[PATCH v16 5/7] qcom-tgu: Add support to configure next action
From: Songwei Chai
Date: Thu Jul 30 2026 - 04:16:55 EST
From: Songwei Chai <songchai@xxxxxxxxxxxxxxxx>
Add "select" node for each step to determine if another step is taken,
trigger(s) are generated, counters/timers incremented/decremented, etc.
Reviewed-by: Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
Signed-off-by: Songwei Chai <songchai@xxxxxxxxxxxxxxxx>
---
.../ABI/testing/sysfs-bus-amba-devices-tgu | 16 +++++
drivers/hwtracing/qcom/tgu.c | 68 ++++++++++++++++++-
drivers/hwtracing/qcom/tgu.h | 41 +++++++++++
3 files changed, 123 insertions(+), 2 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
index 705e75c776d4..fa9e9083065e 100644
--- a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
+++ b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
@@ -21,3 +21,19 @@ KernelVersion: 7.2
Contact: Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Songwei Chai <songwei.chai@xxxxxxxxxxxxxxxx>
Description:
(RW) Set/Get the decode mode with specific step for TGU.
+
+What: /sys/bus/amba/devices/<tgu-name>/step[0:7]_condition_select/reg[0:3]
+Date: August 2026
+KernelVersion: 7.2
+Contact: Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Songwei Chai <songwei.chai@xxxxxxxxxxxxxxxx>
+Description:
+ (RW) Set/Get the next action with specific step for TGU.
+
+What: /sys/bus/amba/devices/<tgu-name>/step[0:7]_condition_select/default
+Date: August 2026
+KernelVersion: 7.2
+Contact: Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Songwei Chai <songwei.chai@xxxxxxxxxxxxxxxx>
+Description:
+ (RW) Set/Get the default next action for a specific step of the
+ TGU. This is the last register of the condition select region
+ and is applied when none of the numbered select registers match.
diff --git a/drivers/hwtracing/qcom/tgu.c b/drivers/hwtracing/qcom/tgu.c
index e83295217e7a..7f0a74514e40 100644
--- a/drivers/hwtracing/qcom/tgu.c
+++ b/drivers/hwtracing/qcom/tgu.c
@@ -30,6 +30,16 @@ static int calculate_array_location(struct tgu_drvdata *drvdata,
case TGU_CONDITION_DECODE:
return step_index * (drvdata->num_condition_decode) +
reg_index;
+ case TGU_CONDITION_SELECT:
+ /*
+ * The 'default' register is the last one in the select region;
+ * it is exposed with a sentinel reg number, translated here to
+ * its actual position.
+ */
+ if (reg_index == TGU_SELECT_DEFAULT_REG)
+ reg_index = drvdata->num_condition_select - 1;
+ return step_index * (drvdata->num_condition_select) +
+ reg_index;
default:
break;
}
@@ -79,6 +89,9 @@ static ssize_t tgu_dataset_show(struct device *dev,
case TGU_CONDITION_DECODE:
return sysfs_emit(buf, "0x%x\n",
drvdata->value_table->condition_decode[index]);
+ case TGU_CONDITION_SELECT:
+ return sysfs_emit(buf, "0x%x\n",
+ drvdata->value_table->condition_select[index]);
default:
break;
}
@@ -120,6 +133,10 @@ static ssize_t tgu_dataset_store(struct device *dev,
tgu_drvdata->value_table->condition_decode[index] = val;
ret = size;
break;
+ case TGU_CONDITION_SELECT:
+ tgu_drvdata->value_table->condition_select[index] = val;
+ ret = size;
+ break;
default:
ret = -EINVAL;
break;
@@ -158,6 +175,17 @@ static umode_t tgu_node_visible(struct kobject *kobject,
if (tgu_attr->reg_num < drvdata->num_condition_decode)
return attr->mode;
break;
+ case TGU_CONDITION_SELECT:
+ /*
+ * The next-action ('default') register is exposed as its own
+ * statically named attribute and is always present. The numbered
+ * data registers occupy the positions before it.
+ */
+ if (tgu_attr->reg_num == TGU_SELECT_DEFAULT_REG)
+ return attr->mode;
+ if (tgu_attr->reg_num < drvdata->num_condition_select - 1)
+ return attr->mode;
+ break;
default:
break;
}
@@ -196,6 +224,18 @@ static ssize_t tgu_write_all_hw_regs(struct tgu_drvdata *drvdata)
drvdata->base + CONDITION_DECODE_STEP(i, j));
}
}
+
+ for (i = 0; i < drvdata->num_step; i++) {
+ for (j = 0; j < drvdata->num_condition_select; j++) {
+ index = check_array_location(drvdata, i,
+ TGU_CONDITION_SELECT, j);
+ if (index == -EINVAL)
+ goto exit;
+
+ writel(drvdata->value_table->condition_select[index],
+ drvdata->base + CONDITION_SELECT_STEP(i, j));
+ }
+ }
/* Enable TGU to program the triggers */
writel(1, drvdata->base + TGU_CONTROL);
exit:
@@ -268,6 +308,12 @@ static void tgu_set_conditions(struct tgu_drvdata *drvdata)
drvdata->num_condition_decode, TGU_MAX_CONDITION_DECODE);
drvdata->num_condition_decode = TGU_MAX_CONDITION_DECODE;
}
+
+ /* select region has an additional 'default' register */
+ drvdata->num_condition_select = TGU_DEVID_CONDITIONS(devid) + 1;
+
+ if (drvdata->num_condition_select > TGU_MAX_CONDITION_SELECT)
+ drvdata->num_condition_select = TGU_MAX_CONDITION_SELECT;
}
static void tgu_disable(struct tgu_drvdata *drvdata)
@@ -389,6 +435,14 @@ static const struct attribute_group *tgu_attr_groups[] = {
CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(5),
CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(6),
CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(7),
+ CONDITION_SELECT_ATTRIBUTE_GROUP_INIT(0),
+ CONDITION_SELECT_ATTRIBUTE_GROUP_INIT(1),
+ CONDITION_SELECT_ATTRIBUTE_GROUP_INIT(2),
+ CONDITION_SELECT_ATTRIBUTE_GROUP_INIT(3),
+ CONDITION_SELECT_ATTRIBUTE_GROUP_INIT(4),
+ CONDITION_SELECT_ATTRIBUTE_GROUP_INIT(5),
+ CONDITION_SELECT_ATTRIBUTE_GROUP_INIT(6),
+ CONDITION_SELECT_ATTRIBUTE_GROUP_INIT(7),
NULL,
};
@@ -396,8 +450,8 @@ static int tgu_probe(struct amba_device *adev, const struct amba_id *id)
{
struct device *dev = &adev->dev;
struct tgu_drvdata *drvdata;
- unsigned int *priority, *condition;
- size_t priority_size, condition_size;
+ unsigned int *priority, *condition, *select;
+ size_t priority_size, condition_size, select_size;
int i, j;
int ret;
@@ -452,6 +506,16 @@ static int tgu_probe(struct amba_device *adev, const struct amba_id *id)
drvdata, i, TGU_CONDITION_DECODE, j)] =
TGU_CONDITION_DECODE_NOT;
+ select_size = drvdata->num_condition_select * drvdata->num_step;
+
+ select = devm_kcalloc(dev, select_size,
+ sizeof(*(drvdata->value_table->condition_select)),
+ GFP_KERNEL);
+ if (!select)
+ return -ENOMEM;
+
+ drvdata->value_table->condition_select = select;
+
drvdata->enabled = false;
/*
* Create the sysfs groups only after the backing storage is fully
diff --git a/drivers/hwtracing/qcom/tgu.h b/drivers/hwtracing/qcom/tgu.h
index 8b6a46995a5f..cee55f66f629 100644
--- a/drivers/hwtracing/qcom/tgu.h
+++ b/drivers/hwtracing/qcom/tgu.h
@@ -55,6 +55,7 @@
#define STEP_OFFSET 0x1D8
#define PRIORITY_START_OFFSET 0x0074
#define CONDITION_DECODE_OFFSET 0x0050
+#define CONDITION_SELECT_OFFSET 0x0060
#define PRIORITY_OFFSET 0x60
#define REG_OFFSET 0x4
@@ -67,6 +68,8 @@
* TGU_MAX_STEPS static tables define step0..step7
* TGU_MAX_PRIORITY_REGS STEP_PRIORITY_LIST defines reg0..reg17
* TGU_MAX_CONDITION_DECODE decode region 0x50..0x5F holds 4 u32 registers
+ * TGU_MAX_CONDITION_SELECT select region 0x60..0x73 holds 5 u32 registers
+ * (the last one being the 'default' next-action)
*
* A device whose DEVID reports counts above these bounds is clamped, so writes
* never fall outside the ioremap()'d window or spill into an adjacent region.
@@ -75,6 +78,7 @@
#define TGU_MAX_STEPS 8
#define TGU_MAX_PRIORITY_REGS 18
#define TGU_MAX_CONDITION_DECODE 4
+#define TGU_MAX_CONDITION_SELECT 5
/* Calculate compare step addresses */
#define PRIORITY_REG_STEP(step, priority, reg)\
@@ -84,6 +88,9 @@
#define CONDITION_DECODE_STEP(step, decode) \
(CONDITION_DECODE_OFFSET + REG_OFFSET * decode + STEP_OFFSET * step)
+#define CONDITION_SELECT_STEP(step, select) \
+ (CONDITION_SELECT_OFFSET + REG_OFFSET * select + STEP_OFFSET * step)
+
#define tgu_dataset_rw(name, step_index, type, reg_num) \
(&((struct tgu_attribute[]){ { \
__ATTR(name, 0644, tgu_dataset_show, tgu_dataset_store), \
@@ -97,6 +104,20 @@
reg_num)
#define STEP_DECODE(step_index, reg_num) \
tgu_dataset_rw(reg##reg_num, step_index, TGU_CONDITION_DECODE, reg_num)
+#define STEP_SELECT(step_index, reg_num) \
+ tgu_dataset_rw(reg##reg_num, step_index, TGU_CONDITION_SELECT, reg_num)
+
+/*
+ * The last register of the 'condition select' region is the next-action
+ * ('default') register. Its position depends on the runtime value of
+ * num_condition_select, so it is exposed as a dedicated statically named
+ * "default" attribute carrying a sentinel reg number, rather than renaming
+ * a shared static attribute at runtime.
+ */
+#define TGU_SELECT_DEFAULT_REG 0xffff
+#define STEP_SELECT_DEFAULT(step_index) \
+ tgu_dataset_rw(default, step_index, TGU_CONDITION_SELECT, \
+ TGU_SELECT_DEFAULT_REG)
#define STEP_PRIORITY_LIST(step_index, priority) \
{STEP_PRIORITY(step_index, 0, priority), \
@@ -128,6 +149,15 @@
NULL \
}
+#define STEP_SELECT_LIST(n) \
+ {STEP_SELECT(n, 0), \
+ STEP_SELECT(n, 1), \
+ STEP_SELECT(n, 2), \
+ STEP_SELECT(n, 3), \
+ STEP_SELECT_DEFAULT(n), \
+ NULL \
+ }
+
#define PRIORITY_ATTRIBUTE_GROUP_INIT(step, priority)\
(&(const struct attribute_group){\
.attrs = (struct attribute*[])STEP_PRIORITY_LIST(step, priority),\
@@ -142,12 +172,20 @@
.name = "step" #step "_condition_decode" \
})
+#define CONDITION_SELECT_ATTRIBUTE_GROUP_INIT(step)\
+ (&(const struct attribute_group){\
+ .attrs = (struct attribute*[])STEP_SELECT_LIST(step),\
+ .is_visible = tgu_node_visible,\
+ .name = "step" #step "_condition_select" \
+ })
+
enum operation_index {
TGU_PRIORITY0,
TGU_PRIORITY1,
TGU_PRIORITY2,
TGU_PRIORITY3,
TGU_CONDITION_DECODE,
+ TGU_CONDITION_SELECT,
};
/* Maximum priority that TGU supports */
@@ -171,6 +209,7 @@ struct tgu_attribute {
struct value_table {
unsigned int *priority;
unsigned int *condition_decode;
+ unsigned int *condition_select;
};
static inline void TGU_LOCK(void __iomem *addr)
@@ -202,6 +241,7 @@ static inline void TGU_UNLOCK(void __iomem *addr)
* @num_reg: Maximum number of registers
* @num_step: Maximum step size
* @num_condition_decode: Maximum number of condition_decode
+ * @num_condition_select: Maximum number of condition_select
*
* This structure defines the data associated with a TGU device,
* including its base address, device pointer, the lock serialising
@@ -216,6 +256,7 @@ struct tgu_drvdata {
int num_reg;
int num_step;
int num_condition_decode;
+ int num_condition_select;
};
#endif
--
2.34.1