coresight: cti: Initial CoreSight CTI Driver

This introduces a baseline CTI driver and associated configuration files.

Uses the platform agnostic naming standard for CoreSight devices, along
with a generic platform probing method that currently supports device
tree descriptions, but allows for the ACPI bindings to be added once these
have been defined for the CTI devices.

Driver will probe for the device on the AMBA bus, and load the CTI driver
on CoreSight ID match to CTI IDs in tables.

Initial sysfs support for enable / disable provided.

Default CTI interconnection data is generated based on hardware
register signal counts, with no additional connection information.
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-2-mathieu.poirier@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/Kconfig

@@ -110,4 +110,16 @@ config CORESIGHT_CPU_DEBUG
 	  properly, please refer Documentation/trace/coresight-cpu-debug.rst
 	  for detailed description and the example for usage.
 
+config CORESIGHT_CTI
+	bool "CoreSight Cross Trigger Interface (CTI) driver"
+	depends on ARM || ARM64
+	help
+	  This driver provides support for CoreSight CTI and CTM components.
+	  These provide hardware triggering events between CoreSight trace
+	  source and sink components. These can be used to halt trace or
+	  inject events into the trace stream. CTI also provides a software
+	  control to trigger the same halt events. This can provide fast trace
+	  halt compared to disabling sources and sinks normally in driver
+	  software.
+
 endif

drivers/hwtracing/coresight/Makefile

@@ -17,3 +17,6 @@ obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \
 obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
 obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o
 obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o
+obj-$(CONFIG_CORESIGHT_CTI) += coresight-cti.o \
+				coresight-cti-platform.o \
+				coresight-cti-sysfs.o

drivers/hwtracing/coresight/coresight-cti-platform.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019, The Linaro Limited. All rights reserved.
+ */
+
+#include <linux/of.h>
+
+#include "coresight-cti.h"
+
+/* get the hardware configuration & connection data. */
+int cti_plat_get_hw_data(struct device *dev,
+			 struct cti_drvdata *drvdata)
+{
+	int rc = 0;
+	struct cti_device *cti_dev = &drvdata->ctidev;
+
+	/* if no connections, just add a single default based on max IN-OUT */
+	if (cti_dev->nr_trig_con == 0)
+		rc = cti_add_default_connection(dev, drvdata);
+	return rc;
+}
+
+struct coresight_platform_data *
+coresight_cti_get_platform_data(struct device *dev)
+{
+	int ret = -ENOENT;
+	struct coresight_platform_data *pdata = NULL;
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (IS_ERR_OR_NULL(fwnode))
+		goto error;
+
+	/*
+	 * Alloc platform data but leave it zero init. CTI does not use the
+	 * same connection infrastructuree as trace path components but an
+	 * empty struct enables us to use the standard coresight component
+	 * registration code.
+	 */
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/* get some CTI specifics */
+	ret = cti_plat_get_hw_data(dev, drvdata);
+
+	if (!ret)
+		return pdata;
+error:
+	return ERR_PTR(ret);
+}

drivers/hwtracing/coresight/coresight-cti-sysfs.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Linaro Limited, All rights reserved.
+ * Author: Mike Leach <mike.leach@linaro.org>
+ */
+
+#include <linux/coresight.h>
+
+#include "coresight-cti.h"
+
+/* basic attributes */
+static ssize_t enable_show(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	int enable_req;
+	bool enabled, powered;
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	enable_req = atomic_read(&drvdata->config.enable_req_count);
+	spin_lock(&drvdata->spinlock);
+	powered = drvdata->config.hw_powered;
+	enabled = drvdata->config.hw_enabled;
+	spin_unlock(&drvdata->spinlock);
+
+	if (powered)
+		return sprintf(buf, "%d\n", enabled);
+	else
+		return sprintf(buf, "%d\n", !!enable_req);
+}
+
+static ssize_t enable_store(struct device *dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t size)
+{
+	int ret = 0;
+	unsigned long val;
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	if (val)
+		ret = cti_enable(drvdata->csdev);
+	else
+		ret = cti_disable(drvdata->csdev);
+	if (ret)
+		return ret;
+	return size;
+}
+static DEVICE_ATTR_RW(enable);
+
+static ssize_t powered_show(struct device *dev,
+			    struct device_attribute *attr,
+			    char *buf)
+{
+	bool powered;
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	spin_lock(&drvdata->spinlock);
+	powered = drvdata->config.hw_powered;
+	spin_unlock(&drvdata->spinlock);
+
+	return sprintf(buf, "%d\n", powered);
+}
+static DEVICE_ATTR_RO(powered);
+
+/* attribute and group sysfs tables. */
+static struct attribute *coresight_cti_attrs[] = {
+	&dev_attr_enable.attr,
+	&dev_attr_powered.attr,
+	NULL,
+};
+
+static const struct attribute_group coresight_cti_group = {
+	.attrs = coresight_cti_attrs,
+};
+
+const struct attribute_group *coresight_cti_groups[] = {
+	&coresight_cti_group,
+	NULL,
+};

drivers/hwtracing/coresight/coresight-cti.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018 Linaro Limited, All rights reserved.
+ * Author: Mike Leach <mike.leach@linaro.org>
+ */
+
+#ifndef _CORESIGHT_CORESIGHT_CTI_H
+#define _CORESIGHT_CORESIGHT_CTI_H
+
+#include <asm/local.h>
+#include <linux/spinlock.h>
+#include "coresight-priv.h"
+
+/*
+ * Device registers
+ * 0x000 - 0x144: CTI programming and status
+ * 0xEDC - 0xEF8: CTI integration test.
+ * 0xF00 - 0xFFC: Coresight management registers.
+ */
+/* CTI programming registers */
+#define CTICONTROL		0x000
+#define CTIINTACK		0x010
+#define CTIAPPSET		0x014
+#define CTIAPPCLEAR		0x018
+#define CTIAPPPULSE		0x01C
+#define CTIINEN(n)		(0x020 + (4 * n))
+#define CTIOUTEN(n)		(0x0A0 + (4 * n))
+#define CTITRIGINSTATUS		0x130
+#define CTITRIGOUTSTATUS	0x134
+#define CTICHINSTATUS		0x138
+#define CTICHOUTSTATUS		0x13C
+#define CTIGATE			0x140
+#define ASICCTL			0x144
+/* Integration test registers */
+#define ITCHINACK		0xEDC /* WO CTI CSSoc 400 only*/
+#define ITTRIGINACK		0xEE0 /* WO CTI CSSoc 400 only*/
+#define ITCHOUT			0xEE4 /* WO RW-600 */
+#define ITTRIGOUT		0xEE8 /* WO RW-600 */
+#define ITCHOUTACK		0xEEC /* RO CTI CSSoc 400 only*/
+#define ITTRIGOUTACK		0xEF0 /* RO CTI CSSoc 400 only*/
+#define ITCHIN			0xEF4 /* RO */
+#define ITTRIGIN		0xEF8 /* RO */
+/* management registers */
+#define CTIDEVAFF0		0xFA8
+#define CTIDEVAFF1		0xFAC
+
+/*
+ * CTI CSSoc 600 has a max of 32 trigger signals per direction.
+ * CTI CSSoc 400 has 8 IO triggers - other CTIs can be impl def.
+ * Max of in and out defined in the DEVID register.
+ * - pick up actual number used from .dts parameters if present.
+ */
+#define CTIINOUTEN_MAX		32
+
+/**
+ * Group of related trigger signals
+ *
+ * @nr_sigs: number of signals in the group.
+ * @used_mask: bitmask representing the signal indexes in the group.
+ * @sig_types: array of types for the signals, length nr_sigs.
+ */
+struct cti_trig_grp {
+	int nr_sigs;
+	u32 used_mask;
+	int sig_types[];
+};
+
+/**
+ * Trigger connection - connection between a CTI and other (coresight) device
+ * lists input and output trigger signals for the device
+ *
+ * @con_in: connected CTIIN signals for the device.
+ * @con_out: connected CTIOUT signals for the device.
+ * @con_dev: coresight device connected to the CTI, NULL if not CS device
+ * @con_dev_name: name of connected device (CS or CPU)
+ * @node: entry node in list of connections.
+ */
+struct cti_trig_con {
+	struct cti_trig_grp *con_in;
+	struct cti_trig_grp *con_out;
+	struct coresight_device *con_dev;
+	const char *con_dev_name;
+	struct list_head node;
+};
+
+/**
+ * struct cti_device - description of CTI device properties.
+ *
+ * @nt_trig_con: Number of external devices connected to this device.
+ * @ctm_id: which CTM this device is connected to (by default it is
+ *          assumed there is a single CTM per SoC, ID 0).
+ * @trig_cons: list of connections to this device.
+ * @cpu: CPU ID if associated with CPU, -1 otherwise.
+ */
+struct cti_device {
+	int nr_trig_con;
+	u32 ctm_id;
+	struct list_head trig_cons;
+	int cpu;
+};
+
+/**
+ * struct cti_config - configuration of the CTI device hardware
+ *
+ * @nr_trig_max: Max number of trigger signals implemented on device.
+ *		 (max of trig_in or trig_out) - from ID register.
+ * @nr_ctm_channels: number of available CTM channels - from ID register.
+ * @enable_req_count: CTI is enabled alongside >=1 associated devices.
+ * @hw_enabled: true if hw is currently enabled.
+ * @hw_powered: true if associated cpu powered on, or no cpu.
+ * @trig_in_use: bitfield of in triggers registered as in use.
+ * @trig_out_use: bitfield of out triggers registered as in use.
+ * @trig_out_filter: bitfield of out triggers that are blocked if filter
+ *		     enabled. Typically this would be dbgreq / restart on
+ *		     a core CTI.
+ * @trig_filter_enable: 1 if filtering enabled.
+ * @xtrig_rchan_sel: channel selection for xtrigger connection show.
+ * @ctiappset: CTI Software application channel set.
+ * @ctiinout_sel: register selector for INEN and OUTEN regs.
+ * @ctiinen: enable input trigger to a channel.
+ * @ctiouten: enable output trigger from a channel.
+ * @ctigate: gate channel output from CTI to CTM.
+ * @asicctl: asic control register.
+ */
+struct cti_config {
+	/* hardware description */
+	int nr_ctm_channels;
+	int nr_trig_max;
+
+	/* cti enable control */
+	atomic_t enable_req_count;
+	bool hw_enabled;
+	bool hw_powered;
+
+	/* registered triggers and filtering */
+	u32 trig_in_use;
+	u32 trig_out_use;
+	u32 trig_out_filter;
+	bool trig_filter_enable;
+	u8 xtrig_rchan_sel;
+
+	/* cti cross trig programmable regs */
+	u32 ctiappset;
+	u8 ctiinout_sel;
+	u32 ctiinen[CTIINOUTEN_MAX];
+	u32 ctiouten[CTIINOUTEN_MAX];
+	u32 ctigate;
+	u32 asicctl;
+};
+
+/**
+ * struct cti_drvdata - specifics for the CTI device
+ * @base:	Memory mapped base address for this component..
+ * @csdev:	Standard CoreSight device information.
+ * @ctidev:	Extra information needed by the CTI/CTM framework.
+ * @spinlock:	Control data access to one at a time.
+ * @config:	Configuration data for this CTI device.
+ * @node:	List entry of this device in the list of CTI devices.
+ * @csdev_release: release function for underlying coresight_device.
+ */
+struct cti_drvdata {
+	void __iomem *base;
+	struct coresight_device	*csdev;
+	struct cti_device ctidev;
+	spinlock_t spinlock;
+	struct cti_config config;
+	struct list_head node;
+	void (*csdev_release)(struct device *dev);
+};
+
+/* private cti driver fns & vars */
+extern const struct attribute_group *coresight_cti_groups[];
+int cti_add_default_connection(struct device *dev,
+			       struct cti_drvdata *drvdata);
+int cti_add_connection_entry(struct device *dev, struct cti_drvdata *drvdata,
+			     struct cti_trig_con *tc,
+			     struct coresight_device *csdev,
+			     const char *assoc_dev_name);
+struct cti_trig_con *cti_allocate_trig_con(struct device *dev, int in_sigs,
+					   int out_sigs);
+int cti_enable(struct coresight_device *csdev);
+int cti_disable(struct coresight_device *csdev);
+struct coresight_platform_data *
+coresight_cti_get_platform_data(struct device *dev);
+
+#endif  /* _CORESIGHT_CORESIGHT_CTI_H */

drivers/hwtracing/coresight/coresight.c

@@ -955,6 +955,9 @@ static struct device_type coresight_dev_type[] = {
 	{
 		.name = "helper",
 	},
+	{
+		.name = "ect",
+	},
 };
 
 static void coresight_device_release(struct device *dev)

include/linux/coresight.h

@@ -41,6 +41,7 @@ enum coresight_dev_type {
 	CORESIGHT_DEV_TYPE_LINKSINK,
 	CORESIGHT_DEV_TYPE_SOURCE,
 	CORESIGHT_DEV_TYPE_HELPER,
+	CORESIGHT_DEV_TYPE_ECT,
 };
 
 enum coresight_dev_subtype_sink {
@@ -68,6 +69,12 @@ enum coresight_dev_subtype_helper {
 	CORESIGHT_DEV_SUBTYPE_HELPER_CATU,
 };
 
+/* Embedded Cross Trigger (ECT) sub-types */
+enum coresight_dev_subtype_ect {
+	CORESIGHT_DEV_SUBTYPE_ECT_NONE,
+	CORESIGHT_DEV_SUBTYPE_ECT_CTI,
+};
+
 /**
  * union coresight_dev_subtype - further characterisation of a type
  * @sink_subtype:	type of sink this component is, as defined
@@ -78,6 +85,8 @@ enum coresight_dev_subtype_helper {
  *			by @coresight_dev_subtype_source.
  * @helper_subtype:	type of helper this component is, as defined
  *			by @coresight_dev_subtype_helper.
+ * @ect_subtype:        type of cross trigger this component is, as
+ *			defined by @coresight_dev_subtype_ect
  */
 union coresight_dev_subtype {
 	/* We have some devices which acts as LINK and SINK */
@@ -87,6 +96,7 @@ union coresight_dev_subtype {
 	};
 	enum coresight_dev_subtype_source source_subtype;
 	enum coresight_dev_subtype_helper helper_subtype;
+	enum coresight_dev_subtype_ect ect_subtype;
 };
 
 /**
@@ -196,6 +206,7 @@ static struct coresight_dev_list (var) = {				\
 #define sink_ops(csdev)		csdev->ops->sink_ops
 #define link_ops(csdev)		csdev->ops->link_ops
 #define helper_ops(csdev)	csdev->ops->helper_ops
+#define ect_ops(csdev)		csdev->ops->ect_ops
 
 /**
  * struct coresight_ops_sink - basic operations for a sink
@@ -262,11 +273,23 @@ struct coresight_ops_helper {
 	int (*disable)(struct coresight_device *csdev, void *data);
 };
 
+/**
+ * struct coresight_ops_ect - Ops for an embedded cross trigger device
+ *
+ * @enable	: Enable the device
+ * @disable	: Disable the device
+ */
+struct coresight_ops_ect {
+	int (*enable)(struct coresight_device *csdev);
+	int (*disable)(struct coresight_device *csdev);
+};
+
 struct coresight_ops {
 	const struct coresight_ops_sink *sink_ops;
 	const struct coresight_ops_link *link_ops;
 	const struct coresight_ops_source *source_ops;
 	const struct coresight_ops_helper *helper_ops;
+	const struct coresight_ops_ect *ect_ops;
 };
 
 #ifdef CONFIG_CORESIGHT