Merge tag 'devfreq-next-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux

Pull devfreq updates for v5.6 from Chanwoo Choi:

"1. Update devfreq core

 - Add new 'name' attribute of sysfs to show the device name
   : /sys/class/devfreq/devfreqX/name

 - Make 'trans_stat' sysfs reset by entering zero(0)
   : echo 0 > /sys/class/devfreq/devfreqX/trans_stat

 - Add debugfs support with 'devfreq_summary' to show the summary
   : /sys/kernel/debug/devfreq/devfreq_summary

 - Change the type of time variable to 64bit to avoid overflows.

 - Make separate devfreq_stats including the statistics information.

 - Fix minor coding-style like indentation and kernel-doc warnings.

 2. Update devfreq drivers

 - Add new imx8m-ddrc.c devfreq driver for dynamic scaling of DDR frequency.
   It changes the DDR frequency by using ARM SMCCC(SMC Calling Convention)
   interface to control TF-A firmware.

 - Add COMPILE_TEST dependency for rk3399_dmc.c.

 - Clean-up code for exynos-bus.c and rk3399_dmc.c without behavior changes

 3. Update devfreq-event drivers

 - Fix excessive stack usage of exynos-ppmu.c and clean-up code of
   rockchip-dfi.c without behavior changes."

* tag 'devfreq-next-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux: (24 commits)
  PM / devfreq: Add debugfs support with devfreq_summary file
  PM / devfreq: exynos: Rename Exynos to lowercase
  PM / devfreq: imx8m-ddrc: Fix inconsistent IS_ERR and PTR_ERR
  PM / devfreq: exynos-bus: Add error log when fail to get devfreq-event
  PM / devfreq: exynos-bus: Disable devfreq-event device when fails
  PM / devfreq: rk3399_dmc: Disable devfreq-event device when fails
  PM / devfreq: imx8m-ddrc: Remove unused defines
  PM / devfreq: exynos-bus: Reduce goto statements and remove unused headers
  PM / devfreq: rk3399_dmc: Add COMPILE_TEST and HAVE_ARM_SMCCC dependency
  PM / devfreq: rockchip-dfi: Convert to devm_platform_ioremap_resource
  PM / devfreq: rk3399_dmc: Add missing of_node_put()
  PM / devfreq: rockchip-dfi: Add missing of_node_put()
  PM / devfreq: Fix multiple kernel-doc warnings
  PM / devfreq: exynos-bus: Extract exynos_bus_profile_init_passive()
  PM / devfreq: exynos-bus: Extract exynos_bus_profile_init()
  PM / devfreq: Move declaration of DEVICE_ATTR_RW(min_freq)
  PM / devfreq: Move statistics to separate struct devfreq_stats
  PM / devfreq: Add clearing transitions stats
  PM / devfreq: Change time stats to 64-bit
  PM / devfreq: Add new name attribute for sysfs
  ...

Documentation/ABI/testing/sysfs-class-devfreq

@@ -7,6 +7,13 @@ Description:
 		The name of devfreq object denoted as ... is same as the
 		name of device using devfreq.
 
+What:		/sys/class/devfreq/.../name
+Date:		November 2019
+Contact:	Chanwoo Choi <cw00.choi@samsung.com>
+Description:
+		The /sys/class/devfreq/.../name shows the name of device
+		of the corresponding devfreq object.
+
 What:		/sys/class/devfreq/.../governor
 Date:		September 2011
 Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
@@ -48,12 +55,15 @@ What:		/sys/class/devfreq/.../trans_stat
 Date:		October 2012
 Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
 Description:
-		This ABI shows the statistics of devfreq behavior on a
-		specific device. It shows the time spent in each state and
-		the number of transitions between states.
+		This ABI shows or clears the statistics of devfreq behavior
+		on a specific device. It shows the time spent in each state
+		and the number of transitions between states.
 		In order to activate this ABI, the devfreq target device
 		driver should provide the list of available frequencies
-		with its profile.
+		with its profile. If need to reset the statistics of devfreq
+		behavior on a specific device, enter 0(zero) to 'trans_stat'
+		as following:
+			echo 0 > /sys/class/devfreq/.../trans_stat
 
 What:		/sys/class/devfreq/.../userspace/set_freq
 Date:		September 2011

Documentation/devicetree/bindings/memory-controllers/fsl/imx8m-ddrc.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/fsl/imx8m-ddrc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: i.MX8M DDR Controller
+
+maintainers:
+  - Leonard Crestez <leonard.crestez@nxp.com>
+
+description:
+  The DDRC block is integrated in i.MX8M for interfacing with DDR based
+  memories.
+
+  It supports switching between different frequencies at runtime but during
+  this process RAM itself becomes briefly inaccessible so actual frequency
+  switching is implemented by TF-A code which runs from a SRAM area.
+
+  The Linux driver for the DDRC doesn't even map registers (they're included
+  for the sake of "describing hardware"), it mostly just exposes firmware
+  capabilities through standard Linux mechanism like devfreq and OPP tables.
+
+properties:
+  compatible:
+    items:
+      - enum:
+        - fsl,imx8mn-ddrc
+        - fsl,imx8mm-ddrc
+        - fsl,imx8mq-ddrc
+      - const: fsl,imx8m-ddrc
+
+  reg:
+    maxItems: 1
+    description:
+      Base address and size of DDRC CTL area.
+      This is not currently mapped by the imx8m-ddrc driver.
+
+  clocks:
+    maxItems: 4
+
+  clock-names:
+    items:
+      - const: core
+      - const: pll
+      - const: alt
+      - const: apb
+
+  operating-points-v2: true
+  opp-table: true
+
+required:
+  - reg
+  - compatible
+  - clocks
+  - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/imx8mm-clock.h>
+    ddrc: memory-controller@3d400000 {
+        compatible = "fsl,imx8mm-ddrc", "fsl,imx8m-ddrc";
+        reg = <0x3d400000 0x400000>;
+        clock-names = "core", "pll", "alt", "apb";
+        clocks = <&clk IMX8MM_CLK_DRAM_CORE>,
+                 <&clk IMX8MM_DRAM_PLL>,
+                 <&clk IMX8MM_CLK_DRAM_ALT>,
+                 <&clk IMX8MM_CLK_DRAM_APB>;
+        operating-points-v2 = <&ddrc_opp_table>;
+    };

drivers/devfreq/Kconfig

@@ -77,7 +77,7 @@ config DEVFREQ_GOV_PASSIVE
 comment "DEVFREQ Drivers"
 
 config ARM_EXYNOS_BUS_DEVFREQ
-	tristate "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"
+	tristate "ARM Exynos Generic Memory Bus DEVFREQ Driver"
 	depends on ARCH_EXYNOS || COMPILE_TEST
 	select DEVFREQ_GOV_SIMPLE_ONDEMAND
 	select DEVFREQ_GOV_PASSIVE
@@ -91,6 +91,16 @@ config ARM_EXYNOS_BUS_DEVFREQ
 	  and adjusts the operating frequencies and voltages with OPP support.
 	  This does not yet operate with optimal voltages.
 
+config ARM_IMX8M_DDRC_DEVFREQ
+	tristate "i.MX8M DDRC DEVFREQ Driver"
+	depends on (ARCH_MXC && HAVE_ARM_SMCCC) || \
+		(COMPILE_TEST && HAVE_ARM_SMCCC)
+	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	select DEVFREQ_GOV_USERSPACE
+	help
+	  This adds the DEVFREQ driver for the i.MX8M DDR Controller. It allows
+	  adjusting DRAM frequency.
+
 config ARM_TEGRA_DEVFREQ
 	tristate "NVIDIA Tegra30/114/124/210 DEVFREQ Driver"
 	depends on ARCH_TEGRA_3x_SOC || ARCH_TEGRA_114_SOC || \
@@ -115,14 +125,15 @@ config ARM_TEGRA20_DEVFREQ
 
 config ARM_RK3399_DMC_DEVFREQ
 	tristate "ARM RK3399 DMC DEVFREQ Driver"
-	depends on ARCH_ROCKCHIP
+	depends on (ARCH_ROCKCHIP && HAVE_ARM_SMCCC) || \
+		(COMPILE_TEST && HAVE_ARM_SMCCC)
 	select DEVFREQ_EVENT_ROCKCHIP_DFI
 	select DEVFREQ_GOV_SIMPLE_ONDEMAND
 	select PM_DEVFREQ_EVENT
 	help
-          This adds the DEVFREQ driver for the RK3399 DMC(Dynamic Memory Controller).
-          It sets the frequency for the memory controller and reads the usage counts
-          from hardware.
+	  This adds the DEVFREQ driver for the RK3399 DMC(Dynamic Memory Controller).
+	  It sets the frequency for the memory controller and reads the usage counts
+	  from hardware.
 
 source "drivers/devfreq/event/Kconfig"
 

drivers/devfreq/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE)	+= governor_passive.o
 
 # DEVFREQ Drivers
 obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ)	+= exynos-bus.o
+obj-$(CONFIG_ARM_IMX8M_DDRC_DEVFREQ)	+= imx8m-ddrc.o
 obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ)	+= rk3399_dmc.o
 obj-$(CONFIG_ARM_TEGRA_DEVFREQ)		+= tegra30-devfreq.o
 obj-$(CONFIG_ARM_TEGRA20_DEVFREQ)	+= tegra20-devfreq.o

drivers/devfreq/devfreq-event.c

@@ -346,9 +346,9 @@ EXPORT_SYMBOL_GPL(devfreq_event_add_edev);
 
 /**
  * devfreq_event_remove_edev() - Remove the devfreq-event device registered.
- * @dev		: the devfreq-event device
+ * @edev	: the devfreq-event device
  *
- * Note that this function remove the registered devfreq-event device.
+ * Note that this function removes the registered devfreq-event device.
  */
 int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
 {

drivers/devfreq/devfreq.c

@@ -10,6 +10,7 @@
 #include <linux/kernel.h>
 #include <linux/kmod.h>
 #include <linux/sched.h>
+#include <linux/debugfs.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/init.h>
@@ -33,6 +34,7 @@
 #define HZ_PER_KHZ	1000
 
 static struct class *devfreq_class;
+static struct dentry *devfreq_debugfs;
 
 /*
  * devfreq core provides delayed work based load monitoring helper
@@ -209,10 +211,10 @@ static int set_freq_table(struct devfreq *devfreq)
 int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
 {
 	int lev, prev_lev, ret = 0;
-	unsigned long cur_time;
+	u64 cur_time;
 
 	lockdep_assert_held(&devfreq->lock);
-	cur_time = jiffies;
+	cur_time = get_jiffies_64();
 
 	/* Immediately exit if previous_freq is not initialized yet. */
 	if (!devfreq->previous_freq)
@@ -224,8 +226,8 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
 		goto out;
 	}
 
-	devfreq->time_in_state[prev_lev] +=
-			 cur_time - devfreq->last_stat_updated;
+	devfreq->stats.time_in_state[prev_lev] +=
+			cur_time - devfreq->stats.last_update;
 
 	lev = devfreq_get_freq_level(devfreq, freq);
 	if (lev < 0) {
@@ -234,13 +236,13 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
 	}
 
 	if (lev != prev_lev) {
-		devfreq->trans_table[(prev_lev *
-				devfreq->profile->max_state) + lev]++;
-		devfreq->total_trans++;
+		devfreq->stats.trans_table[
+			(prev_lev * devfreq->profile->max_state) + lev]++;
+		devfreq->stats.total_trans++;
 	}
 
 out:
-	devfreq->last_stat_updated = cur_time;
+	devfreq->stats.last_update = cur_time;
 	return ret;
 }
 EXPORT_SYMBOL(devfreq_update_status);
@@ -535,7 +537,7 @@ void devfreq_monitor_resume(struct devfreq *devfreq)
 			msecs_to_jiffies(devfreq->profile->polling_ms));
 
 out_update:
-	devfreq->last_stat_updated = jiffies;
+	devfreq->stats.last_update = get_jiffies_64();
 	devfreq->stop_polling = false;
 
 	if (devfreq->profile->get_cur_freq &&
@@ -807,28 +809,29 @@ struct devfreq *devfreq_add_device(struct device *dev,
 		goto err_out;
 	}
 
-	devfreq->trans_table = devm_kzalloc(&devfreq->dev,
+	devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev,
 			array3_size(sizeof(unsigned int),
 				    devfreq->profile->max_state,
 				    devfreq->profile->max_state),
 			GFP_KERNEL);
-	if (!devfreq->trans_table) {
+	if (!devfreq->stats.trans_table) {
 		mutex_unlock(&devfreq->lock);
 		err = -ENOMEM;
 		goto err_devfreq;
 	}
 
-	devfreq->time_in_state = devm_kcalloc(&devfreq->dev,
+	devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev,
 			devfreq->profile->max_state,
-			sizeof(unsigned long),
+			sizeof(*devfreq->stats.time_in_state),
 			GFP_KERNEL);
-	if (!devfreq->time_in_state) {
+	if (!devfreq->stats.time_in_state) {
 		mutex_unlock(&devfreq->lock);
 		err = -ENOMEM;
 		goto err_devfreq;
 	}
 
-	devfreq->last_stat_updated = jiffies;
+	devfreq->stats.total_trans = 0;
+	devfreq->stats.last_update = get_jiffies_64();
 
 	srcu_init_notifier_head(&devfreq->transition_notifier_list);
 
@@ -1259,6 +1262,14 @@ int devfreq_remove_governor(struct devfreq_governor *governor)
 }
 EXPORT_SYMBOL(devfreq_remove_governor);
 
+static ssize_t name_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct devfreq *devfreq = to_devfreq(dev);
+	return sprintf(buf, "%s\n", dev_name(devfreq->dev.parent));
+}
+static DEVICE_ATTR_RO(name);
+
 static ssize_t governor_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
@@ -1461,6 +1472,7 @@ static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
 
 	return sprintf(buf, "%lu\n", min_freq);
 }
+static DEVICE_ATTR_RW(min_freq);
 
 static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
 			      const char *buf, size_t count)
@@ -1501,7 +1513,6 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
 
 	return count;
 }
-static DEVICE_ATTR_RW(min_freq);
 
 static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
 			     char *buf)
@@ -1580,18 +1591,47 @@ static ssize_t trans_stat_show(struct device *dev,
 				devfreq->profile->freq_table[i]);
 		for (j = 0; j < max_state; j++)
 			len += sprintf(buf + len, "%10u",
-				devfreq->trans_table[(i * max_state) + j]);
-		len += sprintf(buf + len, "%10u\n",
-			jiffies_to_msecs(devfreq->time_in_state[i]));
+				devfreq->stats.trans_table[(i * max_state) + j]);
+
+		len += sprintf(buf + len, "%10llu\n", (u64)
+			jiffies64_to_msecs(devfreq->stats.time_in_state[i]));
 	}
 
 	len += sprintf(buf + len, "Total transition : %u\n",
-					devfreq->total_trans);
+					devfreq->stats.total_trans);
 	return len;
 }
-static DEVICE_ATTR_RO(trans_stat);
+
+static ssize_t trans_stat_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct devfreq *df = to_devfreq(dev);
+	int err, value;
+
+	if (df->profile->max_state == 0)
+		return count;
+
+	err = kstrtoint(buf, 10, &value);
+	if (err || value != 0)
+		return -EINVAL;
+
+	mutex_lock(&df->lock);
+	memset(df->stats.time_in_state, 0, (df->profile->max_state *
+					sizeof(*df->stats.time_in_state)));
+	memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),
+					df->profile->max_state,
+					df->profile->max_state));
+	df->stats.total_trans = 0;
+	df->stats.last_update = get_jiffies_64();
+	mutex_unlock(&df->lock);
+
+	return count;
+}
+static DEVICE_ATTR_RW(trans_stat);
 
 static struct attribute *devfreq_attrs[] = {
+	&dev_attr_name.attr,
 	&dev_attr_governor.attr,
 	&dev_attr_available_governors.attr,
 	&dev_attr_cur_freq.attr,
@@ -1605,6 +1645,81 @@ static struct attribute *devfreq_attrs[] = {
 };
 ATTRIBUTE_GROUPS(devfreq);
 
+/**
+ * devfreq_summary_show() - Show the summary of the devfreq devices
+ * @s:		seq_file instance to show the summary of devfreq devices
+ * @data:	not used
+ *
+ * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file.
+ * It helps that user can know the detailed information of the devfreq devices.
+ *
+ * Return 0 always because it shows the information without any data change.
+ */
+static int devfreq_summary_show(struct seq_file *s, void *data)
+{
+	struct devfreq *devfreq;
+	struct devfreq *p_devfreq = NULL;
+	unsigned long cur_freq, min_freq, max_freq;
+	unsigned int polling_ms;
+
+	seq_printf(s, "%-30s %-10s %-10s %-15s %10s %12s %12s %12s\n",
+			"dev_name",
+			"dev",
+			"parent_dev",
+			"governor",
+			"polling_ms",
+			"cur_freq_Hz",
+			"min_freq_Hz",
+			"max_freq_Hz");
+	seq_printf(s, "%30s %10s %10s %15s %10s %12s %12s %12s\n",
+			"------------------------------",
+			"----------",
+			"----------",
+			"---------------",
+			"----------",
+			"------------",
+			"------------",
+			"------------");
+
+	mutex_lock(&devfreq_list_lock);
+
+	list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
+#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
+		if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE,
+							DEVFREQ_NAME_LEN)) {
+			struct devfreq_passive_data *data = devfreq->data;
+
+			if (data)
+				p_devfreq = data->parent;
+		} else {
+			p_devfreq = NULL;
+		}
+#endif
+
+		mutex_lock(&devfreq->lock);
+		cur_freq = devfreq->previous_freq,
+		get_freq_range(devfreq, &min_freq, &max_freq);
+		polling_ms = devfreq->profile->polling_ms,
+		mutex_unlock(&devfreq->lock);
+
+		seq_printf(s,
+			"%-30s %-10s %-10s %-15s %10d %12ld %12ld %12ld\n",
+			dev_name(devfreq->dev.parent),
+			dev_name(&devfreq->dev),
+			p_devfreq ? dev_name(&p_devfreq->dev) : "null",
+			devfreq->governor_name,
+			polling_ms,
+			cur_freq,
+			min_freq,
+			max_freq);
+	}
+
+	mutex_unlock(&devfreq_list_lock);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
+
 static int __init devfreq_init(void)
 {
 	devfreq_class = class_create(THIS_MODULE, "devfreq");
@@ -1621,6 +1736,11 @@ static int __init devfreq_init(void)
 	}
 	devfreq_class->dev_groups = devfreq_groups;
 
+	devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
+	debugfs_create_file("devfreq_summary", 0444,
+				devfreq_debugfs, NULL,
+				&devfreq_summary_fops);
+
 	return 0;
 }
 subsys_initcall(devfreq_init);
@@ -1814,7 +1934,7 @@ static void devm_devfreq_notifier_release(struct device *dev, void *res)
 
 /**
  * devm_devfreq_register_notifier()
-	- Resource-managed devfreq_register_notifier()
+ *	- Resource-managed devfreq_register_notifier()
  * @dev:	The devfreq user device. (parent of devfreq)
  * @devfreq:	The devfreq object.
  * @nb:		The notifier block to be unregistered.
@@ -1850,7 +1970,7 @@ EXPORT_SYMBOL(devm_devfreq_register_notifier);
 
 /**
  * devm_devfreq_unregister_notifier()
-	- Resource-managed devfreq_unregister_notifier()
+ *	- Resource-managed devfreq_unregister_notifier()
  * @dev:	The devfreq user device. (parent of devfreq)
  * @devfreq:	The devfreq object.
  * @nb:		The notifier block to be unregistered.

drivers/devfreq/event/Kconfig

@@ -15,7 +15,7 @@ menuconfig PM_DEVFREQ_EVENT
 if PM_DEVFREQ_EVENT
 
 config DEVFREQ_EVENT_EXYNOS_NOCP
-	tristate "EXYNOS NoC (Network On Chip) Probe DEVFREQ event Driver"
+	tristate "Exynos NoC (Network On Chip) Probe DEVFREQ event Driver"
 	depends on ARCH_EXYNOS || COMPILE_TEST
 	select PM_OPP
 	select REGMAP_MMIO
@@ -24,7 +24,7 @@ config DEVFREQ_EVENT_EXYNOS_NOCP
 	  (Network on Chip) Probe counters to measure the bandwidth of AXI bus.
 
 config DEVFREQ_EVENT_EXYNOS_PPMU
-	tristate "EXYNOS PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"
+	tristate "Exynos PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"
 	depends on ARCH_EXYNOS || COMPILE_TEST
 	select PM_OPP
 	help
@@ -34,7 +34,7 @@ config DEVFREQ_EVENT_EXYNOS_PPMU
 
 config DEVFREQ_EVENT_ROCKCHIP_DFI
 	tristate "ROCKCHIP DFI DEVFREQ event Driver"
-	depends on ARCH_ROCKCHIP
+	depends on ARCH_ROCKCHIP || COMPILE_TEST
 	help
 	  This add the devfreq-event driver for Rockchip SoC. It provides DFI
 	  (DDR Monitor Module) driver to count ddr load.

drivers/devfreq/event/exynos-nocp.c

 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * exynos-nocp.c - EXYNOS NoC (Network On Chip) Probe support
+ * exynos-nocp.c - Exynos NoC (Network On Chip) Probe support
  *
  * Copyright (c) 2016 Samsung Electronics Co., Ltd.
  * Author : Chanwoo Choi <cw00.choi@samsung.com>

drivers/devfreq/event/exynos-nocp.h

 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * exynos-nocp.h - EXYNOS NoC (Network on Chip) Probe header file
+ * exynos-nocp.h - Exynos NoC (Network on Chip) Probe header file
  *
  * Copyright (c) 2016 Samsung Electronics Co., Ltd.
  * Author : Chanwoo Choi <cw00.choi@samsung.com>

drivers/devfreq/event/exynos-ppmu.c

 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * exynos_ppmu.c - EXYNOS PPMU (Platform Performance Monitoring Unit) support
+ * exynos_ppmu.c - Exynos PPMU (Platform Performance Monitoring Unit) support
  *
  * Copyright (c) 2014-2015 Samsung Electronics Co., Ltd.
  * Author : Chanwoo Choi <cw00.choi@samsung.com>
@@ -101,17 +101,22 @@ static struct __exynos_ppmu_events {
 	PPMU_EVENT(dmc1_1),
 };
 
-static int exynos_ppmu_find_ppmu_id(struct devfreq_event_dev *edev)
+static int __exynos_ppmu_find_ppmu_id(const char *edev_name)
 {
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(ppmu_events); i++)
-		if (!strcmp(edev->desc->name, ppmu_events[i].name))
+		if (!strcmp(edev_name, ppmu_events[i].name))
 			return ppmu_events[i].id;
 
 	return -EINVAL;
 }
 
+static int exynos_ppmu_find_ppmu_id(struct devfreq_event_dev *edev)
+{
+	return __exynos_ppmu_find_ppmu_id(edev->desc->name);
+}
+
 /*
  * The devfreq-event ops structure for PPMU v1.1
  */
@@ -556,13 +561,11 @@ static int of_get_devfreq_events(struct device_node *np,
 			 * use default if not.
 			 */
 			if (info->ppmu_type == EXYNOS_TYPE_PPMU_V2) {
-				struct devfreq_event_dev edev;
 				int id;
 				/* Not all registers take the same value for
 				 * read+write data count.
 				 */
-				edev.desc = &desc[j];
-				id = exynos_ppmu_find_ppmu_id(&edev);
+				id = __exynos_ppmu_find_ppmu_id(desc[j].name);
 
 				switch (id) {
 				case PPMU_PMNCNT0:

drivers/devfreq/event/exynos-ppmu.h

 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * exynos_ppmu.h - EXYNOS PPMU header file
+ * exynos_ppmu.h - Exynos PPMU header file
  *
  * Copyright (c) 2015 Samsung Electronics Co., Ltd.
  * Author : Chanwoo Choi <cw00.choi@samsung.com>

drivers/devfreq/event/rockchip-dfi.c

@@ -177,7 +177,6 @@ static int rockchip_dfi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct rockchip_dfi *data;
-	struct resource *res;
 	struct devfreq_event_desc *desc;
 	struct device_node *np = pdev->dev.of_node, *node;
 
@@ -185,8 +184,7 @@ static int rockchip_dfi_probe(struct platform_device *pdev)
 	if (!data)
 		return -ENOMEM;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	data->regs = devm_ioremap_resource(&pdev->dev, res);
+	data->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(data->regs))
 		return PTR_ERR(data->regs);
 
@@ -200,6 +198,7 @@ static int rockchip_dfi_probe(struct platform_device *pdev)
 	node = of_parse_phandle(np, "rockchip,pmu", 0);
 	if (node) {
 		data->regmap_pmu = syscon_node_to_regmap(node);
+		of_node_put(node);
 		if (IS_ERR(data->regmap_pmu))
 			return PTR_ERR(data->regmap_pmu);
 	}

drivers/devfreq/exynos-bus.c

@@ -15,11 +15,10 @@
 #include <linux/device.h>
 #include <linux/export.h>
 #include <linux/module.h>
-#include <linux/of_device.h>
+#include <linux/of.h>
 #include <linux/pm_opp.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
-#include <linux/slab.h>
 
 #define DEFAULT_SATURATION_RATIO	40
 
@@ -127,6 +126,7 @@ static int exynos_bus_get_dev_status(struct device *dev,
 
 	ret = exynos_bus_get_event(bus, &edata);
 	if (ret < 0) {
+		dev_err(dev, "failed to get event from devfreq-event devices\n");
 		stat->total_time = stat->busy_time = 0;
 		goto err;
 	}
@@ -287,52 +287,12 @@ static int exynos_bus_parse_of(struct device_node *np,
 	return ret;
 }
 
-static int exynos_bus_probe(struct platform_device *pdev)
+static int exynos_bus_profile_init(struct exynos_bus *bus,
+				   struct devfreq_dev_profile *profile)
 {
-	struct device *dev = &pdev->dev;
-	struct device_node *np = dev->of_node, *node;
-	struct devfreq_dev_profile *profile;
+	struct device *dev = bus->dev;
 	struct devfreq_simple_ondemand_data *ondemand_data;
-	struct devfreq_passive_data *passive_data;
-	struct devfreq *parent_devfreq;
-	struct exynos_bus *bus;
-	int ret, max_state;
-	unsigned long min_freq, max_freq;
-	bool passive = false;
-
-	if (!np) {
-		dev_err(dev, "failed to find devicetree node\n");
-		return -EINVAL;
-	}
-
-	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
-	if (!bus)
-		return -ENOMEM;
-	mutex_init(&bus->lock);
-	bus->dev = &pdev->dev;
-	platform_set_drvdata(pdev, bus);
-
-	profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);
-	if (!profile)
-		return -ENOMEM;
-
-	node = of_parse_phandle(dev->of_node, "devfreq", 0);
-	if (node) {
-		of_node_put(node);
-		passive = true;
-	} else {
-		ret = exynos_bus_parent_parse_of(np, bus);
-		if (ret < 0)
-			return ret;
-	}
-
-	/* Parse the device-tree to get the resource information */
-	ret = exynos_bus_parse_of(np, bus);
-	if (ret < 0)
-		goto err_reg;
-
-	if (passive)
-		goto passive;
+	int ret;
 
 	/* Initialize the struct profile and governor data for parent device */
 	profile->polling_ms = 50;
@@ -341,10 +301,9 @@ static int exynos_bus_probe(struct platform_device *pdev)
 	profile->exit = exynos_bus_exit;
 
 	ondemand_data = devm_kzalloc(dev, sizeof(*ondemand_data), GFP_KERNEL);
-	if (!ondemand_data) {
-		ret = -ENOMEM;
-		goto err;
-	}
+	if (!ondemand_data)
+		return -ENOMEM;
+
 	ondemand_data->upthreshold = 40;
 	ondemand_data->downdifferential = 5;
 
@@ -354,15 +313,14 @@ static int exynos_bus_probe(struct platform_device *pdev)
 						ondemand_data);
 	if (IS_ERR(bus->devfreq)) {
 		dev_err(dev, "failed to add devfreq device\n");
-		ret = PTR_ERR(bus->devfreq);
-		goto err;
+		return PTR_ERR(bus->devfreq);
 	}
 
 	/* Register opp_notifier to catch the change of OPP  */
 	ret = devm_devfreq_register_opp_notifier(dev, bus->devfreq);
 	if (ret < 0) {
 		dev_err(dev, "failed to register opp notifier\n");
-		goto err;
+		return ret;
 	}
 
 	/*
@@ -372,33 +330,44 @@ static int exynos_bus_probe(struct platform_device *pdev)
 	ret = exynos_bus_enable_edev(bus);
 	if (ret < 0) {
 		dev_err(dev, "failed to enable devfreq-event devices\n");
-		goto err;
+		return ret;
 	}
 
 	ret = exynos_bus_set_event(bus);
 	if (ret < 0) {
 		dev_err(dev, "failed to set event to devfreq-event devices\n");
-		goto err;
+		goto err_edev;
 	}
 
-	goto out;
-passive:
+	return 0;
+
+err_edev:
+	if (exynos_bus_disable_edev(bus))
+		dev_warn(dev, "failed to disable the devfreq-event devices\n");
+
+	return ret;
+}
+
+static int exynos_bus_profile_init_passive(struct exynos_bus *bus,
+					   struct devfreq_dev_profile *profile)
+{
+	struct device *dev = bus->dev;
+	struct devfreq_passive_data *passive_data;
+	struct devfreq *parent_devfreq;
+
 	/* Initialize the struct profile and governor data for passive device */
 	profile->target = exynos_bus_target;
 	profile->exit = exynos_bus_passive_exit;
 
 	/* Get the instance of parent devfreq device */
 	parent_devfreq = devfreq_get_devfreq_by_phandle(dev, 0);
-	if (IS_ERR(parent_devfreq)) {
-		ret = -EPROBE_DEFER;
-		goto err;
-	}
+	if (IS_ERR(parent_devfreq))
+		return -EPROBE_DEFER;
 
 	passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL);
-	if (!passive_data) {
-		ret = -ENOMEM;
-		goto err;
-	}
+	if (!passive_data)
+		return -ENOMEM;
+
 	passive_data->parent = parent_devfreq;
 
 	/* Add devfreq device for exynos bus with passive governor */
@@ -407,11 +376,61 @@ static int exynos_bus_probe(struct platform_device *pdev)
 	if (IS_ERR(bus->devfreq)) {
 		dev_err(dev,
 			"failed to add devfreq dev with passive governor\n");
-		ret = PTR_ERR(bus->devfreq);
-		goto err;
+		return PTR_ERR(bus->devfreq);
+	}
+
+	return 0;
+}
+
+static int exynos_bus_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node, *node;
+	struct devfreq_dev_profile *profile;
+	struct exynos_bus *bus;
+	int ret, max_state;
+	unsigned long min_freq, max_freq;
+	bool passive = false;
+
+	if (!np) {
+		dev_err(dev, "failed to find devicetree node\n");
+		return -EINVAL;
 	}
 
-out:
+	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
+	if (!bus)
+		return -ENOMEM;
+	mutex_init(&bus->lock);
+	bus->dev = &pdev->dev;
+	platform_set_drvdata(pdev, bus);
+
+	profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);
+	if (!profile)
+		return -ENOMEM;
+
+	node = of_parse_phandle(dev->of_node, "devfreq", 0);
+	if (node) {
+		of_node_put(node);
+		passive = true;
+	} else {
+		ret = exynos_bus_parent_parse_of(np, bus);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Parse the device-tree to get the resource information */
+	ret = exynos_bus_parse_of(np, bus);
+	if (ret < 0)
+		goto err_reg;
+
+	if (passive)
+		ret = exynos_bus_profile_init_passive(bus, profile);
+	else
+		ret = exynos_bus_profile_init(bus, profile);
+
+	if (ret < 0)
+		goto err;
+
 	max_state = bus->devfreq->profile->max_state;
 	min_freq = (bus->devfreq->profile->freq_table[0] / 1000);
 	max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);

drivers/devfreq/rk3399_dmc.c

@@ -364,7 +364,8 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
 			if (res.a0) {
 				dev_err(dev, "Failed to set dram param: %ld\n",
 					res.a0);
-				return -EINVAL;
+				ret = -EINVAL;
+				goto err_edev;
 			}
 		}
 	}
@@ -372,8 +373,11 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
 	node = of_parse_phandle(np, "rockchip,pmu", 0);
 	if (node) {
 		data->regmap_pmu = syscon_node_to_regmap(node);
-		if (IS_ERR(data->regmap_pmu))
-			return PTR_ERR(data->regmap_pmu);
+		of_node_put(node);
+		if (IS_ERR(data->regmap_pmu)) {
+			ret = PTR_ERR(data->regmap_pmu);
+			goto err_edev;
+		}
 	}
 
 	regmap_read(data->regmap_pmu, RK3399_PMUGRF_OS_REG2, &val);
@@ -391,7 +395,8 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
 		data->odt_dis_freq = data->timing.lpddr4_odt_dis_freq;
 		break;
 	default:
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_edev;
 	};
 
 	arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0,
@@ -425,7 +430,8 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
 	 */
 	if (dev_pm_opp_of_add_table(dev)) {
 		dev_err(dev, "Invalid operating-points in device tree.\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_edev;
 	}
 
 	of_property_read_u32(np, "upthreshold",
@@ -465,6 +471,9 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
 
 err_free_opp:
 	dev_pm_opp_of_remove_table(&pdev->dev);
+err_edev:
+	devfreq_event_disable_edev(data->edev);
+
 	return ret;
 }
 

include/linux/devfreq.h

@@ -107,6 +107,20 @@ struct devfreq_dev_profile {
 	unsigned int max_state;
 };
 
+/**
+ * struct devfreq_stats - Statistics of devfreq device behavior
+ * @total_trans:	Number of devfreq transitions.
+ * @trans_table:	Statistics of devfreq transitions.
+ * @time_in_state:	Statistics of devfreq states.
+ * @last_update:	The last time stats were updated.
+ */
+struct devfreq_stats {
+	unsigned int total_trans;
+	unsigned int *trans_table;
+	u64 *time_in_state;
+	u64 last_update;
+};
+
 /**
  * struct devfreq - Device devfreq structure
  * @node:	list node - contains the devices with devfreq that have been
@@ -122,6 +136,7 @@ struct devfreq_dev_profile {
  *		devfreq.nb to the corresponding register notifier call chain.
  * @work:	delayed work for load monitoring.
  * @previous_freq:	previously configured frequency value.
+ * @last_status:	devfreq user device info, performance statistics
  * @data:	Private data of the governor. The devfreq framework does not
  *		touch this.
  * @user_min_freq_req:	PM QoS minimum frequency request from user (via sysfs)
@@ -132,15 +147,12 @@ struct devfreq_dev_profile {
  * @suspend_freq:	 frequency of a device set during suspend phase.
  * @resume_freq:	 frequency of a device set in resume phase.
  * @suspend_count:	 suspend requests counter for a device.
- * @total_trans:	Number of devfreq transitions
- * @trans_table:	Statistics of devfreq transitions
- * @time_in_state:	Statistics of devfreq states
- * @last_stat_updated:	The last time stat updated
+ * @stats:	Statistics of devfreq device behavior
  * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
  * @nb_min:		Notifier block for DEV_PM_QOS_MIN_FREQUENCY
  * @nb_max:		Notifier block for DEV_PM_QOS_MAX_FREQUENCY
  *
- * This structure stores the devfreq information for a give device.
+ * This structure stores the devfreq information for a given device.
  *
  * Note that when a governor accesses entries in struct devfreq in its
  * functions except for the context of callbacks defined in struct
@@ -174,11 +186,8 @@ struct devfreq {
 	unsigned long resume_freq;
 	atomic_t suspend_count;
 
-	/* information for device frequency transition */
-	unsigned int total_trans;
-	unsigned int *trans_table;
-	unsigned long *time_in_state;
-	unsigned long last_stat_updated;
+	/* information for device frequency transitions */
+	struct devfreq_stats stats;
 
 	struct srcu_notifier_head transition_notifier_list;