PM / devfreq: Move governor.h to a public header location

Some device drivers (and out-of-tree modules) might want to define
device-specific device governors. Rather than restricting all of them to
be a part of drivers/devfreq/ (which is not possible for out-of-tree
drivers anyway) move governor.h to include/linux/devfreq-governor.h and
update all drivers to use it.

The devfreq_cpu_data is only used internally, by the passive governor,
so it is moved to the driver source rather than being a part of the
public interface.

Reported-by: Robie Basak <robibasa@qti.qualcomm.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Link: https://patchwork.kernel.org/project/linux-pm/patch/20251030-governor-public-v2-1-432a11a9975a@oss.qualcomm.com/

1 files changed, 102 insertions, 0 deletions

diff --git a/include/linux/devfreq-governor.h b/include/linux/devfreq-governor.h
new file mode 100644
index 000000000000..dfdd0160a29f
--- /dev/null
+++ b/include/linux/devfreq-governor.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * governor.h - internal header for devfreq governors.
+ *
+ * Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This header is for devfreq governors
+ */
+
+#ifndef __LINUX_DEVFREQ_DEVFREQ_H__
+#define __LINUX_DEVFREQ_DEVFREQ_H__
+
+#include <linux/devfreq.h>
+
+#define DEVFREQ_NAME_LEN			16
+
+#define to_devfreq(DEV)	container_of((DEV), struct devfreq, dev)
+
+/* Devfreq events */
+#define DEVFREQ_GOV_START			0x1
+#define DEVFREQ_GOV_STOP			0x2
+#define DEVFREQ_GOV_UPDATE_INTERVAL		0x3
+#define DEVFREQ_GOV_SUSPEND			0x4
+#define DEVFREQ_GOV_RESUME			0x5
+
+#define DEVFREQ_MIN_FREQ			0
+#define DEVFREQ_MAX_FREQ			ULONG_MAX
+
+/*
+ * Definition of the governor feature flags
+ * - DEVFREQ_GOV_FLAG_IMMUTABLE
+ *   : This governor is never changeable to other governors.
+ * - DEVFREQ_GOV_FLAG_IRQ_DRIVEN
+ *   : The devfreq won't schedule the work for this governor.
+ */
+#define DEVFREQ_GOV_FLAG_IMMUTABLE			BIT(0)
+#define DEVFREQ_GOV_FLAG_IRQ_DRIVEN			BIT(1)
+
+/*
+ * Definition of governor attribute flags except for common sysfs attributes
+ * - DEVFREQ_GOV_ATTR_POLLING_INTERVAL
+ *   : Indicate polling_interval sysfs attribute
+ * - DEVFREQ_GOV_ATTR_TIMER
+ *   : Indicate timer sysfs attribute
+ */
+#define DEVFREQ_GOV_ATTR_POLLING_INTERVAL		BIT(0)
+#define DEVFREQ_GOV_ATTR_TIMER				BIT(1)
+
+/**
+ * struct devfreq_governor - Devfreq policy governor
+ * @node:		list node - contains registered devfreq governors
+ * @name:		Governor's name
+ * @attrs:		Governor's sysfs attribute flags
+ * @flags:		Governor's feature flags
+ * @get_target_freq:	Returns desired operating frequency for the device.
+ *			Basically, get_target_freq will run
+ *			devfreq_dev_profile.get_dev_status() to get the
+ *			status of the device (load = busy_time / total_time).
+ * @event_handler:      Callback for devfreq core framework to notify events
+ *                      to governors. Events include per device governor
+ *                      init and exit, opp changes out of devfreq, suspend
+ *                      and resume of per device devfreq during device idle.
+ *
+ * Note that the callbacks are called with devfreq->lock locked by devfreq.
+ */
+struct devfreq_governor {
+	struct list_head node;
+
+	const char name[DEVFREQ_NAME_LEN];
+	const u64 attrs;
+	const u64 flags;
+	int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
+	int (*event_handler)(struct devfreq *devfreq,
+				unsigned int event, void *data);
+};
+
+void devfreq_monitor_start(struct devfreq *devfreq);
+void devfreq_monitor_stop(struct devfreq *devfreq);
+void devfreq_monitor_suspend(struct devfreq *devfreq);
+void devfreq_monitor_resume(struct devfreq *devfreq);
+void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay);
+
+int devfreq_add_governor(struct devfreq_governor *governor);
+int devfreq_remove_governor(struct devfreq_governor *governor);
+
+int devm_devfreq_add_governor(struct device *dev,
+			      struct devfreq_governor *governor);
+
+int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
+int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
+void devfreq_get_freq_range(struct devfreq *devfreq, unsigned long *min_freq,
+			    unsigned long *max_freq);
+
+static inline int devfreq_update_stats(struct devfreq *df)
+{
+	if (!df->profile->get_dev_status)
+		return -EINVAL;
+
+	return df->profile->get_dev_status(df->dev.parent, &df->last_status);
+}
+#endif /* __LINUX_DEVFREQ_DEVFREQ_H__ */