perf/amlogic: Add support for Amlogic meson G12 SoC DDR PMU driver

Add support for Amlogic Meson G12 Series SOC - DDR bandwidth PMU driver
framework and interfaces. The PMU can not only monitor the total DDR
bandwidth, but also individual IP module bandwidth.

Signed-off-by: Jiucheng Xu <[e-mail]>
Tested-by: Chris Healy <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Will Deacon <[e-mail]>

MAINTAINERS

···
 F:	Documentation/hid/amd-sfh*
 F:	drivers/hid/amd-sfh-hid/
 
+AMLOGIC DDR PMU DRIVER
+M:	Jiucheng Xu <[e-mail]>
+L:	[e-mail]
+S:	Supported
+W:	http://www.amlogic.com
+F:	drivers/perf/amlogic/
+F:	include/soc/amlogic/
+
 AMPHION VPU CODEC V4L2 DRIVER
 M:	Ming Qian <[e-mail]>
 M:	Shijie Qin <[e-mail]>

drivers/perf/Kconfig

···
 
 source "drivers/perf/arm_cspmu/Kconfig"
 
+source "drivers/perf/amlogic/Kconfig"
+
 endmenu

drivers/perf/Makefile

···
 obj-$(CONFIG_APPLE_M1_CPU_PMU) += apple_m1_cpu_pmu.o
 obj-$(CONFIG_ALIBABA_UNCORE_DRW_PMU) += alibaba_uncore_drw_pmu.o
 obj-$(CONFIG_ARM_CORESIGHT_PMU_ARCH_SYSTEM_PMU) += arm_cspmu/
+obj-$(CONFIG_MESON_DDR_PMU) += amlogic/

drivers/perf/amlogic/Kconfig

···
+# SPDX-License-Identifier: GPL-2.0-only
+config MESON_DDR_PMU
+	tristate "Amlogic DDR Bandwidth Performance Monitor"
+	depends on ARCH_MESON || COMPILE_TEST
+	help
+          Provides support for the DDR performance monitor
+          in Amlogic SoCs, which can give information about
+          memory throughput and other related events. It
+          supports multiple channels to monitor the memory
+          bandwidth simultaneously.

drivers/perf/amlogic/Makefile

···
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_MESON_DDR_PMU) += meson_ddr_pmu_g12.o
+
+meson_ddr_pmu_g12-y	:= meson_ddr_pmu_core.o meson_g12_ddr_pmu.o

drivers/perf/amlogic/meson_ddr_pmu_core.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022 Amlogic, Inc. All rights reserved.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/init.h>
+#include <linux/irqreturn.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+#include <linux/version.h>
+
+#include <soc/amlogic/meson_ddr_pmu.h>
+
+struct ddr_pmu {
+	struct pmu pmu;
+	struct dmc_info info;
+	struct dmc_counter counters;	/* save counters from hw */
+	bool pmu_enabled;
+	struct device *dev;
+	char *name;
+	struct hlist_node node;
+	enum cpuhp_state cpuhp_state;
+	int cpu;			/* for cpu hotplug */
+};
+
+#define DDR_PERF_DEV_NAME "meson_ddr_bw"
+#define MAX_AXI_PORTS_OF_CHANNEL	4	/* A DMC channel can monitor max 4 axi ports */
+
+#define to_ddr_pmu(p)		container_of(p, struct ddr_pmu, pmu)
+#define dmc_info_to_pmu(p)	container_of(p, struct ddr_pmu, info)
+
+static void dmc_pmu_enable(struct ddr_pmu *pmu)
+{
+	if (!pmu->pmu_enabled)
+		pmu->info.hw_info->enable(&pmu->info);
+
+	pmu->pmu_enabled = true;
+}
+
+static void dmc_pmu_disable(struct ddr_pmu *pmu)
+{
+	if (pmu->pmu_enabled)
+		pmu->info.hw_info->disable(&pmu->info);
+
+	pmu->pmu_enabled = false;
+}
+
+static void meson_ddr_set_axi_filter(struct perf_event *event, u8 axi_id)
+{
+	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+	int chann;
+
+	if (event->attr.config > ALL_CHAN_COUNTER_ID &&
+	    event->attr.config < COUNTER_MAX_ID) {
+		chann = event->attr.config - CHAN1_COUNTER_ID;
+
+		pmu->info.hw_info->set_axi_filter(&pmu->info, axi_id, chann);
+	}
+}
+
+static void ddr_cnt_addition(struct dmc_counter *sum,
+			     struct dmc_counter *add1,
+			     struct dmc_counter *add2,
+			     int chann_nr)
+{
+	int i;
+	u64 cnt1, cnt2;
+
+	sum->all_cnt = add1->all_cnt + add2->all_cnt;
+	sum->all_req = add1->all_req + add2->all_req;
+	for (i = 0; i < chann_nr; i++) {
+		cnt1 = add1->channel_cnt[i];
+		cnt2 = add2->channel_cnt[i];
+
+		sum->channel_cnt[i] = cnt1 + cnt2;
+	}
+}
+
+static void meson_ddr_perf_event_update(struct perf_event *event)
+{
+	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+	u64 new_raw_count = 0;
+	struct dmc_counter dc = {0}, sum_dc = {0};
+	int idx;
+	int chann_nr = pmu->info.hw_info->chann_nr;
+
+	/* get the remain counters in register. */
+	pmu->info.hw_info->get_counters(&pmu->info, &dc);
+
+	ddr_cnt_addition(&sum_dc, &pmu->counters, &dc, chann_nr);
+
+	switch (event->attr.config) {
+	case ALL_CHAN_COUNTER_ID:
+		new_raw_count = sum_dc.all_cnt;
+		break;
+	case CHAN1_COUNTER_ID:
+	case CHAN2_COUNTER_ID:
+	case CHAN3_COUNTER_ID:
+	case CHAN4_COUNTER_ID:
+	case CHAN5_COUNTER_ID:
+	case CHAN6_COUNTER_ID:
+	case CHAN7_COUNTER_ID:
+	case CHAN8_COUNTER_ID:
+		idx = event->attr.config - CHAN1_COUNTER_ID;
+		new_raw_count = sum_dc.channel_cnt[idx];
+		break;
+	}
+
+	local64_set(&event->count, new_raw_count);
+}
+
+static int meson_ddr_perf_event_init(struct perf_event *event)
+{
+	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+	u64 config1 = event->attr.config1;
+	u64 config2 = event->attr.config2;
+
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
+		return -EOPNOTSUPP;
+
+	if (event->cpu < 0)
+		return -EOPNOTSUPP;
+
+	/* check if the number of parameters is too much */
+	if (event->attr.config != ALL_CHAN_COUNTER_ID &&
+	    hweight64(config1) + hweight64(config2) > MAX_AXI_PORTS_OF_CHANNEL)
+		return -EOPNOTSUPP;
+
+	event->cpu = pmu->cpu;
+
+	return 0;
+}
+
+static void meson_ddr_perf_event_start(struct perf_event *event, int flags)
+{
+	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+
+	memset(&pmu->counters, 0, sizeof(pmu->counters));
+	dmc_pmu_enable(pmu);
+}
+
+static int meson_ddr_perf_event_add(struct perf_event *event, int flags)
+{
+	u64 config1 = event->attr.config1;
+	u64 config2 = event->attr.config2;
+	int i;
+
+	for_each_set_bit(i, (const unsigned long *)&config1, sizeof(config1))
+		meson_ddr_set_axi_filter(event, i);
+
+	for_each_set_bit(i, (const unsigned long *)&config2, sizeof(config2))
+		meson_ddr_set_axi_filter(event, i + 64);
+
+	if (flags & PERF_EF_START)
+		meson_ddr_perf_event_start(event, flags);
+
+	return 0;
+}
+
+static void meson_ddr_perf_event_stop(struct perf_event *event, int flags)
+{
+	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+
+	if (flags & PERF_EF_UPDATE)
+		meson_ddr_perf_event_update(event);
+
+	dmc_pmu_disable(pmu);
+}
+
+static void meson_ddr_perf_event_del(struct perf_event *event, int flags)
+{
+	meson_ddr_perf_event_stop(event, PERF_EF_UPDATE);
+}
+
+static ssize_t meson_ddr_perf_cpumask_show(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct ddr_pmu *pmu = dev_get_drvdata(dev);
+
+	return cpumap_print_to_pagebuf(true, buf, cpumask_of(pmu->cpu));
+}
+
+static struct device_attribute meson_ddr_perf_cpumask_attr =
+__ATTR(cpumask, 0444, meson_ddr_perf_cpumask_show, NULL);
+
+static struct attribute *meson_ddr_perf_cpumask_attrs[] = {
+	&meson_ddr_perf_cpumask_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ddr_perf_cpumask_attr_group = {
+	.attrs = meson_ddr_perf_cpumask_attrs,
+};
+
+static ssize_t
+pmu_event_show(struct device *dev, struct device_attribute *attr,
+	       char *page)
+{
+	struct perf_pmu_events_attr *pmu_attr;
+
+	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
+	return sysfs_emit(page, "event=0x%02llx\n", pmu_attr->id);
+}
+
+static ssize_t
+event_show_unit(struct device *dev, struct device_attribute *attr,
+		char *page)
+{
+	return sysfs_emit(page, "MB\n");
+}
+
+static ssize_t
+event_show_scale(struct device *dev, struct device_attribute *attr,
+		 char *page)
+{
+	/* one count = 16byte = 1.52587890625e-05 MB */
+	return sysfs_emit(page, "1.52587890625e-05\n");
+}
+
+#define AML_DDR_PMU_EVENT_ATTR(_name, _id)				\
+{									\
+	.attr = __ATTR(_name, 0444, pmu_event_show, NULL),		\
+	.id = _id,							\
+}
+
+#define AML_DDR_PMU_EVENT_UNIT_ATTR(_name)				\
+	__ATTR(_name.unit, 0444, event_show_unit, NULL)
+
+#define AML_DDR_PMU_EVENT_SCALE_ATTR(_name)				\
+	__ATTR(_name.scale, 0444, event_show_scale, NULL)
+
+static struct device_attribute event_unit_attrs[] = {
+	AML_DDR_PMU_EVENT_UNIT_ATTR(total_rw_bytes),
+	AML_DDR_PMU_EVENT_UNIT_ATTR(chan_1_rw_bytes),
+	AML_DDR_PMU_EVENT_UNIT_ATTR(chan_2_rw_bytes),
+	AML_DDR_PMU_EVENT_UNIT_ATTR(chan_3_rw_bytes),
+	AML_DDR_PMU_EVENT_UNIT_ATTR(chan_4_rw_bytes),
+	AML_DDR_PMU_EVENT_UNIT_ATTR(chan_5_rw_bytes),
+	AML_DDR_PMU_EVENT_UNIT_ATTR(chan_6_rw_bytes),
+	AML_DDR_PMU_EVENT_UNIT_ATTR(chan_7_rw_bytes),
+	AML_DDR_PMU_EVENT_UNIT_ATTR(chan_8_rw_bytes),
+};
+
+static struct device_attribute event_scale_attrs[] = {
+	AML_DDR_PMU_EVENT_SCALE_ATTR(total_rw_bytes),
+	AML_DDR_PMU_EVENT_SCALE_ATTR(chan_1_rw_bytes),
+	AML_DDR_PMU_EVENT_SCALE_ATTR(chan_2_rw_bytes),
+	AML_DDR_PMU_EVENT_SCALE_ATTR(chan_3_rw_bytes),
+	AML_DDR_PMU_EVENT_SCALE_ATTR(chan_4_rw_bytes),
+	AML_DDR_PMU_EVENT_SCALE_ATTR(chan_5_rw_bytes),
+	AML_DDR_PMU_EVENT_SCALE_ATTR(chan_6_rw_bytes),
+	AML_DDR_PMU_EVENT_SCALE_ATTR(chan_7_rw_bytes),
+	AML_DDR_PMU_EVENT_SCALE_ATTR(chan_8_rw_bytes),
+};
+
+static struct perf_pmu_events_attr event_attrs[] = {
+	AML_DDR_PMU_EVENT_ATTR(total_rw_bytes, ALL_CHAN_COUNTER_ID),
+	AML_DDR_PMU_EVENT_ATTR(chan_1_rw_bytes, CHAN1_COUNTER_ID),
+	AML_DDR_PMU_EVENT_ATTR(chan_2_rw_bytes, CHAN2_COUNTER_ID),
+	AML_DDR_PMU_EVENT_ATTR(chan_3_rw_bytes, CHAN3_COUNTER_ID),
+	AML_DDR_PMU_EVENT_ATTR(chan_4_rw_bytes, CHAN4_COUNTER_ID),
+	AML_DDR_PMU_EVENT_ATTR(chan_5_rw_bytes, CHAN5_COUNTER_ID),
+	AML_DDR_PMU_EVENT_ATTR(chan_6_rw_bytes, CHAN6_COUNTER_ID),
+	AML_DDR_PMU_EVENT_ATTR(chan_7_rw_bytes, CHAN7_COUNTER_ID),
+	AML_DDR_PMU_EVENT_ATTR(chan_8_rw_bytes, CHAN8_COUNTER_ID),
+};
+
+/* three attrs are combined an event */
+static struct attribute *ddr_perf_events_attrs[COUNTER_MAX_ID * 3];
+
+static struct attribute_group ddr_perf_events_attr_group = {
+	.name = "events",
+	.attrs = ddr_perf_events_attrs,
+};
+
+static umode_t meson_ddr_perf_format_attr_visible(struct kobject *kobj,
+						  struct attribute *attr,
+						  int n)
+{
+	struct pmu *pmu = dev_get_drvdata(kobj_to_dev(kobj));
+	struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
+	const u64 *capability = ddr_pmu->info.hw_info->capability;
+	struct device_attribute *dev_attr;
+	int id;
+	char value[20]; // config1:xxx, 20 is enough
+
+	dev_attr = container_of(attr, struct device_attribute, attr);
+	dev_attr->show(NULL, NULL, value);
+
+	if (sscanf(value, "config1:%d", &id) == 1)
+		return capability[0] & (1ULL << id) ? attr->mode : 0;
+
+	if (sscanf(value, "config2:%d", &id) == 1)
+		return capability[1] & (1ULL << id) ? attr->mode : 0;
+
+	return attr->mode;
+}
+
+static struct attribute_group ddr_perf_format_attr_group = {
+	.name = "format",
+	.is_visible = meson_ddr_perf_format_attr_visible,
+};
+
+static ssize_t meson_ddr_perf_identifier_show(struct device *dev,
+					      struct device_attribute *attr,
+					      char *page)
+{
+	struct ddr_pmu *pmu = dev_get_drvdata(dev);
+
+	return sysfs_emit(page, "%s\n", pmu->name);
+}
+
+static struct device_attribute meson_ddr_perf_identifier_attr =
+__ATTR(identifier, 0444, meson_ddr_perf_identifier_show, NULL);
+
+static struct attribute *meson_ddr_perf_identifier_attrs[] = {
+	&meson_ddr_perf_identifier_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ddr_perf_identifier_attr_group = {
+	.attrs = meson_ddr_perf_identifier_attrs,
+};
+
+static const struct attribute_group *attr_groups[] = {
+	&ddr_perf_events_attr_group,
+	&ddr_perf_format_attr_group,
+	&ddr_perf_cpumask_attr_group,
+	&ddr_perf_identifier_attr_group,
+	NULL,
+};
+
+static irqreturn_t dmc_irq_handler(int irq, void *dev_id)
+{
+	struct dmc_info *info = dev_id;
+	struct ddr_pmu *pmu;
+	struct dmc_counter counters, *sum_cnter;
+	int i;
+
+	pmu = dmc_info_to_pmu(info);
+
+	if (info->hw_info->irq_handler(info, &counters) != 0)
+		goto out;
+
+	sum_cnter = &pmu->counters;
+	sum_cnter->all_cnt += counters.all_cnt;
+	sum_cnter->all_req += counters.all_req;
+
+	for (i = 0; i < pmu->info.hw_info->chann_nr; i++)
+		sum_cnter->channel_cnt[i] += counters.channel_cnt[i];
+
+	if (pmu->pmu_enabled)
+		/*
+		 * the timer interrupt only supprt
+		 * one shot mode, we have to re-enable
+		 * it in ISR to support continue mode.
+		 */
+		info->hw_info->enable(info);
+
+	dev_dbg(pmu->dev, "counts: %llu %llu %llu, %llu, %llu, %llu\t\t"
+			"sum: %llu %llu %llu, %llu, %llu, %llu\n",
+			counters.all_req,
+			counters.all_cnt,
+			counters.channel_cnt[0],
+			counters.channel_cnt[1],
+			counters.channel_cnt[2],
+			counters.channel_cnt[3],
+
+			pmu->counters.all_req,
+			pmu->counters.all_cnt,
+			pmu->counters.channel_cnt[0],
+			pmu->counters.channel_cnt[1],
+			pmu->counters.channel_cnt[2],
+			pmu->counters.channel_cnt[3]);
+out:
+	return IRQ_HANDLED;
+}
+
+static int ddr_perf_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+	struct ddr_pmu *pmu = hlist_entry_safe(node, struct ddr_pmu, node);
+	int target;
+
+	if (cpu != pmu->cpu)
+		return 0;
+
+	target = cpumask_any_but(cpu_online_mask, cpu);
+	if (target >= nr_cpu_ids)
+		return 0;
+
+	perf_pmu_migrate_context(&pmu->pmu, cpu, target);
+	pmu->cpu = target;
+
+	WARN_ON(irq_set_affinity(pmu->info.irq_num, cpumask_of(pmu->cpu)));
+
+	return 0;
+}
+
+static void fill_event_attr(struct ddr_pmu *pmu)
+{
+	int i, j, k;
+	struct attribute **dst = ddr_perf_events_attrs;
+
+	j = 0;
+	k = 0;
+
+	/* fill ALL_CHAN_COUNTER_ID event */
+	dst[j++] = &event_attrs[k].attr.attr;
+	dst[j++] = &event_unit_attrs[k].attr;
+	dst[j++] = &event_scale_attrs[k].attr;
+
+	k++;
+
+	/* fill each channel event */
+	for (i = 0; i < pmu->info.hw_info->chann_nr; i++, k++) {
+		dst[j++] = &event_attrs[k].attr.attr;
+		dst[j++] = &event_unit_attrs[k].attr;
+		dst[j++] = &event_scale_attrs[k].attr;
+	}
+
+	dst[j] = NULL; /* mark end */
+}
+
+static void fmt_attr_fill(struct attribute **fmt_attr)
+{
+	ddr_perf_format_attr_group.attrs = fmt_attr;
+}
+
+static int ddr_pmu_parse_dt(struct platform_device *pdev,
+			    struct dmc_info *info)
+{
+	void __iomem *base;
+	int i, ret;
+
+	info->hw_info = of_device_get_match_data(&pdev->dev);
+
+	for (i = 0; i < info->hw_info->dmc_nr; i++) {
+		/* resource 0 for ddr register base */
+		base = devm_platform_ioremap_resource(pdev, i);
+		if (IS_ERR(base))
+			return PTR_ERR(base);
+
+		info->ddr_reg[i] = base;
+	}
+
+	/* resource i for pll register base */
+	base = devm_platform_ioremap_resource(pdev, i);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	info->pll_reg = base;
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+
+	info->irq_num = ret;
+
+	ret = devm_request_irq(&pdev->dev, info->irq_num, dmc_irq_handler,
+			       IRQF_NOBALANCING, dev_name(&pdev->dev),
+			       (void *)info);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+int meson_ddr_pmu_create(struct platform_device *pdev)
+{
+	int ret;
+	char *name;
+	struct ddr_pmu *pmu;
+
+	pmu = devm_kzalloc(&pdev->dev, sizeof(struct ddr_pmu), GFP_KERNEL);
+	if (!pmu)
+		return -ENOMEM;
+
+	*pmu = (struct ddr_pmu) {
+		.pmu = {
+			.module		= THIS_MODULE,
+			.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
+			.task_ctx_nr	= perf_invalid_context,
+			.attr_groups	= attr_groups,
+			.event_init	= meson_ddr_perf_event_init,
+			.add		= meson_ddr_perf_event_add,
+			.del		= meson_ddr_perf_event_del,
+			.start		= meson_ddr_perf_event_start,
+			.stop		= meson_ddr_perf_event_stop,
+			.read		= meson_ddr_perf_event_update,
+		},
+	};
+
+	ret = ddr_pmu_parse_dt(pdev, &pmu->info);
+	if (ret < 0)
+		return ret;
+
+	fmt_attr_fill(pmu->info.hw_info->fmt_attr);
+
+	pmu->cpu = smp_processor_id();
+
+	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME);
+	if (!name)
+		return -ENOMEM;
+
+	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, name, NULL,
+				      ddr_perf_offline_cpu);
+	if (ret < 0)
+		return ret;
+
+	pmu->cpuhp_state = ret;
+
+	/* Register the pmu instance for cpu hotplug */
+	ret = cpuhp_state_add_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+	if (ret)
+		goto cpuhp_instance_err;
+
+	fill_event_attr(pmu);
+
+	ret = perf_pmu_register(&pmu->pmu, name, -1);
+	if (ret)
+		goto pmu_register_err;
+
+	pmu->name = name;
+	pmu->dev = &pdev->dev;
+	pmu->pmu_enabled = false;
+
+	platform_set_drvdata(pdev, pmu);
+
+	return 0;
+
+pmu_register_err:
+	cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+
+cpuhp_instance_err:
+	cpuhp_remove_state(pmu->cpuhp_state);
+
+	return ret;
+}
+
+int meson_ddr_pmu_remove(struct platform_device *pdev)
+{
+	struct ddr_pmu *pmu = platform_get_drvdata(pdev);
+
+	perf_pmu_unregister(&pmu->pmu);
+	cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+	cpuhp_remove_state(pmu->cpuhp_state);
+
+	return 0;
+}

drivers/perf/amlogic/meson_g12_ddr_pmu.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022 Amlogic, Inc. All rights reserved.
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+#include <linux/version.h>
+
+#include <soc/amlogic/meson_ddr_pmu.h>
+
+#define PORT_MAJOR		32
+#define DEFAULT_XTAL_FREQ	24000000UL
+
+#define DMC_QOS_IRQ		BIT(30)
+
+/* DMC bandwidth monitor register address offset */
+#define DMC_MON_G12_CTRL0		(0x20  << 2)
+#define DMC_MON_G12_CTRL1		(0x21  << 2)
+#define DMC_MON_G12_CTRL2		(0x22  << 2)
+#define DMC_MON_G12_CTRL3		(0x23  << 2)
+#define DMC_MON_G12_CTRL4		(0x24  << 2)
+#define DMC_MON_G12_CTRL5		(0x25  << 2)
+#define DMC_MON_G12_CTRL6		(0x26  << 2)
+#define DMC_MON_G12_CTRL7		(0x27  << 2)
+#define DMC_MON_G12_CTRL8		(0x28  << 2)
+
+#define DMC_MON_G12_ALL_REQ_CNT		(0x29  << 2)
+#define DMC_MON_G12_ALL_GRANT_CNT	(0x2a  << 2)
+#define DMC_MON_G12_ONE_GRANT_CNT	(0x2b  << 2)
+#define DMC_MON_G12_SEC_GRANT_CNT	(0x2c  << 2)
+#define DMC_MON_G12_THD_GRANT_CNT	(0x2d  << 2)
+#define DMC_MON_G12_FOR_GRANT_CNT	(0x2e  << 2)
+#define DMC_MON_G12_TIMER		(0x2f  << 2)
+
+/* Each bit represent a axi line */
+PMU_FORMAT_ATTR(event, "config:0-7");
+PMU_FORMAT_ATTR(arm, "config1:0");
+PMU_FORMAT_ATTR(gpu, "config1:1");
+PMU_FORMAT_ATTR(pcie, "config1:2");
+PMU_FORMAT_ATTR(hdcp, "config1:3");
+PMU_FORMAT_ATTR(hevc_front, "config1:4");
+PMU_FORMAT_ATTR(usb3_0, "config1:6");
+PMU_FORMAT_ATTR(device, "config1:7");
+PMU_FORMAT_ATTR(hevc_back, "config1:8");
+PMU_FORMAT_ATTR(h265enc, "config1:9");
+PMU_FORMAT_ATTR(vpu_read1, "config1:16");
+PMU_FORMAT_ATTR(vpu_read2, "config1:17");
+PMU_FORMAT_ATTR(vpu_read3, "config1:18");
+PMU_FORMAT_ATTR(vpu_write1, "config1:19");
+PMU_FORMAT_ATTR(vpu_write2, "config1:20");
+PMU_FORMAT_ATTR(vdec, "config1:21");
+PMU_FORMAT_ATTR(hcodec, "config1:22");
+PMU_FORMAT_ATTR(ge2d, "config1:23");
+
+PMU_FORMAT_ATTR(spicc1, "config1:32");
+PMU_FORMAT_ATTR(usb0, "config1:33");
+PMU_FORMAT_ATTR(dma, "config1:34");
+PMU_FORMAT_ATTR(arb0, "config1:35");
+PMU_FORMAT_ATTR(sd_emmc_b, "config1:36");
+PMU_FORMAT_ATTR(usb1, "config1:37");
+PMU_FORMAT_ATTR(audio, "config1:38");
+PMU_FORMAT_ATTR(aififo, "config1:39");
+PMU_FORMAT_ATTR(parser, "config1:41");
+PMU_FORMAT_ATTR(ao_cpu, "config1:42");
+PMU_FORMAT_ATTR(sd_emmc_c, "config1:43");
+PMU_FORMAT_ATTR(spicc2, "config1:44");
+PMU_FORMAT_ATTR(ethernet, "config1:45");
+PMU_FORMAT_ATTR(sana, "config1:46");
+
+/* for sm1 and g12b */
+PMU_FORMAT_ATTR(nna, "config1:10");
+
+/* for g12b only */
+PMU_FORMAT_ATTR(gdc, "config1:11");
+PMU_FORMAT_ATTR(mipi_isp, "config1:12");
+PMU_FORMAT_ATTR(arm1, "config1:13");
+PMU_FORMAT_ATTR(sd_emmc_a, "config1:40");
+
+static struct attribute *g12_pmu_format_attrs[] = {
+	&format_attr_event.attr,
+	&format_attr_arm.attr,
+	&format_attr_gpu.attr,
+	&format_attr_nna.attr,
+	&format_attr_gdc.attr,
+	&format_attr_arm1.attr,
+	&format_attr_mipi_isp.attr,
+	&format_attr_sd_emmc_a.attr,
+	&format_attr_pcie.attr,
+	&format_attr_hdcp.attr,
+	&format_attr_hevc_front.attr,
+	&format_attr_usb3_0.attr,
+	&format_attr_device.attr,
+	&format_attr_hevc_back.attr,
+	&format_attr_h265enc.attr,
+	&format_attr_vpu_read1.attr,
+	&format_attr_vpu_read2.attr,
+	&format_attr_vpu_read3.attr,
+	&format_attr_vpu_write1.attr,
+	&format_attr_vpu_write2.attr,
+	&format_attr_vdec.attr,
+	&format_attr_hcodec.attr,
+	&format_attr_ge2d.attr,
+	&format_attr_spicc1.attr,
+	&format_attr_usb0.attr,
+	&format_attr_dma.attr,
+	&format_attr_arb0.attr,
+	&format_attr_sd_emmc_b.attr,
+	&format_attr_usb1.attr,
+	&format_attr_audio.attr,
+	&format_attr_aififo.attr,
+	&format_attr_parser.attr,
+	&format_attr_ao_cpu.attr,
+	&format_attr_sd_emmc_c.attr,
+	&format_attr_spicc2.attr,
+	&format_attr_ethernet.attr,
+	&format_attr_sana.attr,
+	NULL,
+};
+
+/* calculate ddr clock */
+static unsigned long dmc_g12_get_freq_quick(struct dmc_info *info)
+{
+	unsigned int val;
+	unsigned int n, m, od1;
+	unsigned int od_div = 0xfff;
+	unsigned long freq = 0;
+
+	val = readl(info->pll_reg);
+	val = val & 0xfffff;
+	switch ((val >> 16) & 7) {
+	case 0:
+		od_div = 2;
+		break;
+
+	case 1:
+		od_div = 3;
+		break;
+
+	case 2:
+		od_div = 4;
+		break;
+
+	case 3:
+		od_div = 6;
+		break;
+
+	case 4:
+		od_div = 8;
+		break;
+
+	default:
+		break;
+	}
+
+	m = val & 0x1ff;
+	n = ((val >> 10) & 0x1f);
+	od1 = (((val >> 19) & 0x1)) == 1 ? 2 : 1;
+	freq = DEFAULT_XTAL_FREQ / 1000;        /* avoid overflow */
+	if (n)
+		freq = ((((freq * m) / n) >> od1) / od_div) * 1000;
+
+	return freq;
+}
+
+#ifdef DEBUG
+static void g12_dump_reg(struct dmc_info *db)
+{
+	int s = 0, i;
+	unsigned int r;
+
+	for (i = 0; i < 9; i++) {
+		r  = readl(db->ddr_reg[0] + (DMC_MON_G12_CTRL0 + (i << 2)));
+		pr_notice("DMC_MON_CTRL%d:        %08x\n", i, r);
+	}
+	r  = readl(db->ddr_reg[0] + DMC_MON_G12_ALL_REQ_CNT);
+	pr_notice("DMC_MON_ALL_REQ_CNT:  %08x\n", r);
+	r  = readl(db->ddr_reg[0] + DMC_MON_G12_ALL_GRANT_CNT);
+	pr_notice("DMC_MON_ALL_GRANT_CNT:%08x\n", r);
+	r  = readl(db->ddr_reg[0] + DMC_MON_G12_ONE_GRANT_CNT);
+	pr_notice("DMC_MON_ONE_GRANT_CNT:%08x\n", r);
+	r  = readl(db->ddr_reg[0] + DMC_MON_G12_SEC_GRANT_CNT);
+	pr_notice("DMC_MON_SEC_GRANT_CNT:%08x\n", r);
+	r  = readl(db->ddr_reg[0] + DMC_MON_G12_THD_GRANT_CNT);
+	pr_notice("DMC_MON_THD_GRANT_CNT:%08x\n", r);
+	r  = readl(db->ddr_reg[0] + DMC_MON_G12_FOR_GRANT_CNT);
+	pr_notice("DMC_MON_FOR_GRANT_CNT:%08x\n", r);
+	r  = readl(db->ddr_reg[0] + DMC_MON_G12_TIMER);
+	pr_notice("DMC_MON_TIMER:        %08x\n", r);
+}
+#endif
+
+static void dmc_g12_counter_enable(struct dmc_info *info)
+{
+	unsigned int val;
+	unsigned long clock_count = dmc_g12_get_freq_quick(info) / 10; /* 100ms */
+
+	writel(clock_count, info->ddr_reg[0] + DMC_MON_G12_TIMER);
+
+	val = readl(info->ddr_reg[0] + DMC_MON_G12_CTRL0);
+
+	/* enable all channel */
+	val =  BIT(31) |	/* enable bit */
+	       BIT(20) |	/* use timer  */
+	       0x0f;		/* 4 channels */
+
+	writel(val, info->ddr_reg[0] + DMC_MON_G12_CTRL0);
+
+#ifdef DEBUG
+	g12_dump_reg(info);
+#endif
+}
+
+static void dmc_g12_config_fiter(struct dmc_info *info,
+				 int port, int channel)
+{
+	u32 val;
+	u32 rp[MAX_CHANNEL_NUM] = {DMC_MON_G12_CTRL1, DMC_MON_G12_CTRL3,
+					DMC_MON_G12_CTRL5, DMC_MON_G12_CTRL7};
+	u32 rs[MAX_CHANNEL_NUM] = {DMC_MON_G12_CTRL2, DMC_MON_G12_CTRL4,
+					DMC_MON_G12_CTRL6, DMC_MON_G12_CTRL8};
+	int subport = -1;
+
+	/* clear all port mask */
+	if (port < 0) {
+		writel(0, info->ddr_reg[0] + rp[channel]);
+		writel(0, info->ddr_reg[0] + rs[channel]);
+		return;
+	}
+
+	if (port >= PORT_MAJOR)
+		subport = port - PORT_MAJOR;
+
+	if (subport < 0) {
+		val = readl(info->ddr_reg[0] + rp[channel]);
+		val |=  (1 << port);
+		writel(val, info->ddr_reg[0] + rp[channel]);
+		val = 0xffff;
+		writel(val, info->ddr_reg[0] + rs[channel]);
+	} else {
+		val = BIT(23);		/* select device */
+		writel(val, info->ddr_reg[0] + rp[channel]);
+		val = readl(info->ddr_reg[0] + rs[channel]);
+		val |= (1 << subport);
+		writel(val, info->ddr_reg[0] + rs[channel]);
+	}
+}
+
+static void dmc_g12_set_axi_filter(struct dmc_info *info, int axi_id, int channel)
+{
+	if (channel > info->hw_info->chann_nr)
+		return;
+
+	dmc_g12_config_fiter(info, axi_id, channel);
+}
+
+static void dmc_g12_counter_disable(struct dmc_info *info)
+{
+	int i;
+
+	/* clear timer */
+	writel(0, info->ddr_reg[0] + DMC_MON_G12_CTRL0);
+	writel(0, info->ddr_reg[0] + DMC_MON_G12_TIMER);
+
+	writel(0, info->ddr_reg[0] + DMC_MON_G12_ALL_REQ_CNT);
+	writel(0, info->ddr_reg[0] + DMC_MON_G12_ALL_GRANT_CNT);
+	writel(0, info->ddr_reg[0] + DMC_MON_G12_ONE_GRANT_CNT);
+	writel(0, info->ddr_reg[0] + DMC_MON_G12_SEC_GRANT_CNT);
+	writel(0, info->ddr_reg[0] + DMC_MON_G12_THD_GRANT_CNT);
+	writel(0, info->ddr_reg[0] + DMC_MON_G12_FOR_GRANT_CNT);
+
+	/* clear port channel mapping */
+	for (i = 0; i < info->hw_info->chann_nr; i++)
+		dmc_g12_config_fiter(info, -1, i);
+}
+
+static void dmc_g12_get_counters(struct dmc_info *info,
+				 struct dmc_counter *counter)
+{
+	int i;
+	unsigned int reg;
+
+	counter->all_cnt = readl(info->ddr_reg[0] + DMC_MON_G12_ALL_GRANT_CNT);
+	counter->all_req   = readl(info->ddr_reg[0] + DMC_MON_G12_ALL_REQ_CNT);
+
+	for (i = 0; i < info->hw_info->chann_nr; i++) {
+		reg = DMC_MON_G12_ONE_GRANT_CNT + (i << 2);
+		counter->channel_cnt[i] = readl(info->ddr_reg[0] + reg);
+	}
+}
+
+static int dmc_g12_irq_handler(struct dmc_info *info,
+			       struct dmc_counter *counter)
+{
+	unsigned int val;
+	int ret = -EINVAL;
+
+	val = readl(info->ddr_reg[0] + DMC_MON_G12_CTRL0);
+	if (val & DMC_QOS_IRQ) {
+		dmc_g12_get_counters(info, counter);
+		/* clear irq flags */
+		writel(val, info->ddr_reg[0] + DMC_MON_G12_CTRL0);
+		ret = 0;
+	}
+	return ret;
+}
+
+static const struct dmc_hw_info g12a_dmc_info = {
+	.enable		= dmc_g12_counter_enable,
+	.disable	= dmc_g12_counter_disable,
+	.irq_handler	= dmc_g12_irq_handler,
+	.get_counters	= dmc_g12_get_counters,
+	.set_axi_filter	= dmc_g12_set_axi_filter,
+
+	.dmc_nr = 1,
+	.chann_nr = 4,
+	.capability = {0X7EFF00FF03DF, 0},
+	.fmt_attr = g12_pmu_format_attrs,
+};
+
+static const struct dmc_hw_info g12b_dmc_info = {
+	.enable		= dmc_g12_counter_enable,
+	.disable	= dmc_g12_counter_disable,
+	.irq_handler	= dmc_g12_irq_handler,
+	.get_counters	= dmc_g12_get_counters,
+	.set_axi_filter	= dmc_g12_set_axi_filter,
+
+	.dmc_nr = 1,
+	.chann_nr = 4,
+	.capability = {0X7FFF00FF3FDF, 0},
+	.fmt_attr = g12_pmu_format_attrs,
+};
+
+static const struct dmc_hw_info sm1_dmc_info = {
+	.enable		= dmc_g12_counter_enable,
+	.disable	= dmc_g12_counter_disable,
+	.irq_handler	= dmc_g12_irq_handler,
+	.get_counters	= dmc_g12_get_counters,
+	.set_axi_filter	= dmc_g12_set_axi_filter,
+
+	.dmc_nr = 1,
+	.chann_nr = 4,
+	.capability = {0X7EFF00FF07DF, 0},
+	.fmt_attr = g12_pmu_format_attrs,
+};
+
+static int g12_ddr_pmu_probe(struct platform_device *pdev)
+{
+	return meson_ddr_pmu_create(pdev);
+}
+
+static int g12_ddr_pmu_remove(struct platform_device *pdev)
+{
+	meson_ddr_pmu_remove(pdev);
+
+	return 0;
+}
+
+static const struct of_device_id meson_ddr_pmu_dt_match[] = {
+	{
+		.compatible = "amlogic,g12a-ddr-pmu",
+		.data = &g12a_dmc_info,
+	},
+	{
+		.compatible = "amlogic,g12b-ddr-pmu",
+		.data = &g12b_dmc_info,
+	},
+	{
+		.compatible = "amlogic,sm1-ddr-pmu",
+		.data = &sm1_dmc_info,
+	},
+	{}
+};
+
+static struct platform_driver g12_ddr_pmu_driver = {
+	.probe = g12_ddr_pmu_probe,
+	.remove = g12_ddr_pmu_remove,
+
+	.driver = {
+		.name = "meson-g12-ddr-pmu",
+		.of_match_table = meson_ddr_pmu_dt_match,
+	},
+};
+
+module_platform_driver(g12_ddr_pmu_driver);
+MODULE_AUTHOR("Jiucheng Xu");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Amlogic G12 series SoC DDR PMU");

include/soc/amlogic/meson_ddr_pmu.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2022 Amlogic, Inc. All rights reserved.
+ */
+
+#ifndef __MESON_DDR_PMU_H__
+#define __MESON_DDR_PMU_H__
+
+#define MAX_CHANNEL_NUM		8
+
+enum {
+	ALL_CHAN_COUNTER_ID,
+	CHAN1_COUNTER_ID,
+	CHAN2_COUNTER_ID,
+	CHAN3_COUNTER_ID,
+	CHAN4_COUNTER_ID,
+	CHAN5_COUNTER_ID,
+	CHAN6_COUNTER_ID,
+	CHAN7_COUNTER_ID,
+	CHAN8_COUNTER_ID,
+	COUNTER_MAX_ID,
+};
+
+struct dmc_info;
+
+struct dmc_counter {
+	u64 all_cnt;	/* The count of all requests come in/out ddr controller */
+	union {
+		u64 all_req;
+		struct {
+			u64 all_idle_cnt;
+			u64 all_16bit_cnt;
+		};
+	};
+	u64 channel_cnt[MAX_CHANNEL_NUM]; /* To save a DMC bandwidth-monitor channel counter */
+};
+
+struct dmc_hw_info {
+	void (*enable)(struct dmc_info *info);
+	void (*disable)(struct dmc_info *info);
+	/* Bind an axi line to a bandwidth-monitor channel */
+	void (*set_axi_filter)(struct dmc_info *info, int axi_id, int chann);
+	int (*irq_handler)(struct dmc_info *info,
+			   struct dmc_counter *counter);
+	void (*get_counters)(struct dmc_info *info,
+			     struct dmc_counter *counter);
+
+	int dmc_nr;			/* The number of dmc controller */
+	int chann_nr;			/* The number of dmc bandwidth monitor channels */
+	struct attribute **fmt_attr;
+	const u64 capability[2];
+};
+
+struct dmc_info {
+	const struct dmc_hw_info *hw_info;
+
+	void __iomem *ddr_reg[4];
+	unsigned long timer_value;	/* Timer value in TIMER register */
+	void __iomem *pll_reg;
+	int irq_num;			/* irq vector number */
+};
+
+int meson_ddr_pmu_create(struct platform_device *pdev);
+int meson_ddr_pmu_remove(struct platform_device *pdev);
+
+#endif /* __MESON_DDR_PMU_H__ */