[PATCH 14/24] gtrace: Add CoreSight funnel driver
Zane Leung
liangzhen at linux.spacemit.com
Thu Oct 22 20:14:55 PDT 2026
Add a CoreSight funnel driver for the gtrace framework, derived from
drivers/hwtracing/coresight/coresight-funnel.c.
Signed-off-by: Zane Leung <liangzhen at linux.spacemit.com>
---
drivers/hwtracing/gtrace/Kconfig | 13 +
drivers/hwtracing/gtrace/Makefile | 1 +
drivers/hwtracing/gtrace/coresight-funnel.c | 430 ++++++++++++++++++++
3 files changed, 444 insertions(+)
create mode 100644 drivers/hwtracing/gtrace/coresight-funnel.c
diff --git a/drivers/hwtracing/gtrace/Kconfig b/drivers/hwtracing/gtrace/Kconfig
index 5dce4474db7c..081af9c0c670 100644
--- a/drivers/hwtracing/gtrace/Kconfig
+++ b/drivers/hwtracing/gtrace/Kconfig
@@ -101,3 +101,16 @@ config GTRACE_CORESIGHT
To compile this driver as a module, choose M here: the module
will be called coresight.
+
+config CORESIGHT_FUNNEL
+ tristate "CoreSight Trace Funnel driver"
+ depends on GTRACE_CORESIGHT
+ default y
+ help
+ This driver provides support for the CoreSight funnel component.
+ The funnel merges trace data from multiple input ports into a single
+ output stream. It supports both static funnels (platform bus,
+ arm,coresight-static-funnel) and dynamic funnels (AMBA bus).
+
+ To compile this driver as a module, choose M here: the module
+ will be called coresight-funnel.
diff --git a/drivers/hwtracing/gtrace/Makefile b/drivers/hwtracing/gtrace/Makefile
index 0833a40c397c..d2745c961a75 100644
--- a/drivers/hwtracing/gtrace/Makefile
+++ b/drivers/hwtracing/gtrace/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_RVTRACE_RAMSINK) += rvtrace-ramsink.o
obj-$(CONFIG_RVTRACE_FUNNEL) += rvtrace-funnel.o
obj-$(CONFIG_RVTRACE_ATBBRIDGE) += rvtrace-atbbridge.o
obj-$(CONFIG_GTRACE_CORESIGHT) += coresight-platform.o
+obj-$(CONFIG_CORESIGHT_FUNNEL) += coresight-funnel.o
diff --git a/drivers/hwtracing/gtrace/coresight-funnel.c b/drivers/hwtracing/gtrace/coresight-funnel.c
new file mode 100644
index 000000000000..e7a3f185da56
--- /dev/null
+++ b/drivers/hwtracing/gtrace/coresight-funnel.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
+ *
+ * Description: CoreSight Funnel driver for the gtrace framework.
+ * Derived from drivers/hwtracing/coresight/coresight-funnel.c.
+ */
+
+#include <linux/acpi.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/amba/bus.h>
+#include <linux/clk.h>
+
+#include "coresight.h"
+
+#define FUNNEL_FUNCTL 0x000
+#define FUNNEL_PRICTL 0x004
+
+#define FUNNEL_HOLDTIME_MASK 0xf00
+#define FUNNEL_HOLDTIME_SHFT 0x8
+#define FUNNEL_HOLDTIME (0x7 << FUNNEL_HOLDTIME_SHFT)
+#define FUNNEL_ENSx_MASK 0xff
+
+/**
+ * struct funnel_drvdata - specifics associated to a funnel component
+ * @base: memory mapped base address for this component.
+ * @atclk: optional clock for the core parts of the funnel.
+ * @pclk: APB clock if present, otherwise NULL
+ * @comp: component vitals needed by the framework.
+ * @priority: port selection order.
+ */
+struct funnel_drvdata {
+ void __iomem *base;
+ struct clk *atclk;
+ struct clk *pclk;
+ struct gtrace_component *comp;
+ unsigned long priority;
+};
+
+static int dynamic_funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
+{
+ u32 functl;
+ int rc = 0;
+ struct gtrace_component *comp = drvdata->comp;
+
+ CS_UNLOCK(drvdata->base);
+
+ functl = readl_relaxed(drvdata->base + FUNNEL_FUNCTL);
+ /* Claim the device only when we enable the first slave */
+ if (!(functl & FUNNEL_ENSx_MASK)) {
+ rc = coresight_claim_device_unlocked(comp);
+ if (rc)
+ goto done;
+ }
+
+ functl &= ~FUNNEL_HOLDTIME_MASK;
+ functl |= FUNNEL_HOLDTIME;
+ functl |= (1 << port);
+ writel_relaxed(functl, drvdata->base + FUNNEL_FUNCTL);
+ writel_relaxed(drvdata->priority, drvdata->base + FUNNEL_PRICTL);
+done:
+ CS_LOCK(drvdata->base);
+ return rc;
+}
+
+static int funnel_enable(struct gtrace_component *comp,
+ struct gtrace_connection *in,
+ struct gtrace_connection *out)
+{
+ int rc = 0;
+ struct funnel_drvdata *drvdata = dev_get_drvdata(comp->dev.parent);
+ bool first_enable = false;
+
+ if (in->dest_refcnt == 0) {
+ if (drvdata->base)
+ rc = dynamic_funnel_enable_hw(drvdata, in->dest_port);
+ if (!rc)
+ first_enable = true;
+ }
+ if (!rc)
+ in->dest_refcnt++;
+
+ if (first_enable)
+ dev_dbg(&comp->dev, "FUNNEL inport %d enabled\n",
+ in->dest_port);
+ return rc;
+}
+
+static void dynamic_funnel_disable_hw(struct funnel_drvdata *drvdata,
+ int inport)
+{
+ u32 functl;
+ struct gtrace_component *comp = drvdata->comp;
+
+ CS_UNLOCK(drvdata->base);
+
+ functl = readl_relaxed(drvdata->base + FUNNEL_FUNCTL);
+ functl &= ~(1 << inport);
+ writel_relaxed(functl, drvdata->base + FUNNEL_FUNCTL);
+
+ /* Disclaim the device if none of the slaves are now active */
+ if (!(functl & FUNNEL_ENSx_MASK))
+ coresight_disclaim_device_unlocked(comp);
+
+ CS_LOCK(drvdata->base);
+}
+
+static void funnel_disable(struct gtrace_component *comp,
+ struct gtrace_connection *in,
+ struct gtrace_connection *out)
+{
+ struct funnel_drvdata *drvdata = dev_get_drvdata(comp->dev.parent);
+ bool last_disable = false;
+
+ if (--in->dest_refcnt == 0) {
+ if (drvdata->base)
+ dynamic_funnel_disable_hw(drvdata, in->dest_port);
+ last_disable = true;
+ }
+
+ if (last_disable)
+ dev_dbg(&comp->dev, "FUNNEL inport %d disabled\n",
+ in->dest_port);
+}
+
+static ssize_t priority_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ unsigned long val = drvdata->priority;
+
+ return sprintf(buf, "%#lx\n", val);
+}
+
+static ssize_t priority_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ int ret;
+ unsigned long val;
+ struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ ret = kstrtoul(buf, 16, &val);
+ if (ret)
+ return ret;
+
+ drvdata->priority = val;
+ return size;
+}
+static DEVICE_ATTR_RW(priority);
+
+static u32 get_funnel_ctrl_hw(struct funnel_drvdata *drvdata)
+{
+ u32 functl;
+
+ CS_UNLOCK(drvdata->base);
+ functl = readl_relaxed(drvdata->base + FUNNEL_FUNCTL);
+ CS_LOCK(drvdata->base);
+
+ return functl;
+}
+
+static ssize_t funnel_ctrl_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ u32 val;
+ struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ pm_runtime_get_sync(dev->parent);
+
+ val = get_funnel_ctrl_hw(drvdata);
+
+ pm_runtime_put(dev->parent);
+
+ return sprintf(buf, "%#x\n", val);
+}
+static DEVICE_ATTR_RO(funnel_ctrl);
+
+static struct attribute *coresight_funnel_attrs[] = {
+ &dev_attr_funnel_ctrl.attr,
+ &dev_attr_priority.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(coresight_funnel);
+
+static int funnel_probe(struct device *dev, struct resource *res)
+{
+ void __iomem *base;
+ struct gtrace_platform_data *pdata = NULL;
+ struct funnel_drvdata *drvdata;
+ struct gtrace_component_id id = {
+ .type = GTRACE_CORESIGHT_FUNNEL,
+ .version = CORESIGHT_COMPONENT_ID_VERSION,
+ };
+ int ret;
+
+ if (is_of_node(dev_fwnode(dev)) &&
+ of_device_is_compatible(dev->of_node, "arm,coresight-funnel"))
+ dev_warn_once(dev, "Uses OBSOLETE CoreSight funnel binding\n");
+
+ drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ ret = coresight_get_enable_clocks(dev, &drvdata->pclk, &drvdata->atclk);
+ if (ret)
+ return ret;
+
+ pdata = coresight_get_platform_data(dev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+
+ /*
+ * Map the device base for dynamic-funnel, which has been
+ * validated by AMBA core.
+ */
+ if (res) {
+ base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+ drvdata->base = base;
+ pdata->groups = coresight_funnel_groups;
+ pdata->io_mem = true;
+ pdata->base = base;
+ coresight_clear_self_claim_tag(pdata);
+ }
+
+ dev_set_drvdata(dev, drvdata);
+
+ drvdata->comp = gtrace_register_component(&id, "cs_funnel", pdata);
+ if (IS_ERR(drvdata->comp))
+ return PTR_ERR(drvdata->comp);
+
+ return 0;
+}
+
+static void funnel_remove(struct device *dev)
+{
+ struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
+
+ gtrace_unregister_component(drvdata->comp);
+}
+
+#ifdef CONFIG_PM
+static int funnel_runtime_suspend(struct device *dev)
+{
+ struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(drvdata->atclk);
+ clk_disable_unprepare(drvdata->pclk);
+
+ return 0;
+}
+
+static int funnel_runtime_resume(struct device *dev)
+{
+ struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(drvdata->pclk);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(drvdata->atclk);
+ if (ret)
+ clk_disable_unprepare(drvdata->pclk);
+
+ return ret;
+}
+#endif
+
+static const struct dev_pm_ops funnel_dev_pm_ops = {
+ SET_RUNTIME_PM_OPS(funnel_runtime_suspend, funnel_runtime_resume, NULL)
+};
+
+static int funnel_platform_probe(struct platform_device *pdev)
+{
+ struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ int ret;
+
+ pm_runtime_get_noresume(&pdev->dev);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
+ ret = funnel_probe(&pdev->dev, res);
+ pm_runtime_put(&pdev->dev);
+ if (ret)
+ pm_runtime_disable(&pdev->dev);
+
+ return ret;
+}
+
+static void funnel_platform_remove(struct platform_device *pdev)
+{
+ struct funnel_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
+
+ if (WARN_ON(!drvdata))
+ return;
+
+ funnel_remove(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+}
+
+static const struct of_device_id funnel_match[] = {
+ {.compatible = "arm,coresight-static-funnel"},
+ {}
+};
+
+MODULE_DEVICE_TABLE(of, funnel_match);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id funnel_acpi_ids[] = {
+ {"ARMHC9FE", 0, 0, 0}, /* ARM Coresight Static Funnel */
+ {"ARMHC9FF", 0, 0, 0}, /* ARM CoreSight Dynamic Funnel */
+ {},
+};
+MODULE_DEVICE_TABLE(acpi, funnel_acpi_ids);
+#endif
+
+static struct platform_driver funnel_driver = {
+ .probe = funnel_platform_probe,
+ .remove = funnel_platform_remove,
+ .driver = {
+ .name = "coresight-funnel",
+ /* THIS_MODULE is taken care of by platform_driver_register() */
+ .of_match_table = funnel_match,
+ .acpi_match_table = ACPI_PTR(funnel_acpi_ids),
+ .pm = &funnel_dev_pm_ops,
+ .suppress_bind_attrs = true,
+ },
+};
+
+static int dynamic_funnel_probe(struct amba_device *adev,
+ const struct amba_id *id)
+{
+ int ret;
+
+ ret = funnel_probe(&adev->dev, &adev->res);
+ if (!ret)
+ pm_runtime_put(&adev->dev);
+
+ return ret;
+}
+
+static void dynamic_funnel_remove(struct amba_device *adev)
+{
+ funnel_remove(&adev->dev);
+}
+
+static const struct amba_id dynamic_funnel_ids[] = {
+ {
+ .id = 0x000bb908,
+ .mask = 0x000fffff,
+ },
+ {
+ /* Coresight SoC-600 */
+ .id = 0x000bb9eb,
+ .mask = 0x000fffff,
+ },
+ { 0, 0, NULL },
+};
+
+MODULE_DEVICE_TABLE(amba, dynamic_funnel_ids);
+
+static struct amba_driver dynamic_funnel_driver = {
+ .drv = {
+ .name = "coresight-dynamic-funnel",
+ .pm = &funnel_dev_pm_ops,
+ .suppress_bind_attrs = true,
+ },
+ .probe = dynamic_funnel_probe,
+ .remove = dynamic_funnel_remove,
+ .id_table = dynamic_funnel_ids,
+};
+
+static const struct gtrace_component_id coresight_funnel_ids[] = {
+ { .type = GTRACE_CORESIGHT_FUNNEL,
+ .version = CORESIGHT_COMPONENT_ID_VERSION, },
+ {},
+};
+
+static struct gtrace_driver coresight_funnel_driver = {
+ .id_table = coresight_funnel_ids,
+ .start_port = funnel_enable,
+ .stop_port = funnel_disable,
+ .driver = {
+ .name = "coresight-funnel",
+ },
+};
+
+static int __init funnel_init(void)
+{
+ int ret;
+
+ ret = gtrace_register_driver(&coresight_funnel_driver);
+ if (ret)
+ return ret;
+
+ ret = coresight_init_driver("funnel", &dynamic_funnel_driver, &funnel_driver);
+ if (ret) {
+ gtrace_unregister_driver(&coresight_funnel_driver);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void __exit funnel_exit(void)
+{
+ coresight_remove_driver(&dynamic_funnel_driver, &funnel_driver);
+ gtrace_unregister_driver(&coresight_funnel_driver);
+}
+
+module_init(funnel_init);
+module_exit(funnel_exit);
+
+MODULE_AUTHOR("Pratik Patel <pratikp at codeaurora.org>");
+MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier at linaro.org>");
+MODULE_AUTHOR("Zane Leung <liangzhen at linux.spacemit.com>");
+MODULE_DESCRIPTION("Arm CoreSight Funnel Driver");
+MODULE_LICENSE("GPL v2");
--
2.34.1
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