i2c-scmi: Support IBM SMBus CMI devices

*) add a new HID for IBM SMBus CMI devices
*) add methods for IBM SMBus CMI devices
*) hook different HID with different control methods set
*) minor tweaks as suggested by Jean Delvare

Slightly modified by Darrick to use #define'd IBM SMBUS HID from Darrick's ACPI
scan quirk patch.

Signed-off-by: Crane Cai <crane.cai@amd.com>
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 23 insertions, 8 deletions

diff --git a/drivers/i2c/busses/i2c-scmi.c b/drivers/i2c/busses/i2c-scmi.c
index 365e0becaf12..4c9fb4cd4bb5 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 = {
@@ -41,8 +42,16 @@ 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}
 };
 
@@ -150,11 +159,11 @@ 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 +299,13 @@ 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 +328,9 @@ 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 +358,7 @@ 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 +372,11 @@ 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);