From 03967ce2e5e4332edd1e023360707a1086f42242 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Tue, 7 Jul 2020 13:11:51 -0600 Subject: acpigen: Support writing a package 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 Reviewed-by: Wolfgang Wallner Reviewed-by: Bin Meng --- include/acpi/acpigen.h | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'include/acpi/acpigen.h') 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 -- cgit