[PATCH v2 2/3] coresight: funnel: Support static funnel

[Wanglai Shi]

From: Leo Yan <leo.yan@xxxxxxxxxx>

Since CoreSight hardware topology can use a 'hidden' funnel in the
trace data path, this kind funnel doesn't have register for accessing
and is used by default from hardware design perspective.  Below is an
example for related hardware topology:

  +------+  +------+
  | cpu0 |->| ETM  |-\
  +------+  +------+  \-> +--------+  +-----+
   ......                 | Funnel |->| ETF |-\    Hidden funnel
  +------+  +------+  /-> +--------+  +-----+  \        |
  | cpu3 |->| ETM  |-/                          \       V
  +------+  +------+                             \-> +--------+
                                                     | Funnel |-> ...
  +------+  +------+                             /-> +--------+
  | cpu4 |->| ETM  |-\                          /
  +------+  +------+  \-> +--------+  +-----+  /
   ......                 | Funnel |->| ETF |-/
  +------+  +------+  /-> +--------+  +-----+
  | cpu7 |->| ETM  |-/
  +------+  +------+

The CoreSight funnel driver only supports dynamic funnel with
registration register resource, thus it cannot support for the static
funnel case and it's impossible to create trace data path for this case.

This patch is to extend CoreSight funnel driver to support both for
static funnel and dynamic funnel.  For the dynamic funnel it reuses the
code existed in the driver, for static funnel the driver will support
device probe if without providing register resource and the driver skips
registers accessing when detect the register base is NULL.

Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
---
 .../hwtracing/coresight/coresight-funnel.c    | 112 +++++++++++++-----
 1 file changed, 85 insertions(+), 27 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index 927925151509..c6ba864ae488 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c
@@ -12,6 +12,7 @@
 #include <linux/err.h>
 #include <linux/fs.h>
 #include <linux/slab.h>
+#include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/coresight.h>
 #include <linux/amba/bus.h>
@@ -43,7 +44,7 @@ struct funnel_drvdata {
 	unsigned long		priority;
 };
 
-static int funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
+static int dynamic_funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
 {
 	u32 functl;
 	int rc = 0;
@@ -71,17 +72,19 @@ static int funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
 static int funnel_enable(struct coresight_device *csdev, int inport,
 			 int outport)
 {
-	int rc;
+	int rc = 0;
 	struct funnel_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
-	rc = funnel_enable_hw(drvdata, inport);
+	if (drvdata->base)
+		rc = dynamic_funnel_enable_hw(drvdata, inport);
 
 	if (!rc)
 		dev_dbg(drvdata->dev, "FUNNEL inport %d enabled\n", inport);
 	return rc;
 }
 
-static void funnel_disable_hw(struct funnel_drvdata *drvdata, int inport)
+static void dynamic_funnel_disable_hw(struct funnel_drvdata *drvdata,
+				      int inport)
 {
 	u32 functl;
 
@@ -103,7 +106,8 @@ static void funnel_disable(struct coresight_device *csdev, int inport,
 {
 	struct funnel_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
-	funnel_disable_hw(drvdata, inport);
+	if (drvdata->base)
+		dynamic_funnel_disable_hw(drvdata, inport);
 
 	dev_dbg(drvdata->dev, "FUNNEL inport %d disabled\n", inport);
 }
@@ -177,54 +181,67 @@ static struct attribute *coresight_funnel_attrs[] = {
 };
 ATTRIBUTE_GROUPS(coresight_funnel);
 
-static int funnel_probe(struct amba_device *adev, const struct amba_id *id)
+static int funnel_probe(struct device *dev, struct resource *res)
 {
 	int ret;
 	void __iomem *base;
-	struct device *dev = &adev->dev;
 	struct coresight_platform_data *pdata = NULL;
 	struct funnel_drvdata *drvdata;
-	struct resource *res = &adev->res;
 	struct coresight_desc desc = { 0 };
-	struct device_node *np = adev->dev.of_node;
+	struct device_node *np = 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;
+		dev->platform_data = pdata;
 	}
 
 	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
 	if (!drvdata)
 		return -ENOMEM;
 
-	drvdata->dev = &adev->dev;
-	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
+	drvdata->dev = dev;
+	drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */
 	if (!IS_ERR(drvdata->atclk)) {
 		ret = clk_prepare_enable(drvdata->atclk);
 		if (ret)
 			return ret;
 	}
-	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);
+	/*
+	 * 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)) {
+			ret = PTR_ERR(base);
+			goto out_disable_clk;
+		}
+		drvdata->base = base;
+		desc.groups = coresight_funnel_groups;
+	}
 
-	drvdata->base = base;
-	pm_runtime_put(&adev->dev);
+	dev_set_drvdata(dev, drvdata);
 
 	desc.type = CORESIGHT_DEV_TYPE_LINK;
 	desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_MERG;
 	desc.ops = &funnel_cs_ops;
 	desc.pdata = pdata;
 	desc.dev = dev;
-	desc.groups = coresight_funnel_groups;
 	drvdata->csdev = coresight_register(&desc);
+	if (IS_ERR(drvdata->csdev)) {
+		ret = PTR_ERR(drvdata->csdev);
+		goto out_disable_clk;
+	}
+
+	pm_runtime_put(dev);
 
-	return PTR_ERR_OR_ZERO(drvdata->csdev);
+out_disable_clk:
+	if (ret && !IS_ERR_OR_NULL(drvdata->atclk))
+		clk_disable_unprepare(drvdata->atclk);
+	return ret;
 }
 
 #ifdef CONFIG_PM
@@ -253,7 +270,48 @@ static const struct dev_pm_ops funnel_dev_pm_ops = {
 	SET_RUNTIME_PM_OPS(funnel_runtime_suspend, funnel_runtime_resume, NULL)
 };
 
-static const struct amba_id funnel_ids[] = {
+static int static_funnel_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	/* Static funnel do not have programming base */
+	ret = funnel_probe(&pdev->dev, NULL);
+
+	if (ret) {
+		pm_runtime_put_noidle(&pdev->dev);
+		pm_runtime_disable(&pdev->dev);
+	}
+
+	return ret;
+}
+
+static const struct of_device_id static_funnel_match[] = {
+	{.compatible = "arm,coresight-funnel"},
+	{}
+};
+
+static struct platform_driver static_funnel_driver = {
+	.probe          = static_funnel_probe,
+	.driver         = {
+		.name   = "coresight-static-funnel",
+		.of_match_table = static_funnel_match,
+		.pm	= &funnel_dev_pm_ops,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver(static_funnel_driver);
+
+static int dynamic_funnel_probe(struct amba_device *adev,
+				const struct amba_id *id)
+{
+	return funnel_probe(&adev->dev, &adev->res);
+}
+
+static const struct amba_id dynamic_funnel_ids[] = {
 	{
 		.id     = 0x000bb908,
 		.mask   = 0x000fffff,
@@ -266,14 +324,14 @@ static const struct amba_id funnel_ids[] = {
 	{ 0, 0},
 };
 
-static struct amba_driver funnel_driver = {
+static struct amba_driver dynamic_funnel_driver = {
 	.drv = {
-		.name	= "coresight-funnel",
+		.name	= "coresight-dynamic-funnel",
 		.owner	= THIS_MODULE,
 		.pm	= &funnel_dev_pm_ops,
 		.suppress_bind_attrs = true,
 	},
-	.probe		= funnel_probe,
-	.id_table	= funnel_ids,
+	.probe		= dynamic_funnel_probe,
+	.id_table	= dynamic_funnel_ids,
 };
-builtin_amba_driver(funnel_driver);
+builtin_amba_driver(dynamic_funnel_driver);
-- 
2.17.1