V4L/DVB (6451): v4l2: add support for bus-based I2C drivers

Two new headers were added: one for I2C drivers that are only used
by V4L2 drivers converted to the new bus-based I2C API, and one that
can be used by both converted and unconverted drivers (at the expense of
some additional overhead).

To support the legacy I2C API a helper function was added to v4l2-common.c.

These headers take care of all the 'boilerplate' code that all V4L2 I2C drivers
have in common and will automatically support the bus-based I2C API introduced
in kernel 2.6.22.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/drivers/media/video/v4l2-common.c b/drivers/media/video/v4l2-common.c
index a4d68d3ba5e..32607a612b1 100644
--- a/drivers/media/video/v4l2-common.c
+++ b/drivers/media/video/v4l2-common.c
@@ -1013,6 +1013,35 @@ int v4l2_chip_match_host(u32 match_type, u32 match_chip)
 
 /* ----------------------------------------------------------------- */
 
+/* Helper function for I2C legacy drivers */
+
+int v4l2_i2c_attach(struct i2c_adapter *adapter, int address, struct i2c_driver *driver,
+                const char *name, int (*probe)(struct i2c_client *))
+{
+        struct i2c_client *client;
+        int err;
+
+        client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
+        if (client == 0)
+                return -ENOMEM;
+
+        client->addr = address;
+        client->adapter = adapter;
+        client->driver = driver;
+        snprintf(client->name, sizeof(client->name) - 1, name);
+
+        err = probe(client);
+        if (err == 0) {
+                i2c_attach_client(client);
+        }
+        else {
+                kfree(client);
+        }
+        return err;
+}
+
+/* ----------------------------------------------------------------- */
+
 EXPORT_SYMBOL(v4l2_norm_to_name);
 EXPORT_SYMBOL(v4l2_video_std_construct);
 
@@ -1038,6 +1067,8 @@ EXPORT_SYMBOL(v4l2_chip_match_i2c_client);
 EXPORT_SYMBOL(v4l2_chip_ident_i2c_client);
 EXPORT_SYMBOL(v4l2_chip_match_host);
 
+EXPORT_SYMBOL(v4l2_i2c_attach);
+
 /*
  * Local variables:
  * c-basic-offset: 8