rockchip/soc/drivers: Add DTPM description for rk3399

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>
Link: https://lore.kernel.org/r/20220128163537.212248-6-daniel.lezcano@linaro.org

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 && 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

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

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]{ /* sentinel */ }
+};
+
+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");