hwmon: (w83791d) Convert to a new-style i2c driver

The new-style w83791d driver implements the optional detect()
callback to cover the use cases of the legacy driver.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Marc Hulsman <m.hulsman@tudelft.nl>

1 files changed, 71 insertions, 134 deletions

diff --git a/drivers/hwmon/w83791d.c b/drivers/hwmon/w83791d.c
index 85077c4c8039..e4e91c9d480a 100644
--- a/drivers/hwmon/w83791d.c
+++ b/drivers/hwmon/w83791d.c
@@ -247,7 +247,6 @@ static u8 div_to_reg(int nr, long val)
 }
 
 struct w83791d_data {
-        struct i2c_client client;
         struct device *hwmon_dev;
         struct mutex update_lock;
 
@@ -286,9 +285,11 @@ struct w83791d_data {
         u8 vrm;                 /* hwmon-vid */
 };
 
-static int w83791d_attach_adapter(struct i2c_adapter *adapter);
-static int w83791d_detect(struct i2c_adapter *adapter, int address, int kind);
-static int w83791d_detach_client(struct i2c_client *client);
+static int w83791d_probe(struct i2c_client *client,
+                         const struct i2c_device_id *id);
+static int w83791d_detect(struct i2c_client *client, int kind,
+                          struct i2c_board_info *info);
+static int w83791d_remove(struct i2c_client *client);
 
 static int w83791d_read(struct i2c_client *client, u8 register);
 static int w83791d_write(struct i2c_client *client, u8 register, u8 value);
@@ -300,12 +301,22 @@ static void w83791d_print_debug(struct w83791d_data *data, struct device *dev);
 
 static void w83791d_init_client(struct i2c_client *client);
 
+static const struct i2c_device_id w83791d_id[] = {
+        { "w83791d", w83791d },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, w83791d_id);
+
 static struct i2c_driver w83791d_driver = {
+        .class          = I2C_CLASS_HWMON,
         .driver = {
                 .name = "w83791d",
         },
-        .attach_adapter = w83791d_attach_adapter,
-        .detach_client = w83791d_detach_client,
+        .probe          = w83791d_probe,
+        .remove         = w83791d_remove,
+        .id_table       = w83791d_id,
+        .detect         = w83791d_detect,
+        .address_data   = &addr_data,
 };
 
 /* following are the sysfs callback functions */
@@ -905,49 +916,12 @@ static const struct attribute_group w83791d_group = {
         .attrs = w83791d_attributes,
 };
 
-/* This function is called when:
-     * w83791d_driver is inserted (when this module is loaded), for each
-       available adapter
-     * when a new adapter is inserted (and w83791d_driver is still present) */
-static int w83791d_attach_adapter(struct i2c_adapter *adapter)
-{
-        if (!(adapter->class & I2C_CLASS_HWMON))
-                return 0;
-        return i2c_probe(adapter, &addr_data, w83791d_detect);
-}
-
 
-static int w83791d_create_subclient(struct i2c_adapter *adapter,
-                                struct i2c_client *client, int addr,
-                                struct i2c_client **sub_cli)
-{
-        int err;
-        struct i2c_client *sub_client;
-
-        (*sub_cli) = sub_client =
-                        kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
-        if (!(sub_client)) {
-                return -ENOMEM;
-        }
-        sub_client->addr = 0x48 + addr;
-        i2c_set_clientdata(sub_client, NULL);
-        sub_client->adapter = adapter;
-        sub_client->driver = &w83791d_driver;
-        strlcpy(sub_client->name, "w83791d subclient", I2C_NAME_SIZE);
-        if ((err = i2c_attach_client(sub_client))) {
-                dev_err(&client->dev, "subclient registration "
-                        "at address 0x%x failed\n", sub_client->addr);
-                kfree(sub_client);
-                return err;
-        }
-        return 0;
-}
-
-
-static int w83791d_detect_subclients(struct i2c_adapter *adapter, int address,
-                                int kind, struct i2c_client *client)
+static int w83791d_detect_subclients(struct i2c_client *client)
 {
+        struct i2c_adapter *adapter = client->adapter;
         struct w83791d_data *data = i2c_get_clientdata(client);
+        int address = client->addr;
         int i, id, err;
         u8 val;
 
@@ -971,10 +945,7 @@ static int w83791d_detect_subclients(struct i2c_adapter *adapter, int address,
 
         val = w83791d_read(client, W83791D_REG_I2C_SUBADDR);
         if (!(val & 0x08)) {
-                err = w83791d_create_subclient(adapter, client,
-                                                val & 0x7, &data->lm75[0]);
-                if (err < 0)
-                        goto error_sc_0;
+                data->lm75[0] = i2c_new_dummy(adapter, 0x48 + (val & 0x7));
         }
         if (!(val & 0x80)) {
                 if ((data->lm75[0] != NULL) &&
@@ -986,10 +957,8 @@ static int w83791d_detect_subclients(struct i2c_adapter *adapter, int address,
                         err = -ENODEV;
                         goto error_sc_1;
                 }
-                err = w83791d_create_subclient(adapter, client,
-                                        (val >> 4) & 0x7, &data->lm75[1]);
-                if (err < 0)
-                        goto error_sc_1;
+                data->lm75[1] = i2c_new_dummy(adapter,
+                                              0x48 + ((val >> 4) & 0x7));
         }
 
         return 0;
@@ -997,53 +966,31 @@ static int w83791d_detect_subclients(struct i2c_adapter *adapter, int address,
 /* Undo inits in case of errors */
 
 error_sc_1:
-        if (data->lm75[0] != NULL) {
-                i2c_detach_client(data->lm75[0]);
-                kfree(data->lm75[0]);
-        }
+        if (data->lm75[0] != NULL)
+                i2c_unregister_device(data->lm75[0]);
 error_sc_0:
         return err;
 }
 
 
-static int w83791d_detect(struct i2c_adapter *adapter, int address, int kind)
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int w83791d_detect(struct i2c_client *client, int kind,
+                          struct i2c_board_info *info)
 {
-        struct i2c_client *client;
-        struct device *dev;
-        struct w83791d_data *data;
-        int i, val1, val2;
-        int err = 0;
-        const char *client_name = "";
+        struct i2c_adapter *adapter = client->adapter;
+        int val1, val2;
+        unsigned short address = client->addr;
 
         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
-                goto error0;
+                return -ENODEV;
         }
 
-        /* OK. For now, we presume we have a valid client. We now create the
-           client structure, even though we cannot fill it completely yet.
-           But it allows us to access w83791d_{read,write}_value. */
-        if (!(data = kzalloc(sizeof(struct w83791d_data), GFP_KERNEL))) {
-                err = -ENOMEM;
-                goto error0;
-        }
-
-        client = &data->client;
-        dev = &client->dev;
-        i2c_set_clientdata(client, data);
-        client->addr = address;
-        client->adapter = adapter;
-        client->driver = &w83791d_driver;
-        mutex_init(&data->update_lock);
-
-        /* Now, we do the remaining detection. */
-
         /* The w83791d may be stuck in some other bank than bank 0. This may
            make reading other information impossible. Specify a force=...
            parameter, and the Winbond will be reset to the right bank. */
         if (kind < 0) {
                 if (w83791d_read(client, W83791D_REG_CONFIG) & 0x80) {
-                        dev_dbg(dev, "Detection failed at step 1\n");
-                        goto error1;
+                        return -ENODEV;
                 }
                 val1 = w83791d_read(client, W83791D_REG_BANK);
                 val2 = w83791d_read(client, W83791D_REG_CHIPMAN);
@@ -1052,15 +999,13 @@ static int w83791d_detect(struct i2c_adapter *adapter, int address, int kind)
                         /* yes it is Bank0 */
                         if (((!(val1 & 0x80)) && (val2 != 0xa3)) ||
                             ((val1 & 0x80) && (val2 != 0x5c))) {
-                                dev_dbg(dev, "Detection failed at step 2\n");
-                                goto error1;
+                                return -ENODEV;
                         }
                 }
                 /* If Winbond chip, address of chip and W83791D_REG_I2C_ADDR
                    should match */
                 if (w83791d_read(client, W83791D_REG_I2C_ADDR) != address) {
-                        dev_dbg(dev, "Detection failed at step 3\n");
-                        goto error1;
+                        return -ENODEV;
                 }
         }
 
@@ -1075,30 +1020,33 @@ static int w83791d_detect(struct i2c_adapter *adapter, int address, int kind)
                 /* get vendor ID */
                 val2 = w83791d_read(client, W83791D_REG_CHIPMAN);
                 if (val2 != 0x5c) {     /* the vendor is NOT Winbond */
-                        dev_dbg(dev, "Detection failed at step 4\n");
-                        goto error1;
+                        return -ENODEV;
                 }
                 val1 = w83791d_read(client, W83791D_REG_WCHIPID);
                 if (val1 == 0x71) {
                         kind = w83791d;
                 } else {
                         if (kind == 0)
-                                dev_warn(dev,
+                                dev_warn(&adapter->dev,
                                         "w83791d: Ignoring 'force' parameter "
                                         "for unknown chip at adapter %d, "
                                         "address 0x%02x\n",
                                         i2c_adapter_id(adapter), address);
-                        goto error1;
+                        return -ENODEV;
                 }
         }
 
-        if (kind == w83791d) {
-                client_name = "w83791d";
-        } else {
-                dev_err(dev, "w83791d: Internal error: unknown kind (%d)?!?\n",
-                        kind);
-                goto error1;
-        }
+        strlcpy(info->type, "w83791d", I2C_NAME_SIZE);
+
+        return 0;
+}
+
+static int w83791d_probe(struct i2c_client *client,
+                         const struct i2c_device_id *id)
+{
+        struct w83791d_data *data;
+        struct device *dev = &client->dev;
+        int i, val1, err;
 
 #ifdef DEBUG
         val1 = w83791d_read(client, W83791D_REG_DID_VID4);
@@ -1106,15 +1054,18 @@ static int w83791d_detect(struct i2c_adapter *adapter, int address, int kind)
                         (val1 >> 5) & 0x07, (val1 >> 1) & 0x0f, val1);
 #endif
 
-        /* Fill in the remaining client fields and put into the global list */
-        strlcpy(client->name, client_name, I2C_NAME_SIZE);
+        data = kzalloc(sizeof(struct w83791d_data), GFP_KERNEL);
+        if (!data) {
+                err = -ENOMEM;
+                goto error0;
+        }
 
-        /* Tell the I2C layer a new client has arrived */
-        if ((err = i2c_attach_client(client)))
-                goto error1;
+        i2c_set_clientdata(client, data);
+        mutex_init(&data->update_lock);
 
-        if ((err = w83791d_detect_subclients(adapter, address, kind, client)))
-                goto error2;
+        err = w83791d_detect_subclients(client);
+        if (err)
+                goto error1;
 
         /* Initialize the chip */
         w83791d_init_client(client);
@@ -1141,43 +1092,29 @@ static int w83791d_detect(struct i2c_adapter *adapter, int address, int kind)
 error4:
         sysfs_remove_group(&client->dev.kobj, &w83791d_group);
 error3:
-        if (data->lm75[0] != NULL) {
-                i2c_detach_client(data->lm75[0]);
-                kfree(data->lm75[0]);
-        }
-        if (data->lm75[1] != NULL) {
-                i2c_detach_client(data->lm75[1]);
-                kfree(data->lm75[1]);
-        }
-error2:
-        i2c_detach_client(client);
+        if (data->lm75[0] != NULL)
+                i2c_unregister_device(data->lm75[0]);
+        if (data->lm75[1] != NULL)
+                i2c_unregister_device(data->lm75[1]);
 error1:
         kfree(data);
 error0:
         return err;
 }
 
-static int w83791d_detach_client(struct i2c_client *client)
+static int w83791d_remove(struct i2c_client *client)
 {
         struct w83791d_data *data = i2c_get_clientdata(client);
-        int err;
-
-        /* main client */
-        if (data) {
-                hwmon_device_unregister(data->hwmon_dev);
-                sysfs_remove_group(&client->dev.kobj, &w83791d_group);
-        }
 
-        if ((err = i2c_detach_client(client)))
-                return err;
+        hwmon_device_unregister(data->hwmon_dev);
+        sysfs_remove_group(&client->dev.kobj, &w83791d_group);
 
-        /* main client */
-        if (data)
-                kfree(data);
-        /* subclient */
-        else
-                kfree(client);
+        if (data->lm75[0] != NULL)
+                i2c_unregister_device(data->lm75[0]);
+        if (data->lm75[1] != NULL)
+                i2c_unregister_device(data->lm75[1]);
 
+        kfree(data);
         return 0;
 }