The PLL introduces jitter, which in turn introduces noice if used
to clock the DAC. Thus, avoid the PLL output, and use the PLL input
to drive the DAC clock, if possible.
This is described for the PCM5142/PCM5242 chips in the answers to the
forum post "PCM5142/PCM5242 DAC clock source" at the TI E2E community
pages (1).
(1) http://e2e.ti.com/support/data_converters/audio_converters/f/64/t/389994
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Mark Brown <broonie@kernel.org>
Using the PLL in master mode requires using an external connection
between one of the GPIO pins (configured as PLL/4 output) and the
SCK pin. It also requires the external clock to be fed to some other
GPIO pin instead of the SCK pin.
This is described for the PCM5122 chip in the answers to the forum post
"PCM5122 DAC as I2S master troubles with PLL mode" at the TI E2E
community pages (1). The clocking functionality is also much better
described in the datasheet for the chip PCM5242, which seems to be
register compatible with PCM512x and PCM514x (which both have severely
lacking datasheets).
(1) http://e2e.ti.com/support/data_converters/audio_converters/f/64/t/267830
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use register field names from the seemingly compatible PCM5242 datasheet,
as the PCM512x and PCM514x datasheets are severly lacking.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Mark Brown <broonie@kernel.org>
Move to the new style of defining the bus interfaces in separate modules
in order to simplify dependencies.
Signed-off-by: Mark Brown <broonie@linaro.org>
There are some analogue volume controls in page 1 of the register map so
implement support for them now that we can access the registers.
Signed-off-by: Mark Brown <broonie@linaro.org>
The PCM512x devices use a paged register map covering the entire register
range. Implement support for this, mapping pages in at addresses starting
at 0x100 for ease of use (though since the pages are numbered from 0 there
is going to be an off by one when looking at the first byte as a page
number).
Also mark the new registers as accessible with the exception of the
coefficient RAM which is a bit fiddly and may benefit from some extra
handling to linearise the blocks.
Signed-off-by: Mark Brown <broonie@linaro.org>
The PCM512x devices are a family of monolithic CMOS integrated circuits
that include a stereo digital-to-analog converter and additional support
circuitry.
This is an initial driver which supports some core functionality for the
device which covers common use cases but does not cover all features.
Currently only slave clocking modes with automatic clock configuration
are supported and most of the DSP configuration for the device is not
enabled.
Signed-off-by: Mark Brown <broonie@linaro.org>
Peter Rosin