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path: root/drivers/acpi/x86/apple.c
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Diffstat (limited to 'drivers/acpi/x86/apple.c')
-rw-r--r--drivers/acpi/x86/apple.c141
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);
+}