A package collects together several elements. Add an easy way of writing a package header and updating its length later.
Signed-off-by: Simon Glass sjg@chromium.org Reviewed-by: Wolfgang Wallner wolfgang.wallner@br-automation.com Reviewed-by: Bin Meng bmeng.cn@gmail.com ---
Changes in v4: - Use 'writing' instead of emitting in test comment
Changes in v3: - Fix 'easy of testing' typo - Move two function comments into the previous patch
include/acpi/acpigen.h | 32 ++++++++++++++++++++++++++++++++ lib/acpi/acpigen.c | 12 ++++++++++++ test/dm/acpigen.c | 27 +++++++++++++++++++++++++++ 3 files changed, 71 insertions(+)
diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h index 18409b613c..c1a6bc263c 100644 --- a/include/acpi/acpigen.h +++ b/include/acpi/acpigen.h @@ -17,6 +17,11 @@ struct acpi_ctx; /* Top 4 bits of the value used to indicate a three-byte length value */ #define ACPI_PKG_LEN_3_BYTES 0x80
+/* ACPI Op/Prefix codes */ +enum { + PACKAGE_OP = 0x12, +}; + /** * acpigen_get_current() - Get the current ACPI code output pointer * @@ -106,4 +111,31 @@ void acpigen_write_len_f(struct acpi_ctx *ctx); */ void acpigen_pop_len(struct acpi_ctx *ctx);
+/** + * acpigen_write_package() - Start writing a package + * + * A package collects together a number of elements in the ACPI code. To write + * a package use: + * + * acpigen_write_package(ctx, 3); + * ...write things + * acpigen_pop_len() + * + * If you don't know the number of elements in advance, acpigen_write_package() + * returns a pointer to the value so you can update it later: + * + * char *num_elements = acpigen_write_package(ctx, 0); + * ...write things + * *num_elements += 1; + * ...write things + * *num_elements += 1; + * acpigen_pop_len() + * + * @ctx: ACPI context pointer + * @nr_el: Number of elements (0 if not known) + * @returns pointer to the number of elements, which can be updated by the + * caller if needed + */ +char *acpigen_write_package(struct acpi_ctx *ctx, int nr_el); + #endif diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c index 11fc38419a..9043c2bc72 100644 --- a/lib/acpi/acpigen.c +++ b/lib/acpi/acpigen.c @@ -71,6 +71,18 @@ void acpigen_pop_len(struct acpi_ctx *ctx) p[2] = len >> 12 & 0xff; }
+char *acpigen_write_package(struct acpi_ctx *ctx, int nr_el) +{ + char *p; + + acpigen_emit_byte(ctx, PACKAGE_OP); + acpigen_write_len_f(ctx); + p = ctx->current; + acpigen_emit_byte(ctx, nr_el); + + return p; +} + void acpigen_emit_stream(struct acpi_ctx *ctx, const char *data, int size) { int i; diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c index c756847093..aaffc6a4cf 100644 --- a/test/dm/acpigen.c +++ b/test/dm/acpigen.c @@ -404,3 +404,30 @@ static int dm_test_acpi_len(struct unit_test_state *uts) return 0; } DM_TEST(dm_test_acpi_len, 0); + +/* Test writing a package */ +static int dm_test_acpi_package(struct unit_test_state *uts) +{ + struct acpi_ctx *ctx; + char *num_elements; + u8 *ptr; + + ut_assertok(alloc_context(&ctx)); + + ptr = acpigen_get_current(ctx); + + num_elements = acpigen_write_package(ctx, 3); + ut_asserteq_ptr(num_elements, ptr + 4); + + /* For ease of testing, just emit a byte, not valid package contents */ + acpigen_emit_byte(ctx, 0x23); + acpigen_pop_len(ctx); + ut_asserteq(PACKAGE_OP, ptr[0]); + ut_asserteq(5, get_length(ptr + 1)); + ut_asserteq(3, ptr[4]); + + free_context(&ctx); + + return 0; +} +DM_TEST(dm_test_acpi_package, 0);