On Mon, 2022-12-12 at 09:40 +0100, Krzysztof Kozlowski wrote:
On 12/12/2022 03:43, Trevor Wu (吳文良) wrote:
- uniqueItems: true
- items:
minimum: 0maximum: 15- "^mediatek,etdm-in[1-2]-mclk-always-on-rate-hz$":
- description: Specify etdm in mclk output rate for
always on case.
How is it different than assigned-clock-rates?
This includes clock enabling at init stage.
assigned-clock-rates are also at init stage. I asked what is different.
If the property is used, there are three parts included in dai driver probe function.
- set clock parent (which APLL)
- set clock rate (MCLK rate)
- enable clock (MCLK On)
The first two parts can be done by existing dts clock properties, but the last one can't. When MCLK should be enabled at boot time and kept on, this property is used. That's why I say the property is designed for always-on case.
Heh, so the "always on case" means this property enables clock? How is this even DT property? That's not how clocks should be kept enabled. You need proper clock provider and consumer.
Hi Krzysztof,
Sorry, I don't know it is not appropriate to notify driver that the clock should be ketp enabled after boot.
The original idea is that enabling this clock in the machine driver, but a property to inform machine driver is also required when the machine driver is shared by different codec combination. And it's easier to handle set_rate and set_parent in etdm dai driver, so I put the property here.
Do you mean if the clock consumer(audio codec or external DSP) requries the clock, the consumer should enable the clock by itself?
Thanks, Trevor