platform/x86: dell-wmi: Convert to the WMI bus infrastructure

Move some initialization out of _init and into _probe.
Update signatures and logic to use the wmi bus and device structures.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
[dvhart: drop deprecated sparse_keymap_free, order declarations, add commit msg]
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

drivers/platform/x86/dell-wmi.c

@@ -36,6 +36,7 @@
 #include <linux/acpi.h>
 #include <linux/string.h>
 #include <linux/dmi.h>
+#include <linux/wmi.h>
 #include <acpi/video.h>
 #include "dell-smbios.h"
 
@@ -53,6 +54,10 @@ static bool wmi_requires_smbios_request;
 MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
 MODULE_ALIAS("wmi:"DELL_DESCRIPTOR_GUID);
 
+struct dell_wmi_priv {
+	struct input_dev *input_dev;
+};
+
 static int __init dmi_matched(const struct dmi_system_id *dmi)
 {
 	wmi_requires_smbios_request = 1;
@@ -86,7 +91,7 @@ static const struct dmi_system_id dell_wmi_smbios_list[] __initconst = {
  * notifications (rather than requests for change) or are also sent
  * via the keyboard controller so should not be sent again.
  */
-static const struct key_entry dell_wmi_keymap_type_0000[] __initconst = {
+static const struct key_entry dell_wmi_keymap_type_0000[] = {
 	{ KE_IGNORE, 0x003a, { KEY_CAPSLOCK } },
 
 	/* Key code is followed by brightness level */
@@ -207,7 +212,7 @@ struct dell_dmi_results {
 };
 
 /* Uninitialized entries here are KEY_RESERVED == 0. */
-static const u16 bios_to_linux_keycode[256] __initconst = {
+static const u16 bios_to_linux_keycode[256] = {
 	[0]	= KEY_MEDIA,
 	[1]	= KEY_NEXTSONG,
 	[2]	= KEY_PLAYPAUSE,
@@ -256,7 +261,7 @@ static const u16 bios_to_linux_keycode[256] __initconst = {
  * These are applied if the 0xB2 DMI hotkey table is present and doesn't
  * override them.
  */
-static const struct key_entry dell_wmi_keymap_type_0010[] __initconst = {
+static const struct key_entry dell_wmi_keymap_type_0010[] = {
 	/* Fn-lock */
 	{ KE_IGNORE, 0x151, { KEY_RESERVED } },
 
@@ -294,7 +299,7 @@ static const struct key_entry dell_wmi_keymap_type_0010[] __initconst = {
 /*
  * Keymap for WMI events of type 0x0011
  */
-static const struct key_entry dell_wmi_keymap_type_0011[] __initconst = {
+static const struct key_entry dell_wmi_keymap_type_0011[] = {
 	/* Battery unplugged */
 	{ KE_IGNORE, 0xfff0, { KEY_RESERVED } },
 
@@ -309,13 +314,12 @@ static const struct key_entry dell_wmi_keymap_type_0011[] __initconst = {
 	{ KE_IGNORE, 0x02f6, { KEY_RESERVED } },
 };
 
-static struct input_dev *dell_wmi_input_dev;
-
-static void dell_wmi_process_key(int type, int code)
+static void dell_wmi_process_key(struct wmi_device *wdev, int type, int code)
 {
+	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
 	const struct key_entry *key;
 
-	key = sparse_keymap_entry_from_scancode(dell_wmi_input_dev,
+	key = sparse_keymap_entry_from_scancode(priv->input_dev,
 						(type << 16) | code);
 	if (!key) {
 		pr_info("Unknown key with type 0x%04x and code 0x%04x pressed\n",
@@ -338,33 +342,18 @@ static void dell_wmi_process_key(int type, int code)
 		dell_laptop_call_notifier(
 			DELL_LAPTOP_KBD_BACKLIGHT_BRIGHTNESS_CHANGED, NULL);
 
-	sparse_keymap_report_entry(dell_wmi_input_dev, key, 1, true);
+	sparse_keymap_report_entry(priv->input_dev, key, 1, true);
 }
 
-static void dell_wmi_notify(u32 value, void *context)
+static void dell_wmi_notify(struct wmi_device *wdev,
+			    union acpi_object *obj)
 {
-	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
-	acpi_status status;
-	acpi_size buffer_size;
 	u16 *buffer_entry, *buffer_end;
+	acpi_size buffer_size;
 	int len, i;
 
-	status = wmi_get_event_data(value, &response);
-	if (status != AE_OK) {
-		pr_warn("bad event status 0x%x\n", status);
-		return;
-	}
-
-	obj = (union acpi_object *)response.pointer;
-	if (!obj) {
-		pr_warn("no response\n");
-		return;
-	}
-
 	if (obj->type != ACPI_TYPE_BUFFER) {
 		pr_warn("bad response type %x\n", obj->type);
-		kfree(obj);
 		return;
 	}
 
@@ -409,13 +398,14 @@ static void dell_wmi_notify(u32 value, void *context)
 		switch (buffer_entry[1]) {
 		case 0x0000: /* One key pressed or event occurred */
 			if (len > 2)
-				dell_wmi_process_key(0x0000, buffer_entry[2]);
+				dell_wmi_process_key(wdev, 0x0000,
+						     buffer_entry[2]);
 			/* Other entries could contain additional information */
 			break;
 		case 0x0010: /* Sequence of keys pressed */
 		case 0x0011: /* Sequence of events occurred */
 			for (i = 2; i < len; ++i)
-				dell_wmi_process_key(buffer_entry[1],
+				dell_wmi_process_key(wdev, buffer_entry[1],
 						     buffer_entry[i]);
 			break;
 		default: /* Unknown event */
@@ -428,7 +418,6 @@ static void dell_wmi_notify(u32 value, void *context)
 
 	}
 
-	kfree(obj);
 }
 
 static bool have_scancode(u32 scancode, const struct key_entry *keymap, int len)
@@ -442,9 +431,7 @@ static bool have_scancode(u32 scancode, const struct key_entry *keymap, int len)
 	return false;
 }
 
-static void __init handle_dmi_entry(const struct dmi_header *dm,
-				    void *opaque)
-
+static void handle_dmi_entry(const struct dmi_header *dm, void *opaque)
 {
 	struct dell_dmi_results *results = opaque;
 	struct dell_bios_hotkey_table *table;
@@ -515,19 +502,20 @@ static void __init handle_dmi_entry(const struct dmi_header *dm,
 	results->keymap_size = pos;
 }
 
-static int __init dell_wmi_input_setup(void)
+static int dell_wmi_input_setup(struct wmi_device *wdev)
 {
+	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
 	struct dell_dmi_results dmi_results = {};
 	struct key_entry *keymap;
 	int err, i, pos = 0;
 
-	dell_wmi_input_dev = input_allocate_device();
-	if (!dell_wmi_input_dev)
+	priv->input_dev = input_allocate_device();
+	if (!priv->input_dev)
 		return -ENOMEM;
 
-	dell_wmi_input_dev->name = "Dell WMI hotkeys";
-	dell_wmi_input_dev->phys = "wmi/input0";
-	dell_wmi_input_dev->id.bustype = BUS_HOST;
+	priv->input_dev->name = "Dell WMI hotkeys";
+	priv->input_dev->id.bustype = BUS_HOST;
+	priv->input_dev->dev.parent = &wdev->dev;
 
 	if (dmi_walk(handle_dmi_entry, &dmi_results)) {
 		/*
@@ -602,7 +590,7 @@ static int __init dell_wmi_input_setup(void)
 
 	keymap[pos].type = KE_END;
 
-	err = sparse_keymap_setup(dell_wmi_input_dev, keymap, NULL);
+	err = sparse_keymap_setup(priv->input_dev, keymap, NULL);
 	/*
 	 * Sparse keymap library makes a copy of keymap so we don't need the
 	 * original one that was allocated.
@@ -611,17 +599,24 @@ static int __init dell_wmi_input_setup(void)
 	if (err)
 		goto err_free_dev;
 
-	err = input_register_device(dell_wmi_input_dev);
+	err = input_register_device(priv->input_dev);
 	if (err)
 		goto err_free_dev;
 
 	return 0;
 
  err_free_dev:
-	input_free_device(dell_wmi_input_dev);
+	input_free_device(priv->input_dev);
 	return err;
 }
 
+static void dell_wmi_input_destroy(struct wmi_device *wdev)
+{
+	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
+
+	input_unregister_device(priv->input_dev);
+}
+
 /*
  * Descriptor buffer is 128 byte long and contains:
  *
@@ -720,46 +715,55 @@ static int dell_wmi_events_set_enabled(bool enable)
 	return dell_smbios_error(ret);
 }
 
+static int dell_wmi_probe(struct wmi_device *wdev)
+{
+	struct dell_wmi_priv *priv = devm_kzalloc(
+		&wdev->dev, sizeof(struct dell_wmi_priv), GFP_KERNEL);
+
+	dev_set_drvdata(&wdev->dev, priv);
+
+	return dell_wmi_input_setup(wdev);
+}
+
+static int dell_wmi_remove(struct wmi_device *wdev)
+{
+	dell_wmi_input_destroy(wdev);
+	return 0;
+}
+static const struct wmi_device_id dell_wmi_id_table[] = {
+	{ .guid_string = DELL_EVENT_GUID },
+	{ },
+};
+
+static struct wmi_driver dell_wmi_driver = {
+	.driver = {
+		.name = "dell-wmi",
+	},
+	.id_table = dell_wmi_id_table,
+	.probe = dell_wmi_probe,
+	.remove = dell_wmi_remove,
+	.notify = dell_wmi_notify,
+};
+
 static int __init dell_wmi_init(void)
 {
 	int err;
-	acpi_status status;
-
-	if (!wmi_has_guid(DELL_EVENT_GUID) ||
-	    !wmi_has_guid(DELL_DESCRIPTOR_GUID)) {
-		pr_warn("Dell WMI GUID were not found\n");
-		return -ENODEV;
-	}
 
 	err = dell_wmi_check_descriptor_buffer();
 	if (err)
 		return err;
 
-	err = dell_wmi_input_setup();
-	if (err)
-		return err;
-
-	status = wmi_install_notify_handler(DELL_EVENT_GUID,
-					 dell_wmi_notify, NULL);
-	if (ACPI_FAILURE(status)) {
-		input_unregister_device(dell_wmi_input_dev);
-		pr_err("Unable to register notify handler - %d\n", status);
-		return -ENODEV;
-	}
-
 	dmi_check_system(dell_wmi_smbios_list);
 
 	if (wmi_requires_smbios_request) {
 		err = dell_wmi_events_set_enabled(true);
 		if (err) {
 			pr_err("Failed to enable WMI events\n");
-			wmi_remove_notify_handler(DELL_EVENT_GUID);
-			input_unregister_device(dell_wmi_input_dev);
 			return err;
 		}
 	}
 
-	return 0;
+	return wmi_driver_register(&dell_wmi_driver);
 }
 module_init(dell_wmi_init);
 
@@ -767,7 +771,7 @@ static void __exit dell_wmi_exit(void)
 {
 	if (wmi_requires_smbios_request)
 		dell_wmi_events_set_enabled(false);
-	wmi_remove_notify_handler(DELL_EVENT_GUID);
-	input_unregister_device(dell_wmi_input_dev);
+
+	wmi_driver_unregister(&dell_wmi_driver);
 }
 module_exit(dell_wmi_exit);