[PATCH v14 3/7] qcom-tgu: Add signal priority support

Songwei Chai
2026-04-17T07:35:08Z

Like circuit of a Logic analyzer, in TGU, the requirement could be
configured in each step and the trigger will be created once the
requirements are met. Add priority functionality here to sort the
signals into different priorities. The signal which is wanted could
be configured in each step's priority node, the larger number means
the higher priority and the signal with higher priority will be sensed
more preferentially.

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 | 161 ++++++++++++++++++
drivers/hwtracing/qcom/tgu.h | 114 +++++++++++++
3 files changed, 282 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
index f877a00fcaa5..223873789ca6 100644
--- a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
+++ b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
@@ -7,3 +7,10 @@ Description:
Accepts only one of the 2 values - 0 or 1.
0 : disable TGU.
1 : enable TGU.
+
+What: /sys/bus/amba/devices/<tgu-name>/step[0:7]_priority[0:3]/reg[0:17]
+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 sensed signal with specific step and priority for TGU.
diff --git a/drivers/hwtracing/qcom/tgu.c b/drivers/hwtracing/qcom/tgu.c
index 49c8f710b931..7d69986c3e3d 100644
--- a/drivers/hwtracing/qcom/tgu.c
+++ b/drivers/hwtracing/qcom/tgu.c
@@ -14,14 +14,123 @@

#include "tgu.h"

+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;
+}
+
+static ssize_t tgu_dataset_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct tgu_drvdata *drvdata = dev_get_drvdata(dev);
+ struct tgu_attribute *tgu_attr =
+ 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]);
+}
+
+static ssize_t tgu_dataset_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct tgu_drvdata *tgu_drvdata = dev_get_drvdata(dev);
+ struct tgu_attribute *tgu_attr =
+ container_of(attr, struct tgu_attribute, attr);
+ unsigned long val;
+ int index;
+ int ret;
+
+ ret = kstrtoul(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ guard(spinlock)(&tgu_drvdata->lock);
+ index = calculate_array_location(tgu_drvdata, tgu_attr->step_index,
+ tgu_attr->operation_index,
+ tgu_attr->reg_num);
+
+ tgu_drvdata->value_table->priority[index] = val;
+
+ return size;
+}
+
+static umode_t tgu_node_visible(struct kobject *kobject,
+ struct attribute *attr,
+ int n)
+{
+ struct device *dev = kobj_to_dev(kobject);
+ struct tgu_drvdata *drvdata = dev_get_drvdata(dev);
+ struct device_attribute *dev_attr =
+ container_of(attr, struct device_attribute, attr);
+ struct tgu_attribute *tgu_attr =
+ container_of(dev_attr, struct tgu_attribute, attr);
+
+ if (tgu_attr->step_index >= drvdata->num_step)
+ return SYSFS_GROUP_INVISIBLE;
+
+ if (tgu_attr->reg_num >= drvdata->num_reg)
+ return 0;
+
+ return attr->mode;
+}
+
static void tgu_write_all_hw_regs(struct tgu_drvdata *drvdata)
{
+ int i, j, k, index;
+
TGU_UNLOCK(drvdata->base);
+ 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(
+ drvdata, i, j, k);
+
+ writel(drvdata->value_table->priority[index],
+ drvdata->base +
+ PRIORITY_REG_STEP(i, j, k));
+ }
+ }
+ }
/* Enable TGU to program the triggers */
writel(1, drvdata->base + TGU_CONTROL);
TGU_LOCK(drvdata->base);
}

+static void tgu_set_reg_number(struct tgu_drvdata *drvdata)
+{
+ int num_sense_input;
+ int num_reg;
+ u32 devid;
+
+ devid = readl(drvdata->base + TGU_DEVID);
+
+ num_sense_input = TGU_DEVID_SENSE_INPUT(devid);
+ num_reg = (num_sense_input * TGU_BITS_PER_SIGNAL) / LENGTH_REGISTER;
+
+ if ((num_sense_input * TGU_BITS_PER_SIGNAL) % LENGTH_REGISTER)
+ num_reg++;
+
+ drvdata->num_reg = num_reg;
+}
+
+static void tgu_set_steps(struct tgu_drvdata *drvdata)
+{
+ u32 devid;
+
+ devid = readl(drvdata->base + TGU_DEVID);
+
+ drvdata->num_step = TGU_DEVID_STEPS(devid);
+}
+
static int tgu_enable(struct device *dev)
{
struct tgu_drvdata *drvdata = dev_get_drvdata(dev);
@@ -121,6 +230,38 @@ static const struct attribute_group tgu_common_grp = {

static const struct attribute_group *tgu_attr_groups[] = {
&tgu_common_grp,
+ PRIORITY_ATTRIBUTE_GROUP_INIT(0, 0),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(0, 1),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(0, 2),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(0, 3),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(1, 0),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(1, 1),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(1, 2),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(1, 3),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(2, 0),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(2, 1),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(2, 2),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(2, 3),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(3, 0),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(3, 1),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(3, 2),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(3, 3),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(4, 0),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(4, 1),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(4, 2),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(4, 3),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(5, 0),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(5, 1),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(5, 2),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(5, 3),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(6, 0),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(6, 1),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(6, 2),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(6, 3),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(7, 0),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(7, 1),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(7, 2),
+ PRIORITY_ATTRIBUTE_GROUP_INIT(7, 3),
NULL,
};

@@ -128,6 +269,8 @@ 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;
int ret;

drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
@@ -143,12 +286,30 @@ static int tgu_probe(struct amba_device *adev, const struct amba_id *id)

spin_lock_init(&drvdata->lock);

+ tgu_set_reg_number(drvdata);
+ tgu_set_steps(drvdata);
+
ret = sysfs_create_groups(&dev->kobj, tgu_attr_groups);
if (ret) {
dev_err(dev, "failed to create sysfs groups: %d\n", ret);
return ret;
}

+ drvdata->value_table =
+ devm_kzalloc(dev, sizeof(*drvdata->value_table), GFP_KERNEL);
+ if (!drvdata->value_table)
+ return -ENOMEM;
+
+ priority_size = MAX_PRIORITY * drvdata->num_reg * drvdata->num_step;
+
+ priority = devm_kcalloc(dev, priority_size,
+ sizeof(*drvdata->value_table->priority),
+ GFP_KERNEL);
+ if (!priority)
+ return -ENOMEM;
+
+ drvdata->value_table->priority = priority;
+
drvdata->enabled = false;

pm_runtime_put(&adev->dev);
diff --git a/drivers/hwtracing/qcom/tgu.h b/drivers/hwtracing/qcom/tgu.h
index dd7533b9d735..f994d83acb1d 100644
--- a/drivers/hwtracing/qcom/tgu.h
+++ b/drivers/hwtracing/qcom/tgu.h
@@ -10,6 +10,114 @@
#define TGU_CONTROL 0x0000
#define TGU_LAR 0xfb0
#define TGU_UNLOCK_OFFSET 0xc5acce55
+#define TGU_DEVID 0xfc8
+
+#define TGU_DEVID_SENSE_INPUT(devid_val) \
+ ((int)FIELD_GET(GENMASK(17, 10), devid_val))
+#define TGU_DEVID_STEPS(devid_val) \
+ ((int)FIELD_GET(GENMASK(6, 3), devid_val))
+#define TGU_BITS_PER_SIGNAL 4
+#define LENGTH_REGISTER 32
+
+/*
+ * TGU configuration space Step configuration
+ * offset table space layout
+ * x-------------------------x$ x-------------x$
+ * | |$ | |$
+ * | | | reserve |$
+ * | | | |$
+ * |coresight management | |-------------|base+n*0x1D8+0x1F4$
+ * | registers | |---> |priority[3] |$
+ * | | | |-------------|base+n*0x1D8+0x194$
+ * | | | |priority[2] |$
+ * |-------------------------| | |-------------|base+n*0x1D8+0x134$
+ * | | | |priority[1] |$
+ * | step[7] | | |-------------|base+n*0x1D8+0xD4$
+ * |-------------------------|->base+0x40+7*0x1D8 | |priority[0] |$
+ * | | | |-------------|base+n*0x1D8+0x74$
+ * | ... | | | condition |$
+ * | | | | select |$
+ * |-------------------------|->base+0x40+1*0x1D8 | |-------------|base+n*0x1D8+0x60$
+ * | | | | condition |$
+ * | step[0] |--------------------> | decode |$
+ * |-------------------------|-> base+0x40 |-------------|base+n*0x1D8+0x50$
+ * | | | |$
+ * | Control and status space| |Timer/Counter|$
+ * | space | | |$
+ * x-------------------------x->base x-------------x base+n*0x1D8+0x40$
+ *
+ */
+#define STEP_OFFSET 0x1D8
+#define PRIORITY_START_OFFSET 0x0074
+#define PRIORITY_OFFSET 0x60
+#define REG_OFFSET 0x4
+
+/* Calculate compare step addresses */
+#define PRIORITY_REG_STEP(step, priority, reg)\
+ (PRIORITY_START_OFFSET + PRIORITY_OFFSET * priority +\
+ REG_OFFSET * reg + 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), \
+ step_index, \
+ type, \
+ reg_num, \
+ } })[0].attr.attr)
+
+#define STEP_PRIORITY(step_index, reg_num, priority) \
+ tgu_dataset_rw(reg##reg_num, step_index, TGU_PRIORITY##priority, \
+ reg_num)
+
+#define STEP_PRIORITY_LIST(step_index, priority) \
+ {STEP_PRIORITY(step_index, 0, priority), \
+ STEP_PRIORITY(step_index, 1, priority), \
+ STEP_PRIORITY(step_index, 2, priority), \
+ STEP_PRIORITY(step_index, 3, priority), \
+ STEP_PRIORITY(step_index, 4, priority), \
+ STEP_PRIORITY(step_index, 5, priority), \
+ STEP_PRIORITY(step_index, 6, priority), \
+ STEP_PRIORITY(step_index, 7, priority), \
+ STEP_PRIORITY(step_index, 8, priority), \
+ STEP_PRIORITY(step_index, 9, priority), \
+ STEP_PRIORITY(step_index, 10, priority), \
+ STEP_PRIORITY(step_index, 11, priority), \
+ STEP_PRIORITY(step_index, 12, priority), \
+ STEP_PRIORITY(step_index, 13, priority), \
+ STEP_PRIORITY(step_index, 14, priority), \
+ STEP_PRIORITY(step_index, 15, priority), \
+ STEP_PRIORITY(step_index, 16, priority), \
+ STEP_PRIORITY(step_index, 17, priority), \
+ NULL \
+ }
+
+#define PRIORITY_ATTRIBUTE_GROUP_INIT(step, priority)\
+ (&(const struct attribute_group){\
+ .attrs = (struct attribute*[])STEP_PRIORITY_LIST(step, priority),\
+ .is_visible = tgu_node_visible,\
+ .name = "step" #step "_priority" #priority \
+ })
+
+enum operation_index {
+ TGU_PRIORITY0,
+ TGU_PRIORITY1,
+ TGU_PRIORITY2,
+ TGU_PRIORITY3,
+};
+
+/* Maximum priority that TGU supports */
+#define MAX_PRIORITY 4
+
+struct tgu_attribute {
+ struct device_attribute attr;
+ u32 step_index;
+ enum operation_index operation_index;
+ u32 reg_num;
+};
+
+struct value_table {
+ unsigned int *priority;
+};

static inline void TGU_LOCK(void __iomem *addr)
{
@@ -35,6 +143,9 @@ static inline void TGU_UNLOCK(void __iomem *addr)
* @dev: Pointer to the associated device structure
* @lock: Spinlock for handling concurrent access to private data
* @enabled: Flag indicating whether the TGU device is enabled
+ * @value_table: Store given value based on relevant parameters
+ * @num_reg: Maximum number of registers
+ * @num_step: Maximum step size
*
* This structure defines the data associated with a TGU device,
* including its base address, device pointers, clock, spinlock for
@@ -46,6 +157,9 @@ struct tgu_drvdata {
struct device *dev;
spinlock_t lock;
bool enabled;
+ struct value_table *value_table;
+ int num_reg;
+ int num_step;
};

#endif
--
2.34.1