xref: /openbmc/linux/drivers/hwtracing/coresight/coresight-tpdm.c (revision b3c71626)

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
 */

#include <linux/amba/bus.h>
#include <linux/bitmap.h>
#include <linux/coresight.h>
#include <linux/coresight-pmu.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>

#include "coresight-priv.h"
#include "coresight-tpdm.h"

DEFINE_CORESIGHT_DEVLIST(tpdm_devs, "tpdm");

/* TPDM enable operations */
static int tpdm_enable(struct coresight_device *csdev,
		       struct perf_event *event, u32 mode)
{
	struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);

	spin_lock(&drvdata->spinlock);
	if (drvdata->enable) {
		spin_unlock(&drvdata->spinlock);
		return -EBUSY;
	}

	drvdata->enable = true;
	spin_unlock(&drvdata->spinlock);

	dev_dbg(drvdata->dev, "TPDM tracing enabled\n");
	return 0;
}

/* TPDM disable operations */
static void tpdm_disable(struct coresight_device *csdev,
			 struct perf_event *event)
{
	struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);

	spin_lock(&drvdata->spinlock);
	if (!drvdata->enable) {
		spin_unlock(&drvdata->spinlock);
		return;
	}

	drvdata->enable = false;
	spin_unlock(&drvdata->spinlock);

	dev_dbg(drvdata->dev, "TPDM tracing disabled\n");
}

static const struct coresight_ops_source tpdm_source_ops = {
	.enable		= tpdm_enable,
	.disable	= tpdm_disable,
};

static const struct coresight_ops tpdm_cs_ops = {
	.source_ops	= &tpdm_source_ops,
};

static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
{
	void __iomem *base;
	struct device *dev = &adev->dev;
	struct coresight_platform_data *pdata;
	struct tpdm_drvdata *drvdata;
	struct coresight_desc desc = { 0 };

	pdata = coresight_get_platform_data(dev);
	if (IS_ERR(pdata))
		return PTR_ERR(pdata);
	adev->dev.platform_data = pdata;

	/* driver data*/
	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
	if (!drvdata)
		return -ENOMEM;
	drvdata->dev = &adev->dev;
	dev_set_drvdata(dev, drvdata);

	base = devm_ioremap_resource(dev, &adev->res);
	if (IS_ERR(base))
		return PTR_ERR(base);

	drvdata->base = base;

	/* Set up coresight component description */
	desc.name = coresight_alloc_device_name(&tpdm_devs, dev);
	if (!desc.name)
		return -ENOMEM;
	desc.type = CORESIGHT_DEV_TYPE_SOURCE;
	desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS;
	desc.ops = &tpdm_cs_ops;
	desc.pdata = adev->dev.platform_data;
	desc.dev = &adev->dev;
	desc.access = CSDEV_ACCESS_IOMEM(base);
	drvdata->csdev = coresight_register(&desc);
	if (IS_ERR(drvdata->csdev))
		return PTR_ERR(drvdata->csdev);

	spin_lock_init(&drvdata->spinlock);
	/* Decrease pm refcount when probe is done.*/
	pm_runtime_put(&adev->dev);

	return 0;
}

static void __exit tpdm_remove(struct amba_device *adev)
{
	struct tpdm_drvdata *drvdata = dev_get_drvdata(&adev->dev);

	coresight_unregister(drvdata->csdev);
}

/*
 * Different TPDM has different periph id.
 * The difference is 0-7 bits' value. So ignore 0-7 bits.
 */
static struct amba_id tpdm_ids[] = {
	{
		.id = 0x000f0e00,
		.mask = 0x000fff00,
	},
	{ 0, 0},
};

static struct amba_driver tpdm_driver = {
	.drv = {
		.name   = "coresight-tpdm",
		.owner	= THIS_MODULE,
		.suppress_bind_attrs = true,
	},
	.probe          = tpdm_probe,
	.id_table	= tpdm_ids,
	.remove		= tpdm_remove,
};

module_amba_driver(tpdm_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Trace, Profiling & Diagnostic Monitor driver");