]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/i2c/i2c-core.c
[SCSI] fix netlink kernel-doc
[linux-2.6-omap-h63xx.git] / drivers / i2c / i2c-core.c
index b346a687ab593a89834270e64b91f2b8b1c4c66f..42e852d79ffaa5b001dda2c44219cad064a537e7 100644 (file)
@@ -437,6 +437,10 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 {
        int res = 0, dummy;
 
+       /* Can't register until after driver model init */
+       if (unlikely(WARN_ON(!i2c_bus_type.p)))
+               return -EAGAIN;
+
        mutex_init(&adap->bus_lock);
        mutex_init(&adap->clist_lock);
        INIT_LIST_HEAD(&adap->clients);
@@ -696,6 +700,10 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
 {
        int res;
 
+       /* Can't register until after driver model init */
+       if (unlikely(WARN_ON(!i2c_bus_type.p)))
+               return -EAGAIN;
+
        /* new style driver methods can't mix with legacy ones */
        if (is_newstyle_driver(driver)) {
                if (driver->attach_adapter || driver->detach_adapter
@@ -978,7 +986,10 @@ static void __exit i2c_exit(void)
        bus_unregister(&i2c_bus_type);
 }
 
-subsys_initcall(i2c_init);
+/* We must initialize early, because some subsystems register i2c drivers
+ * in subsys_initcall() code, but are linked (and initialized) before i2c.
+ */
+postcore_initcall(i2c_init);
 module_exit(i2c_exit);
 
 /* ----------------------------------------------------
@@ -1676,6 +1687,28 @@ s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
 }
 EXPORT_SYMBOL(i2c_smbus_write_word_data);
 
+/**
+ * i2c_smbus_process_call - SMBus "process call" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @value: 16-bit "word" being written
+ *
+ * This executes the SMBus "process call" protocol, returning negative errno
+ * else a 16-bit unsigned "word" received from the device.
+ */
+s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value)
+{
+       union i2c_smbus_data data;
+       int status;
+       data.word = value;
+
+       status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+                               I2C_SMBUS_WRITE, command,
+                               I2C_SMBUS_PROC_CALL, &data);
+       return (status < 0) ? status : data.word;
+}
+EXPORT_SYMBOL(i2c_smbus_process_call);
+
 /**
  * i2c_smbus_read_block_data - SMBus "block read" protocol
  * @client: Handle to slave device