[media] adv7180: Do implicit register paging
The ad7180 has multiple register pages which can be switched between by writing to a register. Currently the driver manually switches between pages whenever a register outside of the default register map is accessed and switches back after it has been accessed. This is a bit tedious and also potential source for bugs. This patch adds two helper functions that take care of switching between pages and reading/writing the register. The register numbers for registers are updated to encode both the page (in the upper 8-bits) and the register (in the lower 8-bits) numbers. Having multiple pages means that a register access is not a single atomic i2c_smbus_write_byte_data() or i2c_smbus_read_byte_data() call and we need to make sure that concurrent register access does not race against each other. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Federico Vaga <federico.vaga@gmail.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
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