acpi: Support generation of a generic register
Allow writing out a generic register.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
[bmeng: Fix build failures on Sandbox]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
index 1e0a489..45691b7 100644
--- a/lib/acpi/acpigen.c
+++ b/lib/acpi/acpigen.c
@@ -14,6 +14,7 @@
#include <uuid.h>
#include <acpi/acpigen.h>
#include <acpi/acpi_device.h>
+#include <acpi/acpi_table.h>
#include <dm/acpi.h>
u8 *acpigen_get_current(struct acpi_ctx *ctx)
@@ -299,6 +300,76 @@
acpigen_pop_len(ctx);
}
+static void acpigen_write_register(struct acpi_ctx *ctx,
+ const struct acpi_gen_regaddr *addr)
+{
+ /* See ACPI v6.3 section 6.4.3.7: Generic Register Descriptor */
+ acpigen_emit_byte(ctx, ACPI_DESCRIPTOR_REGISTER);
+ acpigen_emit_byte(ctx, 0x0c); /* Register Length 7:0 */
+ acpigen_emit_byte(ctx, 0x00); /* Register Length 15:8 */
+ acpigen_emit_byte(ctx, addr->space_id);
+ acpigen_emit_byte(ctx, addr->bit_width);
+ acpigen_emit_byte(ctx, addr->bit_offset);
+ acpigen_emit_byte(ctx, addr->access_size);
+ acpigen_emit_dword(ctx, addr->addrl);
+ acpigen_emit_dword(ctx, addr->addrh);
+}
+
+void acpigen_write_resourcetemplate_header(struct acpi_ctx *ctx)
+{
+ /*
+ * A ResourceTemplate() is a Buffer() with a
+ * (Byte|Word|DWord) containing the length, followed by one or more
+ * resource items, terminated by the end tag.
+ * (small item 0xf, len 1)
+ */
+ acpigen_emit_byte(ctx, BUFFER_OP);
+ acpigen_write_len_f(ctx);
+ acpigen_emit_byte(ctx, WORD_PREFIX);
+ ctx->len_stack[ctx->ltop++] = ctx->current;
+
+ /*
+ * Add two dummy bytes for the ACPI word (keep aligned with the
+ * calculation in acpigen_write_resourcetemplate_footer() below)
+ */
+ acpigen_emit_byte(ctx, 0x00);
+ acpigen_emit_byte(ctx, 0x00);
+}
+
+void acpigen_write_resourcetemplate_footer(struct acpi_ctx *ctx)
+{
+ char *p = ctx->len_stack[--ctx->ltop];
+ int len;
+ /*
+ * See ACPI v6.3 section 6.4.2.9: End Tag
+ * 0x79 <checksum>
+ * 0x00 is treated as a good checksum according to the spec
+ * and is what iasl generates.
+ */
+ acpigen_emit_byte(ctx, ACPI_END_TAG);
+ acpigen_emit_byte(ctx, 0x00);
+
+ /*
+ * Start counting past the 2-bytes length added in
+ * acpigen_write_resourcetemplate_header() above
+ */
+ len = (char *)ctx->current - (p + 2);
+
+ /* patch len word */
+ p[0] = len & 0xff;
+ p[1] = (len >> 8) & 0xff;
+
+ acpigen_pop_len(ctx);
+}
+
+void acpigen_write_register_resource(struct acpi_ctx *ctx,
+ const struct acpi_gen_regaddr *addr)
+{
+ acpigen_write_resourcetemplate_header(ctx);
+ acpigen_write_register(ctx, addr);
+ acpigen_write_resourcetemplate_footer(ctx);
+}
+
/*
* ToUUID(uuid)
*