* Dell WMI hotkeys
*
* Copyright (C) 2008 Red Hat <mjg@redhat.com>
+ * Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
*
* Portions based on wistron_btns.c:
* Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
#include <acpi/video.h>
MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
+MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
MODULE_LICENSE("GPL");
#define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
+#define DELL_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"
+
+static u32 dell_wmi_interface_version;
MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
+MODULE_ALIAS("wmi:"DELL_DESCRIPTOR_GUID);
/*
* Certain keys are flagged as KE_IGNORE. All of these are either
};
-static const struct dell_bios_hotkey_table *dell_bios_hotkey_table;
+struct dell_dmi_results {
+ int err;
+ struct key_entry *keymap;
+};
+/* Uninitialized entries here are KEY_RESERVED == 0. */
static const u16 bios_to_linux_keycode[256] __initconst = {
-
- KEY_MEDIA, KEY_NEXTSONG, KEY_PLAYPAUSE, KEY_PREVIOUSSONG,
- KEY_STOPCD, KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN,
- KEY_WWW, KEY_UNKNOWN, KEY_VOLUMEDOWN, KEY_MUTE,
- KEY_VOLUMEUP, KEY_UNKNOWN, KEY_BATTERY, KEY_EJECTCD,
- KEY_UNKNOWN, KEY_SLEEP, KEY_PROG1, KEY_BRIGHTNESSDOWN,
- KEY_BRIGHTNESSUP, KEY_UNKNOWN, KEY_KBDILLUMTOGGLE,
- KEY_UNKNOWN, KEY_SWITCHVIDEOMODE, KEY_UNKNOWN, KEY_UNKNOWN,
- KEY_SWITCHVIDEOMODE, KEY_UNKNOWN, KEY_UNKNOWN, KEY_PROG2,
- KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN,
- KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN, KEY_MICMUTE,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, KEY_PROG3
+ [0] = KEY_MEDIA,
+ [1] = KEY_NEXTSONG,
+ [2] = KEY_PLAYPAUSE,
+ [3] = KEY_PREVIOUSSONG,
+ [4] = KEY_STOPCD,
+ [5] = KEY_UNKNOWN,
+ [6] = KEY_UNKNOWN,
+ [7] = KEY_UNKNOWN,
+ [8] = KEY_WWW,
+ [9] = KEY_UNKNOWN,
+ [10] = KEY_VOLUMEDOWN,
+ [11] = KEY_MUTE,
+ [12] = KEY_VOLUMEUP,
+ [13] = KEY_UNKNOWN,
+ [14] = KEY_BATTERY,
+ [15] = KEY_EJECTCD,
+ [16] = KEY_UNKNOWN,
+ [17] = KEY_SLEEP,
+ [18] = KEY_PROG1,
+ [19] = KEY_BRIGHTNESSDOWN,
+ [20] = KEY_BRIGHTNESSUP,
+ [21] = KEY_UNKNOWN,
+ [22] = KEY_KBDILLUMTOGGLE,
+ [23] = KEY_UNKNOWN,
+ [24] = KEY_SWITCHVIDEOMODE,
+ [25] = KEY_UNKNOWN,
+ [26] = KEY_UNKNOWN,
+ [27] = KEY_SWITCHVIDEOMODE,
+ [28] = KEY_UNKNOWN,
+ [29] = KEY_UNKNOWN,
+ [30] = KEY_PROG2,
+ [31] = KEY_UNKNOWN,
+ [32] = KEY_UNKNOWN,
+ [33] = KEY_UNKNOWN,
+ [34] = KEY_UNKNOWN,
+ [35] = KEY_UNKNOWN,
+ [36] = KEY_UNKNOWN,
+ [37] = KEY_UNKNOWN,
+ [38] = KEY_MICMUTE,
+ [255] = KEY_PROG3,
};
static struct input_dev *dell_wmi_input_dev;
key = sparse_keymap_entry_from_scancode(dell_wmi_input_dev,
reported_key);
if (!key) {
- pr_info("Unknown key %x pressed\n", reported_key);
+ pr_info("Unknown key with scancode 0x%x pressed\n",
+ reported_key);
return;
}
buffer_end = buffer_entry + buffer_size;
+ /*
+ * BIOS/ACPI on devices with WMI interface version 0 does not clear
+ * buffer before filling it. So next time when BIOS/ACPI send WMI event
+ * which is smaller as previous then it contains garbage in buffer from
+ * previous event.
+ *
+ * BIOS/ACPI on devices with WMI interface version 1 clears buffer and
+ * sometimes send more events in buffer at one call.
+ *
+ * So to prevent reading garbage from buffer we will process only first
+ * one event on devices with WMI interface version 0.
+ */
+ if (dell_wmi_interface_version == 0 && buffer_entry < buffer_end)
+ if (buffer_end > buffer_entry + buffer_entry[0] + 1)
+ buffer_end = buffer_entry + buffer_entry[0] + 1;
+
while (buffer_entry < buffer_end) {
len = buffer_entry[0];
kfree(obj);
}
-static const struct key_entry * __init dell_wmi_prepare_new_keymap(void)
+static void __init handle_dmi_entry(const struct dmi_header *dm,
+ void *opaque)
{
- int hotkey_num = (dell_bios_hotkey_table->header.length - 4) /
- sizeof(struct dell_bios_keymap_entry);
+ struct dell_dmi_results *results = opaque;
+ struct dell_bios_hotkey_table *table;
struct key_entry *keymap;
- int i;
+ int hotkey_num, i;
+
+ if (results->err || results->keymap)
+ return; /* We already found the hotkey table. */
+
+ if (dm->type != 0xb2 || dm->length <= 6)
+ return;
+
+ table = container_of(dm, struct dell_bios_hotkey_table, header);
+
+ hotkey_num = (table->header.length - 4) /
+ sizeof(struct dell_bios_keymap_entry);
keymap = kcalloc(hotkey_num + 1, sizeof(struct key_entry), GFP_KERNEL);
- if (!keymap)
- return NULL;
+ if (!keymap) {
+ results->err = -ENOMEM;
+ return;
+ }
for (i = 0; i < hotkey_num; i++) {
const struct dell_bios_keymap_entry *bios_entry =
- &dell_bios_hotkey_table->keymap[i];
- u16 keycode = bios_entry->keycode < 256 ?
- bios_to_linux_keycode[bios_entry->keycode] :
- KEY_RESERVED;
+ &table->keymap[i];
+
+ /* Uninitialized entries are 0 aka KEY_RESERVED. */
+ u16 keycode = (bios_entry->keycode <
+ ARRAY_SIZE(bios_to_linux_keycode)) ?
+ bios_to_linux_keycode[bios_entry->keycode] :
+ KEY_RESERVED;
+
+ /*
+ * Log if we find an entry in the DMI table that we don't
+ * understand. If this happens, we should figure out what
+ * the entry means and add it to bios_to_linux_keycode.
+ */
+ if (keycode == KEY_RESERVED) {
+ pr_info("firmware scancode 0x%x maps to unrecognized keycode 0x%x\n",
+ bios_entry->scancode, bios_entry->keycode);
+ continue;
+ }
if (keycode == KEY_KBDILLUMTOGGLE)
keymap[i].type = KE_IGNORE;
keymap[hotkey_num].type = KE_END;
- return keymap;
+ results->keymap = keymap;
}
static int __init dell_wmi_input_setup(void)
{
+ struct dell_dmi_results dmi_results = {};
int err;
dell_wmi_input_dev = input_allocate_device();
dell_wmi_input_dev->phys = "wmi/input0";
dell_wmi_input_dev->id.bustype = BUS_HOST;
- if (dell_new_hk_type) {
- const struct key_entry *keymap = dell_wmi_prepare_new_keymap();
- if (!keymap) {
- err = -ENOMEM;
- goto err_free_dev;
- }
+ if (dmi_walk(handle_dmi_entry, &dmi_results)) {
+ /*
+ * Historically, dell-wmi ignored dmi_walk errors. A failure
+ * is certainly surprising, but it probably just indicates
+ * a very old laptop.
+ */
+ pr_warn("no DMI; using the old-style hotkey interface\n");
+ }
+
+ if (dmi_results.err) {
+ err = dmi_results.err;
+ goto err_free_dev;
+ }
- err = sparse_keymap_setup(dell_wmi_input_dev, keymap, NULL);
+ if (dmi_results.keymap) {
+ dell_new_hk_type = true;
+
+ err = sparse_keymap_setup(dell_wmi_input_dev,
+ dmi_results.keymap, NULL);
/*
* Sparse keymap library makes a copy of keymap so we
* don't need the original one that was allocated.
*/
- kfree(keymap);
+ kfree(dmi_results.keymap);
} else {
err = sparse_keymap_setup(dell_wmi_input_dev,
dell_wmi_legacy_keymap, NULL);
input_unregister_device(dell_wmi_input_dev);
}
-static void __init find_hk_type(const struct dmi_header *dm, void *dummy)
+/*
+ * Descriptor buffer is 128 byte long and contains:
+ *
+ * Name Offset Length Value
+ * Vendor Signature 0 4 "DELL"
+ * Object Signature 4 4 " WMI"
+ * WMI Interface Version 8 4 <version>
+ * WMI buffer length 12 4 4096
+ */
+static int __init dell_wmi_check_descriptor_buffer(void)
{
- if (dm->type == 0xb2 && dm->length > 6) {
- dell_new_hk_type = true;
- dell_bios_hotkey_table =
- container_of(dm, struct dell_bios_hotkey_table, header);
+ struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object *obj;
+ acpi_status status;
+ u32 *buffer;
+
+ status = wmi_query_block(DELL_DESCRIPTOR_GUID, 0, &out);
+ if (ACPI_FAILURE(status)) {
+ pr_err("Cannot read Dell descriptor buffer - %d\n", status);
+ return status;
+ }
+
+ obj = (union acpi_object *)out.pointer;
+ if (!obj) {
+ pr_err("Dell descriptor buffer is empty\n");
+ return -EINVAL;
+ }
+
+ if (obj->type != ACPI_TYPE_BUFFER) {
+ pr_err("Cannot read Dell descriptor buffer\n");
+ kfree(obj);
+ return -EINVAL;
}
+
+ if (obj->buffer.length != 128) {
+ pr_err("Dell descriptor buffer has invalid length (%d)\n",
+ obj->buffer.length);
+ if (obj->buffer.length < 16) {
+ kfree(obj);
+ return -EINVAL;
+ }
+ }
+
+ buffer = (u32 *)obj->buffer.pointer;
+
+ if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720)
+ pr_warn("Dell descriptor buffer has invalid signature (%*ph)\n",
+ 8, buffer);
+
+ if (buffer[2] != 0 && buffer[2] != 1)
+ pr_warn("Dell descriptor buffer has unknown version (%d)\n",
+ buffer[2]);
+
+ if (buffer[3] != 4096)
+ pr_warn("Dell descriptor buffer has invalid buffer length (%d)\n",
+ buffer[3]);
+
+ dell_wmi_interface_version = buffer[2];
+
+ pr_info("Detected Dell WMI interface version %u\n",
+ dell_wmi_interface_version);
+
+ kfree(obj);
+ return 0;
}
static int __init dell_wmi_init(void)
int err;
acpi_status status;
- if (!wmi_has_guid(DELL_EVENT_GUID)) {
- pr_warn("No known WMI GUID found\n");
+ if (!wmi_has_guid(DELL_EVENT_GUID) ||
+ !wmi_has_guid(DELL_DESCRIPTOR_GUID)) {
+ pr_warn("Dell WMI GUID were not found\n");
return -ENODEV;
}
- dmi_walk(find_hk_type, NULL);
+ err = dell_wmi_check_descriptor_buffer();
+ if (err)
+ return err;
err = dell_wmi_input_setup();
if (err)
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