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>
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@ -359,8 +359,8 @@ This loads the given module (can be NULL if no module needs to be loaded) and
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calls i2c_new_device() with the given i2c_adapter and chip/address arguments.
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If all goes well, then it registers the subdev with the v4l2_device. It gets
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the v4l2_device by calling i2c_get_adapdata(adapter), so you should make sure
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that adapdata is set to v4l2_device when you setup the i2c_adapter in your
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driver.
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to call i2c_set_adapdata(adapter, v4l2_device) when you setup the i2c_adapter
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in your driver.
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You can also use v4l2_i2c_new_probed_subdev() which is very similar to
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v4l2_i2c_new_subdev(), except that it has an array of possible I2C addresses
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@ -368,6 +368,14 @@ that it should probe. Internally it calls i2c_new_probed_device().
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Both functions return NULL if something went wrong.
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Note that the chipid you pass to v4l2_i2c_new_(probed_)subdev() is usually
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the same as the module name. It allows you to specify a chip variant, e.g.
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"saa7114" or "saa7115". In general though the i2c driver autodetects this.
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The use of chipid is something that needs to be looked at more closely at a
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later date. It differs between i2c drivers and as such can be confusing.
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To see which chip variants are supported you can look in the i2c driver code
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for the i2c_device_id table. This lists all the possibilities.
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struct video_device
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-------------------
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