[PATCH v2 10/44] acpi: Support generation of a generic register

From: Simon Glass <sjg@chromium.org>
To: u-boot@lists.denx.de
Subject: [PATCH v2 10/44] acpi: Support generation of a generic register
Date: Tue,  7 Jul 2020 21:32:11 -0600	[thread overview]
Message-ID: <20200708033246.2626378-8-sjg@chromium.org> (raw)
In-Reply-To: <20200708033246.2626378-1-sjg@chromium.org>

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>
---

(no changes since v1)

 include/acpi/acpi_device.h |  1 +
 include/acpi/acpigen.h     | 28 +++++++++++++++
 lib/acpi/acpigen.c         | 71 ++++++++++++++++++++++++++++++++++++++
 test/dm/acpigen.c          | 46 ++++++++++++++++++++++++
 4 files changed, 146 insertions(+)

diff --git a/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
index 0bb9a4eec1..15800b2e24 100644
--- a/include/acpi/acpi_device.h
+++ b/include/acpi/acpi_device.h
@@ -20,6 +20,7 @@ struct udevice;
 
 /* ACPI descriptor values for common descriptors: SERIAL_BUS means I2C */
 #define ACPI_DESCRIPTOR_LARGE		BIT(7)
+#define ACPI_DESCRIPTOR_REGISTER	(ACPI_DESCRIPTOR_LARGE | 2)
 #define ACPI_DESCRIPTOR_INTERRUPT	(ACPI_DESCRIPTOR_LARGE | 9)
 #define ACPI_DESCRIPTOR_GPIO		(ACPI_DESCRIPTOR_LARGE | 12)
 #define ACPI_DESCRIPTOR_SERIAL_BUS	(ACPI_DESCRIPTOR_LARGE | 14)
diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h
index 4a606125de..1f37c9c31c 100644
--- a/include/acpi/acpigen.h
+++ b/include/acpi/acpigen.h
@@ -13,6 +13,7 @@
 #include <linux/types.h>
 
 struct acpi_ctx;
+struct acpi_gen_regaddr;
 struct acpi_gpio;
 
 /* Top 4 bits of the value used to indicate a three-byte length value */
@@ -21,6 +22,8 @@ struct acpi_gpio;
 #define ACPI_METHOD_NARGS_MASK		0x7
 #define ACPI_METHOD_SERIALIZED_MASK	BIT(3)
 
+#define ACPI_END_TAG			0x79
+
 /* ACPI Op/Prefix codes */
 enum {
 	ZERO_OP			= 0x00,
@@ -318,6 +321,31 @@ void acpigen_write_method_serialized(struct acpi_ctx *ctx, const char *name,
  */
 void acpigen_write_sta(struct acpi_ctx *ctx, uint status);
 
+/**
+ * acpigen_write_resourcetemplate_header() - Write a ResourceTemplate header
+ *
+ * @ctx: ACPI context pointer
+ */
+void acpigen_write_resourcetemplate_header(struct acpi_ctx *ctx);
+
+/**
+ * acpigen_write_resourcetemplate_footer() - Write a ResourceTemplate footer
+ *
+ * @ctx: ACPI context pointer
+ */
+void acpigen_write_resourcetemplate_footer(struct acpi_ctx *ctx);
+
+/**
+ * acpigen_write_register_resource() - Write a register resource
+ *
+ * This writes a header, the address information and a footer
+ *
+ * @ctx: ACPI context pointer
+ * @addr: Address to write
+ */
+void acpigen_write_register_resource(struct acpi_ctx *ctx,
+				     const struct acpi_gen_regaddr *addr);
+
 /**
  * acpigen_write_sleep() - Write a sleep operation
  *
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
index 1e0a489d7b..45691b7961 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 @@ void acpigen_write_sta(struct acpi_ctx *ctx, uint status)
 	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)
  *
diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c
index 1031185b96..d1bdd18ce5 100644
--- a/test/dm/acpigen.c
+++ b/test/dm/acpigen.c
@@ -12,6 +12,7 @@
 #include <malloc.h>
 #include <acpi/acpigen.h>
 #include <acpi/acpi_device.h>
+#include <acpi/acpi_table.h>
 #include <asm/gpio.h>
 #include <asm/unaligned.h>
 #include <dm/acpi.h>
@@ -947,3 +948,48 @@ static int dm_test_acpi_scope(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_acpi_scope, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/* Test writing a resource template */
+static int dm_test_acpi_resource_template(struct unit_test_state *uts)
+{
+	struct acpi_gen_regaddr addr;
+	struct acpi_ctx *ctx;
+	u8 *ptr;
+
+	ut_assertok(alloc_context(&ctx));
+	ptr = acpigen_get_current(ctx);
+
+	addr.space_id = ACPI_ADDRESS_SPACE_EC;
+	addr.bit_width = 32;
+	addr.bit_offset = 8;
+	addr.access_size = ACPI_ACCESS_SIZE_DWORD_ACCESS;
+	addr.addrl = TEST_INT64 & 0xffffffff;
+	addr.addrh = TEST_INT64 >> 32;
+	acpigen_write_register_resource(ctx, &addr);
+
+	ut_asserteq(BUFFER_OP, *ptr++);
+	ut_asserteq(0x17, get_length(ptr));
+	ptr += 3;
+	ut_asserteq(WORD_PREFIX, *ptr++);
+	ut_asserteq(0x11, get_unaligned((u16 *)ptr));
+	ptr += 2;
+	ut_asserteq(ACPI_DESCRIPTOR_REGISTER, *ptr++);
+	ut_asserteq(0xc, *ptr++);
+	ut_asserteq(0, *ptr++);
+	ut_asserteq(ACPI_ADDRESS_SPACE_EC, *ptr++);
+	ut_asserteq(32, *ptr++);
+	ut_asserteq(8, *ptr++);
+	ut_asserteq(ACPI_ACCESS_SIZE_DWORD_ACCESS, *ptr++);
+	ut_asserteq(TEST_INT64 & 0xffffffff, get_unaligned((u32 *)ptr));
+	ptr += 4;
+	ut_asserteq(TEST_INT64 >> 32, get_unaligned((u32 *)ptr));
+	ptr += 4;
+	ut_asserteq(ACPI_END_TAG, *ptr++);
+	ut_asserteq(0x00, *ptr++);
+	ut_asserteq_ptr(ptr, ctx->current);
+
+	free_context(&ctx);
+
+	return 0;
+}
+DM_TEST(dm_test_acpi_resource_template, 0);
-- 
2.27.0.383.g050319c2ae-goog
