i2c: Convert the pcf8591 driver to a new-style i2c driver

The new-style pcf8591 driver implements the optional detect() callback
to cover the use cases of the legacy driver.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 40 insertions, 54 deletions

diff --git a/drivers/i2c/chips/pcf8591.c b/drivers/i2c/chips/pcf8591.c
index db735379f22f..16ce3e193776 100644
--- a/drivers/i2c/chips/pcf8591.c
+++ b/drivers/i2c/chips/pcf8591.c
@@ -72,28 +72,15 @@ MODULE_PARM_DESC(input_mode,
 #define REG_TO_SIGNED(reg)      (((reg) & 0x80)?((reg) - 256):(reg))
 
 struct pcf8591_data {
-        struct i2c_client client;
         struct mutex update_lock;
 
         u8 control;
         u8 aout;
 };
 
-static int pcf8591_attach_adapter(struct i2c_adapter *adapter);
-static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind);
-static int pcf8591_detach_client(struct i2c_client *client);
 static void pcf8591_init_client(struct i2c_client *client);
 static int pcf8591_read_channel(struct device *dev, int channel);
 
-/* This is the driver that will be inserted */
-static struct i2c_driver pcf8591_driver = {
-        .driver = {
-                .name   = "pcf8591",
-        },
-        .attach_adapter = pcf8591_attach_adapter,
-        .detach_client  = pcf8591_detach_client,
-};
-
 /* following are the sysfs callback functions */
 #define show_in_channel(channel)                                        \
 static ssize_t show_in##channel##_input(struct device *dev, struct device_attribute *attr, char *buf)   \
@@ -180,58 +167,46 @@ static const struct attribute_group pcf8591_attr_group_opt = {
 /*
  * Real code
  */
-static int pcf8591_attach_adapter(struct i2c_adapter *adapter)
-{
-        return i2c_probe(adapter, &addr_data, pcf8591_detect);
-}
 
-/* This function is called by i2c_probe */
-static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind)
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int pcf8591_detect(struct i2c_client *client, int kind,
+                          struct i2c_board_info *info)
 {
-        struct i2c_client *client;
-        struct pcf8591_data *data;
-        int err = 0;
+        struct i2c_adapter *adapter = client->adapter;
 
         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE
                                      | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
-                goto exit;
+                return -ENODEV;
+
+        /* Now, we would do the remaining detection. But the PCF8591 is plainly
+           impossible to detect! Stupid chip. */
+
+        strlcpy(info->type, "pcf8591", I2C_NAME_SIZE);
+
+        return 0;
+}
+
+static int pcf8591_probe(struct i2c_client *client,
+                         const struct i2c_device_id *id)
+{
+        struct pcf8591_data *data;
+        int err;
 
-        /* OK. For now, we presume we have a valid client. We now create the
-           client structure, even though we cannot fill it completely yet. */
         if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) {
                 err = -ENOMEM;
                 goto exit;
         }
         
-        client = &data->client;
         i2c_set_clientdata(client, data);
-        client->addr = address;
-        client->adapter = adapter;
-        client->driver = &pcf8591_driver;
-
-        /* Now, we would do the remaining detection. But the PCF8591 is plainly
-           impossible to detect! Stupid chip. */
-
-        /* Determine the chip type - only one kind supported! */
-        if (kind <= 0)
-                kind = pcf8591;
-
-        /* Fill in the remaining client fields and put it into the global 
-           list */
-        strlcpy(client->name, "pcf8591", I2C_NAME_SIZE);
         mutex_init(&data->update_lock);
 
-        /* Tell the I2C layer a new client has arrived */
-        if ((err = i2c_attach_client(client)))
-                goto exit_kfree;
-
         /* Initialize the PCF8591 chip */
         pcf8591_init_client(client);
 
         /* Register sysfs hooks */
         err = sysfs_create_group(&client->dev.kobj, &pcf8591_attr_group);
         if (err)
-                goto exit_detach;
+                goto exit_kfree;
 
         /* Register input2 if not in "two differential inputs" mode */
         if (input_mode != 3) {
@@ -252,24 +227,16 @@ static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind)
 exit_sysfs_remove:
         sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
         sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
-exit_detach:
-        i2c_detach_client(client);
 exit_kfree:
         kfree(data);
 exit:
         return err;
 }
 
-static int pcf8591_detach_client(struct i2c_client *client)
+static int pcf8591_remove(struct i2c_client *client)
 {
-        int err;
-
         sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
         sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
-
-        if ((err = i2c_detach_client(client)))
-                return err;
-
         kfree(i2c_get_clientdata(client));
         return 0;
 }
@@ -316,6 +283,25 @@ static int pcf8591_read_channel(struct device *dev, int channel)
                 return (10 * value);
 }
 
+static const struct i2c_device_id pcf8591_id[] = {
+        { "pcf8591", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, pcf8591_id);
+
+static struct i2c_driver pcf8591_driver = {
+        .driver = {
+                .name   = "pcf8591",
+        },
+        .probe          = pcf8591_probe,
+        .remove         = pcf8591_remove,
+        .id_table       = pcf8591_id,
+
+        .class          = I2C_CLASS_HWMON,      /* Nearest choice */
+        .detect         = pcf8591_detect,
+        .address_data   = &addr_data,
+};
+
 static int __init pcf8591_init(void)
 {
         if (input_mode < 0 || input_mode > 3) {