[PATCH v3 25/26] coresight: etm4x: Add support for sysreg only devices

Suzuki K Poulose
2020-10-28T22:11:06Z

Add support for devices with system instruction access only.
They don't have a memory mapped interface and thus are not
AMBA devices.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
.../coresight/coresight-etm4x-core.c | 50 +++++++++++++++++--
1 file changed, 45 insertions(+), 5 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 25fab5513604..50a574228866 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -26,6 +26,7 @@
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/perf_event.h>
+#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
#include <asm/sections.h>
@@ -1623,9 +1624,6 @@ static int etm4_probe(struct device *dev, void __iomem *base)
return -ENOMEM;
}

- if (fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))
- drvdata->skip_power_up = true;
-
drvdata->base = base;

spin_lock_init(&drvdata->spinlock);
@@ -1648,6 +1646,11 @@ static int etm4_probe(struct device *dev, void __iomem *base)
if (!drvdata->arch)
return -EINVAL;

+ /* Skip programming TRCPDCR for system instructions. */
+ if (!desc.access.io_mem ||
+ fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))
+ drvdata->skip_power_up = true;
+
etm4_init_trace_id(drvdata);
etm4_set_default(&drvdata->config);

@@ -1706,6 +1709,20 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)
return ret;
}

+static int etm4_probe_platform_dev(struct platform_device *pdev)
+{
+ int ret;
+
+ pm_runtime_get_noresume(&pdev->dev);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
+ ret = etm4_probe(&pdev->dev, NULL);
+
+ pm_runtime_put(&pdev->dev);
+ return ret;
+}
+
static struct amba_cs_uci_id uci_id_etm4[] = {
{
/* ETMv4 UCI data */
@@ -1781,6 +1798,20 @@ static struct amba_driver etm4x_amba_driver = {
.id_table = etm4_ids,
};

+static const struct of_device_id etm_sysreg_match[] = {
+ { .compatible = "arm,coresight-etm-sysreg" },
+ {}
+};
+
+static struct platform_driver etm4_platform_driver = {
+ .probe = etm4_probe_platform_dev,
+ .driver = {
+ .name = "coresight-etm4x",
+ .of_match_table = etm_sysreg_match,
+ .suppress_bind_attrs = true,
+ },
+};
+
static int __init etm4x_init(void)
{
int ret;
@@ -1793,10 +1824,19 @@ static int __init etm4x_init(void)

ret = amba_driver_register(&etm4x_amba_driver);
if (ret) {
- pr_err("Error registering etm4x driver\n");
- etm4_pm_clear();
+ pr_err("Error registering etm4x AMBA driver\n");
+ goto clear_pm;
}

+ ret = platform_driver_register(&etm4_platform_driver);
+ if (!ret)
+ return 0;
+
+ pr_err("Error registering etm4x platform driver\n");
+ amba_driver_unregister(&etm4x_amba_driver);
+
+clear_pm:
+ etm4_pm_clear();
return ret;
}

--
2.24.1