[PATCH 3/3] platform/x86: Intel PMT Crashlog capability driver

[David E. Box]

From: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>

Add support for the Intel Platform Monitoring Technology crashlog
interface.  This interface provides a few sysfs values to allow for
controlling the crashlog telemetry interface as well as a character driver
to allow for mapping the crashlog memory region so that it can be accessed
after a crashlog has been recorded.

This driver is meant to only support the server version of the crashlog
which is identified as crash_type 1 with a version of zero. Currently no
other types are supported.

Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
---
 .../ABI/testing/sysfs-class-pmt_crashlog      |  66 ++
 drivers/platform/x86/Kconfig                  |  10 +
 drivers/platform/x86/Makefile                 |   1 +
 drivers/platform/x86/intel_pmt_crashlog.c     | 588 ++++++++++++++++++
 4 files changed, 665 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-pmt_crashlog
 create mode 100644 drivers/platform/x86/intel_pmt_crashlog.c

diff --git a/Documentation/ABI/testing/sysfs-class-pmt_crashlog b/Documentation/ABI/testing/sysfs-class-pmt_crashlog
new file mode 100644
index 000000000000..40fb4ff437a6
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-pmt_crashlog
@@ -0,0 +1,66 @@
+What:		/sys/class/pmt_crashlog/
+Date:		September 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
+Description:
+		The pmt_crashlog/ class directory contains information
+		for devices that expose crashlog capabilities using the Intel
+		Platform Monitoring Technology (PTM).
+
+What:		/sys/class/pmt_crashlog/crashlogX
+Date:		September 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
+Description:
+		The crashlogX directory contains files for configuring an
+		instance of a PMT crashlog device that can perform crash data
+		recoring. Each crashlogX device has an associated
+		/dev/crashlogX device node. This node can be opened and mapped
+		to access the resulting crashlog data. The register layout for
+		the log can be determined from an XML file of specified guid
+		for the parent device.
+
+What:		/sys/class/pmt_crashlog/crashlogX/guid
+Date:		September 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
+Description:
+		(RO) The guid for this crashlog device. The guid identifies the
+		version of the XML file for the parent device that should be
+		used to determine the register layout.
+
+What:		/sys/class/pmt_crashlog/crashlogX/size
+Date:		September 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
+Description:
+		(RO) The length of the result buffer in bytes that corresponds
+		to the mapping size for the /dev/crashlogX device node.
+
+What:		/sys/class/pmt_crashlog/crashlogX/offset
+Date:		September 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
+Description:
+		(RO) The offset of the buffer in bytes that corresponds
+		to the mapping for the /dev/crashlogX device node.
+
+What:		/sys/class/pmt_crashlog/crashlogX/enable
+Date:		September 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
+Description:
+		(RW) Boolean value controlling if the crashlog functionality
+		is enabled for the /dev/crashlogX device node.
+
+What:		/sys/class/pmt_crashlog/crashlogX/trigger
+Date:		September 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
+Description:
+		(RW) Boolean value controlling  the triggering of the
+		/dev/crashlogX device node. When read it provides data on if
+		the crashlog has been triggered. When written to it can be
+		used to either clear the current trigger by writing false, or
+		to trigger a new event if the trigger is not currently set.
+
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 48335b02014f..50c3234e4f72 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1360,6 +1360,16 @@ config INTEL_PMC_CORE
 		- LTR Ignore
 		- MPHY/PLL gating status (Sunrisepoint PCH only)
 
+config INTEL_PMT_CRASHLOG
+	tristate "Intel Platform Monitoring Technology (PMT) Crashlog driver"
+	help
+	 The Intel Platform Monitoring Technology (PMT) crashlog driver provides
+	 access to hardware crashlog capabilities on devices that support the
+	 feature.
+
+	 For more information, see
+	 <file:Documentation/ABI/testing/sysfs-class-intel_pmt_crashlog>
+
 config INTEL_PMT_TELEMETRY
 	tristate "Intel Platform Monitoring Technology (PMT) Telemetry driver"
 	help
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index ca942e70de8d..1b8b2502d460 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -140,6 +140,7 @@ obj-$(CONFIG_INTEL_MFLD_THERMAL)	+= intel_mid_thermal.o
 obj-$(CONFIG_INTEL_MID_POWER_BUTTON)	+= intel_mid_powerbtn.o
 obj-$(CONFIG_INTEL_MRFLD_PWRBTN)	+= intel_mrfld_pwrbtn.o
 obj-$(CONFIG_INTEL_PMC_CORE)		+= intel_pmc_core.o intel_pmc_core_pltdrv.o
+obj-$(CONFIG_INTEL_PMT_CRASHLOG)	+= intel_pmt_crashlog.o
 obj-$(CONFIG_INTEL_PMT_TELEMETRY)	+= intel_pmt_telemetry.o
 obj-$(CONFIG_INTEL_PUNIT_IPC)		+= intel_punit_ipc.o
 obj-$(CONFIG_INTEL_SCU_IPC)		+= intel_scu_ipc.o
diff --git a/drivers/platform/x86/intel_pmt_crashlog.c b/drivers/platform/x86/intel_pmt_crashlog.c
new file mode 100644
index 000000000000..31d43708055c
--- /dev/null
+++ b/drivers/platform/x86/intel_pmt_crashlog.c
@@ -0,0 +1,588 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel Platform Monitoring Technology Crashlog driver
+ *
+ * Copyright (c) 2020, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * Authors: "Alexander Duyck" <alexander.h.duyck@xxxxxxxxxxxxxxx>
+ */
+
+#include <linux/cdev.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#define DRV_NAME		"pmt_crashlog"
+
+/* Crashlog access types */
+#define ACCESS_FUTURE		1
+#define ACCESS_BARID		2
+#define ACCESS_LOCAL		3
+
+/* Crashlog discovery header types */
+#define CRASH_TYPE_OOBMSM	1
+
+/* Control Flags */
+#define CRASHLOG_FLAG_DISABLE	BIT(27)
+#define CRASHLOG_FLAG_CLEAR	BIT(28)
+#define CRASHLOG_FLAG_EXECUTE	BIT(29)
+#define CRASHLOG_FLAG_COMPLETE	BIT(31)
+#define CRASHLOG_FLAG_MASK	GENMASK(31, 28)
+
+/* Common Header */
+#define CONTROL_OFFSET		0x0
+#define GUID_OFFSET		0x4
+#define BASE_OFFSET		0x8
+#define SIZE_OFFSET		0xC
+#define GET_ACCESS(v)		((v) & GENMASK(3, 0))
+#define GET_TYPE(v)		(((v) & GENMASK(7, 4)) >> 4)
+#define GET_VERSION(v)		(((v) & GENMASK(19, 16)) >> 16)
+
+#define GET_ADDRESS(v)		((v) & GENMASK(31, 3))
+#define GET_BIR(v)		((v) & GENMASK(2, 0))
+
+static DEFINE_IDA(crashlog_devid_ida);
+
+struct crashlog_header {
+	u32	base_offset;
+	u32	size;
+	u32	guid;
+	u8	bir;
+	u8	access_type;
+	u8	crash_type;
+	u8	version;
+};
+
+struct pmt_crashlog_priv;
+
+struct crashlog_entry {
+	struct pmt_crashlog_priv	*priv;
+	struct crashlog_header		header;
+	struct resource			*header_res;
+	void __iomem			*disc_table;
+	unsigned long			crashlog_data;
+	size_t				crashlog_data_size;
+	struct cdev			cdev;
+	dev_t				devt;
+	int				devid;
+	struct ida			*ida;
+};
+
+struct pmt_crashlog_priv {
+	struct device		*dev;
+	struct pci_dev		*parent;
+	struct crashlog_entry	*entry;
+	int			num_entries;
+};
+
+/*
+ * I/O
+ */
+static bool pmt_crashlog_complete(struct crashlog_entry *entry)
+{
+	u32 control = readl(entry->disc_table + CONTROL_OFFSET);
+
+	/* return current value of the crashlog complete flag */
+	return !!(control & CRASHLOG_FLAG_COMPLETE);
+}
+
+static bool pmt_crashlog_disabled(struct crashlog_entry *entry)
+{
+	u32 control = readl(entry->disc_table + CONTROL_OFFSET);
+
+	/* return current value of the crashlog disabled flag */
+	return !!(control & CRASHLOG_FLAG_DISABLE);
+}
+
+static void pmt_crashlog_set_disable(struct crashlog_entry *entry, bool disable)
+{
+	u32 control = readl(entry->disc_table + CONTROL_OFFSET);
+
+	/* clear control bits */
+	control &= ~(CRASHLOG_FLAG_MASK | CRASHLOG_FLAG_DISABLE);
+	if (disable)
+		control |= CRASHLOG_FLAG_DISABLE;
+
+	writel(control, entry->disc_table + CONTROL_OFFSET);
+}
+
+static void pmt_crashlog_set_clear(struct crashlog_entry *entry)
+{
+	u32 control = readl(entry->disc_table + CONTROL_OFFSET);
+
+	/* clear control bits */
+	control &= ~CRASHLOG_FLAG_MASK;
+	control |= CRASHLOG_FLAG_CLEAR;
+
+	writel(control, entry->disc_table + CONTROL_OFFSET);
+}
+
+static void pmt_crashlog_set_execute(struct crashlog_entry *entry)
+{
+	u32 control = readl(entry->disc_table + CONTROL_OFFSET);
+
+	/* clear control bits */
+	control &= ~CRASHLOG_FLAG_MASK;
+	control |= CRASHLOG_FLAG_EXECUTE;
+
+	writel(control, entry->disc_table + CONTROL_OFFSET);
+}
+
+/*
+ * devfs
+ */
+static int pmt_crashlog_open(struct inode *inode, struct file *filp)
+{
+	struct crashlog_entry *entry;
+	struct pci_driver *pci_drv;
+	struct pmt_crashlog_priv *priv;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	entry = container_of(inode->i_cdev, struct crashlog_entry, cdev);
+	priv = entry->priv;
+	pci_drv = pci_dev_driver(priv->parent);
+
+	if (!pci_drv)
+		return -ENODEV;
+
+	filp->private_data = entry;
+	get_device(&priv->parent->dev);
+
+	if (!try_module_get(pci_drv->driver.owner)) {
+		put_device(&priv->parent->dev);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int pmt_crashlog_release(struct inode *inode, struct file *filp)
+{
+	struct crashlog_entry *entry = filp->private_data;
+	struct pmt_crashlog_priv *priv;
+	struct pci_driver *pci_drv;
+
+	priv = entry->priv;
+	pci_drv = pci_dev_driver(priv->parent);
+
+	put_device(&priv->parent->dev);
+	module_put(pci_drv->driver.owner);
+
+	return 0;
+}
+
+static int
+pmt_crashlog_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct crashlog_entry *entry = filp->private_data;
+	struct pmt_crashlog_priv *priv;
+	unsigned long phys = entry->crashlog_data;
+	unsigned long pfn = PFN_DOWN(phys);
+	unsigned long vsize = vma->vm_end - vma->vm_start;
+	unsigned long psize;
+
+	if ((vma->vm_flags & VM_WRITE) ||
+	    (vma->vm_flags & VM_MAYWRITE))
+		return -EPERM;
+
+	priv = entry->priv;
+
+	if (!entry->crashlog_data_size) {
+		dev_err(priv->dev, "Crashlog data not accessible\n");
+		return -EAGAIN;
+	}
+
+	psize = (PFN_UP(entry->crashlog_data + entry->crashlog_data_size) - pfn) *
+		PAGE_SIZE;
+	if (vsize > psize) {
+		dev_err(priv->dev, "Requested mmap size is too large\n");
+		return -EINVAL;
+	}
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	if (io_remap_pfn_range(vma, vma->vm_start, pfn,
+		vsize, vma->vm_page_prot))
+		return -EAGAIN;
+
+	return 0;
+}
+
+static const struct file_operations pmt_crashlog_fops = {
+	.owner =	THIS_MODULE,
+	.open =		pmt_crashlog_open,
+	.mmap =		pmt_crashlog_mmap,
+	.release =	pmt_crashlog_release,
+};
+
+/*
+ * sysfs
+ */
+static ssize_t
+guid_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct crashlog_entry *entry;
+
+	entry = dev_get_drvdata(dev);
+
+	return sprintf(buf, "0x%x\n", entry->header.guid);
+}
+static DEVICE_ATTR_RO(guid);
+
+static ssize_t size_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct crashlog_entry *entry;
+
+	entry = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%lu\n", entry->crashlog_data_size);
+}
+static DEVICE_ATTR_RO(size);
+
+static ssize_t
+offset_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct crashlog_entry *entry;
+
+	entry = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%lu\n", offset_in_page(entry->crashlog_data));
+}
+static DEVICE_ATTR_RO(offset);
+
+static ssize_t
+enable_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct crashlog_entry *entry;
+	int enabled;
+
+	entry = dev_get_drvdata(dev);
+	enabled = !pmt_crashlog_disabled(entry);
+
+	return sprintf(buf, "%d\n", enabled);
+}
+
+static ssize_t
+enable_store(struct device *dev, struct device_attribute *attr,
+	    const char *buf, size_t count)
+{
+	struct crashlog_entry *entry;
+	bool enabled;
+	int result;
+
+	entry = dev_get_drvdata(dev);
+
+	result = kstrtobool(buf, &enabled);
+	if (result)
+		return result;
+
+	pmt_crashlog_set_disable(entry, !enabled);
+
+	return strnlen(buf, count);
+}
+static DEVICE_ATTR_RW(enable);
+
+static ssize_t
+trigger_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct crashlog_entry *entry;
+	int trigger;
+
+	entry = dev_get_drvdata(dev);
+	trigger = pmt_crashlog_complete(entry);
+
+	return sprintf(buf, "%d\n", trigger);
+}
+
+static ssize_t
+trigger_store(struct device *dev, struct device_attribute *attr,
+	    const char *buf, size_t count)
+{
+	struct crashlog_entry *entry;
+	bool trigger;
+	int result;
+
+	entry = dev_get_drvdata(dev);
+
+	result = kstrtobool(buf, &trigger);
+	if (result)
+		return result;
+
+	if (trigger) {
+		/* we cannot trigger a new crash if one is still pending */
+		if (pmt_crashlog_complete(entry))
+			return -EEXIST;
+
+		/* if device is currently disabled, return busy */
+		if (pmt_crashlog_disabled(entry))
+			return -EBUSY;
+
+		pmt_crashlog_set_execute(entry);
+	} else {
+		pmt_crashlog_set_clear(entry);
+	}
+
+	return strnlen(buf, count);
+}
+static DEVICE_ATTR_RW(trigger);
+
+static struct attribute *pmt_crashlog_attrs[] = {
+	&dev_attr_guid.attr,
+	&dev_attr_size.attr,
+	&dev_attr_offset.attr,
+	&dev_attr_enable.attr,
+	&dev_attr_trigger.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(pmt_crashlog);
+
+static struct class pmt_crashlog_class = {
+	.name = "pmt_crashlog",
+	.owner = THIS_MODULE,
+	.dev_groups = pmt_crashlog_groups,
+};
+
+/*
+ * initialization
+ */
+static int pmt_crashlog_make_dev(struct pmt_crashlog_priv *priv,
+				 struct crashlog_entry *entry)
+{
+	struct device *dev;
+	int ret;
+
+	ret = alloc_chrdev_region(&entry->devt, 0, 1, DRV_NAME);
+	if (ret < 0) {
+		dev_err(priv->dev, "alloc_chrdev_region err: %d\n", ret);
+		return ret;
+	}
+
+	/* Create a character device for Samplers */
+	cdev_init(&entry->cdev, &pmt_crashlog_fops);
+
+	ret = cdev_add(&entry->cdev, entry->devt, 1);
+	if (ret) {
+		dev_err(priv->dev, "Could not add char dev\n");
+		return ret;
+	}
+
+	dev = device_create(&pmt_crashlog_class, &priv->parent->dev, entry->devt,
+			    entry, "%s%d", "crashlog", entry->devid);
+
+	if (IS_ERR(dev)) {
+		dev_err(priv->dev, "Could not create device node\n");
+		cdev_del(&entry->cdev);
+	}
+
+	return PTR_ERR_OR_ZERO(dev);
+}
+
+static void
+pmt_crashlog_populate_header(void __iomem *disc_offset,
+			     struct crashlog_header *header)
+{
+	u32 discovery_header = readl(disc_offset);
+
+	header->access_type = GET_ACCESS(discovery_header);
+	header->crash_type = GET_TYPE(discovery_header);
+	header->version = GET_VERSION(discovery_header);
+	header->guid = readl(disc_offset + GUID_OFFSET);
+	header->base_offset = readl(disc_offset + BASE_OFFSET);
+
+	/*
+	 * For non-local access types the lower 3 bits of base offset
+	 * contains the index of the base address register where the
+	 * crashlogetry can be found.
+	 */
+	header->bir = GET_BIR(header->base_offset);
+	header->base_offset ^= header->bir;
+
+	/* Size is measured in DWORDs */
+	header->size = readl(disc_offset + SIZE_OFFSET);
+}
+
+static int pmt_crashlog_add_entry(struct pmt_crashlog_priv *priv,
+				  struct crashlog_entry *entry)
+{
+	struct resource *res = entry->header_res;
+	int ret;
+
+	pmt_crashlog_populate_header(entry->disc_table, &entry->header);
+
+	/* Local access and BARID only for now */
+	switch (entry->header.access_type) {
+	case ACCESS_LOCAL:
+		dev_info(priv->dev, "access_type: LOCAL\n");
+		if (entry->header.bir) {
+			dev_err(priv->dev,
+				"Unsupported BAR index %d for access type %d\n",
+				entry->header.bir, entry->header.access_type);
+			return -EINVAL;
+		}
+
+		entry->crashlog_data = res->start + resource_size(res) +
+				       entry->header.base_offset;
+		break;
+
+	case ACCESS_BARID:
+		dev_info(priv->dev, "access_type: BARID\n");
+		entry->crashlog_data =
+			priv->parent->resource[entry->header.bir].start +
+			entry->header.base_offset;
+		break;
+
+	default:
+		dev_err(priv->dev, "Unsupported access type %d\n",
+			entry->header.access_type);
+		return -EINVAL;
+	}
+
+	dev_info(priv->dev, "crashlod_data address: 0x%lx\n", entry->crashlog_data);
+
+	entry->crashlog_data_size = entry->header.size * 4;
+
+	if (entry->header.crash_type != CRASH_TYPE_OOBMSM) {
+		dev_err(priv->dev, "Unsupported crashlog header type %d\n",
+			entry->header.crash_type);
+		return -EINVAL;
+	}
+
+	if (entry->header.version != 0) {
+		dev_err(priv->dev, "Unsupported version value %d\n",
+			entry->header.version);
+		return -EINVAL;
+	}
+
+	entry->ida = &crashlog_devid_ida;
+
+	entry->devid = ida_simple_get(entry->ida, 0, 0, GFP_KERNEL);
+	if (entry->devid < 0)
+		return entry->devid;
+
+	ret = pmt_crashlog_make_dev(priv, entry);
+	if (ret) {
+		ida_simple_remove(entry->ida, entry->devid);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void pmt_crashlog_remove_entries(struct pmt_crashlog_priv *priv)
+{
+	int i;
+
+	for (i = 0; i < priv->num_entries; i++) {
+		device_destroy(&pmt_crashlog_class, priv->entry[i].devt);
+		cdev_del(&priv->entry[i].cdev);
+
+		unregister_chrdev_region(priv->entry[i].devt, 1);
+		ida_simple_remove(priv->entry[i].ida, priv->entry[i].devid);
+	}
+}
+static int pmt_crashlog_probe(struct platform_device *pdev)
+{
+	struct pmt_crashlog_priv *priv;
+	struct crashlog_entry *entry;
+	int i;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+	priv->dev = &pdev->dev;
+	priv->parent  = to_pci_dev(priv->dev->parent);
+
+	priv->entry = devm_kcalloc(&pdev->dev, pdev->num_resources,
+				   sizeof(*(priv->entry)), GFP_KERNEL);
+
+	for (i = 0, entry = priv->entry; i < pdev->num_resources;
+	     i++, entry++) {
+		int ret;
+
+		entry->header_res = platform_get_resource(pdev, IORESOURCE_MEM,
+							  i);
+		if (!entry->header_res) {
+			pmt_crashlog_remove_entries(priv);
+			return -ENODEV;
+		}
+
+		dev_info(&pdev->dev, "%d res start: 0x%llx, end 0x%llx\n", i,
+			 entry->header_res->start, entry->header_res->end);
+
+		entry->disc_table = devm_platform_ioremap_resource(pdev, i);
+		if (IS_ERR(entry->disc_table)) {
+			pmt_crashlog_remove_entries(priv);
+			return PTR_ERR(entry->disc_table);
+		}
+
+		ret = pmt_crashlog_add_entry(priv, entry);
+		if (ret) {
+			pmt_crashlog_remove_entries(priv);
+			return ret;
+		}
+
+		entry->priv = priv;
+		priv->num_entries++;
+	}
+
+	return 0;
+}
+
+static int pmt_crashlog_remove(struct platform_device *pdev)
+{
+	struct pmt_crashlog_priv *priv;
+
+	priv = (struct pmt_crashlog_priv *)platform_get_drvdata(pdev);
+
+	pmt_crashlog_remove_entries(priv);
+
+	return 0;
+}
+
+static struct platform_driver pmt_crashlog_driver = {
+	.driver = {
+		.name   = DRV_NAME,
+	},
+	.probe  = pmt_crashlog_probe,
+	.remove = pmt_crashlog_remove,
+};
+
+static int __init pmt_crashlog_init(void)
+{
+	int ret = class_register(&pmt_crashlog_class);
+
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&pmt_crashlog_driver);
+	if (ret) {
+		class_unregister(&pmt_crashlog_class);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit pmt_crashlog_exit(void)
+{
+	platform_driver_unregister(&pmt_crashlog_driver);
+	class_unregister(&pmt_crashlog_class);
+	ida_destroy(&crashlog_devid_ida);
+}
+
+module_init(pmt_crashlog_init);
+module_exit(pmt_crashlog_exit);
+
+MODULE_AUTHOR("Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Intel PMT Crashlog driver");
+MODULE_ALIAS("platform:" DRV_NAME);
+MODULE_LICENSE("GPL v2");
-- 
2.20.1