hwmon: (pmbus/adm1275) Validate device ID

Since manufacturer and device ID are known, read and validate it.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
[Dan Carpenter <dan.carpenter@oracle.com>: Fixed memory leak]
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>

1 files changed, 50 insertions, 21 deletions

diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
index 980a4d9d5028..81c7c2ead6f3 100644
--- a/drivers/hwmon/pmbus/adm1275.c
+++ b/drivers/hwmon/pmbus/adm1275.c
@@ -170,35 +170,71 @@ static int adm1275_read_byte_data(struct i2c_client *client, int page, int reg)
         return ret;
 }
 
+static const struct i2c_device_id adm1275_id[] = {
+        { "adm1275", adm1275 },
+        { "adm1276", adm1276 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, adm1275_id);
+
 static int adm1275_probe(struct i2c_client *client,
                          const struct i2c_device_id *id)
 {
+        u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
         int config, device_config;
         int ret;
         struct pmbus_driver_info *info;
         struct adm1275_data *data;
+        const struct i2c_device_id *mid;
 
         if (!i2c_check_functionality(client->adapter,
-                                     I2C_FUNC_SMBUS_READ_BYTE_DATA))
+                                     I2C_FUNC_SMBUS_READ_BYTE_DATA
+                                     | I2C_FUNC_SMBUS_BLOCK_DATA))
                 return -ENODEV;
 
-        data = kzalloc(sizeof(struct adm1275_data), GFP_KERNEL);
-        if (!data)
-                return -ENOMEM;
+        ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, block_buffer);
+        if (ret < 0) {
+                dev_err(&client->dev, "Failed to read Manufacturer ID\n");
+                return ret;
+        }
+        if (ret != 3 || strncmp(block_buffer, "ADI", 3)) {
+                dev_err(&client->dev, "Unsupported Manufacturer ID\n");
+                return -ENODEV;
+        }
 
-        config = i2c_smbus_read_byte_data(client, ADM1275_PMON_CONFIG);
-        if (config < 0) {
-                ret = config;
-                goto err_mem;
+        ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, block_buffer);
+        if (ret < 0) {
+                dev_err(&client->dev, "Failed to read Manufacturer Model\n");
+                return ret;
+        }
+        for (mid = adm1275_id; mid->name[0]; mid++) {
+                if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
+                        break;
+        }
+        if (!mid->name[0]) {
+                dev_err(&client->dev, "Unsupported device\n");
+                return -ENODEV;
         }
 
+        if (id->driver_data != mid->driver_data)
+                dev_notice(&client->dev,
+                           "Device mismatch: Configured %s, detected %s\n",
+                           id->name, mid->name);
+
+        config = i2c_smbus_read_byte_data(client, ADM1275_PMON_CONFIG);
+        if (config < 0)
+                return config;
+
         device_config = i2c_smbus_read_byte_data(client, ADM1275_DEVICE_CONFIG);
-        if (device_config < 0) {
-                ret = device_config;
-                goto err_mem;
-        }
+        if (device_config < 0)
+                return device_config;
+
+        data = kzalloc(sizeof(struct adm1275_data), GFP_KERNEL);
+        if (!data)
+                return -ENOMEM;
+
+        data->id = mid->driver_data;
 
-        data->id = id->driver_data;
         info = &data->info;
 
         info->pages = 1;
@@ -233,7 +269,7 @@ static int adm1275_probe(struct i2c_client *client,
         if (device_config & ADM1275_IOUT_WARN2_SELECT)
                 data->have_oc_fault = true;
 
-        switch (id->driver_data) {
+        switch (data->id) {
         case adm1275:
                 if (config & ADM1275_VIN_VOUT_SELECT)
                         info->func[0] |=
@@ -281,13 +317,6 @@ static int adm1275_remove(struct i2c_client *client)
         return 0;
 }
 
-static const struct i2c_device_id adm1275_id[] = {
-        { "adm1275", adm1275 },
-        { "adm1276", adm1276 },
-        { }
-};
-MODULE_DEVICE_TABLE(i2c, adm1275_id);
-
 static struct i2c_driver adm1275_driver = {
         .driver = {
                    .name = "adm1275",