[2/2] acpi: support IBM SMBus CMI devices

Commit Message

Darrick J. Wong Oct. 23, 2009, 5:03 p.m. UTC

None

Patch

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 14a7481..89f8992 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -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>
 
@@ -1014,6 +1015,41 @@  static void acpi_add_id(struct acpi_device *device, const char *dev_id)
 	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 probe_ibm_smbus_device(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;
@@ -1064,6 +1100,8 @@  static void acpi_device_set_id(struct acpi_device *device)
 			acpi_add_id(device, ACPI_BAY_HID);
 		else if (ACPI_SUCCESS(acpi_dock_match(device)))
 			acpi_add_id(device, ACPI_DOCK_HID);
+		else if (!probe_ibm_smbus_device(device))
+			acpi_add_id(device, ACPI_SMBUS_IBM_HID);
 
 		break;
 	case ACPI_BUS_TYPE_POWER:
diff --git a/drivers/i2c/busses/i2c-scmi.c b/drivers/i2c/busses/i2c-scmi.c
index a15aaf4..22c26c2 100644
--- a/drivers/i2c/busses/i2c-scmi.c
+++ b/drivers/i2c/busses/i2c-scmi.c
@@ -51,7 +51,7 @@  static const struct smbus_methods_t ibm_smbus_methods = {
 
 static const struct acpi_device_id acpi_smbus_cmi_ids[] = {
 	{"SMBUS01", (kernel_ulong_t)&smbus_methods},
-	{"SMBUSIBM", (kernel_ulong_t)&ibm_smbus_methods},
+	{ACPI_SMBUS_IBM_HID, (kernel_ulong_t)&ibm_smbus_methods},
 	{"", 0}
 };
 
diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index f4906f6..83a2960 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -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