usrp-n: configure clocking over the serdes cable

added status to register to readback master/slave mode

removed mimo enum from clock config, its not relevant

added serdes clock config to the update clock config method

5 files changed, 16 insertions, 7 deletions

diff --git a/host/lib/usrp/usrp2/clock_ctrl.cpp b/host/lib/usrp/usrp2/clock_ctrl.cpp
index 428d5539b..7dde88027 100644
--- a/host/lib/usrp/usrp2/clock_ctrl.cpp
+++ b/host/lib/usrp/usrp2/clock_ctrl.cpp
@@ -66,13 +66,11 @@ public:
         this->enable_external_ref(false);
         this->enable_rx_dboard_clock(false);
         this->enable_tx_dboard_clock(false);
+        this->enable_mimo_clock_out(false);
 
         /* private clock enables, must be set here */
         this->enable_dac_clock(true);
         this->enable_adc_clock(true);
-
-        /* always driving the mimo reference */
-        this->enable_mimo_clock_out(true);
     }
 
     ~usrp2_clock_ctrl_impl(void){
diff --git a/host/lib/usrp/usrp2/clock_ctrl.hpp b/host/lib/usrp/usrp2/clock_ctrl.hpp
index db6c52c83..10523fa6b 100644
--- a/host/lib/usrp/usrp2/clock_ctrl.hpp
+++ b/host/lib/usrp/usrp2/clock_ctrl.hpp
@@ -91,8 +91,10 @@ public:
     virtual void enable_test_clock(bool enb) = 0;
 
     /*!
-     * TODO other clock control api here....
+     * Enable/disable the ref clock output over the serdes cable.
+     * \param enb true to enable
      */
+    virtual void enable_mimo_clock_out(bool enb) = 0;
 
 };
 
diff --git a/host/lib/usrp/usrp2/mboard_impl.cpp b/host/lib/usrp/usrp2/mboard_impl.cpp
index deb43bb13..20404635a 100644
--- a/host/lib/usrp/usrp2/mboard_impl.cpp
+++ b/host/lib/usrp/usrp2/mboard_impl.cpp
@@ -154,7 +154,6 @@ void usrp2_mboard_impl::update_clock_config(void){
     //translate pps source enums
     switch(_clock_config.pps_source){
     case clock_config_t::PPS_SMA:  pps_flags |= U2_FLAG_TIME64_PPS_SMA;  break;
-    case clock_config_t::PPS_MIMO: pps_flags |= U2_FLAG_TIME64_PPS_MIMO; break;
     default: throw std::runtime_error("unhandled clock configuration pps source");
     }
 
@@ -175,7 +174,6 @@ void usrp2_mboard_impl::update_clock_config(void){
         switch(_clock_config.ref_source){
         case clock_config_t::REF_INT : _iface->poke32(_iface->regs.misc_ctrl_clock, 0x12); break;
         case clock_config_t::REF_SMA : _iface->poke32(_iface->regs.misc_ctrl_clock, 0x1C); break;
-        case clock_config_t::REF_MIMO: _iface->poke32(_iface->regs.misc_ctrl_clock, 0x15); break;
         default: throw std::runtime_error("unhandled clock configuration reference source");
         }
         _clock_ctrl->enable_external_ref(true); //USRP2P has an internal 10MHz TCXO
@@ -186,7 +184,6 @@ void usrp2_mboard_impl::update_clock_config(void){
         switch(_clock_config.ref_source){
         case clock_config_t::REF_INT : _iface->poke32(_iface->regs.misc_ctrl_clock, 0x10); break;
         case clock_config_t::REF_SMA : _iface->poke32(_iface->regs.misc_ctrl_clock, 0x1C); break;
-        case clock_config_t::REF_MIMO: _iface->poke32(_iface->regs.misc_ctrl_clock, 0x15); break;
         default: throw std::runtime_error("unhandled clock configuration reference source");
         }
         _clock_ctrl->enable_external_ref(_clock_config.ref_source != clock_config_t::REF_INT);
@@ -194,6 +191,16 @@ void usrp2_mboard_impl::update_clock_config(void){
 
     case usrp2_iface::USRP_NXXX: break;
     }
+
+    //Handle the serdes clocking based on master/slave mode:
+    //   - Masters always drive the clock over serdes.
+    //   - Slaves always lock to this serdes clock.
+    //   - Slaves lock their time over the serdes.
+    const bool master_mode = bool(_iface->peek32(_iface->regs.status) & (1 << 8));
+    _clock_ctrl->enable_mimo_clock_out(master_mode);
+    if (not master_mode) _iface->poke32(_iface->regs.misc_ctrl_clock, 0x15);
+    //TODO slaves lock time over the serdes...
+
 }
 
 void usrp2_mboard_impl::set_time_spec(const time_spec_t &time_spec, bool now){
diff --git a/host/lib/usrp/usrp2/usrp2_regs.cpp b/host/lib/usrp/usrp2/usrp2_regs.cpp
index dd0433816..0590082f6 100644
--- a/host/lib/usrp/usrp2/usrp2_regs.cpp
+++ b/host/lib/usrp/usrp2/usrp2_regs.cpp
@@ -57,6 +57,7 @@ usrp2_regs_t usrp2_get_regs(bool use_n2xx_map) {
   x.time64_flags = sr_addr(misc_output_base, x.sr_time64 + 2);
   x.time64_imm = sr_addr(misc_output_base, x.sr_time64 + 3);
   x.time64_tps = sr_addr(misc_output_base, x.sr_time64 + 4);
+  x.status = bp_base + 4*8;
   x.time64_secs_rb = bp_base + 4*10;
   x.time64_ticks_rb = bp_base + 4*11;
   x.compat_num_rb = bp_base + 4*12;
diff --git a/host/lib/usrp/usrp2/usrp2_regs.hpp b/host/lib/usrp/usrp2/usrp2_regs.hpp
index 9936d634a..40c3635fb 100644
--- a/host/lib/usrp/usrp2/usrp2_regs.hpp
+++ b/host/lib/usrp/usrp2/usrp2_regs.hpp
@@ -57,6 +57,7 @@ typedef struct {
     int time64_flags; // flags -- see chart below
     int time64_imm; // set immediate (0=latch on next pps, 1=latch immediate, default=0)
     int time64_tps; // ticks per second rollover count
+    int status;
     int time64_secs_rb;
     int time64_ticks_rb;
     int compat_num_rb;