V4L/DVB (9821): v4l2-common: add i2c helper functions
Add helper functions to load i2c sub-devices, integrating them
into the v4l2-framework.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/v4l2-common.c b/drivers/media/video/v4l2-common.c
index fdc8871..26f3254 100644
--- a/drivers/media/video/v4l2-common.c
+++ b/drivers/media/video/v4l2-common.c
@@ -58,6 +58,7 @@
#include <asm/div64.h>
#define __OLD_VIDIOC_ /* To allow fixing old calls*/
#include <media/v4l2-common.h>
+#include <media/v4l2-device.h>
#include <media/v4l2-chip-ident.h>
#include <linux/videodev2.h>
@@ -801,4 +802,116 @@
return err != -ENOMEM ? 0 : err;
}
EXPORT_SYMBOL(v4l2_i2c_attach);
+
+void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
+ const struct v4l2_subdev_ops *ops)
+{
+ v4l2_subdev_init(sd, ops);
+ /* the owner is the same as the i2c_client's driver owner */
+ sd->owner = client->driver->driver.owner;
+ /* i2c_client and v4l2_subdev point to one another */
+ v4l2_set_subdevdata(sd, client);
+ i2c_set_clientdata(client, sd);
+ /* initialize name */
+ snprintf(sd->name, sizeof(sd->name), "%s %d-%04x",
+ client->driver->driver.name, i2c_adapter_id(client->adapter),
+ client->addr);
+}
+EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init);
+
+
+
+/* Load an i2c sub-device. It assumes that i2c_get_adapdata(adapter)
+ returns the v4l2_device and that i2c_get_clientdata(client)
+ returns the v4l2_subdev. */
+struct v4l2_subdev *v4l2_i2c_new_subdev(struct i2c_adapter *adapter,
+ const char *module_name, const char *client_type, u8 addr)
+{
+ struct v4l2_device *dev = i2c_get_adapdata(adapter);
+ struct v4l2_subdev *sd = NULL;
+ struct i2c_client *client;
+ struct i2c_board_info info;
+
+ BUG_ON(!dev);
+#ifdef MODULE
+ if (module_name)
+ request_module(module_name);
+#endif
+ /* Setup the i2c board info with the device type and
+ the device address. */
+ memset(&info, 0, sizeof(info));
+ strlcpy(info.type, client_type, sizeof(info.type));
+ info.addr = addr;
+
+ /* Create the i2c client */
+ client = i2c_new_device(adapter, &info);
+ /* Note: it is possible in the future that
+ c->driver is NULL if the driver is still being loaded.
+ We need better support from the kernel so that we
+ can easily wait for the load to finish. */
+ if (client == NULL || client->driver == NULL)
+ return NULL;
+
+ /* Lock the module so we can safely get the v4l2_subdev pointer */
+ if (!try_module_get(client->driver->driver.owner))
+ return NULL;
+ sd = i2c_get_clientdata(client);
+
+ /* Register with the v4l2_device which increases the module's
+ use count as well. */
+ if (v4l2_device_register_subdev(dev, sd))
+ sd = NULL;
+ /* Decrease the module use count to match the first try_module_get. */
+ module_put(client->driver->driver.owner);
+ return sd;
+
+}
+EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev);
+
+/* Probe and load an i2c sub-device. It assumes that i2c_get_adapdata(adapter)
+ returns the v4l2_device and that i2c_get_clientdata(client)
+ returns the v4l2_subdev. */
+struct v4l2_subdev *v4l2_i2c_new_probed_subdev(struct i2c_adapter *adapter,
+ const char *module_name, const char *client_type,
+ const unsigned short *addrs)
+{
+ struct v4l2_device *dev = i2c_get_adapdata(adapter);
+ struct v4l2_subdev *sd = NULL;
+ struct i2c_client *client = NULL;
+ struct i2c_board_info info;
+
+ BUG_ON(!dev);
+#ifdef MODULE
+ if (module_name)
+ request_module(module_name);
+#endif
+ /* Setup the i2c board info with the device type and
+ the device address. */
+ memset(&info, 0, sizeof(info));
+ strlcpy(info.type, client_type, sizeof(info.type));
+
+ /* Probe and create the i2c client */
+ client = i2c_new_probed_device(adapter, &info, addrs);
+ /* Note: it is possible in the future that
+ c->driver is NULL if the driver is still being loaded.
+ We need better support from the kernel so that we
+ can easily wait for the load to finish. */
+ if (client == NULL || client->driver == NULL)
+ return NULL;
+
+ /* Lock the module so we can safely get the v4l2_subdev pointer */
+ if (!try_module_get(client->driver->driver.owner))
+ return NULL;
+ sd = i2c_get_clientdata(client);
+
+ /* Register with the v4l2_device which increases the module's
+ use count as well. */
+ if (v4l2_device_register_subdev(dev, sd))
+ sd = NULL;
+ /* Decrease the module use count to match the first try_module_get. */
+ module_put(client->driver->driver.owner);
+ return sd;
+}
+EXPORT_SYMBOL_GPL(v4l2_i2c_new_probed_subdev);
+
#endif