOUT);
+
+	if (r < 0)
+		fprintf(stderr, "%s failed with %d\n", __FUNCTION__, r);
+
+	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, CTRL_TIMEOUT);
+
+	if (r < 0)
+		fprintf(stderr, "%s failed with %d\n", __FUNCTION__, r);
+
+	rtlsdr_demod_read_reg(dev, 0x0a, 0x01, 1);
+}
+
+void rtlsdr_set_gpio_bit(rtlsdr_dev_t *dev, uint8_t gpio, int val)
+{
+	uint8_t r;
+
+	gpio = 1 << gpio;
+	r = rtlsdr_read_reg(dev, SYSB, GPO, 1);
+	r = val ? (r | gpio) : (r & ~gpio);
+	rtlsdr_write_reg(dev, SYSB, GPO, r, 1);
+}
+
+void rtlsdr_set_gpio_output(rtlsdr_dev_t *dev, uint8_t gpio)
+{
+	int r;
+	gpio = 1 << gpio;
+
+	r = rtlsdr_read_reg(dev, SYSB, GPD, 1);
+	rtlsdr_write_reg(dev, SYSB, GPO, r & ~gpio, 1);
+	r = rtlsdr_read_reg(dev, SYSB, GPOE, 1);
+	rtlsdr_write_reg(dev, SYSB, GPOE, r | gpio, 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, 0xa5,
+	};
+
+	/* 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_deinit_baseband(rtlsdr_dev_t *dev)
+{
+	int r = 0;
+
+	if (!dev)
+		return -1;
+
+	if (dev->tuner && dev->tuner->exit) {
+		rtlsdr_set_i2c_repeater(dev, 1);
+		r = dev->tuner->exit(dev); /* deinitialize tuner */
+		rtlsdr_set_i2c_repeater(dev, 0);
+	}
+
+	/* poweroff demodulator and ADCs */
+	rtlsdr_write_reg(dev, SYSB, DEMOD_CTL, 0x20, 1);
+
+	return r;
+}
+
+int rtlsdr_set_xtal_freq(rtlsdr_dev_t *dev, uint32_t rtl_freq, uint32_t tuner_freq)
+{
+	int r = 0;
+
+	if (!dev)
+		return -1;
+
+	if (rtl_freq > 0 &&
+		(rtl_freq < MIN_RTL_XTAL_FREQ || rtl_freq > MAX_RTL_XTAL_FREQ))
+		return -2;
+
+	if (dev->rtl_xtal != rtl_freq) {
+		if (0 == rtl_freq)
+			rtl_freq = DEF_RTL_XTAL_FREQ;
+
+		dev->rtl_xtal = rtl_freq;
+
+		/* update xtal-dependent settings */
+		if (dev->rate)
+			r = rtlsdr_set_sample_rate(dev, dev->rate);
+	}
+
+	if (dev->tun_xtal != tuner_freq) {
+		if (0 == tuner_freq)
+			tuner_freq = dev->rtl_xtal;
+
+		dev->tun_xtal = tuner_freq;
+
+		/* update xtal-dependent settings */
+		if (dev->freq)
+			r = rtlsdr_set_center_freq(dev, dev->freq);
+	}
+
+	return r;
+}
+
+int rtlsdr_get_xtal_freq(rtlsdr_dev_t *dev, uint32_t *rtl_freq, uint32_t *tuner_freq)
+{
+	if (!dev)
+		return -1;
+
+	*rtl_freq = dev->rtl_xtal;
+
+	if (!dev->tuner)
+		return -2;
+
+	*tuner_freq = dev->tun_xtal;
+
+	return 0;
+}
+
+int rtlsdr_set_center_freq(rtlsdr_dev_t *dev, uint32_t freq)
+{
+	int r = -1;
+	double f = (double) freq;
+
+	if (!dev || !dev->tuner)
+		return -1;
+
+	if (dev->tuner->set_freq) {
+		f *= 1.0 + dev->corr / 1e6;
+
+		rtlsdr_set_i2c_repeater(dev, 1);
+		r = dev->tuner->set_freq(dev, (uint32_t) f);
+		rtlsdr_set_i2c_repeater(dev, 0);
+
+		if (!r)
+			dev->freq = freq;
+		else
+			dev->freq = 0;
+	}
+
+	return r;
+}
+
+uint32_t rtlsdr_get_center_freq(rtlsdr_dev_t *dev)
+{
+	if (!dev || !dev->tuner)
+		return 0;
+
+	return dev->freq;
+}
+
+int rtlsdr_set_freq_correction(rtlsdr_dev_t *dev, int ppm)
+{
+	int r;
+
+	if (!dev || !dev->tuner)
+		return -1;
+
+	if (dev->corr == ppm)
+		return -1;
+
+	dev->corr = ppm;
+
+	/* retune to apply new correction value */
+	r = rtlsdr_set_center_freq(dev, dev->freq);
+
+	return r;
+}
+
+int rtlsdr_get_freq_correction(rtlsdr_dev_t *dev)
+{
+	if (!dev || !dev->tuner)
+		return 0;
+
+	return dev->corr;
+}
+
+int rtlsdr_set_tuner_gain(rtlsdr_dev_t *dev, int gain)
+{
+	int r = 0;
+
+	if (!dev || !dev->tuner)
+		return -1;
+
+	if (dev->tuner->set_gain) {
+		rtlsdr_set_i2c_repeater(dev, 1);
+		r = dev->tuner->set_gain((void *)dev, gain);
+		rtlsdr_set_i2c_repeater(dev, 0);
+	}
+
+	if (!r)
+		dev->gain = gain;
+	else
+		dev->gain = 0;
+
+	return r;
+}
+
+int rtlsdr_get_tuner_gain(rtlsdr_dev_t *dev)
+{
+	if (!dev || !dev->tuner)
+		return 0;
+
+	return dev->gain;
+}
+
+int rtlsdr_set_tuner_gain_mode(rtlsdr_dev_t *dev, int mode)
+{
+	int r = 0;
+
+	if (!dev || !dev->tuner)
+		return -1;
+
+	if (dev->tuner->set_gain_mode) {
+		rtlsdr_set_i2c_repeater(dev, 1);
+		r = dev->tuner->set_gain_mode((void *)dev, mode);
+		rtlsdr_set_i2c_repeater(dev, 0);
+	}
+
+	return r;
+}
+
+int rtlsdr_set_sample_rate(rtlsdr_dev_t *dev, uint32_t samp_rate)
+{
+	uint16_t tmp;
+	uint32_t rsamp_ratio;
+	double real_rate;
+
+	if (!dev)
+		return -1;
+
+	/* check for the maximum rate the resampler supports */
+	if (samp_rate > MAX_SAMP_RATE)
+		samp_rate = MAX_SAMP_RATE;
+
+	rsamp_ratio = (dev->rtl_xtal * pow(2, 22)) / samp_rate;
+	rsamp_ratio &= ~3;
+
+	real_rate = (dev->rtl_xtal * pow(2, 22)) / rsamp_ratio;
+
+	if ( ((double)samp_rate) != real_rate )
+		fprintf(stderr, "Exact sample rate is: %f Hz\n", real_rate);
+
+	if (dev->tuner && dev->tuner->set_bw) {
+		rtlsdr_set_i2c_repeater(dev, 1);
+		dev->tuner->set_bw(dev, real_rate);
+		rtlsdr_set_i2c_repeater(dev, 0);
+	}
+
+	dev->rate = samp_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);
+
+	/* reset demod (bit 3, soft_rst) */
+	rtlsdr_demod_write_reg(dev, 1, 0x01, 0x14, 1);
+	rtlsdr_demod_write_reg(dev, 1, 0x01, 0x10, 1);
+
+	return 0;
+}
+
+uint32_t rtlsdr_get_sample_rate(rtlsdr_dev_t *dev)
+{
+	if (!dev)
+		return 0;
+
+	return dev->rate;
+}
+
+rtlsdr_dongle_t *find_known_device(uint16_t vid, uint16_t pid)
+{
+	unsigned int i;
+	rtlsdr_dongle_t *device = NULL;
+
+	for (i = 0; i < sizeof(known_devices)/sizeof(rtlsdr_dongle_t); i++ ) {
+		if (known_devices[i].vid == vid && known_devices[i].pid == pid) {
+			device = &known_devices[i];
+			break;
+		}
+	}
+
+	return device;
+}
+
+uint32_t rtlsdr_get_device_count(void)
+{
+	int i;
+	libusb_context *ctx;
+	libusb_device **list;
+	uint32_t device_count = 0;
+	struct libusb_device_descriptor dd;
+	ssize_t cnt;
+
+	libusb_init(&ctx);
+
+	cnt = libusb_get_device_list(ctx, &list);
+
+	for (i = 0; i < cnt; i++) {
+		libusb_get_device_descriptor(list[i], &dd);
+
+		if (find_known_device(dd.idVendor, dd.idProduct))
+			device_count++;
+	}
+
+	libusb_free_device_list(list, 1);
+
+	libusb_exit(ctx);
+
+	return device_count;
+}
+
+const char *rtlsdr_get_device_name(uint32_t index)
+{
+	int i;
+	libusb_context *ctx;
+	libusb_device **list;
+	struct libusb_device_descriptor dd;
+	rtlsdr_dongle_t *device = NULL;
+	uint32_t device_count = 0;
+	ssize_t cnt;
+
+	libusb_init(&ctx);
+
+	cnt = libusb_get_device_list(ctx, &list);
+
+	for (i = 0; i < cnt; i++) {
+		libusb_get_device_descriptor(list[i], &dd);
+
+		device = find_known_device(dd.idVendor, dd.idProduct);
+
+		if (device) {
+			device_count++;
+
+			if (index == device_count - 1)
+				break;
+		}
+	}
+
+	libusb_free_device_list(list, 1);
+
+	libusb_exit(ctx);
+
+	if (device)
+		return device->name;
+	else
+		return "";
+}
+
+int rtlsdr_open(rtlsdr_dev_t **out_dev, uint32_t index)
+{
+	int r;
+	int i;
+	libusb_device **list;
+	rtlsdr_dev_t *dev = NULL;
+	libusb_device *device = NULL;
+	uint32_t device_count = 0;
+	struct libusb_device_descriptor dd;
+	uint8_t reg;
+	ssize_t cnt;
+
+	dev = malloc(sizeof(rtlsdr_dev_t));
+	if (NULL == dev)
+		return -ENOMEM;
+
+	memset(dev, 0, sizeof(rtlsdr_dev_t));
+
+	libusb_init(&dev->ctx);
+
+	cnt = libusb_get_device_list(dev->ctx, &list);
+
+	for (i = 0; i < cnt; i++) {
+		device = list[i];
+
+		libusb_get_device_descriptor(list[i], &dd);
+
+		if (find_known_device(dd.idVendor, dd.idProduct)) {
+			device_count++;
+		}
+
+		if (index == device_count - 1)
+			break;
+
+		device = NULL;
+	}
+
+	if (!device) {
+		r = -1;
+		goto err;
+	}
+
+	r = libusb_open(device, &dev->devh);
+	if (r < 0) {
+		libusb_free_device_list(list, 1);
+		fprintf(stderr, "usb_open error %d\n", r);
+		goto err;
+	}
+
+	libusb_free_device_list(list, 1);
+
+	r = libusb_claim_interface(dev->devh, 0);
+	if (r < 0) {
+		fprintf(stderr, "usb_claim_interface error %d\n", r);
+		goto err;
+	}
+
+	dev->rtl_xtal = DEF_RTL_XTAL_FREQ;
+
+	rtlsdr_init_baseband(dev);
+
+	/* Probe tuners */
+	rtlsdr_set_i2c_repeater(dev, 1);
+
+	reg = rtlsdr_i2c_read_reg(dev, E4K_I2C_ADDR, E4K_CHECK_ADDR);
+	if (reg == E4K_CHECK_VAL) {
+		fprintf(stderr, "Found Elonics E4000 tuner\n");
+		dev->tuner = &tuners[RTLSDR_TUNER_E4000];
+		goto found;
+	}
+
+	reg = rtlsdr_i2c_read_reg(dev, FC0013_I2C_ADDR, FC0013_CHECK_ADDR);
+	if (reg == FC0013_CHECK_VAL) {
+		fprintf(stderr, "Found Fitipower FC0013 tuner\n");
+		dev->tuner = &tuners[RTLSDR_TUNER_FC0013];
+		goto found;
+	}
+
+	/* initialise GPIOs */
+	rtlsdr_set_gpio_output(dev, 5);
+
+	/* reset tuner before probing */
+	rtlsdr_set_gpio_bit(dev, 5, 1);
+	rtlsdr_set_gpio_bit(dev, 5, 0);
+
+	reg = rtlsdr_i2c_read_reg(dev, FC2580_I2C_ADDR, FC2580_CHECK_ADDR);
+	if ((reg & 0x7f) == FC2580_CHECK_VAL) {
+		fprintf(stderr, "Found FCI 2580 tuner\n");
+		dev->tuner = &tuners[RTLSDR_TUNER_FC2580];
+		goto found;
+	}
+
+	reg = rtlsdr_i2c_read_reg(dev, FC0012_I2C_ADDR, FC0012_CHECK_ADDR);
+	if (reg == FC0012_CHECK_VAL) {
+		fprintf(stderr, "Found Fitipower FC0012 tuner\n");
+		rtlsdr_set_gpio_output(dev, 6);
+		dev->tuner = &tuners[RTLSDR_TUNER_FC0012];
+		goto found;
+	}
+
+found:
+	if (dev->tuner) {
+		dev->tun_xtal = dev->rtl_xtal;
+
+		if (dev->tuner->init)
+			r = dev->tuner->init(dev);
+	}
+
+	rtlsdr_set_i2c_repeater(dev, 0);
+
+	*out_dev = dev;
+
+	return 0;
+err:
+	if (dev) {
+		if (dev->ctx)
+			libusb_exit(dev->ctx);
+
+		free(dev);
+	}
+
+	return r;
+}
+
+int rtlsdr_close(rtlsdr_dev_t *dev)
+{
+	if (!dev)
+		return -1;
+
+	rtlsdr_deinit_baseband(dev);	
+
+	libusb_release_interface(dev->devh, 0);
+	libusb_close(dev->devh);
+
+	libusb_exit(dev->ctx);
+
+	free(dev);
+
+	return 0;
+}
+
+int rtlsdr_reset_buffer(rtlsdr_dev_t *dev)
+{
+	if (!dev)
+		return -1;
+
+	rtlsdr_write_reg(dev, USBB, USB_EPA_CTL, 0x1002, 2);
+	rtlsdr_write_reg(dev, USBB, USB_EPA_CTL, 0x0000, 2);
+
+	return 0;
+}
+
+int rtlsdr_read_sync(rtlsdr_dev_t *dev, void *buf, int len, int *n_read)
+{
+	if (!dev)
+		return -1;
+
+	return libusb_bulk_transfer(dev->devh, 0x81, buf, len, n_read, BULK_TIMEOUT);
+}
+
+static void LIBUSB_CALL _libusb_callback(struct libusb_transfer *xfer)
+{
+	rtlsdr_dev_t *dev = (rtlsdr_dev_t *)xfer->user_data;
+
+	if (LIBUSB_TRANSFER_COMPLETED == xfer->status) {
+		if (dev->cb)
+			dev->cb(xfer->buffer, xfer->actual_length, dev->cb_ctx);
+
+		libusb_submit_transfer(xfer); /* resubmit transfer */
+	} else {
+		/*fprintf(stderr, "transfer status: %d\n", xfer->status);*/
+		rtlsdr_cancel_async(dev); /* abort async loop */
+	}
+}
+
+int rtlsdr_wait_async(rtlsdr_dev_t *dev, rtlsdr_read_async_cb_t cb, void *ctx)
+{
+	return rtlsdr_read_async(dev, cb, ctx, 0, 0);
+}
+
+static int _rtlsdr_alloc_async_buffers(rtlsdr_dev_t *dev)
+{
+	unsigned int i;
+
+	if (!dev)
+		return -1;
+
+	if (!dev->xfer) {
+		dev->xfer = malloc(dev->xfer_buf_num *
+				   sizeof(struct libusb_transfer *));
+
+		for(i = 0; i < dev->xfer_buf_num; ++i)
+			dev->xfer[i] = libusb_alloc_transfer(0);
+	}
+
+	if (!dev->xfer_buf) {
+		dev->xfer_buf = malloc(dev->xfer_buf_num *
+					   sizeof(unsigned char *));
+
+		for(i = 0; i < dev->xfer_buf_num; ++i)
+			dev->xfer_buf[i] = malloc(dev->xfer_buf_len);
+	}
+
+	return 0;
+}
+
+static int _rtlsdr_free_async_buffers(rtlsdr_dev_t *dev)
+{
+	unsigned int i;
+
+	if (!dev)
+		return -1;
+
+	if (dev->xfer) {
+		for(i = 0; i < dev->xfer_buf_num; ++i) {
+			if (dev->xfer[i]) {
+				libusb_free_transfer(dev->xfer[i]);
+			}
+		}
+
+		free(dev->xfer);
+		dev->xfer = NULL;
+	}
+
+	if (dev->xfer_buf) {
+		for(i = 0; i < dev->xfer_buf_num; ++i) {
+			if (dev->xfer_buf[i])
+				free(dev->xfer_buf[i]);
+		}
+
+		free(dev->xfer_buf);
+		dev->xfer_buf = NULL;
+	}
+
+	return 0;
+}
+
+int rtlsdr_read_async(rtlsdr_dev_t *dev, rtlsdr_read_async_cb_t cb, void *ctx,
+			  uint32_t buf_num, uint32_t buf_len)
+{
+	unsigned int i;
+	int r;
+	struct timeval tv = { 1, 0 };
+
+	if (!dev)
+		return -1;
+
+	dev->cb = cb;
+	dev->cb_ctx = ctx;
+
+	if (buf_num > 0)
+		dev->xfer_buf_num = buf_num;
+	else
+		dev->xfer_buf_num = DEFAULT_BUF_NUMBER;
+
+	if (buf_len > 0 && buf_len % 512 == 0) /* len must be multiple of 512 */
+		dev->xfer_buf_len = buf_len;
+	else
+		dev->xfer_buf_len = DEFAULT_BUF_LENGTH;
+
+	_rtlsdr_alloc_async_buffers(dev);
+
+	for(i = 0; i < dev->xfer_buf_num; ++i) {
+		libusb_fill_bulk_transfer(dev->xfer[i],
+					  dev->devh,
+					  0x81,
+					  dev->xfer_buf[i],
+					  dev->xfer_buf_len,
+					  _libusb_callback,
+					  (void *)dev,
+					  BULK_TIMEOUT);
+
+		libusb_submit_transfer(dev->xfer[i]);
+	}
+
+	dev->async_status = RTLSDR_RUNNING;
+
+	while (RTLSDR_INACTIVE != dev->async_status) {
+		r = libusb_handle_events_timeout(dev->ctx, &tv);
+		if (r < 0) {
+			/*fprintf(stderr, "handle_events returned: %d\n", r);*/
+			if (r == LIBUSB_ERROR_INTERRUPTED) /* stray signal */
+				continue;
+			break;
+		}
+
+		if (RTLSDR_CANCELING == dev->async_status) {
+			dev->async_status = RTLSDR_INACTIVE;
+
+			if (!dev->xfer)
+				break;
+
+			for(i = 0; i < dev->xfer_buf_num; ++i) {
+				if (!dev->xfer[i])
+					continue;
+
+				if (dev->xfer[i]->status == LIBUSB_TRANSFER_COMPLETED) {
+					libusb_cancel_transfer(dev->xfer[i]);
+					dev->async_status = RTLSDR_CANCELING;
+				}
+			}
+
+			if (RTLSDR_INACTIVE == dev->async_status)
+				break;
+		}
+	}
+
+	_rtlsdr_free_async_buffers(dev);
+
+	return r;
+}
+
+int rtlsdr_cancel_async(rtlsdr_dev_t *dev)
+{
+	if (!dev)
+		return -1;
+
+	if (RTLSDR_RUNNING == dev->async_status) {
+		dev->async_status = RTLSDR_CANCELING;
+		return 0;
+	}
+
+	return -2;
+}
+
+uint32_t rtlsdr_get_tuner_clock(void *dev)
+{
+	if (!dev)
+		return 0;
+
+	return ((rtlsdr_dev_t *)dev)->tun_xtal;
+}
+
+int rtlsdr_i2c_write_fn(void *dev, uint8_t addr, uint8_t *buf, int len)
+{
+	if (dev)
+		return rtlsdr_i2c_write(((rtlsdr_dev_t *)dev), addr, buf, len);
+
+	return -1;
+}
+
+int rtlsdr_i2c_read_fn(void *dev, uint8_t addr, uint8_t *buf, int len)
+{
+	if (dev)
+		return rtlsdr_i2c_read(((rtlsdr_dev_t *)dev), addr, buf, len);
+
+	return -1;
+}