coresight: Introduce support for Coresight Address Translation Unit

Add the initial support for Coresight Address Translation Unit, which
augments the TMC in Coresight SoC-600 by providing an improved Scatter
Gather mechanism. CATU is always connected to a single TMC-ETR and
converts the AXI address with a translated address (from a given SG
table with specific format). The CATU should be programmed in pass
through mode and enabled even if the ETR doesn't use the translation
by CATU.

This patch provides mechanism to enable/disable the CATU always in the
pass through mode.

We reuse the existing ports mechanism to link the TMC-ETR to the
connected CATU.

i.e, TMC-ETR:output_port0 -> CATU:input_port0

Reference manual for CATU component is avilable in version r2p0 of :
"Arm Coresight System-on-Chip SoC-600 Technical Reference Manual".

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 214 insertions, 0 deletions

diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
new file mode 100644
index 000000000000..9d0cb1f6f16b
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-catu.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Arm Limited. All rights reserved.
+ *
+ * Coresight Address Translation Unit support
+ *
+ * Author: Suzuki K Poulose <suzuki.poulose@arm.com>
+ */
+
+#include <linux/amba/bus.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include "coresight-catu.h"
+#include "coresight-priv.h"
+
+#define csdev_to_catu_drvdata(csdev)	\
+	dev_get_drvdata(csdev->dev.parent)
+
+coresight_simple_reg32(struct catu_drvdata, devid, CORESIGHT_DEVID);
+coresight_simple_reg32(struct catu_drvdata, control, CATU_CONTROL);
+coresight_simple_reg32(struct catu_drvdata, status, CATU_STATUS);
+coresight_simple_reg32(struct catu_drvdata, mode, CATU_MODE);
+coresight_simple_reg32(struct catu_drvdata, axictrl, CATU_AXICTRL);
+coresight_simple_reg32(struct catu_drvdata, irqen, CATU_IRQEN);
+coresight_simple_reg64(struct catu_drvdata, sladdr,
+		       CATU_SLADDRLO, CATU_SLADDRHI);
+coresight_simple_reg64(struct catu_drvdata, inaddr,
+		       CATU_INADDRLO, CATU_INADDRHI);
+
+static struct attribute *catu_mgmt_attrs[] = {
+	&dev_attr_devid.attr,
+	&dev_attr_control.attr,
+	&dev_attr_status.attr,
+	&dev_attr_mode.attr,
+	&dev_attr_axictrl.attr,
+	&dev_attr_irqen.attr,
+	&dev_attr_sladdr.attr,
+	&dev_attr_inaddr.attr,
+	NULL,
+};
+
+static const struct attribute_group catu_mgmt_group = {
+	.attrs = catu_mgmt_attrs,
+	.name = "mgmt",
+};
+
+static const struct attribute_group *catu_groups[] = {
+	&catu_mgmt_group,
+	NULL,
+};
+
+
+static inline int catu_wait_for_ready(struct catu_drvdata *drvdata)
+{
+	return coresight_timeout(drvdata->base,
+				 CATU_STATUS, CATU_STATUS_READY, 1);
+}
+
+static int catu_enable_hw(struct catu_drvdata *drvdata, void *__unused)
+{
+	u32 control;
+
+	if (catu_wait_for_ready(drvdata))
+		dev_warn(drvdata->dev, "Timeout while waiting for READY\n");
+
+	control = catu_read_control(drvdata);
+	if (control & BIT(CATU_CONTROL_ENABLE)) {
+		dev_warn(drvdata->dev, "CATU is already enabled\n");
+		return -EBUSY;
+	}
+
+	control |= BIT(CATU_CONTROL_ENABLE);
+	catu_write_mode(drvdata, CATU_MODE_PASS_THROUGH);
+	catu_write_control(drvdata, control);
+	dev_dbg(drvdata->dev, "Enabled in Pass through mode\n");
+	return 0;
+}
+
+static int catu_enable(struct coresight_device *csdev, void *data)
+{
+	int rc;
+	struct catu_drvdata *catu_drvdata = csdev_to_catu_drvdata(csdev);
+
+	CS_UNLOCK(catu_drvdata->base);
+	rc = catu_enable_hw(catu_drvdata, data);
+	CS_LOCK(catu_drvdata->base);
+	return rc;
+}
+
+static int catu_disable_hw(struct catu_drvdata *drvdata)
+{
+	int rc = 0;
+
+	catu_write_control(drvdata, 0);
+	if (catu_wait_for_ready(drvdata)) {
+		dev_info(drvdata->dev, "Timeout while waiting for READY\n");
+		rc = -EAGAIN;
+	}
+
+	dev_dbg(drvdata->dev, "Disabled\n");
+	return rc;
+}
+
+static int catu_disable(struct coresight_device *csdev, void *__unused)
+{
+	int rc;
+	struct catu_drvdata *catu_drvdata = csdev_to_catu_drvdata(csdev);
+
+	CS_UNLOCK(catu_drvdata->base);
+	rc = catu_disable_hw(catu_drvdata);
+	CS_LOCK(catu_drvdata->base);
+	return rc;
+}
+
+const struct coresight_ops_helper catu_helper_ops = {
+	.enable = catu_enable,
+	.disable = catu_disable,
+};
+
+const struct coresight_ops catu_ops = {
+	.helper_ops = &catu_helper_ops,
+};
+
+static int catu_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	int ret = 0;
+	u32 dma_mask;
+	struct catu_drvdata *drvdata;
+	struct coresight_desc catu_desc;
+	struct coresight_platform_data *pdata = NULL;
+	struct device *dev = &adev->dev;
+	struct device_node *np = dev->of_node;
+	void __iomem *base;
+
+	if (np) {
+		pdata = of_get_coresight_platform_data(dev, np);
+		if (IS_ERR(pdata)) {
+			ret = PTR_ERR(pdata);
+			goto out;
+		}
+		dev->platform_data = pdata;
+	}
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	drvdata->dev = dev;
+	dev_set_drvdata(dev, drvdata);
+	base = devm_ioremap_resource(dev, &adev->res);
+	if (IS_ERR(base)) {
+		ret = PTR_ERR(base);
+		goto out;
+	}
+
+	/* Setup dma mask for the device */
+	dma_mask = readl_relaxed(base + CORESIGHT_DEVID) & 0x3f;
+	switch (dma_mask) {
+	case 32:
+	case 40:
+	case 44:
+	case 48:
+	case 52:
+	case 56:
+	case 64:
+		break;
+	default:
+		/* Default to the 40bits as supported by TMC-ETR */
+		dma_mask = 40;
+	}
+	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(dma_mask));
+	if (ret)
+		goto out;
+
+	drvdata->base = base;
+	catu_desc.pdata = pdata;
+	catu_desc.dev = dev;
+	catu_desc.groups = catu_groups;
+	catu_desc.type = CORESIGHT_DEV_TYPE_HELPER;
+	catu_desc.subtype.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CATU;
+	catu_desc.ops = &catu_ops;
+	drvdata->csdev = coresight_register(&catu_desc);
+	if (IS_ERR(drvdata->csdev))
+		ret = PTR_ERR(drvdata->csdev);
+out:
+	pm_runtime_put(&adev->dev);
+	return ret;
+}
+
+static struct amba_id catu_ids[] = {
+	{
+		.id	= 0x000bb9ee,
+		.mask	= 0x000fffff,
+	},
+	{},
+};
+
+static struct amba_driver catu_driver = {
+	.drv = {
+		.name			= "coresight-catu",
+		.owner			= THIS_MODULE,
+		.suppress_bind_attrs	= true,
+	},
+	.probe				= catu_probe,
+	.id_table			= catu_ids,
+};
+
+builtin_amba_driver(catu_driver);