dell-wmi: Add support for new Dell systems

Newer Dell systems support HotKey features differently from legacy
systems.  A new vendor specifc HotKey SMBIOS table (Type 0xB2) is
defined. This table contains a mapping between scancode and the
corresponding predefined keyfunction ( i.e. keycode).. Also, a new
ACPI-WMI event type (called KeyIDList) with a value of 0x0010 is
defined. Any BIOS containing 0xB2 table will send hotkey notifications
using KeyIDList event.

This is Rezwanul's patch, updated to ensure that brightness events are
not sent if the backlight is controlled via ACPI and with the default
keycode for the display output switching altered to match desktop
expectations.
Signed-off-by: Rezwanul Kabir <Rezwanul_Kabir@dell.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/platform/x86/dell-wmi.c

@@ -31,6 +31,7 @@
 #include <acpi/acpi_drivers.h>
 #include <linux/acpi.h>
 #include <linux/string.h>
+#include <linux/dmi.h>
 
 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
 MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
@@ -38,6 +39,8 @@ MODULE_LICENSE("GPL");
 
 #define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
 
+static int acpi_video;
+
 MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
 
 struct key_entry {
@@ -54,7 +57,7 @@ enum { KE_KEY, KE_SW, KE_IGNORE, KE_END };
  * via the keyboard controller so should not be sent again.
  */
 
-static struct key_entry dell_wmi_keymap[] = {
+static struct key_entry dell_legacy_wmi_keymap[] = {
 	{KE_KEY, 0xe045, KEY_PROG1},
 	{KE_KEY, 0xe009, KEY_EJECTCD},
 
@@ -72,7 +75,7 @@ static struct key_entry dell_wmi_keymap[] = {
 
 	/* The next device is at offset 6, the active devices are at
 	   offset 8 and the attached devices at offset 10 */
-	{KE_KEY, 0xe00b, KEY_DISPLAYTOGGLE},
+	{KE_KEY, 0xe00b, KEY_SWITCHVIDEOMODE},
 
 	{KE_IGNORE, 0xe00c, KEY_KBDILLUMTOGGLE},
 
@@ -96,6 +99,47 @@ static struct key_entry dell_wmi_keymap[] = {
 	{KE_END, 0}
 };
 
+static bool dell_new_hk_type;
+
+struct dell_new_keymap_entry {
+	u16 scancode;
+	u16 keycode;
+};
+
+struct dell_hotkey_table {
+	struct dmi_header header;
+	struct dell_new_keymap_entry keymap[];
+
+};
+
+static struct key_entry *dell_new_wmi_keymap;
+
+static u16 bios_to_linux_keycode[256] = {
+
+	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, 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, 0, 0, 0, 0, 0, 0, 0,
+	KEY_PROG3
+};
+
+
+static struct key_entry *dell_wmi_keymap = dell_legacy_wmi_keymap;
+
 static struct input_dev *dell_wmi_input_dev;
 
 static struct key_entry *dell_wmi_get_entry_by_scancode(int code)
@@ -164,24 +208,78 @@ static void dell_wmi_notify(u32 value, void *context)
 	obj = (union acpi_object *)response.pointer;
 
 	if (obj && obj->type == ACPI_TYPE_BUFFER) {
-		int *buffer = (int *)obj->buffer.pointer;
-		/*
-		 *  The upper bytes of the event may contain
-		 *  additional information, so mask them off for the
-		 *  scancode lookup
-		 */
-		key = dell_wmi_get_entry_by_scancode(buffer[1] & 0xFFFF);
-		if (key) {
+		int reported_key;
+		u16 *buffer_entry = (u16 *)obj->buffer.pointer;
+		if (dell_new_hk_type && (buffer_entry[1] != 0x10)) {
+			printk(KERN_INFO "dell-wmi: Received unknown WMI event"
+					 " (0x%x)\n", buffer_entry[1]);
+			return;
+		}
+
+		if (dell_new_hk_type)
+			reported_key = (int)buffer_entry[2];
+		else
+			reported_key = (int)buffer_entry[1] & 0xffff;
+
+		key = dell_wmi_get_entry_by_scancode(reported_key);
+
+		if (!key) {
+			printk(KERN_INFO "dell-wmi: Unknown key %x pressed\n",
+				reported_key);
+		} else if ((key->keycode == KEY_BRIGHTNESSUP ||
+			    key->keycode == KEY_BRIGHTNESSDOWN) && acpi_video) {
+			/* Don't report brightness notifications that will also
+			 * come via ACPI */
+			return;
+		} else {
 			input_report_key(dell_wmi_input_dev, key->keycode, 1);
 			input_sync(dell_wmi_input_dev);
 			input_report_key(dell_wmi_input_dev, key->keycode, 0);
 			input_sync(dell_wmi_input_dev);
-		} else if (buffer[1] & 0xFFFF)
-			printk(KERN_INFO "dell-wmi: Unknown key %x pressed\n",
-			       buffer[1] & 0xFFFF);
 		}
+	}
+}
+
+
+static void setup_new_hk_map(const struct dmi_header *dm)
+{
+
+	int i;
+	int hotkey_num = (dm->length-4)/sizeof(struct dell_new_keymap_entry);
+	struct dell_hotkey_table *table =
+		container_of(dm, struct dell_hotkey_table, header);
+
+	dell_new_wmi_keymap = kzalloc((hotkey_num+1) *
+				      sizeof(struct key_entry), GFP_KERNEL);
+
+	for (i = 0; i < hotkey_num; i++) {
+		dell_new_wmi_keymap[i].type = KE_KEY;
+		dell_new_wmi_keymap[i].code = table->keymap[i].scancode;
+		dell_new_wmi_keymap[i].keycode =
+			(table->keymap[i].keycode > 255) ? 0 :
+			bios_to_linux_keycode[table->keymap[i].keycode];
+	}
+
+	dell_new_wmi_keymap[i].type = KE_END;
+	dell_new_wmi_keymap[i].code = 0;
+	dell_new_wmi_keymap[i].keycode = 0;
+
+	dell_wmi_keymap = dell_new_wmi_keymap;
+
 }
 
+
+static void find_hk_type(const struct dmi_header *dm, void *dummy)
+{
+
+	if ((dm->type == 0xb2) && (dm->length > 6)) {
+		dell_new_hk_type = true;
+		setup_new_hk_map(dm);
+	}
+
+}
+
+
 static int __init dell_wmi_input_setup(void)
 {
 	struct key_entry *key;
@@ -226,6 +324,9 @@ static int __init dell_wmi_init(void)
 	int err;
 
 	if (wmi_has_guid(DELL_EVENT_GUID)) {
+
+		dmi_walk(find_hk_type, NULL);
+
 		err = dell_wmi_input_setup();
 
 		if (err)
@@ -240,6 +341,8 @@ static int __init dell_wmi_init(void)
 			return err;
 		}
 
+		acpi_video = acpi_video_backlight_support();
+
 	} else
 		printk(KERN_WARNING "dell-wmi: No known WMI GUID found\n");