[alsa-devel] [PATCH v7 0/6] ASoC: Intel: Skylake: Add a clk driver to enable ssp clks early
Sriram Periyasamy
sriramx.periyasamy at intel.com
Tue Jan 16 12:24:07 CET 2018
On Thu, Jan 04, 2018 at 04:55:13PM +0530, Sriram Periyasamy wrote:
> For certain platforms, clocks (mclk/sclk/fs) are required to be up before
> the stream start. Example: some codecs needs the mclk/sclk/fs to be
> enabled early for a successful clock synchronization. Some platforms
> require clock to be enabled at boot and be always ON.
>
> By sending set_dma_control IPC (with the i2s blobs queried from NHLT),
> these clocks can be enabled early after the firmware is downloaded.
>
> With this series, a virtual clock driver is created which provides
> interface to send the required IPCs from machine driver to enable the
> clocks. NHLT is parsed during probe and the clock information is populated.
> The pointer to blob is cached and sent along with the set_dma_control IPC
> structure during the clk prepare/unprepare callback. Clocks are created for
> a ssp if the nhlt table has endpoint configuration for that particular ssp.
>
> Kabylake machine driver uses the clock interface to enable the clocks early
> as it is required by the rt5663 driver for clock synchronization.
>
> v6 -> v7
Hi Mark,
Is this in your review queue? Stephen has given his "Reviewed-by", in case
you are waiting for his ack.
Thanks,
Sriram.
> - Remove the check to deny set_rate when clock is enabled and
> instead use framework flag CLK_SET_RATE_GATE
>
> v5 -> v6
> - Remove unwanted checks from clk ops
>
> - Modify recalc_rate to return just the cached rate and remove the
> rate calculations
>
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