Merge tag 'devfreq-next-for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux

Pull devfreq updates for 5.11 from Chanwoo Choi:

 1. Update devfreq core

  - Add new devfreq_frequency tracepoint to show the frequency change
    information.

  - Add governor feature flag. The devfreq governor is able to set the
    specific flag in order to support a non-common feature. For
    example, if the governor supports the 'immutable' feature, don't
    allow user space to change the governor via sysfs.

  - Add governor sysfs attribute flag for each sysfs file. Prior to that
    the devfreq subsystem allowed all of the sysfs files to be accessed
    regardless of the governor type. But some sysfs fils are not
    supported by specific devfreq governors. In order to only allow the
    sysfs files supported by the governor to be accessed, clarify the
    access permissions of sysfs attributes according to the governor.
    When adding the devfreq governor, specify the available attribute
    information by using DEVFREQ_GOV_ATTR_* symbols. The user can read
    or write the sysfs attributes in accordance to the specified
    access permissions.

  - Clean-up the code to reduce duplication for the devfreq tracepoint
    and to remove redundant governor_name field from struct devfreq.

 2. Update exynos-bus.c devfreq driver

  - Add interconnect API support to the Samsung Exynos Bus Frequency
    driver, exynos-bus.c. Complementing the devfreq driver with
    interconnect functionality allows to ensure that the QoS
    requirements regarding devices accessing the system memory (e.g.
    video processing devices) will be met and allows to avoid issues
    like DMA underrun.

 3. Update tegra devfreq driver

  - Add interconnect support and OPP interface to tegra30-devfreq.c.
    Also, it is to guarantee the QoS requirement of some devices like
    the display controller.

  - Move tegra20-devfreq.c from drivers/devfreq/ into drivers/memory/tegra/
    in order to use the more proper monitoring feature such as EMC_STAT
    which is located in drivers/memory/tegra/.

  - Separate the configuration information for different SoCs in
    tegra30-devfrqe.c. The tegra30-devfreq.c had been supporting both
    tegra30-actmon and tegra124-actmon devices. In order to use the
    more correct configuration data, separate them.

  - Use dev_err_probe() to handle the deferred probe error in
    tegra30-devfreq.c.

 4. Pull the request of 'Tegra SoC and clock controller changes for
    v5.11' sent by Krzysztof Kozlowski <krzk@kernel.org> in order to
    avoid a build error."

* tag 'devfreq-next-for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux:
  PM / devfreq: tegra30: Separate configurations per-SoC generation
  PM / devfreq: tegra30: Support interconnect and OPPs from device-tree
  PM / devfreq: tegra20: Deprecate in a favor of emc-stat based driver
  PM / devfreq: exynos-bus: Add registration of interconnect child device
  dt-bindings: devfreq: Add documentation for the interconnect properties
  soc/tegra: fuse: Add stub for tegra_sku_info
  soc/tegra: fuse: Export tegra_read_ram_code()
  clk: tegra: Export Tegra20 EMC kernel symbols
  PM / devfreq: tegra30: Silence deferred probe error
  PM / devfreq: tegra20: Relax Kconfig dependency
  PM / devfreq: tegra20: Silence deferred probe error
  PM / devfreq: Remove redundant governor_name from struct devfreq
  PM / devfreq: Add governor attribute flag for specifc sysfs nodes
  PM / devfreq: Add governor feature flag
  PM / devfreq: Add tracepoint for frequency changes
  PM / devfreq: Unify frequency change to devfreq_update_target func
  trace: events: devfreq: Use fixed indentation size to improve readability

1 files changed, 163 insertions, 79 deletions

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 861c100f9fac..6aa10de792b3 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -31,6 +31,8 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/devfreq.h>
 
+#define IS_SUPPORTED_FLAG(f, name) ((f & DEVFREQ_GOV_FLAG_##name) ? true : false)
+#define IS_SUPPORTED_ATTR(f, name) ((f & DEVFREQ_GOV_ATTR_##name) ? true : false)
 #define HZ_PER_KHZ	1000
 
 static struct class *devfreq_class;
@@ -367,6 +369,14 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 		return err;
 	}
 
+	/*
+	 * Print devfreq_frequency trace information between DEVFREQ_PRECHANGE
+	 * and DEVFREQ_POSTCHANGE because for showing the correct frequency
+	 * change order of between devfreq device and passive devfreq device.
+	 */
+	if (trace_devfreq_frequency_enabled() && new_freq != cur_freq)
+		trace_devfreq_frequency(devfreq, new_freq, cur_freq);
+
 	freqs.new = new_freq;
 	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
 
@@ -382,18 +392,19 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 	return err;
 }
 
-/* Load monitoring helper functions for governors use */
-
 /**
- * update_devfreq() - Reevaluate the device and configure frequency.
+ * devfreq_update_target() - Reevaluate the device and configure frequency
+ *			   on the final stage.
  * @devfreq:	the devfreq instance.
+ * @freq:	the new frequency of parent device. This argument
+ *		is only used for devfreq device using passive governor.
  *
- * Note: Lock devfreq->lock before calling update_devfreq
- *	 This function is exported for governors.
+ * Note: Lock devfreq->lock before calling devfreq_update_target. This function
+ *	 should be only used by both update_devfreq() and devfreq governors.
  */
-int update_devfreq(struct devfreq *devfreq)
+int devfreq_update_target(struct devfreq *devfreq, unsigned long freq)
 {
-	unsigned long freq, min_freq, max_freq;
+	unsigned long min_freq, max_freq;
 	int err = 0;
 	u32 flags = 0;
 
@@ -418,7 +429,21 @@ int update_devfreq(struct devfreq *devfreq)
 	}
 
 	return devfreq_set_target(devfreq, freq, flags);
+}
+EXPORT_SYMBOL(devfreq_update_target);
 
+/* Load monitoring helper functions for governors use */
+
+/**
+ * update_devfreq() - Reevaluate the device and configure frequency.
+ * @devfreq:	the devfreq instance.
+ *
+ * Note: Lock devfreq->lock before calling update_devfreq
+ *	 This function is exported for governors.
+ */
+int update_devfreq(struct devfreq *devfreq)
+{
+	return devfreq_update_target(devfreq, 0L);
 }
 EXPORT_SYMBOL(update_devfreq);
 
@@ -456,7 +481,7 @@ static void devfreq_monitor(struct work_struct *work)
  */
 void devfreq_monitor_start(struct devfreq *devfreq)
 {
-	if (devfreq->governor->interrupt_driven)
+	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
 		return;
 
 	switch (devfreq->profile->timer) {
@@ -486,7 +511,7 @@ EXPORT_SYMBOL(devfreq_monitor_start);
  */
 void devfreq_monitor_stop(struct devfreq *devfreq)
 {
-	if (devfreq->governor->interrupt_driven)
+	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
 		return;
 
 	cancel_delayed_work_sync(&devfreq->work);
@@ -517,7 +542,7 @@ void devfreq_monitor_suspend(struct devfreq *devfreq)
 	devfreq->stop_polling = true;
 	mutex_unlock(&devfreq->lock);
 
-	if (devfreq->governor->interrupt_driven)
+	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
 		return;
 
 	cancel_delayed_work_sync(&devfreq->work);
@@ -537,12 +562,13 @@ void devfreq_monitor_resume(struct devfreq *devfreq)
 	unsigned long freq;
 
 	mutex_lock(&devfreq->lock);
-	if (!devfreq->stop_polling)
-		goto out;
 
-	if (devfreq->governor->interrupt_driven)
+	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
 		goto out_update;
 
+	if (!devfreq->stop_polling)
+		goto out;
+
 	if (!delayed_work_pending(&devfreq->work) &&
 			devfreq->profile->polling_ms)
 		queue_delayed_work(devfreq_wq, &devfreq->work,
@@ -577,10 +603,10 @@ void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay)
 	mutex_lock(&devfreq->lock);
 	devfreq->profile->polling_ms = new_delay;
 
-	if (devfreq->stop_polling)
+	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
 		goto out;
 
-	if (devfreq->governor->interrupt_driven)
+	if (devfreq->stop_polling)
 		goto out;
 
 	/* if new delay is zero, stop polling */
@@ -735,6 +761,11 @@ static void devfreq_dev_release(struct device *dev)
 	kfree(devfreq);
 }
 
+static void create_sysfs_files(struct devfreq *devfreq,
+				const struct devfreq_governor *gov);
+static void remove_sysfs_files(struct devfreq *devfreq,
+				const struct devfreq_governor *gov);
+
 /**
  * devfreq_add_device() - Add devfreq feature to the device
  * @dev:	the device to add devfreq feature.
@@ -780,7 +811,6 @@ struct devfreq *devfreq_add_device(struct device *dev,
 	devfreq->dev.release = devfreq_dev_release;
 	INIT_LIST_HEAD(&devfreq->node);
 	devfreq->profile = profile;
-	strscpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);
 	devfreq->previous_freq = profile->initial_freq;
 	devfreq->last_status.current_frequency = profile->initial_freq;
 	devfreq->data = data;
@@ -876,7 +906,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 
 	mutex_lock(&devfreq_list_lock);
 
-	governor = try_then_request_governor(devfreq->governor_name);
+	governor = try_then_request_governor(governor_name);
 	if (IS_ERR(governor)) {
 		dev_err(dev, "%s: Unable to find governor for the device\n",
 			__func__);
@@ -892,6 +922,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 			__func__);
 		goto err_init;
 	}
+	create_sysfs_files(devfreq, devfreq->governor);
 
 	list_add(&devfreq->node, &devfreq_list);
 
@@ -922,9 +953,12 @@ int devfreq_remove_device(struct devfreq *devfreq)
 	if (!devfreq)
 		return -EINVAL;
 
-	if (devfreq->governor)
+	if (devfreq->governor) {
 		devfreq->governor->event_handler(devfreq,
 						 DEVFREQ_GOV_STOP, NULL);
+		remove_sysfs_files(devfreq, devfreq->governor);
+	}
+
 	device_unregister(&devfreq->dev);
 
 	return 0;
@@ -1214,7 +1248,7 @@ int devfreq_add_governor(struct devfreq_governor *governor)
 		int ret = 0;
 		struct device *dev = devfreq->dev.parent;
 
-		if (!strncmp(devfreq->governor_name, governor->name,
+		if (!strncmp(devfreq->governor->name, governor->name,
 			     DEVFREQ_NAME_LEN)) {
 			/* The following should never occur */
 			if (devfreq->governor) {
@@ -1276,7 +1310,7 @@ int devfreq_remove_governor(struct devfreq_governor *governor)
 		int ret;
 		struct device *dev = devfreq->dev.parent;
 
-		if (!strncmp(devfreq->governor_name, governor->name,
+		if (!strncmp(devfreq->governor->name, governor->name,
 			     DEVFREQ_NAME_LEN)) {
 			/* we should have a devfreq governor! */
 			if (!devfreq->governor) {
@@ -1347,36 +1381,53 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
 	if (df->governor == governor) {
 		ret = 0;
 		goto out;
-	} else if (df->governor->immutable || governor->immutable) {
+	} else if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)
+		|| IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) {
 		ret = -EINVAL;
 		goto out;
 	}
 
+	/*
+	 * Stop the current governor and remove the specific sysfs files
+	 * which depend on current governor.
+	 */
 	ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
 	if (ret) {
 		dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
 			 __func__, df->governor->name, ret);
 		goto out;
 	}
+	remove_sysfs_files(df, df->governor);
 
+	/*
+	 * Start the new governor and create the specific sysfs files
+	 * which depend on the new governor.
+	 */
 	prev_governor = df->governor;
 	df->governor = governor;
-	strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN);
 	ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
 	if (ret) {
 		dev_warn(dev, "%s: Governor %s not started(%d)\n",
 			 __func__, df->governor->name, ret);
+
+		/* Restore previous governor */
 		df->governor = prev_governor;
-		strncpy(df->governor_name, prev_governor->name,
-			DEVFREQ_NAME_LEN);
 		ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
 		if (ret) {
 			dev_err(dev,
 				"%s: reverting to Governor %s failed (%d)\n",
-				__func__, df->governor_name, ret);
+				__func__, prev_governor->name, ret);
 			df->governor = NULL;
+			goto out;
 		}
 	}
+
+	/*
+	 * Create the sysfs files for the new governor. But if failed to start
+	 * the new governor, restore the sysfs files of previous governor.
+	 */
+	create_sysfs_files(df, df->governor);
+
 out:
 	mutex_unlock(&devfreq_list_lock);
 
@@ -1402,9 +1453,9 @@ static ssize_t available_governors_show(struct device *d,
 	 * The devfreq with immutable governor (e.g., passive) shows
 	 * only own governor.
 	 */
-	if (df->governor->immutable) {
+	if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)) {
 		count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
-				  "%s ", df->governor_name);
+				  "%s ", df->governor->name);
 	/*
 	 * The devfreq device shows the registered governor except for
 	 * immutable governors such as passive governor .
@@ -1413,7 +1464,7 @@ static ssize_t available_governors_show(struct device *d,
 		struct devfreq_governor *governor;
 
 		list_for_each_entry(governor, &devfreq_governor_list, node) {
-			if (governor->immutable)
+			if (IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE))
 				continue;
 			count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
 					   "%s ", governor->name);
@@ -1458,39 +1509,6 @@ static ssize_t target_freq_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(target_freq);
 
-static ssize_t polling_interval_show(struct device *dev,
-				     struct device_attribute *attr, char *buf)
-{
-	struct devfreq *df = to_devfreq(dev);
-
-	if (!df->profile)
-		return -EINVAL;
-
-	return sprintf(buf, "%d\n", df->profile->polling_ms);
-}
-
-static ssize_t polling_interval_store(struct device *dev,
-				      struct device_attribute *attr,
-				      const char *buf, size_t count)
-{
-	struct devfreq *df = to_devfreq(dev);
-	unsigned int value;
-	int ret;
-
-	if (!df->governor)
-		return -EINVAL;
-
-	ret = sscanf(buf, "%u", &value);
-	if (ret != 1)
-		return -EINVAL;
-
-	df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value);
-	ret = count;
-
-	return ret;
-}
-static DEVICE_ATTR_RW(polling_interval);
-
 static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
 			      const char *buf, size_t count)
 {
@@ -1698,6 +1716,53 @@ static ssize_t trans_stat_store(struct device *dev,
 }
 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,
+	&dev_attr_available_frequencies.attr,
+	&dev_attr_target_freq.attr,
+	&dev_attr_min_freq.attr,
+	&dev_attr_max_freq.attr,
+	&dev_attr_trans_stat.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(devfreq);
+
+static ssize_t polling_interval_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct devfreq *df = to_devfreq(dev);
+
+	if (!df->profile)
+		return -EINVAL;
+
+	return sprintf(buf, "%d\n", df->profile->polling_ms);
+}
+
+static ssize_t polling_interval_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct devfreq *df = to_devfreq(dev);
+	unsigned int value;
+	int ret;
+
+	if (!df->governor)
+		return -EINVAL;
+
+	ret = sscanf(buf, "%u", &value);
+	if (ret != 1)
+		return -EINVAL;
+
+	df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value);
+	ret = count;
+
+	return ret;
+}
+static DEVICE_ATTR_RW(polling_interval);
+
 static ssize_t timer_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
@@ -1761,21 +1826,36 @@ out:
 }
 static DEVICE_ATTR_RW(timer);
 
-static struct attribute *devfreq_attrs[] = {
-	&dev_attr_name.attr,
-	&dev_attr_governor.attr,
-	&dev_attr_available_governors.attr,
-	&dev_attr_cur_freq.attr,
-	&dev_attr_available_frequencies.attr,
-	&dev_attr_target_freq.attr,
-	&dev_attr_polling_interval.attr,
-	&dev_attr_min_freq.attr,
-	&dev_attr_max_freq.attr,
-	&dev_attr_trans_stat.attr,
-	&dev_attr_timer.attr,
-	NULL,
-};
-ATTRIBUTE_GROUPS(devfreq);
+#define CREATE_SYSFS_FILE(df, name)					\
+{									\
+	int ret;							\
+	ret = sysfs_create_file(&df->dev.kobj, &dev_attr_##name.attr);	\
+	if (ret < 0) {							\
+		dev_warn(&df->dev,					\
+			"Unable to create attr(%s)\n", "##name");	\
+	}								\
+}									\
+
+/* Create the specific sysfs files which depend on each governor. */
+static void create_sysfs_files(struct devfreq *devfreq,
+				const struct devfreq_governor *gov)
+{
+	if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))
+		CREATE_SYSFS_FILE(devfreq, polling_interval);
+	if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))
+		CREATE_SYSFS_FILE(devfreq, timer);
+}
+
+/* Remove the specific sysfs files which depend on each governor. */
+static void remove_sysfs_files(struct devfreq *devfreq,
+				const struct devfreq_governor *gov)
+{
+	if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))
+		sysfs_remove_file(&devfreq->dev.kobj,
+				&dev_attr_polling_interval.attr);
+	if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))
+		sysfs_remove_file(&devfreq->dev.kobj, &dev_attr_timer.attr);
+}
 
 /**
  * devfreq_summary_show() - Show the summary of the devfreq devices
@@ -1818,7 +1898,7 @@ static int devfreq_summary_show(struct seq_file *s, void *data)
 
 	list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
-		if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE,
+		if (!strncmp(devfreq->governor->name, DEVFREQ_GOV_PASSIVE,
 							DEVFREQ_NAME_LEN)) {
 			struct devfreq_passive_data *data = devfreq->data;
 
@@ -1832,15 +1912,19 @@ static int devfreq_summary_show(struct seq_file *s, void *data)
 		mutex_lock(&devfreq->lock);
 		cur_freq = devfreq->previous_freq;
 		get_freq_range(devfreq, &min_freq, &max_freq);
-		polling_ms = devfreq->profile->polling_ms;
 		timer = devfreq->profile->timer;
+
+		if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, POLLING_INTERVAL))
+			polling_ms = devfreq->profile->polling_ms;
+		else
+			polling_ms = 0;
 		mutex_unlock(&devfreq->lock);
 
 		seq_printf(s,
 			"%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n",
 			dev_name(&devfreq->dev),
 			p_devfreq ? dev_name(&p_devfreq->dev) : "null",
-			devfreq->governor_name,
+			devfreq->governor->name,
 			polling_ms ? timer_name[timer] : "null",
 			polling_ms,
 			cur_freq,