[PATCH v3 3/6] ASoC: audio-graph-card: Support setting component plls and sysclks

Richard Fitzgerald rf at opensource.cirrus.com
Mon Dec 21 05:38:22 EST 2020

On 18/12/2020 00:03, Kuninori Morimoto wrote:
> Hi Richard
> Thank you for your patch.
> This is v3 patch, but I think this is the first time for me
> to receive patch...

Yes sorry.
Somehow I missed you off V1 and V2 emails.

>> Some codecs need plls and/or sysclks to be configured using the
>> snd_soc_component_set_[sysclk|pll] functions. These drivers cannot
>> necessarily be converted to use the clock framework. If the codec is on
>> a I2C/SPI bus, a nested clk_get would be needed to enable the bus clock.
>> But the clock framework does not support nested operations and this would
>> deadlock.
>> This patch adds new dt properties that list phandles of components with
>> the pll/sysclk settings to be applied. Multiple settings can be given for
>> the same phandle to allow for components with multiple clocks and plls.
>> The plls and sysclks are enabled when the card bias level moves to STANDBY
>> and disabled when it moves to OFF.
>> The implementation does not attempt to handle specifying complex clock
>> ordering interdependencies between components. The plls and sysclks are
>> applied to a component as it is passed to the card set_bias_level/
>> set_bias_level_post callbacks. It follows from this that the order
>> components are configured is the order that they are passed to those
>> callbacks.
>> Signed-off-by: Richard Fitzgerald <rf at opensource.cirrus.com>
>> ---
>>   include/sound/simple_card_utils.h     |  25 +++
>>   sound/soc/generic/audio-graph-card.c  |  16 +-
>>   sound/soc/generic/simple-card-utils.c | 236 ++++++++++++++++++++++++++
>>   3 files changed, 275 insertions(+), 2 deletions(-)
> I understand that you need sysclk/pll and .set_bias_level_xxx().
> But I guess makes it generic code is difficult (?).
> Thus, as Sameer doing on Tegra, creating custom audio-graph-card is better
> idea for you ?
> # Now I'm creating new audio-graph-card2 which also supports
> # overwriting/customizing each/all functions.
> # It is not full compatible with audio-graph-card, but almost same if you
> # uses normal connection.
> # I hope I can post it next year
> Thank you for your help !!
> Best regards
> ---
> Kuninori Morimoto

More information about the linux-arm-kernel mailing list