ASoC: wm8904: Add DMIC and DRC support

Merge series from Francesco Dolcini <francesco@dolcini.it>:

This patch series adds DMIC and DRC support to the WM8904 driver, a new
of_ helper is added to simplify the driver code.

DRC functionality is added in the same patch series to provide the
necessary dynamic range control to make DMIC support useful.

The WM8904 supports digital microphones on two of its inputs:
IN1L/DMICDAT1 and IN1R/DMICDAT2. These two inputs can either be
connected to an ADC or to the DMIC system. There is an ADC for each
line, and only one DMIC block. This DMIC block is either connected to
DMICDAT1 or to DMICDAT2. One DMIC data line supports two digital
microphones via time multiplexing.

The pin's functionality is decided during hardware design (IN1L vs
DMICDAT1 and IN1R vs DMICDAT2). This is reflected in the Device Tree.

If one line is analog and one is DMIC, we need to be able to switch
between ADC and DMIC at runtime. The DMIC source is known from the
Device Tree. If both are DMIC inputs, we need to be able to switch the
DMIC source. There is no need to switch between ADC and DMIC at runtime.

Therefore, kcontrols are dynamically added by the driver depending on
its Device Tree configuration.

This is a heavy rework of a previous patch series provided by Alifer
Moraes and Pierluigi Passaro,
https://lore.kernel.org/lkml/20220307141041.27538-1-alifer.m@variscite.com.

3 files changed, 45 insertions, 32 deletions

diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index aa8ea1a4dbe5..adae71544cbd 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -57,14 +57,26 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
         crates_indexes[display_name] = len(crates)
         crates.append(crate)
 
-    # First, the ones in `rust/` since they are a bit special.
-    append_crate(
-        "core",
-        sysroot_src / "core" / "src" / "lib.rs",
-        [],
-        cfg=crates_cfgs.get("core", []),
-        is_workspace_member=False,
-    )
+    def append_sysroot_crate(
+        display_name,
+        deps,
+        cfg=[],
+    ):
+        append_crate(
+            display_name,
+            sysroot_src / display_name / "src" / "lib.rs",
+            deps,
+            cfg,
+            is_workspace_member=False,
+        )
+
+    # NB: sysroot crates reexport items from one another so setting up our transitive dependencies
+    # here is important for ensuring that rust-analyzer can resolve symbols. The sources of truth
+    # for this dependency graph are `(sysroot_src / crate / "Cargo.toml" for crate in crates)`.
+    append_sysroot_crate("core", [], cfg=crates_cfgs.get("core", []))
+    append_sysroot_crate("alloc", ["core"])
+    append_sysroot_crate("std", ["alloc", "core"])
+    append_sysroot_crate("proc_macro", ["core", "std"])
 
     append_crate(
         "compiler_builtins",
@@ -75,7 +87,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
     append_crate(
         "macros",
         srctree / "rust" / "macros" / "lib.rs",
-        [],
+        ["std", "proc_macro"],
         is_proc_macro=True,
     )
 
@@ -85,27 +97,28 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
         ["core", "compiler_builtins"],
     )
 
-    append_crate(
-        "bindings",
-        srctree / "rust"/ "bindings" / "lib.rs",
-        ["core"],
-        cfg=cfg,
-    )
-    crates[-1]["env"]["OBJTREE"] = str(objtree.resolve(True))
+    def append_crate_with_generated(
+        display_name,
+        deps,
+    ):
+        append_crate(
+            display_name,
+            srctree / "rust"/ display_name / "lib.rs",
+            deps,
+            cfg=cfg,
+        )
+        crates[-1]["env"]["OBJTREE"] = str(objtree.resolve(True))
+        crates[-1]["source"] = {
+            "include_dirs": [
+                str(srctree / "rust" / display_name),
+                str(objtree / "rust")
+            ],
+            "exclude_dirs": [],
+        }
 
-    append_crate(
-        "kernel",
-        srctree / "rust" / "kernel" / "lib.rs",
-        ["core", "macros", "build_error", "bindings"],
-        cfg=cfg,
-    )
-    crates[-1]["source"] = {
-        "include_dirs": [
-            str(srctree / "rust" / "kernel"),
-            str(objtree / "rust")
-        ],
-        "exclude_dirs": [],
-    }
+    append_crate_with_generated("bindings", ["core"])
+    append_crate_with_generated("uapi", ["core"])
+    append_crate_with_generated("kernel", ["core", "macros", "build_error", "bindings", "uapi"])
 
     def is_root_crate(build_file, target):
         try:
diff --git a/scripts/package/install-extmod-build b/scripts/package/install-extmod-build
index 2966473b4660..b96538787f3d 100755
--- a/scripts/package/install-extmod-build
+++ b/scripts/package/install-extmod-build
@@ -63,7 +63,7 @@ if [ "${CC}" != "${HOSTCC}" ]; then
 	# Clear VPATH and srcroot because the source files reside in the output
 	# directory.
 	# shellcheck disable=SC2016 # $(MAKE) and $(build) will be expanded by Make
-	"${MAKE}" run-command KBUILD_RUN_COMMAND='+$(MAKE) HOSTCC='"${CC}"' VPATH= srcroot=. $(build)='"${destdir}"/scripts
+	"${MAKE}" run-command KBUILD_RUN_COMMAND='+$(MAKE) HOSTCC='"${CC}"' VPATH= srcroot=. $(build)='"$(realpath --relative-base=. "${destdir}")"/scripts
 
 	rm -f "${destdir}/scripts/Kbuild"
 fi
diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs
index 5ebd42ae4a3f..76aaa8329413 100644
--- a/scripts/rustdoc_test_gen.rs
+++ b/scripts/rustdoc_test_gen.rs
@@ -15,8 +15,8 @@
 //!   - Test code should be able to define functions and call them, without having to carry
 //!     the context.
 //!
-//!   - Later on, we may want to be able to test non-kernel code (e.g. `core`, `alloc` or
-//!     third-party crates) which likely use the standard library `assert*!` macros.
+//!   - Later on, we may want to be able to test non-kernel code (e.g. `core` or third-party
+//!     crates) which likely use the standard library `assert*!` macros.
 //!
 //! For this reason, instead of the passed context, `kunit_get_current_test()` is used instead
 //! (i.e. `current->kunit_test`).