Merge branch 'pm-cpufreq'

* pm-cpufreq: (37 commits)
  cpufreq: Add Tegra186 cpufreq driver
  cpufreq: imx6q: Fix error handling code
  cpufreq: imx6q: Set max suspend_freq to avoid changes during suspend
  cpufreq: imx6q: Fix handling EPROBE_DEFER from regulator
  cpufreq: schedutil: Use policy-dependent transition delays
  cpufreq: schedutil: Reduce frequencies slower
  cpufreq: intel_pstate: Add support for Gemini Lake
  cpufreq: intel_pstate: Eliminate intel_pstate_get_min_max()
  cpufreq: intel_pstate: Do not walk policy->cpus
  cpufreq: intel_pstate: Introduce pid_in_use()
  cpufreq: intel_pstate: Drop struct cpu_defaults
  cpufreq: intel_pstate: Move cpu_defaults definitions
  cpufreq: intel_pstate: Add update_util callback to pstate_funcs
  cpufreq: intel_pstate: Use different utilization update callbacks
  cpufreq: intel_pstate: Modify check in intel_pstate_update_status()
  cpufreq: intel_pstate: Drop driver_registered variable
  cpufreq: intel_pstate: Skip unnecessary PID resets on init
  cpufreq: intel_pstate: Set HWP sampling interval once
  cpufreq: intel_pstate: Clean up intel_pstate_busy_pid_reset()
  cpufreq: intel_pstate: Fold intel_pstate_reset_all_pid() into the caller
  ...

MAINTAINERS

@@ -3463,6 +3463,7 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
 T:	git git://git.linaro.org/people/vireshk/linux.git (For ARM Updates)
 B:	https://bugzilla.kernel.org
 F:	Documentation/cpu-freq/
+F:	Documentation/devicetree/bindings/cpufreq/
 F:	drivers/cpufreq/
 F:	include/linux/cpufreq.h
 F:	tools/testing/selftests/cpufreq/

arch/arm/boot/dts/ste-dbx5x0.dtsi

@@ -1189,11 +1189,6 @@ external-bus@50000000 {
 			status = "disabled";
 		};
 
-		cpufreq-cooling {
-			compatible = "stericsson,db8500-cpufreq-cooling";
-			status = "disabled";
-		};
-
 		mcde@a0350000 {
 			compatible = "stericsson,mcde";
 			reg = <0xa0350000 0x1000>, /* MCDE */

drivers/cpufreq/Kconfig.arm

@@ -247,6 +247,12 @@ config ARM_TEGRA124_CPUFREQ
 	help
 	  This adds the CPUFreq driver support for Tegra124 SOCs.
 
+config ARM_TEGRA186_CPUFREQ
+	tristate "Tegra186 CPUFreq support"
+	depends on ARCH_TEGRA && TEGRA_BPMP
+	help
+	  This adds the CPUFreq driver support for Tegra186 SOCs.
+
 config ARM_TI_CPUFREQ
 	bool "Texas Instruments CPUFreq support"
 	depends on ARCH_OMAP2PLUS

drivers/cpufreq/Makefile

@@ -77,6 +77,7 @@ obj-$(CONFIG_ARM_SPEAR_CPUFREQ)		+= spear-cpufreq.o
 obj-$(CONFIG_ARM_STI_CPUFREQ)		+= sti-cpufreq.o
 obj-$(CONFIG_ARM_TEGRA20_CPUFREQ)	+= tegra20-cpufreq.o
 obj-$(CONFIG_ARM_TEGRA124_CPUFREQ)	+= tegra124-cpufreq.o
+obj-$(CONFIG_ARM_TEGRA186_CPUFREQ)	+= tegra186-cpufreq.o
 obj-$(CONFIG_ARM_TI_CPUFREQ)		+= ti-cpufreq.o
 obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ)	+= vexpress-spc-cpufreq.o
 obj-$(CONFIG_ACPI_CPPC_CPUFREQ) += cppc_cpufreq.o

drivers/cpufreq/dbx500-cpufreq.c

@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/cpufreq.h>
+#include <linux/cpu_cooling.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/platform_device.h>
@@ -18,6 +19,7 @@
 
 static struct cpufreq_frequency_table *freq_table;
 static struct clk *armss_clk;
+static struct thermal_cooling_device *cdev;
 
 static int dbx500_cpufreq_target(struct cpufreq_policy *policy,
 				unsigned int index)
@@ -32,6 +34,22 @@ static int dbx500_cpufreq_init(struct cpufreq_policy *policy)
 	return cpufreq_generic_init(policy, freq_table, 20 * 1000);
 }
 
+static int dbx500_cpufreq_exit(struct cpufreq_policy *policy)
+{
+	if (!IS_ERR(cdev))
+		cpufreq_cooling_unregister(cdev);
+	return 0;
+}
+
+static void dbx500_cpufreq_ready(struct cpufreq_policy *policy)
+{
+	cdev = cpufreq_cooling_register(policy->cpus);
+	if (IS_ERR(cdev))
+		pr_err("Failed to register cooling device %ld\n", PTR_ERR(cdev));
+	else
+		pr_info("Cooling device registered: %s\n", cdev->type);
+}
+
 static struct cpufreq_driver dbx500_cpufreq_driver = {
 	.flags  = CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS |
 			CPUFREQ_NEED_INITIAL_FREQ_CHECK,
@@ -39,6 +57,8 @@ static struct cpufreq_driver dbx500_cpufreq_driver = {
 	.target_index = dbx500_cpufreq_target,
 	.get    = cpufreq_generic_get,
 	.init   = dbx500_cpufreq_init,
+	.exit  = dbx500_cpufreq_exit,
+	.ready  = dbx500_cpufreq_ready,
 	.name   = "DBX500",
 	.attr   = cpufreq_generic_attr,
 };

drivers/cpufreq/imx6q-cpufreq.c

@@ -161,8 +161,13 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
 
 static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
 {
+	int ret;
+
 	policy->clk = arm_clk;
-	return cpufreq_generic_init(policy, freq_table, transition_latency);
+	ret = cpufreq_generic_init(policy, freq_table, transition_latency);
+	policy->suspend_freq = policy->max;
+
+	return ret;
 }
 
 static struct cpufreq_driver imx6q_cpufreq_driver = {
@@ -173,6 +178,7 @@ static struct cpufreq_driver imx6q_cpufreq_driver = {
 	.init = imx6q_cpufreq_init,
 	.name = "imx6q-cpufreq",
 	.attr = cpufreq_generic_attr,
+	.suspend = cpufreq_generic_suspend,
 };
 
 static int imx6q_cpufreq_probe(struct platform_device *pdev)
@@ -222,6 +228,13 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev)
 	arm_reg = regulator_get(cpu_dev, "arm");
 	pu_reg = regulator_get_optional(cpu_dev, "pu");
 	soc_reg = regulator_get(cpu_dev, "soc");
+	if (PTR_ERR(arm_reg) == -EPROBE_DEFER ||
+			PTR_ERR(soc_reg) == -EPROBE_DEFER ||
+			PTR_ERR(pu_reg) == -EPROBE_DEFER) {
+		ret = -EPROBE_DEFER;
+		dev_dbg(cpu_dev, "regulators not ready, defer\n");
+		goto put_reg;
+	}
 	if (IS_ERR(arm_reg) || IS_ERR(soc_reg)) {
 		dev_err(cpu_dev, "failed to get regulators\n");
 		ret = -ENOENT;
@@ -255,7 +268,7 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev)
 	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
 	if (ret) {
 		dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
-		goto put_reg;
+		goto out_free_opp;
 	}
 
 	/* Make imx6_soc_volt array's size same as arm opp number */

drivers/cpufreq/mt8173-cpufreq.c

@@ -573,14 +573,33 @@ static struct platform_driver mt8173_cpufreq_platdrv = {
 	.probe		= mt8173_cpufreq_probe,
 };
 
-static int mt8173_cpufreq_driver_init(void)
+/* List of machines supported by this driver */
+static const struct of_device_id mt8173_cpufreq_machines[] __initconst = {
+	{ .compatible = "mediatek,mt817x", },
+	{ .compatible = "mediatek,mt8173", },
+	{ .compatible = "mediatek,mt8176", },
+
+	{ }
+};
+
+static int __init mt8173_cpufreq_driver_init(void)
 {
+	struct device_node *np;
+	const struct of_device_id *match;
 	struct platform_device *pdev;
 	int err;
 
-	if (!of_machine_is_compatible("mediatek,mt8173"))
+	np = of_find_node_by_path("/");
+	if (!np)
 		return -ENODEV;
 
+	match = of_match_node(mt8173_cpufreq_machines, np);
+	of_node_put(np);
+	if (!match) {
+		pr_warn("Machine is not compatible with mt8173-cpufreq\n");
+		return -ENODEV;
+	}
+
 	err = platform_driver_register(&mt8173_cpufreq_platdrv);
 	if (err)
 		return err;

drivers/cpufreq/qoriq-cpufreq.c

@@ -52,17 +52,27 @@ static u32 get_bus_freq(void)
 {
 	struct device_node *soc;
 	u32 sysfreq;
+	struct clk *pltclk;
+	int ret;
 
+	/* get platform freq by searching bus-frequency property */
 	soc = of_find_node_by_type(NULL, "soc");
-	if (!soc)
-		return 0;
-
-	if (of_property_read_u32(soc, "bus-frequency", &sysfreq))
-		sysfreq = 0;
-
+	if (soc) {
+		ret = of_property_read_u32(soc, "bus-frequency", &sysfreq);
 		of_node_put(soc);
-
+		if (!ret)
 			return sysfreq;
+	}
+
+	/* get platform freq by its clock name */
+	pltclk = clk_get(NULL, "cg-pll0-div1");
+	if (IS_ERR(pltclk)) {
+		pr_err("%s: can't get bus frequency %ld\n",
+		       __func__, PTR_ERR(pltclk));
+		return PTR_ERR(pltclk);
+	}
+
+	return clk_get_rate(pltclk);
 }
 
 static struct clk *cpu_to_clk(int cpu)

drivers/cpufreq/tegra186-cpufreq.c

+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/cpufreq.h>
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include <soc/tegra/bpmp.h>
+#include <soc/tegra/bpmp-abi.h>
+
+#define EDVD_CORE_VOLT_FREQ(core)		(0x20 + (core) * 0x4)
+#define EDVD_CORE_VOLT_FREQ_F_SHIFT		0
+#define EDVD_CORE_VOLT_FREQ_V_SHIFT		16
+
+struct tegra186_cpufreq_cluster_info {
+	unsigned long offset;
+	int cpus[4];
+	unsigned int bpmp_cluster_id;
+};
+
+#define NO_CPU -1
+static const struct tegra186_cpufreq_cluster_info tegra186_clusters[] = {
+	/* Denver cluster */
+	{
+		.offset = SZ_64K * 7,
+		.cpus = { 1, 2, NO_CPU, NO_CPU },
+		.bpmp_cluster_id = 0,
+	},
+	/* A57 cluster */
+	{
+		.offset = SZ_64K * 6,
+		.cpus = { 0, 3, 4, 5 },
+		.bpmp_cluster_id = 1,
+	},
+};
+
+struct tegra186_cpufreq_cluster {
+	const struct tegra186_cpufreq_cluster_info *info;
+	struct cpufreq_frequency_table *table;
+};
+
+struct tegra186_cpufreq_data {
+	void __iomem *regs;
+
+	size_t num_clusters;
+	struct tegra186_cpufreq_cluster *clusters;
+};
+
+static int tegra186_cpufreq_init(struct cpufreq_policy *policy)
+{
+	struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
+	unsigned int i;
+
+	for (i = 0; i < data->num_clusters; i++) {
+		struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
+		const struct tegra186_cpufreq_cluster_info *info =
+			cluster->info;
+		int core;
+
+		for (core = 0; core < ARRAY_SIZE(info->cpus); core++) {
+			if (info->cpus[core] == policy->cpu)
+				break;
+		}
+		if (core == ARRAY_SIZE(info->cpus))
+			continue;
+
+		policy->driver_data =
+			data->regs + info->offset + EDVD_CORE_VOLT_FREQ(core);
+		cpufreq_table_validate_and_show(policy, cluster->table);
+	}
+
+	policy->cpuinfo.transition_latency = 300 * 1000;
+
+	return 0;
+}
+
+static int tegra186_cpufreq_set_target(struct cpufreq_policy *policy,
+				       unsigned int index)
+{
+	struct cpufreq_frequency_table *tbl = policy->freq_table + index;
+	void __iomem *edvd_reg = policy->driver_data;
+	u32 edvd_val = tbl->driver_data;
+
+	writel(edvd_val, edvd_reg);
+
+	return 0;
+}
+
+static struct cpufreq_driver tegra186_cpufreq_driver = {
+	.name = "tegra186",
+	.flags = CPUFREQ_STICKY | CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
+	.verify = cpufreq_generic_frequency_table_verify,
+	.target_index = tegra186_cpufreq_set_target,
+	.init = tegra186_cpufreq_init,
+	.attr = cpufreq_generic_attr,
+};
+
+static struct cpufreq_frequency_table *init_vhint_table(
+	struct platform_device *pdev, struct tegra_bpmp *bpmp,
+	unsigned int cluster_id)
+{
+	struct cpufreq_frequency_table *table;
+	struct mrq_cpu_vhint_request req;
+	struct tegra_bpmp_message msg;
+	struct cpu_vhint_data *data;
+	int err, i, j, num_rates = 0;
+	dma_addr_t phys;
+	void *virt;
+
+	virt = dma_alloc_coherent(bpmp->dev, sizeof(*data), &phys,
+				  GFP_KERNEL | GFP_DMA32);
+	if (!virt)
+		return ERR_PTR(-ENOMEM);
+
+	data = (struct cpu_vhint_data *)virt;
+
+	memset(&req, 0, sizeof(req));
+	req.addr = phys;
+	req.cluster_id = cluster_id;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.mrq = MRQ_CPU_VHINT;
+	msg.tx.data = &req;
+	msg.tx.size = sizeof(req);
+
+	err = tegra_bpmp_transfer(bpmp, &msg);
+	if (err) {
+		table = ERR_PTR(err);
+		goto free;
+	}
+
+	for (i = data->vfloor; i <= data->vceil; i++) {
+		u16 ndiv = data->ndiv[i];
+
+		if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
+			continue;
+
+		/* Only store lowest voltage index for each rate */
+		if (i > 0 && ndiv == data->ndiv[i - 1])
+			continue;
+
+		num_rates++;
+	}
+
+	table = devm_kcalloc(&pdev->dev, num_rates + 1, sizeof(*table),
+			     GFP_KERNEL);
+	if (!table) {
+		table = ERR_PTR(-ENOMEM);
+		goto free;
+	}
+
+	for (i = data->vfloor, j = 0; i <= data->vceil; i++) {
+		struct cpufreq_frequency_table *point;
+		u16 ndiv = data->ndiv[i];
+		u32 edvd_val = 0;
+
+		if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
+			continue;
+
+		/* Only store lowest voltage index for each rate */
+		if (i > 0 && ndiv == data->ndiv[i - 1])
+			continue;
+
+		edvd_val |= i << EDVD_CORE_VOLT_FREQ_V_SHIFT;
+		edvd_val |= ndiv << EDVD_CORE_VOLT_FREQ_F_SHIFT;
+
+		point = &table[j++];
+		point->driver_data = edvd_val;
+		point->frequency = data->ref_clk_hz * ndiv / data->pdiv /
+			data->mdiv / 1000;
+	}
+
+	table[j].frequency = CPUFREQ_TABLE_END;
+
+free:
+	dma_free_coherent(bpmp->dev, sizeof(*data), virt, phys);
+
+	return table;
+}
+
+static int tegra186_cpufreq_probe(struct platform_device *pdev)
+{
+	struct tegra186_cpufreq_data *data;
+	struct tegra_bpmp *bpmp;
+	struct resource *res;
+	unsigned int i = 0, err;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->clusters = devm_kcalloc(&pdev->dev, ARRAY_SIZE(tegra186_clusters),
+				      sizeof(*data->clusters), GFP_KERNEL);
+	if (!data->clusters)
+		return -ENOMEM;
+
+	data->num_clusters = ARRAY_SIZE(tegra186_clusters);
+
+	bpmp = tegra_bpmp_get(&pdev->dev);
+	if (IS_ERR(bpmp))
+		return PTR_ERR(bpmp);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(data->regs)) {
+		err = PTR_ERR(data->regs);
+		goto put_bpmp;
+	}
+
+	for (i = 0; i < data->num_clusters; i++) {
+		struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
+
+		cluster->info = &tegra186_clusters[i];
+		cluster->table = init_vhint_table(
+			pdev, bpmp, cluster->info->bpmp_cluster_id);
+		if (IS_ERR(cluster->table)) {
+			err = PTR_ERR(cluster->table);
+			goto put_bpmp;
+		}
+	}
+
+	tegra_bpmp_put(bpmp);
+
+	tegra186_cpufreq_driver.driver_data = data;
+
+	err = cpufreq_register_driver(&tegra186_cpufreq_driver);
+	if (err)
+		return err;
+
+	return 0;
+
+put_bpmp:
+	tegra_bpmp_put(bpmp);
+
+	return err;
+}
+
+static int tegra186_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_driver(&tegra186_cpufreq_driver);
+
+	return 0;
+}
+
+static const struct of_device_id tegra186_cpufreq_of_match[] = {
+	{ .compatible = "nvidia,tegra186-ccplex-cluster", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tegra186_cpufreq_of_match);
+
+static struct platform_driver tegra186_cpufreq_platform_driver = {
+	.driver = {
+		.name = "tegra186-cpufreq",
+		.of_match_table = tegra186_cpufreq_of_match,
+	},
+	.probe = tegra186_cpufreq_probe,
+	.remove = tegra186_cpufreq_remove,
+};
+module_platform_driver(tegra186_cpufreq_platform_driver);
+
+MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra186 cpufreq driver");
+MODULE_LICENSE("GPL v2");

drivers/thermal/Kconfig

@@ -291,18 +291,6 @@ config ARMADA_THERMAL
 	  Enable this option if you want to have support for thermal management
 	  controller present in Armada 370 and Armada XP SoC.
 
-config DB8500_CPUFREQ_COOLING
-	tristate "DB8500 cpufreq cooling"
-	depends on ARCH_U8500 || COMPILE_TEST
-	depends on HAS_IOMEM
-	depends on CPU_THERMAL
-	default y
-	help
-	  Adds DB8500 cpufreq cooling devices, and these cooling devices can be
-	  bound to thermal zone trip points. When a trip point reached, the
-	  bound cpufreq cooling device turns active to set CPU frequency low to
-	  cool down the CPU.
-
 config INTEL_POWERCLAMP
 	tristate "Intel PowerClamp idle injection driver"
 	depends on THERMAL

drivers/thermal/Makefile

@@ -41,7 +41,6 @@ obj-$(CONFIG_TANGO_THERMAL)	+= tango_thermal.o
 obj-$(CONFIG_IMX_THERMAL)	+= imx_thermal.o
 obj-$(CONFIG_MAX77620_THERMAL)	+= max77620_thermal.o
 obj-$(CONFIG_QORIQ_THERMAL)	+= qoriq_thermal.o
-obj-$(CONFIG_DB8500_CPUFREQ_COOLING)	+= db8500_cpufreq_cooling.o
 obj-$(CONFIG_INTEL_POWERCLAMP)	+= intel_powerclamp.o
 obj-$(CONFIG_X86_PKG_TEMP_THERMAL)	+= x86_pkg_temp_thermal.o
 obj-$(CONFIG_INTEL_SOC_DTS_IOSF_CORE)	+= intel_soc_dts_iosf.o

drivers/thermal/db8500_cpufreq_cooling.c

-/*
- * db8500_cpufreq_cooling.c - DB8500 cpufreq works as cooling device.
- *
- * Copyright (C) 2012 ST-Ericsson
- * Copyright (C) 2012 Linaro Ltd.
- *
- * Author: Hongbo Zhang <hongbo.zhang@linaro.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-#include <linux/cpu_cooling.h>
-#include <linux/err.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-
-static int db8500_cpufreq_cooling_probe(struct platform_device *pdev)
-{
-	struct thermal_cooling_device *cdev;
-
-	cdev = cpufreq_cooling_register(cpu_present_mask);
-	if (IS_ERR(cdev)) {
-		int ret = PTR_ERR(cdev);
-
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev,
-				"Failed to register cooling device %d\n",
-				ret);
-				
-		return ret;
-	}
-
-	platform_set_drvdata(pdev, cdev);
-
-	dev_info(&pdev->dev, "Cooling device registered: %s\n",	cdev->type);
-
-	return 0;
-}
-
-static int db8500_cpufreq_cooling_remove(struct platform_device *pdev)
-{
-	struct thermal_cooling_device *cdev = platform_get_drvdata(pdev);
-
-	cpufreq_cooling_unregister(cdev);
-
-	return 0;
-}
-
-static int db8500_cpufreq_cooling_suspend(struct platform_device *pdev,
-		pm_message_t state)
-{
-	return -ENOSYS;
-}
-
-static int db8500_cpufreq_cooling_resume(struct platform_device *pdev)
-{
-	return -ENOSYS;
-}
-
-#ifdef CONFIG_OF
-static const struct of_device_id db8500_cpufreq_cooling_match[] = {
-	{ .compatible = "stericsson,db8500-cpufreq-cooling" },
-	{},
-};
-MODULE_DEVICE_TABLE(of, db8500_cpufreq_cooling_match);
-#endif
-
-static struct platform_driver db8500_cpufreq_cooling_driver = {
-	.driver = {
-		.name = "db8500-cpufreq-cooling",
-		.of_match_table = of_match_ptr(db8500_cpufreq_cooling_match),
-	},
-	.probe = db8500_cpufreq_cooling_probe,
-	.suspend = db8500_cpufreq_cooling_suspend,
-	.resume = db8500_cpufreq_cooling_resume,
-	.remove = db8500_cpufreq_cooling_remove,
-};
-
-static int __init db8500_cpufreq_cooling_init(void)
-{
-	return platform_driver_register(&db8500_cpufreq_cooling_driver);
-}
-
-static void __exit db8500_cpufreq_cooling_exit(void)
-{
-	platform_driver_unregister(&db8500_cpufreq_cooling_driver);
-}
-
-/* Should be later than db8500_cpufreq_register */
-late_initcall(db8500_cpufreq_cooling_init);
-module_exit(db8500_cpufreq_cooling_exit);
-
-MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
-MODULE_DESCRIPTION("DB8500 cpufreq cooling driver");
-MODULE_LICENSE("GPL");

include/linux/cpufreq.h

@@ -120,6 +120,13 @@ struct cpufreq_policy {
 	bool			fast_switch_possible;
 	bool			fast_switch_enabled;
 
+	/*
+	 * Preferred average time interval between consecutive invocations of
+	 * the driver to set the frequency for this policy.  To be set by the
+	 * scaling driver (0, which is the default, means no preference).
+	 */
+	unsigned int		transition_delay_us;
+
 	 /* Cached frequency lookup from cpufreq_driver_resolve_freq. */
 	unsigned int cached_target_freq;
 	int cached_resolved_idx;

include/linux/tick.h

@@ -117,6 +117,7 @@ extern void tick_nohz_idle_enter(void);
 extern void tick_nohz_idle_exit(void);
 extern void tick_nohz_irq_exit(void);
 extern ktime_t tick_nohz_get_sleep_length(void);
+extern unsigned long tick_nohz_get_idle_calls(void);
 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
 #else /* !CONFIG_NO_HZ_COMMON */

kernel/sched/cpufreq_schedutil.c

@@ -61,6 +61,11 @@ struct sugov_cpu {
 	unsigned long util;
 	unsigned long max;
 	unsigned int flags;
+
+	/* The field below is for single-CPU policies only. */
+#ifdef CONFIG_NO_HZ_COMMON
+	unsigned long saved_idle_calls;
+#endif
 };
 
 static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu);
@@ -93,22 +98,23 @@ static void sugov_update_commit(struct sugov_policy *sg_policy, u64 time,
 {
 	struct cpufreq_policy *policy = sg_policy->policy;
 
+	if (sg_policy->next_freq == next_freq)
+		return;
+
+	if (sg_policy->next_freq > next_freq)
+		next_freq = (sg_policy->next_freq + next_freq) >> 1;
+
+	sg_policy->next_freq = next_freq;
 	sg_policy->last_freq_update_time = time;
 
 	if (policy->fast_switch_enabled) {
-		if (sg_policy->next_freq == next_freq) {
-			trace_cpu_frequency(policy->cur, smp_processor_id());
-			return;
-		}
-		sg_policy->next_freq = next_freq;
 		next_freq = cpufreq_driver_fast_switch(policy, next_freq);
 		if (next_freq == CPUFREQ_ENTRY_INVALID)
 			return;
 
 		policy->cur = next_freq;
 		trace_cpu_frequency(next_freq, smp_processor_id());
-	} else if (sg_policy->next_freq != next_freq) {
-		sg_policy->next_freq = next_freq;
+	} else {
 		sg_policy->work_in_progress = true;
 		irq_work_queue(&sg_policy->irq_work);
 	}
@@ -192,6 +198,19 @@ static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, unsigned long *util,
 	sg_cpu->iowait_boost >>= 1;
 }
 
+#ifdef CONFIG_NO_HZ_COMMON
+static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu)
+{
+	unsigned long idle_calls = tick_nohz_get_idle_calls();
+	bool ret = idle_calls == sg_cpu->saved_idle_calls;
+
+	sg_cpu->saved_idle_calls = idle_calls;
+	return ret;
+}
+#else
+static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; }
+#endif /* CONFIG_NO_HZ_COMMON */
+
 static void sugov_update_single(struct update_util_data *hook, u64 time,
 				unsigned int flags)
 {
@@ -200,6 +219,7 @@ static void sugov_update_single(struct update_util_data *hook, u64 time,
 	struct cpufreq_policy *policy = sg_policy->policy;
 	unsigned long util, max;
 	unsigned int next_f;
+	bool busy;
 
 	sugov_set_iowait_boost(sg_cpu, time, flags);
 	sg_cpu->last_update = time;
@@ -207,40 +227,37 @@ static void sugov_update_single(struct update_util_data *hook, u64 time,
 	if (!sugov_should_update_freq(sg_policy, time))
 		return;
 
+	busy = sugov_cpu_is_busy(sg_cpu);
+
 	if (flags & SCHED_CPUFREQ_RT_DL) {
 		next_f = policy->cpuinfo.max_freq;
 	} else {
 		sugov_get_util(&util, &max);
 		sugov_iowait_boost(sg_cpu, &util, &max);
 		next_f = get_next_freq(sg_policy, util, max);
+		/*
+		 * Do not reduce the frequency if the CPU has not been idle
+		 * recently, as the reduction is likely to be premature then.
+		 */
+		if (busy && next_f < sg_policy->next_freq)
+			next_f = sg_policy->next_freq;
 	}
 	sugov_update_commit(sg_policy, time, next_f);
 }
 
-static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu,
-					   unsigned long util, unsigned long max,
-					   unsigned int flags)
+static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu)
 {
 	struct sugov_policy *sg_policy = sg_cpu->sg_policy;
 	struct cpufreq_policy *policy = sg_policy->policy;
-	unsigned int max_f = policy->cpuinfo.max_freq;
 	u64 last_freq_update_time = sg_policy->last_freq_update_time;
+	unsigned long util = 0, max = 1;
 	unsigned int j;
 
-	if (flags & SCHED_CPUFREQ_RT_DL)
-		return max_f;
-
-	sugov_iowait_boost(sg_cpu, &util, &max);
-
 	for_each_cpu(j, policy->cpus) {
-		struct sugov_cpu *j_sg_cpu;
+		struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j);
 		unsigned long j_util, j_max;
 		s64 delta_ns;
 
-		if (j == smp_processor_id())
-			continue;
-
-		j_sg_cpu = &per_cpu(sugov_cpu, j);
 		/*
 		 * If the CPU utilization was last updated before the previous
 		 * frequency update and the time elapsed between the last update
@@ -254,7 +271,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu,
 			continue;
 		}
 		if (j_sg_cpu->flags & SCHED_CPUFREQ_RT_DL)
-			return max_f;
+			return policy->cpuinfo.max_freq;
 
 		j_util = j_sg_cpu->util;
 		j_max = j_sg_cpu->max;
@@ -289,7 +306,11 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time,
 	sg_cpu->last_update = time;
 
 	if (sugov_should_update_freq(sg_policy, time)) {
-		next_f = sugov_next_freq_shared(sg_cpu, util, max, flags);
+		if (flags & SCHED_CPUFREQ_RT_DL)
+			next_f = sg_policy->policy->cpuinfo.max_freq;
+		else
+			next_f = sugov_next_freq_shared(sg_cpu);
+
 		sugov_update_commit(sg_policy, time, next_f);
 	}
 
@@ -473,7 +494,6 @@ static int sugov_init(struct cpufreq_policy *policy)
 {
 	struct sugov_policy *sg_policy;
 	struct sugov_tunables *tunables;
-	unsigned int lat;
 	int ret = 0;
 
 	/* State should be equivalent to EXIT */
@@ -512,10 +532,16 @@ static int sugov_init(struct cpufreq_policy *policy)
 		goto stop_kthread;
 	}
 
+	if (policy->transition_delay_us) {
+		tunables->rate_limit_us = policy->transition_delay_us;
+	} else {
+		unsigned int lat;
+
 		tunables->rate_limit_us = LATENCY_MULTIPLIER;
 		lat = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
 		if (lat)
 			tunables->rate_limit_us *= lat;
+	}
 
 	policy->governor_data = sg_policy;
 	sg_policy->tunables = tunables;

kernel/time/tick-sched.c

@@ -993,6 +993,18 @@ ktime_t tick_nohz_get_sleep_length(void)
 	return ts->sleep_length;
 }
 
+/**
+ * tick_nohz_get_idle_calls - return the current idle calls counter value
+ *
+ * Called from the schedutil frequency scaling governor in scheduler context.
+ */
+unsigned long tick_nohz_get_idle_calls(void)
+{
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
+
+	return ts->idle_calls;
+}
+
 static void tick_nohz_account_idle_ticks(struct tick_sched *ts)
 {
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE