[alsa-devel] [PATCH 7/8] ASoC: tegra: config fifos on hw_param changes

[Jon Hunter]

On 17/09/2019 19:12, Ben Dooks wrote:
> If the hw_params uses a different bit or channel count, then we
> need to change both the I2S unit's CIF configuration as well as
> the APBIF one.
> 
> To allow changing the APBIF, add a call to reconfigure the RX or
> TX FIFO without changing the DMA or allocation, and get the I2S
> driver to call it once the hw params have been calculate.
> 
> Signed-off-by: Ben Dooks <ben.dooks at codethink.co.uk>
> ---
>  sound/soc/tegra/tegra30_ahub.c | 114 ++++++++++++++++++---------------
>  sound/soc/tegra/tegra30_ahub.h |   5 ++
>  sound/soc/tegra/tegra30_i2s.c  |   2 +
>  3 files changed, 69 insertions(+), 52 deletions(-)
> 
> diff --git a/sound/soc/tegra/tegra30_ahub.c b/sound/soc/tegra/tegra30_ahub.c
> index 952381260dc3..58e05ceb86da 100644
> --- a/sound/soc/tegra/tegra30_ahub.c
> +++ b/sound/soc/tegra/tegra30_ahub.c
> @@ -84,12 +84,40 @@ static int tegra30_ahub_runtime_resume(struct device *dev)
>  	return 0;
>  }
>  
> +int tegra30_ahub_setup_rx_fifo(enum tegra30_ahub_rxcif rxcif,
> +			       struct tegra30_ahub_cif_conf *cif_conf)
> +{
> +	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
> +	u32 reg, val;
> +
> +	pm_runtime_get_sync(ahub->dev);
> +
> +	reg = TEGRA30_AHUB_CHANNEL_CTRL +
> +	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
> +	val = tegra30_apbif_read(reg);
> +	val &= ~(TEGRA30_AHUB_CHANNEL_CTRL_RX_THRESHOLD_MASK |
> +		 TEGRA30_AHUB_CHANNEL_CTRL_RX_PACK_MASK);
> +	val |= (7 << TEGRA30_AHUB_CHANNEL_CTRL_RX_THRESHOLD_SHIFT) |
> +	       TEGRA30_AHUB_CHANNEL_CTRL_RX_PACK_EN |
> +	       TEGRA30_AHUB_CHANNEL_CTRL_RX_PACK_16;
> +	tegra30_apbif_write(reg, val);

Aren't you just programming the same value to the APBIF here that was
previously programmed by the allocate function? I don't see the point in
moving this? What am I missing here?

Cheers
Jon

-- 
nvpublic