staging: unisys: add acpi pnp driver

According to Unisys, another OS detects the PNP0A07 as the auto load
device.  We can also do this in the linux kernel by simply converting the
driver over to the ACPI driver model.

Notes: This changes the usage of __init and it had to be removed from some
functions to avoid a !__init function calling an __init function.
Additionally I also cleaned up the headers in visorchipset.c since I was
adding a header file.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/unisys/visorbus/visorbus_main.c

@@ -2034,7 +2034,7 @@ struct channel_size_info {
 	unsigned long max_size;
 };
 
-int __init
+int
 visorbus_init(void)
 {
 	int rc = 0;

drivers/staging/unisys/visorbus/visorbus_private.h

@@ -155,6 +155,6 @@ bool visorchipset_get_device_info(u32 bus_no, u32 dev_no,
 bool visorchipset_set_bus_context(u32 bus_no, void *context);
 
 /* visorbus init and exit functions */
-int __init visorbus_init(void);
+int visorbus_init(void);
 void visorbus_exit(void);
 #endif

drivers/staging/unisys/visorbus/visorchipset.c

@@ -15,16 +15,7 @@
  * details.
  */
 
-#include "controlvmchannel.h"
-#include "version.h"
-#include "procobjecttree.h"
-#include "visorbus.h"
-#include "periodic_work.h"
-#include "uisutils.h"
-#include "controlvmcompletionstatus.h"
-#include "guestlinuxdebug.h"
-#include "visorbus_private.h"
-
+#include <linux/acpi.h>
 #include <linux/ctype.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
@@ -34,6 +25,16 @@
 #include <linux/uuid.h>
 #include <linux/crash_dump.h>
 
+#include "controlvmchannel.h"
+#include "controlvmcompletionstatus.h"
+#include "guestlinuxdebug.h"
+#include "periodic_work.h"
+#include "procobjecttree.h"
+#include "uisutils.h"
+#include "version.h"
+#include "visorbus.h"
+#include "visorbus_private.h"
+
 #define CURRENT_FILE_PC VISOR_CHIPSET_PC_visorchipset_main_c
 
 #define MAX_NAME_SIZE 128
@@ -2637,17 +2638,12 @@ visorchipset_file_init(dev_t major_dev, struct visorchannel **controlvm_channel)
 	return 0;
 }
 
-
-
-static int __init
-visorchipset_init(void)
+static int
+visorchipset_init(struct acpi_device *acpi_device)
 {
 	int rc = 0;
 	HOSTADDRESS addr;
 
-	if (!unisys_spar_platform)
-		return -ENODEV;
-
 	memset(&busdev_notifiers, 0, sizeof(busdev_notifiers));
 	memset(&controlvm_payload_info, 0, sizeof(controlvm_payload_info));
 	memset(&livedump_info, 0, sizeof(livedump_info));
@@ -2733,8 +2729,8 @@ visorchipset_file_cleanup(dev_t major_dev)
 	unregister_chrdev_region(major_dev, 1);
 }
 
-static void
-visorchipset_exit(void)
+static int
+visorchipset_exit(struct acpi_device *acpi_device)
 {
 	POSTCODE_LINUX_2(DRIVER_EXIT_PC, POSTCODE_SEVERITY_INFO);
 
@@ -2754,6 +2750,45 @@ visorchipset_exit(void)
 
 	visorchipset_file_cleanup(visorchipset_platform_device.dev.devt);
 	POSTCODE_LINUX_2(DRIVER_EXIT_PC, POSTCODE_SEVERITY_INFO);
+
+	return 0;
+}
+
+static const struct acpi_device_id unisys_device_ids[] = {
+	{"PNP0A07", 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, unisys_device_ids);
+
+static struct acpi_driver unisys_acpi_driver = {
+	.name = "unisys_acpi",
+	.class = "unisys_acpi_class",
+	.owner = THIS_MODULE,
+	.ids = unisys_device_ids,
+	.ops = {
+		.add = visorchipset_init,
+		.remove = visorchipset_exit,
+		},
+};
+
+static int init_unisys(void)
+{
+	int result;
+
+	if (!unisys_spar_platform)
+		return -ENODEV;
+
+	result = acpi_bus_register_driver(&unisys_acpi_driver);
+	if (result)
+		return -ENODEV;
+
+	pr_info("Unisys Visorchipset Driver Loaded.\n");
+	return 0;
+};
+
+static void exit_unisys(void)
+{
+	acpi_bus_unregister_driver(&unisys_acpi_driver);
 }
 
 module_param_named(major, visorchipset_major, int, S_IRUGO);
@@ -2767,8 +2802,8 @@ module_param_named(holdchipsetready, visorchipset_holdchipsetready,
 MODULE_PARM_DESC(visorchipset_holdchipsetready,
 		 "1 to hold response to CHIPSET_READY");
 
-module_init(visorchipset_init);
-module_exit(visorchipset_exit);
+module_init(init_unisys);
+module_exit(exit_unisys);
 
 MODULE_AUTHOR("Unisys");
 MODULE_LICENSE("GPL");