[PATCH v14 4/7] qcom-tgu: Add TGU decode support

Songwei Chai
2026-04-17T07:35:41Z

Decoding is when all the potential pieces for creating a trigger
are brought together for a given step. Example - there may be a
counter keeping track of some occurrences and a priority-group that
is being used to detect a pattern on the sense inputs. These 2
inputs to condition_decode must be programmed, for a given step,
to establish the condition for the trigger, or movement to another
steps.

Reviewed-by: Jie Gan <jie.gan@oss.qualcomm.com>
Signed-off-by: Songwei Chai <songwei.chai@oss.qualcomm.com>
---
.../ABI/testing/sysfs-bus-amba-devices-tgu | 7 +
drivers/hwtracing/qcom/tgu.c | 157 +++++++++++++++---
drivers/hwtracing/qcom/tgu.h | 27 +++
3 files changed, 170 insertions(+), 21 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
index 223873789ca6..4ef0d696d3d0 100644
--- a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
+++ b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
@@ -14,3 +14,10 @@ KernelVersion: 7.1
Contact: Jinlong Mao <jinlong.mao@oss.qualcomm.com>, Songwei Chai <songwei.chai@oss.qualcomm.com>
Description:
(RW) Set/Get the sensed signal with specific step and priority for TGU.
+
+What: /sys/bus/amba/devices/<tgu-name>/step[0:7]_condition_decode/reg[0:3]
+Date: April 2026
+KernelVersion: 7.1
+Contact: Jinlong Mao <jinlong.mao@oss.qualcomm.com>, Songwei Chai <songwei.chai@oss.qualcomm.com>
+Description:
+ (RW) Set/Get the decode mode with specific step for TGU.
diff --git a/drivers/hwtracing/qcom/tgu.c b/drivers/hwtracing/qcom/tgu.c
index 7d69986c3e3d..937211923d93 100644
--- a/drivers/hwtracing/qcom/tgu.c
+++ b/drivers/hwtracing/qcom/tgu.c
@@ -18,8 +18,33 @@ static int calculate_array_location(struct tgu_drvdata *drvdata,
int step_index, int operation_index,
int reg_index)
{
- return operation_index * (drvdata->num_step) * (drvdata->num_reg) +
- step_index * (drvdata->num_reg) + reg_index;
+ switch (operation_index) {
+ case TGU_PRIORITY0:
+ case TGU_PRIORITY1:
+ case TGU_PRIORITY2:
+ case TGU_PRIORITY3:
+ return operation_index * (drvdata->num_step) *
+ (drvdata->num_reg) +
+ step_index * (drvdata->num_reg) + reg_index;
+ case TGU_CONDITION_DECODE:
+ return step_index * (drvdata->num_condition_decode) +
+ reg_index;
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+
+static int check_array_location(struct tgu_drvdata *drvdata, int step,
+ int ops, int reg)
+{
+ int result = calculate_array_location(drvdata, step, ops, reg);
+
+ if (result == -EINVAL)
+ dev_err(drvdata->dev, "check array location - Fail\n");
+
+ return result;
}

static ssize_t tgu_dataset_show(struct device *dev,
@@ -30,12 +55,26 @@ static ssize_t tgu_dataset_show(struct device *dev,
container_of(attr, struct tgu_attribute, attr);
int index;

- index = calculate_array_location(drvdata, tgu_attr->step_index,
- tgu_attr->operation_index,
- tgu_attr->reg_num);
-
- return sysfs_emit(buf, "0x%x\n",
- drvdata->value_table->priority[index]);
+ index = check_array_location(drvdata, tgu_attr->step_index,
+ tgu_attr->operation_index, tgu_attr->reg_num);
+
+ if (index == -EINVAL)
+ return index;
+
+ switch (tgu_attr->operation_index) {
+ case TGU_PRIORITY0:
+ case TGU_PRIORITY1:
+ case TGU_PRIORITY2:
+ case TGU_PRIORITY3:
+ return sysfs_emit(buf, "0x%x\n",
+ drvdata->value_table->priority[index]);
+ case TGU_CONDITION_DECODE:
+ return sysfs_emit(buf, "0x%x\n",
+ drvdata->value_table->condition_decode[index]);
+ default:
+ break;
+ }
+ return -EINVAL;
}

static ssize_t tgu_dataset_store(struct device *dev,
@@ -54,13 +93,31 @@ static ssize_t tgu_dataset_store(struct device *dev,
return ret;

guard(spinlock)(&tgu_drvdata->lock);
- index = calculate_array_location(tgu_drvdata, tgu_attr->step_index,
+ index = check_array_location(tgu_drvdata, tgu_attr->step_index,
tgu_attr->operation_index,
tgu_attr->reg_num);

- tgu_drvdata->value_table->priority[index] = val;
+ if (index == -EINVAL)
+ return index;
+
+ switch (tgu_attr->operation_index) {
+ case TGU_PRIORITY0:
+ case TGU_PRIORITY1:
+ case TGU_PRIORITY2:
+ case TGU_PRIORITY3:
+ tgu_drvdata->value_table->priority[index] = val;
+ ret = size;
+ break;
+ case TGU_CONDITION_DECODE:
+ tgu_drvdata->value_table->condition_decode[index] = val;
+ ret = size;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }

- return size;
+ return ret;
}

static umode_t tgu_node_visible(struct kobject *kobject,
@@ -77,13 +134,26 @@ static umode_t tgu_node_visible(struct kobject *kobject,
if (tgu_attr->step_index >= drvdata->num_step)
return SYSFS_GROUP_INVISIBLE;

- if (tgu_attr->reg_num >= drvdata->num_reg)
- return 0;
+ switch (tgu_attr->operation_index) {
+ case TGU_PRIORITY0:
+ case TGU_PRIORITY1:
+ case TGU_PRIORITY2:
+ case TGU_PRIORITY3:
+ if (tgu_attr->reg_num < drvdata->num_reg)
+ return attr->mode;
+ break;
+ case TGU_CONDITION_DECODE:
+ if (tgu_attr->reg_num < drvdata->num_condition_decode)
+ return attr->mode;
+ break;
+ default:
+ break;
+ }

- return attr->mode;
+ return 0;
}

-static void tgu_write_all_hw_regs(struct tgu_drvdata *drvdata)
+static ssize_t tgu_write_all_hw_regs(struct tgu_drvdata *drvdata)
{
int i, j, k, index;

@@ -91,8 +161,10 @@ static void tgu_write_all_hw_regs(struct tgu_drvdata *drvdata)
for (i = 0; i < drvdata->num_step; i++) {
for (j = 0; j < MAX_PRIORITY; j++) {
for (k = 0; k < drvdata->num_reg; k++) {
- index = calculate_array_location(
+ index = check_array_location(
drvdata, i, j, k);
+ if (index == -EINVAL)
+ goto exit;

writel(drvdata->value_table->priority[index],
drvdata->base +
@@ -100,9 +172,23 @@ static void tgu_write_all_hw_regs(struct tgu_drvdata *drvdata)
}
}
}
+
+ for (i = 0; i < drvdata->num_step; i++) {
+ for (j = 0; j < drvdata->num_condition_decode; j++) {
+ index = check_array_location(drvdata, i,
+ TGU_CONDITION_DECODE, j);
+ if (index == -EINVAL)
+ goto exit;
+
+ writel(drvdata->value_table->condition_decode[index],
+ drvdata->base + CONDITION_DECODE_STEP(i, j));
+ }
+ }
/* Enable TGU to program the triggers */
writel(1, drvdata->base + TGU_CONTROL);
+exit:
TGU_LOCK(drvdata->base);
+ return index >= 0 ? 0 : -EINVAL;
}

static void tgu_set_reg_number(struct tgu_drvdata *drvdata)
@@ -131,16 +217,26 @@ static void tgu_set_steps(struct tgu_drvdata *drvdata)
drvdata->num_step = TGU_DEVID_STEPS(devid);
}

+static void tgu_set_conditions(struct tgu_drvdata *drvdata)
+{
+ u32 devid;
+
+ devid = readl(drvdata->base + TGU_DEVID);
+ drvdata->num_condition_decode = TGU_DEVID_CONDITIONS(devid);
+}
+
static int tgu_enable(struct device *dev)
{
struct tgu_drvdata *drvdata = dev_get_drvdata(dev);
+ int ret;

guard(spinlock)(&drvdata->lock);
- drvdata->enabled = true;

- tgu_write_all_hw_regs(drvdata);
+ ret = tgu_write_all_hw_regs(drvdata);
+ if (!ret)
+ drvdata->enabled = true;

- return 0;
+ return ret;
}

static void tgu_do_disable(struct tgu_drvdata *drvdata)
@@ -262,6 +358,14 @@ static const struct attribute_group *tgu_attr_groups[] = {
PRIORITY_ATTRIBUTE_GROUP_INIT(7, 1),
PRIORITY_ATTRIBUTE_GROUP_INIT(7, 2),
PRIORITY_ATTRIBUTE_GROUP_INIT(7, 3),
+ CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(0),
+ CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(1),
+ CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(2),
+ CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(3),
+ CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(4),
+ CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(5),
+ CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(6),
+ CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(7),
NULL,
};

@@ -269,8 +373,8 @@ 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;
- size_t priority_size;
+ unsigned int *priority, *condition;
+ size_t priority_size, condition_size;
int ret;

drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
@@ -288,6 +392,7 @@ static int tgu_probe(struct amba_device *adev, const struct amba_id *id)

tgu_set_reg_number(drvdata);
tgu_set_steps(drvdata);
+ tgu_set_conditions(drvdata);

ret = sysfs_create_groups(&dev->kobj, tgu_attr_groups);
if (ret) {
@@ -310,6 +415,16 @@ static int tgu_probe(struct amba_device *adev, const struct amba_id *id)

drvdata->value_table->priority = priority;

+ condition_size = drvdata->num_condition_decode * drvdata->num_step;
+
+ condition = devm_kcalloc(dev, condition_size,
+ sizeof(*(drvdata->value_table->condition_decode)),
+ GFP_KERNEL);
+ if (!condition)
+ return -ENOMEM;
+
+ drvdata->value_table->condition_decode = condition;
+
drvdata->enabled = false;

pm_runtime_put(&adev->dev);
diff --git a/drivers/hwtracing/qcom/tgu.h b/drivers/hwtracing/qcom/tgu.h
index f994d83acb1d..56e4161a8bc2 100644
--- a/drivers/hwtracing/qcom/tgu.h
+++ b/drivers/hwtracing/qcom/tgu.h
@@ -16,6 +16,8 @@
((int)FIELD_GET(GENMASK(17, 10), devid_val))
#define TGU_DEVID_STEPS(devid_val) \
((int)FIELD_GET(GENMASK(6, 3), devid_val))
+#define TGU_DEVID_CONDITIONS(devid_val) \
+ ((int)FIELD_GET(GENMASK(2, 0), devid_val))
#define TGU_BITS_PER_SIGNAL 4
#define LENGTH_REGISTER 32

@@ -49,6 +51,7 @@
*/
#define STEP_OFFSET 0x1D8
#define PRIORITY_START_OFFSET 0x0074
+#define CONDITION_DECODE_OFFSET 0x0050
#define PRIORITY_OFFSET 0x60
#define REG_OFFSET 0x4

@@ -57,6 +60,9 @@
(PRIORITY_START_OFFSET + PRIORITY_OFFSET * priority +\
REG_OFFSET * reg + STEP_OFFSET * step)

+#define CONDITION_DECODE_STEP(step, decode) \
+ (CONDITION_DECODE_OFFSET + REG_OFFSET * decode + 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), \
@@ -68,6 +74,8 @@
#define STEP_PRIORITY(step_index, reg_num, priority) \
tgu_dataset_rw(reg##reg_num, step_index, TGU_PRIORITY##priority, \
reg_num)
+#define STEP_DECODE(step_index, reg_num) \
+ tgu_dataset_rw(reg##reg_num, step_index, TGU_CONDITION_DECODE, reg_num)

#define STEP_PRIORITY_LIST(step_index, priority) \
{STEP_PRIORITY(step_index, 0, priority), \
@@ -91,6 +99,14 @@
NULL \
}

+#define STEP_DECODE_LIST(n) \
+ {STEP_DECODE(n, 0), \
+ STEP_DECODE(n, 1), \
+ STEP_DECODE(n, 2), \
+ STEP_DECODE(n, 3), \
+ NULL \
+ }
+
#define PRIORITY_ATTRIBUTE_GROUP_INIT(step, priority)\
(&(const struct attribute_group){\
.attrs = (struct attribute*[])STEP_PRIORITY_LIST(step, priority),\
@@ -98,11 +114,19 @@
.name = "step" #step "_priority" #priority \
})

+#define CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(step)\
+ (&(const struct attribute_group){\
+ .attrs = (struct attribute*[])STEP_DECODE_LIST(step),\
+ .is_visible = tgu_node_visible,\
+ .name = "step" #step "_condition_decode" \
+ })
+
enum operation_index {
TGU_PRIORITY0,
TGU_PRIORITY1,
TGU_PRIORITY2,
TGU_PRIORITY3,
+ TGU_CONDITION_DECODE,
};

/* Maximum priority that TGU supports */
@@ -117,6 +141,7 @@ struct tgu_attribute {

struct value_table {
unsigned int *priority;
+ unsigned int *condition_decode;
};

static inline void TGU_LOCK(void __iomem *addr)
@@ -146,6 +171,7 @@ static inline void TGU_UNLOCK(void __iomem *addr)
* @value_table: Store given value based on relevant parameters
* @num_reg: Maximum number of registers
* @num_step: Maximum step size
+ * @num_condition_decode: Maximum number of condition_decode
*
* This structure defines the data associated with a TGU device,
* including its base address, device pointers, clock, spinlock for
@@ -160,6 +186,7 @@ struct tgu_drvdata {
struct value_table *value_table;
int num_reg;
int num_step;
+ int num_condition_decode;
};

#endif
--
2.34.1