Wire up the sbr service into the app (#155)

This is the culmination of several PRs, allowing us to bind this service
to this app.

See
#155 (comment)
for my log of notes along the way.

Here are the related PRs:
- #153 
- #152 
- #151 
- #150 
- #143 
- #142 
- #141 
- #140 
- #138 

And the created/related issues:
- #154 
- #149 
- #148
- #147 
- #145 
- #144 
- #139 
- #125

apps/sbr/BUILD

@@ -10,6 +10,7 @@ cc_binary(
     srcs = ["main.cc"],
     deps = [
         "//apps/sbr/system",
+        "//hw_services/sbr:service",
         "@pigweed//pw_log",
         "@pigweed//pw_system:async",
 

apps/sbr/main.cc

@@ -1,12 +1,22 @@
 #define PW_LOG_MODULE_NAME "MAIN"
 
 #include "apps/sbr/system/system.h"
+#include "hw_services/sbr/service.h"
 #include "pw_log/log.h"
 #include "pw_system/system.h"
 
 int main() {
   apps::sbr::system::Init();
 
+  auto& rpc_server = pw::System().rpc_server();
+
+  static hw_services::sbr::SbrService sbr_service;
+
+  auto& reg_device = apps::sbr::system::LIS3MDLRegisterDevice();
+  sbr_service.Init(pw::System().dispatcher(), pw::System().allocator(),
+                   &reg_device);
+  rpc_server.RegisterService(sbr_service);
+
   PW_LOG_INFO("Started SBR app; waiting for RPCs...");
   apps::sbr::system::Start();
   PW_UNREACHABLE;

apps/sbr/system/BUILD

@@ -19,6 +19,9 @@ cc_library(
         "system.h",
     ],
     visibility = ["//visibility:public"],
+    deps = [
+        "@pigweed//pw_i2c:register_device",
+    ],
 )
 
 cc_library(
@@ -27,7 +30,10 @@ cc_library(
         "host_system.cc",
     ],
     implementation_deps = [
+        "//platforms/host:initiator_host",
         "//third_party/pigweed/system:common_host_system",
+        "@pigweed//pw_i2c:address",
+        "@pigweed//pw_i2c:register_device",
         "@pigweed//pw_system:async",
     ],
     target_compatible_with = incompatible_with_mcu(),
@@ -39,8 +45,14 @@ cc_library(
     srcs = [
         "rp2_system.cc",
     ],
+    implementation_deps = [
+        "@pigweed//pw_i2c:address",
+        "@pigweed//pw_i2c:register_device",
+        "@pigweed//pw_i2c_rp2040",
+    ],
     deps = [
         "//apps/sbr/system:headers",
+        "//hw_drivers/lis3mdl",
         "//third_party/pigweed/system:common_rp2_system",
     ],
 )

apps/sbr/system/host_system.cc

@@ -1,4 +1,6 @@
 #include "apps/sbr/system/system.h"
+#include "platforms/host/initiator_host.h"
+#include "pw_i2c/address.h"
 #include "third_party/pigweed/system/common_host_system.h"
 
 namespace apps {
@@ -7,9 +9,17 @@ namespace system {
 
 void Init() {}
 
-void Start() {
-  // third_party::pigweed::system::
-  PW_HOST_SYSTEM_START(16384, "//apps/sbr:simulator_console")
+void Start(){// third_party::pigweed::system::
+             PW_HOST_SYSTEM_START(16384, "//apps/sbr:simulator_console")}
+
+pw::i2c::RegisterDevice& LIS3MDLRegisterDevice() {
+  constexpr pw::i2c::Address kAddress = pw::i2c::Address::SevenBit<0x01>();
+
+  static platforms::host::HostInitiator initiator;
+  static pw::i2c::RegisterDevice reg_device(
+      initiator, kAddress, cpp20::endian::little,
+      pw::i2c::RegisterAddressSize::k1Byte);
+  return reg_device;
 }
 
 }  // namespace system

apps/sbr/system/rp2_system.cc

@@ -1,4 +1,30 @@
 #include "apps/sbr/system/system.h"
+#include "hw_drivers/lis3mdl/lis3mdl.h"
+#include "pw_i2c_rp2040/initiator.h"
+
+namespace {
+
+pw::i2c::Initiator& I2cInitiator() {
+  constexpr unsigned int kPinSda = 4;
+  constexpr unsigned int kPinScl = 5;
+
+  static constexpr pw::i2c::Rp2040Initiator::Config kI2c0Config{
+      .clock_frequency = 400'000,
+      .sda_pin = kPinSda,
+      .scl_pin = kPinScl,
+  };
+
+  static pw::i2c::Initiator& i2c0_bus = []() -> pw::i2c::Initiator& {
+    static pw::i2c::Rp2040Initiator bus(kI2c0Config, i2c0);
+    bus.Enable();
+    return bus;
+  }();
+
+  return i2c0_bus;
+}
+
+}  // namespace
+
 #include "third_party/pigweed/system/common_rp2_system.h"
 
 namespace apps {
@@ -7,7 +33,14 @@ namespace system {
 
 void Init() { third_party::pigweed::system::CommonRp2Init(); }
 
-void Start() { PW_RP2_SYSTEM_START(2048) }
+void Start(){PW_RP2_SYSTEM_START(2048)}
+
+pw::i2c::RegisterDevice& LIS3MDLRegisterDevice() {
+  static pw::i2c::RegisterDevice reg_device(
+      I2cInitiator(), hw_drivers::lis3mdl::kHighAddress, cpp20::endian::little,
+      pw::i2c::RegisterAddressSize::k1Byte);
+  return reg_device;
+}
 
 }  // namespace system
 }  // namespace sbr

apps/sbr/system/system.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "pw_i2c/register_device.h"
 // The functions in this file return specific implementations of singleton types
 // provided by the system.
 
@@ -13,6 +14,8 @@ void Init();
 /// Starts the main system scheduler. This function never returns.
 [[noreturn]] void Start();
 
+pw::i2c::RegisterDevice& LIS3MDLRegisterDevice();
+
 }  // namespace system
 }  // namespace sbr
 }  // namespace apps

hw_drivers/lis3mdl/BUILD

@@ -28,6 +28,7 @@ cc_library(
     srcs = ["lis3mdl.cc"],
     hdrs = ["lis3mdl.h"],
     visibility = [
+        "//apps/sbr:__subpackages__",
         "//hw_services/sbr:__subpackages__",
     ],
     deps = [