acpi: Support IBM SMBus CMI devices

Commit Message

Jean Delvare March 9, 2010, 9:40 a.m. UTC

None

Patch

--- linux-2.6.34-rc1.orig/drivers/acpi/scan.c	2010-03-09 08:24:53.000000000 +0100
+++ linux-2.6.34-rc1/drivers/acpi/scan.c	2010-03-09 09:50:12.000000000 +0100
@@ -8,6 +8,7 @@ 
 #include <linux/acpi.h>
 #include <linux/signal.h>
 #include <linux/kthread.h>
+#include <linux/dmi.h>
 
 #include <acpi/acpi_drivers.h>
 
@@ -1032,6 +1033,41 @@  static void acpi_add_id(struct acpi_devi
 	list_add_tail(&id->list, &device->pnp.ids);
 }
 
+/*
+ * Old IBM workstations have a DSDT bug wherein the SMBus object
+ * lacks the SMBUS01 HID and the methods do not have the necessary "_"
+ * prefix.  Work around this.
+ */
+static int acpi_ibm_smbus_match(struct acpi_device *device)
+{
+	acpi_handle h_dummy;
+	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
+	int result;
+
+	if (!dmi_name_in_vendors("IBM"))
+		return -ENODEV;
+
+	/* Look for SMBS object */
+	result = acpi_get_name(device->handle, ACPI_SINGLE_NAME, &path);
+	if (result)
+		return result;
+
+	if (strcmp("SMBS", path.pointer)) {
+		result = -ENODEV;
+		goto out;
+	}
+
+	/* Does it have the necessary (but misnamed) methods? */
+	result = -ENODEV;
+	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "SBI", &h_dummy)) &&
+	    ACPI_SUCCESS(acpi_get_handle(device->handle, "SBR", &h_dummy)) &&
+	    ACPI_SUCCESS(acpi_get_handle(device->handle, "SBW", &h_dummy)))
+		result = 0;
+out:
+	kfree(path.pointer);
+	return result;
+}
+
 static void acpi_device_set_id(struct acpi_device *device)
 {
 	acpi_status status;
@@ -1082,6 +1118,8 @@  static void acpi_device_set_id(struct ac
 			acpi_add_id(device, ACPI_BAY_HID);
 		else if (ACPI_SUCCESS(acpi_dock_match(device)))
 			acpi_add_id(device, ACPI_DOCK_HID);
+		else if (!acpi_ibm_smbus_match(device))
+			acpi_add_id(device, ACPI_SMBUS_IBM_HID);
 
 		break;
 	case ACPI_BUS_TYPE_POWER:
--- linux-2.6.34-rc1.orig/include/acpi/acpi_drivers.h	2010-03-09 08:25:29.000000000 +0100
+++ linux-2.6.34-rc1/include/acpi/acpi_drivers.h	2010-03-09 09:50:12.000000000 +0100
@@ -65,6 +65,8 @@ 
 #define ACPI_VIDEO_HID			"LNXVIDEO"
 #define ACPI_BAY_HID			"LNXIOBAY"
 #define ACPI_DOCK_HID			"LNXDOCK"
+/* Quirk for broken IBM BIOSes */
+#define ACPI_SMBUS_IBM_HID		"SMBUSIBM"
 
 /*
  * For fixed hardware buttons, we fabricate acpi_devices with HID