summaryrefslogtreecommitdiffstats
path: root/host/lib/usrp/usrp1/usrp1_impl.cpp
blob: b2da16837c5135696a750310f6c74c366bf3b916 (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
//
// 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/>.
//

#include "usrp1_impl.hpp"
#include "usrp_spi_defs.h"
#include "usrp_commands.h"
#include "fpga_regs_standard.h"
#include "fpga_regs_common.h"
#include "usrp_i2c_addr.h"
#include <uhd/utils/log.hpp>
#include <uhd/utils/safe_call.hpp>
#include <uhd/transport/usb_control.hpp>
#include <uhd/utils/msg.hpp>
#include <uhd/exception.hpp>
#include <uhd/utils/static.hpp>
#include <uhd/utils/images.hpp>
#include <boost/format.hpp>
#include <boost/assign/list_of.hpp>
#include <boost/filesystem.hpp>
#include <boost/thread/thread.hpp>
#include <boost/lexical_cast.hpp>

using namespace uhd;
using namespace uhd::usrp;
using namespace uhd::transport;

const boost::uint16_t USRP1_VENDOR_ID  = 0xfffe;
const boost::uint16_t USRP1_PRODUCT_ID = 0x0002;
const boost::uint16_t FX2_VENDOR_ID    = 0x04b4;
const boost::uint16_t FX2_PRODUCT_ID   = 0x8613;

const std::vector<usrp1_impl::dboard_slot_t> usrp1_impl::_dboard_slots = boost::assign::list_of
    (usrp1_impl::DBOARD_SLOT_A)(usrp1_impl::DBOARD_SLOT_B)
;

/***********************************************************************
 * Discovery
 **********************************************************************/
static device_addrs_t usrp1_find(const device_addr_t &hint)
{
    device_addrs_t usrp1_addrs;

    //return an empty list of addresses when type is set to non-usrp1
    if (hint.has_key("type") and hint["type"] != "usrp1") return usrp1_addrs;

    //Return an empty list of addresses when an address is specified,
    //since an address is intended for a different, non-USB, device.
    if (hint.has_key("addr")) return usrp1_addrs;

    boost::uint16_t vid = hint.has_key("uninit") ? FX2_VENDOR_ID : USRP1_VENDOR_ID;
    boost::uint16_t pid = hint.has_key("uninit") ? FX2_PRODUCT_ID : USRP1_PRODUCT_ID;

    // Important note:
    // The get device list calls are nested inside the for loop.
    // This allows the usb guts to decontruct when not in use,
    // so that re-enumeration after fw load can occur successfully.
    // This requirement is a courtesy of libusb1.0 on windows.

    //find the usrps and load firmware
    BOOST_FOREACH(usb_device_handle::sptr handle, usb_device_handle::get_device_list(vid, pid)) {
        //extract the firmware path for the USRP1
        std::string usrp1_fw_image;
        try{
            usrp1_fw_image = find_image_path(hint.get("fw", "usrp1_fw.ihx"));
        }
        catch(...){
            UHD_MSG(warning) << boost::format(
                "Could not locate USRP1 firmware.\n"
                "Please install the images package.\n"
            );
            return usrp1_addrs;
        }
        UHD_LOG << "USRP1 firmware image: " << usrp1_fw_image << std::endl;

        usb_control::sptr control;
        try{control = usb_control::make(handle);}
        catch(const uhd::exception &){continue;} //ignore claimed

        fx2_ctrl::make(control)->usrp_load_firmware(usrp1_fw_image);
    }

    //get descriptors again with serial number, but using the initialized VID/PID now since we have firmware
    vid = USRP1_VENDOR_ID;
    pid = USRP1_PRODUCT_ID;

    BOOST_FOREACH(usb_device_handle::sptr handle, usb_device_handle::get_device_list(vid, pid)) {
        usb_control::sptr control;
        try{control = usb_control::make(handle);}
        catch(const uhd::exception &){continue;} //ignore claimed

        fx2_ctrl::sptr fx2_ctrl = fx2_ctrl::make(control);
        const mboard_eeprom_t mb_eeprom(*fx2_ctrl, mboard_eeprom_t::MAP_B000);
        device_addr_t new_addr;
        new_addr["type"] = "usrp1";
        new_addr["name"] = mb_eeprom["name"];
        new_addr["serial"] = handle->get_serial();
        //this is a found usrp1 when the hint serial and name match or blank
        if (
            (not hint.has_key("name")   or hint["name"]   == new_addr["name"]) and
            (not hint.has_key("serial") or hint["serial"] == new_addr["serial"])
        ){
            usrp1_addrs.push_back(new_addr);
        }
    }

    return usrp1_addrs;
}

/***********************************************************************
 * Make
 **********************************************************************/
static device::sptr usrp1_make(const device_addr_t &device_addr){
    return device::sptr(new usrp1_impl(device_addr));
}

UHD_STATIC_BLOCK(register_usrp1_device){
    device::register_device(&usrp1_find, &usrp1_make);
}

/***********************************************************************
 * Structors
 **********************************************************************/
usrp1_impl::usrp1_impl(const device_addr_t &device_addr){
    UHD_MSG(status) << "Opening a USRP1 device..." << std::endl;

    //extract the FPGA path for the USRP1
    std::string usrp1_fpga_image = find_image_path(
        device_addr.get("fpga", "usrp1_fpga.rbf")
    );
    UHD_LOG << "USRP1 FPGA image: " << usrp1_fpga_image << std::endl;

    //try to match the given device address with something on the USB bus
    std::vector<usb_device_handle::sptr> device_list =
        usb_device_handle::get_device_list(USRP1_VENDOR_ID, USRP1_PRODUCT_ID);

    //locate the matching handle in the device list
    usb_device_handle::sptr handle;
    BOOST_FOREACH(usb_device_handle::sptr dev_handle, device_list) {
        if (dev_handle->get_serial() == device_addr["serial"]){
            handle = dev_handle;
            break;
        }
    }
    UHD_ASSERT_THROW(handle.get() != NULL); //better be found

    ////////////////////////////////////////////////////////////////////
    // Create controller objects
    ////////////////////////////////////////////////////////////////////
    //usb_control::sptr usb_ctrl = usb_control::make(handle);
    _fx2_ctrl = fx2_ctrl::make(usb_control::make(handle));
    _fx2_ctrl->usrp_load_fpga(usrp1_fpga_image);
    _fx2_ctrl->usrp_init();
    _data_transport = usb_zero_copy::make(
        handle,        // identifier
        6,             // IN endpoint
        2,             // OUT endpoint
        device_addr    // param hints
    );
    _iface = usrp1_iface::make(_fx2_ctrl);
    _soft_time_ctrl = soft_time_ctrl::make(
        boost::bind(&usrp1_impl::rx_stream_on_off, this, _1)
    );
    _dbc["A"]; _dbc["B"]; //ensure that keys exist

    // Normal mode with no loopback or Rx counting
    _iface->poke32(FR_MODE, 0x00000000);
    _iface->poke32(FR_DEBUG_EN, 0x00000000);
    _iface->poke32(FR_RX_SAMPLE_RATE_DIV, 0x00000001); //divide by 2
    _iface->poke32(FR_TX_SAMPLE_RATE_DIV, 0x00000001); //divide by 2
    _iface->poke32(FR_DC_OFFSET_CL_EN, 0x0000000f);

    // Reset offset correction registers
    _iface->poke32(FR_ADC_OFFSET_0, 0x00000000);
    _iface->poke32(FR_ADC_OFFSET_1, 0x00000000);
    _iface->poke32(FR_ADC_OFFSET_2, 0x00000000);
    _iface->poke32(FR_ADC_OFFSET_3, 0x00000000);

    // Set default for RX format to 16-bit I&Q and no half-band filter bypass
    _iface->poke32(FR_RX_FORMAT, 0x00000300);

    // Set default for TX format to 16-bit I&Q
    _iface->poke32(FR_TX_FORMAT, 0x00000000);

    UHD_LOG
        << "USRP1 Capabilities" << std::endl
        << "    number of duc's: " << get_num_ddcs() << std::endl
        << "    number of ddc's: " << get_num_ducs() << std::endl
        << "    rx halfband:     " << has_rx_halfband() << std::endl
        << "    tx halfband:     " << has_tx_halfband() << std::endl
    ;

    ////////////////////////////////////////////////////////////////////
    // Initialize the properties tree
    ////////////////////////////////////////////////////////////////////
    _tree = property_tree::make();
    _tree->create<std::string>("/name").set("USRP1 Device");
    const fs_path mb_path = "/mboards/0";
    _tree->create<std::string>(mb_path / "name").set("USRP1 (Classic)");
    _tree->create<std::string>(mb_path / "load_eeprom")
        .subscribe(boost::bind(&fx2_ctrl::usrp_load_eeprom, _fx2_ctrl, _1));

    ////////////////////////////////////////////////////////////////////
    // setup the mboard eeprom
    ////////////////////////////////////////////////////////////////////
    const mboard_eeprom_t mb_eeprom(*_fx2_ctrl, mboard_eeprom_t::MAP_B000);
    _tree->create<mboard_eeprom_t>(mb_path / "eeprom")
        .set(mb_eeprom)
        .subscribe(boost::bind(&usrp1_impl::set_mb_eeprom, this, _1));

    ////////////////////////////////////////////////////////////////////
    // create clock control objects
    ////////////////////////////////////////////////////////////////////
    _master_clock_rate = 64e6;
    try{
        if (not mb_eeprom["mcr"].empty())
            _master_clock_rate = boost::lexical_cast<double>(mb_eeprom["mcr"]);
    }catch(const std::exception &e){
        UHD_MSG(error) << "Error parsing FPGA clock rate from EEPROM: " << e.what() << std::endl;
    }
    UHD_MSG(status) << boost::format("Using FPGA clock rate of %fMHz...") % (_master_clock_rate/1e6) << std::endl;
    _tree->create<double>(mb_path / "tick_rate").set(_master_clock_rate);

    ////////////////////////////////////////////////////////////////////
    // create codec control objects
    ////////////////////////////////////////////////////////////////////
    BOOST_FOREACH(const std::string &db, _dbc.keys()){
        _dbc[db].codec = usrp1_codec_ctrl::make(_iface, (db == "A")? SPI_ENABLE_CODEC_A : SPI_ENABLE_CODEC_B);
        const fs_path rx_codec_path = mb_path / "rx_codecs" / db;
        const fs_path tx_codec_path = mb_path / "tx_codecs" / db;
        _tree->create<std::string>(rx_codec_path / "name").set("ad9522");
        _tree->create<meta_range_t>(rx_codec_path / "gains/pga/range").set(usrp1_codec_ctrl::rx_pga_gain_range);
        _tree->create<double>(rx_codec_path / "gains/pga/value")
            .coerce(boost::bind(&usrp1_impl::update_rx_codec_gain, this, db, _1));
        _tree->create<std::string>(tx_codec_path / "name").set("ad9522");
        _tree->create<meta_range_t>(tx_codec_path / "gains/pga/range").set(usrp1_codec_ctrl::tx_pga_gain_range);
        _tree->create<double>(tx_codec_path / "gains/pga/value")
            .subscribe(boost::bind(&usrp1_codec_ctrl::set_tx_pga_gain, _dbc[db].codec, _1))
            .publish(boost::bind(&usrp1_codec_ctrl::get_tx_pga_gain, _dbc[db].codec));
    }

    ////////////////////////////////////////////////////////////////////
    // and do the misc mboard sensors
    ////////////////////////////////////////////////////////////////////
    //none for now...
    _tree->create<int>(mb_path / "sensors"); //phony property so this dir exists

    ////////////////////////////////////////////////////////////////////
    // create frontend control objects
    ////////////////////////////////////////////////////////////////////
    _tree->create<subdev_spec_t>(mb_path / "rx_subdev_spec")
        .subscribe(boost::bind(&usrp1_impl::update_rx_subdev_spec, this, _1));
    _tree->create<subdev_spec_t>(mb_path / "tx_subdev_spec")
        .subscribe(boost::bind(&usrp1_impl::update_tx_subdev_spec, this, _1));

    ////////////////////////////////////////////////////////////////////
    // create rx dsp control objects
    ////////////////////////////////////////////////////////////////////
    _tree->create<int>(mb_path / "rx_dsps"); //dummy in case we have none
    for (size_t dspno = 0; dspno < get_num_ddcs(); dspno++){
        fs_path rx_dsp_path = mb_path / str(boost::format("rx_dsps/%u") % dspno);
        _tree->create<double>(rx_dsp_path / "rate/value")
            .coerce(boost::bind(&usrp1_impl::update_rx_samp_rate, this, _1));
        _tree->create<double>(rx_dsp_path / "freq/value")
            .coerce(boost::bind(&usrp1_impl::update_rx_dsp_freq, this, dspno, _1));
        _tree->create<meta_range_t>(rx_dsp_path / "freq/range")
            .set(meta_range_t(-_master_clock_rate/2, +_master_clock_rate/2));
        _tree->create<stream_cmd_t>(rx_dsp_path / "stream_cmd");
        if (dspno == 0){
            //only subscribe the callback for dspno 0 since it will stream all dsps
            _tree->access<stream_cmd_t>(rx_dsp_path / "stream_cmd")
                .subscribe(boost::bind(&soft_time_ctrl::issue_stream_cmd, _soft_time_ctrl, _1));
        }
    }

    ////////////////////////////////////////////////////////////////////
    // create tx dsp control objects
    ////////////////////////////////////////////////////////////////////
    _tree->create<int>(mb_path / "tx_dsps"); //dummy in case we have none
    for (size_t dspno = 0; dspno < get_num_ducs(); dspno++){
        fs_path tx_dsp_path = mb_path / str(boost::format("tx_dsps/%u") % dspno);
        _tree->create<double>(tx_dsp_path / "rate/value")
            .coerce(boost::bind(&usrp1_impl::update_tx_samp_rate, this, _1));
        _tree->create<double>(tx_dsp_path / "freq/value")
            .coerce(boost::bind(&usrp1_impl::update_tx_dsp_freq, this, dspno, _1));
        _tree->create<meta_range_t>(tx_dsp_path / "freq/range") //magic scalar comes from codec control:
            .set(meta_range_t(-_master_clock_rate*0.6875, +_master_clock_rate*0.6875));
    }

    ////////////////////////////////////////////////////////////////////
    // create time control objects
    ////////////////////////////////////////////////////////////////////
    _tree->create<time_spec_t>(mb_path / "time/now")
        .publish(boost::bind(&soft_time_ctrl::get_time, _soft_time_ctrl))
        .subscribe(boost::bind(&soft_time_ctrl::set_time, _soft_time_ctrl, _1));

    _tree->create<std::vector<std::string> >(mb_path / "clock_source/options").set(std::vector<std::string>(1, "internal"));
    _tree->create<std::vector<std::string> >(mb_path / "time_source/options").set(std::vector<std::string>(1, "none"));
    _tree->create<std::string>(mb_path / "clock_source/value").set("internal");
    _tree->create<std::string>(mb_path / "time_source/value").set("none");

    ////////////////////////////////////////////////////////////////////
    // create dboard control objects
    ////////////////////////////////////////////////////////////////////
    BOOST_FOREACH(const std::string &db, _dbc.keys()){

        //read the dboard eeprom to extract the dboard ids
        dboard_eeprom_t rx_db_eeprom, tx_db_eeprom, gdb_eeprom;
        rx_db_eeprom.load(*_fx2_ctrl, (db == "A")? (I2C_ADDR_RX_A) : (I2C_ADDR_RX_B));
        tx_db_eeprom.load(*_fx2_ctrl, (db == "A")? (I2C_ADDR_TX_A) : (I2C_ADDR_TX_B));
        gdb_eeprom.load(*_fx2_ctrl, (db == "A")? (I2C_ADDR_TX_A ^ 5) : (I2C_ADDR_TX_B ^ 5));

        //create the properties and register subscribers
        _tree->create<dboard_eeprom_t>(mb_path / "dboards" / db/ "rx_eeprom")
            .set(rx_db_eeprom)
            .subscribe(boost::bind(&usrp1_impl::set_db_eeprom, this, db, "rx", _1));
        _tree->create<dboard_eeprom_t>(mb_path / "dboards" / db/ "tx_eeprom")
            .set(tx_db_eeprom)
            .subscribe(boost::bind(&usrp1_impl::set_db_eeprom, this, db, "tx", _1));
        _tree->create<dboard_eeprom_t>(mb_path / "dboards" / db/ "gdb_eeprom")
            .set(gdb_eeprom)
            .subscribe(boost::bind(&usrp1_impl::set_db_eeprom, this, db, "gdb", _1));

        //create a new dboard interface and manager
        _dbc[db].dboard_iface = make_dboard_iface(
            _iface, _dbc[db].codec,
            (db == "A")? DBOARD_SLOT_A : DBOARD_SLOT_B,
            _master_clock_rate, rx_db_eeprom.id
        );
        _tree->create<dboard_iface::sptr>(mb_path / "dboards" / db/ "iface").set(_dbc[db].dboard_iface);
        _dbc[db].dboard_manager = dboard_manager::make(
            rx_db_eeprom.id,
            ((gdb_eeprom.id == dboard_id_t::none())? tx_db_eeprom : gdb_eeprom).id,
            _dbc[db].dboard_iface
        );
        BOOST_FOREACH(const std::string &name, _dbc[db].dboard_manager->get_rx_subdev_names()){
            dboard_manager::populate_prop_tree_from_subdev(
                _tree->subtree(mb_path / "dboards" / db/ "rx_frontends" / name),
                _dbc[db].dboard_manager->get_rx_subdev(name)
            );
        }
        BOOST_FOREACH(const std::string &name, _dbc[db].dboard_manager->get_tx_subdev_names()){
            dboard_manager::populate_prop_tree_from_subdev(
                _tree->subtree(mb_path / "dboards" / db/ "tx_frontends" / name),
                _dbc[db].dboard_manager->get_tx_subdev(name)
            );
        }

        //init the subdev specs if we have a dboard (wont leave this loop empty)
        if (rx_db_eeprom.id != dboard_id_t::none() or _rx_subdev_spec.empty()){
            _rx_subdev_spec = subdev_spec_t(db + ":" + _dbc[db].dboard_manager->get_rx_subdev_names()[0]);
        }
        if (tx_db_eeprom.id != dboard_id_t::none() or _tx_subdev_spec.empty()){
            _tx_subdev_spec = subdev_spec_t(db + ":" + _dbc[db].dboard_manager->get_tx_subdev_names()[0]);
        }
    }

    //initialize io handling
    this->io_init();

    ////////////////////////////////////////////////////////////////////
    // do some post-init tasks
    ////////////////////////////////////////////////////////////////////
    //and now that the tick rate is set, init the host rates to something
    BOOST_FOREACH(const std::string &name, _tree->list(mb_path / "rx_dsps")){
        _tree->access<double>(mb_path / "rx_dsps" / name / "rate" / "value").set(1e6);
    }
    BOOST_FOREACH(const std::string &name, _tree->list(mb_path / "tx_dsps")){
        _tree->access<double>(mb_path / "tx_dsps" / name / "rate" / "value").set(1e6);
    }

    if (_tree->list(mb_path / "rx_dsps").size() > 0)
        _tree->access<subdev_spec_t>(mb_path / "rx_subdev_spec").set(_rx_subdev_spec);
    if (_tree->list(mb_path / "tx_dsps").size() > 0)
        _tree->access<subdev_spec_t>(mb_path / "tx_subdev_spec").set(_tx_subdev_spec);
 
}

usrp1_impl::~usrp1_impl(void){
    UHD_SAFE_CALL(
        this->enable_rx(false);
        this->enable_tx(false);
    )
    _tree.reset(); //resets counts on sptrs held in tree
    _soft_time_ctrl.reset(); //stops cmd task before proceeding
    _io_impl.reset(); //stops vandal before other stuff gets deconstructed
}

/*!
 * Capabilities Register
 *
 *    3                   2                   1                   0
 *  1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
 * +-----------------------------------------------+-+-----+-+-----+
 * |               Reserved                        |T|DUCs |R|DDCs |
 * +-----------------------------------------------+-+-----+-+-----+
 */
size_t usrp1_impl::get_num_ddcs(void){
    boost::uint32_t regval = _iface->peek32(FR_RB_CAPS);
    return (regval >> 0) & 0x0007;
}

size_t usrp1_impl::get_num_ducs(void){
    boost::uint32_t regval = _iface->peek32(FR_RB_CAPS);
    return (regval >> 4) & 0x0007;
}

bool usrp1_impl::has_rx_halfband(void){
    boost::uint32_t regval = _iface->peek32(FR_RB_CAPS);
    return (regval >> 3) & 0x0001;
}

bool usrp1_impl::has_tx_halfband(void){
    boost::uint32_t regval = _iface->peek32(FR_RB_CAPS);
    return (regval >> 7) & 0x0001;
}

/***********************************************************************
 * Properties callback methods below
 **********************************************************************/
void usrp1_impl::set_mb_eeprom(const uhd::usrp::mboard_eeprom_t &mb_eeprom){
    mb_eeprom.commit(*_fx2_ctrl, mboard_eeprom_t::MAP_B000);
}

void usrp1_impl::set_db_eeprom(const std::string &db, const std::string &type, const uhd::usrp::dboard_eeprom_t &db_eeprom){
    if (type == "rx") db_eeprom.store(*_fx2_ctrl, (db == "A")? (I2C_ADDR_RX_A) : (I2C_ADDR_RX_B));
    if (type == "tx") db_eeprom.store(*_fx2_ctrl, (db == "A")? (I2C_ADDR_TX_A) : (I2C_ADDR_TX_B));
    if (type == "gdb") db_eeprom.store(*_fx2_ctrl, (db == "A")? (I2C_ADDR_TX_A ^ 5) : (I2C_ADDR_TX_B ^ 5));
}

double usrp1_impl::update_rx_codec_gain(const std::string &db, const double gain){
    //set gain on both I and Q, readback on one
    //TODO in the future, gains should have individual control
    _dbc[db].codec->set_rx_pga_gain(gain, 'A');
    _dbc[db].codec->set_rx_pga_gain(gain, 'B');
    return _dbc[db].codec->get_rx_pga_gain('A');
}