acpi: Add support for writing a _PRW

A 'Power Resource for Wake' list the resources a device depends on for
wake. Add a function to generate this.

Signed-off-by: Simon Glass <sjg@chromium.org>

3 files changed, 50 insertions, 0 deletions

diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h
index 228ac9c..a9b7012 100644
--- a/include/acpi/acpigen.h
+++ b/include/acpi/acpigen.h
@@ -563,4 +563,14 @@ int acpigen_set_enable_tx_gpio(struct acpi_ctx *ctx, u32 tx_state_val,
 			       const char *dw0_read, const char *dw0_write,
 			       struct acpi_gpio *gpio, bool enable);
 
+/**
+ * acpigen_write_prw() - Write a power resource for wake (_PRW)
+ *
+ * @ctx: ACPI context pointer
+ * @wake: GPE that wakes up the device
+ * @level: Deepest power system sleeping state that can be entered while still
+ *	providing wake functionality
+ */
+void acpigen_write_prw(struct acpi_ctx *ctx, uint wake, uint level);
+
 #endif
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
index c609ef4..527de89 100644
--- a/lib/acpi/acpigen.c
+++ b/lib/acpi/acpigen.c
@@ -426,6 +426,16 @@ void acpigen_write_register_resource(struct acpi_ctx *ctx,
 	acpigen_write_resourcetemplate_footer(ctx);
 }
 
+void acpigen_write_prw(struct acpi_ctx *ctx, uint wake, uint level)
+{
+	/* Name (_PRW, Package () { wake, level } */
+	acpigen_write_name(ctx, "_PRW");
+	acpigen_write_package(ctx, 2);
+	acpigen_write_integer(ctx, wake);
+	acpigen_write_integer(ctx, level);
+	acpigen_pop_len(ctx);
+}
+
 /*
  * ToUUID(uuid)
  *
diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c
index 1b2767e..1dc064f 100644
--- a/test/dm/acpigen.c
+++ b/test/dm/acpigen.c
@@ -1097,3 +1097,33 @@ static int dm_test_acpi_write_name(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_acpi_write_name, 0);
+
+/* Test emitting a _PRW component */
+static int dm_test_acpi_write_prw(struct unit_test_state *uts)
+{
+	struct acpi_ctx *ctx;
+	u8 *ptr;
+
+	ut_assertok(alloc_context(&ctx));
+
+	ptr = acpigen_get_current(ctx);
+	acpigen_write_prw(ctx, 5, 3);
+	ut_asserteq(NAME_OP, *ptr++);
+
+	ut_asserteq_strn("_PRW", (char *)ptr);
+	ptr += 4;
+	ut_asserteq(PACKAGE_OP, *ptr++);
+	ut_asserteq(8, acpi_test_get_length(ptr));
+	ptr += 3;
+	ut_asserteq(2, *ptr++);
+	ut_asserteq(BYTE_PREFIX, *ptr++);
+	ut_asserteq(5, *ptr++);
+	ut_asserteq(BYTE_PREFIX, *ptr++);
+	ut_asserteq(3, *ptr++);
+	ut_asserteq_ptr(ptr, ctx->current);
+
+	free_context(&ctx);
+
+	return 0;
+}
+DM_TEST(dm_test_acpi_write_prw, 0);