platform/x86: Move Mellanox platform hotplug driver to platform/mellanox

In preparation for making the hotplug driver build for different
architectures, move mlxcpld-hotplug.c to platform/mellanox and the
header to include/linux/platform_data as mlxreg.h to reflect the new
interface changes to come.

Replace references to CPLD with REG throughout the files, consistent
with the new name.

Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
[dvhart: update copyright, rewrite commit message]
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

3 files changed, 545 insertions, 0 deletions

diff --git a/drivers/platform/mellanox/Kconfig b/drivers/platform/mellanox/Kconfig
new file mode 100644
index 000000000000..d73529203327
--- /dev/null
+++ b/drivers/platform/mellanox/Kconfig
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Platform support for Mellanox hardware
+#
+
+menuconfig MELLANOX_PLATFORM
+	bool "Platform support for Mellanox hardware"
+	depends on X86 || COMPILE_TEST
+	---help---
+	  Say Y here to get to see options for platform support for
+	  Mellanox systems. This option alone does not add any kernel code.
+
+	  If you say N, all options in this submenu will be skipped and disabled.
+
+if MELLANOX_PLATFORM
+
+config MLXREG_HOTPLUG
+	tristate "Mellanox platform hotplug driver support"
+	depends on HWMON
+	depends on I2C
+	---help---
+	  This driver handles hot-plug events for the power suppliers, power
+	  cables and fans on the wide range Mellanox IB and Ethernet systems.
+
+endif # MELLANOX_PLATFORM
diff --git a/drivers/platform/mellanox/Makefile b/drivers/platform/mellanox/Makefile
new file mode 100644
index 000000000000..7c8385e497a8
--- /dev/null
+++ b/drivers/platform/mellanox/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for linux/drivers/platform/mellanox
+# Mellanox Platform-Specific Drivers
+#
+obj-$(CONFIG_MLXREG_HOTPLUG)	+= mlxreg-hotplug.o
diff --git a/drivers/platform/mellanox/mlxreg-hotplug.c b/drivers/platform/mellanox/mlxreg-hotplug.c
new file mode 100644
index 000000000000..5cfc82ba34be
--- /dev/null
+++ b/drivers/platform/mellanox/mlxreg-hotplug.c
@@ -0,0 +1,514 @@
+/*
+ * Copyright (c) 2016-2018 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2016-2018 Vadim Pasternak <vadimp@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_data/mlxreg.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+
+/* Offset of event and mask registers from status register */
+#define MLXREG_HOTPLUG_EVENT_OFF	1
+#define MLXREG_HOTPLUG_MASK_OFF	2
+#define MLXREG_HOTPLUG_AGGR_MASK_OFF	1
+
+#define MLXREG_HOTPLUG_ATTRS_NUM	8
+
+/**
+ * enum mlxreg_hotplug_attr_type - sysfs attributes for hotplug events:
+ * @MLXREG_HOTPLUG_ATTR_TYPE_PSU: power supply unit attribute;
+ * @MLXREG_HOTPLUG_ATTR_TYPE_PWR: power cable attribute;
+ * @MLXREG_HOTPLUG_ATTR_TYPE_FAN: FAN drawer attribute;
+ */
+enum mlxreg_hotplug_attr_type {
+	MLXREG_HOTPLUG_ATTR_TYPE_PSU,
+	MLXREG_HOTPLUG_ATTR_TYPE_PWR,
+	MLXREG_HOTPLUG_ATTR_TYPE_FAN,
+};
+
+/**
+ * struct mlxreg_hotplug_priv_data - platform private data:
+ * @irq: platform interrupt number;
+ * @pdev: platform device;
+ * @plat: platform data;
+ * @hwmon: hwmon device;
+ * @mlxreg_hotplug_attr: sysfs attributes array;
+ * @mlxreg_hotplug_dev_attr: sysfs sensor device attribute array;
+ * @group: sysfs attribute group;
+ * @groups: list of sysfs attribute group for hwmon registration;
+ * @dwork: delayed work template;
+ * @lock: spin lock;
+ * @aggr_cache: last value of aggregation register status;
+ * @psu_cache: last value of PSU register status;
+ * @pwr_cache: last value of power register status;
+ * @fan_cache: last value of FAN register status;
+ */
+struct mlxreg_hotplug_priv_data {
+	int irq;
+	struct platform_device *pdev;
+	struct mlxreg_hotplug_platform_data *plat;
+	struct device *hwmon;
+	struct attribute *mlxreg_hotplug_attr[MLXREG_HOTPLUG_ATTRS_NUM + 1];
+	struct sensor_device_attribute_2
+			mlxreg_hotplug_dev_attr[MLXREG_HOTPLUG_ATTRS_NUM];
+	struct attribute_group group;
+	const struct attribute_group *groups[2];
+	struct delayed_work dwork;
+	spinlock_t lock;
+	u8 aggr_cache;
+	u8 psu_cache;
+	u8 pwr_cache;
+	u8 fan_cache;
+};
+
+static ssize_t mlxreg_hotplug_attr_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct mlxreg_hotplug_priv_data *priv = platform_get_drvdata(pdev);
+	int index = to_sensor_dev_attr_2(attr)->index;
+	int nr = to_sensor_dev_attr_2(attr)->nr;
+	u8 reg_val = 0;
+
+	switch (nr) {
+	case MLXREG_HOTPLUG_ATTR_TYPE_PSU:
+		/* Bit = 0 : PSU is present. */
+		reg_val = !!!(inb(priv->plat->psu_reg_offset) & BIT(index));
+		break;
+
+	case MLXREG_HOTPLUG_ATTR_TYPE_PWR:
+		/* Bit = 1 : power cable is attached. */
+		reg_val = !!(inb(priv->plat->pwr_reg_offset) & BIT(index %
+						priv->plat->pwr_count));
+		break;
+
+	case MLXREG_HOTPLUG_ATTR_TYPE_FAN:
+		/* Bit = 0 : FAN is present. */
+		reg_val = !!!(inb(priv->plat->fan_reg_offset) & BIT(index %
+						priv->plat->fan_count));
+		break;
+	}
+
+	return sprintf(buf, "%u\n", reg_val);
+}
+
+#define PRIV_ATTR(i) priv->mlxreg_hotplug_attr[i]
+#define PRIV_DEV_ATTR(i) priv->mlxreg_hotplug_dev_attr[i]
+static int mlxreg_hotplug_attr_init(struct mlxreg_hotplug_priv_data *priv)
+{
+	int num_attrs = priv->plat->psu_count + priv->plat->pwr_count +
+			priv->plat->fan_count;
+	int i;
+
+	priv->group.attrs = devm_kzalloc(&priv->pdev->dev, num_attrs *
+					 sizeof(struct attribute *),
+					 GFP_KERNEL);
+	if (!priv->group.attrs)
+		return -ENOMEM;
+
+	for (i = 0; i < num_attrs; i++) {
+		PRIV_ATTR(i) = &PRIV_DEV_ATTR(i).dev_attr.attr;
+
+		if (i < priv->plat->psu_count) {
+			PRIV_ATTR(i)->name = devm_kasprintf(&priv->pdev->dev,
+						GFP_KERNEL, "psu%u", i + 1);
+			PRIV_DEV_ATTR(i).nr = MLXREG_HOTPLUG_ATTR_TYPE_PSU;
+		} else if (i < priv->plat->psu_count + priv->plat->pwr_count) {
+			PRIV_ATTR(i)->name = devm_kasprintf(&priv->pdev->dev,
+						GFP_KERNEL, "pwr%u", i %
+						priv->plat->pwr_count + 1);
+			PRIV_DEV_ATTR(i).nr = MLXREG_HOTPLUG_ATTR_TYPE_PWR;
+		} else {
+			PRIV_ATTR(i)->name = devm_kasprintf(&priv->pdev->dev,
+						GFP_KERNEL, "fan%u", i %
+						priv->plat->fan_count + 1);
+			PRIV_DEV_ATTR(i).nr = MLXREG_HOTPLUG_ATTR_TYPE_FAN;
+		}
+
+		if (!PRIV_ATTR(i)->name) {
+			dev_err(&priv->pdev->dev, "Memory allocation failed for sysfs attribute %d.\n",
+				i + 1);
+			return -ENOMEM;
+		}
+
+		PRIV_DEV_ATTR(i).dev_attr.attr.name = PRIV_ATTR(i)->name;
+		PRIV_DEV_ATTR(i).dev_attr.attr.mode = S_IRUGO;
+		PRIV_DEV_ATTR(i).dev_attr.show = mlxreg_hotplug_attr_show;
+		PRIV_DEV_ATTR(i).index = i;
+		sysfs_attr_init(&PRIV_DEV_ATTR(i).dev_attr.attr);
+	}
+
+	priv->group.attrs = priv->mlxreg_hotplug_attr;
+	priv->groups[0] = &priv->group;
+	priv->groups[1] = NULL;
+
+	return 0;
+}
+
+static int mlxreg_hotplug_device_create(struct device *dev,
+					struct mlxreg_hotplug_device *item)
+{
+	item->adapter = i2c_get_adapter(item->bus);
+	if (!item->adapter) {
+		dev_err(dev, "Failed to get adapter for bus %d\n",
+			item->bus);
+		return -EFAULT;
+	}
+
+	item->client = i2c_new_device(item->adapter, &item->brdinfo);
+	if (!item->client) {
+		dev_err(dev, "Failed to create client %s at bus %d at addr 0x%02x\n",
+			item->brdinfo.type, item->bus, item->brdinfo.addr);
+		i2c_put_adapter(item->adapter);
+		item->adapter = NULL;
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+static void mlxreg_hotplug_device_destroy(struct mlxreg_hotplug_device *item)
+{
+	if (item->client) {
+		i2c_unregister_device(item->client);
+		item->client = NULL;
+	}
+
+	if (item->adapter) {
+		i2c_put_adapter(item->adapter);
+		item->adapter = NULL;
+	}
+}
+
+static inline void
+mlxreg_hotplug_work_helper(struct device *dev,
+			   struct mlxreg_hotplug_device *item, u8 is_inverse,
+			   u16 offset, u8 mask, u8 *cache)
+{
+	u8 val, asserted;
+	int bit;
+
+	/* Mask event. */
+	outb(0, offset + MLXREG_HOTPLUG_MASK_OFF);
+	/* Read status. */
+	val = inb(offset) & mask;
+	asserted = *cache ^ val;
+	*cache = val;
+
+	/*
+	 * Validate if item related to received signal type is valid.
+	 * It should never happen, excepted the situation when some
+	 * piece of hardware is broken. In such situation just produce
+	 * error message and return. Caller must continue to handle the
+	 * signals from other devices if any.
+	 */
+	if (unlikely(!item)) {
+		dev_err(dev, "False signal is received: register at offset 0x%02x, mask 0x%02x.\n",
+			offset, mask);
+		return;
+	}
+
+	for_each_set_bit(bit, (unsigned long *)&asserted, 8) {
+		if (val & BIT(bit)) {
+			if (is_inverse)
+				mlxreg_hotplug_device_destroy(item + bit);
+			else
+				mlxreg_hotplug_device_create(dev, item + bit);
+		} else {
+			if (is_inverse)
+				mlxreg_hotplug_device_create(dev, item + bit);
+			else
+				mlxreg_hotplug_device_destroy(item + bit);
+		}
+	}
+
+	/* Acknowledge event. */
+	outb(0, offset + MLXREG_HOTPLUG_EVENT_OFF);
+	/* Unmask event. */
+	outb(mask, offset + MLXREG_HOTPLUG_MASK_OFF);
+}
+
+/*
+ * mlxreg_hotplug_work_handler - performs traversing of CPLD interrupt
+ * registers according to the below hierarchy schema:
+ *
+ *                   Aggregation registers (status/mask)
+ * PSU registers:           *---*
+ * *-----------------*      |   |
+ * |status/event/mask|----->| * |
+ * *-----------------*      |   |
+ * Power registers:         |   |
+ * *-----------------*      |   |
+ * |status/event/mask|----->| * |---> CPU
+ * *-----------------*      |   |
+ * FAN registers:
+ * *-----------------*      |   |
+ * |status/event/mask|----->| * |
+ * *-----------------*      |   |
+ *                          *---*
+ * In case some system changed are detected: FAN in/out, PSU in/out, power
+ * cable attached/detached, relevant device is created or destroyed.
+ */
+static void mlxreg_hotplug_work_handler(struct work_struct *work)
+{
+	struct mlxreg_hotplug_priv_data *priv = container_of(work,
+				struct mlxreg_hotplug_priv_data, dwork.work);
+	u8 val, aggr_asserted;
+	unsigned long flags;
+
+	/* Mask aggregation event. */
+	outb(0, priv->plat->top_aggr_offset + MLXREG_HOTPLUG_AGGR_MASK_OFF);
+	/* Read aggregation status. */
+	val = inb(priv->plat->top_aggr_offset) & priv->plat->top_aggr_mask;
+	aggr_asserted = priv->aggr_cache ^ val;
+	priv->aggr_cache = val;
+
+	/* Handle PSU configuration changes. */
+	if (aggr_asserted & priv->plat->top_aggr_psu_mask)
+		mlxreg_hotplug_work_helper(&priv->pdev->dev, priv->plat->psu,
+					   1, priv->plat->psu_reg_offset,
+					   priv->plat->psu_mask,
+					   &priv->psu_cache);
+
+	/* Handle power cable configuration changes. */
+	if (aggr_asserted & priv->plat->top_aggr_pwr_mask)
+		mlxreg_hotplug_work_helper(&priv->pdev->dev, priv->plat->pwr,
+					   0, priv->plat->pwr_reg_offset,
+					   priv->plat->pwr_mask,
+					   &priv->pwr_cache);
+
+	/* Handle FAN configuration changes. */
+	if (aggr_asserted & priv->plat->top_aggr_fan_mask)
+		mlxreg_hotplug_work_helper(&priv->pdev->dev, priv->plat->fan,
+					   1, priv->plat->fan_reg_offset,
+					   priv->plat->fan_mask,
+					   &priv->fan_cache);
+
+	if (aggr_asserted) {
+		spin_lock_irqsave(&priv->lock, flags);
+
+		/*
+		 * It is possible, that some signals have been inserted, while
+		 * interrupt has been masked by mlxreg_hotplug_work_handler.
+		 * In this case such signals will be missed. In order to handle
+		 * these signals delayed work is canceled and work task
+		 * re-scheduled for immediate execution. It allows to handle
+		 * missed signals, if any. In other case work handler just
+		 * validates that no new signals have been received during
+		 * masking.
+		 */
+		cancel_delayed_work(&priv->dwork);
+		schedule_delayed_work(&priv->dwork, 0);
+
+		spin_unlock_irqrestore(&priv->lock, flags);
+
+		return;
+	}
+
+	/* Unmask aggregation event (no need acknowledge). */
+	outb(priv->plat->top_aggr_mask, priv->plat->top_aggr_offset +
+						MLXREG_HOTPLUG_AGGR_MASK_OFF);
+}
+
+static void mlxreg_hotplug_set_irq(struct mlxreg_hotplug_priv_data *priv)
+{
+	/* Clear psu presense event. */
+	outb(0, priv->plat->psu_reg_offset + MLXREG_HOTPLUG_EVENT_OFF);
+	/* Set psu initial status as mask and unmask psu event. */
+	priv->psu_cache = priv->plat->psu_mask;
+	outb(priv->plat->psu_mask, priv->plat->psu_reg_offset +
+						MLXREG_HOTPLUG_MASK_OFF);
+
+	/* Clear power cable event. */
+	outb(0, priv->plat->pwr_reg_offset + MLXREG_HOTPLUG_EVENT_OFF);
+	/* Keep power initial status as zero and unmask power event. */
+	outb(priv->plat->pwr_mask, priv->plat->pwr_reg_offset +
+						MLXREG_HOTPLUG_MASK_OFF);
+
+	/* Clear fan presense event. */
+	outb(0, priv->plat->fan_reg_offset + MLXREG_HOTPLUG_EVENT_OFF);
+	/* Set fan initial status as mask and unmask fan event. */
+	priv->fan_cache = priv->plat->fan_mask;
+	outb(priv->plat->fan_mask, priv->plat->fan_reg_offset +
+						MLXREG_HOTPLUG_MASK_OFF);
+
+	/* Keep aggregation initial status as zero and unmask events. */
+	outb(priv->plat->top_aggr_mask, priv->plat->top_aggr_offset +
+						MLXREG_HOTPLUG_AGGR_MASK_OFF);
+
+	/* Invoke work handler for initializing hot plug devices setting. */
+	mlxreg_hotplug_work_handler(&priv->dwork.work);
+
+	enable_irq(priv->irq);
+}
+
+static void mlxreg_hotplug_unset_irq(struct mlxreg_hotplug_priv_data *priv)
+{
+	int i;
+
+	disable_irq(priv->irq);
+	cancel_delayed_work_sync(&priv->dwork);
+
+	/* Mask aggregation event. */
+	outb(0, priv->plat->top_aggr_offset + MLXREG_HOTPLUG_AGGR_MASK_OFF);
+
+	/* Mask psu presense event. */
+	outb(0, priv->plat->psu_reg_offset + MLXREG_HOTPLUG_MASK_OFF);
+	/* Clear psu presense event. */
+	outb(0, priv->plat->psu_reg_offset + MLXREG_HOTPLUG_EVENT_OFF);
+
+	/* Mask power cable event. */
+	outb(0, priv->plat->pwr_reg_offset + MLXREG_HOTPLUG_MASK_OFF);
+	/* Clear power cable event. */
+	outb(0, priv->plat->pwr_reg_offset + MLXREG_HOTPLUG_EVENT_OFF);
+
+	/* Mask fan presense event. */
+	outb(0, priv->plat->fan_reg_offset + MLXREG_HOTPLUG_MASK_OFF);
+	/* Clear fan presense event. */
+	outb(0, priv->plat->fan_reg_offset + MLXREG_HOTPLUG_EVENT_OFF);
+
+	/* Remove all the attached devices. */
+	for (i = 0; i < priv->plat->psu_count; i++)
+		mlxreg_hotplug_device_destroy(priv->plat->psu + i);
+
+	for (i = 0; i < priv->plat->pwr_count; i++)
+		mlxreg_hotplug_device_destroy(priv->plat->pwr + i);
+
+	for (i = 0; i < priv->plat->fan_count; i++)
+		mlxreg_hotplug_device_destroy(priv->plat->fan + i);
+}
+
+static irqreturn_t mlxreg_hotplug_irq_handler(int irq, void *dev)
+{
+	struct mlxreg_hotplug_priv_data *priv =
+				(struct mlxreg_hotplug_priv_data *)dev;
+
+	/* Schedule work task for immediate execution.*/
+	schedule_delayed_work(&priv->dwork, 0);
+
+	return IRQ_HANDLED;
+}
+
+static int mlxreg_hotplug_probe(struct platform_device *pdev)
+{
+	struct mlxreg_hotplug_platform_data *pdata;
+	struct mlxreg_hotplug_priv_data *priv;
+	int err;
+
+	pdata = dev_get_platdata(&pdev->dev);
+	if (!pdata) {
+		dev_err(&pdev->dev, "Failed to get platform data.\n");
+		return -EINVAL;
+	}
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->pdev = pdev;
+	priv->plat = pdata;
+
+	priv->irq = platform_get_irq(pdev, 0);
+	if (priv->irq < 0) {
+		dev_err(&pdev->dev, "Failed to get platform irq: %d\n",
+			priv->irq);
+		return priv->irq;
+	}
+
+	err = devm_request_irq(&pdev->dev, priv->irq,
+			       mlxreg_hotplug_irq_handler, 0, pdev->name,
+			       priv);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to request irq: %d\n", err);
+		return err;
+	}
+	disable_irq(priv->irq);
+
+	INIT_DELAYED_WORK(&priv->dwork, mlxreg_hotplug_work_handler);
+	spin_lock_init(&priv->lock);
+
+	err = mlxreg_hotplug_attr_init(priv);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to allocate attributes: %d\n", err);
+		return err;
+	}
+
+	priv->hwmon = devm_hwmon_device_register_with_groups(&pdev->dev,
+					"mlxreg_hotplug", priv, priv->groups);
+	if (IS_ERR(priv->hwmon)) {
+		dev_err(&pdev->dev, "Failed to register hwmon device %ld\n",
+			PTR_ERR(priv->hwmon));
+		return PTR_ERR(priv->hwmon);
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	/* Perform initial interrupts setup. */
+	mlxreg_hotplug_set_irq(priv);
+
+	return 0;
+}
+
+static int mlxreg_hotplug_remove(struct platform_device *pdev)
+{
+	struct mlxreg_hotplug_priv_data *priv = platform_get_drvdata(pdev);
+
+	/* Clean interrupts setup. */
+	mlxreg_hotplug_unset_irq(priv);
+
+	return 0;
+}
+
+static struct platform_driver mlxreg_hotplug_driver = {
+	.driver = {
+		.name = "mlxreg-hotplug",
+	},
+	.probe = mlxreg_hotplug_probe,
+	.remove = mlxreg_hotplug_remove,
+};
+
+module_platform_driver(mlxreg_hotplug_driver);
+
+MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
+MODULE_DESCRIPTION("Mellanox regmap hotplug platform driver");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("platform:mlxreg-hotplug");