[PATCH] platform/x86: wmi: add Positivo WMI key driver

[Edson Juliano Drosdeck <edson.drosdeck@gmail.com>]

Some function keys on the built in keyboard on Positivo's notebooks does
not produce any key events when pressed in combination with the function
key. Some of these keys do report that they are being pressed via WMI
events.

This driver reports key events for Fn+F10,Fn+F11  and a custom key to
launch a custom program.

Other WMI events that are reported by the hardware but not utilized by
this driver are Caps Lock(which already work).

Signed-off-by: Edson Juliano Drosdeck <edson.drosdeck@gmail.com>
---
 drivers/platform/x86/Kconfig        |  11 +++
 drivers/platform/x86/Makefile       |   1 +
 drivers/platform/x86/positivo-wmi.c | 136 ++++++++++++++++++++++++++++
 3 files changed, 148 insertions(+)
 create mode 100644 drivers/platform/x86/positivo-wmi.c

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 22052031c719..f3ad84479460 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -134,6 +134,17 @@ config YOGABOOK_WMI
 	  To compile this driver as a module, choose M here: the module will
 	  be called lenovo-yogabook-wmi.
 
+config POSITIVO_WMI
+	tristate "Positivo WMI key driver"
+	depends on ACPI_WMI
+	depends on INPUT
+	select INPUT_SPARSEKMAP
+	help
+	  This driver provides support for Positvo WMI hotkeys.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called positivo-wmi.
+
 config ACERHDF
 	tristate "Acer Aspire One temperature and fan driver"
 	depends on ACPI && THERMAL
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 2cafe51ec4d8..5458bb9a56d3 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_NVIDIA_WMI_EC_BACKLIGHT)	+= nvidia-wmi-ec-backlight.o
 obj-$(CONFIG_XIAOMI_WMI)		+= xiaomi-wmi.o
 obj-$(CONFIG_GIGABYTE_WMI)		+= gigabyte-wmi.o
 obj-$(CONFIG_YOGABOOK_WMI)		+= lenovo-yogabook-wmi.o
+obj-$(CONFIG_POSITIVO_WMI)		+= positivo-wmi.o
 
 # Acer
 obj-$(CONFIG_ACERHDF)		+= acerhdf.o
diff --git a/drivers/platform/x86/positivo-wmi.c b/drivers/platform/x86/positivo-wmi.c
new file mode 100644
index 000000000000..5fbb4cf42154
--- /dev/null
+++ b/drivers/platform/x86/positivo-wmi.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/* WMI driver for Positivo Laptops
+ *
+ * Copyright (C) 2023 Edson Juliano Drosdeck <edson.drosdeck@gmail.com>
+ * 
+ * */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/input.h>
+#include <linux/input/sparse-keymap.h>
+#include <linux/dmi.h>
+#include <linux/module.h>
+
+MODULE_AUTHOR("Edson Juliano Drosdeck");
+MODULE_DESCRIPTION("Positivo WMI Hotkey Driver");
+MODULE_LICENSE("GPL");
+
+#define POSITIVO_WMI_EVENT_GUID "ABBC0F72-8EA1-11D1-00A0-C90629100000"
+
+MODULE_ALIAS("wmi:"POSITIVO_WMI_EVENT_GUID);
+
+static const struct key_entry positivo_wmi_keymap[] = {
+	{ KE_KEY, 0x1c, { KEY_PROG1} },
+	{ KE_KEY, 0x36, { KEY_WLAN } },
+	{ KE_KEY, 0x37, { KEY_BLUETOOTH } },
+	{ KE_END, 0},
+};
+
+static struct input_dev *positivo_wmi_input_dev;
+
+static void positivo_wmi_notify(u32 value, void *context)
+{
+	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj;
+	int eventcode;
+	acpi_status status;
+
+	status = wmi_get_event_data(value, &response);
+	if (status != AE_OK) {
+		pr_err("bad event status 0x%x\n", status);
+		return;
+	}
+
+	obj = (union acpi_object *)response.pointer;
+	if (obj && obj->type == ACPI_TYPE_INTEGER) {
+		eventcode = obj->integer.value;
+
+		if (!sparse_keymap_report_event(positivo_wmi_input_dev,
+						eventcode, 1, true))
+			pr_err("Unknown key %x pressed\n", eventcode);
+	}
+
+	kfree(response.pointer);
+}
+
+static int positivo_wmi_input_setup(void)
+{
+
+	int err;
+
+	positivo_wmi_input_dev = input_allocate_device();
+	if (!positivo_wmi_input_dev)
+		return -ENOMEM;
+
+	positivo_wmi_input_dev->name = "Positivo laptop WMI hotkeys";
+	positivo_wmi_input_dev->phys = "wmi/input0";
+	positivo_wmi_input_dev->id.bustype = BUS_HOST;
+
+	err = sparse_keymap_setup(positivo_wmi_input_dev,
+				  positivo_wmi_keymap, NULL);
+	if (err)
+		goto err_free_dev;
+	
+	err = input_register_device(positivo_wmi_input_dev);
+	
+	if (err){
+		pr_info("Unable to register input device\n");
+		goto err_free_dev;
+	}
+
+	return 0;
+
+err_free_dev:
+	input_free_device(positivo_wmi_input_dev);
+	return err;
+}
+
+static const struct dmi_system_id positivo_wmi_dmi_table[] __initconst = {
+	{
+		.ident = "Positivo laptop",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Positivo Tecnologia SA"),
+		},
+	},
+	{}
+};
+
+static int __init positivo_wmi_init(void)
+{
+	int err;
+
+	if (!wmi_has_guid(POSITIVO_WMI_EVENT_GUID) ||
+	    !dmi_check_system(positivo_wmi_dmi_table))
+		return -ENODEV;
+
+	err = positivo_wmi_input_setup();
+	if (err)
+		return err;
+
+	err = wmi_install_notify_handler(POSITIVO_WMI_EVENT_GUID,
+					positivo_wmi_notify, NULL);
+		if (ACPI_FAILURE(err)) {
+			pr_err("Unable to setup WMI notify handler\n");
+			goto err_free_input;
+		}
+
+	return 0;
+
+err_free_input:
+	input_unregister_device(positivo_wmi_input_dev);
+	return err;
+
+}
+
+static void __exit positivo_wmi_exit(void)
+{
+       wmi_remove_notify_handler(POSITIVO_WMI_EVENT_GUID);
+       input_free_device(positivo_wmi_input_dev);
+}
+
+module_init(positivo_wmi_init);
+module_exit(positivo_wmi_exit);
-- 
2.39.2