1 files changed, 141 insertions, 0 deletions
diff --git a/drivers/acpi/x86/apple.c b/drivers/acpi/x86/apple.c
new file mode 100644
index 000000000000..51b4cf9f25da
--- /dev/null
+++ b/drivers/acpi/x86/apple.c
@@ -0,0 +1,141 @@
+/*
+ * apple.c - Apple ACPI quirks
+ * Copyright (C) 2017 Lukas Wunner <lukas@wunner.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2) as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitmap.h>
+#include <linux/platform_data/x86/apple.h>
+#include <linux/uuid.h>
+
+/* Apple _DSM device properties GUID */
+static const guid_t apple_prp_guid =
+	GUID_INIT(0xa0b5b7c6, 0x1318, 0x441c,
+		  0xb0, 0xc9, 0xfe, 0x69, 0x5e, 0xaf, 0x94, 0x9b);
+
+/**
+ * acpi_extract_apple_properties - retrieve and convert Apple _DSM properties
+ * @adev: ACPI device for which to retrieve the properties
+ *
+ * Invoke Apple's custom _DSM once to check the protocol version and once more
+ * to retrieve the properties.  They are marshalled up in a single package as
+ * alternating key/value elements, unlike _DSD which stores them as a package
+ * of 2-element packages.  Convert to _DSD format and make them available under
+ * the primary fwnode.
+ */
+void acpi_extract_apple_properties(struct acpi_device *adev)
+{
+	unsigned int i, j = 0, newsize = 0, numprops, numvalid;
+	union acpi_object *props, *newprops;
+	unsigned long *valid = NULL;
+	void *free_space;
+
+	if (!x86_apple_machine)
+		return;
+
+	props = acpi_evaluate_dsm_typed(adev->handle, &apple_prp_guid, 1, 0,
+					NULL, ACPI_TYPE_BUFFER);
+	if (!props)
+		return;
+
+	if (!props->buffer.length)
+		goto out_free;
+
+	if (props->buffer.pointer[0] != 3) {
+		acpi_handle_info(adev->handle, FW_INFO
+				 "unsupported properties version %*ph\n",
+				 props->buffer.length, props->buffer.pointer);
+		goto out_free;
+	}
+
+	ACPI_FREE(props);
+	props = acpi_evaluate_dsm_typed(adev->handle, &apple_prp_guid, 1, 1,
+					NULL, ACPI_TYPE_PACKAGE);
+	if (!props)
+		return;
+
+	numprops = props->package.count / 2;
+	if (!numprops)
+		goto out_free;
+
+	valid = kcalloc(BITS_TO_LONGS(numprops), sizeof(long), GFP_KERNEL);
+	if (!valid)
+		goto out_free;
+
+	/* newsize = key length + value length of each tuple */
+	for (i = 0; i < numprops; i++) {
+		union acpi_object *key = &props->package.elements[i * 2];
+		union acpi_object *val = &props->package.elements[i * 2 + 1];
+
+		if ( key->type != ACPI_TYPE_STRING ||
+		    (val->type != ACPI_TYPE_INTEGER &&
+		     val->type != ACPI_TYPE_BUFFER))
+			continue; /* skip invalid properties */
+
+		__set_bit(i, valid);
+		newsize += key->string.length + 1;
+		if ( val->type == ACPI_TYPE_BUFFER)
+			newsize += val->buffer.length;
+	}
+
+	numvalid = bitmap_weight(valid, numprops);
+	if (numprops > numvalid)
+		acpi_handle_info(adev->handle, FW_INFO
+				 "skipped %u properties: wrong type\n",
+				 numprops - numvalid);
+	if (numvalid == 0)
+		goto out_free;
+
+	/* newsize += top-level package + 3 objects for each key/value tuple */
+	newsize	+= (1 + 3 * numvalid) * sizeof(union acpi_object);
+	newprops = ACPI_ALLOCATE_ZEROED(newsize);
+	if (!newprops)
+		goto out_free;
+
+	/* layout: top-level package | packages | key/value tuples | strings */
+	newprops->type = ACPI_TYPE_PACKAGE;
+	newprops->package.count = numvalid;
+	newprops->package.elements = &newprops[1];
+	free_space = &newprops[1 + 3 * numvalid];
+
+	for_each_set_bit(i, valid, numprops) {
+		union acpi_object *key = &props->package.elements[i * 2];
+		union acpi_object *val = &props->package.elements[i * 2 + 1];
+		unsigned int k = 1 + numvalid + j * 2; /* index into newprops */
+		unsigned int v = k + 1;
+
+		newprops[1 + j].type = ACPI_TYPE_PACKAGE;
+		newprops[1 + j].package.count = 2;
+		newprops[1 + j].package.elements = &newprops[k];
+
+		newprops[k].type = ACPI_TYPE_STRING;
+		newprops[k].string.length = key->string.length;
+		newprops[k].string.pointer = free_space;
+		memcpy(free_space, key->string.pointer, key->string.length);
+		free_space += key->string.length + 1;
+
+		newprops[v].type = val->type;
+		if (val->type == ACPI_TYPE_INTEGER) {
+			newprops[v].integer.value = val->integer.value;
+		} else {
+			newprops[v].buffer.length = val->buffer.length;
+			newprops[v].buffer.pointer = free_space;
+			memcpy(free_space, val->buffer.pointer,
+			       val->buffer.length);
+			free_space += val->buffer.length;
+		}
+		j++; /* count valid properties */
+	}
+	WARN_ON(free_space != (void *)newprops + newsize);
+
+	adev->data.properties = newprops;
+	adev->data.pointer = newprops;
+
+out_free:
+	ACPI_FREE(props);
+	kfree(valid);
+}