Messages in this thread | | | From | Viorel Suman <> | Subject | RE: [RFC PATCH] ASoC: ak4458: use reset control instead of reset gpio | Date | Thu, 19 Nov 2020 16:24:10 +0000 |
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Hi Peter,
> DTS is supposed to look as follows: > > > > / { > > ak4458_reset: gpio-reset { > > compatible = "gpio-reset"; > > reset-gpios = <&pca6416 4 GPIO_ACTIVE_LOW>; > > #reset-cells = <0>; > > initially-in-reset; > > I can not find anything resembling to this in next-20201119. > Where is the implementation and documentation for this gpio-reset?
The board schematics is not publicly available; some info may be seen in DTS files below: https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mm-evk.dts?h=imx_5.4.24_2.1.0 https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mm-ab2.dts?h=imx_5.4.24_2.1.0 https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mp-ab2.dts?h=imx_5.4.24_2.1.0
In examples above the GPIO is handled by machine driver - wrong approach given that it requires machine driver being probed before codec driver.
> > - ak4458->reset_gpiod = devm_gpiod_get_optional(ak4458->dev, > "reset", > > - GPIOD_OUT_LOW); > > - if (IS_ERR(ak4458->reset_gpiod)) > > - return PTR_ERR(ak4458->reset_gpiod); > > + ak4458->reset = devm_reset_control_get_optional_shared(ak4458- > >dev, NULL); > > + if (IS_ERR(ak4458->reset)) > > + return PTR_ERR(ak4458->reset); > > The binding documentation must be updated and you must support the gpio > way as well.
Sure, make sense.
> When I had this discussion around using the reset framework for shared > enable and/or reset pins it was suggested that _if_ such a driver makes > sense then it should internally handle (by using magic strings) the fallback > and work with pre-reset binding.
Thanks, would appreciate if you point me to the discussion you had.
Viorel
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