FROMLIST: coresight-tgu: add support to configure next action

Add "select" node for each step to determine if another step is taken,
trigger(s) are generated, counters/timers incremented/decremented, etc.

Link: https://lore.kernel.org/all/20250423-tgu_patch-v5-5-3b52c105cc63@quicinc.com/
Signed-off-by: Songwei Chai <quic_songchai@quicinc.com>

Author: Songwei Chai

Documentation/ABI/testing/sysfs-bus-coresight-devices-tgu

@@ -20,4 +20,11 @@ Date:           February 2025
 KernelVersion   6.15
 Contact:        Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Sam Chai (QUIC) <quic_songchai@quicinc.com>
 Description:
-                (RW) Set/Get the decode mode with specific step for TGU.
+                (RW) Set/Get the decode mode with specific step for TGU.
+
+What:           /sys/bus/coresight/devices/<tgu-name>/step[0:7]_condition_select/reg[0:3]
+Date:           February 2025
+KernelVersion   6.15
+Contact:        Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Sam Chai (QUIC) <quic_songchai@quicinc.com>
+Description:
+                (RW) Set/Get the next action with specific step for TGU.

drivers/hwtracing/coresight/coresight-tgu.c

@@ -36,6 +36,9 @@ static int calculate_array_location(struct tgu_drvdata *drvdata,
 		ret = step_index * (drvdata->max_condition_decode) +
 		      reg_index;
 		break;
+	case TGU_CONDITION_SELECT:
+		ret = step_index * (drvdata->max_condition_select) + reg_index;
+		break;
 	default:
 		break;
 	}
@@ -81,6 +84,12 @@ static ssize_t tgu_dataset_show(struct device *dev,
 					  drvdata, tgu_attr->step_index,
 					  tgu_attr->operation_index,
 					  tgu_attr->reg_num)]);
+	case TGU_CONDITION_SELECT:
+		return sysfs_emit(buf, "0x%x\n",
+				  drvdata->value_table->condition_select[calculate_array_location(
+					  drvdata, tgu_attr->step_index,
+					  tgu_attr->operation_index,
+					  tgu_attr->reg_num)]);
 	default:
 		break;
 	}
@@ -127,6 +136,13 @@ static ssize_t tgu_dataset_store(struct device *dev,
 			tgu_attr->reg_num)] = val;
 		ret = size;
 		break;
+	case TGU_CONDITION_SELECT:
+		tgu_drvdata->value_table->condition_select[calculate_array_location(
+			tgu_drvdata, tgu_attr->step_index,
+			tgu_attr->operation_index,
+			tgu_attr->reg_num)] = val;
+		ret = size;
+		break;
 	default:
 		break;
 	}
@@ -162,6 +178,16 @@ static umode_t tgu_node_visible(struct kobject *kobject,
 				      attr->mode :
 				      0;
 			break;
+		case TGU_CONDITION_SELECT:
+			/* 'default' register is at the end of 'select' region */
+			if (tgu_attr->reg_num ==
+			    drvdata->max_condition_select - 1)
+				attr->name = "default";
+			ret = (tgu_attr->reg_num <
+			       drvdata->max_condition_select) ?
+				      attr->mode :
+				      0;
+			break;
 		default:
 			break;
 		}
@@ -206,6 +232,20 @@ static ssize_t tgu_write_all_hw_regs(struct tgu_drvdata *drvdata)
 				   CONDITION_DECODE_STEP(i, j));
 		}
 	}
+
+	for (i = 0; i < drvdata->max_step; i++) {
+		for (j = 0; j < drvdata->max_condition_select; j++) {
+			ret = check_array_location(drvdata, i, TGU_CONDITION_SELECT, j);
+			if (ret == -EINVAL)
+				goto exit;
+
+			tgu_writel(drvdata,
+				   drvdata->value_table->condition_select
+					   [calculate_array_location(drvdata, i,
+								     TGU_CONDITION_SELECT, j)],
+				   CONDITION_SELECT_STEP(i, j));
+		}
+	}
 	/* Enable TGU to program the triggers */
 	tgu_writel(drvdata, 1, TGU_CONTROL);
 exit:
@@ -250,6 +290,8 @@ static void tgu_set_conditions(struct tgu_drvdata *drvdata)
 
 	num_conditions = TGU_DEVID_CONDITIONS(devid);
 	drvdata->max_condition_decode = num_conditions;
+	/* select region has an additional 'default' register */
+	drvdata->max_condition_select = num_conditions + 1;
 }
 
 static int tgu_enable(struct coresight_device *csdev, enum cs_mode mode,
@@ -397,6 +439,14 @@ 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,
 };
 
@@ -458,6 +508,15 @@ static int tgu_probe(struct amba_device *adev, const struct amba_id *id)
 	if (!drvdata->value_table->condition_decode)
 		return -ENOMEM;
 
+	drvdata->value_table->condition_select = devm_kzalloc(
+		dev,
+		drvdata->max_condition_select * drvdata->max_step *
+			sizeof(*(drvdata->value_table->condition_select)),
+		GFP_KERNEL);
+
+	if (!drvdata->value_table->condition_select)
+		return -ENOMEM;
+
 	drvdata->enable = false;
 	desc.type = CORESIGHT_DEV_TYPE_HELPER;
 	desc.pdata = adev->dev.platform_data;

drivers/hwtracing/coresight/coresight-tgu.h

@@ -50,6 +50,7 @@
 #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
 
@@ -61,6 +62,9 @@
 #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), \
@@ -76,6 +80,9 @@
 #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)
+
 #define STEP_PRIORITY_LIST(step_index, priority)  \
 	{STEP_PRIORITY(step_index, 0, priority),  \
 	 STEP_PRIORITY(step_index, 1, priority),  \
@@ -106,6 +113,15 @@
 	 NULL           \
 	}
 
+#define STEP_SELECT_LIST(n) \
+	{STEP_SELECT(n, 0), \
+	 STEP_SELECT(n, 1), \
+	 STEP_SELECT(n, 2), \
+	 STEP_SELECT(n, 3), \
+	 STEP_SELECT(n, 4), \
+	 NULL           \
+	}
+
 #define PRIORITY_ATTRIBUTE_GROUP_INIT(step, priority)\
 	(&(const struct attribute_group){\
 		.attrs = (struct attribute*[])STEP_PRIORITY_LIST(step, priority),\
@@ -120,13 +136,20 @@
 		.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_DECODE,
+	TGU_CONDITION_SELECT
 };
 
 /* Maximum priority that TGU supports */
@@ -142,6 +165,7 @@ struct tgu_attribute {
 struct value_table {
 	unsigned int *priority;
 	unsigned int *condition_decode;
+	unsigned int *condition_select;
 };
 
 /**
@@ -155,6 +179,7 @@ struct value_table {
  * @max_reg: Maximum number of registers
  * @max_step: Maximum step size
  * @max_condition_decode: Maximum number of condition_decode
+ * @max_condition_select: Maximum number of condition_select
  *
  * This structure defines the data associated with a TGU device,
  * including its base address, device pointers, clock, spinlock for
@@ -171,6 +196,7 @@ struct tgu_drvdata {
 	int max_reg;
 	int max_step;
 	int max_condition_decode;
+	int max_condition_select;
 };
 
 #endif