arm_scmi: vendors: Qualcomm Generic Vendor Extensions

drivers/devfreq/Kconfig

@@ -56,6 +56,14 @@ config DEVFREQ_GOV_POWERSAVE
 	  the DEVFREQ framework returns the lowest frequency available
 	  at any time.
 
+config DEVFREQ_GOV_REMOTE
+	tristate "Remote"
+	help
+	  A simple governor to track the frequency of devices whose
+	  dvfs control lies outside the kernel. This governor acts
+	  as an observer and provides for ways to track frequency and
+	  set/get information related to the remote dvfs device.
+
 config DEVFREQ_GOV_USERSPACE
 	tristate "Userspace"
 	help
@@ -161,6 +169,19 @@ config ARM_SUN8I_A33_MBUS_DEVFREQ
 	  This adds the DEVFREQ driver for the MBUS controller in some
 	  Allwinner sun8i (A33 through H3) and sun50i (A64 and H5) SoCs.
 
+config SCMI_QCOM_MEMLAT_DEVFREQ
+	tristate "Qualcomm Technologies Inc. SCMI client driver"
+	depends on QCOM_SCMI_GENERIC_EXT || COMPILE_TEST
+	select DEVFREQ_GOV_REMOTE
+	help
+	  This driver uses the MEMLAT (memory latency) algorithm string
+	  hosted on QCOM SCMI Vendor Protocol to detect memory latency
+	  workloads and control frequency/level of the various memory
+	  buses (DDR/LLCC/DDR_QOS).
+
+	  This driver defines/documents the parameter IDs used while configuring
+	  the memory buses.
+
 source "drivers/devfreq/event/Kconfig"
 
 endif # PM_DEVFREQ

drivers/devfreq/Makefile

@@ -4,6 +4,7 @@ obj-$(CONFIG_PM_DEVFREQ_EVENT)	+= devfreq-event.o
 obj-$(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)	+= governor_simpleondemand.o
 obj-$(CONFIG_DEVFREQ_GOV_PERFORMANCE)	+= governor_performance.o
 obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE)	+= governor_powersave.o
+obj-$(CONFIG_DEVFREQ_GOV_REMOTE)	+= governor_remote.o
 obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
 obj-$(CONFIG_DEVFREQ_GOV_PASSIVE)	+= governor_passive.o
 
@@ -16,6 +17,7 @@ obj-$(CONFIG_ARM_MEDIATEK_CCI_DEVFREQ)	+= mtk-cci-devfreq.o
 obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ)	+= rk3399_dmc.o
 obj-$(CONFIG_ARM_SUN8I_A33_MBUS_DEVFREQ)	+= sun8i-a33-mbus.o
 obj-$(CONFIG_ARM_TEGRA_DEVFREQ)		+= tegra30-devfreq.o
+obj-$(CONFIG_SCMI_QCOM_MEMLAT_DEVFREQ)	+= scmi-qcom-memlat-devfreq.o
 
 # DEVFREQ Event Drivers
 obj-$(CONFIG_PM_DEVFREQ_EVENT)		+= event/

drivers/devfreq/devfreq.c

@@ -348,6 +348,10 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 	unsigned long cur_freq;
 	int err = 0;
 
+	/* Frequency already updated, update trans-stat info */
+	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, TRACK_REMOTE))
+		goto update_status;
+
 	if (devfreq->profile->get_cur_freq)
 		devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
 	else
@@ -375,6 +379,7 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 	freqs.new = new_freq;
 	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
 
+update_status:
 	if (devfreq_update_status(devfreq, new_freq))
 		dev_warn(&devfreq->dev,
 			 "Couldn't update frequency transition information.\n");
@@ -1562,6 +1567,10 @@ static ssize_t target_freq_show(struct device *dev,
 {
 	struct devfreq *df = to_devfreq(dev);
 
+	if (!df->profile || !df->governor ||
+	    !IS_SUPPORTED_ATTR(df->governor->attrs, TARGET_FREQ))
+		return -EINVAL;
+
 	return sprintf(buf, "%lu\n", df->previous_freq);
 }
 static DEVICE_ATTR_RO(target_freq);

drivers/devfreq/governor_passive.c

@@ -448,6 +448,7 @@ static int devfreq_passive_event_handler(struct devfreq *devfreq,
 
 static struct devfreq_governor devfreq_passive = {
 	.name = DEVFREQ_GOV_PASSIVE,
+	.attrs = DEVFREQ_GOV_ATTR_TARGET_FREQ,
 	.flags = DEVFREQ_GOV_FLAG_IMMUTABLE,
 	.get_target_freq = devfreq_passive_get_target_freq,
 	.event_handler = devfreq_passive_event_handler,

drivers/devfreq/governor_performance.c

@@ -37,6 +37,7 @@ static int devfreq_performance_handler(struct devfreq *devfreq,
 
 static struct devfreq_governor devfreq_performance = {
 	.name = DEVFREQ_GOV_PERFORMANCE,
+	.attrs = DEVFREQ_GOV_ATTR_TARGET_FREQ,
 	.get_target_freq = devfreq_performance_func,
 	.event_handler = devfreq_performance_handler,
 };

drivers/devfreq/governor_powersave.c

@@ -37,6 +37,7 @@ static int devfreq_powersave_handler(struct devfreq *devfreq,
 
 static struct devfreq_governor devfreq_powersave = {
 	.name = DEVFREQ_GOV_POWERSAVE,
+	.attrs = DEVFREQ_GOV_ATTR_TARGET_FREQ,
 	.get_target_freq = devfreq_powersave_func,
 	.event_handler = devfreq_powersave_handler,
 };

drivers/devfreq/governor_remote.c

@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/devfreq.h>
+#include <linux/devfreq-governor.h>
+
+static int devfreq_remote_track_func(struct devfreq *devfreq, unsigned long *freq)
+{
+	unsigned long cur_freq = 0;
+
+	if (devfreq->profile->get_cur_freq)
+		devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
+
+	*freq = cur_freq;
+
+	return 0;
+}
+
+static int devfreq_remote_track_handler(struct devfreq *devfreq, unsigned int event, void *data)
+{
+	switch (event) {
+	case DEVFREQ_GOV_START:
+		devfreq_monitor_start(devfreq);
+		break;
+
+	case DEVFREQ_GOV_STOP:
+		devfreq_monitor_stop(devfreq);
+		break;
+
+	case DEVFREQ_GOV_UPDATE_INTERVAL:
+		devfreq_update_interval(devfreq, (unsigned int *)data);
+		break;
+
+	case DEVFREQ_GOV_SUSPEND:
+		devfreq_monitor_suspend(devfreq);
+		break;
+
+	case DEVFREQ_GOV_RESUME:
+		devfreq_monitor_resume(devfreq);
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static struct devfreq_governor devfreq_remote_track = {
+	.name = DEVFREQ_GOV_REMOTE,
+	.attrs = DEVFREQ_GOV_ATTR_POLLING_INTERVAL
+		| DEVFREQ_GOV_ATTR_TIMER,
+	.flags = DEVFREQ_GOV_FLAG_IMMUTABLE
+		| DEVFREQ_GOV_FLAG_TRACK_REMOTE,
+	.get_target_freq = devfreq_remote_track_func,
+	.event_handler = devfreq_remote_track_handler,
+};
+
+static int __init devfreq_remote_track_init(void)
+{
+	return devfreq_add_governor(&devfreq_remote_track);
+}
+subsys_initcall(devfreq_remote_track_init);
+
+static void __exit devfreq_remote_track_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_remote_track);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+}
+module_exit(devfreq_remote_track_exit);
+
+MODULE_DESCRIPTION("DEVFREQ Remote Tracking governor");
+MODULE_LICENSE("GPL");

drivers/devfreq/governor_simpleondemand.c

@@ -118,6 +118,7 @@ static int devfreq_simple_ondemand_handler(struct devfreq *devfreq,
 static struct devfreq_governor devfreq_simple_ondemand = {
 	.name = DEVFREQ_GOV_SIMPLE_ONDEMAND,
 	.attrs = DEVFREQ_GOV_ATTR_POLLING_INTERVAL
+		| DEVFREQ_GOV_ATTR_TARGET_FREQ
 		| DEVFREQ_GOV_ATTR_TIMER,
 	.get_target_freq = devfreq_simple_ondemand_func,
 	.event_handler = devfreq_simple_ondemand_handler,

drivers/devfreq/governor_userspace.c

@@ -135,6 +135,7 @@ static int devfreq_userspace_handler(struct devfreq *devfreq,
 
 static struct devfreq_governor devfreq_userspace = {
 	.name = DEVFREQ_GOV_USERSPACE,
+	.attrs = DEVFREQ_GOV_ATTR_TARGET_FREQ,
 	.get_target_freq = devfreq_userspace_func,
 	.event_handler = devfreq_userspace_handler,
 };

drivers/devfreq/hisi_uncore_freq.c

@@ -399,6 +399,7 @@ static struct devfreq_governor hisi_platform_governor = {
 	 * Set interrupt_driven to skip the devfreq monitor mechanism, though
 	 * this governor is not interrupt-driven.
 	 */
+	.attrs = DEVFREQ_GOV_ATTR_TARGET_FREQ,
 	.flags = DEVFREQ_GOV_FLAG_IRQ_DRIVEN,
 	.get_target_freq = hisi_platform_gov_func,
 	.event_handler = hisi_platform_gov_handler,