diff mbox series

[v7,5/5] rockchip/soc/drivers: Add DTPM description for rk3399

Message ID 20220125171809.1273269-6-daniel.lezcano@linaro.org
State Superseded
Headers show
Series powercap/drivers/dtpm: Create the dtpm hierarchy | expand

Commit Message

Daniel Lezcano Jan. 25, 2022, 5:18 p.m. UTC
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 parent.

This patch provides a description of the big / Little CPUs and the
GPU and tie them together under a virtual 'package' name. Only rk3399 is
described now.

The description could be extended in the future with the memory
controller with devfreq.

The description is always a module and it describes the soft
dependencies. The userspace has to load the softdeps module in the
right order.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/soc/rockchip/Kconfig  |  8 +++++
 drivers/soc/rockchip/Makefile |  1 +
 drivers/soc/rockchip/dtpm.c   | 59 +++++++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+)
 create mode 100644 drivers/soc/rockchip/dtpm.c

Comments

Heiko Stuebner Jan. 28, 2022, 10:19 a.m. UTC | #1
Am Dienstag, 25. Januar 2022, 18:18:09 CET schrieb Daniel Lezcano:
> 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 parent.
> 
> This patch provides a description of the big / Little CPUs and the
> GPU and tie them together under a virtual 'package' name. Only rk3399 is
> described now.
> 
> The description could be extended in the future with the memory
> controller with devfreq.
> 
> The description is always a module and it describes the soft
> dependencies. The userspace has to load the softdeps module in the
> right order.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
>  drivers/soc/rockchip/Kconfig  |  8 +++++
>  drivers/soc/rockchip/Makefile |  1 +
>  drivers/soc/rockchip/dtpm.c   | 59 +++++++++++++++++++++++++++++++++++
>  3 files changed, 68 insertions(+)
>  create mode 100644 drivers/soc/rockchip/dtpm.c
> 
> diff --git a/drivers/soc/rockchip/Kconfig b/drivers/soc/rockchip/Kconfig
> index 25eb2c1e31bb..6dc017f02431 100644
> --- a/drivers/soc/rockchip/Kconfig
> +++ b/drivers/soc/rockchip/Kconfig
> @@ -34,4 +34,12 @@ config ROCKCHIP_PM_DOMAINS
>  
>            If unsure, say N.
>  
> +config ROCKCHIP_DTPM
> +	tristate "Rockchip DTPM hierarchy"
> +	depends on DTPM && DRM_PANFROST && m
> +	help
> +	 Describe the hierarchy for the Dynamic Thermal Power
> +	 Management tree on this platform. That will create all the
> +	 power capping capable devices.
> +
>  endif
> diff --git a/drivers/soc/rockchip/Makefile b/drivers/soc/rockchip/Makefile
> index 875032f7344e..05f31a4e743c 100644
> --- a/drivers/soc/rockchip/Makefile
> +++ b/drivers/soc/rockchip/Makefile
> @@ -5,3 +5,4 @@
>  obj-$(CONFIG_ROCKCHIP_GRF) += grf.o
>  obj-$(CONFIG_ROCKCHIP_IODOMAIN) += io-domain.o
>  obj-$(CONFIG_ROCKCHIP_PM_DOMAINS) += pm_domains.o
> +obj-$(CONFIG_ROCKCHIP_DTPM) += dtpm.o
> diff --git a/drivers/soc/rockchip/dtpm.c b/drivers/soc/rockchip/dtpm.c
> new file mode 100644
> index 000000000000..0b73a9cba954
> --- /dev/null
> +++ b/drivers/soc/rockchip/dtpm.c
> @@ -0,0 +1,59 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright 2021 Linaro Limited
> + *
> + * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
> + *
> + * DTPM hierarchy description
> + */
> +#include <linux/dtpm.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +
> +static struct dtpm_node __initdata rk3399_hierarchy[] = {

The driver is tristate so buildable as module but uses __initdata.
As it depends on panfrost (which also can be a module) you
probably want a "__initdata_or_module" here .


> +	[0]{ .name = "rk3399",
> +	     .type = DTPM_NODE_VIRTUAL },
> +	[1]{ .name = "package",
> +	     .type = DTPM_NODE_VIRTUAL,
> +	     .parent = &rk3399_hierarchy[0] },
> +	[2]{ .name = "/cpus/cpu@0",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &rk3399_hierarchy[1] },
> +	[3]{ .name = "/cpus/cpu@1",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &rk3399_hierarchy[1] },
> +	[4]{ .name = "/cpus/cpu@2",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &rk3399_hierarchy[1] },
> +	[5]{ .name = "/cpus/cpu@3",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &rk3399_hierarchy[1] },
> +	[6]{ .name = "/cpus/cpu@100",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &rk3399_hierarchy[1] },
> +	[7]{ .name = "/cpus/cpu@101",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &rk3399_hierarchy[1] },
> +	[8]{ .name = "/gpu@ff9a0000",
> +	     .type = DTPM_NODE_DT,
> +	     .parent = &rk3399_hierarchy[1] },
> +	[9]{ },

hmm, do we want a "/* sentinel */" inside the empty last entry?
I think that is pretty common to denote the "this one is the last entry"
of a dynamic list ;-)

> +};
> +
> +static struct of_device_id __initdata rockchip_dtpm_match_table[] = {
> +        { .compatible = "rockchip,rk3399", .data = rk3399_hierarchy },
> +        {},
> +};
> +
> +static int __init rockchip_dtpm_init(void)
> +{
> +	return dtpm_create_hierarchy(rockchip_dtpm_match_table);
> +}
> +module_init(rockchip_dtpm_init);

Just for my understanding what happens on driver unload?


Thanks
Heiko

> +
> +MODULE_SOFTDEP("pre: panfrost cpufreq-dt");
> +MODULE_DESCRIPTION("Rockchip DTPM driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:dtpm");
> +MODULE_AUTHOR("Daniel Lezcano <daniel.lezcano@kernel.org");
>
Daniel Lezcano Jan. 28, 2022, 3:13 p.m. UTC | #2
Hi Heiko,

thanks for your comments

On 28/01/2022 11:19, Heiko Stübner wrote:
> Am Dienstag, 25. Januar 2022, 18:18:09 CET schrieb Daniel Lezcano:
>> 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 parent.
>>
>> This patch provides a description of the big / Little CPUs and the
>> GPU and tie them together under a virtual 'package' name. Only rk3399 is
>> described now.
>>
>> The description could be extended in the future with the memory
>> controller with devfreq.
>>
>> The description is always a module and it describes the soft
>> dependencies. The userspace has to load the softdeps module in the
>> right order.
>>
>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

[ ... ]

>> +static struct dtpm_node __initdata rk3399_hierarchy[] = {
> 
> The driver is tristate so buildable as module but uses __initdata.
> As it depends on panfrost (which also can be a module) you
> probably want a "__initdata_or_module" here .

Well, actually the dependency is wrong.

It should be:

	depends on DTPM && m

It will be compiled always as a module.

Referring to the Documentation/kernel-hacking/hacking.rst

"After boot, the kernel frees up a special section; functions marked with
``__init`` and data structures marked with ``__initdata`` are dropped
after boot is complete: similarly modules discard this memory after
initialization."

So after the module is loaded and the hierarchy is created, nothing will 
stay in memory (except the future module exit function)


>> +	[0]{ .name = "rk3399",
>> +	     .type = DTPM_NODE_VIRTUAL },
>> +	[1]{ .name = "package",
>> +	     .type = DTPM_NODE_VIRTUAL,
>> +	     .parent = &rk3399_hierarchy[0] },
>> +	[2]{ .name = "/cpus/cpu@0",
>> +	     .type = DTPM_NODE_DT,
>> +	     .parent = &rk3399_hierarchy[1] },
>> +	[3]{ .name = "/cpus/cpu@1",
>> +	     .type = DTPM_NODE_DT,
>> +	     .parent = &rk3399_hierarchy[1] },
>> +	[4]{ .name = "/cpus/cpu@2",
>> +	     .type = DTPM_NODE_DT,
>> +	     .parent = &rk3399_hierarchy[1] },
>> +	[5]{ .name = "/cpus/cpu@3",
>> +	     .type = DTPM_NODE_DT,
>> +	     .parent = &rk3399_hierarchy[1] },
>> +	[6]{ .name = "/cpus/cpu@100",
>> +	     .type = DTPM_NODE_DT,
>> +	     .parent = &rk3399_hierarchy[1] },
>> +	[7]{ .name = "/cpus/cpu@101",
>> +	     .type = DTPM_NODE_DT,
>> +	     .parent = &rk3399_hierarchy[1] },
>> +	[8]{ .name = "/gpu@ff9a0000",
>> +	     .type = DTPM_NODE_DT,
>> +	     .parent = &rk3399_hierarchy[1] },
>> +	[9]{ },
> 
> hmm, do we want a "/* sentinel */" inside the empty last entry?
> I think that is pretty common to denote the "this one is the last entry"
> of a dynamic list ;-)

Sure

>> +};
>> +
>> +static struct of_device_id __initdata rockchip_dtpm_match_table[] = {
>> +        { .compatible = "rockchip,rk3399", .data = rk3399_hierarchy },
>> +        {},
>> +};
>> +
>> +static int __init rockchip_dtpm_init(void)
>> +{
>> +	return dtpm_create_hierarchy(rockchip_dtpm_match_table);
>> +}
>> +module_init(rockchip_dtpm_init);
> 
> Just for my understanding what happens on driver unload?

ATM it is not possible to unload it.

A second series with the hierarchy destruction will follow once this 
series is merged. The module unloading will be added here.
Heiko Stuebner Jan. 28, 2022, 3:48 p.m. UTC | #3
Am Dienstag, 25. Januar 2022, 18:18:09 CET schrieb Daniel Lezcano:
> 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 parent.
> 
> This patch provides a description of the big / Little CPUs and the
> GPU and tie them together under a virtual 'package' name. Only rk3399 is
> described now.
> 
> The description could be extended in the future with the memory
> controller with devfreq.
> 
> The description is always a module and it describes the soft
> dependencies. The userspace has to load the softdeps module in the
> right order.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Reviewed-by; Heiko Stuebner <heiko@sntech.de>
diff mbox series

Patch

diff --git a/drivers/soc/rockchip/Kconfig b/drivers/soc/rockchip/Kconfig
index 25eb2c1e31bb..6dc017f02431 100644
--- a/drivers/soc/rockchip/Kconfig
+++ b/drivers/soc/rockchip/Kconfig
@@ -34,4 +34,12 @@  config ROCKCHIP_PM_DOMAINS
 
           If unsure, say N.
 
+config ROCKCHIP_DTPM
+	tristate "Rockchip DTPM hierarchy"
+	depends on DTPM && DRM_PANFROST && m
+	help
+	 Describe the hierarchy for the Dynamic Thermal Power
+	 Management tree on this platform. That will create all the
+	 power capping capable devices.
+
 endif
diff --git a/drivers/soc/rockchip/Makefile b/drivers/soc/rockchip/Makefile
index 875032f7344e..05f31a4e743c 100644
--- a/drivers/soc/rockchip/Makefile
+++ b/drivers/soc/rockchip/Makefile
@@ -5,3 +5,4 @@ 
 obj-$(CONFIG_ROCKCHIP_GRF) += grf.o
 obj-$(CONFIG_ROCKCHIP_IODOMAIN) += io-domain.o
 obj-$(CONFIG_ROCKCHIP_PM_DOMAINS) += pm_domains.o
+obj-$(CONFIG_ROCKCHIP_DTPM) += dtpm.o
diff --git a/drivers/soc/rockchip/dtpm.c b/drivers/soc/rockchip/dtpm.c
new file mode 100644
index 000000000000..0b73a9cba954
--- /dev/null
+++ b/drivers/soc/rockchip/dtpm.c
@@ -0,0 +1,59 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2021 Linaro Limited
+ *
+ * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
+ *
+ * DTPM hierarchy description
+ */
+#include <linux/dtpm.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+static struct dtpm_node __initdata rk3399_hierarchy[] = {
+	[0]{ .name = "rk3399",
+	     .type = DTPM_NODE_VIRTUAL },
+	[1]{ .name = "package",
+	     .type = DTPM_NODE_VIRTUAL,
+	     .parent = &rk3399_hierarchy[0] },
+	[2]{ .name = "/cpus/cpu@0",
+	     .type = DTPM_NODE_DT,
+	     .parent = &rk3399_hierarchy[1] },
+	[3]{ .name = "/cpus/cpu@1",
+	     .type = DTPM_NODE_DT,
+	     .parent = &rk3399_hierarchy[1] },
+	[4]{ .name = "/cpus/cpu@2",
+	     .type = DTPM_NODE_DT,
+	     .parent = &rk3399_hierarchy[1] },
+	[5]{ .name = "/cpus/cpu@3",
+	     .type = DTPM_NODE_DT,
+	     .parent = &rk3399_hierarchy[1] },
+	[6]{ .name = "/cpus/cpu@100",
+	     .type = DTPM_NODE_DT,
+	     .parent = &rk3399_hierarchy[1] },
+	[7]{ .name = "/cpus/cpu@101",
+	     .type = DTPM_NODE_DT,
+	     .parent = &rk3399_hierarchy[1] },
+	[8]{ .name = "/gpu@ff9a0000",
+	     .type = DTPM_NODE_DT,
+	     .parent = &rk3399_hierarchy[1] },
+	[9]{ },
+};
+
+static struct of_device_id __initdata rockchip_dtpm_match_table[] = {
+        { .compatible = "rockchip,rk3399", .data = rk3399_hierarchy },
+        {},
+};
+
+static int __init rockchip_dtpm_init(void)
+{
+	return dtpm_create_hierarchy(rockchip_dtpm_match_table);
+}
+module_init(rockchip_dtpm_init);
+
+MODULE_SOFTDEP("pre: panfrost cpufreq-dt");
+MODULE_DESCRIPTION("Rockchip DTPM driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:dtpm");
+MODULE_AUTHOR("Daniel Lezcano <daniel.lezcano@kernel.org");