aboutsummaryrefslogtreecommitdiffstats
path: root/host/lib/usrp/dboard/db_dbsrx.cpp
blob: b984608cae00e9606db18e870f57ef62b39eaf21 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
//
// Copyright 2010-2011 Ettus Research LLC
//
// 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 3 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/>.
//

// No RX IO Pins Used

// RX IO Functions

#include "max2118_regs.hpp"
#include <uhd/utils/static.hpp>
#include <uhd/utils/assert_has.hpp>
#include <uhd/utils/algorithm.hpp>
#include <uhd/utils/warning.hpp>
#include <uhd/types/ranges.hpp>
#include <uhd/types/sensors.hpp>
#include <uhd/types/dict.hpp>
#include <uhd/usrp/subdev_props.hpp>
#include <uhd/usrp/dboard_base.hpp>
#include <uhd/usrp/dboard_manager.hpp>
#include <boost/assign/list_of.hpp>
#include <boost/format.hpp>
#include <boost/thread.hpp>
#include <boost/math/special_functions/round.hpp>
#include <utility>
#include <cmath>

using namespace uhd;
using namespace uhd::usrp;
using namespace boost::assign;

/***********************************************************************
 * The DBSRX constants
 **********************************************************************/
static const bool dbsrx_debug = false;

static const freq_range_t dbsrx_freq_range(0.8e9, 2.4e9);

static const freq_range_t dbsrx_pfd_freq_range(0.15e6, 2.01e6);

static const prop_names_t dbsrx_antennas = list_of("J3");

static const uhd::dict<std::string, gain_range_t> dbsrx_gain_ranges = map_list_of
    ("GC1", gain_range_t(0, 56, 0.5))
    ("GC2", gain_range_t(0, 24, 1))
;

/***********************************************************************
 * The DBSRX dboard class
 **********************************************************************/
class dbsrx : public rx_dboard_base{
public:
    dbsrx(ctor_args_t args);
    ~dbsrx(void);

    void rx_get(const wax::obj &key, wax::obj &val);
    void rx_set(const wax::obj &key, const wax::obj &val);

private:
    double _lo_freq;
    double _bandwidth;
    uhd::dict<std::string, double> _gains;
    max2118_write_regs_t _max2118_write_regs;
    max2118_read_regs_t _max2118_read_regs;
    boost::uint8_t _max2118_addr(void){
        return (this->get_iface()->get_special_props().mangle_i2c_addrs)? 0x65 : 0x67;
    };

    void set_lo_freq(double target_freq);
    void set_gain(double gain, const std::string &name);
    void set_bandwidth(double bandwidth);

    void send_reg(boost::uint8_t start_reg, boost::uint8_t stop_reg){
        start_reg = boost::uint8_t(uhd::clip(int(start_reg), 0x0, 0x5));
        stop_reg = boost::uint8_t(uhd::clip(int(stop_reg), 0x0, 0x5));

        for(boost::uint8_t start_addr=start_reg; start_addr <= stop_reg; start_addr += sizeof(boost::uint32_t) - 1){
            int num_bytes = int(stop_reg - start_addr + 1) > int(sizeof(boost::uint32_t)) - 1 ? sizeof(boost::uint32_t) - 1 : stop_reg - start_addr + 1;

            //create buffer for register data (+1 for start address)
            byte_vector_t regs_vector(num_bytes + 1);

            //first byte is the address of first register
            regs_vector[0] = start_addr;

            //get the register data
            for(int i=0; i<num_bytes; i++){
                regs_vector[1+i] = _max2118_write_regs.get_reg(start_addr+i);
                if(dbsrx_debug) std::cerr << boost::format(
                    "DBSRX: send reg 0x%02x, value 0x%04x, start_addr = 0x%04x, num_bytes %d"
                ) % int(start_addr+i) % int(regs_vector[1+i]) % int(start_addr) % num_bytes << std::endl;
            }

            //send the data
            this->get_iface()->write_i2c(
                _max2118_addr(), regs_vector
            );
        }
    }

    void read_reg(boost::uint8_t start_reg, boost::uint8_t stop_reg){
        static const boost::uint8_t status_addr = 0x0;
        start_reg = boost::uint8_t(uhd::clip(int(start_reg), 0x0, 0x1));
        stop_reg = boost::uint8_t(uhd::clip(int(stop_reg), 0x0, 0x1));

        for(boost::uint8_t start_addr=start_reg; start_addr <= stop_reg; start_addr += sizeof(boost::uint32_t)){
            int num_bytes = int(stop_reg - start_addr + 1) > int(sizeof(boost::uint32_t)) ? sizeof(boost::uint32_t) : stop_reg - start_addr + 1;

            //create buffer for register data
            byte_vector_t regs_vector(num_bytes);

            //read from i2c
            regs_vector = this->get_iface()->read_i2c(
                _max2118_addr(), num_bytes
            );

            for(boost::uint8_t i=0; i < num_bytes; i++){
                if (i + start_addr >= status_addr){
                    _max2118_read_regs.set_reg(i + start_addr, regs_vector[i]);
                }
                if(dbsrx_debug) std::cerr << boost::format(
                    "DBSRX: read reg 0x%02x, value 0x%04x, start_addr = 0x%04x, num_bytes %d"
                ) % int(start_addr+i) % int(regs_vector[i]) % int(start_addr) % num_bytes << std::endl;
            }
        }
    }

    /*!
     * Is the LO locked?
     * \return true for locked
     */
    bool get_locked(void){
        read_reg(0x0, 0x0);

        //mask and return lock detect
        bool locked = 5 >= _max2118_read_regs.adc and _max2118_read_regs.adc >= 2;

        if(dbsrx_debug) std::cerr << boost::format(
            "DBSRX: locked %d"
        ) % locked << std::endl;

        return locked;
    }

};

/***********************************************************************
 * Register the DBSRX dboard
 **********************************************************************/
static dboard_base::sptr make_dbsrx(dboard_base::ctor_args_t args){
    return dboard_base::sptr(new dbsrx(args));
}

UHD_STATIC_BLOCK(reg_dbsrx_dboard){
    //register the factory function for the rx dbid (others version)
    dboard_manager::register_dboard(0x000D, &make_dbsrx, "DBSRX");
    //register the factory function for the rx dbid (USRP1 version)
    dboard_manager::register_dboard(0x0002, &make_dbsrx, "DBSRX");
}

/***********************************************************************
 * Structors
 **********************************************************************/
dbsrx::dbsrx(ctor_args_t args) : rx_dboard_base(args){
    //warn user about incorrect DBID on USRP1, requires R193 populated
    if (this->get_iface()->get_special_props().soft_clock_divider and this->get_rx_id() == 0x000D)
        uhd::warning::post(
            str(boost::format(
                "DBSRX: incorrect dbid\n"
                "Expected dbid 0x0002 and R193\n"
                "found dbid == %d\n"
                "Please see the daughterboard app notes" 
                ) % this->get_rx_id().to_pp_string())
        );

    //warn user about incorrect DBID on non-USRP1, requires R194 populated
    if (not this->get_iface()->get_special_props().soft_clock_divider and this->get_rx_id() == 0x0002)
        uhd::warning::post(
            str(boost::format(
                "DBSRX: incorrect dbid\n"
                "Expected dbid 0x000D and R194\n"
                "found dbid == %d\n"
                "Please see the daughterboard app notes" 
                ) % this->get_rx_id().to_pp_string())
        );

    //enable only the clocks we need
    this->get_iface()->set_clock_enabled(dboard_iface::UNIT_RX, true);

    //set the gpio directions and atr controls (identically)
    this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_RX, 0x0); // All unused in atr
    if (this->get_iface()->get_special_props().soft_clock_divider){
        this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, 0x1); // GPIO0 is clock
    }
    else{
        this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, 0x0); // All Inputs
    }

    //send initial register settings
    this->send_reg(0x0, 0x5);

    //set defaults for LO, gains, and filter bandwidth
    _bandwidth = 33e6;
    set_lo_freq(dbsrx_freq_range.start());

    BOOST_FOREACH(const std::string &name, dbsrx_gain_ranges.keys()){
        set_gain(dbsrx_gain_ranges[name].start(), name);
    }

    set_bandwidth(33e6); // default bandwidth from datasheet
}

dbsrx::~dbsrx(void){
}


/***********************************************************************
 * Tuning
 **********************************************************************/
void dbsrx::set_lo_freq(double target_freq){
    target_freq = dbsrx_freq_range.clip(target_freq);

    double actual_freq=0.0, pfd_freq=0.0, ref_clock=0.0;
    int R=0, N=0, r=0, m=0;
    bool update_filter_settings = false;
    //choose refclock
    std::vector<double> clock_rates = this->get_iface()->get_clock_rates(dboard_iface::UNIT_RX);
    const double max_clock_rate = uhd::sorted(clock_rates).back();
    BOOST_FOREACH(ref_clock, uhd::reversed(uhd::sorted(clock_rates))){
        if (ref_clock > 27.0e6) continue;
        if (size_t(max_clock_rate/ref_clock)%2 == 1) continue; //reject asymmetric clocks (odd divisors)

        //choose m_divider such that filter tuning constraint is met
        m = 31;
        while ((ref_clock/m < 1e6 or ref_clock/m > 2.5e6) and m > 0){ m--; }

        if(dbsrx_debug) std::cerr << boost::format(
            "DBSRX: trying ref_clock %f and m_divider %d"
        ) % (ref_clock) % m << std::endl;

        if (m >= 32) continue;

        //choose R
        for(r = 0; r <= 6; r += 1) {
            //compute divider from setting
            R = 1 << (r+1);
            if (dbsrx_debug) std::cerr << boost::format("DBSRX R:%d\n") % R << std::endl;

            //compute PFD compare frequency = ref_clock/R
            pfd_freq = ref_clock / R;

            //constrain the PFD frequency to specified range
            if ((pfd_freq < dbsrx_pfd_freq_range.start()) or (pfd_freq > dbsrx_pfd_freq_range.stop())) continue;

            //compute N
            N = int(std::floor(target_freq/pfd_freq));

            //constrain N to specified range
            if ((N < 256) or (N > 32768)) continue;

            goto done_loop;
        }
    } 

    done_loop:

    //Assert because we failed to find a suitable combination of ref_clock, R and N 
    UHD_ASSERT_THROW(ref_clock <= 27.0e6 and ref_clock >= 0.0);
    UHD_ASSERT_THROW(ref_clock/m >= 1e6 and ref_clock/m <= 2.5e6);
    UHD_ASSERT_THROW((pfd_freq >= dbsrx_pfd_freq_range.start()) and (pfd_freq <= dbsrx_pfd_freq_range.stop()));
    UHD_ASSERT_THROW((N >= 256) and (N <= 32768));

    if(dbsrx_debug) std::cerr << boost::format(
        "DBSRX: choose ref_clock (current: %f, new: %f) and m_divider %d"
    ) % (this->get_iface()->get_clock_rate(dboard_iface::UNIT_RX)) % ref_clock % m << std::endl;

    //if ref_clock or m divider changed, we need to update the filter settings
    if (ref_clock != this->get_iface()->get_clock_rate(dboard_iface::UNIT_RX) or m != _max2118_write_regs.m_divider) update_filter_settings = true;

    //compute resulting output frequency
    actual_freq = pfd_freq * N;

    //apply ref_clock, R, and N settings
    this->get_iface()->set_clock_rate(dboard_iface::UNIT_RX, ref_clock);
    ref_clock = this->get_iface()->get_clock_rate(dboard_iface::UNIT_RX);
    _max2118_write_regs.m_divider = m;
    _max2118_write_regs.r_divider = (max2118_write_regs_t::r_divider_t) r;
    _max2118_write_regs.set_n_divider(N);
    _max2118_write_regs.ade_vco_ade_read = max2118_write_regs_t::ADE_VCO_ADE_READ_ENABLED;
    
    //compute prescaler variables
    int scaler = actual_freq > 1125e6 ? 2 : 4;
    _max2118_write_regs.div2 = scaler == 4 ? max2118_write_regs_t::DIV2_DIV4 : max2118_write_regs_t::DIV2_DIV2;

    if(dbsrx_debug) std::cerr << boost::format(
        "DBSRX: scaler %d, actual_freq %f MHz, register bit: %d"
    ) % scaler % (actual_freq/1e6) % int(_max2118_write_regs.div2) << std::endl;

    //compute vco frequency and select vco
    double vco_freq = actual_freq * scaler;
    if (vco_freq < 2433e6)
        _max2118_write_regs.osc_band = 0;
    else if (vco_freq < 2711e6)
        _max2118_write_regs.osc_band = 1;
    else if (vco_freq < 3025e6)
        _max2118_write_regs.osc_band = 2;
    else if (vco_freq < 3341e6)
        _max2118_write_regs.osc_band = 3;
    else if (vco_freq < 3727e6)
        _max2118_write_regs.osc_band = 4;
    else if (vco_freq < 4143e6)
        _max2118_write_regs.osc_band = 5;
    else if (vco_freq < 4493e6)
        _max2118_write_regs.osc_band = 6;
    else
        _max2118_write_regs.osc_band = 7;

    //send settings over i2c
    send_reg(0x0, 0x4);

    //check vtune for lock condition
    read_reg(0x0, 0x0);

    if(dbsrx_debug) std::cerr << boost::format(
        "DBSRX: initial guess for vco %d, vtune adc %d"
    ) % int(_max2118_write_regs.osc_band) % int(_max2118_read_regs.adc) << std::endl;

    //if we are out of lock for chosen vco, change vco
    while ((_max2118_read_regs.adc == 0) or (_max2118_read_regs.adc == 7)){

        //vtune is too low, try lower frequency vco
        if (_max2118_read_regs.adc == 0){
            if (_max2118_write_regs.osc_band == 0){
                uhd::warning::post(
                    str(boost::format(
                        "DBSRX: Tuning exceeded vco range, _max2118_write_regs.osc_band == %d\n" 
                        ) % int(_max2118_write_regs.osc_band))
                );
                UHD_ASSERT_THROW(_max2118_read_regs.adc != 0); //just to cause a throw
            }
            if (_max2118_write_regs.osc_band <= 0) break;
            _max2118_write_regs.osc_band -= 1;
        }

        //vtune is too high, try higher frequency vco
        if (_max2118_read_regs.adc == 7){
            if (_max2118_write_regs.osc_band == 7){
                uhd::warning::post(
                    str(boost::format(
                        "DBSRX: Tuning exceeded vco range, _max2118_write_regs.osc_band == %d\n" 
                        ) % int(_max2118_write_regs.osc_band))
                );
                UHD_ASSERT_THROW(_max2118_read_regs.adc != 7); //just to cause a throw
            }
            if (_max2118_write_regs.osc_band >= 7) break;
            _max2118_write_regs.osc_band += 1;
        }

        if(dbsrx_debug) std::cerr << boost::format(
            "DBSRX: trying vco %d, vtune adc %d"
        ) % int(_max2118_write_regs.osc_band) % int(_max2118_read_regs.adc) << std::endl;

        //update vco selection and check vtune
        send_reg(0x2, 0x2);
        read_reg(0x0, 0x0);

        //allow for setup time before checking condition again
        boost::this_thread::sleep(boost::posix_time::milliseconds(10));
    }
      
    if(dbsrx_debug) std::cerr << boost::format(
        "DBSRX: final vco %d, vtune adc %d"
    ) % int(_max2118_write_regs.osc_band) % int(_max2118_read_regs.adc) << std::endl;

    //select charge pump bias current
    if (_max2118_read_regs.adc <= 2) _max2118_write_regs.cp_current = max2118_write_regs_t::CP_CURRENT_I_CP_100UA;
    else if (_max2118_read_regs.adc >= 5) _max2118_write_regs.cp_current = max2118_write_regs_t::CP_CURRENT_I_CP_400UA;
    else _max2118_write_regs.cp_current = max2118_write_regs_t::CP_CURRENT_I_CP_200UA;
    
    //update charge pump bias current setting
    send_reg(0x2, 0x2);

    //compute actual tuned frequency
    _lo_freq = this->get_iface()->get_clock_rate(dboard_iface::UNIT_RX) / std::pow(2.0,(1 + _max2118_write_regs.r_divider)) * _max2118_write_regs.get_n_divider();

    //debug output of calculated variables
    if (dbsrx_debug) std::cerr
        << boost::format("DBSRX tune:\n")
        << boost::format("    VCO=%d, CP=%d, PFD Freq=%fMHz\n") % int(_max2118_write_regs.osc_band) % _max2118_write_regs.cp_current % (pfd_freq/1e6)
        << boost::format("    R=%d, N=%f, scaler=%d, div2=%d\n") % R % N % scaler % int(_max2118_write_regs.div2)
        << boost::format("    Ref    Freq=%fMHz\n") % (ref_clock/1e6)
        << boost::format("    Target Freq=%fMHz\n") % (target_freq/1e6)
        << boost::format("    Actual Freq=%fMHz\n") % (_lo_freq/1e6)
        << boost::format("    VCO    Freq=%fMHz\n") % (vco_freq/1e6)
        << std::endl;

    if (update_filter_settings) set_bandwidth(_bandwidth);
    get_locked();
}

/***********************************************************************
 * Gain Handling
 **********************************************************************/
/*!
 * Convert a requested gain for the GC2 vga into the integer register value.
 * The gain passed into the function will be set to the actual value.
 * \param gain the requested gain in dB
 * \return 5 bit the register value
 */
static int gain_to_gc2_vga_reg(double &gain){
    int reg = 0;
    gain = dbsrx_gain_ranges["GC2"].clip(gain);

    // Half dB steps from 0-5dB, 1dB steps from 5-24dB
    if (gain < 5) {
        reg = boost::math::iround(31.0 - gain/0.5);
        gain = double(boost::math::iround(gain) * 0.5);
    } else {
        reg = boost::math::iround(22.0 - (gain - 4.0));
        gain = double(boost::math::iround(gain));
    }

    if (dbsrx_debug) std::cerr << boost::format(
        "DBSRX GC2 Gain: %f dB, reg: %d"
    ) % gain % reg << std::endl;

    return reg;
}

/*!
 * Convert a requested gain for the GC1 rf vga into the dac_volts value.
 * The gain passed into the function will be set to the actual value.
 * \param gain the requested gain in dB
 * \return dac voltage value
 */
static double gain_to_gc1_rfvga_dac(double &gain){
    //clip the input
    gain = dbsrx_gain_ranges["GC1"].clip(gain);

    //voltage level constants
    static const double max_volts = 1.2, min_volts = 2.7;
    static const double slope = (max_volts-min_volts)/dbsrx_gain_ranges["GC1"].stop();

    //calculate the voltage for the aux dac
    double dac_volts = gain*slope + min_volts;

    if (dbsrx_debug) std::cerr << boost::format(
        "DBSRX GC1 Gain: %f dB, dac_volts: %f V"
    ) % gain % dac_volts << std::endl;

    //the actual gain setting
    gain = (dac_volts - min_volts)/slope;

    return dac_volts;
}

void dbsrx::set_gain(double gain, const std::string &name){
    assert_has(dbsrx_gain_ranges.keys(), name, "dbsrx gain name");
    if (name == "GC2"){
        _max2118_write_regs.gc2 = gain_to_gc2_vga_reg(gain);
        send_reg(0x5, 0x5);
    }
    else if(name == "GC1"){
        //write the new voltage to the aux dac
        this->get_iface()->write_aux_dac(dboard_iface::UNIT_RX, dboard_iface::AUX_DAC_A, gain_to_gc1_rfvga_dac(gain));
    }
    else UHD_THROW_INVALID_CODE_PATH();
    _gains[name] = gain;
}

/***********************************************************************
 * Bandwidth Handling
 **********************************************************************/
void dbsrx::set_bandwidth(double bandwidth){
    //clip the input
    bandwidth = uhd::clip<double>(bandwidth, 4e6, 33e6);

    double ref_clock = this->get_iface()->get_clock_rate(dboard_iface::UNIT_RX);
    
    //NOTE: _max2118_write_regs.m_divider set in set_lo_freq

    //compute f_dac setting
    _max2118_write_regs.f_dac = uhd::clip<int>(int((((bandwidth*_max2118_write_regs.m_divider)/ref_clock) - 4)/0.145),0,127);

    //determine actual bandwidth
    _bandwidth = double((ref_clock/(_max2118_write_regs.m_divider))*(4+0.145*_max2118_write_regs.f_dac));

    if (dbsrx_debug) std::cerr << boost::format(
        "DBSRX Filter Bandwidth: %f MHz, m: %d, f_dac: %d\n"
    ) % (_bandwidth/1e6) % int(_max2118_write_regs.m_divider) % int(_max2118_write_regs.f_dac) << std::endl;

    this->send_reg(0x3, 0x4);
}

/***********************************************************************
 * RX Get and Set
 **********************************************************************/
void dbsrx::rx_get(const wax::obj &key_, wax::obj &val){
    named_prop_t key = named_prop_t::extract(key_);

    //handle the get request conditioned on the key
    switch(key.as<subdev_prop_t>()){
    case SUBDEV_PROP_NAME:
        val = get_rx_id().to_pp_string();
        return;

    case SUBDEV_PROP_OTHERS:
        val = prop_names_t(); //empty
        return;

    case SUBDEV_PROP_GAIN:
        assert_has(_gains.keys(), key.name, "dbsrx gain name");
        val = _gains[key.name];
        return;

    case SUBDEV_PROP_GAIN_RANGE:
        assert_has(dbsrx_gain_ranges.keys(), key.name, "dbsrx gain name");
        val = dbsrx_gain_ranges[key.name];
        return;

    case SUBDEV_PROP_GAIN_NAMES:
        val = prop_names_t(dbsrx_gain_ranges.keys());
        return;

    case SUBDEV_PROP_FREQ:
        val = _lo_freq;
        return;

    case SUBDEV_PROP_FREQ_RANGE:
        val = dbsrx_freq_range;
        return;

    case SUBDEV_PROP_ANTENNA:
        val = std::string("J3");
        return;

    case SUBDEV_PROP_ANTENNA_NAMES:
        val = dbsrx_antennas;
        return;

    case SUBDEV_PROP_CONNECTION:
        val = SUBDEV_CONN_COMPLEX_IQ;
        return;

    case SUBDEV_PROP_ENABLED:
        val = true; //always enabled
        return;

    case SUBDEV_PROP_USE_LO_OFFSET:
        val = false;
        return;

    case SUBDEV_PROP_SENSOR:
        UHD_ASSERT_THROW(key.name == "lo_locked");
        val = sensor_value_t("LO", this->get_locked(), "locked", "unlocked");
        return;

    case SUBDEV_PROP_SENSOR_NAMES:
        val = prop_names_t(1, "lo_locked");
        return;

    case SUBDEV_PROP_BANDWIDTH:
        val = 2*_bandwidth; //_bandwidth is low-pass, we want complex double-sided
        return;

    default: UHD_THROW_PROP_GET_ERROR();
    }
}

void dbsrx::rx_set(const wax::obj &key_, const wax::obj &val){
    named_prop_t key = named_prop_t::extract(key_);

    //handle the get request conditioned on the key
    switch(key.as<subdev_prop_t>()){

    case SUBDEV_PROP_FREQ:
        this->set_lo_freq(val.as<double>());
        return;

    case SUBDEV_PROP_GAIN:
        this->set_gain(val.as<double>(), key.name);
        return;

    case SUBDEV_PROP_ENABLED:
        return; //always enabled

    case SUBDEV_PROP_BANDWIDTH:
        this->set_bandwidth(val.as<double>()/2.0); //complex double-sided, we want low-pass
        return;

    default: UHD_THROW_PROP_SET_ERROR();
    }
}