Re: [PATCH 3/5] clk: qcom: Add lpass clock controller driver for SC8280XP

[Johan Hovold <johan@kernel.org>]

On Thu, May 18, 2023 at 12:37:58PM +0100, Srinivas Kandagatla wrote:
> Add support for the lpass clock controller found on SC8280XP based devices.
> This would allow lpass peripheral loader drivers to control the clocks and
> bring the subsystems out of reset.
> 
> Currently this patch only supports resets as the Q6DSP is in control of
> LPASS IP which manages most of the clocks via Q6PRM service on GPR rpmsg
> channel.
> 
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> ---
>  drivers/clk/qcom/Kconfig            |  8 ++++
>  drivers/clk/qcom/Makefile           |  1 +
>  drivers/clk/qcom/lpasscc-sc8280xp.c | 71 +++++++++++++++++++++++++++++
>  3 files changed, 80 insertions(+)
>  create mode 100644 drivers/clk/qcom/lpasscc-sc8280xp.c
> 
> diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
> index 12be3e2371b3..8188f4dedf40 100644
> --- a/drivers/clk/qcom/Kconfig
> +++ b/drivers/clk/qcom/Kconfig
> @@ -514,6 +514,14 @@ config SC_GPUCC_8280XP
>  	  Say Y if you want to support graphics controller devices and
>  	  functionality such as 3D graphics.
>  
> +config SC_LPASSCC_8280XP

Should go after SC_LPASSCC_7280.

> +	tristate "SC8280 Low Power Audio Subsystem (LPASS) Clock Controller"
> +	select SC_GCC_8280XP
> +	help
> +	  Support for the LPASS clock controller on SC8280XP devices.
> +	  Say Y if you want to use the LPASS branch clocks of the LPASS clock
> +	  controller to reset the LPASS subsystem.
> +
>  config SC_LPASSCC_7280
>  	tristate "SC7280 Low Power Audio Subsystem (LPASS) Clock Controller"
>  	select SC_GCC_7280
> diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
> index 9ff4c373ad95..dce2dd639524 100644
> --- a/drivers/clk/qcom/Makefile
> +++ b/drivers/clk/qcom/Makefile
> @@ -71,6 +71,7 @@ obj-$(CONFIG_SC_CAMCC_7280) += camcc-sc7280.o
>  obj-$(CONFIG_SC_DISPCC_7180) += dispcc-sc7180.o
>  obj-$(CONFIG_SC_DISPCC_7280) += dispcc-sc7280.o
>  obj-$(CONFIG_SC_DISPCC_8280XP) += dispcc-sc8280xp.o
> +obj-$(CONFIG_SC_LPASSCC_8280XP) += lpasscc-sc8280xp.o

This looks misplaced too.

>  obj-$(CONFIG_SA_GCC_8775P) += gcc-sa8775p.o
>  obj-$(CONFIG_SA_GPUCC_8775P) += gpucc-sa8775p.o
>  obj-$(CONFIG_SC_GCC_7180) += gcc-sc7180.o
> diff --git a/drivers/clk/qcom/lpasscc-sc8280xp.c b/drivers/clk/qcom/lpasscc-sc8280xp.c
> new file mode 100644
> index 000000000000..118320f8ee40
> --- /dev/null
> +++ b/drivers/clk/qcom/lpasscc-sc8280xp.c
> @@ -0,0 +1,71 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022, Linaro Limited
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/err.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/regmap.h>
> +#include <dt-bindings/clock/qcom,lpasscc-sc8280xp.h>
> +#include "common.h"
> +#include "reset.h"

Nit: add newline separators before dt-bindings and local includes,
respectively?

> +static int __init lpasscc_sc8280xp_init(void)
> +{
> +	return platform_driver_register(&lpasscc_sc8280xp_driver);
> +}
> +subsys_initcall(lpasscc_sc8280xp_init);

Do you really need subsys init for this? I've been using this driver as
a module on the X13s and it seems to work fine.

> +static void __exit lpasscc_sc8280xp_exit(void)
> +{
> +	platform_driver_unregister(&lpasscc_sc8280xp_driver);
> +}
> +module_exit(lpasscc_sc8280xp_exit);
> +
> +MODULE_DESCRIPTION("QTI LPASSCC SC8280XP Driver");
> +MODULE_LICENSE("GPL");

Johan