text: /*
   * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
   * Copyright (C) 2012-2013 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/>.
   */
  
  #ifndef __RTL_SDR_H
  #define __RTL_SDR_H
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  #include <stdint.h>
  #include <rtl-sdr_export.h>
  
  typedef struct rtlsdr_dev rtlsdr_dev_t;
  
  RTLSDR_API uint32_t rtlsdr_get_device_count(void);
  
  RTLSDR_API const char* rtlsdr_get_device_name(uint32_t index);
  
  /*!
   * Get USB device strings.
   *
   * NOTE: The string arguments must provide space for up to 256 bytes.
   *
   * \param index the device index
   * \param manufact manufacturer name, may be NULL
   * \param product product name, may be NULL
   * \param serial serial number, may be NULL
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_get_device_usb_strings(uint32_t index,
  					     char *manufact,
  					     char *product,
  					     char *serial);
  
  /*!
   * Get device index by USB serial string descriptor.
   *
   * \param serial serial string of the device
   * \return device index of first device where the name matched
   * \return -1 if name is NULL
   * \return -2 if no devices were found at all
   * \return -3 if devices were found, but none with matching name
   */
  RTLSDR_API int rtlsdr_get_index_by_serial(const char *serial);
  
  RTLSDR_API int rtlsdr_open(rtlsdr_dev_t **dev, uint32_t index);
  
  RTLSDR_API int rtlsdr_close(rtlsdr_dev_t *dev);
  
  /* configuration functions */
  
  /*!
   * Set crystal oscillator frequencies used for the RTL2832 and the tuner IC.
   *
   * Usually both ICs use the same clock. Changing the clock may make sense if
   * you are applying an external clock to the tuner or to compensate the
   * frequency (and samplerate) error caused by the original (cheap) crystal.
   *
   * NOTE: Call this function only if you fully understand the implications.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param rtl_freq frequency value used to clock the RTL2832 in Hz
   * \param tuner_freq frequency value used to clock the tuner IC in Hz
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_set_xtal_freq(rtlsdr_dev_t *dev, uint32_t rtl_freq,
  				    uint32_t tuner_freq);
  
  /*!
   * Get crystal oscillator frequencies used for the RTL2832 and the tuner IC.
   *
   * Usually both ICs use the same clock.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param rtl_freq frequency value used to clock the RTL2832 in Hz
   * \param tuner_freq frequency value used to clock the tuner IC in Hz
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_get_xtal_freq(rtlsdr_dev_t *dev, uint32_t *rtl_freq,
  				    uint32_t *tuner_freq);
  
  /*!
   * Get USB device strings.
   *
   * NOTE: The string arguments must provide space for up to 256 bytes.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param manufact manufacturer name, may be NULL
   * \param product product name, may be NULL
   * \param serial serial number, may be NULL
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_get_usb_strings(rtlsdr_dev_t *dev, char *manufact,
  				      char *product, char *serial);
  
  /*!
   * Write the device EEPROM
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param data buffer of data to be written
   * \param offset address where the data should be written
   * \param len length of the data
   * \return 0 on success
   * \return -1 if device handle is invalid
   * \return -2 if EEPROM size is exceeded
   * \return -3 if no EEPROM was found
   */
  
  RTLSDR_API int rtlsdr_write_eeprom(rtlsdr_dev_t *dev, uint8_t *data,
  				  uint8_t offset, uint16_t len);
  
  /*!
   * Read the device EEPROM
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param data buffer where the data should be written
   * \param offset address where the data should be read from
   * \param len length of the data
   * \return 0 on success
   * \return -1 if device handle is invalid
   * \return -2 if EEPROM size is exceeded
   * \return -3 if no EEPROM was found
   */
  
  RTLSDR_API int rtlsdr_read_eeprom(rtlsdr_dev_t *dev, uint8_t *data,
  				  uint8_t offset, uint16_t len);
  
  RTLSDR_API int rtlsdr_set_center_freq(rtlsdr_dev_t *dev, uint32_t freq);
  
  /*!
   * Get actual frequency the device is tuned to.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \return 0 on error, frequency in Hz otherwise
   */
  RTLSDR_API uint32_t rtlsdr_get_center_freq(rtlsdr_dev_t *dev);
  
  /*!
   * Set the frequency correction value for the device.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param ppm correction value in parts per million (ppm)
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_set_freq_correction(rtlsdr_dev_t *dev, int ppm);
  
  /*!
   * Get actual frequency correction value of the device.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \return correction value in parts per million (ppm)
   */
  RTLSDR_API int rtlsdr_get_freq_correction(rtlsdr_dev_t *dev);
  
  enum rtlsdr_tuner {
  	RTLSDR_TUNER_UNKNOWN = 0,
  	RTLSDR_TUNER_E4000,
  	RTLSDR_TUNER_FC0012,
  	RTLSDR_TUNER_FC0013,
  	RTLSDR_TUNER_FC2580,
  	RTLSDR_TUNER_R820T,
  	RTLSDR_TUNER_R828D
  };
  
  /*!
   * Get the tuner type.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \return RTLSDR_TUNER_UNKNOWN on error, tuner type otherwise
   */
  RTLSDR_API enum rtlsdr_tuner rtlsdr_get_tuner_type(rtlsdr_dev_t *dev);
  
  /*!
   * Get a list of gains supported by the tuner.
   *
   * NOTE: The gains argument must be preallocated by the caller. If NULL is
   * being given instead, the number of available gain values will be returned.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param gains array of gain values. In tenths of a dB, 115 means 11.5 dB.
   * \return <= 0 on error, number of available (returned) gain values otherwise
   */
  RTLSDR_API int rtlsdr_get_tuner_gains(rtlsdr_dev_t *dev, int *gains);
  
  /*!
   * Set the gain for the device.
   * Manual gain mode must be enabled for this to work.
   *
   * Valid gain values (in tenths of a dB) for the E4000 tuner:
   * -10, 15, 40, 65, 90, 115, 140, 165, 190,
   * 215, 240, 290, 340, 420, 430, 450, 470, 490
   *
   * Valid gain values may be queried with \ref rtlsdr_get_tuner_gains function.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param gain in tenths of a dB, 115 means 11.5 dB.
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_set_tuner_gain(rtlsdr_dev_t *dev, int gain);
  
  /*!
   * Get actual gain the device is configured to.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \return 0 on error, gain in tenths of a dB, 115 means 11.5 dB.
   */
  RTLSDR_API int rtlsdr_get_tuner_gain(rtlsdr_dev_t *dev);
  
  /*!
   * Set the intermediate frequency gain for the device.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param stage intermediate frequency gain stage number (1 to 6 for E4000)
   * \param gain in tenths of a dB, -30 means -3.0 dB.
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_set_tuner_if_gain(rtlsdr_dev_t *dev, int stage, int gain);
  
  /*!
   * Set the gain mode (automatic/manual) for the device.
   * Manual gain mode must be enabled for the gain setter function to work.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param manual gain mode, 1 means manual gain mode shall be enabled.
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_set_tuner_gain_mode(rtlsdr_dev_t *dev, int manual);
  
  /*!
   * Set the sample rate for the device, also selects the baseband filters
   * according to the requested sample rate for tuners where this is possible.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param samp_rate the sample rate to be set, possible values are:
   * 		    225001 - 300000 Hz
   * 		    900001 - 3200000 Hz
   * 		    sample loss is to be expected for rates > 2400000
   * \return 0 on success, -EINVAL on invalid rate
   */
  RTLSDR_API int rtlsdr_set_sample_rate(rtlsdr_dev_t *dev, uint32_t rate);
  
  /*!
   * Get actual sample rate the device is configured to.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \return 0 on error, sample rate in Hz otherwise
   */
  RTLSDR_API uint32_t rtlsdr_get_sample_rate(rtlsdr_dev_t *dev);
  
  /*!
   * Enable test mode that returns an 8 bit counter instead of the samples.
   * The counter is generated inside the RTL2832.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param test mode, 1 means enabled, 0 disabled
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_set_testmode(rtlsdr_dev_t *dev, int on);
  
  /*!
   * Enable or disable the internal digital AGC of the RTL2832.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param digital AGC mode, 1 means enabled, 0 disabled
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_set_agc_mode(rtlsdr_dev_t *dev, int on);
  
  /*!
   * Enable or disable the direct sampling mode. When enabled, the IF mode
   * of the RTL2832 is activated, and rtlsdr_set_center_freq() will control
   * the IF-frequency of the DDC, which can be used to tune from 0 to 28.8 MHz
   * (xtal frequency of the RTL2832).
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param on 0 means disabled, 1 I-ADC input enabled, 2 Q-ADC input enabled
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_set_direct_sampling(rtlsdr_dev_t *dev, int on);
  
  /*!
   * Get state of the direct sampling mode
   *
   * \param dev the device handle given by rtlsdr_open()
   * \return -1 on error, 0 means disabled, 1 I-ADC input enabled
   *	    2 Q-ADC input enabled
   */
  RTLSDR_API int rtlsdr_get_direct_sampling(rtlsdr_dev_t *dev);
  
  /*!
   * Enable or disable offset tuning for zero-IF tuners, which allows to avoid
   * problems caused by the DC offset of the ADCs and 1/f noise.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param on 0 means disabled, 1 enabled
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_set_offset_tuning(rtlsdr_dev_t *dev, int on);
  
  /*!
   * Get state of the offset tuning mode
   *
   * \param dev the device handle given by rtlsdr_open()
   * \return -1 on error, 0 means disabled, 1 enabled
   */
  RTLSDR_API int rtlsdr_get_offset_tuning(rtlsdr_dev_t *dev);
  
  /* streaming functions */
  
  RTLSDR_API int rtlsdr_reset_buffer(rtlsdr_dev_t *dev);
  
  RTLSDR_API int rtlsdr_read_sync(rtlsdr_dev_t *dev, void *buf, int len, int *n_read);
  
  typedef void(*rtlsdr_read_async_cb_t)(unsigned char *buf, uint32_t len, void *ctx);
  
  /*!
   * Read samples from the device asynchronously. This function will block until
   * it is being canceled using rtlsdr_cancel_async()
   *
   * NOTE: This function is deprecated and is subject for removal.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param cb callback function to return received samples
   * \param ctx user specific context to pass via the callback function
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_wait_async(rtlsdr_dev_t *dev, rtlsdr_read_async_cb_t cb, void *ctx);
  
  /*!
   * Read samples from the device asynchronously. This function will block until
   * it is being canceled using rtlsdr_cancel_async()
   *
   * \param dev the device handle given by rtlsdr_open()
   * \param cb callback function to return received samples
   * \param ctx user specific context to pass via the callback function
   * \param buf_num optional buffer count, buf_num * buf_len = overall buffer size
   *		  set to 0 for default buffer count (32)
   * \param buf_len optional buffer length, must be multiple of 512,
   *		  set to 0 for default buffer length (16 * 32 * 512)
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_read_async(rtlsdr_dev_t *dev,
  				 rtlsdr_read_async_cb_t cb,
  				 void *ctx,
  				 uint32_t buf_num,
  				 uint32_t buf_len);
  
  /*!
   * Cancel all pending asynchronous operations on the device.
   *
   * \param dev the device handle given by rtlsdr_open()
   * \return 0 on success
   */
  RTLSDR_API int rtlsdr_cancel_async(rtlsdr_dev_t *dev);
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* __RTL_SDR_H */
  