Add driver to support Coresight device TGU (Trigger Generation Unit).
TGU is a Data Engine which can be utilized to sense a plurality of
signals and create a trigger into the CTI or generate interrupts to
processors. Add probe/enable/disable functions for tgu.

Signed-off-by: songchai <quic_songchai@quicinc.com>
---
 .../testing/sysfs-bus-coresight-devices-tgu   |   9 +
 drivers/hwtracing/coresight/Kconfig           |  11 +
 drivers/hwtracing/coresight/Makefile          |   1 +
 drivers/hwtracing/coresight/coresight-tgu.c   | 211 ++++++++++++++++++
 drivers/hwtracing/coresight/coresight-tgu.h   |  36 +++
 5 files changed, 268 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-tgu
 create mode 100644 drivers/hwtracing/coresight/coresight-tgu.c
 create mode 100644 drivers/hwtracing/coresight/coresight-tgu.h

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tgu b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tgu
new file mode 100644
index 000000000000..ee976b67ff01
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tgu
@@ -0,0 +1,9 @@
+What:		/sys/bus/coresight/devices/<tgu-name>/enable_tgu
+Date:		August 2024
+KernelVersion	6.10
+Contact:	Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Sam Chai (QUIC) <quic_songchai@quicinc.com>
+Description:
+		(RW) Set/Get the enable/disable status of TGU
+		Accepts only one of the 2 values -  0 or 1.
+		0 : disable TGU.
+		1 : enable TGU.
diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index 06f0a7594169..3fe59c745dd4 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -247,4 +247,15 @@ config CORESIGHT_DUMMY
 
 	  To compile this driver as a module, choose M here: the module will be
 	  called coresight-dummy.
+
+config CORESIGHT_TGU
+	tristate "CoreSight Trigger Generation Unit driver"
+	help
+	  This driver provides support for Trigger Generation Unit that is
+	  used to detect patterns or sequences on a given set of signals.
+	  TGU is used to monitor a particular bus within a given region to
+	  detect illegal transaction sequences or slave responses. It is also
+	  used to monitor a data stream to detect protocol violations and to
+	  provide a trigger point for centering data around a specific event
+	  within the trace data buffer.
 endif
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 4ba478211b31..7c2b9e9cf1cd 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -51,3 +51,4 @@ coresight-cti-y := coresight-cti-core.o	coresight-cti-platform.o \
 		   coresight-cti-sysfs.o
 obj-$(CONFIG_ULTRASOC_SMB) += ultrasoc-smb.o
 obj-$(CONFIG_CORESIGHT_DUMMY) += coresight-dummy.o
+obj-$(CONFIG_CORESIGHT_TGU) += coresight-tgu.o
diff --git a/drivers/hwtracing/coresight/coresight-tgu.c b/drivers/hwtracing/coresight/coresight-tgu.c
new file mode 100644
index 000000000000..278dd69ee93d
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-tgu.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/amba/bus.h>
+#include <linux/coresight.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include "coresight-priv.h"
+#include "coresight-tgu.h"
+
+DEFINE_CORESIGHT_DEVLIST(tgu_devs, "tgu");
+
+static void tgu_write_all_hw_regs(struct tgu_drvdata *drvdata)
+{
+	CS_UNLOCK(drvdata->base);
+	/* Enable TGU to program the triggers */
+	tgu_writel(drvdata, 1, TGU_CONTROL);
+	CS_LOCK(drvdata->base);
+}
+
+static int tgu_enable(struct coresight_device *csdev, enum cs_mode mode,
+		      void *data)
+{
+	struct tgu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	spin_lock(&drvdata->spinlock);
+
+	if (drvdata->enable) {
+		spin_unlock(&drvdata->spinlock);
+		return -EBUSY;
+	}
+	tgu_write_all_hw_regs(drvdata);
+	drvdata->enable = true;
+
+	spin_unlock(&drvdata->spinlock);
+	return 0;
+}
+
+static int tgu_disable(struct coresight_device *csdev, void *data)
+{
+	struct tgu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	spin_lock(&drvdata->spinlock);
+
+	if (!drvdata->enable) {
+		spin_unlock(&drvdata->spinlock);
+		return 0;
+	}
+
+	CS_UNLOCK(drvdata->base);
+	tgu_writel(drvdata, 0, TGU_CONTROL);
+	CS_LOCK(drvdata->base);
+
+	drvdata->enable = false;
+	spin_unlock(&drvdata->spinlock);
+	return 0;
+}
+
+static ssize_t enable_tgu_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	bool enabled;
+
+	struct tgu_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	spin_lock(&drvdata->spinlock);
+	enabled = drvdata->enable;
+	spin_unlock(&drvdata->spinlock);
+
+	return sprintf(buf, "%d\n", enabled);
+}
+
+/* enable_tgu_store - Configure Trace and Gating Unit (TGU) triggers. */
+static ssize_t enable_tgu_store(struct device *dev,
+				struct device_attribute *attr, const char *buf,
+				size_t size)
+{
+	int ret = 0;
+	unsigned long val;
+	struct tgu_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	if (val) {
+		ret = pm_runtime_resume_and_get(dev->parent);
+		if (ret)
+			return ret;
+		ret = tgu_enable(drvdata->csdev, CS_MODE_SYSFS, NULL);
+		if (ret)
+			pm_runtime_put(dev->parent);
+	} else {
+		ret = tgu_disable(drvdata->csdev, NULL);
+		if (!ret)
+			pm_runtime_put(dev->parent);
+	}
+
+	if (ret)
+		return ret;
+	return size;
+}
+static DEVICE_ATTR_RW(enable_tgu);
+
+static const struct coresight_ops_helper tgu_helper_ops = {
+	.enable = tgu_enable,
+	.disable = tgu_disable,
+};
+
+static const struct coresight_ops tgu_ops = {
+	.helper_ops = &tgu_helper_ops,
+};
+
+static struct attribute *tgu_common_attrs[] = {
+	&dev_attr_enable_tgu.attr,
+	NULL,
+};
+
+static struct attribute_group tgu_common_grp = {
+	.attrs = tgu_common_attrs,
+	NULL,
+};
+
+static const struct attribute_group *tgu_attr_groups[] = {
+	&tgu_common_grp,
+	NULL,
+};
+
+static int tgu_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	int ret = 0;
+	struct device *dev = &adev->dev;
+	struct coresight_platform_data *pdata;
+	struct tgu_drvdata *drvdata;
+	struct coresight_desc desc = { 0 };
+
+	desc.name = coresight_alloc_device_name(&tgu_devs, dev);
+	if (!desc.name)
+		return -ENOMEM;
+
+	pdata = coresight_get_platform_data(dev);
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
+
+	adev->dev.platform_data = pdata;
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->dev = &adev->dev;
+	dev_set_drvdata(dev, drvdata);
+
+	drvdata->base = devm_ioremap_resource(dev, &adev->res);
+	if (!drvdata->base)
+		return -ENOMEM;
+
+	spin_lock_init(&drvdata->spinlock);
+
+	drvdata->enable = false;
+	desc.type = CORESIGHT_DEV_TYPE_HELPER;
+	desc.pdata = adev->dev.platform_data;
+	desc.dev = &adev->dev;
+	desc.ops = &tgu_ops;
+	desc.groups = tgu_attr_groups;
+
+	drvdata->csdev = coresight_register(&desc);
+	if (IS_ERR(drvdata->csdev)) {
+		ret = PTR_ERR(drvdata->csdev);
+		goto err;
+	}
+
+	pm_runtime_put(&adev->dev);
+	dev_dbg(dev, "TGU initialized\n");
+	return 0;
+err:
+	pm_runtime_put(&adev->dev);
+	return ret;
+}
+
+static struct amba_id tgu_ids[] = {
+	{
+		.id = 0x0003b999,
+		.mask = 0x0003ffff,
+		.data = "TGU",
+	},
+	{ 0, 0 },
+};
+
+static struct amba_driver tgu_driver = {
+	.drv = {
+			.name = "coresight-tgu",
+			.owner = THIS_MODULE,
+			.suppress_bind_attrs = true,
+		},
+	.probe = tgu_probe,
+	.id_table = tgu_ids,
+};
+
+module_amba_driver(tgu_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CoreSight TGU driver");
+
diff --git a/drivers/hwtracing/coresight/coresight-tgu.h b/drivers/hwtracing/coresight/coresight-tgu.h
new file mode 100644
index 000000000000..6e793421066b
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-tgu.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _CORESIGHT_TGU_H
+#define _CORESIGHT_TGU_H
+
+/* Register addresses */
+#define TGU_CONTROL 0x0000
+
+/* Register read/write */
+#define tgu_writel(drvdata, val, off) __raw_writel((val), drvdata->base + off)
+#define tgu_readl(drvdata, off) __raw_readl(drvdata->base + off)
+
+/**
+ * struct tgu_drvdata - Data structure for a TGU (Trigger Generator Unit) device
+ * @base: Memory-mapped base address of the TGU device
+ * @dev: Pointer to the associated device structure
+ * @csdev: Pointer to the associated coresight device
+ * @spinlock: Spinlock for handling concurrent access
+ * @enable: Flag indicating whether the TGU device is enabled
+ *
+ * This structure defines the data associated with a TGU device, including its base
+ * address, device pointers, clock, spinlock for synchronization, trigger data pointers,
+ * maximum limits for various trigger-related parameters, and enable status.
+ */
+struct tgu_drvdata {
+	void __iomem *base;
+	struct device *dev;
+	struct coresight_device *csdev;
+	spinlock_t spinlock;
+	bool enable;
+};
+
+#endif

Hi songchai,

kernel test robot noticed the following build warnings:

[auto build test WARNING on robh/for-next]
[also build test WARNING on linus/master v6.11-rc5 next-20240830]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/songchai/dt-bindings-arm-Add-support-for-Coresight-TGU-trace/20240830-172716
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link:    https://lore.kernel.org/r/20240830092311.14400-3-quic_songchai%40quicinc.com
patch subject: [PATCH v1 2/7] coresight: Add coresight TGU driver
config: arm64-allmodconfig (https://download.01.org/0day-ci/archive/20240831/202408312341.AgielsZe-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 46fe36a4295f05d5d3731762e31fc4e6e99863e9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240831/202408312341.AgielsZe-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408312341.AgielsZe-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/hwtracing/coresight/coresight-tgu.c:6:
   In file included from include/linux/amba/bus.h:19:
   In file included from include/linux/regulator/consumer.h:35:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:21:
   In file included from include/linux/mm.h:2228:
   include/linux/vmstat.h:500:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     500 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     501 |                            item];
         |                            ~~~~
   include/linux/vmstat.h:507:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     507 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     508 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
   include/linux/vmstat.h:514:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     514 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
   include/linux/vmstat.h:519:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     519 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     520 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
   include/linux/vmstat.h:528:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     528 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     529 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
>> drivers/hwtracing/coresight/coresight-tgu.c:194:9: warning: missing field 'data' initializer [-Wmissing-field-initializers]
     194 |         { 0, 0 },
         |                ^
   6 warnings generated.


vim +/data +194 drivers/hwtracing/coresight/coresight-tgu.c

   187	
   188	static struct amba_id tgu_ids[] = {
   189		{
   190			.id = 0x0003b999,
   191			.mask = 0x0003ffff,
   192			.data = "TGU",
   193		},
 > 194		{ 0, 0 },
   195	};
   196	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

On 30/08/2024 11:23, songchai wrote:
> Add driver to support Coresight device TGU (Trigger Generation Unit).
> TGU is a Data Engine which can be utilized to sense a plurality of
> signals and create a trigger into the CTI or generate interrupts to
> processors. Add probe/enable/disable functions for tgu.
> 
> Signed-off-by: songchai <quic_songchai@quicinc.com>

...

> +
> +static struct attribute *tgu_common_attrs[] = {
> +	&dev_attr_enable_tgu.attr,
> +	NULL,
> +};
> +
> +static struct attribute_group tgu_common_grp = {

Not const?

> +	.attrs = tgu_common_attrs,
> +	NULL,
> +};
> +
> +static const struct attribute_group *tgu_attr_groups[] = {
> +	&tgu_common_grp,
> +	NULL,
> +};
> +
> +static int tgu_probe(struct amba_device *adev, const struct amba_id *id)
> +{
> +	int ret = 0;
> +	struct device *dev = &adev->dev;
> +	struct coresight_platform_data *pdata;
> +	struct tgu_drvdata *drvdata;
> +	struct coresight_desc desc = { 0 };

Code is quite mixed here... Bring some order - declarations with and
without assignments.

> +
> +	desc.name = coresight_alloc_device_name(&tgu_devs, dev);
> +	if (!desc.name)
> +		return -ENOMEM;
> +
> +	pdata = coresight_get_platform_data(dev);
> +	if (IS_ERR(pdata))
> +		return PTR_ERR(pdata);
> +
> +	adev->dev.platform_data = pdata;
> +
> +	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
> +	if (!drvdata)
> +		return -ENOMEM;
> +
> +	drvdata->dev = &adev->dev;
> +	dev_set_drvdata(dev, drvdata);
> +
> +	drvdata->base = devm_ioremap_resource(dev, &adev->res);
> +	if (!drvdata->base)
> +		return -ENOMEM;
> +
> +	spin_lock_init(&drvdata->spinlock);
> +
> +	drvdata->enable = false;
> +	desc.type = CORESIGHT_DEV_TYPE_HELPER;
> +	desc.pdata = adev->dev.platform_data;
> +	desc.dev = &adev->dev;
> +	desc.ops = &tgu_ops;
> +	desc.groups = tgu_attr_groups;
> +
> +	drvdata->csdev = coresight_register(&desc);
> +	if (IS_ERR(drvdata->csdev)) {
> +		ret = PTR_ERR(drvdata->csdev);
> +		goto err;
> +	}
> +
> +	pm_runtime_put(&adev->dev);
> +	dev_dbg(dev, "TGU initialized\n");

Drop, useless. Kernel provides you already ways to know probe status.

> +	return 0;
> +err:
> +	pm_runtime_put(&adev->dev);
> +	return ret;
> +}
> +
> +static struct amba_id tgu_ids[] = {

Not const?

> +	{
> +		.id = 0x0003b999,
> +		.mask = 0x0003ffff,
> +		.data = "TGU",
> +	},
> +	{ 0, 0 },
> +};

No module device table?

> +
> +static struct amba_driver tgu_driver = {
> +	.drv = {
> +			.name = "coresight-tgu",
> +			.owner = THIS_MODULE,

Please drop. Also one-less indentation.

> +			.suppress_bind_attrs = true,
> +		},
> +	.probe = tgu_probe,
> +	.id_table = tgu_ids,
> +};
> +
> +module_amba_driver(tgu_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("CoreSight TGU driver");
Best regards,
Krzysztof