coresight-tpiu: add CoreSight TPIU driver

This driver manages CoreSight TPIU (Trace Port Interface Unit)
which acts as a sink. TPIU is typically connected to some offchip
hardware hosting a storage buffer.

Signed-off-by: Pratik Patel <pratikp@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/arm/Kconfig.debug

@@ -1359,5 +1359,14 @@ config CORESIGHT_LINK_AND_SINK_TMC
 	  - ETR) or sink (embedded trace FIFO).  The driver complies with the
 	  generic implementation of the component without special enhancement or
 	  added features.
+
+config CORESIGHT_SINK_TPIU
+	bool "Coresight generic TPIU driver"
+	depends on CORESIGHT_LINKS_AND_SINKS
+	help
+	  This enables support for the Trace Port Interface Unit driver, responsible
+	  for bridging the gap between the on-chip coresight components and a trace
+	  port collection engine, typically connected to an external host for use
+	  case capturing more traces than the on-board coresight memory can handle.
 endif
 endmenu

drivers/coresight/Makefile

@@ -4,3 +4,4 @@
 obj-$(CONFIG_CORESIGHT) += coresight.o
 obj-$(CONFIG_OF) += of_coresight.o
 obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o
+obj-$(CONFIG_CORESIGHT_SINK_TPIU) += coresight-tpiu.o

drivers/coresight/coresight-tpiu.c

@@ -0,0 +1,217 @@
+/* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/coresight.h>
+#include <linux/amba/bus.h>
+
+#include "coresight-priv.h"
+
+#define TPIU_SUPP_PORTSZ	0x000
+#define TPIU_CURR_PORTSZ	0x004
+#define TPIU_SUPP_TRIGMODES	0x100
+#define TPIU_TRIG_CNTRVAL	0x104
+#define TPIU_TRIG_MULT		0x108
+#define TPIU_SUPP_TESTPATM	0x200
+#define TPIU_CURR_TESTPATM	0x204
+#define TPIU_TEST_PATREPCNTR	0x208
+#define TPIU_FFSR		0x300
+#define TPIU_FFCR		0x304
+#define TPIU_FSYNC_CNTR		0x308
+#define TPIU_EXTCTL_INPORT	0x400
+#define TPIU_EXTCTL_OUTPORT	0x404
+#define TPIU_ITTRFLINACK	0xee4
+#define TPIU_ITTRFLIN		0xee8
+#define TPIU_ITATBDATA0		0xeec
+#define TPIU_ITATBCTR2		0xef0
+#define TPIU_ITATBCTR1		0xef4
+#define TPIU_ITATBCTR0		0xef8
+
+/** register definition **/
+/* FFCR - 0x304 */
+#define FFCR_FON_MAN		BIT(6)
+
+/**
+ * @base:	memory mapped base address for this component.
+ * @dev:	the device entity associated to this component.
+ * @csdev:	component vitals needed by the framework.
+ * @clk:	the clock this component is associated to.
+ */
+struct tpiu_drvdata {
+	void __iomem		*base;
+	struct device		*dev;
+	struct coresight_device	*csdev;
+	struct clk		*clk;
+};
+
+static void tpiu_enable_hw(struct tpiu_drvdata *drvdata)
+{
+	CS_UNLOCK(drvdata->base);
+
+	/* TODO: fill this up */
+
+	CS_LOCK(drvdata->base);
+}
+
+static int tpiu_enable(struct coresight_device *csdev)
+{
+	struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+	int ret;
+
+	ret = clk_prepare_enable(drvdata->clk);
+	if (ret)
+		return ret;
+
+	tpiu_enable_hw(drvdata);
+
+	dev_info(drvdata->dev, "TPIU enabled\n");
+	return 0;
+}
+
+static void tpiu_disable_hw(struct tpiu_drvdata *drvdata)
+{
+	CS_UNLOCK(drvdata->base);
+
+	/* Clear formatter controle reg. */
+	writel_relaxed(0x0, drvdata->base + TPIU_FFCR);
+	/* Generate manual flush */
+	writel_relaxed(FFCR_FON_MAN, drvdata->base + TPIU_FFCR);
+
+	CS_LOCK(drvdata->base);
+}
+
+static void tpiu_disable(struct coresight_device *csdev)
+{
+	struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	tpiu_disable_hw(drvdata);
+
+	clk_disable_unprepare(drvdata->clk);
+
+	dev_info(drvdata->dev, "TPIU disabled\n");
+}
+
+static const struct coresight_ops_sink tpiu_sink_ops = {
+	.enable		= tpiu_enable,
+	.disable	= tpiu_disable,
+};
+
+static const struct coresight_ops tpiu_cs_ops = {
+	.sink_ops	= &tpiu_sink_ops,
+};
+
+static int tpiu_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	int ret;
+	void __iomem *base;
+	struct device *dev = &adev->dev;
+	struct coresight_platform_data *pdata = NULL;
+	struct tpiu_drvdata *drvdata;
+	struct resource *res = &adev->res;
+	struct coresight_desc *desc;
+	struct device_node *np = adev->dev.of_node;
+
+	if (np) {
+		pdata = of_get_coresight_platform_data(dev, np);
+		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);
+
+	/* Validity for the resource is already checked by the AMBA core */
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	drvdata->base = base;
+
+	drvdata->clk = adev->pclk;
+	ret = clk_prepare_enable(drvdata->clk);
+	if (ret)
+		return ret;
+
+	/* Disable tpiu to support older devices */
+	tpiu_disable_hw(drvdata);
+
+	clk_disable_unprepare(drvdata->clk);
+
+	desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
+	if (!desc)
+		return -ENOMEM;
+
+	desc->type = CORESIGHT_DEV_TYPE_SINK;
+	desc->subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_PORT;
+	desc->ops = &tpiu_cs_ops;
+	desc->pdata = pdata;
+	desc->dev = dev;
+	drvdata->csdev = coresight_register(desc);
+	if (IS_ERR(drvdata->csdev))
+		return PTR_ERR(drvdata->csdev);
+
+	dev_info(dev, "TPIU initialized\n");
+	return 0;
+}
+
+static int tpiu_remove(struct amba_device *adev)
+{
+	struct tpiu_drvdata *drvdata = amba_get_drvdata(adev);
+
+	coresight_unregister(drvdata->csdev);
+	return 0;
+}
+
+static struct amba_id tpiu_ids[] = {
+	{
+		.id	= 0x0003b912,
+		.mask	= 0x0003ffff,
+	},
+	{ 0, 0},
+};
+
+static struct amba_driver tpiu_driver = {
+	.drv = {
+		.name	= "coresight-tpiu",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= tpiu_probe,
+	.remove		= tpiu_remove,
+	.id_table	= tpiu_ids,
+};
+
+static int __init tpiu_init(void)
+{
+	return amba_driver_register(&tpiu_driver);
+}
+module_init(tpiu_init);
+
+static void __exit tpiu_exit(void)
+{
+	amba_driver_unregister(&tpiu_driver);
+}
+module_exit(tpiu_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("CoreSight Trace Port Interface Unit driver");