Merge pull request #86 from elbeno/uint8_t-register

🐛 Fix writing to registers whose size is less than `sizeof(int)`

Author: lukevalenty

include/groov/config.hpp

@@ -117,7 +117,8 @@ struct field : named_container<Name, SubFields...> {
 
     template <std::unsigned_integral RegType>
     constexpr static auto insert(RegType &dest, type_t value) -> void {
-        dest = (dest & ~mask<RegType>) | (static_cast<RegType>(value) << Lsb);
+        dest = static_cast<RegType>((dest & ~mask<RegType>) |
+                                    (static_cast<RegType>(value) << Lsb));
     }
 
     template <pathlike P> constexpr static auto resolve(P p) {

include/groov/write.hpp

@@ -10,8 +10,6 @@
 
 #include <boost/mp11/algorithm.hpp>
 
-template <typename...> struct undef;
-
 namespace groov {
 namespace detail {
 template <typename Register, typename Spec, typename Mask, typename IdMask,

test/read.cpp

@@ -203,3 +203,31 @@ TEST_CASE("read a register with integral constant address", "[read]") {
     auto r = sync_read(g / "reg"_r);
     CHECK(r["reg"_r] == data<42>);
 }
+
+namespace {
+struct bus_u8 {
+    template <auto Mask> static auto read(auto addr) -> async::sender auto {
+        return async::just_result_of([=] { return *addr; });
+    }
+
+    struct dummy_sender {
+        using is_sender = void;
+    };
+    template <auto...> static auto write(auto...) -> async::sender auto {
+        return dummy_sender{};
+    }
+};
+
+std::uint8_t data_u8{};
+using R_u8 =
+    groov::reg<"reg", std::uint8_t, &data_u8, groov::w::replace, F0, F1, F2>;
+using G_u8 = groov::group<"group", bus_u8, R_u8>;
+constexpr auto grp_u8 = G_u8{};
+} // namespace
+
+TEST_CASE("read a std::uint8_t register", "[read]") {
+    using namespace groov::literals;
+    data_u8 = 0xa5u;
+    auto r = sync_read(grp_u8 / "reg"_r);
+    CHECK(r["reg"_r] == data_u8);
+}

test/write.cpp

@@ -146,7 +146,7 @@ struct ct_address_bus {
 };
 } // namespace
 
-TEST_CASE("write a register with integral constant address", "[read]") {
+TEST_CASE("write a register with integral constant address", "[write]") {
     using R =
         groov::reg<"reg", std::uint32_t, std::integral_constant<int, 42>{}>;
     constexpr auto g = groov::group<"group", ct_address_bus, R>{};
@@ -155,3 +155,32 @@ TEST_CASE("write a register with integral constant address", "[read]") {
     sync_write(g("reg"_r = 0xa5a5'a5a5u));
     CHECK(data<42> == 0xa5a5'a5a5u);
 }
+
+namespace {
+struct bus_u8 {
+    struct dummy_sender {
+        using is_sender = void;
+    };
+    template <auto> static auto read(auto) -> async::sender auto {
+        return dummy_sender{};
+    }
+
+    template <auto Mask, auto IdMask, auto IdValue>
+    static auto write(auto addr, auto value) -> async::sender auto {
+        return async::just_result_of([=] { *addr = (*addr & ~Mask) | value; });
+    }
+};
+
+std::uint8_t data_u8{};
+using R_u8 =
+    groov::reg<"reg", std::uint8_t, &data_u8, groov::w::replace, F0, F1, F2>;
+using G_u8 = groov::group<"group", bus_u8, R_u8>;
+constexpr auto grp_u8 = G_u8{};
+} // namespace
+
+TEST_CASE("write a std::uint8_t register", "[write]") {
+    using namespace groov::literals;
+    data_u8 = 0b1'1010'1u;
+    sync_write(grp_u8("reg.field1"_f = 1));
+    CHECK(data_u8 == 0b1'0001'1u);
+}