Merge tag 'devfreq-next-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux

Merge devfreq updates for v6.17 from Chanwoo Choi:

"- Clean devfreq core and fix bugs
  : Replace sscanf with kstrtoul
  : Remove redundant devfreq_get_freq_range() on adding devfreq driver
  : Check missing NULL pointer check on removing devfreq driver
  : Limit max_freq and min_freq to avoid unreachable value
  : Fix wrong index on trans_stat sysfs node

 - Use devm_* managed function for clock control on sun81-a33-mbus driver

 - Add HiSilicon uncore frequencye scaling driver for for HiSilicon Kunpeng SoCs
  : The uncore domain includes shared system resources such as interconnects
  and L3 cache, and its frequency has a significant impact on system performance
  and power consumption. The driver provides the following functions:
    - Support to scale frequency scaling with governor and user setting
    - Support to query CPUs whose performance is closely related to the uncore domain
    - Communication with the platform controller via an ACPI PCC mailbox
      to perform actual frequency changes"

* tag 'devfreq-next-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux:
  PM / devfreq: Add HiSilicon uncore frequency scaling driver
  PM / devfreq: Allow devfreq driver to add custom sysfs ABIs
  PM / devfreq: sun8i-a33-mbus: Simplify by using more devm functions
  PM / devfreq: Fix a index typo in trans_stat
  PM / devfreq: Check governor before using governor->name
  PM / devfreq: Remove redundant devfreq_get_freq_range() calling in devfreq_add_device()
  PM / devfreq: Limit max_freq with scaling_min_freq
  PM / devfreq: governor: Replace sscanf() with kstrtoul() in set_freq_store()

Author: rafaeljw

Documentation/ABI/testing/sysfs-class-devfreq

@@ -132,3 +132,12 @@ Description:
 
 		A list of governors that support the node:
 		- simple_ondemand
+
+What:		/sys/class/devfreq/.../related_cpus
+Date:		June 2025
+Contact:	Linux power management list <linux-pm@vger.kernel.org>
+Description:	The list of CPUs whose performance is closely related to the
+		frequency of this devfreq domain.
+
+		This file is only present if a specific devfreq device is
+		closely associated with a subset of CPUs.

drivers/devfreq/Kconfig

@@ -90,6 +90,17 @@ 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_HISI_UNCORE_DEVFREQ
+	tristate "HiSilicon uncore DEVFREQ Driver"
+	depends on ACPI && ACPI_PPTT && PCC
+	select DEVFREQ_GOV_PERFORMANCE
+	select DEVFREQ_GOV_USERSPACE
+	help
+	  This adds a DEVFREQ driver that manages uncore frequency scaling for
+	  HiSilicon Kunpeng SoCs. This enables runtime management of uncore
+	  frequency scaling from kernel and userspace. The uncore domain
+	  contains system interconnects and L3 cache.
+
 config ARM_IMX_BUS_DEVFREQ
 	tristate "i.MX Generic Bus DEVFREQ Driver"
 	depends on ARCH_MXC || COMPILE_TEST

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_HISI_UNCORE_DEVFREQ)	+= hisi_uncore_freq.o
 obj-$(CONFIG_ARM_IMX_BUS_DEVFREQ)	+= imx-bus.o
 obj-$(CONFIG_ARM_IMX8M_DDRC_DEVFREQ)	+= imx8m-ddrc.o
 obj-$(CONFIG_ARM_MEDIATEK_CCI_DEVFREQ)	+= mtk-cci-devfreq.o

drivers/devfreq/devfreq.c

@@ -152,11 +152,8 @@ void devfreq_get_freq_range(struct devfreq *devfreq,
 				(unsigned long)HZ_PER_KHZ * qos_max_freq);
 
 	/* Apply constraints from OPP interface */
-	*min_freq = max(*min_freq, devfreq->scaling_min_freq);
-	*max_freq = min(*max_freq, devfreq->scaling_max_freq);
-
-	if (*min_freq > *max_freq)
-		*min_freq = *max_freq;
+	*max_freq = clamp(*max_freq, devfreq->scaling_min_freq, devfreq->scaling_max_freq);
+	*min_freq = clamp(*min_freq, devfreq->scaling_min_freq, *max_freq);
 }
 EXPORT_SYMBOL(devfreq_get_freq_range);
 
@@ -807,7 +804,6 @@ struct devfreq *devfreq_add_device(struct device *dev,
 {
 	struct devfreq *devfreq;
 	struct devfreq_governor *governor;
-	unsigned long min_freq, max_freq;
 	int err = 0;
 
 	if (!dev || !profile || !governor_name) {
@@ -835,6 +831,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 	mutex_lock(&devfreq->lock);
 	devfreq->dev.parent = dev;
 	devfreq->dev.class = devfreq_class;
+	devfreq->dev.groups = profile->dev_groups;
 	devfreq->dev.release = devfreq_dev_release;
 	INIT_LIST_HEAD(&devfreq->node);
 	devfreq->profile = profile;
@@ -875,8 +872,6 @@ struct devfreq *devfreq_add_device(struct device *dev,
 		goto err_dev;
 	}
 
-	devfreq_get_freq_range(devfreq, &min_freq, &max_freq);
-
 	devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);
 	devfreq->opp_table = dev_pm_opp_get_opp_table(dev);
 	if (IS_ERR(devfreq->opp_table))
@@ -1382,15 +1377,11 @@ int devfreq_remove_governor(struct devfreq_governor *governor)
 		int ret;
 		struct device *dev = devfreq->dev.parent;
 
+		if (!devfreq->governor)
+			continue;
+
 		if (!strncmp(devfreq->governor->name, governor->name,
 			     DEVFREQ_NAME_LEN)) {
-			/* we should have a devfreq governor! */
-			if (!devfreq->governor) {
-				dev_warn(dev, "%s: Governor %s NOT present\n",
-					 __func__, governor->name);
-				continue;
-				/* Fall through */
-			}
 			ret = devfreq->governor->event_handler(devfreq,
 						DEVFREQ_GOV_STOP, NULL);
 			if (ret) {
@@ -1743,7 +1734,7 @@ static ssize_t trans_stat_show(struct device *dev,
 	for (i = 0; i < max_state; i++) {
 		if (len >= PAGE_SIZE - 1)
 			break;
-		if (df->freq_table[2] == df->previous_freq)
+		if (df->freq_table[i] == df->previous_freq)
 			len += sysfs_emit_at(buf, len, "*");
 		else
 			len += sysfs_emit_at(buf, len, " ");

drivers/devfreq/governor_userspace.c

@@ -9,6 +9,7 @@
 #include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/devfreq.h>
+#include <linux/kstrtox.h>
 #include <linux/pm.h>
 #include <linux/mutex.h>
 #include <linux/module.h>
@@ -39,10 +40,13 @@ static ssize_t set_freq_store(struct device *dev, struct device_attribute *attr,
 	unsigned long wanted;
 	int err = 0;
 
+	err = kstrtoul(buf, 0, &wanted);
+	if (err)
+		return err;
+
 	mutex_lock(&devfreq->lock);
 	data = devfreq->governor_data;
 
-	sscanf(buf, "%lu", &wanted);
 	data->user_frequency = wanted;
 	data->valid = true;
 	err = update_devfreq(devfreq);