diff options
| author | Hans Verkuil | 2009-03-12 18:34:19 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab | 2009-03-30 12:43:19 -0300 |
| commit | 2c79252326421dd49c059aceec0880d2cf15b17a (patch) | |
| tree | 843430d8471a54dbe04a6363f7d2e30060ed7499 /Documentation | |
| parent | 5e585ef15b3633e1b0c022aa14bc88587827acd3 (diff) | |
V4L/DVB (10980): doc: improve the v4l2-framework documentation.
Emphasize the need to call i2c_set_adapdata and clarify the use of the
chipid in v4l2_i2c_new_(probed_)device().
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/video4linux/v4l2-framework.txt | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index accc376e93cc..51a7b6db118f 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -359,8 +359,8 @@ This loads the given module (can be NULL if no module needs to be loaded) and calls i2c_new_device() with the given i2c_adapter and chip/address arguments. If all goes well, then it registers the subdev with the v4l2_device. It gets the v4l2_device by calling i2c_get_adapdata(adapter), so you should make sure -that adapdata is set to v4l2_device when you setup the i2c_adapter in your -driver. +to call i2c_set_adapdata(adapter, v4l2_device) when you setup the i2c_adapter +in your driver. You can also use v4l2_i2c_new_probed_subdev() which is very similar to v4l2_i2c_new_subdev(), except that it has an array of possible I2C addresses @@ -368,6 +368,14 @@ that it should probe. Internally it calls i2c_new_probed_device(). Both functions return NULL if something went wrong. +Note that the chipid you pass to v4l2_i2c_new_(probed_)subdev() is usually +the same as the module name. It allows you to specify a chip variant, e.g. +"saa7114" or "saa7115". In general though the i2c driver autodetects this. +The use of chipid is something that needs to be looked at more closely at a +later date. It differs between i2c drivers and as such can be confusing. +To see which chip variants are supported you can look in the i2c driver code +for the i2c_device_id table. This lists all the possibilities. + struct video_device ------------------- |