Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 782 insertions, 0 deletions

diff --git a/drivers/platform/x86/dell/dcdbas.c b/drivers/platform/x86/dell/dcdbas.c
new file mode 100644
index 000000000..0ecb7b164
--- /dev/null
+++ b/drivers/platform/x86/dell/dcdbas.c
@@ -0,0 +1,782 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  dcdbas.c: Dell Systems Management Base Driver
+ *
+ *  The Dell Systems Management Base Driver provides a sysfs interface for
+ *  systems management software to perform System Management Interrupts (SMIs)
+ *  and Host Control Actions (power cycle or power off after OS shutdown) on
+ *  Dell systems.
+ *
+ *  See Documentation/driver-api/dcdbas.rst for more information.
+ *
+ *  Copyright (C) 1995-2006 Dell Inc.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmi.h>
+#include <linux/errno.h>
+#include <linux/cpu.h>
+#include <linux/gfp.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mc146818rtc.h>
+#include <linux/module.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+
+#include "dcdbas.h"
+
+#define DRIVER_NAME		"dcdbas"
+#define DRIVER_VERSION		"5.6.0-3.4"
+#define DRIVER_DESCRIPTION	"Dell Systems Management Base Driver"
+
+static struct platform_device *dcdbas_pdev;
+
+static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE;
+static DEFINE_MUTEX(smi_data_lock);
+static u8 *bios_buffer;
+static struct smi_buffer smi_buf;
+
+static unsigned int host_control_action;
+static unsigned int host_control_smi_type;
+static unsigned int host_control_on_shutdown;
+
+static bool wsmt_enabled;
+
+int dcdbas_smi_alloc(struct smi_buffer *smi_buffer, unsigned long size)
+{
+	smi_buffer->virt = dma_alloc_coherent(&dcdbas_pdev->dev, size,
+					      &smi_buffer->dma, GFP_KERNEL);
+	if (!smi_buffer->virt) {
+		dev_dbg(&dcdbas_pdev->dev,
+			"%s: failed to allocate memory size %lu\n",
+			__func__, size);
+		return -ENOMEM;
+	}
+	smi_buffer->size = size;
+
+	dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
+		__func__, (u32)smi_buffer->dma, smi_buffer->size);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dcdbas_smi_alloc);
+
+void dcdbas_smi_free(struct smi_buffer *smi_buffer)
+{
+	if (!smi_buffer->virt)
+		return;
+
+	dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
+		__func__, (u32)smi_buffer->dma, smi_buffer->size);
+	dma_free_coherent(&dcdbas_pdev->dev, smi_buffer->size,
+			  smi_buffer->virt, smi_buffer->dma);
+	smi_buffer->virt = NULL;
+	smi_buffer->dma = 0;
+	smi_buffer->size = 0;
+}
+EXPORT_SYMBOL_GPL(dcdbas_smi_free);
+
+/**
+ * smi_data_buf_free: free SMI data buffer
+ */
+static void smi_data_buf_free(void)
+{
+	if (!smi_buf.virt || wsmt_enabled)
+		return;
+
+	dcdbas_smi_free(&smi_buf);
+}
+
+/**
+ * smi_data_buf_realloc: grow SMI data buffer if needed
+ */
+static int smi_data_buf_realloc(unsigned long size)
+{
+	struct smi_buffer tmp;
+	int ret;
+
+	if (smi_buf.size >= size)
+		return 0;
+
+	if (size > max_smi_data_buf_size)
+		return -EINVAL;
+
+	/* new buffer is needed */
+	ret = dcdbas_smi_alloc(&tmp, size);
+	if (ret)
+		return ret;
+
+	/* memory zeroed by dma_alloc_coherent */
+	if (smi_buf.virt)
+		memcpy(tmp.virt, smi_buf.virt, smi_buf.size);
+
+	/* free any existing buffer */
+	smi_data_buf_free();
+
+	/* set up new buffer for use */
+	smi_buf = tmp;
+
+	return 0;
+}
+
+static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	return sprintf(buf, "%x\n", (u32)smi_buf.dma);
+}
+
+static ssize_t smi_data_buf_size_show(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	return sprintf(buf, "%lu\n", smi_buf.size);
+}
+
+static ssize_t smi_data_buf_size_store(struct device *dev,
+				       struct device_attribute *attr,
+				       const char *buf, size_t count)
+{
+	unsigned long buf_size;
+	ssize_t ret;
+
+	buf_size = simple_strtoul(buf, NULL, 10);
+
+	/* make sure SMI data buffer is at least buf_size */
+	mutex_lock(&smi_data_lock);
+	ret = smi_data_buf_realloc(buf_size);
+	mutex_unlock(&smi_data_lock);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t smi_data_read(struct file *filp, struct kobject *kobj,
+			     struct bin_attribute *bin_attr,
+			     char *buf, loff_t pos, size_t count)
+{
+	ssize_t ret;
+
+	mutex_lock(&smi_data_lock);
+	ret = memory_read_from_buffer(buf, count, &pos, smi_buf.virt,
+					smi_buf.size);
+	mutex_unlock(&smi_data_lock);
+	return ret;
+}
+
+static ssize_t smi_data_write(struct file *filp, struct kobject *kobj,
+			      struct bin_attribute *bin_attr,
+			      char *buf, loff_t pos, size_t count)
+{
+	ssize_t ret;
+
+	if ((pos + count) > max_smi_data_buf_size)
+		return -EINVAL;
+
+	mutex_lock(&smi_data_lock);
+
+	ret = smi_data_buf_realloc(pos + count);
+	if (ret)
+		goto out;
+
+	memcpy(smi_buf.virt + pos, buf, count);
+	ret = count;
+out:
+	mutex_unlock(&smi_data_lock);
+	return ret;
+}
+
+static ssize_t host_control_action_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	return sprintf(buf, "%u\n", host_control_action);
+}
+
+static ssize_t host_control_action_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	ssize_t ret;
+
+	/* make sure buffer is available for host control command */
+	mutex_lock(&smi_data_lock);
+	ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
+	mutex_unlock(&smi_data_lock);
+	if (ret)
+		return ret;
+
+	host_control_action = simple_strtoul(buf, NULL, 10);
+	return count;
+}
+
+static ssize_t host_control_smi_type_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	return sprintf(buf, "%u\n", host_control_smi_type);
+}
+
+static ssize_t host_control_smi_type_store(struct device *dev,
+					   struct device_attribute *attr,
+					   const char *buf, size_t count)
+{
+	host_control_smi_type = simple_strtoul(buf, NULL, 10);
+	return count;
+}
+
+static ssize_t host_control_on_shutdown_show(struct device *dev,
+					     struct device_attribute *attr,
+					     char *buf)
+{
+	return sprintf(buf, "%u\n", host_control_on_shutdown);
+}
+
+static ssize_t host_control_on_shutdown_store(struct device *dev,
+					      struct device_attribute *attr,
+					      const char *buf, size_t count)
+{
+	host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
+	return count;
+}
+
+static int raise_smi(void *par)
+{
+	struct smi_cmd *smi_cmd = par;
+
+	if (smp_processor_id() != 0) {
+		dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
+			__func__);
+		return -EBUSY;
+	}
+
+	/* generate SMI */
+	/* inb to force posted write through and make SMI happen now */
+	asm volatile (
+		"outb %b0,%w1\n"
+		"inb %w1"
+		: /* no output args */
+		: "a" (smi_cmd->command_code),
+		  "d" (smi_cmd->command_address),
+		  "b" (smi_cmd->ebx),
+		  "c" (smi_cmd->ecx)
+		: "memory"
+	);
+
+	return 0;
+}
+/**
+ * dcdbas_smi_request: generate SMI request
+ *
+ * Called with smi_data_lock.
+ */
+int dcdbas_smi_request(struct smi_cmd *smi_cmd)
+{
+	int ret;
+
+	if (smi_cmd->magic != SMI_CMD_MAGIC) {
+		dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
+			 __func__);
+		return -EBADR;
+	}
+
+	/* SMI requires CPU 0 */
+	cpus_read_lock();
+	ret = smp_call_on_cpu(0, raise_smi, smi_cmd, true);
+	cpus_read_unlock();
+
+	return ret;
+}
+EXPORT_SYMBOL(dcdbas_smi_request);
+
+/**
+ * smi_request_store:
+ *
+ * The valid values are:
+ * 0: zero SMI data buffer
+ * 1: generate calling interface SMI
+ * 2: generate raw SMI
+ *
+ * User application writes smi_cmd to smi_data before telling driver
+ * to generate SMI.
+ */
+static ssize_t smi_request_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	struct smi_cmd *smi_cmd;
+	unsigned long val = simple_strtoul(buf, NULL, 10);
+	ssize_t ret;
+
+	mutex_lock(&smi_data_lock);
+
+	if (smi_buf.size < sizeof(struct smi_cmd)) {
+		ret = -ENODEV;
+		goto out;
+	}
+	smi_cmd = (struct smi_cmd *)smi_buf.virt;
+
+	switch (val) {
+	case 2:
+		/* Raw SMI */
+		ret = dcdbas_smi_request(smi_cmd);
+		if (!ret)
+			ret = count;
+		break;
+	case 1:
+		/*
+		 * Calling Interface SMI
+		 *
+		 * Provide physical address of command buffer field within
+		 * the struct smi_cmd to BIOS.
+		 *
+		 * Because the address that smi_cmd (smi_buf.virt) points to
+		 * will be from memremap() of a non-memory address if WSMT
+		 * is present, we can't use virt_to_phys() on smi_cmd, so
+		 * we have to use the physical address that was saved when
+		 * the virtual address for smi_cmd was received.
+		 */
+		smi_cmd->ebx = (u32)smi_buf.dma +
+				offsetof(struct smi_cmd, command_buffer);
+		ret = dcdbas_smi_request(smi_cmd);
+		if (!ret)
+			ret = count;
+		break;
+	case 0:
+		memset(smi_buf.virt, 0, smi_buf.size);
+		ret = count;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+out:
+	mutex_unlock(&smi_data_lock);
+	return ret;
+}
+
+/**
+ * host_control_smi: generate host control SMI
+ *
+ * Caller must set up the host control command in smi_buf.virt.
+ */
+static int host_control_smi(void)
+{
+	struct apm_cmd *apm_cmd;
+	u8 *data;
+	unsigned long flags;
+	u32 num_ticks;
+	s8 cmd_status;
+	u8 index;
+
+	apm_cmd = (struct apm_cmd *)smi_buf.virt;
+	apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
+
+	switch (host_control_smi_type) {
+	case HC_SMITYPE_TYPE1:
+		spin_lock_irqsave(&rtc_lock, flags);
+		/* write SMI data buffer physical address */
+		data = (u8 *)&smi_buf.dma;
+		for (index = PE1300_CMOS_CMD_STRUCT_PTR;
+		     index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
+		     index++, data++) {
+			outb(index,
+			     (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
+			outb(*data,
+			     (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
+		}
+
+		/* first set status to -1 as called by spec */
+		cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
+		outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
+
+		/* generate SMM call */
+		outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
+		spin_unlock_irqrestore(&rtc_lock, flags);
+
+		/* wait a few to see if it executed */
+		num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
+		while ((s8)inb(PCAT_APM_STATUS_PORT) == ESM_STATUS_CMD_UNSUCCESSFUL) {
+			num_ticks--;
+			if (num_ticks == EXPIRED_TIMER)
+				return -ETIME;
+		}
+		break;
+
+	case HC_SMITYPE_TYPE2:
+	case HC_SMITYPE_TYPE3:
+		spin_lock_irqsave(&rtc_lock, flags);
+		/* write SMI data buffer physical address */
+		data = (u8 *)&smi_buf.dma;
+		for (index = PE1400_CMOS_CMD_STRUCT_PTR;
+		     index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
+		     index++, data++) {
+			outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
+			outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
+		}
+
+		/* generate SMM call */
+		if (host_control_smi_type == HC_SMITYPE_TYPE3)
+			outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
+		else
+			outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
+
+		/* restore RTC index pointer since it was written to above */
+		CMOS_READ(RTC_REG_C);
+		spin_unlock_irqrestore(&rtc_lock, flags);
+
+		/* read control port back to serialize write */
+		cmd_status = inb(PE1400_APM_CONTROL_PORT);
+
+		/* wait a few to see if it executed */
+		num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
+		while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
+			num_ticks--;
+			if (num_ticks == EXPIRED_TIMER)
+				return -ETIME;
+		}
+		break;
+
+	default:
+		dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
+			__func__, host_control_smi_type);
+		return -ENOSYS;
+	}
+
+	return 0;
+}
+
+/**
+ * dcdbas_host_control: initiate host control
+ *
+ * This function is called by the driver after the system has
+ * finished shutting down if the user application specified a
+ * host control action to perform on shutdown.  It is safe to
+ * use smi_buf.virt at this point because the system has finished
+ * shutting down and no userspace apps are running.
+ */
+static void dcdbas_host_control(void)
+{
+	struct apm_cmd *apm_cmd;
+	u8 action;
+
+	if (host_control_action == HC_ACTION_NONE)
+		return;
+
+	action = host_control_action;
+	host_control_action = HC_ACTION_NONE;
+
+	if (!smi_buf.virt) {
+		dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__);
+		return;
+	}
+
+	if (smi_buf.size < sizeof(struct apm_cmd)) {
+		dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
+			__func__);
+		return;
+	}
+
+	apm_cmd = (struct apm_cmd *)smi_buf.virt;
+
+	/* power off takes precedence */
+	if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
+		apm_cmd->command = ESM_APM_POWER_CYCLE;
+		apm_cmd->reserved = 0;
+		*((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
+		host_control_smi();
+	} else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
+		apm_cmd->command = ESM_APM_POWER_CYCLE;
+		apm_cmd->reserved = 0;
+		*((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
+		host_control_smi();
+	}
+}
+
+/* WSMT */
+
+static u8 checksum(u8 *buffer, u8 length)
+{
+	u8 sum = 0;
+	u8 *end = buffer + length;
+
+	while (buffer < end)
+		sum += *buffer++;
+	return sum;
+}
+
+static inline struct smm_eps_table *check_eps_table(u8 *addr)
+{
+	struct smm_eps_table *eps = (struct smm_eps_table *)addr;
+
+	if (strncmp(eps->smm_comm_buff_anchor, SMM_EPS_SIG, 4) != 0)
+		return NULL;
+
+	if (checksum(addr, eps->length) != 0)
+		return NULL;
+
+	return eps;
+}
+
+static int dcdbas_check_wsmt(void)
+{
+	const struct dmi_device *dev = NULL;
+	struct acpi_table_wsmt *wsmt = NULL;
+	struct smm_eps_table *eps = NULL;
+	u64 bios_buf_paddr;
+	u64 remap_size;
+	u8 *addr;
+
+	acpi_get_table(ACPI_SIG_WSMT, 0, (struct acpi_table_header **)&wsmt);
+	if (!wsmt)
+		return 0;
+
+	/* Check if WSMT ACPI table shows that protection is enabled */
+	if (!(wsmt->protection_flags & ACPI_WSMT_FIXED_COMM_BUFFERS) ||
+	    !(wsmt->protection_flags & ACPI_WSMT_COMM_BUFFER_NESTED_PTR_PROTECTION))
+		return 0;
+
+	/*
+	 * BIOS could provide the address/size of the protected buffer
+	 * in an SMBIOS string or in an EPS structure in 0xFxxxx.
+	 */
+
+	/* Check SMBIOS for buffer address */
+	while ((dev = dmi_find_device(DMI_DEV_TYPE_OEM_STRING, NULL, dev)))
+		if (sscanf(dev->name, "30[%16llx;%8llx]", &bios_buf_paddr,
+		    &remap_size) == 2)
+			goto remap;
+
+	/* Scan for EPS (entry point structure) */
+	for (addr = (u8 *)__va(0xf0000);
+	     addr < (u8 *)__va(0x100000 - sizeof(struct smm_eps_table));
+	     addr += 16) {
+		eps = check_eps_table(addr);
+		if (eps)
+			break;
+	}
+
+	if (!eps) {
+		dev_dbg(&dcdbas_pdev->dev, "found WSMT, but no firmware buffer found\n");
+		return -ENODEV;
+	}
+	bios_buf_paddr = eps->smm_comm_buff_addr;
+	remap_size = eps->num_of_4k_pages * PAGE_SIZE;
+
+remap:
+	/*
+	 * Get physical address of buffer and map to virtual address.
+	 * Table gives size in 4K pages, regardless of actual system page size.
+	 */
+	if (upper_32_bits(bios_buf_paddr + 8)) {
+		dev_warn(&dcdbas_pdev->dev, "found WSMT, but buffer address is above 4GB\n");
+		return -EINVAL;
+	}
+	/*
+	 * Limit remap size to MAX_SMI_DATA_BUF_SIZE + 8 (since the first 8
+	 * bytes are used for a semaphore, not the data buffer itself).
+	 */
+	if (remap_size > MAX_SMI_DATA_BUF_SIZE + 8)
+		remap_size = MAX_SMI_DATA_BUF_SIZE + 8;
+
+	bios_buffer = memremap(bios_buf_paddr, remap_size, MEMREMAP_WB);
+	if (!bios_buffer) {
+		dev_warn(&dcdbas_pdev->dev, "found WSMT, but failed to map buffer\n");
+		return -ENOMEM;
+	}
+
+	/* First 8 bytes is for a semaphore, not part of the smi_buf.virt */
+	smi_buf.dma = bios_buf_paddr + 8;
+	smi_buf.virt = bios_buffer + 8;
+	smi_buf.size = remap_size - 8;
+	max_smi_data_buf_size = smi_buf.size;
+	wsmt_enabled = true;
+	dev_info(&dcdbas_pdev->dev,
+		 "WSMT found, using firmware-provided SMI buffer.\n");
+	return 1;
+}
+
+/**
+ * dcdbas_reboot_notify: handle reboot notification for host control
+ */
+static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
+				void *unused)
+{
+	switch (code) {
+	case SYS_DOWN:
+	case SYS_HALT:
+	case SYS_POWER_OFF:
+		if (host_control_on_shutdown) {
+			/* firmware is going to perform host control action */
+			printk(KERN_WARNING "Please wait for shutdown "
+			       "action to complete...\n");
+			dcdbas_host_control();
+		}
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block dcdbas_reboot_nb = {
+	.notifier_call = dcdbas_reboot_notify,
+	.next = NULL,
+	.priority = INT_MIN
+};
+
+static DCDBAS_BIN_ATTR_RW(smi_data);
+
+static struct bin_attribute *dcdbas_bin_attrs[] = {
+	&bin_attr_smi_data,
+	NULL
+};
+
+static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
+static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
+static DCDBAS_DEV_ATTR_WO(smi_request);
+static DCDBAS_DEV_ATTR_RW(host_control_action);
+static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
+static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
+
+static struct attribute *dcdbas_dev_attrs[] = {
+	&dev_attr_smi_data_buf_size.attr,
+	&dev_attr_smi_data_buf_phys_addr.attr,
+	&dev_attr_smi_request.attr,
+	&dev_attr_host_control_action.attr,
+	&dev_attr_host_control_smi_type.attr,
+	&dev_attr_host_control_on_shutdown.attr,
+	NULL
+};
+
+static const struct attribute_group dcdbas_attr_group = {
+	.attrs = dcdbas_dev_attrs,
+	.bin_attrs = dcdbas_bin_attrs,
+};
+
+static int dcdbas_probe(struct platform_device *dev)
+{
+	int error;
+
+	host_control_action = HC_ACTION_NONE;
+	host_control_smi_type = HC_SMITYPE_NONE;
+
+	dcdbas_pdev = dev;
+
+	/* Check if ACPI WSMT table specifies protected SMI buffer address */
+	error = dcdbas_check_wsmt();
+	if (error < 0)
+		return error;
+
+	/*
+	 * BIOS SMI calls require buffer addresses be in 32-bit address space.
+	 * This is done by setting the DMA mask below.
+	 */
+	error = dma_set_coherent_mask(&dcdbas_pdev->dev, DMA_BIT_MASK(32));
+	if (error)
+		return error;
+
+	error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
+	if (error)
+		return error;
+
+	register_reboot_notifier(&dcdbas_reboot_nb);
+
+	dev_info(&dev->dev, "%s (version %s)\n",
+		 DRIVER_DESCRIPTION, DRIVER_VERSION);
+
+	return 0;
+}
+
+static int dcdbas_remove(struct platform_device *dev)
+{
+	unregister_reboot_notifier(&dcdbas_reboot_nb);
+	sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
+
+	return 0;
+}
+
+static struct platform_driver dcdbas_driver = {
+	.driver		= {
+		.name	= DRIVER_NAME,
+	},
+	.probe		= dcdbas_probe,
+	.remove		= dcdbas_remove,
+};
+
+static const struct platform_device_info dcdbas_dev_info __initconst = {
+	.name		= DRIVER_NAME,
+	.id		= PLATFORM_DEVID_NONE,
+	.dma_mask	= DMA_BIT_MASK(32),
+};
+
+static struct platform_device *dcdbas_pdev_reg;
+
+/**
+ * dcdbas_init: initialize driver
+ */
+static int __init dcdbas_init(void)
+{
+	int error;
+
+	error = platform_driver_register(&dcdbas_driver);
+	if (error)
+		return error;
+
+	dcdbas_pdev_reg = platform_device_register_full(&dcdbas_dev_info);
+	if (IS_ERR(dcdbas_pdev_reg)) {
+		error = PTR_ERR(dcdbas_pdev_reg);
+		goto err_unregister_driver;
+	}
+
+	return 0;
+
+ err_unregister_driver:
+	platform_driver_unregister(&dcdbas_driver);
+	return error;
+}
+
+/**
+ * dcdbas_exit: perform driver cleanup
+ */
+static void __exit dcdbas_exit(void)
+{
+	/*
+	 * make sure functions that use dcdbas_pdev are called
+	 * before platform_device_unregister
+	 */
+	unregister_reboot_notifier(&dcdbas_reboot_nb);
+
+	/*
+	 * We have to free the buffer here instead of dcdbas_remove
+	 * because only in module exit function we can be sure that
+	 * all sysfs attributes belonging to this module have been
+	 * released.
+	 */
+	if (dcdbas_pdev)
+		smi_data_buf_free();
+	if (bios_buffer)
+		memunmap(bios_buffer);
+	platform_device_unregister(dcdbas_pdev_reg);
+	platform_driver_unregister(&dcdbas_driver);
+}
+
+subsys_initcall_sync(dcdbas_init);
+module_exit(dcdbas_exit);
+
+MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_AUTHOR("Dell Inc.");
+MODULE_LICENSE("GPL");
+/* Any System or BIOS claiming to be by Dell */
+MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");