Merge branch 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging

* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  i2c-scmi: Provide module aliases for automatic loading
  i2c-scmi: Support IBM SMBus CMI devices
  acpi: Support IBM SMBus CMI devices

2 files changed, 62 insertions, 8 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index fb7fc24fe727..189cbc2585fa 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>
 
@@ -1032,6 +1033,41 @@ 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 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 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 (!acpi_ibm_smbus_match(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 365e0becaf12..388cbdc96db7 100644
--- a/drivers/i2c/busses/i2c-scmi.c
+++ b/drivers/i2c/busses/i2c-scmi.c
@@ -33,6 +33,7 @@ struct acpi_smbus_cmi {
 	u8 cap_info:1;
 	u8 cap_read:1;
 	u8 cap_write:1;
+	struct smbus_methods_t *methods;
 };
 
 static const struct smbus_methods_t smbus_methods = {
@@ -41,10 +42,19 @@ static const struct smbus_methods_t smbus_methods = {
 	.mt_sbw  = "_SBW",
 };
 
+/* Some IBM BIOSes omit the leading underscore */
+static const struct smbus_methods_t ibm_smbus_methods = {
+	.mt_info = "SBI_",
+	.mt_sbr  = "SBR_",
+	.mt_sbw  = "SBW_",
+};
+
 static const struct acpi_device_id acpi_smbus_cmi_ids[] = {
-	{"SMBUS01", 0},
+	{"SMBUS01", (kernel_ulong_t)&smbus_methods},
+	{ACPI_SMBUS_IBM_HID, (kernel_ulong_t)&ibm_smbus_methods},
 	{"", 0}
 };
+MODULE_DEVICE_TABLE(acpi, acpi_smbus_cmi_ids);
 
 #define ACPI_SMBUS_STATUS_OK			0x00
 #define ACPI_SMBUS_STATUS_FAIL			0x07
@@ -150,11 +160,11 @@ acpi_smbus_cmi_access(struct i2c_adapter *adap, u16 addr, unsigned short flags,
 
 	if (read_write == I2C_SMBUS_READ) {
 		protocol |= ACPI_SMBUS_PRTCL_READ;
-		method = smbus_methods.mt_sbr;
+		method = smbus_cmi->methods->mt_sbr;
 		input.count = 3;
 	} else {
 		protocol |= ACPI_SMBUS_PRTCL_WRITE;
-		method = smbus_methods.mt_sbw;
+		method = smbus_cmi->methods->mt_sbw;
 		input.count = 5;
 	}
 
@@ -290,13 +300,13 @@ static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi,
 	union acpi_object *obj;
 	acpi_status status;
 
-	if (!strcmp(name, smbus_methods.mt_info)) {
+	if (!strcmp(name, smbus_cmi->methods->mt_info)) {
 		status = acpi_evaluate_object(smbus_cmi->handle,
-					smbus_methods.mt_info,
+					smbus_cmi->methods->mt_info,
 					NULL, &buffer);
 		if (ACPI_FAILURE(status)) {
 			ACPI_ERROR((AE_INFO, "Evaluating %s: %i",
-				   smbus_methods.mt_info, status));
+				   smbus_cmi->methods->mt_info, status));
 			return -EIO;
 		}
 
@@ -319,9 +329,9 @@ static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi,
 
 		kfree(buffer.pointer);
 		smbus_cmi->cap_info = 1;
-	} else if (!strcmp(name, smbus_methods.mt_sbr))
+	} else if (!strcmp(name, smbus_cmi->methods->mt_sbr))
 		smbus_cmi->cap_read = 1;
-	else if (!strcmp(name, smbus_methods.mt_sbw))
+	else if (!strcmp(name, smbus_cmi->methods->mt_sbw))
 		smbus_cmi->cap_write = 1;
 	else
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Unsupported CMI method: %s\n",
@@ -349,6 +359,7 @@ static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level,
 static int acpi_smbus_cmi_add(struct acpi_device *device)
 {
 	struct acpi_smbus_cmi *smbus_cmi;
+	const struct acpi_device_id *id;
 
 	smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL);
 	if (!smbus_cmi)
@@ -362,6 +373,11 @@ static int acpi_smbus_cmi_add(struct acpi_device *device)
 	smbus_cmi->cap_read = 0;
 	smbus_cmi->cap_write = 0;
 
+	for (id = acpi_smbus_cmi_ids; id->id[0]; id++)
+		if (!strcmp(id->id, acpi_device_hid(device)))
+			smbus_cmi->methods =
+				(struct smbus_methods_t *) id->driver_data;
+
 	acpi_walk_namespace(ACPI_TYPE_METHOD, smbus_cmi->handle, 1,
 			    acpi_smbus_cmi_query_methods, NULL, smbus_cmi, NULL);