The ADC is typically shared with remote CPUs not running Linux.
However, there is only one register to power-up/power-down. Remote CPUs
aren't able to power-up the ADC, and rely in Linux doing it instead.
This commit uses the adc-reserved-channels devicetree property to
distinguish shared usage. In this case, the ADC is powered up at
probe time.
If the ADC is used only by the CPU running Linux, power-up/down
at runtime, only when neeeded.
Signed-off-by: Naidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
According to hardware team there should be some delay after
setting channel number, start mode and before setting START.
Add a one microsecond delay for this purpose.
Fixes: 1664f6a5b0 ("iio: adc: Cosmic Circuits 10001 ADC driver")
Signed-off-by: Naidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
regulator_get_voltage() returns a non-negative value in case of success,
and a negative error in case of error. Let's fix this.
Fixes: 1664f6a5b0 ("iio: adc: Cosmic Circuits 10001 ADC driver")
Signed-off-by: Naidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
At present we are incorrectly setting the register to 0x1 to power up
the ADC. Since it is an active high power down register, we need to set
the register to 0x0 to actually power up. Conversely, writing 0x1 to the
register powers it down.
This commit adds a couple of helpers to make the code clearer and then
use them to do the power-up/power-down properly.
Fixes: 1664f6a5b0 ("iio: adc: Cosmic Circuits 10001 ADC driver")
Signed-off-by: Naidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
When some of the ADC channels are reserved for remote CPUs,
the scan index and the corresponding channel number doesn't
match. This leads to convesion on the incorrect channel during
triggered capture.
Fix this by using a scan index to channel mapping encoded
in the iio_chan_spec for this purpose while starting conversion
on a particular ADC channel in trigger handler.
Also, the channel_map is not really used anywhere but in probe(), so
no need to keep track of it. Remove it from device structure.
While here, add 1 to number of channels to register timestamp channel
with the IIO core.
Fixes: 1664f6a5b0 ("iio: adc: Cosmic Circuits 10001 ADC driver")
Signed-off-by: Naidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
