1 files changed, 52 insertions, 28 deletions

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 32f4530cd1e8..cb5e255a84c6 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -109,6 +109,7 @@ struct pmbus_data {
          * so we keep them all together.
          */
         u8 status[PB_NUM_STATUS_REG];
+        u8 status_register;
 
         u8 currpage;
 };
@@ -285,9 +286,10 @@ EXPORT_SYMBOL_GPL(pmbus_clear_faults);
 
 static int pmbus_check_status_cml(struct i2c_client *client)
 {
+        struct pmbus_data *data = i2c_get_clientdata(client);
         int status, status2;
 
-        status = _pmbus_read_byte_data(client, -1, PMBUS_STATUS_BYTE);
+        status = _pmbus_read_byte_data(client, -1, data->status_register);
         if (status < 0 || (status & PB_STATUS_CML)) {
                 status2 = _pmbus_read_byte_data(client, -1, PMBUS_STATUS_CML);
                 if (status2 < 0 || (status2 & PB_CML_FAULT_INVALID_COMMAND))
@@ -344,7 +346,7 @@ static struct pmbus_data *pmbus_update_device(struct device *dev)
                 for (i = 0; i < info->pages; i++)
                         data->status[PB_STATUS_BASE + i]
                             = _pmbus_read_byte_data(client, i,
-                                                    PMBUS_STATUS_BYTE);
+                                                    data->status_register);
                 for (i = 0; i < info->pages; i++) {
                         if (!(info->func[i] & PMBUS_HAVE_STATUS_VOUT))
                                 continue;
@@ -1015,7 +1017,7 @@ static int pmbus_add_sensor_attrs_one(struct i2c_client *client,
                  */
                 if (!ret && attr->gbit &&
                     pmbus_check_byte_register(client, page,
-                                              PMBUS_STATUS_BYTE)) {
+                                              data->status_register)) {
                         ret = pmbus_add_boolean(data, name, "alarm", index,
                                                 NULL, NULL,
                                                 PB_STATUS_BASE + page,
@@ -1683,6 +1685,51 @@ static int pmbus_identify_common(struct i2c_client *client,
         return 0;
 }
 
+static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
+                             struct pmbus_driver_info *info)
+{
+        struct device *dev = &client->dev;
+        int ret;
+
+        /*
+         * Some PMBus chips don't support PMBUS_STATUS_BYTE, so try
+         * to use PMBUS_STATUS_WORD instead if that is the case.
+         * Bail out if both registers are not supported.
+         */
+        data->status_register = PMBUS_STATUS_BYTE;
+        ret = i2c_smbus_read_byte_data(client, PMBUS_STATUS_BYTE);
+        if (ret < 0 || ret == 0xff) {
+                data->status_register = PMBUS_STATUS_WORD;
+                ret = i2c_smbus_read_word_data(client, PMBUS_STATUS_WORD);
+                if (ret < 0 || ret == 0xffff) {
+                        dev_err(dev, "PMBus status register not found\n");
+                        return -ENODEV;
+                }
+        }
+
+        pmbus_clear_faults(client);
+
+        if (info->identify) {
+                ret = (*info->identify)(client, info);
+                if (ret < 0) {
+                        dev_err(dev, "Chip identification failed\n");
+                        return ret;
+                }
+        }
+
+        if (info->pages <= 0 || info->pages > PMBUS_PAGES) {
+                dev_err(dev, "Bad number of PMBus pages: %d\n", info->pages);
+                return -ENODEV;
+        }
+
+        ret = pmbus_identify_common(client, data);
+        if (ret < 0) {
+                dev_err(dev, "Failed to identify chip capabilities\n");
+                return ret;
+        }
+        return 0;
+}
+
 int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
                    struct pmbus_driver_info *info)
 {
@@ -1707,36 +1754,13 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
         mutex_init(&data->update_lock);
         data->dev = dev;
 
-        /* Bail out if PMBus status register does not exist. */
-        if (i2c_smbus_read_byte_data(client, PMBUS_STATUS_BYTE) < 0) {
-                dev_err(dev, "PMBus status register not found\n");
-                return -ENODEV;
-        }
-
         if (pdata)
                 data->flags = pdata->flags;
         data->info = info;
 
-        pmbus_clear_faults(client);
-
-        if (info->identify) {
-                ret = (*info->identify)(client, info);
-                if (ret < 0) {
-                        dev_err(dev, "Chip identification failed\n");
-                        return ret;
-                }
-        }
-
-        if (info->pages <= 0 || info->pages > PMBUS_PAGES) {
-                dev_err(dev, "Bad number of PMBus pages: %d\n", info->pages);
-                return -ENODEV;
-        }
-
-        ret = pmbus_identify_common(client, data);
-        if (ret < 0) {
-                dev_err(dev, "Failed to identify chip capabilities\n");
+        ret = pmbus_init_common(client, data, info);
+        if (ret < 0)
                 return ret;
-        }
 
         ret = pmbus_find_attributes(client, data);
         if (ret)