host: SPI: Read number of supported SPI slaves from device

Add support for reading the number of supported SPI slaves from
the device. This has become necessary because we may have bitfiles
with different capabilities and we want to report this back correctly.

1 files changed, 26 insertions, 15 deletions

diff --git a/host/lib/usrp/x400/x400_radio_control.cpp b/host/lib/usrp/x400/x400_radio_control.cpp
index ef2d6bd21..59207d486 100644
--- a/host/lib/usrp/x400/x400_radio_control.cpp
+++ b/host/lib/usrp/x400/x400_radio_control.cpp
@@ -191,20 +191,32 @@ x400_radio_control_impl::x400_radio_control_impl(make_args_ptr make_args)
 
         auto gpio_port_mapper = std::shared_ptr<uhd::mapper::gpio_port_mapper>(
             new uhd::rfnoc::x400::x400_gpio_port_mapping);
-        auto spicore = uhd::cores::spi_core_4000::make(
-            [this](const uint32_t addr, const uint32_t data) {
-                regs().poke32(addr, data, get_command_time(0));
-            },
-            [this](
-                const uint32_t addr) { return regs().peek32(addr, get_command_time(0)); },
-            x400_regs::SPI_SLAVE_CFG,
-            x400_regs::SPI_TRANSACTION_CFG_REG,
-            x400_regs::SPI_TRANSACTION_GO_REG,
-            x400_regs::SPI_STATUS_REG,
-            gpio_port_mapper);
-
-        _spi_getter_iface = std::make_shared<x400_spi_getter>(spicore);
-        register_feature(_spi_getter_iface);
+
+        // Check if SPI is available as GPIO source, otherwise don't register
+        // SPI_GETTER_IFace
+        auto gpio_srcs = _mb_control->get_gpio_srcs("GPIO0");
+        if (std::count(gpio_srcs.begin(), gpio_srcs.end(), "DB0_SPI") > 0) {
+            auto spicore = uhd::cores::spi_core_4000::make(
+                [this](const uint32_t addr, const uint32_t data) {
+                    regs().poke32(addr, data, get_command_time(0));
+                },
+                [this](const uint32_t addr) {
+                    return regs().peek32(addr, get_command_time(0));
+                },
+                x400_regs::SPI_SLAVE_CFG,
+                x400_regs::SPI_TRANSACTION_CFG_REG,
+                x400_regs::SPI_TRANSACTION_GO_REG,
+                x400_regs::SPI_STATUS_REG,
+                x400_regs::SPI_CONTROLLER_INFO_REG,
+                gpio_port_mapper);
+
+            _spi_getter_iface = std::make_shared<x400_spi_getter>(spicore);
+            register_feature(_spi_getter_iface);
+        } else {
+            UHD_LOG_INFO("x400_radio_control",
+                "SPI functionality not available in this FPGA image. Please update to at "
+                "least version 7.7 to use SPI.");
+        }
     }
 }
 
@@ -816,5 +828,4 @@ std::string x400_radio_control_impl::get_dboard_fe_from_chan(
 
 UHD_RFNOC_BLOCK_REGISTER_FOR_DEVICE_DIRECT(
     x400_radio_control, RADIO_BLOCK, X400, "Radio", true, "radio_clk", "ctrl_clk")
-
 }} // namespace uhd::rfnoc