[PATCH v8 3/4] coresight: cti: add Qualcomm extended CTI identification and quirks

Yingchao Deng
2026-04-26T09:45:23Z

Qualcomm implements an extended variant of the ARM CoreSight CTI with a
different register layout and vendor-specific behavior. While the
programming model remains largely compatible, the register offsets differ
from the standard ARM CTI and require explicit handling.

Detect Qualcomm CTIs via the DEVARCH register and record this in the CTI
driver data. Introduce a small mapping layer to translate standard CTI
register offsets to Qualcomm-specific offsets, allowing the rest of the
driver to use a common register access path.

Additionally, handle a Qualcomm-specific quirk where the CLAIMSET
register is incorrectly initialized to a non-zero value, which can cause
tools or drivers to assume the component is already claimed. Clear the
register during probe to reflect the actual unclaimed state.

No functional change is intended for standard ARM CTI devices.

Co-developed-by: Jinlong Mao <jinlong.mao@oss.qualcomm.com>
Signed-off-by: Jinlong Mao <jinlong.mao@oss.qualcomm.com>
Signed-off-by: Yingchao Deng <yingchao.deng@oss.qualcomm.com>
---
drivers/hwtracing/coresight/coresight-cti-core.c | 28 +++++++++-
drivers/hwtracing/coresight/coresight-cti.h | 4 +-
drivers/hwtracing/coresight/qcom-cti.h | 65 ++++++++++++++++++++++++
3 files changed, 95 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
index c4cbeb64365b..b1c69a3e9b99 100644
--- a/drivers/hwtracing/coresight/coresight-cti-core.c
+++ b/drivers/hwtracing/coresight/coresight-cti-core.c
@@ -21,6 +21,7 @@

#include "coresight-priv.h"
#include "coresight-cti.h"
+#include "qcom-cti.h"

/*
* CTI devices can be associated with a PE, or be connected to CoreSight
@@ -47,6 +48,10 @@ static void __iomem *cti_reg_addr(struct cti_drvdata *drvdata, int reg)
u32 offset = CTI_REG_CLR_NR(reg);
u32 nr = CTI_REG_GET_NR(reg);

+ /* convert to qcom specific offset */
+ if (unlikely(drvdata->is_qcom_cti))
+ offset = cti_qcom_reg_off(offset);
+
return drvdata->base + offset + sizeof(u32) * nr;
}

@@ -170,6 +175,9 @@ void cti_write_intack(struct device *dev, u32 ackval)
/* DEVID[19:16] - number of CTM channels */
#define CTI_DEVID_CTMCHANNELS(devid_val) ((int) BMVAL(devid_val, 16, 19))

+/* DEVARCH[31:21] - ARCHITECT */
+#define CTI_DEVARCH_ARCHITECT(devarch_val) ((int)BMVAL(devarch_val, 21, 31))
+
static int cti_set_default_config(struct device *dev,
struct cti_drvdata *drvdata)
{
@@ -700,6 +708,7 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
struct coresight_desc cti_desc;
struct coresight_platform_data *pdata = NULL;
struct resource *res = &adev->res;
+ u32 devarch;

/* driver data*/
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
@@ -724,6 +733,22 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)

raw_spin_lock_init(&drvdata->spinlock);

+ devarch = readl_relaxed(drvdata->base + CORESIGHT_DEVARCH);
+ if (CTI_DEVARCH_ARCHITECT(devarch) == ARCHITECT_QCOM) {
+ drvdata->is_qcom_cti = true;
+ /*
+ * QCOM CTI does not implement Claimtag functionality as
+ * per CoreSight specification, but its CLAIMSET register
+ * is incorrectly initialized to 0xF. This can mislead
+ * tools or drivers into thinking the component is claimed.
+ *
+ * Reset CLAIMSET to 0 to reflect that no claims are active.
+ */
+ CS_UNLOCK(drvdata->base);
+ writel_relaxed(0, drvdata->base + CORESIGHT_CLAIMSET);
+ CS_LOCK(drvdata->base);
+ }
+
/* initialise CTI driver config values */
ret = cti_set_default_config(dev, drvdata);
if (ret)
@@ -780,7 +805,8 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)

/* all done - dec pm refcount */
pm_runtime_put(&adev->dev);
- dev_info(&drvdata->csdev->dev, "CTI initialized\n");
+ dev_info(&drvdata->csdev->dev,
+ "%sCTI initialized\n", drvdata->is_qcom_cti ? "QCOM " : "");
return 0;
}

diff --git a/drivers/hwtracing/coresight/coresight-cti.h b/drivers/hwtracing/coresight/coresight-cti.h
index dd1ba44518c4..2598601e7b93 100644
--- a/drivers/hwtracing/coresight/coresight-cti.h
+++ b/drivers/hwtracing/coresight/coresight-cti.h
@@ -55,10 +55,11 @@ struct fwnode_handle;
/*
* CTI CSSoc 600 has a max of 32 trigger signals per direction.
* CTI CSSoc 400 has 8 IO triggers - other CTIs can be impl def.
+ * QCOM CTI supports up to 128 trigger signals per direction.
* Max of in and out defined in the DEVID register.
* - pick up actual number used from .dts parameters if present.
*/
-#define CTIINOUTEN_MAX 32
+#define CTIINOUTEN_MAX 128

/*
* Encode CTI register offset and register index in one u32:
@@ -188,6 +189,7 @@ struct cti_drvdata {
raw_spinlock_t spinlock;
struct cti_config config;
struct list_head node;
+ bool is_qcom_cti;
};

/*
diff --git a/drivers/hwtracing/coresight/qcom-cti.h b/drivers/hwtracing/coresight/qcom-cti.h
new file mode 100644
index 000000000000..fd1bf07d7cb4
--- /dev/null
+++ b/drivers/hwtracing/coresight/qcom-cti.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#ifndef _CORESIGHT_QCOM_CTI_H
+#define _CORESIGHT_QCOM_CTI_H
+
+#include "coresight-cti.h"
+
+#define ARCHITECT_QCOM 0x477
+
+/* CTI programming registers */
+#define QCOM_CTIINTACK 0x020
+#define QCOM_CTIAPPSET 0x004
+#define QCOM_CTIAPPCLEAR 0x008
+#define QCOM_CTIAPPPULSE 0x00C
+#define QCOM_CTIINEN 0x400
+#define QCOM_CTIOUTEN 0x800
+#define QCOM_CTITRIGINSTATUS 0x040
+#define QCOM_CTITRIGOUTSTATUS 0x060
+#define QCOM_CTICHINSTATUS 0x080
+#define QCOM_CTICHOUTSTATUS 0x084
+#define QCOM_CTIGATE 0x088
+#define QCOM_ASICCTL 0x08C
+/* Integration test registers */
+#define QCOM_ITCHINACK 0xE70
+#define QCOM_ITTRIGINACK 0xE80
+#define QCOM_ITCHOUT 0xE74
+#define QCOM_ITTRIGOUT 0xEA0
+#define QCOM_ITCHOUTACK 0xE78
+#define QCOM_ITTRIGOUTACK 0xEC0
+#define QCOM_ITCHIN 0xE7C
+#define QCOM_ITTRIGIN 0xEE0
+
+static noinline u32 cti_qcom_reg_off(u32 offset)
+{
+ switch (offset) {
+ case CTIINTACK: return QCOM_CTIINTACK;
+ case CTIAPPSET: return QCOM_CTIAPPSET;
+ case CTIAPPCLEAR: return QCOM_CTIAPPCLEAR;
+ case CTIAPPPULSE: return QCOM_CTIAPPPULSE;
+ case CTIINEN: return QCOM_CTIINEN;
+ case CTIOUTEN: return QCOM_CTIOUTEN;
+ case CTITRIGINSTATUS: return QCOM_CTITRIGINSTATUS;
+ case CTITRIGOUTSTATUS: return QCOM_CTITRIGOUTSTATUS;
+ case CTICHINSTATUS: return QCOM_CTICHINSTATUS;
+ case CTICHOUTSTATUS: return QCOM_CTICHOUTSTATUS;
+ case CTIGATE: return QCOM_CTIGATE;
+ case ASICCTL: return QCOM_ASICCTL;
+ case ITCHINACK: return QCOM_ITCHINACK;
+ case ITTRIGINACK: return QCOM_ITTRIGINACK;
+ case ITCHOUT: return QCOM_ITCHOUT;
+ case ITTRIGOUT: return QCOM_ITTRIGOUT;
+ case ITCHOUTACK: return QCOM_ITCHOUTACK;
+ case ITTRIGOUTACK: return QCOM_ITTRIGOUTACK;
+ case ITCHIN: return QCOM_ITCHIN;
+ case ITTRIGIN: return QCOM_ITTRIGIN;
+
+ default:
+ return offset;
+ }
+}
+
+#endif /* _CORESIGHT_QCOM_CTI_H */

--
2.43.0