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authorHans Verkuil <hverkuil@xs4all.nl>2009-03-12 18:34:19 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-03-30 12:43:19 -0300
commit2c79252326421dd49c059aceec0880d2cf15b17a (patch)
tree843430d8471a54dbe04a6363f7d2e30060ed7499 /Documentation/video4linux
parent5e585ef15b3633e1b0c022aa14bc88587827acd3 (diff)
downloadop-kernel-dev-2c79252326421dd49c059aceec0880d2cf15b17a.zip
op-kernel-dev-2c79252326421dd49c059aceec0880d2cf15b17a.tar.gz
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/video4linux')
-rw-r--r--Documentation/video4linux/v4l2-framework.txt12
1 files changed, 10 insertions, 2 deletions
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index accc376..51a7b6d 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
-------------------
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