UBUNTU: ODM: mfd: Add support for IO functions of AAEON devices

BugLink: https://bugs.launchpad.net/bugs/1929504

This adds the supports for multiple IO functions of the
AAEON x86 devices and makes use of the WMI interface to
control the these IO devices including:

- GPIO
- LED
- Watchdog
- HWMON

It also adds the mfd child device drivers to support
the above IO functions.

Signed-off-by: Kunyang_Fan <kunyang_fan@asus.com>
Review-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Review-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>

MAINTAINERS

@@ -190,6 +190,18 @@ M:	Linus Walleij <linus.walleij@linaro.org>
 F:	Documentation/devicetree/bindings/power/supply/*ab8500*
 F:	drivers/power/supply/*ab8500*
 
+AAEON DEVICE DRIVER WITH WMI INTERFACE
+M:	Edward Lin<edward1_lin@asus.com>
+M:	Kunyang Fan <kunyang_fan@asus.com>
+M:	Frank Hsieh <frank2_hsieh@asus.com>
+M:	Jacob Wu <jacob_wu@asus.com>
+S:	Supported
+F:	drivers/gpio/gpio-aaeon.c
+F:	drivers/hwmon/hwmon-aaeon.c
+F:	drivers/leds/leds-aaeon.c
+F:	drivers/mfd/mfd-aaeon.c
+F:	drivers/watchdog/wdt_aaeon.c
+
 ABI/API
 L:	linux-api@vger.kernel.org
 F:	include/linux/syscalls.h

drivers/mfd/Kconfig

@@ -2218,6 +2218,18 @@ config MFD_QCOM_PM8008
 	  under it in the device tree. Additional drivers must be enabled in
 	  order to use the functionality of the device.
 
+config MFD_AAEON
+	tristate "AAEON WMI MFD devices"
+	depends on ASUS_WMI
+	depends on UBUNTU_ODM_DRIVERS
+	help
+	  Say yes here to support mltiple IO devices on Single Board Computers
+	  produced by AAEON.
+
+	  This driver leverages the ASUS WMI interface to access device
+	  resources.
+
+
 menu "Multimedia Capabilities Port drivers"
 	depends on ARCH_SA1100
 

drivers/mfd/Makefile

@@ -279,6 +279,7 @@ obj-$(CONFIG_MFD_INTEL_M10_BMC_PMCI)   += intel-m10-bmc-pmci.o
 
 obj-$(CONFIG_MFD_ATC260X)	+= atc260x-core.o
 obj-$(CONFIG_MFD_ATC260X_I2C)	+= atc260x-i2c.o
+obj-$(CONFIG_MFD_AAEON)		+= mfd-aaeon.o
 
 rsmu-i2c-objs			:= rsmu_core.o rsmu_i2c.o
 rsmu-spi-objs			:= rsmu_core.o rsmu_spi.o

drivers/mfd/mfd-aaeon.c

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * UP Board main platform driver and FPGA configuration support
+ *
+ * Copyright (c) 2021, AAEON Ltd.
+ *
+ * Author: Kunyang_Fan <knuyang_fan@aaeon.com.tw>
+ *
+ * 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/gpio.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/leds.h>
+#include <linux/wmi.h>
+
+#define AAEON_WMI_MGMT_GUID      "97845ED0-4E6D-11DE-8A39-0800200C9A66"
+
+struct aaeon_wmi_priv {
+	const struct mfd_cell *cells;
+	size_t ncells;
+};
+
+static const struct mfd_cell aaeon_mfd_cells[] = {
+	{ .name = "gpio-aaeon" },
+	{ .name = "hwmon-aaeon"},
+	{ .name = "leds-aaeon"},
+	{ .name = "wdt-aaeon"},
+};
+
+static const struct aaeon_wmi_priv aaeon_wmi_priv_data = {
+	.cells = aaeon_mfd_cells,
+	.ncells = ARRAY_SIZE(aaeon_mfd_cells),
+};
+
+static int aaeon_wmi_probe(struct wmi_device *wdev, const void *context)
+{
+	struct aaeon_wmi_priv *priv;
+
+	if (!wmi_has_guid(AAEON_WMI_MGMT_GUID)) {
+		dev_info(&wdev->dev, "AAEON Management GUID not found\n");
+		return -ENODEV;
+	}
+
+
+	priv = (struct aaeon_wmi_priv *)context;
+	dev_set_drvdata(&wdev->dev, priv);
+
+	return devm_mfd_add_devices(&wdev->dev, 0, priv->cells,
+				    priv->ncells, NULL, 0, NULL);
+}
+
+static const struct wmi_device_id aaeon_wmi_id_table[] = {
+	{ AAEON_WMI_MGMT_GUID, (void *)&aaeon_wmi_priv_data },
+	{}
+};
+
+static struct wmi_driver aaeon_wmi_driver = {
+	.driver = {
+		.name = "mfd-aaeon",
+	},
+	.id_table = aaeon_wmi_id_table,
+	.probe = aaeon_wmi_probe,
+};
+
+module_wmi_driver(aaeon_wmi_driver);
+
+MODULE_DEVICE_TABLE(wmi, aaeon_wmi_id_table);
+MODULE_AUTHOR("Kunyang Fan <kunyang_fan@aaeon.com.tw>");
+MODULE_DESCRIPTION("AAEON Board WMI driver");
+MODULE_LICENSE("GPL v2");