TVRX: works for USRP and USRP2.

3 files changed, 18 insertions, 2 deletions

diff --git a/host/lib/usrp/dboard/db_tvrx.cpp b/host/lib/usrp/dboard/db_tvrx.cpp
index 71aff1680..6b71a3c6e 100644
--- a/host/lib/usrp/dboard/db_tvrx.cpp
+++ b/host/lib/usrp/dboard/db_tvrx.cpp
@@ -377,6 +377,7 @@ void tvrx::set_freq(double freq) {
  **********************************************************************/
 void tvrx::rx_get(const wax::obj &key_, wax::obj &val){
     named_prop_t key = named_prop_t::extract(key_);
+    int codec_rate;
 
     //handle the get request conditioned on the key
     switch(key.as<subdev_prop_t>()){
@@ -403,7 +404,15 @@ void tvrx::rx_get(const wax::obj &key_, wax::obj &val){
         return;
 
     case SUBDEV_PROP_FREQ:
-        val = _lo_freq;
+    /* 
+     * so here we have to do some magic. because the TVRX uses a relatively high IF,
+     * we have to watch the sample rate to see if the IF will be aliased
+     * or if it will fall within Nyquist.
+     */
+        codec_rate = this->get_iface()->get_codec_rate(dboard_iface::UNIT_RX);
+        if(codec_rate/2 > tvrx_if_freq) val = _lo_freq;
+        //ok take a deep breath i am positive there is an easier way to get this number
+        else val = _lo_freq - tvrx_if_freq - (tvrx_if_freq-codec_rate)*int(tvrx_if_freq / (codec_rate/2));
         return;
 
     case SUBDEV_PROP_FREQ_RANGE:
diff --git a/host/lib/usrp/usrp1/codec_ctrl.cpp b/host/lib/usrp/usrp1/codec_ctrl.cpp
index 33b18b196..4aa730573 100644
--- a/host/lib/usrp/usrp1/codec_ctrl.cpp
+++ b/host/lib/usrp/usrp1/codec_ctrl.cpp
@@ -423,7 +423,8 @@ void usrp1_codec_ctrl_impl::set_duc_freq(double freq)
 
 /***********************************************************************
  * Codec Control ADC buffer bypass
- * Enable this for DC-coupled daughterboards (TVRX)
+ * Disable this for AC-coupled daughterboards (TVRX)
+ * By default it is initialized TRUE.
  **********************************************************************/
 void usrp1_codec_ctrl_impl::bypass_adc_buffers(bool bypass) {
     _ad9862_regs.byp_buffer_a = bypass;
diff --git a/host/lib/usrp/usrp1/dboard_iface.cpp b/host/lib/usrp/usrp1/dboard_iface.cpp
index 4f0549a37..1ac15a46a 100644
--- a/host/lib/usrp/usrp1/dboard_iface.cpp
+++ b/host/lib/usrp/usrp1/dboard_iface.cpp
@@ -32,6 +32,8 @@ using namespace uhd;
 using namespace uhd::usrp;
 using namespace boost::assign;
 
+static const dboard_id_t tvrx_id(0x0040);
+
 class usrp1_dboard_iface : public dboard_iface {
 public:
 
@@ -51,6 +53,10 @@ public:
         //init the clock rate shadows
         this->set_clock_rate(UNIT_RX, this->get_clock_rates(UNIT_RX).front());
         this->set_clock_rate(UNIT_TX, this->get_clock_rates(UNIT_TX).front());
+        
+        //yes this is evil but it's necessary for TVRX to work on USRP1
+        if(_rx_dboard_id == tvrx_id) _codec->bypass_adc_buffers(false);
+        //else _codec->bypass_adc_buffers(false); //don't think this is necessary
     }
 
     ~usrp1_dboard_iface()