Hi,
This patch series fixes some fsl-ssi code that does not act exactly as it is described in the reference manuals.
The reference manuals before imx50 do mention that some register bits, including TDMAE/RDMAE, should not be changed while the SSI unit is enabled (SSIEN). At the same time the SDMA unit has a undefined request handling if there are DMA requests before the SDMA engine and its channel is configured. The reference manual states that SSI DMA requests are sent as soon as the FIFO and the DMAE bits are enabled. It does not mention a dependency to SCR's TE/RE bit.
To avoid sending DMA requests before a channel is configured, we have to seperate the fsl-ssi behavior into offline and online configuration. SoCs before imx50 have to use offline configuration while later SoC versions can use online reconfiguration.
This series adds support for online configuration and cleans up the configuration register code especially in fsl_ssi_trigger. At the end we have a seperation between enable/disable logic and the actual configuration register values used to enable/disable TX/RX.
I tested this series on mx53.
Regards,
Markus
Markus Pargmann (9): ASoC: fsl-ssi: Drop AC97 debug register usage ASoC: fsl-ssi: Move ac97 specific setup to seperate function ASoC: fsl-ssi: Move sysfs stats to debugfs ASoC: fsl-ssi: Add imx50-ssi and of_device_id matching ASoC: fsl-ssi: Add offline_config flag ASoC: fsl-ssi: Add configuration helper functions ASoC: fsl-ssi: Move RX/TX configuration to seperate functions ASoC: fsl-ssi: Drop ac97 specific trigger function ARM: DTS: imx5* imx6*, use imx50-ssi
arch/arm/boot/dts/imx51.dtsi | 6 +- arch/arm/boot/dts/imx53.dtsi | 6 +- arch/arm/boot/dts/imx6qdl.dtsi | 6 +- arch/arm/boot/dts/imx6sl.dtsi | 6 +- sound/soc/fsl/fsl_ssi.c | 580 ++++++++++++++++++++++++++--------------- 5 files changed, 389 insertions(+), 215 deletions(-)