[PATCH v3 11/11] coresight-tpdm: Add nodes for dsb msr support

[Tao Zhang]

Add the nodes for DSB subunit MSR(mux select register) support.
The TPDM MSR (mux select register) interface is an optional
interface and associated bank of registers per TPDM subunit.
The intent of mux select registers is to control muxing structures
driving the TPDM’s’ various subunit interfaces.

Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
---
 .../ABI/testing/sysfs-bus-coresight-devices-tpdm   | 12 +++++
 drivers/hwtracing/coresight/coresight-tpdm.c       | 53 ++++++++++++++++++++++
 drivers/hwtracing/coresight/coresight-tpdm.h       | 17 ++++---
 3 files changed, 75 insertions(+), 7 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
index 60ff660..6bdba7d 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
@@ -143,3 +143,15 @@ Description:
 		Accepts only one of the 2 values -  0 or 1.
 		0 : Set the DSB pattern type to false
 		1 : Set the DSB pattern type to true
+
+What:		/sys/bus/coresight/devices/<tpdm-name>/dsb_msr
+Date:		March 2023
+KernelVersion	6.3
+Contact:	Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang (QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+		(Write) Set the MSR(mux select register) of DSB tpdm. Read
+		the MSR(mux select register) of DSB tpdm.
+
+		Accepts the following two values.
+		value 1: Index number of MSR register
+		value 2: The value need to be written
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index c740681..5aaee06 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -42,6 +42,14 @@ static int tpdm_init_datasets(struct tpdm_drvdata *drvdata)
 						    sizeof(*drvdata->dsb), GFP_KERNEL);
 			if (!drvdata->dsb)
 				return -ENOMEM;
+			if (!of_property_read_u32(drvdata->dev->of_node,
+					   "qcom,dsb_msr_num", &drvdata->dsb->msr_num)) {
+				drvdata->dsb->msr = devm_kzalloc(drvdata->dev,
+					(drvdata->dsb->msr_num * sizeof(*drvdata->dsb->msr)),
+					GFP_KERNEL);
+					if (!drvdata->dsb->msr)
+						return -ENOMEM;
+				}
 		} else
 			memset(drvdata->dsb, 0, sizeof(struct dsb_dataset));
 
@@ -769,6 +777,50 @@ static ssize_t dsb_trig_ts_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(dsb_trig_ts);
 
+static ssize_t dsb_msr_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned int i;
+	ssize_t size = 0;
+
+	if (drvdata->dsb->msr_num == 0)
+		return -EINVAL;
+
+	spin_lock(&drvdata->spinlock);
+	for (i = 0; i < TPDM_DSB_MAX_PATT; i++) {
+		size += sysfs_emit_at(buf, size,
+				  "%u 0x%x\n", i, drvdata->dsb->msr[i]);
+	}
+	spin_unlock(&drvdata->spinlock);
+
+	return size;
+}
+
+static ssize_t dsb_msr_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf,
+				  size_t size)
+{
+	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned int num, val;
+	int nval;
+
+	if (drvdata->dsb->msr_num == 0)
+		return -EINVAL;
+
+	nval = sscanf(buf, "%u %x", &num, &val);
+	if ((nval != 2) || (num >= (drvdata->dsb->msr_num - 1)))
+		return -EINVAL;
+
+	spin_lock(&drvdata->spinlock);
+	drvdata->dsb->msr[num] = val;
+	spin_unlock(&drvdata->spinlock);
+	return size;
+}
+static DEVICE_ATTR_RW(dsb_msr);
+
 static struct attribute *tpdm_dsb_attrs[] = {
 	&dev_attr_dsb_mode.attr,
 	&dev_attr_dsb_edge_ctrl.attr,
@@ -781,6 +833,7 @@ static struct attribute *tpdm_dsb_attrs[] = {
 	&dev_attr_dsb_trig_patt_mask.attr,
 	&dev_attr_dsb_trig_ts.attr,
 	&dev_attr_dsb_trig_type.attr,
+	&dev_attr_dsb_msr.attr,
 	NULL,
 };
 
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h
index f9d4dd9..1872f26 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.h
+++ b/drivers/hwtracing/coresight/coresight-tpdm.h
@@ -18,6 +18,7 @@
 #define TPDM_DSB_XPMR(n)	(0x7E8 + (n * 4))
 #define TPDM_DSB_EDCR(n)	(0x808 + (n * 4))
 #define TPDM_DSB_EDCMR(n)	(0x848 + (n * 4))
+#define TPDM_DSB_MSR(n)		(0x980 + (n * 4))
 
 /* Enable bit for DSB subunit */
 #define TPDM_DSB_CR_ENA		BIT(0)
@@ -92,17 +93,19 @@
  * @trig_type:        Enable/Disable trigger type.
  */
 struct dsb_dataset {
-	u32				mode;
-	u32				edge_ctrl[TPDM_DSB_MAX_EDCR];
-	u32				edge_ctrl_mask[TPDM_DSB_MAX_EDCMR];
-	u32				patt_val[TPDM_DSB_MAX_PATT];
-	u32				patt_mask[TPDM_DSB_MAX_PATT];
+	u32			mode;
+	u32			edge_ctrl[TPDM_DSB_MAX_EDCR];
+	u32			edge_ctrl_mask[TPDM_DSB_MAX_EDCMR];
+	u32			patt_val[TPDM_DSB_MAX_PATT];
+	u32			patt_mask[TPDM_DSB_MAX_PATT];
 	bool			patt_ts;
 	bool			patt_type;
-	u32				trig_patt_val[TPDM_DSB_MAX_PATT];
-	u32				trig_patt_mask[TPDM_DSB_MAX_PATT];
+	u32			trig_patt_val[TPDM_DSB_MAX_PATT];
+	u32			trig_patt_mask[TPDM_DSB_MAX_PATT];
 	bool			trig_ts;
 	bool			trig_type;
+	u32			msr_num;
+	u32			*msr;
 };
 
 /**
-- 
2.7.4