Re: [PATCH v5 6/6] qcom/soc/drivers: Add DTPM description for sdm845

[Steev Klimaszewski <steev@kali.org>]

Hi Daniel,

On 12/18/21 7:00 AM, Daniel Lezcano wrote:
> The DTPM framework does support now the hierarchy description.
>
> The platform specific code can call the hierarchy creation function
> with an array of struct dtpm_node pointing to their parents.
>
> This patch provides a description of the big and Little CPUs and the
> GPU and tie them together under a virtual package name. Only sdm845 is
> described.
>
> The description could be extended in the future with the memory
> controller with devfreq if it has the energy information.
>
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
>   drivers/soc/qcom/Kconfig  |  9 ++++++
>   drivers/soc/qcom/Makefile |  1 +
>   drivers/soc/qcom/dtpm.c   | 65 +++++++++++++++++++++++++++++++++++++++
>   3 files changed, 75 insertions(+)
>   create mode 100644 drivers/soc/qcom/dtpm.c
>
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index e718b8735444..f21c1df2f2f9 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -228,4 +228,13 @@ config QCOM_APR
>   	  application processor and QDSP6. APR is
>   	  used by audio driver to configure QDSP6
>   	  ASM, ADM and AFE modules.
> +
> +config QCOM_DTPM
> +	tristate "Qualcomm DTPM hierarchy"

Testing this on a Lenovo Yoga C630 here and...


Should this be tristate?  Is it actually possible to unload the module 
once it's loaded?

Here I have DTPM=y, DTPM_CPU=y, DTPM_DEVFREQ=y, QCOM_DTPM=m

But if I attempt to modprobe -r dtpm,

modprobe: ERROR: ../libkmod/libkmod-module.c:799 
kmod_module_remove_module() could not remove 'dtpm': Device or resource busy



> +	depends on DTPM
> +	help
> +	 Describe the hierarchy for the Dynamic Thermal Power
> +	 Management tree on this platform. That will create all the
> +	 power capping capable devices.
> +
>   endmenu
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index 70d5de69fd7b..cf38496c3f61 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -28,3 +28,4 @@ obj-$(CONFIG_QCOM_LLCC) += llcc-qcom.o
>   obj-$(CONFIG_QCOM_RPMHPD) += rpmhpd.o
>   obj-$(CONFIG_QCOM_RPMPD) += rpmpd.o
>   obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) +=	kryo-l2-accessors.o
> +obj-$(CONFIG_QCOM_DTPM) += dtpm.o
> diff --git a/drivers/soc/qcom/dtpm.c b/drivers/soc/qcom/dtpm.c
> new file mode 100644
> index 000000000000..c15283f59494
> --- /dev/null
> +++ b/drivers/soc/qcom/dtpm.c
> @@ -0,0 +1,65 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright 2021 Linaro Limited
> + *
> + * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
> + *
> + * DTPM hierarchy description
> + */
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/dtpm.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +
> +static struct dtpm_node __initdata sdm845_hierarchy[] = {
> +	[0]{ .name = "sdm845" },
> +	[1]{ .name = "package",
> +	     .parent = &sdm845_hierarchy[0] },
> +	[2]{ .name = "/cpus/cpu@0",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &sdm845_hierarchy[1] },
> +	[3]{ .name = "/cpus/cpu@100",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &sdm845_hierarchy[1] },
> +	[4]{ .name = "/cpus/cpu@200",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &sdm845_hierarchy[1] },
> +	[5]{ .name = "/cpus/cpu@300",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &sdm845_hierarchy[1] },
> +	[6]{ .name = "/cpus/cpu@400",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &sdm845_hierarchy[1] },
> +	[7]{ .name = "/cpus/cpu@500",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &sdm845_hierarchy[1] },
> +	[8]{ .name = "/cpus/cpu@600",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &sdm845_hierarchy[1] },
> +	[9]{ .name = "/cpus/cpu@700",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &sdm845_hierarchy[1] },
> +	[10]{ .name = "/soc@0/gpu@5000000",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &sdm845_hierarchy[1] },
> +	[11]{ },
> +};
> +
> +static struct of_device_id __initdata sdm845_dtpm_match_table[] = {
> +        { .compatible = "qcom,sdm845", .data = sdm845_hierarchy },
> +        {},
> +};
> +
> +static int __init sdm845_dtpm_init(void)
> +{
> +	return dtpm_create_hierarchy(sdm845_dtpm_match_table);
> +}
> +late_initcall(sdm845_dtpm_init);
> +
> +MODULE_DESCRIPTION("Qualcomm DTPM driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:dtpm");
> +MODULE_AUTHOR("Daniel Lezcano <daniel.lezcano@kernel.org");
> +

It does seem to work aside from not being able to modprobe -r the 
module. Although I do see

[   35.849622] dtpm: Registered dtpm node 'sdm845' / 0-0 uW,
[   35.849652] dtpm: Registered dtpm node 'package' / 0-0 uW,
[   35.849676] dtpm: Registered dtpm node 'cpu0-cpufreq' / 40000-436000 uW,
[   35.849702] dtpm: Registered dtpm node 'cpu4-cpufreq' / 
520000-5828000 uW,
[   35.849734] dtpm_devfreq: No energy model available for '5000000.gpu'
[   35.849738] dtpm: Failed to setup '/soc@0/gpu@5000000': -22

If the devfreq issue with the gpu isn't expected, are we missing 
something for the c630?

-- Steev