[PATCH v2 36/39] acpi: Support ordering SSDT data by device

[Simon Glass]

Add a /chosen property to control the order in which the data appears
in the SSDT. This allows matching up U-Boot's output from a dump of the
known-good data obtained from within Linux.

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

Changes in v2:
- Generalise the ACPI function recursion with acpi_recurse_method()

 arch/sandbox/dts/test.dts           |  5 ++-
 doc/device-tree-bindings/chosen.txt |  9 +++++
 drivers/core/acpi.c                 | 62 +++++++++++++++++++++++++++++
 test/dm/acpi.c                      | 17 ++++----
 4 files changed, 84 insertions(+), 9 deletions(-)

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index fefa3af999..7d55d360f6 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -206,12 +206,12 @@
 		compatible = "denx,u-boot-devres-test";
 	};
 
-	acpi-test {
+	acpi_test1: acpi-test {
 		compatible = "denx,u-boot-acpi-test";
 		acpi-ssdt-test-data = "ab";
 	};
 
-	acpi-test2 {
+	acpi_test2: acpi-test2 {
 		compatible = "denx,u-boot-acpi-test";
 		acpi-ssdt-test-data = "cd";
 	};
@@ -829,6 +829,7 @@
 		setting = "sunrise ohoka";
 		other-node = "/some-bus/c-test at 5";
 		int-values = <0x1937 72993>;
+		u-boot,acpi-ssdt-order = <&acpi_test2 &acpi_test1>;
 		chosen-test {
 			compatible = "denx,u-boot-fdt-test";
 			reg = <9 1>;
diff --git a/doc/device-tree-bindings/chosen.txt b/doc/device-tree-bindings/chosen.txt
index 395c9501e3..d4dfc05847 100644
--- a/doc/device-tree-bindings/chosen.txt
+++ b/doc/device-tree-bindings/chosen.txt
@@ -134,3 +134,12 @@ Example
 		phandlepart = <&mmc 1>;
 	};
 };
+
+u-boot,acpi-ssdt-order
+----------------------
+
+This provides the ordering to use when writing device data to the ACPI SSDT
+(Secondary System Descriptor Table). Each cell is a phandle pointer to a device
+node to add. The ACPI information is written in this order.
+
+If the ordering does not include all nodes, an error is generated.
diff --git a/drivers/core/acpi.c b/drivers/core/acpi.c
index 7b295bf921..2f57ff9da2 100644
--- a/drivers/core/acpi.c
+++ b/drivers/core/acpi.c
@@ -106,6 +106,63 @@ static int acpi_add_item(struct acpi_ctx *ctx, struct udevice *dev,
 	return 0;
 }
 
+struct acpi_item *find_item(const char *devname)
+{
+	int i;
+
+	for (i = 0; i < item_count; i++) {
+		struct acpi_item *item = &acpi_item[i];
+
+		if (!strcmp(devname, item->dev->name))
+			return item;
+	}
+
+	return NULL;
+}
+
+static int build_type(struct acpi_ctx *ctx, void *start, enum gen_type_t type)
+{
+	const u32 *order;
+	int size;
+	int count;
+	void *ptr;
+	void *end = ctx->current;
+
+	ptr = start;
+	order = ofnode_read_chosen_prop("u-boot,acpi-ssdt-order", &size);
+	if (!order) {
+		log_warning("Failed to find ordering, leaving as is\n");
+		return 0;
+	}
+
+	count = size / sizeof(u32);
+	while (count--) {
+		struct acpi_item *item;
+		const char *name;
+		ofnode node;
+
+		node = ofnode_get_by_phandle(fdt32_to_cpu(*order++));
+		name = ofnode_get_name(node);
+		item = find_item(name);
+		if (!item) {
+			log_err("Failed to find item '%s'\n", name);
+			return log_msg_ret("find", -ENOENT);
+		}
+		if (item->type == type) {
+			log_debug("   - add %s\n", item->dev->name);
+			memcpy(ptr, item->buf, item->size);
+			ptr += item->size;
+		}
+	}
+
+	if (ptr != end) {
+		log_warning("*** Missing bytes: ptr=%p, end=%p\n", ptr, end);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
 acpi_method acpi_get_method(struct udevice *dev, enum method_t method)
 {
 	struct acpi_ops *aops;
@@ -160,11 +217,16 @@ int acpi_recurse_method(struct acpi_ctx *ctx, struct udevice *parent,
 
 int acpi_fill_ssdt(struct acpi_ctx *ctx)
 {
+	void *start = ctx->current;
 	int ret;
 
 	log_debug("Writing SSDT tables\n");
+	item_count = 0;
 	ret = acpi_recurse_method(ctx, dm_root(), METHOD_FILL_SDDT, TYPE_SSDT);
 	log_debug("Writing SSDT finished, err=%d\n", ret);
+	ret = build_type(ctx, start, TYPE_SSDT);
+	if (ret)
+		return log_msg_ret("build", ret);
 
 	return ret;
 }
diff --git a/test/dm/acpi.c b/test/dm/acpi.c
index 305d8395ff..b0d8d41e49 100644
--- a/test/dm/acpi.c
+++ b/test/dm/acpi.c
@@ -336,16 +336,19 @@ static int dm_test_acpi_fill_ssdt(struct unit_test_state *uts)
 	ut_assertnonnull(buf);
 
 	ctx.current = buf;
-	buf[4] = 'z';	/* sentinal */
+	buf[4] = 'z';	/* sentinel */
 	ut_assertok(acpi_fill_ssdt(&ctx));
 
-	/* These values come from acpi-test's acpi-ssdt-test-data property */
-	ut_asserteq('a', buf[0]);
-	ut_asserteq('b', buf[1]);
+	/*
+	 * These values come from acpi-test2's acpi-ssdt-test-data property.
+	 * This device comes first because of u-boot,acpi-ssdt-order
+	 */
+	ut_asserteq('c', buf[0]);
+	ut_asserteq('d', buf[1]);
 
-	/* These values come from acpi-test2's acpi-ssdt-test-data property */
-	ut_asserteq('c', buf[2]);
-	ut_asserteq('d', buf[3]);
+	/* These values come from acpi-test's acpi-ssdt-test-data property */
+	ut_asserteq('a', buf[2]);
+	ut_asserteq('b', buf[3]);
 
 	ut_asserteq('z', buf[4]);
 
-- 
2.25.1.481.gfbce0eb801-goog