linux/sound/soc/cirrus/Kconfig
Alexander Sverdlin 98e1241c35
ASoC: cirrus: i2s: IRQ-based stream watchdog
I2S controller on EP93xx seems to have undocumented HW issue. According to
"EP93xx User’s Guide", controller can handle underflow and either transmit
last sample or zeroes in such case until FIFO is filled again. In reality
undeflow conditions seem to confuse internal state machine from time to
time and the whole stream gets shifted by one byte (as captured by logic
analyser on the I2S outputs). One could only hear noise instead of original
stream and this continues until the FIFO is disabled and enabled again.

Work this around by watching underflow interrupt and resetting I2S TX
channel + fill FIFO with zero samples until DMA catches up again. This is
a nasty workaround, but it works. Hence, Kconfig option to disable it in
case of problems.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-05-11 11:27:33 +09:00

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config SND_EP93XX_SOC
tristate "SoC Audio support for the Cirrus Logic EP93xx series"
depends on ARCH_EP93XX || COMPILE_TEST
select SND_SOC_GENERIC_DMAENGINE_PCM
help
Say Y or M if you want to add support for codecs attached to
the EP93xx I2S or AC97 interfaces.
config SND_EP93XX_SOC_I2S
tristate
if SND_EP93XX_SOC_I2S
config SND_EP93XX_SOC_I2S_WATCHDOG
bool "IRQ based underflow watchdog workaround"
default y
help
I2S controller on EP93xx seems to have undocumented HW issue.
Underflow of internal I2S controller FIFO could confuse the
state machine and the whole stream can be shifted by one byte
until I2S is disabled. This option enables IRQ based watchdog
which disables and re-enables I2S in case of underflow and
fills FIFO with zeroes.
If you are unsure how to answer this question, answer Y.
endif # if SND_EP93XX_SOC_I2S
config SND_EP93XX_SOC_AC97
tristate
select AC97_BUS
select SND_SOC_AC97_BUS
config SND_EP93XX_SOC_SNAPPERCL15
tristate "SoC Audio support for Bluewater Systems Snapper CL15 module"
depends on SND_EP93XX_SOC && MACH_SNAPPER_CL15 && I2C
select SND_EP93XX_SOC_I2S
select SND_SOC_TLV320AIC23_I2C
help
Say Y or M here if you want to add support for I2S audio on the
Bluewater Systems Snapper CL15 module.
config SND_EP93XX_SOC_SIMONE
tristate "SoC Audio support for Simplemachines Sim.One board"
depends on SND_EP93XX_SOC && MACH_SIM_ONE
select SND_EP93XX_SOC_AC97
select SND_SOC_AC97_CODEC
help
Say Y or M here if you want to add support for AC97 audio on the
Simplemachines Sim.One board.
config SND_EP93XX_SOC_EDB93XX
tristate "SoC Audio support for Cirrus Logic EDB93xx boards"
depends on SND_EP93XX_SOC && (MACH_EDB9301 || MACH_EDB9302 || MACH_EDB9302A || MACH_EDB9307A || MACH_EDB9315A)
select SND_EP93XX_SOC_I2S
select SND_SOC_CS4271_I2C if I2C
select SND_SOC_CS4271_SPI if SPI_MASTER
help
Say Y or M here if you want to add support for I2S audio on the
Cirrus Logic EDB93xx boards.