Coresight: Add TPDA link driver

TPDA(Trace, Profiling and Diagnostics Aggregator) is
to provide packetization, funneling and timestamping of
TPDM data. Multiple monitors are connected to different
input ports of TPDA.This change is to add tpda
enable/disable/probe functions for coresight tpda driver.

 - - - -         - - - -        - - - -
| TPDM 0|      | TPDM 1 |     | TPDM 2|
 - - - -         - - - -        - - - -
    |               |             |
    |_ _ _ _ _ _    |     _ _ _ _ |
                |   |    |
                |   |    |
           ------------------
          |        TPDA      |
           ------------------

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230120095301.30792-2-quic_jinlmao@quicinc.com

1 files changed, 211 insertions, 0 deletions

diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
new file mode 100644
index 000000000000..19c25c9f6157
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-tpda.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/amba/bus.h>
+#include <linux/bitfield.h>
+#include <linux/coresight.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 <linux/platform_device.h>
+
+#include "coresight-priv.h"
+#include "coresight-tpda.h"
+#include "coresight-trace-id.h"
+
+DEFINE_CORESIGHT_DEVLIST(tpda_devs, "tpda");
+
+/* Settings pre enabling port control register */
+static void tpda_enable_pre_port(struct tpda_drvdata *drvdata)
+{
+	u32 val;
+
+	val = readl_relaxed(drvdata->base + TPDA_CR);
+	val &= ~TPDA_CR_ATID;
+	val |= FIELD_PREP(TPDA_CR_ATID, drvdata->atid);
+	writel_relaxed(val, drvdata->base + TPDA_CR);
+}
+
+static void tpda_enable_port(struct tpda_drvdata *drvdata, int port)
+{
+	u32 val;
+
+	val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port));
+	/* Enable the port */
+	val |= TPDA_Pn_CR_ENA;
+	writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
+}
+
+static void __tpda_enable(struct tpda_drvdata *drvdata, int port)
+{
+	CS_UNLOCK(drvdata->base);
+
+	if (!drvdata->csdev->enable)
+		tpda_enable_pre_port(drvdata);
+
+	tpda_enable_port(drvdata, port);
+
+	CS_LOCK(drvdata->base);
+}
+
+static int tpda_enable(struct coresight_device *csdev, int inport, int outport)
+{
+	struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	spin_lock(&drvdata->spinlock);
+	if (atomic_read(&csdev->refcnt[inport]) == 0)
+		__tpda_enable(drvdata, inport);
+
+	atomic_inc(&csdev->refcnt[inport]);
+	spin_unlock(&drvdata->spinlock);
+
+	dev_dbg(drvdata->dev, "TPDA inport %d enabled.\n", inport);
+	return 0;
+}
+
+static void __tpda_disable(struct tpda_drvdata *drvdata, int port)
+{
+	u32 val;
+
+	CS_UNLOCK(drvdata->base);
+
+	val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port));
+	val &= ~TPDA_Pn_CR_ENA;
+	writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
+
+	CS_LOCK(drvdata->base);
+}
+
+static void tpda_disable(struct coresight_device *csdev, int inport,
+			   int outport)
+{
+	struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	spin_lock(&drvdata->spinlock);
+	if (atomic_dec_return(&csdev->refcnt[inport]) == 0)
+		__tpda_disable(drvdata, inport);
+
+	spin_unlock(&drvdata->spinlock);
+
+	dev_dbg(drvdata->dev, "TPDA inport %d disabled\n", inport);
+}
+
+static const struct coresight_ops_link tpda_link_ops = {
+	.enable		= tpda_enable,
+	.disable	= tpda_disable,
+};
+
+static const struct coresight_ops tpda_cs_ops = {
+	.link_ops	= &tpda_link_ops,
+};
+
+static int tpda_init_default_data(struct tpda_drvdata *drvdata)
+{
+	int atid;
+	/*
+	 * TPDA must has a unique atid. This atid can uniquely
+	 * identify the TPDM trace source connected to the TPDA.
+	 * The TPDMs which are connected to same TPDA share the
+	 * same trace-id. When TPDA does packetization, different
+	 * port will have unique channel number for decoding.
+	 */
+	atid = coresight_trace_id_get_system_id();
+	if (atid < 0)
+		return atid;
+
+	drvdata->atid = atid;
+	return 0;
+}
+
+static int tpda_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	int ret;
+	struct device *dev = &adev->dev;
+	struct coresight_platform_data *pdata;
+	struct tpda_drvdata *drvdata;
+	struct coresight_desc desc = { 0 };
+	void __iomem *base;
+
+	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);
+
+	base = devm_ioremap_resource(dev, &adev->res);
+	if (!base)
+		return -ENOMEM;
+	drvdata->base = base;
+
+	spin_lock_init(&drvdata->spinlock);
+
+	ret = tpda_init_default_data(drvdata);
+	if (ret)
+		return ret;
+
+	desc.name = coresight_alloc_device_name(&tpda_devs, dev);
+	if (!desc.name)
+		return -ENOMEM;
+	desc.type = CORESIGHT_DEV_TYPE_LINK;
+	desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_MERG;
+	desc.ops = &tpda_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);
+
+	pm_runtime_put(&adev->dev);
+
+	dev_dbg(drvdata->dev, "TPDA initialized\n");
+	return 0;
+}
+
+static void __exit tpda_remove(struct amba_device *adev)
+{
+	struct tpda_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+
+	coresight_trace_id_put_system_id(drvdata->atid);
+	coresight_unregister(drvdata->csdev);
+}
+
+/*
+ * Different TPDA has different periph id.
+ * The difference is 0-7 bits' value. So ignore 0-7 bits.
+ */
+static struct amba_id tpda_ids[] = {
+	{
+		.id     = 0x000f0f00,
+		.mask   = 0x000fff00,
+	},
+	{ 0, 0},
+};
+
+static struct amba_driver tpda_driver = {
+	.drv = {
+		.name   = "coresight-tpda",
+		.owner	= THIS_MODULE,
+		.suppress_bind_attrs = true,
+	},
+	.probe          = tpda_probe,
+	.remove		= tpda_remove,
+	.id_table	= tpda_ids,
+};
+
+module_amba_driver(tpda_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Trace, Profiling & Diagnostic Aggregator driver");