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SubjectRe: [RFC PATCH 0/5] Flexible sysclk/pll configuration
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On 2/25/2021 11:35 PM, Sameer Pujar wrote:
> This series attempts to add flexible system clock (sysclk) and pll
> configuration for the DAI controller from simple card or audio graph
> card.
>
> Sysclk configuration
> ====================
> Motivation:
> -----------
> The problem this tries to address is, some Codecs may have
> multiple clocks and multiple sources for its sysclk. For example
> sysclk may depend on MCLK provided by SoC or it may used an
> internal pll. The simple card or audio graph card driver is
> generic and can be used on multiple platforms. So if a platform
> using this driver needs a generic configuration, then the Codec
> specific stuff cannot be hardcoded in the driver. Hence it would
> be better if the info is driven from DT, especially from a
> Codec DAI or endpoint subnode.
>
> Solution:
> ---------
> "system-clock-id" and "system-clock-source" DT properties can be
> exposed for a flexible sysclk configuration. These properties
> go into a Codec DAI or endpoint subnode.
>
> Please note that other sysclk related properties like
> "system-clock-frequency" and "system-clock-direction-out" are
> already present.
>
> Currently snd_soc_dai_set_sysclk() does not have an argument
> for source. This series adds this additional field and updates
> all the required drivers. This is needed because ideally sysclk
> "clk_id" and "source" fields are different. Some drivers are
> making use of "clk_id" field to program source information.
> **May be this needs to be corrected going ahead**
>
>
> Pll configuration
> =================
> Motivation:
> -----------
> Similar to sysclk configuration, pll configuration also needs
> little more flexibility. If a Codec has internal pll and it
> can be sourced from multiple clocks a specific configuration
> may be required for a given platform.
>
> Some of the cases are:
> - MCLK (supplied by SoC) --> Codec pll -> Codec sysclk
> - SoC I2S bit clock (BCLK) --> Codec pll -> Codec sysclk
>
> Solution:
> ---------
> Approach is similar to what is done for extending sysclk
> flexibility. Following DT properties are added to address the
> same.
>
> "pll-id"
> "pll-source"
> "pll-input-reference"
> "pll-output-reference"
> "pll-input-frequency"
> "pll-output-frequency"
>
> All these are optional properties. Simple card or audio graph
> card drivers can use above info and call snd_soc_dai_set_pll()
> for necessary configuration.
>
> Sameer Pujar (5):
> ASoC: soc-component: Fix return value of snd_soc_component_set_pll()
> ASoC: soc-dai: Add sysclk source to snd_soc_dai_set_sysclk()
> ASoC: audio-graph-card: Add bindings for sysclk and pll
> ASoC: simple-card-utils: Parse sysclk id and source
> ASoC: simple-card-utils: Support pll configuration
>
> .../bindings/sound/audio-graph-port.yaml | 71 +++++++++
> include/sound/simple_card_utils.h | 35 +++++
> include/sound/soc-dai.h | 4 +-
> sound/soc/amd/acp-da7219-max98357a.c | 2 +-
> sound/soc/amd/acp-rt5645.c | 2 +-
> sound/soc/amd/acp3x-rt5682-max9836.c | 4 +-
> sound/soc/atmel/atmel_wm8904.c | 2 +-
> sound/soc/atmel/mchp-i2s-mcc.c | 2 +-

[...]

> sound/soc/ti/omap-mcbsp.c | 2 +-
> sound/soc/ti/omap3pandora.c | 4 +-
> sound/soc/ti/rx51.c | 2 +-
> sound/soc/uniphier/aio-cpu.c | 4 +-
> sound/soc/ux500/ux500_msp_dai.c | 2 +-
> 271 files changed, 639 insertions(+), 389 deletions(-)
>

Looks like I missed some files to update which make use of
snd_soc_dai_set_sysclk(). I will try to fix that. Meanwhile please
review if the idea is right here.

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