PM / devfreq: event: Add new Exynos NoC probe driver

This patch adds NoC (Network on Chip) Probe driver which provides
the primitive values to get the performance data. The packets that the Network
on Chip (NoC) probes detects are transported over the network infrastructure.
Exynos542x bus has multiple NoC probes to provide bandwidth information about
behavior of the SoC that you can use while analyzing system performance.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Markus Reichl <m.reichl@fivetechno.de>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

Documentation/devicetree/bindings/devfreq/event/exynos-nocp.txt

@@ -0,0 +1,26 @@
+
+* Samsung Exynos NoC (Network on Chip) Probe device
+
+The Samsung Exynos542x SoC has NoC (Network on Chip) Probe for NoC bus.
+NoC provides the primitive values to get the performance data. The packets
+that the Network on Chip (NoC) probes detects are transported over
+the network infrastructure to observer units. You can configure probes to
+capture packets with header or data on the data request response network,
+or as traffic debug or statistic collectors. Exynos542x bus has multiple
+NoC probes to provide bandwidth information about behavior of the SoC
+that you can use while analyzing system performance.
+
+Required properties:
+- compatible: Should be "samsung,exynos5420-nocp"
+- reg: physical base address of each NoC Probe and length of memory mapped region.
+
+Optional properties:
+- clock-names : the name of clock used by the NoC Probe, "nocp"
+- clocks : phandles for clock specified in "clock-names" property
+
+Example : NoC Probe nodes in Device Tree are listed below.
+
+	nocp_mem0_0: nocp@10CA1000 {
+		compatible = "samsung,exynos5420-nocp";
+		reg = <0x10CA1000 0x200>;
+	};

drivers/devfreq/event/Kconfig

@@ -13,6 +13,14 @@ menuconfig PM_DEVFREQ_EVENT
 
 if PM_DEVFREQ_EVENT
 
+config DEVFREQ_EVENT_EXYNOS_NOCP
+	bool "EXYNOS NoC (Network On Chip) Probe DEVFREQ event Driver"
+	depends on ARCH_EXYNOS
+	select PM_OPP
+	help
+	  This add the devfreq-event driver for Exynos SoC. It provides NoC
+	  (Network on Chip) Probe counters to measure the bandwidth of AXI bus.
+
 config DEVFREQ_EVENT_EXYNOS_PPMU
 	bool "EXYNOS PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"
 	depends on ARCH_EXYNOS

drivers/devfreq/event/Makefile

@@ -1,2 +1,4 @@
 # Exynos DEVFREQ Event Drivers
+
+obj-$(CONFIG_DEVFREQ_EVENT_EXYNOS_NOCP) += exynos-nocp.o
 obj-$(CONFIG_DEVFREQ_EVENT_EXYNOS_PPMU) += exynos-ppmu.o

drivers/devfreq/event/exynos-nocp.c

@@ -0,0 +1,304 @@
+/*
+ * exynos-nocp.c - EXYNOS NoC (Network On Chip) Probe support
+ *
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ * Author : Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/devfreq-event.h>
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "exynos-nocp.h"
+
+struct exynos_nocp {
+	struct devfreq_event_dev *edev;
+	struct devfreq_event_desc desc;
+
+	struct device *dev;
+
+	struct regmap *regmap;
+	struct clk *clk;
+};
+
+/*
+ * The devfreq-event ops structure for nocp probe.
+ */
+static int exynos_nocp_set_event(struct devfreq_event_dev *edev)
+{
+	struct exynos_nocp *nocp = devfreq_event_get_drvdata(edev);
+	int ret;
+
+	/* Disable NoC probe */
+	ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+				NOCP_MAIN_CTL_STATEN_MASK, 0);
+	if (ret < 0) {
+		dev_err(nocp->dev, "failed to disable the NoC probe device\n");
+		return ret;
+	}
+
+	/* Set a statistics dump period to 0 */
+	ret = regmap_write(nocp->regmap, NOCP_STAT_PERIOD, 0x0);
+	if (ret < 0)
+		goto out;
+
+	/* Set the IntEvent fields of *_SRC */
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_0_SRC,
+				NOCP_CNT_SRC_INTEVENT_MASK,
+				NOCP_CNT_SRC_INTEVENT_BYTE_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_1_SRC,
+				NOCP_CNT_SRC_INTEVENT_MASK,
+				NOCP_CNT_SRC_INTEVENT_CHAIN_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_2_SRC,
+				NOCP_CNT_SRC_INTEVENT_MASK,
+				NOCP_CNT_SRC_INTEVENT_CYCLE_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_3_SRC,
+				NOCP_CNT_SRC_INTEVENT_MASK,
+				NOCP_CNT_SRC_INTEVENT_CHAIN_MASK);
+	if (ret < 0)
+		goto out;
+
+
+	/* Set an alarm with a max/min value of 0 to generate StatALARM */
+	ret = regmap_write(nocp->regmap, NOCP_STAT_ALARM_MIN, 0x0);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_write(nocp->regmap, NOCP_STAT_ALARM_MAX, 0x0);
+	if (ret < 0)
+		goto out;
+
+	/* Set AlarmMode */
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_0_ALARM_MODE,
+				NOCP_CNT_ALARM_MODE_MASK,
+				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_1_ALARM_MODE,
+				NOCP_CNT_ALARM_MODE_MASK,
+				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_2_ALARM_MODE,
+				NOCP_CNT_ALARM_MODE_MASK,
+				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_3_ALARM_MODE,
+				NOCP_CNT_ALARM_MODE_MASK,
+				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+	if (ret < 0)
+		goto out;
+
+	/* Enable the measurements by setting AlarmEn and StatEn */
+	ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+			NOCP_MAIN_CTL_STATEN_MASK | NOCP_MAIN_CTL_ALARMEN_MASK,
+			NOCP_MAIN_CTL_STATEN_MASK | NOCP_MAIN_CTL_ALARMEN_MASK);
+	if (ret < 0)
+		goto out;
+
+	/* Set GlobalEN */
+	ret = regmap_update_bits(nocp->regmap, NOCP_CFG_CTL,
+				NOCP_CFG_CTL_GLOBALEN_MASK,
+				NOCP_CFG_CTL_GLOBALEN_MASK);
+	if (ret < 0)
+		goto out;
+
+	/* Enable NoC probe */
+	ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+				NOCP_MAIN_CTL_STATEN_MASK,
+				NOCP_MAIN_CTL_STATEN_MASK);
+	if (ret < 0)
+		goto out;
+
+	return 0;
+
+out:
+	/* Reset NoC probe */
+	if (regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+				NOCP_MAIN_CTL_STATEN_MASK, 0)) {
+		dev_err(nocp->dev, "Failed to reset NoC probe device\n");
+	}
+
+	return ret;
+}
+
+static int exynos_nocp_get_event(struct devfreq_event_dev *edev,
+				struct devfreq_event_data *edata)
+{
+	struct exynos_nocp *nocp = devfreq_event_get_drvdata(edev);
+	unsigned int counter[4];
+	int ret;
+
+	/* Read cycle count */
+	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_0_VAL, &counter[0]);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_1_VAL, &counter[1]);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_2_VAL, &counter[2]);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_3_VAL, &counter[3]);
+	if (ret < 0)
+		goto out;
+
+	edata->load_count = ((counter[1] << 16) | counter[0]);
+	edata->total_count = ((counter[3] << 16) | counter[2]);
+
+	dev_dbg(&edev->dev, "%s (event: %ld/%ld)\n", edev->desc->name,
+					edata->load_count, edata->total_count);
+
+	return 0;
+
+out:
+	edata->load_count = 0;
+	edata->total_count = 0;
+
+	dev_err(nocp->dev, "Failed to read the counter of NoC probe device\n");
+
+	return ret;
+}
+
+static const struct devfreq_event_ops exynos_nocp_ops = {
+	.set_event = exynos_nocp_set_event,
+	.get_event = exynos_nocp_get_event,
+};
+
+static const struct of_device_id exynos_nocp_id_match[] = {
+	{ .compatible = "samsung,exynos5420-nocp", },
+	{ /* sentinel */ },
+};
+
+static struct regmap_config exynos_nocp_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = NOCP_COUNTERS_3_VAL,
+};
+
+static int exynos_nocp_parse_dt(struct platform_device *pdev,
+				struct exynos_nocp *nocp)
+{
+	struct device *dev = nocp->dev;
+	struct device_node *np = dev->of_node;
+	struct resource *res;
+	void __iomem *base;
+
+	if (!np) {
+		dev_err(dev, "failed to find devicetree node\n");
+		return -EINVAL;
+	}
+
+	nocp->clk = devm_clk_get(dev, "nocp");
+	if (IS_ERR(nocp->clk))
+		nocp->clk = NULL;
+
+	/* Maps the memory mapped IO to control nocp register */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (IS_ERR(res))
+		return PTR_ERR(res);
+
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	exynos_nocp_regmap_config.max_register = resource_size(res) - 4;
+
+	nocp->regmap = devm_regmap_init_mmio(dev, base,
+					&exynos_nocp_regmap_config);
+	if (IS_ERR(nocp->regmap)) {
+		dev_err(dev, "failed to initialize regmap\n");
+		return PTR_ERR(nocp->regmap);
+	}
+
+	return 0;
+}
+
+static int exynos_nocp_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct exynos_nocp *nocp;
+	int ret;
+
+	nocp = devm_kzalloc(&pdev->dev, sizeof(*nocp), GFP_KERNEL);
+	if (!nocp)
+		return -ENOMEM;
+
+	nocp->dev = &pdev->dev;
+
+	/* Parse dt data to get resource */
+	ret = exynos_nocp_parse_dt(pdev, nocp);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"failed to parse devicetree for resource\n");
+		return ret;
+	}
+
+	/* Add devfreq-event device to measure the bandwidth of NoC */
+	nocp->desc.ops = &exynos_nocp_ops;
+	nocp->desc.driver_data = nocp;
+	nocp->desc.name = np->full_name;
+	nocp->edev = devm_devfreq_event_add_edev(&pdev->dev, &nocp->desc);
+	if (IS_ERR(nocp->edev)) {
+		dev_err(&pdev->dev,
+			"failed to add devfreq-event device\n");
+		return PTR_ERR(nocp->edev);
+	}
+	platform_set_drvdata(pdev, nocp);
+
+	clk_prepare_enable(nocp->clk);
+
+	pr_info("exynos-nocp: new NoC Probe device registered: %s\n",
+			dev_name(dev));
+
+	return 0;
+}
+
+static int exynos_nocp_remove(struct platform_device *pdev)
+{
+	struct exynos_nocp *nocp = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(nocp->clk);
+
+	return 0;
+}
+
+static struct platform_driver exynos_nocp_driver = {
+	.probe	= exynos_nocp_probe,
+	.remove	= exynos_nocp_remove,
+	.driver = {
+		.name	= "exynos-nocp",
+		.of_match_table = exynos_nocp_id_match,
+	},
+};
+module_platform_driver(exynos_nocp_driver);
+
+MODULE_DESCRIPTION("Exynos NoC (Network on Chip) Probe driver");
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
+MODULE_LICENSE("GPL");

drivers/devfreq/event/exynos-nocp.h

@@ -0,0 +1,78 @@
+/*
+ * exynos-nocp.h - EXYNOS NoC (Network on Chip) Probe header file
+ *
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ * Author : Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __EXYNOS_NOCP_H__
+#define __EXYNOS_NOCP_H__
+
+enum nocp_reg {
+	NOCP_ID_REVISION_ID		= 0x04,
+	NOCP_MAIN_CTL			= 0x08,
+	NOCP_CFG_CTL			= 0x0C,
+
+	NOCP_STAT_PERIOD		= 0x24,
+	NOCP_STAT_GO			= 0x28,
+	NOCP_STAT_ALARM_MIN		= 0x2C,
+	NOCP_STAT_ALARM_MAX		= 0x30,
+	NOCP_STAT_ALARM_STATUS		= 0x34,
+	NOCP_STAT_ALARM_CLR		= 0x38,
+
+	NOCP_COUNTERS_0_SRC		= 0x138,
+	NOCP_COUNTERS_0_ALARM_MODE	= 0x13C,
+	NOCP_COUNTERS_0_VAL		= 0x140,
+
+	NOCP_COUNTERS_1_SRC		= 0x14C,
+	NOCP_COUNTERS_1_ALARM_MODE	= 0x150,
+	NOCP_COUNTERS_1_VAL		= 0x154,
+
+	NOCP_COUNTERS_2_SRC		= 0x160,
+	NOCP_COUNTERS_2_ALARM_MODE	= 0x164,
+	NOCP_COUNTERS_2_VAL		= 0x168,
+
+	NOCP_COUNTERS_3_SRC		= 0x174,
+	NOCP_COUNTERS_3_ALARM_MODE	= 0x178,
+	NOCP_COUNTERS_3_VAL		= 0x17C,
+};
+
+/* NOCP_MAIN_CTL register */
+#define NOCP_MAIN_CTL_ERREN_MASK		BIT(0)
+#define NOCP_MAIN_CTL_TRACEEN_MASK		BIT(1)
+#define NOCP_MAIN_CTL_PAYLOADEN_MASK		BIT(2)
+#define NOCP_MAIN_CTL_STATEN_MASK		BIT(3)
+#define NOCP_MAIN_CTL_ALARMEN_MASK		BIT(4)
+#define NOCP_MAIN_CTL_STATCONDDUMP_MASK	BIT(5)
+#define NOCP_MAIN_CTL_INTRUSIVEMODE_MASK	BIT(6)
+
+/* NOCP_CFG_CTL register */
+#define NOCP_CFG_CTL_GLOBALEN_MASK		BIT(0)
+#define NOCP_CFG_CTL_ACTIVE_MASK		BIT(1)
+
+/* NOCP_COUNTERS_x_SRC register */
+#define NOCP_CNT_SRC_INTEVENT_SHIFT		0
+#define NOCP_CNT_SRC_INTEVENT_MASK		(0x1F << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_OFF_MASK		(0x0 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_CYCLE_MASK	(0x1 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_IDLE_MASK		(0x2 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_XFER_MASK		(0x3 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_BUSY_MASK		(0x4 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_WAIT_MASK		(0x5 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_PKT_MASK		(0x6 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_BYTE_MASK		(0x8 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_CHAIN_MASK	(0x10 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+
+/* NOCP_COUNTERS_x_ALARM_MODE register */
+#define NOCP_CNT_ALARM_MODE_SHIFT		0
+#define NOCP_CNT_ALARM_MODE_MASK		(0x3 << NOCP_CNT_ALARM_MODE_SHIFT)
+#define NOCP_CNT_ALARM_MODE_OFF_MASK		(0x0 << NOCP_CNT_ALARM_MODE_SHIFT)
+#define NOCP_CNT_ALARM_MODE_MIN_MASK		(0x1 << NOCP_CNT_ALARM_MODE_SHIFT)
+#define NOCP_CNT_ALARM_MODE_MAX_MASK		(0x2 << NOCP_CNT_ALARM_MODE_SHIFT)
+#define NOCP_CNT_ALARM_MODE_MIN_MAX_MASK	(0x3 << NOCP_CNT_ALARM_MODE_SHIFT)
+
+#endif /* __EXYNOS_NOCP_H__ */