[PATCH v13 5/9] coresight-tpdm: Add integration test support

[Mao Jinlong]

Integration test for tpdm can help to generate the data for
verification of the topology during TPDM software bring up.

Sample:
echo 1 > /sys/bus/coresight/devices/tmc_etf0/enable_sink
echo 1 > /sys/bus/coresight/devices/tpdm0/enable_source
echo 1 > /sys/bus/coresight/devices/tpdm0/integration_test
echo 2 > /sys/bus/coresight/devices/tpdm0/integration_test
cat /dev/tmc_etf0 > /data/etf-tpdm0.bin

Reviewed-by: Suzuki K Poulose <suzuki.poulose at arm.com>
Signed-off-by: Tao Zhang <quic_taozha at quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao at quicinc.com>
---
 .../testing/sysfs-bus-coresight-devices-tpdm  | 13 +++++
 drivers/hwtracing/coresight/coresight-tpdm.c  | 54 +++++++++++++++++++
 drivers/hwtracing/coresight/coresight-tpdm.h  | 14 +++++
 3 files changed, 81 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
new file mode 100644
index 000000000000..e1c2b5a59cb4
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
@@ -0,0 +1,13 @@
+What:		/sys/bus/coresight/devices/<tpdm-name>/integration_test
+Date:		June 2022
+KernelVersion	5.20
+Contact:	Jinlong Mao (QUIC) <quic_jinlmao at quicinc.com>, Tao Zhang (QUIC) <quic_taozha at quicinc.com>
+Description:
+		(Write) Run integration test for tpdm. Integration test
+		will generate test data for tpdm. It can help to make
+		sure that the trace path is enabled and the link configurations
+		are fine.
+
+		Accepts only one of the 2 values -  1 or 2.
+		1 : Generate 64 bits data
+		2 : Generate 32 bits data
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index f6d653a45c99..88df3e687ce2 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -121,6 +121,59 @@ static void tpdm_init_default_data(struct tpdm_drvdata *drvdata)
 	CS_LOCK(drvdata->base);
 }
 
+/*
+ * value 1: 64 bits test data
+ * value 2: 32 bits test data
+ */
+static ssize_t integration_test_store(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf,
+					  size_t size)
+{
+	int i, ret = 0;
+	unsigned long val;
+	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	ret = kstrtoul(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	if (val != 1 && val != 2)
+		return -EINVAL;
+
+	if (!drvdata->enable)
+		return -EINVAL;
+
+	if (val == 1)
+		val = ATBCNTRL_VAL_64;
+	else
+		val = ATBCNTRL_VAL_32;
+	CS_UNLOCK(drvdata->base);
+	writel_relaxed(0x1, drvdata->base + TPDM_ITCNTRL);
+
+	for (i = 0; i < INTEGRATION_TEST_CYCLE; i++)
+		writel_relaxed(val, drvdata->base + TPDM_ITATBCNTRL);
+
+	writel_relaxed(0, drvdata->base + TPDM_ITCNTRL);
+	CS_LOCK(drvdata->base);
+	return size;
+}
+static DEVICE_ATTR_WO(integration_test);
+
+static struct attribute *tpdm_attrs[] = {
+	&dev_attr_integration_test.attr,
+	NULL,
+};
+
+static struct attribute_group tpdm_attr_grp = {
+	.attrs = tpdm_attrs,
+};
+
+static const struct attribute_group *tpdm_attr_grps[] = {
+	&tpdm_attr_grp,
+	NULL,
+};
+
 static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
 {
 	void __iomem *base;
@@ -157,6 +210,7 @@ static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
 	desc.pdata = adev->dev.platform_data;
 	desc.dev = &adev->dev;
 	desc.access = CSDEV_ACCESS_IOMEM(base);
+	desc.groups = tpdm_attr_grps;
 	drvdata->csdev = coresight_register(&desc);
 	if (IS_ERR(drvdata->csdev))
 		return PTR_ERR(drvdata->csdev);
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h
index c8a101cbb4c7..d808fa1e8d4a 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.h
+++ b/drivers/hwtracing/coresight/coresight-tpdm.h
@@ -14,6 +14,20 @@
 /* Enable bit for DSB subunit */
 #define TPDM_DSB_CR_ENA		BIT(0)
 
+/* TPDM integration test registers */
+#define TPDM_ITATBCNTRL		(0xEF0)
+#define TPDM_ITCNTRL		(0xF00)
+
+/* Register value for integration test */
+#define ATBCNTRL_VAL_32		0xC00F1409
+#define ATBCNTRL_VAL_64		0xC01F1409
+
+/*
+ * Number of cycles to write value when
+ * integration test.
+ */
+#define INTEGRATION_TEST_CYCLE	10
+
 /**
  * The bits of PERIPHIDR0 register.
  * The fields [6:0] of PERIPHIDR0 are used to determine what
-- 
2.17.1