We don't actually support configuring the PDM input right now. Rather,
this is useful as a hack.
On Apple Silicon machines, amps are split between two I2S buses which
are logically ANDed internally at the SoC. Odd and even slot groups are
driven by amps on either bus respectively. Since the signals are ANDed,
unused slot groups must be driven as zero to avoid corrupting the data
from the other side.
On most recent machines (TAS2764-based), this is accomplished using the
"SDOUT zero mask" feature of that chip. Unfortunately, TAS2770 does not
support this. It does support zeroing out *all* unused slots, which
works well for machines with a single amp per I2S bus. That is all,
except one.
The 13" M1 MacBook Pro is the only machine using TAS2770 and two amps
per I2S bus:
L Bus: SPK0I SPK0V Hi-Z Hi-Z SPK2I SPK2V Hi-Z Hi-Z
R Bus: Hi-Z Hi-Z SPK1I SPK2V Hi-Z Hi-Z SPK3I SPK3V
To ensure uncorrupted data, we need to force all the Hi-Z periods to
zero. We cannot use the "force all zero" feature, as that would cause a
bus conflict between both amps. We can use the pull-down feature, but
that leaves a few bits of garbage on the trailing edge of the speaker
data, since the pull-down is weak.
This is where the PDM transmit feature comes in. With PDM grounded and
disabled (the default state), the PDM slot is transmitted as all zeroes.
We can use that to force a zero 16-bit slot after the voltage data for
each speaker, cleaning it up. Then the pull-down ensures the line stays
low for the subsequent slot:
L Bus: SPK0I SPK0V PDM0 PulDn SPK2I SPK2V PDM0 PulDn
R Bus: PDM0 PulDn SPK1I SPK2V PDM0 PulDn SPK3I SPK3V
Yes, this is a horrible hack, but it beats adding dummy slots that would
be visible to the userspace capture side. There may be some other way to
fix the logical AND behavior on the MCA side... that would make this
unnecessary.
("How does Apple deal with this"? - they don't, macOS does not use
IVSENSE on TAS2770 machines even though it's physically wired up,
but we want to do so on Linux.)
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
Link: https://patch.msgid.link/20250406-apple-codec-changes-v5-2-50a00ec850a3@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Because the PWR_CTRL field is modeled as the power state of the DAC
widget, and at the same time it is used to implement mute/unmute, we
need some additional book-keeping to have the right end result no matter
the sequence of calls. Without this fix, one can mute an ongoing stream
by toggling a speaker pin control.
Fixes: 1a476abc72 ("tas2770: add tas2770 smart PA kernel driver")
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20220808141246.5749-5-povik+lin@cutebit.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix setting of FSYNC polarity for DAI formats other than I2S. Also
add support for polarity inversion.
Fixes: 1a476abc72 ("tas2770: add tas2770 smart PA kernel driver")
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20220808141246.5749-2-povik+lin@cutebit.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Remove unused variables in the private struct and the code as these
variables are initially set and then there is no additional code
utilizing these variables.
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200923132600.10652-6-dmurphy@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Remove the code to support the asi-format binding property. The code
does nothing except read the property and set a variable. No additional
action is taken except to reset the variable. The property is supposed
to set the rising or falling RX edge detection of the SBCLK but this
edge detection is done by checking the DAI_FMT_INV_MASK.
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200923132600.10652-5-dmurphy@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Update the hardcoded masks with the GENMASK macro. Also update some of
the hardcoded bits with the BIT macro
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200918190548.12598-6-dmurphy@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200719153822.59788-1-grandmaster@al2klimov.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Remove unused defines and structure variables that are not
referenced by the code. If these are needed for future
enhancements then they should be added at that time.
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20191007171157.17813-3-dmurphy@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
